CurrentAetnaPolicy 0661

Joint Resurfacing

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Defines Aetna's medical necessity, contraindications, and coding stance for joint resurfacing procedures (primarily hip resurfacing) and lists procedures considered experimental or not covered. Affects Aetna members and providers requesting authorization for resurfacing procedures.

Policy Summary

PayerAetna

PolicyJoint Resurfacing

Policy CodePolicy 0661

Change TypeNo material change

Effective DateMay 2, 2003

Last ReviewDec 19, 2025

Next Review DateJul 23, 2026

Key ActionDocument failure of at least 12 weeks of conservative therapy in the medical record before requesting authorization for resurfacing procedures.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

65Age threshold (preferred)

12wConservative therapy (min)

>40BMI contraindication

<60GFR contraindication

12,093

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CurrentAetnaPolicy 0661

Joint Resurfacing

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Policy Summary

PayerAetna

PolicyJoint Resurfacing

Policy CodePolicy 0661

Change TypeNo material change

Effective DateMay 2, 2003

Last ReviewDec 19, 2025

Next Review DateJul 23, 2026

Key ActionDocument failure of at least 12 weeks of conservative therapy in the medical record before requesting authorization for resurfacing procedures.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

65Age threshold (preferred)

12wConservative therapy (min)

>40BMI contraindication

<60GFR contraindication

12,093

AOANJRR hips referenced

90%Patient satisfaction (humeral inlay)

Coverage Criteria for Joint Resurfacing

Medical necessity for metal-on-metal hip resurfacing

Aetna considers metal-on-metal hip resurfacing by an FDA-approved device medically necessary when ALL of the following are met:

Primary selection criteria: Member is a physically active non-elderly adult (typically <65 years of age) and has advanced joint disease causing pain and functional disability from osteoarthritis, avascular necrosis, or post‑traumatic arthritis interfering with activities of daily living; and limited range of motion, antalgic gait, and hip pain on passive ROM on physical examination; and radiographic or MRI evidence of severe osteoarthritis (≥2 findings among subchondral cysts, subchondral sclerosis, periarticular osteophytes, joint subluxation, bone‑on‑bone articulation, or joint space narrowing) primarily affecting the femoral head, or early osteonecrosis with <50% femoral head involvement; and normal proximal femoral bone geometry and bone quality; and the member would otherwise require a conventional primary total hip replacement but is likely to outlive the functional lifespan of a traditional prosthesis; and a documented history of unsuccessful conservative therapy (≥12 weeks) addressing all of the following unless contraindicated: anti‑inflammatory medications or analgesics; flexibility and muscle‑strengthening exercises; activity modification; supervised physical therapy; weight reduction as appropriate; assistive device use where appropriate; and therapeutic injections where appropriate.

Contraindications / Not Medically Necessary

Hip resurfacing is considered NOT MEDICALLY NECESSARY when ANY of the following contraindications are present:

Contraindications: Active joint infection or systemic bacteremia not eradicated; active skin infection or open wound in planned surgical site; allergy to metals used in resurfacing (e.g., cobalt, chromium, alumina); inactive/older individuals unlikely to require revisions of a traditional THR; morbid obesity (BMI > 40); inadequate bone stock to support the device; osteonecrosis with >50% femoral head involvement; severe anatomic deformity of the femoral head; skeletally immature patients; moderate‑to‑severe renal insufficiency (GFR < 60 mL/min/1.73 m2); multiple femoral neck cysts >1 cm; vascular insufficiency, muscular atrophy, or neuromuscular disease severe enough to compromise implant stability or recovery; immunosuppression or high‑dose corticosteroid use; females of child‑bearing age due to unknown fetal effects of metal ion release.

Experimental, investigational, or unproven procedures

Procedures considered experimental, investigational, or unproven (not covered):

Experimental or unproven procedures: Adipo‑fascial flap resurfacing for PIP joint after contracture release; facet joint resurfacing; knee resurfacing/partial knee resurfacing (e.g., Makoplasty) and isolated patellar resurfacing (e.g., UniCAP, HemiCAP); metal‑on‑metal hip resurfacing for developmental dysplasia of the hip; metal‑on‑polyethylene hip resurfacing implants; metal resurfacing inlay implant for osteochondral talar defects after failed previous surgery; metatarsophalangeal (MTP) toe joint resurfacing; proximal row carpectomy with capitate resurfacing for SLAC/SNAC wrists and wrist OA; radiocapitellar joint resurfacing; resurfacing capitate pyrocarbon implant (RCPI); shoulder resurfacing (total and hemi) for glenohumeral arthritis, fractures, osteochondral lesions, and other indications; and use of navigation/computer‑assisted navigation during Birmingham hip resurfacing.

Covered when appropriate patient-selection and device considerations are met

Clinical evidence and patient‑selection considerations summarized in background evidence

Patient selection considerations for hip resurfacing: Preferred candidates are younger, active patients with viable proximal femoral bone and normal bone geometry who are likely to outlive a conventional THR; resurfacing conserves femoral bone and may facilitate later conversion to THR; registry and cohort data identify higher revision risk with older age, female sex, smaller femoral head size (<50 mm), developmental dysplasia, and certain implant designs; many published series select patients typically younger than 55–65 years in device‑specific cohorts.

Summary of clinical evidence relevant to coverage

Evidence‑based findings relevant to coverage decisions:

Secondary patellar resurfacing outcomes: Systematic reviews and case series show variable outcomes for secondary patellar resurfacing (SPR) with many patients not achieving clinically important pain relief or satisfaction; evidence quality is generally low and recommendations are weak.

Primary patellar resurfacing vs no resurfacing: Randomized trials and meta‑analyses (e.g., pooled data from 33 RCTs, 5,540 TKAs) report that patellar resurfacing can reduce anterior knee pain (RR ~0.65) and revision risk (RR ~0.63) compared with no resurfacing, though PROM differences are inconsistent and implant design influences outcomes.

Selective resurfacing considerations: Surgeon resurfacing strategies (always, never, selective) show variable patient‑reported outcomes and registry analyses suggest small differences in scores but inconsistent effects on revision rates; implant design and patient selection affect results.

Implant‑specific outcomes:

Evidence summaries (no explicit coverage rules provided)

Evidence highlights and limitations relevant to coverage decisions

Metal talar inlay implant evidence: Prospective case series (n=38; mean follow‑up 5.1 years) reports improvements in many patient‑reported outcomes but also multiple re‑operations and radiographic concerns (cysts, peri‑prosthetic radiolucency); technique requires a medial malleolar osteotomy and excludes lateral lesions; Level IV evidence—longer follow‑up and larger studies needed.

Makoplasty / robotic assistance evidence: Prospective and randomized studies demonstrate improved accuracy of component positioning and fewer alignment outliers with robotic assistance; some trials report non‑significant or small differences in clinical scores and longer operative times; multi‑center cohorts (e.g., 1,007 patients) show high short‑term survivorship (≈98.8% at 2.5 years) but longer‑term RCT evidence on clinical benefit and survivorship is limited.

Evidence summaries relevant to coverage

Clinical findings relevant to coverage decisions (evidence synthesis only):

RA‑TKA evidence: Systematic reviews and comparative studies report improved component positioning accuracy, reduced radiographic outliers, and in several studies improved short‑term PROMs and satisfaction with robotic‑assisted TKA versus manual TKA; learning curve for operating time is typically 7–11 cases; long‑term randomized evidence is lacking.

RA‑TKA perioperative outcomes: Some administrative‑database and single‑surgeon series report shorter length of stay, reduced opioid use, and fewer manipulations under anesthesia with RA‑TKA, but findings may reflect single‑center or surgeon experience and require cautious interpretation.

Focal femoral condyle resurfacing concerns: Systematic review and registry data demonstrate high revision rates for HemiCAP/UniCAP devices (short‑term pooled ~6.7%; registry cumulative revision ~40.6% at 10 years; UniCAP revision up to ~53.66% at 5–7 years), supporting recommendations against routine use for many patients.

RCPI for wrist arthritis:

Evidence summaries (informational)

Background evidence summaries and outcomes (no explicit coverage criteria stated in this section)

RCPI and PRC evidence: PRC with RCPI has been described for SLAC/SNAC wrists and advanced wrist OA; systematic reviews and case series (combined n ~1,804 wrists across studies) report some favorable outcome scores for PRC + RCPI versus PRC alone but evidence is limited (mostly Level IV) and further study is needed.

Patellar resurfacing evidence: Modern trials and meta‑analyses examining patellar resurfacing with contemporary 'patellar‑friendly' implants show mixed results—no consistent clinically significant benefit for anterior knee pain or PROMs in some analyses, while pooled RCT data indicate reductions in anterior knee pain and revision risk but heterogeneity exists across implant designs and studies.

Adipo‑fascial flap for PIPJ: Small retrospective series suggest modest mid‑term improvement in ROM and extension lag after PIPJ adipo‑fascial flap, but evidence is limited and under‑powered (Level III), supporting classification as investigational in this policy context.

Aetna’s policy identifies a group of resurfacing procedures and anatomic sites for which safety and effectiveness are not established and which are treated as experimental, investigational, or unproven. Examples include shoulder resurfacing (total and hemi), facet joint resurfacing, radiocapitellar joint resurfacing, proximal row carpectomy with capitate resurfacing and other wrist resurfacing techniques, and knee resurfacing / partial knee resurfacing / isolated patellar resurfacing (for example, MAKOplasty, UniCAP, HemiCAP). These procedures and variants are listed because available evidence is limited, inconsistent, or lacks long‑term outcomes to establish safety and effectiveness for routine coverage.

Where specific CPT or ICD‑10 codes are associated with these experimental or unproven resurfacing procedures, the policy flags those codes as subject to noncoverage for the indications described. Providers should refer to the policy’s coding sections and document clinical justification when submitting authorization or claims for procedures at these anatomic sites.

The policy provides illustrative CPT and ICD‑10 entries that have been associated with non‑coverage for resurfacing indications. Examples called out include CPT code 25215 (carpectomy; all bones of proximal row) in the wrist context and numerous wrist ICD‑10 diagnosis codes (e.g., M12.541‑M12.549, M13.131‑M13.139, M19.031‑M19.039). The coding appendix also lists general groupings of codes associated with contraindications (for example, Z68.41‑Z68.45 for BMI ≥40).

These example code listings are not exhaustive — they are provided to illustrate coding combinations that the bulletin flags as coverage‑sensitive for the indications described. Providers should verify coverage and authorization requirements for any specific code pairings with the member’s plan.

The document highlights the safety concerns associated with recalled metal‑on‑metal devices, specifically referring to the DePuy ASR system and related components. Published series and systematic reviews reported high early failure and revision rates and a substantial prevalence of adverse local tissue reactions (ALTR), with mean ALTR prevalence reported around 33.5% in ASR series. Blood metal‑ion elevations (cobalt/chromium > 7 μg/L) were associated with higher failure rates and bearing‑related complications.

Because of those device‑specific outcomes and the recall history, the policy advises close clinical surveillance and careful justification when claims relate to these implants; use of recalled or high‑failure systems is associated with higher risk of denial or the need for additional documentation to support medical necessity for revision.

Published shoulder resurfacing series note that humeral head resurfacing is now generally reserved for tightly selected patients: specifically those with concentric glenohumeral osteoarthritis without glenoid erosion or rotator cuff damage. Retrospective series found higher failure rates associated with glenoid wear and rotator cuff tears, prompting authors to limit resurfacing to cases without those features and to consider total shoulder arthroplasty when glenoid disease or cuff pathology is present.

When humeral head resurfacing is considered, the clinical record should document concentric wear pattern, intact (or reparable) rotator cuff status, and rationale for selecting resurfacing over alternatives given the evidence of higher failure when glenoid erosion or cuff damage exist.

The policy identifies several resurfacing procedures and technologies for which evidence is limited or inconsistent. This includes MAKOplasty/robotic‑assisted partial knee resurfacing — multiple assessments (ECRI, CADTH and comparative series) concluded that current evidence is insufficient to show improved long‑term patient outcomes or cost‑effectiveness compared with conventional techniques.

Similarly, focal knee resurfacing systems (for example, HemiCAP and UniCAP) have only small studies with limited follow‑up; systematic reviews and guideline assessments have found inadequate evidence to support routine use. Given these evidence limitations, prior authorization or detailed documentation of indications and prior conservative care is suggested when these technologies are proposed.

A prospective cohort of the HemiCAP‑Wave focal patellofemoral inlay implant reported improved short‑ to mid‑term outcomes but also documented a high mid‑term revision rate: 28% revised within 6 years in the reported series. The policy notes this elevated revision frequency as a caution when considering these implants and when evaluating long‑term durability claims.

Registry and systematic evidence for focal femoral condyle resurfacing (HemiCAP/UniCAP) similarly report concerning revision rates over time, which may limit the clinical indications for these devices and affect coverage decisions.

The technical approach for the metal resurfacing inlay implant used to treat medial talar dome osteochondral defects requires access via a medial malleolar osteotomy. This surgical requirement is explicitly noted by investigators and is an important procedural limitation to document — it constrains the technique to medial lesions and necessitates consideration of osteotomy‑related morbidity.

Because the approach requires a medial malleolar osteotomy, the procedure’s applicability, operative planning, and post‑operative risks differ from less invasive cartilage procedures; these factors should be included in justification and operative documentation when the implant is proposed.

The authors of the metal talar inlay series emphasize that the technique inherently excludes lateral talar dome lesions because implantation access is achieved through a medial malleolar osteotomy. Lateral lesions therefore are not candidates for this specific inlay technique and should be managed with alternative procedures.

Providers proposing a metal inlay implant must document lesion laterality and explain why the medial‑access technique is appropriate for the patient’s defect.

In the text excerpts provided there are no explicit standalone statements formatted as a blanket 'not medically necessary' declaration for additional procedures beyond the contraindications and experimental/unproven lists. Instead, the document uses evidence summaries and device‑specific outcome data to inform coverage considerations and to identify procedures that lack sufficient evidence for routine coverage.

Because the policy frames many limitations as 'experimental, investigational, or unproven' or as contraindications, reviewers should refer to the specific sections and coding appendices for whether a given procedure or code will be adjudicated as not covered in individual cases.

Systematic review and registry data for partial femoral condyle resurfacing devices (UniCAP/HemiCAP) demonstrated high revision rates: short‑term pooled revisions were reported, and registry data noted cumulative revision rates as high as approximately 40.6% at 10 years, with UniCAP revision rates up to approximately 53.66% at 5–7 years in some series. Based on these outcomes, authors and the policy text recommend against routine use of these devices for many middle‑aged patients with focal cartilage defects.

Given those high revision risks, the policy indicates that use of these implants may be limited and that such devices may be considered not recommended or subject to denial depending on the clinical scenario and documentation provided.

The policy lists explicit contraindications for metal‑on‑metal hip resurfacing. Contraindicated groups include females of child‑bearing age (due to unknown fetal effects of metal ion release), individuals who are immunosuppressed or receiving high‑dose corticosteroids, and those who are severely overweight (BMI > 40).

Additional contraindications outlined include skeletal immaturity, inadequate proximal femoral bone stock, active infection or systemic sepsis, moderate‑to‑severe renal insufficiency (GFR < 60 mL/min/1.73 m2), vascular insufficiency or neuromuscular conditions that compromise implant stability, and known or suspected metal sensitivity. Presence of any listed contraindication renders hip resurfacing not medically necessary under the policy.

Administrative notice: Clinical Policy Bulletins are developed to assist in administering plan benefits and are not guarantees of coverage or substitutes for clinical judgment. They provide a general, partial description of plan benefits and do not constitute medical advice or a contract; treating providers retain responsibility for medical care and decisions.

Providers and members should consult the full Clinical Policy Bulletin and the member’s plan documents for definitive coverage determinations and should not interpret the bulletin as an authorization or coverage guarantee.

The policy explicitly restates that hip resurfacing is considered not medically necessary when any of the listed contraindications are present (for example, active infection, metal allergy, morbid obesity with BMI > 40, inadequate bone stock, osteonecrosis involving > 50% of the femoral head, moderate‑to‑severe renal insufficiency with GFR < 60 mL/min/1.73 m2, immunosuppression, or females of child‑bearing potential).

When any of these contraindications apply to a member, hip resurfacing should not be considered an appropriate or covered treatment option under the policy’s criteria.

The policy emphasizes caution with implants or systems that have documented high failure and adverse local tissue reaction (ALTR) rates — for example, the ASR Hip System. Published analyses report elevated revision rates and a high prevalence of ALTR; such device‑specific performance concerns are cited as reasons to consider these systems a higher safety risk and to require strengthened clinical justification or to avoid their use.

Claims involving implants with known high failure or ALTR rates may be subject to closer review and could result in denial if clinical justification and monitoring (including metal‑ion testing where applicable) are not documented.

Biologic glenoid resurfacing (for example, meniscal allograft or biologic patching of the glenoid used with humeral head hemi‑resurfacing) has produced inconsistent clinical results and relatively high complication rates in reported series; one study reported a 32% complication rate with multiple re‑operations. Investigators have therefore recommended caution and, in many cases, consideration of total shoulder arthroplasty when conservative therapy has failed.

Because outcomes are inconsistent and complications and conversions to total shoulder arthroplasty are common in some series, biologic glenoid resurfacing is not supported as a routinely effective alternative and requires detailed documentation of indications and counseling about risks if proposed.

The policy specifically notes that biologic glenoid resurfacing procedures that utilize meniscal allograft have demonstrated inconsistent results and high complication rates in follow‑up series. Investigators concluded that these techniques are not reliably effective and that total shoulder arthroplasty should be strongly considered for patients in whom conservative measures have failed.

When meniscal‑allograft glenoid resurfacing is proposed, providers should document the rationale, prior treatments attempted, and why alternatives such as total shoulder arthroplasty were not selected.

Secondary patellar resurfacing (SPR) performed for persistent anterior knee pain after primary total knee arthroplasty has produced variable and often disappointing results. One retrospective series reported that 59% of patients had no pain improvement and 65% were not satisfied, and systematic reviews characterize the evidence as low quality with only weak recommendations for SPR.

Because of the uncertain benefit and variable patient satisfaction reported in the literature, SPR should be considered with caution; appropriate nonoperative evaluation and imaging correlation (for example, SPECT/CT or triple‑phase bone scan where used in study cohorts) and thorough documentation are recommended before proceeding.

Within the provided policy excerpts the authors do not append additional explicit standalone 'not medically necessary' labels beyond those tied to the listed contraindications and to the devices/procedures classified as experimental, investigational, or unproven. Instead, the document uses the evidence base and device‑specific outcomes to inform coverage decisions and coding sensitivity.

Reviewers should therefore rely on the contraindication list, the experimental/unproven procedure listings, and the coding appendices to determine whether a specific procedure or code is likely to be considered not medically necessary for a given member.

The excerpts reviewed do not contain additional explicit 'not medically necessary' statements beyond those already noted in the contraindications and experimental/unproven lists. The policy frames many limitations as evidence insufficiency or device‑specific concerns rather than as additional blanket noncoverage statements.

Providers should consult the full Clinical Policy Bulletin for any other explicit noncoverage determinations not present in these excerpts.

High revision rates reported in systematic reviews and registry data for focal resurfacing implants (for example, UniCAP and HemiCAP) raise important clinical considerations. The policy highlights that the UniCAP had revision rates approaching 53.66% at 5–7 years in some analyses and that HemiCAP devices have shown elevated mid‑term revision rates (for example, ~28% by 6 years in a cohort).

Given these mid‑ to long‑term failure rates, clinicians should carefully weigh expected durability against alternatives and document patient counseling and rationale when focal resurfacing implants are proposed; such outcome data may also affect coverage decisions.

Coding and Billing Guidance

CPT/HCPCS codes covered if selection criteria are metmixedCovered

27125	Hemiarthroplasty, hip, partial (e.g., femoral stem prosthesis, bipolar arthroplasty)
27130	Arthroplasty, acetabular and proximal femoral prosthetic replacement (total hip arthroplasty)
27033	Arthrotomy hip, including exploration or removal of loose or foreign body
27122	Acetabuloplasty; resection, femoral head (e.g., Girdlestone procedure)
27132	Conversion of previous hip surgery to total hip arthroplasty, with or without autograft or allograft
27360	Partial excision (craterization, saucerization, or diaphysectomy) bone, femur, proximal tibia and/or fibula
S2118	Metal-on-metal total hip resurfacing, including acetabular and femoral components

Other CPT codes related to CPBCPT

23470	Arthroplasty, glenohumeral joint, hemiarthroplasty
23472	Total shoulder (glenoid and proximal humeral replacement)
25215	Carpectomy; all bones of proximal row

ICD-10 codes covered if selection criteria are metICD-10Covered

M16.0-M16.12	Primary osteoarthritis, left hip (range noted)
M16.2-M16.7	Secondary osteoarthritis of hip
M16.9	Osteoarthritis of hip, unspecified
M87.051-M87.059	Idiopathic aseptic necrosis, femur
M87.150-M87.159	Osteonecrosis due to drugs, pelvis and femur
M87.251-M87.256	Osteonecrosis due to previous trauma, pelvis and femur
M87.350-M87.353	Other secondary osteonecrosis, pelvis and femur
M87.850-M87.859	Other osteonecrosis, pelvis and femur
M90.551-M90.559	Osteonecrosis in diseases classified elsewhere, thigh

ICD-10 codes not covered / contraindicated for CPB indications (not all-inclusive)ICD-10Not Covered

Q65.00-Q65.6	Congenital dislocation of hip [developmental dysplasia]
E66.01	Morbid (severe) obesity due to excess calories [BMI greater than 40]
A41.01-A41.9	Other sepsis
M00.051-M00.059	Pyogenic arthritis, hip
N18.1-N18.9	Chronic kidney disease (CKD)
Z68.41-Z68.45	Body mass index (BMI) 40 and over, adult

Examples of CPT/ICD codes noted as not covered for listed indicationsmixedNot Covered

25215	Carpectomy; all bones of proximal row [proximal row carpectomy with capitate resurfacing]
M12.541 - M12.549	Traumatic arthropathy, wrist [Scapholunate advanced collapse]
M13.131 - M13.139	Monoarthritis, not elsewhere classified, wrist
M13.831 - M13.839	Other specified arthritis, wrist
M14.831 - M14.839	Arthropathies in other specified diseases classified elsewhere, wrist
M18.0 - M18.9	Osteoarthritis of first carpometacarpal joint
M19.031 - M19.039	Primary osteoarthritis, wrist
M19.131 - M19.139	Post-traumatic osteoarthritis, wrist
M19.231 - M19.239	Secondary osteoarthritis, wrist
S60.00XA - S69.92XS	Injuries to the wrist, hand and fingers

1–10 of 11

1/2

Imaging supporting RA-TKAmixed

CT (pre-op)

pre-operative computed tomography used for templating and planning (no exact CPT provided in text)

Robotic-associated cost itemsmixed

robotic-specific disposables/fees

intra-operative costs associated with robotic systems (no exact HCPCS/CPT provided)

inv-36: BMI threshold cited as contraindication value

BMI thresholdBMI > 40 is listed as a contraindication to hip resurfacing

ContextAppears in the policy's contraindication list for metal-on-metal hip resurfacing

Implication for authorizationClaims for members with BMI > 40 risk denial unless contraindication rationale documented

inv-37: Femoral head involvement threshold for osteonecrosis (>50%)

Femoral head involvement thresholdOsteonecrosis with greater than 50% femoral head involvement is a contraindication to hip resurfacing

Prior Authorization, Documentation, and Operational Guidance

Prior Authorization

Obtain prior authorization for covered resurfacing codes

Prior authorization is required for CPT/HCPCS codes that are covered only when the policy’s selection criteria are met (examples include 27125, 27130, and HCPCS S2118). Include documentation demonstrating that all coverage criteria (patient selection, imaging, and ≥12 weeks of conservative therapy or documented reason it was not appropriate) are satisfied when requesting authorization.

Examples of covered procedure codes: 27125, 27130, S2118
Authorization should reference medical-record documentation of advanced joint disease and failed conservative therapy (≥12 weeks)

Denial Risk

Verify coverage for coverage‑sensitive codes before billing

The policy lists CPT/ICD-10 codes that are identified as not covered for the indications in this bulletin (examples include carpectomy CPT 25215 and multiple wrist/knee ICD-10 codes); procedures billed with these codes for listed indications may be denied.

Background and Evidence Context

Background: Hip resurfacing is described as a bone‑conserving alternative to total hip arthroplasty for selected, physically active adults who are typically younger than conventional THA candidates; studies and registry data emphasize selection of patients with viable proximal femoral bone, limited femoral head involvement in osteonecrosis, and radiographic features of advanced joint disease confined primarily to the femoral head.

The policy indicates preference for younger, active patients (commonly referenced age thresholds vary but are generally 65 years in cited series) with preserved bone geometry and after failure of a trial of conservative therapy (minimum documented conservative measures of at least 12 weeks are expected). Appropriate patient selection and device considerations are essential to justify resurfacing as an alternative to THA.

Covered when appropriate patient-selection and device considerations are met

Clinical evidence and patient‑selection considerations summarized in background evidence (cross‑reference to evidence above):

Selection and device considerations (background overlap): Hip resurfacing conserves femoral bone and is intended for younger active patients with viable proximal femoral bone; registry and cohort data (eg, AOANJRR series of 12,093 primary resurfacings) identify risk factors for revision including older age, female sex, smaller head size, developmental dysplasia, and certain implant designs—these device‑ and patient‑level factors should inform selection and device choice.

Key Definitions

inv-89: Advanced joint disease — definition and context

DefinitionAdvanced joint disease: pain and functional disability interfering with ADLs from osteoarthritis, avascular necrosis, or post‑traumatic arthritis of the hip with limited ROM/antalgic gait and imaging evidence of severe disease

Imaging criteriaSevere osteoarthritis documented by 2 or more findings (eg, subchondral cysts, subchondral sclerosis, periarticular osteophytes, joint subluxation, bone-on-bone articulation, or joint space narrowing)

Conservative therapy requirementHistory of unsuccessful conservative therapy (≥12 weeks) must be documented unless inappropriate

inv-90: Partial (hemi) hip resurfacing definition

DefinitionPartial (hemi) hip resurfacing: removal and resurfacing of the damaged femoral head surface with a metal shell while leaving the acetabular socket intact

Clinical role

Policy Revision History

2003-05-02effective_date

Policy 0661 (Joint Resurfacing) became effective.

2025-12-19last_reviewLatest

Policy 0661 underwent its most recent review (Last Review: 12/19/2025).

2026-07-23next_review_scheduled

Next scheduled policy review date set for 07/23/2026.

Policy Summary

PayerAetna

PolicyJoint Resurfacing

Policy CodePolicy 0661

Change TypeNo material change

Effective DateMay 2, 2003

Last ReviewDec 19, 2025

Next Review DateJul 23, 2026

Key ActionDocument failure of at least 12 weeks of conservative therapy in the medical record before requesting authorization for resurfacing procedures.

SourceLink

On This Page

Focal patello‑femoral inlay resurfacing (HemiCAP‑Wave) may produce short‑term improvements but has been associated with high mid‑term revision rates (e.g., ~28% within 6 years); focal femoral condyle resurfacing (HemiCAP/UniCAP) exhibits concerning registry revision rates (short‑term pooled ~6.7%, registry 10‑yr ~40.6%, UniCAP up to ~53.7% at 5–7 years) prompting recommendations against routine use for many patients.

Robotic‑assisted UKA/TKA: Robotic‑assisted unicompartmental and total knee techniques improve component positioning accuracy and reduce radiographic outliers; some studies report improved short‑term pain, function, and shorter LOS, but long‑term benefits for survivorship and definitive clinical improvement remain unproven and higher‑quality long‑term data are needed.

Small series and systematic reviews suggest PRC + RCPI can provide favorable PROMs and preserved ROM in selected patients, but evidence is limited by small sample sizes and short follow‑up; long‑term durability and complication profiles remain uncertain.

ContextRequirement appears within primary selection/contraindication criteria for hip resurfacing

Authorization impactOsteonecrosis >50% of femoral head excludes candidate from metal-on-metal resurfacing

inv-38: GFR threshold contraindication (<60 mL/min/1.73 m2)

GFR contraindication thresholdModerate-to-severe renal insufficiency defined as GFR < 60 mL/min/1.73 m2 is a contraindication to hip resurfacing

ContextListed among contraindications for metal-on-metal hip resurfacing due to concerns about metal ion handling

Documentation noteRenal function should be assessed and documented when considering resurfacing

inv-39: High blood metal ion level risk threshold (>7 μg/L cobalt or chromium)

High blood metal-ion risk thresholdBlood cobalt or chromium > 7 μg/L is associated with higher failure risk and bearing-related complications

Source contextReported association between blood metal-ion levels >7 μg/L and higher ALTR/failure in ASR device analyses

Monitoring implicationMetal-ion testing and results may be needed for surveillance or authorization decisions

Example CPT code flagged as not covered for listed indications: 25215
Examples of ICD‑10 codes listed as not covered for listed indications are provided in the coding section (wrist and knee codes)

Prior Authorization

Include device, symptom, and metal‑ion monitoring data in requests

When requesting authorization or justifying resurfacing revisions, include the device model/type, current symptom status, and results of monitoring (including blood metal‑ion levels when applicable) as part of the clinical justification.

Document device type and symptoms (pain, dysfunction)
Include metal‑ion monitoring results (e.g., cobalt/chromium levels) when relevant

Prior Authorization

Request authorization for resurfacing procedures with limited evidence

Prior authorization is recommended when proposing focal knee resurfacing systems (HemiCAP/UniCAP), MAKOplasty partial resurfacing, and other resurfacing systems that have limited or inconsistent evidence; require documentation of conservative management failure and specific indications.

Document prior nonoperative care and rationale for focal resurfacing
Note limited/insufficient evidence for HemiCAP/UniCAP and MAKOplasty in authorization requests

Prior Authorization

Document indication, compartment, and supporting data for robotic UKA

If robotic‑arm assisted UKA is planned, request prior authorization that specifies the indication, targeted compartment, and supporting pre‑operative imaging and clinical scores to support medical necessity.

Specify whether robotic‑arm assisted UKA (e.g., MAKO) is planned
Provide indication, target compartment, pre‑op imaging, and clinical outcome scores (e.g., KOOS, KSS)

Documentation Required

Document rationale and expected benefit for patellar resurfacing during TKA

When patellar resurfacing is proposed at the time of primary TKA, document the clinical indication and the expected patient benefit in the record submitted for authorization; evidence shows routine resurfacing reduces anterior knee pain and revision risk but selective strategies require justification.

State whether resurfacing is routine, selective, or omitted and why
Provide expected benefits (e.g., reduction in anterior knee pain or revision risk)

Note

Follow main policy text when authorization rules are not specified

Some evidence sections describe outcomes without specifying prior authorization rules — providers should follow the main policy criteria and coding guidance in the policy when seeking authorization.

Follow the policy’s coverage criteria and coding lists for authorization decisions
Use evidence summaries to support but not replace required documentation

Documentation Required

Document CT‑based planning and robotic assistance (pre‑op CT/templating)

When CT‑based planning or robotic assistance is used for pre‑operative planning or intra‑operative guidance, document the pre‑op CT, templating results, and any device‑specific planning used to support the request and claims.

Include pre‑operative CT scans and templating reports
Describe robotic planning workflow and predicted implant sizes when available

Prior Authorization

Provide RA‑TKA details and note limited long‑term outcome data

For RA‑TKA authorization requests, include surgeon experience and planned robotic system use and note that available evidence shows improved component positioning and some short‑term outcomes but limited long‑term evidence of clinical benefit.

Document surgeon experience with RA‑TKA (learning‑curve considerations: ~7–11 cases)
State planned robotic platform and expected short‑term benefits (accuracy, LOS/opioid effects)

Prior Authorization

Identify planned wrist resurfacing procedure, diagnosis, and supporting data

For wrist resurfacing procedures, prior authorization should identify the planned operation (e.g., PRC + RCPI versus PRC alone), the diagnosis (SLAC, SNAC, or advanced wrist OA), and submit supporting evidence of necessity and anticipated benefit.

Specify whether PRC + RCPI or PRC alone is planned
Provide diagnosis (SLAC, SNAC, wrist OA) and outcome expectations

Note

References do not replace main prior authorization guidance

The reference listings do not contain explicit prior authorization statements; use the main policy text and coding sections for authorization and coverage determinations.

References are informational; authorization rules are in the policy sections
Refer to the main Clinical Policy Bulletin for code‑level requirements

Prior Authorization

Refer to main policy text for code‑level prior authorization guidance

For specific prior authorization code‑level requirements, refer to the main policy text and the coding lists in this clinical policy bulletin rather than the background evidence sections.

Use the policy’s coding tables to confirm covered versus not‑covered codes
Submit documentation that maps clinical indications to covered CPT/HCPCS/ICD‑10 codes

Step Therapy

Document ≥12 weeks of failed conservative therapy before resurfacing

Document failure of multiple conservative measures for at least 12 weeks (anti‑inflammatories/analgesics, exercise/strengthening, activity modification, supervised physical therapy, weight reduction, assistive devices, and therapeutic injections when appropriate) or document why conservative therapy is not appropriate.

Document at least 12 weeks of non‑surgical management addressing all listed conservative measures unless contraindicated
If conservative therapy is not reasonable, provide clear rationale in the medical record

Note

No additional provider‑action specified in source

The source does not provide additional inventory content for this placeholder callout.

Documentation Required

Counsel and document risks before biologic glenoid resurfacing

Counsel patients and document that biologic glenoid resurfacing has inconsistent results and relatively high complication/reoperation rates; consider total shoulder arthroplasty when conservative treatment fails.

Discuss inconsistent outcomes and 32% complication rate reported with meniscal allograft glenoid resurfacing
Document counseling and alternative surgical options considered

Step Therapy

Sequence humeral head resurfacing after nonoperative care for select anatomy

Reserve humeral head resurfacing for concentric osteoarthritis without glenoid erosion or rotator cuff damage and only after nonoperative options have been tried and documented.

Document concentric OA, intact rotator cuff, and failed nonoperative care prior to authorization
Note authors now reserve humeral head resurfacing for these specific cases

Note

No specific provider action specified

No specific action is provided for this placeholder callout in the inventory; follow the policy sections relevant to the procedure under consideration.

Documentation Required

Document nonoperative care and imaging (SPECT/CT + TPBS) before SPR

Before proposing secondary patellar resurfacing (SPR) for unexplained anterior knee pain after TKA, document prior nonoperative management and obtain diagnostic imaging correlation (SPECT/CT and triple‑phase bone scan) with history and exam.

Document nonoperative therapies attempted for persistent AKP after TKA
Include SPECT/CT and TPBS findings correlated with history/physical when proposing SPR

Step Therapy

No specific step‑therapy required for metal inlay or robotic procedures in excerpts

No step‑therapy protocols are described in the policy for metal inlay implants or robotic procedures in the provided text; do not assume specific step‑therapy sequencing beyond the general conservative therapy expectations.

Policy states no specific step therapy for metal inlay or robotic procedures in the excerpts
Follow general conservative therapy expectation when applicable

Note

No step‑therapy specified in reference excerpts

No step‑therapy requirements are described in this excerpt of the policy.

Step Therapy

RA‑TKA: evidence‑based perioperative findings but no step‑therapy requirement

The evidence reports variable short‑term benefits for RA‑TKA (shorter LOS, reduced opioid use in some series) but no consistent step‑therapy requirement is specified; document expected perioperative benefits but do not rely on a formal step‑therapy sequence.

Document anticipated perioperative benefits (LOS, opioid reduction) when using RA‑TKA
No formal step‑therapy sequencing specified in policy excerpts

Step Therapy

Define and document conservative (non‑surgical) therapy prior to authorization

When conservative therapy is required by the policy, define and document non‑surgical medical management (anti‑inflammatories/analgesics, PT, weight reduction, activity modification, assistive devices, injections) in the medical record prior to surgical authorization.

List specific non‑surgical measures documented and duration (≥12 weeks)
If any conservative measures were contraindicated, document the reason

Note

References contain no step‑therapy mandates

No step‑therapy requirements are present in the policy reference lists; rely on the main policy coverage and documentation sections for requirements.

Note

No additional provider action specified

No additional provider action content was provided in inventory for this placeholder; follow the policy’s applicable sections for procedure‑specific requirements.

Documentation Required

Provide required clinical documentation (disease, failed conservative therapy, bone assessment)

Medical records submitted for authorization must document advanced joint disease findings, failure of conservative therapy for at least 12 weeks (or documented reason conservative therapy is not reasonable), and assessment of bone geometry/quality and risks/benefits in members with comorbidities.

Document imaging evidence of severe osteoarthritis or early osteonecrosis (<50% femoral‑head involvement)
Document normal proximal femoral bone geometry and bone quality or rationale if marginal

Billing Rule

Use coding lists in the policy to prevent coding‑related denials

The policy lists CPT and ICD‑10 codes that are not covered for the indications in this bulletin (examples include carpectomy CPT 25215 and several wrist/knee ICD‑10 codes); ensure billing aligns with the policy’s covered indications to avoid coding‑related denials.

Examples of codes flagged as not covered are provided in the coding section (e.g., 25215; multiple wrist and knee ICD‑10 codes)
Confirm procedure coding matches the documented medical necessity and covered indications

Documentation Required

Monitor and document ASR hip patients (symptoms and metal‑ion levels)

For patients with recalled or high‑failure devices (e.g., ASR), maintain close clinical surveillance and document laboratory monitoring including blood metal‑ion levels; include these data when justifying revision surgery.

Document symptoms and serial metal‑ion results for ASR or similar high‑failure devices
Note that asymptomatic patients with high metal‑ion levels should be closely followed and revision considered

Documentation Required

Include age, disease localization, and prior procedures in justification

When clinical justification is submitted for focal or partial resurfacing, include patient age, precise disease localization (unicompartmental disease), prior conservative and cartilage‑preserving procedures, and rationale for selecting focal/partial resurfacing versus alternatives.

Provide patient age and disease localization (e.g., medial compartment confined disease)
Document prior cartilage procedures or rationale for focal resurfacing selection

Documentation Required

Provide clinical scores and radiographic support for UKA/robotic UKA requests

When seeking authorization for UKA or robotic‑assisted UKA, include validated clinical outcome scores (e.g., KOOS, Knee Society Scores), radiographic evaluations, implant type, and surgical technique documentation to support medical necessity and expected outcomes.

Submit KOOS, KSS/FJS‑12 or other validated scores and radiographs
Describe implant type and planned robotic technique

Documentation Required

Submit SPECT/CT + TPBS and clinical correlation for SPR candidates

For secondary patellar resurfacing, document pre‑operative imaging (SPECT/CT and TPBS) and correlate findings with history and physical exam to support selection and expected benefit.

Include SPECT/CT and triple‑phase bone scan reports showing focal patellar radionuclide concentration when present
Correlate imaging with clinical findings (mal‑tracking or patellofemoral OA)

Documentation Required

Attach study follow‑up, survivorship, and imaging evidence when available

When citing study evidence to support authorization, provide study follow‑up duration, survivorship data, patient‑reported satisfaction, and CT or radiographic confirmation of implant positioning and outcomes when available.

Include follow‑up duration and survivorship statistics when available
Provide radiographic or CT confirmation of implant position if used in planning/studies

Documentation Required

Submit pre‑op CT and templating documentation for RA‑TKA

Document pre‑operative CT scans and templating reports used in RA‑TKA planning to demonstrate predicted implant sizes and planning rationale when submitting authorization or claims.

Attach CT‑based templating that predicted implant size within one size where applicable
Describe how CT planning informed the operative plan

Documentation Required

Document CT‑based 3‑D planning that supports RA‑TKA component sizing

CT‑based 3‑D planning used for RA‑TKA should be documented because studies report high accuracy in predicting component sizes and supporting intra‑operative planning.

Include documentation that CT planning predicted implant size within one size (reported 100% within 1 size in one series)
Document how planning informed intra‑operative adjustments

Documentation Required

Include operative details and outcomes measures for wrist resurfacing requests

For wrist procedures (PRC + RCPI, PRC + Eaton), include the operative indication (SLAC/SNAC or advanced wrist OA), operative details, implants used, and pre/post‑operative outcome measures (ROM, grip strength, DASH/QuickDASH/PRWHE, VAS) when seeking authorization.

State the precise wrist diagnosis and chosen procedure (PRC + RCPI versus alternatives)
Provide operative details, implants, and outcome measure baselines and expectations

Note

Follow main policy documentation for shoulder resurfacing (references informational)

The shoulder resurfacing references listed do not specify additional documentation requirements beyond the main policy; rely on the policy's required clinical documentation when requesting authorization.

Use the policy’s clinical documentation checklist for shoulder resurfacing requests
References are informational and do not replace required documentation

Note

Reference the full Clinical Policy Bulletin for coverage and administrative details

Refer to the full Clinical Policy Bulletin for the most current coverage, documentation, and administrative requirements; policy history and review dates are provided in the bulletin.

Check last review and next review dates in the policy header/footer
Use the full CPB for administrative and coverage details

Billing Rule

Align billing codes with policy‑covered indications to avoid denials

Ensure that billed CPT codes reflect the procedure actually performed and align with the CPB's covered indications; use of CPT codes listed as not covered for the indicated clinical scenario may result in denial.

Confirm procedure coding aligns with documented medical necessity and the policy’s covered CPT/HCPCS codes
Avoid billing codes listed as not covered for the stated indication to reduce denial risk

Denial Risk

Address device‑specific failure risk and justify associated claims

High early failure and revision rates reported for recalled or poorly performing devices (e.g., ASR systems) increase the need for close justification and monitoring and may increase risk of denial if implant‑related risks are not addressed.

Document device history and rationale if considering revision related to recalled/high‑failure devices
Include metal‑ion and surveillance data to justify revision when applicable

Denial Risk

Anticipate denial risk when evidence for focal knee resurfacing or MAKOplasty is insufficient

Insufficient evidence for HemiCAP/UniCAP focal knee resurfacing and for MAKOplasty robotic partial resurfacing may trigger non‑coverage or denial when superiority or routine use is asserted; include conservative therapy failure and specific indication justification.

Document prior conservative care and why alternatives are unsuitable
Provide indication‑specific justification given limited evidence for these technologies

Denial Risk

Provide strong selection documentation for secondary patellar resurfacing

Because secondary patellar resurfacing outcomes are uncertain and many patients report no pain improvement or dissatisfaction, ensure robust documentation of selection criteria and expected benefit to reduce denial risk.

Document selection criteria and expected measurable benefit for SPR
Include validated outcome measures and prior diagnostic evaluation

Denial Risk

Include imaging‑guided selection data for SPR to avoid weak justification

If SPECT/CT and TPBS imaging were not performed when proposing SPR, selection may be inappropriate and weaken the authorization; include imaging‑guided selection data when available to support medical necessity.

Include SPECT/CT + TPBS results showing focal patellar uptake when available
Correlate imaging to clinical exam and prior nonoperative care

Denial Risk

Address clinical limitations, monitoring, and contraindications in authorization requests

Clinical limitations such as need for monitoring, implant selection, and patient selection (contraindications) can affect authorization; ensure documentation addresses monitoring plans and contraindication screening.

Screen and document contraindications listed for metal‑on‑metal hip resurfacing (e.g., BMI >40, GFR <60, female of childbearing potential)
Document monitoring plans (metal ions, clinical surveillance) when relevant

Billing Rule

Ensure accurate coding and documentation of robotic‑assisted procedures

Incorrect or incomplete coding to identify robotic‑assisted procedures (for example, relying solely on CT coding within 60 days pre‑op) can limit ability to classify cases and may impact coverage analyses and payment; include explicit documentation of robotic assistance in the record.

Document robotic assistance in operative reports and authorization requests
Include pre‑op CT and robot‑specific disposables/fees where applicable

Denial Risk

Expect denial risk for focal femoral condyle resurfacing with high revision rates

High reported revision rates for certain focal femoral condyle resurfacing devices (UniCAP) — up to ~53–54% at 5–7 years and registry cumulative ~40.6% at 10 years — may prompt denial or non‑recommendation; include registry data and justification when seeking coverage.

Provide registry and study revision‑rate data when citing focal resurfacing devices
Address alternative treatment rationale given high revision risk

Denial Risk

Screen for and document contraindications that could make resurfacing not medically necessary

Contraindications listed for metal‑on‑metal hip resurfacing (e.g., females of child‑bearing age, immunosuppressed patients, BMI >40, GFR <60) should be screened and documented because presence of any contraindication renders resurfacing not medically necessary.

Screen for and document contraindications from the appendix (including BMI >40 and GFR <60 mL/min/1.73 m2)
If any contraindication is present, note that resurfacing is considered not medically necessary

Note

References do not contain authorization rules — use policy sections

No authorization rules are specified in the references section; rely on the policy's coverage, coding, and documentation sections for authorization determinations.

Note

Clinical Policy Bulletin is informational—refer to full bulletin for coverage specifics

Administrative footer notes that Clinical Policy Bulletins assist in administering plan benefits but do not guarantee coverage; direct providers to the full bulletin for benefit details and coverage conditions.

Clinical Policy Bulletins are informational and do not constitute a contract or guarantee of coverage
Refer to plan documents for member‑specific benefit determinations

Summary of clinical evidence relevant to coverage decisions

Summary of clinical evidence relevant to coverage decisions (background evidence):

Patellar resurfacing evidence summary: Systematic reviews, RCTs, and meta‑analyses provide mixed findings: pooled RCT data (33 RCTs, 5,540 TKAs) found reduced anterior knee pain (RR 0.65) and lower revision risk (RR 0.63) with patellar resurfacing, while other contemporary studies using 'patellar‑friendly' implants show no clinically significant benefit—implant design and patient selection influence outcomes.

Secondary patellar resurfacing summary: Secondary patellar resurfacing outcomes are heterogeneous; systematic reviews report modest proportions of patients achieving PROM improvement or satisfaction (pooled improvement ~53%, satisfaction ~59%), but study quality and selection criteria vary and evidence is low to moderate quality.

Robotic knee arthroplasty evidence summary: Robotic assistance in UKA/TKA improves implant alignment and reduces outliers; short‑term cohort and multi‑center data show high survivorship and improved early outcomes in some series (eg, RA‑UKA survivorship ~98.8% at 2.5 years), yet long‑term randomized evidence on improved survivorship is lacking.

Categorized as a form of hip resurfacing that conserves femoral bone and may facilitate future conversion to THR

Example devicesExamples of FDA‑approved systems used for resurfacing include Birmingham Hip Resurfacing, Cormet, Conserve Plus

inv-91: Total hip resurfacing (HRA) definition

DefinitionTotal hip resurfacing (HRA): resurfacing that involves both the femoral shell and resurfacing of the acetabular socket with a metal cup

Procedure detailA metal hemisphere fits over the femoral head and articulates with a metal acetabular cup; conserves femoral bone compared with THR

Indicated populationTypically intended for younger active patients with viable proximal femoral bone

inv-92: Surface replacement arthroplasty (SRA) definition

DefinitionSurface replacement arthroplasty (SRA): procedure where only joint surfaces are removed and replaced, preserving most native bone and avoiding opening the medullary canal

Contrast with THRUnlike THR, SRA preserves the femoral head and neck and uses smaller‑volume implants

Clinical noteModern metal‑on‑metal SRA aims to improve wear characteristics compared to older metal‑on‑polyethylene designs

inv-93: Surface replacement arthroplasty (hip resurfacing) alternate description

Alternate descriptionHip resurfacing (SRA) removes only joint surfaces, preserves femoral bone, does not open medullary canal, and uses smaller‑volume implants

PurposeDesigned to conserve bone and maintain normal femoral loading while allowing later conversion to THR if needed

Evidence considerationLong‑term survival data and systemic effects of elevated metal ions remain under investigation

inv-94: Shoulder resurfacing definition

DefinitionShoulder resurfacing: humeral‑head‑conserving procedure replacing damaged portions of the humeral head with a cap or partial/complete coverage implant; may be hemi‑resurfacing or combined with glenoid treatment

Clinical useConsidered for younger, active adults with glenohumeral arthritis, humeral head fractures, or osteochondral lesions to preserve bone stock

Device exampleCopeland resurfacing head is an FDA‑recognized device used for humeral head resurfacing

inv-95: Focal/partial knee resurfacing definition (HemiCAP/UniCAP)

DefinitionFocal/partial knee resurfacing: implants (eg, HemiCAP, UniCAP) that resurface a localized area of the femoral condyle or patellofemoral joint to preserve bone and delay TKA

Intended patientsUsed for younger, active patients with focal full‑thickness cartilage defects confined to one compartment

Evidence caveatAvailable evidence limited; registry data show concerning long‑term revision rates for some devices

inv-96: Humeral head inlay arthroplasty (HemiCAP-type) definition

DefinitionHumeral head inlay arthroplasty (HemiCAP‑type): joint‑preserving resurfacing that maps and implants a contoured component matched to a patient’s humeral head defect to maintain head‑neck‑shaft anatomy

Clinical outcomesCase series report improved pain and function with high patient satisfaction at mid‑term follow‑up, but evidence is level IV

Surgical noteAllows intra‑operative surface mapping and placement of a defect‑matched contoured articular component

inv-97: Secondary patellar resurfacing (SPR) definition

DefinitionSecondary patellar resurfacing (SPR): a procedure performed after primary TKA to address persistent anterior knee pain by resurfacing the patella

Outcomes cautionStudies report many patients have no pain improvement and high dissatisfaction rates, making benefit uncertain

Selection noteImaging and diagnostic correlation often used to select candidates prior to SPR

inv-98: Robotic-arm assisted UKA definition

DefinitionRobotic‑arm assisted UKA: unicompartmental knee arthroplasty performed with robotic‑arm guidance (eg, MAKO RIO) to improve implant positioning accuracy

Reported benefitsRandomized and cohort studies show improved component positioning accuracy and reduced radiographic outliers versus conventional UKA

Documentation implicationPre‑op CT‑based planning and documentation of robotic assistance recommended for authorization and outcomes reporting

inv-99: HemiCAP-Wave implant definition

DefinitionHemiCAP‑Wave implant: focal patello‑femoral inlay resurfacing implant used for large trochlear cartilage lesions (ICRS grade 3–4) > 4 cm2

Outcomes noteShort‑ to mid‑term improved pain and function reported but high mid‑term revision rate (~28% within 6 years) observed

Level of evidenceProspective cohort evidence (Level IV) with limited follow‑up

inv-100: MTP joint definition (first MTP / hallux rigidus)

DefinitionMTP joint (first MTP / hallux rigidus): metatarsophalangeal joint between metatarsal head and proximal phalanx; first MTP commonly called the big toe joint; hallux rigidus denotes restricted mobility due to arthritis

Clinical applicationMTP joint resurfacing devices are designed to resurface the metatarsal head for hallux rigidus and post‑traumatic arthritis

Device examplesExamples include CAP great toe resurfacing hemi‑arthroplasty and OsteoMed metatarsal resurfacing systems

inv-101: Birmingham Hip Resurfacing (BHR) definition

DefinitionBirmingham Hip Resurfacing (BHR): an FDA‑approved hip resurfacing system that preserves more femoral bone and requires accurate acetabular and femoral component positioning

Clinical noteAccurate component positioning is critical to reduce wear and failure; navigation evidence for BHR is limited

Example roleMentioned as an FDA‑approved device option for selected younger, active patients

inv-102: Metal resurfacing inlay implant definition

DefinitionMetal resurfacing inlay implant: a metal inlay device implanted into the talar dome to treat osteochondral defects, often requiring a medial malleolar osteotomy for access

Anatomic limitationTechnique typically limited to medial talar lesions because a medial malleolar osteotomy is required (lateral lesions excluded)

Evidence summaryProspective case series (n=38) reported mid‑term improvements but notable re‑operations and radiographic concerns; longer follow‑up needed

inv-103: Robotic-assisted TKA/UKA definition

DefinitionRobotic‑assisted TKA/UKA: surgical procedures using robotic systems (eg, MAKO RIO, ROBODOC) to assist bone preparation and component placement aiming to improve alignment, component positioning, and gap balance

Reported advantagesStudies report improved component positioning, reduced radiographic outliers, more consistent gap balance, and improved short‑term PROMs in some series

LimitationsLong‑term benefits and survivorship impact remain uncertain; learning curve (operative time proficiency) often 7–11 cases

inv-104: Pre-operative CT-based templating definition

DefinitionPre‑operative CT‑based templating: use of CT scans before surgery to create a 3D plan for implant sizing and positioning, commonly used in RA‑TKA protocols

PerformanceCT‑based 3D templating predicted implant size within 1 size in nearly all cases and had higher accuracy than 2‑D templating in cited cohorts

Documentation implicationPre‑op CT planning should be documented to support robotic‑assisted cases and authorization where applicable

inv-105: Balanced knee (gap difference) definition

DefinitionBalanced knee (gap difference): a knee in which medial and lateral flexion or extension gap differences are within a specified threshold (eg, within 2 mm considered balanced in cited RA‑TKA cohort)

Clinical metricBalanced knees defined by post‑bone cut medial/lateral gap differences within ±2 mm in cited series

RelevanceRobotic systems may improve achievement of balanced gaps compared to manual techniques

inv-106: rTKA / RA-TKA definition

DefinitionrTKA / RA‑TKA: robotic‑assisted total knee arthroplasty using robotic or computer‑assisted systems to plan and guide component positioning and bone preparation

Evidence notesSystematic reviews report improved positioning accuracy and reduced outliers but limited long‑term RCT evidence regarding survivorship

Operational noteLearning curve for operative time/proficiency reported at roughly 7–11 cases

inv-107: HemiCAP / UniCAP definition

DefinitionHemiCAP / UniCAP: partial femoral condyle focal resurfacing implants intended to treat focal full‑thickness cartilage defects of the femoral condyle

Clinical concernEvidence and registry data report high long‑term revision rates (eg, UniCAP ~53.7% at 5–7 years; cumulative 10‑yr revision ~40.6% for some series)

ImplicationLimited evidence and high revision risk may affect coverage and authorization decisions

inv-108: RCPI definition

DefinitionRCPI: Resurfacing Capitate Pyrocarbon Implant used with proximal row carpectomy to treat selected advanced wrist arthritis or carpal injuries

Clinical roleRCPI combined with PRC may be an alternative to 4‑corner fusion or total wrist arthroplasty in select patients

Evidence caveatAvailable studies are small and follow‑up limited; concerns remain about implant cost and long‑term durability

inv-109: Conservative therapy definition

DefinitionConservative therapy: non‑surgical medical management

Policy requirementAt least 12 weeks of documented conservative therapy (eg, medications, PT, exercise, weight reduction, activity modification, assistive devices, injections) is expected before resurfacing unless contraindicated

DocumentationMedical record must clearly address failure of conservative measures or justify why they are inappropriate

inv-110: PRC + RCPI definition

DefinitionPRC + RCPI: proximal row carpectomy combined with resurfacing capitate pyrocarbon implant for selected SLAC/SNAC wrists or advanced wrist OA

Reported outcomesSystematic reviews report some favorable PROMs and reduced disability versus PRC alone but evidence is limited (small sample of RCPI cases)

Documentation guidanceAuthorization should include indication, operative details, and outcome measures when PRC + RCPI is proposed

inv-111: Metal-on-metal hip resurfacing definition

DefinitionMetal‑on‑metal hip resurfacing: a hip resurfacing technique using metal bearings (metal femoral cap against metal acetabular cup)

Safety concernsStudies report elevated serum metal ion concentrations and associations with adverse local tissue reactions and higher revision rates for some devices

Contraindication considerationsDevice‑specific failures (eg, ASR) and metal sensitivity are noted contraindications or factors affecting coverage

inv-112: Humeral head resurfacing / shoulder resurfacing definition

DefinitionHumeral head resurfacing / shoulder resurfacing: surface replacement procedures for the shoulder that replace the damaged humeral head portion with a cap or partial/complete coverage implant

Clinical scopeMay be performed alone (hemi‑resurfacing) or with glenoid treatment; intended for younger, active patients to preserve bone stock

Evidence noteCase series report functional improvements but long‑term comparative evidence is limited

inv-113: Patellar resurfacing / knee resurfacing definition

DefinitionPatellar resurfacing / knee resurfacing: procedures involving resurfacing of the patella or focal femoral condyle to treat localized cartilage lesions or anterior knee pain

Evidence summaryRandomized trials and meta‑analyses show mixed results; pooled data suggest routine patellar resurfacing may reduce anterior knee pain and revision risk but selective or secondary resurfacing evidence is inconsistent

Coverage implicationSecondary patellar resurfacing outcomes are uncertain; documentation and imaging correlation are important for candidate selection