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CurrentAetnaPolicy 0753

Core Decompression for Avascular Necrosis

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This policy governs the medical necessity and coverage of core decompression for avascular necrosis of the hip and lists interventions considered experimental/investigational. It affects providers and members under Aetna's coverage for treatment of femoral head/neck osteonecrosis.

Policy Summary

PayerAetna

PolicyCore Decompression for Avascular Necrosis

Policy CodePolicy 0753

Change TypeNo material change noted

Effective DateApr 25, 2008

Last ReviewOct 4, 2023

Next Review DateAug 8, 2024

Key ActionObtain prior authorization for hip core decompression (HCPCS S2325) with documentation of early/pre-collapse stage, lesion extent, and prior conservative therapy.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

I–IIEligible AVN stages

III+Late/collapse stages

10k–20kAnnual US cases (est.)

60–80%Selected series 5–10 yr success

84%Steinberg I success

Coverage Criteria — Core Decompression

inv-01: Medical necessity: Core decompression (hip, early stages)

Covered when ALL of the following are met

Core decompression medical necessity

Anatomic site: Femoral head and/or neck (hip).
Policy applies to hip only; AVN of other joints is considered investigational per policy.

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Policy Summary

PayerAetna

PolicyCore Decompression for Avascular Necrosis

Policy CodePolicy 0753

Change TypeNo material change noted

Effective DateApr 25, 2008

Last ReviewOct 4, 2023

Next Review DateAug 8, 2024

Key ActionObtain prior authorization for hip core decompression (HCPCS S2325) with documentation of early/pre-collapse stage, lesion extent, and prior conservative therapy.

SourceLink

On This Page

inv-03: Hip — preservation (pre-collapse) indication — Core decompression for the femoral head may be considered medically reasonable when ALL of the following are met:

Core decompression for the femoral head may be considered medically reasonable when ALL of the following are met:

Eligibility for hip core decompression: 1) Diagnosis of osteonecrosis of the femoral head; 2) Disease is early/pre-collapse (eg Ficat/ARCO/Steinberg stage I–II); 3) Necrotic lesion size is small or medium as documented by MRI (not a large lesion); 4) Symptoms correlate with imaging findings and conservative management (eg protected weight-bearing, analgesics) has been inadequate or joint-preserving surgery is indicated.

inv-04: Adjunctive augmentation — Adjuncts and technique considerations that may influence effectiveness:

Adjuncts and technique considerations that may influence effectiveness:

Adjuncts with supportive but limited evidence: Implantation of autologous bone‑marrow mononuclear cells or concentrated bone marrow (BMMC/BMAC), use of platelet-rich products (PRP/PRF), and non‑vascularized autologous bone grafting have shown improved pain, delayed progression, or prolonged time-to-collapse in small randomized or observational studies; however, studies are limited by small sample sizes, heterogeneity of techniques, and variable follow-up.

Technique specifics to document: When adjunctive biologic materials or grafts are used, documentation should specify cell source and processing, concentration/scaffold (eg tricalcium phosphate, CaSO4–CaPO4), and graft type because outcomes vary by technique.

Limitations and caution: Some augmentation approaches (eg CD combined with demineralized bone matrix or certain injectable synthetic bone graft substitutes) have reported high long‑term failure or conversion-to‑THA rates in small series and require cautious interpretation and further evidence.

inv-05: Other joints — limited evidence — Core decompression for other joints (knee, ankle, shoulder):

Core decompression for other joints (knee, ankle, shoulder):

Knee/ankle/shoulder core decompression evidence: Evidence is currently insufficient to support routine use of core decompression for AVN of the knee, ankle, and shoulder; published studies are small, heterogeneous, and often uncontrolled. Core decompression may be considered only in selected cases or within clinical studies.

inv-06: Coverage for core decompression (other joints) — Covered when ALL of the following are met

Covered when ALL of the following are met

Core decompression coverage criteria for non-hip joints: 1) Disease is early/pre‑collapse radiographic stage (eg Ficat/Arlet I–II or equivalent) confirmed by MRI; 2) Persistent or severe symptoms despite appropriate conservative management (eg protected weight‑bearing, orthoses, analgesics) or patient is an appropriate candidate for joint-preserving surgery; 3) Documentation of relevant risk factors and clinical course (eg corticosteroid use, immune disease) is provided; 4) Goal of treatment is joint preservation and patient is counseled that progression to collapse and arthroplasty remains possible.

Evidence quality and expected outcomes vary by joint and study; consider enrollment in clinical trials when evidence is limited.

inv-02: Experimental/investigational interventions — Not covered / considered experimental and investigational

Not covered / considered experimental and investigational

Experimental/investigational interventions: Core decompression for AVN of other joints (ankle, elbow, knee, mandibular condyle, shoulder), core decompression for late/post‑collapse (stage III or higher) hip AVN, post‑arthroscopic osteonecrosis, combined core decompression and intralesional autologous bone marrow–derived cell therapies, and adjunctive treatments including autologous bone marrow mononuclear cells/BMAC/BMSCs, platelet concentrates (PRP/PRF), bisphosphonates, BMPs (eg rhBMP‑2), demineralized bone matrix, erythropoietin, extracorporeal shockwave, growth factors, intraosseous ibandronate, laser therapy, mesenchymal stem cells, ozone therapy, parathyroid hormone, platelet‑rich fibrin, PRP combined with stem cells, PRP+MSCs+synthetic grafts, and synthetic bone graft substitutes (eg calcium sulphate and calcium phosphate) are considered experimental/investigational because effectiveness has not been established.

List is not all-inclusive.

The policy identifies combined procedures — specifically core decompression (CD) combined with bone marrow aspiration concentrate (BMAC) or intralesional autologous bone marrow–derived cell therapies — as experimental/investigational because effectiveness has not been established. The document also discusses CD with a range of biologic adjuncts (eg, PRP, MSCs, synthetic grafts) and emphasizes that evidence is heterogeneous across studies, with variable techniques, cell processing, scaffolds, and follow-up durations that limit definitive conclusions about benefit when CD is combined with cell therapies.

When CD plus BMAC/BMDCT is considered clinically (eg, in a research or case‑by‑case context), prior authorization and documentation should specify the exact adjunct, cell source and processing, scaffold used (eg, tricalcium phosphate), and the clinical rationale, because pooled analyses suggest potential benefit but randomized, standardized evidence is limited and inconsistent.

Multiple series and pooled analyses indicate that outcomes are substantially worse for late/post‑collapse disease (eg, ARCO/Steinberg/Ficat stage III–IV). Retrospective cohorts and small series report higher conversion rates to total hip arthroplasty (THA) and poorer survivorship in stage III–IV hips, and several authors consider late-stage disease an unfavorable indication or contraindication for core decompression.

Randomized and controlled data are limited in advanced stages; available observational reports describe markedly lower survival and greater need for arthroplasty when decompression is performed after collapse, supporting the policy stance that CD is primarily applicable to early/pre‑collapse disease.

Reports of CD combined with certain injectable synthetic bone graft substitutes (notably PRO‑DENSE, a calcium sulfate/calcium phosphate composite) showed a high early failure rate in ARCO stage IIC and IIIA femoral head lesions, with rapid graft resorption and conversion to THA in many cases. These findings indicate a failure signal for that specific synthetic graft combination in those stages and caution against routine use.

In one prospective series, core decompression combined with autologous bone marrow concentrate and tricalcium phosphate did not prevent radiographic progression to collapse; median survival to any collapse was 7 months and median time to THA was 23 months. This trial concluded that the combined approach failed to halt radiographic progression in early-stage osteonecrosis of the hip.

The evidence base is heterogeneous with many small observational series, variable adjunct techniques, inconsistent outcome measures, and limited long‑term randomized data. Network meta‑analyses and systematic reviews have often found no clear differences among CD variants and non‑operative care for conversion to THA or radiographic progression, and study quality ranges from very low to moderate. These limitations reduce confidence in broad coverage conclusions for adjunctive or novel CD techniques.

Across multiple reports, patients with advanced or collapsed femoral head disease (eg Ficat/Arlet or ARCO stage III–IV) have markedly worse outcomes after core decompression, with lower survivorship and higher rates of conversion to arthroplasty compared with early‑stage disease. Several series show survival functions that differ significantly by stage, supporting the position that CD is less effective in advanced/collapsed stages.

A randomized, double‑blind trial is cited reporting the inefficacy of autologous bone marrow concentrate in stage III osteonecrosis (Hauzeur et al.). In addition, a small randomized trial (Pepke et al.) of BMAC injection during CD (n=24) showed no short‑term difference in clinical or radiologic outcomes, underscoring that randomized evidence does not uniformly support benefit of autologous BMC in mid‑ to late‑stage disease.

The policy lists several relevant billing and drug code references that relate to coverage and documentation: HCPCS/CPT and drug codes mentioned include S2325 (hip core decompression), P9020 (platelet rich plasma), and various bisphosphonate J‑codes (eg, J1740, J2430, J3489), as well as codes for synthetic grafts and related modalities. Providers should ensure coding aligns with the policy’s selection criteria and the documented indication.

Available literature for core decompression of the knee, ankle, and shoulder is limited and of low quality. Reviews and evidence summaries conclude that there is currently insufficient high‑quality evidence to support routine coverage of CD for these non‑hip joints, and prospective randomized trials are needed before routine medical necessity can be established.

Evidence for talar (ankle) AVN and other non‑hip joints is rated as very low to low quality in systematic reviews; small, heterogeneous studies and potential reporting bias limit interpretation, so no firm conclusions about effectiveness can be drawn for these sites.

A small randomized controlled trial (Pepke et al.; n = 24) detected no short‑term benefit in bone regeneration or clinical outcomes from adding bone marrow concentrate injection during core decompression, reinforcing uncertainty about short‑term efficacy of BMC adjuncts in randomized data.

The excerpted policy and evidence summaries do not present an explicit blanket statement labeling treatments as ‘not medically necessary’ in every context. Instead, they document heterogeneous results and limited high‑quality RCT data for many adjuncts and non‑hip indications, leading to cautious, evidence‑based language that some combinations and indications are considered experimental/investigational rather than universally denied.

For humeral head osteonecrosis in patients with sickle cell disease, systematic reviews report low evidence quality and conclude that core decompression has not been confirmed to prevent or delay disease progression; the role of core decompression in this population therefore remains unproven and requires further high‑quality study.

Coding — Procedure and Diagnosis Codes

Related CPT/HCPCS codes (covered if selection criteria met or related)mixed

0101T	Extracorporeal shock wave involving musculoskeletal system, not otherwise specified, high energy.
0232T	Injection(s), platelet rich plasma, any site, including image guidance, harvesting and preparation when performed.
0481T	Injection(s), autologous white blood cell concentrate (autologous protein solution), any site, including image guidance, harvesting and preparation, when performed.
38232	Bone marrow harvesting for transplantation; autologous.
20955	Bone graft with microvascular anastomosis; fibula.
27071	Partial excision, wing of ilium, symphysis pubis, or greater trochanter of femur, (craterization, saucerization) (eg, osteomyelitis or bone abcess); deep (subfascial or intramuscular).
27170	Bone graft, femoral head, neck, intertrochanteric or subtrochanteric area (includes obtaining bone graft).
38230	Bone marrow harvesting for transplantation; allogenic.
38241	Hematopoietic progenitor cell (HPC); autologous transplantation.
S2325	Hip core decompression.

HCPCS/CPT codes not covered for indications listedmixedNot Covered

C1763	Connective tissue, non-human (includes synthetic).
J1436	Injection, etidronate disodium, per 300 mg.
J1740	Injection, ibandronate sodium, 1 mg.
J2430	Injection, pamidronate disodium, per 30 mg.
J3489	Injection, zoledronic acid, 1 mg.
P9020	Platelet rich plasma, each unit.
S8948	Application of a modality (requiring constant provider attendance) to one or more areas; low-level laser; each 15 minutes.

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

M87.051 - M87.059	Osteonecrosis of femur [early/pre-collapse (stage I or II; before X-ray changes are evident)]
M87.151 - M87.159
M87.251 - M87.256
M87.351 - M87.353
M87.851 - M87.859
M90.551 - M90.559

ICD-10 codes not covered for indications listedICD-10Not Covered

M87.00 - M87.9

Osteonecrosis of bone

CPT codes related to intraosseous proceduresCPT

36680

Placement of needle for intraosseous infusion.

Procedure/Diagnosis Codes (not specified in this section)mixed

none specified

Document discusses interventions and adjuncts but does not list specific CPT/ICD codes in this excerpt

Covered CPT CodesCPT

No codes listed

AVN stage for medical necessity

AVN stage for medical necessityStage I or II (early/pre-collapse; before X‑ray changes are evident)

ApplicabilityApplies to the hip (femoral head and/or neck) for joint‑preserving intent

Exclusion noteLate/post‑collapse disease (stage III or higher) is considered experimental/investigational

BMI as prognostic marker

BMI threshold>= 30 kg/m2 — identified as an independent predictor of progression after CD

Prognostic implicationObesity (BMI ≥30) associated with increased risk of radiographic progression and worse outcomes

Documentation recommendationRecord BMI in prior authorization/clinical documentation to support prognosis assessment

Provider Actions, Authorization & Documentation

Prior Authorization

Prior authorization required for HCPCS S2325

Prior authorization is required for HCPCS S2325 (hip core decompression); coverage is contingent on meeting the policy's selection criteria for early/pre‑collapse (stage I or II) femoral head osteonecrosis.

HCPCS code: S2325 must be requested with PA documentation showing stage I–II disease and supporting clinical/imaging data.

Prior Authorization

Provide clinical justification: stage, size, and rationale

Prior authorization requests should justify lesion stage, lesion size (MRI), and the clinical rationale for core decompression versus alternative nonoperative or joint‑preserving procedures.

Document MRI-based staging and lesion size (small/medium vs large).
Explain why conservative management is inadequate or why joint-preserving surgery is preferred.

Prior Authorization

PA appropriate for core decompression of other joints

When core decompression is requested for non‑hip joints (knee, ankle, shoulder), prior authorization is appropriate to confirm early/pre‑collapse stage disease and persistent symptoms despite conservative care.

Confirm radiographic/MRI early-stage (eg Ficat/ARCO I–II equivalent) and document failed conservative management.
State intent for joint preservation and provide risk‑factor history.

Prior Authorization

Require evidence- and stage-based documentation for authorization

Prior authorization should require documentation of indication (early/pre‑collapse ONFH), prior conservative therapy, and imaging staging because evidence and outcomes vary by disease stage and technique.

Include radiographic/MRI staging (Ficat/ARCO), symptom correlation, and record of prior nonoperative measures.
State planned adjuncts (if any) and intended operative technique.

Prior Authorization

Specify adjuncts and technique in PA requests

Specify the exact adjunct(s) and surgical technique in the prior authorization (for example: CD + bone marrow–derived cells, CD + PRP, CD + synthetic grafting) because published studies differ by method, cell counts, and scaffolds.

List adjunct type (BMAC/BMDCT, PRP, autologous bone, synthetic graft such as CaSO4–CaPO4) and processing/source of biologics.
Describe backfilling material or advanced CD modifications if used.

Prior Authorization

Support PA with disease extent and adjunct rationale

Prior authorization should be supported by documentation of early-stage disease, extent of necrosis (eg modified Kerboul angle or necrotic index), and a clear rationale for any adjunctive therapy given variable evidence of benefit.

Provide modified Kerboul angle or necrotic index and symptom severity (HHS/VAS).
If proposing cell-based adjuncts, include cell counts/CFU data when available.

Note

Administrative history present; no extra PA mandates in excerpt

The document excerpts include administrative policy history but do not state additional explicit prior authorization requirements; reviewers should rely on the PA statements elsewhere in the policy for actionable requirements.

Policy history and review dates are administrative notes and do not add provider-facing PA steps.

Step Therapy

Attempt conservative (nonoperative) management first

Attempt nonoperative measures prior to considering core decompression: rest/protected weight‑bearing, activity modification, NSAIDs/analgesics, orthoses, and pharmacotherapy such as bisphosphonates when appropriate.

Document duration and response to protected weight‑bearing or orthoses.
Record use and response to NSAIDs or bisphosphonate therapy if used.

Step Therapy

Consider conservative care or clinical trial for non‑hip joints

For non‑hip joints, the policy advises considering conservative management or enrollment in clinical trials before approving core decompression due to limited and low‑quality evidence.

Document failed conservative care and consider trial enrollment where available.
Provide justification for proceeding to CD in non‑hip joints given evidence limitations.

Step Therapy

Conservative-first approach for talar/ankle AVN

For talar/ankle AVN, conservative management (protected weight‑bearing, orthoses, and analgesics) is typically attempted first; core decompression is generally reserved for symptomatic pre‑collapse disease that does not respond.

Document initial protected weight‑bearing regimen and response.
If CD is proposed, include imaging showing pre‑collapse (stage II) disease.

Step Therapy

Use a stepwise decision process for CD ± cell therapy

Consider a stepwise approach to selecting CD alone versus CD plus cell‑based therapy because trial and observational results are mixed and apparent benefit is greatest in early/pre‑collapse disease.

When proposing cell-based adjuncts, justify based on early-stage disease and cite available outcome data.
If cell therapy is requested, include details on cell source, counts, and processing.

Note

No explicit step therapy sequencing specified

The excerpt does not provide an explicit mandated step therapy sequence; no formal sequencing requirement is stated in the policy text provided.

Providers should follow the documented conservative-first recommendations and PA requirements but no prescribed steps are listed in the excerpt.

Note

Consider evidence favoring CD + bone marrow–derived therapies

Pooled analyses suggest CD combined with bone marrow–derived cell therapies reduces progression and conversion to arthroplasty compared with CD alone, but randomized data are limited; consider these findings when planning therapy and documenting justification.

Cite pooled ORs (eg OR 0.19 for progression; OR 0.20 for conversion) in rationale when applicable.
Note limitations: heterogeneity and need for larger RCTs.

Note

Identify adjuncts/alternatives and note investigational status

Adjunctive and alternative treatments discussed in the policy include stem cells/BMAC, PRP, bisphosphonates, hyperbaric oxygen, extracorporeal shock wave therapy, and synthetic bone graft substitutes; providers should identify which adjunct is planned and be aware some are considered investigational.

If proposing adjuncts listed as investigational (eg MSCs, PRP, synthetic grafts), include supporting clinical rationale and literature if available.
Be aware certain adjuncts (eg PRO‑DENSE in ARCO IIC/IIIA) have reported high failure rates and may affect coverage.

Billing Rule

Ensure diagnosis and procedure coding align with policy

Document diagnosis coding consistent with the listed ICD‑10 codes for femoral head osteonecrosis (eg M87.051‑M87.059) and include the HCPCS/CPT codes used (for hip core decompression, S2325) in claims and PA requests.

Use covered ICD‑10 codes for early/pre‑collapse femoral head osteonecrosis when selection criteria are met.
Include procedure code S2325 on authorization and claim submissions.

Documentation Required

Document radiographic/MRI stage and lesion size

Document MRI and radiographic staging and report lesion size/location (eg modified Kerboul angle or necrotic index) and symptom status because outcomes are stage‑ and extent‑dependent.

Provide MRI-based stage (Ficat/ARCO) and quantify necrotic extent (modified Kerboul angle or necrotic index).
Include symptom measures (HHS, VAS) and correlation with imaging.

Documentation Required

Include radiographic/MRI staging, lesion details, and prior treatments

Required clinical documentation for authorization should include radiographic and MRI staging (Ficat/Arlet or ARCO), lesion size/location, prior nonoperative measures, and key risk factors (eg corticosteroid use, immune disease).

Attach preoperative X‑rays and MRI reports and specify prior conservative treatments and duration.
List relevant comorbidities and risk factors influencing prognosis.

Documentation Required

Document follow‑up clinical and radiologic outcomes and adjunct details

Capture clinical and radiologic follow‑up data when available (modified Harris Hip Score, MRI/XR findings, time to collapse, need for THA) and detail adjunctive materials used (BMAC source, scaffold type, cell counts) to support treatment outcomes.

Report pre‑ and post‑operative HHS, VAS, and imaging comparisons.
Document source/processing of biologics and implant/graft materials used.

Documentation Required

Include suggested operative and cellular documentation elements

When reporting operative series or supporting documentation for adjunctive biologic procedures, include pre/post radiography/MRI, HHS, VAS, modified Kerboul angle, and cellular metrics such as nucleated cell counts and CFU assays where available.

Provide absolute nucleated cell counts/ml and CFU data if cell therapies were used.
Include objective imaging measures (modified Kerboul angle) and validated clinical scores.

Documentation Required

Provide study‑style clinical documentation elements (stage, BMI, follow‑up)

Clinical studies documenting CD with biologic adjuvants typically report staging (Ficat/modified Kerboul), patient age, BMI, and follow‑up imaging; include these elements in authorization/supporting materials because BMI >=30 and older age predict progression.

Report patient demographics (age, BMI) and document BMI if ≥30.
Provide staging and follow‑up radiographic/MRI data.

Note

Policy history present; no extra documentation mandates here

This portion of the document contains policy history and administrative notes; it does not specify additional provider-facing documentation requirements beyond those in the coverage and authorization sections.

Use the PA and documentation guidance elsewhere in the policy for provider requirements.

Denial Risk

Denial risk: CD for late/post‑collapse (stage III+) hips

Core decompression for late/post‑collapse hip disease (stage III or higher) is considered experimental/investigational and is likely to be denied if submitted for coverage.

Do not submit PA for CD when imaging documents stage III or IV femoral head collapse without explicit medical rationale supported by evidence.
Coverage determinations will follow the policy's experimental/investigational stance for advanced stages.

Denial Risk

Denial risk for CD in non‑hip joints due to limited evidence

Because evidence is insufficient for routine CD in joints other than the hip (knee, ankle, shoulder), requests for CD at these sites may trigger additional review or non‑coverage unless compelling documentation and trial enrollment justification are provided.

Provide evidence of early/pre‑collapse stage and failed conservative care for non‑hip joints.
Consider referring patients for clinical trial participation when appropriate.

Denial Risk

Adjunct graft failure may affect coverage (eg PRO‑DENSE)

High failure rates have been reported when CD was combined with certain injectable synthetic grafts (eg PRO‑DENSE) in ARCO stage IIC and IIIA femoral head lesions; such combinations may be denied or unsupported by payers.

If proposing synthetic graft products, include evidence supporting their use for the specific ARCO/Ficat stage.
Be aware of reported early graft resorption and high conversion rates to THA with PRO‑DENSE in reported series.

Documentation Required

Document progression to collapse and subsequent interventions

Document radiographic progression (collapse) and any subsequent interventions (repeat decompression, conversion to THA) because progression despite CD ± adjuncts is an expected outcome and relevant to treatment assessment.

Record time to collapse and dates/details of any subsequent hip arthroplasty.
Include imaging that documents progression and correlate with clinical scores.

Note

No other explicit administrative PA/denial triggers in excerpt

The excerpted evidence summaries note lack of high‑quality randomized trials and heterogeneity across studies; there are no explicit administrative PA triggers or additional denial criteria stated in these chunks beyond the PA guidance above.

Rely on the policy's stated PA requirements (S2325, staging, documentation) for actionable steps.
Expect clinical discretion where evidence is limited.

Denial Risk

Stage‑related denial risk: higher for advanced disease

Advanced-stage disease (stage III–IV) has substantially lower femoral head survivorship compared with early-stage disease; requests for CD in advanced stages carry higher denial risk and should include strong justification if submitted.

Document why CD is being considered in advanced stages and provide supporting evidence if available.
Be aware stage is an independent predictor of progression and failure.

Note

Policy history note — no provider actions implied

Policy history and review dates are administrative information only and do not impose additional provider action requirements.

Use current PA and documentation guidance rather than policy history for submission requirements.

Background & Epidemiology

One randomized and several observational studies addressing CD with or without cell therapies for non‑hip joints or talar AVN have small sample sizes and limited follow‑up. Consequently, available data do not support routine use of CD for talar AVN or other joints, and conclusions are limited by the low quality and heterogeneity of existing studies.

Definitions & Key Terms

Ficat Classification stage II

Ficat stage II definitionPresence of cysts is considered stage II per the Ficat Classification of AVN of the femoral head

Clinical contextStage II is within the early/pre‑collapse window for which CD may be considered medically necessary

Source noteFicat Classification referenced in policy note

Core decompression — procedural definition

Technical definitionSurgical removal of an 8–10 mm cylindrical core of bone from the antero‑lateral segment of the femoral head

PurposeCreates an open cylindrical channel to relieve intraosseous pressure and may be optionally filled with vascularized or non‑vascularized bone graft

ApproachLateral trochanteric approach to access the antero‑lateral femoral head

Pre-collapse disease

DefinitionPre‑collapse disease: AVN stages prior to femoral head collapse (commonly described as stages I and II)

Clinical relevanceCore decompression is most effective in pre‑collapse stages to preserve the joint and delay THA

Imaging requirementStage confirmation typically by MRI and radiographic staging (eg, Ficat/ARCO/Steinberg)

Lesion size prognostic groups

Prognostic groupsLesions are categorized as small, intermediate, or large based on necrotic extent on imaging

Outcome correlationSmall and medium lesions have better hip‑preserving outcomes after CD than large lesions (higher THA conversion with larger lesions)

DocumentationLesion size should be documented (MRI) for prior authorization and prognosis

Pre-collapse disease definition (alternate)

Alternate definitionPre‑collapse/early‑stage AVN refers to Ficat/Arlet stage I–II or ARCO pre‑collapse where structural femoral head collapse has not occurred

Clinical implicationPatients in this category are the preferred candidates for core decompression

Evidence noteMultiple series report best success rates in early-stage, small‑to‑medium lesions

Definition of BMC/BMAC

DefinitionBMC/BMAC: concentrated autologous bone marrow aspirate containing mesenchymal stem/progenitor cells (used as intralesional adjunct during CD)

PurposeInstilled into the decompression tract to potentially enhance osteogenesis and reduce progression

DocumentationCell source, concentration, and CFU/nucleated cell counts are often reported and should be documented

Definition of APC/PRP/PRF

DefinitionAPC/PRP/PRF: autologous blood‑derived platelet concentrates rich in platelets and growth factors applied to surgical sites to promote healing

Use caseUsed alone or combined with stem cells during CD to potentially improve pain and function; evidence is preliminary

Evidence noteCase series report improved outcomes but randomized data are limited; further study needed

Advanced core decompression (ACD)

DefinitionAdvanced core decompression (ACD): percutaneous removal of necrotic tissue with an expandable reamer followed by refilling the defect with injectable, hard‑setting composite CaSO4–CaPO4 bone graft substitute

ModificationMay include impaction of autologous femoral neck bone into the defect (modified ACD) to improve outcomes

Reported outcomesModified ACD with autologous bone reported 75.9% success (no collapse/conversion) in Steinberg stages 2a–2c in a cohort study

CD + BMSCs / stem cell combination therapy

DefinitionCD + BMSCs / stem cell combination therapy: core decompression followed by implantation/instillation of autologous bone marrow‑derived mesenchymal stem cells or bone marrow buffy coat into the decompression tract

Intended effectAims to enhance bone regeneration, reduce collapse, and decrease conversion to THA compared to CD alone

Evidence summarySystematic reviews and meta‑analyses report improved HHS, reduced necrotic area, lower progression and conversion rates with CD+cells versus CD alone, though study quality and heterogeneity vary

PTH[1-34] (teriparatide)

DefinitionPTH[1-34] (teriparatide): parathyroid hormone fragment studied in animal models as an adjunct to CD to stimulate bone formation and neovascularization

Evidence statusPreclinical studies (eg, rabbit SAON model) show improved bone repair and vascularity after CD with intermittent PTH; clinical data lacking

Research notePreliminary findings require validation in well‑designed clinical trials

BMAC / BMDCT definitions

DefinitionBMAC / BMDCT: concentrated autologous bone marrow preparations (bone marrow aspiration concentrate or bone marrow‑derived cell therapies) instilled into the CD tract to augment regeneration

Clinical useUsed as an adjunct to CD with reported improvements in radiographic progression‑free survival and functional scores in some series/meta‑analyses

Evidence caveatResults mixed across studies; predictors of outcome include BMI and extent of necrosis

Modified Kerboul angle

DefinitionModified Kerboul angle: imaging measure quantifying femoral head necrotic involvement used to assess prognosis and change after interventions

Clinical useLower modified Kerboul angle (smaller necrotic extent) associated with better survivorship and less collapse after CD ± adjuncts

Reported metricStudies report changes in modified Kerboul angle pre‑ and post‑treatment to evaluate treatment effect

Adjunctive treatments

Adjunctive treatments listedAutologous bone marrow concentrate/mesenchymal stem cells, PRP/APC/PRF, autologous bone grafting, synthetic bone graft substitutes (eg CaSO4–CaPO4), bisphosphonates, rhBMPs, extracorporeal shockwave therapy, hyperbaric oxygen, parathyroid hormone

Evidence summaryAdjuncts have variable supporting evidence; some meta‑analyses show benefit for cell therapies, while others show heterogeneity and need for higher‑quality RCTs

Coverage implicationMany adjuncts are considered investigational for general use; documentation of technique and materials is recommended when used

Policy Revision History

2008-04-25effective_date

Policy effective date established.

2023-10-04last_reviewLatest

Policy last reviewed; review entry listed in policy history.