CurrentKaiser PermanentePolicy N/A

Total Knee Arthroplasty (TKA) clinical review/medical necessity

Defines Kaiser Permanente Washington clinical review criteria for total knee and unicompartmental knee arthroplasty (including revisions) for inpatient vs ambulatory level-of-care determinations and medical necessity criteria for non‑Medicare members. Also lists applicable CPT/HCPCS procedure codes and documentation requirements.

Policy Summary

PayerKaiser Permanente

PolicyTotal Knee Arthroplasty (TKA) clinical review/medical necessity

Policy CodePolicy N/A

Change TypeApplicable codes updated (09/22/2025); prior MPC adoption (10/01/2022)

Effective Date

Next Review DateSep 22, 2025

Key ActionProvide last 6 months of clinical notes, document trials of conservative therapy and PT attendance, imaging/arthroscopy evidence, and optimization efforts for BMI, A1c, and tobacco cessation to support medical necessity.

SourceLink

POLICY UPDATE CHANGES

Applicable codes updated on 09/22/2025.

MPC approved to adopt medical necessity criteria for Total Knee Arthroplasty effective 10/01/2022.

Clarified PT episode of care timeframe and Medicare inpatient-only list applicability.

11Procedure codes listed

3Radiographic evidence options

3Pre-op optimization domains

Scope: Defines Kaiser Permanente Washington clinical review criteria for total knee and unicompartmental knee arthroplasty (including revisions), covering inpatient vs ambulatory level-of-care determinations and medical necessity criteria for non‑Medicare members. Coverage stance: covered_with_criteria. Status: CURRENT. Effective/last/next review: last review 2025-07-01, next review 2025-09-22.

Preoperative Thresholds / Optimization Requirements

Duration of disabling pain>= 3 months

Physical therapy attendance>75% of sessions

BMI< 35 preferred; >35 requires documented optimization over 3-6 months; >40 relative contraindication

Hemoglobin A1c< 7.5 preferred; >7.5 requires active management and reduction over 3-6 months; >8.0 relative contraindication

Nicotine/tobacco cessationNicotine-free >= 30 days prior OR 90% reduction in use

Level of Care — Inpatient Total Knee Arthroplasty (Non-Medicare)

For elective total knee replacement or revision/replacement to be approved as inpatient, ONE of the following must be met:

ANY of the following

Bilateral knee replacement
Coexisting neurologic condition (such as multiple sclerosis, hemiparesis, severe Parkinson's, or other neurologic conditions that would likely seriously affect ambulation) where the expected length of stay is planned to be longer than 2 midnights
Meets indications on the Elective Surgical Procedure Level of Care policy

Medical Necessity Criteria — Total Knee & Unicompartmental Arthroplasty (Non-Medicare)

Medical Necessity Criteria — Total Knee & Unicompartmental Arthroplasty (Non-Medicare, applies to ambulatory & inpatient)

May be considered medically necessary for degenerative joint disease when ALL of the following are met:

ALL of the following

Functional disabling pain of at least 3 months duration which interferes with the ability to carry out activities of daily living>= 3 months
Radiographic or arthroscopic evidence (ONE of)
- Moderate multiple osteophytes, definite narrowing of joint space, some sclerosis and possible deformity of bone contour (Kellgren-Lawrence Grade 3)
- Large osteophytes, marked narrowing of joint space, severe sclerosis, and definite deformity of bone contour (Kellgren-Lawrence Grade 4)
- Exposed subchondral bone (full thickness cartilage loss with underlying bone reactive changes) noted on arthroscopy or MRI (Outerbridge Grade IV)
Three months of non-operative, conservative treatment demonstrated by a trial of one or more of: (a) NSAIDs (oral or topical), (b) acetaminophen, (c) intra-articular corticosteroid injection as appropriate3 months
ALL of the following
- Supervised physical therapy, attendance at >75% of sessions>75% attendance
- Flexibility and muscle strengthening exercises
- Reasonable restriction of activities
Preoperative optimization requirements (ALL of)
- BMI < 35; if BMI > 35, documented optimization efforts (sustained weight loss over 3-6 months OR documented participation in weight loss/exercise program). BMI > 40 is a relative contraindication; cases may be reviewed by medical director if optimization attempts documentedBMI < 35 preferred; >35 requires optimization; >40 relative contraindication
- No diabetes, or diabetes with HbA1c < 7.5 (with heart disease no lower than 7.5). Members with A1C >7.5 must be actively managed and show reduction over 3-6 months. A1c >8.0 is a relative contraindication; exceptions reviewed case-by-case with documented efforts and shared decision-makingA1c < 7.5 preferred; >7.5 requires active management; >8.0 relative contraindication
- Nicotine/tobacco users must be actively involved in a cessation program and be nicotine/tobacco-free for minimum 30 days prior to surgery or have a 90% reduction in use; failure of reduction is a relative contraindication but exceptions may proceed with documented shared decision-makingNicotine-free >= 30 days OR 90% reduction

Other Diagnoses Where Knee Arthroplasty May Be Medically Necessary

Other Diagnoses Where Knee Arthroplasty May Be Medically Necessary After Failure of Nonoperative Interventions

Knee arthroplasty may ALSO be considered medically necessary for the following diagnoses after nonoperative failure:

ANY of the following

Distal femur fracture repair in a patient with osteoporosis
Failure of a previous proximal tibial or distal femoral osteotomy
Hemophilic arthropathy
Limb salvage for malignancy
Posttraumatic knee joint destruction
Avascular necrosis (osteonecrosis) of tibial or femoral condyle
Inflammatory arthritis

Procedure Coding

Applicable procedure codes considered medically necessary when criteria metCPTCovered

27437	Arthroplasty, patella; without prosthesis
27438	Arthroplasty, patella; with prosthesis
27440	Arthroplasty, knee, tibial plateau
27441	Arthroplasty, knee, tibial plateau; with debridement and partial synovectomy
27442	Arthroplasty, femoral condyles or tibial plateau(s), knee
27443	Arthroplasty, femoral condyles or tibial plateau(s), knee; with debridement and partial synovectomy
27445	Arthroplasty, knee, hinge prosthesis (eg, Walldius type)
27446	Arthroplasty, knee, condyle and plateau; medial OR lateral compartment
27447	Arthroplasty, knee, condyle and plateau; medial AND lateral compartments with or without patella resurfacing (total knee arthroplasty)
27486	Revision of total knee arthroplasty, with or without allograft; 1 component

1–10 of 12

1/2

Provider Actions & Documentation Requirements

Prior Authorization

Inpatient Level of Care Review required (Non-Medicare)

Inpatient total knee arthroplasty (non‑Medicare) requires a level‑of‑care review. Elective inpatient requests for TKA or revision TKA must meet one of the inpatient criteria; if criteria are not met the orthopedist may submit a separate explanation for inpatient status for case‑by‑case review. Ambulatory requests should follow ambulatory criteria and use the Pre‑authorization Code Check to verify requirements for specific codes.

27438
27446
27447
27486
27487
27488
27437
27440
27441
27442
27443
27445

Documentation Required

Submit clinical documentation to support medical necessity

Submit clinical documentation to support medical necessity with the prior authorization request. Provide the last 6 months of clinical notes from the requesting provider/specialist including history and physical. Document trials of conservative therapy, physical therapy details (attendance >75% if applicable), imaging or arthroscopy evidence of osteoarthritis/ cartilage loss, and preoperative optimization efforts addressing BMI, hemoglobin A1c, and tobacco/nicotine use.

Last 6 months of clinical notes and H&P
Trials of conservative therapy (NSAIDs, acetaminophen, intra‑articular corticosteroid as appropriate)
Physical therapy in last 12 months with supervised PT and >75% attendance, flexibility/strengthening exercises, activity modification (or documentation why PT not appropriate)
Imaging or arthroscopy showing Kellgren‑Lawrence Grade 3–4 or Outerbridge Grade IV
Documentation of BMI optimization efforts if BMI >35 (BMI >40 relative contraindication)
Diabetes management with HbA1c goals and documented improvement if A1c >7.5 (A1c >8.0 relative contraindication)
Nicotine/tobacco cessation program participation and nicotine‑free ≥30 days or ≥90% reduction in use

Billing Rule

Ambulatory vs Inpatient adjustment

If a patient is approved as ambulatory but remains in the facility longer than expected, the claim may be adjusted to inpatient status when appropriate.

Background & Definitions

Background/clinical rationale: Total knee arthroplasty (TKA) is primarily performed to relieve pain and improve function for patients with symptomatic arthritis of the knee (most commonly osteoarthritis, but also rheumatoid arthritis and traumatic arthritis), and may be used for osteonecrosis or malignancy when appropriate. Indications for revision include infection, substantial bone loss, fracture, aseptic loosening, and wear of prosthetic components. Radiographic and arthroscopic severity are described using the Kellgren‑Lawrence grading for osteoarthritis (Grades 3–4 denote moderate to severe disease) and the Outerbridge classification for cartilage loss (Grade IV = full‑thickness cartilage loss/exposed subchondral bone).

Term	Definition
Kellgren-Lawrence Grade 3	Moderate multiple osteophytes, definite narrowing of joint space, some sclerosis and possible deformity of bone contour
Kellgren-Lawrence Grade 4	Large osteophytes, marked narrowing of joint space, severe sclerosis, and definite deformity of bone contour
Outerbridge Grade IV	Full thickness cartilage loss with exposed subchondral bone

Document Name	Number/Type
Total Knee Arthroplasty (L36577)	L36577 / LCD
Billing and Coding: Total Knee Arthroplasty (A57686)	A57686 / LCA

Revision History

09/22/2025revisedLatest

Applicable codes updated on 09/22/2025.

10/01/2022revised

MPC approved to adopt medical necessity criteria for Total Knee Arthroplasty effective 10/01/2022. Added medical necessity criteria for non-Medicare members in addition to level-of-care review.

2022–2023clarified

Multiple administrative clarifications across 2022–2023 edits (clarified PT episode of care timeframe and Medicare inpatient-only list applicability).