CPT Code Overview

CPT 27442 describes arthroplasty of the femoral condyles or tibial plateau(s) of the knee. This procedure involves surgical reconstruction or replacement of one or more articular surfaces of the knee joint to restore function and relieve pain associated with degenerative or traumatic joint conditions.

Service type: Orthopedic Surgery

Typical site of service: Inpatient Hospital (POS 21)

Clinical Context

A 68-year-old patient with progressive knee pain, limited mobility, and radiographic evidence of degenerative joint disease presents for surgical management. Conservative treatments including physical therapy, activity modification, analgesics, and intra-articular injections have failed. The orthopedic surgeon evaluates the patient, documents severity of osteoarthritis and functional impairment, and schedules inpatient arthroplasty of the femoral condyles or tibial plateau(s) under general or regional anesthesia. Preoperative assessment, perioperative inpatient care, and postoperative rehabilitation are part of the clinical workflow for 27442.

Coding Specifications

• Modifiers:

• RT: Used when the procedure is performed on the right side.

• LT: Used when the procedure is performed on the left side.

• 50: Used when the procedure is performed bilaterally in the same operative session.

• 22: Used to report increased procedural services when the work, time, technical difficulty, or patient complexity is substantially greater than typically required.

• Provider Taxonomies:

Related Diagnoses

• M17.10 — Unilateral primary osteoarthritis, unspecified knee

  Clinical relevance: Degenerative joint disease causing pain and functional limitation that may lead to arthroplasty of femoral condyles or tibial plateau(s).

• M17.11 — Unilateral primary osteoarthritis, right knee

  Clinical relevance: Right knee osteoarthritis as a specific laterality indication for 27442 with RT modifier when applicable.

• M17.12 — Unilateral primary osteoarthritis, left knee

  Clinical relevance: Left knee osteoarthritis as a specific laterality indication for 27442 with LT modifier when applicable.

• M17.0 — Bilateral primary osteoarthritis of knee

  Clinical relevance: Bilateral disease that may justify use of bilateral procedure modifier 50 if both knees are treated in the same operative session.

• M23.9 — Internal derangement of knee, unspecified

  Clinical relevance: Intra-articular derangement that can coexist with degenerative changes and may influence the choice of arthroplasty procedure.

• M25.561 — Pain in right knee

  Clinical relevance: Symptom code documenting right knee pain as part of the clinical indication for surgical intervention.

• M25.562 — Pain in left knee

  Clinical relevance: Symptom code documenting left knee pain as part of the clinical indication for surgical intervention.

Related CPT Codes

• 27447 is a more extensive reconstruction of the knee joint and may be an alternative when replacement of the entire joint is required rather than isolated femoral condyle or tibial plateau arthroplasty.

• 27486 and 27487 represent revision procedures for previously implanted total knee arthroplasty components and are used when hardware removal and component revision are required instead of primary arthroplasty 27442.

• 29881 and 29888 are arthroscopic procedures used for diagnostic or reparative interventions (meniscal debridement or ligament reconstruction) and may be performed in the same episode of care as diagnostic or adjunct procedures but are distinct from open arthroplasty 27442.

• 29881 and 29888 can be used as less invasive alternatives for select pathology, while 27486/27487 are used when prior arthroplasty requires revision.

National commercial mean rates are above Medicare for this procedure: Blue Cross Blue Shield, Cigna, UnitedHealth Group, BUCA, and Aetna all report higher mean allowed amounts than Medicare’s mean of $818.94. UnitedHealth Group shows the highest national mean at $1,573.68, while Aetna reports the lowest commercial mean at $666.82, below Medicare.

Rate dispersion (P75 minus P25) varies by payer. UnitedHealth Group and Cigna exhibit the widest interquartile spreads (UHC: $907.00; Cigna: $841.00), indicating greater variability in allowed amounts. Blue Cross Blue Shield and BUCA show moderate dispersion (BCBS: $513.00; BUCA: $642.60). Aetna and Medicare are the tightest (Aetna: $374.06; Medicare: $64.00), with Medicare demonstrating the smallest spread. The table and chart below present the full breakdown.