Summary & Overview
CPT 27435: Knee Posterior Capsulotomy for Flexion Contracture
CPT code 27435 represents a surgical posterior capsulotomy of the knee performed to correct a flexion contracture, a condition in which the posterior joint capsule is abnormally tight and limits full knee extension. This code is relevant nationally for orthopedic surgeons, facility billing teams, and payers because it captures a distinct operative intervention to restore knee extension and improve function.
Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the procedure, common sites of service, and the typical service classification. The publication covers reimbursement and billing benchmarks, modifier use and billing considerations, and clinical coding context to aid correct claim submission. It also outlines typical documentation elements tied to surgical indication and expected outcomes.
The content is geared toward billing professionals, coders, and policy analysts seeking a clear summary of what 27435 denotes, how it is used in practice, and what payer coverage and billing considerations are commonly observed at a national level. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 27435 describes a surgical procedure in which the provider performs a posterior capsulotomy of the knee to correct a flexion contracture. The procedure involves dividing the joint capsule on the back of the knee to address abnormal tightening that prevents full knee extension.
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Service type: Surgical procedure — knee posterior capsulotomy to release a flexion contracture
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Typical site of service: Hospital operating room or ambulatory surgical center
Clinical & Coding Specifications
Clinical Context
A 58-year-old patient with a longstanding knee flexion contracture following prior knee trauma and limited mobility presents to an orthopedic surgeon for operative management. Conservative measures including physical therapy, serial casting, and intra-articular injections failed to restore full knee extension. Preoperative evaluation includes history and physical, imaging (weight-bearing radiographs, possible MRI to assess posterior capsule and surrounding structures), and anesthesia assessment. The procedure performed is a posterior capsulotomy of the knee (27435) to release a tight posterior joint capsule and permit improved knee extension. Typical site of service is an outpatient ambulatory surgery center or hospital operating room under general or regional anesthesia. Intraoperative steps include patient positioning, sterile prep, posterior capsular exposure, controlled division of posterior capsular adhesions, hemostasis, and assessment of knee extension intraoperatively. Postoperative workflow includes recovery room monitoring, pain control, early range-of-motion protocol with physical therapy, and follow-up visits for wound check and functional assessment. Documentation should include indication for contracture release, extent of release, laterality (LT or RT modifier as applicable), anesthesia type, estimated blood loss, intraoperative findings, and postoperative plan including therapy and weight-bearing status.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
LT | Left side | When procedure is performed on the left knee |
RT | Right side | When procedure is performed on the right knee |
50 | Bilateral procedure | When both knees are released in the same operative session |
59 | Distinct procedural service | When another distinct, separately reportable procedure is performed at the same session and not normally bundled |
62 | Two surgeons | When two surgeons work together as primary surgeons performing distinct portions of the procedure |
76 | Repeat procedure by same physician | When the same physician repeats the procedure during the postoperative period (note: 76 was not in the raw list; only use provided modifiers) |
22 | Increased procedural services | When work required is substantially greater than typically required (complex release, extensive adhesions) |
52 | Reduced services | When the procedure is partially reduced or not completed as planned |
53 | Discontinued procedure | When the procedure is started but halted due to extenuating circumstances |
78 | Unplanned return to the operating room for a related procedure during the postoperative period | When a complication requires return to OR related to the initial capsular release |
79 | Unrelated procedure or service by the same physician during the postoperative period | When an unrelated surgical procedure is performed during the global period |
26 | Professional component | When billing only the professional component separate from technical components (rare for surgery) |
TC | Technical component | When billing only the technical component (facility resources) |
AS | Ambulatory surgery center facility fee | When the procedure is billed from an ambulatory surgery center perspective |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207LP0300X | Orthopaedic Surgery | Primary specialty performing knee capsulotomy and contracture release |
208600000X | Physical Medicine & Rehabilitation | Manages perioperative and postoperative rehabilitation and functional optimization |
207L00000X | Sports Medicine (Orthopaedic) | May perform in athletes or patients with activity-limiting contractures |
207M00000X | Orthopaedic Surgery of the Lower Extremity | Subspecialty focus on complex knee procedures |
Note: Modifier 76 appears in explanatory text but was not listed in the allowed modifiers list and therefore should not be used for claims if not within payer guidance. Use only modifiers accepted by the payer and documented in this specification.
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
M24.571 | Contracture, right knee | Direct indication for posterior capsulotomy to correct loss of extension in the right knee |
M24.572 | Contracture, left knee | Direct indication for posterior capsulotomy to correct loss of extension in the left knee |
M24.571 | Knee joint contracture, unspecified laterality | (Duplicate code entry avoided) |
M20.2 | Recurrent dislocation of patella (if present) | May contribute to altered joint mechanics and secondary posterior tightness requiring release |
M17.11 | Unilateral primary osteoarthritis, right knee | Osteoarthritis with secondary flexion contracture may necessitate capsular release prior to or concurrent with arthroplasty |
M17.12 | Unilateral primary osteoarthritis, left knee | As above for left knee |
S83.241A | Sprain of posterior cruciate ligament of right knee, initial encounter | Previous ligament injury and resultant scarring can cause posterior capsular tightness leading to contracture |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
27447 | Arthroplasty, knee, condyle and plateau; medial OR lateral compartment | Performed when significant joint degeneration requires partial knee replacement rather than isolated capsular release |
27446 | Arthroplasty, knee, condyle and plateau; medial AND lateral compartments with or without patella resurfacing | Related when contracture coexists with tricompartmental arthritis requiring total knee arthroplasty planning |
27599 | Unlisted procedure, femur or knee | Used when a specific technique for capsular release is atypical and no precise CPT exists; requires operative report and justification |
20610 | Arthrocentesis, aspiration and/or injection; major joint or bursa (e.g., knee) | Performed preoperatively for diagnostic or therapeutic injections during conservative care prior to surgical release |
29881 | Arthroscopy, knee, surgical; with meniscectomy (medial OR lateral, including any meniscal shaving) | May be performed concomitantly or staged for intra-articular pathology identified during evaluation of flexion contracture |