Summary & Overview
CPT 29876: Knee Arthroscopy for Major Synovectomy, Two+ Compartments
Headline: Major Knee Arthroscopic Synovectomy Gains Continued Relevance in Orthopedics
Lead: CPT 29876 denotes arthroscopic knee surgery for a major synovectomy involving two or more compartments, a procedure used to manage diffuse synovial disease and multifocal intra-articular pathology. Nationally, this code represents an important operative option within orthopedic surgery for patients with extensive synovitis, inflammatory arthropathies, or degenerative conditions affecting multiple knee compartments.
Why it matters: As ambulatory surgery grows, CPT 29876 is commonly performed in outpatient hospitals and ambulatory surgical centers, with implications for facility utilization, coding specificity, and payer coverage policies. The code’s use affects episode cost, resource allocation, and post-operative care pathways.
Key payers covered: Analysis includes major commercial and public payers: Aetna; Blue Cross Blue Shield; Cigna Health; UnitedHealthcare; and Medicare.
What readers will learn: This publication outlines clinical context for CPT 29876, coding considerations, common diagnosis pairings, and relationships to adjacent arthroscopic knee codes. It summarizes payer coverage patterns and billing nuances relevant to facility-based outpatient settings and ambulatory surgical centers. The report highlights where CPT 29876 fits among related procedures such as meniscectomy and chondroplasty, and notes coding situations that commonly arise when multiple procedures are reported.
Scope note: Service-line metadata is missing where indicated. Data not available in the input where applicable.
CPT Code Overview
CPT 29876 describes a surgical arthroscopy of the knee for a major synovectomy involving two or more compartments. This procedure falls within orthopedic surgery and addresses intra-articular disease processes requiring debridement or removal of inflamed synovial tissue across multiple knee compartments. Typical sites of service for CPT 29876 are facility settings, including outpatient hospital (POS 19 or 22) and ambulatory surgical centers (POS 24).
Clinical & Coding Specifications
Clinical Context
A 58-year-old patient presents with progressive knee pain, mechanical symptoms, and reduced function despite conservative management. Examination and imaging confirm multi-compartment intra-articular pathology (e.g., synovial hypertrophy and inflammatory synovitis) consistent with osteoarthritis and/or chronic instability. The orthopedic surgeon schedules an outpatient arthroscopic procedure for a major synovectomy of two or more compartments of the knee to remove inflamed synovium, improve joint mechanics, and obtain tissue for pathology if indicated. The procedure is performed in an ambulatory surgical center or outpatient hospital setting with standard preoperative evaluation, regional or general anesthesia, intraoperative arthroscopic assessment of all compartments, synovial resection in the affected compartments, hemostasis, and standard postoperative recovery and discharge instructions.
Coding Specifications
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Modifier
RT: Applied when the procedure is performed on the right knee. -
Modifier
LT: Applied when the procedure is performed on the left knee. -
Modifier
59: Applied to indicate a distinct procedural service when the synovectomy is separate and distinct from another procedure performed at the same session (use when documentation supports separate anatomical site or separate session component). -
Modifier
51: Applied when multiple procedures are submitted on the same day; used for reporting multiple CPT codes in the same encounter per payer policy.