Summary & Overview
CPT 27330: Knee Synovial Biopsy, Open Surgical Diagnostic
CPT code 27330 denotes an open synovial biopsy of the knee performed via incision over the joint to obtain synovial tissue for diagnostic evaluation. This surgical diagnostic procedure is clinically important for diagnosing inflammatory, infectious, or neoplastic processes of the knee when less-invasive sampling is inadequate. Nationally, accurate coding and clinical documentation for synovial biopsy affect coverage determinations, site-of-service decisions, and resource utilization in both outpatient surgical centers and hospitals.
Key payers commonly involved in coverage and claims for this procedure include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context of the procedure, typical sites of service, and the payers addressed in the analysis. The publication also summarizes common billing themes and highlights benchmarks and policy considerations relevant to reimbursement and claim adjudication across major national payers. The material is intended for billing professionals, practice managers, and clinical staff seeking clarity on coding, documentation expectations, and payer coverage patterns for knee synovial biopsy.
Billing Code Overview
CPT code 27330 describes a synovial biopsy of the knee performed through a direct incision over the knee joint for diagnostic purposes. The procedure involves surgical exposure of the knee joint and collection of synovial tissue for histologic or microbiologic evaluation.
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Service type: Surgical diagnostic procedure
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Typical site of service: Operating room or procedure suite in an ambulatory surgical center or hospital inpatient setting
Clinical & Coding Specifications
Clinical Context
A 46-year-old patient presents with chronic knee pain, swelling, and intermittent locking despite conservative management. Imaging shows persistent joint effusion and synovial thickening suggestive of inflammatory arthritis or synovial neoplasm. The orthopedic surgeon schedules a diagnostic open synovial biopsy of the knee to obtain tissue for histopathology and microbiology. The patient receives preoperative evaluation, informed consent, and regional or general anesthesia in an ambulatory surgical center or hospital operating room. Intraoperatively, a longitudinal incision is made over the affected knee, representative synovium is excised and sent for pathology, hemostasis is achieved, and the incision is closed. Postoperative care includes analgesia, wound instructions, pathology review, and follow-up to discuss results and finalize diagnosis and further management.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
11 | Unplanned return to the operating/procedure room by the same physician following initial procedure for a related procedure during the postoperative period | Use when the surgeon returns to the OR for a complication related to the synovial biopsy during the global period |
22 | Increased procedural services | Use when work, time, or technical difficulty substantially exceeds usual for an open synovial biopsy
| Unusual anesthesia | Use when general anesthesia is medically necessary for an otherwise normally not extensively anesthetized procedure