Summary & Overview
CPT 28320: Surgical Repair of Tarsal Bone Malunion or Nonunion
CPT code 28320 denotes surgical repair of malunion or nonunion of tarsal bones and captures procedures intended to restore alignment, stability, and function of the foot. This code is important nationally because tarsal nonunions and malunions can cause chronic pain, impaired mobility, and secondary degenerative changes that increase utilization of surgical services and postoperative care. Proper coding ensures accurate claims processing and resource allocation for complex foot reconstruction.
Key payers covered in typical analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the procedure, guidance on expected settings of care, and an outline of common billing considerations. The publication also summarizes typical modifiers and payer coverage patterns where available, plus benchmarking metrics and policy updates that affect prior authorization, medical necessity review, and reimbursement pathways.
This summary provides clinicians, coders, and payers with the essential facts about clinical intent, service delivery settings, and the billing landscape for CPT code 28320, helping stakeholders understand where this procedure fits in orthopedic and reconstructive foot care nationally.
Billing Code Overview
CPT code 28320 describes surgical correction of malunion or nonunion of tarsal bones. The procedure addresses fractures of the tarsal bones that have healed in an incorrect position (malunion) or have failed to reunite (nonunion), conditions that can result from poor blood supply or infection. The operative goal is to restore foot function and relieve pain through techniques such as debridement, realignment, bone grafting, and internal fixation as indicated by the clinical situation.
Service Type
- Surgical procedure — reconstructive/orthopedic foot surgery
Typical Site of Service
- Inpatient or outpatient operating room depending on complexity; common settings include hospital-based ORs and ambulatory surgery centers
Clinical & Coding Specifications
Clinical Context
A 48-year-old patient presents to orthopedic surgery clinic with chronic hindfoot pain and difficulty ambulating six months after an untreated or poorly healed calcaneal fracture. Radiographs and CT demonstrate a malunited calcaneus with altered subtalar joint alignment and impingement; symptoms include pain, limited range of motion, and gait disturbance. The orthopedic foot and ankle surgeon schedules a surgical repair to address the malunion/nonunion of the tarsal bones to restore alignment, relieve pain, and improve function. Preoperative workflow includes history and physical, anesthesia evaluation, informed consent, preoperative imaging (weight-bearing radiographs and CT), and optimization of comorbidities. Typical site of service is an inpatient or outpatient surgical center depending on complexity and anticipated postoperative monitoring. The procedure is performed under regional block or general anesthesia, may require open reduction, internal fixation, bone grafting (if nonunion), and possible hardware removal. Postoperative workflow includes pain control, immobilization in cast or boot, wound checks, physical therapy referral, and radiographic follow-up to assess union and alignment.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | Use when the procedure requires substantially greater work than typical (extensive dissection, prolonged time) and documentation supports it. |