Heterotopic Ossification After Arthroscopic Procedures: A Scoping Review of the Literature.

Background: Heterotopic ossification (HO) is the formation of bone in soft tissue resultant from inflammatory processes. Lesion formation after arthroscopic procedures is an uncommon but challenging complication. Optimal prophylaxis and management strategies have not been clearly defined.

Purpose: To present a scoping review of the pathophysiology, risk factors, diagnostic modalities, prophylaxis recommendations, and current treatment practices concerning HO after arthroscopic management of orthopaedic injuries.

Study Design: Scoping review; Level of evidence, 4.

Methods: A scoping review via a PubMed search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The search strategy was based on the terms "heterotopic ossification" AND "arthroscopy." The clinical outcomes review included studies on the arthroscopic management of orthopaedic injuries in which the primary subject matter or a secondary outcome was the development of HO. An analysis of the pathophysiology, diagnostic modalities, and management options was reported.

Results: A total of 43 studies (33,065 patients) reported on HO after hip arthroscopy, while 21 (83 patients) collectively reported on HO after arthroscopic procedures to the shoulder, elbow, knee, or ankle; however, management techniques were not standardized. Identified risk factors for HO included male sex and mixed impingement pathology, while intraoperative capsular management was not suggested as a contributing factor. Diagnosis of ossification foci was performed using radiography and computed tomography. The rate of HO after hip arthroscopy procedures approached 46% without prophylaxis, and administration of nonsteroidal anti-inflammatory drugs (NSAIDs) decreased occurrence rates to 4% but carries associated risks. External beam radiation has not been exclusively studied for use after arthroscopic procedures.

Conclusion: HO is a known complication after arthroscopic management of orthopaedic injuries. NSAID prophylaxis has been demonstrated to be effective after hip arthroscopy procedures. Patients with persistent symptoms and mature lesions may be indicated for surgical excision, although variability is present in patient-reported outcome scores postoperatively.