The Operative Treatment of Scapula Fractures: An Analysis of 10,097 Patients

Abstract

Background: The indications for operative treatment of scapula fractures have been debated over the past decade. Our purpose was to determine 1) the incidence and trends in the operative treatment of scapula fractures, 2) the incidence of conversion from operative fixation to total or hemi-shoulder arthroplasty (THSA) and 3) rates of associated injuries in scapula fractures. We hypothesized that the operative treatment of scapula fractures is increasing over time and that scapula fractures treated with open reduction and internal fixation (ORIF) would have increased risk for conversion to THSA.

Methods: The Humana Inc. administrative claims database was queried from 2008 to 2015. Patients with any scapular fracture, ORIF of scapula fracture, total or hemi-shoulder arthroplasty, and associated injuries were identified by ICD-9 and CPT codes. Analysis was performed for 1) all patients with a scapula fracture undergoing operative fixation (i.e. ORIF and THSA), 2) all scapular fractures treated with ORIF with subsequent conversion to ipsilateral THSA, and 3) all associated injuries.

Results: There were 10,097 scapula fractures (28.4% glenoid, 48% female). 60% occurred in patients 65 years and older. There were 198 (1.96%) fractures (70% glenoid) treated with ORIF. There were 287 (2.84%) fractures (45% glenoid) treated with THSA (76% total shoulder). The rate of ORIF of scapular fractures did not significantly increase (RR=0.87, p=0.58). There was a significant increase in THSA as primary treatment of scapula fractures in 2015 compared to 2007 (RR=0.43, p=0.0016). Conversion from ORIF to THSA was 12.6% (25/198). Scapula fractures treated with ORIF were at significant risk for conversion to THSA (RR=4.77, p<0.0001). Associated injuries occurred in nearly 50% of scapula fractures-other fractures, lung contusion and pneumothorax/hemothorax ranking the highest, accounting for 37%, 14.5% and 8.3% of all associated injuries, respectively.

Conclusion: The incidence of operative treatment of scapula fractures was 1.96% and 2.84% for ORIF and THSA, respectively. Scapular fractures previously treated with ORIF were at significant risk for conversion to THSA. Although ORIF in scapular fractures did not significantly increase over time, both THSA and overall (ORIF+THSA) operative treatment of scapula fractures increased significantly. Level of Evidence: IV.

Keywords: associated injuries; operative fixation; scapula fractures; shoulder arthroplasty.