A structured three-step reduction strategy for locked posterior fracture-dislocation of the proximal humerus through a standard deltopectoral approach: A retrospective case series.

Abstract

Locked posterior fracture-dislocation of the proximal humerus is a rare and technically demanding injury in which the humeral head remains impacted posterior to the glenoid. Although several reduction techniques have been described, the practical details of anterior-only reduction remain incompletely standardized. We evaluated a structured three-step anterior reduction strategy performed through a standard deltopectoral approach. We retrospectively reviewed 16 consecutive patients with acute locked posterior fracture-dislocation of the proximal humerus treated between January 2016 and January 2022. All patients underwent reduction through a single deltopectoral approach followed by locking-plate fixation supplemented with suture fixation. The reduction strategy consisted of (1) establishing an anterior reduction corridor by opening the anterior joint through an L-shaped subscapularis incision or a lesser-tuberosity fracture interval, (2) guiding the humeral head with a periosteal elevator introduced between the humeral head and glenoid, and (3) unlocking and translating the head anteriorly using gentle elevator assistance, controlled arm rotation, and, when head-shaft control was limited, direct digital manipulation. Outcomes included fracture union, avascular necrosis (AVN), recurrent dislocation, implant-related complications, range of motion, Constant-Murley score, and subscapularis function. The mean age was 41.1 ± 8.4 years. The mean interval from injury to surgery was 3.4 ± 1.0 days. All 16 reductions were completed through the initial deltopectoral approach without an additional posterior incision, conversion to arthroplasty, or intraoperative complication. Mean operative time was 85.9 ± 10.5 min and mean estimated blood loss was 152.5 ± 27.7 mL. All fractures achieved radiographic union during available follow-up. At a mean follow-up of 21.2 ± 9.4 months (range, 12-48 months), the mean Constant-Murley score was 85.4 ± 8.6 (range, 70-96). Mean forward flexion, abduction, extension, and external rotation were 151.6 ± 22.7°, 135.0 ± 29.9°, 29.4 ± 10.0°, and 38.1 ± 4.8°, respectively. Internal rotation ranged from T7 to L4. Using the descriptive thresholds applied in the original study (excellent, ≥90; good, 80-89; fair, 70-79), 5 patients were excellent, 8 good, and 3 fair. No AVN, recurrent dislocation, implant-related complication, deep infection, or reoperation was observed during the available follow-up. Lift-off and bear-hug tests were negative in all patients at 12 months. This series supports a structured, reproducible anterior-only reduction strategy for selected acute locked posterior fracture-dislocations of the proximal humerus. The principal contribution is the standardization of the reduction sequence and the description of how the humeral head can be disengaged and translated without a posterior approach. The technique should not be interpreted as a wholly novel reduction maneuver, and the absence of AVN should be interpreted within the available follow-up period. Level IV; Therapeutic study.