Rate of avascular necrosis after fracture dislocations of the proximal humerus: Timing of surgery

BACKGROUND: Avascular necrosis (AVN) of the humeral head is a severe complication after proximal humerus fracture dislocations, and leads to a poorer clinical outcome and subsequent revision surgeries. The aim of the current study was to analyze the influence of time to surgery on the AVN rate after locked plating of dislocation fractures of the proximal humerus. PATIENTS AND METHODS: This retrospective study included 30 patients with a mean age of 63 ± 14 years with dislocation fractures of the proximal humerus type B3 or C3 according the AO/OTA classification. The rates of AVN of the humeral head were determined clinically and radiographically. In addition, the clinical outcome was determined using the Constant score (CS), the age- and sex-adjusted Constant score (CS%), Disabilities of the Arm, Shoulder, and Hand (DASH) score, the range of motion, and complication and revision rates. Patients were subdivided into groups of subjects operated on early (≤48 h after trauma) and those with late surgery (>48 h after trauma), and the relative risk (RR) for complications and revisions was determined for both groups. RESULTS: After a mean follow-up of 37 months (range: 12–66 month) the mean CS% was 60 ± 24 and the mean DASH score was 32 ± 24 points. Ten patients (33%) developed a symptomatic AVN, and ten patients underwent revision surgery. Early surgery was performed on 25 patients while five patients underwent late surgery. After late surgery, all five patients developed AVN, and patients had a fivefold increased RR for AVN (p = 0.002) and subsequent associated surgical revision (RR = 3.3, p = 0.031). CONCLUSION: In fracture dislocations of the proximal humerus, early surgery within 48 h of trauma significantly decreases the risk of AVN and subsequent surgery.