[Treatment of distal humerus fracture with unexposed ulnar nerve medial elbow incision and anatomical locking compression plate].

Objective: To investigate the feasibility and effectiveness of unexposed ulnar nerve medial elbow incision, open reduction and internal fixation of anatomical locking compression plate (LCP) for distal humerus fractures.

Methods: Fourteen patients with distal humerus fracture were treated between January 2014 and June 2017. There were 5 males and 9 females, aged 18-85 years (mean, 65.5 years). The causes of injury included falling from height in 12 cases and traffic accident in 2 cases, all were closed fractures. Fractures were classified according to the AO/Association for the Study of Internal Fixation (AO/ASIF): 3 cases of type A2, 2 cases of type A3, 4 cases of type B2, 2 cases of type C1, 2 cases of type C2, and 1 case of type C3; without ulnar nerve damage. The time from injury to operation was 4-15 days, with an average of 7 days. The type B2 fractures were treated with unexposed ulnar nerve elbow medial incision and anatomic LCP internal fixation, the rest patients were all treated with unexposed ulnar nerve medial plus conventional lateral approach and bilateral LCP internal fixation.

Results: The operation time was 50-140 minutes (mean, 80 minutes), and the intraoperative blood loss was 20-200 mL (mean, 70 mL). There was no blood vessels or nerve damage during operation. All incisions healed by first intension, and no incision infection occurred. All the 14 cases were followed up 9-24 months (mean, 13 months). X-ray films showed that all fractures healed within 4 months without complications such as nonunion and osteomyelitis. No ulnar nerve injury, cubitus varus deformity, and ossifying myositis occurred during follow-up. At last follow-up, the elbow function was assessed by Mayo Elbow Performance score (MEPS), the results were excellent in 8 cases, good in 4 cases, fair in 1 case, and poor in 1 case (type C3 fracture), with the excellent and good rate of 85.7%.

Conclusion: The unexposed ulnar nerve medial elbow incision can be used effectively to reduct the fracture, and it is not prone to ulnar nerve injury. Combined with the lateral approach to treat the distal humerus fracture, which has the advantages of short operation time, few trauma, little bleeding, and reliable effectiveness.