Bipolar hip arthroplasty using conjoined tendon preserving posterior lateral approach in treatment of displaced femoral neck fractures.

BACKGROUND: Hip fractures account for 23.8% of all fractures in patients over the age of 75 years. More than half of these patients are older than 80 years. Bipolar hemiarthroplasty (BHA) was established as an effective management option for these patients. Various approaches can be used for the BHA procedure. However, there is a high risk of postoperative dislocation. The conjoined tendon-preserving posterior (CPP) lateral approach was introduced to reduce postoperative dislocation rates.

AIM: To evaluate the effectiveness and safety of the CPP lateral approach for BHA in elderly patients.

METHODS: We retrospectively analyzed medical data from 80 patients with displaced femoral neck fractures who underwent BHA. The patients were followed up for at least 1 year. Among the 80 patients, 57 (71.3%) were female. The time to operation averaged 2.3 d (range: 1-5 d). The mean age was 80.5 years (range: 67-90 years), and the mean body mass index was 24.9 kg/m2 (range: 17-36 kg/m2 ). According to the Garden classification, 42.5% of patients were type Ⅲ and 57.5% of patients were type Ⅳ. Uncemented bipolar hip prostheses were used for all patients. Torn conjoined tendons, dislocations, and adverse complications during and after surgery were recorded.

RESULTS: The mean postoperative follow-up time was 15.3 months (range: 12-18 months). The average surgery time was 52 min (range: 40-70 min) with an average blood loss of 120 mL (range: 80-320 mL). The transfusion rate was 10% (8 of 80 patients). The gemellus inferior was torn in 4 patients (5%), while it was difficult to identify in 2 patients (2.5%) during surgery. The posterior capsule was punctured by the fractured femoral neck in 3 patients, but the conjoined tendon and the piriformis tendon remained intact. No patients had stem varus greater than 3 degrees or femoral fracture. There were no patients with stem subsidence more than 5 mm at the last follow-up. No postoperative dislocations were observed throughout the follow-up period. No significance was found between preoperative and postoperative mean Health Service System scores (87.30 ± 2.98 vs 86.10 ± 6.10, t = 1.89, P = 0.063).

CONCLUSION: The CPP lateral approach can effectively reduce the incidence of postoperative dislocation without increasing perioperative complications. For surgeons familiar with the posterior lateral approach, there is no need for additional surgical instruments, and it does not increase surgical difficulty.