Do design adaptations of a trochanteric nail make sense for Asian patients? Results of a multicenter study of the PFNA-II in Japan.

ABSTRACT

PURPOSE: Asian patients with osteoporosis suffer from an increased incidence of hip fracture and a potentially increased risk of fixation failure due to anatomical differences compared to Caucasians. To cope with these differences, an Asian size- and geometry-adapted Proximal Femoral Nail Antirotation (PFNA-II) was developed. The objective of this prospective multicenter study was to assess the risk of fracture fixation complications (FFCs), the occurrence of mismatch and the quality of life status of patients treated with the PFNA-II. PATIENTS AND METHODS: 176 Japanese patients with an isolated, unstable, closed trochanteric fracture were treated with the PFNA-II. Patients were prospectively screened for anticipated complications and classified accordingly; complications were centrally reviewed by a complication review board to avoid bias by the treating surgeon, and categorized using a standardized reporting system. Outcome measurements included the occurrence and evaluation of FFCs, the radiological assessment of mismatch and quality of life measured with the EQ-5D score. RESULTS: 3 Intraoperative and 15 postoperative complications were found in 16/176 patients. The risk of sustaining any intraoperative or postoperative FFC was 1.7% (3/176; 95% CI 0.35-4.9) and 8% (14/176; 95% CI 4.4-13), respectively. The most likely cause for FFCs was the "bone/fracture" factor (9/14 patients). Radiologically detectable contact of the implant with the inner cortex ("mismatch") was reported for 17/173 patients (10%). CONCLUSIONS: The reported complication risks and mismatches are reasonable for this patient cohort. The geometry- and size-adapted PFNA-II is relatively safe but requires standardized assessment in a larger target cohort.