Pinloc or Hansson pins: a multicenter, randomized controlled study of 439 patients treated for femoral neck fractures

OBJECTIVES: To compare the recently developed Hansson Pinloc system, which features 3 cylindrical parallel pins with hooks connected through a fixed-angle interlocking plate, with the Hansson Pin System (2 hook pins) for the treatment of femoral neck fractures. DESIGN: One hundred fourteen patients with displaced femoral neck fractures and 325 patients with nondisplaced fractures from 9 orthopaedic centers were randomized to either Hansson Pinloc system or Hansson Pin System and followed for 2 years or until death. Age at inclusion was 50 years or older. MAIN OUTCOME MEASUREMENTS: The primary outcome was failure (defined as early displacement, nonunion, symptomatic avascular necrosis, or deep infection). Secondary outcomes included revision surgery, Timed Up and Go (TUG) test and patient-reported outcome measures (PROMs: EQ-5D and WOMAC). RESULTS: For nondisplaced fractures, the incidence of failure was 14% (23/169) in the Pinloc group and 16% (25/156) in the Hansson group. For displaced fractures, the analysis was stratified by age. Patients aged 50–69 years with displaced fractures showed a 2-year failure rate of 44% (17/39) in the Pinloc group versus 44% (16/36) in the Hansson group. For patients 70 years or older with displaced fractures, 33% (7/21) in the Pinloc group versus 22% (4/18) in the Hansson group failed. At 3 and 12 months, no clinically significant differences between treatment groups were found for EQ-5D-3L, WOMAC, or for the TUG in any fracture type or age group. CONCLUSIONS: There were no advantages for Pinloc in any of the studies aspects. LEVEL OF EVIDENCE: 1