Intramedullary femoral nailing through the trochanteric fossa versus greater trochanter tip: a randomized controlled study with in-depth functional outcome results.

Abstract

In a level 1 university trauma center, an explorative randomized controlled study was performed to compare soft tissue damage and functional outcome after antegrade femoral nailing through a trochanteric fossa (also known as piriform fossa) entry point to a greater trochanter entry point in patients with a femoral shaft fracture. Nineteen patients were enrolled and randomly assigned to two nail insertion groups; ten patients were treated with an Unreamed Femoral Nail(®) (UFN, Synthes(®), Solothurn, Switzerland) inserted at the trochanteric fossa and nine patients were treated with an Antegrade Femoral Nail(®) (AFN, Synthes(®), Solothurn, Switzerland) inserted at the tip of the greater trochanter. The main outcome measures were pain, gait, nerve and muscle function, along with endurance. Magnetic resonance imaging (MRI), electromyography (EMG), and Cybex isokinetic testings were performed at, respectively, 2 and 6weeks and at a minimum of 12months after surgery. The MRI and EMG showed, in both groups, signs of iatrogenic abductor musculature lesions (four in the UFN group and four in the AFN group) and superior gluteal nerve injury (five in the UFN group and four in the AFN group). The isokinetic measurements and the patient-reported outcomes showed moderate reduction in abduction strength and endurance, as well as functional impairment with slight to moderate interference with daily life in both groups, with no appreciable differences between the groups. Anatomical localization of the entry point seems to be important for per-operative soft tissue damage and subsequent functional impairment. However, the results of this study did not show appreciable differences between femoral nailing through the greater trochanter tip and nailing through the trochanteric fossa.