Antegrade intramedullary nailing via a piriformis fossa start point is the treatment of choice for most femoral shaft fractures in adults. Recently alternate approaches for intramedullary nailing of the femur have been advocated, including retrograde nailing and trochanteric start point antegrade nailing. Reasons cited for considering altenative starting points to the piriformis fossa include a concern about the damage to the hip abductor muscles that may occur during access to the piriformis fossa. There is very little literature about long- term muscle function after standard antegrade intramedullary nailing and the conclusions of the available studies are conflicting.

The purpose of this study was to document the hip abductor muscle strength following standard antegrade intramedullary nailing utilizing two different objective measures (KinCom and gait analysis).

Objective evidence of hip abductor muscle strength will assist in planning new nailing techniques.

Twenty-two patients with isolated femoral shaft fractures who were treated with standard antegrade reamed interlocking intramedullary nailing and who had a minimum one year follow-up were identified. The patients were examined for muscle strength, range of motion and limb length. All of the patients answered a questionnaire and completed the SF-36 and Musculoskeletal Functional Assessment outcome measures. All patients had isokinetic muscle testing of their hip abductors, hip extensors and knee extensors using the KinCom muscle testing machine. Ten of the patients also underwent formal gait lab analysis.

Isokinetic muscle testing showed no significant difference from the uninjured contralateral side in hip abduction, hip extension or knee extension. The gait lab analysis failed to show any important changes in gait pattern. SF-36 scores were comparable to norms. MFA scores did not indicate any significant long term disability.

Antegrade reamed interlocking intramedullary nailing of femoral shaft fractures utilizing a standard piri-formis fossa starting point is not associated with any significant long term hip abductor muscle strength deficit. Gait pattern returns to normal following femoral shaft fracture treated with this technique and functional outcomes are good.

Introduction and Aims: Recently alternate approaches for intra-medullary femoral nailing have been advocated, including retrograde nailing and trochanteric start point antegrade nailing in an attempt to avoid damage to the hip abductor muscles that may occur during access to the piriformis fossa. The aim of this study was to document the hip abductor muscle strength following standard antegrade intra-medullary nailing utilising two different objective measures.

Method: Twenty-two patients with isolated femoral shaft fractures who were treated with standard ante-grade reamed interlocking intra-medullary nailing and who had a minimum one-year follow-up were identified. The patients were examined for muscle strength, range of motion and limb length. All of the patients answered a questionnaire and completed the SF-36 and Musculoskeletal Functional Assessment outcome measures. All patients had isokinetic muscle testing of their hip abductors, hip extensors and knee extensors using the KinCom muscle testing machine. Eleven of the patients also underwent formal gait lab analysis.

Results: Isokinetic muscle testing showed no significant difference from the uninjured contralateral side in hip abduction, hip extension or knee extension. The gait lab analysis failed to show any important changes in gait pattern in the time spatial and hip moment parameters. SF-36 scores were comparable to norms (mean physical component score 53 and mean mental component 51). MFA scores did not indicate any significant long-term disability.

Conclusion:Antegrade reamed interlocking intra-medullary nailing of femoral shaft fractures utilising a standard piriformis fossa starting point is not associated with any significant long-term hip abductor muscle strength deficit. Gait pattern returns to normal following femoral shaft fracture treated with this technique and functional outcomes are good.