Session V - Femur

Lower Extremity Muscle Recovery after Antegrade or Retrograde Intramedullary Nailing of Femoral Diaphyseal Fractures: A Randomized, Prospective Study

Bruce G. French, MD; Robert Cantu, MD; Brian L. Davison, MD;

Attila Poka; Brett Kim; Sue Van Woerkom, RN (n-all authors);

Grant Medical Center, Columbus, Ohio, USA

Purpose: Indications for retrograde versus antegrade insertion of femoral nails remain controversial. No objective assessment has been conducted to evaluate the functional recovery between the two groups. The goals of this study are: (1) to evaluate muscle recovery of the hip and knee after intramedullary (IM) nailing of the femur and compare this to the intact/noninjured side and (2) to compare muscle recovery of the hip and knee of patients treated with an antegrade or retrograde IM nail.

Method: All femoral fractures treated with an IM nail between February 1998 and December 2002 were prospectively randomized to receive either an antegrade or retrograde implant. This was an IRB-approved study. Inclusion criteria included: (1) randomized insertion of femoral nail; (2) skeletally mature; (3) no significant cognitive impairment; (4) healed fracture; (5) at least 1 year follow-up; (6) no other ipsilateral lower extremity/pelvic/acetabular fractures; (7) no contralateral pelvic/acetabular, femur, or tibia fracture; and (8) ability to adequately perform Biodex protocol. One licensed physical therapist performed testing. Biodex testing included knee flexion/extension exercises and hip abduction/adduction exercises. Peak torque, maximum work for one repetition, and total work were recorded for the knee and hip.

Results: During the study period, a total of 381 patients with 398 femur fractures underwent IM nailing of the femur. Of the 381 patients, 96 met the inclusion criteria. Time from injury to testing averaged 37 months. Biodex testing was performed on 26 patients (16 antegrade and 10 retrograde). Of the measures of the knee, statistically significant differences were found between the involved and uninvolved leg in peak torque in extension (p=0.004), maximum work for one extension repetition (p=0.002) ,and total work performed in extension (p=0.017). There were no statistically significant knee outcome measures considering location of nail entry point. At the hip, the total work performed during abduction was the only statistically significant variable, with retrograde being better than antegrade (p=0.045). If only the fractures involving the isthmus are considered, none of the hip measures were significant. For the knee, the peak torque in extension was significantly lower for the involved leg (p=0.043).

Conclusion: We found significant quadriceps weakness compared to the uninjured side. There was no significant effect of the insertion site. Hip abductors appeared to be statistically weaker 1 year after an antegrade nail compared to a retrograde nail.

Significance: These results help the surgeon inform the patient of the long-term muscular/functional deficits associated with an acute femur fracture and subsequent treatment modalities.