QUADRICEPS MUSCLE FUNCTION FOLLOWING HARVEST OF THE RECTUS FEMORIS MUSCLE AS A MYOFASCIAL FLAP FOR COMPLEX GROIN WOUND RECONSTRUCTION
Hani Sbitany, MD, Peter F. Koltz, MD, Nirav Patel, BA, John A. Girotto, MD, Stephen J. Vega, MD, Howard N. Langstein, MD.
University of Rochester, Rochester, NY, USA.
Purpose: The use of a pedicled rectus femoris myofascial flap for vascularized soft tissue coverage of complex groin wounds has become an increasingly utilized option. Advantages of this flap include a sufficient arc of rotation to reach the groin and inguinal region, a dependable vascular pedicle, and low donor site morbidity. Despite these advantages, there continue to be concerns as to whether the harvest of this muscle results in a deficit in quadriceps strength. We aim to show that the use of the rectus femoris flap for groin wound reconstruction results in no residual functional deficit in thigh strength.
Methods: Results of 106 consecutive rectus femoris flaps for groin wound reconstruction performed at a single institution over a 10-year period were retrospectively reviewed. From this cohort, 76 were identified as unilateral flaps, and 20 of these patients were successfully consented for post-operative testing of thigh function. Testing included both a subjective questionnaire eliciting patient ratings of post-operative thigh strength, and objective muscle strength testing. An isometric dynamometer was used to test true quadriceps muscle strength, measured as peak torque generated, for both the operative thigh and the non-operative thigh. Furthermore, all patients were tested for time required to complete five consecutive sit to stand exercises. An age and sex-matched control group of 20 subjects with no operative history or known discrepancy of thigh strength underwent similar testing.
Results: Operative subjects tested (mean age 72) were an average of 33.2 months post-operative. Dynamometer studies showed a mean non-operative thigh peak torque generated of 135.3 foot-lbs, and a mean operative thigh peak torque of 104.7 foot-lbs, for a percent difference in isometric knee extensor strength of 21%, favoring the non-operative thigh. Mean % difference in isometric knee extensor strength in the control group comparing dominant to nondominant thighs was 17.3% (p=.77), favoring the dominant leg. There was a difference, however, in mean time to 5 consecutive squatting to standing exercises (18.7 seconds for operative group vs. 6.9 seconds for non-operative group; p = .02). On questionnaire, operative subjects rated post-operative leg strength a mean of 4.83 out of 10, compared to pre-operative strength. Further, they rated operative leg strength 5.5 out of 10 compared to strength of the non-operative leg.
Conclusions: Patients undergoing harvest of the rectus femoris muscle as a myofascial flap for complex groin wound reconstruction did exhibit a lower peak torque generated by the operative leg relative to the non-operative leg. However, a similar difference in thigh strength was observed in the matched control cohort, where both legs were non-operative. Thus, there is little isolated deficit in quadriceps strength as a result of rectus femoris harvest. Interestingly, subjective questionnaires regarding post-operative function demonstrated that patient’s perceived deficits are greater than actual measured deficits. They rated their ability to perform the majority of basic daily physical activities as average; however, our results indicate that harvest of this muscle results in little functional deficit.