Paper #57 - ISHA Annual Scientific Meeting 2016

The Biomechanical Effect Of Ischiofemoral Impingement And Femoral Version On Lumbar Facet Loads During Hip Extension

Juan Gómez-Hoyos, MD, Medellín COLOMBIA
Anthony Khoury, MSc, Dallas, TX UNITED STATES
Ricardo Goncalves Schroder, PT, Dallas, TX UNITED STATES
William Márquez-Arabia, MD, Medellín COLOMBIA
Asadullah Helal, BS, Dallas, TX UNITED STATES
Ian James Palmer, PhD, Oklahoma City, OK UNITED STATES
Hal David Martin, DO, Dallas, TX UNITED STATES

Hip Preservation Center at Baylor University Medical Center at Dallas, Dallas, Texas, UNITED STATES

FDA Status Not Applicable

Summary: The biomechanical effect of ischiofemoral impingement and femoral version on lumbar facet loads during hip extension.

Abstract:
Purpose. The purpose of this study was to assess the effect of ischiofemoral impingement, abnormal femoral version, and the iliofemoral ligament on lumbar facet joint loads during hip extension.
Methods. Twenty-five hips from fresh frozen T1-to-toes cadaveric specimens were tested. A complete pre-testing imaging evaluation was performed using CT scan. Through a posterior lumbar spine approach L3-4 and L4-5 facet joints were dissected. Ultrasensitive, and previously validated, piezoresistive force sensors were placed in lumbar facet joints of L3-4 and L4-5. Lumbar facet loads during hip extension (from zero to 10 and 20 degrees) were measured in native hip conditions and after three different conditions in two separate cohorts. Cohort1 (n=12): condition 1) simulated ischiofemoral impingement by performing lesser trochanteric osteotomy and lengthening. Cohort 2 (n=13): condition 2) Native versus increased (+30 degrees) and decreased (-10 degrees) femoral version by performing a femoral osteotomy, and condition 3) native versus decreased femoral version after release of the iliofemoral ligament. Paired t-tests were performed comparing normal versus simulated ischiofemoral impingement on the L3-L4 and L4-L5 facet joint loads. Repeated measures ANOVA with post hoc paired t-tests were performed to compare the native versus abnormal femoral neck version and the native versus retroverted femur with iliofemoral ligament release on the L3-4 and L4-5 facet joint loads.
Results. Cohort 1: After simulating IFI, mean absolute differences of facet joint load were 10.8 N (SEM±4.53, p=0.036) for L3-4 at 10 degrees of hip extension, 13.71 N (SEM±4.53, p=0.012) for L3-4 at 20 degrees of hip extension, 11.49 N (SEM±4.33, p=0.024) for L4-5 at 10 degrees of hip extension, and 6.67 N (SEM±5.43, p=0.245) for L4-5 at 20 degrees of hip extension. And a statistically significant increase in L3-4 and L4-5 lumbar facet joint loads of 30.81% was found on average.
Cohort 2: After simulating increased and decreased femoral neck version, mean absolute differences of L3-4 facet joint load at 10 degrees of hip extension were 24.8 N (SEM±8.3, p=0.013) between native and -10 femoral version and 39.6 N (SEM±14.4, p=0.020) between 30 degrees and -10 degrees femoral version. Mean absolute differences of L3-4 facet joint load at 20 degrees of hip extension were 56.9 N (SEM±22.9, p=0.030) between 30 degrees and -10 degrees femoral version. Trends for a femoral version effect were found in L4-5 facet loads at 10 degrees (p=0.088) and 20 degrees (0.063) of hip extension. After releasing the iliofemoral ligament in a retroverted condition (-10 degrees) a statistically significant decrease in L3-4 and L4-5 lumbar fact joint loads of 186.84% was found on average.
Conclusion. Ischiofemoral impingement (cohort 1) significantly increased L3-4 and L4-5 lumbar facet joint load when compared to non-ischiofemoral impingement native hips. Decreased femoral version (cohort 2) decreased L3-4 and L4-5 facet loads. Release of the iliofemoral ligament decreased the facet loads in all specimens of femoral retroversion.