Page 14 - Delaware Medical Journal - November 2016

The Effect of Surgical Approach on Strength and Function after Total Hip Arthroplasty
Joseph Zeni Jr., PT, PhD; Kathleen Madara, PT, DPT; James Rubano, MD
Background: Although total hip arthroplasty (THA) has become standard procedure to manage the symptoms of end-stage osteoarthritis (OA), there are multiple surgical approaches to access the hip joint. To date, there is limited information on the effect of surgical approach on
muscle strength and performance-based measures of functional ability after THA.
Questions/Purposes: The purpose of this study was to compare the effect of posterior or anterolateral surgical approaches on strength and function after THA. We hypothesized that individuals who underwent a posterior approach would have greater strength
and performance-based measures of function than individuals who underwent an anterolateral approach one year after surgery. We also hypothesized that there would be no difference in pain or self-reported outcomes at follow-up.
Methods: 63 subjects were tested two to four weeks prior to THA and then three months
and 12 months after THA. Subjects were divided into a posterior approach and lateral approach groups. Patients completed functional testing, strength measures, as well as self-reported questionnaires at each time point. Repeated-measures analysis of variance (ANOVA) tests
were performed to test the change between the pre-operative and one year time point. Descriptive data were reported for all three time points.
Results: There was a significant interaction effect for hip abduction strength (p=0.025) and the lateral group was significantly weaker at one year (p=0.018). No other variable demonstrated a significant interaction effect; however, all other variables with the exception of hip abductor strength (p=0.883) and pain on the non-operated side (p=0.527) demonstrated a significant main effect of time (p≤0.01) in which there was significant improvement at 1 year.
Conclusion: The lateral surgical approaches result in weaker hip abduction one year after THA; however significant and clinically meaningful improvements in functional ability were seen for most subjects, regardless of surgical approach.
IntroductionTotal hip arthroplasty (THA) successfully relieves
pain and improves self-reported function for individuals with hip osteoarthritis (OA).1 Although THA has become standard procedure to manage the symptoms of end-stage OA, there are multiple surgical approaches to access the hip joint. Typical approaches include the anterior,2 anterolateral,3 lateral,4 and posterior5 approaches. Posterior and anterolateral or lateral approaches are most common,6 but current recommendations suggest that the surgeon should choose the approach with which 7
Although the majority of patients demonstrate substantial reduction in pain after THA, residual weakness is common.
When accessing the hip using the anterolateral or lateral approaches, the surgeon compromises or transects the gluteus medius and/or the gluteus minimus to expose the femoral
head. Therefore, there is a potential for postoperative hip weakness due to this soft tissue damage. These muscles play a role in frontal plane, trunk, pelvis and hip biomechanics,8,9 as well as functional performance.10,11 In the posterior approach, the abductor muscles are spared, but there is typically blunt dissection of the gluteus maximus, as well as transection of the piriformis and deep hip external rotators as they insert onto the greater trochanter.
Given the different anatomical structures affected with each approach, it is possible that the anterolateral and lateral
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Del Med J | November 2016 | Vol. 88 | No. 11
Abstract