Patient characteristics.

<p>Patient characteristics.</p

Cup position in the two groups.

<p>Cup position in the two groups.</p

Example of measurements in TraumaCad®.

<p>(A) Anteversion and inclination on postoperative anterior-posterior radiographs of the pelvis. (B) Center of rotation (COR) marked on the operated side. The femoral shaft line was drawn from the center of two parallel lines with the shortest length across the femur extracted from two points marked at the distal level of the lesser trochanter and 20 mm distal from the lesser trochanter.</p

The Gait Deviation Index Is Associated with Hip Muscle Strength and Patient-Reported Outcome in Patients with Severe Hip Osteoarthritis—A Cross-Sectional Study

<div><p>Background</p><p>The Gait Deviation Index summarizes overall gait ‘quality’, based on kinematic data from a 3-dimensional gait analysis. However, it is unknown which clinical outcomes may affect the Gait Deviation Index in patients with primary hip osteoarthritis. The aim of this study was to investigate associations between Gait Deviation Index as a measure of gait ‘quality’ and hip muscle strength and between Gait Deviation Index and patient-reported outcomes in patients with primary hip osteoarthritis.</p><p>Method</p><p>Forty-seven patients (34 males), aged 61.1 ± 6.7 years, with BMI 27.3 ± 3.4 (kg/m²) and with severe primary hip osteoarthritis underwent 3-dimensional gait analysis. Mean Gait Deviation Index, pain after walking and maximal isometric hip muscle strength (flexor, extensor, and abductor) were recorded. All patients completed the ‘Physical Function Short-form of the Hip disability and Osteoarthritis Outcome Score (HOOS-Physical Function) and the Hip disability and Osteoarthritis Outcome Score subscales for pain (HOOS-Pain) and quality-of-life (HOOS-QOL).</p><p>Results</p><p>Mean Gait Deviation Index was positively associated with hip abduction strength (p<0.01, <i>r</i> = 0.40), hip flexion strength (p = 0.01, <i>r</i> = 0.37), HOOS-Physical Function (p<0.01, <i>r</i> = 0.41) HOOS-QOL (p<0.01, <i>r</i> = 0.41), and negatively associated with HOOS-Pain after walking (p<0.01, <i>r</i> = -0.45). Adjusting the analysis for walking speed did not affect the association.</p><p>Conclusion</p><p>Patients with the strongest hip abductor and hip flexor muscles had the best gait ‘quality’. Furthermore, patients with higher physical function, quality of life scores and lower pain levels demonstrated better gait ‘quality’. These findings indicate that interventions aimed at improving hip muscle strength and pain management may to a moderate degree improve the overall gait ‘quality’ in patients with primary hip OA.</p></div

Radiographic cup position following posterior and lateral approach to total hip arthroplasty. An explorative randomized controlled trial

<div><p>The two most common surgical approaches to total hip arthroplasty are the posterior approach and lateral approach. The surgical approach may influence cup positioning and restoration of the offset, which may affect the biomechanical properties of the hip joint.</p><p>The primary aim was to compare cup position between posterior approach and lateral approach. Secondary aims were to compare femoral offset, abductor moment arm and leg length discrepancy between the two approaches. Eighty patients with primary hip osteoarthritis were included in a randomized controlled trial and assigned to total hip arthroplasty using posterior approach or lateral approach. Postoperative radiographs from 38 patients in each group were included in this study for measurement of cup anteversion and inclination. Femoral offset, cup offset, total offset, abductor moment arm and leg length discrepancy were measured on preoperative and postoperative radiographs in 28 patients in each group. We found that mean anteversion was 5° larger in the posterior approach group (95% CI, -8.1 to -1.4; p = 0.006), while mean inclination was 5° less steep (95% CI, 2.7 to 7.2; p<0.001) compared with the lateral approach group. The posterior approach group had a larger mean femoral offset of 4.3mm (95% CI, -7.4 to -1.3, p = 0.006), mean total offset of 6.3mm (95% CI, -9.6 to -3; p<0.001) and mean abductor moment arm of 4.8mm (95% CI, -7.6 to -1.9; p = 0.001) compared with the lateral approach group. We found a larger cup anteversion but less steep cup inclination in the posterior approach group compared with the lateral approach group. Femoral offset and abductor moment arm were restored after total hip arthroplasty using lateral approach but significantly increased when using posterior approach.</p></div

Radiographic cup position following posterior and lateral approach to total hip arthroplasty. An explorative randomized controlled trial

<div><p>The two most common surgical approaches to total hip arthroplasty are the posterior approach and lateral approach. The surgical approach may influence cup positioning and restoration of the offset, which may affect the biomechanical properties of the hip joint.</p><p>The primary aim was to compare cup position between posterior approach and lateral approach. Secondary aims were to compare femoral offset, abductor moment arm and leg length discrepancy between the two approaches. Eighty patients with primary hip osteoarthritis were included in a randomized controlled trial and assigned to total hip arthroplasty using posterior approach or lateral approach. Postoperative radiographs from 38 patients in each group were included in this study for measurement of cup anteversion and inclination. Femoral offset, cup offset, total offset, abductor moment arm and leg length discrepancy were measured on preoperative and postoperative radiographs in 28 patients in each group. We found that mean anteversion was 5° larger in the posterior approach group (95% CI, -8.1 to -1.4; p = 0.006), while mean inclination was 5° less steep (95% CI, 2.7 to 7.2; p<0.001) compared with the lateral approach group. The posterior approach group had a larger mean femoral offset of 4.3mm (95% CI, -7.4 to -1.3, p = 0.006), mean total offset of 6.3mm (95% CI, -9.6 to -3; p<0.001) and mean abductor moment arm of 4.8mm (95% CI, -7.6 to -1.9; p = 0.001) compared with the lateral approach group. We found a larger cup anteversion but less steep cup inclination in the posterior approach group compared with the lateral approach group. Femoral offset and abductor moment arm were restored after total hip arthroplasty using lateral approach but significantly increased when using posterior approach.</p></div

CONSORT flow diagram for enrolment of the patients according to inclusion and exclusion criteria and available radiographs.

<p>Please see text in ‘Participants’ and ‘Data collection’ for the trial’s inclusion criteria and the study’s radiographic inclusion criteria.</p

Cup position within/outside target zone.

<p>28 cups from the PA group (green) and 25 cups from the LA group (red) lie within the ‘target zone’.</p

Simple and adjusted associations between mGDI as the dependent variable and hip muscle strength, pain and HOOS scores as independent variables.

<p>Simple and adjusted associations between mGDI as the dependent variable and hip muscle strength, pain and HOOS scores as independent variables.</p

Descriptive outcome data for the patients: mean Gait Deviation Index, hip muscle strength and pain for the affected limb and patient-reported outcome measures.

<p>Descriptive outcome data for the patients: mean Gait Deviation Index, hip muscle strength and pain for the affected limb and patient-reported outcome measures.</p