Casey Hebert1, Mark P Smyth2, Erik Woodard3, Collin C Bills4, Marc J Mihalko5, William M Mihalko6. 1. University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering, 1211 Union Avenue, Suite 510, Memphis, TN 38104, USA. Electronic address: chebert5@uthsc.edu. 2. University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering, 1211 Union Avenue, Suite 510, Memphis, TN 38104, USA. Electronic address: msmyth83@gmail.com. 3. University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering, 1211 Union Avenue, Suite 510, Memphis, TN 38104, USA. Electronic address: ewoodar3@uthsc.edu. 4. University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering, 1211 Union Avenue, Suite 510, Memphis, TN 38104, USA. Electronic address: colinbills@hotmail.com. 5. University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering, 1211 Union Avenue, Suite 510, Memphis, TN 38104, USA. Electronic address: mmihalko@campbellclinic.com. 6. University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery & Biomedical Engineering, 1211 Union Avenue, Suite 510, Memphis, TN 38104, USA. Electronic address: wmihalko@campbellclinic.com.
Abstract
BACKGROUND: Multiple factors contribute to range of motion of the hip joint in the transverse plane: bony anatomy, hip capsule, corresponding ligaments, articular labrum, ligamentum teres, and negative intra-articular pressure. We hypothesized that violation of the negative pressure of the hip and simulation of an effusion would increase range of motion in the transverse plane in a cadaver model. METHODS: Ten hip specimens were obtained and dissected with the femur and iliac wing mounted in a custom joint-testing rig in neutral position. Specimens were tested at 0 and at 90° of flexion with 1.5Nm internal and external rotational torque. Three conditions were assessed: (1) intact specimen, (2) an effusion modeled by a 10ml saline infusion, and (3) a capsular tear. FINDINGS: The modeled effusion decreased rotational range of motion limits in both 0 and 90° of flexion, with a greater effect on the specimens at 0° flexion in external rotation with 4.1° less external rotation (p=0.009). A modeled capsular tear increased rotational motion limits in 0° of flexion in both internal and external rotation and in 90° flexion in internal rotation only (p<0.025). INTERPRETATION: An effusion may decrease the rotation of the hip, and a capsular tear may increase its rotation. This should be considered in hips with traumatic capsular tears or arthroscopic portals.
BACKGROUND: Multiple factors contribute to range of motion of the hip joint in the transverse plane: bony anatomy, hip capsule, corresponding ligaments, articular labrum, ligamentum teres, and negative intra-articular pressure. We hypothesized that violation of the negative pressure of the hip and simulation of an effusion would increase range of motion in the transverse plane in a cadaver model. METHODS: Ten hip specimens were obtained and dissected with the femur and iliac wing mounted in a custom joint-testing rig in neutral position. Specimens were tested at 0 and at 90° of flexion with 1.5Nm internal and external rotational torque. Three conditions were assessed: (1) intact specimen, (2) an effusion modeled by a 10ml saline infusion, and (3) a capsular tear. FINDINGS: The modeled effusion decreased rotational range of motion limits in both 0 and 90° of flexion, with a greater effect on the specimens at 0° flexion in external rotation with 4.1° less external rotation (p=0.009). A modeled capsular tear increased rotational motion limits in 0° of flexion in both internal and external rotation and in 90° flexion in internal rotation only (p<0.025). INTERPRETATION: An effusion may decrease the rotation of the hip, and a capsular tear may increase its rotation. This should be considered in hips with traumatic capsular tears or arthroscopic portals.
Authors: Viviane Bortoluzzi Frasson; Marco Aurélio Vaz; Anete Beling Morales; Anna Torresan; Marco Aurélio Telöken; Paulo David Fortis Gusmão; Marcus Vinicius Crestani; Bruno Manfredini Baroni Journal: Braz J Phys Ther Date: 2018-11-20 Impact factor: 3.377