Effects of hip joint transverse plane range of motion with a modeled effusion and capsular tear: A cadaveric study.
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.


RESULTS
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).


CONCLUSIONS
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.
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.
Casey
C
Hebert
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.
Mark P
MP
Smyth
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.
Erik
E
Woodard
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.
Collin C
CC
Bills
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.
Marc J
MJ
Mihalko
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.
William M
WM
Mihalko
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D005269:Femur; D025981:Hip Injuries / Q000503:physiopathology; D006621:Hip Joint / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D006833:Hydrarthrosis / Q000503:physiopathology*; D017746:Joint Capsule / Q000293:injuries* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D016059:Range of Motion, Articular / Q000502:physiology*
Capsular tear; Effusion; Hip joint; Instability; Joint capsule