The 2007 Frank Stinchfield Award. The biomechanics of the hip labrum and the stability of the hip.
We explored the mechanical factors leading to the formation of labral tears and the effect of these lesions on hip kinematics at the extremes of joint motion. Using a 3D motion analysis system, the stability of six cadaveric hips was measured during loading maneuvers known to impose anterior loads on the joint margin. These measurements were repeated following venting of the capsule, and after creation of a 15-mm tear in the intact labrum. Compared to the intact hip, 43% and 60% less force was required to distract the femur by 3 mm after venting and creation of a tear. An ER torque of 177 in-lbf in 30 degrees of flexion caused the vented and torn specimens to rotate 1.5 degrees +/- 2.7 degrees and 7.1 degrees +/- 4.7 degrees more than the intact specimen, and the femoral head to displace 1.21 +/- 0.53 mm and 0.67 +/- 0.35 mm, respectively. A breach of the integrity of labral function is shown to lead to decreased femoral stability relative to the acetabulum during extreme ranges of motion.
Crawford
Matthew J
MJ
The Barnhart Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA.
Dy
Christopher J
CJ
Alexander
Jerry W
JW
Thompson
Matthew
M
Schroder
Steven J
SJ
Vega
Charles E
CE
Patel
Rikin V
RV
Miller
Andrew R
AR
McCarthy
Joseph C
JC
Lowe
Walter R
WR
Noble
Philip C
PC
D000077:Acetabulum / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001363:Awards and Prizes; D001696:Biomechanical Phenomena / Q000295:instrumentation; D002102:Cadaver; D003198:Computer Simulation; D004867:Equipment Design; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D017746:Joint Capsule / Q000293:injuries*; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008953:Models, Anatomic; D018583:Pliability; D011857:Radiographic Image Interpretation, Computer-Assisted; D016059:Range of Motion, Articular; D012399:Rotation; D014057:Tomography, X-Ray Computed; D019415:Torque; D016474:Weight-Bearing