The envelope of passive motion allowed by the capsular ligaments of the hip

• Published in: Journal of biomechanics 2015-11, Vol.48 (14), p.3803-3809
• Main Authors: van Arkel, Richard J, Amis, Andrew A, Jeffers, Jonathan R.T
• Format: Article
• Language: English
• Subjects: Aged; Arthritis; Arthroscopy; Biomechanics; Biomedical materials; Cadaver; Capsule; Constraints; Envelopes; Hip; Hip joint; Hip Joint - physiology; Humans; Hydraulics; Joint Capsule - physiology; Joint surgery; Ligaments; Ligaments, Articular - physiology; Male; Morphology; Physical Medicine and Rehabilitation; Preserving; Range of motion; Range of Motion, Articular; Rotation; Slack; Surgery; Surgical implants; Torque
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/j.jbiomech.2015.09.002

Abstract Laboratory data indicate the hip capsular ligaments prevent excessive range of motion, may protect the joint against adverse edge loading and contribute to synovial fluid replenishment at the cartilage surfaces of the joint. However, their repair after joint preserving or arthroplasty surgery is not routine. In order to restore their biomechanical function after hip surgery, the positions of the hip at which the ligaments engage together with their tensions when they engage is required. Nine cadaveric left hips without pathology were skeletonised except for the hip joint capsule and mounted in a six-degrees-of-freedom testing rig. A 5 N m torque was applied to all rotational degrees-of-freedom separately to quantify the passive restraint envelope throughout the available range of motion with the hip functionally loaded. The capsular ligaments allowed the hip to internally/externally rotate with a large range of un-resisted rotation (up to 50±10°) in mid-flexion and mid-ab/adduction but this was reduced towards the limits of flexion/extension and ab/adduction such that there was a near-zero slack region in some positions ( p