In this section
@article{van:2018:10.2106/JBJS.17.00251,
author = {van, Arkel R and Ng, KCG and Muirhead-Allwood, S and Jeffers, J},
doi = {10.2106/JBJS.17.00251},
journal = {Journal of Bone and Joint Surgery: American Volume},
pages = {1--10},
title = {Capsular ligament function after total hip arthroplasty},
url = {http://dx.doi.org/10.2106/JBJS.17.00251},
volume = {100},
year = {2018}
}
TY - JOUR
AB - Background: The hip joint capsule passively restrains extreme range of motion, protecting the native hip against impingement, dislocation, and edge-loading. We hypothesized that following total hip arthroplasty (THA), the reduced femoral head size impairs this protective biomechanical function.Methods: In cadavers, THA was performed through the acetabular medial wall, preserving the entire capsule, and avoiding the targeting of a particular surgical approach. Eight hips were examined. Capsular function was measured by rotating the hip in 5 positions. Three head sizes (28, 32, and 36 mm) with 3 neck lengths (anatomical 0, +5, and +10 mm) were compared.Results: Internal and external rotation range of motion increased following THA, indicating late engagement of the capsule and reduced biomechanical function (p < 0.05). Internal rotation was affected more than external. Increasing neck length reduced this hypermobility, while too much lengthening caused nonphysiological restriction of external rotation. Larger head sizes only slightly reduced hypermobility.Conclusions: Following THA, the capsular ligaments were unable to wrap around the reduced-diameter femoral head to restrain extreme range of motion. The posterior capsule was the most affected, indicating that native posterior capsule preservation is not advantageous, at least in the short term. Insufficient neck length could cause capsular dysfunction even if native ligament anatomy is preserved, while increased neck length could overtighten the anterior capsule.Clinical Relevance: Increased understanding of soft-tissue balancing following THA could help to prevent instability and improve early function. This study illustrates how head size and neck length influence the biomechanical function of the hip capsule in the early postoperative period.
AU - van,Arkel R
AU - Ng,KCG
AU - Muirhead-Allwood,S
AU - Jeffers,J
DO - 10.2106/JBJS.17.00251
EP - 10
PY - 2018///
SN - 0021-9355
SP - 1
TI - Capsular ligament function after total hip arthroplasty
T2 - Journal of Bone and Joint Surgery: American Volume
UR - http://dx.doi.org/10.2106/JBJS.17.00251
UR - https://journals.lww.com/jbjsjournal/Fulltext/2018/07180/Capsular_Ligament_Function_After_Total_Hip.9.aspx
VL - 100
ER -
The Biomechanics Group
Mechanical Engineering
³Ô¹ÏºÚÁÏ
South Kensington Campus
City & Guilds Building
Exhibition Road
London SW7 2AZ
+44 (0) 20 7589 5111