The dimensions of the hip capsule can be measured using magnetic resonance imaging and may have a role in arthroscopic planning

Abstract

Purpose The purpose of this study was to systematically evaluate the dimensions and thickness of the hip joint capsule. Secondarily, the study assessed whether there were any described correlations between capsule thickness and stability of the hip joint. Methods Four databases (PubMed, Ovid [MEDLINE], Cochrane Database, and EMBASE) were searched from database inception to May 2018, and two reviewers independently and in duplicate screened the resulting literature. Methodological quality of all included papers was assessed using the Methodological index for non‐randomized studies (MINORS) criteria. Mean differences were combined in a meta‐analysis using a random effects model when possible. Results A total of 14 studies (1 level I, 1 level II, 4 level III, 5 level IV) were identified including 796 patients (1013 hips) with a mean age of 39.5 years (range 2–95). Of the included patients, 55.2% were female and they were followed up for a mean of 7.6 months (range 1–12.5 months). The thickness of the capsule was measured in cadaveric specimens, ultrasound, and magnetic resonance imaging (MRI), with MRI measurements reported most consistently and with the least variation. Mean thickness of the anterior capsule in patients without hip disease on MRI ranged from 4.4 and 4.7 mm. Mean thickness of the anterior capsule in patients with FAI ranged between 4.9 and 5.0 mm. Males had significantly thicker capsules than females (mean difference = 1.92 mm, 0.35–3.49, P = 0.02). Clinical laxity of the hip joint, as well as female gender was correlated with thinner anterior joint capsules. Conclusion The thickness of the anterior hip capsule can be measured consistently using MRI. A thinner anterior capsule may be associated with clinical laxity of the hip joint. The relevance of capsular thickness on postoperative instability following hip arthroscopy is poorly understood and warrants further investigation. The thickness of the anterior hip capsule, as measured on MRI, has the potential to be used as part of the clinical decision‐making in capsular management strategies. Level of evidence IV.

Predictors of Outcomes After Hip Arthroscopic Surgery for Femoroacetabular Impingement: A Systematic Review

“…The methodology of the following systematic review was adopted from a previous study. 29 This systematic review was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Three online databases (Embase, PubMed, and Ovid [MEDLINE]) were searched from database inception until May 19, 2018, for studies investigating the predictors of clinical outcomes after hip arthroscopic surgery for FAI.…”

Dynamic changes of the joint capsule in relation to the zona orbicularis: An anatomical study with possible implications for hip stability mechanism

“…Images of the joint capsule, including the zona orbicularis, have been analyzed previously. However, these studies have mainly focused on the ability to visualize (Malagelada et al, 2015;Wagner et al, 2012) or the capsular thickness (Kay et al, 2020;Strickland et al, 2018); the articular cavity surrounded by the joint capsule has never been studied quantitatively. Micro-CT analysis in the present study revealed that the inward protrusion of the joint capsule surrounded the narrowest area of the articular cavity, which was ovoid T A B L E 1 Area of the articular cavity and its ratio to the neck of femur Note: The narrowest cross-sectional area of the neck of the femur perpendicular to its longitudinal axis, and those of the articular cavities perpendicular to the same axis, were measured.…”

Advanced Hip Arthroscopy: What’s New?

“…The thickness of the capsule can be measured using MRI and may be helpful in guiding capsular management. Patients with thicker capsules are known to have less laxity in their hip compared to patients with thinner capsules [94]. Table 26.4 summarizes the common indications and contraindications for capsular closure.…”