Generalized Joint Hypermobility Is Predictive of Hip Capsular Thickness

Abstract

Background:The pathomechanics of hip microinstability are not clearly defined but are thought to involve anatomical abnormalities, repetitive forces across the hip, and ligamentous laxity.Purpose/Hypothesis:The purpose of this study was to explore the relationship between generalized joint hypermobility (GJH) and hip capsular thickness. The hypothesis was that GJH would be predictive of a thin hip capsule.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A prospective study was performed on 100 consecutive patients undergoing primary hip arthroscopy for the treatment of hip pain. A Beighton test score (BTS) was obtained prior to each procedure. The maximum score was 9, and a score of ≥4 was defined as hypermobile. Capsular thickness at the level of the anterior portal, corresponding to the location of the iliofemoral ligament, was measured arthroscopically using a calibrated probe. The presence of ligamentum teres (LT) pathology was also recorded.Results:Fifty-five women and 45 men were included in the study. The mean age was 32 years (range, 18-45 years). The median hip capsule thickness was statistically greater in men than women (12.5 and 7.5 mm, respectively). The median BTS for men was 1 compared with 4 for women (P < .001). A statistically significant association was found between BTS and capsular thickness; a BTS of <4 is strongly predictive of having a capsular thickness of ≥10 mm, while a BTS ≥4 correlates with a capsular thickness of <10 mm. There was a statistically greater incidence of LT tears in patients with a capsular thickness of ≤7.5 mm and a BTS of ≥4 (P < .001).Conclusion:Measurement of the GJH is highly predictive of hip capsular thickness. A BTS of <4 correlates significantly with a capsular thickness of ≥10 mm, while a BTS ≥4 correlates significantly with a thickness of <10 mm.

Editorial Commentary: Hip Arthroscopy Capsular Management—Cut Your Cloth to Measure!

“…4 The texture and elasticity of the hip capsule vary considerably between patients. 5,6 In those patients with hypermobility, the capsule is thin and stretchy, like spandex, whereas in those with stiffer tissues, it is more like sack cloth. 5 Second, arthroscopic surgery takes place under water.…”

“…5,6 In those patients with hypermobility, the capsule is thin and stretchy, like spandex, whereas in those with stiffer tissues, it is more like sack cloth. 5 Second, arthroscopic surgery takes place under water. As such, the tissue is continually absorbing the fluid that is pumped into the hip, which leads to engorgement as the case proceeds, thus altering not only its dimension but also its structural properties.…”

“…Indeed, patients with dysplasia are also more likely to have thinner capsules, hypermobility, and hip capsular redundancy. 5 Consequently, capsular management is critically important in this group.…”

Hip Pain in the Athlete Part 2: How to Work Up, Diagnosis, and Manage Femoroacetabular Impingement

“…The joint laxity is evaluated using the Beighton score or the Brighton criteria for joint hypermobility syndromes. 9 These two tests are useful when examining athletes whose sport requires extreme hip range of motion maneuvers such as ballet dancers, gymnasts, figure skaters, martial artists, and others. 10 One study showed that patients with FAI have a higher prevalence of increased joint laxity.…”

“…10 One study showed that patients with FAI have a higher prevalence of increased joint laxity. 9 In addition, a negative correlation has been reported between Beighton score and hip capsular thickness in patients who undergo primary hip arthroscopy for FAI. 9,11 Hip range of motion is evaluated in hip flexion, extension, internal rotation, external rotation, abduction, and adduction position (►Fig.…”