Ehlers-Danlos Syndrome: Arthroscopic Management for Extreme Soft-Tissue Hip Instability.

PURPOSE: To present outcomes in a series of patients with Ehlers-Danlos syndrome (EDS)-hypermobility type who underwent hip arthroscopy for associated hip pain and extreme capsular laxity.

METHODS: A retrospective chart review identified 16 hips with confirmed EDS--hypermobility type that underwent hip arthroscopy for continued pain and capsular laxity. All patients had complaints of "giving way" and pain, an easily distractible hip with manual traction under fluoroscopy, and a patulous capsule at the time of surgery. No patient had osseous evidence of acetabular hip dysplasia or prior confirmed hip dislocation. Outcomes were evaluated preoperatively and postoperatively with the modified Harris Hip Score (mHHS), the 12-Item Short Form Health Survey (SF-12), and a visual analog scale (VAS) for pain.

RESULTS: Evidence of symptomatic femoroacetabular impingement (FAI) was found in 15 hips (93.8%). The 16th hip had subjective giving way with a positive anterior impingement test and was easily distractible, had a labral tear, and had a patulous capsule at the time of surgery. The mean follow-up period was 44.61 months (range, 12 to 99 months). The mean preoperative lateral center-edge angle was 31.8° (range, 25° to 44°), and the mean Tönnis angle was 3.6° (range, -2° to 8°). Mean femoral version measured on computed tomography (CT) scans was 19.2° (range, -4.0° to 31.0°). Of the hips, 13 underwent primary arthroscopy and 3 underwent revision. All hips underwent hip arthroscopy with an interportal capsular cut only and arthroscopic capsular plication. There were 13 labral repairs, 2 labral debridements, 8 rim resections, 15 femoral resections, 2 psoas tenotomies, and 1 microfracture. Improved stability with an inability to distract the hip with manual traction under fluoroscopy was noted in all hips after plication. The mean alpha angle preoperatively was 58.7° on anteroposterior radiographs and 63.6° on lateral radiographs compared with 47.4° and 46.1°, respectively, postoperatively. There were significant improvements for all outcomes (mHHS, P = .002; SF-12 score, P = .027; and VAS score, P = .0004). The mean mHHS, SF-12 score, and VAS score were 45.6 points, 62.4 points, and 6.5 points, respectively, preoperatively compared with 88.5 points, 79.3 points, and 1.6 points, respectively, at a mean follow-up of 45 months. No EDS patients were lost to follow-up or excluded from analysis. The mean improvement in mHHS from preoperatively to postoperatively was 42.9 points, and there were no iatrogenic dislocations. One patient underwent further revision arthroscopy for recurrent pain, subjective giving way, and capsular laxity.

CONCLUSIONS: FAI and extreme capsular laxity can be seen in the setting of EDS. Although increased femoral version was common, acetabular dysplasia was not common in our study. Meticulous capsular plication, arthroscopic correction of FAI when present, and labral preservation led to dramatic improvements in outcomes and subjective stability without any iatrogenic dislocations in this potentially challenging patient population.

LEVEL OF EVIDENCE: Level IV, therapeutic case series.