Ehlers-Danlos syndrome: arthroscopic treatment of excessive hip instability

A recently published study in the journal Arthroscopy presented the results in a series of patients with Ehlers-Danlos syndrome and hypermobility who underwent hip arthroscopy for persistent pain and increased capsular hyperlaxity.
A retrospective review was carried out of 16 patients with confirmed hypermobility-type Ehlers-Danlos syndrome who underwent hip arthroscopy for continuing pain and capsular hyperlaxity. All the patients reported symptoms of instability and pain, and during surgery the hip distracted easily on traction and a patulous capsule was seen. No patient had bony dysplasia of the hip and none had had a previous dislocation. The results were assessed before and after surgery with the Harris hip score, SF12 and VAS for pain.
Evidence of symptomatic femoroacetabular impingement was seen in 15 hips. The 16th hip showed instability with a positive anterior impingement test and distracted very easily, and showed a tear of the labrum and a patulous capsule during surgery. The mean follow-up was 44.61 months. The mean centre-edge angle was 31.8, while the mean Tonnis angle was 3.6. The mean femoral version was measured on CT and was 19.2°. Of all the hips, 13 underwent primary arthroscopy and three revision arthroscopy. In every hip, an interportal capsulotomy alone was performed during the hip arthroscopy, together with arthroscopic capsular plication. 13 labral repairs were carried out. Two debridements of the labrum. Eight resections of the bony rim of the acetabulum. 15 resections of the femoroacetabular impingement lesion, two iliopsoas tenotomies and, in one case, microfracture. An improved stability of the joint was seen, with an inability to distract the hip with manual traction under fluoroscopic guidance. The mean alpha angle after surgery was 58.7° on the anteroposterior radiograph and 63.6° on the lateral radiographs, compared with the preoperative angles, which were 47.4° and 46.1° respectively. All the outcome scores showed improvement.
The authors concluded that femoroacetabular impingement and excessive capsular hyperlaxity may be seen in Ehlers-Danlos syndrome. Although increased femoral version was common in most cases, acetabular dysplasia was not seen to the same degree in their study. Careful capsular plication, arthroscopic correction of the femoroacetabular impingement and preservation of the labrum led to a dramatic improvement in the outcomes and in the subjective sense of stability of the joint, with no case of iatrogenic dislocation in these difficult patients.