Radiofrequency capsular shrinkage shows little benefit for patients with voluntary shoulder instability

Investigators found that 10 of 13 shoulders treated for voluntary instability had an instability recurrence within 4 months postop.

Radiofrequency capsular shrinkage shows little benefit for treating patients with voluntary shoulder instability, although repeated applications may improve the results, according to a small study by researchers in England.

Samir N. Massoud, FRCSI(Orth), and colleagues at the Royal Berkshire Hospital, Reading, reviewed outcomes for all patients treated with the procedure for voluntary shoulder instability between 1997 and 1999. The researchers defined such instability as "the ability and willingness to displace the head of the humerus from the glenoid fossa in an anterior, inferior or posterior direction with the arm at the side," according to the study, published in the Journal of Shoulder and Elbow Surgery.

The study included 13 shoulders of four men and eight women treated at a mean age of 23 years. Of these, eight patients (67%) had an unstable opposite shoulder and 11 patients (92%) showed signs of generalized ligamentous laxity, the authors reported.

In all cases, involuntary instability continued to occur despite having completed 12 months of physiotherapy, which had ceased their voluntary instability, they noted.

Surgeons performed all radiofrequency procedures with the patients under general anesthesia and positioned in the lateral decubitus position. In one patient with anteroinferior instability, surgeons treated the superior, middle and inferior glenohumeral ligaments, the rotator interval, inferior recess and anterior capsule. All other shoulders had multidirectional instability and received the same radiofrequency applications, with the posterior capsule additionally treated, according to the study.

Postoperatively, surgeons placed patients' arms in a sling for several days for comfort. Arm motion was permitted, although patients were told to avoid extreme arm movements for 6 weeks. Proprioceptive physiotherapy was also initiated within 1 week postop, the authors reported.

At follow-up, the Constant score averaged 66.7 points and mean Rowe scores improved to 43.8 points from 18.5 points preoperatively. Rowe scores for function averaged 0 points preoperatively and averaged 13.5 points at follow-up. Three shoulders (23.1%) had excellent results, one (7.7%) had a fair result and nine (69.2%) had poor results, according to the study.

"On the basis of the satisfaction rating, three patients (23.1%) felt that they had a much better shoulder, two (15.4%) had a better shoulder and eight (61.5%) felt that the shoulder was the same," the authors wrote.

Four patients had previous instability surgery, and all four experienced a recurrence of instability postoperatively. In addition, six of the nine shoulders without prior instability surgery experienced a recurrence. All recurrences occurred within 4 months postop, according to the study.

"In our study, a satisfactory outcome was achieved in three of nine shoulders (33.3%) after radiofrequency capsular shrinkage in patients who had no previous instability surgery. A further two of these nine shoulders stabilized with repeat shrinkage treatment. At final review, with repeated shrinkage, five of nine shoulders (55.6%) were stable," the authors reported.

"[All] four patients who had previous attempts at stabilization ... had an unsatisfactory outcome with radiofrequency capsular shrinkage and with subsequent attempts at stabilization," they noted.

For more information:
Massoud SN, Levy O, Copeland SA. Radiofrequency capsular shrinkage for voluntary shoulder instability. J Shoulder Elbow Surg. 2007;16:43-48.