Arthroscopic thermal shrinkage effective for chronic ankle instability

At final follow-up, 19 of 22 ankles had good or excellent Karlsson and Peterson scores for pain and function.

Arthroscopically shrinking capsular tissue can effectively reduce chronic ankle instability in young, active patients, a study by Italian surgeons shows.

Marco Maiotti, MD, and colleagues at the San Giovanni-Addolorata-Calvary Hospital and at the Tor Vergata University in Rome retrospectively reviewed their experience performing the procedure on 22 ankles of 22 male soccer players. These patients had a mean age of 18 years and a mean postoperative follow-up of 42 months.

Preoperatively, all patients had chronic lateral ankle instability that had persisted for at least six months. All patients also had failed initial conservative treatment, including peroneal strengthening, orthoses and proprioceptive training, according to the study.

Surgeons performed the arthroscopic procedures with patients in the supine position using an arthroscopic pump, a 30° arthroscope, local anesthesia and a thigh tourniquet. In all cases, the surgeon observed elongation of the lateral capsular tissue.

Nine ankles (41%) also showed evidence of cartilage damage — eight with Noyes Type I and one with Noyes Type II. No cases showed osteochondral defects, the authors said. Five cases required debridement and synovectomy to improve visualization of their talar dome and to reduce synovial hypertrophy. Another case required a shaving procedure due to a Type II chondral lesion, according to the study.

For thermal shrinkage, surgeons used a bipolar radiofrequency (RF) generator set to 67°C. They inserted the RF probe via the anterolateral portal after arthroscopicaly visualizing the lateral portion of the capsule, the authors said.

“The movement of the RF probe tip, from the posterolateral capsular recess to the anterior one, was based on visual identification of macroscopic tissue shrinkage,” they said.

Postoperative protocol included nonweight-bearing for two weeks. Over the next three to four weeks, patients progressed from partial weight-bearing to full weight-bearing as tolerated, the authors said. Patients also initiated a physical therapy rehabilitation program, they noted.

No patients experienced nerve injury, infection or reduced joint motion. At final follow-up, anterior talar translation significantly improved from a mean of 6.8 ± 0.6 mm at preop to 3.1 ± 1.2 mm (P<.05). Talar tilt also significantly improved, from a mean of 11.2° ± 1° at preop to 4.2° ± 1.7° (P<.05), according to the study.

Karlsson and Peterson score for pain and function increased a mean 37.2 ± 6.8 points and averaged 89.3 points (range 70 to 98 points) at final follow-up. The researchers considered 19 ankles to have achieved excellent or good results. Of the remaining three, two were considered fair and one was considered poor, according to the study.

For more information:
Maiotti M, Massoni C, Tarantino U. The use of arthroscopic thermal shrinkage to treat chronic lateral ankle instability in young athletes. Arthroscopy. 2005;6:751-757.