Quick union found with arthroscopic ankle and subtalar arthrodeses

Reduced pain and minimal complications are added advantages to procedures.

Arthroscopic ankle and subtalar arthrodeses may provide high union rates and fast healing with few complications, according to a San Diego investigator.

In a non-randomized study of his patients who underwent either arthroscopic subtalar arthrodesis (ASTA) or arthroscopic ankle arthrodesis (AAA), James P. Tasto, MD, an orthopedist at San Diego Sports Medicine and Orthopaedic Center, and clinical professor at the University of California, San Diego, found that all 25 patients who received ASTA united by an average of 8.1 weeks postoperative. He also discovered no complications in this group.

His analysis of 60 patients who underwent AAA revealed four delayed unions and three nonunions. Patients took an average 10.8 weeks to fully heal, Tasto reported in his abstract. He told Orthopedics Today there was one major complication, a pulmonary embolism that occurred 3 weeks postoperative. Also, there were several minor problems that arose in the perioperative and postoperative periods, " ... which include two cases of fibular talar/calcaneal impingement and one patient with unexplained persistent pain in spite of a successful fusion," said Tasto, a member of the Orthopedics Today editorial board.

Patients experienced minimal pain in the immediate postoperative period, Tasto said in a presentation to the American Orthopaedic Foot and Ankle Society's 22nd Annual Summer Meeting.

Encourage use

"In general, the reduced morbidity and the positive outcomes that we have experienced with the arthroscopic approach should encourage the practitioner who is familiar with both arthroscopy and hindfoot disorders to look carefully at this technique and consider adopting it for selected cases," he said.

Tasto followed the subtalar cohort for a mean of 4.4 years (range 6 months to 13 years). The group included slightly more women and most of the cohort had preoperative diagnoses of post-traumatic arthritis or osteoarthritis. Similarly, the AAA group also had more women.

"In the AAA group, there were 55 [patients] with osteoarthritis, rheumatoid arthritis and post-traumatic arthritis, four with neurological defects and one [with] avascular necrosis," Tasto wrote in his abstract. He followed the AAA group for a mean of 5.1 years (range 6 months to 15 years).

Delayed unions, failures

Tasto said that the delayed and failed unions found in the AAA group were indicative of the patients' preoperative condition. "I'd say in general, those patients who had nonunion or delayed union presented the same problems preoperatively that they do with the open procedure," he said. "These would be smokers, [those with] avascular necrosis of the talus and neurological disorders as well as patients who are immunosuppressed. Those represent the failures and the delayed unions in the ankle arthrodesis population, where as we had no failures in the subtalar group."

The study highlights the success of ASTA, while showing better results with AAA compared to conventional open procedures.

He said he attributes the apparent high success rate for the arthroscopic approach to both the ankle and the subtalar joint to the ability to decorticate the affected surface and maintain the normal geometry, as well as preserving the blood supply with the microinvasive technique. "We also feel that the postoperative protocol of immediate weight-bearing has also aided in the rather rapid time until union and the overall union rate."

For more information:
Tasto JP. Arthroscopic ankle and subtalar arthrodeses: 14-year prospective study and follow-up. Presented at the American Orthopaedic Foot and Ankle Society 22nd Annual Summer Meeting. July 14-16, 2006. La Jolla, Calif.