Greater change in symptom score seen with arthroscopic ankle arthrodesis

Issue: July 2011

While a comparison of open and arthroscopic ankle arthrodesis showed that both techniques significantly diminished osteoarthritis symptoms in patients, the arthroscopic procedure demonstrated a significantly shorter length of stay and greater change from baseline arthritis scores.

“Minimally invasive techniques for foot and ankle surgery should be developed as they result in lower cost and better outcomes,” study investigator Alastair Younger, MD, FRCSC, told Orthopedics Today. He presented his team’s findings at the 2011 Annual Meeting of the Arthroscopy Association of North America.

Younger and his colleagues prospectively collected data from adult patients with isolated end-stage ankle arthritis who underwent ankle fusion at two institutions. The investigators excluded patients who had an infection, previous ankle or hindfoot fusion, and arthroplasty. Patients with significant deformities that needed corrective osteotomy or fusion in a joint other than the ankle, or those patients with arthritis in the triple joint complex were also excluded.

“For the purposes of the study, patients with concomitant ipsilateral hindfoot arthritis were only included if the ankle pathology alone required surgical intervention,” Younger said.

At one center, 30 ankles underwent open arthrodesis. At another institution, 30 ankles had an arthroscopic arthrodesis. The groups had a similar mean age and body mass index.

Sustained improvement

The investigators found that baseline ankle osteoarthritis scores (AOS) for the open group decreased from 56.8 to 33.5 at 1-year postoperatively and to 29.24 at 2-year follow-up. The arthroscopic group showed a significantly greater improvement from a baseline AOS of 56 points to 17.5 points at 1 year and 17.2 points at 2 years.

“We were surprised that the improvements were maintained in time,” Younger said. “We thought we might see a difference at 6 months, but we anticipated the results would be the same at 1 year. We expected that the only difference between the groups would be swelling, but there is clearly a longer term benefit that we have not been able to outline. We have looked at this also using our own isolated Vancouver data and the results bear up. It may be a selection bias, so a randomized clinical trial would be required to determine is this is upheld.”

Minimal complications

The arthroscopic group also showed a significantly shorter length of stay compared with the open group (2.5 days vs. 3.7 days). The study revealed no significant difference in tourniquet times between the groups (107 minutes vs. 99 minutes).

The open group had one non-union, which underwent a revision and successfully united. “There was one delayed wound healing in each group, and two further surgeries to remove symptomatic hardware in the arthroscopic group,” Younger said.

He noted that equipment needs to be developed to ensure that the arthroscopic procedure can be performed effectively.

“All of the instrumentation used is borrowed from other applications — the arthroscope was designed for the elbow, and the shavers were designed for the shoulder and the knee,” Younger said. – Gina Brockenbrough, MA

Reference:

Younger A, Townshend DN, Di Silvestro M, et al. Prospective comparison of open and arthroscopic ankle arthrodesis using validated outcome score with 2-year minimum follow-up. Paper #SS-55. Presented at the 2011 Annual Meeting of the Arthroscopy Association of North America. April 14-16. San Francisco.

Alastair Younger, MD, FRCSC, can be reached at Providence Health Care, 401-1160 Burrard St., Vancouver, BC V6Z 2E8, Canada; 604-683-3585; email: asyounger@shaw.ca.

Disclosure: Younger is a consultant for Linvatec, BioMimetic and SBI.