Arthroscopic technique effective for thumb arthritis at two years

Arthroscopic hemitrapeziectomy may speed postop recovery, reduce scarring and joint contracture, and help preserve joint stability.

An arthroscopic surgical technique can effectively treat carpometacarpal joint arthritis, at least over the short-term.

In a prospective study, Scott G. Edwards, MD, found that patients maintained significant improvements in pain and function over two years follow-up. However, additional follow-up is required to determine the long-term efficacy of the procedure compared to more traditional open procedures, he noted.

According to Edwards, arthroscopic hemitrapeziectomy has several proposed advantages over those traditional techniques, including the following:

faster postop recovery;
less scarring; and
less joint contracture.

It can also help preserve joint stability while reducing the risk of neurovascular injury and thumb column height subsidence, “which some would argue can lead to less deformity and weakness,” he said. However, these are all hypothetical advantages and have not been proven, he noted.

Edwards is an orthopedic surgeon and chief of elbow and hand surgery at Georgetown University Hospital in Washington, D.C. He evaluated the subjective and objective outcomes of thumb carpometacarpal arthritis in 15 patients treated using arthroscopic hemitrapeziectomy. The study excluded patients with excessive thumb metacarpalphalangeal joint hyperextension and those with obvious pantrapezial degeneration.

“Pretty much anyone else was included, including patients with subchondral cysts, subluxation, mild scaphotrapezoid-trapezia (STT) degeneration and workmen’s compensation patients,” said Edwards, who presented the results at the Joint American Society for Surgery of the Hand/American Society for Hand Therapists Annual Meeting in San Antonio.

Arthroscopic technique

The surgical technique involved a 1.9 mm arthroscope inserted through portals on either side of the first dorsal compartment. After removing any synovitis and loose bodies, the surgeon then removed 4 mm of the distal portion of the trapezial with a burr, Edwards said.

“In our study, we also utilized thermal capsular shrinkage and tightened the remaining capsule. We then pinned it in anatomic reduction, not in distraction,” he added.

Postoperatively, patients followed a protocol similar to those used following more traditional open techniques — six weeks of immobilization followed by six weeks of physical therapy, according to the study abstract.

Results maintained at two years

Following surgery, proximal migration of the first metacarpal averaged 3 mm, or about 15% of the trapezial space. Average first metarcarpal translation also decreased to 10 mm from 30 mm preoperatively, Edwards said.

At 12 weeks follow-up, the mean Disabilities of the Arm Shoulder and Hand (DASH) score dramatically improved to 9.6 from 60.8 at preop. Grip and pinch strengths also improved, although to a lesser degree. At 12 weeks, grip strength increased an average of 15 pounds and pinch strength improved an average of 3 pounds, according to the abstract.

Wrist and digital motion did not change from preoperative measurements. Additionally, opposition to the fifth metacarpal head decreased an average 15 mm from preop, according to the abstract.

At two years follow-up, all patients maintained their improvements, Edwards noted. Additionally, over 90% of patients reported being either pleased or satisfied with the procedure, and all patients were pleased with their cosmetic results, he added.

One patient experienced a symptomatic neuroma caused by pin placement. No patients had any other complications, and no revision surgeries were required.

“This is a safe technique and is best suited for patients with isolated trapeziometacarpal arthritis,” Edwards said, adding that mild STT involvement is not necessarily a contraindication.

“Patients can expect a significant increase in function and a decrease in pain within the first three months, and these results can be expected to hold firm over the first two years,” he said.

For more information:

Edwards SG. Prospective outcomes of thumb carpometacarpal (CMC) arthritis treated with arthroscopic hemitrapeziectomy: Minimum follow-up of two years. #PAS20. Presented at the Joint Annual ASSH/ASHT Meeting. Sept. 22-24, 2005. San Antonio, Texas.