Sunday, October 25, 2009 - 10:05 AM

Treatment of Advanced-Stage Thumb Basal Joint Arthritis with Modified Thompson Technique Using APL Tendon: An Average 5.5-Year Follow-up

Mehdi N. Adham, MD, FACS, Andrew Kochevar, MD, and Michael F. Angel, MD.

Purpose Long-term (66-month) clinical results of trapeziectomy and ligament reconstruction using a modified Thompson technique with the APL tendon, have not been previously reported. Advantages of this technique include: retaining the FCR tendon as an important stabilizer of the wrist for pinch and grip functions, converting the APL tendon from a potential destabilizing to a stabilizing force, and avoidance of incisions on the flexor surface of the forearm.  The goal of this study was to evaluate the long-term clinical results of this technique with an average 5.5-year follow-up for the primary treatment of advanced-stage basal joint arthritis (Eaton stages III and IV).

Methods The senior author has performed 210 thumb basal joint arthroplasties using a modified Thompson technique. This was an independent pilot study to evaluate long-term results.  Twenty-five thumbs in 18 patients from a single surgeon's practice were evaluated after ligament reconstruction arthroplasty for surgical treatment of advanced thumb basal joint arthritis. Treatment consisted of piecemeal excision of the entire trapezium, ligament reconstruction and interposition using the APL tendon, and 8 weeks of K-wire immobilization of the thumb metacarpal. Patients were seen, examined, and queried regarding their thumbs.  Range of motion, lateral pinch, tip pinch, grip strength, and outcomes questionnaires including the Arthritis Impact Measurement Scales 2 Short Form (AIMS2-SF) were evaluated at an average of 66 months after surgery.

Results At 5.5 years follow-up, 17 of 18 patients (94%) experienced “excellent” or “good” relief of pain and were “very satisfied” with their operation(s).  Given identical preoperative circumstances, 18/18 (100%) patients would choose to have the operation again.  Range of motion evaluation showed 24 of 25 thumbs adducted fully into the plane of the palm and 24 of 25 opposed to the fifth metacarpal head.  Comparisons between preoperative and 66-month postoperative strength measurements demonstrated an average 13.8% increase in grip strength, 11.8% increase in key pinch strength, and a 6.3 % increase in tip pinch strength over preoperative values.  Postoperative AIMS2-SF data demonstrated improvement in “Hand and finger function” and “Arthritis pain” categories compared with preoperative levels.

Conclusions Trapezial excision and ligament reconstruction using a modified Thompson technique with the APL tendon restored a stable, pain-free thumb that yielded excellent strength and motion five and one-half years after the procedure. Compared with published reports of techniques that harvest all or part of FCR tendon, the modified Thompson technique retains the entire FCR tendon for continued wrist stability. In addition, this technique decreases the effect of APL tendon abduction force at the base of thumb metacarpal and contributes to greater joint stability.