Patients often ask when they will be able to resume keyboard activity following carpal tunnel release (CTR). Until now, there has been no evidence to support any estimate.
Investigators at Vanderbilt University in Nashville screened nearly 400 patients with CTS and excluded many because of nonsurgical management, other upper extremity pathology, age less than 20 or greater than 70 years, previous carpal tunnel surgery, difficulty with English, or no home computer access to the Internet. Those included all has positive electrodiagnostic testing and typed at least 30 words per minute (wpm) using both hands with fingers resting on the middle row of home keys. Slow typing, unconventional finger positioning, or disinterest in participating left 38 subjects, 11 of whom during the study period either did not have surgery or had bilateral CTR.
The final 27 subjects took one of 10 forms of a standardized 500-character typing test at home before CTR and then took other forms of the same test on the same computer 8-10 days after surgery and again 2, 3, 4, 5, 6, 8, and 12 weeks after surgery. In addition, the subjects completed on-line the Michigan Hand Questionnaire and the Boston Carpal Tunnel Questionnaire (functional and symptom severity components) before surgery, 8-10 days after surgery and again 3, 6, and 12 weeks after surgery.
Each patient underwent open CTR and wore a soft dressing until sutures were removed 8-10 days later. As needed, the investigators contacted patients by phone and reminded them to take the tests at the defined intervals. The typing tests were electronically graded for speed and accuracy. Continue reading …
RESULTS: Average age was 55, 89% were women, 7% were worker compensation cases, 96% were right-hand dominant, and 67% had the right hand operated on. Daily computer use was less than 4 hours in 33%, 4-6 hours in 26%, and greater than 6 hours in 41% of patients.
Average typing speed before surgery was 50 wpm and was 45 wpm 8-10 days later. By 3 weeks after surgery, average typing speed exceeded pre-operative values and continued to improve to nearly 54 wpm at 12 weeks. Typing accuracy remained between 92 and 94% at all time periods. Variations in age, symptom duration, or electrodiagnostic severity did not affect results. The investigators felt that smoking and worker compensation status might affect results, but the numbers were too small (wc =2, smoking = 1) to pursue analysis.
The outcomes measures all showed continued improvement throughout the study period and paralleled the improvement in typing speed.
DISCUSSION: We can now tell patients that on average their typing speed and accuracy will at least equal pre-operative levels within 3 weeks of open CTR. The study focused on peak typing performance and not on endurance or return to work, so individual patients, particularly those with jobs requiring sustained keyboard activity, may require a longer convalescence or may not meet the reported averages.
Average typing speed at 12 weeks exceeded the pre-operative speed, which implies that CTS may impair typing performance.
COMMENT: I liked this study. It was carefully designed and performed. The novel use of home testing and internet reporting facilitated frequent, consistent, and compliant testing for each patient. I suspect we will see more of this type of testing because study subjects frequently become weary of returning to clinic for follow-up testing, especially if they are doing well and a return visit conflicts with their routine activities.
The study did not include patients who did not have electrodiagnostic testing or who had negative testing, and follow-on studies could appropriately look at those groups. Likewise, it would be interesting to observe typing performance in patients with CTS before and after non-operative management with orthoses with or without cortisone injections.