Open versus endoscopic carpal tunnel release: a decision analysis

The endoscopic technique for the surgical treatment of carpal tunnel syndrome was developed to decrease postoperative morbidity and accelerate a patient's return to normal activities and work. We used the methods of decision analysis to compare the total cost of the open versus the endoscopic technique. We adopted a societal perspective and included estimates of the costs of medical procedures and complications, as well as lost wages. Our base case analysis showed that the 2 techniques have similar total costs, given the assumptions of our model. The endoscopic approach is more costly if the complication rate of endoscopic surgery exceeds 6.2% (base case estimate, 5.0%). The endoscopic technique is more costly if the risk of career ending injury exceeds 0.001 (base case estimate, 0.0004) and if the average work absence following a complication exceeds 15.5 months (base case estimate, 12 months). In addition, the endoscopic technique is more costly if the difference between the 2 techniques in mean time to return to work is less than 21 days (base case estimate, 26 days). These findings have different implications for recipients and non-recipients of workers' compensation. If endoscopically treated patients return to work an average of 42 days faster than patients treated with the open technique (24 days vs 66 days), as was documented for non-recipients of workers' compensation in one large study, the endoscopic strategy would be less costly ($5,599 for endoscopic release vs $7,340 for open surgery). If endoscopically treated patients return to work an average of just 10 days sooner (103 days vs 113 days), however, as was documented for workers' compensation recipients in the same study, the open technique would be less costly ($11,353 for open release vs $11,959 for the endoscopic technique). The relative costs are not sensitive to the direct medical costs of complications. These findings allow prediction of the costs of endoscopic and open surgery under a range of assumptions concerning key parameters. The analyses also emphasize the need for more precise data on risks and costs of surgical treatments for carpal tunnel syndrome.