Use of the Accordion Severity Grading System for negative outcomes of carpal tunnel syndrome.

A universal classification of the negative outcomes of carpal tunnel release surgery does not, as yet, exist. In order to avoid the use of arbitrary factors we have applied the Accordion Severity Grading System, which uses rigorously defined qualitative terms to classify complications. It also provides a uniform manner for grading the severity of complications, enabling outcome comparisons between centres. We analysed the negative outcomes of 500 device-assisted carpal tunnel releases performed over a 2-year period in the author's department. In order to establish a standardised list of complications we used the terms employed within the guidelines of the American Academy of Orthopaedic Surgeons. Most of these terms were subsequently defined using the data variables and definitions taken from the American College of Surgeons National Surgical Quality Improvement Program or the Medical Subject Headings of the National Library of Medicine. We also adopted the quantitative severity weighting, as proposed by the Accordion system, in order to determine the postoperative morbidity index for our assisted carpal tunnel releases. The most common complications were pain and reversible damage to peripheral nerves. Other common negative events, other than complications, included hand weakness, which we classified as a sequela of the procedure, and incomplete retinaculum release, which we classified as failure to cure. The overall postoperative morbidity index for complications was 0.014. Although the Accordion system was developed for more complex procedures, it may also be adopted for carpal tunnel release surgery where it provides an objective and universal method for the classification of complications.