Kyphosis one level above the cervical disc disease: is the kyphosis cause or effect?

If present, kyphotic angulation is generally at the level of the cervical disc disease (CDD) in the neck, but sometimes occurs at one level above the CDD. We name this situation as kyphosis one level above (KOLA). KOLA CDD has not been studied previously. In this study, we present 18 patients who had KOLA among 147 patients operated for CDD over a 5-year period. Seven of these 18 patients also received surgery for their KOLA. As new, surgical treatment of kyphotic level was performed with plating and without bony fusion in 5 patients. Clinical outcomes (according to Odom's criteria) and kyphotic corrections of KOLA patients receiving and not receiving surgery for their kyphosis during were compared. The 7 KOLA patients having surgery to correct the kyphosis had a mean 20.14+/-3.13 degrees correction in their kyphosis (from mean 12.85 to -7.28 degrees), whereas the 11 patients undergoing surgery only for CDD showed only a mean 3.00+/-2.52 degrees correction (from mean 7.45 to 4.45 degrees). When kyphotic corrections were compared, statistically significant difference was found between 2 groups (P<0.01). Clinical outcome scores showed a trend towards improvement in the patients operated upon for kyphosis correction. KOLA may be a factor in the development of cervical disc herniation and spondylosis, and should be treated if more than 11 degrees. In cervical region, upper adjacent level disease may be an extension of KOLA. Larger studies can further define the relationship between KOLA and CDD, and indications for surgical correction of KOLA.