Lumbar osteotomy for correction of thoracolumbar kyphotic deformity in ankylosing spondylitis. A structured review of three methods of treatment

OBJECTIVES Three operative techniques have been described to correct thoracolumbar kyphotic deformity (TLKD) resulting from ankylosing spondylitis (AS) at the level of the lumbar spine: opening wedge osteotomy, polysegmental wedge osteotomies, and closing wedge osteotomy. Little knowledge exists on the indication for, and outcome of these corrective lumbar osteotomies. METHODS A structured review of the medical literature was performed. RESULTS A search of the literature revealed 856 patients reported in 41 articles published between 1945 and 1998. The mean age at time of operation was 41 years, male-female ratio 7.5 to 1. In 451 patients an open wedge osteotomy was performed. Polysegmental wedge osteotomies were performed in 249 patients and a closing wedge osteotomy in 156 patients. Most of the studies primarily focus on the surgical technique. Technical outcome data were poorly reported. Sixteen reports, including 523 patients, met the inclusion criteria of this study, and could be analysed for technical outcome data. The average correction achieved with each surgical techniques ranged from 37 to 40 degrees. Loss of correction was mainly reported in patients treated by open wedge osteotomy and polysegmental wedge osteotomies. Neurological complications were reported in all three techniques. The perioperative mortality was 4%. Pulmonary, cardiac and intestinal problems were found to be the major cause of fatal complications. CONCLUSION Lumbar osteotomy for correction of TLKD resulting from AS is a major surgery. The indication for these lumbar osteotomies as well as the degree of correction in the lumbar spine has not yet been established. Furthermore, there is a need for a generally accepted clinical score that encompasses accurate preoperative and postoperative assessment of the spinal deformity. The results of this review suggest that the data from the literature are not suitable for decision making with regard to surgical treatment of TLKD resulting from AS.