Surgical treatment of congenital kyphosis

Study Design. In this study, 26 cases of congenital kyphosis and kyphoscoli osis treated surgically were retrospectively reviewed. Objective. To assess the clinical outcomes and surgical indications for pos terior only versus anteroposterior surgery in the child. Summary of Background Data. Congenital kyphosis usually is progressive with out surgical intervention. Current recommended treatment includes posterior arthrodesis for deformities of less than 50 degrees to 60 degrees, and ant erior release or decompression, anterior fusion, and posterior instrumented arthrodesis for large deformities and cord compression. Methods. Cases involving myelodysplasia, spinal dysgenesis, and skeletal dy splasia were excluded from the study. Kyphoscoliosis was included if the ky photic deformity was greater than the scoliotic deformity. Patients were gr ouped by age and surgical technique. The patients in group P1 underwent pos terior arthrodesis at an age younger than 3 years, and those in group P2 un derwent the procedure at an age older than 3 years. The patients in group A P1 underwent anterior and posterior procedures at an age younger than 3 yea rs, and those in group AP2 underwent the procedures at an age older than 3 years. The preoperative deformity, complications, and postoperative deformi ty correction were analyzed. There were nine Type 1 (failure of formation), nine Type 2 (failure of segmentation), and eight Type 3 (mixed) deformitie s. Four patients had associated spinal dysraphism. Three patients with Type 1 deformities had clinical or radiographic evidence of cord compression. Results. In Group P1, five patients at an average age of 16 months underwen t posterior arthrodesis alone for an average kyphotic deformity of 49 degre es. The immediate postoperative correction improved over a period of 6 year s and 9 months by an additional 10 degrees, resulting in a final deformity of 26 degrees. Pseudarthrosis developed in two patients, requiring fusion m ass augmentation or anterior arthrodesis. Neither patient was instrumented. In Group P2, five patients at an average age of 13 years and 7 months unde rwent posterior arthrodesis with instrumentation for kyphotic deformity of 59 degrees. Approximately 30 degrees of intraoperative correction was achie ved safely using compression instrumentation and positioning. No further co rrection occurred with growth. The final residual kyphotic deformity was 29 degrees after a follow-up period of 4 years and 5 months. In Group AP1, se ven patients underwent anterior release or vertebra resection for deformity correction and posterior arthrodesis for an average kyphotic deformity of 480 at the age of 16 months. There were no iatrogenic neurologic injuries. The final residual kyphotic deformity was 22 degrees after a follow-up peri od of 6 years and 3 months. In Group AP2, nine patients underwent anterior release or decompression with posterior arthrodesis for kyphotic deformity of 77 degrees at the age of 11 years and 6 months. The deformity was correc ted to 37 degrees, with no significant loss over a follow-up period of 5 ye ars and 2 months. There were two postoperative neurologic complications. Conclusions. After reviewing their experience, the authors made the followi ng observations: 1) The pseudarthrosis rate was low even without routine au gmentation of fusion mass if instrumentation was used; 2) gradual correctio n of kyphosis may occur with growth in patients younger than 3 years with T ypes 2 and 3 deformities after posterior fusion, but appears to be unpredic table; 3) the risk of neurologic injury with anterior and posterior fusion for kyphotic deformity was associated with greater age, more severe deformi ty, and preexisting spinal cord compromise.