Spine deformities in patients with Ehlers-Danlos syndrome, type IV - late results of surgical treatment

BACKGROUND Spinal deformities in Ehlers-Danlos syndrome are usually progressive and may require operative treatment. There is limited number of studies describing late results of surgery in this disease. METHODS This is a retrospective study of the records of 11 patients with Ehlers-Danlos syndrome type IV, treated surgically between 1990 and 2007. All patients underwent surgical treatment for spinal deformity. Duration of operation, type of instrumentation, intraoperative blood loss, complications and number of additional surgeries were noted. Radiographic measurement was performed on standing AP and lateral radiographs acquired before surgery, just after and at final follow up. RESULTS The mean follow up period was 5.5 ± 2.9 years (range 1-10 years). The mean preoperative thoracic and lumbar curve were 109.5 ± 19.9° (range 83° - 142°) and 75.6 ± 26.7° (range 40° - 108°) respectively. Posterior spine fusion alone was performed on 6 patients and combined anterior and posterior fusion (one- or two stage) on 5 cases. Posterior segmental spinal instrumentation was applied with use of hooks, screws and wires. The mean postoperative thoracic and lumbar curve improved to 79.3 ± 16.1° (range 56° - 105°) and 58.5 ± 27.7° (range 10° - 95°) respectively, with a slight loss of correction during follow up. The average thoracic and lumbar correction was 26.4 ± 14.9% (range 5.3 - 50.4%) and 26.3 ± 21.2% (range 7.9 - 75%). Postoperatively, the mean kyphosis was 79.5 ± 40.3° (range 21° -170°), and lordosis was 50.8 ± 18.6° (range 20° -79°). Hyperkyphosis increased during follow up while lordosis remained stable. Mean Th12-L2 angle was -3.5 ±9.9° (range -19° - 15°) postoperatively and did not change significantly during follow up. CONCLUSIONS Huge spinal deformities in patients with Ehlers-Danlos syndrome require complex and extensive surgery. There is a big risk of sagittal imbalance in this group.