Mid-term to long-term clinical and functional outcomes of minimally invasive correction and fusion for adults with scoliosis

Object. The goal of this study was to assess the operative outcomes of adult patients with scoliosis who were treated surgically with minimally invasive correction and fusion. Methods. This was a retrospective study of 28 consecutive patients who underwent minimally invasive correction and fusion over 3 or more levels for adult scoliosis. Hospital and office charts were reviewed for clinical data. Functional outcome data were collected at each visit and at the last follow-up through self-administered questionnaires. All radiological measurements were obtained using standardized computer measuring tools. Results. The mean age of the patients in the study was 67.7 years (range 22-81 years), with a mean follow-up time of 22 months (range 13-37 months). Estimated blood loss for anterior procedures (transpsoas discectomy and interbody fusions) was 241 ml (range 20-2000 ml). Estimated blood loss for posterior procedures, including L5-S1 transsacral interbody fusion (and in some cases L4-5 and L5-S1 transsacral interbody fusion) and percutaneous screw fixation, was 231 ml (range 50-400 ml). The mean operating time, which was recorded from incision time to closure, was 232 minutes (range 104-448 minutes) for the anterior procedures, and for posterior procedures it was 248 minutes (range 141-370 minutes). The mean length of hospital stay was 10 days (range 3-20 days). The pre-operative Cobb angle was 22 (range 15-62), which corrected to 7 (range 0-22). All patients maintained correction of their deformity and were noted to have solid arthrodesis on plain radiographs. This was further confirmed on CT scans in 21 patients. The mean preoperative visual analog scale and treatment intensity scale scores were 7.05 and 53.5; postoperatively these were 3.03 and 25.88, respectively. The mean preoperative 36-Item Short Form Health Survey and Oswestry Disability Index scores were 55.73 and 39.13; postoperatively they were 61.50 and 7, respectively. In terms of major complications, 2 patients had quadriceps palsies from which they recovered within 6 months, 1 sustained a retrocapsular renal hematoma, and 1 patient had an unrelated cerebellar hemorrhage. Conclusions. Minimally invasive surgical correction of adult scoliosis results in mid-to long-term outcomes similar to traditional surgical approaches. Whereas operating times are comparable to those achieved with open approaches, blood loss and morbidity appear to be significantly lower in patients undergoing minimally invasive deformity correction. This approach may be particularly useful in the elderly. (DOI: 10.3171/2010.1.FOCUS09272)