Mini-incision Schwab grade 4 osteotomy combined with percutaneous pedicle screw fixation for old thoracolumbar compression fractures with kyphosis deformity

Objective To analyze the clinical results of mini-incision Schwab grade 4 osteotomy combined with percutaneous pedicle screw fixation for old thoracolumbar compression fractures combined with kyphosis deformity. Methods A retrospective case series study was made on 14 patients with old thoracolumbar compression fractures combined with thoracolumbar kyphosis undergone mini-incision Schwab grade 4 osteotomy plus percutaneous pedicle screw fixation from January 2014 to May 2015. There were 5 males and 9 females, with mean age of 64.5 years (range, 58-70 years). The period between injury and surgery ranged between 6 and 14 months (mean, 8.6 months). At the time of surgery, the fracture was already healed in 10 patients, while non-healing was found in other 4 patients. Preoperative visual analogue score (VAS) of back pain was (8.5±1.1)points (range, 6.5-10 points). Three patients were associated with neurological dysfunction [American Spinal Injury Association (ASIA) grade D]. Apex of kyphosis located at T12 in 6 patients and at L1 in 8 patients. Preoperative kyphosis Cobb angle was (42.5±6.0)°(range, 39.5°-47.2°). Operation time, blood loss, perioperative complications, postoperative kyphosis Cobb angle, bone fusion, state of implants, neurological function and VAS were determined. Results Operation time was (280±50)min, and blood loss was (110±70)ml. No segmental vessels injury, neurological deficit or dural disruption occurred during the surgery and after surgery. Compared to the preoperative detection, kyphosis Cobb angle was improved to (9.3±1.7)°(range, 6.2°-12.1°) after operation(P<0.05), with the correction rate of 78.1%. Post-operative CT showed 7 screws (6.3%, 7/112) were grade 1 screws. The follow-up was lasted for mean 25.2 months (range, 14-28.9 months). At the latest follow-up, the kyphosis Cobb angle was (9.6±4.1)°(range, 6.0°-13.1°), revealing no correction loss. Interbody bone fusion was good, with no instrumentation-related complications observed. Three patients with neurological dysfunction (ASIA grade D) were recovered to ASIA grade E. Compared to the preoperative detection, back pain was improved with the VAS of (2.6±1.0) points at the latest follow-up (P<0.05). Conclusion Mini-incision Schwab grade 4 osteotomy combined with percutaneous pedicle screw fixation of old thoracolumbar compression fractures with kyphosis deformity can attain satisfactory and reliable efficacy and bone fusion, with low incidence of complications. Key words: Spinal fractures; Thoracic vertebrae; Lumbar vertebrae; Kyphosis