Scoliosis is a three-dimensional deformity (coronal, axial, and sagittal), so it makes sense that a 3-D imaging method for evaluating the condition and measuring the impact of surgical correction would outperform traditional two-dimensional imaging techniques. That’s exactly what Newton et al. found in their Level II diagnostic study in the October 21, 2015 edition of The Journal of Bone & Joint Surgery.
The authors analyzed 3-D and 2-D images from 120 patients with adolescent idiopathic scoliosis (AIS), before and after surgery with segmented thoracic pedicle-screw instrumentation. The mean preoperative Cobb angle on the standard 2-D view was 55° ± 10°, while on the 3-D view it was 52° ± 9° (p ≤ 0.001). The mean T5-T12 kyphosis on the 2-D view measured 18° ± 13° preoperatively and 27° ± 6° postoperatively, while the mean T5-T12 kyphosis on the 3-D view measured 6° ± 14° preoperatively and 26° ± 6° postoperatively. The difference between the 2-D and 3-D measurements of T5-T12 kyphosis strongly correlated with apical vertebral rotation.
The significant preoperative overrepresentation of the T5-T12 kyphosis on standard 2-D imaging compared with 3-D assessments led the authors to conclude that “the sagittal profile evaluated by the standard lateral view is unreliable and often results in a false sense of thoracic kyphosis.” They go on to claim that “measurement with the 3-D, segmental local vertebral approach can be a useful, surgeon-oriented method for evaluating the deformity of scoliosis as well as the correction associated with surgical treatment.”
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Here is a summary of selected findings from Level I and II studies cited in the June 17, 2015 Specialty Update on spine surgery:
- A database study to determine the prevalence of venous thromboembolic events after spinal fusion found that risk factors for such events included hypercoagulability, certain medical comorbidities, older age, and male sex.
- An RCT comparing allograft alone versus allograft plus bone marrow concentrate to accomplish spine fusion in adults with spondylolisthesis found very poor union rates in both groups, although allograft with bone marrow concentrate delivered slightly better results.
- A meta-analysis of five studies (253 patients) found no pain or functional differences when unilateral percutaneous kyphoplasty was compared with bilateral (same-vertebra) kyphoplasty for osteoporotic compression fractures. The unilateral approach was associated with shorter operative times, however.
- An RCT comparing the analgesic efficacy and clinical utility of gabapentin, pregabalin, and placebo in patients undergoing spinal surgery found that pregabalin outperformed the other two interventions immediately after surgery postoperative and up to three months postoperatively.
- In an RCT comparing open-door to French-door laminoplasty for cervical compressive myelopathy, both techniques were found to be equivalent in terms of neurological recovery and perioperative complications, but patients receiving the open-door technique had more kyphosis and less cervical range of motion postoperatively.
- An update to a 2002 Cochrane review found no significant outcome differences between supervised and home-exercise rehabilitation programs after lumbar disc surgery.
- A systematic review/meta-analysis showed that radiofrequency denervation of facet joints is more effective than placebo in achieving functional improvement and pain control in patients with chronic low back pain.
- A Level II diagnostic study concluded that with a magnification of 150% and a good pair of flexion and extension radiographs following anterior cervical arthrodesis, pseudarthrosis was noted with >1 mm of motion between fused interspinous processes with 96.1% specificity and a positive predictive value of 96.9%.
- A Level I therapeutic study comparing the efficacy of intravenous tranexamic acid, epsilon-aminocaproic acid, and placebo to reduce bleeding in 125 adolescent patients undergoing posterior fusion for idiopathic scoliosis found less intraoperative and postoperative blood loss and higher hematocrit levels with the antifibrinolytics than with placebo. However, transfusion requirements were no different between the groups.
- A randomized comparison of navigated versus freehand techniques for pedicle screw insertion during lumbar procedures found that surgeon radiation exposure with freehand technique is up to 10 times greater than with use of navigation.