Burt Yaszay

Preservation of thoracic kyphosis is critical to maintain lumbar lordosis in the surgical treatment of adolescent idiopathic scoliosis.

Study Design. Retrospective analysis of prospectively collected multicenter series. Objective. To evaluate the sagittal profile of surgically treated adolescent idiopathic scoliosis (AIS) patients. Summary of Background Data. With the increasing popularity of segmental pedicle screw spinal instrumentation, thoracic kyphosis (TK) is often sacrificed to achieve coronal and axial plane correction. Methods. Radiographs of AIS patients with a Lenke type 1 deformity and minimum 2-year follow-up after selective thoracic fusion (lowest instrumented vertebra of T11, T12, or L1) were evaluated. Changes in TK were correlated with changes in lumbar lordosis (LL). Patients were divided according to approach (open/thoracoscopic anterior vs. posterior). Analysis of variance was used to compare pre and postoperative radiographic measures. Results. Two hundred fifty-one patients (age: 14 ± 2 years) were included. Sixty seven percentages of the patients had anterior surgery (97 open anterior, 71 thoracoscopic) and 33% (83 patients) had posterior spinal fusion. A decrease in postoperative TK was significantly correlated (P ≤ 0.001) with a decrease in LL at first erect (r = 0.3), 1 year (r = 0.4) and 2 years (r = 0.4), independent of surgical approach. LL decreased significantly at the first erect regardless of approach (P = 0.003); however, at 2-year postoperative TK and LL were significantly decreased after a posterior approach (P ≤ 0.001) when compared with an anterior approach that added kyphosis. The decrease in LL (5.6° ± 9.7°) was nearly twice the decrease in TK (2.8° ± 11.4°) in the posterior group at 2-years. Conclusion. Given that thoracic AIS is often associated with a preexisting reduction in TK, ideal surgical correction should address this deformity. Procedures which further reduce TK also reduce LL. It is unclear if the loss of LL from thoracic scoliosis correction will compound the loss of LL that occurs with age and lead to further decline in sagittal balance. With this concern, we recommend a posterior column lengthening and/or an anterior column shortening to achieve restoration of normal TK and maximal LL.

Innovation in growing rod technique: a study of safety and efficacy of a magnetically controlled growing rod in a porcine model.

Study Design. Prospective in vivo randomized study. Objective. To evaluate the safety and efficacy of a distraction-based magnetically controlled growing rod (MCGR) in a porcine model. Summary of Background Data. A high number of complications related to frequent surgical rod lengthenings has been a generally accepted outcome in growing rod surgery for early-onset scoliosis. A potentially safer technique is a system that does not require repetitive surgery. Methods. Seven-month-old pigs were randomly assigned to an experiment group (EG; n = 6) and a sham group (SG; n = 3). One animal in the EG became paralyzed because of a misplaced pedicle screw and was killed per the study protocol. Therefore, a total of 8 animals completed the study. The EG underwent weekly spine distraction using the MCGR. Spinal height was assessed by vertebral unit height measurements on weekly lateral radiographs. Results. A total of 49 mm of distraction across the unfused vertebral levels was planned during a 7-week period (7 mm per wk). Radiographical analysis of the MCGR device revealed an average distraction of 39 mm (range, 32–46 mm), resulting in achievement of 80% of predicted spinal height. Prior to removal of implants, spinal height for the EG was similar to the SG. However, accelerated increase in vertebral unit height was noted in the EG during the 3-week period after implant removal, which resulted in significantly greater overall spinal height in the EG (32.2% vs. 11.7%, P ⩽ 0.05). No MCGR-related complications occurred. Conclusion. The MCGR provided 80% of predicted spinal height by noninvasive remote distraction in this animal model. The accelerated increase in spinal height of the experimental animals after implant removal was an unexpected finding which requires additional research to better understand the effect of distraction on spinal growth. This study establishes a foundation for future research in an attempt to use a less invasive technique in distraction-based correction of early-onset scoliosis.

Are antifibrinolytics helpful in decreasing blood loss and transfusions during spinal fusion surgery in children with cerebral palsy scoliosis

Study Design. Therapeutic comparative study. Objective. To evaluate the safety and efficacy of antifibrinolytic (AF) agents in reducing blood loss and transfusions during posterior spinal fusion (PSF) in children with cerebral palsy (CP) scoliosis. Summary of Background Data. Scoliosis surgery in CP children is associated with substantial blood loss. Few reports on the role of AFs exist. Methods. A multicenter, retrospective review of a prospectively collected database of 84 consecutively enrolled patients with CF (age < 18 years) with spinal deformity who underwent PSF and instrumentation. The use of AFs, tranexamic acid (TXA), epsilon-aminocaproic acid (EACA), or none was based on the surgeon preference. Estimated blood loss (EBL), transfusion requirements, and length of stay were recorded. Analysis was performed with the independent-samples t test and 1-way analysis of variance with post hoc Bonferroni analysis. Results. The average age at the time of surgery was 14.4 ± 2.6 years. The groups were well matched in preoperative major deformity, age, levels fused, and operating time. Forty-four patients received AFs (30 TXA and 14 EACA), and 40 received no antifibrinolytics (NAF). The EBL averaged 1684 mL for the AFs group and 2685 mL for the NAF group (P = 0.002). There was more cell salvage transfusion in the NAF group. No significant differences were found in total transfusion requirements. There was a trend for decreased hospital stay in the AFs group. No adverse effects were seen. On comparison of the 3 groups (NAF, TXA, and EACA), a significant difference was observed between the TXA and the other groups with respect to EBL and cell salvage transfusion. Conclusion. AFs significantly reduced intraoperative EBL associated with PSF, with no adverse effects; however, we could not demonstrate significant differences in total transfusion, except in cell salvage. TXA was more effective than EACA in decreasing the EBL and cell salvage transfusion.

Which Lenke 1a Curves Are at the Greatest Risk for Adding-on... and Why?

Study Design. Multicenter review of prospectively collected data. Objective. The purpose of this study was to evaluate the incidence of distal adding-on and associated risk factors in each of the 2 Lenke 1A curve patterns. Summary of Background Data. Previous work has demonstrated 2 distinct Lenke 1A curve patterns on the basis of the tilt of L4 (1A-L and 1A-R) that are different in form and treatment. Methods. A query of a prospective multicenter adolescent idiopathic scoliosis database identified 195 patients with Lenke 1A curves. Patients were grouped on the basis of the direction of the L4 vertebral tilt: 1A-L (left) and 1A-R (right). The incidences as well as clinical and radiographical risk factors for adding-on were identified for each group. Adding-on was defined as an increase in the Cobb angle of at least 5° and distalization of the end vertebra of the thoracic curve or a change in disc angulation of 5° or greater below the lowest instrumented vertebra from the first erect to 2-year postoperative radiographs. Results. Forty (21%) patients met the criteria for adding-on. The average increase in Cobb angle was 11.9° for those categorized as having adding-on compared with 3.8° in the non–adding-on group. Lenke 1A-R curves were 2.2 times more likely to experience adding-on than 1A-L curves. In the 1A-R curves, patients who added-on were fused at an average of 1.6 levels proximal to the neutral vertebra versus an average of 0.9 levels proximal to the neutral vertebra for the patients who did not add-on (P = 0.023). Patients who added-on were fused at an average of 2.5 levels above stable versus 2.1 levels above stable in those who did not (P = 0.06). Age and skeletal maturity were not identified as risk factors in the 1A-R curves. In 1A-L curves, younger (12.7 vs. 14.7 yr, P = 0.002) and less skeletally mature patients based on Risser grading (70% vs. 14% Risser 0, P = 0.004) were more likely to experience adding-on. Conclusion. Understanding the difference between Lenke 1A-L and 1A-R curve types may be helpful in preventing the adding-on phenomena postoperatively. To prevent adding-on in 1A-R curves, we recommend fusing distally to 1 level above the neutral vertebra or 1 to 2 levels above the stable vertebra. In 1A-L curves, adding-on may simply be a need to balance some lumbar curve progression in a young, skeletally immature patient.

Adolescent idiopathic scoliosis: should 100% correction be the goal?

IntroductionWhat constitutes optimal thoracic curve scoliosis correction is controversial. The development and application of powerful pedicle screw-aided instrumentation constructs has, in some cases, led to hypercorrection of the thoracic scoliosis with resulting coronal imbalance, trunk shift, and shoulder imbalance. The purpose of this study was to compare the clinical and radiographic outcomes between Lenke 1 patients with the highest and lowest degree of correction to assess this risk. Our hypothesis was that greater scoliosis curve correction can be done without producing secondary decompensation. MethodsUsing a prospective AIS database, Lenke 1 curves, with 2-year follow-up (n=385) were ranked by percent coronal correction. The top 15% or high correction group (>80% coronal correction) were compared with the bottom 15% or low correction group (<40% coronal correction). Clinical and radiographic outcomes, including parameters of coronal and sagittal balance, were compared using ANOVA and &khgr;2 tests (P⩽0.007). ResultsThe high correction group (n=39) and the low correction group (n=40) did not differ preoperatively except in lumbar flexibility. In the coronal plane, the high correction group did not show postoperative clinical imbalance (trunk shift and shoulder height) and had better radiographic balance (C7-CSVL shift). The deformity-flexibility quotient (DFQ), which is the ratio of residual lumbar curve to remaining unfused lumbar segments, was lower (optimal) in the high correction group. The residual rib hump was also better. In the sagittal plane, the high correction group had less kyphosis secondary to a loss of kyphosis compared with a gain (improvement) in the low correction group. Despite these differences, SRS scores were not different. ConclusionsMaximizing Lenke 1 curve correction to achieve greater lumbar correction and improved clinical appearance can be done without compromising coronal balance but may occur at the expense of sagittal alignment. However, surgeons who are learning to apply powerful new corrective methods should be cautious in trying to obtain full correction. Proper preoperative evaluation, fusion level selection, and surgical technique are needed to attain this outcome.

Efficacy of hemivertebra resection for congenital scoliosis: a multicenter retrospective comparison of three surgical techniques.

Study Design. Multicenter, retrospective study. Objective. To compare the outcomes of three surgical treatments for congenital spinal deformity due to a hemivertebra. Summary of Background Data. Congenital anomalies of the spine can cause significant and progressive scoliosis and kyphosis. Their management may be challenging and controversy remains over the “best” surgical treatment. Methods. A multicenter retrospective study of patients with congenital spinal deformity due to 1 or 2 level hemivertebra(e) was performed. The surgical treatments included hemiepiphysiodesis or in situ fusion (group 1), instrumented fusion without hemivertebra excision (group 2), or instrumented hemivertebra excision (group 3). Results. Seventy-six patients with minimum 2-year follow-up were evaluated. The mean age was 8 years (range: 1–18). The hemivertebra were fully segmented, nonincarcerated (67%), incarcerated (1%), and semisegmented (32%). There were 65 patients with single hemivertebra and 11 patients with double hemivertebra. There were 14 (18.4%) group 1, 20 (26.3%) group 2, and 42 (55.3%) group 3 patients. Group 1 (37 ± 14°) and group 3 (35 ± 26°) patients had smaller preoperative curves than group 2 patients (55 ± 26°) (P < 0.01). Group 3 had better percent correction at 2 years than groups 1 and 2 (P < 0.001). Group 3 had shorter fusion (P = 0.001), less estimated blood loss (EBL, P = 0.03), and a trend toward shorter operative times than group 2 (P = 0.10). The overall complication rate for the entire group was 30% group 1 (23%), group 2 (17%), and group 3 (44%) (P = 0.09). Conclusion. While hemivertebra resection for congenital scoliosis had a higher complication rate than either hemiepiphysiodesis/in situ fusion or instrumentated fusion without resection, posterior hemivertebra resection in younger patients resulted in better percent correction than the other two techniques.

The effect of surgical approaches on pulmonary function in adolescent idiopathic scoliosis.

Study Design Retrospective study. Objective To evaluate the effects of 4 surgical approaches for adolescent idiopathic scoliosis on pulmonary function and document their trend across a 2-year period. Summary of Background Data Understanding the effects of surgical approaches on pulmonary function is critical in the treatment of adolescent idiopathic scoliosis. Depending on the surgical approach, studies have demonstrated improvement, decline, or no effect on pulmonary function. Methods Sixty-one patients were evaluated for vital capacity (VC) and peak flow (PF) before and following surgery at 1, 3, 6, 12, and 24 months. Patients were separated into the following groups: group 1—posterior fusion only, group 2—posterior fusion with thoracoplasty, group 3—thoracoscopic anterior fusion, group 4—open anterior thoracolumbar fusion. Results Between groups, no difference was found in age, preoperative curve magnitude, percent curve correction or baseline VC and PF. At 1-month postoperatively, group 3 had lower VC than group 1 (P<0.01). After 1 month, no difference was seen between groups. Compared with before surgery, group 2 demonstrated a significant decline in VC and PF at 1 month and returned to baseline at 3 months (P<0.01). Group 3 had a significant decline in VC and PF at 1, 3, and 6 months whereas group 4 had a decline in VC at 1 month (P<0.01). Conclusions Scoliosis approaches that violate the chest wall demonstrate a significant decline in postoperative pulmonary function. Documented return of pulmonary function did not occur until 3 months for posterior fusion with thoracoplasty, 3 months for open anterior fusion and 1 year for video-assisted thoracoscopic surgery.

Special article: Update on the magnetically controlled growing rod: tips and pitfalls.

Magnetically controlled growing rods (MCGR) have become an important treatment option in young patients with spinal deformities. This device allows for gradual lengthening on an outpatient setting with continuous neurological monitoring in an awake patient. With its growing popularity and interest, this study reports the tips, pitfalls, and complications of the MCGR for management of scoliosis. On 3 June 2015 at the University of Hong Kong, 32 participants from 16 regions shared their experience with MCGR. Current indications for surgery include early-onset scoliosis patients. Adolescent idiopathic scoliosis and congenital scoliosis patients have less favourable outcomes. The number of instrumented levels should be minimised, as all instrumented levels must be included in the definitive fusion surgery. Rod contouring is important and owing to the straight portion of the rod housing the magnet, there is limited proximal rod portion for proper contouring, which may predispose to proximal junctional kyphosis. There is currently no consensus on the rod configuration, timing, frequency, technique, and amount of distraction. Risk factors for distraction failure include larger patients, internal magnets too close to each other, and magnets too close to the apex of the major curve. Future studies should resolve the issues regarding the technique of distraction, optimal frequency and amount of distraction per session. More comprehensive cost analyses should be performed.

Surgical treatment of Lenke 1 main thoracic idiopathic scoliosis: results of a prospective, multicenter study.

Study Design. Prospective, consecutive, nonrandomized, multicenter study. Objective. The purpose of this study was to compare the outcomes of idiopathic scoliosis treatment for Lenke 1 curves with 3 treatment approaches. Summary of Background Data. Surgical treatment options for Lenke 1 or primary main thoracic curve pattern in adolescent idiopathic scoliosis include thoracoscopic anterior spinal fusion, open anterior spinal fusion, and posterior spinal fusion (PSF) and instrumentation procedures. Methods. This was a prospective, consecutive, nonrandomized, multicenter study of surgical correction in adolescent idiopathic scoliosis. Patients with Lenke type 1 curve patterns from 7 sites were enrolled in this minimum 2-year follow-up study. Changes in pre- to postoperative radiographs, pulmonary function tests, Scoliosis Research Society questionnaire scores, and trunk rotation measures were compared. Results. A total of 149 patients (age: 14.5 ± 2 yr) were included (91% follow-up at 2 yr). The 3 groups were similar preoperatively in thoracic and lumbar curve size. There were 55 patients with thoracoscopic anterior spinal fusion, 17 patients with open anterior spinal fusion, and 64 patients with PSF. The fusion included on average 3 to 4 more levels in PSF than the 2 anterior approaches (P ⩽ 0.001). Surgical time tended to be greater in the anterior groups by approximately 2 to 3 hours; however, blood loss was greatest with PSF. At 2 years, all 3 approaches showed similar improvements in the thoracic Cobb angle, coronal balance, the lumbar Cobb angle, Scoliosis Research Society questionnaire scores, and trunk rotation measures. The PSF approach resulted in overall reduction in kyphosis compared with the anterior approaches. Postoperative hyperkyphosis was an issue only in the 2 anterior groups. Major complication rates were similar. Conclusion. All 3 approaches resulted in similarly satisfactory outcomes for the majority of patients with specific advantages to each technique. The patients with PSF had more levels fused, yet with the shortest operative time. The thoracoscopic anterior spinal fusion group had the smallest incisions and the lowest requirement for transfusion. The open anterior spinal fusion group had a modest loss of pulmonary function without any clear advantages compared with the other 2 groups. Level of Evidence: 2

ACGME core competencies: Where are we?

Beginning in July 2002, the Accreditation Council for Graduate Medical Education (ACGME) instructed all residency programs to require their residents to demonstrate competency in 6 core areas: patient care, interpersonal and communication skills, medical knowledge, professionalism, practice-based learning, and systems-based practice. The goal was to have objective markers of performance that would serve as a gauge to determine a programs accreditation. To determine the experiences of orthopedic residency programs with regard to the ACGMEs core competencies, a national survey was administered to orthopedic program directors and selected orthopedic residents. Of those orthopedic programs that responded, most appeared to be complying with the ACGME requirements. Both directors and residents thought patient care and medical knowledge ranked most important, while practice-based learning and systems-based practice were assigned the lowest ranks. Barriers to implementation of the core competencies included low priority compared with clinical duties, lack of faculty or resident education, and lack of formal orthopedic core competencies. Residents and program directors agreed that their programs would benefit from a definition of each of the core competencies, including a greater commitment to the processes involved in surgical procedures. This study demonstrated a commitment to the core competencies by the programs that responded. The survey also suggested this commitment would be aided by improved definitions of some of the competencies for the orthopedic resident.