Scheuermann’s disease surgery. Major problems: non-systematic literature review (part II)

Objective. To analyze literature data on the frequency of junctional kyphosis in surgery for Scheuermann’s disease, its relationship withspinopelvic parameters, risk factors and prevention of its development.Material and Methods. A search for sources in Scopus and Web of Science databases revealed 62 articles published from 1975 to 2021 and containing the required information. Of these, 56 publications meet the inclusion criteria.Results. The selected 56 articles contain data on 2,110 patients. In total, 247 (11.8 %) cases of proximal junctional kyphosis were diagnosed, including 6 (0.3 %) cases of proximal junctional failure. The total number of distal junctional kyphosis cases was 124 (5.9 %). Forty-five reoperations were performed. Many potential risk factors have been identified in publications, but there is no consensus on any of them.As a result, there is no a well-founded common position on the prevention of junctional kyphosis development. Spinopelvic parameters in Scheuermann’s disease are significantly less than those in the general population and do not tend to change after surgical correction of kyphosis. As for their relationship with the risk of development of proximal and distal junctional kyphosis, there is no consensus to date.Conclusion. This review is the largest in terms of coverage of literary sources on the problem of the development of junctional kyphosis in surgery for Scheuermann’s disease. The causes for the development of this complication remain unknown, hence there is the lack of generally accepted methods of prevention. New studies with long postoperative follow-up are needed.

Predicting development of severe clinically relevant distal junctional kyphosis following adult cervical deformity surgery, with further distinction from mild asymptomatic episodes

OBJECTIVE This retrospective cohort study aimed to develop a formal predictive model distinguishing between symptomatic and asymptomatic distal junctional kyphosis (DJK). In this study the authors identified a DJK rate of 32.2%. Predictive models were created that can be used with high reliability to help distinguish between severe symptomatic DJK and mild asymptomatic DJK through the use of surgical factors, radiographic parameters, and patient variables. METHODS Patients with cervical deformity (CD) were stratified into asymptomatic and symptomatic DJK groups. Symptomatic: 1) DJK angle (DJKA) > 10° and either reoperation due to DJK or > 1 new-onset neurological sequela related to DJK; or 2) either a DJKA > 20° or ∆DJKA > 20°. Asymptomatic: ∆DJK > 10° in the absence of neurological sequelae. Stepwise logistic regressions were used to identify factors associated with these types of DJK. Decision tree analysis established cutoffs. RESULTS A total of 99 patients with CD were included, with 32.2% developing DJK (34.3% asymptomatic, 65.7% symptomatic). A total of 37.5% of asymptomatic patients received a reoperation versus 62.5% symptomatic patients. Multivariate analysis identified independent baseline factors for developing symptomatic DJK as follows: pelvic incidence (OR 1.02); preoperative cervical flexibility (OR 1.04); and combined approach (OR 6.2). Having abnormal hyperkyphosis in the thoracic spine, more so than abnormal cervical lordosis, was a factor for developing symptomatic disease when analyzed against asymptomatic patients (OR 1.2). Predictive modeling identified factors that were predictive of symptomatic versus no DJK, as follows: myelopathy (modified Japanese Orthopaedic Association score 12–14); combined approach; uppermost instrumented vertebra C3 or C4; preoperative hypermobility; and > 7 levels fused (area under the curve 0.89). A predictive model for symptomatic versus asymptomatic disease (area under the curve 0.85) included being frail, T1 slope minus cervical lordosis > 20°, and a pelvic incidence > 46.3°. Controlling for baseline deformity and disability, symptomatic patients had a greater cervical sagittal vertical axis (4–8 cm: 47.6% vs 27%) and were more malaligned according to their Scoliosis Research Society sagittal vertical axis measurement (OR 0.1) than patients without DJK at 1 year (all p < 0.05). Despite their symptomatology and higher reoperation rate, outcomes equilibrated in the symptomatic cohort at 1 year following revision. CONCLUSIONS Overall, 32.2% of patients with CD suffered from DJK. Symptomatic DJK can be predicted with high reliability. It can be further distinguished from asymptomatic occurrences by taking into account pelvic incidence and baseline cervicothoracic deformity severity.

Planning Cervical Deformity Surgery Including DJK Prevention Strategies

Distal junctional kyphosis (DJK) is a major concern following cervical deformity (CD) correction, leading to failed realignment and revision surgery. In this chapter, we describe our approach to the treatment of cervical deformity and the steps taken to minimize the risk of DJK post-operatively by tailoring the construction to the individual patient. In this chapter, we describe our approach to the treatment of cervical deformity and the steps taken to minimize the risk of DJK post-operatively by tailoring the construction to the individual patient. First we focus on characterization of the baseline deformity. Secondly, we assess our patients clinically. Thirdly, we simulate the correction with the use of novel in-construct measurements. The fourth step is to develop a DJK prevention strategy tailored to the individual. The last step is to perform surgery and check correction during the operation.

Resection of congenital hemivertebra in pediatric scoliosis: the experience of a two-specialty surgical team

OBJECTIVE Institutions investigating value and quality emphasize utilization of two attending surgeons with different areas of technical expertise to treat complex surgical cases and to minimize complications. Here, the authors chronicle the 12-year experience of using a two–attending surgeon, two-specialty model to perform hemivertebra resection in the pediatric population. METHODS Retrospective cohort data from 2008 to 2019 were obtained from the NewYork-Presbyterian Morgan Stanley Children’s Hospital operative database. This database included all consecutive pediatric patients < 21 years old who underwent hemivertebra resection performed with the two–attending surgeon (neurosurgeon and orthopedic surgeon) model. Demographic information was extracted. Intraoperative complications, including durotomy and direct neurological injury, were queried from the clinical records. Intraoperative neuromonitoring data were evaluated. Postoperative complications were queried, and length of follow-up was determined from the clinical records. RESULTS From 2008 to 2019, 22 patients with a median (range) age of 9.1 (2.0–19.3) years underwent hemivertebra resection with the two–attending surgeon, two-specialty model. The median (range) number of levels fused was 2 (0–16). The mean (range) operative time was 5 hours and 14 minutes (2 hours and 59 minutes to 8 hours and 30 minutes), and the median (range) estimated blood loss was 325 (80–2700) ml. Navigation was used in 14% (n = 3) of patients. Neither Gardner-Wells tongs nor halo traction was used in any operation. Neuromonitoring signals significantly decreased or were lost in 14% (n = 3) of patients. At a mean ± SD (range) follow-up of 4.6 ± 3.4 (1.0–11.6) years, 31% (n = 7) of patients had a postoperative complication, including 2 instances of proximal junctional kyphosis, 2 instances of distal junctional kyphosis, 2 wound complications, 1 instance of pseudoarthrosis with hardware failure, and 1 instance of screw pullout. The return to the operating room (OR) rate was 27% (n = 6), which included patients with the abovementioned wound complications, distal junctional kyphosis, pseudoarthrosis, and screw pullout, as well as a patient who required spinal fusion after loss of motor evoked potentials during index surgery. CONCLUSIONS Twenty-two patients underwent hemivertebra resection with a two–attending surgeon, two-specialty model over a 12-year period at a specialized children’s hospital, with a 14% rate of change in neuromonitoring, 32% rate of nonneurological complications, and a 27% rate of unplanned return to the OR.

Distal Junctional Kyphosis after Posterior Spinal Fusion in Lenke 1 and 2 Adolescent Idiopathic Scoliosis-Exploring Detailed Features of the Sagittal Stable Vertebra Concept

Study Design: A retrospective cohort study. Objective: To investigate the factors contributing to the development of postoperative distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF) with lowest instrumented vertebrae (LIV) at or above L1. Methods: Patients with Lenke type 1 or 2 curves who underwent PSF with LIV at or above L1 with a minimum follow-up of 2 years were evaluated. The primary outcome measure was the occurrence of postoperative DJK. Radiographic parameters of sagittal alignment and inclusion/exclusion of sagittal stable vertebra (SSV) in PSF were analyzed to determine their associations with the occurrence of postoperative DJK. Results: Overall, 122 patients (mean age: 15.1 ± 3.2 years) were included. The overall incidence of postoperative DJK was 6.6%. DJK was observed in 19.0% (8/42) of patients whose SSV was not included in PSF and not in patients with SSV included in PSF (n = 80). In the SSV-excluded group, univariate analysis found two significant risk factors for DJK: postoperative thoracic kyphosis (TK, T5-12) and postoperative thoracolumbar kyphosis (TLK, T11-L2). The ROC curve revealed that postoperative TK ≥ 25° and TLK ≥ 10° best predicted the occurrence of postoperative DJK in the SSV-excluded group. The incidence was significantly higher in cases with postoperative TK ≥ 25° or TLK ≥ 10° (7/13 = 53.8%) than in those with postoperative TK < 25° and TLK < 10° (1/29 = 3.4%). Conclusions: The current study revealed that postoperative TK ≥ 25° or postoperative TLK ≥ 10° with SSV excluded from PSF were related to DJK after PSF for Lenke type 1 and type 2 AIS. When the SSV is intended to be spared from PSF to save more motion segments, TK and TLK should be carefully evaluated and attained in a lesser magnitude (TK < 25°, TLK < 10°) after surgery.