In vivo deformation of anatomically pre-bent rods in thoracic adolescent idiopathic scoliosis

Some surgical strategies can maintain or restore thoracic kyphosis (TK); however, next-generation surgical schemes for adolescent idiopathic scoliosis (AIS) should consider anatomical corrections. A four-dimensional correction could be actively achieved by curving the rod. Thus, anatomically designed rods have been developed as notch-free, pre-bent rods for easier anatomical reconstruction. This study aimed to compare the initial curve corrections obtained using notch-free rods and manually bent, notched rods for the anatomical reconstruction of thoracic AIS. Two consecutive series of 60 patients who underwent anatomical posterior correction for main thoracic AIS curves were prospectively followed up. After multilevel facetectomy, except for the lowest instrumented segment, either notch-free or notched rods were used. Patient demographic data, radiographic measurements, and sagittal rod angles were analyzed within 1 week after surgery. Patients with notch-free rods had significantly higher postoperative TK than patients with notched rods (P < .001), but both groups achieved three-dimensional spinal corrections and significantly increased postoperative rates of patients with T6–T8 TK apex (P = .006 for notch-free rods and P = .008 for notched rods). The rod deformation angle at the concave side was significantly lower in the notch-free rods than in the notched rods (P < .001). The notch-free, pre-bent rod can maintain its curvature, leading to better correction or maintenance of TK after anatomical spinal correction surgery than the conventional notched rod. These results suggest the potential benefits of anatomically designed notch-free, pre-bent rods over conventional, manually bent rods.

Long-Term (Over Five Years) Results of Surgical Correction of Scheuermann’s Kyphosis

Study design. Retrospective cohort study.Objective. The study objective is to assess long-term results of surgical correction of kyphosis due to Scheuermann’s disease.Summary of Background Data. Despite a large number of studies on surgical correction of juvenile kyphosis, articles discussing long-term (over five years) results of these interventions are very rare.Methods. The study group included 43 patients (m/f ratio, 34/9). The mean age was 19.1 (14–32) years; the mean postoperative follow-up was 6 + 10 (5–20) years. Two-stage surgery including discectomy and interbody fusion followed by posterior correction and fusion was conducted in 35 cases (group A). Eight patients (group B) underwent only posterior correction and spinal fusion. The following parameters were determined for each patient: Thoracic Kyphosis (TK); Lumbar Lordosis (LL), Sagittal Vertical Axis (SVA); Sagittal Stable Vertebra (SSV); First Lordotic Vertebra (FLV); Proximal Junctional Angle (PJA); and Distal Junctional Angle (DJA). All measurements were performed immediately before surgery, one week after surgery, and at the end of the follow-up period. All patients answered the SRS-24 questionnaire after surgery and at end of the follow-up.Results. Groups A and B were comparable in age and sex, BMI and initial Cobb angle (P < 0.05). The curve decreased from 77.8° to 40.7° in group A and from 81.7° to 41.6° in group B. The loss of correction was 9.1° and 6.0° in groups A and B, respectively. At ID < 1.2, deformity correction and correction loss were 35° (44.0 %) and 7.1°, respectively; at ID ˃ 1.2, deformity correction and correction loss were 44.5° (54.7 %) and 3.9°, respectively (P < 0.05).Proximal junctional kyphosis was detected in 21 out of 43 patients (48.8 %). The rate of PJK was 45.4 % in those patients whose upper end vertebra was included in the fusion and 60 % in individuals whose upper end vertebra was not included. PJK developed in eight (47.8 %) out of 17 patients who received ≥ 50 % kyphosis correction and in 13 (50 %) individuals who had < 50 % deformity correction. The rate of DJK development was 39.5 %. The lower instrumented vertebra (LIV) was located proximal to the sagittal stable vertebra in 16 cases, with 12 of them being diagnosed with DJK (75 %). In 27 patients, LIV was located either at the SSV level or distal to it, the number of DJK cases was 5 (18.5 %) (P < 0.05). Only two patients with complications required unplanned interventions. According to the patient questionnaires, the surgical outcome score increases between the immediate and long-term postoperative periods for all domains and from 88.4 to 91.4 in total. The same applies to answer to the question No. 24 (“Would you have the same treatment again if you had the same condition?”): rate of positive answers ranges from 82 to 86 %.Conclusions. Two-stage surgery, as a more difficult and prolonged one, has no advantages over one-stage operation in terms of magnitude and stability of the achieved effect. The problem of choosing the area of spinal fusion is far from being solved. Surgical treatment improves the quality of life of patients with Scheuermann’s disease; the improvement is also observed in the long-term postoperative period.

Under-contouring of rods: a potential risk factor for proximal junctional kyphosis after posterior correction of Scheuermann kyphosis

OBJECTIVEScheuermann kyphosis (SK) could require surgical treatment in certain situations. A posterior reduction is the most widespread treatment so far, although the development of proximal junctional kyphosis (PJK) is one of the possible complications of this procedure. The contour of the proximal part of the rod could influence the occurrence of PJK in SK patients. The objective of this study was to analyze the impact of the proximal rod contour on the occurrence of a PJK complication in SK patients.METHODSThis retrospective monocentric study was performed in the Nanjing Spine Surgery Department. All eligible patients had undergone posterior correction surgery with pedicle screws only between 2002 and 2017 and had at least 24 months of follow-up. The presence of PJK was quantified on radiographs using the proximal junctional angle (PJA > 10° at the last follow-up). The authors propose a new radiological parameter to measure the angulation of the proximal part of the instrumentation: the proximal contouring rod angle (PCRA) is the angle between the upper endplate of the upper instrumented vertebra (UIV) and the lower endplate of the second vertebra caudal to the UIV. The patients were analyzed according to the presence or absence of PJK. A t-test, receiver operating characteristic (ROC) curve analysis, and logistic regression analysis were performed for statistical analysis.RESULTSSixty-two patients treated for SK were included in this study. The mean age was 18.6 ± 8.5 years, and the mean follow-up was 42.5 ± 16.4 months. The mean correction rate of global kyphosis was 46.4% ± 13.7%. At the last follow-up, 17 patients (27.4%) presented with PJK. No significant difference was found between the PJK and non-PJK groups in terms of age and other preoperative variables. A significant difference in the postoperative PCRA was found between the PJK and non-PJK groups (8.2° ± 4.9° vs 15.7° ± 6.6°, respectively; p = 0.001). A postoperative PCRA less than 10.1° predicted a significantly higher risk for PJK (p = 0.002, OR 2.431, 95% CI 1.781–4.133).CONCLUSIONSUnder-contouring of the proximal part of the rods (lower than 10°) is a risk factor for PJK after posterior correction of SK.

Scoliosis in Shprintzen–Goldberg Syndrome

We report a case of scoliosis in a 12-year-old girl with Shprintzen–Goldberg syndrome. She was diagnosed with Shprintzen–Goldberg syndrome at birth. She was hospitalized for a surgical treatment because scoliosis gradually progressed. Preoperative X-ray confirmed 80° symptomatic scoliosis in T10–L5. Posterior correction and fusion were performed, and postoperative X-ray showed a correction to 43°in T10-L5. Limited subcutaneous tissues and fragile bones must be considered when selecting the appropriate surgical method. Accurate placement of a screw into thin pedicle is essential to obtain sufficient correction and fusion. The use of a navigation system is recommended.