ABSTRACT
STUDY DESIGN: Retrospective comparative study.OBJECTIVES: To compare the reliability of 2 criteria to predict the radiological outcomes of corrective surgery in cases of adolescent idiopathic scoliosis (AIS) with structural thoracolumbar/lumbar (TL/L) curves.SUMMARY OF LITERATURE REVIEW: Distal fusion level selection in AIS with structural TL/L curves is debatable.MATERIALS AND METHODS: This study included 131 AIS patients with structural TL/L curves who underwent corrective surgery in which distal fusion was stopped at L3. Whole-spine standing radiographs and bending radiographs were obtained preoperatively. The patients were divided into 2 groups according to their findings on bending radiographs (dynamic criterion) and by the last touching vertebra and the lower end vertebra (static criterion). Radiological outcomes were assessed by reviewing postoperative radiographs. Reliability tests were conducted to compare the predictability of radiological outcomes using these 2 methods. In addition, radiological parameters were compared between both criteria.RESULTS: Among 131 patients, 25 showed radiologically poor outcomes (19.1%). The sensitivity of the dynamic and static criteria was 0.69 and 0.50, respectively. The specificity of each criterion was 0.49 and 0.64, respectively. Overall, the dynamic criterion showed superior reliability (p=0.03). However, no significant difference in radiological parameters could be found in a comparison of both criteria.CONCLUSIONS: Although the dynamic criterion was more sensitive for predicting poor radiological outcomes when stopping fusion at L3 in patients with structural TL/L curves, its specificity was lower than that of the static criterion. Thus, both dynamic and static criteria should be considered when selecting the distal fusion level in cases of AIS with structural TL/L curves.
Subject(s)
Adolescent , Humans , Retrospective Studies , Scoliosis , Sensitivity and Specificity , SpineABSTRACT
STUDY DESIGN: Retrospective analysis of adolescent idiopathic scoliosis. PURPOSE: This study aimed to investigate the influence of distinct distal fusion levels on spinopelvic parameters in patients with adolescent idiopathic scoliosis (AIS) who underwent posterior instrumentation and fusion surgery. OVERVIEW OF LITERATURE: The distal fusion level selection in treatment of AIS is the one of milestone to effect on surgical outcome. Most of the paper focused on the coronal deformity correction and balance. The literature have lack of knowledge about spinopelvic changing after surgical treatment and the relation with distal fusion level. We evaluate the spinopelvic and pelvic parameter alteration after fusion surgery in treatment of AIS. METHODS: A total of 100 patients with AIS (88 females and 12 males) were retrospectively reviewed. Patients were assigned into the following three groups according to the distal fusion level: lumbar 2 (L2), lumbar 3 (L3), and lumbar 4 (L4). Using a lateral plane radiograph of the whole spine, spinopelvic angular parameters such as thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were radiologically assessed. RESULTS: The mean age was 15±2.4 years, and the mean follow-up period was 24.27±11.69 months. Regarding the lowest instrumented vertebra, patients were categorized as follows: 30 patients in L2 (group 1), 40 patients in L3 (group 2), and 30 patients in L4 (group 3). TK decreased from 36.60±13.30 degrees preoperatively to 26.00±7.3 degrees postoperatively in each group (p=0.001). LL decreased from 52.8±9.4 degrees preoperatively to 44.30±7.50 degrees postoperatively (p=0.001). Although PI showed no difference preoperatively among the groups, it was statistically higher postoperatively in group 3 than in the other groups (p 0.05). However, mean SS was significantly higher in group 3 (p=0.042, p < 0.05). PT decreased from 15.50±7.90 degrees preoperatively to 15.2±7.10 degrees postoperatively. The positive relationship (28.5%) between LL and PI measurements was statistically significant (r=0.285; p=0.004, p < 0.01). Furthermore, the positive relationship (36.5%) between LL and SS measurements was statistically significant (r=0.365; p=0.001, p < 0.01). CONCLUSIONS: When the distal instrumentation level in AIS surgery is below L3, a significant change in PT and SS (pelvic parameters) is anticipated.
Subject(s)
Adolescent , Animals , Female , Humans , Congenital Abnormalities , Follow-Up Studies , Incidence , Kyphosis , Lordosis , Retrospective Studies , Scoliosis , SpineABSTRACT
STUDY DESIGN: A retrospective study for clinical, radiographic assessment. OBJECTIVES: To determine the appropriate level of distal fusion for the posterior instrumentation and fusion for thoracic hyperkyphosis by investigating the relationship between the sagittal stable (the most proximal vertebra touched by the vertical line from the posterior-superior corner of the sacrum), first lordotic (just caudal to the first lordotic disc) and lowest instrumented vertebrae. LITERATURE REVIEW SUMMARY: It has been recommended that the distal level of fusion for thoracic hyperkyphosis should include not only the distal end vertebra of kyphosis, but also the first lordotic disc beyond the transitional zone, distally. However, distal junctional breakdown was noted, even when these rules have been followed. MATERIALS AND METHODS: Thirty-one patients, with a mean age of 18, ranging from 13 to 38 years, who underwent long posterior instrumentation and fusion for thoracic hyperkyphosis, with a minimum of 2 years of follow up, were reviewed. The preoperative diagnosis included: Scheuermann`s disease (n=29), posttraumatic kyphosis (n=1) and postlaminectomy kyphosis (n=1). According to the level of distal fusion, the patients were divided into two groups. Group I (n=24): lowest instrumented vertebra (LIV), including the sagittal stable vertebra (SSV), Group II (n=7): lowest instrumented vertebra proximal to the sagittal stable vertebra. Patients were evaluated utilizing both standing radiographs and chart reviews. RESULTS: The mean thoracic kyphosis was 86.6+/-8.5 before surgery, which had been corrected to 53.0+/-10.4 by the final follow-up, with a correction rate of 39%. The average sagittal balance was slightly negative (0.24+/-3.8 cm) before surgery, and became more negative (1.33+/-2.8 cm) by the final follow-up. There were no statistical differences in the thoracic kyphosis between the two groups. However, there was a statistically significant difference, with Group II having a more posterior translation of the center of the LIV from the posterior sacral vertical line, preoperatively, than at the final follow-up in Group I (p=0.003). In Group I, distal junctional problems developed in only 2 of the 24 (8%) patients, whereas in Group II, they occurred in 5 of the 7 (71%) patients (p<0.05). Despite extending the fusion to the first lordotic vertebra, distal junctional problems developed in 3 of the 8 (38%) patients. CONCLUSIONS: The distal end of the fusion for thoracic hyperkyphosis should include the sagittal stable vertebra. The levels of distal fusion that include the first lordotic vertebra, but not the sagittal stable vertebra, are not always appropriate for the prevention of postoperative distal junctional kyphosis.
Subject(s)
Humans , Diagnosis , Follow-Up Studies , Kyphosis , Retrospective Studies , SpineABSTRACT
STUDY DESIGN: A retrospective study for clinical, radiographic assessment. OBJECTIVES: To determine the appropriate level of distal fusion for the posterior instrumentation and fusion for thoracic hyperkyphosis by investigating the relationship between the sagittal stable (the most proximal vertebra touched by the vertical line from the posterior-superior corner of the sacrum), first lordotic (just caudal to the first lordotic disc) and lowest instrumented vertebrae. LITERATURE REVIEW SUMMARY: It has been recommended that the distal level of fusion for thoracic hyperkyphosis should include not only the distal end vertebra of kyphosis, but also the first lordotic disc beyond the transitional zone, distally. However, distal junctional breakdown was noted, even when these rules have been followed. MATERIALS AND METHODS: Thirty-one patients, with a mean age of 18, ranging from 13 to 38 years, who underwent long posterior instrumentation and fusion for thoracic hyperkyphosis, with a minimum of 2 years of follow up, were reviewed. The preoperative diagnosis included: Scheuermann`s disease (n=29), posttraumatic kyphosis (n=1) and postlaminectomy kyphosis (n=1). According to the level of distal fusion, the patients were divided into two groups. Group I (n=24): lowest instrumented vertebra (LIV), including the sagittal stable vertebra (SSV), Group II (n=7): lowest instrumented vertebra proximal to the sagittal stable vertebra. Patients were evaluated utilizing both standing radiographs and chart reviews. RESULTS: The mean thoracic kyphosis was 86.6+/-8.5 before surgery, which had been corrected to 53.0+/-10.4 by the final follow-up, with a correction rate of 39%. The average sagittal balance was slightly negative (0.24+/-3.8 cm) before surgery, and became more negative (1.33+/-2.8 cm) by the final follow-up. There were no statistical differences in the thoracic kyphosis between the two groups. However, there was a statistically significant difference, with Group II having a more posterior translation of the center of the LIV from the posterior sacral vertical line, preoperatively, than at the final follow-up in Group I (p=0.003). In Group I, distal junctional problems developed in only 2 of the 24 (8%) patients, whereas in Group II, they occurred in 5 of the 7 (71%) patients (p<0.05). Despite extending the fusion to the first lordotic vertebra, distal junctional problems developed in 3 of the 8 (38%) patients. CONCLUSIONS: The distal end of the fusion for thoracic hyperkyphosis should include the sagittal stable vertebra. The levels of distal fusion that include the first lordotic vertebra, but not the sagittal stable vertebra, are not always appropriate for the prevention of postoperative distal junctional kyphosis.
Subject(s)
Humans , Diagnosis , Follow-Up Studies , Kyphosis , Retrospective Studies , SpineABSTRACT
PURPOSE: To analyze surgical outcomes of thoracolumbar and lumbar scoliosis treated with segmental pedicle screw fixation, and to determine the exact distal fusion level. MATERIALS AND METHODS: Seven idiopathic thoracolumbar and lumbar scoliosis patients (6 thoracolumar and 1 lumbar scoliosis, 7 females with mean age of 15.9 years) subjected to segmental pedicle screw fixation with a minimum follow-up of 2 years were retrospectively analyzed for deformity correction, stable vertebra, lower instrumeted vertebral tilt (LIVT) and coronal balance using pre and post-operative standing radiographs. The bending stable vertebra and the rotational correction of L3 were measured in preoperative bending radiographs. The L3 rotation in the bending radiographs was less than Nash-Moe grade II in all patients. The bending stable vertebra was L3 in 4 patients and L4 in 3. An unsatisfactory result was defined as an LIVT of more than 10degrees or a coronal imbalance of more than 10 mm. RESULTS: Distal fusion went down to L3 in 6 patients and L4 in one patient whose bending stable vertebra had been L4 preoperatively. The preoperative average major curve of 52degrees was corrected to 10degrees (81% correction). The preoperative average thoracic curve of 27degrees and the average lumbosacral curve of 26degrees were corrected to 14degrees and 5degrees, respectively. Two patients with distal fusion to L3 showed unsatisfactory results; LIVT was more than 10degrees in both patients and coronal imbalance more than 10 mm in one. Both the patients had bending stable vertebra of L4 preoperatively. CONCLUSION: In the correction of thoracolumbar and lumbar scoliosis with segmental pedicle screw fixation, the curve could be fused to L3 when the L3 rotation in the bending radiograph was less than Nash-Moe grade II and the bending stable vertebra was L3.
Subject(s)
Female , Humans , Congenital Abnormalities , Follow-Up Studies , Retrospective Studies , Scoliosis , SpineABSTRACT
STUDY DESIGN: Retrospective study. OBJECTIVES: To determine the exact distal fusion level in the treatment of single thoracic idiopathic scoliosis (King III and IV) with segmental pedicle screw fixation and rod rotation. SUMMARY OF LITERATURE REVIEW: Pedicle screw fixation effectively shortens the distal fusion extent by improved 3-D deformity correction. However, the selection of distal fusion extent remains controversial in single thoracic idiopathic scoliosis. MATERIAL AND METHODS: Forty-two single thoracic adolescent idiopathic scoliosis patients subject to segmental pedicle screw fixation and rod rotation with minimum follow-up of 2 years (2-6 years) were analyzed. The patients were grouped according to the distal fusion level with reference to the standing neutral vertebra (NV) for comparison of deformity correction, radiological and clinical spinal balance using standing radiographs. Distal fusion down to NV +1 was in 9 patients, NV in 5, NV-1 in 9, NV-2 in 12 and NV-3 in 7 patients respectively. RESULTS: Preoperative 50+/-11 degrees of thoracic deformity was corrected to 13+/-5 degrees showing 74% of curve correction. Preoperative 23+/-7 degrees of lumbar deformity was corrected to 2+/-8 degrees showing 93% of curve correction. Postoperative adding on deformity was obtained in 14 patients. Significant difference was found not by King classification but by distal fusion level: significantly higher chance of unsatisfactory results from not going to the NV-1 (p=0.001). CONCLUSIONS: In correction of single thoracic idiopathic scoliosis with segmental pedicle screw fixation, the curve should be fused to NV-1 saving one or more motion segments when compared to the fusion to the stable vertebra.