Lumbar Curve Correction Research Articles

Selective thoracic fusion in AIS curves: the definition of target outcomes improves the prediction of spontaneous lumbar curve correction (SLCC)

The decision of when to use selective thoracic fusion (STF) and the prediction of spontaneous lumbar curve correction (SLCC) remain difficult. Using a novel methodological approach, the authors yielded for a better prediction of SLCC and analyzed the efficacy of anterior scoliosis correction and fusion (ASF). A retrospective analysis of 273 patients treated with ASF for STF was performed. In total, 87 % of the patients showed a Lenke 1 curve pattern. The lumbar curve modifier was classified as A in 66 % of the patients, B in 21 % of the patients and C in 13 % of the patients. The fusion length averaged 6.7 levels. The analysis included an assessment of radiographic deformity and correction, surgery characteristics, complications and revisions and clinical outcomes to improve the prediction of SLCC. Patients with a Type A-L, Type B or Type C modifier were stratified into a target follow-up lumbar curve (LC) category of ≤20° or >20°. Linear regression analyses were performed to assess the accuracy of predicting LC magnitude, and a multivariate logistic regression model was built using the following preoperative (preop) predictors: main thoracic curve (MTC), LC, MTC-bending and LC-bending. The output variable indicated whether a patient had an LC >20° at follow-up. A variable selection algorithm was applied to identify significant predictors. Two thresholds (cut-offs) were applied to the test sample to create high positive and negative prediction values. The data from 33 additional patients were gathered prospectively to create an independent test sample to learn how the model performed with independent data as a test of the generalizability of the model. The average patient age was 17 years, and the average follow-up period was 33 months. The MTC was 53.1° ± 10.2° preoperatively, 29.8° ± 10.5° with bending and was 25.4° ± 9.7° at follow-up (p < 0.01). The LC was 35.7° ± 7.5° preoperatively, 8.9° ± 5.8° with bending, and 21.8° ± 7.0° at follow-up (p < 0.01). After applying a variable selection algorithm, the preop LC [p < 0.02, odds ratio (OR) = 1.09] and preop LC-bending (p < 0.009, OR = 1.14) remained in the model as significant predictors. The performance of the linear regression model was tested in an independent test sample, and the difference between the observed and predicted values was only 1° ± 4.5°. Based on the test sample, the lower threshold was set to 25 %, and the upper threshold was set to 75 %. Patients with prediction values of 25-75 % were identified by the model, but by definition of the model, no prediction was made. In the test sample, 87 % of the patients were correctly classified as having an LC ≤20° at follow-up, and 84 % of the patients were correctly classified as having an LC >20°. The model test in the independent test sample revealed that 100 % of the patients were correctly classified as having an LC ≤20°, and 86 % of the patients were correctly classified as having an LC >20°. After analyzing a sufficiently large sample of 273 patients who underwent ASF for STF, significant predictors for SLCC were established and reported according to the surgical outcomes. Application of the prediction models can aid surgeons in the decision-making process regarding when to perform STF. Our results indicate that with stratification of outcomes into target curves (e.g., an LC <20°), future benchmarks for STF might be more conclusive.

Comparison of anterior and posterior vertebral column resection versus anterior release with posterior internal distraction for severe and rigid scoliosis

This study aimed to compare efficacy, safety, and cost between staged vertebral column resection (VCR) and anterior release with internal distraction in treating severe and rigid idiopathic scoliosis. We examined the records of 43 patients with severe and rigid idiopathic scoliosis treated in our hospital. Group A included 26 patients who underwent anterior VCR followed by posterior vertebral column resection and instrumentation from July 2007 to October 2009. Group B included 17 patients who underwent anterior release with temporary posterior internal distraction, followed by posterior fusion and instrumentation from November 2009 to June 2011. The average preoperative main curve for group A was 101.3° (range 90°-130°) and for group B was 104.8° (range 90°-136°). Minimum follow-up was 2 years. Radiographic and clinical outcomes were compared between the groups. A t test demonstrated that the differences between the groups in preoperative and postoperative coronal and sagittal imbalance, thoracic kyphosis correction, and lumbar lordosis were not statistically significant. Patients in group B showed better postoperative (P = 0.031) and final (P = 0.030) main thoracic curve correction (76.8 and 75.6 %, respectively) than patients in group A (68.3 and 67.7 %, respectively). Patients in group B had better thoracolumbar or lumbar curve correction (85.8 %) than those in group A (76.8 %; P = 0.048). The differences in blood loss and operation time were not statistically significant (P = 0.094 and P = 0.060, respectively). Hospital stay was longer (P = 0.001) and patient cost was higher (P < 0.001) for patients in group B. One patient in group A required ventilator support for 12 h after anterior surgery. One transient dyspnea occurred in group B. No neurologic deficits occurred in either group. Anterior release with posterior internal distraction produces better corrective effects than anterior and posterior VCR, though hospital stay and costs are greater.

Selection of Lower Instrumented Vertebra in Treating Lenke Type 2A Adolescent Idiopathic Scoliosis

A retrospective, observational, and multicenter study. To identify the ideal lower instrumented vertebra (LIV) to prevent distal adding-on after surgical correction of Lenke type 2A curve. LIV level may affect the risk of postsurgical adding-on. The choice of the last touching vertebra (LTV)-the most caudal vertebra of the main thoracic curve that touches the central sacral vertical line when standing-as an appropriate LIV has been validated for Lenke type 1A but not type 2A curve. Radiographs obtained before, immediately after, and 2 years after surgery were evaluated for 116 consecutive patients who underwent posterior thoracic fusion surgery for Lenke type 2A curve. The LIV was proximal to the LTV in 18 patients (PLTV), distal in 43 (DLTV), and at the LTV in 55 (ALTV). Significant independent factors associated with adding-on were analyzed first by univariate analysis, and then by stepwise logistic regression analysis. Distal adding-on was present in 16 patients (13.8%) at follow-up: 9 PLTV (50.0%), 3 DLTV (7.0%), and 4 ALTV (7.3%). Adding-on was significantly more common in the PLTV group. One PLTV-group patient required revision surgery to treat adding-on. Univariate analysis identified the following significant factors associated with adding-on: the T2-T5 kyphosis angle and shoulder height before, immediately after, and 2 years after surgery; the lumbar Cobb angle at the 2-year follow-up; the 2-year postoperative lumbar curve correction rate; and the difference between the LIV and the end vertebra, neutral vertebra, and LTV levels. Significant independent risk factors identified by stepwise logistic regression analysis included the clavicle angle at follow-up, the correction rate of the lumbar curve immediately after surgery, and the difference between the LIV and LTV levels. A LIV at or distal to the LTV may prevent postoperative adding-on in Lenke type 2A curve. 3.

Prognosis of spontaneous thoracic curve correction after the selective anterior fusion of thoracolumbar/lumbar (Lenke 5C) curves in idiopathic scoliosis

Background contextPrognosis of minor lumbar curve correction after selective thoracic fusion in idiopathic scoliosis is well defined. However, the prognosis of minor thoracic curve after isolated anterior fusion of the major lumbar curve has not been well described. PurposeTo define the prognosis of spontaneous thoracic curve correction after selective anterior fusion of the lumbar/thoracolumbar curve in idiopathic scoliosis. Study designA retrospective cohort study on the prognosis of the minor curve after selective anterior correction and fusion of the lumbar/thoracolumbar curve in idiopathic scoliosis. Patient sampleIdiopathic lumbar scoliosis patients treated with anterior spinal fusion. Outcome measuresThe Scoliosis Research Society 22 questionnaire was used as an outcome measure at the final follow-up. MethodsTwenty-eight patients were included in this study. Four patients were male, 24 patients were female, and average age at the time of surgery was 16 years. Mean follow-up was 48 months. According to the Lenke Classification, 22 patients were 5CN, 5 were 5C−, and 1 was 5C+. All operations were performed in the same institution. Standing long posterior-anterior and lateral radiographs were taken just before surgery, 1 week after surgery, and at final follow-up. ResultsThe mean preoperative Cobb angle of the lumbar (major) curve was 53° (standard deviation [SD]=8.6) and that of the thoracic (minor) curve was 38.4° (SD=6.24). The lumbar and thoracic curves were corrected to 10° (SD=7.6) and 25° (SD=8.3) postoperatively and measured 17° (SD=10.6) and 27° (SD=7.7), respectively, at the last follow-up. There was a significant difference between the preoperative and postoperative measurements of the minor curves (p<.05). However, there was no significant difference between the early postoperative and the final follow-up measurements (p>.05). Regarding the overall sagittal balance, there was no significant difference between preoperative, early, and late postoperative measurements (p>.05). ConclusionsSelective anterior fusion of the major thoracolumbar/lumbar curve was an effective method for the treatment of Lenke Type 5C curves. Minor thoracic curves did not progress after selective fusion of thoracolumbar/lumbar curves in minimum 2-year follow-up.

Comparison of in-brace correction between supine, molded, asymmetric TLSOs and standing, CAD, symmetric TLSOs

Results For the 22 symmetric CAD TLSOs, initial in brace correction of thoracic curves was 9.1 degrees, with average out of brace thoracic curve 25.2 degrees, and lumbar curve correction of 10.3 degrees, with average out of brace lumbar curve 27.8 degrees. The percentage of correction in CAD versions was 36.1% thoracic, and 37.1% lumbar. For the 12 asymmetric, TLSOs molded supine with manipulation, initial in brace correction of thoracic curves was 13.3 degrees, with average out of brace thoracic curve 26.7 degrees, and lumbar curve correction of 12.1 degrees, with average out of brace lumbar curve 26.6 degrees. The percentage of correction in supine, molded TLSOs was 49.8% thoracic, and 45.5% lumbar.

Secondary Curve Behavior in Lenke Type 1C Adolescent Idiopathic Scoliosis After Thoracoscopic Selective Anterior Thoracic Fusion

Analysis of a case series of 24 patients with Lenke 1C adolescent idiopathic scoliosis (AIS) receiving selective thoracoscopic anterior scoliosis correction. To report the behavior of the compensatory lumbar curve in a group of patients with Lenke IC AIS after thoracoscopic anterior scoliosis correction and to compare the results of this study with previously published data. Several prior studies have reported spontaneous lumbar curve correction for both anterior and posterior selective fusions in patients with Lenke 1C/King-Moe 2; however, to our knowledge no previous studies have reported outcomes of thoracoscopic anterior correction for this curve type. All patients with AIS with a curve classification of Lenke 1C and a minimum of 24-month follow-up were obtained from a consecutive series of 190 patients with AIS who underwent thoracoscopic anterior instrumented fusion. Cobb angles of the major curve, instrumented levels, compensatory lumbar curve, and T5-T12 kyphosis were recorded, as well as coronal spinal balance, T1 tilt angle, and shoulder balance. All radiographical parameters were measured before surgery and at 2, 6, 12, and 24 months after surgery. Twenty-four female patients with right thoracic curves had a mean thoracic Cobb angle of 53.0° before surgery, decreasing to 24.9° 2 years after surgery. The mean lumbar compensatory Cobb angle was 43.5° before surgery, spontaneously correcting to 25.4° 2 years after surgery, indicating balance between the thoracic and lumbar scoliotic curves. The lumbar correction achieved (41.8%) compares favorably to previous studies. Selective thoracoscopic anterior fusion allows spontaneous lumbar curve correction and achieves coronal balance of main thoracic and compensatory lumbar curves, good cosmesis, and patient satisfaction. Correction and balance are maintained 24 months after surgery.

Spontaneous lumbar curve correction in selective anterior instrumentation and fusion of idiopathic thoracic scoliosis of Lenke type C

Posterior pedicle screw instrumented correction and fusion have become the gold standard in the surgical treatment of thoracic scoliosis. However, in thoracic Lenke type C curves selective posterior fusion of the thoracic curve may lead to spinal imbalance. The aim of the study was to analyse the radiological results of selective anterior thoracic fusion using a standard open dual rod technique with special respect to spontaneous lumbar curve correction (SLCC). Twenty-eight patients (26 patients with Lenke 1C and 2 patients with Lenke 2C curves) with an average age of 15 years were surgically treated with an anterior dual rod system through a standard open double thoracotomy approach. Average clinical and radiological follow-up was 4 years (24-84 months). Fusion was carried out mostly from end-to-end vertebra. The primary curve was corrected from 61.6° (average correction on reverse bending films 42.9 %) to 27.1° (56.0 % correction) with an average loss of correction of 2.2°. The secondary lumbar curve measured 47.7° preoperatively (40-56°, average correction on reverse bending films 66.2 %) and corrected spontaneously to 30.1° (36 % SLCC) and remained stable without any cases of deterioration or decompensation during follow-up. Lumbar apical vertebral translation increased minimally by an average of 4 mm directly, postoperatively, and returned to an average of preoperative values during follow-up. All but two curves remained as type C lumbar modifier at follow-up. Preoperatively, three patients showed a marked coronal imbalance of more than 3 cm (all left, average 4.0 cm); at follow-up, two patients were still out of balance by more than 3 cm (all to the left, average 3.4 cm). Preoperatively, a marked shoulder imbalance of more than 1.0 cm was found in 11 patients; this was corrected in all patients to <1.0 cm at follow-up. The apical vertebral rotation measured according to Perdriolle was corrected from 23.5° to 15.0° in the thoracic spine (36.2 % correction) with an average clinical reduction of the rib hump of 63.2 %. In the lumbar spine, there was no relevant radiological derotation; however, clinically, the lumbar hump corrected spontaneously by 44.3 %. Thoracic kyphosis measured 28.5° preoperatively and 32.3° at follow-up. All six patients with a preoperative hypokyphosis (<20°) of an average of 9.5° were successfully corrected to an average thoracic kyphosis of 23.8° at follow-up. There were no cases of junctional thoracolumbar kyphosis. There were neither reoperations nor implant failures with pseudarthrosis. Selective anterior correction and fusion in primary thoracic curves with lumbar modifier type Lenke C resulted in a reliable and satisfactory SLCC. Advantages of anterior versus posterior techniques are the true segmental derotation with excellent rib hump correction and a superior restoration of thoracic kyphosis.

Could clinical ultrasound improve the fitting of spinal orthosis for the patients with AIS?

This study aimed to improve the effectiveness of orthotic treatment for the patients with AIS using the three-dimensional clinical ultrasound (3D CUS) method in which the optimal location of pressure pad of spinal orthosis was determined with the assistance of ultrasound image analysis. By means of 3D CUS method, the spinous process angle (SPA) could be traced and used as a clinical parameter to estimate the Cobb's angle in order to determine the location of pressure pad. Twenty-one patients (test group) and 22 patients (control group) were recruited to the ultrasound-assisted fitting method and the conventional fitting method, respectively. All the measurements were done by a blinded observer. The intra-rater reliability of using 3D CUS to measure SPA was found >0.9 [ICC (3,3)=0.91, p<0.05]. In the test group, 13 out of 21 patients were required to adjust the location of pressure pad in order to achieve the largest curvature correction. The mean immediate in-brace corrections (Cobb's angle measured from radiographs) of the test group (mean thoracic curve correction: 10.3°, mean lumbar curve correction: 10.1°) were found significantly higher (p<0.005) than that of the control group (mean thoracic curve correction: 4.6°, mean lumbar curve correction: 6.0°). The results showed that the ultrasound-assisted fitting method of spinal orthosis was effective and beneficial to 62% of the patients in this study. The 3D CUS could be considered as an effective, non-invasive and fast assessment method to scoliosis, especially in enhancing the effectiveness of orthotic treatment and its applications could also be further extended to other spinal deformities.

Which Factors Influence Spontaneous Lumbar Curve Correction After Selective Thoracic Fusion In Lenke Type IB And C Curves?

Which Factors Influence Spontaneous Lumbar Curve Correction After Selective Thoracic Fusion In Lenke Type IB And C Curves?

Selective Thoracic Fusion in Adolescent Idiopathic Scoliosis

Analysis of multicenter, prospectively collected data. To determine how selection of the lowest instrumented vertebra (LIV) relative to the stable vertebra (SV) and the end vertebra (EV) effects correction of the main thoracic curve, compensatory lumbar curve, and incidence of coronal decompensation after selective thoracic fusion. Traditionally, in Lenke type 1B and 1C curves, the LIV is selected as the SV; however, selecting the LIV continues to be controversial. Inclusion criteria were patients with adolescent idiopathic scoliosis (AIS) with Lenke type 1B, 1C, or 3C curves that had a selective thoracic fusion with the LIV from T11 to L1 (n=172). The patients were divided into three curve patterns on the basis of the relative position of SV and EV. Group SBE (stable below end) (n=93) had SV below EV, group SAE (stable at end) (n=66) had SV at the EV, and group EBS (end below stable) (n=13) has EV below SV. In addition, each group was divided into six subgroups based on the selected LIV: LIV above SV, at the SV, below SV, above EV, at the EV, and below EV. Each was compared for preoperative and 2-year postoperative radiographic parameters and clinical data. In group SBE, the 2-year postoperative thoracic curve correction rate when the LIV was below the EV (64%+16%) was significantly greater than when the LIV was at the EV (54%+13%; P<0.001). The 2-year postoperative spontaneous lumbar curve correction (SLCC) rate similarly correlated with the LIV selection subgroups, 52%+20% and 43%+19%, respectively (P=0.03). In group SAE, the 2-year postoperative thoracic curve correction rate when the LIV was below the EV/SV (64%+14%) was significantly greater than when the LIV was at the EV/SV (52%+14%; P=0.004). The 2-year postoperative SLCC rate for group SAE similarly correlated with the LIV selection subgroup, 56%+16% and 38%+21%, respectively (P<0.01). In group EBS, the 2-year postoperative thoracic curve correction and SLCC rates were not significantly different among the LIV selection subgroups; however, the incidence of decompensation was 38%. When performing a selective thoracic fusion of Lenke type 1B, 1C, and 3C AIS curves in which the SV was at/or below the EV, the greatest correction of the main thoracic and compensatory lumbar curves occurred when the LIV was at/or at least one level distal to the SV. This more distal LIV did not result in an increased rate of truncal imbalance.

Selective fusion in adolescent idiopathic scoliosis

Selective fusion in adolescent idiopathic scoliosis

Spontaneous Lumbar Curve Correction in Selective Thoracic Fusions of Idiopathic Scoliosis

A retrospective evaluation of adolescent idiopathic scoliosis (AIS) patients treated with selective thoracic instrumentation and fusion. To evaluate the predictors and the effect of surgical approach (anterior versus posterior) on spontaneous lumbar curve correction (SLCC) after selective thoracic fusion in patients with structural thoracic and compensatory lumbar curves. Spontaneous coronal correction of the unfused lumbar curve has been described previously; however controversy continues regarding the effect of surgical approach on SLCC. One hundred thirty-two anterior and 44 posterior selective thoracic fusions instrumented distally to T11, T12, or L1 were identified from a multicenter AIS database. A 2-way ANOVA was used to compare SLCC with regards to surgical approach and the lowest instrumented vertebra (LIV). A Pearson's correlation analysis was utilized to identify radiographic variables associated with SLCC. A secondary analysis of surgical approach was then performed on 28 pairs of patients matching the factors that correlated positively with SLCC. The average SLCC for the anterior approach (44% +/- 19%) was less than that for the posterior approach (49% +/- 19%; P = 0.07), and was found to increase significantly with a more distal LIV (P = 0.03). Pearson's correlation analysis revealed the strongest correlations between SLCC and preoperative lumbar curve flexibility (r = 0.20) and 2-year postoperative thoracic curve percent correction (r = 0.47). A secondary analysis of SLCC in paired curves matched by LIV, lumbar curve flexibility and thoracic percent correction revealed no difference between anterior (48%) and posterior (49%) approaches (P = 0.75). Anterior and posterior instrumented fusions performed selectively on the appropriate curves result in equal SLCC when matched by LIV, flexibility of the lumbar curve, and percent thoracic curve correction achieved. This suggests that the observed phenomenon of SLCC after selective thoracic fusion in AIS is independent of surgical approach and can be reliably achieved with either technique.

Infection After the Surgical Treatment of Adolescent Idiopathic Scoliosis

Retrospective case-control. The purpose of this study was to evaluate a single surgeon's experience with infection after surgical treatment of adolescent idiopathic scoliosis, with a focus on the diagnosis, treatment, and impact on radiographic and patient-reported outcomes. Although previous studies have evaluated this postoperative complication, no studies to date have looked at the impact of this complication on both radiographic and patient-reported outcomes. From 1986 to 2004, 236 patients were identified who underwent surgical treatment of adolescent idiopathic scoliosis and had at least 2-year follow-up. The medical records of patients who developed infection were retrospectively reviewed in detail. Preoperative and most recent postoperative radiographic parameters and Scoliosis Research Society 24 outcomes of both infected and noninfected patients were compared. Of 236 patients 7 (3%) developed an infection. One was acute (17 days postoperative), and 6 were delayed (average 34.2 months postoperative). The most common presenting complaints included back pain (5 of 7) and localized swelling (4 of 7). All patients with delayed infection were treated with 1 surgery (irrigation and debridement, instrumentation removal) and 6 weeks of intravenous antibiotics. Of 6 patients 3 had pseudarthrosis. Culture results were: Staphylococcus epidermidis (n = 2), Propionibacterium acnes (n = 1), Enterococcus faecalis (n = 1), Group A Streptococcus (n = 1), no growth (n = 1). The patient with acute infection required 6 surgical procedures and 16 weeks of antibiotics. Cultures were positive for methicillin resistant Staphylococcus aureus and Serratia marscesens. Revision fusion surgery was performed 5 months after the infection was treated. Compared with the noninfected patients, those with infection had lower percent thoracic (P = 0.01) and lumbar (P = 0.06) curve correction. There was no difference in the pain, function, self-image, satisfaction, or total Scoliosis Research Society 24 scores. Postoperative infection after the surgical treatment of idiopathic scoliosis can successfully be treated with irrigation and debridement, instrumentation removal, and a course of antibiotics. Although less curve correction was achieved in the infected group, there were no differences in patient-reported outcomes when compared with the noninfected group.

Enhanced Capacity for Spontaneous Correction of Lumbar Curve in the Treatment of Major Thoracic–Compensatory C Modifier Lumbar Curve Pattern in Idiopathic Scoliosis

Retrospective radiographic review. To evaluate the outcome of maximal selective thoracic correction with controllable corrective forces provided by cantilevel bending technique (CBT) for idiopathic scoliosis (IS) in the presence of widely deviated compensatory lumbar curve. Current intraoperative instrumentation and fusion techniques for selective fusion involve undercorrection of the thoracic curve while allowing for spontaneous lumbar curve correction and maintaining overall coronal balance. Since the lumbar curve is nonstructural and compensatory, procedures for selective thoracic fusion should approximate the best possible correction of thoracic curve such that resultant spontaneous lumbar curve correction and compensation is maximized. Thirty-seven consecutive IS patients with main thoracic compensatory minor "C" modifier lumbar curves underwent maximal selective thoracic correction by CBT at a single institution. Radiographs were analyzed before surgery, immediately after surgery, and at most recent follow-up (range, 2-6 years). A mean 83% thoracic correction was closely matched by a 81% lumbar correction at most recent follow-up. The mean thoracic curve correction/flexibility ratio was 2.4. Enhanced capacity for spontaneous correction of lumbar curve was evidenced by the mean correction/flexibility ratio of 1.2. Spontaneous correction of lumbar apical translation occurred in all patients. Global coronal imbalance was common before surgery (mean, 11 mm), and remained similarly so after surgery (mean, 12 mm). Use of CBT facilitates 3-dimensional control of corrective forces and allows for maximum selective instrumentation-assisted thoracic and spontaneous lumbar curve correction in patients with Lenke 1C or 2C IS.

Posterior Only Versus Combined Anterior and Posterior Approaches to Lumbar Scoliosis in Adults

Retrospective study. To compare the radiographic lumbar curve correction between a posterior only and combined anterior-posterior approach in patients with adult spinal deformity. In adolescent idiopathic scoliosis correction, posterior only has been compared with the combined anterior-posterior approach; however, there have been no corollary studies in adult scoliosis. Traditionally, rigid lumbar curves have been treated with a combined anterior and posterior approach; however, the absolute indications for this approach are unclear. A total of 180 patients with degenerative or adult idiopathic spinal deformity and curves measuring between 40 degrees and 70 degrees who underwent reconstructive spinal fusion. The minimum follow-up period was 28 months and average follow-up was 53 months. Of the 155 patients who underwent surgery, 80 underwent posterior only (35 with idiopathic and 45 with degenerative scoliosis) while 75 patients (30 with idiopathic and 35 with degenerative scoliosis) underwent combined anterior-posterior surgery. The groups were compared by age at operation, preoperative deformity, levels operated and postoperative correction and balance. There were no significant differences in sagittal and coronal plane curve and balance correction between the posterior only and the combined anterior-posterior groups. When the patients were subdivided into degenerative adult scoliosis and idiopathic adult scoliosis, there were again no significant differences in the sagittal and coronal curves or balance between the posterior only and combined anterior and posterior approaches. While the posterior only group and the same-day anterior and posterior surgery group had a similar major complication rate of 24% and 23%, respectively, patients who underwent staged anterior and posterior surgery had a major complication rate of 45%. When combined with extensive posterior releases, posterior only approach is just as effective as combined anterior and posterior surgery for adult lumbar scoliosis measuring between 40 degrees and 70 degrees .

Predictability of the spontaneous lumbar curve correction after selective thoracic fusion in idiopathic scoliosis

In this study we tried to achieve a better understanding of the biodynamic mechanism of balance in the scoliotic spine. Therefore we focused on the pre- and postoperative spine of patients with idiopathic scoliosis with a primary thoracic curve and a secondary lumbar curve. Several studies showed that the lumbar curve spontaneously corrects and improves after selective thoracic fusion. We try to understand and describe this spontaneous compensatory lumbar curve correction after selective thoracic correction and fusion. We performed a retrospective examination of pre- and postoperative radiographs of the spine of 38 patients with idiopathic scoliosis King type II and III. Frontal Cobb angles of the thoracic and lumbar curves were assessed on pre- and postoperative antero-posterior and side bending radiographs. We determined the postoperative corrections of the thoracic and lumbar curves. Relative (%) corrections and correlations of the postoperative corrections were calculated. The group was divided in three subgroups, depending on lumbar curve modifier, according to Lenkes classification system. The calculations were done for the whole group as for each subgroup. As expected, significant correlations were present between the relative correction of the main thoracic and the lumbar curve (mean R = 0.590; P = 0.001). The relation between relative thoracic and lumbar correction decreased with the lumbar modifier type. This study shows a highly significant correlation between the relative corrections of the main thoracic curve and the lumbar curve after selective thoracic fusion in idiopathic scoliosis. This correlation depends on lumbar curve modifier type. This new classification system seems to be of great predictable value for the spontaneous correction of the lumbar curve. Depending on the curve-type, a different technique for predicting the outcome should be used. The lumbar curve correction does not occur throughout the whole lumbar curve. Most correction is achieved in the upper part of the curve. The distal lumbar curve seems to be more rigid and less important in the spontaneous curve correction.

Analysis of Patients With Nonambulatory Neuromuscular Scoliosis Surgically Treated to the Pelvis With Intraoperative Halo-Femoral Traction

Retrospective case-control study. To compare patients treated with and without intraoperative halo-femoral traction to assess neuromuscular spinal deformity correction as well as the safety of the technique. Optimal sitting balance can be achieved in nonambulatory neuromuscular patients with pelvic obliquity by maneuvering a Galveston-type rod or inserting screws into the iliac wings; however, this is often clinically challenging because of the small, soft bone-stock in the pelvis of these patients. A total of 40 patients with nonambulatory neuromuscular scoliosis were treated surgically with a T2 or T3-sacrum instrumented posterior spinal fusion. There were 20 patients (12 who underwent posterior spinal fusion-alone and 8 anterior/posterior spinal fusion) who had intraoperative halo-femoral traction performed unilaterally on the high side iliac wing compared to a control group of 20 patients (15 who underwent posterior spinal fusion-alone and 5 anterior/posterior spinal fusion) operatively treated without halo-femoral traction. Each group had 14 patients with spastic (cerebral palsy) scoliosis, and 6 with flaccid (muscular dystrophy) scoliosis deformities. Minimum follow-up for all patients was 2 years (range 3-12). Preoperative lumbar scoliosis averaged 87 degrees (range 30 degrees-141 degrees) in the halo-femoral traction group and 67 degrees (range 28 degrees-108 degrees) in the control group (P = 0.012). Postoperative lumbar Cobb decreased to 35 degrees (range 15 degrees-60 degrees) in the halo-femoral traction group and 32 degrees (range 4 degrees-66 degrees) in the control group (P = 0.181). Preoperative pelvic obliquity averaged 26 degrees (range 8 degrees-47 degrees) in the halo-femoral traction group and 17 degrees (range 8 degrees-44 degrees) in the control group (P = 0.017); postoperative averaged 6 degrees (range 1 degrees-23 degrees) in the halo-femoral traction group and 7 degrees (range 0 degrees-27 degrees) in the control group. Average pelvic obliquity correction was 78% in the halo-femoral traction group and 52% in the control group (P = 0.001). There were no intraoperative or postoperative halo-femoral traction apparatus-related complications noted (pin cut-out, femoral fractures, pin-sight infections, etc.). Intraoperative use of halo-femoral traction during the surgical treatment of patients with nonambulatory neuromuscular scoliosis provided significantly improved lumbar curve and pelvic obliquity correction. Intraoperative halo-femoral traction had no associated perioperative complications.

Selective Posterior Thoracic Fusions for Adolescent Idiopathic Scoliosis

A retrospective review of adolescent idiopathic scoliosis (AIS) patients with major thoracic-compensatory lumbar C modifier curves treated with a selective posterior fusion using an all-hook construct versus pedicle screw construct. To compare the clinical and radiographic results of selective posterior thoracic fusion using hooks versus pedicle screws in patients with major thoracic-compensatory lumbar C modifier AIS curves. Although spontaneous lumbar curve correction often occurs following a selective thoracic spinal fusion, there are few reports that focus on selective posterior thoracic spinal fusion in the presence of a lumbar C modifier curve. Sixty-six consecutive patients with major thoracic-compensatory lumbar C modifier AIS curves underwent selective posterior thoracic fusion to T12 or L1 at a single institution (1987-2001). Hooks were used for instrumentation in 32 patients and pedicle screws were used in 34 patients. Patients were evaluated at a minimum 2-year follow-up. To test for differences between groups analysis of covariance (ANCOVA) was used. There was no statistical difference between the preoperative thoracic and lumbar Cobb values for the hook group versus the pedicle screw group. The amount of correction obtained surgically of the thoracic Cobb and the amount of spontaneous lumbar Cobb correction were significantly greater in the pedicle screw group (P < 0.001). The incidence of postoperative coronal decompensation, with a greater than 20 mm shift to the left of the C7 plumbline, was higher in the hook group (13 patients) as compared with the pedicle screw Group 4 patients (P < 0.005). There were no complications or reoperations in either group. Selective thoracic fusion of main thoracic-compensatory lumbar C modifier AIS curves with pedicle screws allowed for better thoracic correction and less postoperative coronal decompensation than seen with hooks.

Anterior dual rod instrumentation in idiopathic thoracic scoliosis

For anterior correction and instrumentation of thoracic curves single rod techniques are widely used. Disadvantages of this technique include screw pullouts, rod fractures and limited control of kyphosis. This is a prospective study of 23 consecutive patients with idiopathic thoracic scoliosis treated with a new anterior dual rod system. Aim of the study was to evaluate the safety and efficacy of this new technique in the surgical treatment of idiopathic thoracic scoliosis. To the best knowledge of the authors, this is the largest series on dual rod dual screw instrumentation over the entire fusion length in thoracic scoliosis. Twenty-three patients with an average age of 15 years were surgically treated with a new anterior dual rod system through a standard open double thoracotomy approach. Average clinical and radiological follow-up was 28 months (24-46 months). Fusion was carried out mostly from end-to-end vertebra. The primary curve was corrected from 66.6 degrees to 28.3 degrees (57.5% correction) with an average loss of correction of 2.0 degrees at Cobb levels and of 1.3 degrees at fusion levels. Spontaneous correction of the secondary lumbar curve averaged 43.2% (preoperative Cobb angle 41.2 degrees ). The apical vertebral rotation was corrected by 41.1% with a consecutive correction of the rib hump of clinically 66.7%. The thoracic kyphosis measured 29.2 degrees preoperatively and 33.6 degrees at follow-up. In seven patients with a preoperative hyperkyphosis of on average 47.3 degrees thoracic kyphosis was corrected to 41.0 degrees . This new instrumentation enables an entire dual rod instrumentation over the whole thoracic fusion length. It offers primary stability without the need of postoperative bracing. Dual screw dual rod instrumentation offers the advantages of a high screw pullout resistance, an increased overall stability and satisfactory sagittal plane control.

Selektive ventrale Derotationsspondylodese bei idiopathischen Thorakalskoliosen: eine prospektive Studie

Radiometric curve analysis of instrumented primary and spontaneous secondary curve correction after anterior correction and fusion of idiopathic thoracic scoliosis. Sixty-four patients with idiopathic thoracic scoliosis were prospectively evaluated. All patients were operated either with the Zielke-VDS or with a primary stable double rod instrumentation with selective fusion of the thoracic curve from end-to end-vertebra. Follow-up averaged 29 months (24 - 52 months). The Cobb angle of the primary curve averaged 63.2 degrees preoperatively and was corrected to 21.4 degrees postoperatively with an average loss of correction of 5.3 degrees (58 % final curve correction). Apical thoracic vertebral rotation was corrected by 48 %. The secondary lumbar curve measured 38.2 degrees preoperatively (72 % correction on the bending films) and was spontaneously corrected by 57 % to 16.4 degrees without significant loss of correction in the final follow-up. Apical vertebral rotation averaged 11.3 degrees in the lumbar curve and was corrected spontaneously by 24 % to 8.6 degrees without significant loss of correction. Lumbar apex vertebra deviation showed no significant reduction. There was no case of lumbar curve decompensation in either frontal or sagittal plane. Implant related complications were observed in 7 patients (rod breakage), but no pseudarthrosis occurred. There were no neurological complications noted. Selective anterior correction and fusion in idiopathic thoracic scoliosis enables a satisfactory correction of both primary and lumbar secondary curves. The advantage of selective anterior correction and fusion of thoracic scoliosis is the short fusion length, better derotation and satisfactory correction of the secondary lumbar curve. The disadvantages of single threaded rod techniques in terms of lack of primary stability and a kyphogenic effect have been eliminated by the development of a primary stable, small size double rod instrumentation.