Correction Of Pelvic Obliquity Research Articles

Spine deformities in patients with cerebral palsy; the role of the pelvis.

IntroductionProgressive neuromuscular spinal deformities with pelvic obliquity and loss of sitting balance are typical features of severely affected patients with cerebral palsy. The pelvis represents the key bone between the spine and the lower extremity when it comes to deciding whether and when to operate and if spine or hip surgery first is beneficial. The pelvis can be looked at as the lowest vertebra and as the rooftop of the lower extremities.Biomechanical considerationsTo allow for a normal spinal shape, the pelvis needs to be horizontal in the frontal plane and mildly anterior tilted in the sagittal plane, less for sitting and more for standing. Any abnormal pelvic position requires spinal compensation and challenges the equilibrium control of the individual. Both anatomical neighbourhoods – the spine and the hip joints — have to be considered when spinal deformities, hip instability and contractures evolve, in conservative therapy (bracing, physiotherapy, seating in the wheelchair) and when surgical interventions are weighed out against each other.Surgical considerationsMultiple anatomical factors such as sagittal profile and pelvic orientiation, pelvic transverse plane asymmetries and lumbosacral malformations have to be considered in case the pelvis is instrumented with sacral and iliac screws. Rotational deformities and asymmetries of the pelvic bones make the safe insertion of long screws challenging. Advantages of primary pelvic fixation include correction of pelvic obliquity, especially considering the lever arm of the whole spinal construct. The risk of revision surgery due to progression of distal curves is also reduced. Disadvantages of pelvic fixation include the complexity of the additional intervention, which may result in longer operating times, increased risk of blood loss, infection and hardware malpositioning.

Clinical Effectiveness of S2-Alar Iliac Screws in Spinopelvic Fixation in Pediatric Neuromuscular Scoliosis: Systematic Literature Review.

Study Design:Systematic literature review.Objectives:To comprehensively review the S2-alar iliac (S2-AI) screw technique for pelvic fixation in pediatric neuromuscular scoliosis.Methods:Articles identified from the PubMed and EMBASE databases were reviewed for relevance and applicability, and the studies were summarized.Results:Eight articles met the inclusion criteria. A total of 277 pediatric patients underwent spinopelvic fixation using S2-AI fixation for neuromuscular scoliosis; the mean follow-up was 3 years (range = 0.75-6 years). Six articles had level III evidence (5 retrospective cohort studies, 1 observational study), and 2 articles had level IV evidence (case series). Wound complications occurred in 34 (12.2%) patients. Instrumentation complications occurred in 36 patients (13.0%), including lucency around the screw (6.5%), screw fracture (3.6%), disengaging of the set/screw or rod from the tulip head (2.8%), and screw displacement (0.7%). Three patients (1.1%) required reoperation for instrumentation failures. The overall reoperation rate—including 3 hardware replacements and 3 cases of L5-S1 pseudarthrosis—was 2.1%. The mean Cobb angle correction was 51.4°, and the mean pelvic obliquity correction was 14.8°; deformity correction was maintained at 3- and 5-year follow-ups. There were 10 (3.6%) cases of implant prominence/implant-related pain, 1 case of sacroiliac joint pain (resolved with longer screw placement), and no major neurological or vascular complications secondary to S2-AI screw placement.Conclusions:This review suggests that the use of S2-AI screws in pediatric neuromuscular scoliosis is efficacious with a reasonable safety profile and provides a useful technique for pelvic fixation in children with scoliosis.

Pelvic Obliquity Correction in Distraction-Based Growth Friendly Implants

DesignMulticenter retrospective review. ObjectiveTo evaluate radiographic outcomes and complication rates of patients treated with distraction based implants and pelvic fixation with either screws (sacral-alar-iliac [SAI] screws or iliac screws) or hooks (S hook iliac fixation). Summary of Background DataMultiple options exist for pelvic fixation in distraction-based growing rod systems; however, limited comparative data are available. MethodsEarly-onset scoliosis (EOS) patients of all diagnoses with distraction-based implants that had pelvic fixation from 2000 to 2013 were reviewed from two EOS multicenter databases. Patients were divided into two groups by type of pelvic fixation: (1) screw group (SAI screws or iliac screws) or (2) S hooks. Exclusion criteria were as follows: index instrumentation ≥10 years old and follow up <2 years. A total of 153 patients met the inclusion criteria. Mean age at index surgery was 6.1 years (range 1.0-9.9 years) and mean follow-up was 4.9 years. ResultsPelvic fixation in the 153 patients was as follows: screw group = 42 and S hook group = 111. When comparing patients with >20° of initial pelvic obliquity, the screw group had significantly more correction; mean 26° ± 13° for the screw group versus mean 17° ± 7° in the S hook group (p = .039). There was no significant difference in change in T1–S1 length (40 vs. 39 mm, p = .89) or correction of Cobb angle (30° vs. 24°, p = .24). The total complication rate for the screw group was 14% (6/42) versus 25% (28/111) in the S hook group, though this did not achieve significance (p = .25). The most common complications were device migration (13), implant failure (8), and implant prominence (4) for S hooks and implant failure (3), implant prominence (2), and device migration (1) for the screw group. ConclusionIn distraction-based growth-friendly constructs, pelvic fixation with screws achieved better correction of pelvic obliquity than S hooks. Complications were almost twice as common with S hooks than screws, though this did not reach statistical significance.

Sublaminar polyester band fixation construct in the treatment of neuromuscular scoliosis.

PurposeMultiple fixation techniques exist for treating progressive neuromuscular scoliosis including pedicle screws, sublaminar bands/wires, hooks or a combination of instruments. Most sublaminar band constructs are supplemented with pedicle screws, hooks and/or sublaminar wires particularly at the top of the construct. There are no studies to date that describe an all/predominant sublaminar band construct. The purpose of this study was to investigate the outcomes of a sublaminar polyester band construct to treat neuromuscular scoliosis.MethodsA retrospective review was conducted of 32 cases of neuromuscular scoliosis treated with posterior spinal fusion using a sublaminar band construct between 2013 and 2016 by a single surgeon at a single centre. Preoperative, immediate postoperative and two-year follow-up radiographs and clinical records were reviewed. Sagittal, coronal and pelvic obliquity correction was measured. Blood loss, length of surgery and complications were recorded.ResultsIn all, 29 patients were included. Mean postoperative coronal plane correction was 57% (0% to 92%) and maintained at two-year follow-up. Mean sagittal balance was 2.3 cm (-2.5 to 6.4). Mean lumbar lordosis angle decreased by 7° (44° to 37°). Mean thoracic kyphosis angle increased by 9° (23° to 32°). Mean pelvic obliquity decreased by 50% (from 15° to 7°). There were four major complications (14%) and eight minor complications (21%). Mean blood loss was 1304 cc (250 cc to 2450 cc).ConclusionSublaminar polyester band fixation constructs provide a viable option in correction of deformity in patients with neuromuscular scoliosis with comparable outcomes with what is reported with other constructs.Level of Evidence:V

Pedicle Subtraction Osteotomy Versus Multiple Posterior Column Osteotomies in Severe and Rigid Neuromuscular Scoliosis.

Retrospective analysis. The aim of this study is to compare the safety and efficacy of the apical pedicle subtraction osteotomy (PSO) technique with multiple posterior column osteotomies (PCOs) in nonambulatory patients with severe, rigid neuromuscular scoliosis. Neuromuscular scoliosis frequently causes intolerance to sitting due to pelvic obliquity, trunk decompensation, and associated back and rib impingement pain which diminish the patient's functional capacity. In the case of rigid curves, spinal osteotomy techniques are occasionally required for effective correction. We retrospectively reviewed our patients with severe and rigid neuromuscular scoliosis with associated pelvic obliquity who were treated with posterior instrumented fusion extending to pelvis with more than 1-year postoperative follow-up. We compared radiological and clinical results of PSO and multiple PCO techniques in severe rigid neuromuscular scoliosis with pelvic obliquity of more than 15° in traction radiograph under general anesthesia. Hospital records were also reviewed for operative time, intraoperative blood loss, amount of blood transfusion, duration of hospital stay, and complications. There were 12 patients in the PSO group and 10 patients in the PCO group. There was no significant difference between groups in terms of major curve magnitude, sagittal parameters or pelvic obliquity. Although not statistically significant, PSO technique did trend toward better scoliosis correction (post-op Cobb angle 56.1° vs. 66.7° [P = 0.415]). PSO technique provided a significantly better correction in pelvic obliquity (59% vs. 84%) (P = 0.001). There was no significant difference in average intraoperative blood loss, transfusion, and operative times including anesthesia time, hospital stay, or complications. PSO may be an option in correction of severe and rigid neuromuscular scoliosis. It provides better correction of pelvic obliquity without increasing operative time, need for transfusion, or duration of hospitalization as compared to multiple apical PCO technique. Traction radiograph under general anesthesia is a valuable tool in surgical decision making. 4.

Comparison of combined anterior-posterior approach versus posterior-only approach in neuromuscular scoliosis: a systematic review and meta-analysis.

Neuromuscular scoliosis (NS) is a complicated spinal disorder, and it could be treated through posterior-only approach (POA) or combined anterior-posterior approach (APA), which one is better and how to choose the surgical tactic is still in controversy. So comparing POA with APA parameters in the treatment of NS is meaningful. Database of PubMed, Embase and Cochrane Library was systematically searched, and the studies, which focus on the comparisons of POA and APA in the treatment of NS, were included. The meta-analysis was performed by RevMan 5.3. Seven retrospective studies with 602 patients were included in meta-analysis. In previous analysis, statistically significant differences were observed in the major parameters between APA and POA. However, the results of subgroup meta-analysis, which focused on the correction angle and loss angle to eliminate the influence of different preoperative angles, were tend to no difference between two groups, except loss angle of scoliosis (MD, 6.4; 95% CI -0.19 to 13) and correction angle of pelvic obliquity (MD, -3.44; 95% CI -6.71 to -0.17). Our meta-analysis suggested that POA was similar to APA in the correction of scoliosis in coronal and sagittal planes. However, APA had advantages in the correction of pelvic obliquity and decreasing the loss of angle between postoperation and follow-up in main scoliosis, whereas POA had advantages in operative time, blood loss, duration of hospital stay and complications. Level II. These slides can be retrieved under Electronic Supplementary Material.

Segmental Pedicle Screw Instrumentation and Fusion Only to L5 in the Surgical Treatment of Flaccid Neuromuscular Scoliosis.

A retrospective cohort study was performed. The purpose of this study was to determine the efficacy and safety of stopping segmental pedicle screw instrumentation constructs at L5 in the treatment of neuromuscular scoliosis. Duchenne muscular dystrophy and spinal muscular atrophy are flaccid neuromuscular disorders in which gradual deterioration is the hallmark and have a lot of characteristics in common despite differences in etiology. Instrumentation and fusion to the sacrum/pelvis has been a mainstay in the surgical treatment of flaccid neuromuscular scoliosis and recommended to correct pelvic obliquity. However, the caudal extent of instrumentation and fusion in the surgical treatment of flaccid neuromuscular scoliosis has remained a matter of considerable debate and there have been few studies on the use of segmental pedicle screw instrumentation for flaccid neuromuscular scoliosis. From 2005 to 2007, a total of 27 consecutive patients with neuromuscular disorders (20 Duchenne muscular dystrophy and 7 spinal muscular atrophy), aged 11 to 17 years, underwent segmental pedicle screw instrumentation and fusion only to L5. Assessment was performed clinically and with radiologic measurements. Minimum 2-year follow-up was required for inclusion in this study. Twenty patients were enrolled in this study. No patient was lost to follow-up. All patients had L5 tilt of less than 15° and a coronal curve with apex L2 or higher preoperatively. Preoperative coronal curve averaged 70° (range: 51°-88°), with a postoperative mean of 15° (range: 5°-25°) and 17° (range: 6°-27°) at the last follow-up. The pelvic obliquity improved from 15° (range: 9°-25°) preoperatively to 5° (range: 3°-8°) postoperatively and 6° (range: 3°-8°) at the last follow-up. The L5 tilt improved from 9° (range: 2°-14°) preoperatively to 2° (range: 0°-4°) postoperatively and 2° (range: 0°-5°) at the last follow-up. Physiologic sagittal plane alignment was recreated after surgery and maintained long-term. There was no significant loss of correction of coronal curve and pelvic obliquity. There was no major complication. Segmental pedicle screw instrumentation and fusion to L5 was safe and effective in patients with flaccid neuromuscular scoliosis with apex L2 or higher and minimal L5 tilt of less than 15°. Segmental pedicle screw instrumentation ending at L5 offered the ability to correct spinal deformity and pelvic obliquity initially, intermediate and even long-term, with no major complications. This method in appropriate patients can be a viable alternative to instrumentation and fusion to the sacrum/pelvis in the surgical treatment of flaccid neuromuscular scoliosis. N/A.

Minimally Invasive Surgery for Neuromuscular Scoliosis: Results and Complications in a Series of One Hundred Patients.

Study Design.A retrospective review.Objective.To report the results of an alternative technique using a minimally invasive fusionless surgery. The originality is based on the progressive correction of the deformities with proximal and distal fixation and on the reliability of the pelvic fixation using iliosacral screws on osteoporotic bones.Summary of Background Data.Spinal deformities are common in neuromuscular diseases. Conventional treatment involves bracing, followed by spinal instrumented fusion. Growing rod techniques are increasingly advocated but have a high rate of complications.Methods.The technique relies on a bilateral double rod sliding construct anchored proximally by four hooks claws and distally to the pelvis by iliosacral screws through a minimally invasive approach. Hundred patients with neuromuscular scoliosis underwent the same fusionless surgery extended from T1 to the pelvis. The average age at initial surgery was 11 + 6 years. Diagnoses included cerebral palsy (61), spinal muscular atrophy (22), muscular dystrophy (10), and other neurological etiologies (7). Cobb angle and pelvic obliquity were measured before and after initial surgery, and at final follow-up. Complications were reviewed.Results.At latest follow-up 3 + 9 years (range 2 yr–6 + 3 yr), the mean Cobb angle improved from 89° to 35° which corresponds to 61% correction. Mean pelvic obliquity improved from 29° to 5°, which corresponds to 83% correction. Mean T1-S1 length increased from 30.02 to 37.28 cm. Mean preoperative hyper kyphosis was reduced from 68.44° to 33.29°. Complications occurred in 26 patients including mechanical complications (12) and wound infections (16). No arthrodesis was required at last follow-up.Conclusion.This original fusionless technique is safe and effective, preserving spinal and thoracic growth. It provides a significant correction of spinal deformities and pelvic obliquity with a reduced complications rate. The strength and stability of this modular construct over time allow the avoidance of final arthrodesis.Level of Evidence: 4

Surgical treatment of patients with myelomeningocele-related spine deformities: study of 26 cases.

Scoliosis, kyphosis, and sacral agenesis (SA) are common spine deformities in myelomeningocele (MMC) patients. Surgery of spine deformities in MMC patients is associated with various difficulties as infection, pathological skin breakage, instrumentation failure, and neurological deterioration. The purposes of this study are to share our clinical experience and discuss different surgical techniques which are defined in the literature. We retrospectively evaluated our database of patients with MMC who underwent surgical procedures for spine deformities from 2014 to 2016. Demographic and clinical data, surgical parameters, surgical techniques and levels, pre- and postoperative deformity angles, level of posterior fusion defect, spinal malformations, neurological evaluation of lower extremities and complications were collated. We divided the cases into three groups according to the type of deformities. The groups were lumbar kyphosis (Group 1), congenital scoliosis (Group 2), and paralytic scoliosis (Group 3). There were 26 patients in the study. Fifteen patients were male and 11 patients were female. The median age of the patients was 8.03 (range = 3-17years) at the time of operation. There were 10 patients in Group 1, 7 patients in Group 2, and 9 patients in Group 3. In Group 1, preoperative kyphosis angle varied between 51° and 160°, with an average of 95.7°. In Group 2, preoperative Cobb angle varied between 57° and 150°, with an average of 106.6°. Kyphosis was present in 4 patients. Preoperative kyphosis angle varied between 74° and 140°, with an average of 93°. In Group 3, preoperative Cobb angle varied between 45° and 145°, with an average of 72.5°. Spinal deformity in children with MMC has been considered to cause severe disability. Surgical treatment is a challenging procedure with a wide spectrum of complications, but can provide good correction of spinal deformity and pelvic obliquity, and improve the quality of life. Self-growing systems which are a new alternative to traditional growing rod systems, must be considered to preserve growing potential of spine.

Pelvic Obliquity Correction in Distraction Based Growing Spine Constructs

Pelvic Obliquity Correction in Distraction Based Growing Spine Constructs

Outcomes and complications of S2 alar iliac fixation technique in patients with neuromuscular scoliosis: experience in a third level pediatric hospital.

Multiple techniques are utilized for distal fixation in patients with neuromuscular scoliosis. Although there is evidence of benefit with S2 alar iliac (S2AI) fixation, this remains controversial. The objective of this study is to evaluate the radiological outcomes and complications associated with this surgical technique in a pediatric population. An observational retrospective case series study was performed. All pediatric patients between January 2011 and February 2014 diagnosed with neuromuscular scoliosis associated with pelvic obliquity, which required surgery with fixation unto S2AI, were included. Clinical, radiological findings, and adverse events were presented with measures of central tendency. Comparison of deformity correction was carried out using a non-parametric analysis for related samples (Wilcoxon signed-rank test). Significance was set at P<0.05. A total of 31 patients diagnosed with neuromuscular scoliosis that met inclusion criteria were analyzed. The leading cause of neuromuscular scoliosis in 23 (74.2%) patients was spastic cerebral palsy (CP). The correction of pelvic obliquity in the immediate postoperative period was of 76%, which is statistically significant. The extent of correction that patients maintained at the end of the follow-up was analyzed, and it was found that there were no significant differences in this magnitude, compared with the immediate postoperative pelvic obliquity. The mean follow-up time was 9±7 months. Regarding postoperative adverse events, occurred in 64.5% of patients, the most common outcome was pneumonia (14.8%). The overall rate of complications related to instrumentation was low (1.9%), which corresponds to one patient with an intra-articular screw in the left hip that required repositioning. S2AI fixation for the treatment of neuromuscular scoliosis is a safe alternative, in which the onset of adverse events is related to the comorbidities of patients instead of the surgical procedure itself. An approximate correction of 76% of pelvic obliquity is maintained during the follow-up.

Sacral-Alar-Iliac Fixation in Children with Neuromuscular Scoliosis: Minimum 5-Year Follow-Up.

To investigate the 5-year outcomes of children with neuromuscular scoliosis treated with sacral-alar-iliac screws. We reviewed clinical and radiographic records of patients aged ≤18 years treated by 1 pediatric orthopedic surgeon for neuromuscular scoliosis with spinal fusion using sacral-alar-iliac pelvic anchors. Thirty-eight patients with a minimum 5-year radiographic follow-up (mean, 6.0 ± 1.2 years) were studied. The mean patient age was 13 ± 2.0 years, and 47% were female. The mean number of levels fused was 18 ± 0.7. Two-thirds (66%) of the patients were diagnosed with cerebral palsy. Between the preoperative period and final follow-up, the patients exhibited a mean correction of the major coronal curve of 79% (preoperative, 85° to final, 18°) and a mean 57% correction of the pelvic obliquity (preoperative, 16° to final, 7°). Patients maintained the correction of mean pelvic obliquity from the early postoperative period (6°) to final follow-up (7°). Preoperatively, 76% of the patients had a pelvic obliquity of >10°, compared with 26% of patients postoperatively. There were no cases of neurologic or vascular complications or pseudarthrosis. Radiographs revealed bilateral sacral-alar-iliac screw lucency in 8 patients; 4 of these patients had deep wound infections, and the other 4 were asymptomatic. Unilateral screw fracture was found in 1 patient with an 8-mm-diameter screw (1.3%; 1 of 76 screws); the patient was observed and remained asymptomatic. There were no cases of set screw displacement, screw back-out, or rod dislodgement. Sacral-alar-iliac screws are safe and effective pelvic anchors for use in children with neuromuscular scoliosis.

The Fate of the Neuromuscular Hip After Spinal Fusion.

The goals of treatment of neuromuscular scoliosis are to achieve a balanced spine and level pelvis with most constructs including pelvic fixation. However, the pelvis can become a stiff "end vertebra" that prevents compensatory mechanisms to adjust to hip deformities in this patient population. The purpose of this study is to determine the frequency of hip pathology and surgery after spinal fusion in this patient population. We performed a retrospective chart and radiographic review of cerebral palsy patients who underwent posterior spinal fusion (PSF) at our institution from 2005 to 2011. We collected radiographic data of preoperative and postoperative pelvic obliquity and hip reduction status and position (up, level, down). We further evaluated patients requiring hip surgery (containment or salvage). Of 47 patients with an average follow-up of 3.5 years after spinal fusion, 21 (45%) underwent a hip procedure. Thirty-eight patients (81%) demonstrated or developed hip subluxation/dislocation. Hip pathology occurred more often in the up hip, but the pathologic down hip more often underwent a hip surgery. Eight new hip subluxation/dislocations occurred after spine surgery. Three (38%) of the new postoperative subluxation/dislocations required hip surgery; all had pelvic obliquity <6 degrees. Eleven patients underwent hip surgery before PSF, 7 were varus femoral osteotomies for subluxation, whereas 5 hips required salvage. In follow-up after PSF, none of these had a new dislocation. Ten patients required hip surgery after PSF at a mean of 1.6 years after PSF. Eight patients had a salvage procedure for painful hip and 2 varus femoral osteotomies for subluxations. In our cerebral palsy patients who underwent PSF, 45% of these patients required a hip procedure. In the patients who had containment before PSF, the hips maintained reduction after spinal fixation. After correction of pelvic obliquity, 17% of patients had new-onset hip subluxation/dislocation after PSF. Postoperative subluxation/dislocation was not dependent on whether the hip was up or down preoperatively. IV, Retrospective.

Recurrence of Deep Surgical Site Infection in Cerebral Palsy After Spinal Fusion Is Rare

Study DesignRetrospective review of prospective registry. ObjectivesTo assess the following in children with cerebral palsy (CP) who develop deep surgical site infection (DSSI) after spinal fusion: (1) rate of infection recurrence after treatment; (2) treatments used; (3) radiographic outcomes; and (4) differences in Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) scores versus those of children with no infection (NI). Summary of Background DataStudies show high rates of surgical site infection in patients with CP but do not address late recurrence or quality-of-life effects. MethodsOne hundred fifty-one children with CP underwent spinal fusion surgery from 2008 through 2011 and had ≥2-year follow-up. Patients who developed DSSI were compared with patients with NI. Student t tests were used to analyze deformity; analysis of variance was used to analyze CPCHILD scores in both groups preoperatively and at final follow-up. ResultsEleven patients developed DSSI. Causative organisms were polymicrobial infection (5 cases), Escherichia coli (2 cases), and Proteus mirabilis, Staphylococcus aureus, Enterococcus faecalis, and Peptostreptococcus (1 case each). All patients underwent irrigation and debridement and received at least 6 weeks of antibiotics. Six had negative-pressure-dressing-assisted wound closure; 5 had primary closure. At mean 4-year follow-up (range, 3–5 years) no patient had recurrent infection. From immediate postoperative to final follow-up, no patient had significant loss of coronal curve (p = .77) or pelvic obliquity (p = .71) correction. However, at final follow-up, comfort and emotions, overall quality-of-life, and total CPCHILD scores in the DSSI group were significantly lower compared with the NI group (p = .005, .022, and .026, respectively). ConclusionsIn children with CP who developed DSSI after spinal fusion, there was no recurrence of infection or deformity after infection treatment. CPCHILD scores in patients with DSSI were lower compared with the NI group.

Resolution of pelvic obliquity after correction surgery for congenital scoliosis

Objective To investigate resolution of pelvic obliquity after spinal correction surgery for congenital scoliosis and explore predictor factors of correction of pelvic obliquity after surgery. Methods A retrospective study was performed on congenital scoliosis (CS) patients who underwent scoliosis correction surgery in our hospital from March 2000 to May 2016. A total of 352 patients received correction surgery for scoliosis. According to inclusion criteria and exclusion criteria, 21 CS patients with pelvic obliquity and without leg inequality were included. Of the 21 patients, 9 were males and 12 were females. The mean age was (13.2±10.2) years (range 4 to 36 years). 10 patients were diagnosed as hemivertebrae, 7 as unsegmentation and 4 mixed. 6 CS patients received posterior correction surgery for scoliosis without any osteotomy. 10 received posterior instrumentation and posterior vertebral column resection. 5 received posterior instrumentation and pedicle subtraction osteotomy. The following parameters were measured at pre- and postoperative standing full spine X-ray radiographs: Cobb angle of major curve, trunk shift (TS), pelvic obliquity angle (POA), L5 obliquity angle (L5OA), and lumbar-sacral angle (LSA). Bivariate correlation analysis was conducted to investigate radiographic factors related to correction of pelvic obliquity after surgery. Results Preoperative Cobb angle of major curve improved from 63°±27° to 37°±18° after surgery. Preoperative trunk shift decreased from (42±31) mm to (21±11) mm after surgery. Preoperative pelvic obliquity angle decreased from 16°±7° to 7°±4° after surgery. Preoperative L5 obliquity angle decreased from 23°±11° to 10°±5°after surgery. Preoperative lumbar-sacral angle decreased from 12°±6° to 7°±4° after surgery. The differences of preoperative and postoperative radiographic parameters were statistically significant. Preoperative POA was not correlated to preoperative Cobb angle of major curve, but positively Cobb angle of major curve correlated to preoperative TS, L5OA, and LSA. The difference of pre- and postoperative POA were positively correlated to the differences of pre- and postoperative Cobb angle of major curve, TS, L5OA, and LSA. Conclusion Scoliosis correction surgery could effectively level pelvic for patients with congenital scoliosis and pelvic obliquity. L5OA and LSA could be predictors for pelvic obliquity after scoliosis correction surgery. Key words: Scoliosis; Pelvis; Radiography

The Long-term Outcome of Early Spine Fusion for Scoliosis in Children With Cerebral Palsy.

Retrospective review of radiographs and charts (case-only). The aim of this study was to describe the long-term outcomes of spine fusion for neuromuscular scoliosis in children below 10 years of age with cerebral palsy (CP). Severely involved children with CP may develop early-onset scoliosis. The outcome of spine fusion is not clear and there are no studies focused on spine fusion in this young patient population. This is a retrospective review of 33 children who underwent spine fusion with unit-rod instrumentation between 1989 and 2006 for CP neuromuscular scoliosis, aged below 10 years at spine fusion, and with follow-up >5 years. Demographic, medical, and radiographic data were retrospectively assessed. Repeated measure analysis of variance and Kaplan-Meier survival estimates were used for data assessment. Thirty-three of 42 patients who underwent spine fusion in this period, 19 boys and 14 girls, met the inclusion criteria. Of 9 patients who were excluded, 3 were lost to follow-up and remaining 6 died within 5 years of surgery. Mean age at surgery was 8.3 years (range, 4.4-9.9 y). Mean follow-up was 9.8 years (range, 5.5-15.8 y). Gross motor function classification system level was V in 31 patients and IV in 2 patients. Thirty-one patients (94%) had seizure disorder, 29 patients (88%) had gastric feeding tubes, and 9 patients (27%) had tracheostomy tubes. Eighty-five percent of the patients had posterior-only surgery. Mean Cobb angles preoperative, immediately postoperative, and at final follow-up were 85, 21, and 24 degrees, respectively. Mean postoperative pelvic obliquity correction was 15±9 degrees (P<0.001). At final follow-up, there was no significant change from the postoperative measurements. Complications included 1 deep wound infection and 10 other problems. Eleven patients (28.2%) died after a mean follow-up of 5.6±3.8 years. In our cohort with early-onset neuromuscular scoliosis, spine fusion was associated with minimal short-term and long-term morbidity, but there was 28% mortality at 10 years of follow-up and 50% predicted mortality at 15 years.

Correction of Pelvic Obliquity After Spinopelvic Fixation in Children With Cerebral Palsy: A Comparison Study With Minimum Two-Year Follow-up

Study DesignSingle institution cohort data were collected prospectively and reviewed retrospectively. ObjectivesThis study aims to compare outcomes among three different instrumentation types: unit rod, iliac screws, and sacral alar iliac (SAI) screws in terms of pelvic obliquity correction in children with cerebral palsy (CP). Summary of Background DataThe optimal choice for spinopelvic fixation in CP scoliosis with pelvic obliquity is controversial. MethodsPatients with minimum 2 years' follow-up were divided into three groups according to instrumentation type and matched based on preoperative pelvic obliquity and coronal major curve magnitude. Radiographic measurements included horizontal pelvic obliquity angle (PO), spinopelvic angle (SPA), coronal and sagittal Cobb angles, and T1 pelvic angle. Procedures were performed in one pediatric institution between 2004 and 2012. All measurements were performed by a single independent reviewer who was not involved in the procedures. ResultsSeventy-seven patients (42 unit rod, 14 iliac screw, and 21 SAI screw) were included. Gender and age distribution was similar across all groups (56% males, 44% females, mean age 13.5 years). Mean follow-up was 3.6 years. Comparing pre- and postoperative measurements, there was a significant decrease (p < .05) in PO, SPA, and coronal major cob angle in all groups. No significant loss of correction occurred during follow-up. Postoperatively, TPA improved in all groups. Nonsymptomatic loosening was noted in 59% of unit rods, 57% of iliac screws, and 52% of SAI screws. One prominent iliac screw needed removal. One nonsymptomatic rod fracture, one infected pseudarthrosis, and one rod malposition occurred in unit rod group. ConclusionsThis study suggests that for correction of pelvic obliquity in cerebral palsy scoliosis, iliac and SAI screws were similar to the unit rod in comparative effectiveness and implant safety profile. Level of evidenceTherapeutic study, Level III.

Sacral-Alar-Iliac Fixation in Pediatric Deformity: Radiographic Outcomes and Complications

Study DesignRetrospective case series. ObjectivesTo assess the radiographic outcomes and complications of sacral-alar-iliac (SAI) fixation in children. Summary of Background DataPelvic fixation in children undergoing spinal deformity surgery can be challenging because of complex anatomy, compound biomechanical forces at the lumbosacral junction, and poor bone quality. MethodsRadiographic and clinical records of 80 consecutive patients aged 18 years or younger who underwent posterior spinal fusion surgery with SAI fixation by one pediatric orthopedic surgeon and who had a minimum 2 years of follow-up (mean follow-up: 3.5 years, range, 2–7 years) were retrospectively reviewed. Changes in coronal curve magnitude and pelvic obliquity were assessed using Student t tests. Significance was set at a p value less than .05 for all analyses. ResultsPelvic obliquity correction averaged 77%, from 26 ± 13 degrees before surgery to 6 ± 4 degrees at final follow-up (p < .001); 91% of the patients were corrected to a pelvic obliquity of less than 10 degrees. Coronal curve correction averaged 72%, from 78 ± 27 degrees before surgery to 22 ± 15 degrees at final follow-up (p < .001). No patient had vascular or neurologic complications or died perioperatively. Twenty patients (25%) had radiographic evidence of implant-related problems, of which there were nine screw fractures (all in the neck of screws with ≤8-mm outer diameter). Six patients had symptomatic complications associated with SAI fixation (three patients with pseudarthrosis at the lumbosacral junction, all of whom required revision surgery, two patients with implant prominence, and one patient with pain related to implant). Other complications included seven instances of wound dehiscence, three deep wound infections, and one superficial wound infection. ConclusionsSAI fixation provided a low-profile alternative to iliac screws for the correction of pelvic obliquity. The largest possible diameter screws are recommended, ideally >8 mm. Level of EvidenceLevel 4.

Sacral Alar Iliac Fixation for Spine Deformity.

As the anatomy of the lumbosacral junction presents a unique challenge for the spine surgeon with regard to achieving a solid fusion, we describe the sacral alar iliac (SAI) technique, which can be used for the placement of pelvic anchors during posterior spinal arthrodesis. Position the patient prone on a radiolucent table. In approaching the starting point, perform limited dissection of the soft tissue between the S1 and S2 dorsal foramina, while taking care to minimize unnecessary dissection and blood loss. As the ideal screw pathway is one-third in the sacral ala and two-thirds in the ilium, start at the junction between the 1st and 2nd sacral segments, cross the sacroiliac joint, travel caudally toward the sciatic notch, cross between the inner and outer table of the ilium, and end close to the anterior inferior iliac spine cranial to the acetabular roof (Figs. 5-A and 5-B). In most children and adults, use screws with an outer diameter ≥9 mm, which are recommended to prevent screw breakage. Ensure that the SAI screws are in line with the remainder of the spinal anchors to allow for ease of rod insertion. Perform carefully layered wound closure per routine at the end of the case, with special attention to meticulous hemostasis. In a review of the cases of 32 pediatric patients treated with SAI fixation, Sponseller et al.27 reported a mean pelvic obliquity correction of 70% and a mean major coronal Cobb angle correction of 67%.

Are S1 Screws a Useful Adjunct to Iliac Screws in Long Fusions to the Sacrum in Cerebral Palsy?

Multicenter prospective database review of patients with cerebral palsy (CP) and spinal deformity. To determine if the type of distal fixation is associated with improved correction of coronal deformity or pelvic obliquity (PO) at 2 years in long posterior fusions to the sacrum. Multiple techniques are utilized for distal fixation in patients with CP. Although there is emerging evidence that the augmentation of iliac screws with S1 screws may be beneficial, this remains controversial. A prospective, multicenter database was used to identify patients with CP who underwent long posterior fusions to the sacrum. Eighty-eight patients were included, 52 with iliac screws (I) and 36 with iliac and S1 screws (IS) for distal fixation. Preoperative, first erect, and 2-year follow-up radiographs and complications were analyzed. Statistical analysis was performed using ANOVA and repeated measures ANOVA with significance set at P < 0.05. Scoliosis was the primary deformity in greater than 90% of patients in both groups (P=0.84). Preoperative coronal deformity was similar (I = 83°, IS = 87°, P = 0.49), but correction was better with the use of S1 screws on the first erect radiograph and at 2 years (I = 35°, IS = 22°, P = 0.001), reflecting correction of 58% and 74% for iliac and iliac-S1 screws, respectively (P < 0.001). Preoperative PO was similar (I = 29°, IS = 30°, P = 0.71) and was noted to improve more in the iliac-S1 group by 2 years (I = 11°, IS = 5°, P = 0.004), representing correction of 60% and 77% for the iliac and iliac-S1 groups, respectively (P = 0.018). There was no difference in the rate of major (P = 0.27) or minor (P = 0.65) complications in either group. Bilateral S1 and iliac screws are associated with improved spinal deformity and PO correction at 2 years in the CP population. Two points of distal fixation, S1, and ilium should be considered for this population. 3.