Aims. Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated soft tissue contractures not only imbalances the pelvis, but also poses the risk of dislocation, accelerated polyethylene liner wear, and early loosening. Methods. In all, ten hips in ten patients with PPRP with fixed pelvic obliquity who underwent THA as per an algorithmic approach in two centres from January 2014 to March 2018 were followed-up for a minimum of two years (2 to 6). All patients required one or more additional soft tissue procedures in a pre-determined sequence to correct the pelvic obliquity. All were invited for the latest clinical and radiological assessment. Results. The mean Harris Hip Score at the latest follow-up was 79.2 (68 to 90). There was significant improvement in the coronal pelvic obliquity from 16.6. o. (SD 7.9. o. ) to 1.8. o. (SD 2.4. o. ; p < 0.001). Radiographs of all ten hips showed stable prostheses with no signs of loosening or migration, regardless of whether paralytic or non-paralytic hip was replaced. No complications, including dislocation or infection related to the surgery, were observed in any patient. The subtrochanteric shortening osteotomy done in two patients had united by nine months. Conclusion. Simultaneous correction of soft tissue contractures is necessary for obtaining a stable hip with balanced pelvis while treating hip arthritis by THA in patients with PPRP and fixed pelvic obliquity. Cite this article: Bone Jt Open 2021;2(9):696–704

Aims. Hip dysplasia (HD) leads to premature osteoarthritis. Timely detection and correction of HD has been shown to improve pain, functional status, and hip longevity. Several time-consuming radiological measurements are currently used to confirm HD. An artificial intelligence (AI) software named HIPPO automatically locates anatomical landmarks on anteroposterior pelvis radiographs and performs the needed measurements. The primary aim of this study was to assess the reliability of this tool as compared to multi-reader evaluation in clinically proven cases of adult HD. The secondary aims were to assess the time savings achieved and evaluate inter-reader assessment. Methods. A consecutive preoperative sample of 130 HD patients (256 hips) was used. This cohort included 82.3% females (n = 107) and 17.7% males (n = 23) with median patient age of 28.6 years (interquartile range (IQR) 22.5 to 37.2). Three trained readers’ measurements were compared to AI outputs of lateral centre-edge angle (LCEA), caput-collum-diaphyseal (CCD) angle, pelvic obliquity, Tönnis angle, Sharp’s angle, and femoral head coverage. Intraclass correlation coefficients (ICC) and Bland-Altman analyses were obtained. Results. Among 256 hips with AI outputs, all six hip AI measurements were successfully obtained. The AI-reader correlations were generally good (ICC 0.60 to 0.74) to excellent (ICC > 0.75). There was lower agreement for CCD angle measurement. Most widely used measurements for HD diagnosis (LCEA and Tönnis angle) demonstrated good to excellent inter-method reliability (ICC 0.71 to 0.86 and 0.82 to 0.90, respectively). The median reading time for the three readers and AI was 212 (IQR 197 to 230), 131 (IQR 126 to 147), 734 (IQR 690 to 786), and 41 (IQR 38 to 44) seconds, respectively. Conclusion. This study showed that AI-based software demonstrated reliable radiological assessment of patients with HD with significant interpretation-related time savings. Cite this article: Bone Jt Open 2022;3(11):877–884

Introduction. While research has been carried out widely for sagital pelvic tilt, research reports for coronal pelvic obliquity are few. The aim of this study is to evaluate changes of the pelvic obliquity before and after total hip arthroplasty. Material and Methods. This retrospective study includes 146 cases of hips that were received total hip arthroplasty. There were 20 cases of revision, and 2 cases of re-revision. 17 cases were received bilateral total hip arthroplasty. The standing plain X-ray was used for evaluation of the pelvic obliquity in both before and 1-year after surgery. The correlation of pelvic obliquity was assessed between before and after surgery. 146 cases were classified into 3 groups (A, B, and C) according to the severity of the pelvic obliquity (0º−3º, 3º−6º, and >6º). Among the groups, statistical analysis was evaluated in the leg length discrepancy and the range of motion of the hip (flexion, extension, abduction, adduction, internal and external rotation) before and after surgery with 95% confidence intervals. Results. The mean pelvic obliquity angle was 2.6º with the range of 0 to 15.9º preoperatively, while the mean angle was 2.0º with the range of 0 to 8.8º postoperatively. There was statistical correlation in pelvic obliquity between before and after surgery. The mean leg length discrepancy was −8.3 before surgery, and was 0.1 after surgery. Comparing three groups of pelvic obliquity, preoperative leg length discrepancy was significantly longer in larger pelvic obliquity groups. The range of motion in hip flexion was also significantly smaller in larger pelvic obliquity groups. There were not significant differences in postoperative leg length discrepancy and other parameters. Discussion. The most important finding of present study was that postoperative pelvic obliquity related only the preoperative leg length discrepancy and the range of motion in hip flexion. We expected that pelvic obliquity is improved by correction of leg length difference. Nevertheless, there were not significant differences in postoperative leg length discrepancy. This indicated that contracture of the hip joint is contribute to pelvic obliquity more than leg length discrepancy. Previous study reported that pelvic obliquity would be improved by physical therapy 4 to 6 month after surgery. However, in our data, pelvic obliquity still remained at 1-year follow up. Moreover, postoperative pelvic obliquity related the preoperative range of motion in hip flexion. Therefore, preoperative pelvic obliquity is one of the most important parameter to make decision of postoperative leg length discrepancy. There is certain limitation in our study. We did not assess patient outcome in each groups. Extensive studies are needed to reveal correlation between pelvic obliquity and patient outcome. Conclusion. Pelvic obliquity related the preoperative leg length discrepancy and the range of motion in hip flexion. Contracture of the hip joint may cause pelvic obliquity

Introduction: Pelvic obliquity is a constant problem in neuromuscular scoliosis. Galveston and Luque L rod techniques are well described and achieve good correction of pelvic obliquity. We describe a sacral and iliac screw construct integrated with double-rod, pedicle screws and hook system, for correction of pelvic obliquity. Method: 44 patients underwent posterior or combined anterior and posterior fusion to pelvis, for correction of neuromuscular scoliosis and pelvic obliquity. Average age at the time of surgery was 13.8 years. All patients were wheelchair-bound and nine of them were therapeutic walkers. Average follow-up was 44 months (range 24–69 months). Twenty-six patients had combined anterior and posterior surgery. All patients had posterior instrumentation to pelvis and 18 had anterior instrumentation as well. Eighteen patients had posterior instrumented fusion alone. Anterior instrumentation (when used) was Synergy and posterior instrumentation was Synergy or Colorado for all patients. Result: Average time for surgery was 5 hours and 20 minutes and average blood loss 3600 ml. The average pre-operative Cobb angle was 69° and pelvic obliquity 23°. Post-operative average Cobb angle was 29° and pelvic obliquity 7.5°. At the latest follow-up the average Cobb angle was 36° and pelvic obliquity 10°. There were three deep wound infections. Two of the sacral screws have become prominent and two patients had de-linking of the iliac screw with the rod on one side. None showed significant loss of correction. Conclusion: The sacraliliac screw construct with double rod segmental instrumentation achieved good correction of pelvic obliquity in patients with neuromuscular scoliosis. Implant related problems were infrequent

Introduction. Limb-length discrepancy (LLD) is a common postoperative complication after total hip arthroplasty (THA). This study focuses on the correlation between patients’ perception of LLD after THA and the anatomical and functional leg length, pelvic and knee alignments and foot height. Previous publications have explored this topic in patients without significant spinal pathology or previous spine or lower extremity surgery. The objective of this work is to verify if the results are the same in case of stiff or fused spine. Methods. 170 patients with stiff spine (less than 10° L1-S1 lordosis variation between standing and sitting) were evaluated minimum 1 year after unilateral primary THA implantation using EOS® images in standing position (46/170 had previous lumbar fusion). We excluded cases with previous lower limbs surgery or frontal and sagittal spinal imbalance. 3D measures were performed to evaluate femoral and tibial length, femoral offset, pelvic obliquity, hip-knee-ankle angle (HKA), knee flexion/hyperextension angle, tibial and femoral rotation. Axial pelvic rotation was measured as the angle between the line through the centers of the hips and the EOS x-ray beam source. The distance between middle of the tibial plafond and the ground was used to investigate the height of the foot. For data with normal distribution, paired Student's t-test and independent sample t-test were used for analysis. Univariate logistic regression was used to determine the correlation between the perception of limb length discrepancy and different variables. Multiple logistic regression was used to investigate the correlation between the patient perception of LLD and variables found significant in the univariate analysis. Significance level was set at 0.05. Results. Anatomical femoral length correlated with patients’ perception of LLD but other variables were significant (the height of the foot, sagittal and frontal knee alignment, pelvic obliquity and pelvic rotation more than 10°). Interestingly some factors induced an unexpected perception of LLD despite a non-significant femoral length discrepancy less than 1cm (pelvic rotation and obliquity, height of the foot). Conclusions. LLD is a multifactorial problem. This study showed that the anatomical femoral length as the factor that can be modified with THA technique or choice of prosthesis is not the only important factor. A comprehensive clinical and radiological evaluation is necessary preoperatively to investigate spinal stiffness, pelvic obliquity and rotation, sagittal and coronal knee alignment and foot deformity in these patients. Our study has limitations as we do not have preoperative EOS measurements for all patients. We cannot assess changes in leg length as a result of THA. We also did not investigate the degree of any foot deformities as flat foot deformity may potentially affect the patients perception of the leg length. Instead, we measured the distance between the medial malleolus and ground that can reflect the foot arch height. More cases must be included to evaluate the potential influence of pelvis anatomy and functional orientation (pelvic incidence, sacral slope and pelvic tilt) but this study points out that spinal stiffness significantly decreases the LLD tolerance previously reported in patients without degenerative stiffness or fusion

The patients were reviewed with the aim of determining whether extending the fusion to the sacrum was needed or would affect the pelvic obliquity over the long term. Twenty-four patients with quadriplegic cerebral palsy, (non-ambulators) aged between 5–23 who underwent corrective surgery for their scoliosis were included in the study. Twelve patients were stabilized to the sacrum (LUQUE-Galveston technique) and 12 to L4 or L5 in the lumbar spine using pedicle screws. The patients were divided into two groups. Group 1 Pelvic obliquity less than 20° – no stabilisation to the pelvis. Group 2 Pelvic obliquity more than 20° – stabilisation to the pelvis. Group 1 – Patients with pre-operative pelvic obliquity less than 20° maintained their pre-operative pelvic obliquity without significant deterioration (less than 6° change). Group 2 – Patients with pelvic obliquity of 20° or more stabilised to the sacrum maintained or improved their correction until fusion. One patient had a draining sinus six months after the index operation for which removal of metalware (after fusion) was needed. No patient had a non union of the fusion mass. We believe that patients with a pelvic obliquity of less than 20 degrees at the time of surgery don’t need stabilization to the pelvis. Lumbar pedicle screws give sufficient stability to the distal construct and preserve mobility at the lumbosacral junction. Operative times and blood loss were reduced in those patients not fixed to the pelvis. There appears to be no significant loss of correction of the pelvis obliquity over time

Introduction: The study was to evaluate the effectiveness using a new type of instrumentation, a U-rod, in the treatment of neuromuscular scoliosis. This technique provides a method of secure fixation and excellent correction in neuromuscular curves, including correction of pelvic obliquity by terminating the rod construct in pedicle screws at Lumbar 5 without crossing the lumbosacral joint. The need for surgery for progressive neuromuscular scoliosis is not controversial. However, often the type of instrumentation to be used is. Initially, Luque rods provided strong segmental fixation and the advent of the unit rod allowed strong segmental fixation with excellent fixation to the pelvis. However, there are cases where instrumentation to the pelvis is neither feasible nor necessary. The U-rod offers the structural stability of a unit rod, being one continuous rod, avoiding the instability often seen with linked Luque rods, but without the need to invade the pelvis. The U-rod terminates in pedicle screws at Lumbar 4 or 5, is fixed segmentally to the remainder of the spine, and connects pelvic obliquity through the pull of the iliolumbar ligaments. Methods and Results: 11 patients have been treated with the U-rod, all for neuromuscular curves. Minimum follow-up is two years. Primary indications for use of the U-rod are: 1) ambulatory neuromuscular patient, 2) a lumbar curve with less than 15° tilt of Lumbar 5 on Sacral 1, despite the degree of pelvic obliquity, 3) a non-ambulatory neuromuscular patient meeting the above criteria for lumbar tilt/and/or pelvic obliquity. Correction of curves has been excellent, accomplished either by posterior instrumentation alone or posterior instrumentation following anterior discectomy. The greater the degree of correction of the lumbar curve, the greater the correction of the pelvic obliquity Pelvic obliquity of up to 45° has been corrected with instrumentation to Lumbar 5 and the correction has been maintained. Conclusions: In selected patients, the U-rod offers the ability to correct neuromuscular curves, including those with significant pelvic obliquity , without the necessity to invade the pelvis or cross the Lumbar 5 Sacral 1 joint. This is important in ambulatory neuromuscular patients. In non-ambulatory patients the unit rod offers convenience, decreased operative time, blood loss, and preserving the iliac crest for bone grafting

Pelvic bone defect in patients with severe congenital dysplasia of the hip (CDH) lead to abnormalities in lumbar spine and lower limb alignment that can determine total hip arthroplasty (THA) patients' outcome. These variables may be different in uni- or bilateral CDH. We compared the clinical outcome and the spinopelvic and lower limb radiological changes over time in patients undergoing THA due to uni- or bilateral CHD at a minimum follow-up of five years. Sixty-four patients (77 hips) undergoing THA due to severe CDH between 2006 and 2015 were analyzed: Group 1 consisted of 51 patients with unilateral CDH, and group 2, 113 patients (26 hips) with bilateral CDH. There were 32 females in group 1 and 18 in group 2 (p=0.6). The mean age was 41.6 years in group 1 and 53.6 in group 2 (p<0.001). We compared the hip, spine and knee clinical outcomes. The radiological analysis included the postoperative hip reconstruction, and the evolution of the coronal and sagittal spinopelvic parameters assessing the pelvic obliquity (PO) and the sacro-femoro-pubic (SFP) angles, and the knee mechanical axis evaluating the tibio-femoral angle (TFA). At latest follow-up, the mean Harris Hip Score was 88.6 in group 1 and 90.7 in group 2 (p=0.025). Postoperative leg length discrepancy of more than 5 mm was more frequent in group 1 (p=0.028). Postoperative lumbar back pain was reported in 23.4% of the cases and knee pain in 20.8%, however, there were no differences between groups. One supracondylar femoral osteotomy and one total knee arthroplasty were required. The radiological reconstruction of the hip was similar in both groups. The PO angle improved more in group 1 (p=0.01) from the preoperative to 6-weeks postoperative and was constant at 5 years. The SFP angle improved in both groups but there were no differences between groups (p=0.5). 30 patients in group 1 showed a TFA less than 10º and 17 in group 2 (p=0.7). Although the clinical outcome was better in terms of hip function in patients with bilateral CDH than those with unilateral CDH, the improvement in low back and knee pain was similar. Patients with unilateral dysplasia showed a better correction of the PO after THA. All spinopelvic and knee alignment parameters were corrected and maintained over time in most cases five years after THA

For clinical movement analysis, optical marker-based motion capture is the gold standard. With the advancement of AI-driven computer vision, markerless motion capture (MMC) has emerged. Validity against the marker-based standard has only been examined for lightly-dressed subjects as required for marker placement. This pilot study investigates how different clothing affects the measurement of typical gait metrics. Gait tests at self-selected speed (4 km/h) were performed on a treadmill (Motek Grail), captured by 9 cameras (Qualisys Miqus, 720p, f=100Hz) and analyzed by a leading MMC application (Theia, Canada). A healthy subject (female, h=164cm, m=54kg) donned clothes between trials starting from lightly dressed (LD: bicycle tight, short-sleeved shirt), adding a short skirt (SS: hip occlusion) or a midi-skirt (MS: partial knee occlusion) or street wear (SW: jeans covering ankle, long-sleeved blouse), the lattern combined with a short jacket (SWJ) or a long coat (SWC). Gait parameters (mean±SD, t=10s) calculated (left leg, mid-stance) were ankle pronation (AP-M), knee flexion (KF-M), pelvic obliquity (PO-M) and trunk lateral lean (TL-M) representing clinically common metrics, different joints and anatomic planes. Four repetitions of the base style (LD) were compared to states of increased garment coverage using the t-test (Bonferroni correction). For most gait metrics, differences between the light dress (LD) and various clothing styles were absent (p>0.0175), small (< 2SD) or below the minimal clinically important differences (MCID). For instance, KF-M was for LD=10.5°±1.7 versus MD=12.0°±0.5 (p=0.07) despite partial knee cover. AP-M measured for LD=5.2°±0.6 versus SW=4.1°±0.7 (p<0.01) despite ankle cover-up. The difference for KF-M between LD=10.5°±1.7 versus SWL=6.0°±0.9, SW and SWJ (7.6°±1.5, p<0.01) indicates more intra-subject gait variability than clothing effect. This study suggests that typical clothings styles only have a small clinically possibly negligible effect on common gait parameters measured with MMC. Thus, patients may not need to change clothes or be instructed to wear specific garments. In addition to avoiding marker placement, this further increases speed, ease and economy of clinical gait analysis with MMC facilitating high volume or routine application

Objective: This study investigates whether fixation down to lumbar spine only can prevent pelvic tilt compared to pelvic fixation, in the surgical treatment of Duchenne Muscular Dystrophy (DMD). Design: Retrospective and prospective clinical outcome study, with long-term follow up. Materials and Methods: Nineteen cases of DMD with scoliosis had early stabilisation (mean age 11.5 years, range 9–16) with sublaminar wires and rods, and pedicle screws up to the lumbar spine. This cohort was followed up for a mean 4.2 years (3–10 years). 31 cases in another centre had late stabilisation (mean age 14.5 years, range 10–17), with Luque rod and sublaminar wire fixation, and pelvic fixation using L-rod (22 cases) configuration or Galveston technique (9 cases) and were followed up for 4.6 years (0.5–11.5 years). Post-op morbidity, Cobb angle correction and pelvic obliquity data were collected retrospectively and prospectively for comparison. Results: In the lumbar fixation group FVC was 58%, the mean Cobb angle and pelvic obliquity were 19.8° and 9° preoperative, 3.2° and 2.2° direct postoperative, and 5.2° and 2.9° at final follow up respectively. The mean estimated blood loss was 3.3 litres and average hospital stay 7.7 days. In the pelvic fixation group FVC was 44%, the mean Cobb angle and pelvic obliquity were 48° and 19.8° preoperative, 16.7° and 7.2° direct postoperative, and 22° and 11.6° at final follow up respectively. The mean blood loss (4.1 litres) and the average hospital stay (17 days) were significantly higher (p< 0.05) compared to the lumbar fixation group. The pelvic fixation group had higher complication rate at the lower end of fixation. No progression of the pelvic obliquity was noted in the lumbar fixation group during follow up. Conclusion: Lumbar fixation may be adequate for scoliosis in DMD, if the stabilisation is performed early, before the pelvis becomes tilted, and scoliosis becomes significant. The caudal pedicular fixation in the lumbar spine stops rotation of the spine around the rods, and prevent pelvic tilt to occur. Pelvic fixation may be necessary in presence of established pelvic obliquity and larger scoliosis, but is associated with higher morbidity and complications

Purpose: Posterior spinal fusion (PSF), with or without anterior spinal fusion (ASF), in conjunction with Luque rod instrumentation (LRI) and Galveston technique is a common procedure in neuromuscular spinal deformity. However, few studies have specifically studied the long-term results and complications of Galveston technique. The purpose of this study was to analyze the long-term results of Galveston technique in combination with PSF, with or without ASF, and LRI in the correction of neuromuscular spinal deformity. We were specifically interested in the stability of the distal foundation, lumbosacral fusion, correction of the associated pelvic obliquity, and complications. Method: Analyzing our Pediatric Orthopaedic Spine Database between 1992–2006, we identified 107 consecutive patients with a neuromuscular spinal deformity who underwent a PSF, with or without ASF, and LRI including Galveston technique, who had a minimum of 2 years postoperative follow-up. There were 55 females and 52 males with a mean age at surgery of 13.5 ± 3.5 years. The mean follow-up was 7.8 ± 3.7 years. We analyzed the coronal and sagittal plane alignment and pelvic obliquity preoperatively, postoperatively, and at last follow-up. We recorded any complications directly related to the Galveston technique. Results: The mean preoperative major curve was 76 ± 21 degrees. At last postoperative follow-up, this measured 33 ± 16 degrees. The mean preoperative pelvic obliquity was 17 ± 10 degrees and at last follow-up 7 ± 6 degrees. Seven patients (6.5%) had Galveston technique complications: three rod breakages, three implant distal migrations and one patient with both rod breakage and distal migration. These occurred late and only one patient required revision surgery. Conclusion: The Galveston technique is an excellent procedure for lumbosacral stabilization in patients with neuromuscular spinal deformity. It provides a solid distal foundation for a lumbosacral fusion and for correction of spinal deformity and pelvic obliquity, with minimal complications

Introduction: Malposition of the pelvis at the time of acetabular component insertion can contribute to malpositioning of the acetabular component. This study measures the variation in intraoperative positioning of the pelvis on the operating table during surgery by matching intraoperative radiographs with pre-operative computed tomograms (CT) using 2D-3D matching. Methods: This prospective study was comprised of a random sample of 45 patients (n = 45, 26 female, 19 male) who had received a total hip arthroplasty (THA) from a single surgeon from 10/21/2003 to 9/6/2007. No THA candidate was excluded for any reason, including body habitus (mean BMI = 27.7, range 17.5 – 42.3), underlying disease process, age (mean age at surgery = 57, range 27 – 80), sex or side of surgery (21 left THAs, 24 right THAs). According to our standard clinical treatment protocol, each patient had a pre-operative CT scan for CT-based surgical navigation of the hip arthroplasty and each patient had an intraoperative radiograph taken to assess component positioning. All THAs were performed in the lateral decubitus position on a radiolucent peg-board positioning device. Each patient’s intraoperative pelvic radiograph was taken after acetabular component and trial femoral component insertion with the leg placed in a neutral position on the operating table and with the xray plate aligned squarely with the operating table. The orientation of the pelvis on the operating table was calculated by comparing the intraoperative 2D projection to the 3D CT dataset using software that can perform 2D-3D matching (XAlign). This software has been validated previously. By matching the 3D CT dataset to the magnification and orientation of the plain radiograph, the position of the anterior pelvic plane relative to the operating table could be calculated. Results: The mean pelvic tilt (rotation around the medial-lateral axis) was 6.84 degrees of anterior pelvic tilt (lordosis) with a standard deviation of 7.95 degrees and a range from 27.24 degrees of lordosis to 4.96 degrees of kyphosis. The mean pelvic obliquity (rotation around the longitudinal axis) was 2.89 degrees anterior from neutral with a standard deviation of 9.44 degrees and a range from 29.36 anterior to 16.59 posterior from neutral. The mean pelvic rotation (rotation around the anterior-posterior axis) was 2.56 degrees cephelad, with a standard deviation of 4.10 degrees and a range from 10.88 degrees cephalad to 5.97 degrees caudad. Pearson correlation statistics showed no relation among pelvic position and body mass index or age. A correlation was seen between pelvic obliquity and pelvic rotation. Conclusion: This study shows a high variability of intraoperative pelvic positioning in the clinical setting using accurate measurement tools. The greatest variation was seen in pelvic obliquity which has the greatest influence on anteversion/retroversion of the acetabular component. Additionally, pelvic obliquity and rotation appear related in our series. Since all of our intraoperative radiographs were taken with the leg in a neutral position, it is likely that the pelvis is even more greatly malpositioned at other times during the surgery when forces applied by retractors or upon the leg may be greater

Introduction and Aims: Surgical correction of pelvic obliquity is an important component of spinal instrumentation for neuromuscular scoliosis, though instrumentation to the pelvis has high reported complication rates. This study evaluates the results of pelvic fixation during surgical correction of neuromuscular scoliosis in a consecutive series of 62 children and adolescents. Method: A retrospective chart and radiographic review of 62 consecutive patients treated with spinal fusions to the pelvis as treatment for neuromuscular scoliosis was performed. Follow-up ranged from two to seven years. Diagnoses included cerebral palsy (36 patients), muscular dystrophy (16 patients), myelomeningocele (three patients), spinal muscular atrophy (three patients) and other disorders (four patients). Mean age at surgery was 13.5 years. Pelvic fixation techniques used included Luque-Galveston or iliosacral screw fixation. Correction of deformity in each patient was assessed with Cobb angle measurements of scoliosis, thoracic kyphosis, and lumbar lordosis. Pelvic obliquity and coronal decompensation was also assessed. Results: The Luque-Galveston spinal instrumentation technique was used in 54 patients and iliosacral screw fixation was used in eight patients. Seventeen patients had an additional anterior release and fusion without instrumentation. The mean Cobb angle measured 73 degrees pre-operatively and 31 degrees (mean correction 59%) post-operatively. The mean Cobb angle on latest follow-up was 33 degrees (loss of correction 12%). Thoracic kyphosis remained essentially unchanged, as did lumbar lordosis (56 pre-op and 61 on follow-up). Pelvic obliquity corrected from a mean of 16 degrees pre-operatively to eight degrees on most recent follow-up. Mean pre-operative coronal decompensation measured 135mm, and follow-up decompensation measured 46mm. Eleven patients with Galveston fixation exhibited the ‘windshield-wiper’ sign, with a radiolucency of 2mm or more, though most were asymptomatic. Wound infection was observed in 6% (3/54) of the patients who underwent Galveston instrumentation and 50% (4/8) who had iliosacral screws. In patients treated with Galveston fixation, three had symptomatic prominant hardware and one had hardware breakage for an overall mechanical failure rate of 7% (4/54). In contrast, two patients with iliosacral screws had construct breakage and pseudoarthrosis for a mechanical failure rate of 25% (2/8), though the numbers in the iliosacral screw group are small. Conclusions: In this series, Galveston pelvic fixation during spinal instrumentation treatment of neuromuscular scoliosis was associated with satisfactory results and with less complications than generally reported in the literature. This technique is recommended as the preferred method for pelvic fixation in severe neuromuscular scoliosis associated with pelvic obliquity

INTRODUCTION: Malposition of the pelvis at the time of acetabular component insertion can contribute to malpositioning of the acetabular component. This study measures the variation in intraoperative positioning of the pelvis on the operating table during surgery by matching intraoperative radiographs with pre-operative computed tomograms (CT) using 2D-3D matching. METHODS: This prospective study was comprised of a random sample of 45 patients (n = 45, 26 female, 19 male) who had received a total hip arthroplasty (THA) from a single surgeon from 10/21/2003 to 9/6/2007. No THA candidate was excluded for any reason, including body habitus (mean BMI = 27.7, range 17.5 – 42.3), underlying disease process, age (mean age at surgery = 57, range 27 – 80), sex or side of surgery (21 left THAs, 24 right THAs). According to our standard clinical treatment protocol, each patient had a pre-operative CT scan for CT-based surgical navigation of the hip arthroplasty and each patient had an intraoperative radiograph taken to assess component positioning. All THAs were performed in the lateral decubitus position on a radiolucent peg-board positioning device. Each patient’s intraoperative pelvic radiograph was taken after acetabular component and trial femoral component insertion with the leg placed in a neutral position on the operating table and with the xray plate aligned squarely with the operating table. The orientation of the pelvis on the operating table was calculated by comparing the intraoperative 2D projection to the 3D CT data-set using software that can perform 2D-3D matching (XAlign). This software has been validated previously. By matching the 3D CT dataset to the magnification and orientation of the plain radiograph, the position of the anterior pelvic plane relative to the operating table could be calculated. RESULTS: The mean pelvic tilt (rotation around the medial-lateral axis) was 6.84 degrees of anterior pelvic tilt (lordosis) with a standard deviation of 7.95 degrees and a range from 27.24 degrees of lordosis to 4.96 degrees of kyphosis. The mean pelvic obliquity (rotation around the longitudinal axis) was 2.89 degrees anterior from neutral with a standard deviation of 9.44 degrees and a range from 29.36 anterior to 16.59 posterior from neutral. The mean pelvic rotation (rotation around the anterior-posterior axis) was 2.56 degrees cephelad, with a standard deviation of 4.10 degrees and a range from 10.88 degrees cephalad to 5.97 degrees caudad. Pearson correlation statistics showed no relation among pelvic position and body mass index or age. A correlation was seen between pelvic obliquity and pelvic rotation. CONCLUSION: This study shows a high variability of intraoperative pelvic positioning in the clinical setting using accurate measurement tools. The greatest variation was seen in pelvic obliquity which has the greatest influence on anteversion/retroversion of the acetabular component. Additionally, pelvic obliquity and rotation appear related in our series. Since all of our intraoperative radiographs were taken with the leg in a neutral position, it is likely that the pelvis is even more greatly malpositioned at other times during the surgery when forces applied by retractors or upon the leg may be greater

Introduction and Objective. Slipped Capital Femoral Epiphysis (SCFE) is one of the most common hip disorders in children and is characterized by a proximal femoral deformity, resulting in early osteoarthritis. Several studies have suggested that SCFE patients after in situ fixation show an altered gait pattern. Early identification of gait alterations might lead to earlier intervention programs to prevent osteoarthritis. The aim of this study is to analyse gait alterations in SCFE patients after in situ fixation compared to typically developed children, using the Computer Assisted Rehabilitation Environment (CAREN) system. Materials and Methods. This is a cross-sectional, multi-center case-control study in the Netherlands. Eight SCFE patients and eight age- and sex-matched typically developed were included from two hospitals. Primary outcomes were kinematic parameters (absolute joint angles), studied with gait analysis using statistical parametric mapping (SPM). Secondary outcomes were spatiotemporal parameters, the Notzli alpha angle, muscle activation patterns (EMG), and clinical questionnaires (VAS, Borg CR10, SF-36, and HOOS), analyzed using non-parametric statistical methods. Results. Patients (mean BMI=28±9 kg/m. 2. ) showed altered gait patterns, with significantly increased external hip rotation and decreased downward pelvic obliquity during the pre-swing phase of the gait cycle compared to typically developed (mean BMI=22±3 kg/m. 2. ). Walking speed, cadence, % stance time, and step length were reduced in SCFE patients. Coefficient of variances of cadence, stance time, and step length were increased. Patients had a mean alpha angle of 64, SD=7.9. Clinical questionnaires showed that general health (SF-36) was 80±25, energy/fatigue (SF-36) was 67±15, pain (VAS) was 0±1.5, and total HOOS score was 85±18. Conclusions. SCFE patients after in situ fixation appear to have developed a compensation mechanism, showing slight alterations in gait parameters, good general health, little functional limitations of the hip, and no self-reported pain. Cam deformities, altered joint loading, and this compensation mechanism might influence long-term early osteoarthritis. BMI reduction should be implemented in care plans, as obesity might also play a role in unfavorable long-term outcomes

Purpose: To assess quality of life in quadriplegic cerebral palsy (CP) after scoliosis surgery. Methods: This is a study of 43 consecutive patients undergoing instrumented scoliosis correction for quadriplegic CP (2003–2008). The parents completed (telephone) the original DuPont questionnaire (Tsirikos et al 2004, JPO) and 4 additional questions. Each of the 17 items scores from 1 (best) to 5 (worst) with 3 being no change. Retrospective case note and radiograph review was performed. Two patients had died by the time of follow-up (1 perioperative, 1 unrelated) leaving 41 patients (23 female, 18 male) for analysis. Mean age was 14.0 at surgery, mean follow-up of 2.6 years (0.25–5.3). GMFCS types 2–4 (8), 5 (31). Mean preoperative Cobb angle 78° and pelvic obliquity 18°. There were 34 posterior and 7 anterior and posterior instrumentations. Results: Mean DuPont score for the original 13 questions was 2.00 compared with 1.75 in the DuPont study. The scores for individual questions ranged from 1.35 to 2.76. The mean score of the 4 additional questions was 2.43, related to transfer ability, reflux and communication. 95% of parents would recommend the surgery again. 75.6% reported an improvement in their child’s ability to sit. Cobb angle correction was 53%, pelvic obliquity correction was 47%. The mean DuPont score is not significantly correlated with Cobb angle or pelvic obliquity correction. Conclusions: This is the first UK study evaluating the parental view of outcome for scoliosis surgery in quadriplegic CP. Outcome does not seem to be related to radiographic correction. 39 of 41 parents would recommend the surgery. Ethics approval: none – Clinical Effectiveness Department & PALS. Interest Statement: None

Purpose: To determine whether skull-femoral traction is a predictor of final surgical correction in scoliosis surgery and obviates the need for anterior release in severe deformities. Methods: 20 patients underwent skeletal femoral traction with a maximum of 50% of their body weight with the use of supracondylar femoral pins. A unilateral pin was used in the presence of pelvic obliquity and bilateral pins in patients with a neutral pelvis. Counter traction was applied through Gardner Well tongs at approximately one third the weight. Pre-op radiographs were compared with dynamic films, intra-op traction films and immediate and final post-operative films. Complications related to traction were recorded. All patients underwent posterior alone surgery for their scoliosis corrections. Results: The mean curve magnitude was 80.3 degrees. NO anterior releases were performed. Intra-operative traction provided a mean correction of 60%. Final surgical correction was 70%. Level pelvis was achieved in all patients with pelvic obliquity. Traction provided up to 80% of the final correction in older adult scoliotics (> 50 yo) thus minimizing the force required on the pedicle screws to achieve correction. No traction related complications occurred. Conclusions: Intra-op skull-femoral traction aides in the correction of severe scoliotic curves. Excellent corrections were achieved without the need for anterior releases. Traction reduced pelvic obliquity in the neuromuscular patients. Reducing the magnitude of the curves facilitated exposure of the posterior spine and minimized forces applied to the pedicle screws during scoliosis correction

Objective: To evaluate per-operative and postoperative complications following surgical correction of neuromuscular scoliosis and assess the amount of radiological correction of Cobb’s angle and pelvic obliquity angle. Design: Retrospective study of 25 consecutive patients with neuromuscular scoliosis (10 Duchenne Muscular Dystrophy, 8 Cerebral palsy, 2 Neurofibromatosis, and 1 each of Spinal Muscular Atrophy, Friedrich’s Ataxia, Spina Bifida, Rett’s Syndrome and incarcerated hemi-vertibrae) who had surgical correction for their spinal disorders between 1999 and 2002. Background: Aims of surgical correction in neuromuscular scoliosis include improving sitting ability, cardio-respiratory function and cosmesis. Patients studied underwent a combination of anterior release, posterior spinal fusion and pelvic fixation. Due to the length and complexity of procedures many of these patients need two stage surgical procedures on two separate occasions to achieve this goal. However our practice is performing these two stage procedures in one sitting with post operative ITU support. Results: Patients were aged between 4 and 16 years of age with mean preoperative Cobb angles of 75.9° and pelvic obliquity of 18°. A mean correction of 55.8° of Cobb angle and 12° of Pelvic obliquity were achieved. We had mean operating time of 413 minutes with a mean blood loss of 50.2 ml/ Kg body weight. All patients were admitted to ITU post operatively with a mean stay in ITU of 5.8 days. All patients achieved clinical and radiological spinal fusion. Instrumentation had to be removed from one patient after fusion because of persistent infection. Conclusion: Surgery for Neuromuscular Scoliosis is time consuming and complicated. With anticipation of blood loss, complications and ITU support, we can successfully perform the two-stage procedure in one sitting

Introduction: Historically segmental sublaminar wiring (SLW) fixation has been used for the correction of spinal deformity in neuromuscular scoliosis, however pedicle screw (PS) fixation is gaining popularity. We compared the results of both techniques in patients with Duchenne Muscular Dystrophy (DMD). Methods: Two groups of patients with DMD were matched according to the age at surgery, magnitude of deformity and vital capacity. Indications for surgery included loss of sitting balance, rapid decline of vital capacity and curve progression. In Group 1 (22 patients) SLW fixation was used from T2 to S1 with the Galveston technique. In Group 2 (18 patients) PS fixation was used from T2 to L5. Minimum follow-up was 2 years (range 2–13 years). Radiographs, SRS-22 and lung function tests were performed at standardised intervals. Results: Mean Cobb angle in Group 1 improved from 47° (range 26°–75°) to 23.5° (range10°–36°) and mean pelvic obliquity improved from 15° (range8°–25°) to 2.4° (range0°–8°). Mean Cobb angle in Group 2 improved from 46° (range28°–82°) to 8.5° (range 0°–18°) and mean pelvic obliquity improved from 15° (range7°–30°) to 1.1° (range 0°–6°) [p< 0.05]. Mean operating time and blood loss were less in Group 2 [p< 0.05]. In Group 1, the infection rate and instrumentation failure was higher, and SRS-22 outcomes showed no significant difference between the groups. Interestingly the mean Body Mass Index (BMI) in Group 2 was much higher than group 1. Conclusions: PS fixation resulted in superior correction and controlled pelvic obliquity to a large extent without the need for pelvic fixation. Lower rates of infection and failure of instrumentation were noted with PS fixation, despite high BMI of patients presumably due to steroid therapy. We recommend the use of PS instrumentation for the correction of spinal deformity in DMD

Introduction. Limb length discrepancy after THA can result in medicolegal litigation. It can create discomfort for the patient and potentially cause back pain or affect the longevity of the implant. Some patients tolerate the length inequality better compared to others despite difference in anatomical femoral length after surgery. Methods and materials. We analyzed the 3D EOS images of 75 consecutive patients who underwent primary unilateral THA (27 men, 48 women). We measured the 3D length of the femur and tibia (anatomical length), the 3D global anatomical length (the sum of femur and tibia anatomical lengths), the 3D functional length (center of the femoral head to center of the ankle), femoral neck-shaft angle, hip-knee-ankle angle, knee flexum/recurvatum angle, sacral slopes and pelvic incidence. We correlated these parameters with the patient perception of the leg length. Results. The values for leg length and pelvic parameters are shown in table 1. 37 patients had a perception of the LLD (49.3%). When the global anatomical length was shorter on the operated side, the perception of the discrepancy was observed in 56% of the cases. In case of anatomical length longer on the operated side, the perception of the discrepancy was described by the patients in 46% of the cases. The LLD perception was correlated with difference in functional length (p=0.0001), pelvic obliquity (p=0.003) and sacral slope (p=0.023). The anatomical femoral length was not correlated with the LLD perception (p=0,008). Discussion. The perception of LLD is a multifactorial complication. We found that the anatomical femoral length (that can be directly affected by the position of the stem) is not the only important factor. The functional length of the lower extremity which can also be affected by the knee deformities is better correlated with the LLD. The pelvic obliquity and version also affect the patient perception of the LLD