Aims. Excessive posterior pelvic tilt (PT) may increase the risk of anterior instability after total hip arthroplasty (THA). The aim of this study was to investigate the changes in PT occurring from the preoperative supine to postoperative standing position following THA, and identify factors associated with significant changes in PT. Methods. Supine PT was measured on preoperative CT scans and standing PT was measured on preoperative and one-year postoperative standing lateral radiographs in 933 patients who underwent primary THA. Negative values indicate posterior PT. Patients with > 13° of posterior PT from preoperative supine to postoperative standing (ΔPT ≤ -13°) radiographs, which corresponds to approximately a 10° increase in functional anteversion of the acetabular component, were compared with patients with less change (ΔPT > -13°). Logistic regression analysis was used to assess preoperative demographic and spinopelvic parameters predictive of PT changes of ≤ -13°. The area under receiver operating characteristic curve (AUC) determined the diagnostic accuracy of the predictive factors. Results. PT changed from a mean of 3.8° (SD 6.0°)) preoperatively to -3.5° (SD 6.9°) postoperatively, a mean change of -7.4 (SD 4.5°; p < 0.001). A total of 95 patients (10.2%) had ≤ -13° change in PT from preoperative supine to postoperative standing. The strongest predictive preoperative factors of large changes in PT (≤ -13°) from preoperative supine to postoperative standing were a large posterior change in PT from supine to standing, increased supine PT, and decreased standing PT (p < 0.001). Flexed-seated PT (p = 0.006) and female sex (p = 0.045) were weaker significant predictive factors. When including all predictive factors, the accuracy of the AUC prediction was 84.9%, with 83.5% sensitivity and 71.2% specificity. Conclusion. A total of 10% of patients had > 13° of posterior PT postoperatively compared with their supine pelvic position, resulting in an increased functional anteversion of > 10°. The strongest predictive factors of changes in postoperative PT were the preoperative supine-to-standing differences, the anterior supine PT, and the posterior standing PT. Surgeons who introduce the acetabular component with the patient supine using an anterior approach should be aware of the potentially large increase in functional anteversion occurring in these patients. Cite this article: Bone Joint J 2024;106-B(3 Supple A):74–80

Acetabular component positioning is commonly referenced with the pelvis in the supine position in direct anterior approach THA. Changes in pelvic tilt (PT) from the pre-operative supine to the post-operative standing positions have not been well investigated and may have relevance to optimal acetabular component targeting for reduced risk of impingement and instability. The aims of this study were therefore to determine the change in PT that occurs from pre-operative supine to post-operative standing, and whether any factors are associated with significant changes in tilt ≥13° in posterior direction. 13° in a posterior direction was chosen as that amount of posterior rotation creates an increase in functional anteversion of the acetabular component of 10°. 1097 THA patients with pre-operative supine CT and standing lateral radiographic imaging and 1 year post-operative standing lateral radiographs (interquartile range 12–13 months) were reviewed. Pre-operative supine PT was measured from CT as the angle between the anterior pelvic plane (APP) and the horizontal plane of the CT device. Standing PT was measured on standing lateral x-rays as the angle between the APP and the vertical line. Patients with ≥13° change from supine pre-op to standing post-op (corresponding to a 10° change in cup anteversion) were grouped and compared to those with a <13° change using unpaired student's t-tests. Mean pre-operative supine PT (3.8±6.0°) was significantly different from mean post-operative standing PT (−3.5±7.1°, p<0.001), ie mean change of −7.3±4.6°. 10.4% (114/1097) of patients had posterior PT changes ≥13° supine pre-op to standing post-op. A significant number of patients, ie 1 in 10, undergo a clinically significant change in PT and functional anteversion from supine pre-op to standing post-op. Surgeons should be aware of these changes when planning component placement in THA

The spinopelvic alignment is often assessed via the Pelvic Incidence-Lumbar Lordosis (PI-LL) mismatch. Here we describe and validate a simplified method to evaluating the spinopelvic alignment through the L1-Pelvis angle (L1P). This method is set to reduce the operator error and make the on-film measurement more practicable. 126 standing lateral radiographs of patients presenting for Total Hip Arthroplasty were examined. Three operators were recruited to label 6 landmarks. One operator repeated the landmark selection for intra-operator analysis. We compare PI-LL mismatch obtained via the conventional method, and our simplified method where we estimate this mismatch using PI-LL = L1P - 90°. We also assess the method's reliability and repeatability. We found no significant difference (p > 0.05) between the PI-LL mismatch from the conventional method (mean 0.22° ± 13.6) compared to L1P method (mean 0.0° ± 13.1). The overall average normalised root mean square error (NRMSE) for PI-LL mismatch across all operators is 7.53% (mean -3.3° ± 6.0) and 6.5% (mean -2.9° ± 4.9) for the conventional and L1P method, respectively. In relation to intra-operator repeatability, the correlation coefficients are 0.87 for PI, 0.94 for LL, and 0.96 for L1P. NRMSE between the two measurement sets are PI: 9.96%, LL: 5.97%, and L1P: 4.41%. A similar trend is observed in the absolute error between the two sets of measurements. Results indicate an equivalence in PI-LL measurement between the methods. Reproducibility of the measurements and reliability between operators were improved. Using the L1P angle, the classification of the sagittal spinal deformity found in the literature translates to: normal L1P<100°, mild 100°<L1P<110°, and severe L1P>110°. Surgeons adopting our method should expect a small improvement in reliability and repeatability of their measurements, and a significant improvement of the assessment of the mismatch through the visualisation of the angle L1P

Aims. The aim of the study was to compare two methods of calculating pelvic incidence (PI) and pelvic tilt (PT), either by using the femoral heads or acetabular domes to determine the bicoxofemoral axis, in patients with unilateral or bilateral primary hip osteoarthritis (OA). Methods. PI and PT were measured on standing lateral radiographs of the spine in two groups: 50 patients with unilateral (Group I) and 50 patients with bilateral hip OA (Group II), using the femoral heads or acetabular domes to define the bicoxofemoral axis. Agreement between the methods was determined by intraclass correlation coefficient (ICC) and the standard error of measurement (SEm). The intraobserver reproducibility and interobserver reliability of the two methods were analyzed on 31 radiographs in both groups to calculate ICC and SEm. Results. In both groups, excellent agreement between the two methods was obtained, with ICC of 0.99 and SEm 0.3° for Group I, and ICC 0.99 and SEm 0.4° for Group II. The intraobserver reproducibility was excellent for both methods in both groups, with an ICC of at least 0.97 and SEm not exceeding 0.8°. The study also revealed excellent interobserver reliability for both methods in both groups, with ICC 0.99 and SEm 0.5° or less. Conclusion. Either the femoral heads or acetabular domes can be used to define the bicoxofemoral axis on the lateral standing radiographs of the spine for measuring PI and PT in patients with idiopathic unilateral or bilateral hip OA. Cite this article: Bone Joint J 2021;103-B(8):1345–1350

We investigated the safety and efficacy of treating osteoporotic vertebral compression fractures with an intravertebral cleft by balloon kyphoplasty. Our study included 27 patients who were treated in this way. The mean follow-up was 38.2 months (24 to 54). The anterior and middle heights of the vertebral body and the kyphotic angle were measured on standing lateral radiographs before surgery, one day after surgery, and at final follow-up. Leakage of cement was determined by CT scans. A visual analogue scale and the Oswestry disability index were chosen to evaluate pain and functional activity. Statistically significant improvements were found between the pre- and post-operative assessments (p < 0.05) but not between the post-operative and final follow-up assessments (p > 0.05). Asymptomatic leakage of cement into the paravertebral vein occurred in one patient, as did leakage into the intervertebral disc in another patient. We suggest that balloon kyphoplasty is a safe and effective minimally invasive procedure for the treatment of osteoporotic vertebral compression fractures with an intravertebral cleft

This matched cohort study aims to (a) assess differences in spinopelvic characteristics of patients having sustained a dislocation following THA and a control THA group without dislocation; (b) identify spinopelvic characteristics associated with risk of dislocation and; (c) propose an algorithm to define the optimum cup orientation for minimizing dislocation risk. Fifty patients with a history of THA dislocation (29 posterior-, 21 anterior dislocations) were matched for age, gender, body mass index, index diagnosis, and femoral head size with 100 controls. All patients were reviewed and underwent detailed quasi-static radiographic evaluations of the coronal- (offset; center-of-rotation; cup inclination/anteversion) and sagittal- reconstructions (pelvic tilt, pelvic incidence, lumbar lordosis, pelvic-femoral-angle, cup ante-inclination). The spinopelvic balance (PI-LL), combined sagittal index (CSI= Pelvic-femoral-angle + Cup Anteinclination) and Hip-User-Index were determined. sagittal index (CSI= Pelvic-femoral-angle + Cup Anteinclination) and Hip-User-Index were determined. Parameters were compared between the two groups (2-group analysis) and between controls and per direction of dislocation (3-group analysis). There were marginal coronal differences between the groups. Sagittal parameters (lumbar-lordosis, pelvic-tilt, CSI, PI-LL and Hip-User-Index) differed significantly. PI-LL (>10°) and standing pelvic tilt (>18°) were the strongest predictors of dislocation risk (sensistivity:70%/specificity:70%). All hips with a standing CSI<195° dislocated posteriorly and all with CSI>260° dislocated anteriorly. A CSI between 200–245° was associated with significantly reduced risk of dislocation (OR:6; 95%CI:2.5–15.0; p<0.001). In patients with unbalanced and/or rigid lumbar spine, standing CSI of 215–245° was associated with significantly reduced dislocation risk (OR:10; 95%CI:3.2–29.8; p<0.001). PI-LL and standing pelvic-tilt determined from pre-operative, standing, lateral spinopelvic radiograph can be useful screening tools, alerting surgeons of patients at increased dislocation risk. Measurement of the pelvic-femoral angle pre-operatively provides valuable information to determine the optimum, cup orientation associated with reduced dislocation risk by aiming for a standing CSI of 200–245°

Aim: This study presents analysis of the largest case series to date in the published literature of patients with Hurler Syndrome, to identify the severity of thoraco-lumbar kyphosis, risk factors for progression and results of intervention. Methods and Results: Forty two patients with MPS-I had treatment with Bone-marrow transplantation and/ or enzyme replacement therapy between June 1995 and October 2007. These patients had regular systematic clinical review and were seen at least annually. Standing lateral radiographs of the thoracolumbar spine were retrieved and analysed. At initial examination (average age 1y 1m) the thoracolumbar kyphosis measured a mean of 39.6 degrees (SD 12 degrees). Analysis of non-operatively treated patients revealed that patients with an initial kyphosis angle (average age 1y 2m) of less than 40 degrees were significantly less likely to develop progressive kyphosis over the average follow-up period of 3.5 years (mean initial angle 30 degrees and at final follow-up 34 degrees) than those with an angle greater than 40 degrees (mean angle initially 46 degrees and at final follow-up 61 degrees), p=0.005 (repeated measures ANOVA). Seven patients underwent surgical intervention at mean age of 3 years for progressive deformity with favourable results. Conclusion: Thoracolumbar kyphosis is of variable severity in Hurler’s syndrome and patient’s who present with a kyphosis angle of greater than forty degrees on initial radiographic examination are significantly more likely to develop progressive kyphosis. Ethics approval: None. Interest Statement: None

Introduction. Spinopelvic parameters describe the orientation, shape, and morphology of the spine and pelvis. In children without spinal deformity, these parameters change during the first 10 years of life; however, spinopelvic parameters need to be defined in children with significant early-onset scoliosis (EOS). The purpose of this study is to examine the effects of EOS on sagittal spinopelvic alignment. We hypothesise that sagittal spinopelvic parameters for patients with EOS will differ from age-matched children without spinal deformity. These values will act as a baseline for future studies and may predict postoperative complications such as proximal junctional kyphosis and implant failure in children being treated with growing systems. Methods. Standing, lateral radiographs of 82 untreated patients with EOS with Cobb angle greater than 50° were evaluated. Sagittal spine parameters (sagittal balance, thoracic kyphosis [TK], lumbar lordosis [LL]) and sagittal pelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and modified pelvic radius angle [PR]) were measured. These results were compared with those reported by Mac-Thiong and colleagues (Spine, 2004) for a group of similar aged children without spinal deformity. Results. Patients had a mean age of 5·17 years and mean Cobb angle of 73·3° (□}17·3°). Mean sagittal spine parameters were: sagittal balance (+2·4 cm [□}4·03]), TK (38·2° [□}20·8°]), and LL (47·8° [□}17·7°]). These values were similar to those reported for asymptomatic patients (table). Mean sagittal pelvic parameters were: PI (47·1° [□}15·6°]), PT (10·3° [□}10·7°]), SS (35·5° [□}12·2°]), and PR (57·1° [□}21·2°]). Although PI was similar to age-matched controls, PT was significantly higher and there was a trend for lower SS in the study population. Conclusions. Sagittal plane spine parameters in children with EOS were similar to those in children without spinal deformity. Pelvic parameters (PI, SS, PR) were similar between groups; however, children with EOS had signs of pelvic retroversion (increased pelvic tilt)

Introduction. Spinopelvic parameters describe the orientation, shape, and morphology of the spine and pelvis. These parameters change during the first 10 years of life in children without spinal deformity; however, spinopelvic parameters have yet to be defined in children with significant early-onset scoliosis (EOS). Sagittal plane alignment could affect the natural history and outcome of interventions for EOS. As a result, spinopelvic parameters are being defined for this population. On the basis of the landmarks used for measurement of these parameters, there may be inherent error in performing these measurements on the immature pelvis. The purpose of this study is to define the variability associatedwith the measurement of spinopelvic parameters in children with EOS. Methods. Standing, lateral radiographs of 11 patients with untreated EOS were evaluated. Sagittal spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and modified pelvic radius angle [PR]) were measured. To assess intraobserver reliability, these measurements were repeated 15 days apart. To define interobserver reliability, radiographs were measured by 2 independent observers. Results. Average age was 5·7 years and average Cobb angle was 80·8°. Repeated measurements by one observer showed no significant differences for any of the parameters. Paired samples correlations showed a moderate correlation between measurements of PI (0·564), whereas stronger correlations were demonstrated for measurements of PT (0·816), SS (0·947), and PR (0·789). Interobserver analysis showed a significant difference in measurement of SS (p=0·003), whereasmeasurements of PI, PT, and PR did not differ significantly between independent observers. Conclusions. Intraobserver variabilty yielded acceptable correlations for PT, SS, and PR; however, we noted only a moderate correlation for PI. Interobserver analysis showed a significant difference only in SS. The intraobserver and interobserver variablity of measurements for PT and PR were superior than were those for PI and SS. This finding may be related to difficulties in determining the orientation of the sacral endplate in the immature pelvis when measuring PI and SS

Minimal-invasive augmentation techniques have been advocated to treat osteoporotic vertebral body fractures (VBFs). Kyphoplasty is designed to address both fracture-related pain as well as the kyphotic deformity usually associated with the fracture. Previous studies have indicated the potential of the technique for immediate pain relief and reduction of vertebral height, but whether this is a lasting effect, has not been well investigated. The current prospective study reports on our experience and the one-year results in 27 kyphoplasty procedures in 24 patients with PMMA for osteoporotic VBFs. Pain was assessed on a 0–10 VAS. Deformity and reduction of the vertebral body was measured as the angulation between the two endplates on standing lateral radiographs. All parameters were taken pre-op, one day and two months post-operatively and after one year. Multiple regression analysis was conducted to determine the importance of independent factors as predictors of the achieved fracture reduction. All but one patient experienced pain relief directly following the procedure with a lasting effect after 2 months and also one year in 25 cases. An average vertebral kyphosis reduction of 47.7% was achieved with no loss of reduction after one year. Pain relief was not related to the amount of reduction. The potential for reduction was related to pre-op kyphosis, level treated, and fracture age, but not to the age of the patient. In this series, kyphoplasty was an effective treatment of VBFs in terms of pain relief and durable reduction of deformity. However, whether spinal realignment results in an improved long-term clinical outcome remains to be investigated

Purpose. Spinopelvic parameters describe the orientation, shape, and morphology of the spine and pelvis. In children without spinal deformity, these parameters have been shown to change during the first ten years of life; however, spinopelvic parameters have yet to be defined in children with significant Early Onset Scoliosis (EOS). The purpose of this study is to examine the effects of EOS on sagittal spinopelvic alignment. Method. Standing, lateral radiographs of 82 untreated patients with EOS greater than 50 degrees were evaluated. Sagittal spine parameters (sagittal balance, thoracic kyphosis (TK), lumbar lordosis (LL)) and sagittal pelvic parameters (pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), modified pelvic radius angle (PR)) were measured. These results were compared to those reported by Mac-Thiong et al (Spine, 2004) for a group of asymptomatic (i.e. without spinal deformity) children of similar age. Results. These patients had a mean age of 5.17 years and mean scoliosis of 73.3 17.3. Mean sagittal spine parameters were: sagittal balance (+2.4 4.03 cm), TK (38.2 20.8), and LL (47.8 17.7). These values were similar to those reported for asymptomatic subjects. Mean sagittal pelvic parameters were measured for PI (47.1 15.6), PT (10.3 10.7), SS (35.5 12.2), and PR (57.1 21.2). Although PI was similar to age-matched normals, PT was significantly higher and SS trended lower in the study population. Conclusion. Sagittal plane spine parameters in children with EOS were similar to those found in children without spinal deformity. Likewise, pelvic parameters (PI, SS, PR) were similar; however, those children with EOS signs of pelvic retroversion (increased pelvic tilt). This data may be useful as a baseline in determining prognosis for children with EOS who are treated with growing systems

Purpose: To determine the reliability of six measurement techniques for lumbosacral kyphosis. Method: Using custom computer software, four raters evaluated 60 standing lateral radiographs of the lumbosacral spine during two sessions at a one week interval. The sample size consisted of 20 normal, 20 low and 20 high grade spondylolisthetic subjects. Six parameters were included for analysis: Boxall’s slip angle; Dubousset’s lumbosacral angle (LSA); the Spinal Deformity Study Group’s (SDSG) LSA; dysplastic SDSG LSA; sagittal rotation (SR); kyphotic Cobb angle (k-Cobb). Intra- and inter- rater reliability for all parameters was assessed using intra-class correlation coefficients (ICC). Correlations between parameters and slip percentage were evaluated with Pearson coefficients. Results: The intra-rater ICC’s for all the parameters ranged between 0.81 and 0.97 and the inter-rater ICC’s were between 0.74 and 0.98. All parameters except sagittal rotation showed a medium to large correlation with slip percentage. Dubousset’s LSA and the kyphotic Cobb angle showed the largest correlations (r=−0.78 and r=−0.50, respectively). Sagittal rotation was associated with the weakest correlation (r=−0.10). All other parameters had medium correlations with percent slip (r=0.31 to 0.43). Conclusion: All measurement techniques provided substantial to almost perfect inter- and intra- rater reliability. Dubousset’s LSA showed the strongest correlation with slip grade. However, this parameter does not reflect the local dysplastic changes that occur in lower L5 and upper S1 endplates. A longitudinal study evaluating the best suited parameter for predicting the risk of progression and response to surgical treatment is warranted

Study Design/Objectives: A pilot study to predict thoracolumbar kyphosis progression secondary to fracture in non-operatively treated patients. Summary of Background Data: Progressive saggital plane deformity can cause persistent pain after thoracolumbar vertebral fractures. Little data exists to suggest at what interval after the index injury the patient attains a low risk of developing further angular deformity in non-operatively treated patients. Methods: Supine and erect radiographs were assessed and the degree of fracture kyphosis was determined using an Oxford Cobbometer. The fracture kyphosis was recorded for each follow up appointment along with time after the fracture. A time/data analysis was performed using the Blyth-Still-Casella exact interval. Results: This study included 22 patients (13 male, 9 female) with average age 67.2 years (range, 14–87 years). The average length of follow up was 11.5 months (range, 5.3–19.9 months) and the average number of radiographs taken within this period was 4 (range, 2–6). The change in fracture kyphosis was plotted against time following fracture. Based on 15 patients with data extending to 200 days follow up, it was observed that the rate of change in fracture kyphosis between two time points of 100 and 150 days predicted the trend in kyphosis progression until the end of follow up in 14 out of the 15 patients. This observed rate of 14/15 (0.93) has a 95% confidence interval of 0.7 to 0.99 (Blyth-Still-Casella exact interval). Conclusions: The standing lateral radiograph of patients with conservatively treated thoracolumbar fractures at 3 and 4.5 months post injury can be used to predict fracture kyphosis progression. Using this protocol, patients can be safely discharged earlier from outpatient follow up reducing radiological exposure

Distraction bone-block arthrodesis has been advocated for the treatment of the late sequelae of fracture of the os calcis. Between 1997 and 2003 we studied a consecutive series of 17 patients who had in situ arthrodesis for subtalar arthritis after fracture of the os calcis with marked loss of talocalcaneal height. None had undergone any previous attempts at reconstruction. We assessed the range of dorsiflexion and plantar flexion and measured the talocalcaneal height, talocalcaneal angle and talar declination angle on standing lateral radiographs, comparing them with the normal foot. The mean follow-up was for 78.7 months (48 to 94). The mean American Orthopaedic Foot and Ankle Society hindfoot score improved from 29.8 (13 to 48) to 77.8 (48 to 94) (Student’s t-test, p < 0.001). The mean loss of talocalcaneal height was 10.3 mm (2 to 17) and the mean talar declination angle was 6.7° (0° to 16°) which was 36% of the normal side. One patient suffered anterior ankle pain but none had anterior impingement. Two patients complained of difficulty in ascending slopes and stairs and four in descending. The mean ankle dorsiflexion on the arthrodesed side was 11.6° (0° to 24°) compared with 14.7° (0° to 24°) on the normal side, representing a reduction of 21.1%. The mean plantar flexion on the arthrodesed side was 35.5° (24° to 60°) compared with 44.6° (30° to 60°) on the normal side, a reduction of 20.4%. These results suggest that anterior impingement need not to be a significant problem after subtalar arthrodesis for fracture of the os calcis, even when the loss of talocalcaneal height is marked. We recommend in situ arthrodesis combined with lateral-wall ostectomy for all cases of subtalar arthritis following a fracture of the os calcis, without marked coronal deformity, regardless of the degree of talocalcaneal height loss

The purpose was to assess the effect of the posterior slope on the long-term outcome of unicompartmental arthroplasty in knees with intact and deficient anterior cruciate ligaments. We retrospectively reviewed ninety-nine unicompartmental arthroplasties after a mean duration of follow-up of sixteen years (12 to 20 years). At the time of the arthroplasty, the anterior cruciate ligament was considered to be normal in fifty knees, damaged in thirty-one, and absent in eighteen. At the most recent follow-up, we measured the posterior tibial slope and the anterior tibial translation on standing lateral radiographs. In the group of seventy-seven knees that had not been revised by the time of the most recent follow-up, there was a significant linear relationship between anterior tibial translation (mean, 3.7 mm) and posterior tibial slope (mean, 4.3) (p = 0.01). The mean posterior slope of the tibial implant was significantly less in the group of seventy-seven knees without loosening of the implant than it was in the group of seventeen knees with loosening of the implant (p = 0.03). Five ruptures of the anterior cruciate ligament occurred in knees in which the ligament had been considered to be normal at the time of implantation; the posterior tibial slope in these five knees was greater than 13 degrees. Clinical evaluation revealed normal or nearly normal anteroposterior stability at the time of the most recent follow-up in all sixty-six unrevised knees in which the anterior cruciate ligament had been present at the time of implantation. Of the eighteen knees in which the anterior cruciate ligament had been absent at the time of the arthroplasty, eleven still had the implant in situ at the time of the most recent follow-up; the mean posterior tibial slope in these 11 knees was less than 5 degrees. Seven knees in which the anterior cruciate ligament had been absent at the time of the arthroplasty were revised. In these 7 knees, the tibial prosthesis was implanted with a posterior slope greater than 8 degrees. These findings suggest that more than 7 degrees of posterior slope of the tibial implant should be avoided, particularly if the anterior cruciate ligament is absent at the time of implantation. An intact anterior cruciate ligament, even when partly degenerated, was associated with the maintenance of normal anteroposterior stability of the knee for an average of sixteen years following unicompartmental knee arthroplasty

Study Design: The effect of Total Hip Replacement surgery (THR) upon spinal sagittal alignment and low back pain was assessed in patients with severe hip osteoarthritis. Summary of Background Data: Osteoarthritis in the hip joint is associated with abnormal posture and gait due to hip flexion contracture and hip pain. This in turn may cause abnormal spinal sagittal alignment and secondarily induce low back and leg pain. However, there have been no reports regarding the corrective effect of Total Hip Replacement surgery upon spinal sagittal alignment in patients with osteoarthritis of the hip. Methods: This study prospectively analyzed the results of 25 patients (15 females and 10 males, average age 67.4 years (32–84)) undergoing THR for severe osteoarthritis of the hip. Pre and post-surgical assessment included; sagittal measurement of Sacral Inclination (SI) and total Lumbar Lordosis (L1-S1) on standing lateral radiographs. Functional clinical outcomes for hip as well as low back were also evaluated using the Oswestry back Questionnaire, the Modified Harris Hip Score and Visual Analog Scale for lower back pain and hip pain accordingly. All the radiographic and clinical evaluations were completed both before THR surgery and 3 months following the surgery during routine follow up. Results: Mean Lumbar Lordosis before the surgery and in the follow up was 50.36 and 50.32 respectively. Mean sacral inclination before and after surgery were 39.06 and 38.16 respectively. Mean Functional outcomes as assessed by the HHS score before and after the surgery were 45.74 and 81.8 respectively. Mean Oswestry Questionnaire scores before and after the surgery were 36.72 and 24.08 respectively. Mean VAS scores for hip pain before and after the surgery were 7.08 and 2.52 respectively. Mean VAS scores for lower back pain before and after the surgery were 5.04 and 3.68 respectively. Discussion: No Significant difference was found between the sagittal alignment of the spine before THR and 3 months following it. Interestingly, total hip replacement surgery significantly improved spinal functional outcome as well as relieved low back and hip pain

Spinopelvic mobility describes the change in lumbar lordosis and pelvic tilt from standing to sitting position. For 1° of posterior pelvic tilt, functional cup anteversion increases by 0.75° after total hip arthroplasty (THA). Thus, spinopelvic mobility is of high clinical relevance regarding the risk of implant impingement and dislocation. Our study aimed to 1) determine the proportion of OA-patients with stiff, normal or hypermobile spino-pelvic mobility and 2) to identify clinical or static standing radiographic parameters predicting spinopelvic mobility. This prospective diagnostic cohort study followed 122 consecutive patients with end-stage osteoarthritis awaiting THA. Preoperatively, the Oxford Hip Score, Oswestry Disability Index and Schober's test were assessed in a standardized clinical examination. Lateral view radiographs were taken of the lumbar spine, pelvis and proximal femur using EOS© in standing position and with femurs parallel to the floor in order to achieve a 90°-seated position. Radiographic measurements were performed for the lumbar lordosis angle (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI) and pelvic-femoral-angle (PFA). The difference in PT between standing and seated allowed for patient classification based on spino-pelvic mobility into stiff (±30°). From the standing to the sitting position, the pelvis tilted backwards by a mean of 19.6° (SD 11.6) and the hip was flexed by a mean of 57° (SD 17). Change in pelvic tilt correlated inversely with change in hip flexion. Spinopelvic mobility is highly variable in patients awaiting THA and we could not identify any clinical or static standing radiographic parameter predicting the change in pelvic tilt from standing to sitting position. In order to identify patients with stiff or hypermobile spinopelvic mobility, we recommend performing lateral view radiographs of the lumbar spine, pelvis and proximal femur in all patients awaiting THA. Thereafter, implants and combined cup inclination/anteversion can be individually chosen to minimize the risk of dislocation. No predictors could be identified. We recommend performing sitting and standing lateral view radiographs of the lumbar spine and pelvis to determine spinopelvic mobility in patients awaiting THA

In scoliosis, it is well known that lateral deformity is coupled with vertebral axial rotation. Coupled motion in the sagittal plane, however, has not been investigated. Objective: To investigate the behavior of the sagittal alignment changes when coronal deformity was corrected in idiopathic thoracic scoliosis. Method: 36 idiopathic scoliosis patients with thoracic curves were examined before surgery. Coronal deformity was corrected using the Fulcrum Bending technique1, and biplane radiographs were taken to monitor the correction of the deformity, as well as the coupled sagittal alignment changes. Sagittal alignment was measured from T4/T5 to T12 using Cobb’s method. Difference of less or equal to 3 degrees between two measurements was treated as no change. Results were compared with those measured from standing lateral radiographs prior to and at 1 week after surgery (Posterior correction and fusion with ISOLA: n=15; CD-Horizon: n=8; Moss-Miami: n=11, USS: n=2). Pearson correlation was used for statistical analysis. Results: (A) When scoliosis was corrected under fulcrum bending, the coupled changes in the thoracic kyphosis were decreased if it was greater than 20 degrees (n= 18), increased if less than 20 degrees (n= 2), and kept no change if it was around 20 degrees (n= 16). These changes were not related to the amount of deformity or flexibility in the coronal plane (Table I). (B) There was strong relationship between the sagittal alignment measured on the pre-operative fulcrum bending and postoperative lateral radiographs (P< 0.01). However, the final sagittal alignment was neither correlated with the magnitude or flexibility of the coronal deformity, nor the instrumentation applied (P> 0.05). Discussion: A coupling exists between the coronal lateral deformity and the sagittal alignment in thoracic scoliosis. It seems that the sagittal alignment in a scoliotic spine tends to “normalize” with correction of the deformity: a “hyper-kyphotic” spine tends to reduce, and a “hypo-kyphotic” one tends to increase the kyphosis. Post-operative sagittal alignment seems to be decided by the coupling motion and the amount of curvature of the pre-bent rod, as neither the nature (degree or flexibility or curve pattern) of the coronal deformity nor the choice of instrumentation were related to the post-operative sagittal alignment

Our study aims were to establish correlations between the incidence of patellofemoral pain and clinical, functional and radiographic outcomes in Total Knee Arthroplasty (TKR), using the Duracon prosthesis without patella resurfacing. A consecutive cohort of 52 patients (71 knees) were reviewed at a special follow up clinic at a mean of 29 months. All operations were carried out by a single surgeon or under his direct supervision using a standard procedure. Patients were evaluated clinically and asked directly if they had anterior knee pain. American Knee Society Scores (AKSS) and knee alignment were assessed and patients completed SF-12 and WOMAC questionnaires. Standardised 45 degree skyline and standing lateral radiographs were taken and assessed by a single blinded observer, and patella tilt and displacement measured using Gomes’ method, and patella height measured using the Insall-Salvati ratio. Knees with patellofemoral pain underwent triple phase bone scintigraphy using Technetium 99m-MDP with vascular, blood pool and static (3 hour) imaging. Significant patellofemoral pain was identified in 8 knees (11%), in 6 patients. This group had a reduced mean AKSS compared to knees without patellofemoral pain, although 50% still had a good to excellent outcome as judged by the AKSS. Only 2 knees with patellofemoral pain had abnormal alignment (2 and 12 degrees valgus). The mean SF-12 and WOMAC scores did not differ significantly between knees with patellofemoral pain and those without. Patella tilt and displacement were a common finding in this cohort, and could be as great as 17 degrees and 30% respectively without patellofemoral dysfunction. Paradoxically the mean values for these parameters were found to be reduced in knees with patellofemoral pain. Patella height did not substantially vary between knees with patellofemoral pain and those without. Bone scintigraphy of 7 of the knees with patellofemoral pain revealed a spectrum of activity from complete normality (3 knees) to tricompartmental increase in activity (2 knees). Increased activity localised to the patellofemoral articulation was evident in 2 knees. We conclude that despite favourable overall results, the Duracon prosthesis fails to eliminate patellofemoral pain without patella resurfacing. This conflicts with excellent reported results using this anatomic prosthesis with patella resurfacing. The presence of patellofemoral pain correlates well with a poor AKKS, but the role of plain radiography and bone scintigraphy as investigative tools remains unclear

Study Design: Retrospective Series. Objectives: To analyse loss of correction of the anterior wedge angle and the components responsible for the recurrence of kyphosis after surgical stabilisation of dorsolumbar fractures, and to assess the return of functional capacity in these patients. Materials and Methods: Between January 1998 and March 2003, 34 patients had posterior stabilisation performed with the Universal Spine System (Synthes) for dorsolumbar fracture at a single level with no neurological deficit. There were 26 AO Type A fractures, 5 Type B fractures, and 3 Type C fractures. Serial standing lateral radiographs were taken from the immediate postoperative period to the most recent follow-up. The anterior wedge angle, the heights of the discs above and below the fractured vertebra, and the heights of the vertebral bodies above, at, and below the fractured level were measured. The height at each level was measured in three segments (anterior, middle and posterior). The values were normalised to avoid discrepancies while comparing radiographs. The difference in the height of each segment measured between the immediate postoperative period and the most recent follow-up were computed. Short Form 36 (SF-36) was used to assess the functional outcome in each. Results: The mean follow-up period was 23.6 months (9 to 48 months). The mean anterior wedge angle was 10.1 ± 7.2 degrees in the immediate postoperative period and 17.1 ± 10.9 degrees at latest follow-up (p< 0.001). The mean loss of correction was 7.0 ± 8.5 degrees (−11 to 24) and this showed a linear relationship to the preoperative anterior wedge angle. Furthermore there was a linear increase in the loss of correction of the angle as the follow-up period increased. The correlation between the corresponding difference in the height of each segment and the degree of loss of correction of the anterior wedge angle showed significant correlation to the decrease in the anterior segment height at the fractured vertebral body level (Pearson’s coefficient r=0.53 significant at 0.01 level, p=0.001). The mean physical function score from SF-36 was 56.3 and the mean bodily pain score was 49.7. There was no relationship to the angle of kyphosis at follow-up to the physical function score (r=0.12, p=0.50) and the bodily pain score (r=0.14, p=0.44). Conclusions: There is a progressive loss of correction (increasing kyphosis) after posterior stabilisation with instrumentation that roughly approximates the initial decrease in anterior height of the fractured vertebral body. The degree of loss of correction does not depend on the type of fracture. The loss of correction is related to the preoperative angle of kyphosis