The reconstruction of peri-acetabular defects after severe bone loss or pelvic resection for tumor is among the most challenging surgical intervention. The Lumic® prosthesis (Implantcast, Buxtehude, Germany) was first introduced in 2008 in an effort to reduce the mechanical complications encountered with the classic peri-acetabular reconstruction techniques and to improve functional outcomes. Few have evaluated the results associated with the use of this recent implant.

A retrospective study from five Orthopedic Oncology Canadian centers was conducted. Every patient in whom a Lumic® endoprosthesis was used for reconstruction after peri-acetabular resection or severe bone loss with a minimal follow-up of three months was included. The charts were reviewed and data concerning patients’ demographics, peri-operative characteristics and post-operative complications was collected. Surgical and functional outcomes were also assessed.

Sixteen patients, 11 males and five females, were included and were followed for 28 months [3 – 60]. Mean age was 55 [17–86], and mean BMI reached 28 [19.6 – 44]. Twelve patients (75%) had a Lumic® after a resection of a primary sarcoma, two following pelvic metastasis, one for a benign tumor and one after a comminuted acetabular fracture with bone loss. Twelve patients (75%) had their surgery performed in one stage whereas four had a planned two-stage procedure. Mean surgical time was 555 minutes [173-1230] and blood loss averaged 2100 mL [500-5000]. MSTS score mean was 60.3 preoperatively [37.1 – 97] and 54.3 postoperatively [17.1-88.6]. Five patients (31.3%) had a cemented Lumic® stem. All patients got the dual mobility bearing, and 10 patients (62.5%) had the largest acetabular cup implanted (60 mm). In seven of these 10 patients the silver coated implant was used to minimize risk of infection. Five patients (31.3%) underwent capsular reconstruction using a synthetic fabric aiming to reduce the dislocation risk. Five patients had per-operative complications (31.3%), four were minor and one was serious (comminuted iliac bone fracture requiring internal fixation). Four patients dislocated within a month post-operatively and one additional patient sustained a dislocation one year post-operatively. Eight patients (50%) had a post-operative surgical site infection. All four patients who had a two-stage surgery had an infection. Ten patients (62.5%) needed a reoperation (two for fabric insertion, five for wash-outs, and three for implant exchange/removal). One patient (6.3%) had a septic loosening three years after surgery. At the time of data collection, 13 patients (81.3%) were alive with nine free of disease. Silver coating was not found to reduce infection risk (p=0.2) and capsuloplasty did not prevent dislocation (p=1).

These results are comparable to the sparse data published. Lumic® endoprosthesis is therefore shown to provide good functional outcomes and low rates of loosening on short to medium term follow-up. Infection and dislocation are common complications but we were unable to show benefits of capsuloplasty and of the use of silver coated implants. Larger series and longer follow-ups are needed.

The reconstruction of peri-acetabular defects after severe bone loss or pelvic resection for tumor is among the most challenging surgical intervention. The Lumic® prosthesis (Implantcast, Buxtehude, Germany) was first introduced in 2008 in an effort to reduce the mechanical complications encountered with the classic peri-acetabular reconstruction techniques and to improve functional outcomes. Few have evaluated the results associated with the use of this recent implant.

A retrospective study from five Orthopedic Oncology Canadian centers was conducted. Every patient in whom a Lumic® endoprosthesis was used for reconstruction after peri-acetabular resection or severe bone loss with a minimal follow-up of three months was included. The charts were reviewed and data concerning patients’ demographics, peri-operative characteristics and post-operative complications was collected. Surgical and functional outcomes were also assessed.

Sixteen patients, 11 males and five females, were included and were followed for 28 months [3 – 60]. Mean age was 55 [17-86], and mean BMI reached 28 [19.6 – 44]. Twelve patients (75%) had a Lumic® after a resection of a primary sarcoma, two following pelvic metastasis, one for a benign tumor and one after a comminuted acetabular fracture with bone loss. Twelve patients (75%) had their surgery performed in one stage whereas four had a planned two-stage procedure. Mean surgical time was 555 minutes [173-1230] and blood loss averaged 2100 mL [500-5000]. MSTS score mean was 60.3 preoperatively [37.1 – 97] and 54.3 postoperatively [17.1-88.6]. Five patients (31.3%) had a cemented Lumic® stem. All patients got the dual mobility bearing, and 10 patients (62.5%) had the largest acetabular cup implanted (60 mm). In seven of these 10 patients the silver coated implant was used to minimize risk of infection. Five patients (31.3%) underwent capsular reconstruction using a synthetic fabric aiming to reduce the dislocation risk. Five patients had per-operative complications (31.3%), four were minor and one was serious (comminuted iliac bone fracture requiring internal fixation). Four patients dislocated within a month post-operatively and one additional patient sustained a dislocation one year post-operatively. Eight patients (50%) had a post-operative surgical site infection. All four patients who had a two-stage surgery had an infection. Ten patients (62.5%) needed a reoperation (two for fabric insertion, five for wash-outs, and three for implant exchange/removal). One patient (6.3%) had a septic loosening three years after surgery. At the time of data collection, 13 patients (81.3%) were alive with nine free of disease. Silver coating was not found to reduce infection risk (p=0.2) and capsuloplasty did not prevent dislocation (p=1).

These results are comparable to the sparse data published. Lumic® endoprosthesis is therefore shown to provide good functional outcomes and low rates of loosening on short to medium term follow-up. Infection and dislocation are common complications but we were unable to show benefits of capsuloplasty and of the use of silver coated implants. Larger series and longer follow-ups are needed.

Given the low prevalence of sarcoma, international cooperation is necessary to recruit sufficient numbers of patients for surgical trials. The PARITY (Prophylactic Antibiotic Regimens in Tumour Surgery) trial is the first international multicentre trial in orthopedic oncology and successfully achieved target enrollment of 600 patients across 12 countries. It is important to reflect upon the challenges encountered and experiences gained to inform future trials. The objective of this study is to describe recruitment patterns and examine the differences in enrollment across different PARITY sites and identify variables associated with varying levels of recruitment.

Data from this study was obtained from the PARITY trial Methods Centre and correspondence data. We performed descriptive statistics to demonstrate the recruitment patterns over time. We compared recruitment, time to set up, and time to enroll the first patient between North American and international sites, and sites that had dedicated research personnel. Two-tailed non-paired t-tests were performed to compare average monthly recruitment rates between groups with significance being set at alpha=0.05.

A total of 600 patients from 48 clinical sites and 12 countries were recruited from January 2013 through to October 2019. Average monthly enrollment increased every year of the study. There were 36 North American and 12 international sites. North American sites were able to set up significantly faster than international sites (19.3 vs. 28.3 months p=0.037). However, international sites had a significantly higher recruitment rate per month once active (0.2/month vs. 0.62/month, p=0.018). Of active sites, 40 (83%) had research support personnel and 8 (17%) sites did not. Sites with research personnel were able to reach ‘enrolment ready’ status significantly faster than sites without research support (19.6 vs. 30.7 months, p=0.032). However, there was no significant difference in recruitment rate per month once the sites began enrolling (0.28/month vs. 0.2/month, p=0.63). Trial sites that took longer than 1 year to recruit their first patient had 3x lower average recruitment rate compared to sites that were able to recruit their first patient within a year of being enrolment ready.

The PARITY trial is the first multicentre RCT in orthopaedic oncology. The PARITY investigators were able to increase the recruitment levels throughout the trial and generally avoid trial fatigue. This was a North American based trial which may explain the longer start up times internationally given the different regulatory bodies associated with drug-related trials. However, international sites should be considered critical as they were able to recruit significantly more patients per month once active. The absence of research support personnel should not preclude a site from inclusion. These sites took longer to setup but had no difference in monthly recruitment once active. This study will create a framework for identifying and targeting high yield sites for future randomized control trials within orthopaedic oncology to maximum recruitment and resource allocation. Data quality is another consideration that will be addressed in future analyses of the PARITY trial.

Lung cancer is the most common cancer diagnosed, the leading cause of cancer-related deaths, and bone metastases occurs in 20–40% of lung cancer patients. They often present symptomatically with pain or skeletal related events (SREs), which are independently associated with decreased survival. Bone modifying agents (BMAs) such as Denosumab or bisphosphonates are routinely used, however no specific guidelines exist from the National Comprehensive Cancer Center or the European Society of Medical Oncologists. Perhaps preventing the formation of guidelines is the lack of a high-quality quantitative synthesis of randomized controlled trial (RCT) data to determine the optimal treatment for the patient important outcomes of 1) Overall survival (OS), 2) Time to SRE, 3) SRE incidence, and 4) Pain Resolution. The objective of this study was to perform the first systematic review and network meta-analysis (NMA) to assess the best BMA for treatment of metastatic lung cancer to bone.

We conducted our study in accordance to the PRISMA protocol. We performed a librarian assisted search of MEDLINE, PubMed, EMBASE, and Cochrane Library and Chinese databases including CNKI and Wanfang Data. We included studies that are RCTs reporting outcomes specifically for lung cancer patients treated with a bisphosphonate or Denosumab. Screening, data extraction, risk of bias and GRADE were performed in duplicate. The NMA was performed using a Bayesian probability model with R. Results are reported as relative risks, odds ratios or mean differences, and the I2 value is reported for heterogeneity. We assessed all included articles for risk of bias and applied the novel GRADE framework for NMAs to rate the quality of evidence supporting each outcome.

We included 132 RCTs comprising 11,161 patients with skeletal metastases from lung cancer. For OS, denosumab was ranked above zoledronic acid (ZA) and estimated to confer an average of 3.7 months (95%CI: −0.5 – 7.6) increased survival compared to untreated patients. For time to SRE, denosumab was ranked first with an average of 9.1 additional SRE-free months (95%CI: 4.0 – 14.0) compared to untreated patients, while ZA conferred an additional 4.8 SRE-free months (2.4 – 7.0). Patients treated with the combination of Ibandronate and systemic therapy were 2.3 times (95%CI: 1.7 – 3.2) more likely to obtain successful pain resolution, compared to untreated. Meta-regression showed no effect of heterogeneity length of follow-up or pain scales on the observed treatment effects. Heterogeneity in the network was considered moderate for overall survival and time to SRE, mild for SRE incidence, and low for pain resolution. While a generally high risk of bias was observed across studies, whether they were from Western or Chinese databases. The overall GRADE for the evidence underlying our results is High for Pain control and SRE incidence, and Moderate for OS and time to SRE.

This study represents the most comprehensive synthesis of the best available evidence guiding pharmacological treatment of bone metastases from lung cancer. Denosumab is ranked above ZA for both overall survival and time to SRE, but both treatments are superior to no treatment. ZA was first among all bisphosphonates assessed for odds of reducing SRE incidence, while the combination of Ibandronate and radionuclide therapy was most effective at significantly reducing pain from metastases. Clinicians and policy makers may use this synthesis of all available RCT data as support for the use of a BMA in MBD for lung cancer.

Femoroacetabular impingement (FAI) deformities are a potential precursor to hip osteoarthritis and an important contributor to non-arthritic hip pain. Some hips with FAI deformities develop symptoms of pain in the hip and groin that are primarily position related. The reason for pain generation in these hips is unclear. Understanding potential impingement mechanisms in FAI hips will help us understand pain generation. Impingement between the femoral head-neck contour and acetabular rim has been proposed as a pathomechanism in FAI hips. This proposed pathomechanism has not been quantified with direct measurements in physiological postures. Research question: Is femoroacetabular clearance different in symptomatic FAI hips compared to asymptomatic FAI and control hips in sitting flexion, adduction, and internal rotation (FADIR) and squatting postures?

We recruited 33 participants: 9 with symptomatic FAI, 13 with asymptomatic FAI, and 11 controls from the Investigation of Mobility, Physical Activity, and Knowledge Translation in Hip Pain (IMAKT-HIP) cohort. We scanned each participant's study hip in sitting FADIR and squatting postures using an upright open MRI scanner (MROpen, Paramed, Genoa, Italy). We quantified femoroacetabular clearance in sitting FADIR and squatting using beta angle measurements which have been shown to be a reliable surrogate for acetabular rim pressures. We chose sitting FADIR and squatting because they represent, respectively, passive and active maneuvers that involve high flexion combined with internal/external rotation and adduction/abduction, which are thought to provoke impingement.

In the squatting posture, the symptomatic FAI group had a significantly smaller minimum beta angle (−4.6º±15.2º) than the asymptomatic FAI (12.5º ±13.2º) (P= 0.018) and control groups (19.8º ±8.6º) (P=0.001). In the sitting FADIR posture, both symptomatic and asymptomatic FAI groups had significantly smaller beta angles (−9.3º ±14º [P=0.010] and −3.9º ±9.7º [P=0.028], respectively) than the control group (5.7º ±5.7º).

Our results show loss of clearance between the femoral head-neck contour and acetabular rim (negative beta angle) occurred in symptomatic FAI hips in sitting FADIR and squatting. We did not observe loss of clearance in the asymptomatic FAI group for squatting, while we did observe loss of clearance for this group in sitting FADIR. These differences may be due to accommodation mechanisms in the active, squatting posture that are not present in the passive, sitting FADIR posture. Our results support the hypothesis that impingement between the femoral head-neck contour and acetabular rim is a pathomechanism in FAI hips leading to pain generation.

It is unclear why ACL rupture increases osteoarthritis risk, regardless of ACL reconstruction. Our aims were: 1) to establish the reliability and accuracy of a direct method of determining tibiofemoral contact in vivo with UO-MRI, 2) to assess differences in knees with ACL rupture treated nonoperatively versus operatively, and 3) to assess differences in knees with ACL rupture versus healthy knees.

We recruited a convenience sample of patients with prior ACL rupture. Inclusion criteria were: 1) adult participants between 18–50 years old; 2) unilateral, isolated ACL rupture within the last five years; 3) if reconstructed, done within one year from injury; 4) intact cartilage; and 5) completed a graduated rehabilitation program culminating in return to sport or recreational activities. Participants were excluded if they had other ligament ruptures, osteoarthritis, an incompletely rehabilitated injury, were prohibited from undergoing MRI, or had a history of ACL re-rupture. Using the UO-MRI, we investigated tibiofemoral contact area, centroid location, and six degrees of freedom alignment under standing, weightbearing conditions with knees extended. We compared patients with ACL rupture treated nonoperatively versus operatively, and ACL ruptured knees versus healthy control knees. We assessed reliability using the intra-class correlation coefficient, and accuracy by comparing UO-MRI contact area with a 7Tesla MRI reference standard. We used linear mixed-effects models to test the effects of ACL rupture and ACL reconstruction on contact area. We used a paired t test for centroid location and alignment differences in ACL ruptured knees versus control knees, and the independent t test for differences between ACL reconstruction and no reconstruction. Analyses were performed using R version 3.5.1. We calculated sample size based on a previous study that showed a contact area standard deviation of 13.6mm2, therefore we needed eight or more knees per group to detect a minimum contact area change of 20mm2with 80% power and an α of 0.05.

We recruited 18 participants with ACL rupture: eight treated conservatively and 10 treated with ACL reconstruction. There were no significant differences between the operative and nonoperative ACL groups in terms of age, gender, BMI, time since injury, or functional knee scores (IKDC and KOOS). The UO-MRI demonstrated excellent inter-rater, test-retest, and intra-rater reliability with ICCs for contact area and centroid location ranging from 0.83–1.00. Contact area measurement was accurate to within 5% measurement error. At a mean 2.7 years after injury, we found that ACL rupture was associated with a 10.4% larger medial and lateral compartment contact areas (P=0.001), with the medial centroid located 5.2% more posterior (P=0.001). The tibiae of ACL ruptured knees were 2.3mm more anterior (P=0.003), and 2.6° less externally rotated (P=0.010) relative to the femur, than contralateral control knees. We found no differences between ACL reconstructed and nonreconstructed knees.

ACL rupture was associated with significant mechanical changes 2.7 years out from injury, which ACL reconstruction did not restore. These findings may partially explain the equivalent risk of post-traumatic osteoarthritis in patients treated operatively and nonoperatively after ACL rupture.

Up to 20 percent of patients remain dissatisfied after primary total knee arthroplasty (TKA) surgery. Understanding the reasons for dissatisfaction post TKA may allow for better patient selection and optimized treatment for those who remain dissatisfied. The association between function, mobility and satisfaction are not well understood. The purpose of this study was to investigate the association between post-TKA satisfaction and i) pre-operative, ii) post-operative, and iii) change in knee joint function during gait.

Thirty-one patients scheduled to receive primary TKA for knee osteoarthritis (OA) diagnosis were recruited and visited the Dynamics of Human Motion laboratory for instrumented walking gait analysis (using a synchronized NDI Optotrak motion capture system and AMTI force platforms in the walkway) at two time points, first within the week prior to their surgery, and second at approximately one year after surgery. At their post-operative visit, patients were asked to indicate their satisfaction with their knee prosthesis on a scale from zero to 100, with zero being totally unsatisfied and 100 being completely satisfied. Knee joint mechanics during gait at both time points were characterized by discriminant scores, the projection of their three-dimensional knee angles and moments during gait onto an existing discriminant model that was created to optimize separation of severe knee OA and healthy asymptomatic gait patterns. This discriminant model was created using data from 73 healthy participants and 73 with severe knee OA, and includes the magnitude and pattern features (captured with principal component analysis) of the knee adduction and flexion moment, and the magnitude of the knee flexion angle during gait. Larger discriminant scores indicate improved function toward healthy patterns, and smaller scores indicate more severe function. Associations between post-operative satisfaction and pre, post and change in discriminant scores were examined using Pearson correlation analyses. We also examined associations between satisfaction and pre-operative BMI, EQ5D and Oxford 12 scores, as well as changes in these scores from pre to post-TKA.

Discriminant scores representing knee joint function during gait significantly improved on average after surgery (P =0.05).

While overall knee joint function improved after primary TKA surgery, the amount of improvement in function was not reflected in post-operative patient satisfaction. However, the pre-operative function of the patient was negatively associated with satisfaction, indicating that patients with higher pre-operative function are overall less satisfied with their TKA surgery, regardless of any functional improvement due to the surgery. Interestingly, the only significant association with post-operative satisfaction was knee joint function, and the relationship between function and patient satisfaction following TKA appears to relate only to the baseline functional state of the patient, and not with functional improvement. This suggests that dissatisfaction post-surgery is more likely reflecting the unmet expectations of a higher functioning patient, and has implications for the need for improved understanding of pre-operative patient functional variability in TKA triage and expectation management.

Accurate comparison of outcomes regarding various surgical options in knee arthroplasty calls for an improved method of joint line analysis that takes into account the preoperative cartilage thickness. Current methods for measuring joint lines have limitations. This is commonly done on anteroposterior or lateral radiographs, by measuring landmarks defining the joint line with reference to a common landmark such as the fibular head, the medial femoral epicondyle or the tibial tuberosity. These radiographic methods are unable to measure important differences between the medial and lateral joint lines. Furthermore, poor accuracies due to sensitivity to patient and X-ray beam positions have been reported for these methods. The aim of this study was to introduce a method to measure the joint line shift for any desired flexion angle of the joint by taking into account the cartilage thickness on both the medial and lateral sides and under weightbearing conditions.

The suggested method inludes four steps (Figure 1): a) preoperative joint imaging and 3D-2D matching between pre-operative 3D models and bi-planar 2D images; b) postoperative joint imaging and 3D-2D matching between implant 3D models and 3D models of the bones to bi-planar 2D images; c) superimposition of the locations of the implant components on the preoperative joint positions to determine changes in the joint line on the medial and lateral sides of the joint for both extension and flexion positions.

To determine the tibial joint line, the three-dimensional model of the polyethylene inlay was added to the metal tray according to the design of its locking mechanism. Two-dimensional cross-sectional slices of the combined bone and implant models were obtained perpendicular to the tibial tray and passed through the most distal points of the medial and lateral condyles of the femoral component. Joint line shift was measured as the distance between the most distal point on the condyle of the femoral component and the most proximal point on the articular surface of the tibial polyethylene in the direction normal to the mediolateral edge of the tibial tray in the cross-sectional slice.

The method was tested on six cadaveric specimens. The joint line shift, measured using the new method, was in the range of −0.2 to 1.3 mm on average (SD=1.3 to 3.8 mm for medial and lateral, flexion and extension). This was significantly different (p≤0.01) from the results of a previously post-op based registration method which did not account for the cartilage thickness. These results demonstrate the importance of the preoperative joint space when analyzing the joint line, and highlight the utility of the newly introduced method. The method introduced in this study combines the preoperative and postoperative images to provide accurate 3D measures of joint line shifts. The method incorporates cartilage thickness in the analysis and is insensitive to patient and X-ray beam position, and can be applied at any flexion angle of the knee. The method yields much smaller measures of joint line shift than a previous approach, which suggests that the previous method may have overestimated joint line shift substantially.

Distal femoral fracture fixation has historically been associated with high rates of reoperation because of mal-union, non-union and implant failure. We hypothesised that recent advances in distal femoral locking plate design and material along with an improved understanding of biomechanical principles would improve outcome. In a 5-year retrospective study utilising electronic patient records and serial radiographs (including recall by letter where there was no radiological evidence of union) we identified a series of 129 distal femoral fractures treated with modern locking plates in 123 patients. The majority were female (80%), elderly (mean 73 years) and infirm (72/123 ASA 3 or more). A consultant performed the operation in 67% of cases. 49% were followed to radiological union, while 25% died within the follow up period. Reoperation rate for implant failure was 4%, with all failures occurring early (within 5 months). Our follow up correlates with the infirm elderly population concerned. Our cohort shares many similarities with hip fracture patients and we propose that this group should receive equal surgical priority and optimum management also be rewarded by enhanced tariffs. Modern locking plates used in combination with the correct biomechanical principles are performing well in our centre.

Introduction

Bony deformities in the hip that cause femoroacetabular impingement (FAI) can be resected in order to delay the onset of osteoarthritis and improve hip range of motion. However, achieving accurate osteoplasty arthroscopically is challenging because the narrow hip joint capsule limits field of view. Recently, image-based navigation using a preoperative plan has been shown to improve the accuracy of femoral bone surfaces following arthroscopic osteoplasty for FAI. The current standard for intraoperative monitoring, 3D x-ray fluoroscopy, is accurate at the initial registration step to within 0.8±0.5mm but involves radiation. Intraoperative 3D ultrasound (US) is a promising radiation-free alternative for providing real-time visual feedback during FAI osteoplasty. The objective was to determine if intraoperative 3D US of the femoral head/neck region can be registered to a CT-based preoperative plan with comparable accuracy to fluoroscopic navigation in order to visualise progress during arthroscopic FAI osteoplasty.

INTRODUCTION

Rotational malalignment of the components in total knee arthroplasty has been linked to patellar maltracking, improper soft tissue balance, abnormal kinematics, premature wear of the polyethylene inlay, and subsequent clinical complications such as anterior knee pain (Barrack et al., 2001; Zihlmann et al., 2005; Lakstein at al., 2010). This study investigates an innovative image-based device that is designed to be used along with an intraoperative Isocentric (ISO-C) 3D imaging C-arm, and the conventional surgical instruments for positioning the femoral component at accurate rotational alignment angles.

INTRODUCTION

Poor acetabular cup orientation in total hip arthroplasty (THA) can cause dislocation and impingement, and lead to osteolysis (Little et al., 2009) and inflammatory soft tissue reactions (Haan et al., 2008). While the intrinsic accuracy of cup positioning in navigation is reported as low as 1° (Parratte et al., 2009), a large anterior pelvic tilt may lead to an offset of the same magnitude in the final cup anteversion (Wolf et al., 2005). The objectives of this study are to demonstrate feasibility of a new, non-invasive radiographic tool for accurate preoperative determination of a patient's specific pelvis angle, and intraoperative and postoperative assessment of the acetabular cup orientation with respect to boney landmarks.

Introduction

The most common method for accurate kinematic analysis of the knee arthroplasty uses bi-planar fluoroscopy and model-based RSA. The main challenge is to have access to reverse-engineered CAD models of the implant components, if not provided by the company, making this method impractical for a clinical study involving many types or sizes of implants. An alternative could be to reconstruct the 3D primitive features of the implant, such as cylindrical pegs, flat surfaces and circular boundaries, based on their 2D projections. This method was applied by Kaptein et al. (2006) for hip implants. However, despite its broad potential, it has not yet been applied for studying TKA kinematics. This study develops a methodology for feature-based RSA of TKA and investigates the range of accuracies in comparison to model-based RSA.

Introduction

Poor clinical outcomes following total knee arthroplasty (TKA) can be related to improper alignment of the components. The main challenge is the variability in biomechanical references, especially in cases of severe deformity or dysplasia, and in determining the surgical landmarks intraoperatively. An intraoperative imaging tool can be very useful to assess the alignments when there is still a chance for correction. We investigated, on cadaveric specimens, the accuracy of using iso-centric (ISO-C) imaging (that reconstructs 3D from multiple 2D fluoroscopic images) for this purpose.

Aim

This study aims to determine the value of MRI in children with hip pain which remained unexplained following routine investigations including ultrasound examination.