Rehabilitation following periacetabular osteotomy for acetabular dysplasia: A qualitative interview study exploring challenges, hopes and expectations among patients in Denmark and Australia.

INTRODUCTION: Guidelines have been proposed for post-operative rehabilitation following periacetabular osteotomy (PAO). However, the perspectives of individuals undergoing PAO have not been considered. AIM: The present study aimed to explore the perceived challenges of everyday life and hopes for and expectations of post-PAO rehabilitation from the perspective of individuals with acetabular dysplasia living in Denmark and Australia. METHODS: In this qualitative study, we used a hermeneutic phenomenological approach with semi-structured interviews to explore the perspectives of 25 participants (four males), aged 16-43 years, who underwent a PAO. Purposeful sampling was used to provide variations in age and sex. Inclusion criteria were age above 15 years, radiographic evidence of acetabular dysplasia, PAO within the last seven weeks and undergoing post-operative rehabilitation. Inductive content analysis was adopted to code and analyse interviews. RESULTS: The analysis of the interview transcripts revealed four major themes: different expectations, self-confidence, tailored rehabilitation and aligning expectations. Several subthemes emerged within each theme, and similar patterns with minor variations were identified across countries. However, the financial burden of self-funded surgery and rehabilitation challenged some Australian participants, whereas none of the Danish participants mentioned this challenge. CONCLUSION: Our findings elucidate the diverse range of hopes and expectations in individuals undergoing PAO, and how these relate to their perceived challenges. In particular, the findings highlight the importance of aligning expectations between individuals and clinicians when designing the rehabilitation.

Determination of preoperative risk factors for iliopsoas tendonitis after total hip arthroplasty: A simulation study.

This study aims to identify preoperative risk factors for iliopsoas tendonitis after total hip arthroplasty, a complication typically attributed to acetabular cup position and orientation, using a validated iliopsoas impingement detection simulation. Analyzing CT scans and X-rays of 448 patients using a validated preoperative planning protocol, patients were simulated for iliopsoas impingement and categorized into at-risk and not at-risk groups based on a prior validation study, with a 23% at-risk incidence. Implementing a propensity score matching algorithm to reduce covariate imbalance, we identified factors that may exacerbate risk of iliopsoas tendonitis. Parameters that were investigated included standing pelvic tilt, functional femoral rotation, and the difference between the planned acetabular cup diameter and native femoral head diameter (ΔC-NFH). Comparing pelvic tilt, we found a significant difference between the groups (at-risk: -6.0°, not at-risk: -0.7°; p << 0.01). A similar trend was noted for ΔC-NFH (at-risk: +5.7 mm, not at-risk: +5.1 mm; p = 0.01). Additional simulations of at-risk patients indicated increased anteversion of the acetabular cup reduces impingement risk more effectively than medialisation. These findings suggest that spinopelvic parameters may exacerbate iliopsoas irritation risk, underscoring their importance in preoperative planning and patient expectation management. Similar findings of a greater than 6 mm difference between cup size and native femoral head diameter being a significant risk for iliopsoas tendonitis have been observed before, underscoring its potential veracity. These results may provide surgeons with a simple threshold that can be used in determining a cup size to reduce the risk of iliopsoas tendonitis.

Comparison of iliopsoas tendonitis after hip resurfacing arthroplasty and total hip arthroplasty: A case-controlled investigation using a validated simulation.

Iliopsoas tendonitis, typically caused by impingement with the acetabular cup, occurs in up to 18% of patients after total hip arthroplasty (THA) and up to 30% of patients after hip resurfacing arthroplasty (HRA). We have developed a simulation for detecting iliopsoas impingement and validated it in a previous study of THA patients. However, due to the difference in incidence between HRA and THA, this study had two aims. First, to validate the simulation in a cohort of HRA patients and, second, to comparethe results of the HRA and THA patients to understand any differences in their etiology. We conducted a retrospective search in an experienced surgeon's database for HRA patients with iliopsoas tendonitisand control patients without iliopsoas tendonitis, resulting in two cohorts of 12 patients. Using CT scans, 3D models of the each patient's prosthetic and bony anatomy were generated, landmarked, and simulated. Regarding validation of the simulation for HRA patients, impingement significantly predicted the probability of iliopsoas tendonitis in logistic regression models and the simulation had a sensitivity of 83%, specificity of 100%, and an AUC ROC curve of 0.95. Unexpectedly, the HRA cohort exhibited less impingement than the THA cohort. Our novel simulation has now been demonstrated to detect iliopsoas impingement and differentiate between the symptomatic and asymptomatic cohorts in investigations of THA and HRA patients. This tool has the potential to be used preoperatively, to guide decisions about optimal cup placement, and postoperatively, to assist in the diagnosis of iliopsoas tendonitis.

Resection of Traumatic Triradiate Bar Led To Restored Triradiate Growth: A Case Report.

CASE: A 2-year-old boy suffered an injury to the acetabular physis resulting in the formation of an osseus bar across all 3 limbs of the triradiate, growth arrest, and secondary hip dysplasia. This condition was treated with bony bar resection using an anterior intrapelvic approach. Over a follow-up period of more than 3 years, there was notable restoration of triradiate cartilage growth. CONCLUSION: Our case demonstrates that resection of a triradiate bar can be an effective treatment of premature traumatic triradiate closure. Early recognition and intervention are preferable before secondary changes in the acetabulum have fully developed.

Utility assessment of virtual reality technology in orthopaedic surgical training.

BACKGROUND: Virtual reality (VR) has proved to be a useful technology beyond the field of surgery in areas that are highly dependent on consolidating motor tasks. Despite being reliant on these skills, the uptake of VR in orthopaedics has been extremely limited. Therefore, this study's purpose was to help assess the utility of applying this technology in teaching different experience levels of orthopaedic training. Secondary objectives were to assess enjoyability and feasibility to complete modules prior to surgery. METHODS: The study explored which experience level of orthopaedic trainee benefits the most from the proposed haptic VR package. Participants completed a total hip arthroplasty module using the Fundamental Surgery package. Qualitative data was collected in the form of a post completion survey of 24 participants. Quantitative data was collected in the form of module completion time and percentage of skills completed. RESULTS: 37.5% of participants rated non-training orthopaedic registrars as the experience level that would benefit the most from using VR. 88% of participants would recommend this module to a colleague and found the module very enjoyable (4.2 out of 5). 50% of participants took between 25 and 31.5 min to finish and completed between 80% and 95% of tasks in the module. CONCLUSIONS: The study demonstrated that non-training orthopaedic registrars were most likely to benefit using this particular VR package. Most users found the experience to be enjoyable and would recommend it to a colleague. It was also deemed feasible to complete the module prior to performing an operation.

Iliopsoas tendonitis after total hip arthroplasty : an improved detection method with applications to preoperative planning.

AIMS: Iliopsoas impingement occurs in 4% to 30% of patients after undergoing total hip arthroplasty (THA). Despite a relatively high incidence, there are few attempts at modelling impingement between the iliopsoas and acetabular component, and no attempts at modelling this in a representative cohort of subjects. The purpose of this study was to develop a novel computational model for quantifying the impingement between the iliopsoas and acetabular component and validate its utility in a case-controlled investigation. METHODS: This was a retrospective cohort study of patients who underwent THA surgery that included 23 symptomatic patients diagnosed with iliopsoas tendonitis, and 23 patients not diagnosed with iliopsoas tendonitis. All patients received postoperative CT imaging, postoperative standing radiography, and had minimum six months' follow-up. 3D models of each patient's prosthetic and bony anatomy were generated, landmarked, and simulated in a novel iliopsoas impingement detection model in supine and standing pelvic positions. Logistic regression models were implemented to determine if the probability of pain could be significantly predicted. Receiver operating characteristic curves were generated to determine the model's sensitivity, specificity, and area under the curve (AUC). RESULTS: Highly significant differences between the symptomatic and asymptomatic cohorts were observed for iliopsoas impingement. Logistic regression models determined that the impingement values significantly predicted the probability of groin pain. The simulation had a sensitivity of 74%, specificity of 100%, and an AUC of 0.86. CONCLUSION: We developed a computational model that can quantify iliopsoas impingement and verified its accuracy in a case-controlled investigation. This tool has the potential to be used preoperatively, to guide decisions about optimal cup placement, and postoperatively, to assist in the diagnosis of iliopsoas tendonitis.Cite this article: Bone Jt Open 2023;4(1):3-12.

Functional Femoral Anteversion: Axial Rotation of the Femur and its Implications for Stem Version Targets in Total Hip Arthroplasty.

Background: Acetabular and femoral component positioning are important considerations in reducing adverse outcomes after total hip arthroplasty (THA). Previous assessments of femoral anteversion examined anatomic femoral anteversion (AFA) referenced to anatomic landmarks. However, this does not provide a functional understanding of the femur's relationship to the hip. We investigate a new measurement, functional femoral anteversion (FFA), and sought to measure its variability across a large sample of patients undergoing THA. Methods: A total of 1008 consecutive patients underwent THA surgery between September 2019 and July 2021. All patients were measured for supine and standing functional femoral rotation (FFR), AFA, and FFA. Results: The mean standing FFA was 13.2° ± 12.2° (-27.8° to 52.3°). The mean change in FFR from supine to standing was -2.2° ± 11.8° (-43.0° to 41.9°). Of all, 161 (16%) patients had standing FFA version greater than 25°. Four hundred sixty (46%) patients had standing FFR (internal or external) greater than 10°. One hundred twenty-three (12%) patients exhibited an increase in external rotation from supine to standing of greater than 10°. A moderate, negative linear relationship was observed between AFA and standing external femoral rotation (P <<.001, R = -0.46), indicating people may externally rotate their femur as AFA decreases with age. Conclusions: Functional alignment of the femur in patients requiring THA is understudied. It is now understood that the femur, like the pelvis, can rotate substantially between functional positions. Enhancing our understanding of FFA and FFR may improve both acetabular and femoral component positioning.

Criteria for the Operating Room Confirmation of the Diagnosis of Hip Instability: The Results of an International Expert Consensus Conference.

PURPOSE: The purpose of this study was to establish an international expert consensus on operating room findings that aid in the diagnosis of hip instability. METHODS: An expert panel was convened to build an international consensus on the operating room diagnosis/confirmation of hip instability. Seventeen surgeons who have published or lectured nationally or internationally on the topic of hip instability were invited to participate. Fifteen panel members completed a pre-meeting questionnaire and agreed to participate in a 1-day consensus meeting on May 15, 2021. A review of the literature was performed to identify published intraoperative reference criteria used in the diagnosis of hip instability. Studies were included for discussion if they reported and intraoperative findings associated with hip instability. The evidence for and against each criteria was discussed, followed by an anonymous voting process. For consensus, defined a priori, items were included in the final criteria set if at least 80% of experts agreed. RESULTS: A review of the published literature identified 11 operating room criteria that have been used to facilitate the diagnosis of hip instability. Six additional criteria were proposed by panel members as part of the pre-meeting questionnaire. Consensus agreement was achieved for 8 criteria, namely ease of hip distraction under anesthesia (100.0% agreement), inside-out pattern of chondral damage (100.0% agreement), location of chondral damage on the acetabulum (93.3% agreement), pattern of labral damage (93.3% agreement), anteroinferior labrum chondral damage (86.7% agreement), perifoveal cartilage damage (97.6% agreement), a capsular defect (86.7% agreement), and capsular status (80.0% agreement). Consensus was not achieved for 9 items, namely ligamentum teres tear (66.7% agreement), arthroscopic stability tests (46.7% agreement), persistent distraction after removal of traction (46.7% agreement), findings of examination under anesthesia (46.7% agreement), the femoral head divot sign (40.0% agreement), inferomedial synovitis (26.7% agreement), drive-through sign (26.7% agreement), iliopsoas irritation (26.7% agreement) and ligamentum teres-labral kissing lesion (13.3% agreement). All experts agreed on the final list of 8 criteria items reaching consensus. CONCLUSION: This expert panel identified 8 criteria that can be used in the operating room to help confirm the diagnosis of hip instability. LEVEL OF EVIDENCE: Level V expert opinion.

Acetabular retroversion is prevalent and proportional to the severity of slipped upper femoral epiphysis.

AIMS: Slipped upper femoral epiphysis (SUFE) has well documented biochemical and mechanical risk factors. Femoral and acetabular morphologies seem to be equally important. Acetabular retroversion has a low prevalence in asymptomatic adults. Hips with dysplasia, osteoarthritis, and Perthes' disease, however, have higher rates, ranging from 18% to 48%. The aim of our study was to assess the prevalence of acetabular retroversion in patients presenting with SUFE using both validated radiological signs and tomographical measurements. METHODS: A retrospective review of all SUFE surgical cases presenting to the Royal Children's Hospital, Melbourne, Australia, from 2012 to 2019 were evaluated. Preoperative plain radiographs were assessed for slip angle, validated radiological signs of retroversion, and standardized postoperative CT scans were used to assess cranial and mid-acetabular version. RESULTS: In all, 116 SUFEs presented in 107 patients who underwent surgical intervention; 47 (52%) were male, with a mean age of 12.7 years (7.5 to 16.6). Complete radiological data was available for 91 patients (99 hips) with adequate axial CT imaging of both hips. Overall, 82 patients (82%) underwent pinning in situ (PIS), with subcapital realignment surgery (SRS) performed in 17 patients (18%) (slip angles > 75°). Contralateral prophylactic PIS was performed in 72 patients (87%). On the slip side, 62 patients (68%) had one or more radiological sign of retroversion. Tomographical acetabular retroversion was more pronounced cranially than caudally of the acetabulum on both the affected side and the contralateral side (p < 0.001) as expected in the normal population. Increasing severity of the slip was found to be directly proportional to the degree of reduction in cranial and central acetabular version (p < 0.05) in the SUFE hips. CONCLUSION: Acetabular retroversion is more prevalent in patients with SUFE than previously reported, and have been shown be correlated to the severity of the slip presentation. The presence of radiological signs of acetabular retroversion could be used to justify prophylactic contralateral pinning. Cite this article: Bone Jt Open 2022;3(2):158-164.

Does the use of i-FACTOR bone graft affect bone healing in those undergoing periacetabular osteotomy (PAO) for developmental dysplasia of the hip (DDH)? A retrospective study.

The aims of this study were to compare, in patients with and without the use of i-FACTOR bone graft during periacetabular osteotomy (PAO) surgery for developmental dysplasia of the hip (DDH), (i) bone healing at six-weeks post-operatively (ii) rate of complications. This was a retrospective review of case records. Participants were people aged 15-50 years undergoing rectus-sparing minimally invasive PAO surgery for DDH. Group 1: patients with i-FACTOR, Group 2: No i-FACTOR. The primary outcome was the rate of bone healing on radiographs at 6 weeks. The likelihood of bone healing was compared using logistic regression with Generalised Estimating Equations (GEE) and expressed as odds ratios (95% confidence intervals (CIs; P < 0.05)). The occurrence of complications was extracted from surgical records. The i-FACTOR group had 3-times greater odds of partial/full union than those without [adjusted odds ratio (95% CIs, P-value)]: [3.265 (1.032 to 10.330, P = 0.044)]. The i-FACTOR group had 89% partial/full union at 6-weeks, compared to 69% of the non-i-FACTOR group. Half of the patients had leaking of bone graft in the i-FACTOR group versus 10% in the non-i-FACTOR group, 26% of the i-FACTOR group and 12% of the non-i-FACTOR group had neuropraxia of the lateral femoral cutaneous nerve (LFCN). Complication rates were low, and similar between groups. However, the rate of LFCN neuropraxia and bone graft leakage was higher in the i-FACTOR. These findings should be confirmed in a future prospective randomised clinical trial and include outcomes such as pain and quality of life.

Rationale and feasibility assessment of an institution-based virtual reality hub in orthopaedic surgical training: an Australian pilot study.

BACKGROUND: Virtual reality (VR) has been established as a valuable tool outside of medicine but there has been limited uptake in orthopaedics despite being a specialty heavily dependent on psychomotor skills. The purpose of this study was to assess the feasibility of setting up an on-site virtual reality surgical training hub for an orthopaedic surgery unit. A secondary objective was to document encountered hurdles to assist other institutions with a similar process. METHODS: The study explored the logistical and organizational considerations in the process of creating a virtual reality training area. This included: review of location, set up management, funding arrangements, set up time, research opportunities and training time. Set up and completion times were recorded during a separate trial of 24 participants ranging from medical students to senior consultant orthopaedic surgeons. RESULTS: A VR training area was successfully established over a period of 3 months. A dedicated area for training where the equipment remains permanently was designated to facilitate ease of use. Average set up took 7.5 min to turn the computer on and 25 min for the participants to start the module. Issues identified during set up were recorded. CONCLUSIONS: The study demonstrated that it is possible to set up a dedicated area for virtual reality surgical training within a hospital unit. A dedicated lockable area is the most feasible method of establishing such a space and reduces the requirement to recalibrate and transfer equipment around the hospital.

Efficacy of tantalum rod insertion for preventing femoral head collapse in osteonecrosis in a paediatric population: a pilot study.

Femoral head osteonecrosis in the paediatric population is difficult to treat, with the primary goals of management being prevention of subchondral collapse and the avoidance of early total hip replacement. This study aims to describe the use of a porous tantalum rod implant to provide mechanical support in preventing femoral head collapse in a paediatric population. A retrospective chart-based analysis of patients with osteonecrosis of the hip was performed at our institution to identify those who had undergone tantalum rod insertion. A total of 10 patients (fives males and five females, median age 12.5 years, 9-18) had tantalum rods implanted between December 2013 and February 2018. One patient was excluded due to follow-up at a different institution. The radiographic degree of osteonecrosis was characterized according to the Ficat classification and the Kerboul angle. Radiographic assessment of pre- and post-operative plain films was performed. The outcome measures were Tonnis grade and percentage collapse of the femoral head. Nine patients with a mean follow-up time of 18.4 months were included in the analysis. There was no significant increase in the femoral head collapse percentage post tantalum rod insertion compared to pre-operatively (P = 0.63). There was a significant increase in the Tonnis grade post-operatively (P < 0.05), with sub-group analysis showing minimal increase in Ficat Stage 1 patients. This study is the first to examine the role of tantalum rod insertion in preventing femoral head collapse in a paediatric population, with results suggesting potential benefit in a subset of patients.

Intraoperative assessment of femoral head perfusion during surgical hip dislocation for slipped capital femoral epiphysis.

Avascular necrosis is the most devastating complication of slipped capital femoral epiphysis, leading to collapse of the femoral head, increased risk of osteoarthritis and the requirement of early total hip arthroplasty. It is believed that intraoperative femoral head perfusion assessment may be an accurate predictor of post-operative avascular necrosis (radiographic collapse). At our institution, femoral head perfusion is assessed intraoperatively during all sub-capital realignment procedures. We hypothesize that our method is accurate in predicting the risk of developing post-operative avascular necrosis. In this retrospective study, we collected data from all patients that had intraoperative blood flow measurements during sub-capital realignment procedures. We correlated this with long-term radiographs looking for radiographic collapse. The intraoperative femoral head perfusion assessments during sub-capital realignment procedures for slipped capital femoral epiphysis at our institution, between January 2015 and March 2020 inclusive were assessed for reliability. In total, 26 of 35 patients had intraoperative femoral head perfusion present. Only 2 (8%) of these patients developed radiographic collapse. In contrast, 7 (78%) of the 9 patients who did not have femoral head perfusion present intraoperatively developed radiographic collapse, indicating that our method may be reliable in predicting a patient's post-operative risk of developing avascular necrosis.

Slipped capital femoral epiphysis, fixation by single screw in situ: A kinematic and radiographic study.

BACKGROUND: Slipped capital femoral epiphysis is known to produce characteristic deformities in the proximal femur, which affect hip motion and may cause a limp. This paper assessed the 3D gait kinematics in adolescents after single screw fixation of moderate to severe, stable, unilateral slipped capital femoral epiphysis. Our goals were to characterize the 3D kinematic patterns and to investigate the correlation between the severity of radiological deformity and severity of gait disturbance. METHODS: This was a retrospective study of patients seen at our institution between 2000 and 2009. Antero-posterior and frog lateral X-rays were reviewed to measure: Southwick's lateral slip angle, the alpha angle of Notzli and Klein's line offset. Quantitative 3D gait data was collected using a state of the art motion capture system. Kinematic waveforms were compared using a functional data analysis version of the t-test. FINDINGS: There were 30 patients with an average age at pinning of 13y (10-17y). Mean gait profile scores were significantly abnormal for slipped side (10.8°) versus sound side (6.8°), slipped side versus normal (5.6°) and sound side versus normal. There was little statistically significant correlation between severity of radiographic deformity and degree of gait disturbance. INTERPRETATION: Major kinematic pattern deviations could be associated with (a) morphology of the proximal femur and potential femoral acetabular impingement problems and (b) leg length discrepancy. Gait analysis was able to quantify the kinematic deviations due to the anatomical deformities.

Radiographic assessment of bone remodelling in slipped upper femoral epiphyses using Klein's line and the α angle of femoral-acetabular impingement: a retrospective review.

BACKGROUND: Bone remodelling in patients with earlier slipped upper femoral epiphysis (SUFE) has been shown to have a generally positive effect on both clinical and radiologic parameters. This study aims to further assess the effect of bone remodelling on the femoral head-neck relationship in SUFE patients, with the aid of 2 radiographic measurements not earlier used for this assessment. METHODS: A retrospective review of radiographs was performed on all patients surgically managed for SUFE at a tertiary institution between 2000 and 2006. The postoperative and the most recent review radiographs were used for analysis. Alpha angles of Notzli (generally used to measure cam-type femoral-acetabular impingement) and displacement from Klein's line were measured as markers of femoral head-neck relationship. RESULTS: A total of 59 hips were evaluated with a median mean follow-up time of 17.7 months. Patients had mild-to-moderate SUFE. The postoperative α angle mean reduced by 17.7 degrees (95% confidence interval: 13.6-21.8, P<0.001) at follow up. The displacement from Klein's line improved by a mean of 4.8 mm (95% confidence interval: 3.9-5.8 mm, P<0.001), over the review period. CONCLUSIONS: The femoral head-neck relationship, measured by both the Notzli α angle and the displacement from Klein's line, becomes significantly closer to normal after in situ pinning of mild-to-moderate SUFE, compatible with favorable bone remodelling. Both of these indices show promise for use in prospective study and standardized clinical follow up of patients with SUFE, and could be especially useful in assessing for future femoral-acetabular impingement. LEVEL OF EVIDENCE: III.

Posterior divergent dislocation of the elbow in children and adolescents: a report of three cases and review of the literature.

Divergent dislocation of the elbow is defined as a specific elbow dislocation in which the distal humerus is forced between the proximal radius and ulna, resulting in separation or divergence of the proximal forearm bones. This is an uncommon injury in children, with 14 cases reported in the last 23 years. The authors report three additional cases and the findings from cadaver elbow dissections in which the injury was reproduced. The authors propose that there is only one type of divergent dislocation, resulting from indirect forces transmitted to the elbow from a fall on the outstretched hand. The injury predominantly occurs in younger children because joint laxity is a predisposing cause. Early recognition, followed by a closed reduction and a 3- to 4-week period of cast immobilization, should result in a full recovery for most children.