Comparison of Contrast-enhanced Ultrasound and Contrast-enhanced Magnetic Resonance Imaging in the Assessment of Infant Hip Perfusion and Prediction of Proximal Femoral Growth Disturbance Following Closed and Open Reduction for Developmental Dysplasia of the Hip: A Preliminary Study.

OBJECTIVE: Proximal femoral growth disturbance (PFGD) is a significant complication associated with surgical treatment of infant hip dislocation. Contrast-enhanced magnetic resonance imaging (CEMRI) has been utilized to assess perfusion in these hips and avoid PFGD. Contrast-enhanced ultrasound (CEUS) is an imaging technique utilized to evaluate perfusion in other organs. The aims of this study were to compare perfusion of dysplastic infant hips with CEUS and CEMRI after surgical treatment and to determine whether CEUS was as effective as CEMRI at predicting PFGD. METHODS: A retrospective analysis of patients undergoing closed or open reduction for infant hip dislocation between 2012 and 2019 was performed. All patients underwent intraoperative CEUS and postoperative CEMRI to assess femoral epiphyseal perfusion using intravenous contrast. Perfusion status was rated as normal, partially decreased, or globally decreased in both modalities. Agreement in perfusion status between CEUS and CEMRI was assessed. Patients were followed for a minimum of 2 years postoperatively and assessed for PFGD. RESULTS: Eighteen patients (28% males) underwent closed or open reduction at an average age of 8 months (3 to 16 mo). The agreement in perfusion status between CEUS and CEMRI was substantial (α = 0.74). Patients were followed for a median of 3 years. PFGD developed in 3 hips (17%). For the detection of PFGD, both imaging modalities performed very well and with no difference in the diagnostic utility of CEUS compared with CEMRI. Considering normal perfusion alone the accuracy, sensitivity, and specificity for CEUS were 83%, 100%, and 80%, and for CEMRI were 78%, 100%, and 73%, respectively. Considering global decreased perfusion alone, the accuracy, sensitivity, and specificity for CEUS were 94%, 67%, and 100%, and for CEMRI were 89%, 67%, and 93%, respectively. CONCLUSIONS: CEUS is a viable intraoperative method to assess infant hip perfusion. This pilot study appears to be comparable to CEMRI at visualizing perfusion of infant hips and as good or better in predicting PFGD after hip reduction. Prospective studies of this imaging technique should be performed to confirm the findings of this retrospective review. LEVEL OF EVIDENCE: Level II-development diagnostic criteria on the basis of consecutive patients (with generally preferred standard).

[Solidarity with children and people with disabilities? : An economic analysis of reconstructive hip interventions in pediatric orthopedics]. / Solidarität mit Kindern und Menschen mit Behinderung? : Eine Wirtschaftlichkeitsanalyse hüftrekonstruierender Eingriffe in der Kinderorthopädie.

BACKGROUND: Brain damage in childhood can be caused cerebral palsy (CP) or be due to other diseases. Disturbance of muscle tone results in consecutive development of hip subluxation. Hip reconstructive surgery can significantly improve the mobility and quality of care of children. However, the DRG for surgical care of these conditions has been increasingly devalued. In Germany, this has already led to a reduction of pediatric orthopedics departments, accompanied by an important risk of insufficient treatment options for children and people with disabilities. METHOD: The aim of this retrospective study was an economic analysis of pediatric orthopedic interventions using the example of neurogenic hip decentration. For this purpose, the revenue-cost situation in patients with CP or other causes of brain damage was evaluated at a maximum care hospital in the period of 2019-2021. RESULTS: The entire analysis period showed a deficit. The non-CP-group showed the most important deficit. In CP-patients, however, the plus decreased each year and resulted in a deficit in 2021. CONCLUSION: While the distinction between cerebral palsy and other forms of brain damage in children is usually not relevant for treatment, it is evident that the non-CP group is massively underfinanced. Overall, the negative economic balance of pediatric orthopedics in the field of neurogenic hip reconstruction is clearly revealed. In the current interpretation of the DRG system, children with disabilities cannot be offered cost-effective care at a maximum-care university center.

Incidence of Instability Following Primary Total Hip Arthroplasty Continues to Decline in the Medicare Population.

BACKGROUND: Instability has been the primary cause of failure following primary total hip arthroplasty (THA) leading to revision hip surgery. The purpose of this study was to determine if instability rates have further declined following advances in primary THA, including dual mobility articulations, direct anterior approaches, advanced technologies, and improved knowledge of the hip-spine relationships. METHODS: Using the 5% Medicare Part B claims data from 1999 to 2019, we identified 81,573 patients who underwent primary THA for osteoarthritis. Patients who experienced instability at 3 months, 6 months, 1 year, and 2 years were identified. Multivariate cox regression analyses evaluated the effect of patient and procedure characteristics on the risk of instability. RESULTS: Instability at 1 year following primary THA declined from approximately 4% in 2000 to 2.3% in 2010 and 1.6% in 2018. The leading cause of revision surgery was infection (18.6%), followed by periprosthetic fracture (14%), mechanical loosening (11.5%), and instability (9.4%). High-risk groups for instability continue to include increased age, higher Charlson index, obesity, lumbar spine pathology, and neurocognitive disorders. CONCLUSION: Instability is no longer the leading etiology of failure following primary THA with a decline of approximately 40% over the past decade. Infection, periprosthetic fracture, mechanical loosening, and then instability are now the leading causes of failure. Multiple factors may play a role in the decline of instability, including increased use of dual mobility articulations, direct anterior approaches, improved knowledge of the hip-spine relationships, and use of advanced technologies.

[Preoperative MR imaging for hip dysplasia : Assessment of associated deformities and intraarticular pathologies]. / Präoperative MRT-Bildgebung bei Hüftdysplasie : Abklärung assoziierter Deformitäten und intraartikulärer Pathologien.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a known reason for hip pain for adolescents and young adults. Preoperative imaging is increasingly recognized as an important factor due to the recent advances in MR imaging. OBJECTIVES: The aim of this article is to give an overview of preoperative imaging for DDH. The acetabular version and morphology, associated femoral deformities (cam deformity, valgus and femoral antetorsion) and intraarticular pathologies (labrum and cartilage damage) and cartilage mapping are described. METHODS: After an initial evaluation with AP radiographs, CT or MRI represent the methods of choice for the preoperative evaluation of the acetabular morphology and cam deformity, and for the measurement of femoral torsion. Different measurement techniques and normal values should be considered, especially for patients with increased femoral antetorsion because this could lead to misinterpretation and misdiagnosis. MRI allows analysis of labrum hypertrophy and subtle signs for hip instability. 3D MRI for cartilage mapping allows quantification of biochemical cartilage degeneration and yields great potential for surgical decision-making. 3D-CT and, increasingly, 3D MRI of the hip to generate 3D pelvic bone models and subsequent 3D impingement simulation can help to detect posterior extraarticular ischiofemoral impingement. RESULTS AND DISCUSSION: Acetabular morphology can be divided in anterior, lateral and posterior hip dysplasia. Combined osseous deformities are common, such as hip dysplasia combined with cam deformity (86%). Valgus deformities were reported in 44%. Combined hip dysplasia and increased femoral antetorsion can occur in 52%. Posterior extraarticular ischiofemoral impingement between the lesser trochanter and the ischial tuberosity can occur in patients with increased femoral antetorsion. Typically, labrum damage and hypertrophy, cartilage damage, subchondral cysts can occur in hip dysplasia. Hypertrophy of the muscle iliocapsularis is a sign for hip instability. Acetabular morphology and femoral deformities (cam deformity and femoral anteversion) should be evaluated before surgical therapy for patients with hip dysplasia, considering the different measurement techniques and normal values of femoral antetorsion.

Quantitative assessment of hip morphology to enhance the identification of hip dysplasia in German Shepherd Dogs.

OBJECTIVE: To develop quantitative measures that, when combined with the Fédération Cynologique Internationale (FCI) score, would potentially enhance the accuracy of the scoring process. ANIMALS: 153 client-owned purebred German Shepherd Dogs with normal and near normal (71 dogs) and dysplastic coxofemoral joint (82 dogs). PROCEDURES: Center edge (CE) angle, Norberg angle (NA), indexes of dorsal acetabular femoral head (AFH) coverage width and area, acetabular index angle, and inclination angle were determined. We also investigated the correlation between selected variables. Coxofemoral joints were classified into normal, near normal, and mildly, moderately, and severely dysplastic joints based on the morphometric criteria previously established by the conventional FCI scoring. Variables were compared among the 5 groups using ANOVA. Linear relationships were determined using Spearman correlation coefficients. RESULTS: All radiographic measurements differed significantly (P < .0001) among the 5 assigned groups (normal, near normal, mildly dysplastic, moderately dysplastic, and severely dysplastic hip joints). NA was the only measure that differed significantly (P ≤ .03) between the 5 assigned groups. Positive correlations were identified between Norberg and CE angles (rs = 0.93), between width and area indexes of dorsal AFH coverage (rs = 0.92), and between the measurement techniques utilized to assess lateral versus dorsal AFH coverage (rs ≥ 0.65). CLINICAL RELEVANCE: Evaluation of lateral and dorsal AFH coverage may help to refine the scoring system used to select German Shepherd Dogs for breeding. German Shepherd Dogs with NA < 103°, CE angle < 20.8°, dorsal AFH coverage width index ≤ 49%, and/or dorsal AFH coverage area index ≤ 51% should be considered to have mild, moderate, or severe hip dysplasia and are therefore not good candidates for breeding. Borderline values between near normal and mildly dysplastic joints should be reevaluated.

Assessment of patients' self-reported levels of adherence to postoperative restrictions following total hip replacement.

BACKGROUND: Postoperative precautions that limit hip movement reduce the incidence of postoperative dislocation following total hip replacement (THR). It is assumed that patients adhere to these precautions, but true adherence is unknown. AIMS: To assess adherence to postoperative precautions, including bending, twisting, crossing of legs, sleeping position and sitting position following primary THR surgery. METHODS: A self-reporting questionnaire explored patient adherence to precautions following primary THR. Questionnaires were sent to 120 patients following elective primary THR at two orthopaedic centres in England between November 2016 and April 2017. Patients were also asked to report the duration of adherence and the difficulty associated with adherence to each of the precautions. RESULTS: Eighty-three percent (99/120) of patients responded. Of these, 56% (56/99) were female and 44% (44/99) were male. Mean age was 66.0 (standard deviation 9.4) years. Seventy-six percent of patients were classified as 'highly adherent' to the precautions in hospital, and this reduced to 68% when patients went home. The median duration of adherence to the precaution to avoid crossing legs was 6 weeks [interquartile range (IQR) 6-6]. For the remaining four precautions, the median duration of adherence was consistently 6 weeks (IQR 4-6). CONCLUSION: High levels of adherence to precautions following THR were identified. However, patients reported difficulty adhering to the precautions, which may explain why 24% of patients were not able to adhere to the precautions> 90% of the time. Patients reported that the most difficult precaution to adhere to was supine sleeping, and the least difficult precautions to adhere to were avoiding crossing legs and using a raised chair.

Treatment patterns and clinical and economic burden of hip dislocation following primary total hip arthroplasty in England.

AIMS: The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England. METHODS: This retrospective evaluation used data from the UK Clinical Practice Research Datalink database. Patients were eligible if they underwent a primary THA (index date) and had medical records available 90 days pre-index and 180 days post-index. Bilateral THAs were excluded. Healthcare costs and resource use were evaluated over two years. Changes (pre- vs post-THA) in generic quality of life (QoL) and joint-specific disability were evaluated. Propensity score matching controlled for baseline differences between patients with and without THA dislocation. RESULTS: Among 13,044 patients (mean age 69.2 years (SD 11.4), 60.9% female), 191 (1.5%) had THA dislocation. Two-year median direct medical costs were £15,333 (interquartile range (IQR) 14,437 to 16,156) higher for patients with THA dislocation. Patients underwent revision surgery after a mean of 1.5 dislocations (1 to 5). Two-year costs increased to £54,088 (IQR 34,126 to 59,117) for patients with multiple closed reductions and a revision procedure. On average, patients with dislocation had greater healthcare resource use and less improvement in EuroQol five-dimension index (mean 0.24 (SD 0.35) vs 0.44 (SD 0.35); p < 0.001) and visual analogue scale (0.95 vs 8.85; p = 0.038) scores, and Oxford Hip Scores (12.93 vs 21.19; p < 0.001). CONCLUSION: The cost, resource use, and QoL burden of THA dislocation in England are substantial. Further research is required to understand optimal timing of revision after dislocation, with regard to cost-effectiveness and impact on QoL. Cite this article: Bone Joint J 2022;104-B(7):811-819.

Assessment of the endoprosthesis offset in a dysplastic coxarthrosis.

Incorrectly developed acetabulum and subluxated hip joint may cause many problems for proper implantation of endoprosthesis. The aim of this work is to assess the radiological results of offset restoration and selection of endoprosthesis implant in a dysplastic hip joint. The study group consisted of patients who had a surgery in the period between 2016 and 2018. All of them had a cementless total hip endoprosthesis. The group consisted of 91 patients (96 hip joints), with an average age of 42 years (31-47 years). 55 left and 41 right hip joints. 70 females and 21 males. The control group consisted of patients who were not diagnosed with hip joint dysplasia. The control group consisted of 70 patients (70 hip joints), with an average age of 35 years (19-55 years). 53 females and 17 males. The radiographic assessment included the measuring of medialization and distalization which describe the offset of hip joint. The joint decentration was classified according to Crowe. Based on radiographic measurements we have achieved statistically significant (p<0.05) changes in medialization and distalization parameters. We have not noticed a statistically significant difference for medialization parameter (p=0.8259) after a surgery when compared to the control group. For all patients we have achieved a restoration of correct offset in the horizontal plane. The main idea behind endoprosthesis in a dysplastic coxarthosis is the implantation of endoprosthesis cup in an anatomically correct location. Small screw- in cup and conical stem offer great possibility of restoring correct offset of a dysplastic hip joint.

Impact of scan quality on AI assessment of hip dysplasia ultrasound.

AIMS: Early diagnosis of developmental dysplasia of the hip (DDH) using ultrasound (US) is safe, effective and inexpensive, but requires high-quality scans. The effect of scan quality on diagnostic accuracy is not well understood, especially as artificial intelligence (AI) begins to automate such diagnosis. In this paper, we developed a 10-point scoring system for reporting DDH US scan quality, evaluated its inter-rater agreement and examined its effect on automated assessment by an AI system-MEDO-Hip. METHODS: Scoring was based on iliac wing straightness and angulation; visibility of labrum, os ischium and femoral head; motion; and other artifacts. Four readers from novice to expert separately scored the quality of 107 scans with this 10-point scale and with holistic grading on a scale of 1-5. MEDO-Hip interpreted the same scans, providing a diagnostic category or identifying the scan as uninterpretable. RESULTS: Inter-rater agreement for the 10-point scale was significantly higher than holistic scoring ICC 0.68 vs 0.93, p < 0.05. Inter-rater agreement on the categorisation of individual features, by Cohen's kappa, was highest for os ischium (0.67 ± 0.06), femoral head (0.65 ± 0.07) and iliac wing (0.49 ± 0.12) indices, and lower for the presence of labrum (0.21 ± 0.19). MEDO-Hip interpreted all images of a quality > 7 and flagged 13/107 as uninterpretable. These were low-quality images (3 ± 1.2 vs. 7 ± 1.8 in others, p < 0.05), with poor visualization of the os ischium and noticeable motion. AI accuracy in cases with quality scores < = 7 was 57% vs. 89% on other cases, p < 0.01. CONCLUSION: This study validates that our scoring system reliably characterises scan quality, and identifies cases likely to be misinterpreted by AI. This could lead to more accurate use of AI in DDH diagnosis by flagging low-quality scans likely to provide poor diagnosis up front.

Cost-effectiveness of dual-mobility components in patients with displaced femoral neck fractures.

AIMS: Total hip arthroplasty (THA) with dual-mobility components (DM-THA) has been shown to decrease the risk of dislocation in the setting of a displaced neck of femur fracture compared to conventional single-bearing THA (SB-THA). This study assesses if the clinical benefit of a reduced dislocation rate can justify the incremental cost increase of DM-THA compared to SB-THA. METHODS: Costs and benefits were established for patients aged 75 to 79 years over a five-year time period in the base case from the Canadian Health Payer's perspective. One-way and probabilistic sensitivity analysis assessed the robustness of the base case model conclusions. RESULTS: DM-THA was found to be cost-effective, with an estimated incremental cost-effectiveness ratio (ICER) of CAD $46,556 (£27,074) per quality-adjusted life year (QALY). Sensitivity analysis revealed DM-THA was not cost-effective across all age groups in the first two years. DM-THA becomes cost-effective for those aged under 80 years at time periods from five to 15 years, but was not cost-effective for those aged 80 years and over at any timepoint. To be cost-effective at ten years in the base case, DM-THA must reduce the risk of dislocation compared to SB-THA by at least 62%. Probabilistic sensitivity analysis showed DM-THA was 58% likely to be cost-effective in the base case. CONCLUSION: Treating patients with a displaced femoral neck fracture using DM-THA components may be cost-effective compared to SB-THA in patients aged under 80 years. However, future research will help determine if the modelled rates of adverse events hold true. Surgeons should continue to use clinical judgement and consider individual patients' physiological age and risk factors for dislocation. Cite this article: Bone Joint J 2021;103-B(12):1783-1790.

Assessment of hip displacement in children with cerebral palsy using machine learning approach.

Manual measurements of migration percentage (MP) on pelvis radiographs for assessing hip displacement are subjective and time consuming. A deep learning approach using convolution neural networks (CNNs) to automatically measure the MP was proposed. The pre-trained Inception ResNet v2 was fine tuned to detect locations of the eight reference landmarks used for MP measurements. A second network, fine-tuned MobileNetV2, was trained on the regions of interest to obtain more precise landmarks' coordinates. The MP was calculated from the final estimated landmarks' locations. A total of 122 radiographs were divided into 57 for training, 10 for validation, and 55 for testing. The mean absolute difference (MAD) and intra-class correlation coefficient (ICC [2,1]) of the comparison for the MP on 110 measurements (left and right hips) were 4.5 [Formula: see text] 4.3% (95% CI, 3.7-5.3%) and 0.91, respectively. Sensitivity and specificity were 87.8% and 93.4% for the classification of hip displacement (MP-threshold of 30%), and 63.2% and 94.5% for the classification of surgery-needed hips (MP-threshold of 40%). The prediction results were returned within 5 s. The developed fine-tuned CNNs detected the landmarks and provided automatic MP measurements with high accuracy and excellent reliability, which can assist clinicians to diagnose hip displacement in children with CP.

Deep Learning Artificial Intelligence Model for Assessment of Hip Dislocation Risk Following Primary Total Hip Arthroplasty From Postoperative Radiographs.

BACKGROUND: Dislocation is a common complication following total hip arthroplasty (THA), and accounts for a high percentage of subsequent revisions. The purpose of this study is to illustrate the potential of a convolutional neural network model to assess the risk of hip dislocation based on postoperative anteroposterior pelvis radiographs. METHODS: We retrospectively evaluated radiographs for a cohort of 13,970 primary THAs with 374 dislocations over 5 years of follow-up. Overall, 1490 radiographs from dislocated and 91,094 from non-dislocated THAs were included in the analysis. A convolutional neural network object detection model (YOLO-V3) was trained to crop the images by centering on the femoral head. A ResNet18 classifier was trained to predict subsequent hip dislocation from the cropped imaging. The ResNet18 classifier was initialized with ImageNet weights and trained using FastAI (V1.0) running on PyTorch. The training was run for 15 epochs using 10-fold cross validation, data oversampling, and augmentation. RESULTS: The hip dislocation classifier achieved the following mean performance (standard deviation): accuracy = 49.5 (4.1%), sensitivity = 89.0 (2.2%), specificity = 48.8 (4.2%), positive predictive value = 3.3 (0.3%), negative predictive value = 99.5 (0.1%), and area under the receiver operating characteristic curve = 76.7 (3.6%). Saliency maps demonstrated that the model placed the greatest emphasis on the femoral head and acetabular component. CONCLUSION: Existing prediction methods fail to identify patients at high risk of dislocation following THA. Our radiographic classifier model has high sensitivity and negative predictive value, and can be combined with clinical risk factor information for rapid assessment of risk for dislocation following THA. The model further suggests radiographic locations which may be important in understanding the etiology of prosthesis dislocation. Importantly, our model is an illustration of the potential of automated imaging artificial intelligence models in orthopedics. LEVEL OF EVIDENCE: Level III.

Healthcare resource utilization and costs for hip dislocation following primary total hip arthroplasty in the medicare population.

AIM: To estimate 2-year healthcare resource utilization (HCRU) and costs of dislocation following primary total hip arthroplasty (THA). MATERIALS AND METHODS: This retrospective evaluation used medical claims from the US Medicare database. Patients were eligible if they were ≥65 years old, underwent a primary elective inpatient THA between 1 January 2010 and 31 December 2016 (index), and had continuous Medicare coverage and enrollment ≥365 days prior to index (baseline). Exclusion criteria were prior THA, concomitant infection, non-Medicare primary payer, or enrolled in Medicare due to end-stage renal disease. One- and 2-year HCRU and costs across all service types and settings of care excluding retail pharmacy were evaluated. Propensity score matching and direct matching adjusted for confounding. RESULTS: Among Medicare patients who underwent THA and met inclusion criteria (n = 450,355; mean age ∼74, and two-thirds female), 7,680 (1.7%) had a hip dislocation. After matching, 4,551 patients without and 4,551 patients with dislocation were selected. Percentage utilization, mean days of service, and claims payments amounts were significantly greater for patients with vs without THA dislocation for variables such as THA hospitalization, home health agency, skilled nursing facility, inpatient rehabilitation facility, other inpatient admission, long-term care hospital, and outpatient care. Findings were consistent for 1- and 2-year follow-up, although differences were more pronounced for 1-year. Per-patient-cost increases with dislocation were $19,590 over 1 year and $24,211 over 2 years. Two-thirds of the cost increase was due to other inpatient admission and the remaining one-third was due to skilled nursing facility, outpatient, inpatient rehabilitation facility, and home health agency costs. LIMITATIONS: Administrative claims are not collected for research and lack clinical information. Results may not be generalizable to other patients or settings of care. CONCLUSIONS: This large US retrospective database study demonstrated the substantial HCRU and cost burden of THA dislocation.

Study protocol: Effectiveness of dual-mobility cups compared with uni-polar cups for preventing dislocation after primary total hip arthroplasty in elderly patients - design of a randomized controlled trial nested in the Dutch Arthroplasty Registry.

Background and purpose - Dislocation is the leading reason for early revision surgery after total hip arthroplasty (THA). The dual-mobility (DM) cup was developed to provide more stability and mechanically reduce the risk of dislocation. Despite the increased use of DM cups, high-quality evidence of their (cost-)effectiveness is lacking. The primary objective of this randomized controlled trial (RCT) is to investigate whether there is a difference in the number of hip dislocations following primary THA, using the posterolateral approach, with a DM cup compared with a unipolar (UP) cup in elderly patients 1 year after surgery. Secondary outcomes include the number of revision surgeries, patient-reported outcome measures (PROMs), and cost-effectiveness.Methods and analysis - This is a prospective multicenter nationwide, single-blinded RCT nested in the Dutch Arthroplasty Registry. Patients ≥ 70 years old, undergoing elective primary THA using the posterolateral approach, will be eligible. After written informed consent, 1,100 participants will be randomly allocated to the intervention or control group. The intervention group receives a THA with a DM cup and the control group a THA with a UP cup. PROMs are collected preoperatively, and 3 months, 1 and 2 years postoperatively. Primary outcome is the difference in number of dislocations between the UP and DM cup within 1 year, reported in the registry (revisions), or by the patients (closed or open reduction). Data will be analyzed using multilevel models as appropriate for each outcome (linear/logistic/survival). An economic evaluation will be performed from the healthcare and societal perspective, for dislocation and quality adjusted life years (QALYs).Trial registration - This RCT is registered at www.clinicaltrials.gov with identification number NCT04031820.

Postoperative Failure Frequency of Short External Rotator and Posterior Capsule With Successful Reinsertion After Primary Total Hip Arthroplasty: An Ultrasound Assessment.

BACKGROUND: The reinsertion of the short external rotators and posterior capsule to the greater trochanter in the posterolateral approach has been considered an effective strategy to reduce the risk of dislocation. However, during clinical practice, no verification and monitoring of the status of such reinsertions is carried out. The objective of this study is to estimate the frequency of postoperative failure with successful reinsertion of the short external rotator and posterior capsule of the hip through ultrasound after primary total hip arthroplasty (THA) using the posterolateral approach. METHODS: A prospective observational study was conducted involving patients with primary total hip arthroplasty via posterolateral approach in which reinsertion of hip's short external rotators and posterior capsule were successful reinserted during surgery from January to December 2019. The status of the reinsertion was assessed with an ultrasound between the 6 and 8 weeks after surgery. Reinsertion failure was considered when the reinserted structures were not fully visualized in the ultrasound during internal and external rotation. RESULTS: Sixty-eight patients were included in this study (mean age: 58.7 ± 13.8 years; 44.1% (30) women). The incidence of failure of the reinsertion of short external rotators and posterior capsule was 16.2% (n = 11) (95% confidence interval 9.3-26.7). A postoperative increased femoral offset was found more frequently in cases with failure (36.4% vs 17.5%); a similar trend was observed in the leg length discrepancy (36.4% vs 22.8%). However, these differences were not statistically significant (P > .05). CONCLUSION: Between the 6th and 8th postoperative week, approximately 2 of the 10 short external rotator and posterior capsule reinsertions fail in cases with successful intraoperative repair using absorbable suture. This estimate is comparable and even lower than previous reports. EVIDENCE LEVEL: II, Prospective Observational Study.

Can dual mobility cups prevent dislocation without increasing revision rates in primary total hip arthroplasty? A systematic review.

BACKGROUND: Dislocation is one of the leading causes for early revision surgery after total hip arthroplasty (THA). To address this problem, the dual mobility (DM) cup was developed in the 1970s by the French. Despite the increased and, in some countries, broad use of DM cups, high quality evidence of their effectiveness compared to traditional unipolar (UP) cups is lacking. There are a few well-conducted literature reviews, but the level of evidence of the included studies was moderate to low and the rates of revision were not specifically investigated. Therefore, we did a systematic review to investigate whether there is a difference in the rate of dislocations and revisions after primary THA with a DM cup or a UP cup. METHODS: We conducted a systematic literature search in PubMed, Embase and Cochrane databases in July 2019. The articles were selected based upon their quality, relevance and measurement of the predictive factor. We used the MINORS criteria to determine the methodological quality of all studies. RESULTS: The initial search resulted in 702 citations. After application of the inclusion and exclusion criteria, eight articles met our eligibility criteria and were graded. Included studies were of medium to low methodological quality with a mean score of 14/24 (11-16) points following the MINORS criteria. In the case-control studies, a total of 549 DM cups and 649 UP cups were included. In the registry studies, a total of 5.935 DM cups and 217.362 UP cups were included. In the case-control studies, one (0.2%) dislocation was reported for the DM cups and 46 (7.1%) for the UP cup (p=0.009, IQR=0.00-7.00). Nine (1.6%) revisions, of which zero due to dislocation, were reported for the DM cup and 39 (6.0%), of which 30 due to dislocation, for the UP cup (p=0.046, CI=-16.93-5.73). In the registry studies 161 (2.7%) revisions were reported for the DM cup, of which 14 (8.7%) due to dislocation. For the UP cup, 3.332 (1.5%) revisions were reported (p=0.275, IQR=41.00-866.25), of which 1.093 (32.8%) due to dislocation (p=0.050, IQR=3.50-293.25). CONCLUSION: This review suggests lower rates of dislocation and lower rates of revision for dislocation in favor of the DM cups. Concluding, DM cups might be an effective solution to reduce dislocation in primary THA. To evaluate the efficacy of DM cups compared to UP cups, an economic evaluation alongside a randomized controlled trial is needed focusing on patient important endpoints. LEVEL OF EVIDENCE: III, systematic review of level III studies.

Assessment of the medium- to long-term radiographically confirmed outcome for juvenile dogs with hip dysplasia treated with double pelvic osteotomy.

OBJECTIVE: To assess the medium- to long-term radiographically confirmed outcomes in juvenile dogs with hip dysplasia (HD) that did and did not undergo double pelvic osteotomy (DPO). STUDY DESIGN: Retrospective case-controlled. ANIMALS: Twenty-six dogs with HD that were candidates for DPO; 22 dogs underwent DPO (16 bilateral, six unilateral); four dogs did not. METHODS: Initial and follow-up radiographs of DPO candidates (2011-2017) that did and did not undergo surgery were reviewed, and the British Veterinary Association and Kennel Club Hip Dysplasia Scheme score (BVA-HD), osteoarthritis score (OAS) and laxity index score (LI) were determined. Baseline and follow-up BVA-HD, OAS, and change in radiographically confirmed scores were compared by using analysis of variance for correlated samples. RESULTS: There was no significant difference in BVA-HD or OAS between surgically treated and nonsurgically treated cohorts at baseline. Follow-up radiographs (median, 49 months) revealed that most (34/38) hips had a BVA-HD ≤10 after DPO, while four of eight hips from the nonsurgical cohort had BVA-HD >10. Follow-up BVA-HD and OAS were lower in hips after surgery (BVA-HD median 2.15, interquartile range [Q1-Q3] 1.3-4.1; OAS median 1.9, Q1-Q3 1.1-4.1) compared with the nonsurgically treated cohort (BVA-HD median 11.4, Q1-Q3 8.1-17.5, P < .01; OAS median 7.0, Q1-Q3 5.1-13.4, P < .01). Seven hips with an LI >1 had no radiographically confirmed progression of osteoarthritis after DPO. CONCLUSION: Double pelvic osteotomy prevented radiographically confirmed progression of osteoarthritis in the medium- to long-term. Laxity index score > 1 was not a contraindication for DPO in this study. CLINICAL SIGNIFICANCE: Double pelvic osteotomy prevents progression of radiographically confirmed features of osteoarthritis in juvenile dogs with HD.

Cost-effectiveness analysis of a surveillance program to prevent hip dislocation in children with cerebral palsy.

OBJECTIVE: In this study we conducted an economic evaluation of a surveillance programme to prevent hip dislocation in children with cerebral palsy. METHOD: We developed a model that compared costs and health outcomes of children with cerebral palsy with and without a surveillance programme. Information from a number of sources was combined into a decision analytical model, primarily based on data from a comparative study with a 20-year follow-up. Effectiveness was measured using Quality-Adjusted Life Years (QALYs). The analysis took the perspective of the Spanish National Health Service. We undertook extensive sensitivity analyses including a probabilistic sensitivity analysis. RESULTS: The surveillance programme led to higher QALYs and higher health care costs, with an estimated incremental cost per QALY gained of 12,282€. The results were robust to model assumptions. The probability that the programme was cost-effective was estimated to be over 80% at the threshold of 25.000€/QALY recommended in Spain. CONCLUSION: This study indicates that surveillance programmes to prevent hip dislocation in children with cerebral palsy are likely to be cost-effective.

Only 8% of major preventable adverse events after hip arthroplasty are filed as claims: a Swedish multi-center cohort study on 1,998 patients.

Background and purpose - Hip arthroplasty is one of the most performed surgeries in Sweden, and the rate of adverse events (AEs) is fairly high. All patients in publicly financed healthcare in Sweden are insured by the Mutual Insurance Company of Swedish County Councils (Löf). We assessed the proportion of patients that sustained a major preventable AE and filed an AE claim to Löf.Patients and methods - We performed retrospective record review using the Global Trigger Tool to identify AEs in a Swedish multi-center cohort consisting of 1,998 patients with a total or hemi hip arthroplasty. We compared the major preventable AEs with all patient-reported claims to Löf from the same cohort and calculated the proportion of filed claims.Results - We found 1,066 major preventable AEs in 744 patients. Löf received 62 claims for these AEs, resulting in a claim proportion of 8%. 58 of the 62 claims were accepted by Löf and received compensation. The claim proportion was 13% for the elective patients and 0.3% for the acute patients. The most common AE for filing a claim was periprosthetic joint infection; of the 150 infections found 37 were claimed.Interpretation - The proportion of filed claims for major preventable AEs is very low, even for obvious and serious AEs such as periprosthetic joint infection.

Investigating the impact of measurement uncertainty in the radiographic surveillance of hip displacement in cerebral palsy: A Monte Carlo simulation.

Hip surveillance programmes have greatly improved the management of hip dysplasia in children with cerebral palsy. Reimer's migration percentage is the most common index for quantifying hip dysplasia from planar radiographs. However, measurement uncertainty could undermine the diagnostic accuracy. A Monte Carlo simulation was created to investigate the impact of measurement error on decision making in hip surveillance programmes. The simulation was designed to mimic the annual surveillance of children with cerebral palsy (Gross Motor Functional Classification System levels III-V) between 2 and 8 years of age. Simulation parameters for the natural history of hip dysplasia and measurement error were derived from published data. At each measurement interval, the influence of uncertainty in the measurement of Reimer's migration percentage on decision-making was investigated. The probability of a child being indicated for intervention in error during the course of the simulation was relatively high, particularly in the highest functioning cohort where the positive predictive value of Reimer's migration percentage was at best 70% and at worse less than 20%. Including a rate of progression term within the decision-making algorithm had a negative effect on positive predictive power. This simulation suggests that hip surveillance programmes are sensitive to detecting genuine hip dysplasia but can have poor positive predictive power, potentially resulting in unnecessary indication for intervention.