Ipsilateral above-knee amputation in patient with recurrent dislocation after total hip arthroplasty: A case report.

Amputation secondary to vascular complications of recurrent dislocations after total hip arthroplasty (THA) is an extremely rare. We describe an unusual case of above-knee amputation resulting from vascular complications after recurrent dislocations of a THA. A 63-year-old male patient with walking pain and limp has a history of acetabular fracture and central dislocation of the femoral head. He was diagnosed as post-traumatic arthritis and subluxation of the femoral head and suffered from four similar dislocations in 210 days after the THA. The patient received conservative treatment after every hip dislocation. However, four months after the fourth reduction, the emergent femoral artery and popliteal artery exploration and catheter thrombectomy were performed at another hospital. An ipsilateral above-knee amputation was done after sepsis and failure of the revascularization procedure. Clinicians should be cognizant that above-knee amputation resulting from vascular complications after recurrent dislocations of a THA may occur. The lack of adherence to critical treatment may have led to the severe outcome of amputation. In conclusion, patient education and compliance are essential for both the treatment of hip dislocations and arterial occlusion. More active and effective measures should be used to prevent such catastrophic events.

A complementary analytical tool for hip prosthesis dislocation: Thermal imaging in rehabilitation.

The use of routine ionizing imaging in identify and classify patients with dislocation or infection after surgery has some medical contraindication, in addition to risks associated with the ionizing load and elevated costs. A novel, less expensive and non-ionizing imaging technique, called infrared thermal imaging, can be proposed as a complementary method to routinely evaluate hip prosthesis patients and track their inflammation response following serious complications. Here we report a case of a total hip prosthesis which was dislocated during inpatient rehabilitation, and ultimately reduced without surgical procedure. During the process, routine clinical and radiographic diagnosis was complemented with an infrared examination. The infrared images were easy to take bedside, without direct contact with the area of surgery, and well tolerated. After the dislocation reduction, the thermal imaging procedure provided important feedbacks on the local inflammation, helping to exclude other complications such as the infections.

Outcome Scores and Survivorship of Patients Undergoing Primary Hip Arthroscopy With Borderline Hip Dysplasia: A Propensity-Matched Study With Minimum 10-Year Follow-up.

BACKGROUND: Patients with borderline hip dysplasia (BHD) and concomitant femoroacetabular impingement syndrome (FAIS) have demonstrated similar outcomes at short- and midterm follow-up compared with equivalent patients without dysplasia. However, comparisons between these groups at long-term follow-up have yet to be investigated. PURPOSE: To compare long-term clinical outcomes between patients with BHD undergoing primary hip arthroscopy for FAIS versus matched control patients without BHD. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A retrospective cohort study was conducted on patients with BHD (lateral center-edge angle, 18°-25°) who underwent hip arthroscopy for FAIS between January 2012 and February 2013. Patients were propensity matched in a 1:3 ratio by age, sex, and body mass index to control patients without BHD who underwent primary hip arthroscopy. Groups were compared in terms of patient-reported outcomes (PROs) preoperatively and at 10 years postoperatively, including the Hip Outcome Score Activities of Daily Living subscale (HOS-ADL) and Sports subscale (HOS-SS), modified Harris Hip Score, 12-item International Hip Outcome Tool, visual analog scale (VAS) for pain and satisfaction. Achievement rates for minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) were compared between groups. Kaplan-Meier survivorship curves were assessed between groups. RESULTS: At a mean follow-up of 10.3 ± 0.3 years, 28 patients with BHD (20 women; age, 30.8 ± 10.8 years) were matched to 84 controls who underwent primary hip arthroscopy. Both groups significantly improved from preoperative assessment in all PRO measures at 10 years (P < .001 for all). PRO scores were similar between groups, aside from HOS-SS (BHD, 62.9 ± 31.9 vs controls, 80.1 ± 26.0; P = .030). Rates of MCID achievement were similar between groups for all PROs (HOS-ADL: BHD, 76.2% vs controls, 67.9%, P = .580; HOS-SS: BHD, 63.2% vs controls, 69.4%, P = .773; modified Harris Hip Score: BHD, 76.5% vs controls, 67.9%, P = .561; VAS pain: BHD, 75.0% vs controls, 91.7%, P = .110). Rates of PASS achievement were significantly lower in the BHD group for HOS-ADL (BHD, 39.1% vs controls, 77.4%; P = .002), HOS-SS (BHD, 45.5% vs controls, 84.7%; P = .001), and VAS pain (BHD, 50.0% vs controls, 78.5%; P = .015). No significant difference was found in the rate of subsequent reoperation on the index hip between groups. Kaplan-Meier survival analysis demonstrated comparable survivorship at long-term follow-up (P = .645). CONCLUSION: After primary hip arthroscopy, patients with BHD in the setting of FAIS had significantly improved PRO scores at 10-year follow-up, comparable with propensity-matched controls without BHD. Rates of MCID achievement were similar between groups, although patients with BHD had lower rates of PASS achievement. Patients with BHD had similar long-term hip arthroscopy survivorship compared with controls, with no significant difference in rates of revision hip arthroscopy or conversion to total hip arthroplasty.

Clinical reasoning for the continuation or discontinuation of hip precautions after total hip arthroplasty in Switzerland: a qualitative study.

BACKGROUND: Growing evidence raises doubts about the need for routine hip precautions after primary total hip replacements to reduce the risk of postoperative dislocation. However, hip precautions are still routinely and widely prescribed in postoperative care in Switzerland. We aimed to investigate experts' clinical reasoning for hip precaution recommendations after total hip arthroplasty. METHODS: Using a convenience sampling strategy, 14 semi-structured expert interviews were conducted with surgeons, physiotherapists, and occupational therapists in the vicinity of an inpatient rehabilitation clinic in Switzerland. Data analysis followed Mayring's principle of inductive and deductive structuring content analysis. RESULTS: Expert statements from the interviews were summarised into four main categories and 10 subcategories. Categories included statements on the incidences of dislocation and underlying risk factors; current preferences and use of hip precautions; their effect on physical function, anxiety, or costs; and patient's adherence to the movement restrictions. Hip surgeons routinely prescribed hip precautions, although in different variations. Fear of dislocation and caution are barriers to changing current practice. Some surgeons are considering individualised prescribing based on patients' risk of dislocation, which therapists would welcome. CONCLUSION: A lack of clear instructions from the surgeon leads to ambiguity among therapists outside the acute hospital. A shared understanding of the need for and nature of hip precautions, guidelines from societies, or at least specific instructions from surgeons to therapists are warranted.

[Evaluation of spino-pelvic mobility; its importance in preventing total hip replacement dislocation]. / Evaluación de la movilidad espino-pélvica; su importancia para prevenir la luxación de prótesis total de cadera.

Recently, it has been recognized that changes in sagittal alignment and spinopelvic mobility due to alterations of the lumbosacral spine can influence the dislocation of a hip replacement. The biggest difficulties for this problem are: a) the bibliography related to this topic has been written in English and there is confusion in its terminology; b) there is no consensus on what parameters should be used to identify, measure, and estimate the risks of dislocation occurring; c) the basic concepts that interrelate spinal disorders and prosthetic dislocation are not clearly understood; and d) spine and hip surgeons pursue different goals. The objective of this narrative review is to overcome the aforementioned difficulties by using a strategy to answer some questions: Is hip dislocation really a problem? What is the interrelationship between alterations in the pelvic spinal balance and the dislocation of a prosthesis? How is sagittal balance and lumbosacral mobility defined and how can their alterations be measured? What are their compensatory mechanisms to achieve a good functioning and how these mechanisms can be used to correctly orient the acetabulum? To document this review, we consulted the databases of PubMed, Scopus, SciELO and Google Scholar with the keywords: Spinopelvic, Total Hip Arthroplasty, Hip Dislocation, Spine-Pelvis-hip Arthroplasty. The articles that, in the author's opinion, were the most objective and/or relevant for the study of this topic were selected.

Recientemente se ha reconocido que los cambios en alineación sagital y la movilidad espino-pélvica por alteraciones de la columna lumbosacra pueden ejercer influencia en la luxación de una prótesis de cadera. Las mayores dificultades para este problema son: a) que la bibliografía relacionada con este tema se ha escrito en idioma inglés y hay confusiones en su terminología; b) no hay consenso de cuáles son los parámetros que deben utilizarse para identificarla, medirla y para estimar los riesgos de que ocurra una luxación; c) no se conocen con claridad los conceptos básicos que interrelacionen los trastornos de la columna y la luxación protésica; y d) que los cirujanos de columna y artroplásticos de cadera persiguen diferentes objetivos. Esta revisión narrativa persigue como objetivo allanar las dificultades antes mencionadas, utilizando como estrategia contestar algunas preguntas: ¿la luxación de cadera es realmente un problema?; ¿cuál es la interrelación entre las alteraciones en el balance espino-pélvico y la luxación de una prótesis?; ¿cómo se define el balance sagital y la movilidad lumbosacra y cómo se pueden medir sus alteraciones?; ¿cuáles son sus mecanismos compensatorios para lograr un buen funcionamiento, y cómo se pueden aprovechar estos mecanismos para orientar correctamente el acetábulo? Para documentar esta revisión se consultaron las bases de datos de PubMed, Scopus, SciELO y Google Académico con las palabras clave: Spinopelvic, Total Hip Arthroplasty, Hip Dislocation, Spine-Pelvis-hip Arthroplasty. Se seleccionaron los artículos que a juicio del autor fueron los más objetivos y/o relevantes para el estudio de este tema.

Use of the flat panel detector fluoroscope reduces radiation exposure during periacetabular osteotomy.

The Periacetabular Osteotomy is a technically demanding procedure that requires precise intraoperative evaluation of pelvic anatomy. Fluoroscopic images pose a radiation risk to operating room staff, scrubbed personnel, and the patient. Most commonly, a Standard Fluoroscope with an Image Intensifier is used. Our institution recently implemented the novel Fluoroscope with a Flat Panel Detector. The purpose of this study was to compare radiation dosage and accuracy between the two fluoroscopes. A retrospective review of a consecutive series of patients who underwent Periacetabular Osteotomy for symptomatic hip dysplasia was completed. The total radiation exposure dose (mGy) was recorded and compared for each case from the standard fluoroscope (n = 27) and the flat panel detector (n = 26) cohorts. Lateral center edge angle was measured and compared intraoperatively and at the six-week postoperative visit. A total of 53 patients (96% female) with a mean age and BMI of 17.84 (± 6.84) years and 22.66 (± 4.49) kg/m2 (standard fluoroscope) and 18.23 (± 4.21) years and 21.99 (± 4.00) kg/m2 (flat panel detector) were included. The standard fluoroscope averaged total radiation exposure to be 410.61(± 193.02) mGy, while the flat panel detector averaged 91.12 (± 49.64) mGy (p < 0.0001). The average difference (bias) between intraoperative and 6-week postoperative lateral center edge angle measurement was 0.36° (limits of agreement: - 3.19 to 2.47°) for the standard fluoroscope and 0.27° (limits of agreement: - 2.05 to 2.59°) for the flat panel detector cohort. Use of fluoroscopy with flat panel detector technology decreased the total radiation dose exposure intraoperatively and produced an equivalent assessment of intraoperative lateral center edge angle. Decreasing radiation exposure to young patients is imperative to reduce the risk of future comorbidities.

Caudoventral hip luxation in 160 dogs (2003-2023): A multicenter retrospective case series.

OBJECTIVE: To describe patient characteristics, etiology, treatment outcomes and complications of caudoventral hip luxation (CvHL) in a large cohort of dogs and investigate factors associated with nonsurgical treatment outcomes. STUDY DESIGN: Multicenter retrospective case series. ANIMAL POPULATION: A total of 160 client-owned dogs (170 limbs). METHODS: Medical records from 2003 to 2023 were reviewed for signalment, history, treatment outcomes and complications. Logistic regression was performed to investigate factors associated with nonsurgical treatment outcome. RESULTS: Low-trauma accidents accounted for 82.9% of cases. Over-represented breeds included poodles (38.1%) and poodle crosses (11.3%). On a per-treatment basis, success rates of closed reduction alone, closed reduction/Ehmer sling, closed reduction/hobbles were 9.1%, 15.2% and 48.8%, respectively. When accounting for repeated attempts using closed reduction alone, Ehmer sling, or hobbles, eventual success rate increased to 10.3%, 18.5% and 61.8%, respectively. Success rate for toggle rod stabilization was 88.2%. Complication rate of hobbles was 31.9% versus 60.6% for Ehmer slings. Use of hobbles (OR:7.62, p = .001, CI:2.23-26.05), treatment by specialist surgeons (OR:2.68, p = .047, CI: 1.01-7.08) and increasing age (OR:1.15, p < .005, CI: 1.08-1.23) were associated with successful nonsurgical treatments. CONCLUSION: Low-trauma etiology, and poodles and their crosses were over-represented in cases of CvHL. Success rate of nonsurgical treatments was lower than previously reported. Hobbles were 7.6 times more likely to be successful when compared to dogs treated without hobbles and remains a viable noninvasive first-line treatment. CLINICAL SIGNIFICANCE/IMPACT: Hobbles are recommended as a low-morbidity first-line treatment for CvHL. An Ehmer sling is not recommended. Toggle rod stabilization is an effective surgical treatment for CvHL.

Outcomes of Flexibility Sport Athletes With Borderline Hip Dysplasia After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Propensity-Matched Analysis at Minimum 2-Year Follow-up.

BACKGROUND: Hip arthroscopy has proved successful in treating femoroacetabular impingement syndrome (FAIS) in patients with and without borderline hip dysplasia (BHD). Despite a high prevalence of BHD in patients who participate in sports with high flexibility requirements, a paucity of literature evaluates the efficacy of hip arthroscopy in treating FAIS in flexibility sport athletes with BHD. PURPOSE: To compare minimum 2-year patient-reported outcomes (PROs) and achievement of clinically significant outcomes in flexibility sport athletes with BHD undergoing primary hip arthroscopy for FAIS with capsular plication with results in flexibility sport athletes without dysplasia. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Data were prospectively collected for patients undergoing primary hip arthroscopy for FAIS with BHD, defined as a lateral center-edge angle of 18° to 25°, who reported participation in a sport with a high flexibility requirement, including dance, gymnastics, figure skating, yoga, cheerleading, and martial arts, according to previous literature. These patients were matched 1:2 to flexibility sport athletes without dysplasia, controlling for age, sex, and body mass index. Preoperative and minimum 2-year postoperative PROs were collected and compared between groups. Cohort-specific minimal clinically important difference and patient acceptable symptom state achievement was compared between groups. RESULTS: In total, 52 flexibility sport athletes with BHD were matched to 104 flexibility sport athletes without BHD. Both groups showed similar sport participation (P = .874) and a similar level of competition (P = .877). Preoperative lateral center-edge angle (22.2°± 1.6° vs 31.5°± 3.9°; P < .001) and Tönnis angle (10.9°± 3.7° vs 5.8°± 4.4°; P < .001) differed between groups. Capsular plication was performed in all cases. Both groups achieved significant improvement in all PROs (P < .001) with no differences in postoperative PROs between groups (P≥ .147). High minimal clinically important difference (BHD group: 95.7%; control group: 94.8%) and patient acceptable symptom state (BHD group: 71.7%; control group: 72.2%) achievement for any PRO was observed with no differences between groups (P≥ .835). CONCLUSION: Flexibility sport athletes with BHD achieved similar outcomes as those of flexibility sport athletes without BHD after hip arthroscopy for FAIS with capsular plication.

3D pre-operative planning and patient-specific guides for re-directional peri-acetabular osteotomy in children and adolescents.

Surgical procedures to correct hip dysplasia associated with subluxation or dislocation of the femoral head are complex. The 3D geometric abnormalities of the acetabulum and proximal femur vary across patients. We, therefore, suggest a patient-specific surgical treatment involving computer-assisted 3D planning of the peri-acetabular osteotomies, taking into account the femoral head position; 3D printing of patient-specific guides for the cuts, repositioning, and fixation; and intra-operative application of the simulated displacements with their fixation. LEVEL OF EVIDENCE: IV.

Noninterportal capsulotomy of hip arthroscopy showed improved outcomes in borderline hip dysplasia: A retrospective study with minimum 2-year follow-up.

PURPOSE: The present study aimed to evaluate the functional outcomes of hip arthroscopy using a noninterportal capsulotomy technique to address labral tears in patients with borderline hip dysplasia (BHD). Additionally, we also compared these outcomes with those of patients with BHD who underwent the standard repaired interportal capsulotomy (RIPC) arthroscopy. METHODS: Data from patients with BHD were retrieved from a database of patients who underwent arthroscopic hip surgery with noninterportal capsulotomy or RIPC to treat labral tears between January 2014 and December 2020. Data collected included both pre- and postoperative patient-reported outcomes (PROs). RESULTS: A total of 58 patients (noninterportal capsulotomy, n = 37; RIPC, n = 21) with a mean age of 30.9 ± 5.6 and 28.6 ± 5.5 years, respectively, met the inclusion criteria. All of the patients underwent a minimal 2-year follow-up. The mean lateral centre-edge angle was 23.3 ± 1.2° in the noninterportal capsulotomy group and 23.7 ± 1.0° in the RIPC group, with no significant difference. The PROs improved from the preoperative to the latest follow-up, with a p < 0.001. There were no differences between the groups. CONCLUSION: Using strict patient selection criteria, hip arthroscopy with noninterportal capsulotomy demonstrated significant pre- to postoperative improvements in patients with BHD and achieved results comparable to those from hip arthroscopy with RIPC. LEVEL OF EVIDENCE: Level III.

Dual-mobility bearings reduce instability but may not be the only answer in revision total hip arthroplasty for recurrent dislocation.

Aims: There is little information in the literature about the use of dual-mobility (DM) bearings in preventing re-dislocation in revision total hip arthroplasty (THA). The aim of this study was to compare the use of DM bearings, standard bearings, and constrained liners in revision THA for recurrent dislocation, and to identify risk factors for re-dislocation. Methods: We reviewed 86 consecutive revision THAs performed for dislocation between August 2012 and July 2019. A total of 38 revisions (44.2%) involved a DM bearing, while 39 (45.3%) and nine (10.5%) involved a standard bearing and a constrained liner, respectively. Rates of re-dislocation, re-revision for dislocation, and overall re-revision were compared. Radiographs were assessed for the positioning of the acetabular component, the restoration of the centre of rotation, leg length, and offset. Risk factors for re-dislocation were determined by Cox regression analysis. The modified Harris Hip Scores (mHHSs) were recorded. The mean age of the patients at the time of revision was 70 years (43 to 88); 54 were female (62.8%). The mean follow-up was 5.0 years (2.0 to 8.75). Results: DM bearings were used significantly more frequently in elderly patients (p = 0.003) and in hips with abductor deficiency (p < 0.001). The re-dislocation rate was 13.2% for DM bearings compared with 17.9% for standard bearings, and 22.2% for constrained liners (p = 0.432). Re-revision-free survival for DM bearings was 84% (95% confidence interval (CI) 0.77 to 0.91) compared with 74% (95% CI 0.67 to 0.81) for standard articulations, and 67% (95% CI 0.51 to 0.82) for constrained liners (p = 0.361). Younger age (hazard ratio (HR) 0.92 (95% CI 0.85 to 0.99); p = 0.031), lower comorbidity (HR 0.44 (95% CI 0.20 to 0.95); p = 0.037), smaller heads (HR 0.80 (95% CI 0.64 to 0.99); p = 0.046), and retention of the acetabular component (HR 8.26 (95% CI 1.37 to 49.96); p = 0.022) were significantly associated with re-dislocation. All DM bearings which re-dislocated were in patients with abductor muscle deficiency (HR 48.34 (95% CI 0.03 to 7,737.98); p = 0.303). The radiological analysis did not reveal a significant relationship between restoration of the geometry of the hip and re-dislocation. The mean mHHSs significantly improved from 43 points (0 to 88) to 67 points (20 to 91; p < 0.001) at the final follow-up, with no differences between the types of bearing. Conclusion: We found that the use of DM bearings reduced the rates of re-dislocation and re-revision in revision THA for recurrent dislocation, but did not guarantee stability. Abductor deficiency is an important predictor of persistent instability.

The outcome of revision total hip arthroplasty for instability.

Aims: Instability is a common indication for revision total hip arthroplasty (THA). However, even after the initial revision, some patients continue to have recurrent dislocation. The aim of this study was to assess the risk for recurrent dislocation after revision THA for instability. Methods: Between 2009 and 2019, 163 patients underwent revision THA for instability at Stanford University Medical Center. Of these, 33 (20.2%) required re-revision due to recurrent dislocation. Cox proportional hazard models, with death and re-revision surgery for periprosthetic infection as competing events, were used to analyze the risk factors, including the size and alignment of the components. Paired t-tests or Wilcoxon signed-rank tests were used to assess the outcome using the Veterans RAND 12 (VR-12) physical and VR-12 mental scores, the Harris Hip Score (HHS) pain and function, and the Hip disability and Osteoarthritis Outcome score for Joint Replacement (HOOS, JR). Results: The median follow-up was 3.1 years (interquartile range 2.0 to 5.1). The one-year cumulative incidence of recurrent dislocation after revision was 8.7%, which increased to 18.8% at five years and 31.9% at ten years postoperatively. In multivariable analysis, a high American Society of Anesthesiologists (ASA) grade (hazard ratio (HR) 2.72 (95% confidence interval (CI) 1.13 to 6.60)), BMI between 25 and 30 kg/m2 (HR 4.31 (95% CI 1.52 to 12.27)), the use of specialized liners (HR 5.39 (95% CI 1.97 to 14.79) to 10.55 (95% CI 2.27 to 49.15)), lumbopelvic stiffness (HR 6.03 (95% CI 1.80 to 20.23)), and postoperative abductor weakness (HR 7.48 (95% CI 2.34 to 23.91)) were significant risk factors for recurrent dislocation. Increasing the size of the acetabular component by > 1 mm significantly decreased the risk of dislocation (HR 0.89 (95% CI 0.82 to 0.96)). The VR-12 physical and HHS (pain and function) scores improved significantly at mid term. Conclusion: Patients requiring revision THA for instability are at risk of recurrent dislocation. Higher ASA grades, being overweight, a previous lumbopelvic fusion, the use of specialized liners, and postoperative abductor weakness are significant risk factors.

Incidence, treatment, and outcomes of modern dual-mobility intraprosthetic dissociations.

Aims: Dual-mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a rare complication of DM that is believed to have decreased with contemporary implants. This study aimed to report incidence, treatment, and outcomes of contemporary DM IPD. Methods: A total of 1,453 DM components were implanted at a single academic institution between January 2010 and December 2021: 695 in primary and 758 in revision THA. Of these, 49 presented with a dislocation of the large DM head and five presented with an IPD. At the time of closed reduction of the large DM dislocation, six additional IPDs occurred. The mean age was 64 years (SD 9.6), 54.5% were female (n = 6), and mean follow-up was 4.2 years (SD 1.8). Of the 11 IPDs, seven had a history of instability, five had abductor insufficiency, four had prior lumbar fusion, and two were conversions for failed fracture management. Results: The incidence of IPD was 0.76%. Of the 11 IPDs, ten were missed either at presentation or after attempted reduction. All ten patients with a missed IPD were discharged with a presumed reduction. The mean time from IPD to surgical treatment was three weeks (0 to 23). One patient died after IPD prior to revision. Of the ten remaining hips with IPD, the DM head was exchanged in two, four underwent acetabular revision with DM exchange, and four were revised to a constrained liner. Of these, five (50%) underwent reoperation at a mean 1.8 years (SD 0.73), including one additional acetabular revision. No patients who underwent initial acetabular revision for IPD treatment required subsequent reoperation. Conclusion: The overall rate of IPD was low at 0.76%. It is essential to identify an IPD on radiographs as the majority were missed at presentation or after iatrogenic dissociation. Surgeons should consider acetabular revision for IPD to allow conversion to a larger DM head, and take care to remove impinging structures that may increase the risk of subsequent failure.

Genome wide association study in Swedish Labrador retrievers identifies genetic loci associated with hip dysplasia and body weight.

Genome wide association studies (GWAS) have been utilized to identify genetic risk loci associated with both simple and complex inherited disorders. Here, we performed a GWAS in Labrador retrievers to identify genetic loci associated with hip dysplasia and body weight. Hip dysplasia scores were available for 209 genotyped dogs. We identified a significantly associated locus for hip dysplasia on chromosome 24, with three equally associated SNPs (p = 4.3 × 10-7) in complete linkage disequilibrium located within NDRG3, a gene which in humans has been shown to be differentially expressed in osteoarthritic joint cartilage. Body weight, available for 85 female dogs, was used as phenotype for a second analysis. We identified two significantly associated loci on chromosome 10 (p = 4.5 × 10-7) and chromosome 31 (p = 2.5 × 10-6). The most associated SNPs within these loci were located within the introns of the PRKCE and CADM2 genes, respectively. PRKCE has been shown to play a role in regulation of adipogenesis whilst CADM2 has been associated with body weight in multiple human GWAS. In summary, we identified credible candidate loci explaining part of the genetic inheritance for hip dysplasia and body weight in Labrador retrievers with strong candidate genes in each locus previously implicated in the phenotypes investigated.

Management of long bone fractures and traumatic hip dislocations in paediatric patients: study protocol for a prospective global multicentre observational cohort registry.

INTRODUCTION: Management controversy and clinical equipoise exist in treatments of long bone fractures and traumatic hip dislocation in paediatric patients due to the lack of high-quality clinical evidence. This protocol describes the effort of a large prospective global multicentre cohort study (registry) aiming at providing quality data to assist evidence-based treatment decision-making. METHODS AND ANALYSIS: Eligible paediatric patients (N=750-1000) with open physes suffering from proximal humerus fractures, distal humerus fractures, proximal radius fractures, forearm shaft fractures, traumatic hip dislocations, femoral neck fractures or tibial shaft fractures will be recruited over a period of 24-36 months. Hospitalisation and treatment details (including materials and implants) will be captured in a cloud-based, searchable database. Outcome measures include radiographic assessments, clinical outcomes (such as range of motion, limb length discrepancies and implant removal), patient-reported outcomes (Patient Reported Outcomes Of Fracture, Patient-Reported Outcomes Measurement Information System (PROMIS) and EuroQol-5D (EQ-5D-Y)) and adverse events.Aside from descriptive statistics on patient demographics, baseline characteristics, types of fractures and adverse event rates, research questions will be formulated based on data availability and quality. A statistical analysis plan will be prepared before the statistical analysis. ETHICS AND DISSEMINATION: Ethics approval will be obtained before patients are enrolled at each participating site. Patient enrolment will follow an informed consent process approved by the responsible ethics committee. Peer-reviewed publication is planned to disseminate the study results. TRIAL REGISTRATION NUMBER: NCT04207892.

Neonatal Ultrasound and Radiographic Markers of Hip Dysplasia in Young Adults.

OBJECTIVES: To examine radiologic outcomes at skeletal maturity of sonographically normal, immature, mildly, and severely dysplastic newborn hips. METHODS: During 1988 to 1990, 11 925 newborns were enrolled in a randomized controlled trial examining screening strategies for developmental hip dysplasia. In total, 4469 were invited to clinical and radiologic follow-up 18 years later, of which 1735 had received neonatal ultrasound. Radiographic markers for dysplasia in left adult hips included the center-edge (CE) angle. RESULTS: At follow-up, 984 of 1735 (56.7%) with newborn ultrasound met, of which 966 (614 females) had valid radiographs and were thus included. For females, 34 (10.2%) and 1 (0.3%) of the 332 sonographically normal left neonatal hips were judged borderline (20°≤ CE <25°) or dysplastic (CE <20°) at skeletal maturity respectively. Corresponding numbers were 36 (19.7%) and 3 (1.6%) of the 183 immature, 12 (15.6%) and 2 (2.6%) of the 77 mildly dysplastic, and 3 (13.6%) and 3 (13.6%) of the 22 severely dysplastic neonatal left hips (P ≤ .001). In males, no associations were found. In females, adult joint hypermobility was associated with sonographic neonatal hip instability (P = .046), as well as with adult acetabular dysplasia (P = .024). CONCLUSIONS: Significant associations between neonatal hip phenotypes and adult dysplasia were revealed in females. This indicates the possibility of different mechanisms affecting the course of developmental dysplasia of the hip for females and males, prompting consideration of prolonged clinical and radiologic follow-up for females with dysplastic neonatal hips. Results in males are limited by low numbers of dysplastic hips. The significance of joint hypermobility warrants further investigation.