UNASSIGNED: Metallosis which is traditionally associated with Metal-on-Metal (MoM) hip arthroplasty can occur with other bearing surfaces too, posing diagnostic challenges. They can be asymptomatic or present with local and systemic symptoms. This article reports a case of metallosis in a total hip replacement (THR) with metal on polyethylene (PE) articulation who presented with dislocation. It also reviews the pathology and various presentations of metallosis following hip arthroplasty.
UNASSIGNED: A 35-year-old female patient presented 4 years after a left THR with recurrent dislocation. It was an uncemented prosthesis with metal on PE articulation. Serology and radiological investigations were done to evaluate for infection, implant loosening, implant malposition, etc. The femoral stem appeared to be in varus malposition. She was posted for revision surgery with a pre-operative plan to change the femoral stem and head if necessary. Intraoperative signs of local metallosis were noticed. Debridement was done along with the change of the femoral stem and bearing surface to ceramic on PE. Metallosis was also later confirmed by the histopathological report. The patient has been symptom-free during the 2-year follow-up period.
UNASSIGNED: Metallosis can occur even in non-MoM articulations and a high degree of clinical suspicion is required to detect the same preoperatively. Classical signs of metallosis can often be absent in the early disease and subtle signs of instability must be looked out for even in the absence of obvious misalignment in radiographic assessment. Metallosis when combined with malposition or malalignment can be more detrimental. If detected early before osteolysis and periarticular soft tissue damage sets in, a complete revision of all the implant components and abductor damage can be avoided. In suspected cases, a lower threshold should be adopted for sending blood and joint aspirates for cobalt-chromium levels.

UNASSIGNED: Posterior native hip dislocations (NHD) are high-energy injuries. Thompson-Epstein Type I dislocations describe those without significant associated femoral or acetabular fracture. The aim of this study was to compare the clinical and radiological outcomes of patients with Type I NHDs. We also evaluate the association between radiological indicators of femoroacetabular impingement (FAI) and NHD.
UNASSIGNED: A retrospective study from January 2012 to May 2021 compared skeletally mature patients (⩾16 years) with Type I posterior NHD to age and gender-matched controls with Type II-V posterior NHD. Patient demographics, mechanism of injury, complications and patient-reported outcome measures (PROMs) are presented. Post reduction radiographs and computed tomography were used to assess for FAI. Univariate analyses were performed to evaluate radiological outcomes.
UNASSIGNED: 13 patients (77% male) with Type I posterior NHD were compared to a control group of 40 patients (80% male) with Type II-V posterior NHD. 11 patients in the study group and 14 in the control group experienced isolated injuries (p = 0.01). Post-reduction complications were similar. The study group had significantly lower post-injury osteoarthritis incidence (n = 0) compared to controls (n = 18, p = 0.0083). Patients reported a mean Oxford Hip Score of 43.5 ± 2.2 and EQ-5D-VAS score of 87.1 ± 7.4, with 6 patients indicating minimal symptoms across all EQ-5D-5L domains. Radiological femoroacetabular impingement (FAI) was prevalent in both groups, especially among males.
UNASSIGNED: Patients who underwent emergent closed reduction of Type I NHD demonstrated good short to medium term outcomes. Our radiological findings suggest a high prevalence of FAI. Future work should aim to quantify longer term outcomes following this injury. We call for further comparative studies of patients who suffer NHD with and without fractures to aid our understanding of risk factors. Given the rarity of this injury, multicentre efforts will be required to capture large numbers of patients.

Structural deformities of the acetabulum secondary to developmental dysplasia of the hip (DDH) are one of the most common causes requiring total hip arthroplasty (THA), whether in conjunction with femoral osteotomy in cases of Crowe dislocation 4. Several techniques have been described, studied, and compared, but there is no superiority of one technique over another. Currently, most hip surgeons perform a subtrochanteric osteotomy. With a follow-up of 10 years, good results have been obtained, so there is a need to present a therapeutic alternative with potential benefits, mainly in restoring the center of rotation of the hip, preserving the proximal bone component, and reducing complications. Therefore, this study aims to describe the surgical technique of CTA in conjunction with supracondylar shortening osteotomy in a 29-year-old female patient, using an uncemented acetabular cup, a short uncemented stem with ceramic-polyethylene bearing, and distal fixation with a 4-hole plate LC-LCP, with the goal of restoring the natural biomechanics of the hip.
Las deformidades estructurales del acetábulo como secuelas de displasia en el desarrollo de la cadera es una de las patologías más frecuentes que ameritan como tratamiento la cirugía de artroplastía total de cadera (ATC) asociada o no a osteotomía femoral en casos de luxación inveterada clasificada como Crowe 4. Múltiples técnicas han sido descritas, estudiadas y comparadas; sin embargo, no existe superioridad de una sobre otra. Actualmente, la osteotomía realizada por la mayoría de los cirujanos de cadera es subtrocantérica, se han reportado buenos resultados a 10 años de seguimiento. La necesidad de presentar una alternativa terapéutica con posibles beneficios, principalmente en la restitución del centro de rotación de la cadera, preservación de componente óseo proximal y disminución de las complicaciones, es meritoria en el campo quirúrgico. Por lo tanto, este estudio se propone describir la técnica quirúrgica de ATC asociada a osteotomía de acortamiento supracondílea en un paciente femenino de 29 años, con uso de copa acetabular no cementada, vástago corto no cementado con par de fricción cerámica-polietileno y fijación distal con placa LC-LCP de cuatro orificios, con el objetivo de restaurar la biomecánica natural de la cadera.

UNASSIGNED: In developmental dysplasia of the hip (DDH), concentric reduction of dislocated hips cannot be achieved by closed reduction in many cases, and open reduction is required (\'failure of reduction\'). The incidence of cases requiring open reduction and the significance of risk factors for unsuccessful reduction remain unclear. We investigated the overall rate and the risk factors for failed closed reduction in DDH.
UNASSIGNED: We followed the Cochrane recommendations in our systematic review and meta-analysis. We performed a systematic search in three medical databases to identify all studies reporting on pediatric patients with hip dislocation in DDH on 2 July 2022. Eligible studies reported on the rate of failure in children younger than 36 months. We calculated odds ratios (ORs) with 95% CIs from two-by-two tables (event rate in risk group, event rate in non-risk group).
UNASSIGNED: We identified 13 316 studies and included 62 studies (5281 hips) for failure rate and 34 studies (3810 hips) for risk factor analysis. The overall rate of failure in closed reduction was 20%. The risk of failure of reduction increased with the grade of dislocation and was significantly higher for high dislocations (group 0-24: IHDI 4 vs IHDI 2 OR: 17.45, CI: 9.26-32.92; Tönnis 4 vs Tönnis 2 OR: 14.67, CI: 1.21-177.37; Graf IV vs Graf III OR: 3.4, CI: 2.27-5.09). Male gender was also a significant risk factor (OR: 2.27, CI: 1.13-4.56) in group 0-36.
UNASSIGNED: Higher grade dislocations and male gender are significant risk factors for failure of reduction in closed reduction in hip dislocation in DDH.

OBJECTIVE: This study aims to assess the incidence of hip displacement and dislocation (denominated as hip migration) among ambulant and non-ambulant Danish children with cerebral palsy (CP) by estimating their cumulative incidence of migrated hips. A secondary objective is to compare the prevalence across different Danish regions.
METHODS: Data were obtained from the Danish Cerebral Palsy Follow-Up Program (CPOP) from the years 2008 to 2021. This population-based cohort study included 1388 children with CP (58% male; 42% female) as subjects; aged 0-15 years; with an average age of 5.4 years at their last follow-up. The children were categorized according to their Gross Motor Function Classification System (GMFCS) level into ambulators (GMFCS I-III) and non-ambulators (GMFCS IV-V). The Kaplan-Meier estimator was employed to calculate the cumulative incidence of migrated hips from birth until the date of their last radiographic follow-up. Differences between ambulatory and non-ambulatory children and regional differences were assessed with the Log-rank test.
RESULTS: Median radiological follow-up for ambulators was 51 months and 94 months for non-ambulators. The cumulative incidence of hip dislocation was 0.3% (95% CI: 0-0.8%) and 22.0% (95% CI: 9.2-34.8%) for ambulators and non-ambulators, respectively (p < 0.0001), whereas the incidence of hip displacement was 21.1% (95% CI: 16.3-25.9%) and 76.7% (95% CI: 68.6-84.7%) for ambulators and non-ambulators, respectively (p < 0.0001). There were no significant regional differences in the incidence of hip dislocation among ambulators, but there were significant differences for non-ambulators. Moreover, significant regional differences were detected in hip displacement for both ambulators and non-ambulators.
CONCLUSIONS: The prevalence of hip migration in Danish children with CP is significantly higher among non-ambulators, who are at an increased risk of hip migration compared to their ambulant counterparts. However, the low frequency of radiographic follow-up for ambulators might cause the incidence of hip migration to be underestimated. This study highlights the necessity of continued targeted surveillance and interventions in Danish non-ambulators.

UNASSIGNED: Laterality and bilaterality have been reported as prognostic variables in developmental dysplasia of the hip (DDH) outcomes. However, there is little clarity across the literature on the reporting of laterality in developmental dysplasia of the hip (DDH) due to the variability in severity of the condition. It is widely accepted that the left hip is most frequently affected; however, the true incidence of unilateral left, unilateral right and bilateral cases can be hard to quantify and compare across studies. The purpose of this study was to examine laterality accounting for graded severity in a multi-centre, international prospective observational study of infants with hip dysplasia to demonstrate the complexity of this issue.
UNASSIGNED: A multi-centre, prospective hip dysplasia database was analyzed from 2010 to April 2015. Baseline diagnosis was used to classify patients into a graded laterality category accounting for hip status within the DDH spectrum.
UNASSIGNED: A total of 496 patients were included in the analysis; 328 were <6 months old at diagnosis and 168 were between 6 and 18 months old. Of these patients, 421 had at least one frankly dislocated hip. Unilateral left hip dislocations were most common, with 223 patients, followed by unilateral right and bilateral dislocations with 106 and 92 respectively. Stratifying these patients based on status of the contralateral hip, 54 unilateral left and 31 unilateral right dislocated patients also had a dysplastic or unstable contralateral hip. There were significantly fewer bilateral patients in the 6 to 18-month group (p = 0.0005). When classifying laterality by affected hip, bilaterality became the predominant finding, comprising 42% of all patients.
UNASSIGNED: Findings from this multi-centre prospective study demonstrate the necessity to account for the graded severity in hip status when reporting DDH laterality. To accurately compare laterality across studies, a standardized, comprehensive classification should be established, as contralateral hip status may impact prognosis and treatment outcomes.
UNASSIGNED: Level II Prognostic Study.

BACKGROUND: Up to one-third of children with cerebral palsy (CP) develop migration of the hip, and the risk increases with a higher Gross Motor Function Classification System (GMFCS). In progressive hip migration in young children, adductor tenotomy is an accepted treatment option to delay or prevent progressive hip migration. However, there is quite a large variability in reported results. This systematic review aims to determine the effectiveness of a soft-tissue release in the prevention of progressive hip migration in children with CP.
METHODS: This systematic review was performed in accordance with the guidelines of the Cochrane Handbook for Systematic Reviews and the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols statements. Our inclusion criteria were studies describing pediatric, skeletally immature patients with CP and a \"hip at risk\" of progressive hip migration. Exclusion criteria were simultaneous bony reconstructions, case reports, technical notes, published abstracts, or studies with a follow-up under 1 year postoperatively. The primary outcomes were defined as failure rate (progressive hip migration and/or need for bony surgery, as defined by each paper) and change in migration percentage (MP) at final follow-up. As secondary analyses, we evaluated the outcome after specific subtypes of surgeries and assessed whether performing lengthening of iliopsoas, neurectomy of the anterior branch of the obturator nerve, age at the time of surgery, GMFCS level, and postoperative management impact the outcome.
RESULTS: Our literature search identified 380 titles. Eighty-four articles underwent full-text review, of which 27 met our inclusion/exclusion criteria and were subsequently selected for quantitative analysis. A prevalence meta-analysis was performed including 17 studies (2,213 hips). Mean follow-up ranged from 12 to 148.8 months. The mean preoperative MP was 33.4% (2,740 hips) and 29.9% at follow-up. The overall reported failure rate was 39% (95% confidence interval, 26%-52%). Performing a release of only adductor longus had a failure rate of 87%, whereas more extensive soft-tissue releases showed significantly better results with failure rates ranging from 0 to 44% (p < 0.001). Lengthening of the iliopsoas had no significant impact on failure rate (p = 0.48), nor did performing an obturator neurectomy (p = 0.92).
CONCLUSIONS: The failure rate of adductor tenotomies to prevent progressive hip migration appears to be as high as 39% in studies with a varying follow-up. The failure rates are significantly higher when isolated release of the adductor longus is performed. This systematic review supports clinical decision making in children with CP and early hip migration.
METHODS: Level IIA. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND: Intraarticular hip pain represents a substantial clinical challenge, with recent studies implicating lesions in the ligamentum teres as potential contributors. Even more so, damage to the ligamentum teres is particularly prevalent among young patients undergoing joint-preserving interventions. Although several studies have investigated the biomechanical attributes of the ligamentum teres, inconsistencies in reported findings and reliance on cadaveric or animal models have raised concerns regarding the extrapolation of results to clinical practice. Furthermore, there is a lack of research examining ligamentum teres biomechanics specifically within the relevant patient cohort-individuals who benefit from joint-preserving surgical interventions.
OBJECTIVE: We sought (1) to determine the biomechanical properties (ultimate load to failure, tensile strength, stiffness, and elastic modulus) of fresh-frozen ligaments from patients undergoing surgical hip dislocation, and (2) to identify patient-specific factors that are associated with them.
METHODS: This was an institutional review board-approved study on intraoperatively harvested ligamentum teres from 74 consecutive patients undergoing surgical hip dislocation for joint preservation (August 2021 to September 2022). After the exclusion of patients with previous surgery, posttraumatic deformities, avascular necrosis, slipped capital femoral epiphysis, and Perthes disease, 31 ligaments from 31 patients were analyzed. The mean age of the study group was 27 ± 8 years, and 61% (19) of participants were male. The main indication for surgery was femoroacetabular impingement. Standardized AP pelvic and axial radiographs and CT scans were performed in all patients for better radiological description of the population and to identify associated radiological factors. The ligament was thoroughly transected at its origin on the fossa acetabuli and at the insertion area on the fovea capitis and stored at -20°C until utilization. Specimens were mounted to a materials testing machine via custom clamps that minimized slippage and the likelihood of failure at the clamp. Force-displacement and stress-strain curves were generated. Ultimate failure load (N), tensile strength (MPa), stiffness (N/mm), and elastic modulus (MPa) were determined. Using a multivariate regression analysis and a subgroup analysis, we tested demographic, degenerative, and radiographic factors as potential associated factors.
RESULTS: The ligamentum teres demonstrated an ultimate load to failure of 126 ± 92 N, and the tensile strength was 1 ± 1 MPa. The ligaments exhibited a stiffness of 24 ± 15 N/mm and an elastic modulus of 7 ± 5 MPa. After controlling for potential confounding variables like age, fossa/fovea degeneration, and acetabular/femoral morphologies, we found that female sex was an independent factor for higher tensile strength, stiffness, and elastic modulus. Excessive femoral version was independently associated with lower load to failure (HR 122 [95% CI 47 to 197]) and stiffness (HR 15 [95% CI 2 to 27]). Damage to the acetabular fossa was associated with reduced load to failure (HR -93 [95% CI -159 to -27]).
CONCLUSIONS: Overall, the ligamentum teres is a relatively weak ligament. Sex, degeneration, and excessive femoral version are influencing factors on strength of the ligamentum teres. The ligamentum teres exhibits lower strength compared with other joint-stabilizing ligaments, which calls into question its overall contribution to hip stability.
CONCLUSIONS: Young patients undergoing hip-preserving surgery are the population at risk for ligamentum teres lesions. Baseline values for load to failure, tensile strength, elastic modulus, and stiffness are needed to better understand those lesions in this cohort of interest.

UNASSIGNED: Floating hip with hip dislocation is a very high-energy, devastating, and rare injury whose treatment is very challenging, and the outcome is usually poor.
UNASSIGNED: A 35-year-old man presented posterior wall fracture acetabulum and dislocation of the hip with ipsilateral distal third shaft femur fracture with intra-articular extension fracture and un-displaced patella fracture. We achieved a reduction of hip dislocation by a knee-spanning external fixator followed by open reduction and internal fixation with anatomical locking plate for distal third femur fracture with intra-articular extension followed by open reduction and internal fixation for posterior wall of acetabulum with recon plate in Kocher-Langenbeck approach in stages. The patient was able to partial weight bear after 12 weeks of the injury and mobilized independently without any support after 5 months.
UNASSIGNED: Floating hip with hip dislocation is difficult to manage but reducing the hip dislocation with knee spanning external fixator and management in stages will reduce the complications and better outcome.

BACKGROUND: Prosthetic dislocation after total hip arthroplasty (THA) is one of the most common causes of revision THA. Dual-mobility (DM) bearings were introduced to mitigate complications; however, there is minimal data on their performance in younger patients. This study compared results of patients who were under 55 years of age undergoing primary THA with DM or fixed-bearing (FB) implants.
METHODS: A retrospective review of patients younger than 55 years who underwent primary THA with at least 2 years of follow-up between June 2011 and August 2019 was performed. Patients were stratified into two cohorts based on the implant they received (DM vs. FB). Primary outcomes were 90-day all-cause readmission, dislocation, all-cause revision, 90-day readmission and revision due to dislocation, and implant component survivorship. Demographic differences were assessed using chi-squared and independent samples t-tests. Outcomes were compared using multivariate linear and logistic regressions to control for confounding variables.
RESULTS: A total of 803 patients were included (DM = 73, FB = 730). The DM and FB cohorts had similar rates of 90- day all-cause readmission (6.8% vs. 3.2%; p = 0.243) and 90-day readmission due to dislocation (4.1% vs. 0.8%; p = 0.653). At a mean follow-up of 4.42 ± 1.91 years, dislocation (4.1% vs. 1.1%; p = 0.723) and all-cause revision (5.5% vs. 4.9%; p = 0.497) rates between the DM and FB cohorts were similar. Kaplan Meier analysis yielded no significant differences in survivorship between groups for all-cause revision (95.1% vs. 94.5%; p = 0.923), revision due to dislocation (100% vs. 98.9%; p = 0.370), and acetabular component revision (97.3% vs. 98.6%; p = 0.418).
CONCLUSIONS: Dual mobility implants demonstrate similar dislocation rates and implant survivorship compared to FB in patients less than 55 years of age. Larger trials with long-term follow-up may be required to further elucidate the effects of DM bearings compared to FB inserts in younger patients undergoing primary THA.