Hip Dislocation Research Articles

Early Hip Dislocation Rate in a Consecutive Series of 1093 Primary Total Hip Arthroplasties Using Imageless Navigation

Purpose: Postoperative hip dislocation remains a major complication in total hip arthroplasty. Various studies have demonstrated that several factors influence dislocation. While computer-assisted navigation has been proposed to enhance component alignment, its impact on dislocation rates remains unclear. This study aimed to investigate the early dislocation incidence and associated risk factors in primary total hip arthroplasty (THA) using imageless navigation. Methods: A retrospective review of patients undergoing imageless-navigated THA between February 2013 and December 2022 was conducted. Inclusion criteria comprised primary THA with a minimum 6-month follow-up. Statistical analysis included univariate regression to identify dislocation risk factors. Results: A total of 1093 THAs were analyzed. Dislocation occurred in 16 cases (1.5%), six in elective procedures (0.76%), and 10 in femoral neck fracture (FNF) (3.28%). The univariate regression analysis revealed that FNF emerged as a significant risk factor (OR = 4.418, P = 0.004), while age, gender, femoral head size, and save zone cup placement of Lewinnek did not significantly affect dislocation rates. Conclusions: Navigation use showed a reduced rate of early dislocation. FNF is a factor associated with postoperative hip dislocation in primary THA.

Comparative study of total hip arthroplasty with and without femoral osteotomy in Crowe Ⅳ developmental dysplasia of the hip

To compare the clinical effects of total hip arthroplasty(THA) with and without femoral osteotomy in Crowe Ⅳ developmental hip dislocation(DDH). The data on 46 patients who underwent THA for unilateral Crowe Ⅳ DDH between 2012 and 2017 were analyzed retrospectively. They were divided into two groups according to the different surgical methods. There were 24 patients in the osteotomy group, 3 males and 21 females, with an average age of (47.3±9.0) years old ranged from 34 to 57 years old;and 22 patients in the non-osteotomy group, 2 males and 20 females, with an average age of (51.6±8.3) years old ranged from 40 to 61 years old. The operative time, bleed loss, postoperative drainage volume, postoperative complications, ROM of hip, Harris hip score, limb length discrepancy(LLD), and radiological data were recorded. The femoral dislocation height and the implantation depth of sleeve were measured. All patients were followed up. The mean follow-up time was (3.8±1.2) years ranged from 2 to 6 years in the osteotomy group and (3.2±0.9) years ranged from 1 to 5 years in the non-osteotomy group. The operative time(136.8±18.9) min, bleed loss (709.8±89.4) ml, postoperative drainage volume(308.8±98.2) ml of osteotomy group were all significantly greater than those of non-osteotomy group(100.7±15.8)min, (516.5±103.3) ml, (245.3±79.3) ml (P<0.05). The Harris score at the latest follow up was significantly increased compared with preoperative score in two groups (P<0.05), but there was no significant difference between two groups (P>0.05). The LLD at last follow up was significantly increased compared with preoperative LLD in two groups, the LLD in non-osteotomy group(0.7±0.2) cm showed signifcant smaller than the two osteotomy group(1.2±0.4) cm. Between osteotomy and non-osteotomy groups, the preoperative range of motion of hip joint [(89.5±19.7) °vs (102.5±16.8) °], the preoperative height of dislocation of femoral head [(4.56±0.61) cm vs (3.10±0.73) cm], the proximal implant depth of S-ROM [(0.93±0.36) cm vs (1.67±0.28) cm] was significantly different (P<0.05). Eleven patients in the osteotomy group still had claudication, and 4 patients in the non-osteotomy group had mild claudication (P<0.05). In non-osteotomy group, 3 patients developed nerve injury (1 patient of sciatic nerve, 2 patients of femoral nerve) and 1 case developed periprosthetic fracture. In osteotomy group, 2 case of dislocation and 2 cases of periprosthetic fractures. Whether osteotomy or not can achieve satisfactory results for treating Crowe type Ⅳ DDH and significantly improve LLD. However, osteotomy is more complex and time-consuming, limb length difference is greater, and the incidence of claudication is higher. Furthermore, patients with smaller preoperative hip mobility, higher femoral dislocation, limb lengthening≥4 cm and severely narrow femoral proximal canals are prone to be peformed with subtrochanteric osteotomy.

Practice Patterns Vary Widely in the Care of Pediatric and Adolescent Pelvic and Acetabular Fractures: A CORTICES Survey.

Pediatric pelvic and acetabular fractures are rare but potentially devastating injuries and significant management variation exists across the United States. This study sought to elucidate treatment decision-making trends, involvement of adult trauma fellowship-trained surgeons in pediatric care, and pre- and postoperative transfer patterns. Pediatric orthopaedic surgeons who serve as trauma liaisons at 20 PTCs were surveyed regarding training, practice volume, and factors contributing to institutional management of pelvic and acetabular injuries. Five clinical scenarios of pelvic ring and acetabular fractures that varied by injury pattern, age, and sex were presented. Descriptive statistics were used to summarize the results. Eighteen institutions responded to the survey (90% response rate, 16 Level, 1 PTC). All surgeons were pediatric fellowship-trained (77.7% in practice >5y). The four most common factors affecting whether surgeons independently managed both pelvic ring and acetabular fractures were patient age, fracture characteristics, displacement and need for surgery. The majority reported managing <10 acetabular (72.2%) but >10 pelvic ring (77.8%) injuries per year. In the clinical scenarios, patients <10 were more likely to have treatment decisions made by a pediatric orthopaedic surgeon. Older patients were more likely to be transferred to another institution for surgery but were often transferred back to the PTC postoperatively. In all clinical scenarios other than posterior hip dislocation, a trauma fellowship-trained surgeon was more likely to be the operative surgeon, even when the patient was not transferred. There is substantial variation in the management of pediatric and adolescent pelvic and acetabular fractures. Even at tertiary care PTCs, volumes are low, and trauma fellowship-trained surgeons are often involved in decision-making and operative management. Age and injury pattern seem to play a large role in variation, and patient transfers between facilities are common. V.

Femoral Head Fractures: Evaluation, Management, and Outcomes.

Fractures of the femoral head typically occur after high-energy trauma. Radiographs and cross-sectional imaging are used to appropriately classify and identify associated injuries or morphologic characteristics that may influence management. Identification of the radiographic and clinical hallmarks of an irreducible variant is critical to optimizing the patient's outcome. Nonsurgical treatment can be used in the setting of small, infrafoveal femoral head fractures without hip instability. When surgical treatment is indicated, an anterior (Smith-Petersen), posterior (Kocher-Langenbeck), or surgical hip dislocation approach may be used depending on injury details and surgeon preference. The purpose of this review was to summarize current evidence on femoral head fractures regarding indications, variant patterns, surgical approaches, and outcomes.

Outcomes of open reduction for hip dislocations in children with connective tissue disorders*

Purpose: While children with hypermobility and/or ligamentous laxity due to coexisting connective tissue disorders might be expected to have worse outcomes after open reduction for hip dislocations, there is minimal prior research on this topic. Methods: All open reduction surgeries for hip dislocations performed at a single urban, tertiary-care children’s hospital from 2009 to 2023 were reviewed retrospectively. Those with connective tissue disorders secondary to a diagnosed syndrome or genetic disorder were included. Patients with &lt;1 year of follow-up or hip instability in the setting of Trisomy 21 were excluded. Clinical and radiographic data was collected. Instances of re-dislocation, proximal femoral growth disturbance, residual acetabular dysplasia, and arthrofibrosis were recorded. Results: Twenty-three hips (15 patients) were included. Mean age at the time of surgery was 19.6 months (Range: 8.2–36.0 months), and mean follow-up was 4.3 years. The most common connective tissue disorder condition included was Ehlers-Danlos syndrome (13%). A majority of open reductions were performed via an anterior approach (96%). Seven hips (30%) underwent a concomitant pelvic osteotomy without femoral osteotomy and seven hips (30%) underwent both pelvic and femoral osteotomies. Twenty-two hips (96%) were International Hip Dysplasia Institute grade 1 at the final follow-up. Re-dislocation occurred in four hips (17%); eight hips (35%) demonstrated residual acetabular dysplasia, five hips (22%) demonstrated proximal femoral growth disturbance, and nine hips (39%) developed stiffness postoperatively. Conclusions: Patients with connective tissue disorders and ligamentous laxity have comparable rates of residual acetabular dysplasia, proximal femoral growth disturbance, and (surprisingly) stiffness as typical developmental dysplasia of the hip following open hip reduction surgery. Although the re-dislocation rate in the connective tissue disorders group was approximately 2–3 times higher, the difference did not reach statistical significance. Given that the study was limited by a low sample size, however, it is possible that the findings of no difference in residual acetabular dysplasia and proximal femoral growth disturbance were potentially due to a lack of power. Level of evidence: IV.

Using 2D U-Net convolutional neural networks for automatic acetabular and proximal femur segmentation of hip MRI images and morphological quantification: a preliminary study in DDH

BackgroundDevelopmental dysplasia of the hip (DDH) is a common pediatric orthopedic condition characterized by varying degrees of acetabular dysplasia and hip dislocation. Current 2D imaging methods often fail to provide sufficient anatomical detail for effective treatment planning, leading to higher rates of misdiagnosis and missed diagnoses. MRI, with its advantages of being radiation-free, multi-planar, and containing more anatomical information, can provide the crucial morphological and volumetric data needed to evaluate DDH. However, manual techniques for measuring parameters like the center–edge angle (CEA) and acetabular index (AI) are time-consuming. Automating these processes is essential for accurate clinical assessments and personalized treatment strategies.MethodsThis study employed a U-Net-based CNN model to automate the segmentation of hip MRI images in children. The segmentation process was validated using a leave-one-out method during training. Subsequently, the segmented hip joint images were utilized in clinical settings to perform automated measurements of key angles: AI, femoral neck angle (FNA), and CEA. This automated approach aimed to replace manual measurements and provide an objective reference for clinical assessments.ResultsThe U-Net-based network demonstrates high effectiveness in hip segmentation compared to manual radiologist segmentations. In test data, it achieves average DSC values of 0.9109 (acetabulum) and 0.9244 (proximal femur), with a 91.76% segmentation success rate. The average ASD values are 0.3160 mm (acetabulum) and 0.6395 mm (proximal femur) in test data, with Ground Truth (GT) edge points and predicted segmentation maps having a mean distance of less than 1 mm. Using automated segmentation models for clinical hip angle measurements (CEA, AI, FNA) shows no statistical difference compared to manual measurements (p > 0.05).ConclusionUtilizing U-Net-based image segmentation and automated measurement of morphological parameters significantly enhances the accuracy and efficiency of DDH assessment. These methods improve precision in automatic measurements and provide an objective basis for clinical diagnosis and treatment of DDH.

Ultrasound is an accurate imaging modality for diagnosing hip luxation in dogs presenting with hind limb lameness.

To determine the accuracy of ultrasound for diagnosing hip luxation in dogs presenting for hind limb lameness. 24 client-owned dogs presenting with pelvic limb lameness and concern for hip luxation were enrolled in this prospective diagnostic accuracy study from April 1, 2021, to July 1, 2022. An experienced ultrasonographer and a novice ultrasonographer, both masked to the diagnoses, performed hip ultrasonography using a point-of-care ultrasound machine. The experienced evaluator also performed a more comprehensive ultrasonography with a high-end ultrasound machine to characterize concurrent pelvis and hip disease. Pelvic radiographs served as the criterion standard for the diagnosis of hip luxation. Ultrasonographic diagnosis of hip luxation demonstrated high accuracy, ranging from 84.2% to 100% for detecting the presence of luxation and 80.6% to 98.1% for diagnosing the direction of luxation for the novice and experienced evaluators, respectively, with substantial interevaluator agreement (κ = 0.722). Compared to radiographs, ultrasound accurately diagnosed the presence of osteoarthrosis with almost perfect agreement (κ = 0.913) and the presence of fractures of the femoral head/neck and the nonaxial portions of the pelvis with substantial intermodality agreement (κ = 0.775). In 36% of patients, ultrasound identified injury to soft tissue structures that contribute to hip stability, including the gluteal muscles, gemelli, and joint capsule. Ultrasound can be utilized to accurately diagnose the presence of hip luxation and document concurrent hip and pelvic disease. Applications include the use of ultrasonography as part of a routine point-of-care protocol to catalogue injuries in patients with acute trauma and in mobile practice or remote settings where radiography is not readily available.

Femoral head and acetabular necrosis combined with hip subluxation in people with HIV: a case report and literature review

IntroductionHIV is widely prevalent in all regions of the world. The use of antiretroviral drugs has dramatically reduced the mortality rate of HIV-related diseases, but correspondingly increased the incidence of chronic complications in HIV-positive people. Related studies have found that the incidence of osteonecrosis of the femoral head is higher in HIV-positive people, but the co-occurrence of femoral head necrosis, acetabular necrosis and hip joint dislocation in HIV-positive patients is rare.MethodsWe report a 50-year-old man with a 15-month history of progressively worsening right hip pain with movement restriction. According to the CT findings of the other hospital, the patient was admitted to the hospital with femoral head necrosis. After the admission, the relevant X-ray, CT and MRI examinations showed that the right femoral head collapsed and deformed, with the surrounding bone sclerosis, bone fragments, loose body of the joint, right hip subluxation, acetabular marginal osteogeny, and local microcystic degeneration. The left femoral head was in good shape, and cystic degeneration can be seen under the articular surface. The patient was finally diagnosed with femoral head necrosis and acetabular necrosis combined with hip subluxation.ResultsThe pain of the patient was significantly relieved after the operation, and the patient was discharged from the hospital one week after the start of treatment to continue rehabilitation training. During the follow-up one month after the operation, the self-reported pain disappeared completely, and the limitation of activity was significantly improved.

Intra-articular anterior inferior iliac spine avulsion with hip instability: A retrospective study

BackgroundIntraarticular anteroinferior iliac spine (AIIS) avulsion fractures combined with hip dislocation are infrequently reported in medical literature. This study aims to present the outcomes of surgical treatment for this rare type of injury. MethodsWe retrospectively analyzed six cases of AIIS avulsion fracture with hip dislocation treated surgically. All patients underwent emergency hip reduction under sedation followed by open reduction and internal fixation using 4 mm cannulated screws through the iliofemoral approach. ResultsAfter an average follow-up period of 50 months, all fractures healed. Clinically, four patients were rated as having an excellent outcome and two as good, according to the Harris Hip Score. Radiological assessment using Matta's grading system showed excellent results in five patients and good in one. All patients were able to resume their pre-injury activity levels within six months post-surgery. ConclusionSurgical fixation of AIIS avulsion fractures with associated hip instability demonstrates favourable outcomes, ranging from good to excellent, in both clinical and radiological assessments at medium-term follow-up. This suggests that surgical intervention is a viable option for managing such injuries.

Timely Hip Surgery Access in Children With Cerebral Palsy: Unaffected by Social Disadvantage at a Large Urban Safety Net Hospital.

Socioeconomic disadvantage has been shown to limit timely access to pediatric orthopaedic care and can result in poor surgical outcomes. Insurance coverage has often served as a proxy for socioeconomic status; however, area deprivation index (ADI) and child opportunity index (COI) are more comprehensive measures of social determinants of health (SDOH). The treatment of hip displacement in children with cerebral palsy (CP) requires early radiographic identification and continuous surveillance, which may be impacted by SDOH. This study seeks to evaluate the influence of insurance, ADI, and COI on preoperative Reimer migration percentage and need for pelvic osteotomy during varus derotation osteotomy (VDRO) in children with CP. This retrospective cohort study examined 219 patients with CP who underwent VDRO surgery for hip subluxation or dislocation at a tertiary referral center (135 male, mean age 7.9y, SD: 2.9, range: 2.4 to 17.2; 17 GMFCS II, 21 GMFCS III, 89 GMFCS IV, 92 GMFCS V) from 2004 to 2022. Imaging and clinical documentation for patients with CP and hip displacement, age <18 years with ≥1 year of follow-up, treated with VDRO were reviewed. GMFCS level, preoperative Reimer migration percentages (MP), surgical details, and demographic and socioeconomic data were collected, and addresses were used to determine ADI (2018 version) and COI (2.0 database). The relationship of ADI, COI, and insurance type to preoperative Reimer MP of the more displaced hip and the need for pelvic osteotomy were analyzed with linear regressions and logistic regressions. The mean preoperative Reimer MP was 64.4% (SD: 25.0, range: 0 to 100). As expected, patients functioning at higher GMFCS levels presented with greater Reimer MPs. The average Reimer MP was 34.0 for GMFCS II, 44.2 for GMFCS III, 64.6 for GMFCS IV, and 74.5 for GMFCS V (P<0.01). The mean ADI state decile (1 to 10 scale) and COI (1 to 100 scale) for the cohort were 5.6 (SD: 2.2, range: 1 to 10) and 37.2 (SD: 28.1, range: 4 to 100), respectively. ADI (P=0.77), COI (P=0.30), and insurance type (P=0.78) were not related to preoperative Reimer MP. However, patients with lower ADIs (OR 0.83, 95% CI [0.70, 0.99], P=0.04) and higher COIs (OR 1.01, 95% CI [1.00, 1.03], P=0.03) underwent pelvic osteotomies at a higher rate. ADI, COI, and insurance type were not related to preoperative Reimer MP. Interestingly, greater social disadvantage was associated with a lower frequency of pelvic osteotomy at the time of VDRO. Our data demonstrate that at our institution, greater social disadvantage does not result in limited access to timely orthopaedic care for children with CP. This is likely due to adequate governmental insurance coverage for children with neuromuscular disorders in this state and the active involvement of pediatric orthopaedic surgeons in government-sponsored clinics, including ongoing hip screening programs for children with CP. These results provide hope that healthcare disparities can potentially be mitigated.

Surgical Outcomes of Total Hip Arthroplasty with Paavilainen Osteotomy in Patients Who Have High Developmental Hip Dislocation: Mean 4.4 Year Follow-Up

BackgroundAlthough subtrochanteric osteotomy is a common procedure, the use of Paavilainen osteotomy combined with total hip arthroplasty (THA) for high developmental hip dislocation is less documented. This study assessed the efficacy and complications of this approach, with a particular focus on the risk factors for nonunion post-osteotomy. MethodsAll patients who had high dislocated hip dysplasia who underwent combined THA and Paavilainen osteotomy, were retrospectively reviewed with over one year of follow-up. A total of 44 patients (51 hips) were included, with an average follow-up period of 4.4 years (range, 1.97 to 6.94). Anatomical data of the hip joints were measured on pre- and postoperative radiographs. Demographic data, Trendelenburg sign, complications related to this procedure, Harris Hip Score (HHS), and EuroQoL-5-Dimension 5-Level (EQ-5D-5L) health questionnaire were collected from the medical chart. Binary logistic regression analysis was used to identify predictors for bone nonunion. ResultsOut of the 51 hips, eight displayed a positive Trendelenburg sign. Patients' HHS saw an improvement from 43.8 ± 11.8 preoperatively to 85.7 ± 11.1 at the latest follow-up (P < 0.001), accompanied by a substantial enhancement in the average EQ-5D-5L score from 0.38 ± 0.15 to 0.87 ± 0.13 (P < 0.001). Nonunion, as the most concerning complication, occurred in 12% (seven of 56) of osteotomy cases. The contact length between the osteotomy block and femoral cortex was a key risk factor for nonunion. The Receiver operating characteristic (ROC) analysis identified 2.15 centimeters (cm) as the critical bone contact length for healing. ConclusionsPaavilainen osteotomy combined with THA and subtrochanteric osteotomy proved effective and less complex than other techniques for high-dislocation hip dysplasia. A bone contact length between the greater trochanteric fragment and the femoral cortex of less than 2.15 cm is a risk factor for nonunion.

Arthroscopic Fixation With Absorbable Suture Anchors for Pipkin Type I Femoral Head Fractures—Letter V Technique

Femoral head fractures are relatively uncommon high-energy injuries and usually associated with traumatic hip dislocation. Pipkin classified these fractures into 4 types according to the location of the head fragment related to the fovea and associated lesions on the femoral neck or acetabulum. Traditional open reduction and internal fixation for femoral head fracture has been proven to be effective, but it could be associated with significant complications. Arthroscopic fixation with screws is a less-invasive alternative to open reduction and internal fixation that offers several advantages. However, technical challenges could be encountered during the procedure and catastrophic consequences could occur in cases of fixation failure. Therefore, we propose an effective arthroscopic technique for Pipkin type I (small fracture caudal to the fovea capitis) femoral head fractures that uses an absorbable suture anchors. The anchors provide initial stability to the fracture fragments, and then the sutures are tied in a double-pulley fashion to further secure the fracture. Finally, a triangular suture bridge (“letter V”) is created, which supplies a convenient and stable fixation for proper femoral head fracture.

Computer-Assisted Total Hip Arthroplasty Improves Acetabular Prosthesis Placement Accuracy: A Multicenter, Randomized Controlled Clinical Study.

The long-term effectiveness of total hip arthroplasty (THA) largely depends on the accuracy of acetabular prosthesis placement. To improve the accuracy of acetabular prosthesis placement, we utilized a new surgical navigation system: visual treatment solution (VTS). The purpose of this study was to verify the efficacy and safety of this system in assisting THA. This was a prospective, multicenter, randomized controlled trial. One hundred and twenty-four patients undergoing primary THAs were included. The experimental group underwent VTS-assisted THA, and the control group underwent traditional surgical techniques. The main efficacy evaluation indicators were the proportion of anteversion and inclination angles in the Lewinnek safe zone, and secondary evaluation indicators included operation time, Western Ontario and McMaster University Osteoarthritis index (WOMAC) score, Harris score, short-form-36 (SF-36) score, and hip dislocation rate. Statistical analysis was performed mainly by t-test and chi-square test. The proportion of both anteversion and inclination angles in the safe zone was 93.1% in the experimental group and 50.9% in the control group; the difference was significant (p < 0.01). The average operation time was 112.5 min in the experimental group and 92.6 min in the control group; the difference was significant (p < 0.01). There were no significant differences in WOMAC score, Harris score, or SF-36 score between the experimental and control groups at 3 months after the operation (p > 0.05). The dislocation rate was 0% in the experimental group and 1.6% in the control group; the difference was not significant (p > 0.05). VTS-assisted THA can significantly improve the accuracy of acetabular prosthesis placement. However, there were no differences in short-term clinical outcomes or dislocation rates between the two groups.

Post-operative short-term clinical evaluation of direct lateral (Harding) approach in primary total hip replacement.

To evaluate patients' functional outcomes after total hip arthroplasty through a direct lateral approach. The prospective, observational, descriptive study was conducted at Al-Yarmouk Teaching Hospital, Baghdad, Iraq, from May 2019 to June 2020, and comprised patients aged 28-81 years having advanced osteoarthritis and avascular necrosis who underwent cementless total hip arthroplasty. The patients were followed up for 6 months. Outcome was assessed using the Harris hip score, Trendelenburg sign, post-operative hip dislocation, post-operative infection, and heterotopic ossifications. Data was analysed using Excel version 2019. Of the 30 patients, 14(47%) were males and 16(53%) were females. The overall mean age was 49.8±15.28 years. The mean pre-operative Harris hip score was 43.166±8.27, while it was 83.566±3.83 post-operatively (p<0.001). There was 1(3.33%) case of heterotopic ossification, 3(10%) had Trendelenburg sign. There was no case of postoperative hip dislocation or infection. The lateral hip approach was found to be associated with good post-operative hip stability and good post-operative functional outcome with low post-operative risk of infection.

Posterior approaches to the acetabulum.

Posterior approaches, particularly the Kocher-Langenbeck approach, remain the workhorses in the treatment of acetabular fractures. Various modifications have been developed, each offering specific advantages depending on surgical requirements. The modified Gibson approach, for example, is suggested to provide enhanced visualization of the superior acetabulum, although recent cadaveric studies have not consistently substantiated this benefit. The Ganz approach, which involves bigastric trochanteric osteotomy with safe surgical hip dislocation, is particularly advantageous for managing complex and comminuted posterior acetabular fractures, as it enables a 360° view of the acetabulum and femoral head. Overall, posterior approaches are associated with low rates of complications, with heterotopic ossification being the most prevalent. The choice of surgical approach and patient positioning should be guided by the surgeon's preference and expertise, tailored to the specific fracture pattern and patient characteristics.

Management and Outcomes of Anterior Hip Dislocation with Multiple Comminuted Fractures from a Vehicular Crush Injury in a 44-Year-Old Woman

Management and Outcomes of Anterior Hip Dislocation with Multiple Comminuted Fractures from a Vehicular Crush Injury in a 44-Year-Old Woman

The push-through total femoral prosthesis for revision of a total hip or knee replacement with extreme bone loss.

The aim of the present study was to assess outcomes of using the push-through total femoral prothesis (PTTF) for revision total hip replacement with extreme bone loss. 10 consecutive patients who received PTTF between 2012 and 2018 for revision hip arthroplasty were included in the study. Primary functional outcomes were assessed using Harris Hip Score (HHS), Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) scores. Range of motion, complications, and ambulatory status were also recorded to assess secondary outcomes. 2 of 10 patients underwent surgery with PTTF for both knee and hip arthroplasty revision. The mean time between index surgery and PTTF was 15 years (3-32 yrs). Acetabular components were revised in 6 of 10 patients during PTTF application. After a mean follow-up of 5.9 years, hip dislocations occurred in 3 patients. All of the dislocated hips were ones with retained conventional non-constrained acetabular bearings. Patient satisfaction was high (MSTS: 67%, HHS: 61.2%, TESS 64.6%) despite high re-operation rate (40%) and minor postoperative problems. PTTF should be considered for hip and knee arthroplasty revision procedures in patients with an extreme bone defect. Consistent usage of constrained liners should be considered to avoid hip dislocation, which was our main problem following the procedure.

Intelligent diagnostic method for developmental hip dislocation

BackgroundDevelopmental dislocation of the hip joint (DDH) is a condition that severely threatens children’s healthy growth. Without timely and correct treatment, it will lead to osteoarthritis and hip dysfunction in the evolution of children.ObjectiveIt is essential to develop an intelligent model for diagnosing hip dislocation and performing accurate quantitative analysis.MethodsIn this paper, 46 cases of computed tomography (CT) images were retrospectively collected, including 19 cases of hip dislocation and 27 cases of healthy people. The experiment first uses ITK-SNAP to sketch the ilium and femoral head in the original image. Then, it uses 3D U-Net to send the label of the background, ilium, and femoral head into three channels, respectively, to realize the three-dimensional segmentation of the ilium and femoral head. Next, the extraction of the surface of the acetabulum and femoral head is performed. Subsequently, the erroneous points are eliminated, and the spherical surfaces of the acetabulum and femoral head are fitted using the least squares method. Ultimately, the spherical center distance is calculated quantitatively to predict whether the hip joint is dislocated.ResultsUnder the independent test set, the segmentation average dice coefficients of the ilium and femoral head are 89% and 93%, respectively. The spherical center distance between the acetabulum and femoral head is calculated quantitatively. If the value exceeds 10 mm, it is considered a hip dislocation. Compared with the doctor’s diagnosis, the accuracy result is 94.4%.ConclusionThis paper successfully implements a precise and automated intelligent diagnostic system for the identification of hip dislocation. Commencing with the development of a 3D segmentation algorithm for the ilium and femoral head, we further introduce a novel method that computes the spherical distance for the prediction of hip dislocation. This approach provides robust quantitative analysis, thereby facilitating more informed clinical decision-making.

Hip Instability in Children With Spinal Muscular Atrophy: A Retrospective Study.

Hip subluxation and dislocation are known problems for children with spinal muscular atrophy (SMA). Medical complexity of these children typically results in absence of monitoring and intervention for pathologic hips. Patterns of hip migration and acetabular morphology in SMA have not been described. This study examines the natural progression of hip instability across all types of SMA in a pediatric population. Following institutional review board approval, a retrospective chart review of all children with SMA at our institution was performed. All x-rays taken before the age of 18 years containing adequate projections of the pelvis were measured for Reimer migration index (MI), acetabular depth ratio (ADR), and acetabular index (AI). Demographics and clinical data were collected including use of nusinersen, ambulatory status, contractures, and hip pain. Linear mixed effects model was fit to serial MI measures of individual hips with fixed effects consisting of SMA type, age at x-ray, and their interaction. ADR and AI measures were similarly modeled following conversion of raw values to z-scores based on the model developed by Novais et al Slope indicated rate of measure change as a function of age. Forty-five children (22 males) with SMA types 1 to 3 were included in this retrospective study. Six children were classified as type 1, 25 were type 2, and 14 were type 3. The interaction of age by SMA type was statistically significant (P=0.01), indicating a difference in the rate of hip subluxation between the 3 SMA types as measured by MI. By age 4, MI values were different from one another across all 3 groups (P<0.01). ADR decreased with age across all SMA types. The slopes of ADR regression lines were negative and statistically significant between the 3 groups (P=0.002). AI values were higher for all types of SMA, which is the opposite of expected in normal hips. Hip subluxation occurs across all SMA types, most rapidly in SMA type 1. Regression lines of ADR and AI compared with those seen in unaffected populations suggest hips in children with SMA demonstrate a difference in morphology of the acetabulum and do not follow normal adaptive remodeling. As treatments advance and the population of SMA patients becomes more mobile, there is an increased need to monitor hip instability in children with SMA, thus making orthopaedic management an important consideration.

Long-term computed tomographic osteolytic analysis of highly cross-linked polyethylene prosthesis after total hip arthroplasty

To analyze the occurrence of osteolysis in total hip arthroplasty (THA) with highly cross-linked polyethylene prosthesis during a follow-up of more than 15 years. The clinical data of 84 patients (105 hips) treated with THA in the Affiliated Hospital of Kanazawa Medical University in Japan between June 2000 and April 2004 and met the selection criteria was retrospectively analyzed. There were 7 males and 77 females, aged from 41 to 75 years, with an average of 56.4 years. There were 94 hips with secondary hip osteoarthritis, 4 hips after pelvic osteotomy, 2 hips with primary hip osteoarthritis, 2 hips with traumatic hip osteoarthritis, 2 hips with osteonecrosis of the femoral head, and 1 hip with rheumatoid arthritis. According to Crowe classification, there were 79 hips of type Ⅰ, 19 hips of type Ⅱ, 6 hips of type Ⅲ, and 1 hip of type Ⅳ. The highly cross-linked polyethylene acetabular liner combined with a 26 mm zirconia femoral head were used in all patients. X-ray films were taken after operation to analyze the radiation transmission and osteolysis around the acetabular prosthesis. The vertical distance (the distance between the teardrop line at the lower edge of the pelvis and the perpendicular line of the hip rotation center), the horizontal distance (the horizontal distance between the hip rotation center and the interteardrop line and the vertical line at the lower edge of the teardrop), and the acetabular cup anteversion angle were measured at last follow-up. The acetabular and femoral osteolysis was analyzed by CT scan and three-dimensional multiplanar reconstruction (3D-MPR). Combined with X-ray film and CT results, osteolysis was evaluated according to the Narkbunnam score. Deep vein thrombosis of lower limbs occurred in 2 cases. All patients were followed up 15-18 years, with an average of 15.9 years. One hip dislocation and 1 periprosthetic fracture occurred postoperatively, and no acetabular loosening or prosthetic lining ruptures occurred. Except for 1 patient who had a radiolucent line in the acetabulum after operation, the other 83 patients did not show any radiolucent line in the acetabulum or the femur. None of the patients underwent hip revision. X-ray films at last follow-up showed an acetabular cup anteversion angle of -10°-39°, with an average of 22°; a vertical distance of 3.5-47.1 mm, with an average of 24.6 mm; and a horizontal distance of 22.6-48.1 mm, with an average of 31.7 mm. There was no acetabular or femoral osteolysis in all patients on X-ray films and CT 3D-MPR images at last follow-up, and the Narkbunnam score was 0 in any region. Highly cross-linked polyethylene prosthesis does not increase the risk of long-term complications such as osteolysis after THA.