Biomechanical analysis of load distribution in porcine hip joints at different acetabular coverages.

BACKGROUND: Developmental dysplasia of the hip causes secondary osteoarthritis. Finite element analysis suggests high hip joint contact pressure in patients with hip dysplasia and a reduction in contact pressure after periacetabular osteotomy. However, few biomechanical studies have examined the load distribution in the hip joint. This study aimed to investigate the biomechanical properties of load distribution in porcine hip joints at different acetabular coverages. METHODS: Six porcine hip joints were analyzed using three models: 1) neutral coverage, 2) 15° under-coverage (defined as dysplasia model), and 3) 15° over-coverage created by varying the acetabular coverage. The load distribution was assessed using a pressure-mapping sensor system after applying a loading force of 100 N to the hip joint. RESULTS: In the dysplasia model, the load was concentrated at the acetabular rim; in the neutral and over-coverage models, it was dispersed. The average contact pressure was significantly higher in the dysplasia model than in the neutral coverage model ([0.42 vs. 0.3 MPa]; p = 0.004). The contact area was significantly smaller in the dysplasia model than in the neutral coverage model ([250.7 vs. 345.0 mm2]; p = 0.004). No significant differences were observed in contact pressure or area between the neutral and over-coverage models. CONCLUSIONS: Insufficient acetabular coverage in the dysplasia model demonstrated higher contact pressure and smaller contact area than the neutral model. Conversely, the contact pressure and area in the over-coverage model did not differ significantly from those in the normal model. Therefore, surgeons should note that acetabular coverage overcorrection has limited effect; normalization is crucial during periacetabular osteotomy.

Is AI 3D-printed PSI an accurate option for patients with developmental dysplasia of the hip undergoing THA?

BACKGROUND: In traditional surgical procedures, significant discrepancies are often observed between the pre-planned templated implant sizes and the actual sizes used, particularly in patients with congenital hip dysplasia. These discrepancies arise not only in preoperative planning but also in the precision of implant placement, especially concerning the acetabular component. Our study aims to enhance the accuracy of implant placement during Total Hip Arthroplasty (THA) by integrating AI-enhanced preoperative planning with Patient-Specific Instrumentation (PSI). We also seek to assess the accuracy and clinical outcomes of the AI-PSI (AIPSI) group in comparison to a manual control group. METHODS: This study included 60 patients diagnosed with congenital hip dysplasia, randomly assigned to either the AIPSI or manual group, with 30 patients in each. No significant demographic differences between were noted the two groups. A direct anterior surgical approach was employed. Postoperative assessments included X-rays and CT scans to measure parameters such as the acetabular cup anteversion angle, acetabular cup inclination angle, femoral stem anteversion angle, femoral offset, and leg length discrepancy. Functional scores were recorded at 3 days, 1 week, 4 weeks, and 12 weeks post-surgery. Data analysis was conducted using SPSS version 22.0, with the significance level was set at α = 0.05. RESULTS AND CONCLUSION: The AIPSI group demonstrated greater prosthesis placement accuracy. With the aid of PSI, AI-planned THA surgery provides surgeons with enhanced precision in prosthesis positioning. This approach potentially offers greater insights and guidelines for managing more complex anatomical variations or cases.

Total hip arthroplasty with porous tantalum trabecular metal pads in patients with Crowe IV developmental dysplasia of the hip: a midterm followup study.

PURPOSE: Crowe IV developmental dysplasia of the hip (DDH) is a catastrophic hip disease. Moreover, obtaining ideal clinical efficacy in conventional total hip arthroplasty (THA) is often difficult. In this study, we aimed to assess the mid-term clinical results of THA with porous tantalum trabecular metal (TM) pads for acetabular reconstruction in the treatment of Crowe IV DDH. METHODS: A cohort of 28 patients (32 hips) diagnosed with Crowe type IV DDH who underwent acetabular reconstruction during THA using TM pads with scheduled follow-up between 2011 and 2018, were included in this study. Eight cases were men and 24 were women, with a mean age of 48.4 years (range, 36-72 years) and a mean follow-up was 74.3 months (range, 42-132 months). All patients underwent acetabular reconstruction using TM pads and total hip replacement with subtrochanteric osteotomy. RESULTS: At the final follow-up, 28 hips (87.5%) demonstrated mild or no postoperative limping. The Harris Hip Score improved from 58.4 ± 10.6 preoperatively to 85.6 ± 8.9. The mean pain, stiffness, and function scores on the Western Ontario and McMaster University Osteoarthritis index were 86.5 ± 10.2, 87.3 ± 12.4 and 85.4 ± 11.6 respectively. The mean score of patient satisfaction was 90.4 ± 7.6. Additionally, the SF-12 physical summary score was 41.8 ± 5.6 and the SF-12 mental summary score was 51.6 ± 5.4. TM construct survivorship due to all-cause failure was 90.6% at 5 years with 3 hips at risk, 87.5% at 10 years with 4 hips at risk. The survivorship due to failure from aseptic loosening was 96.9% at 5 years with 1hips at risk and 93.75% at 10 years with 2 hips at risk. CONCLUSION: This study demonstrated satisfactory mid-term clinical and radiological results with the application of TM pads for acetabular reconstruction combined with THA in patients with Crowe IV DDH. TRIAL REGISTRATION NUMBER: ChiCTR1800014526, Date: 18/01/2018.

Risk factors for avascular necrosis of the femoral head after developmental hip dislocation reduction surgery and construction of Nomogram prediction model.

BACKGROUND: To analyze the risk factors for the development of avascular necrosis (AVN) of the femoral head after reduction surgery in children with developmental hip dysplasia (DDH), and to establish a prediction nomogram. METHODS: The clinical data of 134 children with DDH (169 hips) treated with closure reduction or open reduction from December 2016 to December 2019 were retrospectively analyzed. Independent risk factors for AVN after DDH reduction being combined with cast external immobilization were determined by univariate analysis and multivariate logistic regression and used to generate nomograms predicting the occurrence of AVN. RESULTS: A total of 169 hip joints in 134 children met the inclusion criteria, with a mean age at surgery of 10.7 ± 4.56 months (range: 4-22 months) and a mean follow-up duration of 38.32 ± 27.00 months (range: 12-94 months). AVN developed in 42 hip joints (24.9%); univariate analysis showed that the International Hip Dysplasia Institute (IHDI) grade, preoperative development of the femoral head ossification nucleus, cartilage acetabular index, femoral head to acetabular Y-shaped cartilage distance, residual acetabular dysplasia, acetabular abduction angle exceeding 60°, and the final follow-up acetabular index (AI) were associated with the development of AVN (P < 0.05). Multivariate logistic regression analysis showed that the preoperative IHDI grade, development of the femoral head ossification nucleus, acetabular abduction angle exceeding 60°, and the final follow-up AI were independent risk factors for AVN development (P < 0.05). Internal validation of the Nomogram prediction model showed a consistency index of 0.833. CONCLUSION: Preoperative IHDI grade, preoperative development of the femoral head ossification nucleus, final AI, and acetabular abduction angle exceeding 60° are risk factors for AVN development. This study successfully constructed a Nomogram prediction model for AVN after casting surgery for DDH that can predict the occurrence of AVN after casting surgery for DDH.

An in-depth analysis of young adults with osteonecrosis secondary to developmental dysplasia of the hip who underwent total hip arthroplasty.

BACKGROUND: Patients with osteonecrosis of the femoral head secondary to DDH frequently require total hip arthroplasty (THA), but it is not well understood which factors necessitate this requirement. We determined the incidence of THA in patients who have osteonecrosis secondary to DDH and factors associated with need for THA. METHODS: We included patients who received closed or open reductions between 1995 and 2005 with subsequent development of osteonecrosis. We determined osteonecrosis according to Bucholz and Ogden; osteoarthritis severity (Kellgren-Lawrence), subluxation (Shenton's line); neck-shaft angle; and acetabular dysplasia (centre-edge and Sharp angles). We also recorded the number of operations of the hip in childhood and reviewed case notes of patients who received THA to describe clinical findings prior to THA. We assessed the association between radiographic variables and the need for THA using univariate logistic regression. RESULTS: Of 140 patients (169 hips), 22 patients received 24 THA (14%) at a mean age of 21.3 ± 3.7 years. Associated with the need for THA were grade III osteonecrosis (OR 4.25; 95% CI 1.70-10.77; p = 0.0019), grade IV osteoarthritis (21.8; 7.55-68.11; p < 0.0001) and subluxation (8.22; 2.91-29.53; p = 0.0003). All patients who required THA reported at least 2 of: severe pain including at night, stiffness, and reduced mobility. Acetabular dysplasia and number of previous operations were not associated with the need for THA. CONCLUSIONS: We identified a 14% incidence of THA by age 34 years in patients with osteonecrosis secondary to DDH. Grade III osteonecrosis (global involvement femoral head and neck) was strongly associated with THA, emphasising the importance to avoid osteonecrosis when treating DDH.

In-hospital complications and readmission patterns in 13,937 patients with developmental dysplasia of the hip undergoing total hip arthroplasty: Evidence from the Chinese national database.

PURPOSE: Clarifying the prognosis and readmission patterns of patients with developmental dysplasia of the hip (DDH) following total hip arthroplasty (THA) would provide important references for clinical management for this population. Using the Chinese national inpatient database (i.e., Hospital Quality Monitoring System [HQMS]), we aimed to compare in-hospital complications and readmission patterns following THA in patients with DDH and primary osteoarthritis (OA). METHODS: Patients undergoing THA for DDH and OA between 2013 and 2019 were identified using the HQMS. Demographics and clinical characteristics were compared between the two groups. After propensity score matching, in-hospital complications and readmission patterns were compared using a logistic regression model. RESULTS: According to the analysis of 13,937 propensity-score matched pairs, there were no significant differences in the incidence of in-hospital death (0.01 % vs 0.04 %, P = 0.142), transfusion (8.09 % vs 7.89 %, P = 0.536), wound infection (0.31 % vs 0.25 %, P = 0.364), deep venous thrombosis (0.45 % vs 0.43 %, P = 0.786), pulmonary embolism (0.03 % vs 0.05 %, P = 0.372) or all-cause readmission (2.87 % vs 3.12 %, P = 0.219) between two groups. However, DDH patients had higher surgical readmission rates than OA patients (1.43 % vs 1.14 %, P = 0.033). When analyzing causes of surgical readmission, DDH patients had increased risk of dislocation (0.37 % vs 0.21 %, P = 0.011) and aseptic loosening (0.17 % vs 0.07 %, P = 0.024) than OA patients. CONCLUSION: DDH patients had an increased risk of surgical readmission following THA, mainly driven by dislocation and aseptic loosening, which should be recognized and appropriately prevented.

Factors Influencing Noise Following Primary Ceramic-on-Ceramic Total Hip Arthroplasty.

BACKGROUND: The noise associated with ceramic-on-ceramic (CoC) total hip arthroplasty (THA) has been a concerning issue, while its underlying causes remain unclear. METHODS: We conducted a retrospective analysis of 119 patients (174 primary CoC THAs) who had a mean follow-up of 28 months (range, 12 to 106). A questionnaire was designed to collect information on nature, frequency, onset, duration, and impact of the noise. Postoperative x-rays were evaluated. Clinical evaluations, including Harris and Oxford hip scores, were documented at follow-up time points (6 weeks, 3 months, 6 months, and 1 year). RESULTS: Of the 174 hips, 31.6% reported noise, including 26 popping (14.9%), 24 clicking (12.1%), and 5 grinding (2.9%). No patients reported squeaking. Noisy hips had lower age (P = .009) and body mass index (P = .019). Among patients with developmental dysplasia of the hip, 17 of 55 hips reported noise associated with smaller cup anteversion angle (P = .004), greater body height (P = .022), and larger acetabular cup size (P = .049). Noise typically began at a mean of 193 days (range, 1 to 2,598) after surgery and disappeared spontaneously in 50.9% of hips before final follow-up, with an average disappearance time of 211 days (range, 60 to 730). Noise did not affect daily life in 74.5% of patients, while 26.9% of patients who had popping reported painful sensations. One patient experienced joint dislocation, and another experienced a ceramic liner fracture during follow-up. No statistical difference was observed in outcome scores between noise and silent groups at 4 follow-up time points. CONCLUSIONS: Incidence of noise after primary CoC THA is relatively high. Smaller cup anteversion and larger acetabular cup size were associated with noise production in patients who had developmental dysplasia of the hip.

Surgeon Recommendations for Physical Activity in Patients With Pediatric Hip Conditions.

BACKGROUND: While physical activity (PA) is important during youth, it is unclear if children and adolescents with developmental dysplasia of the hip (DDH), Legg-Calvé-Perthes disease (LCPD), or slipped capital femoral epiphysis (SCFE) are expected or encouraged to return to PA once they have healed. This study examines the orthopaedic surgeons' role in advising pediatric hip patients on the PA they should engage in, assessing their practice, opinions, and consensus when making recommendations. METHODS: Orthopaedic surgeons were invited from member lists of 4 hip study groups. The survey included demographics, opinions regarding PA, and 10 case scenarios that queried respondents on the duration and intensity of PA as well as the restrictions on activity type that they would recommend for DDH, LCPD, or SCFE patients. Consensus was evaluated on a scale ranging from 0 to 1, with a value of 0 indicating no agreement among respondents and a value of 1 indicating complete agreement. RESULTS: A total of 51 orthopaedic surgeons responded. While 94% agreed that it is important for school-aged hip patients to return to PA after they have healed, 53% believed that PA may compromise the hip and contribute to the development of osteoarthritis. Average standardized consensus was 0.92 for suggesting the patient engage in some amount of PA, 0.44 for suggesting the recommended daily minimum of 60 minutes of moderate-to-vigorous physical activity (MVPA), and 0.33 for suggesting restrictions on activity type. The most frequently selected restrictions included avoiding impact activities (93%, 235/254) and contact activities (58%, 147/254), followed by weight-bearing activities (24%, 62/254). Respondents were not aware of existing PA guidelines, although 57% expressed interest in following guidelines and 39% were uncertain. CONCLUSIONS: While there is consensus among orthopaedic surgeons that children with chronic hip conditions should engage in PA, there is considerable variation when recommending the recommended daily MVPA minimum and placing restrictions on activity type. This study suggests interest among orthopaedic surgeons in developing PA guidelines that optimize outcomes for pediatric hip patients. LEVEL OF EVIDENCE: Level II-Survey study.

Medial Protrusio Technique Versus Structural Autologous Bone-Grafting Technique in Total Hip Arthroplasty for Crowe Type II to III Hip Dysplasia.

BACKGROUND: It is unclear whether acetabular reconstruction techniques have any impact on clinical outcomes. This study aimed to determine (1) whether acetabular reconstruction techniques influenced the position of the acetabular cup and (2) whether clinical outcomes based on the acetabular reconstruction techniques differ in patients undergoing total hip arthroplasty (THA) with Crowe II to III developmental dysplasia of the hip. METHODS: This was a retrospective analysis of prospectively collected data from 69 patients (74 hips) who were treated with cementless THA using medial protrusio technique (MPT) or structural autologous bone-grafting technique (SABT). There were 39 patients (41 hips) included in the MPT group and 30 patients (33 hips) in the SABT group. Clinical and radiographic outcomes were evaluated. RESULTS: All patients were followed up for at least 3 years. There were similar results between the 2 groups in terms of blood loss, Harris hip score, leg length discrepancy, cup inclination, cup anteversion, and proportion of cup coverage (P > .05). The operative time was significantly longer in the SABT group compared with the MPT group (P < .001). The postoperative vertical center of rotation was significantly higher in the MPT group compared with the SABT group (P = .001), and postoperative horizontal center of rotation was significantly shallower in the SABT group compared with the MPT group (P < .001). CONCLUSION: The MPT and SABT provide similar clinical and radiographic outcomes in the management of Crowe II to III developmental dysplasia of the hip by cementless THA. However, the MPT has the advantage of a shorter operative time, whereas the SABT is more conducive to placing the acetabular cup in an anatomic position. LEVEL OF EVIDENCE: Level III, Therapeutic, Case-Control Study.

Family History of Developmental Dysplasia of the Hip is a Risk Factor for the Progression of Hip Osteoarthritis.

BACKGROUND: Developmental dysplasia of the hip (DDH) is considered to have genetic predisposition and presents many intrafamilial occurrences. However, there is no report that evaluates the effect of DDH family history on the progression after the onset of hip osteoarthritis (OA). METHODS: Medical interviews about detailed clinical information including family history were conducted on 298 consecutive patients who had undergone surgery for OA due to DDH. Clinical or radiographic items that are associated with the severity of DDH (total hip arthroplasty [THA], involvement of bilateral DDH, onset age of hip pain, and three radiological indices of DDH: center-edge angle, sharp angle, and acetabular roof obliquity) were collected and evaluated in multivariate analyses for their associations with DDH family history in a qualitative or quantitative manner. Survival time analyses for THA as the endpoint was also performed to evaluate the effects of DDH family history on the progression of OA. RESULTS: The DDH family history showed significant associations with bilateral involvement of DDH (odds ratio = 2.09 [95% confidence interval {CI} 1.05 to 4.16]; P = .037), early onset of hip pain (P = .0065), and radiological severity of DDH (P = .016). The DDH family history showed a significant association with undergoing THA (odds ratio = 2.25 [95% CI 1.09 to 4.66]; P = .029), further supported by the Cox regression analyses (hazards ratio = 1.56 [95% CI 1.15 to 2.11]; P = .0044). CONCLUSION: A DDH family history is a risk factor for the progression of hip OA. Stronger genetic predisposition to DDH leads to faster onset and progression of hip OA.

Innovative Hip Distraction Approaches for Total Hip Arthroplasty in Crowe IV Developmental Dysplasia or Similar High-Riding Patients.

BACKGROUND: Total hip arthroplasty (THA) for dislocated hips (Crowe IV dysplasia) presents unique challenges. Conventional approaches involve subtrochanteric osteotomies, but are complex with additional fixation and potentially lead to limb length discrepancies, nerve palsies, and other complications. An alternative strategy is a staged approach, where the femoral head (or remnant) is gradually lowered (distraction technique) to align with the true acetabulum over a period of time, followed by a second-stage anatomically acetabular-positioned THA. External fixation distraction and telescoping internal lengthening devices have been utilized to achieve preoperative alignment. We evaluated these techniques, including the types, time, and amount of distraction needed, as well as outcomes and complication rates. METHODS: In this retrospective case series, 14 patients (9 women, 5 men), who had a mean age of 32 years (range, 16 to 67), underwent staged surgical interventions using hip distraction using external fixators or internal lengthening devices for hip dysplasia and other pathologies (Perthes disease, osteonecrosis) in preparation for a second-stage anatomically placed THA. The mean follow-up duration for external-fixation patients was 10 years (range, 6.5 to 13.4). RESULTS: Staged treatment involved external fixators (n = 8) or internal lengthening devices (n = 6) with a device placement mean of 48 days (range, 42 to 71). The amount of distraction ranged from 6 to 12 cm. There were 2 patients who required uncomplicated revision of the internal lengthening devices, and another patient had a temporary peroneal nerve palsy. There was 1 patient who underwent an acetabular revision at 7 years. CONCLUSIONS: We focused on a challenging patient cohort that emphasizes the efficacy of staged interventions in managing Crowe Type IV dysplasia and similar cases. Favorable outcomes were found with the immediate transition to THA after device removal that effectively addressed soft-tissue contractures and femoral migration. Despite the need for further validation via larger, prospective studies, this innovative approach may pave the way toward optimizing this strategy for these difficult hip pathologies.

Cementless Total Hip Arthroplasty With Paavilainen Femoral Shortening Osteotomy Can Provide Good Results at 10 Years in Patients Who Have Crowe IV Developmental Dysplasia of the Hip.

BACKGROUND: The aim of this study was to present the clinical and radiologic results of primary total hip arthroplasty (THA) using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV developmental dysplasia of the hip. METHODS: We retrospectively analyzed the results of primary THA using the Paavilainen technique in 335 hips. The mean follow-up was 10.2 years. The degree of limp, leg-length discrepancy, and patient satisfaction were assessed. The Oxford Hip Score was used to examine functional outcomes. A number of radiographic parameters were also assessed. RESULTS: The most common reason for revision surgery was nonunion of the distally advanced greater trochanter. This complication was observed in 22 hips (6.5%). The 10-year survival for acetabular components, it was 97.3%, and for femoral components was 98.7% with aseptic loosening as the end point, and 85.9% with reoperation for any reason as the end point. Patients demonstrated improved functional outcomes. The mean limb lengthening was 27.8 mm. Nonunion was more common if the contact length of the proximal femoral fragment with the lateral surface of the distal femoral fragment was less than 35 mm. CONCLUSIONS: Cementless primary THA using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV dysplasia of the hip demonstrates good clinical and radiologic postoperative results. If the contact between the fragments after osteotomy is less than 35 mm, there is a high risk of nonunion, and supplemental fixation may be warranted.

Twelve to Twenty-year Follow-up of Dega Acetabuloplasty in Patients With Developmental Dysplasia of the Hip: Is it as Effective as Expected?

BACKGROUND: Although Dega acetabuloplasty is widely used for the treatment of developmental dysplasia of the hip, there is a paucity of data on long-term outcomes. The purpose of the study was to evaluate the rate of residual acetabular dysplasia after Dega acetabuloplasty. METHODS: Patients of a previously reported consecutive series of 35 patients (43 hips) operated by a single surgeon were recontacted for long-term follow-up. Of these, 25 patients (32 hips) consented, with a follow-up rate of 71% (74% of hips). The mean age at the time of surgery was 35 (18 to 65) months. The presence of residual dysplasia was noted according to the lateral center-edge angle of Wiberg, femoral head extrusion index, and Tönnis angle. The latest radiographic outcome was evaluated according to the Severin classification and patients were clinically evaluated according to the modified McKay criteria. RESULTS: The mean follow-up duration of 16.5 (12 to 20) years yielded an average age of 19.2 (14 to 23) years at the time of analysis. According to lateral center-edge angle, femoral head extrusion index, and Tönnis angle, 5 (15.6%) hips were dysplastic and 2 (6.3%) hips were reoperated for resubluxation. Thus, a total of 7 hips (21.9%) were considered to have residual dysplasia. With the exception of 2 hips that underwent further osteotomies, no other hips were re-subluxated or redislocated. Overcoverage was noted in 6 (18.7%) hips. There were 26 Severin group I and II (81.3%), 4 Severin group III (12.5%), and 2 Severin group IV (6.2%) hips. According to modified McKay criteria, 20 (62.5%) hips were excellent, 7 (21.9%) hips were good, and 5 (15.6%) were fair. Severin classification and modified McKay criteria were correlated with dysplasia ( P < 0.05). CONCLUSIONS: Seventy-eight percent of the hips treated by Dega acetabuloplasty for developmental dysplasia of the hip did not have acetabular dysplasia at a mean follow-up of 16 years. Even in well-treated asymptomatic hips, patients should be followed regularly, especially for residual dysplasia. LEVEL OF EVIDENCE: Level IV.

Intraoperative 3D Fluoroscopy During Open Reduction for DDH: An Effective Alternative to Postoperative CT/MRI.

BACKGROUND: Computed tomography CT or magnetic resonance imaging (MRI) has been the most used imaging modality to assess hip reduction in developmental dysplasia of the hip (DDH) after open reduction (OR). In 2015, intraoperative 3D fluoroscopy (3D) was introduced at our center as an alternative to CT/MRI. 3D offers the advantage that if hip reduction is insufficient, it can be addressed at the time of surgery. The purpose of this study was to assess the efficacy of 3D in comparison to CT/MRI. METHODS: This was a single-centre, retrospective comparative study of two consecutive cohorts: those with OR and 3D between 2015 and 2017 and those with OR and CT/MRI between 2012 and 2014. Time to imaging, re-imaging, length of stay (LOS), re-operation, and redislocation or subluxation after cast removal were evaluated. RESULTS: Forty-two patients (46 hips) had 3D, and 30 patients (32 hips) had CT/MRI. Significant differences were found between groups in time to imaging, cast changes, and LOS. All 3D was intraoperative (46 hips), and only 69% (22 hips) of CT/MRI was on the day of surgery ( P <0.01). In the 3D group, 1 hip (2%) had a cast change under the same anesthetic, and 4 hips (13%) from CT/MRI had cast changes in subsequent surgery ( P =0.03). The mean LOS in days for 3D was 1.72 and 2.20 for CT/MRI ( P =0.03). There were no statistically significant differences between groups in further imaging and subluxations or re-dislocations at cast removal. Two hips (4%) in the 3D group had MRI, but with no further intervention ( P =0.51), and at cast removal, there were 3 subluxations in each group ( P =0.69) and 1 redislocation in the 3D group ( P =1.00). CONCLUSIONS: Intraoperative 3D improved time to imaging, allowed for cast changes at surgery and had a shorter LOS. Moreover, there were no significant differences found in adverse outcomes between those who underwent 3D versus CT/MRI. 3D should thus be considered an effective alternative to CT/MRI for assessing hip reduction during OR for DDH. LEVEL OF EVIDENCE: Diagnostic Study, level II.

Arthroscopic debridement and reduction is an effective procedure for failed closed reduction in young children with developmental dislocation of the hip.

PURPOSE: To assess the efficacy of arthroscopic debridement and reduction through two medial portals for the treatment of developmental dislocation of the hip (DDH) with failure of initial closed reduction and to explore key pathological structures obstructing reduction. METHODS: Forty-eight children with 58 irreducible dislocated hips treated by arthroscopic reduction between January 2017 and December 2020 were retrospectively evaluated. Arthroscopic reduction was performed via two medial portals located in the superior and inferior adductor longus. All intra-articular obstacles were eliminated via arthroscopy, followed by manual reduction and spica cast immobilization. The surgical duration, extent of improvement in the safe zone, and extent of secondary surgical treatment were noted. All the children were followed up for > 24 months. Hip function and radiographic outcomes were evaluated. RESULTS: All 58 hips showed safe zone improvement and concentric reduction after arthroscopic debridement. Hypertrophic ligamentum teres and thickened pulvinars were detected and resected in all hips. Constrictive capsules preventing reduction were observed in 15 hips, which needed to be further released. No inverted labrum was observed. Secondary surgery was performed in four hips with redislocation and seven hips with subluxation during follow-up. The remaining 47 hips (81.03%) maintained their reduction at the last follow-up. Excellent and good clinical outcomes were achieved in 95.74% of patients according to McKay's criteria. Two hips, three hips, and one hip were diagnosed with grade I, II, and III osteonecrosis of the femoral head, respectively. CONCLUSION: This study demonstrated that arthroscopic debridement and reduction is a safe and feasible choice for treating irreducible DDH.

A novel intraoperative acetabular reaming center locating method in total hip arthroplasty for Crowe type IV developmental dysplasia of the hip: a retrospective cohort study.

PURPOSE: Although the principles of hip reconstruction are consistent, due to lack of reliable anatomical landmarks, how to decide the acetabular cup reaming centre intraoperatively in Crowe IV patients with developmental dysplasia of the hip (DDH) remains unclear. This study aims to address this question. METHODS: Fifty-eight Crowe IV patients were enrolled from 2017 to 2019. By examining our previous clinical data, we analyzed the anatomical morphology of Crowe IV acetabulum and proposed a method of locating intraoperative reaming centering for implantation of a standard-sized acetabular cup, which is the upper two thirds of the posterior border of the true acetabulum. All patients included in this study were reamed according to this method. The average postoperative follow-up was 4.1 years (3-5 years). The position of the centre of rotation (COR), cup coverage (CC), and optimal range of joint motion (ROM) were examined by 3D computer simulation measurement. Postoperative complications and hip Harris score were collected and analyzed. RESULTS: The morphology of the type IV DDH true acetabulum was mostly triangular. The intraoperative reaming centre were centered on the upper two thirds of the posterior border of the true acetabulum. The postoperative 3D CC was 80.20% ± 7.63% (64.68-90.24%, 44-48-mm cup size). The patients' mean Harris score improved from 39.7 ± 20.4 preoperatively to 91.5 ± 8.12 at the last follow-up. CONCLUSION: Our study demonstrated that satisfactory CC and clinical results could be achieved by implanting a standard-sized cup with the reaming centre on the upper two thirds of the posterior border of the true acetabulum.

An Eastern Europe and Middle East multinational expert Delphi consensus study on the prevention, diagnosis, and treatment of developmental dysplasia of the hip before walking age.

PURPOSE: The incidence of developmental dysplasia of the hip (DDH) is higher in Eastern Europeans and Middle Easterners. This study aimed to establish consensus among experts in this geographical area on the management of DDH before walking age. METHODS: Fourteen experienced orthopedic surgeons agreed to participate in a four-round online consensus panel by the Delphi method. The questionnaire included 31 statements concerning the prevention, diagnosis, and treatment of DDH before walking age. RESULTS: Consensus was established for 26 (84%) of 31 statements. Hip ultrasonography is the proper diagnostic tool under six months in DDH; universal newborn hip screening between three and six weeks is necessary; positive family history, breech presentation, female gender, and postnatal swaddling are the most important risk factors; Ortolani, Barlow tests, and limitation of abduction are the most important clinical findings; Pavlik harness is the first bracing preference; some Graf type IIa hips and all Graf type IIb and worse hips need abduction bracing treatment; the uppermost age limit for closed and open reductions is 12 months and 12-24 months, respectively; anatomic reduction is essential in closed and open reductions, postoperative MRI or CT is not always indicated; anterior approach open reduction is better than medial approach open reduction; forceful reduction and extreme positioning of the hips (> 60° hip abduction) are the two significant risk factors for osteonecrosis of the femoral head. CONCLUSION: The findings of the present study may be useful for clinicians because a practical reference, based on the opinions of the multinational expert panel, but may not be applicable to all settings is provided.

Robotic-assisted total hip arthroplasty in patients with developmental dysplasia of the hip.

PURPOSES: Due to the morphological diversity of deformities, technical difficulties, improperly designed components, and so on, THA remains a challenging task in dysplastic hips, especially in highly dislocated hips. The purpose of this study was to comprehensively evaluate the clinical outcomes of robot-assisted THA in patients with DDH through a large cohort study, including the precision of acetabular cup positioning, indicators of inflammatory response, indicators of muscle damage, and complications. METHODS: We retrospectively analyzed patients with DDH who underwent THA in our prospectively constructed joint registry between August 2018 and August 2022. Finally, 147 manual THAs and 147 robotic-assisted THAs were included in the final analysis. Patient demographics, indicators of inflammation, indicators of muscle damage, operative time, Harris hip scores (HHS), and forgotten joint score (FJS) were recorded for analysis. The precision of the positioning of the acetabular component was assessed with plain radiographs. RESULTS: In the Crowe II/III groups, the reconstructed center of rotation (COR) in the robotic-assisted group was closer to the anatomical COR with less variation than the manual group (absolute horizontal distances of COR 3.5 ± 2.8 vs. 5.4 ± 4.9 mm, p < 0.05; absolute vertical distances of COR 6.4 ± 4.1 vs. 11.7 ± 8.2 mm, p = 0.001). For all Crowe subtypes, the robotic-assisted THA significantly increased the proportion of acetabular cups located in the safety zone within 5° (all p < 0.05). Interleukin-6 and creatine kinase levels were slightly lower and significantly different in the robotic-assisted group at three days postoperatively (all p < 0.05). CONCLUSIONS: Compared to the manual technique, the robot-assisted technique improved the precision and reproducibility of acetabular component positioning, particularly in DDH patients with Crowe types II/III. The robotic-assisted technique did not increase operative time, bleeding, complications, or revision rates, and had a slighter early inflammatory response and muscle damage.

Risk factor analysis of femoral avascular necrosis after operation for Tönnis grade IV developmental dysplasia of the hip.

PURPOSE: We explored the risk factors for avascular necrosis (AVN) after surgery using open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV developmental dysplasia of the hip (DDH). METHODS: In this retrospective study, we collected data of patients with Tönnis grade IV DDH treated with open reduction and pelvic osteotomy combined with femoral osteotomy from January 2012 to May 2020. The patients were divided into the AVN group and non-AVN group using the Kalamchi-MacEwen classification system. The clinical and imaging data of the two groups were collected, and the possible risk factors were included in the analysis. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors and odds ratios of AVN. RESULTS: In all, 254 patients (mean age; 2.6±0.9 years, 278 hips) were included. The mean follow-up time was 3.8±1.5 years. A total of 89 hips (32%) were finally classified as AVN (Kalamchi-MacEwen II-IV). Univariate analysis showed significant associations with AVN for age (p=0.006), preoperative femoral neck anteversion (FAV) (p<0.001), femoral osteotomy length to dislocation height ratio (FDR) <1 (p<0.001), and the epiphyseal ossific nucleus diameter to the neck diameter ratio (ENR) <50% (p=0.009). Multivariate logistic regression analysis showed that only excessive preoperative FAV (OR: 1.04; 95% CI: 1.02-1.05; p<0.001) and FDR<1 (OR: 3.58; 95% CI: 2.03-6.31; p<0.001) were independent risk factors for femoral head necrosis. CONCLUSION: Excessive preoperative FAV and FDR<1 are important risk factors for femoral AVN after open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV DDH. For children with DDH with high dislocation and excessive FAV, clinicians should fully evaluate their condition and design more personalized treatment programs to prevent AVN.

Open reduction after failed closed reduction following failed Pavlik harness treatment in developmental dysplasia of the hip: One- or two-stage?

INTRODUCTION: The current published evidence for the treatment of developmental dysplasia of the hip (DDH) with failed closed reduction (CR) following failed Pavlik harness (PH) treatment is still limited. This study aimed to determine whether an one-stage open reduction (OR) would lead to a similar outcome to a two-stage OR in these patients. Meanwhile, the occurrence of femoral head avascular necrosis (AVN) and further surgery (pelvic osteotomy, PO) within the follow-up period was investigated. MATERIALS AND METHODS: A consecutive series of DDH patients who failed CR following failed PH treatment and received OR finally between January 2008 and December 2020 were studied. The patients were divided into two groups. One group of which received OR immediately after failed CR (one-stage OR group, Group A), and the other received a delayed OR (two-stage OR group, Group B). The McKay's criteria, acetabular index (AI) and the degree of dislocation of the hips were evaluated for the final outcomes. RESULTS: At the last follow-up, 54 (84.4%) of the 64 hips in Group A and 26 (83.9%) of 31 hips in Group B were in excellent or good condition. Comparison between the two groups revealed that there were no differences in terms of McKay grading (P = 0.950), AI (P = 0.783), incidence of AVN (P = 0.745), and also incidence of PO (P = 1.000). However, a significant lower mean AI was found in Group A, when the OR was performed in Group B (31.06 ± 4.45° vs. 33.87 ± 4.12°, P = 0.004). CONCLUSION: Both of the one- and two-stage OR may acheive favorable outcomes. Moreover, one-stage OR is of without the general anesthesia risk associated with two-stage OR. We therefore advocate that an OR should be performed in appropriate DDH patients during the same session once a failed CR is detected.