ObjectiveTo compare the short-term clinical and radiographic outcomes of a 3D-printed trabecular titanium acetabular cup system (AK Medical, Beijing, China) with a conventional porous titanium-coated acetabular cup system (Pinnacle Gription Sector Acetabular System, DePuy Synthes/Johnson & Johnson, USA) in primary total hip arthroplasty (THA) for Crowe type I–III developmental dysplasia of the hip (DDH) with limited acetabular bone defects not requiring metal augments or structural bone grafting.MethodsThis retrospective study included 104 patients (105 hips) who underwent primary THA for DDH between January 2022 and July 2023, including 51 hips in the 3D-printed trabecular titanium cup group and 54 hips in the conventional porous titanium-coated cup group, with a mean follow-up of approximately 24 months. The primary outcome was the proportion of cups meeting at least 3 of the 5 Moore radiographic criteria at final follow-up, with early revision classified as failure of the index cup. VAS and HHS were analyzed using patient-clustered generalized estimating equations (GEE). The primary radiographic endpoint was compared using Fisher's exact test, with stabilized inverse probability of treatment weighting (IPTW) used as an adjusted sensitivity analysis.ResultsOperative time, intraoperative blood loss, length of stay, and postoperative acetabular cup position parameters were similar between groups. VAS scores were lower in the 3D-printed cup group at 1 week, 1 month, and 3 months postoperatively. A significant group-by-time interaction was observed for HHS; HHS was higher in the 3D-printed group at 1 and 6 months, the between-group difference at 3 months did not reach statistical significance, and outcomes were similar between groups from 12 months onward. In the primary analysis, which conservatively classified early revision as failure, the proportions meeting the prespecified final-follow-up radiographic criterion were 46/51 (90.2%) and 40/54 (74.1%), respectively (P = 0.042; crude OR = 3.22, 95% CI: 1.07–9.73). After stabilized IPTW, the weighted proportions were 92.9% and 75.7%, with a weighted OR of 4.21 (95% CI: 1.35–13.17, P = 0.013). In the serial-radiograph subset of 82 hips, the proportions meeting the ≥3/5 Moore criterion at 3 and 6 months were similar between groups and increased over time; P for the group-by-time interaction was 0.097. Complication events were infrequent, and safety findings were interpreted descriptively.ConclusionIn primary THA for Crowe type I–III DDH with limited acetabular bone defects not requiring augments or structural bone grafting, the 3D-printed trabecular titanium acetabular cup system was associated with a higher proportion of hips meeting the final-follow-up radiographic integration endpoint and with better early VAS and HHS outcomes. No clear early between-group difference in the radiographic endpoint was observed at 3 or 6 months. This study compared two specific implant systems; longer follow-up is required to evaluate long-term fixation and implant survivorship.

BACKGROUND Crowe type IV developmental dysplasia of the hip (DDH) is characterized by complete proximal subluxation/dislocation of the femoral head, a small hypoplastic true acetabulum, and marked proximal femoral deformity. Total hip arthroplasty (THA) in Crowe IV DDH often requires femoral osteotomy for safe reduction. This retrospective study compared THA combined with low femoral neck osteotomy (LRNO) vs subtrochanteric osteotomy (SO). MATERIAL AND METHODS We reviewed 73 patients with Crowe IV DDH who underwent unilateral cementless THA from January 2017 to June 2024 (LRNO, n=37; SO, n=36). Primary outcomes were the Harris Hip Score (HHS) and Oxford Hip Score (OHS) at 12 months; scores were also assessed at 1, 3, and 6 months. Secondary outcomes included operative time, blood loss/transfusion, incision length, postoperative leg length discrepancy (LLD), perioperative laboratory changes, and complications. RESULTS Baseline characteristics were comparable (P>0.05). LRNO achieved higher HHS and OHS at 1 and 3 months (both P<0.001), with no between-group differences at 6 or 12 months (both P>0.05). LRNO had shorter operative time (P<0.001), smaller incision (P<0.001), less blood loss (P=0.002), lower transfusion requirements (blood, P<0.001; plasma, P=0.003), smaller postoperative LLD (P<0.001), and smaller decreases in hemoglobin and albumin (both P<0.001) than SO. Complication rates did not differ (P>0.05). CONCLUSIONS In Crowe IV DDH, THA with LRNO provides faster early functional recovery and improved perioperative efficiency with comparable 12-month function and short-term safety to SO.

Background:The impact of fracture reduction quality on clinical outcomes in hip arthroplasty for intertrochanteric fractures remains insufficiently characterized. This study aimed to establish a standardized postoperative radiographic evaluation system for reduction quality and assess its correlation with postoperative function and complications. Methods:A retrospective cohort study included 237 patients undergoing hip arthroplasty for intertrochanteric fractures (2012-2024). Reduction quality was classified as optimal, acceptable, or poor based on four criteria: (1) greater trochanter alignment, (2) lesser trochanter reduction, (3) femoral stem stability, and (4) postoperative femoral anteversion (optimal: 13 ± 3°; acceptable: 6-10° or 16-20°; poor: <6° or >20°). Outcomes included Harris Hip Scores, Engh's scores, delayed healing, and complications. Statistical analyses were adjusted for AO/OTA fracture classification. Results:Optimal reduction (Grade A, n = 107) correlated with superior Harris Hip Scores (92.57 ± 4.27 vs. 82.46 ± 7.05, P < 0.001), lower delayed healing (3.74% vs. 14.29%, P = 0.031), and reduced abductor weakness (1.87% vs. 14.29%, P = 0.014). Acceptable reductions (Grade B, n = 74) showed intermediate outcomes. Poor reductions (Grade C, n = 56) exhibited the highest complication rates. Engh's scores were significantly higher in Grade A (97.20% vs. 73.21%, P = 0.002). Dislocation and heterotopic ossification rates did not differ significantly (P > 0.05). Conclusion:This study introduced and validated a standardized radiographic evaluation system to assess reduction quality in arthroplasty for intertrochanteric fractures, emphasizing the prognostic importance of anatomic trochanteric alignment and cortical continuity. High-quality reduction is critical for optimizing functional recovery and minimizing complications in arthroplasty for intertrochanteric fractures. Future research should explore long-term outcomes and advanced fixation techniques to enhance reduction precision.

Hip preservation surgery with vascularized iliac bone flap transplantation is currently an important method for treating patients with early-stage femoral head necrosis and collapse. However, if hip preservation fails, total hip arthroplasty (THA) is the only treatment option. This study aimed to compare the clinical efficacy and complications of direct anterior (DAA) and posterior (PA) approaches for subsequent THA in patients with failed hip preservation. The data of patients who initially underwent vascularized iliac crest bone grafting for hip preservation, and subsequently progressed to end-stage hip osteonecrosis which required THA from January 2013 to March 2020 were retrospectively analysed. These patients were divided into two groups (group DAA; group PA). Baseline information of the included patients was collected. Surgical time, blood loss, and perioperative complications were compared between the two groups. Visual analog scale (VAS) results were recorded for all patients at 1, 3,and 6 months postoperatively to assess the severity of pain. Harris hip scores (HHS) were evaluated at 3, 6, and 12 months postoperatively to assess hip joint function recovery. Radiographic measurements were used to evaluate prosthesis placement. The study included 62 patients (62 hips), with 28 patients (28 hips) in the DAA group and 34 patients (34 hips) in the PA group. The two groups were well-balanced in terms of basic characteristics (p > 0.05). Perioperative outcomes comparison revealed that in subsequent THA surgeries, PA was associated with significantly longer surgical time and greater intraoperative blood loss than DAA (p < 0.05). Patients who received THA in the direct anterior approach experienced less pain The direct anterior approach demonstrated superior pain relief within the first month and third month postoperatively compared to the posterior approach (p < 0.05). Furthermore, at the 3-month follow-up, patients receiving DAA had significantly higher HHS scores than those undergoing PA, suggesting enhanced joint function recovery benefits from DAA (79.54 ± 7.91 vs. 76.62 ± 7.76, p = 0.000). In cases where vascularized iliac crest bone grafting for hip preservation fails, subsequent THA performed via DAA appears to result in shorter surgical time and less intraoperative blood loss compared to PA. However, compared with PA, DAA seems to have a higher risk of complications, so surgeons need to be extra cautious during surgery.

Objective: In hip disease patients, pain and movement restrictions might cause changes in bone strength and increase the likelihood of falls, finally leading to hip fracture. The aim of this study was to identify the incidence of, characteristics of and risk factors for hip fracture in patients with existing hip disease. Methods: This was a retrospective cohort study. Patients with existing hip disease treated at both outpatient and inpatient departments of our institute were identified by searching the electronic medical record system and followed retrospectively for the occurrence of hip fracture. Demographic and clinical characteristics, such as age, sex and kind of primary hip disease, were collected from the electronic medical record system. The incidence and timing of hip fracture were estimated, and a Cox regression model was built to identify the independent risk factors for hip fracture in these patients. Results: A total of 9710 eligible patients were included. After a mean follow-up of 3.97 years, hip fractures were identified in 95 patients, for an estimated incidence of hip fracture of 978.37 per 100,000 patients. The femoral neck was involved in 49 fractures (51.58 %), and the femoral trochanter was involved in 45 fractures (47.37 %). Four independent risk factors and one protective factor for hip fracture in patients with hip diseases were identified: age (HR = 1.116, 95 % CI = 1.094–1.138), the presence of osteonecrosis of the femoral head (HR = 2.201, 95 % CI = 1.217–3.980), a lower Harris hip score (HR = 0.966, 95 % CI = 0.949–0.982), a history of previous hip surgery (HR = 2.126, 95 % CI = 1.304–3.466) and the use of walking aids (HR = 0.588, 95 % CI = 0.354–0.975). A scoring system with a total score of 20 points was built, which included all of the above risk factors. The predictive scores for a low risk (estimated incidence of hip fracture ≤30 %), a moderate risk (estimated incidence of hip fracture 31 %–69 %), and a high risk (estimated incidence of hip fracture ≥70 %) of hip fracture were ≤8.5 points, 9.0–13.0 points and ≥13.5 points, respectively. Conclusion: The incidence of hip fracture in the special population of patients with existing hip disease was determined. Elderly patients, patients with a history of hip surgery, patients with osteonecrosis and patients with poor Harris hip scores were at increased risk of hip fracture. In patients with a predictive score greater than 9 points, indicating a moderate to high risk of hip fracture, the use of a walking aid might reduce the risk of hip fracture.

BackgroundThe soft-tissue tension is closely associated with postoperative hip dislocation in patients undergoing total hip arthroplasty (THA), especially for those patients with neurological disorders and insufficient muscle tension. The aim of this study is to explore the effect of limb lengthening on the incidence of complications following THA in patients with neurological disorders and insufficient muscle tension.MethodsThis retrospective analysis examines individuals with neurological disorders, such as ischemic stroke and poliomyelitis, who underwent primary total hip arthroplasty (THA) at our medical center between January 2015 and April 2021. Demographic and baseline characteristics (such as age, gender, muscle strength) were obtained from medical records. The limb length, offset and the positional parameters of both acetabular and femoral component were measured on pre- and postoperative plain radiograph. The primary outcome was the occurrence of hip dislocation. The secondary outcome included the incidence of other complications and the hip function (determined by Harris score). The correlation between the occurrence of hip dislocation and limb lengthening was analyzed.ResultsA total of 258 patients were finally analyzed. The hip dislocations were identified in 35 patients (overall incidence = 13.57%). The incidence of early dislocation was lower in patients whose limb-length discrepancy (LLD) was over 20 mm (incidence = 4.1% for LLD >20 mm, 12.2% for LLD 10 mm–20 mm and 17% for LLD <10 mm). The odds ratio (OR) was 0.206 and 95% confidence interval (CI) was 0.058–0.737 (compared between LLD <10 mm and LLD >20 mm). But the no difference was identified regarding on the incidence of late dislocation among patients with different LLD. Moreover, the overall incidence of other complications was elevated in patients with LLD >20 mm (incidence = 17.58% for LLD >20 mm, 11.11% for LLD 10 mm–20 mm and 3.19% for LLD <10 mm; OR = 6.464, 95% CI = 1.768–23.640). And the Harris scores, which reflected the hip function, was gradually decreased with the increasing in LLD. In terms of the relationship between the offset and dislocation rate, it was found that increased offset discrepancy was associated with decreased dislocation incidence (incidence = 4.71% for offset discrepancy >10 mm, 12.5% for offset discrepancy 5 mm–10 mm and 17.20% for offset discrepancy <5 mm; OR = 0.238, 95% CI = 0.076–0.742). Furthermore, increased offset discrepancy also bring a reduction in late dislocation. The incidences of late dislocation were 0%, 2.5% and 10.8% for offset discrepancy >10 mm, offset discrepancy 5 mm–10 mm and 17.20% for offset discrepancy respectively. Different from that of LDD, the incidences of other complications were similar among patients with different offset discrepancy. Besides, no influence of offset discrepancy on the hip function was identified in this study.ConclusionUnfortunately, although increasing in limb length could partially reduce early dislocation postoperatively, it could not affect the incidence of late dislocation in those patients with neurological disorders and insufficient muscle tension. Moreover, over limb lengthening was associated with other postoperative complications and worse hip function. Instead, additional offset could reduce the probability of postoperative dislocation, without increasing the incidence of other complications. Therefore, femoral stem with lower cervico-diaphyseal angle (higher offset) should be recommended to patients with neurological disorders who were in high risk of postoperative dislocation. Isolated increasing in limb length should be avoided.

BACKGROUND he present study was performed to evaluate the clinical efficacy of Tri-Lock bone preservation stems vs conventional Corail stems in primary total hip arthroplasty via direct anterior approach. MATERIAL AND METHODS In this retrospective analysis, patients receiving THA via DAA in a single-center hospital from January 2019 to March 2020 were assessed for eligibility and assigned to either a Tri-Lock BPS group or a Corail group based on the use of prostheses. Outcome measures for the efficiency evaluation of the 2 prostheses included perioperative outcomes, imaging results, Harris Hip Score, Western Ontario and McMaster University Osteoarthritis Index, and visual analog scale scores at 3, 6, 12, and 24 months postoperatively. RESULTS A total of 204 patients were included, including 98 patients (98 hips) in the Tri-Lock BPS group and 106 patients (106 hips) in the Corail group. Patients receiving Tri-Lock BPS exhibited better pain relief than those with Coral stems. Tri-Lock BPS had a higher safety profile vs Corail stems by significantly reducing the risk of complications (P=0.004). A markedly increased HHS score (84.42±16.27 vs 78.61±12.78, P=0.002) and a lower WOMAC score (25.08±15.39 vs 32.14±11.56, P=0.001) at 3 months postoperatively were observed in patients with Tri-Lock BPS vs those with Corail stems, indicating better restoration of hip function using Tri-Lock BPS. CONCLUSIONS During total hip arthroplasty via DAA, Tri-Lock BPS causes a smaller surgical wound, reduces the operative time and intraoperative bleeding, and produces less soft-tissue damage vs Corail stems, providing great benefits in femoral prosthesis placement.

BACKGROUND This study was performed to evaluate the clinical effectiveness of needle aspiration vs surgical excision for symptomatic synovial cysts of the hip. MATERIAL AND METHODS This retrospective study analyzed the clinical data of patients diagnosed with synovial cysts of the hip and treated in a single-center hospital from January 2012 to April 2022. Patients receiving needle aspiration were assigned to group A and those treated with surgery were assigned to group B. Demographic characteristics, etiology, symptoms, cyst location, postoperative complications and recurrence, Harris Hip Score (HHS) and Visual Analog Scale of Pain (VAS) scores before treatment and at 3, 6, and 12 months after treatment were recorded to assess hip function in both groups. RESULTS This study recruited 44 patients, with 18 patients in group A and 26 in group B, and the 2 arms were well-balanced in terms of baseline patient profiles. Needle aspiration resulted in significantly better pain mitigation for patients at 24 h, 48 h, and 72 h after treatment vs surgical interventions (P<0.05). Needle joint aspiration resulted in significantly better function restoration of the hip joint than surgery at 3 months after treatment, as evidenced by the lower HHS score of 85.31±13.16 in group A vs 78.51±11.66 in group B (P=0.002). Surgery was associated with a significantly lower incidence of disease relapse (0.00%) vs needle aspiration (27.7%) (P=0.004). CONCLUSIONS Needle aspiration in the treatment of symptomatic synovial cysts of the hip causes less damage to the soft tissue and leads to faster recovery in the short term than surgical resection. Surgical resection has a lower recurrence rate and better long-term efficacy.

BACKGROUND This retrospective study from a single center aimed to compare outcomes following total hip arthroplasty (THA) in 302 patients diagnosed with Association Research Circulation Osseous (ARCO) stage III and stage IV osteonecrosis of the femoral head (ONFH). MATERIAL AND METHODS The study included 302 patients who underwent THA for ONFH between January 2018 and September 2021. Patient groups included ARCO stage III (n=145) and ARCO stage IV (n=157). Outcomes measured included duration of disease, operative time, intraoperative blood volume, postoperative length of hospital stay, pain measured by the visual analog scale (VAS) score, Harris hip score (HHS), and forgotten joint score (FJS). RESULTS Patients with ARCO stage III ONFH had a significantly shorter operative time (P=0.009), shorter length of hospital stay (P=0.021), and reduced volume of intraoperative bleeding (P=0.021) compared with patients with ARCO stage IV ONFH. There were no significant differences in disease duration (P=0.310), postoperative complications (P=0.07), preoperative (P=0.086, P=0.156) and postoperative (P=0.062, P=0.173) HHS and VAS scores, respectively. Patients with stage III ONFH reported significantly higher FJS scores at 3 months, 6 months, and 1 year after THA. CONCLUSIONS Patients who underwent hip arthroplasty for ARCO stage III femoral head necrosis experienced shorter operative time and hospital stay, less intraoperative bleeding, and better restoration of hip function than those with ARCO stage IV. Moreover, stage III patients were more prone to "forget" their hip arthroplasty experience within 1 year of surgery.

Autosomal dominant osteopetrosis (ADOP) is an extremely rare congenital bone disease. We report a case of a hip disorder in combination with ADOP, which was treated by total hip arthroplasty, resulting in a good recovery and a significant improvement in the patient’s ability to perform daily activities.

Background:The objective of this study was to assess the long-term survival rate, complications, as well as the clinical and radiological outcomes of hemiarthroplasty and total hip arthroplasty using constrained polyethylene liners in patients with ischemic stroke.Methods:This study was a retrospective cohort study that included patients with ischemic stroke who underwent hip arthroplasty from March 2010 to September 2017. In the Constrained Acetabular Liners (CAL) group, patients received an uncemented acetabular shell with a constrained polyethylene liner. The Dual Mobility (DM) group underwent hemiarthroplasty (HA). Additionally, hip function, range of motion, quality of life, the incidence of clinical complications, and prosthesis stability were investigated.Results:96 patients with unilateral femoral neck fractures who underwent hip replacement with CAL were included in the CAL group, while 103 patients who underwent hip replacement with a dual mobility head were included in the DM group. VAS, and SF-36 data were available for both CAL and DM groups. At the 1-year postoperative follow-up, the HHS in the CAL group was significantly lower than that in the DM group (80.83 ± 3.91 vs. 83.17 ± 4.15, P < 0.05). The VAS score in the CAL group peaked at the 1-year follow-up (2.07 ± 0.91 vs. 1.49 ± 0.85, P < 0.05). However, there were no significant differences between the two groups in terms of HSS, VAS, and SF-36 at the last follow-up after surgery. Operative time and the amount of bleeding in the DM group were significantly lower than those in the CAL group (105.30 ± 29.68 vs. 94.85 ± 31.07; 355.11 ± 123.95 vs. 302.22 ± 107.68, P < 0.05). Additionally, there was no significant difference in the mean leg length discrepancy between the two groups.Conclusion:The clinical, imaging, and postoperative complications of the CAL and DM groups were analyzed. The prognosis for DM appears to be more beneficial for early patient recovery, but a higher likelihood of recurrent dislocation is observed. CAL offers excellent stability for primary THA in high-risk patients; however, attention should be given to preventing aseptic loosening.

Background Core decompression (CD) is considered the most popular treatment method for patients with Association Research Circulation Osseous (ARCO) stage I-II osteonecrosis of the femoral head (ONFH). However, the definitive indication for CD is currently not well established. Methods This was a retrospective cohort study. Patients who were diagnosed with ARCO stage I-II ONFH and who underwent CD were included. According to the prognosis, the patients were divided into two groups: collapse of the femoral head after CD and noncollapse of the femoral head. Independent risk factors for the failure of CD treatment were identified. Subsequently, a new scoring system that included all these risk factors was built to help estimate the individual risk of CD failure in patients who were planning to undergo CD. Results The study included 1537 hips after decompression surgery. The overall failure rate of CD surgery was 52.44%. Seven independent prognostic factors for failed CD surgery were identified, such as male sex (HR = 75.449; 95% confidence interval (CI), 42.863-132.807), Aetiology (Idiopathic HR = 2.762; 95% CI, 2.016–3.788, Steroid-induced HR = 2.543; 95% CI, 1.852–3.685), if the patient had a seated occupation (HR = 3.937; 95% CI, 2.712–5.716), age (HR = 1.045; 95% CI, 1.032–1.058), haemoglobin level (HR = 0.909; 95% CI, 0.897–0.922), disease duration (HR = 1.217; 95% CI, 1.169–1.267) and the combined necrosis angle (HR = 1.025; 95% CI, 1.022–1.028). The final scoring system included these seven risk factors, and the area under the curve of this scoring system was 0.935 (95% confidential interval = 0.922–0.948). Conclusion This new scoring system might provide evidence-based medical proof for determining whether a patient with ARCO stage I - II ONFH might benefit from CD surgery. This scoring system is crucial for making clinical decisions. Consequently, this scoring system is recommended before CD surgery, which could help determine the potential prognosis of patients.

BACKGROUND The present study was performed to evaluate the efficacy of direct anterior approach (DAA) versus posterolateral approach (PLA) for total hip arthroplasty (THA) in patients with Parkinson's disease (PD). The aim of the study was to compare the speed of recovery of hip function and postoperative complications between the 2 approaches. MATERIAL AND METHODS The study included 285 Parkinson's patients who underwent THA; 209 eligible patients were recruited for analysis as per the inclusion criteria and assigned into DAA group (n=90) and PLA group (n=119) according to the surgical approach. Postoperative Harris Hip Score (HHS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and Forgotten joint score (FJS) were collected to assess hip function. RESULTS The DAA had a statistically lower incidence of postoperative complications than the PLA, particularly the rate of postoperative dislocation. Perioperative outcomes showed a longer operative time in the DAA than in the PLA group and more intraoperative blood loss in the DAA than in the PLA group. At 3 months postoperatively, the HHS and WOMAC scores in the DAA group showed significantly higher scores compared to the PLA group versus the DAA group. However, these differences disappeared at 6 months postoperatively and the FJS in the DAA group had a statistically higher score compared to the PLA group. CONCLUSIONS In patients with Parkinson's disease complicated with hip disease, the DAA approach exhibited a lower rate of dislocation than the PLA approach and had faster recovery of hip function.

Background Comparing the outcomes of debridement and total hip arthroplasty (THA) with antibiotic-loaded spacer implantation and subsequent THA for the treatment of patients affected by primary advanced septic arthritis (SA) of the hip in adults. Methods All of the 20 patients (20 hips) underwent two-stage surgery. Nine patients were submitted to surgical debridement first and then THA (group 1), while 11 patients were treated with antibiotic-loaded spacer and subsequent THA (group 2). Patients were evaluated based on the recurrence of infection, Harris hip score, visual analogue scale (VAS) pain score, and leg length discrepancy. Results No cases of infection, deep vein thrombosis, death, and loosening of the hip prosthesis were observed during follow-up. The mean follow-up time was 29.09 ± 10.80 months in group 1 and 28.22 ± 14.80 months in group 2. Before the THA surgery, the mean leg length discrepancy was 2.80 ± 2.03 cm in group 1 and 0.50 ± 0.23 cm in group 2 (P < 0.05). In the latest follow-up, the Harris hip scores of patients were 90.33 ± 4.85 in group 1 and 94.36 ± 2.34 in group 2 (P < 0.05), respectively. There was no statistically significant difference in the VAS pain score of the hip between the two groups (P > 0.05). Conclusions Debridement and antibiotic-loaded spacer and subsequent THA were effective in eradicating the infection for advanced SA. However, antibiotic-loaded spacer and subsequent THA was superior for effectively maintaining the length of the lower limb and function of the hip.

To evaluate the feasibility of partial replacement of femoral head with cadaveric hip joint specimens. In two cases of specimens of adult hip portion of simulated femoral head replacement surgery, under the C arm monitoring, using hollow trephine, build bone tunnel along the direction of the femoral neck, remove the weight-bearing area dead bone (simulation), making bone defect area, the appropriate size of the femoral head prosthesis into the area and imaging results show that the femoral head prosthesis and bone defect area peripheral bone matching is good. Preliminary results show that this method has certain feasibility.

Objective:To evaluate the stress distribution and displacement of femoral and implant models after partial femoral head replacement by finite element analysis.Methods:A healthy adult volunteer was selected to obtain the full-length CT scan data of femur. Mimics 20.0 software, Geomagic software and UG NX 12.0 software were used to establish the model of femoral head ischemic necrosis. The femoral head prosthesis was designed and developed after bone tunnel resection. The finite element simulation was conducted to simulate the one-leg standing environment, and the stress distribution and displacement data of the femur and the implant model were obtained.Results:The femoral stress distribution mainly concentrated on the lower part of the femoral neck and both sides of the femoral shaft cortical bone, the maximum stress was 48.25 Mpa, the maximum displacement was 10.98mm. The stress of the implant model was mainly distributed under the main structure of the metal implant, with a maximum stress of 147.2 Mpa and a maximum displacement of 9.58mm.Conclusions:After partial replacement of femoral head, the curvature of prosthetic head and femoral head is the same, and the stress conduction mode is the same as that of normal hip joint. However, stress concentration occurs at the joint between prosthetic head and stem, and the choice of materials with higher strength should be considered.

Objective To investigate the effect of drainage on heterotopic ossification (HO) after total hip arthroplasty (THA) and to evaluate other postoperative complications and joint dysfunction between patients with and without drainage. Methods In this retrospective cohort study, the medical records of patients who underwent THA from 2017 to 2019 were reviewed. The patients were divided into a drainage group and non-drainage group. Standard preoperative anteroposterior and lateral radiographs were assessed by senior radiologists for HO analysis. Clinical indicators included the hemoglobin concentration, superficial infection, blood transfusion, hematoma formation, hip range of motion (ROM), erythrocyte sedimentation rate, C-reactive protein concentration, dressing changes, visual analogue scale score, and Harris Hip Score (HHS). Results The incidence of HO was significantly higher in the drainage than non-drainage group (32.0% vs. 16.3%). The presence of severe HO (Brooker grade III or IV) was also different between the groups. Patients in the non-drainage group had smaller ROM early after surgery, but the final ROM and HHS did not differ significantly between the groups. Conclusions The rate and degree of HO after THA were significantly different between patients with and without drainage. There is no added advantage of closed suction drainage over no drainage in primary THA.

ARCO stage Ⅲ avascular necrosis of femoral head (ANFH) is accompanied by collapse of the femoral head. For young patients with ANFH, it is still controversial to adopt hip replacement or hip-preserved surgery. Based upon our experience and previous experiments on the treatment of ANFH, the research group adopted minimally invasive hip preservation surgery. Before the operation, the detailed planning was made according to X-ray, CT images and 3D printing models. During the operation, core decompression was performed under C-arm fluoroscopy. The autologous intact bone-cartilage graft was obtained from the comparatively unimportant part of the femoral condyle, which was then transplanted to fill the collapsed area of the femoral head under C-arm. The iliac bone graft was resected to fill the tunnels in the femoral condyle and proximal femur. After the operation, the CT scan demonstrated that the intact bone-cartilage graft was flush with the surrounding femoral head, achieving the purpose of preoperative planning. This minimally invasive surgery provides a valuable and useful reference for young patients with ARCO stage Ⅲ ANFH.

ObjectivesTo determine the potential risk factors for intraoperative periprosthetic femoral fractures in patients with developmental dysplasia of the hip (DDH) undergoing total hip arthroplasty (THA).MethodsThis was a retrospective study. Patients who were diagnosed with DDH and undergoing THA (by artificial joint replacement) at our hospital from January 1999 to December 2019 were included in this study. Clinical and radiological factors were obtained from their medical records, such as age, sex, Crowe classification, morphological features of proximal femur, and features of surgical procedure. The outcome of interest was the occurrence of intraoperative periprosthetic femoral fracture, which was recorded and classified according to the Vancouver classification system. According to the fracture status, the patients were divided into two groups: the fracture group and the non‐fracture group. Multivariate logistic regression model was built to identify the risk factors for these fractures.ResultsA total of 1252 hips were finally included. Intraoperative periprosthetic femoral fractures were identified in 62 hips. The incidence of intraoperative periprosthetic femoral fractures in patients with DDH undergoing THA was 4.95%. There were 22 patients (proportion = 35.48%, incidence = 1.76%) with Type A fractures, 38 (proportion = 61.29%, incidence = 3.04%) with Type B fractures, and two (proportion = 3.23%, incidence = 0.16%) with Type C fractures. Six independent risk factors for intraoperative periprosthetic femoral fractures were identified: osteoporosis (OR = 3.434; 95% CI, 1.963–6.007), previous surgical history (OR = 4.797; 95% CI, 2.446–9.410), Dorr Type A canal (OR = 3.025; 95% CI, 1.594–5.738), retained femoral neck length (OR = 1.121; 95% CI, 1.043–1.204), implanted metaphyseal‐diaphyseal fixation stems (OR = 3.208; 95% CI, 1.562–6.591), and implanted stem with anteversion design (OR = 2.916; 95% CI, 1.473–5.770).ConclusionsThe overall incidence of intraoperative periprosthetic femoral fractures in patients with DDH undergoing THA was 4.95%, which was at a moderate level compared to patients with other diseases undergoing THA. Six independent risk factors were identified: osteoporosis, previous surgical history, Dorr Type A canal, insufficient neck osteotomy level, implantation of metaphyseal‐diaphyseal fixation stem, and implantation of a stem with an anteversion design. Comprehending these risk factors might help surgeons prevent the occurrence of these intraoperative periprosthetic femoral fractures in patients with DDH.

背景:假体无菌性松动与假体周围骨溶解严重影响人工关节假体的使用寿命,影响置换效果,增加治疗费用.假体无菌性松动与假体周围骨溶解的机制研究为其治疗提供了新的方向.目的:针对人工关节假体周围骨溶解的机制和治疗做一综述.方法:应用计算机在PubMed、Web of Science和知网数据库检索涉及假体无菌性松动与假体周围骨溶解的相关研究,检索关键词为"periprosthetic osteolysis""aseptic loosening""假体周围骨溶解""假体无菌性松动",检索时间为2000年3月至2020年9月,最终纳入文献69篇.结果与结论:①可能改变植入物诱导反应的关键点是:巨噬细胞极化,假体周围细胞的促破骨细胞信号,核因子κB受体活化因子配体介导的破骨细胞生成,参与炎症/破骨细胞生成的核因子κB和丝裂原活化蛋白激酶途径,假体周围膜坏死与凋亡的延伸;②机械因素,如重复应力/应变也可能导致假体周围骨溶解,但是这些因素难以改变;③对假体周围骨溶解病理生理学的详细了解为其预防措施提供了新的可能性,可在未来显著降低人工关节置换后假体周围骨溶解和无菌性松动的发生率.