Search

Background Total hip replacement arthroplasty (THA) in hip dysplasia patients has a higher complication rate than in patients with simple hip osteoarthritis due to anatomical deformation and previous surgical history. Hence the associated complications need to be probed. Methods From 2015 to 2020, 1525 patients underwent THA performed by two surgeons at a single institution. A total of 152 patients involving 172 THAs were included. Hip dysplasia was evaluated radiologically using Crowe classification. The patients were classified into dual-mobility (DM) and fixed-bearing (FB) acetabular cup groups. The occurrence of postoperative complications, including dislocation and functional evaluation of the hip joint, was analyzed before and after surgery using the modified Harris hip score. Results There was no difference in the preoperative demographics and radiographic parameters between the groups. The size of the external bearing of the DM acetabular cup (41.83 ± 2.66 mm) and the size of the femoral head implant in the FB acetabular cup (33.03 ± 1.99 mm) were significantly different (P value < 0.001). The incidence of postoperative hip dislocation was significantly lower in the DM group (DM 0% vs. FB 9.0%) (P value = 0.003). The hip joint function score showed no difference before surgery (DM 42.92 vs FB 50.12) or 2 years after surgery (DM 91.80 vs FB 92.03). Conclusion Treating hip dysplasia patients with THA using a dual-mobility acetabular cup can reduce postoperative dislocations, and could be used for the better management of these patients.

Aims: This study aimed to compare the accuracy and reliability of computed tomography (CT) anteversion measurements between the conventional axial plane (CAP) and functional coronal plane (FCP). Methods: We retrospectively reviewed 68 patients who underwent primary unilateral total hip arthroplasty (THA) and postoperative CT. Values obtained using PolyWare software were considered the reference standard. The anteversion of the acetabular component was measured in the CAP as anatomical anteversion and in the reformatted FCP as radiographic anteversion using a reconstruction software. Reliability was assessed using the intraclass correlation coefficient. Results: The mean anteversion of the acetabular component in the CAP and FCP CT images was 29.18° ± 6.06° and 21.17° ± 5.38°, respectively. The CT anteversion measurement was more accurate in the reformatted FCP than in the CAP owing to its similarity with the reference standard (20.70° ± 4.39°, p = 0.281). The CT anteversion was larger in the CAP than in the FCP, showing a significant linear correlation and a difference of 8.01°. The intra- and interobserverreliabilities were excellent for all measurement methods. Conclusion: The reformatted FCP CT image is useful in the accurate measurement of anteversion after THA. This study will also help measure anteversion through CT.

Rationale: Total hip arthroplasty (THA) with a polyethylene (PE) liner is 1 of the most effective and successful treatment strategies for end-stage hip disorders. Vitamin E-infused highly cross-linked polyethylene is theoretically known to prevent failure due to oxidative degradation in the body, and is resistant to wear; therefore, successful long-term survival of THA is expected. Patient concerns: In June 2019, approximately 1.5 years after THA, the patient sat down and stood up without any specific issue; however, an unusual bullet sound occurred around the left hip joint. Since then, his discomfort persisted, and he was admitted to the emergency department. Diagnosis: Plain radiography and metal artifact reduction computed tomography performed in the emergency department revealed eccentric elevation of the prosthetic femoral head and suspected PE liner failure. Intervention: Revision surgery was performed for modular component exchange. To reduce the dislocation risk without performing cup exchange, conversion to dual-mobility articulation was performed. Outcomes: During the regular follow-up post-surgery, the patient could perform daily life activities without any discomfort, and dislocation was not observed. At 2 years postoperatively, no significant changes were observed in the radiographic images. Lessons: This case report presents an unexpected failure of THA due to superior rim fracture and excessive wear at the locking mechanism of the vitamin E-infused highly cross-linked polyethylene liner. This is an interesting case, as early PE liner failure occurred without strong labor intensity or trauma. A modular component exchange was performed with a dual-mobility bearing, and no issues were observed approximately 2 years after the reoperation. Therefore, third-generation highly cross-linked polyethylene liners can also cause early failure without a clear cause, and this case report highlights the necessity of considering several strategies for reoperation. Study Design: Case report.

Introduction This study aimed to evaluate the early results of primary total hip arthroplasty (THA) using dual mobility (DM) cups in patients at a risk of dislocation and compare them with that of fixed bearing (FB) THA. Materials and methods This retrospective study included patients who had undergone primary THA between January 2016 and December 2018 and were at a risk of dislocation. A propensity score-matched analysis was conducted for 63 THA procedures with vitamin-E infused highly cross-linked polyethylene (VEPE) DM bearing and 63 THA procedures performed with FB from the same manufacturer for a mean follow-up period of 3.1 and 3.5 years, respectively. The radiologic outcomes at the last follow-up and incidence of postoperative complications were evaluated and compared statistically between the two groups. The modified Harris hip score (mHHS) was used to assess patient-reported outcomes. Results Postoperative dislocation occurred in 4 cases (6.3%) in the FB group, but did not occur in the DM group (p = 0.042). There was no difference in the radiologic outcomes and postoperative complications between the two groups. The mHHS at the last follow-up showed satisfactory outcomes in both the groups (DM group, 90.5; FB group, 88.1), without a statistical difference between the groups. Conclusion The early results of THA using VEPE DM bearing showed better outcomes than that of THA with FB for patients at a risk of dislocation. A longer follow-up period is recommended to assess the stability and overall outcomes.

This study aimed to evaluate the early results of primary total hip arthroplasty (THA) using dual mobility (DM) cups in patients at a risk of dislocation and compare them with that of fixed bearing (FB) THA. This retrospective study included patients who had undergone primary THA between January 2016 and December 2018 and were at a risk of dislocation. A propensity score-matched analysis was conducted for 63 THA procedures with vitamin-E infused highly cross-linked polyethylene (VEPE) DM bearing and 63 THA procedures performed with FB from the same manufacturer for a mean follow-up period of 3.1 and 3.5 years, respectively. The radiologic outcomes at the last follow-up and incidence of postoperative complications were evaluated and compared statistically between the two groups. The modified Harris hip score (mHHS) was used to assess patient-reported outcomes. Postoperative dislocation occurred in 4 cases (6.3%) in the FB group, but did not occur in the DM group (p = 0.042). There was no difference in the radiologic outcomes and postoperative complications between the two groups. The mHHS at the last follow-up showed satisfactory outcomes in both the groups (DM group, 90.5; FB group, 88.1), without a statistical difference between the groups. The early results of THA using VEPE DM bearing showed better outcomes than that of THA with FB for patients at a risk of dislocation. A longer follow-up period is recommended to assess the stability and overall outcomes.

Background: This study aimed to evaluate the long-term results of bipolar hemiarthroplasty (BHA) in patients aged < 60 years and to analyze the risk factors for acetabular erosion after BHA. Methods: This retrospective study included 114 patients who underwent BHA were followed-up for at least 10 years. The mean age was 54.1 years, and the mean follow-up duration was 13.8 years. The patients were divided into two groups according to the presence of acetabular erosion, and the preoperative parameters were compared between the two groups. Moreover, the risk factors related to acetabular erosion after BHA were analyzed using statistical comparisons.Results: Reoperation was performed in 44 of the 114 patients (38.6%). The survival rate when the end point was reoperation related to acetabular erosion was found to be significantly time-dependent: 73.2% at 5 years, 48.8% at 10 years, and 25.9% at 15 years. The acetabular erosion group showed significantly younger age at the time of surgery, higher body mass index (BMI), more avascular necrosis of the femoral head, and smaller prosthetic femoral head. The final multivariate logistic regression analysis showed that young age at the time of surgery were independent risk factors for acetabular erosion after BHA in patients aged < 60 years.Conclusion: The minimum 10-year follow-up outcomes of BHA in patients aged < 60 years showed a relatively high conversion rate to total hip arthroplasty. When considering BHA in younger patients, more careful decisions should be made with respect to patient’s choice, keeping in mind that long-term survival cannot be guaranteed.

Background –Establishing the ideal indications for conservative treatment for elderly patients with valgus impacted femoral neck fractures is difficult because few studies have identified predictive factors for the failure of this treatment method. This study aimed to report the outcomes of conservative treatment for elderly patients with valgus impacted femoral neck fractures and determine risk factors that lead to treatment failure. Methods –From January 2009 to December 2018, 206 patients with valgus impacted femoral neck fracture were identified at two institutions. Elderly patients with valgus impacted femoral neck fractures corresponding to an Orthopedic Trauma Association/AO Foundation (OTA/AO) classification of 31-B1.1 or 31-B1.2 who were treated conservatively were included in the study. The following data was collected to compare the preoperative characteristics of patients with valgus impacted femoral neck fractures: age, sex, bone mineral density, medical comorbidities (hypertension, diabetes mellitus, ischemic heart disease, arrhythmia, chronic kidney disease [CKD], and stroke), medial cortex displacement, valgus angle, posterior tilt, and retroversion. These data were used to assess the independent predictors for failure of conservative treatment using multiple logistic regression analysis. Results –The failure rate after conservative treatment for valgus impacted femoral neck fracture in the enrolled patient group was 27.3% (15 of 55). CKD, presence of medial cortex displacement, high posterior tilt, and high retroversion were all identified as independent predictors for failure. The cut-off values for retroversion and posterior tilt that predicted treatment failure were 12.5° (area under curve [AUC] 0.768, p = 0.002, 95% confidence interval [CI] 0.632–0.903, sensitivity 0.733, 1-specificity 0.300) and 7.5° (AUC 0.712, p = 0.016, 95% CI 0.542- 0.881, sensitivity 0.667, 1-specificity 0.325), respectively. Conclusions –The present study showed that a high union rate could be obtained if the indications for conservative treatment in for elderly patients with valgus impacted femoral neck fractures are well-defined. Thus, we believe that conservative treatment can be a viable option for valgus impacted femoral neck fractures when elderly patients with high-risk comorbidities have acceptable fracture angulation, no medial cortex displacement, and no CKD. Level of Evidence –Level III, retrospective cohort study.

Purpose: Total hip arthroplasty (THA) is an available surgical option for failed acetabular fracture, previously managed by open reduction and internal fixation. This study aimed to report the postoperative outcomes of cementless THA in patients with this condition. Materials and Methods: Between November 2000 and September 2016, 25 consecutive cementless THAs for failed internal fixation after acetabular fractures with a minimum follow-up of 2 years were analyzed. The mean age at the time of surgery was 58 years (36–85 years), and the time elapsed between fracture and THA was 70 months (7–213 months). Clinical and radiologic evaluations were performed on all patients. Results: Clinically, the mean Harris hip score at the last follow-up was 88 points. Walking ability recovered to pre-injury status in 92% patients, and activities of daily living recovered in 96% patients. Radiographically, none of the acetabular cups showed evidence of migration and loosening during the mean follow-up of 50 months. All cases showed stable femoral stem fixation at the last follow-up. Dislocation occurred in three cases (12%). Conclusion: Outcomes of cementless THA after failed internal fixation for acetabular fractures were satisfactory. However, a relatively high incidence of postoperative dislocation is still a concern.

Background: Although highly positive results for wear reduction of highly cross-linked polyethylene (HXLPE) have been reported around the 10-year follow-up, the long-term result related to reoperation and wear-related survival is still an issue. Therefore, this study aimed to compare the follow-up results of a single manufacture’s polyethylene liner for >15 years in terms of survival and wear rate. Methods: This retrospective cohort study included 134 primary total hip arthroplasties (THAs) who were followed up for at least 15 years. The mean age at the time of surgery was 50.7 years (conventional polyethylene [CPE] group = 22; HXLPE group = 112). Linear and volumetric wear rates of polyethylene were measured, and the reoperation rate and radiographic osteolysis were evaluated and Kaplan-Meier survival analysis was performed in both groups. Implant-related complications were also examined. Results: HXLPE group showed a significantly lower wear rate in both linear and volumetric wear. None of the hip radiographs showed evidence of loosening or osteolysis in the HXLPE group. The survival rates at 15- to 18-year follow-up were 90.9% and 95.5% in the CPE and HXLPE groups when all-cause reoperation was the endpoint, and 90.9% and 100.0% when the wear-related reoperation was the endpoint, respectively. Implant-related complications were not different between the 2 groups. Conclusions: Wear reduction and osteolysis showed a great advantage in HXLPE after a 15-year follow-up. Although the CPE and HXLPE showed excellent survival, wear and osteolysis were more frequent in the CPE; therefore, the high risk of reoperation in the future should be considered.

Objectives: This retrospective cohort study investigated perioperative C-reactive protein (CRP) value for early detection of postoperative systemic infective complications in elderly patients with intertrochanteric femoral fractures. Methods: A total of 250 patients aged > 65 years, with intertrochanteric[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2019)

The long-term use of adefovir and tenofovir–antiviral medications commonly used to treat chronic hepatitis B–can be associated with proximal renal tubular dysfunction resulting in significant hypophosphatemic osteomalacia. However, there have been few reports about pathological fractures requiring surgical stabilization in cases of antiviral drug-induced hypophosphatemic osteomalacia. We present the case of a 51-year-old man who sustained bilateral pathological hip fractures associated with antiviral drug-induced hypophosphatemic osteomalacia. To treat a lamivudine-resistant hepatitis-B viral infection, the patient received adefovir for 7 years followed by tenofovir for the subsequent 3 years. He had suffered from polyarthralgia and generalized weakness for 2 years prior to presentation at our clinic. Misdiagnosis and inadequate management of his condition accelerated weakness of the bone matrix and ultimately induced pathological fractures. The patient was managed via cementless total hip arthroplasty on the left hip and internal fixation on the right hip. This case highlights that orthopaedic surgeons should consider the possibility of hypophosphatemic osteomalacia if patients receiving antiviral drugs complain of polyarthralgia and generalized weakness.