Low Dislocation Rate Research Articles

Low dislocation rate following revision total hip arthroplasty (THA) with dual mobility cup with minimum 2-year follow-up.

Dislocation is the second most common indication for revision total hip arthroplasty (THA). In revision cases the dislocation rate can be as high as 5-30%. The aim of this study was to assess the outcome, specifically the dislocation rate in revision THA where a dual mobility cup was used. We retrospectively reviewed all the revision THAs where a dual mobility cup (G7) was used. The pre-operative and post-operative oxford hip scores were recorded. Patients' electronic records and radiographs were studied for the indications, approaches used, post-operative complications, re-operation rates, and re-revision surgery. Between 2016 and 2020, we performed 59 revision total hip replacements where a dual mobility cup (G7) was used. There were 23 males and 36 females. The average age was 74 years (range, 64-89). Acetabular components were revised in 47 (80%) cases and both the femoral and the acetabular components were revised in 12 (20%) cases. The average follow-up time was 4 years (range, 2-6 years). Average pre-operative and post-operative oxford hip scores were 17 and 36 respectively. The improvement was significant with P value of <.001. Complications were noted in 5 (8%) patients. One patient had dislocation. This patient required re-revision with constrained liner. One patient had intraoperative fracture of the femur and was treated with plate and cables. We conclude that the dual mobility cup can significantly reduce the risk of dislocation when used in revision THA.

A Modified Transgluteal Approach Sparing Abductor Function in Total Hip Arthroplasty Results in a Low Postoperative Dislocation Rate: A Retrospective Study of Short- and Long-Term Outcomes.

Background A modified transgluteal approachin total hip arthroplasty (THA) can be utilized to preserve abductor muscle function and reduce dislocation rate. We present a study evaluating outcomes for a modified transgluteal approach using a validated patient-reported outcome measure (PROM) tool, the Oxford Hip Score (OHS). Methods This was a retrospective single-centre study over a four-year period. Short-term data was collected including intraoperative and postoperative complications, length of stay (LOS) in the hospital, and time from operation to mobilising independently. One year of data was collected, including plain radiograph findings and the incidence of Trendelenburg gait. Patients were contacted at a mean time of 2.7 years post-operatively so that OHS could be conducted. Results A total of 100 patients were identified within the inclusion criteria. The mean LOS for all patients was 2.8 days. The mean time from operation to mobilising independently without walking aids was 4.9 weeks. At the one-year follow-up, there was satisfactory radiographic assessment in 100% of patients. The mean OHS was 45.5 at 2.7 years, indicating satisfactory joint function in all patients. Conclusion This study supports the use of the modified transgluteal approach in THA, showing favourable outcomes in the time from operation to cessation in the use of walking aids, LOS and OHS. We report zero cases of Trendelenburg gait at the one-year follow-up and no dislocations at the three-year follow-up. Further studies are required to compare the outcomes of TGA to other approaches in THA.

Large cohort study on prevention strategies for dislocation in total hip arthroplasty

Dislocation is a major complication of total hip arthroplasty (THA). This study aimed to assess the dislocation rate after THA using the combined strategy of using CT-based navigation, large diameter heads, and posterior soft tissue repair in a large cohort. We included 1410 patients who had undergone primary cementless THA using the CT-based navigation system. The posterior approach was used by a single surgeon for all patients. The participants included 143 (10.1%) men and 1267 (89.9%) women, with a mean age of 65 years. The mean body mass index was 24kg/m2. Additionally, the incidence rate of postoperative dislocation per year was calculated. The dislocation onset was classified as early when the dislocation occurred within 2 years of the primary THA and late when it occurred more than 2 years after the primary THA. Recurrence and revision rates in patients with dislocations were investigated. The postoperative dislocation rate was 0.56% (8 patients). The mean time to dislocation onset was 11.2 (0.5-20.0) months postoperatively. All postoperative dislocations occurred in the early phase whereas none in the late phase, showing a significant difference (p<0.01). Six (0.43%) patients experienced recurrent dislocations or required revision. THA using the combined strategy resulted in low dislocation rates, especially without late dislocation.

Comparative Study between Dual Mobility Total Hip Replacement versus Bipolar Hemiarthroplasty in the Treatment of Displaced Femoral Neck Fractures in the Elderly

Abstract Background Total hip arthroplasty (THA) or hemiarthroplasty are the most popular treatments for dislocated intracapsular hip fractures. Objective to compare dual mobility total hip arthroplasty and bipolar hemiarthroplasty as a management for the femoral neck fracture in elderly and evaluating the functional outcome. The objective is to perform a systematic review of the outcomes of use of the dual mobility total hip arthroplasty compared to bipolar hemiarthroplasty. Patients and Methods We included randomized controlled trials, including cluster RCTs, controlled (non-randomized) clinical trials or cluster trials, prospective and retrospective comparative cohort studies and case control or nested case-control studies. Results There was statistically significant decrease in the Harris Hip score in BA group (78.31±9.25) than THA group (82.72±7.53). There was statistically significant increase in the percentage of patients with dislocation in BA group (6.2%) than THA group (1.9%). Data Sources Medline databases (PubMed, Medscape, ScienceDirect. EMF-Portal) and all materials available in the Internet till 2023. Conclusion dual mobility cup total hip arthroplasty offers for the patients many advantages such as stability, lower dislocation rates and longevity, all those pros make it a superior treatment choice that bipolar hemiarthroplasty.

Use of Dual Mobility Cups Reduce Dislocation Risk After Internal Fixation for Acetabular Fracture Concomitant With Total Hip Arthroplasty in Patients Who are Over 60 Years Old

Treatment of complex acetabular fractures in patients over 60 remains challenging. Functional treatments for these fractures have yielded disappointing outcomes. Internal fixation may fail facing this porotic bone, and postoperative non-weight-bearing may expose the patient to decubitus complications. Our hypothesis was that use of a dual-mobility cup (DMC) reduces dislocation risk after concomitant internal fixation and total hip arthroplasty (THA) for acetabular fracture in patients who are over 60 years old. A retrospective, observational noncomparative and continuous study was conducted from January 2015 to September 2022. Patients aged over 60 years who had displaced acetabular fractures, treated surgically via concomitant internal fixation and THA, using a DMC exclusively through the Kocher-Langenbeck approach and a minimum follow-up was of one year, were included. There were 45 patients (45 hips) who had an average age of 71 years (range, 60 to 88) who were included (75.5% men). The main mechanisms of injury were the motor vehicle accidents (in 21 cases (46.7%)). Bicolumn fractures were prevalent (46.6%). The analysis of complications included intraoperative nerve palsy, postoperative dislocations, deep infections, periprosthetic fractures, and loosening. Clinical assessment included the Harris hip score and the level of return to previous activities. Radiological evaluation assessed fracture union, periprosthetic osteolysis, graft integration, the presence of leg length discrepancy and heterotopic ossification. There was one case of dislocation (2.2%) requiring reoperation for replacement of the prosthetic neck, and one patient (2.2%) experienced early THA infection, successfully treated with surgical lavage and antibiotics. Functional outcomes showed a mean Harris hip score of 88 (range, 69 to 99) and 84% of patients resumed their previous activities. Radiological follow-up revealed no loosening. This study has shown that the use of DMC in concomitant THA with open reduction and internal fixation for acetabular facture in patient over age 60 years achieved a low dislocation rate with favorable clinical and radiological outcomes and a low complication rate.

Glenolabral Articular Disruption (GLAD) Is Not Associated with Worse Outcomes or Higher Instability Recurrence after Arthroscopic Bankart Repair-A Matched-Pair Analysis.

Background: This study aimed to compare clinical outcomes and recurrence of instability after arthroscopic Bankart repair (ABR) in patients with anterior shoulder instability, with and without a GLAD lesion, while distinguishing between primary and recurrent instability. Methods: Consecutive patients who underwent isolated ABR between January 2012 and December 2021 were included. Patients with a concomitant GLAD lesion were matched in with patients without a GLAD lesion according to the following criteria: age, sex, BMI, follow-up time, and primary versus recurrent instability. At minimum two-year follow-up, the clinical outcome (Rowe score, redislocation rate) and the functional outcome, including the American Shoulder and Elbow Surgeons (ASES) score, Western Ontario Shoulder Instability Index (WOSI), Oxford Shoulder Instability Score (OSIS), satisfaction (1-10 scale, 0 = unsatisfied, 10 = very satisfied), and Visual Analogue Scale (VAS), were compared between groups. Results: In total, 28 patients (14 GLAD vs. 14 Bankart; age: 32.5 ± 13.0 years; sex: 92.9% male; BMI: 24.6 ± 2.2) were included 6.9 ± 2.8 (2-11) years after isolated ABR (follow-up rate 63.6%). Clinical and functional outcome did not differ significantly between patients with versus without GLAD lesions (ASES score: 100 [96.5-100] vs. 97.5 [93.3-100], p = 0.27); WOSI (%): 9.0 [3.7-24.5] vs. 3.8 [0.8-8.9], p = 0.22; Rowe score: 90.0 [75.0-100] vs. 95.0 [78.8-100], p = 0.57; OSIS: 46 [44.7-48] vs. 46 [43.0-48], p = 0.54; satisfaction: 8.9 ± 1.4 vs. 8.0 ± 1.4, p = 0.78; VAS 0 [0-1.3] vs. 0 [0-1.0]. In both groups, two patients (14.3%) reported a redislocation during the observation period. Conclusions: At short- to mid-term follow-up, ABR showed favorable outcomes, low dislocation rates, and high patient satisfaction, regardless of the presence of a GLAD lesion or primary versus recurrent instability. However, follow-up time was heterogeneous, and the follow-up rate was marginal.

MID-TERM RESULTS OF THE NEW ENDO-SPACER TECHNIQUE IN TWO-STAGE SEPTIC EXCHANGE SURGERY FOR PERIPROSTHETIC JOINT INFECTION OF THE HIP

Mechanical failure due to dislocation, fracture and acetabular wear as well as persistence of infection are the main complications associated with the use of hip spacers in the treatment of periprosthetic joint infections (PJI).We have developed a novel, custom-made spacer as part of two-stage septic hip replacement and present the two- to five-year results after reimplantation.We prospectively examined a total of 73 patients over our study period in whom our new spacer technique was used. The technique includes a dual mobility inlay and a cemented straight stem in combination with antibiotic-loaded PMMA bone cement which allows full weight bearing meanwhile the interim period. The follow-up ranged between 24 and 60 months after reimplantation as second stage of a two-stage approach. The patients were contacted as part of the follow-up using a questionnaire concerning reoperation, reinfection as well as hip function by using the Harris Hip Score.72 patients (98,6%) could be reimplanted, one patient is still using the spacer prothesis for 45 months because of excellent functional results with a Harris Hip Score of 95, nevertheless reimplantation is planned. The reinfection rate was less than 7% after reimplantation. The dislocation rate was 5%, and in total there was an overall complication rate of less than 10%. The Harris Hip Score was significantly improved.The ENDO spacer surgical technique is a promising option in the treatment of periprosthetic joint infections (PJI) for two-stage septic exchange with a low dislocation rate and good infection control after reimplantation. In addition, it enables early mobilization with the possibility of full weight-bearing in the interval between spacer implantation and reimplantation.

Revision Hip Arthroplasty Performed by Fellowship-Trained Versus Non–Fellowship-Trained Surgeons: A Comparison of Perioperative Management and Complications

Successful revision hip arthroplasty (rTHA) requires major resource allocation and a surgical team adept at managing these complex cases. The purpose of this study was to compare the results of rTHA performed by fellowship-trained and non-fellowship-trained surgeons. A national administrative database was utilized to identify 5,880 patients who underwent aseptic rTHA and 1,622 patients who underwent head-liner exchange for infection by fellowship-trained and non-fellowship-trained surgeons from 2010 to 2020 with a 5-year follow-up. Postoperative opioid and anticoagulant prescriptions were compared among surgeons. Patients treated by fellowship-trained and non-fellowship-trained surgeons had propensity scores matched based on age, sex, comorbidity index, and diagnosis. The 5-year surgical complications were compared using descriptive statistics. Multivariable analysis was performed to determine the odds of failure following head-liner exchange when performed by a fellowship-trained versus non-fellowship-trained surgeon. Aseptic rTHA patients treated by fellowship-trained surgeons received fewer opioids (132 versus 165 milligram morphine equivalents per patient) and nonaspirin anticoagulants (21.4 versus 32.0%, P < .001). Fellowship-training was associated with lower dislocation rates (9.9 versus 14.2%, P= .011), fewer postoperative infections, and fewer periprosthetic fractures and re-revisions (15.2 versus 21.3%, P < .001). Head-liner exchange for infection performed by fellowship-trained surgeons was associated with lower odds of failure (31.2 versus 45.7%, odds ratio 0.76, 95% confidence interval 0.62 to 0.91, P < .001). rTHA performed by adult reconstruction fellowship-trained surgeons results in fewer re-revisions in aseptic cases and head-liner exchanges. Variations in resources, volumes, and perioperative protocols may account for some of the differences.

Promising results following derotational femoral osteotomy in patellofemoral instability with increased femoral anteversion: A systematic review on current indications, outcomes and complication rate.

Patellofemoral joint instability (PFJI) can surgically be treated with a multitude of approaches, depending on the underlying pathology. In the presence of increased femoral anteversion, some authors have reported good results with a derotational distal femoral osteotomy (DeDFO). The purpose of the study was to investigate the indications, outcomes and complication rate of DeDFO for PFJI. A systematic review was performed according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) by searching Medline, Embase, Web of Science and Cochrane Library databases through 1 December2023. Included were levels 1-4 clinical studies of skeletally mature patients undergoing a DeDFO for PFJI irrespective of concomitant procedures. Study characteristics, indications, radiological and clinical outcomes, surgical technique and concomitant procedures, re-dislocation and complication rate were all analysed, as was methodological quality. A total of 12 studies including 310 patients (325 knees) were included. Three studies were cohort studies, all others were case series. The mean patient age across the studies was 22 years, and the mean follow-up was 29.4 months. Femoral anteversion cut-off was between 20° and 30°. Every study included at least one concurrent soft tissue, bony or combined procedure. Across all studies, one case of re-dislocation was reported (0.3%) and four implant or osteotomy-related complications (1.2%) were reported. All studies reported a statistically significant increase in clinical scores. This systematic review of DeDFO for patellofemoral instability in the presence of increased femoral anteversion demonstrates promising clinical results and an extremely low dislocation and complication rate. The heterogeneity of the cut-off in anteversion and concomitant procedures, especially tibial tubercle osteotomy with seemingly identical results, indicates the need for high-quality evidence for treating patellofemoral instability. Based upon this systematic review, we strongly recommend that DeDFO be added to the 'menu à la carte' of PFJI. Level III Systematic Review.

Lower Intraoperative and Immediate Postoperative Complications in Robotic Versus Conventional Primary Total Hip Arthroplasty: A Retrospective Cohort Analysis of Over 360,000 Patients.

Although a trend of an improved alignment with robotic total hip arthroplasty (THA) over conventional methods has surfaced from recent series, it is unknown whether these results translate into meaningful enhancements in postoperative outcomes. To address this lack in the literature, we compared the perioperative morbidity and mortality with robotic and conventional THA in a large national cohort of 367,894 patients. We hypothesized that no significant differences would exist in the outcomes between the two groups. Records were extracted from 2016-2019 from the National Inpatient Sample (NIS) database Healthcare Cost and Utilization Project which is the largest in-patient database in the United States. From 367,894 THAs, robotics were employed for 7,863 patients. The remaining 360,031 conventional THAs served as controls. The two groups were compared for demographics, admission, and hospital stay details including costs, and mortality and morbidity data including medical and surgical complications. Descriptive statistics were used for demographic data while analytical statistics including t-tests, chi-squared tests, Fischer exact test, and Pearson chi-squared tests were used for perioperative outcomes. Statistical significance was set at p<0.005. Demographic distributions between robotic and conventional THA groups displayed similar age and sex characteristics. Shorter mean lengths of stay (1.87 days) were seen in robotic THA versus conventional THA (2.33 days) while higher costs were noted for the former (mean $68,686.71 vs $66,840.39) (p<0.005). Low overall mortality (0.03% robotic, 0.09% conventional) was seen in both groups (p>0.005). Higher comparative incidences of anemia, acute renal failure, and pneumonia were seen in conventional THA (p<0.005) while no significant differences were noted for other complications including myocardial infarction, pulmonary embolism, deep vein thrombosis, and cardiac arrest (p>0.005). Among others, lower dislocation rates, mechanical complications, periprosthetic joint infection, and periprosthetic fractures were seen with robotic THA (p<0.005). Wound complications and superficial infection rates did not differ between the two groups (p>0.005). Evidence has emerged from our results to support more routine adaptation of the robotic option of performing a THA. These can be based on lower local, systemic, and mechanical complications as demonstrated by the present study. Further evaluation of these results in follow-up would help establish the foothold of robotic surgery in total hip replacement in the modern context.

Complication rates after direct anterior vs posterior approach for hip hemiarthroplasty in elderly individuals with femoral neck fractures.

Dislocation rates after hemiarthroplasty reportedly vary from 1% to 17%. This serious complication is associated with increased morbidity and mortality rates. Approaches to this surgery are still debated, with no consensus regarding the superiority of any single approach. To compare early postoperative complications after implementing the direct anterior and posterior approaches (PL) for hip hemiarthroplasty after femoral neck fractures. This is a comparative, retrospective, single-center cohort study conducted at a university hospital. Between March 2008 and December 2018, 273 patients (a total of 280 hips) underwent bipolar hemiarthroplasties (n = 280) for displaced femoral neck fractures using either the PL (n = 171) or the minimally invasive direct anterior approach (DAA) (n = 109). The choice of approach was related to the surgeons' practices; the implant types were similar and unrelated to the approach. Dislocation rates and other complications were reviewed after a minimum follow-up of 6 mo. Both treatment groups had similarly aged patients (mean age: 82 years), sex ratios, patient body mass indexes, and patient comorbidities. Surgical data (surgery delay time, operative time, and blood loss volume) did not differ significantly between the groups. The 30 d mortality rate was higher in the PL group (9.9%) than in the DAA group (3.7%), but the difference was not statistically significant (P = 0.052). Among the one-month survivors, a significantly higher rate of dislocation was observed in the PL group (14/154; 9.1%) than in the DAA group (0/105; 0%) (P = 0.002). Of the 14 patients with dislocation, 8 underwent revision surgery for recurrent instability (posterior group), and one of them had 2 additional procedures due to a deep infection. The rate of other complications (e.g., perioperative and early postoperative periprosthetic fractures and infection-related complications) did not differ significantly between the groups. These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate (< 1%) than the PL.

DUAL-MOBILITY ARTICULATION CONFERS LOWER DISLOCATION AND REVISION RATES: A STUDY USING REVIEW OF REVIEWS METHODOLOGY

Dislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty.Understand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence.Medline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision.564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6-8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p &lt; 0.00001), total lower rate of cup revision (p &lt; 0.00001, higher incidence of fracture (p&gt;0.05).DM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs.

Posterior Approach and Inferior Capsulotomy in Bipolar Hemiarthroplasty for Femoral Neck Fractures: Comparison with Superior Capsulotomy.

Hemiarthroplasty is frequently used to treat displaced femoral neck fractures in elderly patients, but it has a higher risk of postoperative dislocation. We introduced the posterior approach and inferior capsulotomy (PAICO) to enhance joint stability after bipolar hemiarthroplasty for femoral neck fracture. We evaluated whether the PAICO would have a lower dislocation rate than the conventional posterior approach with superior capsulotomy. From January 2021 to December 2021, we prospectively recruited 25 patients (25 hips) aged 50 years or older who underwent bipolar hemiarthroplasty for femoral neck fractures due to low-energy trauma as the PAICO group. We compared the PAICO group with a historical control group who had undergone hemiarthroplasty in 7 institutes between 2010 and 2020. The primary endpoint was dislocation within 1 year after the surgery. We compared data from the PAICO group with the data from the historical control group from the Korean Hip Fracture Registry which was carried out in South Korea. A total of 25 patients (25 hips) were enrolled in the present study; 3,477 patients (3,571 hips) who underwent bipolar hemiarthroplasty were reviewed as the historical control group. In the PAICO group, we observed no dislocation, whereas the dislocation rate in the control group was 1.3%. In patients with displaced femoral neck fractures, the PAICO approach demonstrated comparable results in operation time and complication rates when compared to bipolar hemiarthroplasty using superior capsulotomy. Notably, there were no observed cases of dislocation among patients who underwent the PAICO approach. We recommend this PAICO approach to surgeons using the posterior approach, hoping to prevent dislocation in bipolar hemiarthroplasty.

DUAL MOBILITY ARTICULATION CONFERS LOWER DISLOCATION AND REVISION RATES: A STUDY USING REVIEW OF REVIEWS METHODOLOGY

AbstractIntroductionDislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty.AimsUnderstand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence.MethodsMedline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision.Results564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6–8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p &lt; 0.00001), total lower rate of cup revision (p &lt; 0.00001, higher incidence of fracture (p&gt;0.05).ConclusionDM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs.Declaration of Interest(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Results of the transition from posterolateral to anterior minimally invasive approach for total hip arthroplasty

BackgroundThe anterior minimally invasive (AMI) approach reduces soft tissue damage, risk of dislocation and enhances recovery, but it is associated with certain complications. The aim of this study is to compare the outcomes of patients who underwent total hip arthroplasty (THA) through posterolateral (PL) and AMI approaches performed by the same surgeon, in order to determine the learning curve associated with this new approach.MethodsThis retrospective cohort study included patients who underwent THA via PL and AMI approach between 2017 and 2022, with a minimum follow-up of 1 year. Hip fracture and oncologic patients were excluded. Demographic variables, functional scores and perioperative complications were assessed. A bivariate analysis was performed to identify differences between groups.ResultsData of 124 AMI and 120 PL patients were analyzed. Demographic characteristics among groups were homogeneous. Functional outcomes at 3 months were superior for AMI (Oxford: 43 vs. 38; p < 0.05), no dislocations were identified (0% vs. 4.2%; p < 0.05) and no differences in the transfusion rate were found (6.5% AMI vs. 6.7% PL; p = 0.996). Infection rate was 4% for AMI and 3.4% for PL (p = 0.572). Surgical time was shorter for the PL approach, but the median surgical time of the last 25 AMI cases was shorter.ConclusionsThe AMI approach is an excellent alternative for patients requiring THA. Although surgical time and perioperative bleeding were greater during the learning curve, this approach offers improved functional outcomes and a lower dislocation rate, without significant differences in transfusion and infection outcomes, demonstrating that responsible innovation and safe implementation of new techniques is possible.

Dislocation Following Anterior and Posterior Total Hip Arthroplasty in the Setting of Spinal Deformity and Stiffness: Evolving Trends Using a High-Risk Protocol at a Single Tertiary Center

Patients who have spinal stiffness and deformity are at the highest risk for dislocation after total hip arthroplasty (THA). Previous reports of this cohort are limited to antero-lateral and postero-lateral (PL) approaches. We investigated the dislocation rate after direct anterior (DA) and PL approach THA with a contemporary high-risk protocol to optimize stability. We investigated patients undergoing THA who had preoperative biplanar imaging from January-December 2019. Patients were identified using radiographic criteria of spinal-stiffness (<10-degree change in sacral slope from standing to seated) and deformity (flatback deformity with >10-degree difference in pelvic incidence and lumbar lordosis). There were 367 patients identified (181 DA, 186 PL). The primary outcome was dislocation rate at 2-years postoperatively. Risk-factors for dislocation were evaluated using logistic regressions (significance level of 0.05). There were 6 (1.6%) dislocations in the entire cohort, with low dislocation rates for both DA (0.6%) and PL-THA (2.7%). We observed increased utilization of dual mobility with larger outer head bearings (>38 mm) with PL-THA (34.4 versus 5.0%, P < .01) and conversely increased utilization of 32-mm femoral-heads with DA-THA (39.4 versus 7.0%, P < .001). Surgical approach (PL) was not a significant risk-factor for dislocation (odds ratio: 5.03, P = .15). Patients who had a history of lumbar-fusion had 8-times higher odds for dislocation (OR: 8.20, P = .020). To the best of our knowledge, this is the largest series to date evaluating DA and PL-THA in the hip-spine 2B-group. Our results demonstrate lower dislocation rate than expected with either surgical approach using a high-risk protocol.

Hemiarthroplasty Versus Total Hip Arthroplasty for Femoral Neck Fracture in Elderly Patients: Twelve-Month Risk of Revision and Dislocation in an Instrumental Variable Analysis of Medicare Data.

There is practice variation in the selection of a total hip arthroplasty (THA) or a hemiarthroplasty (HA) for the treatment of displaced femoral neck fractures in elderly patients. Large data sets are needed to compare the rates of rare complications following these procedures. We sought to examine the relationship between surgery type and secondary hip surgery (revision or conversion arthroplasty) at 12 months following the index arthroplasty, and that between surgery type and dislocation at 12 months, among elderly Medicare beneficiaries who underwent THA or HA for a femoral neck fracture, taking into account the potential for selection bias. We performed a population-based, retrospective study of elderly (>65 years of age) Medicare beneficiaries who underwent THA or HA following a femoral neck fracture. Two-stage, instrumental variable regression models were applied to nationally representative Medicare medical claims data from 2017 to 2019. Of the 61,695 elderly patients who met the inclusion criteria, of whom 74.1% were female and 92.2% were non-Hispanic White, 10,268 patients (16.6%) underwent THA and 51,427 (83.4%) underwent HA. The findings from the multivariable, instrumental variable analyses indicated that treatment of displaced femoral neck fractures with THA was associated with a significantly higher risk of dislocation at 12 months compared with treatment with HA (2.9% for the THA group versus 1.9% for the HA group; p = 0.001). There was no significant difference in the likelihood of 12-month revision/conversion between THA and HA. The use of THA to treat femoral neck fractures in elderly patients is associated with a significantly higher risk of 12-month dislocation, as compared with the use of HA, although the difference may not be clinically important. A low overall rate of dislocation was found in both groups. The risk of revision/conversion at 12 months did not differ between the groups. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

EXPERIENCE OF THE 150 MM LUBINUS SP II FEMORAL STEM IN A UK CENTRE: EXCELLENT SURVIVORSHIP, LOW DISLOCATION, AND NEGLIGIBLE PERIPROSTHETIC FRACTURE RATES UP TO 15 YEARS FOLLOWING PRIMARY TOTAL HIP ARTHROPLASTY

The Lubinus SP II is an anatomical femoral stem with high survivorship levels notably described in the Swedish Arthroplasty Register. As the clinical and economic burden of revision total hip arthroplasty (THA) and periprosthetic fracture (PPF) continues to increase, it has been suggested that use of anatomical stems may facilitate more uniform cement mantles and improve implant survival. The primary aim of this study was to determine the long-term survivorship and PPF rate of the Lubinus SP II 150mm stem in a single UK centre.Between January 2007 and April 2012, 1000 consecutive THAs were performed using the Lubinus SP II femoral stem in our institution. Patient demographics and operative details were collected in a prospective arthroplasty database. Patient records and national radiographic archives were then reviewed at a mean of 12.3 years (SD 1.3) following surgery to identify occurrence of subsequent revision surgery, dislocation or periprosthetic fracture.Mean patient age at surgery was 69.3 years (SD 10.1, 24–93 years). There were 634 women (63%). Osteoarthritis was the operative indication in 974 patients (97%). There were 13 revisions in total (4 for recurrent dislocation, 3 for infection, 6 for acetabular loosening) and 16 dislocations (1.6%). Stem survivorship at 10 years was 99.6% (95 % confidence interval [CI], 99.5%–99.7%) and at 15 years was 98.8% (98.7%–98.9%). The 15-year stem survival for aseptic loosening was 100%. Analysis of all cause THA failure demonstrated a survivorship of 99.1% (99.0%–99.3%) at 10 years and 98.2% (98.1%–98.3%) at 15 years. There were 4 periprosthetic fractures in total (0.4%) at mean 12.3 year follow-up.The Lubinus SP II stem demonstrated excellent survivorship, low dislocation rates and negligible PPF rates up to 15 years following primary THA. Use of anatomical stems such as the Lubinus SPII would appear to be a wise clinical and economic investment for patients and healthcare systems alike.

Dislocation and survival rate of dual mobility cups in revision total hip arthroplasty in patients with high risk of instability.

Instability remains as an unsolved complication after revision total hip arthroplasty (rTHA). Dual mobility (DM) cups have decreased dislocation rate in rTHA; however, there are few clinical studies that evaluate the risk of dislocation after rTHA in patients with high risk of instability. Between 2007 and 2019, 95 consecutive rTHA using a DM cup, in 93 patients with instability risk factors were retrospectively reviewed. Instability risk factors were defined as follows: deficient abductor mechanism (22.1%), previous dislocation (68.4%), Paprosky 3 acetabular bone defect (21.1%), neuromuscular disease (4.2%), lumbar spine arthrodesis (6.3%), and more than one previous surgery (33.6%). Mean follow-up was 4.3 ± 2.4years. Clinical and radiographic parameters were reported. DM cup survival was determined using a Kaplan-Meier analysis with re-revision for any cause as the end-point. Surgical complications and re-dislocation rate was recorded. Seven DM cups were re-revised; three due to aseptic loosening, three due to peri-prosthetic joint infection (PJI), and one due to instability. At sevenyears follow-up, the survival rate of the DM cup using re-revision for any reason as the end-point was 82.4% (95% confidence interval, 66.4-98.4%). There were 12 (12.6%) complications: two (2.1%) dislocations, six (6.3%) PJI, four (4.2%) peri-prosthetic fractures. Our findings suggest DM cups are effective reducing dislocation rate in rTHA in patients with a high risk of instability, without increasing early aseptic loosening and with a low rate of dislocation. Nevertheless, longer follow-up is needed to confirm implant stability and dislocation rates in the long term.

RETRIEVAL ANALYSIS OF DUAL MOBILITY POLYETHYLENE LINERS FOR TOTAL HIP ARTHROPLASTY

Dual mobility (DM) total hip replacements (THRs) were introduced to reduce dislocation risk, which is the most common cause of early revision. Although DM THRs have shown good overall survivorship and low dislocation rates, the mechanisms which describe how these bearings function in-vivo are not fully understood. Therefore, the study aim was to comprehensively assess retrieved DM polyethylene liners for signs of damage using visual inspection and semi-quantitative geometric assessment methods.Retrieved DM liners (n=18) were visually inspected for the presence of surface damage, whereby the internal and external surfaces were independently assigned a score of one (present) or zero (not present) for seven damage modes. The severity of damage was not assessed. The material composition of embedded debris was characterised using energy-dispersive x-ray analysis (EDX). Additionally, each liner was geometrically assessed for signs of wear/deformation [1].Scratching and pitting were the most common damage modes on either surface. Additionally, burnishing was observed on 50% of the internal surfaces and embedded debris was identified on 67% of the external surfaces. EDX analysis of the debris identified several materials including titanium, cobalt-chrome, iron, and tantalum. Geometric analysis demonstrated highly variable damage patterns across the liners.The incidence of burnishing was three times greater for the internal surfaces, suggesting that this acts as the primary articulation site. The external surfaces sustained more observable damage as evidenced by a higher incidence of embedded debris, abrasion, delamination, and deformation. In conjunction with the highly variable damage patterns observed, these results suggest that DM kinematics are complex and may be influenced by several factors (e.g., soft tissue fibrosis, patient activities) and thus further investigation is warranted.