Early Dislocation Research Articles

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

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

Discontinuing the recommendation of hip precautions does not increase the risk of early dislocation after primary total hip arthroplasty using 36-mm heads: a population-based study from the Danish Hip Arthroplasty Register.

Dislocation is a severe complication following total hip arthroplasty (THA). Hip precautions have been recommended in the initial postoperative period but evidence supporting this practice is limited. We therefore conducted a population-based study to evaluate the association between discontinuing recommending postoperative hip precautions and the risk of early dislocation. This is a cohort study with data from the Danish Hip Arthroplasty Register and the Danish National Patient Register. We included patients who underwent primary THA for osteoarthritis in 2004-2019 in public hospitals in the Capital Region of Denmark. The cohort was divided into the hip precautions group, comprising patients operated on between 2004 and 2009, and the no-precautions group operated on between 2014 and 2019. The primary outcome was the difference in the absolute risk of dislocation within 3 months post-surgery. The secondary outcome assessed the same risk within 2 years. We evaluated the difference in absolute risk using absolute risk regression (ARR). The cumulative incidence of dislocation within 3 months was 2.9% (confidence interval [CI] 2.5-3.3) in the hip precautions group and 3.5% (CI 3.1-3.9) in the no-precautions group. The risk of dislocation was higher in the no-precautions group but failed to reach statistical significance in the crude (ARR 1.2, CI 0.9-1.6) and multivariate model (ARR 1.4, CI 0.9-2.2). We found a higher but statistically insignificant increase in the risk of early dislocation in the no-precautions group. The lack of significance in the association may be explained by the increased use of 36-mm femoral heads after the guideline revision.

A comparison of dislocation risk between dual mobility and traditional constructs used in proximal femoral replacement

BackgroundProximal femoral replacement (PFR) is a reconstruction technique after tumor resection or for revision of failed total hip arthroplasty (THA). However, despite acceptable long-term oncologic and functional outcomes, extensive soft tissue or bone loss increases the risk for prosthetic instability. Instability may depend on the construct chosen for reconstruction, with current options including bipolar, constrained, or dual mobility implants. Clinical studies comparing patient outcomes after PFR with these three different constructs are limited. MethodsThis study retrospectively examined a single tertiary academic institution's experience with PFR over a fifteen-year period. The medical records of patients who underwent PFR for indications such as tumor and failed THA with bone loss were reviewed. Patients were stratified into cohorts based on use of bipolar, constrained, or dual mobility implants. Patient demographics, disease characteristics, perioperative data, and data on prosthetic dislocations were recorded. ANOVA and chi-square testing was performed for continuous and categorical variables, respectively. The threshold for statistical significance was set to p < 0.05. Results106 patients were identified who underwent PFR. 46 underwent PFR with bipolar prosthesis (follow-up: 20 ± 24.57 months), 42 with constrained liner (follow-up: 30.45 ± 35.32 months), and 18 with dual mobility (follow-up: 15.38 ± 15.67 months). Only BMI (p = 0.036) and smoking history (P = 0.002) differed between groups. Dislocations occurred in 4 (8.7 %) patients who underwent reconstruction with bipolar prosthesis, compared to 8 (19.0 %) with constrained liner, and 3 (16.7 %) patients with dual mobility. Mean time to dislocation was significantly longer in dual mobility patients (P = 0.009). There were no differences in instances of early dislocation between groups (P = 00.238). ConclusionWhile study numbers are low, mean time to dislocation was significantly longer with dual mobility. Additional large-scale longitudinal studies are needed to fully elucidate the differences in outcomes amongst these three treatments.

Early Prosthetic Hip Dislocation: Does the Timing of the Dislocation Matter?

BackgroundEarly dislocation following total hip arthroplasty (THA) is a common reason for revision. The purpose of this study was to determine if the acuity of the dislocation episode affects the risk of revision surgery. MethodsA retrospective review of a national, all-payer administrative database comprised of claims from 2010 to 2020 was used to identify patients who had a prosthetic hip dislocation at various postoperative time intervals (0 to 7, 7 to 30, 30 to 60, and 60 to 90 days). Of the 45,352 primary unilateral THA patients who had sufficient follow-up, there were 2,878 dislocations within 90 days. Dislocators were matched 1:1 based on age, sex, and a comorbidity index with a control group (no dislocation). Demographics, surgical indications, comorbidities, ten-year revision rates, and complications were compared among cohorts. Multivariable logistic regression analysis was performed to identify risk factors for revision THA following early dislocation. ResultsAmong matched cohorts, dislocation at any time interval was associated with significantly increased odds of subsequent 10-years revision (OR [odds ratio] = 25.60 to 33.4, P < .001). Acute dislocators within 7 days did not have an increased risk of all cause revisions at 10 years relative to other early dislocators. Revision for indication of instability decreased with time to first dislocation (<7 days: 85.7% versus 60 to 90 days: 53.9%). Primary diagnoses of posttraumatic arthritis (OR = 2.53 [1.84 to 3.49], P < .001), hip fracture (OR = 3.8 [2.53 to 5.72], P < .001), and osteonecrosis (OR = 1.75 [1.12 to 2.73], P = .010) were most commonly associated with revision surgery after an early dislocation. ConclusionsDislocation within 90 days of THA is associated with increased odds of subsequent revision. Early dislocation within 7 days of surgery has similar all cause revision-free survivorship, but an increased risk of a subsequent revision for instability when compared to patients who dislocated within 7 to 90 days

Multivariate Analysis of Risk Factors for In-Hospital Dislocation Following Primary Total Hip Arthroplasty.

Background: Early dislocation following primary total hip arthroplasty (THA) is a rare but devastating complication and represents a source of patient morbidity and financial burden to the healthcare system. The objective of this study was to identify patient characteristics and comorbidities that are associated with increased early in-hospital dislocation rates following primary THA. Methods: A retrospective cohort study was conducted using patient data from the Nationwide Inpatient Sample (NIS) database; we identified patients who had undergone THA from 2016 to 2019 and compared those with an early periprosthetic dislocation prior to discharge to those without. The patient characteristics and comorbidities were compared using univariate analysis with a subsequent investigation of statistically significant variables using multivariate analysis. The variables were compared using chi square, Fisher's exact test, and independent sample t-tests with data assessed using odds ratio with 95% confidence intervals. Results: A total of 5151 patients sustained an early dislocation compared to 362,743 who did not. Those who sustained an in-hospital dislocation were more likely to share the following characteristics: female sex (OR 1.21, p < 0.01), age > 70 (OR 1.45, p < 0.01), Caucasian ethnicity (OR 1.22, p < 0.01), SLE (OR 1.87, p < 0.01), and Parkinson's disease (OR 1.93, p < 0.01). Certain characteristics were also associated with decreased odds of having an in-hospital dislocation including elective surgery (OR 0.14, p < 0.01), tobacco use (OR 0.8, p < 0.01), diabetes without complications (OR 0.87, p < 0.01), and a history of heart valve replacement (OR 0.81, p < 0.01). The length of stay was significantly longer (4.7 days vs. 2.3 days) as was the total hospital charges (USD $101,517 vs. USD $66,388) for the early in-hospital dislocation group. Conclusions: Several patient characteristics and comorbidities are associated with early in-hospital dislocation episodes following total hip arthroplasty including female sex, age > 70, non-elective surgery, SLE, and Parkinson's. This information may be useful to help guide intraoperative implant selection and/or postoperative protocol in select patient populations to limit early instability as well as decrease the financial burden associated with this postoperative complication.

Total blood loss after hip hemiarthroplasty for femoral neck fracture: Anterior versus posterior approach

IntroductionFemoral neck fractures constitute a public health problem due to significant associated morbidity and mortality amongst the ageing population. Perioperative blood loss can increase this morbidity. Blood loss, as well as the influence that the surgical approach exerts on it, remains poorly evaluated. We therefore conducted a retrospective comparative study in order to: (1) compare total blood loss depending on whether the patients were operated on using an anterior or posterior approach, (2) compare the transfusion rates, operating times and hospital stays between these two groups and, (3) analyze dislocation rates. HypothesisTotal blood loss is greater from an anterior approach following a hip hemiarthroplasty for femoral neck fracture, compared to the posterior approach. Material and methodsThis retrospective single-center comparative study included 137 patients operated on by hip hemiarthroplasty between December 2020 and June 2021, and seven patients were excluded. One hundred and thirty patients were analyzed: 69 (53.1%) had been operated on via the anterior Hueter approach (AA) and 61 (46.9%) via the posterior Moore approach (PA). The analysis of total blood loss was based on the OSTHEO formula to collect perioperative “hidden” blood loss. The risk of early dislocation (less than 6 months) was also analyzed. ResultsTotal blood loss was similar between the two groups, AA: 1626±506mL versus PA: 1746±692mL (p=0.27). The transfusion rates were also similar between the two groups, AA: 23.2% versus PA: 31.1% (p=0.31) as well as the duration of hospitalization, AA: 8.5±3.2 versus PA: 8.2±3.3 days (p=0.54). The operating time was shorter in the PA group (Δ=10.3±14.1minutes [p<0.001]) with a greater risk of early dislocation when the patient was operated on by PA with AA: 9.8% versus PA: 1.4% (p=0.03). ConclusionThis study does not demonstrate any influence of the approach (anterior or posterior) on total blood loss. Transfusion rates and length of hospitalization were similar between the groups with a slightly shorter operating time but a greater risk of early dislocations after posterior hemiarthroplasty in a population at high anesthesia-related risk. Level of proofIII, comparative study of continuous series.

15-year survivorship of a unique dual-modular femoral stem in primary hip arthroplasty

BackgroundHip offset, version, and length are interdependent femoral variables which determine stability and leg length. Balancing these competing variables remains a core challenge in hip arthroplasty. The potential benefits of modular femoral stems have been overshadowed by higher rates of failure. The objective of this study was to assess the survivorship of a unique dual-modular femoral stem at an average 15-year follow-up period.MethodsThe records of all patients with osteoarthritis who underwent primary total hip arthroplasty with this device between 2004–2009 were reviewed. There were no exclusions for BMI or other factors. We examined the data with Kaplan–Meier survival analysis. The primary endpoint for survival was mechanical failure of the modular neck-body junction.ResultsThe survivorship of this device in 172 subjects was 100% with none experiencing mechanical failure of the modular junction at an average of 15 years. 60 patients died of causes unrelated to their THA and 9 patients were lost to follow-up. There were three early (≤ 12 months) dislocations (1.7%), and seven total dislocations (4.1%). 16 patients underwent reoperations during the follow-up period, none for any complication of the modular junction. Radiographic results showed well-fixed femoral stems in all cases. There were no leg length discrepancies of greater than 10 mm, and 85% were within 5 mm.ConclusionThere were no mechanical failures of the modular junction in any of the subjects over the average 15-year period, demonstrating that this dual-modular design is not associated with increased failure rates. We achieved a 1.7% early dislocation rate and a 4.1% total dislocation rate without any clinically significant leg length discrepancies.

Insufficient stem antetorsion and lower cup abduction is a combined risk factor for posterior hip dislocation in patients undergoing THA for femoral neck fractures: a retrospective analysis

BackgroundThe role of acetabular and femoral component positions with respect to the risk of post-operative instability and dislocation remains debated. In this study, we aimed to identify potential risk factors for early dislocation following primary total hip arthroplasty (THA) for displaced intracapsular femoral neck fractures (FNF) using radiological measurements.MethodsWe retrospectively analyzed data for patients who underwent cementless primary THA for FNF using a posterolateral approach between January 2018 and December 2021. Follow-up duration, age, sex, affected side, and mean time from THA to dislocation were recorded. Leg-length inequality, abductor lever arm, vertical and horizontal femoral offsets, vertical and horizontal hip centers of rotation, abduction, anteversion of the acetabulum and femoral prosthesis, and combined anteversion were measured.ResultsThe study sample included 17 men and 34 women, with 21 and 30 patients undergoing left- and right-hip operations, respectively. The mean patient age was 70.18 ± 7.64 years, and the mean follow-up duration was 27.73 ± 13.52 months. The mean time between THA and dislocation was 1.58 ± 0.79 months. Seven patients (13.73%) sustained posterior dislocation of the hip. The abduction angle (36.05 ± 6.82° vs. 45.68 ± 8.78°) (p = 0.008) and anteversion of the femoral prosthesis (8.26 ± 4.47° vs. 19.47 ± 9.01°) (p = 0.002) were significantly lower in the dislocation group than in the control group. There were no significant differences in other parameters.ConclusionsInsufficient stem antetorsion combined with lower abduction angle of the acetabular component were associated with a high risk of dislocation, especially in patients with deep flexion or internal rotation of the flexed hip joint and knees, or in patients with a stiff spine or anterior pelvic tilt, impingement may then occur in the neck of the prosthesis and cup component, ultimately resulting in posterior dislocation. These findings could remind surgeons to avoid simultaneous occurrence of both in THA surgery. These results provide new insight into risk factors for hip dislocation in patients undergoing primary THA for FNF and may aid in reducing the risk of instability and dislocation.Level of evidenceProspective comparative study Level II.

Does the limb lengthening reduce the incidence of hip dislocation in patients with neurological disorders and insufficient muscle tension who undergoing hip arthroplasty?

The 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. This 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. A 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. Unfortunately, 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.

Dislocation after Revision Total Hip Arthroplasty: A Comparison between Dual Mobility and Conventional Total Hip Arthroplasty.

The objective of this study was to analyze the results from a cohort of patients who underwent a revision total hip arthroplasty (THA) using a dual mobility cup (DMC) implant. A retrospective review of revised THAs was conducted using the database from a single tertiary referral hospital. A total of 91 revision THAs from 91 patients were included in the study. There were 46 male hips and 45 female hips. The mean age was 56.3±14.6 years, and the mean follow-up period was 6.4±5.9 years. In performance of revision THAs, the DMC implants were used in 18 hips (19.8%), and the conventional implants were used in 73 hips (80.2%). During the follow-up period, three dislocations were identified, and the overall dislocation rate was 3.3%. Early dislocation (at one month postoperatively) occurred in one patient, while late dislocation (at a mean of 7.5 years) occurred in two patients. There was no occurrence of dislocation in the DMC group (0%), and three dislocations were detected in the conventional group (4.1%). However, no significant difference in the rate of dislocation was observed between the two groups (P=0.891). Although the rate of dislocation was higher in the conventional group, there were no statistically significant differences between the two groups due to the small number of patients. Nevertheless, we believe that the dual mobility design is advantageous in terms of reducing dislocation rate and can be recommended as an option for a revision THA.

Observation of the short-term curative effect of using SuperPATH approach to treat elderly femoral neck fractures with schizophrenia.

As China enters an aging society, the incidence of femoral neck fractures is increasing year by year. For some patients, total hip arthroplasty (THA) is the treatment of choice for displaced femoral neck fractures. Schizophrenia is a common combination of elderly patients with femoral neck fractures, and there are few reports on the treatment. This study describes the short-term efficacy of the supercapsular percutaneously assisted (SuperPATH) approach in the treatment of patients suffered with displaced femoral neck fractures combined with schizophrenia. A retrospective analysis of 20 elderly patients with displaced femoral neck fractures combined with schizophrenia who underwent THA using the SuperPATH approach. Record demographic data, postoperative reexamination of X-ray film to observe the position and the loosening condition of the prosthesis, the length of hospitalization, complications in the hospital and after discharge. The Harris score of hip joint function was used to evaluate postoperative hip joint function. The average age of the 20 patients was 73.1 years. All patients were followed up by outpatient clinic or telephone. The follow-up time was 3-12 months, with an average of 9.2 months. There was no incision infection, no tissue structure damage such as important nerves and blood vessels, and no complications such as early dislocation, loosening of the joint prosthesis, and deep vein thrombosis of lower extremities. The efficacy of the last follow-up was evaluated according to the Harris score of hip joint function: an average of 91 points (78-98 points); 13 cases were excellent, 5 cases were good, and 2 cases were fair. The SuperPATH approach has the advantages of less surgical damage, shorter recovery time, good surgical safety, preserving the normal tension of the muscles around the hip joint, and reducing the incidence rate of early postoperative dislocation of the joint prosthesis. The THA of the SuperPATH approach can treat patients with displaced femoral neck fractures combined with schizophrenia safely and effectively.

Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry.

The treatment of shoulder osteoarthritis in the young patient remains challenging. The higher functional demands and higher expectations of the young patient cohort are often coupled with increased failure and revision rates. Consequently, shoulder surgeons are faced with a unique challenge with implant selection. The aim of this study was to compare the survivorship and reasons for revision of 5 classes of shoulder arthroplasty in patients aged <55 years with a primary diagnosis of osteoarthritis by use of data from a large national arthroplasty registry. The study population included all primary shoulder arthroplasty procedures undertaken for osteoarthritis in patients aged <55 years and reported to the registry between September 1999 and December 2021. Procedures were grouped into the following classes: total shoulder arthroplasty (TSA), hemiarthroplasty resurfacing (HRA), hemiarthroplasty stemmed metallic head (HSMH), hemiarthroplasty stemmed pyrocarbon head (HSPH), and reverse total shoulder arthroplasty (RTSA). The outcome measure was the cumulative percent revision, which was defined using Kaplan-Meier estimates of survivorship to describe the time to the first revision. Hazard ratios (HRs) were calculated from Cox proportional hazards models, adjusting for age and sex, to compare revision rates among groups. There were 1564 shoulder arthroplasty procedures in patients aged <55 years, of which 361 (23.1%) were HRA, 70 (4.5%) were HSMH, 159 (10.2%) were HSPH, 714 (45.7%) were TSA, and 260 (16.6%) were RTSA. HRA had a higher rate of revision than RTSA after 1 year (HRA = 2.51 (95% CI 1.30, 4.83), P=.005), with no difference prior to that time. In addition, HSMH had a higher rate of revision than RTSA for the entire period (HR,2.69 [95% confidence interval, 1.28-5.63], P=.008). There was no significant difference in the rate of revision for HSPH and TSA when they were compared with RTSA. Glenoid erosion was the most common cause of revision for HRA (28.6% of revisions) and HSMH (50%). Instability/dislocation was the leading cause of revision for RTSA (41.7%) and HSPH (28.6%), and for TSA, the majority of revisions were for either instability/dislocation (20.6%) or loosening (18.6%). These results should be interpreted within the context of the lack of availability of long-term data on RTSA and HSPH stems. RTSA outperforms all implants regarding revision rates at mid-term follow-up. The high early dislocation rate associated with RTSA, as well as the lack of revision options available to address this, indicates that careful selection of patients and a greater appreciation of anatomic risk factors are needed in the future.

О конъюнктивальной аутопластике лоскутом «на ножке» при глубоких язвах и микроперфорациях роговицы

In case of corneal ulcers of various origin that are difficult for medical treatment, urgent surgery is indicated, including the usage of plastic materials. In the absence of them, the surgery of choice is conjunctival autoplasty of the cornea. Recent modifications of such surgical procedure don’t rule out complications as early dislocation of the flap and the progress of infection under it. A comparative analysis of the technique and outcomes of the applied autoconjunctival plasty with a pedunculated flap and the proposed modification of the procedure, performed in 9 patients, was carried out. It is concluded that the operation is a simple and effective method of eliminating corneal ulcers and ulcers complicated by descemetocele and corneal microperforation. Keywords: cornea, ulcerative defect, deepithelialization, autoconjunctival plasty.

Effects of anterior capsule repair during total hip arthroplasty using the anterolateral approach in the supine position

PurposeSoft-tissue tension is an important factor for preventing dislocations after total hip arthroplasty. The purpose of this study was to evaluate the effects of anterior capsule repair for preventing dislocation during primary total hip arthroplasty using the anterolateral approach in the supine position (ALS). MethodsThis study retrospectively compared the clinical and radiographic outcomes between patients who underwent total hip arthroplasty via the ALS with or without anterior capsule repair at our institute. The cup (radiographic inclination and radiographic anteversion) and stem alignment, operative time, clinical score, and complication were evaluated. ResultsAmong the 393 hips evaluated, 193 and 200 belonged to the resection and repair groups, respectively. There were significant differences in the inclination and anteversion of the cup and flexion insertion of the stem (42.3° vs. 40.3°, 15.8° vs. 19.8°, and 27.5% vs. 34.0%, respectively). No significant differences in operative time and postoperative Japanese Orthopedic Association hip score were noted. Early dislocation was more common in the resection group compared to the repair group (2 hips vs. 0 hip, respectively), albeit not significantly (1.03% vs. 0%, p ​= ​0.241). ConclusionOur results demonstrated that the clinical benefit of the anterior capsule repair for preventing dislocation was limited in ALS.

The Allium Ureteral Stent for the Treatment of Ureteral Complications Following Renal Transplantation-A Single-Center, Single-Surgeon Series.

Ureteral complications such as urinary leak, ureteral necrosis or ureteral stenosis are common complications after renal transplantation with major short- and long-term issues, including graft impairment and graft loss. At present, there is no agreement on the optimal management of ureteral complications. The aim of the current study was to evaluate the safety and efficacy of the self-expanding, large-caliber Allium ureteral stent in patients with ureteral complications following renal transplantation. In this retrospective study, the electronic database of Charité University Hospital was screened for patients receiving the self-expandable Allium ureteral stent in the transplant ureter after kidney transplantation between January 2016 and March 2022. Descriptive statistics were used to describe the outcomes. There were six men and four women with a median age of 61 years (interquartile range, 55 to 68 years). Nine out of 10 patients had ureteric stenosis, which was diagnosed at a median of two years (interquartile range 10 months to 9 years) following renal transplantation. The median operating time was 49 min (interquartile range, 30 to 60 min). Endoscopic Allium stent placement was successful in all patients with ureteric stenosis. The median length of stay in the hospital was four days (interquartile range 2 to 7 days). Only one patient (#5) had a postoperative grade IIIb Clavien-Dindo complication. Patients had follow-ups every 3 months with ultrasound and serum creatinine. Dislocation of the Allium stent was seen in four patients; all occurred within three months. Ultimately, three patients required ureteric re-implantation, two of which had early dislocation of the stent. Six patients are managed with a permanent Allium stent. The median dwell time was 11 months (interquartile range 3 to 20 months) and maximum dwell time was 23 months. The overall success rate was 60% (6 out of 10). According to our data, the Allium stent represents a safe and minimally invasive option with a success rate of 60%. It might, therefore, represent an alternative to DJ stents, nephrostomies or immediate re-implantation. As all dislocations occurred within three months, frequent early postoperative follow-up is required.

Understanding risk for early dislocation resulting in reoperation within 90 days of reverse total shoulder arthroplasty: extreme rare event detection through cost-sensitive machine learning

Reliable prediction of postoperative dislocation after reverse total shoulder arthroplasty (RSA) would inform patient counseling as well as surgical and postoperative decision making. Understanding interactions between multiple risk factors is important to identify those patients most at risk of this rare but costly complication. To better understand these interactions, a game theory-based approach was undertaken to develop machine learning models capable of predicting dislocation-related 90-day readmission following RSA. A retrospective review of the Nationwide Readmissions Database was performed to identify patients who underwent RSA between 2016 and 2018 with a subsequent readmission for prosthetic dislocation. Of the 74,697 index procedures included in the data set, 740 (1%) experienced a dislocation resulting in hospital readmission within 90 days. Five machine learning algorithms were evaluated for their ability to predict dislocation leading to hospital readmission within 90 days of RSA. Shapley additive explanation (SHAP) values were calculated for the top-performing models to quantify the importance of features and understand variable interaction effects, with hierarchical clustering used to identify cohorts of patients with similar risk factor combinations. Of the 5 models evaluated, the extreme gradient boosting algorithm was the most reliable in predicting dislocation (C statistic = 0.71, F2 score = 0.07, recall = 0.84, Brier score = 0.21). SHAP value analysis revealed multifactorial explanations for dislocation risk, with presence of a preoperative humerus fracture; disposition involving discharge or transfer to a skilled nursing facility, intermediate care facility, or other nonroutine facility; and Medicaid as the expected primary payer resulting in strong, positive, and unidirectional effects on increasing dislocation risk. In contrast, factors such as comorbidity burden, index procedure complexity and duration, age, sex, and presence or absence of preoperative glenohumeral osteoarthritis displayed bidirectional influences on risk, indicating potential protective effects for these variables and opportunities for risk mitigation. Hierarchical clustering using SHAP values identified patients with similar risk factor combinations. Machine learning can reliably predict patients at risk for postoperative dislocation resulting in hospital readmission within 90 days of RSA. Although individual risk for dislocation varies significantly based on unique combinations of patient characteristics, SHAP analysis revealed a particularly at-risk cohort consisting of young, male patients with high comorbidity burdens who are indicated for RSA after a humerus fracture. These patients may require additional modifications in postoperative activity, physical therapy, and counseling on risk-reducing measures to prevent early dislocation after RSA.

Risk Factors for Early and Late Intraocular Lens Dislocation

Purpose: To evaluate risk factors predisposing to intraocular lens (IOL) dislocation after cataract surgery.Methods: The medical and surgical records of patients diagnosed with IOL dislocation between January 2011 and December 2021 after undergoing extracapsular cataract extraction, phacoemulsification, and phacoemulsification with pars plana vitrectomy at Hallym University Sacred Heart Hospital were reviewed retrospectively. Preoperative factors (ocular parameters and demographics) and intra-operative factors (surgery time, surgeon, and intra-operative complications) were compared according to early, late, and bilateral dislocation.Results: In 68 patents and 71 eyes, the average age at the diagnosis of dislocation was 63.3 years, and there were more males (77.5%) than females. Possible major factors predisposing to IOL dislocation were high myopia (9 eyes), retinal detachment (8 eyes), neodymium-doped yttrium aluminum garnet capsulotomy (6 eyes), and normal tension glaucoma (6 eyes). The rate of out-of-the bag dislocation was higher in early dislocation than in late. Early dislocation had a significantly older age, longer surgery time, and higher intraoperative complication rate during cataract surgery than did late dislocation. There was no difference in surgery time for late dislocated eyes compared to non-dislocated eyes. There was no difference in the incidence of dislocation between phacoemulsification and phacoemulsification with pars plana vitrectomy; there were seven eyes with prior vitrectomy only, with late dislocation. Of the seven patients with bilateral IOL dislocation, one had retinitis pigmentosa, two had retinal detachment, and one had high myopia. Bilateral dislocation patients were significantly younger at the time of cataract surgery, compared to unilateral dislocation patients.Conclusions: Early dislocation was associated with long surgery time and intraoperative complications, while late dislocation had no significant correlation with surgery-related factors. A history of vitrectomy and combined vitrectomy with cataract surgery seemed to be associated with late dislocation, but this association was not significant.

Preoperative demographics and laboratory markers may be associated with early dislocation after total hip arthroplasty

PurposeThe purpose of this study was to identify modifiable medical comorbidities, laboratory markers and flaws in perioperative management that increase the risk of acute dislocation in total hip arthroplasty (THA) patients.MethodsAll THA with primary indications of osteoarthritis from 2007 to 2020 were queried from the National Surgical Quality Improvement Program (NSQIP) database. Demographic data, preoperative laboratory values, recorded past medical history, operative details as well as outcome and complication information were collected. The study population was divided into two cohorts: non-dislocation and dislocation patients. Statistics were performed to compare the characteristics of both cohorts and to identify risk factors for prosthetic dislocation (α < 0.05).Results275,107 patients underwent primary THA in 2007 to 2020, of which 1,258 (0.5%) patients experienced a prosthetic hip dislocation. Demographics between non-dislocation and dislocation cohorts varied significantly in that dislocation patients were more likely to be female, older, with lower body mass index and a more extensive past medical history (all p < 0.05). Moreover, hypoalbuminemia and moderate/severe anemia were associated with increased risk of dislocation in a multivariate model (all p < 0.05). Finally, use of general anesthesia, longer operative time, and longer length of hospital stay correlated with greater risk of prosthetic dislocation (all p < 0.05).ConclusionsElderly female patients and patients with certain abnormal preoperative laboratory values are at risk for sustaining acute dislocations after index THA. Careful interdisciplinary planning and medical optimization should be considered in high-risk patients as dislocations significantly increase the risk of sepsis, cerebral vascular accident, and blood transfusions on readmission.

Low dislocation rate one year after total hip arthroplasty at a tertiary hospital in South Africa

BACKGROUND: Total hip arthroplasty (THA) is one of the most performed and most researched procedures worldwide, and there is an ever-growing demand for THA in an already resource-constrained system in South Africa. Early dislocation after THA remains a serious and costly problem; however, few THA outcome studies have been performed locally. This study therefore aimed to calculate the incidence of dislocation after THA and to identify risk factors for dislocation after THA in a South African academic hospital METHODS: In this retrospective cohort review, files and radiographs of 543 patients were reviewed for dislocation during the first year after primary THA. The reason for the THA, the surgical data, the implant data, and whether and when dislocation occurred were recorded for each patient. Fisher's exact tests and independent t-tests were done to analyse the association between variables and a patient's odds of experiencing a dislocation after THA RESULTS: Twenty (3.7%) out of 543 THAs dislocated during the first year, 17 of these within the first three months. The surgical approach used was not shown to be a significant risk factor (p = 0.650) for dislocation, although the Hardinge approach had been used for all 20 cases of dislocation. Similar dislocation rates (p = 0.967) were found for THAs done for displaced neck of femur (NOF) fractures (3.6%) and for elective THAs (3.7%). Trauma THAs made up more than half (55%) of our study population. Femoral head sizes &lt; 32 mm (p = 0.390 for neck of femur THA and p = 0.451 for elective THA) and a single mobility design (p = 0.494) both produced a higher dislocation rate, although this was not statistically significant. Surgeon experience did not prove to be significant for our study population (p = 0.570 CONCLUSION: The dislocation rate after THA at our institution is lower than rates reported in the literature for NOF THA and similar to rates reported for elective THA. This was found despite the dislocation rate for the Hardinge approach being nearly eight times higher than expected. Minimal surgeon experience, implant coupling and smaller femoral head size did not prove to be significant risk factors for dislocation after THA Level of evidence: Level 4

At least four-year follow-up results of total hip replacement surgery using a direct anterior approach

Objective: This study aims to evaluate the clinical and radiological results of patients who were followed for at least 4 years after treatment with total hip arthroplasty, which was performed using a direct anterior approach and to compare the results with different surgical approaches in the literature.&#x0D; Materials and Methods: The study included 37 patients who underwent total hip replacement using the direct anterior approach. Harris hip scores and lower extremity functional scores were recorded. The correlations between the scores and gender, diagnosis, body mass index, time of walking time, length of hospital stay, and inclination angle were examined. &#x0D; Results: Of the cases,26(70.3%) were female and 11(29.7%) were male. The mean age was 51.2 (26-76) years. The patients were followed up for an average of 58 (48-72) months. No significant difference was determined between the improvement in Harris hip score and gender, age, body mass index, and length of hospital stay. Postoperative acetabular inclination was 40.8° (35 - 55). The early dislocation was observed in one of our patients. Serous discharge developed in three patients. In three patients, n.cutaneus femoralis lateralis injury developed. The periprosthetic fracture was observed during surgery in five patients.&#x0D; Conclusion: In our study, it was seen that patients have successful and fast functional results when total hip replacement using a direct anterior approach was performed. Compared to the literature, faster recovery is observed in the early period compared to other approaches; however, no difference is seen between the approaches in the mid- and long term. &#x0D; Keywords: Direct anterior approach, Total hip arthroplasty, mid-term results