Dislocation of bipolar hemiarthroplasty: rate, contributing factors, and outcome

Predicting Instability Risk Following Hemiarthroplasty for Femoral Neck Hip Fractures in Geriatric Patients

BACKGROUND

Although a rare complication, dislocation following hemiarthroplasty (HA) for a femoral neck hip fracture is associated with increased mortality, readmission, and possible revision surgery. To date many of the specific risk factors have been difficult to demonstrate. Patient factors, surgical factors, as well as morphological factors need to be assessed. Therefore, the purpose of this study was to elucidate the risk factors for dislocation of HA following femoral neck hip fractures in the geriatric population.

METHODS

This was a retrospective review of 270 patients who had hip fractures. Medical records between the years 2016 and 2022 informed binomial regression predictive models. The discriminative ability of variables in the final model and acetabular anteversion to predict dislocation was assessed with area under the curve (AUC) estimates.

RESULTS

Center edge angle (odds ratio 1.23), abduction angle (odds ratio 1.17), and depth width ratio (2.96e-11) were significant predictors of dislocation (P = .003, .028, and <.001, respectively). Center edge angle and depth width ratio (<44.1 ° and .298), respectively, were cut scores for risk. Dementia had a high discriminative of ability, as did men (AUC = 0.617, 0.558, respectively). Acetabular anteversion was not predictive of dislocation (P = .259) and theorized anteversion safe zones had poor discriminative ability with AUCs of 0.510 and 0.503, respectively.

CONCLUSIONS

Morphological factors related to hip dysplasia and a shallow acetabulum, which can be assessed with a radiograph alone, were found to be predictors of instability following HA in the elderly. Hemiarthroplasty implant design and manufacturer, and also acetabular version did not contribute to instability risk.

Outcomes Following Hemiarthroplasty for Femoral Neck Fracture in Patients Who Have Hemiparesis

BACKGROUND

Hemiparesis increases the risk of femoral neck fracture (FNF) in the elderly, which frequently necessitates hemiarthroplasty. There are limited reports on the outcomes of hemiarthroplasty in patients who have hemiparesis. The purpose of this study was to evaluate hemiparesis as a potential risk factor for medical and surgical complications following hemiarthroplasty.

METHODS

Hemiparetic patients who have concomitant FNF and underwent hemiarthroplasty with at least 2 years of follow-up were identified using a national insurance database. A 10:1 matched control cohort of patients who did not have hemiparesis was created for comparison. There were 1,340 patients who have and 12,988 patients who did not have hemiparesis undergoing hemiarthroplasty for FNF. Multivariate logistic regression analyses were used to evaluate rates of medical and surgical complications between the 2 cohorts.

RESULTS

Aside from increased rates of medical complications including cerebrovascular accident (P < .001), urinary tract infection (P = .020), sepsis (P = .002), and myocardial infarction (P < .001), patients who have hemiparesis also experienced higher rates of dislocation within 1 and 2 years (Odds Ratio (OR) 1.54, P = .009; OR 1.52, P = .010). Hemiparesis was not associated with higher risk of wound complications, periprosthetic joint infection, aseptic loosening, and periprosthetic fracture, but was associated with higher incidence of 90-day ED-visits (OR 1.16, P = .031) and 90-day readmission (OR 1.32, P < .001).

CONCLUSION

While patients who have hemiparesis do not have increased risk of implant-related complications other than dislocation, they are at increased risk of developing medical complications following hemiarthroplasty for FNF.

Patients undergoing hip hemiarthroplasty who require early return to theatre have early increased mortality and worse functional outcomes at short term follow-up

BACKGROUND

Re-operation following hip hemiarthroplasty is potentially devastating due to a frail, co-morbid surgical cohort. We aimed to assess the outcomes of patients who required early return to theatre (RTT) within 30 days of index operation in a high-volume hip fracture unit.

METHODS

A retrospective review of a prospectively maintained database was undertaken. All hip hemiarthroplasties performed between 1st January 2010 and 31st December 2019 was included. Demographic details, complications including reason for return to theatre, length of stay, discharge destination, functional outcome and mortality were collected and reviewed.

RESULTS

4340 hip hemiarthroplasty procedures were performed, of which 64 patients (1.47%) required early RTT within 30 days of index procedure and 4276 patients did not require early-RTT. The most common reasons for RTT were infection (n = 47) and dislocation (n = 15). There were no cases of peri‑prosthetic fracture requiring RTT within 30 days. Patients requiring early RTT had a significantly increased rate of mortality within 120 days; 32.8% (21 of the 64 patients) versus 13.6% (580 out of the 4276) not requiring early RTT (p < 0.001). The median length of acute inpatient admission for patients who required early RTT was significantly longer at 31 days (range 6-185 days) compared to 10 days (range 3-171 days, p < 0.001) for those without early RTT. Early RTT was associated with a poorer functional mobility outcome at 120 days post-operatively, with a significantly greater reduction in Barthel score compared to the non-RTT cohort (p < 0.05).

CONCLUSION

Patients requiring early RTT following hip hemiarthroplasty had a significantly increased length of stay, mortality and worse functional outcome compared to patients who did not require early RTT within 30 days.

Does Surgical Approach Influence Complication Rate of Hip Hemiarthroplasty for Femoral Neck Fractures? A Literature Review and Meta-Analysis

Background: Femoral neck fractures are an epidemiologically significant issue with major effects on patients and health care systems, as they account for a large percentage of bone injuries in the elderly. Hip hemiarthroplasty is a common surgical procedure in the treatment of displaced femoral neck fractures. Several surgical approaches may be used to access the hip joint in case of femoral neck fractures, each with its own benefits and potential drawbacks, but none of them has consistently been found to be superior to the others. This article aims to systematically review and compare the different approaches in terms of the complication rate at the last follow-up. Methods: an in-depth search on PubMed/Scopus/Web of Science databases and a cross-referencing search was carried out concerning the articles comparing different approaches in hemiarthroplasty and reporting detailed data. Results: A total of 97,576 hips were included: 1030 treated with a direct anterior approach, 4131 with an anterolateral approach, 59,110 with a direct lateral approach, and 33,007 with a posterolateral approach. Comparing the different approaches, significant differences were found in both the overall complication rate and the rate of revision surgery performed (p < 0.05). In particular, the posterolateral approach showed a significantly higher complication rate than the lateral approach (8.4% vs. 3.2%, p < 0.001). Furthermore, the dislocation rate in the posterolateral group was significantly higher than in the other three groups considered (p < 0.026). However, the posterolateral group showed less blood loss than the anterolateral group (p < 0.001), a lower intraoperative fractures rate than the direct anterior group (p < 0.035), and shorter mean operative time than the direct lateral group (p < 0.018). Conclusions: The posterolateral approach showed a higher complication rate than direct lateral approach and a higher prosthetic dislocation rate than the other three types of surgical approaches. On the other hand, patients treated with posterolateral approach showed better outcomes in other parameters considered, such as mean operative time, mean blood loss and intraoperative fractures rate. The knowledge of the limitations of each approach and the most common associated complications can lead to choosing a surgical technique based on the patient's individual risk.

No Difference in Dislocation Rates Comparing DMC-THA for Displaced Femoral Neck Fracture and for Osteoarthritis-A Matched-Pair Analysis

Background

We hypothesized the risk of prosthetic instability would be similar in patients treated for femoral neck fracture (FNF) comparatively to patients treated for osteoarthritis (OA) using a dual-mobility cup-total hip arthroplasty (DMC-THA).

Methods

One hundred and nine patients (109 hips), with a mean age of 69.6 ± 3 years (65-75 years), underwent DMC-THA using a posterolateral approach for a FNF (study group). Patients were matched for age and sex with 109 OA patients treated by the same procedure (control).

Results

Postoperatively, there were four dislocations of the large articulation in the study group, and none in the control (p = 0.12). Periprosthetic joint infection (PJI) was the most common surgical complication and was more frequent in the study group. Postoperatively, functional results were at least good in > 90% patients in both groups. At the last follow-up, patients in the study group had recovered autonomy and physical activity comparable to those of the preoperative period.

Conclusion

We found no increased risk of dislocation after DMC-THA using a posterolateral approach for FNF as compared to the same procedure for OA. In this study, function and independence were restored postoperatively in the vast majority of patients. DMC-THA appears as a viable therapeutic option in autonomous patients with a displaced FNF.

A comparison of different surgical approaches to hemiarthroplasty for the femoral neck fractures: A meta-analysis

There are three traditional surgical approaches to hemiarthroplasty (HA) for femoral neck fractures, respectively, the anterior approach (AA), the lateral approach (LA) and the posterior approach (PA). However, the optimum approach is still controversial, the purpose of this meta-analysis is to identify the merits and demerits of all three approaches. All clinical published studies in PubMed, Web of Science, Embase, and the Cochrane Library from January 2000 to April 2022 were searched which compared different surgical approaches and covered surgery-related outcomes and frequent complications. Five randomized controlled trials and 26 cohort studies for a total of 31 clinical trials were included in the meta-analysis. The dislocation of PA was significantly higher than LA (OR: 3.00 95% CI: 2.25-4.01 I ² = 27% P < 0.00001) and AA (OR: 6.61 95% CI: 2.28-19.13 I ² = 0% P = 0.0005); PA was substantially more than LA in terms of risk of postoperative reoperation (P < 0.05); meanwhile, AA has markedly shorter hospital length of stays than LA. The remaining items showed no significant differences in the results.The results of this meta-analysis demonstrated that the risk of PA dislocation and reoperation is higher with hemiarthroplasty, and AA has markedly shorter hospital length of stays than LA.

Effect of hip hemiarthroplasty dislocation on mortality after hip fracture surgery

INTRODUCTION

Hip arthroplasty is the treatment of choice for displaced femoral neck fractures among the older population. The hip prosthesis dislocation is one of the most pointed potential complications after hip arthroplasty, but there is a lack of updated information on the effect of dislocation on the survival of older hip fracture patients so treated by hip hemiarthroplasty. We aim to evaluate the standalone effect of hip prosthesis dislocation after hip fracture hemiarthroplasty on patients' survival outcomes.

MATERIALS AND METHODS

We conducted a retrospective multicenter study, including 6631 femoral neck fracture patients over 65 surgically treated by hemiarthroplasty. We made follow-up cut-offs 30-days, 6 weeks, 90-days, and one year after hospital discharge determining hip dislocation rate and patients' survival.

RESULTS

The women population represented 78.7%, and the mean age of the population was 85.2 ± 6.7 years. Hip prosthesis dislocation incidence was 1.9% in the first 90-days after discharge, representing 91.54% of primary dislocations yearly noted. We reported statistically significant increased mortality rates of patients presenting at least one hip prosthesis dislocation event (from 16.0% to 24.6% at 90-day after discharge, and 29.5% to 44.7% at one year), and also significantly decreasing patient survival function at 90-day (P = .016) and one-year follow-up (P < .001). The recurrent dislocation events (26.15%) showed even higher mortality rates (up to 60.6%, p < .001). The multivariate Cox regression model determined that prosthesis dislocation was the only significant variable (P = .035) affecting patient survival, increasing the risk of dying before one year of follow-up by 2.7 times.

DISCUSSION

Our study stands for the standalone hip prosthesis dislocation entailing a higher risk of death after hip fracture hemiarthroplasty in the older population.

Effect of hip hemiarthroplasty dislocation on mortality after hip fracture surgery

INTRODUCTION

Hip arthroplasty is the treatment of choice for displaced femoral neck fractures among the older population. The hip prosthesis dislocation is one of the most pointed potential complications after hip arthroplasty, but there is a lack of updated information on the effect of dislocation on the survival of older hip fracture patients so treated by hip hemiarthroplasty. We aim to evaluate the standalone effect of hip prosthesis dislocation after hip fracture hemiarthroplasty on patients' survival outcomes.

MATERIALS AND METHODS

We conducted a retrospective multicenter study, including 6631 femoral neck fracture patients over 65 surgically treated by hemiarthroplasty. We made follow-up cut-offs 30-days, 6 weeks, 90-days, and one year after hospital discharge determining hip dislocation rate and patients' survival.

RESULTS

The women population represented 78.7%, and the mean age of the population was 85.2±6.7 years. Hip prosthesis dislocation incidence was 1.9% in the first 90-days after discharge, representing 91.54% of primary dislocations yearly noted. We reported statistically significant increased mortality rates of patients presenting at least one hip prosthesis dislocation event (from 16.0% to 24.6% at 90-day after discharge, and 29.5% to 44.7% at one year), and also significantly decreasing patient survival function at 90-day (p=0.016) and one-year follow-up (p<0.001). The recurrent dislocation events (26.15%) showed even higher mortality rates (up to 60.6%, p<0.001). The multivariate Cox regression model determined that prosthesis dislocation was the only significant variable (p=0.035) affecting patient survival, increasing the risk of dying before one year of follow-up by 2.7 times.

DISCUSSION

Our study stands for the standalone hip prosthesis dislocation entailing a higher risk of death after hip fracture hemiarthroplasty in the older population.

Modern cemented Furlong hemiarthroplasty: Are dislocations rates better?

BACKGROUND

Dislocation following hip hemiarthroplasty is a major complication with increased mortality and morbidity. Data looking at dislocation following contemporary bipolar stems are lacking in literature.

METHODS

Retrospective review of our prospective national hip fracture database over a two-year period. Group 1 comprised of consecutive patients receiving bipolar Furlong prosthesis (N222) while Group 2 was made up of a historical cohort (uncemented; N254). Clinical and radiological records were reviewed to determine dislocation rates, causes and associative factors of dislocations. Data were analysed using SPSS.

RESULTS

Following 476 hemiarthroplasties performed during the study period, 12 (2.5%) dislocations were reported (eight in Group 1; four in Group 2). There was no significant difference in dislocation rates (3.6% vs 1.6%) between groups (p = 0.159). Subgroup analysis of Group 1 demonstrated a significant difference in dislocations with Furlong cemented (6%) as compared with Furlong uncemented (0%) hemiarthroplasties (p = 0.024). Following dislocation, death rates increased to 8.3% from 1.7% in both groups.

CONCLUSION

There is a statistically significant increase in dislocation rate following use of cemented Furlong prosthesis when compared to similar uncemented prosthesis at the same treatment period. However, when compared to traditional uncemented prosthesis, there is no difference in dislocation rates.

The impact of increasing femoral offset and stem anteversion on postoperative dislocation in bipolar hemiarthroplasty

BACKGROUND

Femoral offset and anteversion have been reported to affect the incidence of dislocation following bipolar hemiarthroplasty, although the magnitudes of contributions of the femoral offset and stem anteversion on dislocation, both singly and in combination is not fully understood.

METHODS

Using the CT data of 61 patients (61 hips), including 30 male and 31 female who underwent bipolar hemiarthroplasty, three-dimensional dynamic motion analysis was performed using a modular implant that enabled adjustment of femoral offset and stem anteversion independently. The pattern of impingement and relationship between femoral offset/stem anteversion and range of motion were evaluated using the software.

FINDINGS

We found that a higher femoral offset and stem anteversion correlate with a greater range of motion of flexion and internal rotation. Furthermore, an increased femoral offset has a great effect on increasing range of motion of flexion than stem anteversion, and increased both femoral offset and stem anteversion have fewer effect on the flexion, whereas increasing stem anteversion has a great impact on internal rotation than offset, especially in the case with lower femoral anteversion. However, a higher stem anteversion decrease the range of motion of external rotation, whereas a higher femoral offset leads to an increased range of motion of external rotation.

INTERPRETATION

We demonstrated that both a higher femoral offset and stem anteversion substantially affected the range of motion in flexion, internal rotation and external rotation. However, these are not independent, but rather mutually confounding, the surgeons should consider retaining femoral/anterior offset in bipolar hemiarthroplasty.

Uncoupling of the Femoral Head in a Case of Bipolar Hemiarthroplasty Dislocation

Bipolar hemiarthroplasty of the hip is a routinely done procedure in the elderly with neck of femur fractures. An uncommon yet widely recognized complication is the dislocation of hemiarthroplasty. Uncoupling of the femoral head from the stem implant can complicate such dislocations. Such uncoupling requires open reduction. Here, we present a case where the patient sustained a hip dislocation and uncoupling following a bipolar hemiarthroplasty.

Should we employ preoperative templating in hip hemiarthroplasty after femoral neck fracture? A nested case-control study

INTRODUCTION

Dislocation following hip hemiarthroplasty is a serious complication. It remains unclear if acetabular morphology is associated with a higher risk of dislocation. The aim of our study was to investigate whether there are differences in hip morphology radiological parameters between patients who have suffered a dislocation episode, and those who have not suffered a dislocation.

MATERIAL AND METHODS

Between January 2015 and December 2018, a nested case-control study was performed. From 707 patients who underwent hip hemiarthroplasty because of femoral neck fracture, 50 patients (50 hips) suffered an episode of dislocation. They were randomly matched with 94 patients (100 hips) without dislocation (ratio 1:2). Clinical data regarding demographics, medical comorbidities and surgical and radiological parameters were studied.

RESULTS

Statistically significantly smaller lateral centre-edge angle (LCEA) and femoral offset (FO) and greater Tönnis angle were found in the dislocation group. No differences in acetabular angle were seen. Neurological impairment prevalence was statistically significantly higher in patients who suffered a dislocation (60% vs. 44%, p = 0.011).

CONCLUSIONS

The current study suggests that a smaller LCEA and FO, a greater TA, and neurological impairment could be related to a higher risk of hip hemiarthroplasty dislocation after femoral neck fracture in the elderly. We consider that preoperative templating could be helpful in identifying abnormal parameters and carefully planning surgery could lead to changes in treatment strategy, such as choosing a dual-mobility total hip arthroplasty.

Total hip arthroplasty or hemiarthroplasty for femoral neck fractures in elderly patients with neuromuscular imbalance

AIM

This study aimed at comparing clinical outcomes between total hip arthroplasty (THA) and hemiarthroplasty (HA) in elderly patients with neuromuscular imbalance (stroke, Parkinsonism, etc.).

METHODS

A total of 226 elderly patients with neuromuscular imbalance and femoral neck fractures treated with THA or HA were recruited at a single center, and their clinical data retrospectively reviewed. Mean follow-up time was 40.5 months (range 24-78), the primary outcome was secondary hip procedure while secondary outcomes included function, pain, health-related quality of life, complications, and death. Kaplan-Meier survival curves were used to determine the estimated survivorship, with re-operation as the end point. Logistic regression analyses were performed to assess the effects of different surgical procedures on mortality while linear regression analysis was used to evaluate the function, pain and quality of life.

RESULTS

Kaplan-Meier survivorship, with an end point of re-operation for any reason in the THA group, was 90.3% (95% CI 82.3-98.3), which was not significantly different from 95.9% (95% CI 93.0-98.8) for the HA group (p = 0.137). The most common cause of re-operation in both groups was dislocation. There were no significant differences with regards to postoperative complications (including dislocation). Compared to HA, THA exhibited better functional outcomes, quality of life and low pain intensity. Notably, there was no difference in 2 year mortality rates between the groups, however, HA was associated with a higher mortality rate beyond 2 years (OR 0.137; 95% CI 0.030-0.630; p = 0.011).

CONCLUSION

THA is an effective therapeutic procedure for femoral neck fractures in elderly patients with neuromuscular imbalance.

Superior functional outcome with dual mobility THR as compared to conventional THR in fracture neck femur: a prospective cohort study

Introduction: Total Hip Replacement (THR) in displaced Fracture Neck of Femur (FNOF) is associated with higher dislocation rates. Conventional THR with a large femoral head and anterior approach has reduced the instability, but it remains higher than THR done for other aetiology. Recent studies have shown reduced dislocation rates with dual mobility THR (DMTHR) for FNOF; however, there is a lack of comparative research to show its superiority over conventional THR. Further, its role in the Asian subcontinent, where the patient requires sitting cross-legged or squatting, has not been studied. Methods: A prospective cohort study of 103 elderly patients with displaced FNOF with a minimum follow-up of 1-year. Fifty-two patients were operated on with DMTHR and fifty-one patients with conventional THR. Both the groups were matched in terms of demographic data, surgical approach, and postoperative protocol. Radiological and functional outcomes in terms of Harris Hip Score (HHS), Range of motion, Patient Reported Outcome Measures (PROM), and Dislocation rate were compared between the two groups. Results: Mean HHS of the DMTHR group was 76.37 at three months and 87.02 at the end of the 1-year postoperatively, which was significantly better than the conventional THR group 65.65 at three months and 72.96 at 1-year. The range of motion was significantly better in the DMTHR group than the conventional THR group. There was no significant difference in radiological outcomes and postoperative dislocation rate between the two groups. Conclusion: Dual mobility implants give better results than conventional implants for primary THA in elderly patients of displaced FNOF regarding better function and greater range of motion.

Cemented versus uncemented hemiarthroplasty for femoral neck fractures in patients with neuromuscular diseases: a minimum of 2 years' follow-up study

BACKGROUND

The aim of this study was to compare the outcomes of cemented and uncemented hemiarthroplasty for femoral neck fractures in patients with neuromuscular disease.

METHODS

We reviewed 156 patients with neuromuscular disease who underwent hemiarthroplasty between June 2015 and December 2019. Patients were divided into cemented group (n = 105) and uncemented group (n = 51), with a minimum follow-up of 2 years. Factors including preoperative features, duration of surgery, intraoperative blood loss, complications, pain, Harris hip scores (HHS), and quality of life were compared across groups, and Kaplan-Meier curves were used to estimate survival.

RESULTS

In the uncemented group, the mean duration of surgery was 16.0 min. shorter (p = 0.001) and the mean intraoperative blood loss was 71.1 mL less (p = 0.01). Visual analog scales (VAS), HHS, and European Quality of Life-5 Dimensions (EQ-5D) scores were not different between the groups. Despite a few potential trends, we did not observe a difference in complications such as periprosthetic fractures and dislocations. The rates of mortality were similar between groups (p=0.821).

CONCLUSIONS

Both arthroplasties may be used with good medium-term results in the treatment of femoral neck fractures in patients with neuromuscular diseases.

Cementless Hemiarthroplasty for Intracapsular Femoral Neck Fractures in the Octa- and Nonagenarians

Backgroud

Current evidence supports the use of cemented hemiarthroplasty for treatment of intracapsular femoral neck fractures since it is associated with a lower risk of implant-related complications. However, many medical centers employ the cementless technique for the frail elderly population because it is faster and has lower cardiovascular risks and perioperative mortality. This observational study reports the outcomes of cementless bipolar hemiarthroplasty for intracapsular femoral neck fractures in patients aged 80 years and older.

Methods

A total of 424 patients (female, 77.1%) with a mean age of 86.9 years were operated for intracapsular femoral neck fractures between January 2009 and December 2017. Of those, 66.7% had an American Society of Anaesthesiologists (ASA) score of 3 or more. All operations were performed with the posterolateral surgical approach and all patients received a cementless stem. Intraoperative and perioperative values and in-hospital outcomes were evaluated, and clinical and radiographical follow-up was done at 40 days, 90 days, and when possible between 5 months and 12 months postoperatively. Multivariate analysis was performed to evaluate if there were factors affecting mortality.

Results

The mean operative time was 50 minutes. There were no deaths intraoperatively. Intraoperative periprosthetic fractures occurred in 2.1% of the cases with 66.7% of them fixed through cerclage wires intraoperatively. The median length of hospitalization was 11 days (interquartile range, 8.75–15) and 2.4% of patients died while in hospital after surgery. Approximately 91.5% of patients presented with perioperative anemia. Only 1.9% of the complications were related to the implant, 62.5% of which were dislocations. More than 90% of patients were ambulatory either autonomously or with support at each follow-up assessment. Age, male sex, and higher ASA score were related to increased mortality.

Conclusions

Despite some limitations, this observational study underlines that a cementless femoral stem of modern design can give good clinical outcomes, thus being an appropriate solution especially for the frail elderly.

Disassembly of bilateral bipolar heads within 10 years after hip hemiarthroplasties for avascular necrosis of femoral heads: a case report

Prosthetic joint surgeries, total hip arthroplasty (THA) or bipolar hemiarthroplasty (BHA) and joint preservation surgeries can be performed for avascular osteonecrosis of femoral head (ONFH) with collapse. Although excellent surgical results have been reported, long-term survivorship and postoperative complications are a great concern. The purpose of this study was to report a case of bilateral disassembly of bipolar heads within 10 years after BHA for ONFH. A 61-year-old man, whose occupation was carpenter, underwent bilateral BHA for ONFH at another hospital when he was 57 years old. He had acute right hip pain during working and visited our institute. Radiographs revealed intra-articular (outer and inner head) disassembly of the right bipolar head, and conversion to THA was performed. Five years later, he had contralateral (left) hip pain. Radiographs revealed disassembly of bipolar head, as had occurred with the right hip, and similar conversion surgery was performed for the left hip. Marked wear and detachment of the polyethylene bearings of the outer head and failure of the locking mechanism between a skirted 22-mm-diameter inner head and polyethylene insert were observed in both hips at each revision surgery. Degeneration of the acetabulum were also observed in both hips. The failure of the self-centering mechanism because of degenerative change of the acetabulum, impingement of the outer head and neck, and high activity seemed to be the causes of disassembly of the bilateral bipolar heads. Therefore, it is important to select the type of prostheses depending on the age, activity and occupation of each patient.

Risk Factors with Multilevel Evidence for Dislocation in Patients with Femoral Neck Fractures After Hip Hemiarthroplasty: A Systematic Review

BACKGROUND

Hip hemiarthroplasty (HA) is a standard surgical procedure for elderly patients with displaced fracture of the femoral neck, where dislocation is a possible complication. This study is a systematic review on the risk factors of implant dislocation in patients with femoral neck fracture following hip hemiarthroplasty (HA), and evaluates the methodological quality of the included studies.

METHODS

Studies on risk factor assessment of dislocation following hip HA were sourced from EMBASE, Ovid, PubMed and ScienceDirect databases. The quality of included studies was evaluated using an improved quality evaluation method combined with a best-evidence synthesis method.

RESULTS

A total of 130,127 patients were involved in 17 observational studies included in this systematic review, with a dislocation rate that ranged between 0.76 and 12.2% (overall incidence was 4-5% by meta-analysis). According to the applied quality evaluation criteria, eight studies were considered to be of high quality, six to be of medium quality, and three to be of low quality. The posterolateral surgical approach was identified as the only risk factor supported by strong evidence, while patients with small acetabular coverage and low postoperative offset were identified as risk factors supported by moderate evidence, and 11 other risk factors were supported by limited evidence.

CONCLUSION

This systematic review provides some evidence in helping surgeons develop optimal prevention strategies for dislocation following hip HA during the perioperative period based on common risk factors identified in the literature. However, conclusive evidence supporting most of these risk factors is lacking and more methodologically rigorous studies are required to increase the confidence of recommendations.

Factors affecting dislocation after bipolar hemiarthroplasty in patients with femoral neck fracture

PURPOSE

This study aimed to investigate the anatomic risk factors associated with dislocation following bipolar hemiarthroplasty for the treatment of femoral neck fracture.

MATERIALS AND METHODS

We retrospectively reviewed 208 consecutive patients (133 women, 75 men) with femoral neck fractures who were treated with bipolar hemiarthroplasty between 2015 and 2018. A comparative analysis was performed between dislocation (n = 18) and non-dislocation (n = 190) groups in terms of patient demographics, surgical and pelvic morphologic factors, and clinical outcomes, including postoperative Harris and modified Harris hip scores. Independent risk factors affecting dislocation were also evaluated.

RESULTS

The mean follow-up period was 30.8 ± 2.0 (range, 12-48) months. The mean age was 79.2 ± 7.4 (range, 71-94) years. The dislocation rate was 8.6% (18/208), and the mean dislocation time after operation was 2.0 ± 1.1 (range, 1-4) months. Patient-related factors did not differ between the dislocated and non-dislocated groups. As regards dislocation, statistically significant difference was observed in surgical and pelvic morphologic factors, including femoral offset, residual femoral neck length, trochanter upper end and femoral head center distance, and height of the hip center of the operated side (p = 0.025, p = 0.013, p = 0.002, p = 0.008, respectively). Moreover, the femoral offset, height of the hip center, and femoral neck-shaft angle of the non-operated side are significantly different between the groups (p = 0.007, p = 0.001, p = 0.027, respectively). Decrease in the center edge (CE) angle, offset of prosthesis, and increase in femoral head extrusion index (FHEI) of the operated side and decrease in the height of the hip center of the non-operated side increased the risk of dislocation (p = 0.030, OR: 1,306; p = 0.041, OR: 8.15; p = 0.020, OR: 1.038; p = 0.010, OR: 2.02, respectively).

CONCLUSIONS

Pelvic morphologic features and surgical factors were found to affect dislocation. Patients with smaller OP, CE angle of the operated side, and higher FHEI and smaller height of the hip center of the non-operated side should be carefully monitored to decrease postoperative dislocation.

Morphological risk factors associated with dislocation after bipolar hemiarthroplasty of the hip in patients with femoral neck fractures-a nested case-control study

Background

The relationship between preoperative hip measurements and dislocation after bipolar hemiarthroplasty is presently unclear. In the current study, we investigated the morphological risk factors associated with dislocation after bipolar hemiarthroplasty of the hip in patients with femoral neck fractures.

Methods

Between January 2011 and June 2017, a nested case-control design study was used to analyze the risk factors for dislocation in 348 patients who had undergone bipolar hemiarthroplasty because of femoral neck fractures. Twelve patients underwent at least one dislocation postoperatively. Sixty patients without dislocation were selected as controls matched in terms of time of surgery, age, and sex, at a ratio of 1:5. Patient acetabular measurements were compared between the dislocation group and the control group, including the center-edge angle, abduction angle, acetabular width and depth, depth-to-width ratio, femoral neck offset, leg length discrepancy, and femoral head coverage ratio. A multivariate logistic regression model was used to evaluate the morphological risk factors of dislocation.

Results

Postoperatively, the incidence of dislocation was 3.4%. A smaller center-edge angle was found to be a risk factor associated with dislocation after bipolar hemiarthroplasty of the hip. Patients with small acetabular depth and a small acetabular depth–width ratio were prone to dislocation. Patients with a center-edge angle of ≤ 45.4° or an acetabular depth of ≤ 19.12 mm were more likely to suffer dislocation.

Conclusions

Careful preoperative measurements before bipolar hemiarthroplasty of the hip are important. Surgical intervention for femoral neck fracture patients with a shallow acetabulum should be carefully planned and total hip arthroplasty should be considered when necessary.

Does Surgeon Fellowship Training Influence Outcomes in Hemiarthroplasty for Femoral Neck Fracture?

BACKGROUND

The aim of this study is to compare the outcomes (90 days and 1 year) of patients with femoral neck fracture undergoing hemiarthroplasty by surgeons with different fellowship training: trauma, arthroplasty, and general orthopedics.

METHODS

This study is a retrospective review of consecutive patients undergoing hip hemiarthroplasty for femoral neck fracture from 2010 to 2018. Comorbidities, perioperative details, demographics, injury variables, and time-to-surgery were compared between the fellowship training cohorts, in addition to outcomes including dislocation, periprosthetic joint infection, and mortality at 90 days and 1 year.

RESULTS

A total of 298 hips with an average age of 77.8 years underwent hemiarthroplasty for femoral neck fracture. Arthroplasty surgeons had a significantly shorter operative duration (82 minutes, P = .0014) and utilized the anterior approach more frequently (P < .0001). The general orthopedists had a significantly increased total surgical complication risk compared to both the arthroplasty and trauma fellowship-trained cohorts at both 90 days (11.8% vs 1.6% vs 3.9%, P = .015) and 1 year (18.2% vs 4.9% vs 7.1%, P = .008). The overall mortality risk was 11.7% at 90 days and 22.8% at 1 year. When adjusted for covariates, including comorbidities, gender, age, and preoperative walking capacity, both the arthroplasty fellowship-trained cohort (odds ratio 0.381, 95% confidence interval 0.159-0.912, P = .030) and the general orthopedist cohort (odds ratio 0.495; 95% confidence interval 0.258-0.952, P = .035) had reduced risk of 1-year mortality compared to the trauma fellowship-trained cohort.

CONCLUSION

Hemiarthroplasty performed for femoral neck fractures may result in fewer complications when performed by arthroplasty fellowship-trained surgeons. An arthroplasty weekly on-call schedule and adjusted institutional protocols may be utilized to improve outcomes and reduce complications.

LEVEL OF EVIDENCE

Level II, retrospective cohort.

Hemiarthroplasty vs Total Hip Arthroplasty for the Management of Displaced Neck of Femur Fractures: A Systematic Review and Meta-Analysis

BACKGROUND

Displaced femoral neck fractures (DFNF) are common and can be treated with osteosynthesis, hemiarthroplasty (HA), or total hip arthroplasty (THA). There is no consensus as to which intervention is superior in managing DFNF.

METHODS

Studies were identified through a systematic search of the MEDLINE database, EMBASE database, and Cochrane Controlled Trials. Included studies were randomized or controlled trials (1966 to August 2018) comparing THA with HA for the management of DFNF. (https://www.crd.york.ac.uk/PROSPERO Identifier: CRD42018110057).

RESULTS

Seventeen studies were included totaling 1364 patients (660 THA and 704 HA). THA was found to be superior to HA in terms of risk of reoperation, Harris Hip Score and Quality of Life (Short Form 36). Overall, the risk of dislocation was greater in THA group than HA in the first 4 years, after which there was no difference. There was no difference between THA and HA in terms of mortality or infection.

CONCLUSION

Overall, THA appears to be superior to HA. THA should be the recommended intervention for DFNF in patients with a life expectancy >4 years and in patients younger than 80 years. However, both HA and THA are reasonable interventions in patients older than 80 years and with shorter life expectancy.

Reduced Revision Risk for Dual-Mobility Cup in Total Hip Replacement Due to Hip Fracture: A Matched-Pair Analysis of 9,040 Cases from the Nordic Arthroplasty Register Association (NARA)

BACKGROUND

The dual-mobility acetabular cup (DMC) has an additional bearing consisting of a mobile polyethylene component between the prosthetic head and the outer metal shell. This design has gained popularity in revision total hip arthroplasty (THA) and in primary treatment of femoral neck fractures with the anticipation of a reduced risk of THA instability. Our primary aim was to evaluate the overall revision risk of these cups on the basis of data from the Nordic Arthroplasty Register Association (NARA) database, and our secondary aim was to study specific revision causes including dislocation.

METHODS

Propensity score matching for age, sex, fixation of the cup and stem, and the year of surgery (2001 to 2014) was used to match 4,520 hip fractures treated with a DMC to 4,520 hip fractures treated with conventional THA (control group). Competing risk regression analyses with revision or death as the end point were used. Revision was defined as a secondary surgical procedure in which any component of the implant was removed or exchanged. In addition, revision of the cup was analyzed.

RESULTS

The DMCs had a lower risk of revision compared with conventional THA, with an adjusted hazard ratio (AHR) of 0.75 (95% confidence interval [CI] = 0.62 to 0.92). This was consistent after adjusting for surgical approach. DMCs had a lower risk of revision due to dislocation (AHR = 0.45 [95% CI = 0.30 to 0.68]) but we found no difference regarding revision for deep infection. Revision of the acetabular component, both in general and due to dislocation, was more frequent with the use of conventional cups. The risk of death was higher in the DMC group (AHR = 1.49 [95% CI = 1.40 to 1.59]).

CONCLUSIONS

The use of a DMC as primary treatment for hip fracture was associated with a lower risk of revision in general and due to dislocation in particular. The total number of DMCs analyzed (4,520) likely exceeds any cohort of DMC-treated fractures published to date.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Hip precautions not meaningful after hemiarthroplasty due to hip fracture. Cluster-randomized study of 394 patients operated with direct anterolateral approach

AIMS

We aimed to compare two treatment regimes, one with and one without postoperative precautions in hemiarthroplasty patients, in terms of dislocation rate and patient-reported outcome. Direct lateral approach was used.

PATIENTS AND METHODS

394 patients were included in a cluster-randomized study 2010-2014. Depending on which ward they were admitted to, they were allotted to free rehabilitation (non-precaution group, NPG, n = 226) or our conventional regime with precautions and mandatory assistive equipment (precaution group, PG, n = 168). Patients were followed during hospital stay, at 6 weeks (postal questionnaire), 3 month (visit) and 6 months (reading of medical records) by means of function tests, health-related quality of life (EQ-5D) and other patient-reported outcome measures (PROM).

RESULTS

One patient in each group had dislocation(s). We found no statistically significant differences regarding in-hospital-mortality, severe adverse events, EQ5D index or other PROM. In the NPG, rehabilitation personnel had significantly shorter work effort during hospital stay (p < 0.001). 7 in the NPG and 13 of the PG had reoperations (p = 0.038), 4 and 8 had deep infections, 3 and 5 periprosthetic fractures.

CONCLUSION

Rehabilitation precautions are not needed for preventing dislocation when direct lateral approach is used. Without precautions, rehabilitation personnel implement significantly shorter work effort during hospital. We found no statistically significant differences regarding PROM and complications except for somewhat more reoperations in total in the precaution group.

Radiographic evaluation of linear wear of bipolar hemiarthroplasty devices in vivo

BACKGROUND

The indications for bipolar hemiarthroplasty (BHA) have been narrowing as those for total hip arthroplasty (THA) have been expanding in cases of femoral neck fracture and initial stages of osteonecrosis of femoral head (ONFH). It is difficult to measure wear in vivo after BHA because the equipment used has a dual bearing system with an inner head inside a metal outer cup. The present study aimed to (1) use a roentgenograph to measure linear wear in vivo after BHA with different acetabular conditions around the bipolar cup, and (2) compare the linear wear of polyethylene between integral bipolar cup (IBC) and Centrax prostheses.

METHODS

From among patients who had undergone BHA in our department after 1996, we analyzed 48 joints with osteoarthritis (OA) and without acetabular cartilage, as well as 25 joints with ONFH of stage 3 or less, in which the acetabular cartilage remains. Two types of bipolar cup prostheses were used: the IBC, which was gamma-sterilized in air using 2-Mrad irradiation, and the Centrax, which was gamma-sterilized in nitrogen using 3-Mrad irradiation. To image the inner head in vivo, we used high-pressure X-ray photography; we measured linear wear of the polyethylene with software using Martell Method 1.

RESULTS

Comparing mean annual linear wear between the OA and ONFH groups, using IBC prostheses in both groups, there was a significant difference (0.213 mm vs. 0.096 mm, respectively; P = 0.0177). There was a significant difference between the Centrax and IBC prostheses in OA patients in terms of linear wear (0.04 mm vs. 0.213 mm; P = 0.0181).

CONCLUSION

The linear wear of polyethylene in BHA implants can be affected by the material used to manufacture the bipolar cup. Such implants should only be used for appropriate indications.

Management and outcome of the dislocated hip hemiarthroplasty

AIMS

This study describes and compares the operative management and outcomes in a consecutive case series of patients with dislocated hemiarthroplasties of the hip, and compares outcomes with those of patients not sustaining a dislocation.

PATIENTS AND METHODS

Of 3326 consecutive patients treated with hemiarthroplasty for fractured neck of femur, 46 (1.4%) sustained dislocations. Of the 46 dislocations, there were 37 female patients (80.4%) and nine male patients (19.6%) with a mean age of 83.8 years (66 to 100). Operative intervention for each, and subsequent dislocations, were recorded. The following outcome measures were recorded: dislocation; mortality up to one-year post-injury; additional surgery; residential status; mobility; and pain score at one year.

RESULTS

Of 43 dislocations, 30 (70%) occurred within one month and 42 (98%) occurred within three months of hip fracture surgery. Seven (16%) of these patients were treated with a single closed reduction and sustained no further dislocations. Four (9%) were treated with open reduction and experienced no further dislocations. Three (7%) hips were left dislocated and the remaining 32 (74%) patients required additional surgery of further closed reduction, revision, or excision arthroplasty. The one-year mortality rates for patients treated with two or fewer reductions (open or closed), successful revision arthroplasty, and excision arthroplasty were 3/14 (21%), 1/7 (14%), and 8/14 (57%) respectively. The only statistically significant difference in mortality was the difference between patients who did not sustain a dislocation and those who did and were treated by excision arthroplasty (p = 0.03). Patients treated by excision arthroplasty had the greatest reduction in mobility scores and highest pain scores. The excision arthroplasty group also included the greatest proportion of patients not able to mobilize and the smallest proportion of patients remaining in their own home.

CONCLUSION

Most dislocations of hemiarthroplasties of the hip occur within one month of surgery. Closed reduction is generally unsuccessful. For those patients with unsuccessful closed reduction, revision arthroplasty should be considered when possible, as this results in a better functional outcome with a lower mortality than excision arthroplasty.

Hip Hemiarthroplasty in Neurologic or Cognitively Impaired Patients: A Case Series of Post-operative Dislocations

Introduction:

Hemiarthroplasty is the operation of choice for displaced intracapsular neck of femur fracture in elderly patients with low physical demands. Dislocation in this frail patient cohort can have devastating consequences. The patients with neurological and cognitive impairment are at additional risk secondary to imbalance of muscle tone and a reduced ability to engage with rehabilitation.

Case Report:

We present three cases of early post-operative dislocation of hip hemiarthroplasties, all of whom suffered from neurological and cognitive impairment, and highlight the uncontrollable patient factors that contributed to dislocation.

Conclusion:

The posterior approach was associated with all cases of dislocation in patients who also were neurologic or cognitively impaired. Posterior approach is safe to perform in the general population for hip hemiarthroplasty; however, the surgeon should consider avoiding the use of the posterior approach in this high-risk group.

Surgical Approaches and Hemiarthroplasty Outcomes for Femoral Neck Fractures: A Meta-Analysis

BACKGROUND

The lateral approach (LA), posterior approach (PA), and anterior approach (AA) are conventional surgical access routes for hemiarthroplasty in proximal femoral fractures. This meta-analysis assesses and compares the outcomes and attempts to identify the best approach for hemiarthroplasty in the treatment of proximal femoral fractures.

METHODS

An electronic search was performed from inception to October 25, 2017, for comparative studies including at least 2 of the conventional approaches. Outcomes including operation time, surgical blood loss, perioperative fractures, wound infections, dislocations, and hospital length of stay were plotted in forest plots.

RESULTS

Twenty-one eligible studies were selected including 3 randomized, controlled trials, 7 prospective and 11 retrospective cohort studies. The odds ratio (OR) for dislocations was significantly higher for the PA compared with the AA (OR, 2.61; 95% confidence interval [CI], 1.26 to 5.43; P = .01) and the LA (OR, 2.90; 95% CI, 1.63 to 5.14; P = .0003). The PA had a higher risk of reoperation compared to the AA (OR, 1.25; 95% CI, 1.12 to 1.41; P < .0001). No significant differences were found concerning perioperative fractures, wound infections, and hospital length of stay. Some studies suggest a better short-term functional outcome using the AA compared to the PA.

CONCLUSION

The PA for hemiarthroplasty in proximal femoral fractures poses an increased risk of dislocation and reoperation compared to the LA and AA. There are no evident advantages of the PA and its routine use for fracture-related hemiarthroplasty should be questioned.

The Dislocated Hip Hemiarthroplasty: Current Concepts of Etiological factors and Management

Background:

Hip hemiarthroplasty (HA) following an intracapsular neck of femur fracture is an increasingly common procedure as a result of an ageing population. Patients are often frail and so morbidity and mortality figures are significant. As a result the National Institute for Health and Clinical Excellence (NICE) has formulated guidelines and a Best Practice Tariff (BPT) in an attempt to improve the care of such patients. Dislocation following HA is a potentially devastating complication with a reported incidence ranging from 1 to 15%. Multiple causative factors have been cited and studied in an effort to reduce the incidence of this complication which has a high rate of recurrence following the first episode and is associated with a high mortality rate and significant financial burden on the health economy. This paper reviews the available literature in an effort to identify the most pertinent factors affecting dislocation rates and thus reduce the incidence of this serious complication.

Methods:

A comprehensive review of the literature was performed using the search engine PubMed with the keywords ‘hip’, ‘hemiarthroplasty’ and ‘dislocation’. Two hundred and forty three articles were identified and assessed by the 3 authors independently. Data from fifty-two articles pertinent to the review on hemiarthroplasty dislocation epidemiology, risk factors and management were extracted in a standardised fashion.

Results:

Following review of the papers multiple causative factors relating to HA dislocation were identified and grouped into 4 broad categories for analysis. The factors with the strongest correlation with dislocation included patient cognition, previous failed surgery, delay to surgery, surgical approach and femoral offset.

Conclusion:

Hip hemiarthroplasty remains the gold standard for elderly patients with intracapsular neck of femur fractures. In each individual case the factors most strongly associated with postoperative dislocation should be recognised. Delays to surgery should be minimised and the posterior approach avoided. In addition to good surgical technique, particular attention should be paid to restoring the patient’s native femoral offset and post operatively those with cognitive impairment should be closely monitored.

What Are the Risk Factors for Dislocation of Hip Bipolar Hemiarthroplasty Through the Anterolateral Approach? A Nested Case-control Study

BACKGROUND

Hip dislocation after treatment of a femoral neck fracture with a hemiarthroplasty remains an important problem in the treatment of hip fractures, but the associations between patient factors and surgical factors, and how these factors contribute to dislocation in patients who have undergone bipolar hemiarthroplasty through an anterolateral approach for femoral neck fracture currently are only poorly characterized.

QUESTIONS/PURPOSES

We evaluated patients with bipolar hemiarthroplasty dislocation after surgery for femoral neck fracture treated through an anterolateral approach and asked: (1) What are the frequency, characteristics, and risk factors of bipolar hemiarthroplasty dislocations? (2) What are the frequency, characteristics, and risk factors of bipolar hemiarthroplasty dissociations?

METHODS

A review of hospital records for patients who underwent bipolar hip hemiarthroplasty for femoral neck fracture at one hospital between July 2004 and August 2014 was conducted. During that time, 1428 patients were admitted with a diagnosis of femoral neck fracture; 508 of these patients underwent bipolar hip hemiarthroplasty, of whom 61 died and 23 were lost to followup during the first year, leaving 424 (83%) available for analysis. The remainder of the patients during that time were treated with internal fixation (512), unipoloar hip arthroplasty (17), or THA (391). For each patient with dislocation, we selected five control patients from the cohort according to sex, age (± 3 years), and year of entry in the study to eliminate some confounding factors. We recorded patient characteristics regarding demographics, medical comorbidities, Katz score, American Society of Anesthesiologists score, Mini-Mental State Examination (MMSE) score, and anesthesia type. Medical comorbidities included diabetes, chronic pulmonary disease, heart disease, neuromuscular diseases, and dementia. Univariate analyses were used to search for possible risk factors. Conditional logistic regression analyses on dislocation or dissociation were performed to estimate hazard rates (HRs) and corresponding 95% CIs with covariates of a probability less than 0.1 in univariate analysis.

RESULTS

In this cohort, there were 26 dislocations including four that were also dissociations. The proportion of patients experiencing a dislocation was 6% (26 of 424). The mean interval from surgery to dislocation was 56 weeks (range, 0-433 weeks), and 18 dislocations (69%) occurred within 3 months after surgery. Three variables were independently associated with an increased risk of hip dislocation: dementia (HR, 3.51; 95% CI, 1.19-10.38; p = 0.02), discrepancy of offset (HR, 1.72; 95% CI, 1.15-2.58; p = 0.008), and lower MMSE score (HR, 0.93; 95% CI, 0.88-0.98; p = 0.007). The proportion of patients experiencing a dissociation was 0.9% (four of 424). The result of conditional logistic regression for dissociation showed that cup size smaller than 43 mm was the risk factor (HR = 513.05). However, there was no statistical difference with the probability equaling 0.47.

CONCLUSIONS

After the anterolateral approach for treatment of femoral neck fracture using bipolar hemiarthroplasty, 6% of hips dislocated and 0.9% experienced dissociation. Cognitive dysfunction and discrepancy of offset were independent risk factors associated with an increased risk of prosthetic dislocation. The small cup without a safety ring may be the risk factor of dissociation. Discrepancy of offset should be avoided during the operation by performing an accurate femoral osteotomy and choosing an adequate femoral stem neck length. For patients with cognitive dysfunction and a small cup, suturing the joint capsule during the operation and reinforcing protective measures after surgery might reduce the occurrence of dislocation and dissociation, however a study addressing this is necessary to confirm this.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Cemented Unipolar Prosthesis for the Management of Displaced Femoral Neck Fractures in the Dependent Osteopenic Elderly

BACKGROUND

Significant variability exists across orthopedic surgeons in the management of the displaced femoral neck fracture in the elderly patient (>75 years old). These patients tend to be less healthy, have inferior bone quality, and gait instability leading to increased risk of periprosthetic fracture, compromised implant fixation, dislocation, and need for revision. The surgeon's goals should be to restore mobility while eliminating pain and need for reoperation.

METHODS

In this review article, we examine the best available evidence in the literature to determine which strategy achieves optimal outcomes. We examine outcome studies comparing use of hemiarthroplasty and total hip arthroplasty, unipolar and bipolar hemiarthroplasty, and cemented vs cementless fixation of femoral stems.

RESULTS AND CONCLUSIONS

For the active, healthy, and lucid patient, or one who has preexisting groin pain, who sustains a displaced femoral neck fracture, the literature supports a total hip arthroplasty. Patients sustaining a displaced femoral neck fracture and who are less active, have decreased bone mass, and are at increased risk of falls would benefit most from a device that optimally balances the need for revision surgery, restores ambulation, and eliminates pain. Thus, the current evidence favors cemented, unipolar hemiarthroplasty for the dependent osteopenic elderly patient with a displaced femoral neck fracture.

Dissociation of a Bipolar Prosthesis after Right Hip Hemiarthroplasty

We report the case of an 84-year-old woman with a dissociated bipolar component of her right hip hemiarthroplasty. Dissociation of components is a rare but increasingly recognized consequence of modular componentry. Radiologists should be aware of the distinction between dislocation of a prosthesis and dissociation of its bipolar components, and be able to describe these complications accurately in their interpretations.

Short-term Outcomes of Femoral Neck Fractures Treated With Hemiarthroplasty Using the Anterior Approach

The direct anterior approach has recently gained popularity for patients undergoing elective total hip arthroplasty. It is unknown whether the reported benefits of the direct anterior approach to elective total hip arthroplasty can be extrapolated to patients undergoing hemiarthroplasty after femoral neck fracture. A retrospective review of 101 patients was performed to compare the outcomes of patients treated with hemiarthroplasty using the direct anterior approach (group 1) with those of patients undergoing the procedure with the posterior, anterolateral, or lateral approach (group 2). No differences in age, American Society of Anesthesiologists classification, and preinjury ambulatory status were identified between treatment groups. No difference in operative time was found between those undergoing the anterior approach (98.7 minutes) and those undergoing other surgical approaches (96.5 minutes) (P=.76). No difference in either the need for transfusion or the number of blood products transfused was seen (P=.21) postoperatively. Patients undergoing the direct anterior approach were more likely to be discharged by postoperative day 3 (P=.004) despite no difference in the recorded number of feet ambulated in the hospital. At a mean clinical follow-up of 16 weeks, there was no difference in the rate of return to baseline ambulatory status between groups (P=.07). The overall rates of major and minor complications for all patients were 23% and 26%, respectively, with no statistically significant differences between groups. The overall dislocation rate of all patients was found to be 3%. All dislocations were observed in group 2. Larger prospective studies are needed to further define the benefits of the direct anterior approach in this patient population.

Dislocation and dissociation of bipolar hip hemiarthroplasty

Hemiarthroplasty of the hip is a commonly performed procedure for subcapital neck of femur fractures. Dislocation of the hemiarthroplasty is a recognised but uncommon complication. Dislocations can be complicated by the uncoupling or dissociation of the femoral head component from the femoral stem. Dissociations are rare and require open reduction. We present a case of a patient with a hip hemiarthroplasty dislocation and dissociation subsequent to a fall.

Capsule repair may reduce dislocation following hip hemiarthroplasty through a direct lateral approach: a cadaver study

Reported rates of dislocation in hip hemiarthroplasty (HA) for the treatment of intra-capsular fractures of the hip, range between 1% and 10%. HA is frequently performed through a direct lateral surgical approach. The aim of this study is to determine the contribution of the anterior capsule to the stability of a cemented HA through a direct lateral approach. A total of five whole-body cadavers were thawed at room temperature, providing ten hip joints for investigation. A Thompson HA was cemented in place via a direct lateral approach. The cadavers were then positioned supine, both knee joints were disarticulated and a digital torque wrench was attached to the femur using a circular frame with three half pins. The wrench applied an external rotation force with the hip in extension to allow the hip to dislocate anteriorly. Each hip was dislocated twice; once with a capsular repair and once without repairing the capsule. Stratified sampling ensured the order in which this was performed was alternated for the paired hips on each cadaver. Comparing peak torque force in hips with the capsule repaired and peak torque force in hips without repair of the capsule, revealed a significant difference between the 'capsule repaired' (mean 22.96 Nm, standard deviation (sd) 4.61) and the 'capsule not repaired' group (mean 5.6 Nm, sd 2.81) (p < 0.001). Capsular repair may help reduce the risk of hip dislocation following HA.

Unipolar versus bipolar hemiarthroplasty for displaced femoral neck fractures: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Whether bipolar hemiarthroplasty (BH) for displaced femoral neck fractures has benefit over unipolar hemiarthroplasty (UH) remains controversial. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the relative effects between BH and UH.

METHODS

A systematic literature search (up to April, 2014) was conducted to include RCTs comparing BH with UH for displaced femoral neck fractures. Two authors independently assessed methodological quality of the included studies and extracted data. Surgical information and postoperative outcomes were analyzed.

RESULTS

A total of 10 RCTs including 1,190 patients were indentified. Our results demonstrated that BH was associated with similar or better outcomes in hip function, hip pain, and quality of life while with a higher cost compared with UH. Moreover, there were no significant differences between BH and UH with regard to operation time, blood loss, blood transfusion, hospital stay, mortality, reoperation, dislocation, and complications. BH could significantly decrease the incidence of acetabular erosion at 1 year follow-up compared with UH (RR = 0.24, 95% confidence interval (CI) = 0.06 to 0.89, P = 0.03), but no significant difference was observed at 4 months, 2 years, and 4 years follow-ups.

CONCLUSIONS

Based on the current evidence, BH is not superior to UH in terms of surgical information and postoperative results. Despite similar or better clinical outcomes compared with UH, BH with a higher cost could not decrease long-term acetabular erosion rate.

Outcomes of 807 Thompson hip hemiarthroplasty procedures and the effect of surgical approach on dislocation rates

The majority of displaced intracapsular fractures in our unit are managed with a Thompson hip hemiarthroplasty. Recent UK guidance from the National Institute for Health and Care Excellence has, however, advised against the continued used of the Thompson implant in patients with hip fracture. The aim of this study was to review the outcomes and complications after Thompson hip hemiarthroplasty, including the impact of modern surgical approaches and cementing, whilst controlling for confounding factors. We reviewed the outcomes following Thompson hip hemiarthroplasty from a series of 807 cases performed between April 2008 and November 2013. Of these, 721 (89.3%) were cemented and 86 (10.7%) uncemented. A total of 575 (71.3%) procedures were performed in female patients. The anterolateral approach was performed in 753 (93.3%) and the posterior approach with enhanced soft tissue repair in 54 (6.7%). Overall, there were 23 dislocations (2.9%). Dislocation following the posterior approach occurred in 13.0% (seven of 54) in comparison to 2.1% (16 of 753) with the anterolateral approach (odds ratio (OR) 8.5 (95% confidence interval (CI) 2.8-26.3), p < 0.001). Patients were discharged home in 459 cases (56.9%), to a care home or other hospital in 273 cases (33.8%). Of the total number of patients, 75 died during their admission (9.3%), and 51.8% (338 of 653) returned home within 30 days. The 30-day mortality was 7.1% (57 cases) and the 1-year mortality was 16.6% (116 of 699). We recommend against the continued use of the posterior approach in hip hemiarthroplasty, as enhanced soft tissue repair did not reduce the dislocation rates to an acceptable level in this series utilising the Thompson implant. Our findings, however, demonstrate satisfactory results for patients treated with the Thompson hip hemiarthroplasty performed through an anterolateral approach. We suggest that the continued use of this implant in a carefully selected patient cohort is justifiable.

Predictors and outcomes of treatment in hip hemiarthroplasty dislocation

INTRODUCTION

Dislocation following hip hemiarthroplasty (HHA), its incidence, predictors, treatment outcomes and mortality were investigated in a single centre series.

METHODS

The prospectively collected data on neck of femur fracture admissions compiled over 11 years were reviewed. Place of residence, place of fall, past medical history, intraoperative factors (grade of surgeon, delay in surgery, type of implant and operative time), postoperative complications and mortality were compared between patients who suffered a dislocation and those who did not. In the dislocation group, the mean number of dislocations, reduction method, type and fate of implant, and mortality were investigated.

RESULTS

Prospective data on 8,631 admissions were collected; 41% of these were managed with a HHA. The dislocation rate was 0.76%. A delay in surgery of >24 hours was associated with a fourfold increase in the dislocation risk. The majority (81%) of dislocations occurred in the first six weeks and closed manipulation was the definitive treatment in only 23% of the cases. The mortality rate was not increased following HHA dislocation.

CONCLUSIONS

The delay in surgery was the most important predictor of HHA dislocation. Closed reduction was associated with a high failure rate. While an initial attempt at closed reduction for a first dislocation is recommended, for redislocators, we recommend early exploration/revision as an alternative to repeat manipulations.

Bipolar hemiarthroplasty for femoral neck fracture using the direct anterior approach

AIM: To evaluate whether walking ability recovers early after bipolar hemiarthroplasty (BHA) using a direct anterior approach.

METHODS: Between 2008 and 2010, 81 patients with femoral neck fracture underwent BHA using the direct anterior approach (DAA) or the posterior approach (PA). The mean observation period was 36 mo. The age, sex, body mass index (BMI), time from admission to surgery, length of hospitalization, outcome after discharge, walking ability, duration of surgery, blood loss and complications were compared.

RESULTS: There was no significant difference in the age, sex, BMI, time from admission to surgery, length of hospitalization, outcome after discharge, duration of surgery and blood loss between the two groups. Two weeks after the operation, assistance was not necessary for walking in the hospital in 65.0% of the patients in the DAA group and in 33.3% in the PA group (P < 0.05). As for complications, fracture of the femoral greater trochanter developed in 1 patient in the DAA group and calcar crack and dislocation in 1 patient each in the PA group.

CONCLUSION: DAA is an approach more useful for BHA for femoral neck fracture in elderly patients than total hip arthroplasty in terms of the early acquisition of walking ability.

New method for measuring acetabular component positioning with EOS imaging: feasibility study on dry bone

PURPOSE

Malposition of the acetabular cup is the most common cause of total hip arthroplasty (THA) dislocation. The position of a total hip implant is usually analysed on computed tomography (CT) scan. We aim to prove it is possible to measure, with good accuracy, the position of an acetabular cup using the low-dose irradiation (EOS) imaging.

MATERIAL AND METHODS

We implanted an acetabular cup in a pelvic dry bone and measured cup anteversion and inclination with scanography. We performed 14 series of EOS acquisitions with different inclination, rotation and pelvic tilt, which were analysed by five observers. Two observers repeated angle measurements. We then calculated measurement inter- and intrareproducibility and accuracy.

RESULTS

Using a confidence interval (CI) of 95 %, inter- and intra-observer reproducibility were ±1.6, and ±1.4°, respectively, for cup inclination; accuracy in comparison with CT was ±2.6°. Using a 95 % CI, inter- and intra-observer reproducibility for cup anteversion were ±2.5° and ±2.3°, respectively. Measurement accuracy compared with CT was ±3.9°.

CONCLUSION

EOS imaging system is superior to standard radiography in terms of measuring acetabular anteversion and inclination.

Hospital cost of treating early dislocation following hip arthroplasty

Dislocation is a frequent and costly complication of hip arthroplasty. The purpose of this study was to assess the financial impact on the treating institution of this complication in patients with primary hemiarthroplasty (HA), total hip arthroplasty (THA) and revision surgery (RTHA). Between October 2001 and August 2009, 2014 consecutive hip arthroplasties were performed at our institution, of which 87 (18 HA, 44 THA and 25 RTHA) dislocated within 6 weeks of the primary operation. The average cost of treating implant dislocation by closed reduction, open reduction or revision was assessed and expressed as a percentage cost increase compared to an uncomplicated procedure. Of the 87 dislocated implants all needed one or more closed reductions and 52 eventually required revision surgery. An early dislocation increased the cost of HA, THA and RTHA by 472%, 342% and 352%, respectively.

Decreasing mortality after femoral neck fracture treated with bipolar hemiarthroplasty during the last twenty years

PURPOSE

The aim of our study was to investigate trends over time in the mortality of elderly patients after femoral neck fractures treated with bipolar hemiarthroplasty.

METHODS

Altogether 487 cases of femoral neck fracture treated with bipolar hemiarthroplasty were observed during a 20-year period. Mortality rates were calculated for five years postoperatively. To account for the age distribution of the study population standardised mortality ratios (SMR) with respect to the age-specific mortality of the German population were determined and compared. Additional changes of the SMRs over time and the influence of the time delay before surgery on long-term mortality were evaluated.

RESULTS

Femoral neck fractures treated with bipolar hemiendoprosthesis have a significant impact on mortality. Postoperative mortality is increased in patients of all age groups, but the effect diminishes in higher age groups. The influence on mortality was significantly greater for men than for women. The SMR has decreased from 3.52 before 1995 to 1.2 after 2006. Since 2006 there is no longer an increase in mortality after surgical treatment of a femoral neck fracture compared to general German population of the same age.

CONCLUSION

Femoral neck fractures treated with bipolar hemiendoprosthesis result in a significantly increased mortality, however in our population this impact has significantly decreased over time. The effect on mortality is less in women and higher age groups than in men and younger patients. No influence of the time between accident and surgery on mortality could be detected.

Treatment of femoral neck fractures with bipolar hemiarthroplasty using a modified minimally invasive posterior approach in patients with neurological disorders

Bipolar hemiarthroplasty is a useful treatment for displaced femoral neck fractures in elderly patients. Although uncommon, dislocation is problematic, particularly in older patients, and those with neurologic disorders are at an increased risk for this complication. Recently, a modified posterior approach to the hip intended to enhance hip joint stability by preserving the short external rotators was described. Therefore, the dislocation rate was compared after bipolar hemiarthroplasty using the modified or standard minimally invasive posterior approach.A retrospective analysis was performed of 67 patients older than 65 years with displaced femoral neck fractures and neurological disorders who underwent bipolar hemiarthroplasty using the modified and standard approaches in 28 and 39 hips, respectively. Follow-up averaged 19.3 months. Dislocation rates for the treatment and control groups were 0% and 7.7%, respectively (P<.01). No significant difference existed in postoperative bleeding, operative time, or length of hospital stay between groups. These data suggest a lower dislocation rate after bipolar hemiarthroplasty via the modified, short external rotator-sparing approach for treating displaced femoral neck fractures in elderly patients with neurological disorders.

Dual mobility cups hip arthroplasty as a treatment for displaced fracture of the femoral neck in the elderly. A prospective, systematic, multicenter study with specific focus on postoperative dislocation

INTRODUCTION

Displaced fractures of the femoral neck in the elderly are best treated with arthroplasty. The type of arthroplasty to be used, either hemi- or total hip arthroplasty, remains controversial as total hip replacements potentially have a higher rate of dislocation.

HYPOTHESIS

Dual mobility cups have a low dislocation rate when used to manage acute fractures of the femoral neck.

PATIENTS AND METHODS

In a multicenter prospective study conducted in France over an inclusion time of 3 months, all displaced fractures of the femoral neck treated with arthroplasty were operated on with insertion of a dual mobility cup. Patients had clinical and radiological assessment at 3, 6, and 9 months postoperative.

RESULTS

Two hundred and fourteen hips in 214 patients with a mean age of 83 years (range, 70-103 years) were included. None of the patients was lost to follow-up. The mortality rate after 9 months was 19%. Two patients (1%) had early postoperative infection successfully treated with lavage and antibiotics. Three patients (1.4%), operated through a posterior approach, presented one postoperative dislocation, all of which were posterior. Reduction was performed through closed external manipulation under general anesthesia. There was no recurrence of dislocation.

DISCUSSION

This low rate of dislocation after acute total hip replacement using dual mobility design cups favorably compares with hemiarthroplasties. Dual mobility cups might therefore be considered a valuable option to prevent postoperative dislocation when treating displaced intracapsular fractures of the proximal femur in elderly patients if a total hip replacement is recommended. Further study is needed before extending the indications for total hip arthroplasty following a fracture of the femoral neck, to assess the potential cost and complications of a longer procedure with its potential acetabular complication, and weigh them against the potential benefits.

Is the dislocation rate higher after bipolar hemiarthroplasty in patients with neuromuscular diseases?

BACKGROUND

Patients with neuromuscular disease reportedly have a higher incidence of postoperative dislocation after bipolar hemiarthroplasty. Although the literature has focused on a high prevalence of preoperative neurologic conditions in patients who had dislocations after bipolar hemiarthroplasties, the relative incidence of dislocation in patients with neuromuscular disease and without is unclear.

QUESTIONS/PURPOSES

We therefore (1) asked whether the incidence of postoperative dislocation after bipolar hemiarthroplasty was greater in patients with neuromuscular disease than for those without, and (2) whether function differed between the two groups, and (3) explored potential risk factors for dislocation in two groups.

METHODS

We retrospectively reviewed 190 patients who underwent bipolar hemiarthroplasties for fracture of the femoral neck between 1996 and 2008. Of the 190 patients, 42 had various neuromuscular diseases and 148 had no history of neuromuscular disease. Intraoperative stability was tested and posterior soft tissue repair was performed in all patients. We determined the incidence of dislocation, postoperative leg length discrepancy, and femoral offset in patients with or without neuromuscular disease.

RESULTS

The incidence of dislocation was 2.6% in all patients. We observed similar rates of dislocation in the two groups: 4.8% (two of 42 hips) in patients with neuromuscular disease and 2.0% (three of 148 hips) in patients without neuromuscular disease.

CONCLUSIONS

In femoral neck fractures in patients with neuromuscular disease, careful preoperative management and operative technique such as a posterior soft tissue repair might decrease the risk of postoperative dislocation; therefore, we consider the bipolar hemiarthroplasty a reasonable treatment option.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.