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

Substantial Improvement in Self-Reported Mental Health Following Total Hip Arthroplasty Occurs Independent of Anesthetic Technique

BACKGROUND

The influence of anesthetic type on mental health after total hip arthroplasty (THA) is poorly understood. Adverse effects of general anesthesia (GA) on cognition following major non-cardiac surgery are well known, but mental health following THA is less well-studied. We hypothesized that neuraxial anesthesia (NA) would provide favorable mental health profiles compared with GA after THA.

METHODS

Prospectively collected Patient-Reported Outcomes Measurement Information System-10 (PROMIS) Global Mental Health (GMH) scores at preoperative baseline, and 1, 3, and 6 months after THA were accessed on 4,353 patients in the Pulmonary Embolism Prevention After HiP and KneE Replacement (PEPPER) Trial (ClinicalTrials.gov: NCT02810704). Anesthesia was categorized as: general (GA), neuraxial (NA), and neuraxial with peripheral block (NAP). The GMH was assessed longitudinally and compared between groups.

RESULTS

Postoperative GMH improved (P < .05) over preoperative in every anesthetic group. Groups receiving NA had higher baseline GMH scores. Improvement in GMH was diminished after GA alone and plateaued after 1 month. Adding NA or peripheral nerve block to GA conferred additional benefit to GMH improvement.

CONCLUSIONS

Patient-perceived mental health improves significantly after THA regardless of anesthetic type. Patients who have higher baseline GMH scores more commonly received NA, likely due to nonsurgical care determinants; these differences in mental wellness persisted at follow-up. Adjunctive NA or peripheral nerve block favored GMH improvement, whereas solitary GA diminished GMH improvement, which plateaued after 1 month. Substantial mental health benefits of THA may overshadow subtle differences in GMH attributable to anesthetic type.

Incidence of dislocation and associated risk factors in patients with a femoral neck fracture operated with an uncemented hemiarthroplasty

BACKGROUND

Several factors might be associated with risk of dislocating following uncemented hemiarthroplasty (HA) due to femoral neck fracture (FNF). Current evidence is limited with great variance in reported incidence of dislocation (1-15%). Aim of this study was to identify the cumulative incidence of first-time dislocation following HA and to identify the associated risk factors.

METHOD

We performed a retrospective cohort study of patients receiving an HA (BFX Biomet stem, posterior approach) at Copenhagen University Hospital, Bispebjerg, in 2010-2016. Patients were followed until death or end of study (dec 2018). Dislocation was identified by code extraction from the Danish National Patient Registry. Variables included in the multivariate model were defined pre-analysis to include: age, sex and variables with a p-value < 0.1 in univariate analysis. A regression model was fitted for 90 days dislocation as the assumption of proportional hazard rate (HR) was not met here after.

RESULTS

We identified 772 stems (some patients occurred with both right and left hip) and 58 stems suffered 90 dislocations during the observation period, resulting in a 7% (CI 5-9) incidence of dislocation 90 days after index surgery. 55 of the 58 stems (95%) experienced the first dislocation within 90 days after surgery. Only absence of dementia was identified as an independent protective factor in the cause-specific model (HR 0.46 (CI 0.23-0.89)) resulting in a 2.4-fold cumulative risk of experiencing a dislocation in case of dementia. Several other variables such as age, sex, various medical conditions, surgery delay and surgical experience were eliminated as statistical risk factors. We found a decrease in survival probability for patients who experienced a dislocation during follow-up.

CONCLUSIONS

The incidence of first-time dislocation of HA (BFX Biomet stem, posterior approach) in patients with a hip fracture is found to be 7% 90 days after surgery. Due to the non-existing attribution bias, we claim it to be the true incidence. Dementia was among several variables identified as the only risk factor for dislocation. In perspective, we may consider treating patients with dementia by other methods than HA e.g., HA with cement or with a more constrained solution. Also, a surgical approach that reduce the risk of dislocation should be considered.

The outcomes of constrained total hip arthroplasty for recurrent dislocation of hip hemiarthroplasty

INTRODUCTION

The incidence of hemiarthroplasty dislocation for fracture neck of femurs ranges between 1 and 15% and the one-year mortality is 49- 70%. Revision of hemiarthroplasty to total hip replacement using a constrained liner has shown to improve the morbidity and mortality rates. The aim of the study was to assess whether conversion of dislocated hemiarthroplasty to total hip replacement improve functional and one year mortality.

METHODS

A retrospective analysis of the number of patients who had recurrent dislocations of hemiarthroplasty for fracture neck of femurs were carried out. The data were obtained from NHFD (National Hip Fracture Database) and internal hospital computer systems (Medway, Theatre notes and PACS) between Dec 2008 and Dec 2020. Patient demographics including age, sex, Abbreviated Mental Test Score (AMTS), functional assessment, mortality at one and two years were documented. The risk factors which led to dislocations such as Parkinsons disease, Cerebrovascular accidents, Musculo-neuropathies and Alzheimer`s disease was also noted.

RESULTS

A total of 3994 patients were admitted during the study period of which 1735 (43.4%) patients had hemiarthroplasty. Fifty-six (3.23%) patients had dislocation of hemiarthroplasty. The mean age was 81.4 years (range - 61 to 95). There were 40 (71.4%) females and 16 males (28.6%). The average AMTS score was 5.3. All 56 patients had closed manipulative reduction under anaesthesia within in 12 h of admission. Thirty-one patients (55.4%) went on to have recurrent dislocations of which 18 patients (58.4%) had total hip replacement using captive cup, 6 patients (19.4%) had open reduction,3 patients (9.7%) had excision arthroplasty procedure and four patients (12.5%) had no intervention, Eighteen patients who had total hip replacement with constrained captive for followed up to a minimum of two years (range2- 12 years). There were no intraoperative complications, dislocation or periprosthetic fractures in the follow up period. There was no mortality at the end of two years of follow up in this group, two-year mortality for the patients with alternative management for dislocated hemiarthroplasty was 76.67.

CONCLUSION

Treatment of recurrent hemiarthroplasty dislocation by revising to a total hip replacement with a constrained liner gives good functional and mortality outcomes.

Acetabular Morphology Predicts the Risk of Dislocation Following Hemiarthroplasty for Femoral Neck Fractures in the Elderly

BACKGROUND

Hip hemiarthroplasty dislocation is a devastating complication. Among other preoperative risk factors, acetabular morphology has been rarely studied. The purpose of the study was to evaluate the influence of preoperative native acetabular morphology on hemiarthroplasty dislocation.

METHODS

We retrospectively reviewed 867 patients who underwent hip hemiarthroplasty for femoral neck fracture between January 1, 2014 and January 1, 2019. The 380 included patients were treated with an anterior-based muscle-sparing approach. The central-edge angle (CEA) and acetabular depth-to-width ratio (ADWR) of the fractured hip were measured preoperatively on the anteroposterior pelvic view. Receiver operating characteristic curves were performed to analyze the optimal cutoff for CEA and ADWR. Hemiarthroplasty dislocation occurred in 18 patients (4.7%), and the remaining 362 patients were used as the control group.

RESULTS

No significant differences in terms of sex, age, dementia, neuromuscular disease, and body mass index were found between the 2 groups. The 18 patients who had a hip dislocation had significantly smaller mean CEA than the control group (P = .0001) (mean 36.1 ± 7.5° and 43.2 ± 5.6°, respectively) as well as ADWR (mean 34 ± 6 versus 37 ± 4, respectively) (P = .001). Using the receiver operating characteristic analysis, we report significant cutoffs of 38.5° for CEA (P = .0001) and 34.5 for the ADWR (P = .017).

CONCLUSION

Higher rates of hemiarthroplasty dislocation were observed in patients who had a preoperative CEA of less than 38.5° and an ADWR of less than 34.5. Patients who have preoperative acetabular morphological risk factors for dislocation might be better candidates for a total hip arthroplasty.

Complications of Hip Hemiarthroplasty

Hip hemiarthroplasty is a commonly performed orthopedic surgery, used to treat proximal femur fractures in the elderly population. Although hip hemiarthroplasty is frequently successful in addressing these injuries, complications can occur. Commonly seen complications include dislocation, periprosthetic fracture, acetabular erosion, and leg-length inequality. Less frequently seen complications include neurovascular injury and capsular interposition. This article presents a comprehensive review of the complications associated with the management of hip hemiarthroplasty. [Orthopedics. 2023;46(4):e199-e209.].

Comparative Effectiveness of Total Hip Arthroplasty and Hemiarthroplasty for Femoral Neck Fracture: A Propensity-Score-Matched Cohort Study

BACKGROUND

The optimal treatment of older patients with a displaced femoral neck fracture remains a controversial topic. This study aimed to compare clinical outcomes across a matched group of patients with a femoral neck fracture treated with either hemiarthroplasty or total hip arthroplasty (THA).

METHODS

Routinely collected health-care databases were linked to create a population-based cohort of 49,597 patients ≥60 years old from Ontario, Canada, who underwent hemiarthroplasty or THA for a femoral neck fracture between 2002 and 2017. A propensity-score-matched cohort was created using relevant and available predictors of treatment assignment and outcomes of interest. Clinical outcomes consisting of hip dislocation, revision surgery, hospital readmission, and death were compared in the matched cohort using survival analysis.

RESULTS

Over 99% of THA patients (4,612) were adequately matched 1:1 to hemiarthroplasty patients (total matched cohort = 9,224). Patients treated with THA were at higher risk for hip dislocation at 30 days and 1 and 2 years postoperatively (2-year risk, 1.8% for THA versus 0.8% for hemiarthroplasty; p < 0.001). There was no difference in the short-term (30-day) or long-term (up to 10-year) risk of revision surgery between treatment groups. There was no significant difference in the risk of 30-day hospital readmission between groups. The risk of death at 1 year and 2 years postoperatively was lower for patients treated with THA.

CONCLUSIONS

For patients with a hip fracture, shared decision-making should involve discussion of the potential higher risk of short-term hip dislocation after THA compared with hemiarthroplasty. The risk of revision surgery was similar between treatment groups at up to 10 years of follow-up.

LEVEL OF EVIDENCE

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

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.

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.

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.

Factors associated with dislocation after bipolar hemiarthroplasty through an (antero-)lateral approach in elderly patients with a femoral neck fracture: a retrospective cohort study with a nested case-control subanalysis of radiographic parameters

Introduction

Dislocations of hip hemiarthroplasty (HHA) are serious complications. The aim of the study was to identify clinical aspects and radiographic parameters of the hip that put patients at risk for dislocation after HHA for femoral neck fractures.

Methods

This retrospective analysis included elderly patients with a femoral neck fracture treated with a HHA. A lateral (90.7%) and an anterolateral (9.3%) approach was applied. On pelvic radiographs, a nested-controlled analysis was performed. Two control patients were matched to one patient suffering a dislocation with respect to age, sex, and body-mass-index (BMI).

Results

In 527 HHA, 10 dislocations (1.9%) were identified. In the dislocation group (DG), all patients were female (100% vs. 73.5%, p = 0.071). No significant differences between the DG and the control group (CG) were found with respect to age, body-mass-index (BMI), ASA Score, routine laboratory parameters, and comorbidity. Radiographic analysis revealed a smaller center edge angle (CEA, 39.0, IQR 33.0–42.5 vs. 43.0, IQR 41.0–46.0, p = 0.013), a more varus neck-shaft angle (NSA, 130.0, IQR 125.8–133.5 vs. 135.0, IQR 134.0–137.0, p = 0.011) of the contralateral side and a higher femoral head extrusion index (FHEI) in the DG (FHEI, 11.5, IQR 9.8–16.3 vs. 2.0 IQR 0.0–9.0, p = 0.003). In addition, a greater trochanteric fracture was associated with an increased likelihood for HHA dislocations (30.0% vs 6.0%, p = 0.022).

Conclusion

A smaller radiographic center edge angle, a more varus neck-shaft angle of the contralateral side, a higher femoral head extrusion index and intraoperative fractures of the greater trochanter are associated with an increased risk of HHA dislocation.

Hip arthroplasty for acute hip fracture in patients with neurological disorders: A report Of 9,702 cases from the Swedish arthroplasty register

INTRODUCTION

The purpose of this study was to investigate neurological disorder as a risk factor for dislocation following arthroplasty for acute hip fractures. We also analysed medical and surgical adverse events (AE), readmission, reoperation, revision, and mortality as secondary outcomes.

METHODS

A longitudinal cohort study using prospectively collected and aggregated data from the Swedish Hip Arthroplasty Register (SHAR) and the Swedish national patient register. All patients presenting with an acute hip fracture and treated with an arthroplasty in the period from 2005 to 2014 from the SHAR were identified. Patients in receipt of bilateral arthroplasties were excluded. Patients with a relevant pre-existing and diagnosed neurological disorder, as defined by ICD-10 codes, were identified (n = 9,702). All other cases (n = 29,411) were available for logistic regression propensity score matching. Patients were 1:1 matched on age, sex, Charlson comorbidity index, total versus hemiarthroplasty, head size, surgical approach, and year of surgery. Dislocations, adverse events, readmission, reoperation, revision, and mortality were studied using Kaplan-Meier analysis and Cox regression.

RESULTS

The risk of dislocations was higher for patients with neurological disorder (HR=1.19, CI 1.03- 1.39, p<0.05). Neurological disorder was associated with increased risk of encountering an adverse event (p<0.001 at 90-days); these patients were at higher risk of dying (HR=1.51, CI 1.47-1.56, p<0.001) however they were less likely to be readmitted (HR=0.73, CI 0.70- 0.76, p<0.001). No excess risks of reoperation (HR=1.02, CI 0.90-1.17; p = 0.73) or revision (HR=1.00, CI 0.86-1.17; p = 0.99) were identified in the study group.

DISCUSSION

Compared to matched controls, individuals with a preoperatively identified neurological diagnosis had higher rates of mortality, dislocations, and adverse events, but this cohort was not at increased risk of reoperation or revision. This study highlights an area of focus for future research to improve the long-term outcomes in patients with neurological disease undergoing arthroplasty for an acute hip fracture.

Dual mobility cups do not reduce the revision risk for patients with acute femoral neck fracture: A matched cohort study from the Swedish Arthroplasty Register

INTRODUCTION

Dual mobility cups (DMC) are gaining in popularity, as a method to reduce the risk of dislocation after fracture-related hip arthroplasty. Our aim was to compare revision rate in general, as well as due to dislocation and infection, after DMC and conventional THA due to femoral neck fracture, for each of the two groups of lateral and posterior approach.

MATERIALS AND METHODS

This observational cohort study based on the Swedish Arthroplasty Register (SAR) compared 2242 patients with dual mobility cups (DMC) and 6726 with conventional total hip arthroplasty (cTHA), all due to acute fracture 2005-2019. This was after propensity score matching of 1:3 (age, gender, ASA). Kaplan-Meier survival analysis was used to investigate the 5-year revision rate after DMC and cTHA in the posterior and lateral approach groups.

RESULTS

The rates of revision in general, and due to dislocation or infection, were similar for DMC and cTHA in the different approach groups during the follow-up. The cumulative revision rate after posterior approach was 4.7% (95% CI 3.1-6.2) for DMC and 4.8% (3.8-5.7) for cTHA at 5 years. For lateral approach, the result was 2.3% (CI 1.3-3.3) for DMC and 3.7% (CI 3.0-4.4) for cTHA. The 5-year results for cumulative revision rate due to dislocation after posterior approach were 1.3% (0.4-2.2) for DMC and 2.2% (1.5-2.8) for cTHA. Corresponding results for lateral approach was 0.4% (0-0.8) for DMC and 0.7% (0.4-1) for cTHA.

DISCUSSION

With implant revision surgery as outcome, we could not detect any differences between DMC and cTHA. Further studies with high external validity are needed regarding total dislocation rate, patient-reported outcome, cost-effectiveness and learning curve, to make a definitive recommendation on the use of DMC for fracture cases.

CONCLUSIONS

As treatment of acute femoral neck fractures, total hip arthroplasty with a dual mobility cup have similar outcome in terms of revisions in general, and due to dislocation or infections specifically, as one with conventional bearing. The similar outcome is regardless of surgical approach.

The effects of dementia on the prognosis and mortality of hip fracture surgery: a systematic review and meta-analysis

OBJECTIVES

Dementia is a common mental disorder that affects the life quality in elders. Recently, emerging studies reported the negative impacts of dementia on prognosis after hip surgeries. However, the integrated and reliable role of dementia in hip surgery is not illustrated.

METHODS

We searched the relevant literatures before June 2020 and extracted the data that met the inclusion criteria. The influence of dementia on postoperative walking ability, complications including infection, cardiovascular complications, hip dislocation, delirium, and respiratory complications, and survival rate at different periods were evaluated. Qualitative and quantitative analysis were conducted using Review Manager Version 5.3.

RESULTS

The meta-analysis enrolled a total of 30 studies with 1,037,049 patients. The pooled results revealed that there were significant negative impacts of dementia on the recovery of postoperative walking ability, postoperative infection, hip dislocation, delirium and respiratory complications and mortality at different periods.

CONCLUSIONS

Dementia is a crucial risk factor for the poor prognosis after hip fracture surgery. Therefore, when making clinical strategies for hip fracture patients with dementia, countermeasures for possible complications should be generated.

Established Trauma Triage Score Predicts Risk of Falling After Femoral Neck Fracture Arthroplasty Surgery

INTRODUCTION

The purpose of this study is to determine whether the Score for Trauma Triage in the Geriatric and Middle-Aged (STTGMA) patients is able to predict fall, fracture, periprosthetic fracture, or dislocation risk after femoral neck fracture arthroplasty surgery.

METHODS

Four hundred one patients who underwent hip arthroplasty surgery after a femoral neck fracture at one urban academic medical center were stratified into groups based on their risk scores assigned at femoral neck fracture presentation. The cohort was reviewed for the occurrence of postdischarge falls, secondary fractures, and prosthetic dislocations that resulted in a presentation to the emergency department (ED) after discharge from their hip fracture surgery. The incidence and timing of these complications after discharge were compared between the low-risk and high-risk groups.

RESULTS

The low-risk group included 201 patients, and the high-risk group included 200 patients. The high-risk group had significantly more postdischarge falls resulting in ED presentation (49 vs. 32, p = .035) that occurred significantly sooner (12.6 vs. 18.3 months, p = .034) after discharge.

CONCLUSIONS

The STTGMA model was able to successfully stratify patients who are at a higher risk of sustaining a fall after an arthroplasty procedure for a femoral neck fracture.

Hip Hemiarthroplasty for Fractured Neck of Femur Revised to Total Hip Arthroplasty: Outcomes Are Influenced by Patient Age Not Articulation Options

BACKGROUND

Hip hemiarthroplasty is the most common arthroplasty option for fractured neck of femur (FNOF). Revision to total hip arthroplasty (THA) is occasionally required. This study aimed to assess the outcome of hemiarthroplasty revised to THA and to assess the impact of femoral head size, dual mobility (DM), and constrained liners.

METHODS

All aseptic 1^st revisions reported to the Australian Joint Replacement Registry after hemiarthroplasty performed for FNOF when a THA was used as the revision procedure were included from September 1999 to December 2019. The primary outcome measure was the cumulative percent revision for all-causes and dislocation. The impact of prosthesis factors on revision THA was assessed: standard head THA (≤32 mm), large head THA (≥36 mm), DM, and constrained liners. Outcomes were compared using Kaplan Meyer and competing risk.

RESULTS

There were 96,861 hemiarthroplasties performed, with 985 revised to THA. The most common reasons for 1^st revision were loosening (49.3%), fracture (17.7%), and dislocation (11.0%). Of the hemiarthroplasty procedures revised to THA, 76 had a 2^nd revision. The most common reasons for 2^nd revision were fracture (27.6%), dislocation (26.3%), loosening (23.7%), and infection (18.4%). Femoral head size, DM, or constrained liner use did not alter the incidence of all-cause 2^nd revision. This did not change when solely looking at patients still alive. A 2^nd revision was more likely in patients aged <75 years.

CONCLUSION

The outcome of hemiarthroplasty performed for FNOF revised to THA is influenced by patient age, not by the articulation used.

Dislocation of hemiarthroplasty after hip fracture is common and the risk is increased with posterior approach: result from a national cohort of 25,678 individuals in the Swedish Hip Arthroplasty Register

Background and purpose - Reported revision rates due to dislocation after hemiarthroplasty span a wide range. Dislocations treated with closed reduction are rarely reported despite the fact that they can be expected to constitute most of the dislocations that occur. We aimed to describe the total dislocation rate on the national level, and to identify risk factors for dislocation.Patients and methods - We co-processed a national cohort of 25,678 patients in the Swedish Hip Arthroplasty Register, with the National Patient Register (NPR) and Statistics Sweden. Dislocation was defined as the occurrence of any ICD-10 or procedural code related to hip dislocation recorded in the NPR, with a minimum of 1-year-follow-up. In theory, all early dislocations should thereby be traced, including those treated with closed reduction only.Results - 366/13,769 (2.7%) patients operated on with direct lateral approach dislocated, compared with 850/11,834 (7.2%) of those with posterior approach. Posterior approach was the strongest risk factor for dislocation (OR = 2.7; 95% CI 2.3-3.1), followed by dementia (OR = 1.3; CI 1.1-1.5). The older the patients, the lower the risk of dislocation (OR = 0.98 per year of age; CI 0.98-1.0). Neither bipolar design nor cementless stems influenced the risk.Interpretation - The choice of posterior approach and dementia was associated with an increased dislocation risk. When hips treated with closed reduction were identified, the frequency of dislocation with use of direct lateral and posterior approach more than doubled and tripled, respectively, compared with when only revisions due to dislocation are measured.

Outcomes of dual-mobility total hip arthroplasty versus bipolar hemiarthroplasty for patients with femoral neck fractures: a systematic review and meta-analysis

Background

Elderly patients with femoral neck fractures are at a higher risk of dislocation after hip arthroplasty procedures. In comparison with total hip arthroplasty (THA), bipolar hemiarthroplasty (HA) and dual-mobility total hip arthroplasty (DM-THA) can be an effective alternative treatment which increases the effective head size and overall stability of the prosthesis. We aim to review the current evidence on the outcome after DM-THA and HA for femoral neck fractures in the elderly.

Methods

We performed a comprehensive review of literatures on PubMed, Embase, Web of Science, and the Cochrane Library for randomized controlled trials and comparative interventional studies. Of the 936 studies identified, 8 met the inclusion criteria (541 DM-THA and 603 HA procedures). Two reviewers independently reviewed and graded each study and recorded relevant data including dislocation rate, implant failure rate, reoperation rate, 1-year mortality rate, Harris hip score (HHS), operation time, and intraoperative blood loss.

Results

DM-THA was associated with a lower dislocation rate (OR 3.599; 95% CI 1.954 to 6.630), a lower reoperation rate (OR 2.056; 95% CI 1.211 to 3.490), an increased operation time (SMD − 0.561; 95% CI − 0.795 to − 0.326) and more intraoperative blood loss (SMD − 0.778; 95% CI − 1.238 to − 0.319), compared with the HA group. Moreover, the multivariate regression analysis revealed that age, female sex, posterolateral surgical approach, and choice of DM-THA or HA were not associated with dislocation or reoperation.

Conclusions

Based on the current evidence, the advantages reported for DM-THA over HA with regard to dislocation and reoperation rate in elderly patients with FNF remain inconclusive. High-quality studies on the high-risk patients with cognitive disorder or dementia are necessary to validate the value of DM-THA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02316-6.

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.

Risk factors for dislocation after bipolar hemiarthroplasty: a retrospective case-control study of patients with CT data

Purpose

Bipolar hemiarthroplasty has been shown to have a lower rate of dislocation than total hip arthroplasty. However, as the influencing risk factors for bipolar hemiarthroplasty dislocation remain unclear, we aimed to analyse patient and surgeon-specific influencing risk factors for bipolar hemiarthroplasty dislocation.

Methods

We retrospectively analysed patients who were operated between 2012 and 2018 and had dislocated bipolar hemiarthroplasty and matched them to patients without a dislocated bipolar hemiarthroplasty, operated between 2018 and 2019. The study was limited to patients who received either a pre- or postoperative pelvic computed tomography. Besides demographic, morphologic, and physiologic data, we analysed duration of surgery; ASA score; Charlson Comorbidity Index; Almelo Hip Fracture Score; Parker Score; and acetabular morphology angles including acetabular anteversion angle, posterior acetabular sector angle, posterior wall angle, and acetabular roofing.

Results

We included nine patients with a dislocated bipolar hemiarthroplasty and 30 with a non-dislocated bipolar hemiarthroplasty. Patient-specific factors prompting a higher risk for dislocated bipolar hemiarthroplasty were longer duration of surgery (min) (115 ± 50 vs. 80 ± 27, p = 0.01); dementia (56% vs. 13%, p < 0.01); smaller posterior acetabular sector angle (°) (96 ± 6 vs. 109 ± 10, p < 0.01); and smaller posterior wall angle (°) (67 ± 6 vs. 77 ± 10, p = 0.02).

Conclusion

Dementia and insufficient posterior wall angle were associated with higher risk of dislocation in bipolar hemiarthroplasty

Outcomes of total hip arthroplasty using dual mobility components in patients with a femoral neck fracture

AIMS

Dislocation is the most common indication for further surgery following total hip arthroplasty (THA) when undertaken in patients with a femoral neck fracture. This study aimed to assess the complication rates of THA with dual mobility components (THA-DMC) following a femoral neck fracture and to compare outcomes between THA-DMC, conventional THA, and hemiarthroplasty (HA).

METHODS

We performed a systematic review of all English language articles on THA-DMC published between 2010 and 2019 in the MEDLINE, EMBASE, and Cochrane databases. After the application of rigorous inclusion and exclusion criteria, 23 studies dealing with patients who underwent treatment for a femoral neck fracture using THA-DMC were analyzed for the rate of dislocation. Secondary outcomes included reoperation, periprosthetic fracture, infection, mortality, and functional outcome. The review included 7,189 patients with a mean age of 77.8 years (66.4 to 87.6) and a mean follow-up of 30.9 months (9.0 to 68.0).

RESULTS

THA-DMC was associated with a significantly lower dislocation rate compared with both THA (OR 0.26; 95% CI 0.08 to 0.79) and HA (odds ratio (OR) 0.27; 95% confidence interval (CI) 0.15 to 0.50). The rate of large articulations and of intraprosthetic dislocation was 1.5% (n = 105) and 0.04% (n = 3) respectively.

CONCLUSION

THA-DMC when used in patients with a femoral neck fracture is associated with a lower dislocation rate compared with conventional arthroplasty options. There was no increase in the rates of other complication when THA-DMC was used. Future cost analysis and prospective, comparative studies are required to assess the potential benefit of using THA-DMC in these patients. Cite this article: Bone Joint J 2020;102-B(7):811-821.

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.

Alzheimer Dementia in the Orthopaedic Patient

Alzheimer disease is a neurologic disorder characterized by the progressive cognitive decline. As the population continues to age, orthopaedic surgeons need to become familiar with surgical and nonsurgical treatment considerations in this complex population. Despite the advances in geriatric and dementia care, surgical and postoperative management of both elective and emergent surgery remain complex and controversial in this patient population. Appropriate perioperative and postoperative management can optimize outcomes, and the management can significantly affect the quality of life of patient and caregiver and limit disease burden. Any treatment decision should be guided first and foremost by the goals of care as agreed between the surgeon, other providers, and family. Surgical management must be demand matched to the patient accounting for the severity of disease, life expectancy, and the social support system. The authors conducted a literature review of Alzheimer dementia care in orthopaedic patients via a Pubmed search of relevant articles published since 1980.

Efficacy of Different Posterior Capsulotomies on Dislocations in Hip Hemiarthroplasty: T-Shaped Capsulotomy versus Longitudinal Capsulotomy

BACKGROUND

Dislocation following hip hemiarthroplasty is one of the leading reasons necessitating a resurgery. Many studies suggested that the type of the surgical approach is the main cause for dislocation. However, no consensus has been reached yet regarding the type of the surgical approach. In this prospective clinical study, we aimed to compare the efficacy of two different capsulotomy techniques on dislocations, applied during hip hemiarthroplasties performed through the posterior approach.

MATERIALS AND METHODS

We investigated the dislocation rates in 287 patients (aged 65 and above) who underwent cemented bipolar hemiarthroplasty for displaced femoral neck fractures through the posterior capsular approach using two different capsulotomy techniques between 2009 and 2016. Patients were followed up for 12 months after hemiarthroplasty. Patients were evaluated in two groups; on whom hemiarthroplasty was performed as longitudinal (146 patients) and as T-shaped capsulotomy (141 patients).

RESULTS

Posterior dislocations occurred in seven (5%) patients who underwent hemiarthroplasty with T-shaped capsulotomy. No dislocation was observed in 146 patients who underwent hip hemiarthroplasty through posterior longitudinal capsulotomy. The difference between the two study groups was statistically significant (P < 0.007).

CONCLUSION

Capsule integrity can be achieved through a strong capsule repair which is possible through hemiarthroplasty with longitudinal capsulotomy. Longitudinal capsulotomy is an effective technique in preventing dislocations following hip hemiarthroplasty.

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.

The independent patient factors that affect length of stay following hip fractures

Introduction Management of hip fractures has evolved over recent years to drive better outcomes including length of hospital stay. We aimed to identify and quantify the effect that patient factors influence acute hospital and total health service length of stay. Methods A retrospective observational study based on National Hip Fracture Database data was conducted from 1 January 2014 to 31 December 2015. A multiple regression analysis of 330 patients was carried out to determine independent factors that affect acute hospital and total hospital length of stay. Results American Society of Anesthesiologists (ASA) grade 3 or above, Abbreviated Mental Test Score (AMTS) less than 8 and poor mobility status were independent factors, significantly increasing length of hospital stay in our population. Acute hospital length of stay can be predicted as 8.9 days longer when AMTS less than 8, 4.2 days longer when ASA grade was 3 or above and 20.4 days longer when unable to mobilise unaided (compared with independently mobile individuals). Other factors including total hip replacement compared with hemiarthroplasty did not independently affect length of stay. Conclusions Our analysis in a representative and generalisable population illustrates the importance of identifying these three patient characteristics in hip fracture patients. When recognised and targeted with orthogeriatric support, the length of hospital stay for these patients can be reduced and overall hip fracture care improved. Screening on admission for ASA grade, AMTS and mobility status allows prediction of length of stay and tailoring of care to match needs.

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.

Reduced revision rate and maintained function after hip arthroplasty for femoral neck fractures after transition from posterolateral to direct lateral approach

Background and purpose - The direct lateral (DL) approach to the hip for femoral neck fractures (FNF) has been shown to reduce the rate of dislocation and reoperations. We evaluate the effect of transition from the posterolateral (PL) to DL approach on reoperation and dislocation rates and patients' reported outcome. Patients and methods - In a prospective cohort study between 2012 and 2015, we enrolled 362 patients (median age 83 years, 70% women, mean follow-up 25 months) with a displaced FNF. The first group of 146 patients were operated using the PL and the second group of 216 patients with a DL approach, after change of our routines. A multivariable Cox regression analysis was used to evaluate factors associated with dislocation and reoperation. A generalized linear model was used to evaluate the functional outcome by comparing WOMAC and Harris hip scores between the 2 groups. Results - The reoperation rate was reduced from 13% in the PL to 6% in the DL group and the dislocation rate from 13% to 4%. Cox proportional hazard analysis identified the PL approach as the only factor associated with an increased risk of reoperation (hazard ratio =2.5, 95% CI 1.2-5.2). Age, sex, ASA classification, type of arthroplasty, cognitive dysfunction, or the experience of the surgeon had no effect on the risk of reoperation. Patient-reported outcome was similar between the 2 groups. Interpretation - In patients with FNF we have reduced the reoperation and dislocation rates by changing the surgical approach used for hip arthroplasty without affecting the patient-reported functional outcome.

Conversion of Hip Hemiarthroplasty to Total Hip Arthroplasty Utilizing a Dual-Mobility Construct Compared With Large Femoral Heads

BACKGROUND

Conversion of hemiarthroplasty to total hip arthroplasty (THA) has a historically high, up to 20%, postoperative dislocation rate. As such, dual-mobility (DM) constructs are an attractive option to mitigate this complication. We analyzed survivorship free of revision, complications, and clinical outcomes of hemiarthroplasties conversion to THAs utilizing DM constructs compared with large femoral heads (≥36 mm).

METHODS

Conversion of 16 hemiarthroplasties to THAs with a specific DM construct compared with 13 conversions utilizing large femoral heads (≥36 mm) from 2011 to 2014 were reviewed. Mean age at conversion in the DM group was 75 years (range, 57-93 years); 75% were female. Significantly more patients with a dislocated hemiarthroplasty were converted to DM constructs compared to large femoral heads (44% vs 0%; P = .01). Mean follow-up was 3 years.

RESULTS

Survivorship free of revision was 100% in the DM group compared with 92% in the large femoral head cohort at 2 years (P = .7). One (8%) patient converted to a large femoral head underwent revision to a constrained liner for recurrent dislocations while no patients experienced a postoperative dislocation in the DM group (P = .4). Harris Hip Scores improved from 54 to 82 (P < .01) in the DM group, and from 52 to 86 in the large femoral head group (P < .01).

CONCLUSION

Larger effective femoral heads used during conversion of hemiarthroplasties to THAs resulted in high survivorship free of revision, minimal complications, and excellent clinical outcomes at short-term follow-up. In patients at highest risk for postoperative dislocation, including those with dislocating hemiarthroplasties, DM constructs resulted in no postoperative dislocations.

What are the risk factors for dislocation in primary total hip arthroplasty? A multicenter case-control study of 128 unstable and 438 stable hips

INTRODUCTION

Dislocation after total hip arthroplasty (THA) is a leading reason for surgical revision. The risk factors for dislocation are controversial, particularly those related to the patient and to the surgical procedure itself. The differences in opinion on the impact of these factors stem from the fact they are often evaluated using retrospective studies or in limited patient populations. This led us to carry out a prospective case-control study on a large population to determine: 1) the risk factors for dislocation after THA, 2) the features of these dislocations, and 3) the contribution of patient-related factors and surgery-related factors.

HYPOTHESIS

Risk factors for dislocation related to the patient and procedure can be identified using a large case-control study.

PATIENTS AND METHODS

A multicenter, prospective case-control study was performed between January 1 and December 31, 2013. Four patients with stable THAs were matched to each patient with a dislocated THA. This led to 566 primary THA cases being included: 128 unstable, 438 stable. The primary matching factors were sex, age, initial diagnosis, surgical approach, implantation date and type of implants (bearing size, standard or dual-mobility cup).

RESULTS

The patients with unstable THAs were 67±12 [37-73]years old on average; there were 61 women (48%) and 67 men (52%). Hip osteoarthritis (OA) was the main reason for the THA procedure in 71% (91/128) of the unstable group. The dislocation was posterior in 84 cases and anterior in 44 cases. The dislocation occurred within 3 months of the primary surgery in 48 cases (38%), 3 to 12 months after in 23 cases (18%), 1 to 5years after in 20 cases (16%), 5 to 10years after in 17 cases (13%) and more than 10years later in 20 cases. The dislocation recurred within 6 months of the initial dislocation in 23 of the 128 cases (18%). The risk factors for instability were a high ASA score with an odds ratio (OR) of 1.93 (95% CI: 1.4-2.6), neurological disability (cognitive, motor or psychiatric disorders) with an OR of 3.9 (95% CI: 2.15-7.1), history of spinal disease (lumbar stenosis, spinal fusion, discectomy, scoliosis and injury sequelae) with an OR of 1.89 (95% CI: 1.0-3.6), unrepaired joint capsule (all approaches) with an OR of 4.1 (95% CI: 2.3-7.37), unrepaired joint capsule (posterior approach) with an OR of 6.0 (95% CI: 2.2-15.9), and cup inclination outside Lewinnek's safe zone (30°-50°) with OR of 2.4 (95% CI: 1.4-4.0).

DISCUSSION

This large comparative study isolated important patient-related factors for dislocation that surgeons must be aware of. We also found evidence that implanting the cup in 30° to 50° inclination has a major impact on preventing dislocation.

LEVEL OF EVIDENCE

Level III; case-control study.

A systematic review and meta-analysis of the direct anterior approach for hemiarthroplasty for femoral neck fracture

BACKGROUND

We performed a systematic review and meta-analysis to assess whether the direct anterior approach (DAA) is associated with improved functional and clinical outcomes compared to other surgical approaches for hemiarthroplasty for displaced femoral neck fractures.

MATERIALS AND METHODS

Randomized trials and cohort studies of hemiarthroplasty performed via DAA versus another surgical approach (anterolateral, lateral, posterolateral, posterior) were included. Our primary outcome was postoperative functional mobility. Secondary outcomes included overall complication rate, dislocation rate, perioperative fracture, infection rate, re-operation rate, overall mortality, operative time, pain, intra-operative blood loss, and length of stay.

RESULTS

Nine studies met inclusion criteria, comprising a total of 698 hips (330 direct anterior, 57 anterolateral, 89 lateral, 114 posterolateral, 108 posterior approach). With regard to functional mobility, DAA was favored in 4 studies, and no study favored another approach over DAA. DAA had a significantly lower dislocation rate compared to posterior capsular approaches. Analysis of other secondary outcomes did not identify statistically significant differences.

CONCLUSION

This is the first systematic review and meta-analysis of the DAA for hemiarthroplasty. Available evidence suggests superior early functional mobility with the DAA. The DAA is associated with a significantly lower dislocation rate compared to posterior capsular approaches for hemiarthroplasty.