Unipolar versus bipolar Exeter hip hemiarthroplasty: a prospective cohort study on 830 consecutive hips in patients with femoral neck fractures

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.

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.].

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.

Hip Hemiarthroplasty: The Misnomer of a Narrow Femoral Canal and the Cost Implications

Objective

Hemiarthroplasty has been identified as the treatment of choice for displaced intracapsular femoral neck fractures. A modular prosthesis is sometimes preferred for its sizing options in narrow femoral canals, despite its higher cost and no advantage in clinical outcomes. Thus, in this study, we investigated the factors affecting surgeons’ choice of prosthesis, hypothesizing that modular hemiarthroplasty is overused for narrow femoral canals compared to monoblock hip hemiarthroplasty.

Methods

A retrospective study of a regional level 1 trauma center was conducted. Patients who had sustained femoral neck fractures from March 2013 to December 2016 were included in this study. Inclusion criterion was modular hemiarthroplasty for a narrow femoral canal. A matched group of patients who underwent monobloc hemiarthroplasty (MH) was created through randomization. The main outcome measurements were sex, age, Dorr classification, and femoral head size. We measured the protrusion of the greater trochanter beyond the level of the lateral femoral cortex postoperatively. Modular hemiarthroplasty patients were templated on radiographs using TraumaCad for Stryker Exeter Trauma Stem (ETS®).

Results

In total, 533 hemiarthroplasty procedures were performed, of which 27 were modular for a narrow femoral canal. The ratio of modular to monobloc was 1:18. Average head size was 46.7 mm ± 3.6 mm for monobloc and 44.07 ± 1.5 for modular (P= 0.001). There were four malaligned stems in the monobloc group versus 14 in the modular group (P= 0.008). Unsatisfactory lateralization was noted in 18 patients (7 mm ± 2.9 mm) in the modular group compared with 8 (4.7 mm ± 3.9 mm) in the monobloc group (P= 0.029). Dorr classification was A or B in 24 patients in the modular group and 18 in the monobloc group (P = 0.006). Templating revealed that modular was not required in 25 patients.

Conclusions

As per our findings, it was determined that patients with a narrow femoral canal intraoperatively should not receive modular hemiarthroplasty. This is especially true for female patients with small femoral head and narrow femoral canal dimensions (Dorr A and B). They would require extensive careful planning. Surgical techniques should be explored through education intraoperatively to achieve lateralization during femoral stem preparation. This may avoid prolonged anesthetic time and achieve potential cost savings.

Unipolar versus bipolar hemiarthroplasty for hip fractures in patients aged 90 years or older: A bi-centre study comparing 209 patients

BACKGROUND

This study aimed to evaluate the outcome of unipolar and bipolar hemiarthroplasty to treat hip fractures in patients aged ≥ 90 years.

METHODS

We conducted this study from 2007 to 2018 based on the electronic databases of two hospitals. Patients aged ≥ 90 years, treated for Arbeitsgemeinschaft Osteosynthese 31-B3 type fractures, were included. One hospital conducted the treatment only with unipolar prostheses; the other hospital used only bipolar prostheses. We assessed 23 peri‑ and postoperative variables including any revision, dislocation, and survival. The follow-up was completed after a minimum of 2 years postoperatively. At follow-up, the functional status was evaluated via telephone using the Parker score for every living patient.

RESULTS

One-hundred unipolar prostheses, and 109 bipolar prostheses were examined. The patients' mean age was 92.9 years (range 90-102). Dementia was differently distributed between the groups (p < 0.001), with a lower survival risk (Odds Ratio 1.908; Confidence Interval 1.392 - 2.615; log rank <0.001). Based on this result, unipolar demonstrated significantly higher mortality rates compared with bipolar prostheses (log rank < 0.001). No effects were found for dislocation, revision and overall complication rate. At follow-up, 37 patients were available for functional status. The mean Parker score was 3.7 (range 0-9), with no effect.

CONCLUSIONS

Intracapsular hip fractures in patients aged ≥ 90 years can be treated with unipolar or bipolar hemiarthroplasty. The type of prostheses did not influence dislocation, revision, general complication, or functional status. The groups were significantly affected by dementia, a risk factor for shorter survival.

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.

Revision Risk After Unipolar or Bipolar Hemiarthroplasty for Femoral Neck Fractures: An Instrumental Variable Analysis of 62,875 Procedures from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

There remains much international practice variation regarding the choice of a unipolar or bipolar prosthesis design for displaced femoral neck fractures that are treated with hemiarthroplasty. The purpose of the present study was to compare revision rates following primary hemiarthroplasty for femoral neck fracture to determine if the unipolar hemiarthroplasty design increases the risk of revision arthroplasty for all causes.

METHODS

Instrumental variable analysis was performed with use of data that had been entered into the Australian Orthopaedic Association National Joint Replacement Registry from September 1, 1999, to December 31, 2018. Sixty-two thousand, eight hundred and seventy-five patients with femoral neck fractures that were treated with primary modular unipolar or bipolar hemiarthroplasty procedure were analyzed. Hospital preference for prosthesis design in the 12 months prior to the index procedure was used as an instrument to adjust for unmeasured confounding. The primary outcome was time to first revision for any cause. Secondary analyses were performed on the reason for revision (infection, dislocation, periprosthetic fracture, or acetabular erosion), the use of cement femoral stem fixation, and the type of stem (polished or matte).

RESULTS

Modular unipolar hemiarthroplasty was associated with a higher rate of revision at >2.5 years (hazard ratio [HR], 1.86; 95% confidence interval [CI], 1.46 to 2.36; p < 0.001), but there was no difference between the groups before 2.5 years (HR, 0.98; 95% CI, 0.85 to 1.13; p = 0.79). Protective factors for revision included female sex (HR, 0.82; 95% CI, 0.74 to 0.9), use of cemented fixation (HR, 0.69; 95% CI, 0.62 to 0.77), and surgery performed in a public hospital setting (HR 0.79; 95% CI, 0.70 to 0.89). Modular unipolar prostheses had a greater risk of revision for acetabular erosion, particularly in later time periods (HR at ≥5.5 years, 5.10; 95% CI, 2.40 to 10.83; p < 0.001), while being protective against periprosthetic fractures (HR, 0.72; 95% CI, 0.59 to 0.87; p < 0.001) at all time points. There was no difference in terms of the risk of revision for infection, dislocation, or stem type.

CONCLUSIONS

Bipolar hemiarthroplasty designs resulted in a lower risk of revision than unipolar designs. Unipolar hemiarthroplasties are justified for patients with femoral neck fracture and a shorter life expectancy (≤2.5 years).

LEVEL OF EVIDENCE

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

Survival Rate and Application Number of Total Hip Arthroplasty in Patients With Femoral Neck Fracture: An Analysis of Clinical Studies and National Arthroplasty Registers

BACKGROUND

Total hip arthroplasty (THA) is an increasingly popular treatment option for fractured neck of femur (NOF). The primary aim of this study is to systematically review all literature on primary THA and hemiarthroplasty (HA) after fractured NOF to calculate an overall revision rate. Furthermore, we wanted to compare primary THA implantations after fractured NOF between different countries in terms of THA number per inhabitant.

METHODS

All clinical studies on THA and HA for femoral neck fractures between 1999 and 2019 were reviewed and evaluated with a special interest on revision rate. Revision rate was calculated as "revision per 100 component years." THA registers were compared between different countries with respect to the number of primary implantations per inhabitant.

RESULTS

THA studies showed a mean revision rate of 11.8% after 10 years, which was lower than a 24.6% 10-year revision rate for HA. We identified 8 arthroplasty registers that revealed an annual average incidence of THA for fractured NOF of 9.7 per 100,000 inhabitants.

CONCLUSION

This study showed that patients with THA were less likely to be revised at 10 years compared to HA. We found similar annual numbers of THAs for fractured NOF per inhabitant across countries. The results of this analysis can be used to rank present and future national THA numbers within an international context.

The effects of cement fixation on survival in elderly patients with hip hemiarthroplasty: a nationwide cohort study

BACKGROUND

Hip hemiarthroplasty (HHA) is a common treatment for hip fractures in the elderly population. Because of the fatal effects of bone cement implantation syndrome, the safety of cement utilization to enhance implant firmness in the femur is controversial. The aim of this study was to investigate the postoperative survival of elderly patients receiving HHA with and without cement fixation.

METHODS

Claim data from the National Health Insurance Database and the National Register of Deaths Database were used for analysis in this retrospective cohort study. From 2008 to 2014, 25,862 patients aged 80 years or older treated with hip hemiarthroplasty were included in the analysis. A Cox proportional risk model was used to analyse the effects of cement utilization on postoperative mortality.

RESULTS

The cemented group had a significantly higher mortality risk than the non-cemented group within 7, 30, 180 days and 1 year after the operation. The effect of bone cement on postoperative mortality was significantly stronger within 7 days than within 30, 180 days and 1 year. In addition, the male gender, age > 85 years and higher score on the Charlson Comorbidity Index were also risk factors for mortality (p < 0.05). Patients who received HHA in lower-volume hospitals had higher mortality rates within 180 days and 1 year than those in higher-volume hospitals. Compared with patients who were operated on by high-volume surgeons, those who received surgery performed by lower-volume surgeons were more likely to die within 30 days (aHR = 1.22), 180 days (aHR = 1.16) and 1 year (aHR = 1.19), respectively.

CONCLUSIONS

The postoperative mortality rate of elderly patients undergoing HHA was significantly higher in the cemented group than in the non-cemented group.

Unipolar versus bipolar hemiarthroplasty for displaced femoral neck fractures: A pooled analysis of 30,250 participants data

PURPOSE

To assess the clinical outcomes of unipolar versus bipolar hemiarthroplasty for displaced intracapsular femoral neck fractures in older patients and to report whether bipolar implants yield better long-term functional results.

METHODS

We searched PubMed, Scopus, EBSCO, and Cochrane Library for relevant randomized clinical trials (RCTs) and observational studies, comparing unipolar and bipolar hemiarthroplasty. Data were extracted from eligible studies and pooled as relative risk (RR) or mean difference (MD) with corresponding 95% confidence intervals (CI) using RevMan software for Windows.

RESULTS

A total of 30 studies were included (13 RCTs and 17 observational studies). Analyses included 30,250 patients with a mean age of 79 years and mean follow-up time of 24.6 months. The overall pooled estimates showed that bipolar was superior to unipolar hemiarthroplasty in terms of hip function, range of motion and reoperation rate, but at the expense of longer operative time. In the longer term the unipolar group had higher rates of acetabular erosion compared to the bipolar group. There was no significant difference in terms of hip pain, implant related complications, intraoperative blood loss, mortality, six-minute walk times, medical outcomes, and hospital stay and subsequently cost.

CONCLUSIONS

Bipolar hemiarthroplasty is associated with better range of motion, lower rates of acetabular erosion and lower reoperation rates compared to the unipolar hemiarthroplasty but at the expense of longer operative time. Both were similar in terms of mortality, and surgical or medical outcomes. Future large studies are recommended to compare both methods regarding the quality of life.

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.

Modular bipolar hemiarthroplasty for fracture neck of femur using contemporary cementing technique: Long-term results of a single design

Introduction:

The use of bipolar prosthesis in the management of displaced fracture neck of femur has remained controversial. There has been a lack of long-term studies in its results and survivorship, especially in acetabular erosion.

Methods:

We retrospectively reviewed 108 single design bipolar hemiarthroplasties (105 patients) performed in a single centre between 1999 and 2008, with a mean follow-up of 7.4 years (range: 2.2–18.3 years). General indications of surgery include displaced fracture with age less than 75, narrow femoral canals not permitting the use of a monoblock implant or as salvage procedure for failed internal fixation.

Results:

Six hips (5%) required further surgery – two patients had debridement for infection and four patients required revision to total hip arthroplasty (THA) due to infection or aseptic loosening. There was no dislocation. No revision was required for acetabulum erosion. Kaplan–Meier analysis showed a 15-year survival free of revision due to any reason to be 93.1% and due to aseptic loosening to be 97.1%.

Discussion:

Our centre has shown excellent clinical results and low revision rate with the cemented bipolar system. In the context of displaced fracture neck of femur, the long-term results can be compared with THA which is associated with higher perioperative morbidity.

Does surgeon volume influence the outcome after hip hemiarthroplasty for displaced femoral neck fractures; early outcome, complications, and survival of 752 cases

INTRODUCTION

Surgeon volume of hip arthroplasties is of importance with regard to complication and revision rates in total hip arthroplasty. For hip hemiarthroplasty, the effect of surgeon volume on outcome is far less studied. We analyzed the outcome of hip hemiarthroplasties performed by orthopedic surgeons in a retrospective cohort in different volume categories, focusing on early survival of the prosthesis and complications.

METHODS

Between March 2009 and January 2014, 752 hemiarthroplasties were performed for intracapsular femoral neck fracture by 27 orthopedic surgeons in a large Dutch teaching hospital. Surgeons were divided into four groups, a resident group and three groups based on the number of total hip arthroplasties and hemiarthroplasties performed per year: a low-volume (< 10 arthroplasties per year), moderate-volume (10-35 arthroplasties per year), and high-volume groups (> 35 arthroplasties per year). Outcome measures were stem survival using a competing risk analysis, complication rates, and mortality. Chi-square tests were used to compare complication rates and mortality between groups.

RESULTS

Patients were followed for a minimum of 2 years or until revision or death. Overall 60% of the patients included had died at time of follow-up. We found comparable stem survival rates in the low-volume group (n = 48), moderate-volume group (n = 201), high-volume group (n = 446), and resident group (n = 57). There were no significant differences between the groups with regard to dislocation rate, incidence of periprosthetic fracture, infection, and mortality.

CONCLUSION

Surgeon volume and experience did not influence early outcome and complication rates in hip hemiarthroplasty. Hemiarthroplasty can safely be performed by both experienced hip surgeons and low-volume surgeons.

In-vivo postoperative motion analysis of metal and ceramic bipolar hip hemiarthroplasty

BACKGROUND

We hypothesized that ceramic bipolar shows less impingement between stem neck and outer head compared to metal bipolar, because of its low coefficient of friction with the acetabulum cartilage. In this paper, a three dimensional (3D) postoperative motion analysis has been used to assess the different motion characteristics of metal and ceramic bipolar hip hemiarthroplasty systems.

METHODS

This study was conducted on 40 patients divided in two matched cohorts: 20 patients with metal bipolar and 20 patients with the ceramic bipolar. We obtained motion pictures from standing position to maximum abduction in flexion by fluoroscopy then analyzed by 2D-3D image matching method. The motion range of the "Outer head angle", "Stem neck angle" and the "Stem neck and outer head angle" was compared between the metal bipolar group and the ceramic bipolar group.

RESULTS

The metal bipolar group's inner head's range of movement was greater than the ceramic bipolar group. Impingement between stem neck and outer head occurred in 30% of metal group patients. There were no impingement cases for the ceramic bipolar group.

CONCLUSIONS

The ceramic bipolar shows less impingement between stem neck and outer head compared to the metal bipolar. Ceramic bipolar may reduce the typical bipolar related complication and exert less effect on the acetabular cartilage due to less surface coefficient of friction.

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.

Evidence based management of intracapsular neck of femur fractures

Neck of femur fractures are occurring at an increased incidence. Functionally independent patients without cognitive impairment can expect reasonable life expectancy. This indicates the need for a durable surgical option that optimises the chance to return to pre-injury functional status, with minimal risk of complications and reoperation. Most fractures are displaced. Surgical options include internal fixation, hemiarthroplasty or total hip arthroplasty (THA). Evidence is conclusive that arthroplasty options outperform internal fixation in terms of function, quality of life and reoperation rates. In anyone other than young patients where head preserving surgery is required, arthroplasty is the standard of care. Hemiarthroplasty is the heavily favoured arthroplasty option for surgeons. However, in patients other than the extreme elderly, medically infirm, neurologically impaired, or with little or no ambulatory capacity, the evidence to support hemiarthroplasty is lacking. In functionally independent patients without cognitive impairment, THA should be considered the gold standard, producing better functional and quality of life outcomes, lower reoperation rates and better cost effectiveness, with no difference in complications or mortality. An increased risk of dislocation does exist. This may be reduced with modern surgical technique and implant options. Low amounts of research have been afforded to undisplaced fractures. For this fracture type, surgery is the standard of care. Despite a higher risk of reoperation, internal fixation is the preferred option for all age groups. Further study is required to identify the difference between internal fixation and THA, in particular, for unstable fracture patterns in elderly patients.

Total hip arthroplasty after failed treatment of proximal femur fracture

INTRODUCTION

Total hip arthroplasty (THA) is a good option as a salvage procedure after failed treatment of proximal femur fracture. The anatomy of the proximal femur, however, makes this surgery complicated and challenging. The purpose of this study was to evaluate the radiographic and clinical outcomes of THA after failed treatment of proximal femur fractures.

MATERIALS AND METHODS

We retrospectively analysed 50 consecutive THAs (42 women, 8 men; mean age 77 years) after failed treatment of a proximal femur fracture. Mean postoperative follow-up was 58.1 months. Preoperative diagnoses were femoral neck fracture in 18 hips and trochanteric fracture in 32 hips, including three that were infected. Failure resulted from cutout in 22 cases, osteonecrosis in 12, non-union with failed fixation in nine, postoperative osteoarthritis in four, and infection in three. Factors compared included radiographic assessment, complication rate, visual analogue scale (VAS), and Harris Hip Scores (HHS). Radiographic variables included femoral neck anteversion and cup and stem alignment.

RESULTS

Absolute values of the differences in femoral neck anteversion between the affected and healthy sides were 6.0° in the femoral neck fracture group and 19.2° in the trochanteric fracture group (p = 0.01). There were no significant differences in cup anteversion (p = 0.20) or stem anteversion (p = 0.08). The complication rate was significantly higher in the trochanteric fracture group than in the femoral neck fracture group (25 vs 0%, p < 0.0001). Postoperative complications in the trochanteric fracture group included three periprosthetic fractures (9.4%), two dislocations (6.3%), two surgical-site infections (6.3%), and one stem penetration (3.1%). Although no significant differences between groups were seen in the VAS or HHS at final follow-up (p = 0.32, 0.09, respectively), these measures were significantly improved at final follow-up in both groups (p < 0.0001 for both).

CONCLUSIONS

Performing THA after failed treatment of trochanteric fractures requires consideration of complication risk and incorrect femoral neck anteversion.

Five cases of early dissociation between the bipolar hip endoprosthesis cup components; either spontaneously or during reduction maneuvers

Bipolar hemiarthroplasty is frequently used in the treatment of intracapsular hip fractures. Dissociation of the bipolar components can happen during the hip dislocation, the reduction maneuvers, or spontaneously without any dislocation. Here we report early dissociation between bipolar components in two cases during the attempt of closed reduction maneuvers and three cases with spontaneous dissociation without any trauma. To prevent or minimize this complication; the reduction of dislocated hips must be achieved very gently under general anesthesia with fluoroscopic control. During the initial operation the surgeons must be sure that the bipolar components are locked to each other and after final reduction, especially in osteoarthritic acetabulums, that the cup position is not in varus position.

Is It Time to Phase Out the Austin Moore Hemiarthroplasty? A Propensity Score Matched Case Control Comparison versus Cemented Hemiarthroplasty

We compared the Austin Moore hemiarthroplasty versus cemented hemiarthroplasties using a propensity score matched cased control study. For a consecutive cohort of 450 patients with displaced intracapsular neck of femur fractures, 128 matched cases in each group were selected based on age, gender, walking status, nursing home residency, delays in surgery, ASA score, and the Charlson comorbidity score. At a mean follow-up of 16.3 months, we evaluated their outcomes. Significantly more patients with AMA experienced thigh pain (RR = 3.5, 95% CI: 1.67-7.33, p = 0.000), overall complications (RR = 4.47, 95% CI: 1.77-11.3, p = 0.000), and implant loosening (RR = 8.42, 95% CI: 2.63-26.95, p = 0.000). There were no definite cement related deaths in this series. There was no significant difference in mortality, walking status, and the number of revisions between the groups. We support the routine use of cemented hemiarthroplasty instead of the Austin Moore for treating elderlies with displaced intracapsular neck of femur fractures.

Hip arthroplasty for the treatment of displaced fractures of the femoral neck in elderly patients

This review summarises the evidence for the treatment of displaced fractures of the femoral neck in elderly patients. Results from randomised clinical trials and national register studies are presented when available.

The advantages of arthroplasty compared with internal fixation are supported by several studies. A number of studies contribute to the discussions of total hip arthroplasty (THA) versus hemiarthroplasty and unipolar versus bipolar hemiarthroplasty, but no clear-cut evidence-based recommendation can be made. THA may be particularly advantageous for active, lucid patients with a relatively long life expectancy. For patients who are physiologically older, hemiarthoplasty is probably satisfactory, and for the oldest patients with more comorbidities, unipolar implants are considered to be sufficient. If the hospital can support emergency THA surgery in sufficient numbers and quality, there may be few patients who warrant bipolar hemiarthroplasty.

The direct lateral approach reduces the risk of dislocation compared with the posterior approach. Cemented implants lower the risk of periprosthetic fracture and its subsequent morbidity and mortality. As the risk of peri-operative death related to bone cement can be reduced by adequate measures, cemented implants are recommended in fracture cases.

Take home message: There remains a great variation in the surgical management of patients with a hip fracture, and an evidence-based approach should improve the outcomes for this vulnerable patient group.

Cite this article: Bone Joint J 2016;98-B:291–7.

Anatomy, classification and treatment of intracapsular hip fractures

Hip fractures are increasingly common, given the increasing ageing, osteoporotic population with significant medical comorbidities. This review summarizes the anatomy of the proximal femur, reviews classification systems and gives recommendations for use of each treatment modality.

Low femoral antetorsion as a risk factor for bony impingement after bipolar hemiarthroplasty

Introduction

Reports of dislocation after bipolar hemiarthroplasty (BHA) abound in literature, and several studies have mentioned the factors that are associated with an increased risk of dislocation. However, there is no report detailing the pattern of impingement in BHA and how femoral antetorsion can affect the range of motion (ROM) after BHA.

Purpose

The purpose of this study was to evaluate the pattern of impingement in BHA and whether femoral antetorsion affects the ROM after BHA using three-dimensional (3D) dynamic motion analysis.

Methods

Using the computed tomography (CT) data of 60 patients (60 hips), including 31 men and 29 women who underwent BHA for the treatment of idiopathic osteonecrosis (ION) of the femoral head, we calculated the antetorsion of the femoral neck, ROM of flexion (Flex), internal rotation (Int-R), and external rotation (Ext-R) using a CT-based 3D simulation software. We evaluated the pattern of impingement and the relationship between femoral antetorsion and ROM in BHA. As for the implant position in the 3D simulation software, the anteversion of the femoral implant was set to be the same as the natural antetorsion of the femoral neck and neck length was set to be the standard neck in all cases.

Results

This study revealed the mechanism of impingement in BHA: (1) bone to bone impingement and (2) implant to bone impingement. We found a significant decrease in the ROM of Flex and Int-R inversely proportional to the femoral antetorsion. In patients with lower femoral antetorsion, the ROM of Flex and Int-R decreased due to bony impingement (the anterior great trochanteric region of the femur impinges on the anteroinferior edge of the anteroinferior iliac spine). Whereas, high anteversion of the femoral implant may decrease the ROM of Ext-R; however, our results also showed that even the lowest ROM of Ext-R with 10° hip extension was over 40°.

Conclusions

We demonstrated that lower femoral antetorsion substantially affects the ROM of Flex and Int-R due to bony impingement. For these patients, there should be consideration given to retaining femoral “anterior offset” in BHA.

Femoral neck fractures: current management

Femoral neck fractures are a commonly encountered injury in orthopaedic practice and result in significant morbidity and mortality. It is essential that surgeons are able to recognize specific fracture patterns and patient characteristics that indicate the use of particular implants and methods to effectively manage these injuries. Use of the Garden and Pauwels classification systems has remained the practical mainstay of femoral neck fracture characterization that help dictate appropriate treatment. Operative options include in situ fixation, closed or open reduction and internal fixation, hemiarthroplasty, and total hip arthroplasty. Recent reports demonstrate diversity among orthopaedic surgeons in regard to the optimal treatment of femoral neck fractures and changing trends in management. The present discussion focuses on the current indications and methods for femoral neck fracture management to provide direction with respect to appropriate and effective care of these injuries.

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.

Dislocation of bipolar hip hemiarthroplasty through a postero-lateral approach for femoral neck fractures: A cohort study

PURPOSE

To analyze postoperative global femoral offset (FO), leg length discrepancy (LLD) and Wiberg angle as risk factors for prosthetic dislocation after treatment with bipolar hemiarthoplasty (HA) through a postero-lateral approach for femoral neck fracture (FNF).

METHODS

Three hundred and seventy three patients treated with a cemented bipolar HA through a postero-lateral approach between January 2006 and December 2013 were included in a cohort study with a follow-up time ranging from 6 months to 7 years. Radiographs and all surgical records were reviewed regarding Global FO, LLD and Wiberg angle. We compared stable hips without dislocation to those with either a single dislocation and those with recurrent instability.

RESULTS

Three hundred and twenty eight hips fulfilled the inclusion criteria and were analyzed in the study. The incidence of prosthetic dislocation was 10.7% (36/373). The mean time from surgery to first dislocation was 3.9 months (0-47) and 62.5% had recurrent dislocations. Patients with dislocation had a statistically significantly decreased postoperative global FO (-6.4 mm vs. -2.8 mm, p = 0.04), LLD (-2 vs. 1.5 mm, p = 0.03) and smaller Wiberg angle (40° vs. 46°, p = 0.01) on the operated side compared with the rest of cohort. In comparison to age and sex-matched control groups from the cohort, the difference in the radiographic parameters were significant in patients with recurrent dislocations but not in patients with a single dislocation.

CONCLUSION

Patients with recurrent dislocations had a decreased postoperative global FO, shorter leg and shallower acetabulum on the operated side compared with their controls. These factors might decrease the soft-tissue tension around the operated hip and predispose to dislocation.

LEVEL OF EVIDENCE

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

Bipolar versus unipolar hemiarthroplasty for displaced femoral neck fractures in the elder patient: a systematic review and meta-analysis of randomized trials

OBJECTIVE

To assess the safety and efficacy that compare bipolar hemiarthroplasty with unipolar hemiarthroplasty for the treatment of femoral neck fracture in the patient aged more than 65 years.

METHODS

We searched databases including PubMed Central, MEDLINE (from 1966), EMBASE (from 1980) and the Cochrane Central Register of Controlled Trials database. Only prospective randomized controlled trials (RCTs) that compare bipolar hemiarthroplasty with unipolar hemiarthroplasty for the treatment of femoral neck fracture in the elder patient were included. RevMan 5.2 from the Cochrane Collaboration was applied to perform the meta-analysis.

RESULTS

Six relevant RCTs with a total of 982 patients were retrieved. From this meta-analysis, mortality rates showed no statistical difference between two treatments, 14.7% for bipolar versus 13.8% for unipolar. The acetabular erosion rates were significantly different between two groups (P=0.01), 1.2% in bipolar versus 5.5% in unipolar group. Overall complication rates, dislocation rates, infection rates and reoperation rates between two groups showed no statistical difference (P>0.05). Neither of two treatments appeared to be superior regarding the clinical function assessed by Harris hip scores or return to pre-injury state rates (P>0.05).

CONCLUSIONS

Both bipolar and unipolar hemiarthroplasty for the treatment of elderly patient suffering displaced femoral neck fracture achieve similar and satisfy clinical outcome in short-term follow-up. Unipolar hemiarthroplasty seems to be a more cost-effectiveness option for elderly patient.

Unipolar hemiarthroplasty versus bipolar hemiarthroplasty in patients with displaced femoral neck fractures: a four-year follow-up of a randomised controlled trial

PURPOSE

The treatment of choice for a displaced femoral neck fracture in the most elderly patients is a cemented hemiarthroplasty (HA). The optimal design, unipolar or bipolar head, remains unclear. The possible advantages of a bipolar HA are a better range of motion and less acetabular wear. The aim of this study was to evaluate hip function, health related quality of life (HRQoL), surgical outcome and acetabular erosion in a medium-term follow-up.

METHODS

One hundred and twenty patients aged 80 or more with a displaced fracture of the femoral neck (Garden III and IV) were randomised to treatment with a cemented Exeter HA using a unipolar or a bipolar head. All patients were able to walk independently, with or without aids, before surgery. Follow-ups were performed at four, 12, 24 and 48 months postoperatively. Assessments included HRQoL (EQ-5D index score), hip function (Harris hip score [HHS]) and radiological acetabular erosion.

RESULTS

The mean EQ-5D index score was generally higher among the patients with bipolar hemiarthroplasties at the follow-ups with a significant difference at 48 months: unipolar HAs 0.59 and bipolar HAs 0.70 (p = 0.04). There was an increased rate of acetabular erosion among the patients with unipolar hemiarthroplasties at the early follow-ups with a significant difference at 12 months (unipolar HAs 20% and bipolar HAs 5%, p = 0.03). At the later follow-ups the incidence of acetabular erosion accelerated in the bipolar group, and there were no significant differences between the groups at the 24- and 48-month follow-ups. There was no difference in HHS or reoperation rate between the groups at any of the follow-ups.

CONCLUSION

The bipolar HAs seem to result in better HRQoL beyond the first two years after surgery compared to unipolar HAs. Bipolar HAs displayed a later onset of acetabular erosion compared to unipolar HAs.

Internal fixation versus cemented hemiarthroplasty for displaced femoral neck fractures in patients with severe cognitive dysfunction: a randomized controlled trial

OBJECTIVES

To compare the outcome of internal fixation (IF) versus a cemented hemiarthroplasty (HA) in patients with a displaced femoral neck fracture and a severe cognitive dysfunction.

DESIGN

A prospective randomized controlled trial.

SETTING

A tertiary care university hospital.

PATIENTS

Sixty patients with a displaced femoral neck fracture were randomized to IF (n = 30) or HA (n = 30). All patients suffered from severe cognitive dysfunction but were able to walk before the fracture.

INTERVENTION

IF using 2 cannulated screws or HA using a cemented Exeter unipolar arthroplasty.

MAIN OUTCOME MEASUREMENTS

Patients were reviewed at 4, 12, and 24 months after the fracture. Outcome assessments included complications, reoperations, hip function (Charnley score), and health-related quality of life (EQ-5Dindex score).

RESULTS

A total of 8 patients were reoperated (14%); 7 in the IF group and 1 in the HA group. The EQ-5Dindex score at the follow-ups were generally lower in the IF group compared with the HA group with a significant difference at 12 months (P = 0.03). No difference was seen in hip function, general complications, or mortality between the groups.

CONCLUSIONS

HA seems to provide a safe option with better health-related quality of life and less risk for reoperations compared with IF for these patients.

LEVEL OF EVIDENCE

Therapeutic level II.

Hemiarthroplasties in young patients with osteonecrosis or a tumour of the proximal femur; an observational cohort study

Background

The failure scenario in total hip arthroplasty (THA), in younger patients, is dependent on the fixation and wear of the acetabular component. In selected cases, where endoprosthetic replacement of the femoral head is unavoidable for limb salvage or functional recovery, hemiarthroplasty can be chosen as an alternative. The purpose of this study is to evaluate hemiarthroplasty as treatment strategy for young patients with osteonecrosis or a tumour of the proximal femur.

Methods

Between 1985 and 2008, 42 hemiarthroplasties (unipolar and bipolar) were performed in patients younger than 65 years with osteonecrosis (n=13) or a tumour of the proximal femur (n=29). All patients were seen at yearly follow-up examination and evaluated. Revision or conversion to a THA was regarded as a failure of the implant. A Kaplan Meier analysis was performed. To determine significant differences between categorical groups, the Pearson chi-square test was used. In numerical groups the independent T-test and One-way ANOVA were used.

Results

After a mean follow-up of 7.1 years, failure of the hemiarthroplasty occurred 6 times. The Kaplan Meier survival analysis with conversion to THA or revision as endpoint of the bipolar hemiarthroplasties (n=38) shows a 96% survival at 15, and 60% at 20 years. In the unipolar type (n=4) we found a conversion rate of 50% within 3 years.

Conclusions

Bipolar hemiarthroplasty is a reasonable alternative in a young patient with osteonecrosis or a tumour of the proximal femur as indication. Because of the high conversion rate after unipolar hemiarthroplasties, we would not recommend this type of prosthesis in the young patient.

Hip arthroplasty after failed fixation of trochanteric and subtrochanteric fractures

BACKGROUND AND PURPOSE

Hip arthroplasty is an option for elderly patients with osteoporosis for the treatment of failure after fixation of trochanteric and subtrochanteric fractures, either as a total hip arthroplasty (THA) or as a hemiarthroplasty (HA). We analyzed the reoperation rate and risk factors for reoperation in a consecutive series of patients.

METHODS

All patients (n = 88) operated from 1999 to 2006 with a THA (n = 63) or an HA (n = 25) due to failure of fixation of a trochanteric fracture (n = 63) or subtrochanteric fracture (n = 25) were included. Background data were collected from the patient records. A search was performed in the national registry of the Swedish National Board of Health and Welfare in order to find information on all reoperations. The follow-up time was 5-11 years.

RESULTS

The reoperation rate was 16% (14/88 hips). A periprosthetic fracture occurred in 6 patients, a deep prosthetic infection in 5 patients, and a dislocation of the prosthesis in 3 patients. Standard-length femoral stems had an increased risk of reoperation (11/47) compared to long stems (3/41) (HR = 4, 95% CI: 1.0-13; p = 0.06).

INTERPRETATION

The high reoperation rate reflects the complexity of the surgery. Using long femoral stems that bridge previous holes and defects may be one way to reduce the risk for reoperation.

The cartilage degeneration and joint motion of bipolar hemiarthroplasty

PURPOSE

The outcomes of bipolar hemiarthoplasty for osteonecrosis of femoral head have been disappointing due to cartilage degeneration and osteolysis. We investigated the cartilage degeneration, joint motion, and factors associated with osteolysis.

METHODS

We retrospectively reviewed 134 bipolar hemiarthroplasties. The wear rate of acetabular cartilage was calculated. The ranges of motion of outer bearing and inner bearing were determined, and the ratio (O/I ratio) was calculated.

RESULTS

The mean degeneration rate of acetabular cartilage was 0.34 ± 0.35 mm/year. We could observe that the outer bearing motion was dominant, but decreased over time. In addition, the degeneration rate of cartilage and the decline rate of outer bearing motion of the osteolysis group were significantly higher than those of the control group.

CONCLUSIONS

Close observation is needed in cases of high degeneration rate of cartilage and rapid decline of outer bearing motion due to possibility of osteolysis.

The vertical hip fracture - a treatment challenge. A cohort study with an up to 9 year follow-up of 137 consecutive hips treated with sliding hip screw and antirotation screw

Background

Femoral neck fractures with a vertical orientation have been associated with an increased risk for failure as they are both axial and rotational unstable and experience increased shear forces compared to the conventional and more horizontally oriented femoral neck fractures. The purpose of this study was to analyse outcome and risk factors for reoperation of these uncommon fractures.

Methods

A cohort study with a consecutive series of 137 hips suffering from a vertical hip fracture, treated with one method: a sliding hips screw with plate and an antirotation screw. Median follow-up time was 4.8 years. Reoperation data was validated against the National Board of Health and Welfare’s national registry using the unique Swedish personal identification number.

Results

The total reoperation rate was 18%. After multivariable Logistic regression analysis adjusting for possible confounding factors there was an increased risk for reoperation for displaced fractures (22%) compared to undisplaced fractures (3%), and for fractures with poor implant position (38%) compared to fractures with adequate implant position (15%).

Conclusions

The reoperation rate was high, and special attention should be given to achieve an appropriate position of the implant.

Total hip arthroplasty versus hemiarthroplasty for displaced femoral neck fractures: meta-analysis of randomized trials

BACKGROUND

Most patients with displaced femoral neck fractures are treated by THA and hemiarthroplasty, but it remains uncertain which if either is associated with better function and lower risks of complications.

QUESTIONS/PURPOSES

We performed a meta-analysis of randomized controlled trials (RCTs) to determine whether THA was associated with lower rates of reoperations, mortality, complications, and better function compared with hemiarthroplasty.

METHODS

We searched the PubMed, Embase, Chinese Biomedicine Literature, and Cochrane Register of Controlled Trials databases and identified 12 RCTs (including a total of 1320 patients) for meta-analysis. Risk ratios (RRs) and weighted mean differences (WMDs) from each trial were pooled using random-effects or fixed-effects models depending on the heterogeneity of the included studies.

RESULTS

THA was associated with a lower risk of subsequent reoperations compared with hemiarthroplasty (RR = 0.53; 95% CI, 0.34-0.84). There was no difference in mortality between patients undergoing THA and hemiarthroplasty (RR = 0.81; 95% CI, 0.60-1.09). For complications, there was a higher risk of dislocation in patients undergoing THA (RR = 1.99; 95% CI, 1.26-3.15), but there were no differences in local infections (RR = 1.60; 95% CI, 0.74-3.46) and general complications (RR = 1.15; 95% CI, 0.91-1.45). Patients with THA had higher Harris hip scores at 1 year (WMD = 3.81; 95% CI, 0.87-6.74) and at 3 or 4 years (WMD = 10.07; 95% CI, 6.92-13.21).

CONCLUSIONS

Despite more dislocations, THA can benefit patients with displaced femoral neck fractures with a lower reoperation rate and higher functional scores.

Dislocation of hip hemiarthroplasty following posterolateral surgical approach: a nested case-control study

PURPOSE

Hip hemiarthroplasty dislocation is a serious complication in treatment of displaced intracapsular hip fractures. We investigated factors associated with an increased risk of dislocation after cemented hip hemiarthroplasty following the posterolateral approach.

METHODS

Between January 2002 and December 2008, 602 hip fractures were treated with cemented unipolar hip hemiarthroplasty. A registry-based analysis was carried out to determine the total number of hemiarthroplasty dislocations in these patients. A control group of 96 patients without dislocation was randomly selected. Logistic regression analysis was performed to evaluate clinical and operative factors associated with dislocation.

RESULTS

Thirty-four patients (5.6%) experienced at least one dislocation. Most were the result of a fall and occurred within two months after surgery. There was a trend for increased dislocation in patients who had been operated on more than 48 hours after admission and in patients who had a longer operative time. Smaller centre-edge angle and hip offset were observed in patients with dislocation. Recurrent dislocation was a significant problem, as 18 patients (62%) experienced multiple dislocations.

CONCLUSIONS

The risk of hemiarthroplasty dislocation following the posterolateral surgical approach may be reduced by prompt surgical treatment and fall prevention in the early postoperative period. Patients with smaller acetabular coverage seem more predisposed to dislocation after the posterolateral approach and may be more suitable for other surgical approaches.