Ten-year patient and prosthesis survival after unipolar hip hemiarthroplasty in female patients over 70 years old

Preoperative Posterior Tilt Increases the Risk of Later Conversion to Arthroplasty After Osteosynthesis for Femoral Neck Fracture

BACKGROUND

Femoral neck fractures (FNFs) are one of the most common injuries in the elderly. Treatment is either internal fixation or primary arthroplasty. The main aim of this study is to assess the risk factors associated with fixation failure leading to further arthroplasty in FNFs treated with cannulated screws.

METHODS

Data on internal fixations of FNFs performed at Turku University Hospital between January 1, 2012 and December 31, 2017 were collected retrospectively from the patient database. Radiographical measurements were performed for preoperative displacement and posterior tilt, postoperative displacement, reduction quality, and implant shaft angle.

RESULTS

Altogether 301 cases were included in the study. The overall reoperation rate was 25% and conversion to arthroplasty was performed in 16% of cases. In the multiple variant analysis, adjusted for age and gender, nondisplaced fractures with a 0°-20° preoperative posterior tilt had a significantly lower risk of later conversion to arthroplasty than did nondisplaced fractures with a ≤0° or ≥20° posterior tilt (odds ratio [OR] 4.0, 95% confidence interval [Cl] 1.8-8.6, P = .0005) and displaced fractures (OR 7.2, 95% CI 3.0-17.4, P < .0001). No statistically significant association was found between preoperatively nondisplaced fractures with a <0° or ≥20° posterior tilt and displaced fractures (OR 0.6, 95% Cl 0.2-1.3, P = .2).

CONCLUSION

Displaced fractures and fractures with a preoperative posterior tilt of <0° or ≥20° have a considerably increased risk of reoperation and conversion to arthroplasty. Primary arthroplasty should be considered as treatment for displaced FNFs and fractures with >20° or <0° posterior tilt, especially in fragile patients, to avoid further operations.

Mortality Rate and Ten Years Survival of Elderly Patients Treated with Total Hip Arthroplasty for Femoral Neck Fractures

Introduction:

Mortality following traumatic femoral neck fractures in the elderly (age >60 years) is influenced by many factors. Addressing some of them may reduce the mortality rate thus improving patient survival and quality of life.

Materials and methods:

This study was a retrospective research using data collected from Hospital Sultanah Bahiyah, Kedah between the years 2008-2018. We measured outcomes such as age, gender, hospital stay, default rate, ambulation post-surgery, American Society of Anaesthesiologists score (ASA) and surgical timing in correlation with mortality rate and 10-year survival of elderly patients treated with Total Hip Arthroplasty for femoral neck fractures in this centre.

Results:

A total of 291 traumatic femoral neck fractures aged above 60 years post total hip arthroplasty performed were included. There was higher number of female (n =233) compared to male (n=53) Estimated 10 years survival from Kaplan Meier was 42.88% (95% CI: 33.15, 52.54). One year mortality rate in our study was found to be 18.9%. The average time to event was 7.1 years (95% CI:33.15, 52.24) with a mean age group of 75.

Discussion:

Total hip arthroplasty patients not ambulating after surgery had a 4.2 times higher hazard ratio compared to ambulators. Those with pre-existing systemic disease (ASA III and IV) were found to have the highest hazard ratio, almost five times that of healthy patients, after adjusting for confounding factors. Delay of more than seven days to surgery was found to be a significant factor in 10-year survival with a hazard ratio of 3.8, compared to surgery performed earlier.

Conclusion:

Delay of more than 7 days to surgery in 10 years survival was significant with high hazard ratio. It is a predictor factor for survival in 10 years. A larger sample size with a prospective design is required to confirm our findings regarding “unacceptable surgical timing” for femoral neck fractures in patients above 60 years of age.

Conservative vs Surgical Treatment of Impacted Femoral Neck Fracture in Patients 75 Years and Older

OBJECTIVE

To evaluate the safety and effectiveness of conservative treatment (CST), internal fixation (IF), and hemiarthroplasty (HA) in treating patients older than 75 years with impacted femoral neck fracture (IFNF).

DESIGN

A randomized clinical trial to compare clinical outcomes of CST, IF, and HA in IFNF patients older than 75 years with a 1:1:1 ratio.

SETTING

Nanjing First Hospital, Nanjing Medical University, Nanjing, China.

PARTICIPANTS

A total of 154 patients with IFNF aged between 75 and 97 years.

INTERVENTION

Patients with IFNF were allocated to CST, IF, and HA. They all received a 36-month follow-up.

MEASUREMENTS

All patients were evaluated by Harris hip score (HHS) (primary outcome) for hip function, European Quality of Life-5 Dimensions (EQ-5D) index scores for health-related quality of life, and visual analogue scale score for hip pain. Operation duration, blood loss, mortality, union rate, complications, and reoperation were also recorded. Assessors were blind to the type of treatment.

RESULTS

The baseline parameters of the three groups were similar. IF group had much lower blood loss than HA group (P < .05), while no significant difference in operative duration was found between the two groups (P > .05). HHS in HA group was significantly higher at 1, 3, and 6 months (P < .05), but no significant difference in HHS was found between CST and IF groups at any of the time points during the overall follow-up (P > .05). EQ-5D index score was higher in HA group at each follow-up within 1 year (P < .05), but the difference was not significant at 2- and 3-year follow-up (P > .05). There was no significant difference in mortality among the three groups at each follow-up point (P > .05). The nonunion rate was 11.76% (6/51) in CST group and 9.80% (5/51) in IF group and showed no significant difference (P > .05).

CONCLUSION

CST may be a feasible way for IFNF in the older patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04219943. J Am Geriatr Soc 68:2214-2221, 2020.

Mid-term survivals of cemented calcar-replacement bipolar hemiarthroplasty for unstable intertrochanteric fractures in elderly patients

BACKGROUND

The literature has limited evidence regarding the mid-term survivals of cemented calcar-replacement bipolar hemiarthroplasty (HA) in elderly patients with unstable intertrochanteric (IT) fracture. The purpose of the present study was to evaluate clinical and radiological outcomes of cemented calcar-replacement bipolar HA for unstable IT fractures in elderly patients.

METHODS

One hundred and twenty-two patients with the mean age of 80.6 years were enrolled in this retrospective study after they met the selection criteria. Demographics, main clinical characteristics, and operative data were recorded for all patients. Functional outcomes were assessed according to Koval's categories. Clinical and radiological evaluations were performed. Kaplan-Meier survival analysis was used to construct the cumulative survival rate. The mean follow-up time was 25.7 ± 2.9 months (ranges 0-72 months).

RESULTS

Based on Koval's categories, 3 or 4-level decrease was detected in 21 patients (17%). Three patients (2 periprosthetic infections, 1 periprosthetic fracture) underwent reoperation during follow-up. No patient underwent revision of bipolar HA prosthesis. Femoral stem loosening and stem subsidence was the most common complication, observed in 22 patients (18%), followed by acetabular erosion that was seen in 12 patients (9.8%). The mean cumulative survival rate of prosthesis was 56.5% (95% confidence interval: 51.3-61.6).

CONCLUSION

Based on the results of our study, cemented calcar-replacement HA is an appropriate treatment option in elderly patients with unstable IT fractures owing to the advantages of satisfactory functional outcomes and lower reoperation rates. However, orthopedic surgeons should consider the low survival rates of cemented calcar-replacement HA prosthesis because of the increased femoral loosening in osteoporotic elderly patients.

Hemiarthroplasty Conversion: A Comparison to Primary and Revision Total Hip Arthroplasty

BACKGROUND

Arthroplasty is the standard of care for elderly patients with displaced femoral neck fractures, with viable options including hemiarthroplasty (HA) and total hip arthroplasty (THA). With time, HA may need to be converted to THA, but it is unclear whether this is more similar to primary or revision THA. We compare complication and revision rates between these groups within 90 days and 2 years postoperatively.

METHODS

We retrospectively reviewed 3 cohorts of patients treated at our institution: primary, conversion, and revision THA. Outcomes studied included intraoperative data, postoperative complications, and revision rates. We analyzed the groups using both parametric (analysis of variance test) and nonparametric (chi-squared test) statistics.

RESULTS

Operative time between primary THA (108.0 minutes), conversion HA (147.9 minutes), and revision THA (160.1 minutes) cohorts differed significantly (P = .011). Estimated blood loss was also different between primary THA (386 mL), conversion HA (587 mL), and revision THA cohorts (529 mL) (P = .011). At 2 years, major complication rates between primary THA (6.2%), conversion HA (11.7%), and revision THA (26.7%) cohorts also differed significantly (P = .003), as was the revision rate in the primary THA (4.6%), conversion HA (10.0%), and revision THA (18.3%) cohorts (P = .043).

CONCLUSION

This is the first study to compare short-term and midterm complications between primary, conversion, and revision THA. We observed conversion HA had similar operative time and estimated blood loss to revision THA, which was significantly higher than primary THA. However, we found that conversion HA more closely resembled primary THA with respect to perioperative complications rates.

Results of Conversion from Failed Austin-Moore Hemiarthroplasty to Cementless Total Hip Arthroplasty in Octogenarian Patients with Advanced Acetabular Erosion: A Minimum of 5 Years of Follow-Up

Austin-Moore hemiarthroplasty (HA) had been selectively used for elderly patients with femoral neck fractures. With increasing life span and activity, the sequela of Austin-Moore HA make the implant no longer favorable. The treatment of failed Austin-Moore HA with advanced acetabular erosion is challenging; however, little has been published regarding this topic. The aim of this study was to evaluate the mid-term results of using cementless total hip arthroplasty (THA) in octogenarians. Between 2008 and 2011, 47 patients (32 women and 15 men) with an average age of 86 years (range 83-89 years) were enrolled in this retrospective study. After an average follow-up period of 6.2 years (range 5.0-7.8 years), no migration or loosening of the cup or femoral stem was found. Harris hip scores improved from 36 (range 15-42) preoperatively to 87 (range 80-90). There were no complications directly associated with the procedure except for superficial infections in two patients. Our results suggest that using cementless THA can result in favorable radiographic and clinical outcomes in octogenarian patients.

Hemiarthroplasty or total hip arthroplasty in recent femoral neck fractures?

The optimal treatment of recent femoral neck fractures remains debated. The available options are internal fixation, hemiarthroplasty (HA) and total hip arthroplasty (THA). There is a consensus in favour of internal fixation in younger patients. In elderly individuals who are institutionalised and have limited physical activity, HA is usually performed when the joint line is intact. Whether HA or THA deserves preference in patients aged 60 years or over is unclear. In addition, there are two types of HA, unipolar and bipolar, and two types of THA, conventional and dual-mobility. Both HA types provide similar outcomes with satisfactory stability but a risk of acetabular wear that may eventually require conversion to THA. THA is associated with better functional outcomes and a lower risk of revision surgery in self-sufficient, physically active patients. Instability is the leading complication of conventional THA and occurs with a higher incidence compared to HA. With all implant types, preoperative factors associated with mortality and complications include walking ability and level of self-sufficiency, nutritional status, and haematocrit. An evaluation of these factors before surgery is of paramount importance. Factors amenable to treatment should be corrected by working jointly with geriatricians to develop a preoperative management strategy. In patients who are self-sufficient, physically active, and free of risk factors, THA remains the option of choice, as it provides better functional outcomes. A dual-mobility implant deserves preference to prevent instability. HA is indicated in patients whose self-sufficiency and physical activity are limited. A unipolar implant should be used, as no evidence exists that bipolar implants provide additional benefits. When performing HA, the posterior approach should be avoided given the risk of instability. For THA, in contrast, the posterior approach is a reliable option in the hands of an experienced surgeon using a dual-mobility cup. Cement fixation of the stem is recommended to minimise the risk of peri-prosthetic fracture.

Risk factors for conversion surgery to total hip arthroplasty of a hemiarthroplasty performed for a femoral neck fracture

INTRODUCTION

The purpose of this study was to determine risk factors for conversion to total hip arthroplasty (THA) in patients originally treated with hemiarthroplasty (HA) for displaced femoral neck fractures.

METHODS

In this case-controlled study, we identified 54 patients who were treated with HA for femoral neck fracture (FNF) who subsequently underwent conversion to THA at our institution between 2003 and 2013. We randomly selected 142 control patients who underwent HA for a displaced FNF without conversion surgery during the same time period. We compared demographic data, implant parameters, and radiographic data between the groups to identify risk factors for conversion surgery.

RESULTS

In the univariate analysis, younger age at index surgery (mean 75 vs. 80 years, p = 0.006), higher body mass index (26.1 vs. 23.7, p = 0.031), bipolar prosthesis (20% vs. 36%, p = 0.024), absence of dementia (6% vs. 23%, p = 0.01), increased leg length compared to contralateral limb (6.5 mm vs. 0.2 mm, p<0.001), and increased HA femoral head size compared to the contralateral femoral head (2.7 mm vs. 1.5 mm, p = 0.02) were associated with a significantly increased risk of conversion surgery. In the multivariate logistic regression, decreased age at index surgery, no dementia, use of a bipolar head, and increased leg length discrepancy (LLD) were associated with risk of conversion.

CONCLUSIONS

Patient characteristics, including younger age, increased BMI, and absence of dementia can lead to increased risk for conversion of HA to THA. Intraoperative considerations of head size and increase in ipsilateral LLD may increase the risk of conversion surgery. These factors should be considered by surgeons who employ HA for displaced FNFs.

Early acetabular cartilage wear following hemiarthroplasty: An ovine model

Objectives: Hemiarthroplasty induces degenerative changes in the hip joint, which are difficult to evaluate in vivo. Radiostereometric analysis (RSA) is a radiographic measurement technique that has recently been used to measure acetabular cartilage wear in vivo. The aim of the study was to measure acetabular cartilage wear, using this technique, in an ovine model during the first 14 weeks post-implantation.

Methods: Measurements of three-dimensional femoral head migration, combined with visual assessments at necropsy and safranin O staining for cartilage integrity, were undertaken.

Results: Mean femoral head migration during the first six weeks was 0.525 mm in the medial, 0.144 mm in the cranial, and 0.517 mm in the dorsal direction. The majority of this migration was confirmed to be cartilage wear in the medial and dorsal aspects of the acetabulum at necropsy and with subsequent histological evaluation depicting significant cartilage degeneration.

Clinical significance: Radiostereometric analysis is the current gold standard technique for in vivo assessment of implant migration following total hip replacement. This study has utilized RSA to quantify the amount of early cartilage wear in vivo, which was supported by ex vivo evaluations. Accurately measuring the amount of cartilage wear will allow future studies to compare component material and design characteristics prior to clinical use.

Risk factors for conversion surgery to total hip arthroplasty of a hemiarthroplasty performed for a femoral neck fracture

INTRODUCTION

The purpose of this study was to determine risk factors for conversion to total hip arthroplasty (THA) in patients originally treated with hemiarthroplasty (HA) for displaced femoral neck fractures.

METHODS

In this case-controlled study, we identified 54 patients who were treated with HA for femoral neck fracture (FNF) who subsequently underwent conversion to THA at our institution between 2003 and 2013. We randomly selected 142 control patients who underwent HA for a displaced FNF without conversion surgery during the same time period. We compared demographic data, implant parameters, and radiographic data between the groups to identify risk factors for conversion surgery.

RESULTS

In the univariate analysis, younger age at index surgery (mean 75 vs. 80 years, p = 0.006), higher body mass index (26.1 vs. 23.7, p = 0.031), bipolar prosthesis (20% vs. 36%, p = 0.024), absence of dementia (6% vs. 23%, p = 0.01), increased leg length compared to contralateral limb (6.5 mm vs. 0.2 mm, p<0.001), and increased HA femoral head size compared to the contralateral femoral head (2.7 mm vs. 1.5 mm, p = 0.02) were associated with a significantly increased risk of conversion surgery. In the multivariate logistic regression, decreased age at index surgery, no dementia, use of a bipolar head, and increased leg length discrepancy (LLD) were associated with risk of conversion.

CONCLUSIONS

Patient characteristics, including younger age, increased BMI, and absence of dementia can lead to increased risk for conversion of HA to THA. Intraoperative considerations of head size and increase in ipsilateral LLD may increase the risk of conversion surgery. These factors should be considered by surgeons who employ HA for displaced FNFs.

Steady state acetabular cartilage wear after bipolar hemiarthroplasty: a case series of 10 patients with radiostereometric analysis

INTRODUCTION

Cartilage wear is a concern after hemiarthroplasty. The precise pattern of the progression of wear has not been evaluated. We previously reported the application of radiostereonetric analysis (RSA) for the measurement of cartilage wear in patients. The purpose of this study was to report the amount and the orientation of the steady state wear of cartilage between 1 and 3 years after bipolar hemiarthroplasty.

METHODS

22 patients with a bipolar hemiarthroplasty for displaced femoral neck fracture were included. 10 patients completed the mean follow up of 37 months. The cartilage wear was evaluated by calculating the migration of the bipolar head in reference to the markers in the acetabulum using RSA.

RESULTS

The mean age of the patients at the final follow-up was 80 (range 67-91) years. The 3-D migration was -0.02 mm (SD 0.30) between 1 and 3 years. The migration in each direction was 0.03 mm (SD 0.49) in medial, 0.03 mm (SD 0.14) in proximal and 0.11 mm (SD 0.29) in posterior directions. 2 patients showed migration of more than 0.2 mm. The large initial migration seen in some patients up to 1 year did not progress further. Total wear after 37 months was 0.43 mm (SD 0.17).

CONCLUSIONS

Cartilage wear progressed slowly in 2 of 10 patients from 1 to 3 years. No pelvic penetration was seen. We believe that RSA will give a basic knowledge about the development and the progression of cartilage wear after hemiarthroplasty.

Corrosion and adverse tissue reaction after modular unipolar hip hemiarthroplasty

Modern unipolar hip hemiarthroplasty, commonly used for displaced femoral neck fracture, is now modular, with both a variable length cobalt-chromium adapter-sleeve and large femoral head. Patients with these modular components may develop symptomatic trunnion corrosion, with elevated serum metal levels. We report the case of an 82-year-old woman, 5.5 years after a modular unipolar hip hemiarthroplasty, who presented with a 4-month history of hip pain and limp. Evaluation showed elevated serum cobalt and chromium levels and an acetabular cyst. At revision, fluid, tissue, and gross inspection were consistent with trunnion corrosion. The hip was revised with a ceramic head and dual mobility acetabular component, with a good result at 1 year. The designs of commercially available, modern unipolar hip hemiarthroplasty prostheses are reviewed.

Hemiarthroplasty for Displaced Femoral Neck Fractures in the Elderly Has a Low Conversion Rate

BACKGROUND

Hemiarthroplasty (HA) has been a mainstay treatment for displaced femoral neck fractures for many years. The purpose of this study was to report the conversion rate of HA to total hip arthroplasty (THA) for displaced femoral neck fractures and compare outcomes between implant constructs (bipolar vs unipolar), fixation options (cemented vs cementless stems), and age groups (<75 years vs ≥75 years).

METHODS

We retrospectively reviewed the results of a consecutive cohort of 686 patients who underwent HA for the treatment of femoral neck fractures at our institution between 1999 and 2013 with a minimum of 2-year follow-up.

RESULTS

The overall component revision rate, including conversion to THA, revision HA, revision with open reduction internal fixation, and Girdlestone procedure, was 5.6% (39/686). Seventeen patients (2.5%) were converted from HA to THA at an average of 1.9 years after index procedure. A significantly lower conversion rate of 1.4% (7/499 patients) was found in the older patient cohort (≥75 years old) compared to 5.3% (11/187) in the younger cohort. The most common causes for conversion surgery to THA were acetabular wear (5 patients), aseptic loosening (4 patients), and periprosthetic fracture (3 patients). There was a significantly lower rate of periprosthetic fracture (0.4% vs 2.5%, P value .025) in the cemented implant group compared to the cementless group. We observed a higher rate of dislocations in the bipolar vs unipolar group (3.8% vs 1%, P value .02) and no other significant differences between these groups.

CONCLUSION

We observed a low reoperation rate for this cohort of patients, relatively higher conversion rates for the younger population, fewer periprosthetic fractures with the use of cemented stems, and no advantage of bipolar over unipolar prostheses.

Periprosthetic fracture in the elderly with anatomic modular cementless hemiarthroplasty

BACKGROUND

The use of an anatomic cementless stem in hemiarthroplasties for femoral intracapsular proximal fracture has been debated, notably because of bone weakness and/or morphological defects related to osteoporosis. We therefore conducted a retrospective study in subjects over 75 years of age who had received an anatomic stem partially coated with hydroxyapatite. The objectives were to determine: 1) the incidence of periprosthetic fractures (PPFs) and, 2) the influence of anatomic factors, including the Cortical Bone Ratio (CBR) (the relation between the endosteal and external diameter of the femoral diaphysis 10cm below the lesser trochanter).

HYPOTHESIS

The risk of PPF with an anatomic cementless implant is greater than with cemented stems.

MATERIAL AND METHODS

We retrospectively analyzed 233 patients followed up for 5 years after their surgery. The stem used was an anatomic stem with a modular neck partially coated with hydroxyapatite. The risk factors examined were age, gender, history of osteoporotic fractures, diverse causes of secondary osteoporosis, and proximal bone stock according to various referenced radiological indices such as the CBR.

RESULTS

Twenty patients (15%) were lost to follow-up, 74 had died (32%) but did not undergo revision for PPF, 15 of the 139 survivors at the last follow-up (10.8%) had had a PPF, five (3.6%; four females, one male) were early fractures (≤2 months after implantation), ten (7.2%; two females, eight males) were late fractures (>2 months). Male gender was protective for PPF occurrence (RR=0.129; 95%CI (0.04-0.39); P=0.0003), whereas secondary factors of osteoporosis (RR=2.035; 95%CI (1.11-3.72); P=0.0211), and CBR>0.49 (RR=227.42; 95%CI (1.072-48,226.76); P=0.0471) were found as risk factors of PPF.

DISCUSSION

The PPF rate was greater than that related to cemented stems, requiring that morphological and clinical factors of bone weakness (collected with the patient history and related to osteoporosis) be taken into account. A CBR>0.49 requires caution on the use of this type of stem.

LEVEL OF EVIDENCE

Level 4. Retrospective study.

The effect of osteoarthritis on functional outcome following hemiarthroplasty for femoral neck fracture: a prospective observational study

BACKGROUND

The influence of pre-existing radiographic osteoarthritis on the functional outcome of elderly patientents with displaced intracapsular fractures of the femoral neck treated by hemiarthroplasty is unclear.

METHODS

We prospectively examined the impact of pre-existing osteoarthritis on the functional outcome of 126 elderly patients with displaced intracapsular fracture of the femoral neck treated by hemiarthroplasty.

RESULTS

The mean age of the cohort was 82.7 years. At 12 months, we observed no statistically significant differences in the Harris hip score (p = 0.545), the timed up and go test (p = 0.298), the Tinetti test (p = 0.381) or the Barthel Index (p = 0.094) between patients with Kellgren and Lawrence grades 3 or 4 osteoarthritis, and patients with grades 0 to 2 changes. Furthermore, there were no differences in complication or revision rates.

CONCLUSIONS

Our findings challenge the hypothesis that pre-existing osteoarthritis is a contraindication to hemiarthroplasty in elderly patients with femoral neck fracture.

Biomechanical rationale for implant choices in femoral neck fracture fixation in the non-elderly

Femoral neck fractures represent a relatively uncommon injury in the non-elderly population often resulting from high-energy trauma. The cornerstone of their management is anatomic reduction and stable internal fixation of the femoral neck in an attempt to salvage the femoral head. Complications including avascular necrosis of the femoral head, non-union and post-traumatic osteoarthritis are not uncommon. The clinical outcomes of these patients can be improved with good pre-operative planning, optimization of surgical procedures and introduction of new improved implants and techniques. In the herein study, we attempt to describe the biomechanical properties of the hip and compare the performance of the most commonly used devices. Experimental evidence suggests that in Pauwels type III fracture patterns a cephalomedullary nail was significantly stronger in axial loading. Moreover, in unstable basicervical patterns cannulated screws (triangular configuration) demonstrated a lower ultimate load to failure, whereas in subcapital or transervical patterns both the cannulated screws (triangular configuration) and the sliding hip screw demonstrated no compromise in fixation strength. The fracture pattern appears to be the major determinant of the ideal type of implant to be selected. For a successful outcome each patient needs to be considered on an individual basis taking into account all patient and implant related factors.

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.

Historical implant or current best standard? Minimum five year follow-up outcomes of cemented Thompson hemiarthroplasties

UK NICE guidelines recommend abandoning the Thompson hemiarthroplasty (TH) in favour of a 'proven prosthesis' such as the Exeter Trauma Stem. The aim of this study was to assess the hip fracture treatment with the TH. Between 2002 and 2006, 430 cemented THs were performed (minimum 5 year follow-up). Death rates at 1 year and 5 years were 26.6% and 67.4% with low complication (Dislocation 1.4%) and revision rate (1.2%). The TH remains a reliable and proven implant in appropriate patients (over the age of 80, with low activity levels, low ambulatory status and who maybe cognitively impaired), due to low complication and revision rates. Modern implants may provide better function or longevity, but there is little evidence to support abandoning the TH.

Survival of patients aged over 80 years after Austin-Moore hemiarthroplasty and bipolar hemiarthroplasty for femoral neck fractures

OBJECTIVES

Hemiarthroplasty is recommended for treatment of displaced femoral neck fractures in physically compromised elderly patients. The objective of this study was to analyze survival of patients aged >80 years after the implantation of either an Austin-Moore type prosthesis or a bipolar bearing prosthesis.

METHODS

An Austin-Moore or bipolar hemiarthroplasty was implanted into 120 patients aged >80 years. Demographic data were collected. Survival rate at 5 years and factors related to mortality were analyzed.

RESULTS

Sixty-two patients received Austin-Moore hemiarthroplasty, and 58 received bipolar hemiarthroplasty. No significant differences in gender, comorbid conditions, ASA scores, duration of hospitalization, intraoperative blood loss, duration from injury to operation, or postoperative morbidity between the two groups were found. However, patients who received the Austin-Moore hemiarthroplasty were older and had shorter operation time than those who received bipolar hemiarthroplasty. Kaplan-Meier estimates of 5 years survival were 40.0% for patients who received Austin-Moore hemiarthroplasty, and 62.9% for patients who received bipolar hemiarthroplasty. Cox proportional hazard regression analysis of risks factors of death revealed that patients who underwent Austin-Moore hemiarthroplasty were 2.0-fold more likely to die when compared to those who received bipolar hemiarthroplasty.

CONCLUSIONS

Elderly patients who receive bipolar hemiarthroplasty may have a more favorable survival outcome when compared to those who receive unipolar hemiarthroplasty.

The conversion rate of bipolar hemiarthroplasty after a hip fracture to a total hip arthroplasty

BACKGROUND

Bipolar hip hemiarthroplasty is used in the management of fractures of the proximal femur. The dual articulation is cited as advantageous in comparison to unipolar prostheses as it decreases acetabular erosion, has a lower dislocation rates and is easier to convert to a total hip arthroplasty (THA) should the need arise. However, these claims are debatable. Our study examines the rate of conversion of the bipolar hemiarthroplasty to THA and the justification for using it on the basis of future conversion to THA.

METHODS

All cases of bipolar hemiarthroplasty performed in our unit for hip fractures over a 9-year period (1999-2007) were reviewed. Medical notes and radiographs of all patients were reviewed, and all surviving patients that were contactable received a telephone follow-up.

RESULTS

Of all 164 patients reviewed with a minimum of 1 year from date of surgery, 4 patients had undergone a conversion of their bipolar prosthesis to THA. Three conversions were performed for infection, dislocation, and fracture. Only one (0.6%) conversion was performed for groin pain.

CONCLUSIONS

Our study show that bipolar hemiarthroplasties for hip fractures have a low conversion rate to THAs and this is comparable to the published conversion rate of unipolar hemiarthroplasties.

Fluid load support and contact mechanics of hemiarthroplasty in the natural hip joint

The articular cartilage covering the ends of the bones of diarthrodial synovial joints is thought to have evolved so that the loads are transferred under different and complex conditions, with a very high degree of efficiency and without compromising the structural integrity of the tissue for the life of an individual. These loading conditions stem from different activities such as walking, and standing. The integrity of cartilage may however become compromised due to congenital disease, arthritis or trauma. Hemiarthroplasty is a potentially conservative treatment when only the femoral cartilage is affected as in case of femoral neck fractures. In hemiarthroplasty, a metallic femoral prosthesis is used to articulate against the natural acetabular cartilage. It has also been hypothesized that biphasic lubrication is the predominant mechanism protecting the cartilage through a very high fluid load support which lowers friction. This may be altered due to hemiarthroplasty and have a direct effect on the frictional shear stresses and potentially cartilage degradation and wear. This study modelled nine activities of daily living and investigated the contact mechanics of a hip joint with a hemiarthroplasty, focussing particularly on the role of the fluid phase. It was shown that in most of the activities studied the peak contact stresses and peak fluid pressures were in the superior dome or lateral roof of the acetabulum. Total fluid load support was very high (~90%) in most of the activities which would shield the solid phase from being subjected to very high contact stresses. This was dependent not only on the load magnitude but also the direction and hence on the location of the contact area with respect to the cartilage coverage. Lower fluid load support was found when the contact area was nearer the edges where the fluid drained easily.

Conversion of failed hemiarthroplasty to total hip arthroplasty: a short to mid-term follow-up study

BACKGROUND

The conversion of hemiarthroplasty (unipolar or bipolar) of the hip to total hip replacement has been reported to be associated with very high rates of intra- and postoperative complications. We present a prospective analysis of the outcome of conversion surgery in patients with failed hemiarthroplasty.

MATERIALS AND METHODS

Forty-four cases, 30 women and 14 men, average age 62 years (range 42-75 years) of failed hemiarthroplasty were converted to total hip replacement between January 1998 and December 2004. Groin pain was the main presenting complaint in the majority of the patients (24 out of 44). Six patients had infection and were operated with staged procedure. All acetabular and the majority (86.5%) of femoral components used in our series were uncemented.

RESULTS

After an average follow-up of 6.4 years (range, two to nine years) Harris hip scores improved from 38 (range 15-62) preoperatively to 86 (range 38 to 100) and 22 (50%) patients were community ambulators without support while 17 (38%) needed minimal support of cane. Fifteen out of 18 (83%) patients who had isolated groin pain preoperatively experienced no pain postoperatively while three patients (17%) reported only partial improvement. Intraoperative and postoperative complications included iatrogenic fracture of the femur in two, femoral perforation in two, partial trochanteric avulsion in two, fracture of the acetabular floor in three hips, and postoperative dislocation in one. None of these complications resulted in a poor long-term outcome. The rate of loosening in our series was 2.3% (one out of 44) after a mean follow-up of 6.4 years with a mean survival of 97.4% at 72 months.

CONCLUSION

Conversion of symptomatic hemiarthroplasty to total hip arthroplasty is a safe option that gives good functional results, with marginally higher rates of intra-operative complications. The patients should be warned of the possibility of incomplete relief of groin pain postoperatively.

Use of oxidized zirconium hemiarthroplasty in hip fractures: clinical results and spectrum analysis

Oxidized zirconium may have improved wear characteristics against polyethylene, but its performance against native cartilage is unknown. Between 1996 and 1998, 52 patients received an oxidized zirconium hemiarthroplasty for the treatment of a hip fracture. Twelve patients (23%) died within 1 year of surgery, and 24 (46%) were surviving at 5 years. In 38 patients with minimum 2-years follow-up, clinical evaluation after surgery averaged 4.5 years with Harris hip scores averaging 78 (range, 55-92). Three patients radiographically showed acetabular protrusion or significant wear, with 2 undergoing revision surgery. An explanted prosthesis demonstrated no appreciable damage by spectrum analysis. Because of the high mortality rate after hip fracture, the clinical benefits of oxidized zirconium hemiarthroplasty in this population, if existent, are difficult to appreciate and currently show no benefits over standard prostheses.

Acetabular outcome after hip hemiarthroplasty in patients with tumors

Hip hemiarthroplasty is performed routinely on patients with tumors of the proximal femur, although the long-term effect on the native acetabulum is unknown. We measured the amount of femoral head migration that would occur with intermediate and long-term followup. We also measured the amount of groin pain experienced by patients with longer followup and the overall rate of conversion to total hip arthroplasty. From a surgical database, we identified 442 patients with tumors who had 447 hip hemiarthroplasties without or with an allograft composite. We reviewed the medical records and radiographs of 32 patients with at least 5 years followup (median followup, 10 years) to determine their clinical and radiographic outcomes. The median proximal and medial migration measurements were 3 mm (range, 0-24 mm) and 2 mm (range 0-20 mm), respectively. Thirty-one patients had minimal or no groin pain. Seven of the 447 arthroplasties (1.6%) were converted to total hip arthroplasties. Even patients with long-term followup usually had minimal pain and radiographic changes. The overall rate of conversion to total hip arthroplasty was low. Concern regarding excessive acetabular wear resulting in conversion to total hip arthroplasty in patients with tumors is not supported by our data.

[Bilateral Moore hemiarthroplasty: 36 years of good tolerance without loosening or osteolysis]

We report an illustrative case of bilateral Moore arthroplasty with the clinical and radiographic results at 36 years follow-up. The femoral prostheses were implanted for necrosis of the femoral head when the patient was 46 years old. At implantation the patient's physical activity level was high (Devane 4) and remained so until retirement at age 65 years. His activity level remained high (Devane 3) to the age of 82 years when the patient suffered a Vancouver B1 periprosthetic fracture on the left. At this date, both arthroplasties were free of loosening an osteolysis. Plate fixation with wiring led to fracture healing. The Postel Merle d'Aubigné score was 17 before the fracture and 16 at healing (with a pain score of 6 both before and after). Radiographically, acetabular cartilage tolerance was excellent. This case illustrates the excellent clinical outcome obtained with the Moore hemiarthroplasty at more than 35 years despite less than satisfactory initial fixation and the absence of resurfacing. The fact that this prosthesis does not have a polyethylene element prevented the development of osteolysis which could have been expected with such a long postoperative period in this a highly active patient. Favorable factors (good abductor lever arm, adapted head diameter, resistance of the acetabular cartilage in a young subject with femoral head necrosis) may have played a role in this particular case since the excellent and sustained outcome was observed on both sides. This exceptional longevity provides useful information for better determining precise indications for head cups for the treatment of necrosis of the femoral head.