Conversion of hemiarthroplasty to total hip arthroplasty: can groin pain be eliminated?

Comparison of Mortality, Length of Hospital Stay and Transfusion between Hemiarthroplasty and Total Hip Arthroplasty in Octo- and Nonagenarian Patients with Femoral Neck Fracture: a Nationwide Study in Korea

BACKGROUND

The purpose of this study was to compare the mortality rate between patients undergoing hemiarthroplasty (HA) and those undergoing total hip arthroplasty (THA) in two age groups: patients aged 65-79 years (non-octogenerian) and patients aged ≥ 80 years (octogenarian).

METHODS

We identified elderly (aged ≥ 65 years) femoral neck fracture patients who underwent primary THA or HA from January 1, 2005 to December 31, 2015 in South Korea using the Health Insurance and Review and Assessment database; the nationwide medical claim system of South Korea. We separately compared the mortality rate between the HA group and THA group in two age groups. A generalized estimating equation model with Poisson distribution and logarithmic link function was used to calculate the adjusted risk ratio (aRR) of death according to the type of surgery.

RESULTS

The 3,015 HA patients and 213 THA patients in younger elderly group, and 2,989 HA patients and 96 THA patients in older elderly group were included. In the younger elderly group, the mortality rates were similar between the two groups. In older elderly group, the aRR of death in the THA group compared to the HA group was 2.16 (95% confidence interval [CI], 1.20-3.87; P = 0.010) within the in-hospital period, 3.57 (95% CI, 2.00-6.40; P < 0.001) within 30-days, and 1.96 (95% CI, 1.21-3.18; P = 0.006) within 60-days.

CONCLUSIONS

In patients older than 80 years, THA was associated with higher postoperative mortality compared to HA. We recommend the use of HA rather than THA in these patients.

Outcomes and survivorship after conversion of failed hip hemiarthroplasty to total hip arthroplasty

BACKGROUND

Arthroplasty is the treatment of choice for elderly patients with displaced femoral neck fractures. When compared to total hip arthroplasty (THA), higher revision rates have been reported for hemiarthroplasty (HA). Conversion of failed HA to THA can be complex, especially in the elderly population at risk for revision surgery complications. We report a single institution's experience with conversion of failed HA to THA at mid-term follow-up.

METHODS

We identified patients converted from failed HA to THA from 2006 to 2016. Clinical data including indication for index and conversion surgery, maintenance or revision of femoral component during conversion, operative time, estimated blood loss, postoperative complications, and need for revision surgery were collected. Descriptive statistics were analysed in SPSS.

RESULTS

The cohort included 21 men and 39 women (mean age of 74.5 years). The mean follow-up after conversion HA to THA was 2.8 years. During conversion surgery, the femoral component was revised in 75.0% and retained in 25.0% of cases. After conversion HA to THA, the rate of major complications and re-revision at 2 years was 11.7% and 10.0%, respectively. Femoral revision versus retention did not affect complication rates (11.1% vs. 6.7%; p = 0.31) or re-revision rates (8.9% vs. 13.3%; p = 1.0).

CONCLUSIONS

In this high-risk population, mid-term follow-up demonstrated tolerable complication and re-revision rates, the majority of which were for instability. We observed high rates of femoral component revision during conversion THA, although this did not increase the likelihood of postoperative complications or need for future surgery.

Hemiarthroplasty for Femoral Neck Fractures in the Elderly: A Comparison of Cemented and Uncemented Femoral Stems

The incidence of displaced femoral neck fractures among elderly patients is increasing as the population ages.Historically, the preferred treatment for displaced femoral neck fractures in elderly patients has been hemiarthroplasty with use of cemented fixation of the implant. However, there is evidence that this technique may be associated with fat embolization and subsequent cardiopulmonary arrest in the early postoperative period. Cementing techniques are also associated with increased operative time when compared with cementless techniques.There is increasing evidence that, among elderly patients, the use of uncemented hemiarthroplasty has equivalent functional outcomes and overall mortality rates when compared with the use of hemiarthroplasty with cemented fixation. The main complication associated with uncemented hemiarthroplasty is intraoperative periprosthetic fracture.

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.

Conversion of Failed Hip Hemiarthroplasty to Low Friction Arthroplasty (LFA)

Purpose: We aimed to study clinical and radiological outcomes of conversion from hemiarthroplasty to Charnley hip replacement (CHR) with a particular concern over reported increased dislocation rate and literature review. Conversion of hip hemiarthroplasty to total hip replacement (THR) is a procedure reported to have high rates of complications. In the literature, there is no specific study on small head conversion. The purpose of this study was to evaluate the conversion of failed hip hemiarthroplasty to CHR with the use of modern implants. Methods: The study included 42 patients, who underwent the above procedure. The operations were carried out using a modern Charnley-type THR with a 22-mm diameter of femoral head and a trans-trochanteric approach. The mean follow-up was 75.7 months (range 25–171). Radiographs from the last follow up were evaluated for loosening and other reasons of failure. Clinical outcome was assessed using postoperative pain, function scores, complications and implant survivorship as well as radiological evaluation. Charnley’s modified pain and mobility scoring system were used for clinical and Hodgkinson and Harris’ criteria were used for radiological assessment. Results: Functionally, all of the patients showed improvement. Mean improvement in the pain level was by average of 2.4. On mobility assessment, 38 patients (90.4%) improved. Three patients (7.1%) had recurrent infections and three (4.8%) cases were treated with revision surgery and pseudarthrosis. Further complications occurred in 19.1%, not requiring operative treatment. On radiological evaluation, one (2.4%) case showed cup demarcation without bone loss, two (4.8%) cup migration, and one (2.4%) stem demarcation. Kaplan Meier survival analysis showed a survival of 90% at 96 months of follow up (95% CI (confidence interval), 60–90). Conclusion: Larger head might not be the answer to decrease the dislocation rate. Complication rates during revision of hip hemiarthroplasty to modern CHR with 22.225-mm head diameter were comparable to first-time THR revision despite having a smaller head.

Evaluation and Management of Failed Hemiarthroplasty

Hemiarthroplasty is a common procedure for treatment of displaced femoral neck fractures in low-demand patients. As hip fracture incidence continues to increase, the need for revision hemiarthroplasty is also expected to increase. Multiple etiologies can result in a failed hemiarthroplasty, including persistent pain, infection, instability, leg-length discrepancy, and trauma. Preoperative clinical, radiographic, and laboratory assessments are critical in determining the etiology of the painful hemiarthroplasty. The standard of care for surgical management of failed hemiarthroplasty is conversion to a total hip arthroplasty. However, establishing the etiology preoperatively is essential to planning before treating the failed hemiarthroplasty.

Alternative Payment Models Should Risk-Adjust for Conversion Total Hip Arthroplasty: A Propensity Score-Matched Study

BACKGROUND

For Medicare beneficiaries, hospital reimbursement for nonrevision hip arthroplasty is anchored to either diagnosis-related group code 469 or 470. Under alternative payment models, reimbursement for care episodes is not further risk-adjusted. This study's purpose was to compare outcomes of primary total hip arthroplasty (THA) vs conversion THA to explore the rationale for risk adjustment for conversion procedures.

METHODS

All primary and conversion THAs from 2007 to 2014, excluding acute hip fractures and cancer patients, were identified in the National Surgical Quality Improvement Program database. Conversion and primary THA patients were matched 1:1 using propensity scores, based on preoperative covariates. Multivariable logistic regressions evaluated associations between conversion THA and 30-day outcomes.

RESULTS

A total of 2018 conversions were matched to 2018 primaries. There were no differences in preoperative covariates. Conversions had longer operative times (148 vs 95 minutes, P < .001), more transfusions (37% vs 17%, P < .001), and longer length of stay (4.4 vs 3.1 days, P < .001). Conversion THA had increased odds of complications (odds ratio [OR] 1.75; 95% confidence interval [CI] 1.37-2.24), deep infection (OR 4.21; 95% CI 1.72-10.28), discharge to inpatient care (OR 1.52; 95% CI 1.34-1.72), and death (OR 2.39; 95% CI 1.04-5.47). Readmission odds were similar.

CONCLUSION

Compared with primary THA, conversion THA is associated with more complications, longer length of stay, and increased discharge to continued inpatient care, implying greater resource utilization for conversion patients. As reimbursement models shift toward bundled payment paradigms, conversion THA appears to be a procedure for which risk adjustment is appropriate.

Midterm Results of Conversion from Failed Bipolar Hemiarthroplasty to Total Hip Arthroplasty

BACKGROUND

Conversion from failed bipolar hemiarthroplasty (HA) to total hip arthroplasty (THA) presents a great challenge to orthopedic surgeons for bipolar head removal and cup placement with or without change of femoral stem. Conversion THA after failed bipolar arthroplasty is known to offer both symptomatic and functional improvement. This study evaluates the midterm functional outcome and complications, especially dislocation associated with femoral head diameter, after conversion THA.

MATERIALS AND METHODS

Forty eight hips with the conversion of bipolar HA to THA were followed up for an average 6.2 years (range 2.0-11.5 years). Twenty one hips had conversion surgery to THA using metal-on-metal articulation (28 or 32 mm head). Nine hips used ceramic-on-ceramic (28-40 mm) and eighteen hips used large head metal-on-metal bearing (>40 mm). Outcome was evaluated using Harris Hip Score (HHS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score. The radiographs were analyzed for evidence of osteolysis and/or loosening. The complications were evaluated, especially dislocation with different femoral head diameter.

RESULTS

Average HHS significantly improved from 42 preoperatively to 86 postoperatively and the average WOMAC score also significantly improved from 47 to 22 postoperatively. Radiological evaluation showed all the femoral components were stable. There was one acetabular component loosening, which required revision 9 years after conversion to THA. One dislocation and one recurrent dislocation were recorded in isolated acetabular revision hip; whereas one dislocation, one recurrent dislocation, and one trochanteric nonunion occurred in the hips with revision of both components. All dislocations occurred in hips with a femoral head size of 28 mm (P = 0.052). The cup and femoral head interval length was the most significant factor contributing to dislocation (P = 0.013).

CONCLUSIONS

Conversion THA after failed bipolar HA offers a reliable pain relief and functional improvement. To prevent dislocation, it is highly recommended to use a larger diameter femoral head, especially where the cup size is big.

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

Purpose of this study was to evaluate the outcomes of patients underwent hemiarthroplasty for proximal femoral fracture converted to total hip arthroplasty (THA).A total of 138 patients from October 2009 till October 2014 had conversion of their failed hemiarthroplasties following a proximal femoral fracture to total hip arthroplasty (THA) in Erfan and Milad hospitals, Tehran. We performed a prospective analysis of the outcome of conversion surgery in patients with failed hemiarthroplasty. The patients had clinical evaluations at 1 month, 6 months, 1 year, and annually thereafter. We used Harris Hip Score (HHS) to evaluate the results of conversion procedure in terms of relief of groin pain and functional improvement.Dislocation occurred in 6 patients (4.34%). The mean period of follow-up was 42 months (range 36-60 months). HHS score improved from mean preoperative score of 44.93 ± 8.40 to 95.41 ± 2.27 at final follow-up. The survivorship analysis with revision of HHS score was 89.1%. Existence of infection (P = .038) and time of primary operation to being symptomatic (P = .009) can predict the postoperative pain significantly.THA is a safe option which can lead to good functional and short-term and mid-term outcomes; and patients should be informed of the possibility of incomplete relief of groin pain or other symptoms postoperatively.

Revision of failed hip hemiarthroplasty. Classification, management, and follow-up

BACKGROUND

Many types of failed hemiarthroplasties have been reported, but there is no classification of these failures.

PATIENTS AND METHODS

Revisions of 217 cases of failed hemiarthroplasty were studied with an average follow-up of 6.2 years. Classification system based on site of problem, mode of failure, and type of revision, was introduced.

RESULTS

In most cases, the intra-operative assessment of failure correlated with the preoperative classification (99%). At the last follow-up, there were 15/217 re-revisions; giving a success rate of 93%.

CONCLUSION

This classification helps in choosing the appropriate revision method, leading to acceptable results.

Comparison of bipolar hemiarthroplasty and total hip arthroplasty for displaced femoral neck fractures in the healthy elderly: a meta-analysis

Background

Displaced femoral neck fractures (FNFs) in healthy elderly patients have traditionally been managed with hemiarthroplasty (HA) or total hip arthroplasty (THA), with studies suggesting that THA may be the better option. However, it has recently been reported that bipolar HA (BHA) also provides good outcomes, and it is not clear as to whether BHA or THA is most appropriate. The purpose of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) comparing the outcomes of BHA with THA for treating FNF in healthy elderly patients.

Methods

We searched the following databases from inception to May 2015 for relevant RCTs without language restrictions: PubMed, the Cochrane Central Register of Controlled Trials, Ovid MEDLINE and EMBASE, CINAHL, the China Biological Medicine Database, International Clinical Trials Registry Platform, Current Controlled Trials, and ClinicalTrials.gov. RCTs that met the inclusion criteria were statistically analyzed using the Cochrane review methods.

Results

Eight RCTs were included (total 1,014 patients; 523 had BHA and 491 had THA). The data from included RCTs were divided into four subgroups according to different follow-up durations. The Harris Hip Score after BHA was not different from that after THA in all subgroups. Both reoperation rate and acetabular erosion rate were higher after BHA after more than 4 years, while there was a higher dislocation rate associated with THA within 4 years. THA was more favorable regarding the EQ_index-5D and the mobility and pain rate, while BHA was more favorable regarding operating time. No significant differences were found regarding infection rate, general complications, 1-year mortality, blood loss, and length of postoperative hospital stay.

Conclusions

For healthy elderly patients with displaced FNFs, treatment with BHA led to better outcomes regarding dislocation rate, while THA was better regarding acetabular erosion rate and reoperation rate. When comparing BHA with THA, there were no significant differences in other important outcomes such as Harris Hip Score, infection rate, general complications, and 1-year mortality. Further high-quality RCTs are needed to provide robust evidence and evaluate the treatment options.

PET/CT study of temporal variations in blood flow to the femoral head following low-energy fracture of the femoral neck

Earlier studies on femoral neck fractures have assessed the blood flow in either the pre- or postoperative period and information is lacking regarding changes in vascular flow to the femoral head after injury. Sixty-two adults with low-energy intracapsular femoral neck fractures were studied prospectively. Mean patient age was 57.2 years (range, 45-82 years). All patients underwent positron emission tomography/computed tomography (PET/CT) prior to surgical intervention and 6 weeks after internal fixation. Internal fixation was done using cannulated cancellous titanium screws and serial follow-up radiographs were obtained (at monthly intervals for the first 3 months followed by 3 monthly intervals between radiographs up to 2 years). On the preoperative PET/CT, 13 patients showed intact vascularity, 31 showed total loss of vascularity, and 18 showed partial loss of vascularity of the femoral head. The 6-week postoperative PET/CT scan showed recovery of blood supply in 23 of the 31 patients with total loss of vascularity and 15 of the 18 patients with partial loss of vascularity of the femoral head. Eleven of 62 patients had total or partial avascularity at the 6-week postoperative PET/CT scan and all 11 patients showed evidence of avascular necrosis on plain radiographs at the end of 2 years. The association between the vascular status of the femoral head at 6 weeks and avascular necrosis at the end of 2 years was statistically significant (P<.001). This study shows that the femoral head undergoes temporal variations in blood flow following femoral neck fracture. Decreased or absent vascularity is seen in approximately 75% of the fractures and 80% of the femoral heads with initial vascular compromise seem to regain blood flow within 6 weeks. Thus, prognostication about vascularity based on single-point preoperative imaging is difficult. The 6-week postoperative PET/CT scan seems to be reliable in predicting the future status of the femoral head. However, decision making regarding hemiarthroplasty or internal fixation at the time of injury may have to depend on factors other than the preoperative vascular status of the femoral head.

A meta-analysis of total hip arthroplasty and hemiarthroplasty outcomes for displaced femoral neck fractures

BACKGROUND

Total hip arthroplasty or hemiarthroplasty are used to treat displaced femoral neck fractures. However, the optimal treatment of these fractures remained controversial.

OBJECTIVE

To assess the effects that compare total hip arthroplasty with hemiarthroplasty for the treatment of femoral neck fractures in the elderly.

METHODS

We searched MEDLINE (January 1980 to 2010), EMBASE (January 1980 to 2010), and the Cochrane Library 2010; issue 1. Only prospective randomized controlled trials (RCTs) that compare total hip arthroplasty with hemiarthroplasty for the treatment of femoral neck fracture in the elderly were included. The analysis was performed with software RevMan5.0 from the Cochrane Collaboration.

RESULTS

We identified seven relevant randomized controlled trials with a total of 828 participants. The meta-analysis showed relative risk of re-operation was 0.40 (95% CI = 0.24-0.67, P = 0.0004), the dislocation was 2.02 (95% CI = 1.26-3.25, P = 0.002), the mobility as functional outcome was 1.70 (95% CI = 1.21-2.38, P = 0.002). It was reported that the average operating room times and blood loss volumes in total hip arthroplasty were more than in hemiarthroplasty (P < 0.001). Other results were not significantly different.

CONCLUSIONS

Total hip arthroplasty is associated with better functional outcome and lower reoperation rate than hemiarthroplasty in treatment of displaced femoral neck fractures in the elderly patients.

Groin pain after replacement of the hip

Persistent groin pain after seemingly successful total hip replacement (THR) appears to have become more common. Recent studies have indicated a high incidence after metal-on-polyethylene and metal-on-metal conventional THR and it has been documented in up to 18% of patients after metal-on-metal resurfacing. There are many causes, including acetabular loosening, stress fracture, and iliopsoas tendonitis and impingement. The evaluation of this problem requires a careful history and examination, plain radiographs and an algorithmic approach to special diagnostic imaging and tests. Non-operative treatment is not usually successful. Specific operative treatment depending on the cause of the pain usually involves revision of the acetabular component, iliopsoas tenotomy or other procedures, and is usually successful. Here, an appropriate algorithm is described.

Painful hemiarthroplasty due to acetabular erosion: a new technique of treatment

We describe a technique to salvage a painful hemiarthroplasty due to erosion of the acetabular cartilage in the absence of loosening of the femoral component. A press-fit metallic acetabular component which matched the femoral component was used as a metal-on-metal articulation. The procedure offered a shorter operation time with less blood loss and no risk of femoral fracture as might have occurred during conventional revision to a total hip replacement. The patient made an unremarkable recovery with a good outcome at follow-up of 15 months.

Clinical results of conversion total hip arthroplasty after failed bipolar hemiarthroplasty

Total hip arthroplasty (THA) has been the most common surgery performed for complications of bipolar arthroplasty. We wanted to evaluate functional results and complications after conversion of bipolar hemiarthroplasty to THA in 25 patients followed for an average of 7.2 years. Indications for conversion included acetabular erosion with well-fixed femoral stem in 13 patients, acetabular erosion with femoral loosening in 8 patients, and periprosthetic fracture in 4 patients. The average Harris Hip Score improved from 41 (34 to 67) before conversion to 85 (65 to 95) at final follow-up. The average Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score improved from 81 (41 to 96) before conversion to 17 (8 to 36) at final follow-up. Pain component of WOMAC improved from an average of 15 (7 to 20) to 4 (0 to 11). The stiffness component of WOMAC improved from 6 (2-8) to 30 (0-4) and the function component improved from 59 (36-68) to 17 (8-36). The complications included 2 recurrent dislocations, 2 dislocations, 1 acetabular loosening, and 1 trochanteric nonunion. One patient required revision of acetabular component. The conversion THA after symptomatic bipolar arthroplasty can offer reliable pain relief and functional improvement. The perioperative complications approximate those of revision THAs.

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.

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.

Bipolar versus total hip arthroplasty in the treatment of avascular necrosis of the femoral head in young patients

The authors evaluate medium-term results of bipolar and total hip arthroplasty as a treatment for avascular necrosis of the femoral head. Between 1990 and 2000, 57 hips (45 patients) were treated with a bipolar (BHA: 37 hips) or total hip arthroplasty (THA: 20 hips) depending on the radiographic and macroscopic aspect of the acetabulum. At surgery, all patients were under 65 years of age (average: 45.09 years). All had the same cementless hydroxylapatite coated femoral stem inserted through an anterolateral approach. The BHA were followed during a mean of 4.49 years. One BHA was lost to follow-up. Seven out of 36 hips (19.44%) were considered failures: three due to a poor functional result (Harris Hip Score (HHS) <70) and four which needed conversion to THA for groin pain. Two hips were revised for periprosthetic fracture. Twenty BHA (55.56%) had a good or excellent result (HHSY80). The THA were followed for a mean of 4.32 years. One THA was lost to follow-up. Four out of 19 hips (21.05%) were considered as failures. Three due to a poor functional result (HHS<70) and one which needed cup revision for recurrent dislocation. Fifteen THA (78.95%) had a good or excellent functional result (HHSY80). BHA as a treatment of avascular necrosis of the femoral head in young patients preserves bone stock for later revisions and can lead to excellent results. But the outcome seems less predictable than after THA. Groin pain associated to BHA can be treated successfully with conversion to THA if necessary. (Hip International 2002; 2: 142-9).

Bipolar hemiarthroplasty for osteonecrosis of the femoral head. A 7- to 18-year followup

This study evaluated clinical and radiographic results of bipolar hemiarthroplasties for the treatment of osteonecrosis of the femoral head. Forty-eight hips in 35 patients with a mean age of 37 years who underwent primary bipolar hemiarthroplasties were observed for an average of 11.4 years. Osteonecrosis was associated with corticosteroid use (21 patients), alcohol (six patients), idiopathic (four patients), and other conditions (four patients). The average Harris hip score was 46 before surgery and 86 at the time of the final followup. Twenty (42%) hips were radiographic failures, and 12 (25%) hips were revised. Groin symptoms were present in 20 (42%) hips. Radiographic proximal migration greater than 4 mm and osteoarthritic signs of the acetabulum indicated a high risk of groin symptoms. The results were inferior to those previously reported for total hip arthroplasty. Thus, for the treatment of osteonecrosis of the femoral head in which necrotic lesions are wide, the authors no longer use this system and currently use total hip arthroplasty.