Cementless femoral fixation in the rheumatoid patient undergoing total hip arthroplasty: minimum 5-year results

Contemporary outcomes of primary total hip arthroplasty in patients with inflammatory arthritis

Aims

Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis.

Methods

We identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m² (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18).

Results

The ten-year cumulative incidence of any revision was 3%, and was highest in psoriatic arthritis patients (16%). The most common indications for the 15 revisions were dislocations (n = 8) and periprosthetic joint infections (PJI; n = 4, all on disease-modifying antirheumatic drugs (DMARDs)). The ten-year cumulative incidence of reoperation was 6.1%, with the most common indications being wound infections (six cases, four on DMARDs) and postoperative periprosthetic femur fractures (two cases, both uncemented femoral components). The ten-year cumulative incidence of complications not requiring reoperation was 13.1%, with the most common being intraoperative periprosthetic femur fracture (15 cases, 14 uncemented femoral components; p = 0.13). Radiological evidence of early femoral component subsidence was observed in six cases (all uncemented). Only one femoral component ultimately developed aseptic loosening. Harris Hip Scores substantially improved (p < 0.001).

Conclusion

Contemporary primary THAs with HXLPE in patients with inflammatory arthritis had excellent survivorship and good functional outcomes regardless of fixation method. Dislocation, PJI, and periprosthetic fracture were the most common complications in this cohort with inflammatory arthritis.

Preoperative Planning and Operative Techniques of the Shorter Tapered Stem Compared to the Metaphyseal Fit Stem in Cementless Total Hip Arthroplasty

BACKGROUND

In order to prevent postoperative dislocation due to prosthetic impingement as a result of total hip arthroplasty (THA), the combined anteversion (CA) theory, which combines the anteversion of the femoral stem and the acetabular socket, has been revised in recent years. Particularly, it is necessary to keep CA within the target zone.

METHODS

The aim of this study was to investigate whether postoperative CA can be kept within the target zone while using the operative technique which prepares the socket first in cementless THA, by estimating the anteversion of the metaphyseal fit stem or the shorter, tapered wedge stem using preoperative 3-dimensional computerized planning, and by adjusting the anteversion of the socket using a navigation system that considers CA. One hundred fourteen patients (118 hips) were recruited for the study.

RESULTS

Postoperative CA in THA using the metaphyseal fit stem was kept within the target zone for 56 of the 60 hips (93.3%). Using the shorter, tapered wedge stem, 49 of the 58 hips (84.4%) were within the target zone. No postoperative dislocations were observed in any hips.

CONCLUSION

We found that the metaphyseal fit stem worked better than the shorter, tapered wedge stem in terms of meeting the planned CA. The shorter, tapered wedge stems were flexible in rotation according to the anatomical configuration of the proximal femur. Therefore, the stem could be placed second with the metaphyseal fit stem, but we recommend placing the stem first with the shorter, tapered wedge stem.

Minimum 10-year results of cementless total hip arthroplasty in patients with rheumatoid arthritis

OBJECTIVES

To retrospectively evaluate the long-term results of cementless total hip arthroplasty (THA) in patients with rheumatoid arthritis (RA) and postoperative patient mortality after THA.

METHODS

This study included 191 hips in 149 RA patients who underwent cementless THA between 1998 and 2005. Mean age at surgery was 54.2 years, and mean follow-up was 12.6 years. Implant and patient survivorships were determined using the Kaplan-Meier method, and the associated influencing factors were determined.

RESULTS

Implant survivals at 17 years were 99.5% for stems, 93.9% for cups, and 90.8% for liners. Among the liners used, THAs with highly cross-linked polyethylene showed better survivals compared with those with conventional polyethylene and alumina-bearing surface (93.4%, 90.9%, and 52.2%, respectively). A total of 64 deaths occurred; 45 patients died within 10 years and 19 patients died between 10 and 17 years. Malignancy (25.0%) was the leading cause of death, followed by pneumonia (20.8%) and sepsis (20.8%). The patient survival rate was 36.9% at 17 years after THA. Multivariate analysis exhibited that older age at operation and greater dose of concomitant corticosteroid resulted in shorter patient survivals.

CONCLUSIONS

Cementless THA worked well in patients with RA. Mortality remained high among RA patients who needed THA.

Cementless total hip arthroplasty for patients with rheumatoid arthritis: a more than 10-year follow-up

BACKGROUND/PURPOSE

In this study, cementless THA was performed for RA patients, and its clinical outcomes, as well as radiographic findings and implant survival rates, were examined more than 10 years after surgery in comparison with the outcomes of the same procedure performed for patients with hip osteoarthritis (OA) during the same period.

METHOD

We studied 28 cases of THA for RA clinically and radiologically at a minimum follow-up duration of 10 years. The patients consisted of 4 males and 22 females, with a mean age at the time of surgery of 53.1. The clinical and radiographic results were compared with an age-matched and sex-matched group of patients who had undergone THA for the diagnosis of primary or secondary OA.

RESULTS

In the RA group, the mean Harris hip score was 48.3 before surgery, and improved to 76.8 at the time of the final survey. In the control group, the score also improved from 46.8 before to 86.5 after surgery, while revealing significant differences between the groups (p = 0.0002). In the RA group, 2 joints required revision THA on the acetabular side due to aseptic loosening, while such revision was not performed on the femoral side despite the presence of more than 2 mm of subsidence in 2 joints. The implant survival rate was 92.9 and 100 % in the RA and control groups, respectively, without significant differences (p = 0.493).

CONCLUSIONS

Although its clinical outcomes were significantly different from those for OA, a satisfactory implant survival rate was achieved, at 92.9 % in RA patients.

Intermediate- to long-term results after hybrid total hip arthroplasty in patients with rheumatoid arthritis

There have been few reports describing intermediate- to long-term results after hybrid total hip arthroplasty in patients with rheumatoid arthritis. We followed up 52 hips in 44 patients aged 5 men and 39 women, with a mean of 11.5 years (range, 5-23.5 years). Revisions had been performed in 6 hips in 6 patients: 1 both acetabular and femoral components for infection, 1 acetabular component for aseptic loosening, 3 acetabular components for recurrent dislocation, and 1 acetabular component for dislodgement of the polyethylene liner from the metal shell. None of other acetabular or femoral components were revised or found to be loose at the final follow-up. Although postoperative dislocation remains a concern, hybrid total hip arthroplasty had an acceptable result in patients with rheumatoid arthritis.

Total hip arthroplasty at the rothman institute

BACKGROUND

Total hip arthroplasty (THA) is one of the most successful surgical interventions devised in modern times. Attempts to change the current THA procedure with unproven innovations bring the risk of increased failure rates while trying to improve the benefit of the surgery.

QUESTIONS/PURPOSES

This manuscript examines the evolution of THA at the Rothman Institute illustrating the key elements that lead the success of this procedure at this institution. These key elements include femoral stem design, use of highly crossed-linked polyethylene and use of pain and rehabilitation protocols. We attempted to describe the long-term results regarding safety, effectiveness, and durability of specific THA implant designs used at this institution drawing on reported evidence in the literature.

METHODS

The authors performed a review of peer-reviewed articles related to the Rothman Institute's experience with THA.

RESULTS

Total hip arthroplasty is an efficient, safe, and durable procedure. It is a highly successful operation to restore function and improve pain. The survivorship of THA procedures at the Rothman Institute is higher than 99% at 10 years based on mechanical failure. The use of collarless, tapered wedge femoral stem, highly crossed-linked polyethylene, and improved pain rehabilitation protocols have contributed to this success.

CONCLUSIONS

There is a well-documented long-term survivorship after THA. Future innovation in THA should address new challenges with younger and more demanding patients, rather than change current methods that have a proven good survivorship. This innovation depends mainly upon improvements in the bearing surfaces and advances in pain control and rehabilitation.

Use of cementless, tapered femoral stems in patients who have a mean age of 20 years

Young patients who undergo total hip arthroplasty are a unique group who has been challenging to successfully treat; however, newer prosthetic materials and designs have the potential to increase implant longevity. Fifty-three hips (40 patients who had a mean age of 20 years) underwent a total hip arthroplasty using a cementless, proximally hydroxyapatite-coated, tapered, femoral stem and a cementless acetabular cup. There was a 96% overall survivorship at approximately 5 years of mean follow-up (range, 2-7 years) with no femoral side failures. Younger patients undergoing total hip arthroplasty with newer component designs and materials may have similar excellent outcomes to older patients.

Cementless total hip arthroplasty in rheumatoid arthritis: a systematic review of the literature

BACKGROUND

Compromised rheumatic bone is a potential risk factor for mechanical complications in cementless total hip arthroplasty (THA) in cases of rheumatoid arthritis (RA). Increased rates of intra-operative fractures, component migration and (early) aseptic loosening are to be expected. Despite this, cementless THA is performed in cases of RA.

METHODS

A literature search on cementless THA in RA was performed in EMBASE (1993-2011), Medline (1966-2011) and the Cochrane Library. A systematic review was conducted with a special emphasis on mechanical complications.

RESULTS

Twenty-three case series and five studies of implant registries were included. Acetabular fractures and/or migration of the cup were reported in 9 out of 22 studies of the cup. Proximal femoral fractures and/or subsidence of the stem were reported in 14 out of 20 studies of the stem. Six studies compared failure rates of uncemented and cemented components due to aseptic loosening. The overall failure rate ratio (uncemented/cemented) for the cup was 0.6 (95% CI: 0.14-2.60) and for the stem 0.71 (95% CI: 0.06-8.55), both favoring uncemented fixation. The failure rates in case series without a control group were compared to the NICE criteria (failure rate/1). The overall failure rate for the cup was 0.97 (95% CI: 0.50-1.88) and for the stem 0.79 (95% CI: 0.44-1.41). Failure rates of aseptic loosening of higher than 1 (favoring cemented fixation) were reported in 6 out of 26 studies of the cup and in 2 out of 25 studies of the stem. In all these studies, the inferior implant designs were blamed, and not the type of fixation or the quality of the bone.

CONCLUSIONS

Despite substantial rates of mechanical stem complications, no evidence was found to establish that cementless components perform less well than cemented components. The results justify the use of cementless THA in RA patients.

Outcome of the cementless Taperloc stem: a comprehensive literature review including arthroplasty register data

BACKGROUND AND PURPOSE

The validity of various data sources for the assessment of the outcome quality of medical devices was investigated by comparative analysis of the published data sources available for a sample of implants. It was the aim of the study to determine the performance of this implant and to identify potential bias factors inherent to the various datasets.

METHODS

A comprehensive literature search was carried out from English-language, peer-reviewed journals and worldwide reports from national arthroplasty registers. Publications from Medline-listed journals were included. The main parameter was revision rate, calculated as "revisions per 100 observed component years" to allow adjusted direct comparison of different datasets.

RESULTS

Of 16 clinical studies that met the inclusion criteria, 9 originated from the implant developer's hospital. In the clinical studies category, publications from the developer's hospital suggested considerably lower revision rates than the other datasets. In fact, the values quoted were 5.5 times below the average of all other studies, and 9.51 times lower than in the Australian arthroplasty register. These differences are statistically significant.

INTERPRETATION

The cementless Taperloc stem is an implant that shows good performance regarding revision rates in registry data and in clinical studies. However, the excellent results published by the developer's clinic are generally not reproducible by other surgeons. In terms of reference data, registry data are able to make an important contribution to the assessment of clinical sample-based studies, particularly regarding evaluation of the extent to which published results are reproducible in daily routine.

Cemented versus cementless total hip replacements in patients fifty-five years of age or older with rheumatoid arthritis

BACKGROUND

results obtained from single-center studies indicate that a cemented total hip replacement is the treatment of choice for the management of patients over fifty-five years of age with rheumatoid arthritis. The aim of this study was to analyze population-based survival rates for cemented and cementless total hip replacements in patients aged fifty-five years or over with rheumatoid arthritis in Finland.

METHODS

between 1980 and 2006, a total of 6000 primary total hip replacements performed for the management of rheumatoid arthritis in patients who were fifty-five years of age or older were entered in the Finnish Arthroplasty Registry. 4019 of them fulfilled our inclusion criteria and were subjected to analysis. The implants were classified into one of three possible groups: (1) a cementless group (a noncemented proximally porous-coated stem and a noncemented porous-coated press-fit cup), (2) a cemented group 1 (a cemented, loaded-taper stem combined with a cemented, all-polyethylene cup), or (3) a cemented group 2 (a cemented, composite-beam stem with a cemented, all-polyethylene cup).

RESULTS

cementless stems and cups, analyzed separately, had a significantly lower risk of revision for aseptic loosening than cemented implants in patients who were fifty-five years of age or older with rheumatoid arthritis. The fifteen-year survival rate of cementless total hip replacements (80%) was comparable with the rates of the cemented groups (86% in cemented group 1 and 79% in cemented group 2) when revisions for any reason were used as the end point.

CONCLUSIONS

cementless and cemented total hip replacements produced comparable long-term results in patients who were fifty-five years of age or older with rheumatoid arthritis.

LEVEL OF EVIDENCE

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

Total hip arthroplasty in inflammatory arthritis in patients under 35 years. A 7 to 19 year follow-up

Total hip arthroplasty in patients with inflammatory arthritis is compromised by the young age of patients at presentation, intake of non-steroidal anti-inflammatory drugs, steroid use and autoimmune diseases which negatively affect bone quality. This study evaluates the survival of total hip arthroplasties (THA) in 32 patients with inflammatory hip disease who were under the age of 35 at the index operation and on which 57 primary total hip arthroplasties were performed between 1989 and 2001. Polished straight tapered cemented stems were used in all 57 hips. There were 10 cemented and 47 uncemented cups. The average follow-up was 12.2 years (range 7-19). Forty-seven hips had more than 10 years follow-up. There were 3 revisions of cemented metal-backed cups for aseptic loosening at 11, 13 and 16 years post-operatively. No uncemented cups and no stems needed revision. Heterotopic ossifications occured in 3 hips with Brooker type-I ossification in 1 hip and Brooker type-II in 2 hips. Cemented polished tapered straight stems demonstrate excellent survival in young patients suffering from inflammatory arthritis.

Hip resurfacing for rheumatoid arthritis: independent assessment of 11-year results from an international register

Total hip replacement has shown good outcomes for patients with rheumatoid arthritis. Can hip resurfacing give similar results for patients with rheumatoid arthritis? Using an international hip resurfacing register, 47 patients with rheumatoid arthritis were identified and age and gender matched to a group of 131 randomly selected patients with osteoarthritis of the hip joint. Patients completed a questionnaire to record function and implant revision. Hierarchical regression, Cox regression and Kaplan-Meier method were used for analysis. There was a significant increase in post operative hip score in both groups (p < 0.001) with rheumatoid group scoring higher as compared to the osteoarthritis group (p = 0.23). The post operative score was not significantly influenced by pre-operative score and age (p = 0.15 and 0.84, respectively) but the pre-operative score was a predictor of implant failure (p = 0.02). Patient mobility was affected by age with younger patients scoring high on mobility as compared to older patients (p = 0.01). The Kaplan-Meier analysis showed a survival rate of 96.3% in the rheumatoid group and 97.8% in the osteoarthritis group. This difference was not significant (Log rank test, p = 0.45). Our results from an independent and international register show that hip resurfacing provides good post-operative hip function and excellent implant survival for patients with rheumatoid arthritis of the hip joint. This procedure can be considered as a viable option for management of rheumatoid arthritis of the hip joint.

Survival of primary total hip arthroplasty in rheumatoid arthritis patients

BACKGROUND AND PURPOSE

There has been a limited amount of research on survival of total hip arthroplasties (THAs) in rheumatoid arthritis (RA). We therefore performed a population-based, nationwide study to compare the survival of primary THAs in RA patients and in osteoarthritis (OA) patients. We also wanted to identify predictors of THA failure in RA patients.

METHODS

Using the Danish Hip Arthroplasty Registry, we identified 1,661 primary THAs in RA patients and 64,858 in OA patients, all of which were inserted between 1995 and 2008. The follow-up period was up to 14 years for both groups.

RESULTS

Regarding overall THA survival, the adjusted RR for RA patients compared to OA patients was 0.81 (95% CI: 0.65-1.01). We found no difference in survival of cups between primary THAs in RA and OA patients. In contrast, there was better overall survival of stems in RA patients than in OA patients, both regarding revision due to aseptic loosening (adjusted RR = 0.58; 95% CI: 0.34-0.99) and for any reason (adjusted RR = 0.63; 95% CI: 0.45-0.88). In RA patients, males had a higher risk of revision than females concerning aseptic loosening of the stem, any revision of the stem, and any revision of both components.

INTERPRETATION

The overall survival of primary THAs in RA patients is similar to THA survival in OA patients. Stem survival appeared to be better in RA patients, while survival of the total THA concept did not show any statistically significant differences between the two groups. In RA patients, males appear to have a greater risk of revision than females.

Cementless total hip arthroplasty in patients with rheumatoid arthritis using a tapered designed titanium hip stem minimum: 10-year results

The results of cementless tapered designed femoral stem were studied at a minimum 10-year follow-up in a non-selected, consecutive group of 27 patients (39 hips) with rheumatoid arthritis. Clinical and radiological analyses were performed in 27 hips, 17 patients (mean age at surgery 45 years) after a mean of 12 years. The postoperative Harris hip score was excellent for 14 hips, 9 hips were rated as good and 4 hips were fair or poor. No stem had to be revised for aseptic loosening. Proximal stress shielding was observed in 26 hips (96%); heterotopic ossification was present in 11 hips (41%). Six hips required revision of the acetabular component. With uncemented tapered femoral fixation excellent 12-year results are achieved in patients with rheumatoid arthritis.

Survivorship of 2000 tapered titanium porous plasma-sprayed femoral components

Tapered titanium porous plasma-sprayed components have performed well in primary THA. To confirm the literature at longer followup we retrospectively reviewed all 1639 patients who underwent 2000 THAs in which a specific porous femoral component was used. One hundred fourteen patients (134 hips) were lost to followup leaving a cohort of 1525 patients (1866 THAs). The component is a tapered titanium plasma spray-coated design that remained relatively unchanged since its first implantation except for circumferential proximal porous coating added in 1986 and an offset option added in 1999. Minimum followup was 24 months (average, 119 months; range, 24 to 275 months). To date there have been 39 femoral revisions for an implant survival of 98%. Using the Kaplan-Meier method, cumulative survival with any stem revision as the end point was 98.6% at 5 years, 98.4% at 10 years, 97.1% at 15 years, and 95.5% at 20 years. Using aseptic revision for failure of ingrowth as the endpoint, stem survival was 99.1%. Kaplan-Meier cumulative survival with aseptic revision for failure of ingrowth as the endpoint was 99.4% at 5 years, 99.3% at 10, 15 and 20 years. Harris hip pain and total scores improved. This titanium, porous plasma spray-coated femoral component continues to demonstrate high long-term survival with a low rate of component revision for any reason or aseptic failure of ingrowth.

LEVEL OF EVIDENCE

Level IV, therapeutic study (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Primary total hip arthroplasty with an uncemented femoral component: two- to seven-year results

This prospective study reports the midterm outcome of total hip arthroplasty performed in a consecutive series of patients using a tapered uncemented femoral component. The cohort consists of 631 patients (700 hips). The clinical records and the routine serial radiographs of these patients were monitored closely over a 5-year period. Follow-up averaged 4.35 years. There was a significant improvement in functional outcome of these patients as measured by Harris hip score and short-form 36.There were 4 revisions for aseptic loosening of the femoral component in this series, accounting for an overall survivorship of 99.4%. The study confirms that the midterm outcome of this stem is excellent, with a low revision rate.

Total hip arthroplasty for rheumatoid arthritis in younger patients: 2,557 replacements in the Finnish Arthroplasty Register followed for 0-24 years

BACKGROUND

The results of total hip arthroplasty (THA) in young patients with rheumatoid arthritis (RA) have been reported in only a few studies. On a nationwide level, the outcome of THA in these patients is unknown. We evaluated the population-based survival of THA in patients under 55 years of age with RA and factors affecting the survival.

PATIENTS

Between 1980 and 2003, 2,557 primary THAs performed for RA in patients less than 55 years of age were reported to the Finnish Arthroplasty Register.

RESULTS

Proximally circumferentially porous-coated uncemented stems had a 15-year survival rate of 89% (95% CI 83-94) with aseptic loosening as endpoint. The risk of stem revision due to aseptic loosening was higher with cemented stems than with proximally porouscoated uncemented stems implanted during the same period (RR 2.4; p < 0.001). In contrast, Cox regression analysis showed that the risk of cup revision was significantly higher for all uncemented cup concepts than for all-polyethylene cemented cups with any cup revision as endpoint. There were no significant differences in survival between the THR concepts.

INTERPRETATIONS

Uncemented proximally circumferentially porous-coated stems and cemented all-poly-ethylene cups are currently the implants of choice for young patients with RA.

Total hip arthroplasty for acute femoral neck fractures using a cementless tapered femoral stem

The purpose of this study was to evaluate the osseointegration potential and implant-related complications of cementless total hip arthroplasty with a titanium alloy collarless, tapered, wedge-shaped femoral stem with a proximal circumferential plasma-spray coating in patients with acute hip fractures. The cohort consists of 85 patients with a mean age of 78.1 years. The mean duration of follow-up was 3.8 years. Total hip arthroplasty conferred significant improvement in function for all patients. All femoral components were stable with evidence of bone ingrowth (84 hips) or fibrous fixation (1 hip). Mild thigh pain was present in 3 patients. The complications included dislocation (3 cases), intraoperative femoral fracture (2 cases), and periprosthetic femoral fracture in the postoperative period (1 case). There was one reoperation for revision of the femoral component in the patient with a periprosthetic fracture. There were 25 (29%) deaths. Cementless total hip arthroplasty using a tapered proximally coated femoral stem is a viable option for the treatment of a displaced hip fracture and preexistent arthritis.

Implant migration after early weightbearing in cementless hip replacement

Twenty-nine patients (five women and 24 men) with an average age of 47 years (range, 24-59 years) had 37 total hip arthroplasties using a hydroxyapatite-coated double-wedge press-fit femoral component. All patients had a Type A bone quality. Patients were either mobilized with weightbearing as tolerated or toe-touch weightbearing for 6 weeks postoperatively. After 6 weeks all patients were advanced to weightbearing as tolerated. Radiostereometric analysis radiographs were taken at 3 days, 6 weeks, and 6 months postoperatively to measure migration of the femoral component. Radiostereometric analysis revealed no difference in stem migration between the two groups as defined by maximal total point migration. There was a difference in the vertical (proximal-distal) migration within the first 6 weeks between groups (0.81 mm versus 0.13 mm), but not afterwards (0.17 mm versus 0.18 mm). Continuous migration after 6 weeks was observed in three patients from each group. There was no loosening in either group within a 2-year followup. Weightbearing as tolerated is recommended for young patients with excellent bone quality after cementless total hip arthroplasty with a double-wedge press-fit femoral component.

LEVEL OF EVIDENCE

Diagnostic study, Level I (testing of previously developed diagnostic criteria in series of consecutive patients--with previously applied reference gold standard). See the Guidelines for Authors for a complete description of levels of evidence.

Hip implant selection for total hip arthroplasty in elderly patients

Total hip arthroplasty in patients 75 years and older should relieve pain, improve function, and last for the rest of the patient's life. The achievement of this goal depends on health status, response to anesthesia, surgical technique, hip implant selection, and recovery from surgery. Considerations regarding hip implant selection in the elderly include bone quality, morphologic features of bone, implant fixation, design of the joint articulation, wear of the joint bearing surface, and implant cost. Implant cost should be negotiated and controlled in the business office and the boardroom rather than the operating room. Two hundred twenty-eight primary hip replacements done in 204 patients 75 years or older were evaluated. Complete clinical and radiographic evaluations were available for 190 hips in 152 patients at a mean 4 years followup (range, 1-11 years). Significant improvement in pain scores and clinical hip scores was observed. Patient outcome criteria were improved consistently. One acetabulum was loose in one patient (acetabular loosening, 0.5%), and five femoral stems were loose in five patients (femoral loosening, 2.6%). Four patients (four hips; 2.1%) required revision operations. One cemented cup (0.5%) in one patient and no cementless cups were revised. Four cemented stems (2.1%) in four patients and no cementless stems were revised. Cemented and cementless hip implants provided reliable results in these patients. In 2002, the author prefers cementless hip implant fixation.

Ten to fifteen-year follow-up after total hip arthroplasty with a tapered cobalt-chromium femoral component (tri-lock) inserted without cement

BACKGROUND

Fixation of the femoral component of a total hip arthroplasty without cement has had variable results. While tapered stems appear to have consistently good results, the duration of follow-up in many series has been relatively short. The purpose of this study was to present a longer-term (ten to fifteen-year) follow-up after total hip arthroplasty with insertion of a tapered femoral component without cement.

METHODS

Sixty-seven total hip arthroplasties were performed with insertion of a tapered, cobalt-chromium femoral component without cement in fifty-eight patients from 1983 to 1986. Thirteen patients (fifteen hips) died prior to the fifteen-year follow-up examination, and three patients (three hips) were lost to follow-up after ten years, leaving forty-two patients (forty-nine hips) who were followed clinically for a mean of fifteen years. Thirty-seven of the forty-nine hips were followed radiographically for fifteen years, and the remaining twelve were followed for a minimum of ten years.

RESULTS

The mean preoperative Charnley score was 3.0 points for pain, 2.7 points for function, and 3.2 points for motion. At the time of the final follow-up, the mean scores were 5.6, 5.6, and 5.2 points, respectively. Although no preoperative Harris hip scores were available, the mean score at the time of the latest follow-up was 92 points (range, 78 to 100 points). There were no revisions because of isolated aseptic loosening of the femoral component (although revision because of aseptic loosening of the acetabular component led to femoral component revision in seven hips). Two femoral components showed radiographic evidence of instability. At fifteen years, the prevalence of thigh pain was 2%. No femoral component that was thought to be stable, with bone ingrowth at two years, lost fixation.

CONCLUSIONS

The design features of this cobalt-chromium femoral component (i.e., the collarless, tapered, wedge fit with circumferential porous coating) are thought to be crucial to the achievement of the good-to-excellent results seen in this study.