Uncemented femoral revision arthroplasty using the modular revision prosthesis MRP-TITAN revision stem

Objective  Restoration of a painless hip joint capable of bearing weight by uncemented implantation of a rotationally stable, modular revision stem anchored in the diaphysis. Indications  Prosthetic stem loosening with osteolytic bone defects (defect classification types I–III according to Paprosky), material failure with broken prosthesis, sub-and/or periprosthetic femoral fractures, and tumors. Contraindication  Extensive osteolysis preventing diaphyseal anchorage of the prosthetic stem. Surgical technique  Transgluteal approach to the hip joint. Removal of the loose prosthetic stem and, if cemented, the bone cement as well. Excision of intramedullary granulation tissue. Reaming of the medullary cavity with flexible reaming shafts and formfit, uncemented implantation of the star-shaped modular revision stem with diaphyseal press-fit. If there is extensive loss of metaphyseal bone stock, augmentation with autogenous-allogenic bone should be performed. Postoperative management  Mobilization on two underarm crutches from the 1st postoperative day. Removal of the Redon drains after 48 hours. Partial loading with 20 kg for 6 weeks postoperatively. If plain radiographs show unchanged seating of the prosthesis after 6 weeks, loading can be increased by 10 kg per week until full weight bearing is achieved; thrombosis prophylaxis is continued throughout. Radiologic checkups will be done after 3, 6, and 12 months. After that, the patient should be checked annually. Results  Forty-five patients (N = 48 prostheses) with an average age of 67.2 years (min/max: 42.4–87.4 years) were investigated. The average implantation time of the Modular revision prosthesis MRP-TITAN revision stem was 4.7 years (min/max: 1.0–9.0 years). The Harris hip score for Paprosky bone defect types I–III had increased from 25.6 preoperatively to 71.4 postoperatively at the time of the final follow-up (p ³ 0.05). Extensively defective bone was diagnosed preoperatively in 32 patients (¹Paprosky IIB). Plain radiographs showed stable anchorage without migration in 44 patients. In one case, the stem (implantation time 2.36 years) was replaced due to increasing axial subsidence (¹5 mm). Good integration of bone graft with subsequent defect regeneration was seen in all patients with bone trans-plant (N = 30). Postoperative dislocation occurred in six patients and required closed reduction in four cases. Open reduction was performed in two patients, whereby the external rotation angle of the prosthetic neck was corrected without dismantling the distally anchored prosthetic stem components. The mechanical failure rate over the follow-up period of 9 years was 1 out of the 48 prospectively investigated prostheses. The rate of survival according to Kaplan-Meier was 97%.     

Good survival of uncemented tapered stems for failed intertrochanteric osteotomy: a mean 16 year follow-up study in 45 patients

Introduction  Inferior survival of cemented total hip arthroplasty has been reported after previous femoral osteotomy. We previously presented 5–15 years results of uncemented femoral stems for this subgroup of patients. The purpose of the present study was to re-evaluate that same patient group at 10–20 years follow-up. Materials and methods  Forty-eight hips in 45 patients had undergone conversion THA for a failed intertrochanteric osteotomy of the hip after a mean of 12 years (2–33 years). Mean time of follow-up was 16 years (10–20 years). Results  At the latest follow-up five patients had died (five hips), and one patient (one hip) remained lost to follow-up. Compared to the previous evaluation, one more patient required femoral revision for aseptic loosening giving a total of four patients (four hips) with femoral revision––one for infection and three for aseptic loosening of the stem. Survival of the stem was 91% at 15 and 20 years respectively; survival with femoral revision for aseptic loosening as an end point was 93%. The median Harris-Hip-Score at final follow-up was 76 points (previously 80 points). Radiolucent lines in Gruen zones 1 and 7 were present in 20 and 17% of hips, respectively. Radiolucencies in other zones were not detected. There was no radiographic evidence of femoral osteolysis, stress-shielding or loosening. Conclusion  The long-term results with this type of uncemented tapered titanium femoral component after proximal femoral osteotomy remain encouraging and compare favorably to those achieved in patients with regular femoral anatomy. This paper has not been under consideration by any other journal. All authors equally contributed to this paper.     

An early comparison of clinical and mechanical aspects of hybrid and uncemented hip resurfacing

Hip resurfacing is a popular operation for hip joint arthritis. It has been performed using hybrid and uncemented components. We aim to compare the two techniques functionally and mechanically over a 2 year post-operative period. We studied anteroposterior (AP) radiographs from 30 patients who had undergone hybrid hip resurfacing and 30 patients who had undergone uncemented hip resurfacing using the transgluteal approach to the hip. We measured the acetabular offset, femoral offset, stem/shaft angle, medialization of the cup, head/neck ratio, cup height, leg length and the implant seating pre-operatively, immediately post-operatively, 1 and 2 years post-operatively. Harris Hip Scores were performed pre-operatively and at 1 year post-operatively. There was no significant loss of offset and no femoral neck thinning at 2 years post-operatively with no loss of leg length. We note a smaller femoral offset and a reduction on average of 2.87 mm in seating of the femoral cap in the uncemented group when compared to the hybrid group at the 1 year postoperative review. Thus, we attribute to movement of the femoral component in the first year postoperatively, and as such restoration of the femoral offset to the pre-operative level. Both groups showed an equal significant improvement in the Harris Hip Scores at the 1 year postoperative period when compared to the pre-operative score. We conclude that uncemented hip resurfacing is statistically as good as the hybrid hip resurfacing, with a stable uncemented femoral component relying on biological cancellous fixation rather than cement fixation. We also note that in both groups, no evidence of neck thinning was noted at the 2 year postoperative period.     

Immediate weight bearing after uncemented total hip arthroplasty with an anteverted stem: a prospective randomized comparison using radiostereometry

BACKGROUND: In uncemented total hip arthroplasty with hydroxyapatite coating, early weight bearing is frequently practiced but there is still not much evidence to support this recommendation. METHOD: In a prospective randomized study we evaluated the effect of partial and full weight bearing after cementless total hip arthroplasty (ABG; Stryker-Howmedica) using radiostereometric analysis (RSA). Between February 1996 and February 2000, 43 consecutive patients (mean age 53 (41-63) years, 23 women) with hip osteoarthrosis received an uncemented and hydroxyapatite-coated prosthesis with an anteverted stem. All patients were operated in a standardized way by three experienced surgeons and they were randomized to partial (P) or full (F) weight bearing during the first 6 weeks after surgery. The patients in the partial weight bearing group were equipped with a pressuresensitive insole signaling when their load exceeded the prescribed weight limit. RESULTS: At 3-month follow-up, the mean proximal (+)/ distal (-) migration of the stem was -0.14 mm (-1.93- 0.11) in group P and -0.31 mm (-4.30-0.16) in group F (p=0.6). At 1-year follow-up, the mean migration was -0.17 mm (-2.18-0.21) and -0.28 mm (-4.31-0.11), respectively (p=0.9). There was no significant difference in stem rotations either (p<0.2). The cup translations, rotations, and femoral head penetration were similar in the two groups (p<0.1). There were no re-operations during the first year. INTERPRETATION: We did not find any adverse effect of full weight bearing immediately after operation, which justifies use of this regimen after uncemented total hip arthroplasty of the ABG type.     

Cemented versus uncemented Thompson's prostheses: a functional outcome study

One hundred and one elderly patients (90 female and 11 male) with a mean age of 83.5 years (range 69–100) were treated for intracapsular femoral neck fracture by Thompson's prosthesis. The prosthesis was fixed in the femoral shaft using Palacos cement in 23% and was inserted uncemented in 77%. We compared the following pre and postoperative variables in each group; mobility of the patient, their activity, walking aids and postoperative thigh pain. We also studied the pre and postoperative hip X-rays.

Our patients did well in both groups. We conclude that there is no statistically significant difference between the variables in the two groups. Thompson's prosthesis can be inserted uncemented. Patients with radiological loosening of the prosthesis are not necessarily symptomatic. Intra and postoperative complications were similar to other published series of hip prostheses.

The femoral neck osteotomy for Thompson's prosthesis can be performed safely well above the calcar femoris without detrimental complications. The original inter-trochanteric cut Thompson described is not necessary for acute fractures. This consequently makes revision of failed Thompson's prosthesis easier.     

Total hip arthroplasty with an uncemented hydroxyapatite-coated tapered titanium stem: results at a minimum of 10 years’ follow-up in 104 hips

Background The purpose of this study was to evaluate the minimum 10-year results of primary total hip arthroplasty using an uncemented, hydroxyapatite-coated tapered stem. Radiological signs of bone remodeling are also presented. Methods We followed a consecutive series of 105 patients (115 hips), who had had an uncemented, proximally hydroxyapatite-coated Bi-Metric femoral component for a mean of 12.2 years (range 10.0–14.9 years). The average age at operation was 52 years. Detailed clinical and radiological analyses were performed after a minimum of 5 and 10 years. Eight patients (10 hips) had died, and one patient was lost to follow-up, leaving 104 hips for final evaluation. The clinical result was evaluated by the Harris Hip Score, complications, and thigh pain. Results All patients still had their femoral components in place at the final follow-up. The average Harris Hip Score after 10 years was 92 (range 50–100) with no deterioration over time. Radiologically, several signs of progressive remodeling were identified, but no stem showed signs of loosening. Conclusions The intermediate clinical and radiological results with this stem are encouraging. In the hands of various surgeons, the stem has performed well in a young, high-risk population.     

The Bicontact cementless primary total hip arthroplasty: long-term results

We report on a prospective series of 201 primary uncemented total hip arthroplasties with a Bicontact prosthesis at a mean follow-up of 12.9 years. The mean Harris hip score improved from 41 before surgery to 89 at final follow-up. Two femoral stems, one each for infection and fracture, and 12 cups were revised. The mean number of years to revision post-primary surgery was 8.7 years (six months to 16 years). The cumulative survival of the prosthesis was 95.42% for any cause at ten years and 93.57% at 12 years. Survivorship for aseptic loosening of the femoral stem was 100%. In our series, the Bicontact uncemented total hip arthroplasty stem without hydroxyapatite coating showed excellent survival and the cup survival was comparable to other leading series.     

Uncemented total hip replacements and thigh pain

We reviewed 51 uncemented total hip replacements (THRs) in 44 patients (mean age 62 years) and average postoperative follow-up period of 4 years. The evaluation system used was based on that of D'Aubigne-Postel-Charnley, and the excellent and very good results totalled over 90%. There were no revisions or aseptic loosenings, and only one late infection and one death due to cardiac infarction. Special attention was paid to the socalled thigh pain phenomenon which, despite current views, was found to be unexpectedly low (only one case) and also gone within 2 years. We feel that the design of the prosthesis used, its kind of alloy, the anatomic shape of the stem and the low modulus of the elasticity as well as the avoidance of the press fitting technique at the distal part of the stem are important factors in avoiding the stress shielding phenomenon and thigh pain.     

Design modifications of the uncemented Furlong hip stem result in minor early subsidence but do not affect further stability

Background and purpose — Even small design modifications of uncemented hip stems may alter the postoperative 3-D migration pattern. The Furlong Active is an uncemented femoral stem which, in terms of design, is based on its precursor—the well-proven Furlong HAC—but has undergone several design changes. The collar has been removed on the Active stem along with the lateral fin; it is shorter and has more rounded edges in the proximal part. We compared the migration patterns of the uncemented Furlong HAC stem and the modified Furlong Active stem in a randomized, controlled trial over 5 years using radiostereometry (RSA).

Patients and methods — 50 patients with primary osteoarthritis were randomized to receive either the HAC stem or the Active stem. The patients underwent repeated RSA examinations (postoperatively, at 3 months, and after 1, 2, and 5 years) and conventional radiography, and they also filled out hip-specific questionnaires.

Results — During the first 3 months, the collarless Active stem subsided to a greater extent than the collar-fitted HAC stem (0.99 mm vs. 0.31 mm, p = 0.05). There were, however, no other differences in movement measured by RSA or in clinical outcome between the 2 stems. After 3 months, both stem types had stabilized and almost no further migration was seen.

Interpretation — The Active stem showed no signs of unfavorable migration. Our results suggest that the osseointegration is not compromised by the new design features.     

Management of late periprosthetic femur fractures: a retrospective cohort of 72 patients

We present our series of 72 patients with periprosthetic fractures. The Vancouver classification was used to evaluate the fractures; there was one type A, seven type B1, 42 type B2, 17 type B3 and five type C fractures. Demographics, pre and postoperative data using Charnley–D’Aubigne-Postel score for assessment of function were recorded. The mean follow-up for all patients was two years. The overall outcome of treatment was graded as excellent, good or poor. An excellent result indicated that the arthroplasty was stable with minimal deformity and no shortening. Stable subsidence of the prosthesis or when the fracture healed with moderate deformity or shortening was deemed as a good result. A loose prosthesis, nonunion, sepsis, severe deformity or shortening was considered poor. In our series 79% (n = 57) had good or excellent results following surgical intervention and 21% (n = 15) had complications; they all had undergone re-operation for various reasons such as nonunion, loosening, dislocation or infection. In B2 fractures the stem is unstable and hence revision of the prosthetic stem has been recommended with or without additional fixation. For B3 fractures an allograft prosthesis composite or tumour prosthesis is considered the treatment choice.     

Total hip replacement with cemented, uncemented, and hybrid prostheses. A comparison of clinical and radiographic results at two to four years

One hundred and thirty-one patients who had 144 cemented or uncemented hip prostheses were followed prospectively for two to four years. A cemented or a hybrid prosthesis (consisting of a cemented femoral component and an uncemented acetabular component) was used in men older than seventy years, in women older than sixty years, and in younger patients in whom adequate initial fixation could not be obtained without cement. Uncemented, porous-surfaced implants were used in all other patients. The over-all clinical results were similar for the three groups. For the fifty-two hips that had a cemented prosthesis, the mean total Harris hip rating was 91 points and the score for pain, 42 points; for the twenty-seven hips that had a hybrid prosthesis, 90 and 43 points; and for the sixty-five hips that had an implant allowing ingrowth of bone in both the acetabulum and the femur, 95 and 43 points. Two prosthetic stems that were designed to allow ingrowth of bone had aseptic loosening; one was revised. Pain in the thigh, usually slight and not disabling, occurred at one year in 24 per cent of the patients in whom a femoral component allowing ingrowth had been used; the prevalence of pain then declined. The incidences of migration of the components and of radiolucent lines were greater in the acetabula that had a cemented component than in those that had a cup allowing ingrowth of bone.     

Documentation of hip prostheses used in NorwayA critical review of the literature from 1996–2000

We have conducted a systematic review of the scientific literature concerning outcome and clinical effectiveness of prostheses used for primary total hip replacement (THR) in Norway. The study is based on two Health Technology Assessment reports from the UK (Faulkner et al. 1998, Fitzpatrick et al. 1998), reviewing the literature from 1980 to 1995. Using a similar search strategy, we have evaluated the literature from 1996 through 2000. We included 129 scientific and medical publications which were assessed according to a specific appraisal protocol. The majority (72%) were observational studies, whereas only 9% were randomized studies. We could not retrieve any peer-reviewed documentation for one third of the implants. The Charnley prosthesis had by far the best and most comprehensive evidence base with better than 90% implant survival after about 10 years. Survival of the Charnley prosthesis declines by about 10% during each of the two following decades. Except for the Charnley and Lubinus IP, no other prosthesis on the market in Norway has given long-term results (> 15 years). 5 other cemented implants have given comparable results at about 10 years of follow-up. Some uncemented stems have shown promising medium-term outcome, but no combination of uncemented cup and stem fulfilled the benchmark criterion of ≥ 90% implant survival at 10 years, which we propose as a minimum requirement for unrestricted clinical use for prostheses used in primary THR. New or undocumented implants should be introduced through a four-step model including preclinical testing, small series evaluated by radiosterometry, randomized clinical trial involving comparison with a well-documented prosthesis, and finally, surveillance of clinical use through registers.     

Migration of uncemented, long-stem femoral components in revision hip arthroplasty:A 2-8 year clinical follow-up of 45 cases and radiostereometric analysis of 13 cases

We reviewed after 48 (24-90) months the clinical results in 45 cases of revision hip arthroplasties where an uncemented, long-stem femoral prosthesis (BIAS®, Zimmer) had been used. A subgroup of 13 cases was followed with radiostereometric analysis (RSA) for 2 years. 3/45 cases had been re-revised, another 12 had unsatisfactory pain scores. The median Harris score was 69 (26-99). 12/13 stems migrated; 11 subsided 4.1 (0.4-7.9) mm, and 8 migrated posteriorly 2.9 (1.9-9.6) mm.

The poor clinical results and large migrations speak against the use of this prosthesis in revision hip arthroplasty.     

Cementless acetabular cup: 6-year follow-up

The aim of this study was to evaluate the long-term outcome of cementless acetabular cups used in primary total hip arthroplasty. From November 1993 to December 1998, we implanted 403 cementless acetabular cups. Here we present a review of 160 patients (97 women) who received cementless acetabular cups with a porous-coated surface. The average postoperative follow-up period was 6 years (range, 4–8 years). The mean age of patients was 68 years for cemented stems (65 hips) and 59 for uncemented stems (95 hips). A total of 104 patients received ceramic-polyethylene components and 56 had ceramic-ceramic components. One patient presented acetabular migration and needed revision after 5 months indicating a failure rate of 0.6%. We believe that our results provides quite good perspectives for future work with this acetabular component. Received: 3 May 2002, Accepted: 10 May 2002     

High revision rate after treatment of femoral neck fractures with an optionally (un)cemented stem

Background  The advantages of uncemented and cemented components in hip arthroplasty have been subject of debate. We have studied on a hemiprosthesis, which can be optionally implanted with or without cement. Since the stem geometry and surface in cemented arthroplasty differs from the uncemented one and cannot be fused into one general design, we hypothesised that this hemiprosthesis used without cement has a considerable high revision rate, based on aseptic loosening. Methods  A hemiprosthesis, which is designed for both cemented and uncemented fixation, was used (Conquest, Smith&Nephew). Preoperatively, the choice of whether to use cement or not was based on the shape and bone quality of the femoral canal. Revision rate and indication, mortality, perioperative complications and radiographic features of 151 consecutive hips in 146 patients were evaluated. Results  Twenty-three stems (15%) were implanted with cement and 128 (85%) without. After a mean follow-up of 2 years, a revision rate of 8.6% and a survival percentage of 90% (CI 85–95) were observed. Twelve uncemented stems warranted revision, compared with one cemented stem. Revision because of aseptic loosening was necessary in 7 (6%) stems, all uncemented. No differences in operation-related mortality and morbidity were observed. Conclusion  Because of the rather high revision rate, the authors advice not to use this hemiprosthesis without cement.     

Cemented Lubinus and Furlog total hip endoprosthesis: a 12-year follow-up study of 175 hips comparing the cementing technique

We analyzed 175 total hip replacements with cemented Lubinus and Furlong arthroplasties in 164 patients with a median age of 65 (32–80) years and followed them for 12 years to evaluate and compare the efficacy of total hip prosthesis designs. Survival analysis was combined with an analysis of radiological findings and a study of functional outcome of the patients. The 12-year survival of Furlong arthroplasty in patients of 60 years of age and older was 0.85 (95% CI 1.00–0.52). The survival of Lubinus arthroplasty in patients younger than 60 years of age was 0.70 (0.91–0.48), while the survival in older patients was 0.75 (0.89–0.61). The 12-year survival of well-cemented Lubinus prosthesis was 0.91 (1.00–0.79), indicating the importance of the cementing technique. The survival of the cups was marginally better than that of the stems. In the 12-year follow-up study, the clinical state and function varied from hips ready for revision to hips where a continuously long survival could be predicted. Harris hip score did not differentiate between patients who had intact and loose components. We conclude that cemented arthroplasty affords a notable alternative with satisfactory long-term survival and function. The better survival of cemented cup than the stem may be utilized as a basis for “reverse” hybrid arthroplasty. Adequate long-term follow-up of all arthroplasties as a quality maintenance and to prevent difficult revisions is a major challenge. Received: 31 May 1999     

Ten-year follow-up of a proximal circumferential porous-coated femoral prosthesis: radiographic evaluation and stability

We studied the radiographic findings on 48 hips in 48 patients to determine the stability of a proximal circumferential porous-coated femoral prosthesis in cementless total hip replacement. The patients had coxarthrosis related to acetabular dysplasia. The follow-up interval in the study was 10 to 13 years. In 36 patients, migration of the femoral component was equal to or less than 2 mm. No patient showed progressive migration. Revision surgery was performed in 37 patients because of migration of the acetabular components. Intraoperatively, no femoral components demonstrated visible motion under stress of the implant–bone interface, and none had been revised. During the follow-up period, two patients had mild thigh pain. Two others sustained fracture of the femur 11 years after surgery due to a fall. Pedestal formation was observed in 39 patients and calcar rounding in 21. The mean diameter of the medullary cavity around the distal part of the prosthesis increased from 13.6 to 16.3 mm average. We conclude that the proximal circumferential porous-coated femoral prosthesis is stable for more than ten years after surgery. The risk of subsequent periprosthetic fractures in elderly patients, however, is a matter of concern. Received: April 23, 2001 / Accepted: August 19, 2001     

Long-term results of the threaded Mecron cup in primary total hip arthroplasty

In the 1970s, high failure rates of cemented acetabular components, especially in young patients, in the middle- and long-term prompted a search for alternatives. The Mecring was one of the most popular first generation uncemented, threaded cups widely used in the 1980s for arthroplasty of the hip. First generation threaded cups commonly had smooth surface treatment and showed unacceptably high failure rates in the mid-term. In a consecutive series of 209 patients, 221 threaded uncemented acetabular cups with smooth surface treatment (Mecring) had been implanted in combination with one type of uncemented stem. Patients were followed up clinically and radiographically. The mean time of follow-up was 17 (range 15–20) years. In 91 (41%) hips the acetabular component had been revised or was awaiting revision: two hips for infection and 84 (38%) for aseptic loosening. Five hips were awaiting revision. The survival rate for all revisions including hips awaiting revision was 49% (95% CI: 41–57%) at 17 years. These results support the view that smooth, threaded acetabular components do not provide satisfactory long-term fixation and should be abandoned. Patients with these components must be closely monitored as the failure rate remains high in the long-term.     

Long-term radiographic results of the Saint Nabor non-cemented acetabular component

Between August 1985 and December 1987, a total of 303 total hip arthroplasties were performed in 275 patients using the Saint Nabor press-fit acetabular component. Radiographic evaluations were performed at an average of 18.1 years for 95 hips in 86 patients. Migration analyses of the femoral and acetabular components were also performed. Seventeen patients had early postoperative complications: aseptic loosening in 1 patient, luxation in 16 patients. Twenty-five patients (25 hips) had late postoperative complications involving aseptic loosening: 21 femoral components, 2 acetabular components, and 2 cases of both components. The average acetabular component migration in the horizontal direction was 1.71 mm and was 0.31 mm in the vertical direction. The Kaplan–Meier survival rate of the acetabular component at 19 years was 95%.     

Higher failure rate and stem migration of an uncemented femoral component in patients with femoral head osteonecrosis than in patients with osteoarthrosis

BACKGROUND: Several authors have found poorer outcome after hip replacement for osteonecrosis than after hip replacement for arthrosis. In a retrospective study we evaluated the performance of an uncemented femoral component in patients with osteonecrosis and arthrosis of the hip. PATIENTS AND METHODS: 31 patients operated for osteonecrosis, and 49 patients operated for osteoarthrosis were included. The median follow-up time was 6.1 (2-11) years for the patients with osteonecrosis, and 5.9 (4-8) for the arthrosis patients. RESULTS: Migration analysis performed by the Einzel-Bild-Roentgen Analysis (EBRA) technique revealed a median stem migration of 1.5 (-8.8-0) mm in the patients with osteonecrosis, but only 0.6 (-2.8-0.7) mm in the patients with arthrosis (p < 0.001). Survivorship analysis with stem revision as endpoint for failure was 74% (95% CI: 55-94) in the osteonecrosis, and 98% (95% CI: 94-100) in the arthrosis group (p = 0.01). INTERPRETATION: We suggest that the higher failure rate and stem migration of uncemented total hip replacement in the patients with osteonecrosis is a consequence of the disease. On the basis of these findings, we recommend close monitoring of the patients with osteonecrosis, which should include migration measurements.