The medium-term results of the cemented Exeter femoral component in patients under 40 years of age

Collarless Taper Slip and Collared Composite Beam Stems Differ in Failure Modes and Reoperation Rates

BACKGROUND

Cemented femoral components are used in older patients based on lower risk of periprosthetic fracture and implant loosening. This study reports the survivorship free of periprosthetic femoral fracture (PPFX), femoral loosening, all-cause revision, and reoperation between 2 philosophies of cemented stems.

METHODS

In total, 1,306 primary hybrid total hip arthroplasties were performed for osteoarthritis between 2000 and 2018 in a retrospective single center study. Cemented stems included 798 EON composite beam (CB) and 508 Exeter collarless taper slip (CTS) stems. Mean age was 77 years. An inverse treated probability weighted model was utilized to control for risk factors including age, gender, body mass index, year, and surgeon.

RESULTS

There was no difference in risk of PPFX at 10 years (CTS 9% vs CB 5%; hazard ratio [HR] 1.4, P = .47). There was an increased risk of intraoperative fractures requiring fixation in the CB cohort (7/798 [5 calcar, 2 greater trochanter] vs 0/508, P < .001), while there was an increased risk of Vancouver B₂ PPFX in the CTS cohort (7/508 vs 0/798; P < 001). There was a higher risk of femoral loosening in the CB cohort (6/798 vs 0/508; P < .0001). Higher survivorship free of revision (98% vs 91%; HR 4, P = .001) and free of reoperation (96% vs 88%; HR 2.5, P = .002) was seen at 10 years in the CB cohort.

CONCLUSION

The risk of PPFX requiring implant revision was increased in the CTS cohort, while there was an increased risk of femoral component loosening and intraoperative fractures seen in the CB cohort. Surgeons should be aware of the different failure modes when choosing implant design for their patient.

Excellent Long-Term Survival Rate of Polished, Tapered, Cemented Stems in Patients Aged 35 Years or Younger With Avascular Necrosis or Inflammatory Arthritis of the Hip

BACKGROUND

Total hip arthroplasty (THA) for avascular necrosis (AVN) or inflammatory arthritis (IA) comes with a relatively high risk of aseptic stem loosening, especially in young patients. There are limited long-term data on the survivorship of polished, tapered, cemented stems in this population. We therefore performed a single-center retrospective study investigating the survival of this particular stem type in young patients with AVN or IA.

METHODS

All patients aged ≤35 years who had received a THA for AVN or IA operated on by the senior author between 1990 and 2010 at the University Hospitals Leuven were identified. In total, 85 THAs in 62 patients were included. Primary endpoint was revision of the femoral component for aseptic loosening. Secondary endpoints were revision of the acetabular component for aseptic loosening, revision for other reasons, and the presence of radiolucencies around the components.

RESULTS

The mean follow-up for the entire cohort was 18.0 ± 5.3 years (range 8.0-28.9). Taking revision for aseptic loosening as endpoint, the survival of cemented stems was 100% after 15 years and 95.1% after 20 years. Survival of uncemented cups (91.3%) was significantly better than survival of cemented cups (50.3%) after 20 years of follow-up for aseptic loosening. Taking revision for any reason as endpoint, the survival of THAs with uncemented and cemented cups was 90% and 43.1% at 20 years respectively. Radiolucencies developed in the cement mantles around 11 of the 81 nonrevised stems, mainly in zones 1 and 7.

CONCLUSION

In this cohort of young patients with high-risk profiles for aseptic stem loosening, polished, tapered, cemented stems showed excellent long-term survival rates and they therefore remain a viable alternative to uncemented stem designs.

Midterm Results of Primary Exeter Cemented Stem in a Select Patient Population

BACKGROUND

Most North American surgeons predominantly use uncemented stems in primary total hip arthroplasties (THAs) and reserve cemented stems for selected older patients and those with poor bone quality. However, data on this "selective use" strategy for cemented stems in the population at risk for periprosthetic fracture and implant loosening are limited. The purpose of this study was to describe implant survivorship, complications, and radiographic results of a specific collarless, polished, tapered cemented stem (Exeter; Stryker) used selectively in a predominantly elderly population undergoing primary THA.

METHODS

We identified 386 patients who underwent a total of 423 primary THAs with selectively utilized Exeter stems for the treatment of osteoarthritis between 2006 and 2017. In the same time period, 11,010 primary THAs were performed with uncemented stems and 961 with non-Exeter cemented stems. The mean patient age was 77 years, 71% were female, and the mean body mass index was 29 kg/m2. Competing risk analysis accounting for death was utilized to determine cumulative incidences of revision and reoperation. The mean follow-up was 5 years (range, 2 to 12 years).

RESULTS

The 10-year cumulative incidence of any femoral component revision in this patient cohort was 4%, with 10 stems revised at the time of the latest follow-up. There were no intraoperative femoral fractures. The indications for revision were postoperative periprosthetic femoral fracture (n = 6), dislocation (n = 3), and infection (n = 1). There were no revisions for femoral loosening. The 10-year cumulative incidence of reoperation was 10%. The 10-year cumulative incidence of Vancouver B periprosthetic femoral fracture was 2%. Radiographically, there were no cases of aseptic loosening or osteolysis. There was a significant improvement in median Harris hip score, from 53 preoperatively to 92 at a mean follow-up of 5 years (p < 0.001).

CONCLUSIONS

The strategy of selectively utilizing a collarless, polished, tapered cemented stem produced a low (4%) cumulative incidence of stem revision at 10 years postoperatively and resulted in no cases of aseptic loosening. The use of the Exeter stem did not eliminate postoperative femoral fractures in this predominantly elderly, female patient population.

LEVEL OF EVIDENCE

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

Temporal subsidence patterns of cemented polished taper-slip stems: a systematic review

The literature was reviewed to establish the levels of stem subsidence for both double and triple-tapered implants in order to determine whether there were any differences in subsidence levels with regard to the methods of measurement, the magnitude and rate of subsidence and clinical outcomes.

All studies reporting subsidence of polished taper-slip stems were identified. Patient demographics, implant design, radiological findings, details of surgical technique, methods of measurement and levels of subsidence were collected to investigate which factors were related to increased subsidence.

Following application of inclusion and exclusion criteria, 28 papers of relevance were identified. The studies initially recruited 3090 hips with 2099 being available for radiological analysis at final follow-up. Patient age averaged 68 years (42–70), 60.4% were female and the average body mass index (BMI) was 27.4 kg/m² (24.1–29.2).

Mean subsidence at one, two, five and 10 years was 0.97 mm, 1.07 mm, 1.47 mm and 1.61 mm respectively. Although double-tapered stems subsided more than triple-tapered stems at all time points this was not statistically significant (p > 0.05), nor was the method of measurement used (p > 0.05).

We report the levels of subsidence at which clinical outcomes and survivorship remain excellent, but based on the literature it was not possible to determine a threshold of subsidence beyond which failure was more likely.

There were relatively few studies of triple-tapered stems, but given that there were no statistically significant differences, the levels presented in this review can be applied to both double and triple-tapered designs.

Cite this article: EFORT Open Rev 2021;6:331-342. DOI: 10.1302/2058-5241.6.200086

The Use of Cement in Hip Arthroplasty: A Contemporary Perspective

Notable advances in hip arthroplasty implants and techniques over the past 60 years have yielded excellent survivorship of fully cemented, hybrid, and reverse hybrid total hip replacements as demonstrated in joint registries worldwide. Major advances in noncemented implants have reduced the use of cement, particularly in North America. Noncemented implants predominate today based on procedural efficiency, concern related to thromboembolic risk, and a historic belief that cement was the primary cause of osteolysis and implant loosening. With the decline of cemented techniques, press-fit fixation has become common even in osteoporotic elderly patients. Unfortunately, there is a troubling rise in intraoperative, as well as early and late postoperative periprosthetic fractures associated with the use of noncemented implants. Despite the success of noncemented fixation, an understanding of modern cement techniques and cemented implant designs is useful to mitigate the risk of periprosthetic fractures. Cemented acetabular components can be considered in elderly patients with osteoporotic or pathologic bone. Cemented stems should be considered with abnormal proximal femoral morphology, conversion of failed hip fixation, inflammatory arthritis, patient age over 75 (especially women), osteoporotic bone (Dorr C), and in the treatment of femoral neck fractures.

Five-year prospective subsidence analysis of 100 cemented polished straight stems: A concise clinical and radiological follow-up observation

Early subsidence (>1.5mm) has been shown to be an indicator for later aseptic loosening of cemented hip stems. For the cemented twinSys^® stem we published excellent short-term results at 2 years. Midterm data for this stem are available from national registers (NZL, NL), however in all of these sources, clinical and radiological results are missing. Aim of our study was to analyse mid-term survival and radiological changes around the cemented twinSys^® stem with special emphasis on subsidence using EBRA-FCA. We conducted a prospective clinical and radiological 5- year follow-up study of 100 consecutive hybrid total hip arthroplasties (THA) using a polished, cemented collarless straight stem (twinSys^®, Mathys AG^® Bettlach, Switzerland) with a cementless monobloc pressfit cup (RM pressfit^®, Mathys AG^® Bettlach, Switzerland). Median age at surgery was 79 (69 to 93) years. No patient was lost to follow-up. Survival rates were calculated using the Kaplan-Meier method. Clinical (Harris Hip Score [HHS]) and radiological (cementing quality, alignment, osteolysis, debonding and cortical atrophy) outcomes and an in-depth subsidence analysis using EBRA-FCA were performed. 22 patients died in the course of follow-up unrelated to surgery, 21 stems had an incomplete radiological follow-up. 2 stems were revised, both due to an infection. The survival rate for the stem at 5 years was 98.0% (95% CI 95.3-100%). The survival rate of the stem for revision due to aseptic loosening at 5 years was 100%. The HHS improved from 53 (14-86) points preoperatively to 90 (49-100) points 5 years after surgery. Osteolysis was found in 2 stems without clinical symptoms. In 49 out of 55 patients with a complete radiological follow- up, the EBRA-FCA analysis was possible and showed an average subsidence of 0.66 (95% CI 0.46 to 0.86) mm 5 years after surgery. 10 patients showed a subsidence >1 mm, 5 of which bigger than 1.5 mm. Subsidence was independent from radiological changes and cementing quality. The cemented twinSys^® stem showed excellent clinical and radiological mid-term results at five years' follow-up and seems to be a reliable implant.

Advantages in Using Cemented Polished Tapered Stems When Performing Total Hip Arthroplasty in Very Young Patients

BACKGROUND

The risk of revision following primary total hip arthroplasty (THA) is increased in young patients who undergo THA for pathologies other than primary osteoarthritis. We report the results of primary THA performed with cemented polished stems in patients aged 40 years and younger for pathologies other than primary osteoarthritis.

METHODS

We investigated 52 patients (65 hips) who underwent primary THA for secondary osteoarthritis with a cemented tapered polished stem between 1990 and 2007. Clinical and radiographic outcomes, available in 46 patients (57 hips), included the Harris Hip Scores, Societe Internationale de Chirurgie Orthopedique et de Traumatologie activity, patient satisfaction, stem survival and reoperations, and assessment of prosthesis-cement-bone radiolucencies, osteolysis, and femoral bone deficiencies.

RESULTS

Median patient age was 34 years (16-40) and follow-up was 14 years (mean 13, range 5-22). Stem survival to the endpoint revision for loosening was 100% and to the endpoint revision for any reason, excluding infection was 88% (95% confidence interval 78-98) at 16 years. No stem was revised for aseptic loosening. Nine stems were revised for other reasons. Radiographically, one stem was definitely loose at 16 years. The median patient Harris pain score improved from marked pain to no pain at latest follow-up. Patient activity level improved, albeit minimally, for 8 years after surgery. At latest follow-up, 98% of the patients remained satisfied with their surgery.

CONCLUSION

Primary THA with a cemented polished stem shows excellent results in young patients with pathology other than primary osteoarthritis. In addition, the stem design facilitates cement within cement exchange and therefore preservation of proximal femoral bone stock at revision surgery.

Results of the cemented Exeter femoral component in patients under the age of 40 : an update at ten to 20 years' follow-up

AIMS

We carried out a further study of the long-term results of the cemented Exeter femoral component in patients under the age of 40 with a mean follow-up of 13.6 years (10 to 20).

PATIENTS AND METHODS

We reviewed our original cohort of 104 cemented Exeter stems in 78 consecutive patients with a mean age of 31 years (16 to 39). Only one patient was lost to radiological follow-up.

RESULTS

A total of six patients (eight hips) had died for reasons unrelated to their surgery. There had been one further periprosthetic fracture from a fall and one fractured femoral stem. No revisions for aseptic loosening were undertaken during the whole study period. Overall, 11 hips had progressive radiolucent lines in one or more zones. The Kaplan Meier survival percentages at ten and 17 years were 97.1% (95% confidence interval (CI) 91.3 to 99.1) and 92.1% (95% CI 74.1 to 97.8) with revision for any reason as the endpoint, and 100% at both ten and 17 years with aseptic loosening (95% CI 83.8 to 100) as the endpoint. No additional hips were classified as radiologically loose.

CONCLUSION

The Exeter femoral component continues to function satisfactorily in young patients for up to 17 years after surgery. Cite this article: Bone Joint J 2017;99-B:192-8.

Prospective two-year subsidence analysis of 100 cemented polished straight stems - a short-term clinical and radiological observation

Background

Cemented stems show good long-term results and the survival of new implants can be predicted by their early subsidence. With EBRA-FCA (Femoral Component Analysis using Einzel-Bild-Röntgen-Analyse) early subsidence as an early indicator for later aseptic loosening can be analysed. For the cemented TwinSys stem mid- and long-term data is only avalible from the New Zeeland Arthroplasty register, thus close monitoring of this implant system is still mandatory.

Methods

We conducted a 2 year follow up of 100 consecutive hybrid THA (Total hip arthroplasty) of a series of 285 primary THA operated between Jan 2009 und Oct 2010. These 100 received a polished, cemented collarless straight stem (twinSys®, Mathys AG® Bettlach, Switzerland) with an uncemented monobloc pressfit cup (RM pressfit®, Mathys AG® Bettlach, Switzerland). The other patients were treated with the uncemented version of this stem and the same cup. Clinical (Harris Hip Score) and radiological (ap and axial x-rays, cementing quality according to Barrack, alignment) outcomes besides an EBRA-FCA subsidence analysis were performed.

Results

Median age at operation was 78 (68 to 93) years. 5 patients died in the course of follow-up unrelated to surgery. The KM (Kaplan-Meier) survival at 2 years for the endpoint reoperation for any reason was 94.9 (95 % confidence interval 90.6–100 %). Survival for the endpoint aseptic loosening at 2 years was 100 %.

The HHS (Harris Hip Score) improved from 56 (14–86) preoperatively to 95 (60–100) 2 years after the operation. Cementing results were judged 47 % Grade A, 45 % Grade B and 7 % Grade C.

Osteolysis was found in 2 stems without clinical symptoms or correlation to subsidence or cementing quality. The EBRA-FCA analysis showed an average subsidence of -0.30 mm (95 % CI -0.5 mm to -0.1 mm). 11 patients showed a subsidence of more than 1 mm. In this group one patient showed a subsidence of 1.5 mm and one of 3.1 mm without further radiological changes.

Conclusions

The twinSys stem showed excellent clinical and radiologic short term results at 2 years follow-up and seems to be a reliable implant.

Early subsidence of shape-closed hip arthroplasty stems is associated with late revision. A systematic review and meta-analysis of 24 RSA studies and 56 survival studies

BACKGROUND AND PURPOSE

Few studies have addressed the association between early migration of femoral stems and late aseptic revision in total hip arthroplasty. We performed a meta-regression analysis on 2 parallel systematic reviews and meta-analyses to determine the association between early migration and late aseptic revision of femoral stems.

PATIENTS AND METHODS

Of the 2 reviews, one covered early migration data obtained from radiostereometric analysis (RSA) studies and the other covered long-term aseptic revision rates obtained from survival studies with endpoint revision for aseptic loosening. Stems were stratified according to the design concept: cemented shape-closed, cemented force-closed, and uncemented. A weighted regression model was used to assess the association between early migration and late aseptic revision, and to correct for confounders. Thresholds for acceptable and unacceptable migration were determined in accordance with the national joint registries (≤ 5% revision at 10 years) and the NICE criteria (≤ 10% revision at 10 years).

RESULTS

24 studies (731 stems) were included in the RSA review and 56 studies (20,599 stems) were included in the survival analysis review. Combining both reviews for the 3 design concepts showed that for every 0.1-mm increase in 2-year subsidence, as measured with RSA, there was a 4% increase in revision rate for the shape-closed stem designs. This association remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. The threshold for acceptable migration of shape-closed designs was defined at 0.15 mm; stems subsiding less than 0.15 mm in 2 years had revision rates of less than 5% at 10 years, while stems exceeding 0.15 mm subsidence had revision rates of more than 5%.

INTERPRETATION

There was a clinically relevant association between early subsidence of shape-closed femoral stems and late revision for aseptic loosening. This association can be used to assess the safety of shape-closed stem designs. The published research is not sufficient to allow us to make any conclusions regarding such an association for the force-closed and uncemented stems.

Femoral bone is preserved using cemented polished stems in young patients

BACKGROUND

Techniques that ensure femoral bone preservation after primary THA are important in younger patients who are likely to undergo revision surgery.

QUESTIONS/PURPOSES

We examined femoral stem survival, bone deficiency at revision arthroplasty, and radiographic bone loss in hips implanted with a cemented polished double-taper stem in a cohort of patients younger than 55 years.

METHODS

We reviewed 197 hips (median patient age, 47 years; range, 16-54 years) after a minimum followup of 2 years (median, 7 years; range, 2-19 years) since primary THA. Clinically, we determined survival to major and minor stem revision and cases of bone deficiency requiring a long stem or impaction bone grafting or created by the need for femoral osteotomy at revision arthroplasty. Radiographically, we assessed stem loosening, femoral osteolysis, and femoral bone deficiency.

RESULTS

Stem survival to major revision for aseptic loosening was 100% at 13 years and for any reason was 97% (95% CI, 93-100%). At revision of seven stems, a long stem was used in one hip, a total femoral replacement in one hip and impaction bone grafting in one hip. No femoral osteotomies were required. Bone was preserved in four hips by cement-within-cement stem exchange. No stems were radiographically loose. Proximal osteolysis was present in 11% of femurs. Femoral bone deficiency was graded as Paprosky Type I (97%) or II (3%) and Endo-Klinik Grade 0 (79%) or I (21%).

CONCLUSIONS

Cemented polished taper stems have high survival at 13 years in young patients and enable femoral bone preservation for subsequent revision.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The Exeter Universal cemented femoral component at 15 to 17 years

The first 325 Exeter Universal stems (309 patients) implanted at the originating centre were inserted between March 1988 and February 1990 by a group of surgeons with differing experience. In this report we describe the clinical and radiological results at a mean of 15.7 years (14.7 to 17.3) after operation with no loss to follow-up. There were 97 patients (108 hips) with replacements still in situ and 31 (31 hips) who had undergone a further procedure. With an endpoint of revision for aseptic loosening, the survivorship at 17 years was 100% and 90.4% for the femoral and acetabular component, respectively. The mean Merle D’Aubigné and Postel scores at review were 5.4 (sd 0.97) for pain and 4.5 (sd 1.72) for function. The mean Oxford score was 38.4 (sd 9.8) (0 to 48 worst-to-best scale) and the mean combined Harris pain and function score was 73.2 (sd 16.9). Radiological review showed excellent preservation of bone stock in the proximal femur and no failures of the femoral component.

Impaction grafting in association with the Charnley-Kerboull cemented femoral component

We describe 129 consecutive revision total hip replacements using a Charnley-Kerboull femoral component of standard length with impaction allografting. The mean follow-up was 8.2 years (2 to 16). Additionally, extramedullary reinforcement was performed using struts of cortical allograft in 49 hips and cerclage wires in 30.

There was one intra-operative fracture of the femur but none later. Two femoral components subsided by 5 mm and 8 mm respectively, and were considered to be radiological failures. No further revision of a femoral component was required. The rate of survival of the femoral component at nine years, using radiological failure as the endpoint, was 98%. Our study showed that impaction grafting in association with a Charnley-Kerboull femoral component has a low rate of subsidence. Reconstruction of deficiencies of distal bone with struts of cortical allograft appeared to be an efficient way of preventing postoperative femoral fracture for up to 16 years.