Anatomic Cementless Stem Research Articles

Short-and medium-term results after THA with a cementless anatomic stem SP-CL (W. LINK, GERMANY)

Since the 80s-90s of the XX century, in connection with the development of technologies, the progress of tribology, innovations in the design of prostheses and the accumulation of more clinical experience, TH arthroplasty has been "rejuvenated" and began to be more widely and successfully applied in middle-aged and young patients. The main indications at the beginning - dysplasia of the hip joint, A.V.N. and juvenile rheumatoid arthritis - subsequently expanded to the whole spectrum of hip pathology in younger people. Straight cementless stems show excellent long-term results, but periprosthetic fractures and gluteal insufficiency are still a problem. In contrast, the flattened proximal-lateral profile of the anatomic cementless SP-CL® stem can protect the greater trochanter and can avoid gluteal insufficiency after THA. Another advantage of this stem design is the rotational stability and natural weight distribution due to the anatomical concept. In this context, we report here our experience with the use of the SP-CL® anatomical cementless stem.

Long-Term Results (Minimum of 20 Years) of a Pure Proximal-Loading Metaphyseal-Fitting Anatomic Cementless Stem Without Distal Stem Fixation in Hip Arthroplasty

BackgroundThere are no reported results for more than 20 years of a pure proximal-loading anatomic cementless femoral stem without diaphyseal stem fixation. The purpose of this study was to evaluate the long-term (minimum 20 years) clinical results, bone remodeling, revision rate, and survivorship of these implants in patients aged less than 60 years. MethodsWe included 523 patients (657 hips), including 319 men and 204 women. The mean body mass index was 26.7 (range, 23-29 kg/m2). The mean age of patients at index surgery was 55 years (range, 20-59 years). The Harris Hip Score, the Western Ontario and McMaster Universities Osteoarthritis Index, and the University of California, Los Angeles activity score were recorded preoperatively and at each follow-up. Mean follow-up was 23.5 years (range, 20-27 years). ResultsThe Harris Hip Score at the final follow-up was a mean 93 points (range, 70-100 points). The Western Ontario and McMaster Universities Osteoarthritis Index and University of California, Los Angeles activity scores at the final follow-up were 16 and 7.6 points, respectively. Five femoral components (0.8%) and 13 acetabular components (2.0%) were revised. All cases in the current series had grade 2 stress shielding; no hips had grade 3 or 4 stress shielding. Kaplan-Meier survivorship of the implants at 23.5 years was 98.0% (95% confidence interval 92%-100%) for the acetabular component and 99.2% (95% confidence interval 93%-100%) for the femoral component. ConclusionA pure proximal-loading metaphyseal-fitting anatomic cementless stem with alumina-on-alumina ceramic bearing couples functioned well, with no osteolysis or mild stress-shielding at an average 23.5-year follow-up.

Ultra-short cementless anatomical stem for intracapsular femoral neck fractures in patients younger than 60 years.

The aim of this study was to present the midterm results of total hip arthroplasty with ultra-short anatomical cementless stem in the primary treatment of displaced intracapsular femoral neck fractures in patients younger 60 years. From 2006 to 2015, 17 hip arthroplasties (with the Proxima stem) were performed in group of 17 patients for the treatment of acute femoral neck fractures Garden type III and IV. The mean follow-up period was 112.7 (range: 64-148) months. Patients were evaluated retrospectively - clinically and radiographically, using the Harris hip scoring system during the year 2020. Seven males and ten females (mean age: 45.0 years) were included in the study. Each of them had one or more risk factors (time delay, comminution of the femoral neck, corticosteroids usage, the presence of coxarthrosis, rheumatoid arthritis, alcohol abuse, etc…), because of which the osteosynthesis was not performed. Harris hip scores were 6.3 preoperatively and 82.9 at the final follow-up. Three patients (17.6%) had complications: luxation, aseptic stem loosening (migration with subsidence - "varisation" and thigh pain) and deep infection. One patient (5.9%) with infection was revised. In carefully selected younger patients with displaced intracapsular femoral neck fracture, where the osteosynthesis as first treatment option should be associated with high risk of complication (avascular femoral head necrosis, non-union) due to the presence of risk factors, the primary total hip arthroplasty could be performed. The ultra-short cementless stem offers promising results in these rare cases in the midterm.

Total hip arthroplasty with ultra-short uncemented stem in patients with osteonecrosis of the femoral head: mid-term results.

Mid-term results (clinical and radiographic) of ultra-short anatomical cementless stem total hip arthroplasty (THA) in patients with osteonecrosis of the femoral head (ONFH) has not often been presented. The aim of this study is to evaluate THA using the Proxima stem in patients with ONFH in the mid-term. The study consists of 73 patients (97 THAs) with a Proxima stem implanted between 2006 and 2015. The mean age of patients was 47.4 years, with a mean follow-up 105.2 months. The clinical results include preoperative and postoperative Harris Hip Scores (HHSs). Radiological follow-up reports on stem migration, bony trabecular development and radiolucent lines. The complications and revisions were registered. Kaplan-Meier survival analysis was performed to determine the implant survival. The average HHS improved significantly from 40.3 preoperatively to 98.0 at the final evaluation (p ˂ 0.0001). Stem migration (subsidence and "varisation") was observed in 11 hips (in 9 of them up to 6th postoperative month without any further progression, in 2 with progressive migration and radiological loosening). Bony trabecular development was detected in modified Gruen zones (1,2,4,6,7 for Proxima stem): in zone 1 (0%), 2 (67.0%), 4 (64.9%), 6 (64.9%), 7 (0%). Radiolucent lines were observed in 1 cup and 6 stems (2 were loose, 4 with fibrous stable fixation). Complications were found in 5 hips (5.1%): squeezing hip once, repeated dislocation in 1, 1 early deep infection, and 2 loose stems. 2 hips (2.1%) were revised (dislocation, infection). The implant survival was 98.9% and 97.9% clinically and radiologically, respectively. Observations in the mid-term show that the clinical and radiological results of the Proxima stem in patients with ONFH are promising. The stem design preserves the proximal femoral bone stock. The bony trabecular appearance confirms physiological proximal femoral load transmission.

A Prospective, Randomized Comparison of the Long-Term Clinical and Radiographic Results of an Ultra-Short vs a Conventional Length Cementless Anatomic Femoral Stem

BackgroundThe purpose of this study is to compare the long-term clinical and radiographic results, survival rates, and complication rates of an ultra-short vs a conventional length cementless anatomic femoral stem. MethodsWe reviewed 759 patients (858 hips) (mean age, 56.3 ± 12.9 y) who had an ultra-short cementless anatomic stem and 759 patients (858 hips) (mean age, 54.8 ± 12.3 y) who had a conventional length cementless anatomic stem. The mean follow-up was 16.5 years (range 14-17) in the ultra-short stem group and 17.5 years (range 17-20) in the conventional stem group. ResultsAt the latest follow-up, there were no significant differences between the 2 groups in terms of the Harris Hip Scores (92 ± 6 vs 91 ± 7 points, P = .173), Western Ontario and McMaster Universities Osteoarthritis scores (12 ± 8 vs 13 ± 7 points, P = .972), University of California Los Angeles activity scores (7.6 vs 7.8 points, P = .841), patient satisfaction scores (7.7 ± 2.3 vs 7.5 ± 2.5 points, P = .981), and survival rates (97.6% vs 96.6%). However, incidence of thigh pain (P = .031) and stress shielding (P = .001) was significantly higher in the conventional length stem group than in the ultra-short anatomic stem group. Complication rates were similar (1.8% vs 2.7%) between the 2 groups. ConclusionAlthough an ultra-short cementless anatomic femoral stem confers equivalent clinical and radiographic outcomes, survival rates, and complication rates to conventional length cementless anatomic stem, the incidence of thigh pain and stress shielding was significantly lower in the ultra-short cementless anatomic stem. Level of EvidenceTherapeutic Level I.

Long-Term Survival (up to 34 Years) of Retained Cementless Anatomic Femoral Stem in Patients

BackgroundThere is a paucity of studies longer than 30 years to determine clinical and radiographic results of retained cementless anatomic stem. The purpose of this study is to determine the long-term (up to 34 years) survival rate of the retained cementless anatomic femoral stem in patients <50 years of age. MethodsIsolated cup revision was performed with retaining primary cementless anatomic femoral stem in 206 patients (149 men and 57 women). Clinical and radiographic results were monitored at each follow-up. At the latest follow-up, computed tomography scans were carried out in all hips to determine the prevalence of osteolysis. The mean follow-up of the retained femoral stem was 30.3 years (range 27-34). The mean follow-up of the revised cup was 25.5 years (range 22-29). ResultsThe mean Harris Hip Score was 91 ± 7.8 points (range 71-100) and the mean Western Ontario and McMaster Universities Osteoarthritis score was 16 ± 7 points (range 7-34) at the final follow-up. The mean University of California, Los Angeles activity score was 7 ± 4 points (range 5-10) at the final follow-up. The overall survival rate of retained cementless femoral stems was 98.9% (95% confidence interval 91-100) at 30.3 years. The survival rate of the revised cup was 93% (95% confidence interval 89-98) at 25.5 years. ConclusionThe rate of aseptic loosening of already osseointegrated femoral stem remains low with ceramic-on-ceramic bearing in young active patients.

Ultra-Short Anatomic Uncemented Femoral Stem and Ceramic-on-Ceramic Bearing in Patients With Idiopathic or Ethanol-Induced Femoral Head Osteonecrosis

BackgroundLong-term result of the ultra-short anatomic cementless stem in the patients with idiopathic or ethanol-induced osteonecrosis of the femoral head has not been assessed. The aim of this study is to evaluate the long-term clinical, radiographic, computed tomography scan, and dual-energy X-ray absorptiometry scanning results, and survivorship of this specific femoral stem in patients with idiopathic or ethanol-induced femoral head osteonecrosis. MethodsTwo hundred fifty-six patients (335 hips) with an average age of 49.8 years (range 20-63) were enrolled in the current study. All patients underwent dual-energy X-ray absorptiometry scanning of the acetabulum and proximal femur preoperatively and at final follow-up. Computed tomography scan was obtained in all patients at final follow-up. The mean follow-up was 14.7 years (range 13-16). ResultsAt final follow-up, the average Harris hip score, Western Ontario and McMaster Universities Osteoarthritis Index score, and University of California, Los Angeles activity score were 94 points, 12 points, and 8 points, respectively. Four stems (1%) underwent revision for aseptic loosening. One acetabular component (0.3%) was revised for recurrent dislocation. No hip was revised for squeaking or clicking sound. Survivorship of the femoral stem was 99.0% (95% confidence interval 94-100) and that of the acetabular component was 99.4% (95% confidence interval 95-100) at 14.7 years. ConclusionUltra-short proximal loading anatomic uncemented femoral stems with ceramic-on-ceramic bearings have excellent survivorship free from aseptic loosening and good clinical results at long term. Level of EvidenceLevel IV

Short to Midterm Follow-Up of Periprosthetic Bone Mineral Density after Total Hip Arthroplasty with the Ribbed Anatomic Stem.

Background Femoral bone remodeling around hip prosthesis after total hip arthroplasty (THA) is definite but unpredictable in time and place. This study aimed to investigate the implant-specific remodeling and periprosthetic bone mineral density (BMD) changes after implantation of the Ribbed anatomic cementless femoral stem. Methods After power analysis, 41 patients who had undergone primary unilateral THA with the Ribbed anatomic cementless stem were included. BMD of the seven Gruen zones was measured by dual-energy X-ray absorptiometry, and the contact, fitness, and fixation of the femoral stem and proximal femur were analyzed by X-ray. Additional clinical outcome parameters were also recorded. Results Compared with the contralateral unoperated side, significant reductions of BMD were detected in the distal zone (Gruen zone 4: 1.665±0.198 versus 1.568±0.242 g/cm2, P=0.001) and middle distal zone (Gruen zone 5: 1.660±0.209 versus 1.608±0.215 g/cm2, P=0.026) on the prosthetic side, but no significant differences in BMD were detected in other zones (Gruen zones 1, 2, 3, 6, and 7). Subgroups analyses indicated no significant correlation between periprosthetic BMD changes and clinical factors including primary disease and body mass index. Visible areas of bone ingrowth indicated solid fixation of the femoral stem and there was no case of loosening. Clinical and functional outcome scores were excellent with mean HHS of 93.13 points and mean WOMAC score of 5.20 points, and three patients described intermittent mild thigh pain at the final follow-up. Conclusions For the Ribbed femoral stem, the periprosthetic BMD was well maintained in the proximal femur, while periprosthetic BMD was significantly reduced in the distal and middle distal zones of the femur. Further clinical investigations are required to examine the efficacy of the Ribbed stem, particularly with regard to long-term survival. This trial is registered with ChiCTR1800017750.

Evolution of the cementless anatomic stem: Risks & rewards

Cementless total hip arthroplasty (THA) is the favored method worldwide, especially in younger patients. Since the first cementless THA in late 1970s, many implant designs and modifications have been made. Despite excellent long-term results for traditional straight cementless stems, periprosthetic fractures or gluteal insufficency are still a concern. In contrast, the flattened lateral profile of the SP-CL® anatomical cementless stem can protect the greater trochanter during the use of cancellous bone compressors and can avoid gluteal insufficiency after THA. Another benefit of this stem design is the rotational stability and the natural load transfer due to the anatomical concept. In this context, we here report our experiences using the SP-CL® anatomical cementless stem.

Clinical Performance of Ultra-Short Anatomic Cementless Versus Fourth-Generation Cemented Femoral Stems for Hip Replacement in Octogenarians

The aim of this study was to determine how ultra-short anatomic cementless vs cemented femoral stems affect the survival of primary total hip arthroplasties in octogenarians. Specifically, the authors investigated whether ultra-short anatomic cementless and cemented femoral components would have similar (1) functional results, (2) radiographic results, (3) revision and survival rates, and (4) complication rates in octogenarians. The authors evaluated 93 consecutive octogenarians (98 hips) in the ultra-short stem group (mean age, 86.5±5.3 years) and 78 consecutive octogenarians (92 hips) in the cemented stem group (mean age, 85.7±5.8 years). The average follow-up was 8.1 years (range, 5-12 years) in the ultra-short anatomic cementless stem group and 7.8 years (range, 5-11 years) in the cemented stem group. Mean preoperative (39 vs 37 points) and postoperative (81 vs 83 points) Harris hip scores were similar in the 2 groups (P=.131 and .128, respectively). The incidence of thigh pain was 0% in both groups. At final follow-up, mean Western Ontario and McMaster Universities Osteoarthritis Index scores (18 vs 14 points) and University of California, Los Angeles activity scores (4.3 vs 4.5 points) were similar in the 2 groups. The revision rate was 3% (3 hips) in the ultra-short stem group and 3% (3 hips) in the cemented stem group. Survivorship of the femoral stem was 97.3% at 8.1 years in the ultra-short stem group and 97.9% at 7.8 years in the cemented stem group (P=.136). Ultra-short anatomic cementless and cemented stems obtained rigid fixation in octogenarians. However, the incidence of undisplaced periprosthetic calcar fracture intraoperatively was significantly higher (P=.003) in the cemented stem group. [Orthopedics. 2018; 41(4):e470-e478.].

Periprosthetic fracture in the elderly with anatomic modular cementless hemiarthroplasty

BackgroundThe use of an anatomic cementless stem in hemiarthroplasties for femoral intracapsular proximal fracture has been debated, notably because of bone weakness and/or morphological defects related to osteoporosis. We therefore conducted a retrospective study in subjects over 75 years of age who had received an anatomic stem partially coated with hydroxyapatite. The objectives were to determine: 1) the incidence of periprosthetic fractures (PPFs) and, 2) the influence of anatomic factors, including the Cortical Bone Ratio (CBR) (the relation between the endosteal and external diameter of the femoral diaphysis 10cm below the lesser trochanter). HypothesisThe risk of PPF with an anatomic cementless implant is greater than with cemented stems. Material and methodsWe retrospectively analyzed 233 patients followed up for 5 years after their surgery. The stem used was an anatomic stem with a modular neck partially coated with hydroxyapatite. The risk factors examined were age, gender, history of osteoporotic fractures, diverse causes of secondary osteoporosis, and proximal bone stock according to various referenced radiological indices such as the CBR. ResultsTwenty patients (15%) were lost to follow-up, 74 had died (32%) but did not undergo revision for PPF, 15 of the 139 survivors at the last follow-up (10.8%) had had a PPF, five (3.6%; four females, one male) were early fractures (≤2 months after implantation), ten (7.2%; two females, eight males) were late fractures (>2 months). Male gender was protective for PPF occurrence (RR=0.129; 95%CI (0.04–0.39); P=0.0003), whereas secondary factors of osteoporosis (RR=2.035; 95%CI (1.11–3.72); P=0.0211), and CBR>0.49 (RR=227.42; 95%CI (1.072–48,226.76); P=0.0471) were found as risk factors of PPF. DiscussionThe PPF rate was greater than that related to cemented stems, requiring that morphological and clinical factors of bone weakness (collected with the patient history and related to osteoporosis) be taken into account. A CBR>0.49 requires caution on the use of this type of stem. Level of evidenceLevel 4. Retrospective study.

Metaphyseal Engaging Short and Ultra-Short Anatomic Cementless Stems in Young and Active Patients

We report 400 patients (mean age, 53years) who received a short stem (17.8years of follow-up) and 201 patients (mean age 53years) who received an ultra-short stem (12.3years of follow-up). At the final follow-up, the mean Harris hip score, WOMAC score and the mean UCLA activity scores were not different between two groups. No patient had thigh pain in either group. Two hips (0.3%) in the short stem group were revised because of early postoperative infection and one hip (0.2%) in the ultra-short stem group was revised for fracture of the proximal femur. Metaphyseal engaging short and ultra-short anatomic cementless stem without diaphyseal fixation provided long-term durable fixation in young and active patients.

Trade-off between stress shielding and initial stability on an anatomical cementless stem shortening: in-vitro biomechanical study

Shortened cementless femoral stems have become popular with the advent of minimally invasive total hip arthroplasty (THA). Successful THA requires initial stem stability and prevention of stress shielding-mediated bone loss, although the effect of stem shortening is controversial. Here we experimentally examined whether stem shortening affects stress shielding and initial stability. Anatomical stems (length, 120 mm) were cut to an 80 mm or 50 mm length. Ten tri-axial strain gauges measured the cortical strain on each stem-implanted femur to evaluate stress shielding. Two transducers measured axial relative displacement and rotation under single-leg stance loading. The 50 mm stem increased the equivalent strains with respect to the original stem in the proximal calcar region (31.0% relative to intact strain), proximal medial region (63.1%), and proximal lateral region (53.9%). In contrast, axial displacement and rotation increased with a decreasing stem length. However, the axial displacement of the 50 mm stem was below a critical value of 150 µm for bone ingrowth. Our findings indicate that, with regard to a reduction in stem length, there is a tradeoff between stress shielding and initial stability. Shortening the stem up to 50 mm can promote proximal load transfer, but bone loss would be inevitable, even with sufficient initial stability for long-term fixation.

Outcome of an ultrashort metaphyseal-fitting anatomic cementless stem in highly active obese and non-obese patients.

The purpose of this study was to investigate the clinical and radiographic results and complication rates after cementless total hip arthroplasty using an ultrashort femoral stem in highly active [University of California, Los Angeles (UCLA) activity level above 8 points] obese and non-obese patients. A total of 108 patients (138 hips) in the obese group [body mass index (BMI) of 30 kg/m(2) or greater] and 125 patients (168 hips) in the nonobese group (BMI of 29 kg/m(2) or less) were enrolled in the study. The mean age was 50.7 ± 11.6 years in the obese group and 48.2 ± 13.0 years in the nonobese group. The mean follow-up was 7.4 years (range six to eight years) and 7.5 years (range six to eight years), respectively. At the final follow-up, there were no significant differences between the highly active obese and nonobese patients with regard to the mean Harris hip score (91 versus 94 points, p = 0.091), the mean Western Ontario and McMaster Universities Osteoarthritis Index (16 versus 11 points, p = 0.135) or the mean UCLA activity scores (8.7 versus 8.8 points, p = 0.400). No hip in either group had thigh pain or a revision or ceramic fracture. The most striking findings in this study were the equivalent results achieved in highly active obese and nonobese patients undergoing primary cementless total hip arthroplasty using an ultrashort metaphyseal-fitting anatomic cementless femoral component.

CORR Insights®: Long-term Results and Bone Remodeling After THA With a Short, Metaphyseal-fitting Anatomic Cementless Stem

This CORR Insights® is a commentary on the article “Long-term Results and Bone Remodeling After THA With a Short, Metaphyseal-fitting Anatomic Cementless Stem” by Kim and colleagues available at: DOI: 10.1007/s11999-013-3354-3. The author certifies that he, or a member of his immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research ® editors and board members are on file with the publication and can be viewed on request. The opinions expressed are those of the writers, and do not reflect the opinion or policy of CORR ® or the Association of Bone and Joint Surgeons®. This CORR Insights® comment refers to the article available at DOI: 10.1007/s11999-013-3354-3.

Long-term Results and Bone Remodeling After THA With a Short, Metaphyseal-fitting Anatomic Cementless Stem

Long-term results of standard total hip arthroplasty (THA) in young patients were not optimal. There are a number of reported disadvantages to longer cementless stems in THA including thigh pain and proximal stress shielding. However, it is unknown whether a short, metaphyseal-fitting anatomic stem without diaphyseal fixation, which represents a possible alternative, will maintain fixation over the longer term. We therefore evaluated long-term (1) clinical results using validated scoring instruments; (2) osseointegration and bone remodeling; (3) complications; and (4) rates of revision and osteolysis in patients younger than 65years who underwent THA with a short, metaphyseal-fitting anatomic cementless stem. We reviewed 500 patients (630 hips) younger than 65years (mean age at surgery, 52.7years) who underwent THA with the Immediate Postoperative Stability stem (IPS; DePuy, Leeds, UK) by one surgeon (Y-HK) from January 1995 to March 2002. Demographic data, Harris hip score, WOMAC score, UCLA activity score, and radiographic data were recorded. All patients underwent dual-energy x-ray absorptiometry scanning of the acetabulum and proximal femur at 2weeks after the operation and at final followup to determine stress shielding. Thigh pain was specifically investigated and scored by patients on a visual analog scale. Other complications were recorded. We determined component survival rates at 15years using revision and aseptic loosening as end points. Minimum followup was 11years (mean, 15.8years; range, 11-18years). The clinical and functional results improved significantly for the Harris hip score, WOMAC, and UCLA activity scores (p<0.001). At latest followup, mean Harris hip, WOMAC, and UCLA activity scores were 94 (range, 71-100), 15 (range, 5-29), and 7.9 (range, 6-9) points, respectively. All hips had osseous integration of the acetabular and femoral components. No patients had thigh pain. Four hips (0.6%) had deep infection and four (0.6%) had a recurrent dislocation. No patients had Grade 3 stress shielding. Fifteen-year survival rates were 98.7% (95% confidence interval [CI], 0.95-1.00) for the acetabular component and 99.4% (95% CI, 0.97-1.00) for the femoral component with revision as the end point and 100% (95% CI, 0.98-1.00) for both components with aseptic loosening as the end point. The short, metaphyseal-fitting anatomic cementless femoral stem provided stable fixation without relying on diaphyseal fixation in younger patients, suggesting metaphyseal fitting alone is sufficient in young patients who have good bone quality. Because we observed no thigh pain and little stress shielding in our patients, modifying the distal stem design as is done with this implant might be advantageous, but this would need to be determined in future comparative studies. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Behaviour of the ultra-short anatomic cementless femoral stem in young and elderly patients

The question arises as to whether it is possible to obtain rigid fixation of the ultra-short metaphyseal-fitting anatomic cementless stem without diaphyseal fixation in the elderly as well as younger patients. We investigated whether ultra-short, metaphyseal-fitting anatomic cementless femoral stem would provide similar functional improvements in the younger and elderly patients, radiographically secure implant fixation would be achieved in both groups, the bone content would be preserved in both groups, and complication rates would be similar in both groups. A total of 100 patients (114 hips) in the younger patient group and 100 patients (112 hips) in the elderly patient group were included in the study. Their mean age was 43.9 ± 6.11 years (range, 31-65 years) in the younger patient group and 78.9 ± 12.1 years (range, 66-91 years) in the elderly patient group. The mean duration of follow-up was 7.5 years (range, six to nine years) in the younger patient group and 7.6 years (range, six to nine years) in the elderly patient group. The mean postoperative Harris hip scores (95 points versus 91 points), WOMAC scores (11 points versus 15 points), thigh pain (none in either group), UCLA activity scores (6.5 points versus 4.5 points), and radiographic results were not significantly different between the two groups. No hip in either group had an aseptic loosening. No hip in either group had clicking or squeaking sounds or ceramic fractures. The cementless ultra-short, metaphyseal-fitting anatomic cementless femoral component provides stable fixation without any need of diaphyseal fixation in both younger and elderly patients. Despite the concern, the poor bone quality in elderly patients did not compromise the stability, and osseointegration of this ultra-short, anatomic cementless femoral stem was achieved in all elderly patients.

Is Diaphyseal Stem Fixation Necessary for Primary Total Hip Arthroplasty in Patients with Osteoporotic Bone (Class C Bone)?

The purpose of this study was to determine the survivorship of the short, metaphyseal-fitting cementless anatomic stem, hip function, thigh pain, and the stress shielding after total hip arthroplasty in 72 patients (81 hips) with Class A bone, 73 patients (83 hips) with Class B bone, and 85 patients (92 hips) with Class C bone. Survival of the femoral stem at 7 years was similar for all 3 classes of bones (100%, 100%, and 98.2%, respectively). At 7 years after the operation, the mean Harris hip scores (95, 93, and 91 points, respectively), WOMAC scores (11, 12, and 15 points, respectively), incidence of thigh pain (none in all 3 groups), radiographic findings and bone mineral density were not significantly different among the 3 groups.

A comparison of a conventionalversusa short, anatomical metaphyseal-fitting cementless femoral stem in the treatment of patients with a fracture of the femoral neck

We compared the clinical and radiological outcomes of two cementless femoral stems in the treatment of patients with a Garden III or IV fracture of the femoral neck. A total of 70 patients (70 hips) in each group were enrolled into a prospective randomised study. One group received a short anatomical cementless stem and the other received a conventional cementless stem. Their mean age was 74.9 years (50 to 94) and 76.0 years (55 to 96), respectively (p = 0.328). The mean follow-up was 4.1 years (2 to 5) and 4.8 years (2 to 6), respectively. Perfusion lung scans and high resolution chest CTs were performed to detect pulmonary microemboli. At final follow-up there were no statistically significant differences between the short anatomical and the conventional stems with regard to the mean Harris hip score (85.7 (66 to 100) versus 86.5 (55 to 100); p = 0.791), the mean Western Ontario and McMaster Universities Osteoarthritis Index (17 (6 to 34) versus 16 (5 to 35); p = 0.13) or the mean University of California, Los Angeles activity score (5 (3 to 6) versus 4 (3 to 6); p = 0.032). No patient with a short stem had thigh pain, but 11 patients (16%) with a conventional stem had thigh pain. No patients with a short stem had symptomatic pulmonary microemboli, but 11 patients with a conventional stem had pulmonary microemboli (symptomatic in three patients and asymptomatic in eight patients). One hip (1.4%) in the short stem group and eight (11.4%) in the conventional group had an intra-operative undisplaced fracture of the calcar. No component was revised for aseptic loosening in either group. One acetabular component in the short stem group and two acetabular components in the conventional stem group were revised for recurrent dislocation. Our study demonstrated that despite the poor bone quality in these elderly patients with a fracture of the femoral neck, osseo-integration was obtained in all hips in both groups. However, the incidence of thigh pain, pulmonary microemboli and peri-prosthetic fracture was significantly higher in the conventional stem group than in the short stem group.

High 10-Year Survival Rate with an Anatomic Cementless Stem (SPS)

BackgroundProximal cementless fixation using anatomic stems reportedly increases femoral fit and avoids stress-shielding. However, thigh pain was reported with the early stem designs. Therefore, a new anatomic cementless stem design was based on an average three-dimensional metaphyseal femoral shape. However, it is unclear whether this stem reduces the incidence of thigh pain.Questions/purposesWe asked whether this stem design was associated with a low incidence of thigh pain and provided durable fixation and high function.MethodsOne hundred seventy-one patients (176 THAs) who had the anatomic proximal hydroxyapatite-coated stem implanted were reviewed. Eleven (6%) patients were lost to followup and 34 (20%) died without revision surgery. We used the Harris hip score (HHS) to assess pain and function. We evaluated femoral stem fixation and stability with the score of Engh et al. and also calculated a 10-year survival analysis. We assessed 126 patients (131 hips) at a mean followup of 10 years (range, 8–11 years)ResultsAt last followup, two patients described slight thigh pain that did not limit their physical activities. All stems appeared radiographically stable and one stem was graded nonintegrated but stable. Five patients had revision surgery: one on the femoral side (for posttraumatic fracture) and four on the acetabular side. Considering stem revision for aseptic loosening as the end point, survivorship was 100% (range, 95.4%–99.9%) at 10 years.ConclusionThis anatomic cementless design using only metaphyseal fixation with a wide mediolateral flare, a sagittal curvature, and torsion, allowed durable proximal stem stability and fixation.Level of EvidenceLevel IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.