Fifteen-year clinical survivorship of Harris-Galante total hip arthroplasty

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Dislocation and survival rate of dual mobility cups in revision total hip arthroplasty in patients with high risk of instability

PURPOSE

Instability remains as an unsolved complication after revision total hip arthroplasty (rTHA). Dual mobility (DM) cups have decreased dislocation rate in rTHA; however, there are few clinical studies that evaluate the risk of dislocation after rTHA in patients with high risk of instability.

METHODS

Between 2007 and 2019, 95 consecutive rTHA using a DM cup, in 93 patients with instability risk factors were retrospectively reviewed. Instability risk factors were defined as follows: deficient abductor mechanism (22.1%), previous dislocation (68.4%), Paprosky 3 acetabular bone defect (21.1%), neuromuscular disease (4.2%), lumbar spine arthrodesis (6.3%), and more than one previous surgery (33.6%). Mean follow-up was 4.3 ± 2.4 years. Clinical and radiographic parameters were reported. DM cup survival was determined using a Kaplan-Meier analysis with re-revision for any cause as the end-point. Surgical complications and re-dislocation rate was recorded.

RESULTS

Seven DM cups were re-revised; three due to aseptic loosening, three due to peri-prosthetic joint infection (PJI), and one due to instability. At seven years follow-up, the survival rate of the DM cup using re-revision for any reason as the end-point was 82.4% (95% confidence interval, 66.4-98.4%). There were 12 (12.6%) complications: two (2.1%) dislocations, six (6.3%) PJI, four (4.2%) peri-prosthetic fractures.

CONCLUSION

Our findings suggest DM cups are effective reducing dislocation rate in rTHA in patients with a high risk of instability, without increasing early aseptic loosening and with a low rate of dislocation. Nevertheless, longer follow-up is needed to confirm implant stability and dislocation rates in the long term.

The intraoperative hip range of motion in total hip arthroplasty predicts postoperative patient's satisfaction for cutting toenails and putting on sock

BACKGROUND

Restricted hip range of motion (ROM) has been proposed as a useful diagnostic tool for osteoarthritis. The relations between the intraoperative hip ROM under anesthesia in total hip arthroplasty (THA) and recovery of clinical mobility outcomes were unclear. This study evaluated the association between the intraoperative hip ROM under anesthesia in THA and the postoperative recovery of clinical mobility, including cutting toenails and putting on socks after THA.

METHODS

The study was performed as a prospective cohort study and included 93 hips in 85 patients who underwent primary anterior-based muscle-sparing THA in the supine position. The hip ROM was evaluated under anesthesia before skin incision and intraoperative stability test. The Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ) was evaluated. A questionnaire on whether and how patients could cut toenails and putting on socks was assessed. The relationship between hip ROM at intraoperative stability tests and JHEQ moving score, cutting toenails, and putting on socks scores were evaluated statistically.

RESULTS

We observed a week positive correlation between intraoperative hip ROM and the total of JHEQ mobility score. A moderate positive correlation was observed between external rotation angle with flexion 90°and cutting toenails and putting on socks score oh JHEQ. 94.6% and 96.8% of the patients could cut their toenails and putting on socks by themselves after surgery. The optimum cutoff range for high patient satisfaction for putting on socks and cutting toenails was 110° for flexion and 35°-40° for the external rotation angle in the intraoperative stability test.

CONCLUSION

Hip ROM during intraoperative stability testing, especially the external rotation angle can predict postoperative outcomes and patient satisfaction for cutting toenails and putting on socks. We suggested that the capsule or capsular ligament release around the hip was increased to provide sufficient ROM without compromising stability.

Average 22-Year Results of Total Hip Arthroplasty Using Harris-Galante Prosthesis in Patients under 50 Years

Background

The Harris-Galante (HG) prosthesis is a first-generation, cementless total hip arthroplasty (THA) prosthesis. Considering the recent increase in the demand for THA in young patients and their life expectancy, a study with a follow-up duration of longer than 20 years in a young population is needed. Therefore, we evaluated the long-term clinical and radiographic results after cementless THA using the HG prosthesis in patients younger than 50 years.

Methods

A total of 61 THAs performed using the HG with a minimum follow-up of 10 years were included. There were 38 men and 11 women with an average age of 46 years and the mean follow-up duration was 22 years. Clinical evaluation included modified Harris Hip Score (HHS) and radiographic analysis consisted of cup inclination, anteversion angle, component stability, osteolysis, liner wear rate, wear-through, liner dissociation, and heterotopic ossification. Complications included recurrent dislocation, periprosthetic femoral fracture, and periprosthetic joint infection. Survivorship analysis included cup and stem revision for aseptic loosening, as well as any revision.

Results

The HHS improved from 46.5 preoperatively to 81.8 postoperatively (p < 0.001). The average linear wear rate was 0.36 mm/yr. A total of 34 hips (56%) were revised: stem revision in 10 (16.4%), cup revision in 9 (14.8%), exchange limited to bearing surface in 8 (13.1%), and revision of all components in 7 (11.5%). Estimated survivorship at 34 years postoperatively was 90.9% for cup revision for aseptic loosening, 80.5% for stem revision for aseptic loosening, and 22.1% for any revision.

Conclusions

THA using the HG prosthesis showed satisfactory estimated survivorship of the acetabular and femoral components at 34 years postoperatively with good clinical outcomes. Bearing-related problems, such as osteolysis and liner dissociation, accounted for 56% of revision operations and were concerns in patients younger than 50 years.

Long-Term Outcomes of 496 Anatomical Cementless Modular Femoral Stems: Eleven to Twenty Years of Follow-Up

BACKGROUND

The aim of the study is to assess the long-term outcomes of this specific stem (anatomical cementless modular stem ESOP), to review the survivorship, complication rate, and radiographic and clinical outcomes.

METHODS

Descriptive and analytical retrospective longitudinal observational study of patients was operated on total hip arthroplasty between 1998 and 2007. Four hundred ninety-six prostheses corresponding to 447 patients were reviewed, mean age was 65.8 years (standard deviation [SD] ±11.6 years), and median follow-up time was 13.4 years (range 1-20). The most used cups were cementless (75.8%). The most frequent friction pairs were metal-polyethylene (53.1%) and ceramic-polyethylene (24.2%). Main variables analyzed were stem survival, subsidence, coronal orientation, osteolysis, reintervention, and Oxford Hip Score.

RESULTS

From 496 implants, there were 22 lost to follow-up (4.4%). Stem revision was performed in 51 patients: 26 periprosthetic joint infections (2-stage revision), 16 periprosthetic fractures, and 8 one-stage revisions (6 real aseptic loosening with negative culture after revision). The stem survivorship at more than 15 years for any reason was 89.2% and for aseptic loosening 97.97%. No specific complications were found due to modularity. The mean subsidence and orientation was 2.06 mm (SD ±5.11 mm) and 0.41° varus (SD ±2.20°) respectively. Subsidence >5 mm or varus >5° was associated with a higher revision rate. Osteolysis was found in 110 patients (zone I = 79, VII = 57), associated with zirconium-polyethylene, without relationship to the stem revision rate or Oxford Hip Score.

CONCLUSION

To our knowledge, this study represents the largest series of this stem, revealing an excellent survival rate and long-term clinical outcomes similar to the best results of classical cementless stems published in the literature.

Osteonecrosis of the hip: is there a difference in the survivorship of total hip arthroplasty with or without previous vascular iliac bone grafting?

Background

Osteonecrosis of the femoral head (ONFH) is a debilitating condition. Vascularized iliac bone graft (VIBG) is a joint-preserving surgery to improve blood supply to the avascular portion of the femoral head which may delay secondary osteoarthritis and total hip arthroplasty (THA). However, whether VIBG will affect the subsequent THA survivorship and outcomes are still uncertain.

Methods

Implant survivorship and clinical outcomes were compared between 27 patients who had undergone prior VIBG and 242 patients who had only undergone THA for ONFH. Baseline characteristics and the postoperative Harris Hip Score (HHS) were also recorded and compared between the two groups. Implant survivorship was determined using Kaplan-Meier survival analysis.

Results

The overall implant survival for all patients who had a primary diagnosis of ONFH and eventually underwent THA was 92.9%. There was no significant difference in the implant survivorship between the group who directly received THA (survivorship of 93%) and the group which failed VIBG and was subsequently converted to THA (survivorship of 91.9%) (p = 0.71). In addition, higher THA revision rates were associated with smokers and drinkers.

Conclusions

VIBG may be a reasonable option as a “buy-time” procedure for ONFH. Even if conversion to THA is eventually required, patients may be reassured that the overall survivorship and clinical outcomes may not be compromised. Patients are recommended to give up smoking and binge drinking prior to THA to increase implant survival rate.

Relationship between use of screws and acetabular cup stability in total hip arthroplasty: a meta-analysis

Objective

The relationship between the use of screws and acetabular cup stability in total hip arthroplasty (THA) remains controversial. We evaluated cup stability in THA with and without the use of screws.

Methods

We performed a systematic literature search to identify studies on cup stability relative to the use of screws in patients undergoing THA before October 2018. Methodological quality assessment and data collection were performed by two individual reviewers. Meta-analysis was performed using Review Manager version 5.3.5.

Results

We included seven trials involving 1402 patients (1469 THAs): 767 patients (809 THAs) with screws and 635 patients (660 THAs) without screws. The findings of meta-analysis indicated that uncemented acetabular component fixation with the use of additional screws was not correlated with migration of the cup, migration on roentgen stereophotogrammetry, or reoperation after THA. Moreover, operation time was not significantly different according to whether screws were used. There was no relationship between use of additional screws and osteoporosis or Harris Hip Score; however, THA with or without the use of screws might be related to bone sclerosis in the C1 region.

Conclusion

Currently, limited evidence shows that the use of screws during THA may not improve cup stability.

Clinical magnetic resonance imaging of arthroplasty at 1.5 T

Magnetic resonance imaging (MRI) has historically been avoided for the routine clinical evaluation of metal implants at many clinical centers due to the presence of artifact that creates in-plane and through-plane distortions and signal intensity voids in generated images. However, when the image acquisition parameters are appropriately modified and advanced multi-spectral pulse sequences are used, high-quality diagnostic images can be generated and may be used for diagnosing patients with suspected periprosthetic pathology. MRI provides superior soft-tissue contrast and excellent sensitivity for mobile water and is, therefore, a valuable tool in the evaluation of these patients, given the increasing prevalence of arthroplasty within the general population. Knowledge of expected normal postoperative appearance in patients with total hip arthroplasty, total knee arthroplasty, and total shoulder arthroplasty facilitates the detection of abnormal findings in this population, as does familiarity with common pathologic conditions encountered in the periprosthetic region. This review article will provide background information regarding the presence of image artifacts, methods to reduce the artifacts, and application of MRI at 1.5 T for evaluating common complications in subjects with total knee arthroplasty, total hip arthroplasty, and total shoulder arthroplasty.

Dual Mobility Cups in Revision Total Hip Arthroplasty: Efficient Strategy to Decrease Dislocation Risk

BACKGROUND

Revision total hip arthroplasty (rTHA) is a challenging surgery with a higher rate of complications than primary arthroplasty, particularly instability and aseptic loosening. The purpose of this study is to compare dual mobility cup (DMC) and standard mobility cup (SMC) in all rTHAs performed at our institution over a decade with a 1 year minimum follow-up.

METHODS

Two hundred ninety-five rTHAs (acetabular only and bipolar revisions) between 2006 and 2016 were retrospectively reviewed. These were divided into those with a DMC (184 revisions) or SMC (111 revisions). Dislocation and complications requiring re-revision were reported.

RESULTS

The rTHA mean age was 69 years ± 13.9 (19-92) and the mean follow-up was 2.3 years. Dislocation risk was statistically lower (P = .01) with a DMC (3.8%; 7/184) than with an SMC (13.5%; 15/111). DMC required re-rTHA in 24/184 (13%) for any reason compared to SMC in 19/111 (17.1%) (P = .34). There was no significant difference in early aseptic loosening (P = .28) between the 2 groups. For young patients (≤55 years), results were similar with a lower dislocation rate in the DMC group (P = .24) and no increased risk of early aseptic loosening (P = .49).

CONCLUSION

This study demonstrates that for all rTHA indications DMC compared to SMC has a significantly decreased risk of postoperative dislocation without risk of early aseptic loosening at medium term follow-up. The use of DMC in rTHA is an important consideration particularly with the predicted increased incidence of both primary and revision THA globally.

Prosthetic femoral head erosion through an acetabular component treated with revision and implant preservation

We present a case report of the rare complication of a femoral head prosthesis eroding through the acetabular liner and shell resulting in a clinical presentation of pseudo-dislocation. The patient presented with a 1-month history of progressive anterior and peritrochanteric hip pain without antecedent trauma. Radiographs demonstrated presumed hip dislocation with superior-posterior superimposition of the femoral head over the acetabular component. The patient underwent revision total hip arthroplasty with intraoperative evidence of extensive metallosis, osteolysis, and femoral head erosion through the acetabular polyethylene liner, acetabular shell, and implantation into the ilium. The femoral stem and acetabular shell were well-fixed, allowing for filling of the defect with bone void filler and cementation of a new polyethylene liner into the acetabular shell.

The 21- to 27-year results of the Harris-Galante cementless total hip arthroplasty

BACKGROUND

The Harris-Galante total hip arthroplasty (THA) is a first-generation cementless THA with a porous coating for biological fixation of the implant. Many studies report excellent long-term results for the acetabular cup, but few long-term studies exist for the femoral stem because of relatively poor short-term and midterm results. Here we present the 21- to 27-year results of the cup and the stem of the Harris-Galante THA.

METHODS

From 1985 to 1991, 102 Harris-Galante THAs were inserted in 82 patients. At the time of the THA, the mean patient age was 54 years (range, 20-78 years). The primary diagnosis was secondary osteoarthritis due to developmental hip dysplasia (69 [68%] hips). The Japanese Orthopaedic Association (JOA) hip score and thigh pain were measures of clinical outcome. Radiographic review was performed retrospectively. Implant survival was evaluated by Kaplan-Meier analysis.

RESULTS

Of 102 hips, 35 hips were from 31 deceased patients, 5 patients (6 hips) were lost to follow-up, 12 hips were revised, and 49 hips were from patients living at the latest follow-up. Among the living patients, 36 hips had a clinical evaluation and 42 hips had a radiograph obtained more than 21 years. The JOA hip score improved from 42 points preoperatively to 83.5 points at the latest follow-up. Thigh pain was reported in 13 hips. One cup and four stems were loose at the latest radiographic review. Most cup revisions were related to acetabular osteolysis. Fifteen hips showed severe stress shielding. Kaplan-Meier analysis of survivorship with any revision, acetabular reoperation, stem revision, and stem loosening as the end point was 87.0%, 90.3%, 95.7% and 86.4%, respectively, at 24.6 years.

CONCLUSIONS

Long-term implant survival and clinical results of the Harris-Galante THA were good. Acetabular osteolysis-related cup loosening was a problem of the cup. Loosening, thigh pain, and stress shielding were problems of the stem.

Correlation between patient age at total hip replacement surgery and lifeexpectancy

Total hip arthroplasty (THA) is one of the most cost-effective hip surgeries among orthopedic procedures. We conducted an extensive literature review with 5,394 papers regarding survival rates after THA. We searched PubMed, Embase and the Cochrane library from January 1(st), 1970 to July 31(th), 2014 looking for all citations about total hip arthroplasty with a long term follow-up (longer than 10 years). The criteria were rigorous: no loss of follow-up, and follow-up more than 10 years. The authors should have known the complete history of patients (whether the patient is alive or dead). Considering the criteria, we found only 15 papers. To evaluate the relationship between follow-up and survival, a linear regression analysis was applied. Considering the papers analysed, and applying the search criteria, we obtained a mean age for the patients above 57.5 years. The chance of survival at 15 years was 57.6%, at 20 years it was 34.6% and at 25 years it is only 11.6%. The relationship between follow-up and survival was significantly linear (p <0.001). Only 11.6% of patients undergoing THA will be still alive 25 years after the surgical procedure. Level of Evidence I, Prognostic Study.

Long-term results using the straight tapered femoral cementless hip stem in total hip arthroplasty: a minimum of twenty-year follow-up

We report the first long-term results of a prospective cohort study after total hip arthroplasty using the cementless Bicontact hip stem. Between 1987 and 1990, 250 total hip arthroplasties in 236 patients were performed using the cementless Bicontact hip stem. The average follow-up was 22.8 years (20.4-24.8) and average age at index surgery was 58.1 years. Eighty-one patients died and 9 were lost to follow-up. We noted 11 stem revisions revealing an overall Kaplan Meier survival rate of 95.0% (CI 95%: 91.1-97.2%). The average Harris Hip Score revealed 81 points (range 24-93). The Bicontact hip stem demonstrated high survival rates despite high ages and osteopenic changes, which are equivalent to other long-term reports of cementless stem fixation.

Hip resurfacing versus total hip arthroplasty: a systematic review comparing standardized outcomes

BACKGROUND

Metal-on-metal hip resurfacing was developed for younger, active patients as an alternative to THA, but it remains controversial. Study heterogeneity, inconsistent outcome definitions, and unstandardized outcome measures challenge our ability to compare arthroplasty outcomes studies.

QUESTIONS/PURPOSES

We asked how early revisions or reoperations (within 5 years of surgery) and overall revisions, adverse events, and postoperative component malalignment compare among studies of metal-on-metal hip resurfacing with THA among patients with hip osteoarthritis. Secondarily, we compared the revision frequency identified in the systematic review with revisions reported in four major joint replacement registries.

METHODS

We conducted a systematic review of English language studies published after 1996. Adverse events of interest included rates of early failure, time to revision, revision, reoperation, dislocation, infection/sepsis, femoral neck fracture, mortality, and postoperative component alignment. Revision rates were compared with those from four national joint replacement registries. Results were reported as adverse event rates per 1000 person-years stratified by device market status (in use and discontinued). Comparisons between event rates of metal-on-metal hip resurfacing and THA are made using a quasilikelihood generalized linear model. We identified 7421 abstracts, screened and reviewed 384 full-text articles, and included 236. The most common study designs were prospective cohort studies (46.6%; n = 110) and retrospective studies (36%; n = 85). Few randomized controlled trials were included (7.2%; n = 17).

RESULTS

The average time to revision was 3.0 years for metal-on-metal hip resurfacing (95% CI, 2.95-3.1) versus 7.8 for THA (95% CI, 7.2-8.3). For all devices, revisions and reoperations were more frequent with metal-on-metal hip resurfacing than THA based on point estimates and CIs: 10.7 (95% CI, 10.1-11.3) versus 7.1 (95% CI, 6.7-7.6; p = 0.068), and 7.9 (95% CI, 5.4-11.3) versus 1.8 (95% CI, 1.3-2.2; p = 0.084) per 1000 person-years, respectively. This difference was consistent with three of four national joint replacement registries, but overall national joint replacement registries revision rates were lower than those reported in the literature. Dislocations were more frequent with THA than metal-on-metal hip resurfacing: 4.4 (95% CI, 4.2-4.6) versus 0.9 (95% CI, 0.6-1.2; p = 0.008) per 1000 person-years, respectively. Adverse event rates change when discontinued devices were included.

CONCLUSIONS

Revisions and reoperations are more frequent and occur earlier with metal-on-metal hip resurfacing, except when discontinued devices are removed from the analyses. Results from the literature may be misleading without consistent definitions, standardized outcome metrics, and accounting for device market status. This is important when clinicians are assessing and communicating patient risk and when selecting which device is most appropriate for individual patients.

Internal iliac artery injury and total hip arthroplasty: discovery after 10 years

Delayed presentation of iliac artery injury by acetabular screw. Screw removal at liner revision of a 10-year-old uncemented acetabular shell resulted in unexpected catastrophic blood loss. Replacing the screw prevented further hemorrhage, and investigation revealed internal iliac artery injury caused by the screw. This was treated successfully by bypass grafting. Careful review of preoperative imaging should aim to identify those at risk and requiring further imaging before undergoing revision surgery.

Early proximal migration of cups is associated with late revision in THA: a systematic review and meta-analysis of 26 RSA studies and 49 survivalstudies

BACKGROUND AND PURPOSE

The association between excessive early migration of acetabular cups and late aseptic revision has been scantily reported. We therefore performed 2 parallel systematic reviews and meta-analyses to determine the association between early migration of acetabular cups and late aseptic revision.

METHODS

One review covered early migration data from radiostereometric analysis (RSA) studies, while the other focused on revision rates for aseptic loosening from long-term survival studies. Thresholds for acceptable and unacceptable migration were classified according the Swedish Hip Arthroplasty Register and the Australian National Joint Replacement Registry: < 5% revision at 10 years.

RESULTS

Following an elaborate literature search, 26 studies (involving 700 cups) were included in the RSA review and 49 studies (involving 38,013 cups) were included in the survival review. For every mm increase in 2-year proximal migration, there was a 10% increase in revision rate, which remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. Consequently, proximal migration of up to 0.2 mm was considered acceptable and proximal migration of 1.0 mm or more was considered unacceptable. Cups with proximal migration of between 0.2 and 1.0 mm were considered to be at risk of having revision rates higher than 5% at 10 years.

INTERPRETATION

There was a clinically relevant association between early migration of acetabular cups and late revision due to loosening. The proposed migration thresholds can be implemented in a phased evidence-based introduction, since they allow early detection of high-risk cups while exposing a small number of patients.

Cup press fit in uncemented THA depends on sex, acetabular shape, and surgical technique

BACKGROUND

Uncemented press-fit cups provide bone fixation in primary THA, but the use of screws is sometimes necessary to achieve primary stability of the socket. However, it is unclear whether and when screws should be used.

QUESTION/PURPOSES

We analyzed the factors related to screw use with a press-fit uncemented cup and assessed whether screw use is associated with the same rates of loosening and revision as a press-fit technique.

METHODS

We retrospectively reviewed 248 patients who underwent THA using the same prosthetic design. Eighty-eight hips had screws to achieve primary cup fixation (Group 1), and 189 did not (Group 2). Mean age was 50 years (range, 14-73 years). We analyzed factors related to the patient, acetabular type, and reconstruction of the rotation center of the hip. Minimum followup was 5 years (mean, 8.9 years; range, 5-12 years).

RESULTS

We found higher screw use in women, patients with less physical activity, Acetabular Types A or C, and a distance from the center of the prosthetic femoral head to the normal center of rotation of more than 3 mm. There were four revisions in Group 1 and five in Group 2. Eight hips had radiographic loosening in Group 1 and nine in Group 2. Cups with a postoperative abduction angle of more than 50° had a higher risk for loosening.

CONCLUSIONS

Press fit was achieved less frequently in women and patients with Acetabular Types A or C and less physical activity; a closer distance to the normal center of rotation decreased screw use. Screw use to augment fixation achieved survival similar to that of a press-fit cup.

LEVEL OF EVIDENCE

Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Successful long-term fixation and progression of osteolysis associated with first-generation cementless acetabular components retrieved post mortem

BACKGROUND

Primary cementless acetabular reconstruction has shown durable long-term fixation. Late failures secondary to aseptic loosening are rare but may occur in patients with previously well-fixed components. In the present study, the histopathological characteristics of postmortem specimens were correlated with wear damage and radiographic data in an attempt to better understand the long-term events in the periacetabular tissue around well-functioning devices.

METHODS

Seventeen primary cementless Harris-Galante I acetabular components with adjacent tissues were harvested after a mean of eleven years (range, four to twenty-five years) from patients whose implants were well functioning at the time of death. Undecalcified and paraffin sections were used to quantify the extent of bone and soft tissues within the porous coating and at the interface between the coating and the surrounding bone. Wear particles were identified with use of polarized light microscopy and energy-dispersive x-ray analysis. Bearing-surface volumetric wear and backside wear damage of the polyethylene liner were assessed.

RESULTS

All of the components were fixed by bone ingrowth (mean extent, 33% ± 21%). Particle-induced granulomas were present in the porous coating and along the interface and progressed through screw holes, ballooning into the retroacetabular bone in the longer-term specimens. Particles of femoral and acetabular origin were identified in the granulomas. Bearing-surface volumetric wear (mean, 41.6 mm3/year) increased with duration and correlated with increasing extent of granuloma in the porous coating and the increasing size of pelvic granulomas. Radiolucencies on radiographs correlated with the extent of bone and fibrous tissue ingrowth. Of the six pelvic granulomas that were identified histologically, only one was apparent on routine radiographs.

CONCLUSIONS

Acetabular fixation by bone ingrowth can be successful into the third decade after implantation. Osteolysis and secondary replacement of bone with particle-induced granuloma are commonly seen in the presence of excellent clinical function. Strategies designed to minimize bearing-surface wear and backside damage are important to maintain long-term bone ingrowth fixation.

Total hip arthroplasty using cementless grit-blasted femoral component: a minimum 10-year follow-up study

The grit-blasted cementless Spotorno (CLS) stem, which has excellent survival rates up to 10 years, is widely used in total hip arthroplasty (THA). We investigated the survivorships of CLS stems in THA at a minimum follow-up of 10 years and sought to identify factors that influence outcomes. A total of 227 hips of 191 patients who underwent cementless THA with a CLS stem were retrospectively reviewed at a mean follow-up of 12.3 years. All patients were evaluated clinically and radiographically according to implant type and surgery-related and patient-related factors. Survivorship was 97.2% when femoral revision for any reason was defined as the end point. Femoral revisions were performed in 3 hips because of periprosthetic fractures. Survivorship for all hips, using revision for any reason as the end point, was 92.6%. Two metal-on-metal THAs were revised because of aseptic loosening or osteolysis around the cup. No significant differences were evident for type of stem, type of bearing surface, stem alignment, or patient-related factors. However, a canal fill index of 80% or less was found to affect cortical remodeling, subsidence, and a change in stem position of 5° or more, which indicates that care must be taken not to undersize stems. In addition, in view of the revisions performed, bearing surfaces appear to importantly influence THA survivorship.

Retrieval analysis of Harris-Galante I and II acetabular liners in situ for more than 10 years

BACKGROUND AND PURPOSE

There have been few reports documenting the wear and oxidation performance of the polyethylene bearing surface of HGPI and HGPII THA devices. We evaluated retrieved HGPI and HGPII acetabular liners that had been in situ for more than 10 years and determined whether there was a relationship between clinical and radiographic factors, surface damage, wear, and oxidation.

MATERIALS AND METHODS

129 HGPI and II acetabular liners with implantation times of > 10 years were retrieved at 4 institutions between 1997 and 2010. The liners were made from a single resin and were gamma radiation-sterilized in air. Surface damage, linear wear, and oxidation index (OI) were assessed. Differences in clinical and radiographic factors, surface damage, linear wear, and OI for the 2 designs were statistically evaluated separately and together.

RESULTS

Articular surface damage and backside damage was similar in the 2 designs. The linear penetration rate was 0.14 (SD 0.07) mm/year for the HGPI liners and 0.12 (SD 0.08) mm/year for the HGPII liners. For both cohorts, the rim had a higher OI than the articular surface. 74% of the liners had subsurface cracking and 24% had a complete fracture through the acetabular rim.

INTERPRETATION

Despite modification of the HGP locking mechanism in the HGPII design, dissociation of the liner from the acetabular shell can still occur if fracture of the rim of the liner develops due to oxidative degradation.

Modern total hip arthroplasty in patients younger than 21 years

Total hip arthroplasty (THA) is not commonly performed in adolescents. However, it may be the only option for pain control with continued mobility for advanced disease. We report our experience with modern alternative-bearing THA in patients younger than 21 years. Twenty-one THAs (18 patients) were followed. Preoperative and postoperative Harris hip scores were recorded, and radiographs were reviewed. Average follow-up was 49 months (range, 25-89). Underlying etiology was chemotherapy-induced osteonecrosis (33%), steroid-induced osteonecrosis (29%), sickle cell disease (24%), and chronic dislocation (14%). Articulation bearings were ceramic/ceramic (67%), metal/highly cross-linked polyethylene (29%), and metal resurfacing (5%). Mean age was 18 years (range, 13-20). Harris hip scores improved from 43.6 to 83.6 (P < .001). At final follow-up, there was no radiographic loosening; 1 THA was revised for a cracked ceramic liner. At intermediate-term follow-up, clinical and radiographic results are favorable after alternative-bearing THA in patients younger than 21 years.

Second-generation modular acetabular components provide fixation at 10 to 16 years

BACKGROUND

First-generation modular titanium fiber-metal-coated acetabular components had high rates of wear, pelvic osteolysis, and liner dissociation. Second-generation components were designed to reduce the incidence of these problems but it is unclear whether the changes achieved these goals.

QUESTIONS/PURPOSES

We asked the following questions: (1) Is the risk of revision surgery for loosening, wear, or liner dissociation low with the second-generation acetabular component? (2) Is the rate of pelvic osteolysis low? (3) Can the liner be exchanged without bone cement?

METHODS

We retrospectively reviewed prospectively collected data from 99 patients (118 hips) undergoing THAs with one second-generation modular titanium acetabular component with routine screw fixation and conventional polyethylene. The minimum followup was 10 years (mean, 12 years; range, 10-16 years). We obtained Harris hip scores and examined radiographs for loosening and osteolysis.

RESULTS

At last followup, all acetabular components were well fixed and no titanium shell had been revised or removed. No liner had dissociation. At most recent followup, the mean Harris hip score was 89. We observed pelvic osteolysis in eight hips (7%). There were three reoperations for dislocation (head-liner exchange only) and three loose femoral components revised. Two liners (at 11 and 14 years) were exchanged for wear-pelvic osteolysis.

CONCLUSIONS

This second-generation modular titanium fiber-metal-coated acetabular component with screw fixation had no loosening, no liner dissociation, and a low rate of pelvic osteolysis at 10 to 16 years. Liner exchange is practical without use of cement. We continue to use this component with highly crosslinked polyethylene liners.

LEVEL OF EVIDENCE

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

Does a collar improve the immediate stability of uncemented femoral hip stems in total hip arthroplasty? A bilateral comparative cadaver study

The aim of this study was to compare the immediate stability of collared vs collarless uncemented femoral stems in total hip arthroplasty. A bilateral comparative study of 20 cadavers (40 hips: 20 collarless, 20 collared) was performed. Forces in the vertical and horizontal planes required to initiate subsidence of femoral stem and subsequent femoral fracture were measured. In vertical plane, subsidence began at an average force of 3129 ± 494 N for collarless stems and 6283 ± 3584 N for collared stems (P = .02). Fracture occurred at a significantly higher force for collared stems (P = <.001). In horizontal plane, subsidence began at an average force of 540 ± 170 N for collarless stems and 678 ± 206 N for collared stems (P = .01). Fracture occurred at a significantly higher force for collared stems (P = .005). Collared uncemented stems have significantly greater immediate stability than collarless. They are able to withstand greater vertical and horizontal forces before the initiation of subsidence and subsequent fracture.

A medium-term comparison of hybrid hip replacement and Birmingham hip resurfacing in active young patients

We compared the medium-term clinical and radiological results of hybrid total hip replacement (THR) with metal-on-metal Birmingham hip resurfacing (BHR) in two groups of 54 young patients matched for age, gender, body mass index and pre-operative levels of activity.

The clinical outcome was assessed by the University of California, Los Angeles (UCLA) activity score, the Oxford Hip Score (OHS) and the EuroQol scores. Radiologically, all hips were assessed for migration and osteolysis, the hybrid THRs for polyethylene wear and the BHRs for a pedestal sign. The mean follow-up of the patients with a hybrid THR was ten years and for those with a BHR, nine years. Four patients with a hybrid THR and one with a BHR had died. In each group five were lost to follow-up. The revision rate of the hybrid THRs was 16.7% (9 of 54) and of the BHRs 9.3% (5 of 54) (p = 0.195). Radiographs of a further eight hybrid THRs demonstrated wear and osteolysis, and they await revision (p = 0.008). Of the unrevised BHRs 90% had radiological changes, of which approximately 50% had progressed over the previous four years. All hybrid THRs demonstrated linear polyethylene wear with a mean of 1.24 mm (0.06 to 3.03). The BHRs recorded superior OHS (p = 0.013), UCLA (p = 0.008), and EuroQol visual analogue scores (p = 0.009).

After nine years, patients with BHRs remained more active and had a lower rate of revision than those with hybrid THRs. Both groups demonstrated progressive radiological changes at medium-term follow-up.

The Harris-Galante cementless THA: a 19- to 25-year follow-up study

The goal of this study was to evaluate the long-term survivorship of primary cementless total hip arthroplasty (THA) using Harris-Galante porous I acetabular and Harris-Galante porous femoral components. From July 1985 to December 1991, we performed primary cementless THA on 76 hips (70 patients). Twenty-nine patients (31 hips) died due to causes unrelated to the THA, and 6 patients (7 hips) were lost to follow-up. Of 76 hips (70 patients) studied, 38 hips (35 patients) were available for follow-up at a mean 22.5 years (range, 19-25 years) postoperatively. Mean patient age at index procedure was 51.2 years (range, 42-65 years). Average Harris Hip Score was 40.5 points preoperatively and 85.8 points at final follow-up. No patient had an early or late postoperative deep infection. Radiographically, the acetabular component fixation was stable in all 38 hips. The femoral component was bone-ingrown in 26 hips, stable-fibrous in 10, and unstable in 2. One unstable hip required revision of the femoral component. Dissociation of the polyethylene liner occurred in 3 hips without fractures of the metal locking tines and required revision of the polyethylene liner and the articular head. A total of 4 hips had documented revision, and 1 femoral component failed radiographically. The survival rate with the endpoint defined as revision surgery and radiographic loosening was 86.8% at 22.5 years of follow-up. Mean polyethylene wear was 0.085 mm/year (range, 0.031-0.15 mm). This study found that the Harris-Galante porous I acetabular and Harris-Galante porous femoral components produce excellent long-term results.

The concentric all-polyethylene Exeter acetabular component in primary total hip replacement

We report the outcome of the flangeless, cemented all-polyethylene Exeter acetabular component at a mean of 14.6 years (10 to 17) after operation. Of the 263 hips in 243 patients, 122 prostheses are still in situ; 112 patients (119 hips) have died, 18 hips have been revised, and three patients (four hips) were lost to follow-up. Radiographs at the final review were available for 110 of the 122 surviving hips. There were acetabular radiolucent lines in 54 hips (49%). Two acetabular components had migrated but neither patient required revision. The Kaplan-Meier survivorship at 15 years with 61 hips at risk with revision for any cause as the endpoint was 89.9% (95% confidence interval (CI) 84.6 to 95.2) and for aseptic loosening of the acetabular component or lysis 91.7% (95% CI 86.6 to 96.8). In 210 hips with a diagnosis of primary osteoarthritis, survivorship with revision for any cause as the endpoint was 93.2% (95% CI 88.1 to 98.3), and for aseptic loosening of the acetabular component 95.0% (95% CI 90.3 to 99.7). The cemented all-polyethylene Exeter acetabular component has an excellent long-term survivorship.

Distribution of periacetabular osteolytic lesions varies according to component design

Using computed tomography, the volume, location, and number of osteolytic lesions were determined adjacent to 38 Harris-Galante 1 (HG-1) acetabular components fixed with screws and 19 porous-coated anatomic (PCA) acetabular components press-fitted without screws. The median implantation times were 16 and 15 years, respectively. The mean total lesion volumes were similar: 11.1 cm(3) (range, 0.7-49 cm(3)) and 9.8 cm(3) (range, 0.4-52 cm(3)), respectively, for hips with HG-1 and PCA components (P = .32). There was a significant difference in the proportion of rim-related, screw or screw hole-related, and combined lesions between the 2 component designs (P < .0001). HG-1 components had more screw and screw hole-related lesions, and PCA components had more rim-related lesions. Although there are concerns regarding screw and screw hole-associated osteolysis, these findings suggest that peripheral fixation may be well maintained in the long term with the use of multiple-hole acetabular components with screw fixation.

Do the potential benefits of metal-on-metal hip resurfacing justify the increased cost and risk of complications?

BACKGROUND

Metal-on-metal hip resurfacing arthroplasty (MoM HRA) may offer potential advantages over total hip arthroplasty (THA) for certain patients with advanced osteoarthritis of the hip. However, the cost effectiveness of MoM HRA compared with THA is unclear.

QUESTIONS/PURPOSES

The purpose of this study was to compare the clinical effectiveness and cost-effectiveness of MoM HRA to THA.

METHODS

A Markov decision model was constructed to compare the quality-adjusted life-years (QALYs) and costs associated with HRA versus THA from the healthcare system perspective over a 30-year time horizon. We performed sensitivity analyses to evaluate the impact of patient characteristics, clinical outcome probabilities, quality of life and costs on the discounted incremental costs, incremental clinical effectiveness, and the incremental cost-effectiveness ratio (ICER) of HRA compared to THA.

RESULTS

MoM HRA was associated with modest improvements in QALYs at a small incremental cost, and had an ICER less than $50,000 per QALY gained for men younger than 65 and for women younger than 55. MoM HRA and THA failure rates, device costs, and the difference in quality of life after conversion from HRA to THA compared to primary THA had the largest impact on costs and quality of life.

CONCLUSIONS

MoM HRA could be clinically advantageous and cost-effective in younger men and women. Further research on the comparative effectiveness of MoM HRA versus THA should include assessments of the quality of life and resource use in addition to the clinical outcomes associated with both procedures.

LEVEL OF EVIDENCE

Level I, economic and decision analysis. See Guidelines for Authors for a complete description of levels of evidence.

Survivorship of polyethylene liner exchanges performed for the treatment of wear and osteolysis among porous-coated cups

For the past 17 years, we have favored treating patients with polyethylene wear and osteolysis by performing a liner exchange with retention of the old shell when possible. Using our institutional database, we identified 187 acetabular revisions in which we had retained the old shell. Among this group, we found 25 rerevisions. These included 10 for hip instability, 9 for cup loosening, 3 for recurrence of excessive wear or osteolysis, 2 for infection, and 1 for dissociation of the replaced liner. The need for rerevision varied with the different retained shell designs. We rerevised 17% of the total hip arthroplasties with old spiked shells, 21% with Arthropor shells, 13% with Triloc shells and 5% with Duraloc shells. Before making a decision to retain or remove a well-fixed old acetabular shell, we recommend consideration of the design's past track record and careful inspection of the condition of the existing shell.

Fifteen-year to twenty-year results of cementless Harris-Galante porous femoral and Harris-Galante porous I and II acetabular components

This study examined long-term survivorship of primary total hip arthroplasty (THA) using cementless Harris-Galante porous femoral and Harris-Galante porous I or II acetabular components. Of 113 hips (101 patients) studied, 60 hips (53 patients) were available for follow-up at a mean of 17.2 years after surgery. A total of 10 hips had documented revision, and 2 hips had failed radiographically. The average Harris hip score was 82. Radiographically, 12 hips demonstrated eccentric wear, 8 had osteolysis, and 1 had a broken tine. The overall survival rate was 87.7%; the mean volumetric wear rate was 74.96 mm(3); and the mean polyethylene linear penetration rate was 0.153 mm/y, similar to that of well-cemented THA in other series. This long-term outcome for an early-generation cementless THA is promising and provides a standard by which to judge the newer generation of cementless implants.

Metal-backed acetabular components with conventional polyethylene: a review of 9113 primary components with a follow-up of 20 years

The Norwegian Arthroplasty Register has shown that several designs of uncemented femoral stems give good or excellent survivorship. The overall findings for uncemented total hip replacement however, have been disappointing because of poor results with the use of metal-backed acetabular components. In this study, we exclusively investigated the medium-to long-term performance of primary uncemented metal-backed acetabular components. A total of 9113 primary uncemented acetabular components were implanted in 7937 patients between 1987 and 2007. These were included in a prospective, population-based observational study. All the implants were modular and metal-backed with ultra-high-molecular-weight polyethylene liners. The femoral heads were made of stainless steel, cobalt-chrome (CoCr) alloy or alumina ceramic. In all, seven different designs of acetabular component were evaluated by the Kaplan-Meier survivorship method and Cox regression analysis. Most acetabular components performed well up to seven years. When the endpoint was revision of the acetabular component because of aseptic loosening, the survival ranged between 87% and 100% at ten years. However, when the endpoint was revision for any reason, the survival estimates were 81% to 92% for the same implants at ten years. Aseptic loosening, wear, osteolysis and dislocation were the main reasons for the relatively poor overall performance of the acetabular components. Prostheses with alumina heads performed slightly better than those with stainless steel or CoCr alloy in subgroups. Whereas most acetabular components performed well at seven years, the survivorship declined with longer follow-up. Fixation was generally good. None of the metal-backed uncemented acetabular components with ultra-high-molecular-weight polyethylene liners in our study had satisfactory long-term results because of high rates of wear, osteolysis, aseptic loosening and dislocation.

Survival of the cementless Spotorno stem in the second decade

High survival rates have been reported for the uncemented CLS Spotorno stem up to 10 years. To confirm survival at longer followup we report the minimum 15-year (mean, 17 years; range, 15-20 years) for 257 hips using this stem. We retrospectively evaluated the clinical and radiographic results of all 326 patients (354 THAs) operated between 1985 and 1989. The patients had a mean age of 57 years using an uncemented grit-blasted, tapered titanium femoral stem. Eighty-six patients (89 hips) died and eight patients (eight hips) were lost to followup, leaving 240 patients (257 hips) for evaluation. The femoral component was revised in 35 hips: eight for infection, nine for periprosthetic fracture, one for traumatic loosening, and 17 for aseptic loosening. Survival of the stem was 88% at 17 years (95% confidence interval, 84%-92%), and survival with femoral revision for aseptic loosening as an end point was 94% (95% confidence interval, 91%-97%). The median Harris hip score at followup was 80 points. No thigh pain was reported. Small osteolytic lesions (< 1 cm(2)) were found in the proximal Gruen zones (1 or/and 7) in 28 hips (15%). No distal femoral osteolysis was found. The long-term survival with this type of femoral component remains high in the second decade.

The Morscher Press Fit acetabular component: a nine- to 13-year review

We reviewed the results at nine to 13 years of 125 total hip replacements in 113 patients using the monoblock uncemented Morscher press-fit acetabular component. The mean age at the time of operation was 56.9 years (36 to 74). The mean clinical follow-up was 11 years (9.7 to 13.5) and the mean radiological follow-up was 9.4 years (7.7 to 13.1). Three hips were revised, one immediately for instability, one for excessive wear and one for deep infection. No revisions were required for aseptic loosening. A total of eight hips (7.0%) had osteolytic lesions greater than 1 cm, in four around the acetabular component (3.5%). One required bone grafting behind a well-fixed implant. The mean wear rate was 0.11 mm/year (0.06 to 0.78) and was significantly higher in components with a steeper abduction angle. Kaplan-Meier survival curves at 13 years showed survival of 96.8% (95% confidence interval 90.2 to 99.0) for revision for any cause and of 95.7% (95% confidence interval 88.6 to 98.4) for any acetabular re-operation.

Assessment of outcomes after hip arthroplasty

Because of the ever-increasing prevalence of joint replacement, it is important that patient outcomes after surgery are continuously reviewed and monitored, with the aim of optimising outcomes after surgery. Of central importance in assessing outcomes is choosing the most appropriate outcome measure. This article reviews five methods of assessing outcomes after hip arthroplasty, namely radiographic analysis, implant survivorship analysis, surgeon-based outcome measures, performance-related assessment and patient-reported outcome measures. The relative strengths and weaknesses of each method of assessment are discussed, with the aim of aiding the surgeon or researcher in choosing an outcome measure when designing a clinical trial.

Early mortality after modern total hip arthroplasty

Because of improvements in surgical technique, anesthesia, and rehabilitation, mortality after hip arthroplasty may be on the decline. The purpose of this study was to determine the 90-day mortality rate after uncemented total hip arthroplasty (THA) performed under regional anesthesia. We retrospectively reviewed 7478 consecutive patients undergoing cementless primary or revision THA between January 2000 and July 2006. Patient survivorship was established and causes of death were obtained by accessing the Social Security Death Index, Centers for Disease Control and Prevention National Death Index, and State Departments of Vital Statistics. There were two intraoperative deaths from cardiac arrest. The overall 30- and 90-day mortality rates were 0.24% (18 of 7478) and 0.55% (41 of 7478), respectively. Thirty-day mortality after primary THA was low at 0.13% (eight of 6272). The most common cause of death was cardiovascular-related. Mortality after modern THA seems to have remained very low despite the availability of this procedure to patients of all ages and comorbidities.

LEVEL OF EVIDENCE

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

Why revision total hip arthroplasty fails

Current outcomes data on revision total hip arthroplasty focuses on specific implants and techniques rather than more general outcomes. We therefore examined a large consecutive series of failed THAs undergoing revision to determine if survivorship and modes of failure differ in comparison to the current data. We retrospectively reviewed the medical records of 1100 revision THAs. The minimum followup was 2 years (mean, 6 years; range, 0-20.4 years). Eighty-seven percent of revision total hips required no further surgery; however, 141 hips (13%) underwent a second revision at a mean of 3.7 years (range, 0.025-15.9 years). Seventy percent (98 hips) had a second revision for a diagnosis different from that of their index revision, while 30% (43 hips) had a second revision for the same diagnosis. The most common reasons for failure were instability (49 of 141 hips, 35%), aseptic loosening (42 of 141 hips, 30%), osteolysis and/or wear (17 of 141 hips, 12%), infection (17 of 141 hips, 12%), miscellaneous (13 of 141 hips, 9%), and periprosthetic fracture (three of 141 hips, 2%). Survivorship for revision total hip arthroplasty using second revision as endpoint was 82% at 10 years. Aseptic loosening and instability accounted for 65% of these failures.

LEVEL OF EVIDENCE

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

Long term results of the Corin C-Fit uncemented total hip arthroplasty in young patients

INTRODUCTION

We conducted a prospective study to evaluate the long-term results after Corin C-Fit uncemented total hip arthroplasty in young patients with hydroxyapatite or porous coated components.

MATERIALS AND METHODS

We prospectively followed 36 patients (38 hips) who had Corin C-Fit uncemented total hip arthroplasties by eight experienced consultant surgeons at two centres. The acetabular and femoral components were hydroxyapatite or porous coated.

RESULTS

The overall 10-year survival rate for the Corin C-Fit arthroplasty was 43%. The 10-year survivorship for the femoral implant was 56% and for the acetabular component 59%.

CONCLUSION

The evidence presented in this study suggests that the Corin C-Fit uncemented total hip arthroplasty has one of the highest mid- and long-term failure rates for both femoral and acetabular components in the literature. We believe this implant should not be used and patients who have had this form of total hip arthroplasty should be kept under regular review.

Polyethylene wear and osteolysis with a new modular titanium acetabular component: results at 7 to 13 years

The first-generation and second-generation modular titanium fiber-metal acetabular components were notable for high rates of pelvic osteolysis and liner dislodgment. This is a prospective, consecutive study of 111 new modular titanium-fiber metal acetabular components with a novel polyethylene locking mechanism at a mean follow-up of 9.5 years (range, 7-13 years). The polyethylene was gamma-irradiated in air in 58 hips and gamma-irradiated in nitrogen in 54 hips. No acetabular component migrated, none were revised, and there was no liner dislodgment. Pelvic osteolysis was seen in only 2 hips. The mean linear wear rate was 0.085 mm/y (range, 0.001-0.3 mm/y). There was a significantly lower rate of wear with polyethylene liners sterilized by gamma-irradiation in nitrogen (P = .0001). The high rate of success and low rate of polyethylene wear and pelvic osteolysis at this length of follow-up may be related to the new design features of this modular acetabular component.

Polyethylene sterilized without irradiation in a polished uncemented acetabular component-a clinical and radiographic analysis

Clinical and radiographic analysis of the Reflection uncemented acetabular component was performed. Features of this component include a polished inner shell and ethylene oxide sterilization. Clinical information was available for 158 hips (mean, 4.6 years follow-up). A total of 19 hips have undergone or were recommended revision, 8 for aseptic loosening or wear (5%). Wear analysis was performed for 38 hips with more than 5 years of follow-up (mean, 6.7 years). Osteolysis was present in 20 of these patients. Penetration rate averaged 0.15 mm/y. Patients with uncemented femoral fixation (vs cemented) had a significantly higher penetration rate. Increased volumetric wear was seen with uncemented femoral fixation, thin liners, and ceramic heads. This component demonstrated relatively high penetration and osteolysis rates. Continued surveillance is recommended, particularly for active patients with thin liners.

The noisy ceramic hip: is component malpositioning the cause?

Noisy ceramics bearing surfaces are a recently recognized problem in total hip arthroplasty. Component malposition as a potential cause has been proposed. Squeaking occurred in 28 (2.7%) of 999 patients undergoing ceramic on ceramic total hip arthroplasty at our institution. Patients were matched, in a 1:2 ratio by anthropometric and demographic variables and also prosthesis size and type. The acetabular position was measured using radiographs and computed tomography. There was no statistically significant difference in cup inclination (P = .25) or version (P = .38) between groups. Four hips that have been revised were available for retrieval analysis. Stripe wear and metal transfer to ceramic components were observed. Etiology of squeaking ceramic total hip arthroplasty remains elusive. Although malposition could be an important contributing factor, the latter cannot be the sole reason based on our findings. Further investigation to elucidate the etiology is warranted.

Second-generation proximally coated titanium femoral component: minimum 7-year results

It is unclear whether resurfacing or fully porous-coated or proximally coated stems are the best femoral components for young patients. First-generation proximally coated titanium fiber-metal femoral components had a high rate of failure. We prospectively followed 56 patients (70 hips) whom we believed were at high risk for loosening of a cemented femoral component; all patients were implanted with one second-generation proximally coated titanium femoral component. Ten patients (11 hips) died and three patients (four hips) were lost to minimum followup. Three models of titanium fiber-metal acetabular component were implanted with screws. Patients were clinically evaluated using the Harris hip score. We used standardized radiographs to assess fixation status and osteolysis. Forty-four patients (55 hips) with a mean age of 45 years were followed for a minimum of 7 years (mean, 10.5 years; range, 7-15 years). No femoral component had been revised for any reason. Bone ingrowth (spot welding) was seen in 41 hips (75%) and proximal femoral osteolysis in only four hips. Reoperations for polyethylene wear were performed in seven patients (12.7%) and two patients had liner exchange for recurrent dislocation. Even with an articulating surface with considerable polyethylene wear debris, these second-generation proximally coated titanium fiber-metal femoral components had a survival rate of 100% at a mean 10.5-year followup.

Time to revision of primary THA is shorter for specialists than nonspecialists

We asked if there was a shorter time to revision, and different indications for revision, for primary total hip arthroplasties performed in the community by general orthopaedic surgeons (nonspecialists) as compared with primary total hip arthroplasties performed by specialists. We retrospectively reviewed 560 revision total hip arthroplasties performed in 486 patients from 1998 to 2006 at our tertiary referral center. One hundred ninety revisions from the community (nonspecialists cohort) and 109 revisions for which the primary arthroplasty was performed by the specialists (specialist cohort) at our center met the criteria for inclusion. These cohorts were analyzed by the time to revision and the indications for revision. Our findings were that the specialists had a shorter mean time to revision (8.3 years versus 10.1 years). This result may reflect a greater concern by specialists over the potential complications of osteolysis as reflected by the finding that the indication for surgery was more often aseptic loosening for the nonspecialists (57.9% versus 12.8%) and osteolysis for the specialists (61.5% versus 15.8%). As a result of possible selection bias in cases referred by the non-specialists, the indications for revision may not represent the modes of failure for arthroplasties performed by nonspecialists.

Nonmodular flexible press-fit cup in primary total hip arthroplasty: 15-year followup

The key rationale for a nonmodular flexible press-fit cup was to maximize long-term stability with a cementless, porous metal-coated cup that is low in stiffness (no metal shell) and to achieve fixation solely through biradial eccentricity between the cup and the acetabular cavity. We asked whether the promising results achieved at 5 and 10 years would be maintained at 15 years. We reviewed 261 patients who received the first 280 Morscher Press-Fit Cups. One hundred twenty patients (126 hips) died. One hundred one patients (112 hips) had a clinical and radiographic followup after a minimum of 13.5 years (mean, 14.7 years; range, 13.5-17.0 years). Twenty-four patients with 26 hips were clinically examined or interviewed by telephone. Three of the 101 patients were lost to followup. We judged the results excellent or good in 96% of the hips. The 15-year overall survivorship was 95.3% and with the end point of aseptic loosening, the survivorship was 97.5%. Wear was greater in cups with an inclination greater than 45 degrees and in metal-polyethylene pairings compared with ceramic-polyethylene pairings. This cup design performs well over the long term.