Cementless total hip arthroplasty with a metal-on-metal bearing in patients younger than 50 years

Revision Risk in a Cohort of US Patients Younger Than 55 Undergoing Primary Elective Total Hip Arthroplasty

BACKGROUND

As indications for elective total hip arthroplasty (THA) expand to younger patients, we sought to (1) compare revision risk following primary elective THA in patients <55 years at the time of their THA to patients aged ≥65 years and (2) identify specific risk factors for revision in patients <55 years.

METHODS

A Kaiser Permanente's total joint replacement registry was used to conduct a cohort study including primary elective THA patients aged ≥18 (2001-2018). In total, 11,671 patients <55 years and 53,106 patients ≥65 years were included. Multiple Cox regression was used to evaluate cause-specific revision risk, including septic revision, aseptic loosening, instability, and periprosthetic fracture. Stepwise Cox regression was used to identify patient and surgical factors associated with cause-specific revision in patients <55 years.

RESULTS

Patients <55 years had a higher risk of septic revision (hazard ratio [HR] = 1.30, 95% confidence interval [CI] = 1.02-1.66), aseptic loosening (HR = 2.60, 95% CI = 1.99-3.40), and instability (HR = 1.35, 95% CI = 1.09-1.68), but a lower risk of revision for periprosthetic fracture (HR = 0.36, 95% CI = 0.22-0.59) compared to patients aged ≥65 years. In the <55 age group, risk factors for septic revision included higher body mass index, drug abuse, and liver disease. Hypertension, anterior approach, and ceramic-on-ceramic were associated with aseptic loosening. White race, American Society of Anesthesiologists classification ≥3, smoker, paralysis, posterior approach, ceramic-on-ceramic, and smaller head diameter were associated with instability.

CONCLUSION

Identified risk factors varied depending on the cause for revision. Although septic revisions were related to patient characteristics, more modifiable factors, such as implant or surgical approach, were associated with revision due to aseptic loosening and instability.

LEVEL OF EVIDENCE

III.

Long-Term Outcome of Small Head Metal-On-Metal Total Hip Arthroplasty: A 15-to-22 Year Follow-Up

BACKGROUND

The Metasul articular interface was a second-generation metal-on-metal (MoM) total hip arthroplasty (THA) that was introduced as a promising interface with improved manufacturing technology, better clearances, and enhanced metal hardness. In December 2001, the manufacturer recalled these implants due to the failure of cup osseointegration.

METHODS

Between 1997 and 2004, 168 consecutive primary Metasul THAs were performed in 144 patients. Most patients received a cementless femoral and porous-coated acetabular component with 28 mm head. A competing risk analysis was performed for determination separately for bearing surface-related, recalled bearing failure, and end point revision for any reason. For clinical patient evaluation, we used Harris hip score and University of California at Los Angeles scores. Cobalt and chromium ion level measurement and standard radiographic assessment was performed.

RESULTS

Of the 168 THAs, 19 hips were revised at a mean period of 15 years as follows: 12 of them were due to recalled acetabular component, five hips had noninterface-related complication, and two true interface surface failure. The survival distribution function of all hips with revision for any reason was 88.4%, for bearing interface relation 98.8%, and 92.6% for recalled cups. The mean Harris hip score and University of California at Los Angeles scores were 85 and 6, respectively, and the median Co and Cr blood levels were 1.0 and 0.91 μg/L.

CONCLUSION

Excluding the recalled components, Metasul articular interface has performed extremely well at a minimum follow-up of 15 years in this relatively young population. There were two interface-related revisions in the entire cohort.

Small-head metal on metal total hip arthroplasty is associated with a high rate of complication and reoperation at mid-term follow-up

Background:

Adverse reactions to metal debris are significant complications after metal-on-metal total hip arthroplasty. Recently, late appearances of adverse reactions to metal debris and subsequent need for reoperations have been reported with small-diameter head metal-on-metal devices. We retrospectively investigated mid-term clinical outcomes of small-head metal-on-metal total hip arthroplasty.

Methods:

We reviewed 159 hips in 139 patients who had a small-head metal-on-metal total hip arthroplasty (M2a Taper; Biomet, Warsaw, IN) with a minimum 5-year follow-up and documented postoperative complications.

Results:

Focal osteolysis in either the femur or acetabulum was observed in 12 hips (7.5%, 44 months after surgery on average), with pseudotumor observed in 8 hips (5%, 120 months after surgery on average). Four hips (2.5%) had dislocations (84 months after surgery on average) and six hips (3.8%, 122 months after surgery on average) underwent reoperation.

Conclusion:

Small-head metal-on-metal total hip arthroplasty is associated with a high degree of complications at mid-term follow-up period. Considering this, we discourage the use of metal-on-metal total hip arthroplasty regardless of head size.

Metasul vs Cerasul bearings: a prospective, randomized study at a mean eighteen years

BACKGROUND

The aims of our study were to compare the clinical, radiographic outcomes and survivals between second-generation metal-on-metal (Metasul) and ceramic-on-ceramic (Cerasul) bearings at a very long-term follow-up.

METHODS

A prospective, randomized study was originally performed on a consecutive series of 250 cementless, 28-mm head and primary total hip arthroplasties between 1999 and 2002. For each bearing (Metasul or Cerasul), 125 THAs were initially included. All cases were evaluated both clinically and radiographically, and survival was assessed, considering revisions for aseptic loosening or for any reason as the end points for failure.

RESULTS

At a mean 18-year follow-up, clinical and radiographic outcomes were similar. Harris Hip Score increased 30% in the Metasul group and 32% in the Cerasul group (p = 0.6). Survival free of aseptic loosening was higher for Cerasul (100%), than for Metasul (94% [CI 88-99.9]) (p = 0.04). Survival free of any revision was 91% ([CI 84-98%]) for Cerasul and 91% ([CI 84-98%]) for Metasul. Fractures of Cerasul insert occurred in four cases (3%) at a mean 12.5 ± 3.3 years (range, 6 to 17 years).

CONCLUSION

At 18 years, Cerasul demonstrated higher survivorship than Metasul considering aseptic loosening as an end point. However, Cerasul liners had high rate of fracture because of its sandwich design (thin ceramic liner into polyethylene). These implants are no more available on the market.

Low Revision Rates at 10 years for Metal on Metal Hip Implants in a Military Population

INTRODUCTION

Prior to being largely abandoned due to unacceptably high failure rates and the adverse physiologic reactions to metal ions, metal-on-metal (MoM) total hip arthroplasty (THA) and hip resurfacing (HR) were in widespread use throughout the USA, and the potential benefit of decreased volumetric wear rates made it of particular interest to those who serve a young active population, such as military surgeons. The aim of our study was to determine the revision rate of metal on metal hip implants performed at our military institution and obtain current patient reported outcomes from this cohort.

MATERIALS AND METHODS

We conducted a retrospective review of patients who underwent MoM total hip arthroplasty (THA) or hip resurfacing (HR) at our institution from 2006 to 2012. Revision status and component type were determined, and patients were contacted to obtain current HOOS JR scores.

RESULTS

We identified 103 THAs in 88 patients and 38 HRs in 33 patients, with mean follow up of 10.2 years. Average age at time of surgery was 48 years, and 85% of the patients were male. The mean HOOS JR score in the THA and HR groups were 84.9 ± 17.6 and 75.8 ± 24.9, respectively (p = 0.38), and were not significantly lower in those who were revised. Two THA revisions occurred for metallosis and one for aseptic loosening of the femoral component. One HR revision occurred for breach of the anterior femoral neck, and one occurred for heterotopicossification.

CONCLUSIONS

Revision rates of MoM THA and HR in this young, predominantly male population were 2.9% and 5.3%, respectively, and patients maintained generally good hip-specific outcomes.

New materials for hip and knee joint replacement: What's hip and what's in kneed?

Over the last three decades there have been significant advancements in the knee and hip replacement technology that has been driven by an issue in the past concerning adverse local tissue reactions, aseptic and septic loosening. The implants and the materials we utilize have improved over the last two decades and in knee and hip replacement there has been a decrease in the failures attributed to wear and osteolysis. Despite these advancements there are still issues with patient satisfaction and early revisions due to septic and aseptic loosening in knee replacement patients. This article reviews the state of current implant material technology in hip and knee replacement surgery, discusses some of the unmet needs we have in biomaterials, and reviews some of the current biomaterials and technology that may be able to solve the most common issues in the knee and hip replacement surgery.

A 20-year follow-up evaluation of total hip arthroplasty in patients younger than 50 using a custom cementless stem

AIM

The purpose of this study is to report the 20-year follow-up of a continuous series of 232 total hip arthroplasties (THAs) performed in patients aged less than 50 at the index surgery.

PATIENTS AND METHODS

This is a retrospective monocentric study which reports the clinical, radiographical and survival results of 232 THAs performed with a custom cementless femoral stem in 212 patients evaluated at follow-up ranging from 14 to 27 years.

RESULTS

At the time of follow-up, the mean Harris Hip Score was 94.1 (range 48-100). The Hip disability and Osteoarthritis Outcome Score was >80 points in all 5 categories for 146 patients (68.9%). 18 hips (8.5%) showed radiographical femoral abnormalities. 23 hips (10.8%) underwent revision of the implants. 13 were isolated cup revisions. 3 more hips had bipolar revisions for aseptic loosening at 15, 20 and 21 years. Taking stem revision for aseptic loosening as an endpoint, survivorship was 96.8% at 20 years (95% confidence interval, 95.1-98.5; patients at risk 76) and 94.5% at 25 years (91.7-97.3; patients at risk 12).

CONCLUSIONS

The results of this study confirm that THA using this custom-designed stem can provide excellent clinical and radiographical outcomes at a mean follow-up of 20 years in patients younger than 50. The individual 3D femoral stem and prosthetic neck has been able to restore extra- and intramedullary functional anatomy in this young and active cohort of patients.

Long-term results of metal on metal total hip arthroplasty in younger patients (<55yrs)

Introduction

Metal on Metal (MoM) hip arthroplasty saw a new era of popularity with development of its second generation bearing surfaces, in the first decade of this century. However, by the end of that decade, concerns had been raised due to metal debris related complications.We aimed to determine the survival of MoM stemmed hip replacement in younger population. We also studied the rate of revision related to adverse reaction to metal debris (ARMD) along with reviewing the clinical and radiological progress of MoM hip arthroplasty in younger age (<55 yrs) group.

Patients & Methods

This is a retrospective cohort study of patients 55 yrs old or younger, who had metal on metal (MoM) hip arthroplasty for osteoarthritis. We had 109 procedures performed on 90 patients with a mean follow up of 10 years. All patients were reviewed as per MHRA guidelines in planned follow-up clinics. Data analyses were performed using SPSS.

Results

Survival of implant in our younger cohort was 88.1% at a mean age if 10 years, with revision for any cause as an endpoint. Most of the patients were happy with the outcome of their hip replacement as they were able to perform activities of daily living and work without compromise. Mean Oxford hip score was 43.Altogether, there were 12 revisions, 7 of these were for metallosis and associated symptoms. Average time to revision was 7 years. Other analysis revealed mean acetabular cup inclination angle to be 49 degrees but no significant correlation was found between this angle and serum metal ion levels. Serum Chromium and Cobalt levels were significantly higher in revision group.

Discussion

Metal on metal hip arthroplasty prime popularity time has gone. In younger population, although revision rates are higher, the surviving implants give a very good outcome in terms of patient satisfaction. Most of the patients report a desired outcome of 'forgotten hip'.

What Is the Long-term Survival for Primary THA With Small-head Metal-on-metal Bearings?

BACKGROUND

Large-head metal-on-metal (MoM) bearing hip replacements have been shown to have a much higher rate of revision than other bearing surfaces. However, small-head (≤ 32 mm) MoM bearing surfaces have been in use for many years with several reports of satisfactory mid- to long-term survivorship. It is unclear whether the long-term survival of small-head MoM devices will continue to be satisfactory or whether the same concerns seen with the large-head MoM devices will ultimately become more prevalent.

QUESTIONS/PURPOSES

We analyzed a large national registry to ask: (1) What is the 15-year Kaplan-Meier survivorship of primary conventional THA using small-head (≤ 32 mm) MoM bearing surfaces compared with large-head MoM bearing surfaces in primary THA? (2) Is there an increased rate of revision for adverse reaction to metal debris (ARMD) in this group of patients over time?

METHODS

The Australian Orthopaedic Association National Joint Replacement Registry longitudinally maintains data on all primary and revision joint arthroplasties with nearly 100% capture. We analyzed all conventional primary THAs performed from Registry inception in September 1999 until December 31, 2015, in patients with a diagnosis of osteoarthritis and using MoM bearing surfaces ≤ 32 mm in diameter, defined as small-head MoM. The study group included 4838 primary THA with ≤ 32-mm MoM bearing surfaces. There were 2506 (51.8%) male patients and the median age of patients undergoing THA with a small-head MoM bearing surface was 64 years (range, 20-92 years of age). The outcome measure was the cumulative percent revision defined as the time to first revision using Kaplan-Meier estimates of survivorship at 15 years; reasons for revision and type of revision were also examined. We specifically investigated whether there was an increased risk of revision for ARMD in this MoM group compared with all other bearing surfaces. We compared these results with large-head MoM THAs (femoral head size > 32 mm).

RESULTS

The cumulative percent revision for small-head MoM designs at 15 years was 8.5% (95% confidence interval [CI], 7.3-9.9). The cumulative percent revision for large-head MoM at 14 years was 27.4% (95% CI, 24.8-30.2). Prostheses with a large-head MoM articulation have a higher rate of revision than small-head MoM bearing surfaces (hazard ratio after 6 years, 5.14; 95% CI, 4.1-6.5; p < 0.001). Over time, there was a gradual increase in the diagnosis of ARMD for small-head MoM and the cumulative incidence of revision for ARMD was 0.8% at 15 years.

CONCLUSIONS

Despite survival that is substantially greater than that of large-head MoM THAs, there has been a marked decrease in the use of small-head MoM designs in our registry. Although the reasons for this are likely multifactorial, the increasing incidence of revisions for ARMD among small-head MoM THAs is concerning.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Long-term clinical results of the Metasul metal-on-metal total hip arthroplasty: 12.6 years follow-up of 128 primary total hip replacements

INTRODUCTION

The purpose of the present study is to report the long-term clinical results of an uncemented total hip arthroplasty (THA) using a Metasul metal-on-metal (MoM) 28-mm bearing and to evaluate the long-term serum cobalt levels.

METHODS

At an average of 12.6 years following primary THA, we retrospectively reviewed the clinical results of the first 116 consecutive patients (128 THAs) in our institution who underwent 28-mm Metasul MoM THA. Of the 78 patients who were able to visit our outpatient clinic, serum cobalt levels were evaluated.

RESULTS

The overall survival rate of the cohort was 96.1% (95% confidence interval [CI], 93.2-99.6), 12.6 years (95% CI, 12.3-12.7 years) following surgery. 3 patients had undergone revision due to aseptic loosening of the stem and 2 patients sustained a periprosthetic fracture. The average modified Harris Hip Score was 90 (72-97) and the average Oxford Hip Score was 56 (48-60), representing both excellent outcome scores. The average serum cobalt of the entire cohort was 20.1 nmol/L (range 8.5-227.7 nmol/L). Serum cobalt levels of patients with a bilateral MoM THA were significantly higher (35.0 nmol/l, p<0.01). No relation between serum cobalt levels, subjective outcome, radiolucent lines on radiographs and survivorship of the implant was noted.

CONCLUSIONS

Long-term results of the metasul MoM bearing articulation in THA seem to be excellent, although cobalt serum levels should be monitored closely.

3rd generation ceramic-on-ceramic cementless total hip arthroplasty: a minimum 10-year follow-up study

INTRODUCTION

3^rd generation ceramic bearings were introduced in total hip arthroplasty (THA) with the potential to have better mechanical strength and wear properties than their predecessors. At present, there are few studies looking at the long-term results of this latest generation of ceramic bearings. The purpose of our study was to investigate the long-term clinical and radiographic results of 3^rd generation ceramic-on-ceramic THA and the incidence of ceramic specific complications such as squeaking and bearing surface fracture.

METHODS

The database of the senior author (J.D.W.) was reviewed. A total of 126 hip replacements performed in 108 patients (average age 39.6 years) with an average follow-up of 12.1 years (10-16 years) was identified. Clinical notes and plain radiographs were reviewed. To measure function, patients were contacted and an Oxford Hip Questionnaire was completed. Patients were also directly questioned about the presence of squeaking or any other sounds from the hip. Radiographs were evaluated for signs of wear, osteolysis, loosening and heterotopic ossification. The abduction angle of the acetabular component was measured.

RESULTS

The average Oxford Hip Score was 39.8 out of 48. Survivorship at 10 years was 94.6% (95% CI) with revision for any cause as the endpoint. There was 1 femoral head fracture, no osteolysis, no squeaking and no detectable wear.

CONCLUSIONS

The good clinical and radiographic results for this series of patients are similar to other recent long-term studies looking at 3^rd generation ceramic-on-ceramic THA. The results compare favourably with other bearing surfaces. The lack of osteolysis associated with this articulation is encouraging and may also make it a good choice for younger patients requiring total hip replacement.

Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients

INTRODUCTION

Total hip arthroplasties (THAs) in younger patients are becoming increasingly popular. However, the outcome of subsequent revisions in younger patients is not well known and, therefore, their success (subsequent revision prosthesis survival) might be overestimated. We investigated available data on the outcome of primary- and subsequent revision THAs performed in the same cohort of patients who underwent primary THA under the age of 50.

METHODS

Medline, Embase and the Cochrane Library (CENTRAL) were searched up until April 13, 2016 for studies that reported both the survival of primary and subsequent revisions THA of single cohorts of patients younger than 50. Eligible articles had to include Kaplan Meier analysis or competing risk analysis for survival of the primary THA at a mean follow-up of 10 years, as well as for the subsequent revision THA within the same cohort.

RESULTS

We found 4,799 unique records; 43 of which were potentially eligible. Only 1 paper met our inclusion criteria. It reported on the survival of 69 primary prostheses at a mean of more than 10 years follow-up and 13 subsequent revisions.

CONCLUSIONS

There is a clear lack of evidence about the outcomes of the revision arthroplasty in younger patients. Only 1 study reported the survival-rate of subsequent revision arthroplasty with the minimum 10-year survival rate of the original THA cohort. In the future, this serious lack of knowledge could result in a large number of patients with no further reconstructive options after failed THA, and a large medical burden for society.

[Endoprostheses in the elderly : Biomaterials, implant selection and fixation technique]

The replacement of hip and knee joints is one of the greatest success stories in orthopedics. Due to continuous improvement of biomaterials and implant design, patient-associated problems are now mostly multifactorial and only rarely caused by the implant. Abrasion was significantly reduced by the introduction of highly cross-linked polyethylene (PE), antioxidant stabilized PE, new ceramics and the development of ceramic and protective surfaces. It is assumed that further reduction of frictional resistance will not lead to a significantly better clinical result: however, the problem of periprosthetic infections and implant-related incompatibility is still unsolved and remains challenging for biomaterial research. For the knee joint PE will be irreplaceable for joint articulation even in the future due to the contact situation. Mobile bearings and fixed bearings are two established successful philosophies, which have shown comparably good clinical results. For the hip joint, it is forecasted that ceramic-on-ceramic will be the system of the future if the correct positioning and mounting of the components can be solved so that the problems, such as development of noise and breakage can be reduced to a minimum. An in-depth understanding and detailed knowledge of the biomaterials by the surgeon can prevent implant-related problems. For elderly patients it is assumed that the economic burden on the public healthcare system will have the strongest impact on implant selection.

3rd generation ceramic-on-ceramic cementless total hip arthroplasty: a minimum 10-year follow-up study

INTRODUCTION

3rd generation ceramic bearings were introduced in total hip arthroplasty (THA) with the potential to have better mechanical strength and wear properties than their predecessors. At present, there are few studies looking at the long-term results of this latest generation of ceramic bearings.The purpose of our study was to investigate the long-term clinical and radiographic results of 3rd generation ceramic-on-ceramic THA and the incidence of ceramic specific complications such as squeaking and bearing surface fracture.

METHODS

The database of the senior author (J.D.W.) was reviewed. A total of 126 hip replacements performed in 108 patients (average age 39.6 years) with an average follow-up of 12.1 years (10-16 years) was identified. Clinical notes and plain radiographs were reviewed. To measure function, patients were contacted and an Oxford Hip Questionnaire was completed. Patients were also directly questioned about the presence of squeaking or any other sounds from the hip. Radiographs were evaluated for signs of wear, osteolysis, loosening and heterotopic ossification. The abduction angle of the acetabular component was measured.

RESULTS

The average Oxford Hip Score was 39.8 out of 48. Survivorship at 10 years was 94.6% (95% CI) with revision for any cause as the endpoint. There was 1 femoral head fracture, no osteolysis, no squeaking and no detectable wear.

CONCLUSIONS

The good clinical and radiographic results for this series of patients are similar to other recent long-term studies looking at 3rd generation ceramic-on-ceramic THA. The results compare favourably with other bearing surfaces. The lack of osteolysis associated with this articulation is encouraging and may also make it a good choice for younger patients requiring total hip replacement.

Comparison of Surgical Parameters and Results between Curved Varus Osteotomy and Rotational Osteotomy for Osteonecrosis of the Femoral Head

Background

Various osteotomies have been introduced to treat osteonecrosis of the femoral head. The purpose of this study was to compare surgical parameters, postoperative limb length discrepancy, and minimum 5-year clinical and radiological results between transtrochanteric curved varus osteotomy (TCVO) and transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head.

Methods

From 2004 to 2009, 103 consecutive TROs (97 patients) followed by 72 consecutive TCVOs (64 patients) were performed for the treatment of osteonecrosis of the femoral head. Of these, 85 patients (91 hips) in the TRO group and 58 patients (65 hips) in the TCVO group completed minimum 5-year clinical and radiological follow-up. The Kaplan-Meier product-limit method was used to estimate survival.

Results

The TCVO group had shorter operation time (p < 0.05) and less estimated blood loss (p = 0.026). Postoperative collapse developed in 26 hips (28.6%) in the TRO group and 7 hips (10.8%) in the TCVO group (p = 0.007). Osteophyte formation was observed in 34 hips (37.4%) in the TRO group and 13 hips (20%) in the TCVO group (p = 0.020). Fifteen hips (16.5%) in the TRO group and 7 hips (10.8%) in the TCVO group underwent conversion total hip arthroplasty (THA). The survival rate at 9 years with radiographic collapse as the endpoint was 68.7% (95% confidence interval [CI], 58.1% to 79.3%) in the TRO group, and 84.7% (95% CI, 71.5% to 97.9%) in the TCVO group. With conversion to THA as the endpoint, the survival rate was 82.2% (95% CI, 73.1% to 91.3%) in the TRO group and 89.2% (95% CI, 81.7% to 96.7%) in the TCVO group.

Conclusions

The comparison indicates that TCVO was better than TRO in terms of surgical parameters including operation time and estimated blood loss while the 9-year survival rates were similar.

Bousquet dual mobility socket for patient under fifty years old. More than twenty year follow-up of one hundred and thirty one hips

PURPOSE

The aim of this study was to analyze dual mobility cup survival rate on young patients under 50 years old at more than 20 years of follow up.

METHODS

One hundred thirty seven hips with a first generation of dual mobility Bousquet cup (Serf) were included. The mean age at the time of the surgery was 41 years and the mean follow-up was 21.9 years.

RESULTS

Twenty year follow-up cup survival rate was 77%. No dislocation occurred, 44 hips were revised (including 21 cup aseptic loosenings isolated, 15 Intra Prosthetic Dislocations), seven hips were lost to follow-up, 11 patients died, and 75 hips were still in situ.

CONCLUSION

First generation dual mobility cup survival on young patient was comparable with literature results. The main complications, cup aseptic loosening and intra prosthetic dislocation, were wear-related. With improvements of the defects of first generation dual mobility, we might expect an even better survival rate with contemporary DM cups.

Long-term Results of a First-Generation Annealed Highly Cross-Linked Polyethylene in Young, Active Patients

The survivorship of total hip arthroplasty in younger patients is dependent on the wear characteristics of the bearing surfaces. Long-term results with conventional polyethylene in young patients show a high failure rate. This study assessed the long-term results of a first-generation annealed highly cross-linked polyethylene (HCLPE) in uncemented total hip arthroplasty in young, active patients. Between 1999 and 2003, 112 total hip arthroplasty procedures performed in 91 patients with an average University of California Los Angeles activity score of 8 and mean age of 53 years (range, 24-65 years) were included from a prospective database. In all patients, a 28-mm metal femoral head on annealed HCLPE (Crossfire; Stryker, Mahwah, New Jersey) was used. At minimum 10-year follow-up (11.5±0.94 years), Kaplan-Meier survivorship was 97% for all failures (1 periprosthetic infection and 1 late dislocation) and 100% for mechanical failure (no revisions for osteolysis or loosening). This study showed low revision rates for wear-related failure and superior survivorship in young, active patients. Oxidation causing failure of the locking mechanism has not been a problem with Crossfire for up to 10 years.

Cementless Total Hip Arthroplasty With Metasul Bearings Provides Good Results in Active Young Patients: A Concise Followup

BACKGROUND

A primary concern of younger, more active patients who have undergone total hip arthroplasty (THA) is the longevity of the implant. Cementless fixation and hard-on-hard bearings are recognized as options to enhance THA durability. Earlier, we published a series of 83 cementless primary THAs using 28-mm metal-on-metal (MoM) bearings in patients aged 50 years or younger; here we provide concise followup on that same group after an additional 8-year survey period.

QUESTIONS/PURPOSES

(1) What is the long-term survivorship of cementless primary THA using 28-mm MoM bearings in patients aged 50 years or younger? (2) What are the clinical and radiographic results of cementless THA in this active patient population? (3) Can any of the observed implant failures or adverse events be attributed to the metallic nature of the bearing couple?

METHODS

We retrospectively reviewed 83 cementless THAs performed in three institutions over a decade (1995-2004) in 68 patients with 28-mm MoM articulation. All patients (15 bilateral) had a median age of 42 years (range, 24-50 years) at the time of the index procedure and 56 of them (82% [70 hips]) had activity level graded Devane 4 or 5 before significant hip pain. A 28-mm Metasul™ articulation was used with an Alloclassic-SL™ cementless stem in all cases paired with three different cementless titanium acetabular components (one threaded and two press-fit cups) from the same manufacturer. Survivorship analysis was calculated according to Dobbs life table, patient clinical results were evaluated with use of the Postel-Merle d'Aubigné scoring system, radiographic analysis was performed by independent observers, and cobalt level was determined in whole blood.

RESULTS

The 15-year survivorship (33 hips at risk) for revision for any reasons (four hips) and for aseptic loosening (one hip) was 96% (95% confidence interval [CI], 81%-99%) and 99% (95% CI, 85%-99.9%), respectively. The median Merle d'Aubigné-Postel score remained stable at 17 points (range, 10-18). Thus far, we have not observed pseudotumors or other adverse reactions to metallic debris. Eight hips have undergone reoperation: trochanteric suture removal (one), psoas tendon impingement (two), and five revisions for periprosthetic fracture (one), late infection (two), acetabular osteolysis (one, as a result of polyethylene backside wear), and one hydroxyapatite-coated cup for aseptic loosening. None of the complications, failures, or revisions observed so far could directly be related to the metallic nature of the 28-mm Metasul bearings used in this selected group of patients.

CONCLUSIONS

The current survey at 13-year median followup has not yet indicated any long-term deleterious effects related to dissemination of metallic ions. Two senior authors continue to use 28- or 32-mm Metasul™ bearings with cementless THA components in young and active patient populations. Longer followup with a more sophisticated imaging study is necessary to confirm this so far positive report.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Adverse Reactions to Metal on Metal Are Not Exclusive to Large Heads in Total Hip Arthroplasty

BACKGROUND

There is some suggestion that smaller diameter heads in metal-on-metal total hip arthroplasty (MoM THA) may be less prone to the adverse reactions to metal debris (ARMD) seen with large-diameter heads.

QUESTIONS/PURPOSES

We reviewed our population of patients with small head (≤ 32 mm) MoM THA to determine (1) the frequency of ARMD; (2) potential risk factors for ARMD in this population; and (3) the etiology of revision and Kaplan-Meier survivorship with revision for all causes.

METHODS

Small-diameter head MoM devices were used in 9% (347 of 3753) of primary THAs during the study period (January 1996 to March 2005). We generally used these implants in younger, more active, higher-demand patients. Three hundred hips (258 patients) had MoM THA using a titanium modular acetabular component with a cobalt-chromium tapered insert and were available for review with minimum 2-year followup (mean, 10 years; range, 2-19 years). Complete followup was available in 86% of hips (300 of 347). Clinical records and radiographs were reviewed to determine the frequency and etiology of revision. Kaplan-Meier survivorship analysis was performed.

RESULTS

ARMD frequency was 5% (14 of 300 hips) and represented 70% (14 of 20) of revisions performed. Using multivariate analysis, no variable tested, including height, weight, body mass index, age, cup diameter, cup angle, use of screws, stem diameter, stem type, head diameter, preoperative clinical score, diagnosis, activity level, or sex, was significant as a risk factor for revision. Twenty hips have been revised: two for infection, four for aseptic loosening, and 14 for ARMD. Kaplan-Meier analysis revealed survival free of component revision for all causes was 95% at 10 years (95% confidence interval [CI], 91%-97%), 92% at 15 years (95% CI, 87%-95%), and 72% at 19 years (95% CI, 43%-90%), and survival free of component revision for aseptic causes was 96% at 10 years (95% CI, 92%-98%), 92% at 15 years (95% CI, 88%-95%), and 73% at 19 years (95% CI, 43%-90%).

CONCLUSIONS

The late onset and devastating nature of metal-related failures is concerning with this small-diameter MoM device. Although the liner is modular, it cannot be exchanged and full acetabular revision is required. Patients with all MoM THA devices should be encouraged to return for clinical and radiographic followup, and clinicians should maintain a low threshold to perform a systematic evaluation. Symptomatic patients should undergo thorough investigation and vigilant observation for ARMD.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Small diameter metal-on-metal total hip arthroplasty at 13 years - a follow-up study

INTRODUCTION

Theoretically, the properties of second-generation metal-on-metal (MoM) bearings are better for wear, osteolysis and longevity. However, follow-up studies of more than 10 years are rare, in particular with hybrid fixation (cemented stainless steel stems and cementless cup), therefore we evaluated the results of this combination after a mean follow-up of 12.8 years: (1) to analyze the survival rate, (2) to compare it with the survival rate in the same series after 6.4 years (95.8% cup, 94.8% stem), (3) to evaluate clinical and radiographic outcome and (4) to analyze these failures.

HYPOTHESIS

The number of revisions would increase after 10 years.

MATERIALS AND METHODS

We evaluated 106 total hip arthroplasties (THA) (Cedior™ press-fit cup with cemented Acora™ (n=50) and Exafit™ (n=56) stems and 28mm Metasul™ bearings performed between January 1999 and December 2002. The survival rate was calculated by the Kaplan-Meier method. The clinical assessment included the Postel Merle d'Aubigné (PMA) and Oxford scores. The radiographic assessment evaluated radiolucencies and osteolysis on standard X-rays. A histological analysis was only performed during revision THA.

RESULTS

After a mean 12.8 years of follow-up (10-16), 53 THA were reviewed in 48 patients. Thirteen THA revisions (14%) were performed including 11 aseptic revisions (5 stem fractures, 2 cases of impingement and 3 loosenings [1 bipolar and 3 cups] and one case of osteolysis). Overall survival, taking into account revision for aseptic loosening, was 87.6% (CI 95%=77.3 to 99.3%). The mean PMA and Oxford scores at the final follow-up were 17.6±0.8 points (16-18) and 16.5±5.2 points (12-38) respectively. The radiological follow-up mainly identified radiolucencies around the stem in Gruen zones 1 and 7 (17 and 21% respectively).

DISCUSSION

The survival rate of hybrid MoM THA in this series decreased after 10 years and is lower than studies evaluating cementless THA with the 28-mm Metasul™ bearings (90.9 to 100% survival). Although the clinical results are satisfactory, survival is lower. However, the role of MoM bearings is relative in these failures, in particular because trunnionoses (stainless steel stem with 28-mm head), impingement and especially 5-stem fractures were the main causes of failure.

LEVEL OF EVIDENCE

IV: retrospective study.

Mid-term clinical results of total hip arthroplasty using a Wagner standard cup for dysplastic hip

BACKGROUND

The outcome of cementless total hip arthroplasty depends on many factors. We must not forget fundamental things those are design of outer surface of the component, that leads bone ingrowth into the prosthesis, better initial stability, and better insertional techniques. The purpose of this study was to review our experience with metal-on-metal total hip arthroplasty with a Wagner standard cup for patients who had acetabular dysplasia.

PATIENTS AND METHODS

Fifty-four patients with 55 hips underwent primary metal-on-metal total hip arthroplasty (Metasul prosthesis) with a Wagner standard cup (44-48 mm in outer diameter) and were followed for a minimum of 10 years. All patients received the same type of cementless femoral component (Natural hip stem) and femoral head (28 mm in diameter).

RESULTS

Seventeen of the 55 Wagner standard cups (30.9%) showed aseptic loosening over a mean period of 3.6 years after surgery, and there were no bone anchors on the outer surface of the 16 retrieved cups.

CONCLUSION

From our experience, the small Wagner standard cup does not achieve sufficient osteointegration and we do not recommend the use of this cup, especially for patients with acetabular dysplasia and/or those with a small stature.

How have alternative bearings and modularity affected revision rates in total hip arthroplasty?

BACKGROUND

Total hip arthroplasty (THA) continues to be one of the most successful surgical procedures in the medical field. However, over the last two decades, the use of modularity and alternative bearings in THA has become routine. Given the known problems associated with hard-on-hard bearing couples, including taper failures with more modular stem designs, local and systemic effects from metal-on-metal bearings, and fractures with ceramic-on-ceramic bearings, it is not known whether in aggregate the survivorship of these implants is better or worse than the metal-on-polyethylene bearings that they sought to replace.

QUESTIONS/PURPOSES

Have alternative bearings (metal-on-metal and ceramic-on-ceramic) and implant modularity decreased revision rates of primary THAs?

METHODS

In this systematic review of MEDLINE and EMBASE, we used several Boolean search strings for each topic and surveyed national registry data from English-speaking countries. Clinical research (Level IV or higher) with ≥ 5 years of followup was included; retrieval studies and case reports were excluded. We included registry data at ≥ 7 years followup. A total of 32 studies (and five registry reports) on metal-on-metal, 19 studies (and five registry reports) on ceramic-on-ceramic, and 20 studies (and one registry report) on modular stem designs met inclusion criteria and were evaluated in detail. Insufficient data were available on metal-on-ceramic and ceramic-on-metal implants, and monoblock acetabular designs were evaluated in another recent systematic review so these were not evaluated here.

RESULTS

There was no evidence in the literature that alternative bearings (either metal-on-metal or ceramic-on-ceramic) in THA have decreased revision rates. Registry data, however, showed that large head metal-on-metal implants have lower 7- to 10-year survivorship than do standard bearings. In THA, modular exchangeable femoral neck implants had a lower 10-year survival rate in both literature reviews and in registry data compared with combined registry primary THA implant survivorship.

CONCLUSIONS

Despite improvements in implant technology, there is no evidence that alternative bearings or modularity have resulted in decreased THA revision rates after 5 years. In fact, both large head metal-on-metal THA and added modularity may well lower survivorship and should only be used in select cases in which the mission cannot be achieved without it. Based on this experience, followup and/or postmarket surveillance studies should have a duration of at least 5 years before introducing new alternative bearings or modularity on a widespread scale.

10-year results of the uncemented Allofit press-fit cup in young patients

BACKGROUND AND PURPOSE

Uncemented acetabular components in primary total hip arthroplasty (THA) are commonly used today, but few studies have evaluated their survival into the second decade in young and active patients. We report on a minimum 10-year follow-up of an uncemented press-fit acetabular component that is still in clinical use.

METHODS

We examined the clinical and radiographic results of our first 121 consecutive cementless THAs using a cementless, grit-blasted, non-porous, titanium alloy press-fit cup (Allofit; Zimmer Inc., Warsaw, IN) without additional screw fixation in 116 patients. Mean age at surgery was 51 (21-60) years. Mean time of follow-up evaluation was 11 (10-12) years.

RESULTS

At final follow-up, 8 patients had died (8 hips), and 1 patient (1 hip) was lost to follow-up. 3 hips in 3 patients had undergone acetabular revision, 2 for deep infection and 1 for aseptic acetabular loosening. There were no impending revisions at the most recent follow-up. We did not detect periacetabular osteolysis or loosening on plain radiographs in those hips that were evaluated radiographically (n = 90; 83% of the hips available at a minimum of 10 years). Kaplan-Meier survival analysis using revision of the acetabular component for any reason (including isolated inlay revisions) as endpoint estimated the 11-year survival rate at 98% (95% CI: 92-99).

INTERPRETATION

Uncemented acetabular fixation using the Allofit press-fit cup without additional screws was excellent into early in the second decade in this young and active patient cohort. The rate of complications related to the liner and to osteolysis was low.

Changes in the prevalence of mood and anxiety disorders among male and female current smokers in the United States: 1990-2001

PURPOSE

The present study investigated whether the prevalence of mood and anxiety disorders has increased over time among current smokers and whether these trends differ by gender and in comparison with nonsmokers.

METHODS

Data were drawn from the National Comorbidity Survey (1990) and the National Comorbidity Survey-Replication (2001), representative samples of the US adult population. Binomial regression analyses were used to determine differences between mood and anxiety disorders among current smokers in 1990 and 2001 and whether these differed by gender and in comparison with those who were former or never current smokers.

RESULTS

Any anxiety disorder, panic attacks, panic disorder, social anxiety disorder and dysthymia were all significantly more common among current smokers in 2001 compared with 1990 and except for social anxiety disorder these increases were significantly greater than any trend found in non-smokers. Increases in panic attacks, social anxiety disorder, and dysthymia were more pronounced in female than in male smokers. Major depressive disorder and generalized anxiety disorder were not found to increase over time among smokers.

CONCLUSIONS

The prevalence of several anxiety disorders and dysthymia among current smokers appears to have increased from 1990 to 2001. Future studies are needed to determine whether these trends have continued. If so, interventions aimed at moving the prevalence lower may have limited success if treatment of mental health problems such as anxiety disorders and certain mood disorders are not considered in the development and dissemination of tobacco control programs.

Excellent survivorship of the Morscher monoblock cup with a 28-mm Metasul-on-Metasul bearing at a mean of 5-year follow-up

The Morscher monoblock cup is designed for optimal osteointegration and holds the potential for excellent long-term survival. The Metasul-on-Metasul bearing was introduced to eliminate wear-induced periprosthetic osteolysis. This study reviews 137 Morscher cups with a 28-mm Metasul-on-Metasul bearing used in primary THA at 5.1years (3.2-6.6) after implantation. One hundred thirty-seven cups were implanted in 119 patients. Three patients (2.2%) had died of unrelated causes, and 10 patients (8.0%) were lost to follow-up. The mean Harris Hip score was 89.8 and the mean WOMAC sum score was 18.5. No cases of acetabular osteolysis were found. The 5-year cup survival rate was 98.5%. The Morscher cup with a 28-mm Metasul-on-Metasul bearing used in uncemented THA showed no acetabular osteolysis and promising survivorship at intermediate-term follow-up.

Minimum ten-year results of a 28-mm metal-on-metal bearing in cementless total hip arthroplasty in patients fifty years of age and younger

PURPOSE

Concerns have been raised in relation to metal-on-metal (MoM) articulations with catastrophic soft-tissue reactions due to metal debris. We reviewed how small head MoM articulations perform in primary uncemented total hip arthroplasty (THA) in young patients at a minimum of ten years.

METHODS

We retrospectively evaluated the clinical and radiographic results of the first 100 consecutive primary cementless THAs using the 28-mm Metasul MoM articulation in 91 patients younger than 50 years of age at the time of surgery.

RESULTS

After 13 years, survival for the endpoint revision due to any reason was 90.9 % and 98.9 % for revision due to aseptic implant loosening. The cumulative incidence of MoM related revisions was 1.2 %. Small proximal femoral osteolysis was found in 18 % of hips. No acetabular osteolysis or loosening was detected. Two hips showed signs of femoral neck impingement with severe damage to the neck.

CONCLUSIONS

Early in the second decade, MoM-associated complications were rare using the 28-mm Metasul articulation, and aseptic loosening was not a major mode of failure in this cohort of young patients.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

Despite the worldwide usage of the cemented Contemporary acetabular component (Stryker), no published data are available regarding its use in patients aged < 50 years. We undertook a mid- to long-term follow-up study, including all consecutive patients aged < 50 years who underwent a primary total hip replacement using the Contemporary acetabular component with the Exeter cemented stem between January 1999 and January 2006. There were 152 hips in 126 patients, 61 men and 65 women, mean age at surgery 37.6 years (16 to 49 yrs). One patient was lost to follow-up.

Mean clinical follow-up of all implants was 7.6 years (0.9 to 12.0). All clinical questionnaire scores, including Harris hip score, Oxford hip score and several visual analogue scales, were found to have improved. The eight year survivorship of all acetabular components for the endpoints revision for any reason or revision for aseptic loosening was 94.4% (95% confidence interval (CI) 89.2 to 97.2) and 96.4% (95% CI 91.6 to 98.5), respectively. Radiological follow-up was complete for 146 implants. The eight year survival for the endpoint radiological loosening was 93.1% (95% CI 86.2 to 96.6). Three surviving implants were considered radiologically loose but were asymptomatic. The presence of acetabular osteolysis (n = 17, 11.8%) and radiolucent lines (n = 20, 13.9%) in the 144 surviving cups indicates a need for continued observation in the second decade of follow-up in order to observe their influence on long-term survival.

The clinical and radiological data resulting in a ten-year survival rate > 90% in young patients support the use of the Contemporary acetabular component in this specific patient group.

Cite this article: Bone Joint J 2013;95-B:1617–25.

The results of metal-on-metal hip resurfacing in patients under 30 years of age

Degenerative hip conditions most commonly affect older patients. However, many cases occur in younger patients. Total hip arthroplasty is the conventional approach; however, hip resurfacing is a viable option. Fifty-three metal-on-metal resurfacings in 46 patients under age 30 were performed. Patients had a variety of etiologies, and were followed clinically and radiographically with mean follow-up of 98.2 months. Clinical scores and x-rays were compared pre-operatively and post-operatively. The last follow-up SF-12 and UCLA scores significantly improved post-operatively (P<0.0001). Range of motion scores also improved (P<0.001), and the mean Harris Hip Score was 88. There were 6 revisions. The Kaplan-Meier survivorship estimate at 8 years was 95%. Metal-on-metal hip resurfacing appears to be an effective procedure for younger patients. Longer-term data are needed for confirmation.

Is bipolar hemiarthroplasty a reliable option for Ficat stage III osteonecrosis of the femoral head? 15- to 24-year follow-up study

PURPOSE

The long-term results of a bipolar hemiarthroplasty (BHA) for osteonecrosis (ON) of the femoral head have not been favorable. The causes have been attributed to cup migration and osteolysis or groin pain. The purpose of this study was to analyze the long-term outcomes and the survivorships of bipolar hemiarthroplasty applied to Ficat stage III ON.

MATERIALS AND METHODS

Between 1985 and 1993, 49 patients (63 hips) underwent cementless BHA for Ficat stage III ON. Of these 49 patients, 43 patients (55 hips) of mean age 42.2 years were available for follow-up review at a mean duration of 20.3 years post operation. Anteroposterior hip serial (including extreme abduction/adduction) radiographs were used to evaluate osteolysis, migration, cartilage wear rate, and the ratio of outer/inner bearing motion (O/I ratio) at the latest follow-up.

RESULTS

The mean Harris hip score improved to 80.8 points at the latest follow-up. Survivorship at 24 years was 79 and 69 % with revision for any reason and development of acetabular osteolysis as the end point. Groin pain was present in 20 (36.4 %) of the 55 hips, and isolated groin pain was not a reason for revision. The patients had revision surgery performed, which showed that the cartilage wear rate was significantly high, and that the O/I ratio was significantly low (p < 0.05).

CONCLUSION

Survivorship determined in this study was more favorable than that of previous studies, and exceeded expectation. The BHA for Ficat stage III ON is not reliable option anymore, considering low survival rate and high osteolysis developmental rate.

Bearing surface considerations for total hip arthroplasty in young patients

Bearing selection for total hip arthroplasty in young patients is important because of the likely long service life of the implant. Careful consideration of the next operation is recommended when choosing components. No prospective, randomized studies exist that document the clear superiority of any bearing couple in young, active patients. Modern metals, ceramics, and polyethylenes all hold promise. Further long-term data on modern bearings are needed to determine the clinical performance of these bearings. This article summarizes the available data on various bearing couples in patients aged younger than 50 years.