Hip Resurfacing News - Medical Studies

Increase risk femoral fracture with osteoporosis drugs

nospam@example.com (Patricia Walter) — Fri, 30 Dec 2011 07:06:51 -0700

For Immediate Release: October 13, 2010 Media Inquiries: Karen Riley, 301-796-4674, karen.riley@fda.hhs.gov Consumer Inquiries: 888-INFO-FDA

FDA: Possible increased risk of thigh bone fracture with bisphosphonates Labeling change adds warning about possible risks of long-term use of osteoporosis drugs

The U.S. Food and Drug Administration today warned patients and health care providers about the possible risk of atypical thigh bone (femoral) fracture in patients who take bisphosphonates, a class of drugs used to prevent and treat osteoporosis. A labeling change and Medication Guide will reflect this risk.

Bisphosphonates inhibit the loss of bone mass in people with osteoporosis. Bisphosphonates have been shown to reduce the rate of osteoporotic fractures -- fractures that can result in pain, hospitalization, and surgery-- in people with osteoporosis. While it is not clear whether bisphosphonates are the cause, atypical femur fractures, a rare but serious type of thigh bone fracture, have been predominantly reported in patients taking bisphosphonates. The optimal duration of bisphosphonate use for osteoporosis is unknown, and the FDA is highlighting this uncertainty because these fractures may be related to use of bisphosphonates for longer than five years.

The labeling changes and Medication Guide will affect only those bisphosphonates approved for osteoporosis, including oral bisphosphonates such as Fosamax, Fosamax Plus D, Actonel, Actonel with Calcium, Boniva, Atelvia, and their generic products, as well as injectable bisphosphonates such as Reclast and Boniva.

Labeling changes and the Medication Guide will not apply to bisphosphonates used for Paget's disease or cancer/hypercalcemia such as Didronel, Zometa, Skelid, and their generic products.

"The FDA is continuing to evaluate data about the safety and effectiveness of bisphosphonates when used long-term for osteoporosis treatment," said RADM Sandra Kweder, M.D., deputy director, Office of New Drugs in the FDA's Center for Drug Evaluation and Research. "In the interim, it's important for patients and health care professionals to have all the safety information available when determining the best course of treatment for osteoporosis."

Today's warning follows a March 10, 2010, Drug Safety Communication announcing the FDA's ongoing safety review of bisphosphonate use and the occurrence of atypical femur fractures. The FDA has since reviewed all available data on bisphosphonate use, including data summarized in the American Society for Bone Mineral Research Task Force report. The report recommended additional product labeling, better identification and tracking of patients experiencing these breaks, and more research to determine whether and how these drugs cause the serious but uncommon fractures.

Based on the FDA's review, the Warnings and Precautions section of all bisphosphonate products for osteoporosis will be revised, and the FDA will require the inclusion of a Medication Guide to better inform patients of the possible increased fracture risk.

The FDA recommends that health care professionals be aware of the possible risk in patients taking bisphosphonates and consider periodic reevaluation of the need for continued bisphosphonate therapy for patients who have been on bisphosphonates for longer than five years.

Patients taking bisphosphonates for osteoporosis should not stop using their medication unless told to do so by their health care professional. Those taking bisphosphonates also should report any new thigh or groin pain to their health care provider and be evaluated for a possible femur fracture. Patients and health care professionals should report side effects with the use of bisphosphonates to the FDA's MedWatch Adverse Event Reporting program at www.fda.gov/MedWatch or by calling (800) 332-1088.

For more information: FDA Drug Safety Communication Consumer Update: Possible Fracture Risk With Osteoporosis Drugs

Metal Ion Levels in Triathlete with Hip Resurfacing

nospam@example.com (Patricia Walter) — Mon, 10 Sep 2007 06:35:49 -0700

Metal ion levels in a triathlete with a metal-on-metal resurfacing arthroplasty of the hip

R. De Haan, MD, Orthopaedic Resident¹; P. Campbell, PhD, Research Scientist, Associate Professor²; S. Reid, MD, PhD, Sports Medicine Physician³; A. K. Skipor, MS, Research Scientist⁴; and K. De Smet, MD, Orthopaedic Surgeon¹

1 ANCA Medical Center, Krijgslaan 181, 9000 Gent, Belgium.
2 J Vernon Luck Snr MD, Orthopaedic Research Center, Orthopaedic Hospital, 2400 S., Flower Street, UCLA, Los Angeles 90007, California, USA.
3 St. Helen’s Private Hospital, 186, Macquarie Street, Hobart, Tasmania 7000, Australia.
4 Department of Orthopaedic Surgery, Rush Presbyterian St Luke’s, Medical Center, Room 756, Cohn Research Building, 1735 West Harrison Street, Chicago, Illinois 60612-3833, USA.

A prospective study of serum and urinary ion levels was undertaken in a triathlete who had undergone a metal-on-metal resurfacing arthroplasty of the hip four years previously. The one monthstudy period included the final two weeks of training, the dayof the triathlon, and the two weeks immediately post-race. Serumcobalt and chromium levels did not vary significantly throughoutthis period, including levels recorded on the day after the11-hour triathlon. Urinary excretion of chromium increased immediatelyafter the race and had returned to pre-race levels six dayslater. The clinical implications are discussed.

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Hip Resurfacing vs Total Hip Replacement Study 2007

nospam@example.com (Patricia Walter) — Thu, 20 Sep 2007 05:19:05 -0700

Study: Surface replacement arthroplasty may offer advantages over THA

Canadian investigators said hip resurfacing resulted in greater patient activity after 2 years.

By Robert Trace
1st on the web (September 19, 2007)
September 2007

SEOUL — Total hip arthroplasty is an established procedure with well-documented complication rates and clinical results, but surface replacement arthroplasty may offer additional clinical benefits to many patients, according to a group of Canadian researchers.

"We decided in 2003 to do a comparative study of hip resurfacing, or surface replacement arthroplasty (SRA), to the gold standard of total hip arthroplasty (THA), since we were not aware of any direct prospective studies out there comparing the two procedures," said Pascal-André Venditolli, MD, of the Maisonneuve-Rosemont Hospital in Quebec.

He and his colleagues randomly assigned 210 hips to receive uncemented metal-on-metal THA (103 hips) or a hybrid metal-on-metal SRA (107 hips). All surgeries were performed by three orthopedic surgeons, who used a posterior approach.

The researchers prospectively collected perioperative and postoperative data, and analyzed the clinical data for a minimum of 2 years.

Postop complications included three isolated traumatic dislocations and one recurrent dislocation in the THA group, which required acetabular cup revision. Two SRAs required revision for late head collapse. No postop femoral neck fractures occurred in the SRA group, he said.

There was one case of loosening at 6 months postop in the resurfacing group, which had shifted varus. There were also two cases of deep venous thrombosis in both patient groups, he said.

Although the investigators did not report a significant difference in surgical time between the two procedures, patients' length of stay in the hospital was significantly shorter for the SRA group compared to the THA patients — 5 days vs. 6.1 days for the THA group (P=.001).

"There was also a significant difference in return to work: 96% of the SRA patients returned to their previous work within 1 year vs. 83% in the THA group," Venditolli said.

Although patients in both groups demonstrated a high satisfaction rate and achieved similar WOMAC and Merle d'Aubigné functional scores, "SRA patients had better UCLA activity scores (7.1 vs. 6.3; P=.037) and returned to heavier activities (P=.035)" after 2 years, he said.

"This randomized study shows that SRA and THA present a similar complication rate, but distinctive complications," Venditolli said. "It also suggests that SRA results in better function and improved patient activity in comparison to THA.

"However, the effect of long-term fixation related to increased activity levels is unknown. Long-term follow-up is necessary to determine the survivorship of SRA over THA," he said.

For more information:

Vendittoli P-A, Lavigne M, Lusignan D, Roy A-G. A randomized study comparing surface replacement arthroplasty to total hip arthroplasty: 2-4 years follow-up. F028-2. Presented at the 15th Triennial Congress of the Asia Pacific Orthopaedic Association. Sept. 9-13, 2007. Seoul.

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Hip Resurfacing Advantages over THR Study

nospam@example.com (Patricia Walter) — Thu, 04 Oct 2007 06:12:05 -0700

Study: Surface replacement arthroplasty may offer advantages over THA

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Canadian investigators said hip resurfacing resulted in greater patient activity after 2 years.

By Robert Trace
1st on the web (September 19, 2007)
September 2007

SEOUL — Total hip arthroplasty is an established procedure with well-documented complication rates and clinical results, but surface replacement arthroplasty may offer additional clinical benefits to many patients, according to a group of Canadian researchers.

"We decided in 2003 to do a comparative study of hip resurfacing, or surface replacement arthroplasty (SRA), to the gold standard of total hip arthroplasty (THA), since we were not aware of any direct prospective studies out there comparing the two procedures," said Pascal-André Venditolli, MD, of the Maisonneuve-Rosemont Hospital in Quebec.

He and his colleagues randomly assigned 210 hips to receive uncemented metal-on-metal THA (103 hips) or a hybrid metal-on-metal SRA (107 hips). All surgeries were performed by three orthopedic surgeons, who used a posterior approach.

The researchers prospectively collected perioperative and postoperative data, and analyzed the clinical data for a minimum of 2 years.

Postop complications included three isolated traumatic dislocations and one recurrent dislocation in the THA group, which required acetabular cup revision. Two SRAs required revision for late head collapse. No postop femoral neck fractures occurred in the SRA group, he said.

There was one case of loosening at 6 months postop in the resurfacing group, which had shifted varus. There were also two cases of deep venous thrombosis in both patient groups, he said.

Although the investigators did not report a significant difference in surgical time between the two procedures, patients' length of stay in the hospital was significantly shorter for the SRA group compared to the THA patients — 5 days vs. 6.1 days for the THA group (P=.001).

"There was also a significant difference in return to work: 96% of the SRA patients returned to their previous work within 1 year vs. 83% in the THA group," Venditolli said.

Although patients in both groups demonstrated a high satisfaction rate and achieved similar WOMAC and Merle d'Aubigné functional scores, "SRA patients had better UCLA activity scores (7.1 vs. 6.3; P=.037) and returned to heavier activities (P=.035)" after 2 years, he said.

"This randomized study shows that SRA and THA present a similar complication rate, but distinctive complications," Venditolli said. "It also suggests that SRA results in better function and improved patient activity in comparison to THA.

"However, the effect of long-term fixation related to increased activity levels is unknown. Long-term follow-up is necessary to determine the survivorship of SRA over THA," he said.

For more information:

Vendittoli P-A, Lavigne M, Lusignan D, Roy A-G. A randomized study comparing surface replacement arthroplasty to total hip arthroplasty: 2-4 years follow-up. F028-2. Presented at the 15th Triennial Congress of the Asia Pacific Orthopaedic Association. Sept. 9-13, 2007. Seoul.

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Hip Resurfacing Femoral Neck Fracture Influenced by Valgus Placement

nospam@example.com (Patricia Walter) — Mon, 28 Jan 2008 13:34:56 -0700

Link http://www.medcompare.com/litupdate.asp?ArticleID=14960&typeid=24

1/1/2008

Journal: Clinical Orthopaedics and Related Research

Citation: 465:71-79, December 2007.

Authors: Carolyn Anglin, PhD, PEng; Bassam A Masri, MD, FRCSC; Jérôme Tonetti, MD; Antony J Hodgson, PhD, PEng; Nelson V Greidanus, MD, FRCSC

Femoral neck fracture is the most common short-term concern after hip resurfacing arthroplasty. Currently, there is little basis to decide between neutral and valgus placement. We loaded 10 notched cadaveric femur pairs to failure; one side was implanted at 0[degrees] relative to the femoral neck and the other at 10[degrees] valgus. All 20 were dual-energy xray absorptiometry-scanned. Failure load correlated with bone mineral density. Valgus placement increased the fracture load by an average of 28% over neutral for specimens with normal bone mineral density but had no effect on fracture load in specimens with low bone mineral density. For specimens with normal bone mineral density (typical of patients undergoing resurfacing arthroplasty), neutral-valgus placement had a greater effect than bone mineral density, explaining 54% of the fracture load variance. Component placement greater than 10[degrees] valgus is likely undesirable because this can lead to an increase in component size and a greater likelihood of notching. To reduce fracture risk, we recommend placing the femoral component in valgus and selecting patients with higher bone mineral density.

Hip Resurfacing Shows Narrower Edge Than Anticipated

nospam@example.com (Patricia Walter) — Tue, 17 Jun 2008 08:19:50 -0700

AAOS SAN FRANCISCO, March 7, 2008 - Some of the purported advantages of hip resurfacing over standard arthroplasty, though not all, seem to be real, researchers found in a randomized trial.

But other pluses in activity and function can probably be chalked up to patient selection bias and expectations, reported Martin Lavigne, M.D., of the University of Montreal, and colleagues, at the American Academy of Orthopaedic Surgeons meeting here.

In the randomized trial, patients who had hip resurfacing were significantly more likely to return to work and sports and had better step and hop test scores than standard arthroplasty patients did.

But functional scores and range of motion were no better than with hip replacement, the investigators found.

Hip resurfacing gained popularity with patients and some orthopedic surgeons on the basis of assumptions about better clinical function and ability to return to a high level of activity.

While retrospective cohort studies reinforced this perceived benefit, Dr. Lavigne said, "obviously there was a bias in the patient selection for hip resurfacing." Patients who sought hip resurfacing tended to be younger, more active, healthier, and expected a more active life after surgery, he said.

The newer procedure is still controversial among orthopedic surgeons despite rapid increases, commented Tom Schmalzried, M.D., of the Orthopaedic Hospital in Los Angeles, in a press conference where there was debate over the two approaches.

"The results of good, modern total hip replacement are really, really good," he said. "So for resurfacing to have a favorable risk-to-benefit ratio, you have to show you are getting something you don't get with total hip replacement."

For a more objective answer to this issue, Dr. Lavigne's group randomized 210 patients who were candidates for either procedure to undergo either uncemented 28-mm metal-on-metal total hip arthroplasty or hybrid metal-on-metal hip resurfacing.

All procedures were done by the same three surgeons with a posterior approach. Patients were informed which surgery they underwent only afterward.

Patients had a mean age around 50. Body mass index was higher in the total hip arthroplasty group.

Functional scores were slightly worse in the hip replacement group at six months (17 versus 11 on the WOMAC scale) but identical by two years (5 for both).

At six months after surgery, hopping on the affected leg was significantly easier for resurfacing group patients ("easy" or "very easy" 91.7% versus 78.9% and "difficult" or "impossible" 8.3% versus 21.1%, P=0.023).

Likewise, climbing stairs in a step test was easier at six months in the resurfacing group compared with the replacement group ("easy" or "very easy" 94.4% versus 76.3% and "difficult" or "impossible" 5.6% versus 23.7%, P=0.015).

Hip resurfacing group patients were also more likely to return to their prior work (96% versus 83%, P=0.02).

The young age of the patients made this an important outcome, Dr. Lavigne said.

Among the patients, 152 had data on activity level pre- and post-procedure.

Despite similar activity levels before surgery (P=0.22), more hip resurfacing than hip replacement patients returned to sports activities by one year after surgery (15% versus 7% high impact and 38% versus 28% moderate impact activity, P=0.022).

On a scale that included activities of daily living as well as sports, the difference tended to favor hip resurfacing but was not significant at one year (P=0.074).

"Both groups returned to a high level of activity," Dr. Lavigne said. "Hip resurfacing patients seem to be more active, but not as much as expected."

Type of surgery had no significant impact on what factors patients reported as limiting their return to sports activities, including implant protection, discomfort, fear of instability, and thigh pain.

Hip range of motion -- including total arc, arc of rotation, flexion-extension arc, and abduction-adduction arc -- was also similar for both groups among the 122 patients with data on this outcome (P>0.05).

Satisfaction with the procedure was uniformly high over time and across treatments.

While resurfacing is a more aggressive technique, Dr. Lavigne said, the rate of complications was similar between groups.

Long-term follow-up will be important to determine whether there are differences in need for revision between the procedures, he concluded.

Dr. Lavigne reported receiving research or institutional support from Zimmer, Stryker Howmedica, Biomet, DePuy, and Smith & Nephew and consulting for Zimmer.

Dr. Schmalzried reported receiving research or institutional support from Stryker, DePuy, Johnson & Johnson, Corin, and Wright Medical Technology; receiving miscellaneous funding from Stryker, DePuy, Johnson & Johnson, Corin, Wright Medical Technology, Zimmer, and Smith & Nephew; receiving royalties from Stryker, DePuy, Johnson & Johnson, Corin, and Wright Medical Technology; holding stock options in Stryker, DePuy, Johnson & Johnson, Corin, Wright Medical Technology, Zimmer, Biomet, Bristol-Myers Squib, and Pfizer; and being a consultant for Stryker.

Primary source: American Academy of Orthopaedic Surgeons meeting
Source reference:
Lavigne M, et al "Range of motion after hip resurfacing and THA: A single-blind randomized clinical study" AAOS meeting 2008; Abstract 058.

Additional source: American Academy of Orthopaedic Surgeons meeting
Source reference:
Lavigne M, et al "A randomized study comparing surface replacement arthroplasty to total hip arthroplasty" AAOS meeting 2008; Abstract 056.

Additional source: American Academy of Orthopaedic Surgeons meeting
Source reference:
Lavigne M, et al "Return to sports after hip resurfacing and total hip arthroplasty: A randomized clinical trial" AAOS meeting 2008; Abstract 053.

Sports Activity After Total Hip Resurfacing Study 2010

nospam@example.com (Patricia Walter) — Fri, 19 Mar 2010 05:45:01 -0700

Sports Activity After Total Hip Resurfacing Study 2010

Original Link http://www.ncbi.nlm.nih.gov/pubmed/20223940?dopt=Abstract

March 11, 2010

Banerjee M, Bouillon B, Banerjee C, Bäthis H, Lefering R, Nardini M, Schmidt J.
Dreifaltigkeits-Krankenhaus and Cologne Merheim Medical Center.

BACKGROUND: Little is known about sports activity after total hip resurfacing.

HYPOTHESIS: Patients undergoing total hip resurfacing can have a high level of sports activity. STUDY DESIGN: Case series; Level of evidence, 4.

METHODS: The authors evaluated the level of sports activities with a standardized questionnaire in 138 consecutive patients (152 hips) 2 years after total hip resurfacing. Range of motion, Harris hip score, and Oxford score were assessed, and radiological analysis was performed.

RESULTS: Preoperatively, 98% of all patients participated in sports activities. Two years postoperatively, 98% of the patients participated in at least 1 sports activity. The level of sports activity decreased after surgery. The number of sports activities per patient decreased from 3.6 preoperatively to 3.2 postoperatively. Intermediate- and high-impact sports, especially tennis, soccer, jogging, squash, and volleyball, showed a significant decrease while the low-impact sports (stationary cycling, Nordic walking, and fitness/weight training) showed a significant increase. Physical activity level at the time of follow-up as measured by the Grimby scale was significantly higher than in the year before surgery. Duration of sports participation per week increased significantly after surgery. Men had a significantly higher sport level than women before and after surgery. Eighty-two percent felt no restriction while performing sports. One-third missed certain sports activities such as jogging, soccer, tennis, and downhill skiing. The Harris hip and Oxford scores showed a significant increase postoperatively.

CONCLUSION: The results of this short-term follow-up study show that sports activity after total hip resurfacing surgery is still possible. Physical activity level increased with a shift toward low-impact sports. Duration of sports participation increased. High-impact sports activities decreased. These findings can be important for the decision-making process for hip surgery and should be communicated to the patient.

Does commitment to rehabilitation influence the clinical outcome of total hip resurfacing arthroplasty study 2010

nospam@example.com (Patricia Walter) — Tue, 23 Mar 2010 05:55:58 -0700

Does commitment to rehabilitation influence the clinical outcome of total hip resurfacing arthroplasty study 2010

Link to original medical study

The purpose of this study was to evaluate whether compliance and rehabilitative efforts were predictors of early clinical outcome of total hip resurfacing arthroplasty.

Methods: A cross-sectional survey was utilized to collect information from 147 resurfacing patients, who were operated on by a single surgeon, regarding their level of commitment to rehabilitation following surgery. Patients were followed for a mean of 52 months (range, 24 to 90 months).

Clinical outcomes and functional capabilities were assessed utilizing the Harris hip objective rating system, the SF-12 Health Survey, and an eleven-point satisfaction score. A linear regression analysis was used to determine whether there was any correlation between the rehabilitation commitment scores and any of the outcome measures, and a multivariate regression model was used to control for potentially confounding factors.

Results: Overall, an increased level of commitment to rehabilitation was positively correlated with each of the following outcome measures: SF-12 Mental Component Score, SF-12 Physical Component Score, Harris Hip score, and satisfaction scores.

These correlations remained statistically significant in the multivariate regression model.

Conclusions: Patients who were more committed to their therapy after hip resurfacing returned to higher levels of functionality and were more satisfied following their surgery.

Author: David MarkerThorsten SeylerAnil BhaveMichael ZywielMichael Mont
Credits/Source: Journal of Orthopaedic Surgery and Research 2010, 5:20

FDA to Collect Adverse Even Data for Metal Hip Implants

nospam@example.com (Patricia Walter) — Thu, 24 Mar 2011 19:08:47 -0700

U.S. FDA to Collect Adverse Event Data Despite UK Recall of Metal Hip Implants

Quality problems with metal-on-metal (MoM) hip replacement systems, like Johnson & Johnson (J&J)’s ASR devices, may not be as widespread as UK data indicates, the U.S. Food and Drug Administration (FDA) says. National Joint Registry of England and Wales data, which last year showed high revision rates for two ASR hip resurfacing systems, led to a UK medical device alert and recommended blood tests, as well as a worldwide J&J recall in August. But the FDA argues the adverse event rate for these devices remains unclear, and the agency is in the process of gathering additional information about adverse events in people with MoM hip implants.

Read More Here http://fdanews.com/newsletter/article?issueId=14568&articleId=135224

High Impact Sports and Metal on Metal Bearing Surface

nospam@example.com (Patricia Walter) — Thu, 03 Apr 2008 08:18:33 -0700

March 2008

SAN FRANCISCO - A study indicates that having a metal-on-metal bearing surface and performing high-impact activities preoperatively may be positive predictors for participating in high-impact sports after total hip arthroplasty.

To determine which patients would participate in high-impact sports activity following total hip arthroplasty (THA) and to examine the factors linked to participation in these sports, David R. Marker, BS, and colleagues submitted pre- and postoperative questionnaires to 303 THA patients who had a mean follow-up of 3 years.

The investigators found that 30% of patients participated in at least one or more high-impact sport postoperatively for an average of 4.3 hours per week.

A regression analysis revealed that a preoperative high activity level and metal-on-metal bearing surface were the only statistically significant factors to predict participation in high-impact sports postoperatively. Moreover, while a comparison of patients participating in high- and low-impact sports revealed similar preoperative Harris Hip Scores, the investigators discovered that the high-impact sport participating patients had higher postop Harris Hip Scores.

"There are many patients participating in these high-impact sports, up to 30% in our cohort," Marker said during his presentation at the American Academy of Orthopaedic Surgeons 75th Annual Meeting, held here. "The preoperative participation, as well as the metal bearing surface, were found to be predictive of postoperative participation. We found [in] the short-term follow-up that the high-impact sports patients had similar and better outcomes."

For more information:

Marker DR, Seyler TM, Ulrich SD, et al. High-impact sports after THA: Is the bearing type and independent predictor of activity level? Paper #16. Presented at the American Academy of Orthopaedic Surgeons 75th Annual Meeting. March 5-9, 2008. San Francisco.

Hip Resurfacing Advantage over THR Study

nospam@example.com (Patricia Walter) — Wed, 26 Sep 2007 15:31:32 -0700

2 Year Study Uncemented Femoral Components by Dr. Gross 2010

nospam@example.com (Patricia Walter) — Fri, 15 Jan 2010 07:22:49 -0700

Thomas P. Gross, M.D. Midlands Orthpaedics p.a. Current status of uncemented femoral components in hip resurfacing Midlands Orthpaedics p.a.

January, 2010

Uncemented femoral components for metal on metal total hip resurfacing have shown excellent results during the initial 3 years that I have been using this new technology. The early results that I have achieved in 0ver 800 cases since March 2007 are equivalent to the early results that I achieved with the same brand cemented femoral component.

Uncemented fixation of implants to bone is a proven technology that has generally surpassed the durability of cemented fixation to bone in traditional hip replacement surgery. In the long term (at 10 years) a higher percentage of hip implants using uncemented fixation still remain attached to the bone than cemented implants, especially in younger more active patients.

Fixation of total hip implants to bone can be accomplished by cement or by porous ingrowth technology (uncemented). Cement fixation is immediate. Cement is an acrylic material (methylmethacrylate) that is very brittle and also fairly toxic to bone cells. Cemented implants gradually loosen from the bone over time by reaction to the cement itself and due to gradual fatigue failure of this material. This process is faster in more active patients and faster in implant situations where the cement is stressed by shear forces rather than by compression forces.

Uncemented components are initially held to the bone by a very tight press-fit which is achieved by accurately preparing the bone so that the implant can be tightly hammered-on. The implants are so tightly wedged–on that the patient can bear full weight on them immediately. They do require a period of six to twelve months of bone ingrowth before they are considered well fixed. There is usually a small chance of failure of this bone ingrowth process in uncemented implants (<1%). But if ingrowth occurs, it is much more durable than cemented fixation and rarely fails in the long term.

Because orthopedic surgeons in America have come to a consensus on the superiority of uncemented fixation in total hips, uncemented fixation has virtually completely replaced cemented fixation in stemmed total hip replacements, despite the fact that these implants are more expensive. 99% of acetabular (socket) components that are used today are of the uncemented type, as are about 90% of femoral stems.

In hip resurfacing there is universal agreement that uncemented fixation is superior for the acetabular component. However, until recently, uncemented femoral components have not been available, therefore most hip resurfacing operations in the past have employed cemented fixation of the femoral component.

At the time that I began hip resurfacing in 1999, there was not yet general agreement that uncemented fixation was superior to cement in hip replacements. However, the evidence was mounting that uncemented fixation was better. I therefore did not think it was logical to use cemented fixation in hip resurfacing, an operation developed specifically with the more active younger patient in mind. The only companies pursuing hip resurfacing at the time were two small English companies: Corin and Midland Medical Technology (maker of the Birmingham implant). I suspect that they did not have the financial resources to develop a more complicated uncemented femoral component with the precision instrumentation required at that time. I originally proposed an uncemented femoral component to Corin 10 years ago, but they were unable to manufacture it at that time.

I therefore worked with Biomet on an uncemented femoral component and the precision instrumentation required for this implant for five years. I first began implanting it in March 2007. The Biomet component has a full coating of Titanium plasma spray under the entire under-surface of the femoral component. Recently we have added an additional layer of hydroxylappatite (HA) to increase the speed and extent of bone ingrowth. This is the best implant available to maximize the chance of bone ingrowth. When I started working with Biomet to develop an uncemented femoral component, Corin also started to work on one. They were able to bring it to market in Europe first; however, their component is only partially porous-coated (less than 50%) with Titanium (but it does have complete hydroxyl appetite coating). I personally do not believe this is good enough for long-term fixation (>10 years), but nobody knows for sure yet. It is not yet available in the US.

Theoretically, cement is the weak link when long-term (> 10 years) fixation of the femoral component is contemplated. If uncemented femoral components can be shown to achieve reliably high rates of ingrowth in the short term, they will probably outperform cemented femoral components in the long-term.

At this point with nearly 2-year follow-up data on a matched group of patients, I see no difference in results whether cement or uncemented fixation is used. At this point we can be fairly certain that bone ingrowth has occurred in these components. Except for two cases where osteonecrosis occurred in the femoral head at 1 year, we have had no failures of bone ingrowth in 430 patients that have are at least one year postop, and 191 that are at least two years postop.

In summary:

Uncemented femoral resurfacing components are now available from BIOMET for any patient who desires them.
No other companies are yet selling these in the US
Corin has had an uncemented femoral component available in Europe for several years.
At 2 years of follow-up there is no difference in the failure rate between cemented or uncemented femoral component.
Uncemented fixation of implants is more durable at 10 years than cement in hip replacement surgery especially in young active patients.
Most clinical data on hip surface replacement to date is based on an uncemented acetabular component and a cemented femoral component.
I now use uncemented components on virtually all hip resurfacing operations, unless the patient specifically requests the cemented femoral device.

Thomas P. Gross, MD

Staples significantly increase risk of postoperative infection study

nospam@example.com (Patricia Walter) — Fri, 02 Apr 2010 05:45:39 -0700

Staples significantly increase risk of postoperative infection study

March 2010 Original Link http://www.orthosupersite.com/view.aspx?rid=62584

The use of staples to close wounds following orthopedic surgery - especially hip surgery - is associated with a significantly greater risk of wound infection than traditional suturing, according to orthopedic researchers from Norwich, England.

Six clinical trials

Toby O. Smith, MSc, BSc (Hons), MCSP, and colleagues analyzed the results of six trials that compared staples and sutures used for wound closure following orthopedic procedures in adult patients. The six clinical trials involved 683 wounds. Of these cases, 322 patients underwent suture closure and 351 patients had staple closure, according to a British Medical Journal press release.

The authors found that wounds closed with staples were more than three times as likely to develop a superficial wound infection compared to wounds closed with sutures. In a subgroup analysis of patients undergoing hip surgery, the risk of developing a wound infection was found to be four times greater after staple closure than suture closure, according to the release.

Staples not recommended

The researchers found no significant difference between staples and sutures in the development of inflammation, discharge, dehiscence, necrosis and allergic reaction.

The authors called for high quality, well-designed trials to confirm their findings.

Although the quality of evidence from the six trials was generally poor, the authors concluded, "With the current evidence, however, patients and doctors should think more carefully about the use of staples for wound closure after hip and knee surgery."

•Reference:
Smith TO, Sexton D, Mann C, et al. Sutures versus staples for skin closure in orthopaedic surgery: meta-analysis. BMJ. [Published online ahead of print March 16, 2010]