Tag Archive | total hip arthroplasty

JBJS Editor’s Choice: How Best to Treat Femoral Neck Fractures in Younger Adults

ORIF or THA for Femoral Neck Fx.gifIn the January 4, 2017 issue of The Journal, Swart et al. provide a well-done Markov decision analysis on the cost effectiveness of three treatment options for femoral neck fractures in patients between the age of 40 and 65: open reduction and internal fixation (ORIF), total hip arthroplasty (THA), and hemiarthroplasty. Plugging the best data available from the current orthopaedic literature into their model, the authors estimated the threshold age above which THA would be the superior strategy in this relatively young population.

For patients in this age group, traditional thinking has been to perform ORIF in order to “save” the patient’s native hip and avoid the likelihood of later revision arthroplasty. However, in this analysis THA emerges as a cost-effective option in otherwise healthy patients >54 years old, in patients >47 years old with mild comorbidity, and in patients >44 years old with multiple comorbidities.

On average, both THA and ORIF have similar outcomes across the age range analyzed. But ORIF with successful fracture healing yields slightly better outcomes and considerably lower costs than THA, whereas patients whose fracture does not heal with ORIF have notably worse outcomes than THA patients. This finding supports my personal bias that anatomical reduction and biomechanically sound fixation must be achieved in this younger population with displaced femoral neck fractures. The analysis confirmed that, because of poor functional outcomes with hemiarthroplasty in this population, hemiarthroplasty should not be considered. Poor hemiarthroplasty outcomes are likely related to the mismatch between the metal femoral head and the native acetabular cartilage, leading to fairly rapid loss of the articular cartilage and subsequent need for revision.

This analysis by Swart et al. provides very valuable data to discuss with younger patients and families when engaging in shared decision making about treating an acute femoral neck fracture. In my experience, most patients in this age group prefer to “keep” their own hip whenever possible, which puts the onus on the surgeon to gain anatomic reduction and biomechanically sound fixation with ORIF.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

The Most-Read JBJS Articles of 2016

11-2016_VCR_II_Template-Final.jpgAs an end-of-year thank-you to the orthopaedic community, we’re offering limited-time full-text access to the five most-read JBJS articles of 2016. The fact that several of these most-read articles were published prior to 2016 is testament to the durable utility of orthopaedic research published in The Journal of Bone & Joint Surgery.

JBJS Reviews Editor’s Choice–Outpatient Joint Replacement?

knee-spotlight-image.png“Necessity is the mother of invention.” In recent years, the demand for total hip, total knee, and unicompartmental knee arthroplasty has grown substantially. However, with limited resources and health-care budgets, there is a need to reduce hospital costs. To that end, a number of surgeons have begun to perform these procedures on an outpatient basis.

Indeed, as the demand for joint replacements grows, it will be imperative to improve patient safety and satisfaction while minimizing costs and optimizing the use of health-care resources. In order to accomplish this goal, surgical teams, nursing staff, and physiotherapists will need to work together to discharge patients from the hospital as soon as safely possible, including on the same day as the operation. The development of accelerated clinical pathways featuring a multidisciplinary approach and involving a range of health-care professionals will result in extensive preoperative patient education, early mobilization, and intensive physical therapy.

In the December 2016 issue of JBJS Reviews, Pollock et al. report on a systematic review that was performed to determine the safety and feasibility of outpatient total hip, total knee, and unicompartmental knee arthroplasty. The authors hypothesized that outpatient arthroplasty would be safe and feasible and that there would be similar complication rates, similar readmission and revision rates, similar clinical outcomes, and decreased costs in comparison with the findings associated with the inpatient procedure. The investigators demonstrated that, in selective patients, outpatient total hip, total knee, and unicompartmental knee arthroplasty can be performed safely and effectively.

A major caveat of this well-conducted study, however, is that, like any systematic review, its overall quality is based on the quality of the individual studies that make up the analysis. In this case, the studies included those that lacked sufficient internal validity, sample size, methodological consistency, and standardization of protocols and outcomes. Thus, going forward, there is a need for more rigorous and adequately powered randomized trials to definitively establish the safety, efficacy, and feasibility of outpatient hip and knee arthroplasty.

Thomas A. Einhorn, MD
Editor, JBJS Reviews

What’s New in Hip Replacement

captureEvery month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.

This month, James Ninomiya, MD, MS, lead author of the September 21, 2016 Specialty Update on Hip Replacement, selected the five most clinically compelling findings from among the nearly 70 studies summarized in the Specialty Update.

Bearing Survivorship

–A meta-analysis found no differences in short- and medium-term implant survivorship among the following three bearing combinations used in THA patients younger than 65 years of age: ceramic on ceramic, ceramic on highly cross-linked polyethylene, and metal on highly cross-linked polyethylene.1

Insight into Aseptic Loosening

–Pathogen-associated molecular patterns (“endotoxins”) on particulate wear debris may be partially responsible for aseptic loosening. An in vitro/in vivo study found that macrophages that did not express the pathogen-associated molecular pattern receptor called TIRAP/Mal had significantly diminished secretion of inflammatory proteins. Patients with a genetic polymorphism suppressing that receptor exhibited decreased osteolysis during in vivo experiments. This suggests that some patients may be genetically more prone to aseptic loosening.

THA in Patients with RA

–A systematic review/meta-analysis of patients who were and were not taking a TNF-α inhibitor for rheumatoid arthritis prior to hip replacement found that those taking the drug had an increased risk of perioperative infection, with an odds ratio of 2.47.2 These results suggest that in order to decrease the risk of perioperative infections, it may be prudent to discontinue these drugs in advance of proposed joint replacement surgery.

Delaying THA for Femoral Head Osteonecrosis

–A systematic review/meta-analysis of patients with femoral head osteonecrosis concluded that injection of autologous bone marrow aspirate containing mesenchymal stem cells during core decompression was superior by a factor of 5 to core decompression alone in preventing collapse of the femoral head and delaying conversion to THA. This information may lead to new treatment paradigms for osteonecrosis.

Preventing Post-THA Dislocations

–A systematic review/meta-analysis that included more than 1,000 patients who underwent THA with a posterior or anterolateral approach found similar dislocation rates among those who were and were not given post-procedure restrictions in motion or activity.4   This suggests that the use of traditional hip precautions may not be necessary, and in fact may impede the rate of recovery following joint replacement surgery.

References

  1. Wyles CC, Jimenez-Almonte JH,  Murad MH, Norambuena-Morales GA, Cabanela ME, Sierra RJ, TrousdaleRT. There are no differences in short- to mid-term survivorship among total hip-bearing surface options: a network meta-analysis. Clin Orthop Relat Res. 2015 Jun;473(6):2031-41. Epub 2014 Dec 17.
  2. Goodman SM, Menon I, Christos PJ, Smethurst R, Bykerk VP. Management of perioperative tumour necrosis factor α inhibitors in rheumatoid arthritis patients undergoing arthroplasty: a systematic review and meta-analysis. Rheumatology (Oxford). 2016 Mar;55(3):573-82. Epub 2015 Oct 7.
  3. Papakostidis C, Tosounidis TH, Jones E, Giannoudis PV. The role of “cell therapy” in osteonecrosis of the femoral head. A systematic review of the literature and meta-analysis of 7 studies. Acta Orthop. 2016 Feb;87(1):72-8. Epub 2015 Jul 29.
  4. Van der Weegen W, Kornuijt A, Das D. Do lifestyle restrictions and precautions prevent dislocation after total hip arthroplasty? A systematic review and meta-analysis of the literature. Clin Rehabil. 2016 Apr;30(4):329-39. Epub 2015 Mar 31.

JBJS Webinar: Effective Management of the Infected Total Joint

infected-knee-for-webinar-postThe incidence of primary total knee and hip arthroplasty is increasing steadily. While the success rates of these procedures are remarkable, failures do occur, and periprosthetic joint infection is the leading culprit in such failures. The standard treatment when deep infection strikes is a two-stage revision.

On Monday, November 14, 2016 at 8:00 PM EST, The Journal of Bone & Joint Surgery (JBJS) will host a complimentary webinar that examines prognostic factors affecting the success of two-stage revision arthroplasty for infected knees and hips.

  • Tad M. Mabry, MD, coauthor of a matched cohort study in JBJS, will examine the impact of morbid obesity on the failure of two-stage revision TKA.
  • JBJS author Antonia F. Chen, MD, will discuss results from a retrospective study that revealed an association between positive cultures at the time of knee/hip component reimplantation and the risk of subsequent treatment failure.

Moderated by JBJS Deputy Editor Charles R. Clark, MD, the webinar will include additional perspectives from two expert commentators—Daniel J. Berry, MD and Andrew A. Freiberg, MD. The last 15 minutes will be devoted to a live Q&A session, during which the audience can ask questions of all four panelists.

Seats are limited, so register now!

“Limited Role” for Hip Arthroscopy in Tönnis Grade-2 Arthritis

Arthroscopy to THA Conversion.gifMany orthopaedists wonder whether—or under what circumstances—arthroscopy confers any clinical benefit in treating hip osteoarthritis. A prospective matched-pair analysis by Chandrasekaran et al. in the June 15, 2016 Journal of Bone & Joint Surgery suggests that arthroscopy does not help prevent the eventual conversion to total hip arthroplasty (THA) in hips with Tönnis grade-2 arthritis (moderate narrowing of the joint space with moderate loss of femoral-head sphericity).

The authors compared two-year outcomes from 37 patients with Tönnis grade-2 hip osteoarthritis who had a hip arthroscopy performed with outcomes from matched cohorts of 37 Tönnis grade-0 and 37 grade-1 hips on which arthroscopy was also performed. In all cases, arthroscopy sought to address symptomatic intra-articular hip disorders refractory to nonoperative management. The cohorts were matched to minimize the confounding effects of age, sex, and BMI on the outcomes.

There were no significant differences among the groups with respect to four patient-reported outcome measures (including the modified Harris hip score), VAS pain scores, and patient satisfaction levels. However, Tönnis grade-2 hips had a significantly higher conversion rate to THA compared to the other two matched cohorts. In absolute terms, a subsequent THA was required for 3 hips in the Tönnis grade-0 group, 5 in the Tönnis grade-1 group, and 15 in the Tönnis grade-2 group.

From this finding, the authors conclude that “hip arthroscopy has a limited role as a joint preservation procedure in select patients with Tönnis grade-2 osteoarthritis…Hip arthroscopy can effectively restore the labral seal and address impingement, but patients may continue to experience symptoms associated with the osteoarthritis.”

JBJS Reviews Editor’s Choice–How Should New Orthopaedic Technology Be Introduced?

Over the past several decades, orthopaedic surgery has enjoyed an explosion in the development of new technologies. These technologies have largely improved the quality of orthopaedic care. The development of new technologies results in both disruptive and nondisruptive evolution and requires that orthopaedic surgeons gain specific knowledge of their appropriate use in clinical practice.

However, despite the advances developed from orthopaedic innovation, many discoveries have been associated with unanticipated adverse events. As an example, the original total hip replacement developed by Charnley featured a 1-piece femoral component with a 22.5-mm head. This was later changed to a larger-diameter head, resulting in increased volumetric wear of conventional polyethylene. In addition, new implants with sharp corners led to cement fractures and the development of so-called cement disease. More recently, metal-on-metal articulations have been associated with metallic particles and ion-induced bone and soft-tissue destruction. Ceramic-on-ceramic articulations may lead to implant breakage, striped wear, and squeaking. There is no question that total hip arthroplasty is an exceptionally successful technology, but there is concern regarding the way in which improvements and innovations gain regulatory approval and surgeon acceptance.

In the May 2016 issue of JBJS Reviews, Goodman et al. discuss the introduction of new technologies in orthopaedic surgery. They review the use of novel biologics and combination products and, in particular, single out platelet-rich plasma for the insufficient clinical evidence to support its use. Moreover, they describe the initial enthusiasm regarding the use of recombinant human BMP-2 for spine fusions but note that a review of clinical trials has revealed that there may be concerns regarding insufficient numbers of patients to assess safety, under-reporting of serious complications, conflict of interest among the investigators, and potential bias.

Goodman et al. address some very simple but nonetheless profound issues. For example, they ask, “How should new technologies be introduced into orthopaedics?” They further ask, “How should a surgeon learn to use new technology?” Perhaps most importantly, they raise the issue of ethical considerations related to the use of new technology.

The future of orthopaedic innovation looks bright. Some have commented that there are too many perceived barriers to gaining regulatory approval of new technologies. Recently, the structure and methodology by which approval of new medical technology is managed across the United States has come under increased scrutiny.

I do not think you can ever be too safe or too careful. This article by Goodman et al. is an excellent review of the issues and considerations. It’s a quick read but leaves plenty of room for thought!

Thomas Einhorn, Editor

JBJS Reviews

Metal-on-Metal Hip Arthroplasty: Where Do We Go From Here?

OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Richard S. Yoon, MD.

We’re entering the “midterm” follow-up period for the metal-on-metal (MoM) hip devices implanted in the early 2000s, and recent reports from around the world are confirming early concerns. Several studies published during the first few months of 2016 report unacceptably high failure rates.

In the Open Orthopaedics Journal, Mogensen et al. reported an 18.4% revision rate in more than 100 CONSERVE MoM hips, at a mean follow-up of 4.5 years. These results led the Danish authors to terminate the use of MoM at their centers.

In the BMJ Open, Langton et al. reported a 16% failure rate among more than 350 Pinnacle MoM hips after about nine years of follow-up. Greiner et al. published a follow-up of prior research in a recent edition of the Journal of Arthroplasty. Among more than 150 MoM modular acetabular components with 5- to 12-year follow-ups, the results related to adverse local tissue reactions and revisions were inferior when compared with those of metal-on-polyethylene articulations. Dhotare et al., in Hip International, reported an alarming failure-rate increase from 7% at six years to 29% at ten years for the Birmingham MoM cup and large metal head.

While we cannot turn back the clock on the past use of MoM devices, we have some information about surveillance and treatment that may help us prevent catastrophic failure.

Data regarding the effects of increasing serum metal ions are mixed. Some studies have found a direct correlation between high metal ion levels and the incidence of adverse tissue reactions (and the need for subsequent revision), while other studies have not.  A recent JBJS study identified cobalt-ion thresholds that could help stratify patients with Birmingham and Corail-Pinnacle hips who are at low risk of metal-debris adverse reactions.

The systemic effects of increased serum metal ions are also being debated. Some case reports have cited neurotoxicity presenting as tinnitus, gait imbalance, and other issues, while a more recent, larger longitudinal study published in the Journal of Arthroplasty did not confirm this correlation. Those authors surmised that increased serum ion levels may cause neurotoxicity-associated symptoms primarily in MoM patients with metal hypersensitivity.

Metal artifact reduction sequence (MARS) MRI has been helpful in early identification of adverse soft tissue reactions. However, there is no general consensus or guideline as to when and how often this technology should be utilized in order to provide consistent surveillance and/or indications for revision.

While we are still trying to understand the finer points of the many variables related to MoM, there is an obvious need to forge consensus. Recently, in the Bone and Joint Journal, Berber et al., representing the International Specialist Centre Collaboration on MoM Hips (ISCCoMH), conducted a survey among six international tertiary referral centers to assess the overall consensus in surveillance and treatment practices. Only a moderate agreement value (kappa = 0.6) was found. This inconsistent agreement led the group to call for international coordination to help set forth guidelines that would standardize and improve surveillance of and treatment for those with MoM hips.

Richard S Yoon, MD is executive chief resident at the NYU Hospital for Joint Diseases.

Cup-Placement Precision Declines as Obesity Increases

Obesity can negatively affect outcomes after total hip arthroplasty (THA), and an inadvertent reduction in cup anteversion may be one reason why, according to findings from Brodt et al. in the May 4, 2016 edition of The Journal of Bone & Joint Surgery.

Cup Anteversion Obesity.gifThe authors retrospectively analyzed postoperative radiographs from 790 THA patients (all of whom were operated on via a direct lateral approach) within three BMI ranges: normal weight (BMI <25 kg/m2), moderately obese (BMI between 25 and 34 kg/m2), and morbidly obese (BMI of ≥35 kg/m2). Reduced cup anteversion significantly correlated with increasing BMI and younger patient age, with the morbidly obese group demonstrating a 3.4° anteversion reduction compared with the normal-weight group. The authors attribute the reduced anteversion to increased pressure applied to dorsal and ventral acetabular rim retractors to ensure adequate visualization during THA surgery in obese patients.

When the authors applied their findings to the Lewinnek “safe zone” for acetabular positioning, only 59% of the morbidly obese patients were in that zone.  While this study was not designed to track subsequent dislocations (a common consequence of incorrect cup positioning), the authors claim that these findings are nevertheless clinically important. “Knowledge of a systemic error in obese patients should raise surgeons’ awareness of the need to perform cup implantation with greater attention,” they conclude.

Cobalt-Ion Thresholds Could Ease Follow-Up Burden on Some MoM Patients

Cobalt.gif In the mid-2000s, before the orthopaedic community was aware of the potentially catastrophic shortcomings of metal-on-metal (MoM) hip implants, nearly half of all hip replacements used MoM components. With so many people walking around today on those prostheses, orthopaedists are looking for rational and effective ways to monitor these patients for adverse reactions to metal debris.

Findings from a diagnostic Level II study by Matharu et al. in the April 20 edition of The Journal of Bone & Joint Surgery will help identify patients who are at low risk of metal-debris adverse reactions, specifically among those who have Birmingham Hip Resurfacing (BHR) and Corail-Pinnacle MoM implants. The authors found that when measuring cobalt ions in whole blood, the optimal threshold for identifying adverse reactions to metal debris was 2.15 µg/L for BHR patients and 3.57 µg/L for Corail-Pinnacle patients. These implant-specific thresholds are lower than the non-implant-specific thresholds proposed by US and UK regulatory agencies, and in this study the cutoffs had good sensitivities and specificities, and their negative predictive values exceeded 98%.

The authors say identifying low-risk individuals will allow orthopaedists to focus surveillance efforts on patients who are at higher risk of adverse reactions to metal debris. They even suggest that patients below the implant-specific thresholds for cobalt could be excluded from regular follow-up regimens, provided they have normal clinical examinations and radiographs.

While lauding Matharu et al. for prospectively determining these thresholds, commentator Lawrence Dorr, MD says these findings need “to be tested at multiple centers to validate [their] superiority,” and he emphasizes that better methods to identify asymptomatic patients who are at high risk of adverse reactions to metal debris still must be developed.