Tag Archive | total hip arthroplasty

JBJS 100: Controlling Bone Growth and Revision THA Stats

JBJS 100Under one name or another, The Journal of Bone & Joint Surgery has published quality orthopaedic content spanning three centuries. In 1919, our publication was called the Journal of Orthopaedic Surgery, and the first volume of that journal was Volume 1 of what we know today as JBJS.

Thus, the 24 issues we turn out in 2018 will constitute our 100th volume. To help celebrate this milestone, throughout the year we will be spotlighting 100 of the most influential JBJS articles on OrthoBuzz, making the original content openly accessible for a limited time.

Unlike the scientific rigor of Journal content, the selection of this list was not entirely scientific. About half we picked from “JBJS Classics,” which were chosen previously by current and past JBJS Editors-in-Chief and Deputy Editors. We also selected JBJS articles that have been cited more than 1,000 times in other publications, according to Google Scholar search results. Finally, we considered “activity” on the Web of Science and The Journal’s websites.

We hope you enjoy and benefit from reading these groundbreaking articles from JBJS, as we mark our 100th volume. Here are two more:

Control of Bone Growth by Epiphyseal Stapling: A Preliminary Report
W P Blount and G R Clarke: JBJS, 1949 July; 31 (3): 464
This 14-page, amply illustrated article was the oldest paper selected by Kavanagh et al. in their 2013 JBJS bibliometric analysis of the 100 classic papers of pediatric orthopaedics. Blount and Clarke proved definitively that long-bone growth could be arrested by appropriately timed epiphyseal stapling and that growth would resume after staple removal. Their work spared many children with linear or angular leg deformities—often a result of polio—from the risk of more invasive operative methods.

Epidemiology of Revision Total Hip Arthroplasty in the US
K J Bozic, S M Kurtz, E Lau, K Ong, T P Vail, D J Berry: JBJS, 2009 January; 91 (1): 128
Fast forwarding 60 years from the Blount and Clarke study, we arrive at this epidemiological analysis of >51,000 revision hip replacements. The findings from this 2009 Level II prognostic study provided information that has guided THA research, implant design, and clinical decision-making throughout the past decade.

With New Technologies, Slow Adoption is Best

MoM for OBuzzThe enemy of the good is the better. It’s an axiom we hear during our surgical training, and it was my first thought when reading the article by Hunt et al. in the February 7, 2018 edition of JBJS.  The authors examine failure rates associated with the rapid adoption and widespread use of metal-on-metal (MoM) total hip arthroplasties (THAs) and hip resurfacings.

Carefully analyzing data from the National Joint Registry for England, Wales and Northern Ireland from 2003 to 2014, Hunt et al. ascertained that MoM hip resurfacings and MoM total hip arthroplasties resulted in 10-year revision rates that were almost 3 and 5 times higher, respectively, than the expected revision rates for standard hip procedures. This meant that within 10 years, there were almost 8 excess revisions for every 100 MoM hip resurfacings and almost 16 excess revisions for every 100 MoM total hip arthroplasties. Just as troubling was the finding that 20% of those excess revisions needed at least one additional revision within 7 years.

As orthopaedic surgeons, we strive to make things better for patients, which may tempt us to try a “new and improved” technology for a nominal (or presumed) improvement in outcome, when the one we are currently using works just fine. It is our responsibility as surgeons not to be blind to the unintended consequences new technologies may have on our patients.

I agree with the blunt directive Hunt et al. issue in the final sentence of their abstract: “This practice of adopting new technologies without adequate supporting data must not be repeated.”

Chad A. Krueger, MD
JBJS Deputy Editor for Social Media

JBJS 100: Carpal Tunnel and THA

JBJS 100Under one name or another, The Journal of Bone & Joint Surgery has published quality orthopaedic content spanning three centuries. In 1919, our publication was called the Journal of Orthopaedic Surgery, and the first volume of that journal constituted Volume 1 of what we know today as JBJS.

Thus, the 24 issues we turn out in 2018 will constitute our 100th volume. To help celebrate this milestone, throughout the year we will be spotlighting 100 of the most influential JBJS articles on OrthoBuzz, making the original content openly accessible for a limited time.

Unlike the scientific rigor of Journal content, the selection of this list was not entirely scientific. About half we picked from “JBJS Classics,” which were chosen previously by current and past JBJS Editors-in-Chief and Deputy Editors. We also selected JBJS articles that have been cited more than 1,000 times in other publications, according to Google Scholar search results. Finally, we considered “activity” on the Web of Science and The Journal’s websites.

We hope you enjoy and benefit from reading these groundbreaking articles from JBJS, as we mark our 100th volume. Here are two more:

The Carpal Tunnel Syndrome: Seventeen Years’ Experience in Diagnosis and Treatment of 654 Hands
George S. Phalen: JBJS, 1966 March; 48 (2): 211
Everything Phalen presented about carpal tunnel syndrome in 1966 holds true more than 50 years later. This includes his descriptions of the anatomical, epidemiologic, histologic, and clinical features of carpal tunnel syndrome and his emphasis on careful history-taking and physical examination.

Periprosthetic Bone Loss in Total Hip Arthroplasty: Polyethylene Wear Debris and the Concept of the Effective Joint Space
T P Schmalzried, M Jasty, W H Harris: JBJS, 1992 Jan; 74 (6): 849
The insights offered by these authors radically altered our thoughts about osteolysis. Using this concept of effective joint space, subsequent investigators and innovators identified methods and designs of hip replacements to retard osteolysis by limiting the generation and spread of particulate debris.

Webinar on Feb. 12—Surgical Approaches to Hip Replacement

Feb Webinar speakers for OBuzzEvery surgical approach to total hip arthroplasty (THA)—posterior, anterior, or lateral and conventional or minimally invasive—has adherents and critics. Despite scores of published studies comparing these different approaches, no single best practice has yet emerged.

On Monday, February 12, 2018 at 6:30 PM EST, JBJS will present a complimentary* webinar that addresses this ongoing debate with recent evidence about five different surgical approaches to THA. Moderated by James Waddell, MD, former President of the Canadian Orthopaedic Association, the webinar will springboard off two JBJS articles:

  • Knut Erik Mjaaland, MD will discuss a registry study that found no significant 5-year outcome differences among four different approaches: two minimally invasive (anterior and anterolateral), and two conventional (posterior and direct lateral).
  • R. Michael Meneghini, MD will explain why his group concluded that the direct anterior approach may confer a greater risk of early femoral component failure due to aseptic loosening, compared with the direct lateral or posterior approaches.

After the authors’ presentations, Anthony Unger, MD and Tad Mabry, MD will add clinical perspectives to the current state of this important research. During the last 15 minutes of the webinar, panelists will answer questions from the audience.

Space is limited, so Register Now.

* This webinar is complimentary for those who attend the event live and will continue to be available for 24 hours following its conclusion.

High Value Joint Replacements at Physician-Owned Hospitals

H image for OBuzzIn the November 15, 2017 issue of The Journal, Courtney et al. carefully evaluate CMS data to compare TKA and THA costs, complications, and patient satisfaction between physician-owned and non-physician-owned hospitals. The authors used risk-adjusted data when comparing complication scores between the two hospital types, in an attempt to address the oft-rendered claim that surgeons at physician-owned facilities “cherry pick” the healthiest patients and operate on the highest-risk patients in non-physician-owned facilities.

In general, the findings suggest that, for TKA and THA, physician-owned hospitals are associated with lower costs to Medicare, fewer complications and readmissions, and superior patient-satisfaction scores compared with non-physician-owned hospitals. These findings should come as no surprise to readers of The Journal. One fundamental principle of health care finance is that physicians control 70% to 80% of the total cost of care with their direct decisions. When physician incentives are aligned with those related to the facility, the result is better care at lower cost.

Nevertheless, many policymakers remain convinced that physician-owners are completely mercenary and base every decision on maximizing profit margins—even if that includes ordering unnecessary tests, performing unnecessary procedures, or using inferior implants. We need more transparency among physician-owners at local and national levels to address these usually-erroneous assumptions, which are frequently repeated by local non-physician-owned health systems. For example, we should be transparent with the percentage of the margin that ends up in the physician-owner’s pocket. Whatever the “right” percentage is, I believe it should not be the dominant factor in a physician’s total income..

The findings from Courtney et al. should spur further debate on this issue. I am confident that the best outcomes for individual patients and the public result when physicians (and their patients) stay in direct control of decision making regarding care, when surgeons are appropriately motivated to be cost- and outcome-effective, and when we all do our part to care for the under- and uninsured.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Certain Comorbidities Boost Risk of Acute Kidney Injury after THA

AKI Risk for OBuzzThe relationship between chronic kidney disease (CKD) and acute kidney injury (AKI) is circular: surgical patients with preexisting CKD are at increased risk of AKI, and even mild or transient AKI is associated with future development of CKD.

In the November 1, 2017 JBJS, Gharaibeh et al. report findings from a retrospective cohort study with a nested case-control analysis that assessed the rate and risk factors associated with AKI after total hip arthroplasty (THA).

From a total of 10,323 THAs analyzed, AKI developed postoperatively in only 114 cases (1.1%). A multivariate analysis of the entire cohort identified four preoperative comorbidities that increased the risk of AKI by 2- to 4-fold: CKD, heart failure, diabetes, and hypertension. In addition to those risk factors, an analysis of the case-control cohort found that increasing BMI and perioperative blood transfusions were also associated with a higher risk of AKI.

Using data from the entire cohort, the authors developed an AKI risk calculator focused on presurgical variables (see graph). Based on that model, which will require independent validation, a 65-year-old man with either CKD or heart failure would have a 2% risk of AKI; the risk would increase to 4% if that patient had CKD and hypertension and to 16.1% in the presence of CKD, hypertension, and heart failure.

The anticipated increase in demand for joint replacements could lead to US surgeons performing approximately 572,000 THAs during the year 2030. A certain (and possibly increasing) proportion of those future procedures will occur in patients who have hypertension, diabetes, heart failure, and/or chronic kidney disease. The findings from Gharaibeh et al., especially the yet-to-be-validated AKI risk score, could help hip surgeons better counsel patients and identify those who might benefit from heightened postsurgical monitoring of kidney function.

What’s New in Hip Replacement 2017

THA for OBuzzEvery 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 T. Ninomiya, MD, MS, lead author of the September 20, 2017 Specialty Update on Hip Replacement, selected the five most clinically compelling findings from among the more than 50 studies covered in the Specialty Update.

Obesity and THA Outcomes
–Obesity is a well-established risk factor for perioperative THA complications. A prospective registry-based study found that reoperation and implant revision or removal rates increased with increasing BMI. More specifically, increasing BMI was associated with increased rates of early hip dislocation and deep periprosthetic infection.

Infection Prevention
–Two studies 1, 2 demonstrated that patients who have intra-articular injections within 3 months prior to THA experienced nearly double the risk of periprosthetic infection in the first postoperative year, compared with those in noninjection control groups.

Surgical Approaches to THA
–A study of >2,100 patients revealed that, despite claims to the contrary, there were no differences in dislocation rates between those who underwent THA using the direct anterior approach and a propensity-score matched cohort who underwent THA using a posterior approach.3

OR Temperature
–What is the optimal temperature for an orthopaedic operating room? Anecdotes are often used to justify keeping operating rooms at uncomfortably high temperatures, which leads to discomfort and fatigue for members of the surgical team. A comprehensive literature review led authors to suggest that preoperative patient warming, intraoperative patient warming with forced-air devices, and keeping OR temperature at ≤19° C is the ideal combination for comfort while still maximizing patient safety and outcomes.

Return to Driving
–Following joint replacement, patients often ask when it will be safe to return to driving. A meta-analysis of 19 studies concluded that the mean time for return to baseline reaction time for braking was 2 weeks following a right-sided hip replacement and 4 weeks following a right-sided knee replacement.4 The authors stressed, however, that return-to-driving recommendations should be individualized for each patient.

References

  1. Schairer WW, Nwachukwu BU, Mayman DJ, Lyman S, Jerabek SA. Preoperative hip injections increase the rate of periprosthetic infection after total hip arthroplasty. J Arthroplasty. 2016 ;31(9)(Suppl):166–169.e1. Epub 2016 Apr 22.
  2. Werner BC, Cancienne JM, Browne JA. The timing of total hip arthroplasty after intraarticular hip injection affects postoperative infection risk. J Arthroplasty. 2016 ;31(4):820–3. Epub 2015 Sep 1.
  3. Maratt JD, Gagnier JJ, Butler PD, Hallstrom BR, Urquhart AG, Roberts KC. No difference in dislocation seen in anterior vs posterior approach total hip arthroplasty. J Arthroplasty. 2016 ;31(9)(Suppl):127–30. Epub 2016 Mar 15.
  4. van der Velden CA, Tolk JJ, Janssen RPA, Reijman M. When is it safe to resume driving after total hip and total knee arthroplasty? A meta-analysis of literature on post-operative brake reaction times. Bone Joint J. 2017 ;99-B(5):566–76.

Has Conventional Polyethylene Become Obsolete in THA?

XLPE for OBuzzHighly cross-linked polyethylene (XLPE) has been in clinical use for nearly 15 years. In acetabular components for total hip arthroplasty (THA), XLPE’s superior wear characteristics and lower revision rates, relative to conventional polyethylene (PE), have been demonstrated in numerous studies. Here is one more: a 10-year Level I study in the October 18, 2017 issue of The Journal of Bone & Joint Surgery by Devane et al.

In this double-blinded, randomized trial, authors measured 2-D, 3-D, and volumetric wear (in mm or mm2), along with wear rates (mm/year), presence or absence of osteolysis, and revision rates in 91 patients at specified time intervals, up to a minimum of 10 years. The following results corroborate the general findings from most other studies on this topic:

  • The mean 3-D wear rate among patients with the XLPE acetabular liner was 0.03 mm/yr, versus 0.27 mm/yr among patients with conventional PE.
  • Eight percent of patients in the XLPE group showed radiographic evidence of osteolysis, versus 38% of patients in the PE group.
  • Patients with the conventional PE liner had a significantly higher revision rate (14.6%) than those with the XLPE liner (1.9%).

There were no significant between-group differences in clinical outcome scores, including the Oxford Hip Score and SF-12 physical well-being score.

The authors note that “the longer-term implications of these findings are unclear,” but their calculations indicated that, through 20 years, none of the XLPE liners would wear through, but 6 of the conventional PE liners would require revision due to wear-through.

Long-term Results Show No Advantage to “Minimalist” THA

Minimal Incision THA for OBuzzThe debate regarding minimally invasive/minimal incision total hip arthroplasty (THA) has been simmering for a decade and a half. When assessing the impact of adult reconstruction procedures, patients and treating physicians alike are most interested in longer-term results. Improved return of function in the first 3 to 6 weeks is of some value to all patients—and perhaps of great value to younger patients—and that has been one of the purported advantages of the “minimalist” approach. But it is the long-term results that really matter.

In the October 18, 2017 issue of The Journal, Stevenson et al. provide 10-year results from a 2005 randomized trial of small-incision posterior hip arthroplasty, and they confirm it adds no clinical, radiographic, or implant-survivorship benefit when compared with a standard posterior approach. An extra caveat here is that these procedures, originally done in 2003-2004, were undertaken by a highly experienced surgeon who had performed >300 minimal-incision THAs. In the hands of surgeons with less experience, smaller incisions may result in suboptimal component positioning and other complications, a point emphasized by Stevenson et al. and by Daniel Berry in his JBJS editorial accompanying the original study.

This long-term data is of great value to patients and surgeons alike. It is my hope that such high-quality evidence will temper the claims used in marketing materials that hype minimally invasive approaches, to which hip surgeons are routinely subjected.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

JBJS Classics: Porous-Coated Hip Components

JBJS Classics Logo.pngOrthoBuzz regularly brings you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators highlight the impact that these articles have had on the practice of orthopaedics. Please feel free to join the conversation by clicking on the “Leave a Comment” button in the box to the left.

In their classic 1987 publication, Drs. Charles Engh, Dennis Bobyn, and Andrew Glassman described clinical and radiographic results of a series of 307 hips with 2-year follow-up, and 89 hips with 5-year follow-up after total hip arthroplasty in which the patients had received an extensively porous-coated femoral stem. The authors also described histologic evaluation of 11 hips retrieved at autopsy or revision.

By 1987 the same authors as well as other investigators had already published observations concerning the influence of femoral stem size, shape, stiffness, and porosity on clinical and radiographic evidence of fixation and stress shielding in humans and animal models.1,2 But this study, which so far has been cited more than 1500 times, goes “above and beyond” by carefully correlating previous observations with histologic sections obtained through human femora.

Among other achievements, Engh et al. described radiographic criteria for categorizing a femoral implant as either stable by bone ingrowth, stable by fibrous tissue ingrowth, or unstable. Implants thought to be stable by fibrous ingrowth had a prominent radio-opaque line around the stem, separated from the implant by a radiolucent space up to 1 mm in thickness. This line was thought to represent a shell of bone with load-carrying capability. However, histology demonstrated that the space between the shell and the implant was composed of dense fibrous tissue. When the shell was present, there tended to be little hypertrophy or atrophy of the adjacent femoral cortex.

Engh et al. noted that radiographs and histology of hips with extensive ingrowth from the endosteum often showed parallel increased porosity of the adjacent cortex – an early manifestation of stress shielding. Overall, 259 (84%) of the femoral stems had radiographic findings suggestive of bone ingrowth, 42 (13%) had findings interpreted as stable fibrous ingrowth, and 2% were thought to be unstable (but not yet revised at the time of the study). Stress shielding was much more common in larger-diameter stems and those with good bone ingrowth compared to smaller implants or those with stable fibrous fixation.

Why do we consider this manuscript a classic? First, the authors include a careful correlation of histology with radiographic and clinical findings, helping illustrate the importance of tight press fit at the isthmus to achieve proximal fixation. The authors also document intracortical porosity as the morphologic manifestation of stress shielding and emphasize the impact of a small increase in stem diameter on axial rigidity.

Designs of femoral stems have evolved considerably since the 1980s,3 and the findings described in this paper helped validate fundamental principles related to load transmission and bone remodeling4-6 and thus helped advance that evolutionary process.

Thomas W. Bauer, MD, PhD
JBJS Deputy Editor

References

  1. Bobyn JD, Pilliar RM, Binnington AG, Szivek JA. The effect of proximally and fully porous-coated canine hip stem design on bone modeling. Journal of orthopaedic research : official publication of the Orthopaedic Research Society 1987;5:393-408.
  2. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC. The optimum pore size for the fixation of porous-surfaced metal implants by the ingrowth of bone. Clinical orthopaedics and related research 1980:263-70.
  3. McAuley JP, Culpepper WJ, Engh CA. Total hip arthroplasty. Concerns with extensively porous coated femoral components. Clinical orthopaedics and related research 1998:182-8.
  4. Huiskes R. Validation of adaptive bone-remodeling simulation models. Stud Health Technol Inform 1997;40:33-48.
  5. Huiskes R, Weinans H, Dalstra M. Adaptive bone remodeling and biomechanical design considerations for noncemented total hip arthroplasty. Orthopedics 1989;12:1255-67.
  6. Weinans H, Huiskes R, Grootenboer HJ. Effects of fit and bonding characteristics of femoral stems on adaptive bone remodeling. J Biomech Eng 1994;116:393-400.