Plate–Tendon Contact: How Important Is It?
There are few things more discouraging for an orthopaedic surgeon than a late postoperative complication after what was an otherwise successful surgery. One such scenario occurs when patients who have undergone open reduction/internal fixation (ORIF) for a distal radial fracture subsequently experience a flexor pollicis longus (FPL) tendon rupture. While previous literature has suggested that plate positioning plays a role in that complication, no studies have evaluated whether newer plate designs decrease contact with the FPL tendon and therefore reduce the risk of rupture.
With that question in mind, Stepan et al. evaluated two cohorts of patients who had undergone ORIF for a distal radial fracture. In the September 4, 2019 issue of JBJS, they report on findings from 40 patients, 20 of whom received a standard distal radial volar locking plate, and 20 of whom received a plate designed with a distal cutout to afford the FPL more room to traverse.
Ultrasound analysis revealed that similar percentages of patients in each group had FPL–plate contact (65% in the FPL-plate group and 79% in the standard-plate group), and there were no differences between groups in terms of FPL tendon degeneration as seen on ultrasound. However, patients who received the FPL plate had significantly less of the tendon come in contact with the plate at 0° and 45° of wrist extension. The authors noted, however, that this difference may have been influenced by the fact that patients with the FPL-specific plate also had significantly lower volar tilt than patients with the standard locking plate. It is therefore not possible to determine whether it was the plate design or the bone position (or both) that led to these results.
It is also noteworthy that the two senior authors of this study work as consultants for the company that manufactures the plates that were evaluated. It is also important to note that because all the patients in this study were asymptomatic, further research is needed to determine the clinical importance of reduced tendon–plate contact area. We should temper our excitement about specially designed volar plates until we have more clinical data supporting their success in avoiding the problem for which they were designed.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Let’s Continue Improving Hip-Implant Longevity
In October 2017, JBJS published results from a 10-year randomized controlled trial by Devane et al. documenting the dramatic reduction in polyethylene wear in total hip arthroplasties (THAs) using highly cross-linked polyethylene (HXLPE). This followed decades of research documenting that wear debris was implicated in macrophage activity that was ultimately responsible for implant loosening. In the September 4, 2019 issue of The Journal, Hart and colleagues produce further evidence of the improved performance of HXLPE, this time showing revision rates among THA patients with osteonecrosis that rival the rates among patients with osteoarthritis.
In this matched cohort of 922 THAs performed from 1999 to 2007 that used an HXLPE bearing, the 15-year cumulative rate of revision was 6.6% among patients treated for osteonecrosis and 4.5% among patients treated for osteoarthritis (p = 0.09). There were no radiographic signs of component loosening in the entire cohort, and, despite a lower median preoperative Harris hip score (HHS) among patients with osteonecrosis, both groups had marked improvements in HHS score. These findings are especially noteworthy because patients with osteonecrosis typically undergo THA at an earlier age and have much higher functional demands than the typical 70- or 80-year-old osteoarthritis patient.
However, the 15-year revision rate—even with HXLPE—remains at 4.5% for osteoarthritis patients, which should provide impetus to continue our work identifying all possible factors and mechanisms that lead to THA revision. A partial list would include bearing-surface wear, reliability of implantation, biomechanics, biomaterials, and patient perception of postoperative pain. Also, in a subgroup analysis, Hart et al. found that the 15-year rate of any reoperation among osteonecrosis patients ranged from 0% for hips with radiation-induced osteonecrosis to 25% for hips with idiopathic osteonecrosis. These findings add to the list of factors for THA success that need further investigation.
The work list for improvements in THA will remain substantive for at least the next few decades, and we may never get to 0% revisions for all patients. But we have certainly demonstrated that our research can produce very worthwhile results.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Morbidly Obese Patients Should Lose ≥20 Pounds Prior to TKA
The obesity epidemic continues throughout much of the developed world. Among the morbidly obese (BMI ≥40 kg/m2), we have a group of patients in whom arthritis is very likely to develop due to excessive loading of articular cartilage, chronic inflammation, and alignment problems. At the same time, many arthroplasty surgeons are wary of treating morbidly obese patients with surgery because of the increased perioperative risks. Although many of these patients still benefit greatly from joint replacement, in today’s “value-based care” environment, some institutions have implemented BMI cutoff thresholds for performing knee or hip arthroplasty. Others have set weight-loss requirements before they will schedule lower-extremity arthroplasty for morbidly obese patients. One still-unanswered question along these lines is: how much weight does a morbidly obese patient need to lose preoperatively in order to improve the outcome after a knee replacement?
Keeney et al. address that question in the August 21, 2019 issue of The Journal. In a retrospective cohort study, the authors evaluated outcomes among 203 morbidly obese patients who underwent a total knee arthroplasty (TKA). They found that a loss of 20 pounds preoperatively was associated with a shorter length of stay and a lower chance of being discharged to a rehab or skilled nursing facility rather than home. However, a 20-pound weight loss had no impact on surgical time or functional outcomes, as measured with the PROMIS-10 physical component score. Of note, only 14% of the evaluated patients lost at least 20 pounds preoperatively (highlighting the difficulty of losing weight in general and among this patient population in particular). There were no benefits of any kind in patients who lost only 5 or 10 pounds preoperatively.
While this study’s sample size is small, the findings provide evidence surgeons can use to encourage (or insist upon) larger amounts of weight loss before arthroplasty procedures in morbidly obese patients. In this study, the patients who lost at least 20 pounds remained morbidly or severely obese, and all the patients eventually regained most or all of the weight they lost. Still, the conclusion that at least 20 pounds of weight loss is beneficial for morbidly obese patients prior to a TKA remains sound. Because of the magnitude of this public health issue, we need more high-quality outcomes research (preferably using more knee-specific functional measures) on preoperative management of morbidly obese patients who are considering lower-extremity arthroplasty.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
How Many X-Rays Does It Take to Treat a Distal Radial Fracture?
We orthopaedists obtain radiographs for many reasons—to diagnose an unknown problem, to determine the progress of healing, and occasionally because we follow X-ray “dogma” acquired over time. That last reason prompted van Gerven et al. to undertake a multicenter, prospective, randomized controlled trial, the findings of which appear in the August 7, 2019 issue of The Journal.
The authors set out to evaluate the clinical utility of radiographs taken after a distal radial fracture in >300 patients. Some of those fractures were treated nonoperatively, while others underwent operative fixation. Surgeons of the patients randomized to the “usual-care” pathway were instructed to obtain radiographs at 1, 2, 6, and 12 weeks following the injury/surgery. Surgeons of patients in the “reduced-imaging” arm did not obtain radiographs beyond 2 weeks after the injury/surgery unless there was a specific clinical reason for doing so.
The authors found no significant differences between groups in any of the 6 patient-reported outcomes measured in the study, including the DASH score. Furthermore, the complication rates were almost identical between the usual-care (11.4%) and reduced-imaging (11.3%) groups. Not surprisingly, patients in the reduced-imaging group had fewer radiographs obtained (median 3 vs 4) and were exposed to a lower overall dose of ionizing radiation than those in the usual-care group.
Probably because the study was conducted in the Netherlands, it did not address the widespread practice of “defensive medicine” in the US—the unnecessary overuse of medical tests and procedures to reduce the risk of a malpractice claim. While that may limit the external validity of these findings among orthopaedists in the United States, this relatively simple yet well-designed study should remind us that it is important to have a definite clinical purpose when ordering a test of any type. A picture may be worth a thousand words, but sometimes it takes only 2 pictures to tell the full story of a healing distal radial fracture.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Polytrauma Patients Face Cancer Risk from Imaging Radiation
Orthopaedic surgeons work with radiation in some capacity almost every day. We would struggle to provide quality patient care if it were not for the many benefits that radiographic images provide us. But the more we are exposed to something, the less we tend to think about it. For example, how often do we discuss the risks of radiation exposure with our patients—especially those who are exposed to a large amount of it after an acute traumatic injury?
The article by Howard et al. in the August 7, 2019 issue of JBJS strongly suggests that polytrauma patients need to better understand the risks associated with radiation exposure as they progress through treatment of their injuries. The authors evaluated the cumulative 12-month postinjury radiation exposure received by almost 2,400 trauma patients who had an Injury Severity Score of 16+ upon admission. Those patients received a median radiation dose (not counting fluoroscopy) of 18.46 mSv, and their mean radiation exposure was 30.45 mSv. These median-versus-mean data indicate that a small subset of patients received substantially more radiation than others, and in fact, 4.8% of the cohort was exposed to ≥100 mSv of radiation. To put these amounts in context, the average human in the UK (where this study was performed) is exposed to about 2 mSv of background radiation per year, and there is good evidence suggesting that carcinogenesis risk increases with acute radiation doses exceeding 50 mSv.
Based on mathematical models (actual occurrences of cancer were not tracked), the authors conclude that for these patients, the median risk of fatal carcinogenesis as a result of medical radiation following injury was 3.4%. In other terms, 85 of these patients would be expected to develop cancer as a result of medical imaging—which struck me as a startling estimate.
So what are we to do? In a Commentary accompanying this study, David A. Rubin, MD, FACR offers some practical suggestions for reducing unnecessary radiation exposure. I personally feel that because the radiation associated with CT scans and radiographs can be, quite literally, life-saving for patients who have sustained traumatic injuries, increasing the chance that patients develop cancer later in life in order to save their life now is a good risk-benefit proposition. But the findings from this study should make us think twice about which imaging tests we order, and they should encourage us to help patients better understand the risks involved.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Good Outcomes and Savings with Preferred-Vendor Program
It has been said that outcomes of total joint arthroplasty are 90% related to surgeon factors (such as prosthetic alignment and fit and soft-tissue management), and only 10% to the implant itself. Historically, surgeon choices of implants for primary total hip and total knee arthroplasty have been based on influences such as the prostheses used during training, prior vendor relationships, specific patient characteristics, and findings in published literature. Absent evidence that the selection of prosthesis vendor affects patient outcomes to any significant degree, and with the universal focus on lowering health care costs, surgeon implant/vendor preferences have come under close scrutiny.
In the August 7, 2019 issue of The Journal, Boylan et al. study the impact of a voluntary preferred single-vendor program at a large, high-volume, urban orthopaedic hospital with >40 (mostly hospital-employed) arthroplasty surgeons. The hospital’s use of hip and knee arthroplasty implants from the preferred vendor rose from 50% to 69% during the program’s first year. In addition, the mean cost per case of cases in which implants from the preferred vendor were used were 23% lower than the mean cost-per-case numbers from the previous year (p<0.001). Boylan et al. noted that low-volume surgeons adopted the initiative at a higher rate than high-volume surgeons, and that surgeons were more compliant with using the preferred vendor for total knee implants than for total hip implants.
Why is it that some higher-volume surgeons seem resistant to change? It is not clear from the data presented in this study whether the answer is familiarity with an instrument system, loyalty to local representatives, or relationships with manufacturers based on financial or personal connections. The authors observed that “collaboration between surgeons and administrators” was a critical success factor in their program, and interestingly, the 3 highest-volume surgeons in this study (who performed an average of ≥20 qualifying cases per month) all used total knee implants from the preferred vendor prior to the initiation of this program.
The provocative findings from this and similar studies lead to many questions ripe for further research. Because hospitals are highly motivated to reduce implant costs in the bundled-payment environment, preferred-vendor programs are gathering steam. We need to better understand how they work (or don’t) for specific surgeons, within surgical departments, and within hospital/insurance systems in order to evaluate their effects on patient outcomes and maximize any cost benefits.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Study Supports Routine Patellar Resurfacing during TKA
The July 17, 2019 issue of The Journal features another investigation evaluating patellar resurfacing. Despite much research (see related OrthoBuzz post), this topic remains controversial among many total knee arthroplasty (TKA) surgeons. This study, by Vertullo et al., analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry. The findings suggest that routine resurfacing of the patella reduces the risk of revision surgery for TKA patients.
The authors evaluated more than 136,000 TKA procedures after placing the cases into three groups based on the surgeon’s patellar-resurfacing preference: infrequent (<10% of the time), selective (10% to 90% of the time), or routine (≥90% of the time). All of the cases evaluated utilized minimally stabilized components and cemented or hybrid fixation techniques, and they all were performed by surgeons who completed at least 50 TKAs per year.
The authors found that patients in the infrequent-resurfacing cohort had a nearly 500% increased risk of undergoing subsequent patellar revision during the first 1.5 years after TKA, compared to those in the routine-resurfacing cohort. Even more surprising to me was the finding that patients in the selective-resurfacing cohort had a >300% increased risk of needing a patellar revision within the first 1.5 years, compared to those in the routine-resurfacing cohort. In addition, the risk of all-cause revision was 20% higher in the selective cohort compared to the routine cohort.
What struck me most about this study were the differences between the selective and routine cohorts. One of the arguments against routine resurfacing of the patella is that surgeons should decide intra-operatively, on a patient-by-patient basis, whether the osteochondral health and biomechanics of the native patella warrant resurfacing. The findings of Vertullo et al. seem to call that reasoning into question. Although the results of this study add to the evidence supporting the routine resurfacing of the patella during TKA, I would like to reiterate a proviso from my earlier post on this topic: resurfacing is associated with added costs and an increased risk of potential complications.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Why US Orthopaedic Residents Overprescribe Opiates
Several authors have described the medical-school experience as “socialization” into the medical field. Medical students often learn the scientific underpinnings simultaneously with the social processes of interviewing/dialoging, examining, and then developing a treatment plan with the patient. One “subspecialty” social process that orthopaedists learn is pain management. While we are certainly encouraged to understand the scientific basis of this important and complex topic, much of the learning comes in the form of mirroring: junior residents do what senior residents instruct them to do, while senior residents follow the direction of attendings. These passed-on habits are culturally ingrained and persistent.
As Young et al. show in the July 17, 2019 issue of The Journal, the pain-management habits learned in training vary greatly from country to country, which is not surprising. Specifically, these authors examined the prescribing of postprocedural opiates by residents in the Netherlands, Haiti, and United States. They found that US residents prescribe significantly more morphine milligram equivalents (MMEs) of opioids at patient discharge than residents from either of the other 2 countries. The authors also showed that residents from the United States were the only group prescribing a significantly greater amount of MMEs to patients younger than 40 years old than to those above the age of 70.
Many pundits pin the phenomenon of opioid overprescribing in the US on the American public’s wish to be free from discomfort, along with the aggressive marketing and advertising of these medications in the United States. While this may be true, I think Young et al. have further identified the major influence that a resident’s training environment may have on prescribing practices. As already mentioned, residents often imitate what they see from more experienced residents and attendings, but sometimes those lessons, especially in pain management, lack a scientific basis.
What is missing from this survey-based study is data on patient satisfaction with postprocedural opiate prescribing. Having been involved in clinical care in Haiti, my impression is that patients there accept the local practice of pain management, constrained as it might be by resource limitations. I suspect the same is true in the United States and the Netherlands. Regardless, these findings demand that emphasis be placed on teaching orthopaedic residents evidence-based pain-management protocols. This will require a concerted effort from teachers and mentors at all levels of our medical-education system. This investigation is an important reminder that developing solutions to the opioid overprescribing problem in the US might begin in residency, where “cultural formation” occurs.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
With or Without Cement, Results with Triathlon TKA Are Same after 2 Years
With the increasing frequency of total knee arthroplasty (TKA) surgeries and the ever-increasing implant options available to orthopaedists for these cases, it is important that we carefully analyze new devices and technologies. We have already seen too many instances in which the enthusiasm for (and use of) a new implant outpaced the evidence for its efficacy and safety, leading to problems for patients, surgeons, and manufacturers alike.
The results of the randomized trial by Nam et al. in the July 3, 2019 issue of The Journal start to tackle this issue. The authors compared operative times, patient outcomes, and radiographic measures between patients who received either a recently introduced cementless or traditionally cemented cruciate-retaining TKA implant of the same design (the Triathlon TKA implant from Stryker). They found no clinically meaningful or statistically significant differences between the two groups in terms of Oxford Knee Score or Knee Society Score at any point during the average 2-year follow-up. In addition, nearly equal percentages of patients in each group reported being “extremely” or “very” satisfied with their functional outcome at 2 years, and radiographically, the researchers found no significant difference between the groups in terms of radiolucency behind the tibial or femoral implants. The one notable between-group difference was operative time, with the cementless cohort having a mean surgical time roughly 11 minutes less than that of the cemented cohort.
These results are encouraging in that they show improved operative efficiency with none of the aseptic loosening that has historically been a concern with cementless knee implants. Still, the authors make it clear that “the burden of proof remains with cementless fixation,” largely because cementless implants cost more than their cemented counterparts. Those higher costs need to be justified by improved outcomes (including implant survivorship), decreased complications, or both in order for cementless implants to displace cemented ones as the “standard of care.”
We are not there yet, but the findings from Nam et al. justify further surveillance of this cementless device. Future high-quality studies incorporating joint registry data and longer patient follow-up will hopefully provide the supporting evidence with which the joint-arthroplasty community can decide whether this relatively new cementless technology should be the implant of choice for certain patient populations.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Placenta-Derived Cells Give Short-term Boost to Tendon Repair
From journal articles to nightly news segments, it’s hard to avoid the barrage of information related to the use of cell-based therapies for musculoskeletal problems. While these approaches may turn out to be enthusiasm outpacing science (see related OrthoBuzz post, “Stemming the Tide of Stem Cell Hype”), one reason for the excitement is rooted in a very simple fact: it is really hard to get many soft tissues to heal, especially in certain patient populations. Moreover, failure of initial repair usually leads to even more biologically inhospitable repair environments. This clinical challenge has led to the zealous investigation of various cell-based compounds to see which ones might assist native soft-tissue cells with the formidable task of quick healing.
In the July 3, 2019 issue of The Journal, Ma et al. investigate the potential for human placenta-derived cells to augment the healing of chemically induced patellar tendon ruptures in rats. The injected placental cells introduced a transitory inflammatory response that led to increased load to failure at the 2-week mark, compared to biomechanical results in control rat tendons injected with saline solution. However, the addition of placenta-derived cells did not increase tendon load to failure beyond 2 weeks, and at no time point were differences seen between the control and experimental groups in tendon strength, stiffness, collagen organization, or cellularity.
While the positive results of this study were short-lived, they are important nonetheless. The animal model used is well thought-out and reproducible, allowing an easy path for future investigators to compare and contrast these results. Placenta-derived cell populations are widely available, and the authors clearly explained how the cells were processed, preserved, and delivered. With the increasing incidence of acute and chronic tendon injuries, and with the results of studies using other cell types being equivocal at best, these findings from Ma et al. are noteworthy.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
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