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More Mortality Data on Hip Fractures in the Elderly

OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew Herring, MD, in response to a recent study in the Journal of Orthopaedic Trauma.

Among the elderly, low-energy hip fractures are common injuries that almost all orthopaedic surgeons encounter. While operative management is typically the standard of care, there are some patients for whom nonoperative treatment is most aligned with their goals of care, usually because of chronic disease, fragility, and/or high risk of perioperative mortality.

When counseling elderly patients and family members about the risks and benefits of surgical management for a hip fracture, we have abundant data. We can estimate the length of rehabilitation, discuss the likelihood of regaining independence with ambulation, and quote the 30-day, 1-year, and 5-year mortality statistics. But what about the risks and benefits of nonoperative care? How long do these patients live? How many are alive 1 year after the fracture?

Chlebeck and colleagues attempt to answer those questions with a retrospective cohort study of 77 hip fracture patients who were treated nonoperatively and a matched cohort of 154 operatively treated hip fracture patients. Nonoperative management was chosen only after a palliative-care consult was obtained and after a thorough multidisciplinary discussion of treatment goals with the patient and family. Patients who elected nonoperative care were treated with early limited weight bearing and a focus on maximizing comfort. Researchers established a comparative operative cohort through 2:1 matched pairing, controlling for age, sex, fracture type, Charlson Comorbidity Index, preinjury living situation, preinjury ambulatory status, and presence of dementia and cardiac arrhythmia.

As one might expect, there was significantly lower mortality in the operative group. The in-hospital, 30-day, and 1-year mortality for nonoperatively treated patients was 28.6%, 63.6%, and 84.4% respectively. The mortality rates seen in the operative cohort were 3.9%, 11.0%, and 36.4% respectively. A Kaplan-Meier survival analysis revealed the median life expectancy in the nonoperative cohort to be 14 days, versus 839 days in the operative group (p <0.0001). Interestingly, the researchers found no difference in hospital length of stay between the two groups (5.4 vs. 7.7 days; p=0.10).

These results provide useful references for orthopedic surgeons to use when counseling hip fracture patients and their families. Surgical intervention remains the standard of care in most instances, and this study suggests that operative care offers a significant mortality benefit over nonoperative care even in relatively unhealthy patients, like those selected for the matched operative cohort.

This study also gives us data to help guide the expectations of patients who decide surgery is not in line with their wishes. Half of the patients who elected nonoperative care in this study died within 14 days of admission, and only 15.6% were still alive at 1 year. Additionally, choosing nonoperative care does not lengthen hospitalization, suggesting that these patients can be quickly transferred to a more comfortable setting.

Matthew Herring, MD is a fellow in orthopaedic trauma at the University of California, San Francisco and a member of the JBJS Social Media Advisory Board.

Diagnosing Infection in “Dry” Prosthetic Joints

Despite a bevy of research and intense clinical focus, definitively diagnosing periprosthetic joint infections (PJIs) remains a major challenge in many patients. There is no single test that can confirm a PJI diagnosis with absolute accuracy, and surgeons often encounter clinical factors that make the diagnostic challenge even more complex. One such scenario is when a surgeon cannot aspirate enough fluid for culture from the affected joint of a patient who may have a PJI. In such situations, important microbiological data that would come from culturing synovial fluid are unavailable, leaving treating surgeons information-poor.

In the June 5, 2019 issue of The Journal, Li et al. provide surgeons with data about a controversial solution to this so-called “dry-tap” problem. The lead author performed aspirations on nearly 300 joints that were suspicious for periprosthetic infection. Eighty-two of those aspirations (29%) yielded ≤1.0 mL of synovial fluid. In those “dry-tap” cases, 10 mL of saline solution was injected into the joint, which was then reaspirated.

When comparing cultures from the aspirates that were the result of a saline lavage to those in which no lavage was performed, the authors found overlapping 95% confidence intervals in sensitivity, specificity, positive predictive value (PPV), and negative predictive value. However, the specificity (0.991 vs 0.857) and PPV (0.987 vs 0.889) were higher in the nonlavage cohort, even if those differences did not reach statistical significance. In addition, no significant differences were found between the groups in terms of relative frequencies of specific pathogen types.

Although the authors conclude that this lavage-and-reaspiration technique “is not necessarily inappropriate,” it is important to note that no post-hoc power analysis was performed, and therefore type II error needs to be considered because the study was probably underpowered. In addition, the International Consensus Meeting (ICM) recommends against lavaging a “dry” joint to obtain fluid for culture, largely because the injected saline will dilute results if a leukocyte esterase strip test or cell count is subsequently performed as part of the PJI-diagnosis process. Still, the authors point out that the data supporting the ICM’s recommendations against this practice are relatively weak, and the specificity and sensitivity data from this study are quite satisfactory.

So does this give us another option for determining whether a periprosthetic joint infection is present in patients from whom little or no synovial fluid can be obtained? Maybe. But this technique requires further investigation before it becomes widely implemented in practice. Without validation, it risks becoming just one more variable that could reinforce our own confirmation biases in these challenging cases. With further validation, however, it could allow pre-revision collection of valuable and accurate culture information from “dry” joints.

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

Pelvic Fracture Classification Will Benefit Elderly Patients

The orthopaedic community began to move away from individual fracture classifications in the mid-1980s. The basis for that shift was the need for wider recognition that fractures represent a “continuous variable,” with infinite varieties of orientations and combinations of fracture lines. Trying to fit fractures into a narrow classification system can lead to confusion and misinformation. Furthermore, surgeons often disagree when determining a fracture’s classification and, therefore, which treatment is best.

To move away from individual classification systems, orthopaedic journals have generally moved toward the compendium of fracture classifications approved by the OTA and AO. Still, there are times when a new fracture classification seems appropriate, and in the June 5, 2019 issue of The Journal, Pieroh et al. have provided us with an example that classifies fragility fractures of the pelvis (FFP). The 4-group FFP classification is based on fracture morphology with different degrees of instability and includes treatment recommendations.

The authors collected the CT scans of 60 patients from 6 different hospitals who were ≥60 years old and had sustained a pelvic fracture from low-energy trauma. These CT scans were shown to 6 experienced surgeons, 6 inexperienced surgeons, and 1 surgeon who had direct experience/training with the FFP system. Each surgeon was asked to classify the pelvic fractures according to the FFP classification. Inter- and intra-rater reliabilities for the fracture classifications were calculated from these readings, and the overall inter-rater Kappa coefficient was found to be 0.53, while the overall intra-rater Kappa coefficient was 0.46 (Kappa coefficients of 0.61 to 0.41 constitute “moderate” reliability). In terms of percent agreement, there was greater agreement between surgeons when it came to classifying FFP Group 1 fractures than for FFP Group 2 and 3 fractures. This is noteworthy because Group 3 fractures are thought to require surgical treatment, while primary treatment for Group 2 fractures is usually nonoperative.

Pelvic fractures that are associated with low bone density and low-energy trauma are becoming increasingly frequent as our population continues to skew older. Having a validated, relatively straightforward classification system like the FFP to assist us in managing these patients will be of great assistance. The sound methodology used to develop the FFP classification system and its decent reliability, face validity, and construct and criterion validity can assure all of us about the usefulness of the FFP classification as the basis for future clinical investigations and to advance the care of these patients.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

FDA Approves Rapid Alpha-Defensin Test for PJI

The US FDA has approved the Synovasure Alpha Defensin Lateral Flow Test Kit for helping detect periprosthetic joint infection (PJI) in the synovial fluid of patients being evaluated for revision joint replacement.

Alpha defensins are proteins released by neutrophils in early response to infection. OrthoBuzz previously summarized a 2018 JBJS study that found this rapid alpha defensin test to have 96.9% overall accuracy.

In the FDA news release about the approval, Tim Stenzel, MD, director of the FDA’s Office of In Vitro Diagnostics and Radiological Health, said the test provides health care professionals with additional information that “could potentially reduce patient risk by avoiding unnecessary revision operations for replacement joints.”

In a Commentary on the 2018 JBJS study, Garth Ehrlich, PhD and Michael Palmer, MD said the device is a “substantive advance,” but not “a panacea.” For one thing, metallosis would still need to be ruled out with MRI, because that noninfectious etiology triggers a false-positive result with this rapid test. Synovasure is also likely to miss detection of slow-growing, chronic bacterial pathogens such as Proprionibacterium acnes, the commentators said.

The Synovasure test kit received approval through the FDA’s de novo premarket pathway, which is reserved for “low- to moderate-risk devices of a new type,” according to the agency.

Electrocautery Damages Metal Hip Implants in 2 Ways

In the setting of revision total hip arthroplasty (THA), the use of electrocautery—and contact between the thermal device and retained components—cannot always be avoided. In the May 15, 2019 issue of The Journal of Bone & Joint Surgery, Sonntag et al. perform two implant-retrieval analyses and a separate in vitro investigation to determine what kinds of damage take place when electrocautery energy meets titanium femoral stems.

The components for retrieval analyses were removed from patients who experienced a fracture of the femoral stem or femoral neck after revision THA. The authors found superficial discoloration and melting marks on the retrieved components, and elemental analysis indicated that material had been transferred from the electrocautery tip. During in vitro testing of 6 titanium alloy femoral stems, the authors found that electrocautery surface damage reduced load-to-failure by up to 47% when compared to undamaged femoral neck specimens. Microscopic analysis revealed notable changes in metal microstructure in electrocautery-exposed components, whereby certain zones exhibited higher strength than others, which, the authors speculate, might result in lower overall fatigue resistance.

Both the retrieval and in vitro analyses showed that electrocautery damage to femoral implants, particularly in the anterolateral region at the base of the neck, reduced implant fatigue resistance. However, the authors say their results need to “be carefully interpreted,” because they are based on only 2 retrievals and a limited number of test specimens. Nevertheless, they conclude that “electrocautery device contact [with femoral implants] should be avoided and the use of conventional scalpels is recommended, where reasonable.”

The Economics of Revision THA for Fractures: Sustainable?

At the risk of  economic oversimplification, it is difficult to sustainably provide a service when payment for it is less than the cost to perform it. But that is one reality exposed by Hevesi et al. in the May 15, 2019 issue of The Journal. Using National Inpatient Sample and ACS-NSQIP data, the authors compared the average costs and 30-day complication rates for revision total hip arthroplasties (THAs) performed for 3 different indications—fractures, wear/loosening, and instability—at both a local and national level. They found that the average hospitalization costs associated with a revision THA related to a fracture were 33% to 48% higher (p < 0.001) than the cost of revision THAs related to wear or instability.

However, the authors emphasize that all 3 of these indications for revision THA are reimbursed at the same rate based on Medicare Diagnosis-Related Group (DRG) codes. DRGs take into account patient comorbidities to determine reimbursement levels—but they do not adjust payments for THA revision according to indication. Hevesi et al. note that the only DRG reimbursement level that would cover the average cost of a revision THA for a fracture would be one performed on a patient with severe medical comorbidities or a major complication. Not surprisingly, patients who underwent a revision THA to treat a fracture were found to have a higher age and more medical comorbidities than those undergoing a revision for wear or instability.

The authors use this data to make a very compelling case that DRGs for revision THA should be changed so they are indication-specific, taking into account the underlying reason for the revision. They observe that “a DRG scheme that does not distinguish between indications for revision THA sets the stage for disincentivizing the care of fracture patients and incentivizing referrals to other facilities.” Those “other facilities” usually end up being large tertiary-care centers, which the authors claim “perform a higher percentage of the costlier revision THA indications.”

This problem of reimbursement inequality is not unique to revision THAs and requires further investigation in many fields. Unless “the system” addresses these subtle but important differences, tertiary referral centers may be inundated with patients who need procedures that cost more to perform than the institutions receive in reimbursement—an unsustainable scenario.

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

Which Germs Cause Pelvic Prosthesis Infections?

Prosthetic infections involving total hip or knee implants are bad enough, but infections involving pelvic endoprostheses following tumor resection can be particularly devastating, often necessitating multiple surgical interventions. And, such infections are disconcertingly common, affecting an estimated 11% to 53% of pelvic endoprostheses.

Findings from a retrospective multisite cohort study by Sanders et al. in the May 1, 2019 issue of The Journal of Bone & Joint Surgery reveal more about the specific microorganisms underlying those infections—and may offer insight into how to prevent them.

The authors analyzed 70 patients who underwent pelvic endoprosthetic reconstruction following a tumor resection. Eighteen patients (26%) developed an infection, and in 14 out of those 18 cases, the infection was determined to be polymicrobial. Cultures from 12 of the 18 patients (67%) were positive for a member of the Enterobacteriaceae family of gram-negative bacteria, which includes Escherichia coli. More generally, microorganisms associated with intestinal flora appeared 32 out of the 42 times that any microorganism was isolated.

At the latest follow-up (median follow-up was 66 months), 9 of the 18 patients still had the original implant, although 2 of those patients had a fistula and another 2 were receiving suppressive antibiotics. Of the remaining 9 patients who had the original implant removed, 3 had a second implant in situ.

The authors emphasize how different these pelvic endoprosthetic infections are from infections related to joint arthroplasty. The close proximity of incisions for periacetabular tumor resection to the gut and other highly colonized areas might contribute to these infections, they speculate. Sanders et al. say the findings of this study may prompt surgeons to employ additional surgical-site antiseptic measures before and during these surgeries and “may justify the use of a broader spectrum of [systemic] antibiotic prophylaxis aimed at gram-negative bacteria.”  They also suggest that investigations into “selective gut decontamination” might yield additional information about how to prevent infections in this surgical setting.

A Rash of Broken Femoral Nails—What’s Up?

I’ll be honest: I have never worried much about breakage of the cephalomedullary nails I implant for proximal femur fractures. Instead, I’m focused on the fracture reduction, soft-tissue handling, and proper implant positioning. These nails are very strong. Sure, failures of these implants may occur and have been reported. But I have never had a lengthy discussion with a patient about the potential risk of the implant breaking during normal activity—and I doubt many other surgeons have either.

That is why the article by Lambers et al. in the May 1, 2019 issue of The Journal grabbed my attention. The authors carefully analyzed 16 cases in which a specific cephalomedullary nail (the TFNA, made from a titanium-molybdenum alloy) broke in 13 patients after an average of 5 months. Of note, 3 patients who underwent a revision with the same type of nail had a repeat fracture of the implant. The majority of these patients had been treated for a reverse oblique intertrochanteric fracture —a type that we all commonly see and treat—and all the fractures had been well reduced at the time of nail insertion.

The implant fractures all occurred at the proximal aperture of the nail and were consistent with fatigue fracture of the alloy. But they all showed a unique “stepped propagation” pattern, whereby, according to the authors, “a planar crack arrested, changed planes by 90°, progressed, arrested, and then changed planes again by 90° until final failure.”

These types of implant failures are not common for this nail, but they apparently happen more often than I thought. I am certain that the manufacturer will be responding to this data, and I look forward to future design changes—especially because the authors hypothesize that prior changes to this nail’s design and/or alloy may have contributed to these breakages. Then again, there may have been errors in technique that made these types of failures more common, or maybe a different implant would have been a better choice for some of these patients. To me, matching fracture type and implant choice is very important.

I look forward to learning more about this issue and will keep these types of implant failures in the back of my mind during hip-fracture cases. In the meantime, Lambers et al. advise “vigilant clinical and radiographic surveillance of patients with unstable hip fracture patterns who undergo osteosynthesis with use of a TFNA implant.”

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

Shared Decision Making among Guatemalan Orthopaedists

The concept of asking and accounting for patient preferences in non-emergent treatment decisions has been discussed in the medical literature for nearly two decades. Michael J. Barry, MD and others have quite fully developed this notion of “shared decision making” (SDM). In the context of patient desires, SDM includes a presentation of the treatment options and the data regarding those treatment options, and a discussion of potential complications involved in each option.

The earliest work on SDM centered around patient choices for managing prostate disease, degenerative disc disease of the lumbar spine, and urinary incontinence. Only recently have orthopaedic surgeons embraced this concept, as more of us get training in and practice the necessary communication skills and cultural competency needed to engage our patients in SDM. But we still have a long way to go when it comes to facility with SDM, and this seems to be especially true in the orthopaedic communities of some non-US countries.

In the May 1, 2019 issue of The Journal, Martinez-Siekavizza et al. report results of a survey on the use of SDM among orthopaedic surgeons in Guatemala. Survey recipients were questioned about their SDM techniques in the clinical scenario of intertrochanteric hip fracture, although hip fracture may not have been the ideal condition to focus on, given the worldwide acceptance that this condition is almost always best managed surgically. Nevertheless, the survey showed that 25% of the surgeon respondents ”never” or “hardly ever” allowed their patients to participate in the treatment decision-making process. While the authors cite many systemic reasons for such lack of patient participation (such as surgical consent not being required in Guatemala and the limited resources in many rural areas of the country that often leave no choices available), 75% non-engagement with patients/families strikes me as very high.

The key facet of shared decision making is discussing all the potential treatment options with the patient. This aspect of SDM seems especially important for nontrauma elective cases in which the “best” treatment option may be less clear than in trauma cases.  Even so, Martinez-Siekavizza et al. found that surgeons who discussed the different treatment options with patients had an almost 3-fold greater likelihood of allowing patients to participate in decision making than those who did not. This makes intuitive sense, as it would be difficult for patients to take part in treatment decisions if they are not informed about the options that exist.

As surgeons, we need to do our best to ensure that patients understand all their treatment options, and we should sharpen our focus on shared decision making during our patient interactions. JBJS looks forward to receiving more manuscripts from all over the world that explore the techniques and value of SDM in orthopaedic patient management.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

VTE Prevention: Is Aspirin Really That Good?

OrthoBuzz occasionally receives posts from guest bloggers. In response to a three recent studiesthe following commentary comes from Jeffrey B. Stambough, MD.

Throughout the last decade, we’ve experienced a boom in anticoagulation options to help prevent venous thromboembolism (VTE) associated with orthopaedic procedures. The use of aggressive anticoagulation, such as warfarin and various heparin formulations, is being questioned, largely due to concerns about bleeding risks and wound complications.  Along with the newer direct oral anticoagulants such as rivaroxaban, over-the-counter aspirin (ASA) is gaining prominence as an anticoagulant due to its high efficacy, low cost, convenience for patients, favorable side-effect profile, and cardioprotective attributes.  Current guidelines include the use of all these thromboprophylactic agents, but three recent studies lend credence to using aspirin as the primary VTE prophylactic agent when performing total joint arthroplasty (TJA).

In a  March 20, 2019 JBJS study analyzing >31,000 TJAs performed at a single institution over 17 years, Rondon et al. found a 3-fold lower 30-day and 2-fold lower 1-year mortality rate in patients receiving ASA (81mg or 325 mg twice daily), compared to those who received non-aspirin thromboprophylaxis (mainly warfarin).  No mortality differences were noted between the two ASA dosing regimens.  While investigating specific causes of death, the authors discovered that the primary cause of death in the non-ASA cohort was cardiac related at all time points.

A second study, from the April 3, 2019 JBJS, looked into the effects of 3 antithrombotic agents on symptomatic VTE rates and periprosthetic infections in high-risk patients undergoing primary or revision TJA.  When compared to the two more potent agents (warfarin and low-molecular-weight heparin), ASA proved more effective at reducing pulmonary embolism (PE) and VTE rates in high-risk patients, and it was also associated with lower rates of periprosthetic joint infection when compared with warfarin.  Thus, it seems that even in patients deemed to be higher risk for developing VTE, ASA may be a safe, effective option.

Lastly, Runner et al. gleaned VTE prophylaxis data from >22,000 TJA cases submitted by surgeons sitting for Part 2 of ABOS between 2014 and 2016.  The findings, reported in the April 2019 issue of the Journal of Arthroplasty, showed similar trends to those seen in the two previously mentioned studies: Mild (distal or superficial deep vein thrombosis [DVT]), moderate (nonfatal PE, proximal DVT) and severe (fatal PE) VTE events, as well as death, were significantly less frequent in those who received ASA compared to more aggressive agents (heparin or one of its analogs, direct oral agents, or warfarin). Also, patients who received ASA with or without mechanical prophylaxis had significantly lower complication rates (95.5% vs. 93.0%, p<0.001).

One firmly held dogma in medicine is that patients who are at higher risk for VTE should be treated with stronger anticoagulation medications. However, these 3 studies support the idea that less aggressive anticoagulation medication (specifically, low-dose aspirin) may be the more effective and safer option for most patients. In our ongoing quest to improve patient outcomes and mitigate risk around the TJA episode, we should consider using aspirin for thromboprophylaxis unless there is an explicit contraindication in a specific patient.

However, we should also keep in mind that these three studies have the common limitations of all retrospective analyses. Recent randomized trials have shown aspirin to be “noninferior” to other anticoagulants for VTE prevention, and in less than 2 years, we should have even more definitive answers to this question from the randomized, multicenter PEPPER trial, with its estimated 25,000 participants.

Jeffrey B. Stambough, MD is an orthopaedic hip and knee surgeon, an assistant professor of orthopaedic surgery at University of Arkansas for Medical Sciences, and a member of the JBJS Social Media Advisory Board.