Fracture liaison services and similar coordinated, multidisciplinary fragility-fracture reduction programs for patients with osteoporosis work (see related OrthoBuzz posts), but until now, the data corroborating that have come from either academic medical centers or large integrated health care systems. The November 7, 2018 issue of The Journal of Bone and Joint Surgery presents solid evidence from a retrospective cohort study that a private orthopaedic practice-based osteoporosis management service (OP MS) also successfully reduces the risk of subsequent fragility fractures in older patients who have already sustained one.
Sietsema et al. collected fee-for-service Medicare data for Michigan residents who had any fracture from April 1, 2010 to September 30, 2014 (mean age of 75 years). From that data, they compared outcomes for patients who received nurse-practitioner-led OP MS care from a single-specialty private orthopaedic practice within 90 days of the first fracture to outcomes among a propensity-score-matched cohort of similar patients who did not receive OP MS care. There were >1,300 patients in each cohort, and both groups were followed for an average of 2 years. The private practice’s OP MS services incorporated the multidisciplinary protocols promulgated by the American Orthopaedic Association’s “Own the Bone” program.
The cohort exposed to OP MS had a longer median time to subsequent fracture (998 versus 743 days), a lower incidence rate of any subsequent fracture (300 versus 381 fractures per 1,000 person-years), and higher incidence rates of osteoporosis medication prescriptions filled (159 versus 90 per 1,000 person-years). Over the first 12 months of the follow-up period, total medical costs did not differ significantly between the 2 cohorts.
These findings are consistent with those reported from academic or integrated health-system settings. According to the authors, this preponderance of evidence “emphasize[s] the importance of coordinated care in reducing subsequent fractures, lengthening the time to their occurrence, and improving patient outcomes.” Sietsema et al. conclude further that “the U.S. Medicare population would benefit from widespread implementation of such models in collaboration with orthopaedic providers and payers.”
In 2015, JBJS launched an “article exchange” collaboration with the Journal of Orthopaedic & Sports Physical Therapy (JOSPT) to support multidisciplinary integration, continuity of care, and excellent patient outcomes in orthopaedics and sports medicine.
During the month of November 2018, JBJS and OrthoBuzz readers will have open access to the JOSPT article titled “Does Health Care Utilization Before Hip Arthroscopy Predict Health Care Utilization After Surgery in the US Military Health System? An Investigation Into Health-Seeking Behavior.”
This observational cohort study found that patients who used more health care prior to hip arthroscopy also used more health care after surgery. The findings lead the authors to conclude that clinicians “should consider prior patterns of health care utilization…when determining care plans and prognosis.”
Perioperative Tranexamic Acid Treatment and Risk of Cardiovascular Events or Death After Total Hip Arthroplasty
Prior research has established that total hip arthroplasty (THA), in and of itself, is associated with a small increased risk of venous thromboembolism (VTE). Hence the concern that routinely administering the antifibrinolytic drug tranexamic acid (TXA) perioperatively, as is commonly done nowadays to reduce blood loss during surgery, might further increase the risk of THA-related thromboembolic events. But the findings from a large population-based cohort study by Dastrup et al. in the October 17, 2018 JBJS, should allay many of those concerns.
The authors evaluated >45,000 Danish patients who had a THA between 2006 and 2013. Approximately 85% of those patients received intravenous TXA perioperatively, while the rest did not. Dastrup et al. evaluated adverse cardiovascular events (VTE, deep venous thrombosis, pulmonary embolism, myocardial infarction, and ischemic stroke) among those patients over 30 postoperative days, and they found no increased risk in any of those outcomes among the patients who received TXA relative to those who did not. These optimistic findings were essentially the same when the authors analyzed the data using a multivariable model and with propensity-score matching.
Dastrup et al. conclude that TXA in the setting of THA is safe with respect to VTE, and David Ayers, MD, commenting on the study, concurs. However, Dr. Ayers cautions that the study did not have the statistical strength to evaluate the potential cardiovascular risks of TXA in THA patients who have undergone previous cardiac procedures, such as stent placement. He therefore suggests that “further safety evaluation should be directed toward [such] patients at higher risk for complications after receiving TXA.”
Over the last 2 decades, research into how various “preexisting conditions” affect the outcomes of orthopaedic interventions has increasingly focused on the impact of mental health (a patient’s “state of mind” and coping abilities) and psychological diagnoses such as depression. The impact of mental health, depression, and personality characteristics on patient-reported outcomes following significant skeletal trauma has been well documented in the trauma literature. In addition, previous studies in knee arthroplasty have identified depression as a major factor in suboptimal patient outcomes.
In the October 17, 2018 issue of The Journal, Halawi et al. teased out the impact of depression and mental health—independently and in combination—on patient-reported outcomes following primary total joint arthroplasty (TJA) in 469 patients at a minimum follow-up of one year.
The authors used the validated SF-12 MCS instrument to assess patient baseline mental health at the time of surgery. They also used the widely accepted WOMAC score to assess joint-specific pain, stiffness, and physical function before and after surgery. Using these tools, the authors showed that, while depression alone may diminish some patient-reported gains obtained from arthroplasty, it does not seem to affect a patient’s overall outcome as much as poor mental health prior to surgery. In this study, patients with depression but good mental health achieved patient-reported outcomes comparable to those among normal controls. Still, patients without depression and in good mental health were found to have the most robust improvements after undergoing TJA.
Orthopaedic surgeons need to better understand the interplay between these complex psychological states and patient outcomes. These authors conclude that the effect of depression on patient-reported outcomes is “less pessimistic than previously thought,” but we welcome further studies examining the link between “the mind” and orthopaedic outcomes. Finally, we should be ready to refer patients to our mental health colleagues when we detect a potential underlying nonphysical condition that might adversely affect the magnitude of benefit from the treatments we offer.
Marc Swiontkowski, MD
The adult joint-reconstruction community has made great strides in the last 2 decades in understanding what causes aseptic loosening of arthroplasty components. For example, revelations about polyethylene particulate debris has led to the production of highly cross-linked polyethylene, which in turn has lowered wear rates, decreased revision rates, and increased the survivorship of total hip implants (see related OrthoBuzz post). Still, polyethylene debris is only one factor that can lead to aseptic loosening. Another important, yet often overlooked, factor is friction between the impacted acetabular shell and the host bone.
In the October 3, 2018 issue of The Journal, Bergmann et al. report data that help us better understand the “friction factor” in aseptic loosening. The authors implanted specially designed, instrumented acetabular components that measured in vivo friction moments among nine patients while they engaged in >1,400 different activities. The authors found that 124 of those activities led to friction moments >4 Nm—which appears to be the upper limit for facilitating a firm union between the acetabular component and the native socket.
Movements such as muscle stretching in the lunge position, the breaststroke in swimming, 2-legged standing with muscles contracted, and a single-legged stance while moving the contralateral leg were among those that created the highest friction between the implant and the host bone—and that could impede bone ingrowth into the acetabular component and thus contribute to aseptic loosening. The study also highlights the importance of periodic unloading of the prosthetic joint to allow proper synovial lubrication, which helps minimize the effects of high-friction moments. The good news is that the vast majority of activities studied do not appear to result in friction forces above the 4 Nm threshold.
Although these data should be confirmed with other in-vivo instrumented prostheses (assuming there are more patients willing to receive acetabular components capable of delivering telemetric data), they provide practical insight into the real-world forces placed on total hip prostheses after implantation. Such information can be used to counsel patients regarding high-friction and sustained-loading activities to be avoided, and it can help physical therapists and surgeons tailor postoperative regimens that optimize patient recovery while minimizing the risk to implanted prostheses.
Marc Swiontkowski, MD
Every 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, Mengnai Li, MD, co-author of the September 19, 2018 Specialty Update on Hip Replacement, selected the five most clinically compelling findings from among the more than 100 studies covered in the Specialty Update.
The Benefits of HXLPE
–A double-blinded study that randomized patients to receive either a conventional polyethylene liner or one made from highly cross-linked polyethylene (HXLPE) found that, after a minimum of 10 years, the HXLPE group had significantly lower wear rates, lower prevalence of osteolysis, and lower revision rates than the conventional-liner group.
Outcomes for Hip Fracture vs OA
–A propensity score-matched cohort analysis of NSQIP data found that total hip arthroplasty (THA) undertaken to treat hip fractures among Medicare beneficiaries was significantly associated with an increased risk of CMS-reportable complications, non-homebound discharge, and readmission, relative to THA undertaken to treat osteoarthritis.1
Infection Risk Factors
–A multicenter retrospective study found that a threshold of 7.7% for hemoglobin A1c was more predictive of periprosthetic joint infection than the commonly used 7%, and the authors suggest that 7.7% should be considered the goal in preoperative patient optimization.2
THA in Patients with RA
–Recently published guidelines from the American College of Rheumatology and AAHKS regarding antirheumatic medication use in patients with rheumatic diseases who are undergoing THA suggest the following:
- Continuing nonbiologic disease-modifying antirheumatic drugs (DMARDs)
- Continuing the same daily dose of corticosteroids
- Withholding biologic agents prior to surgery
- Planning surgery for the end of the biologic dosing cycle.
All recommendations are conditional due to the low or moderate-quality evidence on which they were based.3
–A double-blinded, randomized trial found that oral tranexamic acid (TXA) provided equivalent reductions in blood loss in the setting of primary THA, at greatly reduced cost, compared with intravenous TXA.
- Qin CD, Helfrich MM, Fitz DW, Hardt KD, Beal MD, Manning DW. The Lawrence D. Dorr Surgical Techniques & Technologies Award: differences in postoperative outcomes between total hip arthroplasty for fracture vs osteoarthritis. J Arthroplasty. 2017 Sep;32(9S):S3-7. Epub 2017 Feb 6.
- Tarabichi M, Shohat N, Kheir MM, Adelani M, Brigati D, Kearns SM, Patel P, Clohisy JC, Higuera CA, Levine BR, Schwarzkopf R, Parvizi J, Jiranek WA. Determining the threshold for HbA1c as a predictor for adverse outcomes after total joint arthroplasty: a multicenter, retrospective study. J Arthroplasty. 2017 Sep;32(9S): S263-7: 267.e1. Epub 2017 May 11.
- Goodman SM, Springer B, Guyatt G, Abdel MP, Dasa V, George M, Gewurz- Singer O, Giles JT, Johnson B, Lee S, Mandl LA, Mont MA, Sculco P, Sporer S, Stryker L, Turgunbaev M, Brause B, Chen AF, Gililland J, Goodman M, Hurley-Rosenblatt A, Kirou K, Losina E, MacKenzie R, Michaud K, Mikuls T, Russell L, Sah A, Miller AS, Singh JA, Yates A. 2017 American College of Rheumatology/American Association of Hip and Knee Surgeons guideline for the perioperative management of antirheumatic medication in patients with rheumatic diseases undergoing elective total hip or total knee arthroplasty. J Arthroplasty. 2017 Sep;32(9):2628-38. Epub 2017 Jun 16.
Annual volume projections for total joint arthroplasty (TJA) have been cited frequently and applied broadly, often to estimate future costs. But with a slowdown in the growth of the annual incidence of total knee arthroplasty (TKA), updated projections are needed, and that’s what Sloan et al. provide in the September 5, 2018 issue of JBJS.
Using the National Inpatient Sample to obtain TJA incidence data, the authors first analyzed the volume of primary TJA procedures performed from 2000 to 2014. They then performed regression analyses to project future volumes of TJA procedures. Here are the numbers based on the 2000-to-2014 data:
- Primary total hip arthroplasty (THA) is projected to grow 71%, to 635,000 annual procedures by 2030.
- Primary TKA is projected to grow 85%, to 1.26 million annual procedures by 2030.
However, the TKA procedure growth rate has slowed in recent years, and models based on 2008-to-2014 data project growth to only 935,000 annual TKAs by 2030—325,000 fewer procedures relative to the 2000-to-2014 models.
Earlier studies, notably one by Kurtz et al. in 2007, obviously could not account for the reduced growth rate in TKA after 2008. A 2008 analysis by Wilson et al., based on the Kurtz et al. data, estimated that annual Medicare expenditures on TJA procedures would climb from $5 billion in 2006 to $50 billion in 2030. “Using our projections,” say Sloan et al., “we predict that Medicare expenditures on these procedures in 2030 will be less than half of that predicted by Wilson et al.”
These findings lend credence to the authors’ observation that “it is imperative that projections of orthopaedic procedures be regularly evaluated and updated to reflect current rates.”
The incidence of patients presenting with proximal thigh and groin pain is increasing along with increased interest in recreational athletic activity. When it is associated with a history of increased physical activity, this pain profile often prompts the ordering of a hip MRI if presenting radiographs are unremarkable. However, surgeons often find it difficult to make accurate prognoses and treatment recommendations when the MRI findings suggest a femoral neck stress fracture.
In the September 5, 2018 issue of The Journal, Steele et al. provide us with helpful hints for determining when to proceed with surgical stabilization of the femoral neck in this clinical scenario. Of the femoral neck stress fracture patients in this study who progressed to a surgical procedure, >85% had an effusion on the initial MRI, compared with only 26% of those whose condition resolved with nonoperative treatment. In statistical terms, those who had a hip effusion had an 8-fold increased risk of progression to surgery compared to those without a hip effusion. Meanwhile, the overall fracture-line percentage on the initial MRI turned out to be a poor metric for predicting progression.
Stabilization of a femoral neck stress fracture with percutaneous implants usually improves pain and predictably prevents displacement of the fracture and the attendant risk of nonunion and osteonecrosis of the femoral head. Further clinical research should help validate the seemingly reliable MRI-based predictor identified by these authors.
Marc Swiontkowski, MD