OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Shahriar Rahman, MS in response to a recent study in JAMA Internal Medicine.
Hip fractures are an important cause of morbidity and mortality among the elderly population worldwide. However, age-adjusted hip fracture incidence has decreased in the US over the last 2 decades. While many attribute the decline to improved osteoporosis treatment, the definitive cause remains unknown. A population-based cohort study of participants in the Framingham Heart Study prospectively followed a cohort of >10,000 patients for the first hip fracture between 1970 and 2010.
The age-adjusted incidence of hip fracture decreased by 4.4% per year during this study period. That decrease in hip fracture incidence was coincident with a decrease over those same 4 decades in rates of smoking (from 38% in 1970 to 15% by 2010) and heavy drinking (from 7% to 4.5%), with subjects born more recently having a lower incidence of hip fracture for a given age. Meanwhile, during the study period, the prevalence of other hip-fracture risk factors–such as being underweight, being obese, and experiencing early menopause–remained stable.
This study’s findings should be interpreted in light of 2 major limitations. First of all, there was a lack of contemporaneous bone mineral density data across the study period; secondly, all the study subjects were white. Nevertheless, these findings should encourage physicians to continue carefully managing patients who have osteoporosis and at the same time caution them against smoking and heavy drinking.
Shahriar Rahman, MS is an assistant professor of orthopaedics and traumatology at the Dhaka Medical College and Hospital in Bangladesh and a member of the JBJS Social Media Advisory Board.
Based on ample published data and experience, today’s hip surgeons can give patients who are considering total hip arthroplasty (THA) a good general idea of outcomes to expect. But what if orthopaedists could provide more tailored predictions of THA outcome, and thus help patients more realistically manage expectations?
That is essentially what Hesseling et al. set out to do in their database analysis of 6,030 THA patients gleaned from the Dutch Arthroplasty Register; the findings appear in the December 18, 2019 issue of JBJS. Using the patients’ Oxford Hip Scores (OHS) collected up to 1 year postoperatively and a sophisticated statistical technique called latent class growth modeling, the authors categorized outcome trajectories into 3 categories:
- Fast Starters (n = 5,290)—steep improvement in OHS during the first 3 postoperative months, after which the OHS leveled out
- Late Dippers (n = 463)—more modest improvement in OHS initially, followed by subsequent decline toward the 1-year mark
- Slow Starters (n = 277)—virtually no change at the 3-month mark, followed by an improvement in OHS at 1 year postoperatively
Although the authors were unable to tease out factors that clearly distinguished between late dippers and slow starters, they did identify several factors associated with less-than-fast-starter outcomes:
- Female sex
- Age >75 years
- Anxiety and depression
- American Society of Anesthesiologist (ASA) grade III or IV
- Hybrid fixation (cemented acetabular implant)
- Direct lateral surgical approach
Emphasizing that all 3 subgroups experienced functional improvement after THA, Hesseling et al. nevertheless provide useful information that can help surgeons more accurately estimate which patients might be at risk of a less favorable recovery.
After some relatively poor results in the 1980s, there was a “reboot” with total ankle arthroplasty (TAA) in the late 1990s to improve outcomes so that TAA would provide a reliable treatment for patients with end-stage ankle arthritis. Advances in the understanding of the biomechanical requirements for ankle prostheses and which patients might benefit from them the most—plus the realization that TAA is a technically demanding surgical procedure that requires advanced education—have vastly improved the outcomes of these procedures. In fact, TAA has become reliable enough that we can now begin to tease out the patient variables that seem to affect outcomes.
In the February 6, 2019 issue of The Journal, Cunningham et al. use an extensive clinical TAA registry to identify patient characteristics that impact TAA outcomes. The good news is that, 30-plus years after the inauspicious outcomes of first-generation TAA, overall pain and function significantly improved among the patients in this study. However, current smoking was associated with poorer patient outcomes at the 5-year follow-up, as it seems to be with the vast majority of orthopaedic procedures. Also, at a mean 1- to 2-year follow-up, a previous surgical procedure on the ankle was associated with significantly smaller improvements in at least 1 patient-reported outcome. This makes sense because prior surgery leads to scarring and its attendant risk of infection and increased difficulty with exposure and the ideal placement of TAA components. Cunningham et al. also identified depression as being associated with worse TAA outcomes at all follow-up points, adding to our already ample body of evidence that patient psychological factors play a major role in orthopaedic surgical results.
Interestingly, these authors found that patients undergoing staged bilateral ankle arthroplasty did not do as well as those undergoing simultaneous bilateral TAAs. And somewhat surprisingly, the authors found obesity to be associated with better outcomes at the 5-year follow-up. This may be related to increased bone density and greater soft-tissue coverage, but this finding is still seemingly counterintuitive based on everything else we know about the negative associations between obesity and outcomes of other joint replacements.
As more surgeons and orthopaedic centers make use of TAA, it will be important for us to follow the lead of the total knee and total hip communities in providing large datasets to further clarify which factors—patient-related and surgical—lead to the best and worst patient outcomes. This study by Cunningham et al. provides a starting point upon which other research will hopefully build.
Marc Swiontkowski, MD
Here’s one thing about which medical studies have been nearly unanimous: Smoking is a health hazard by any measure. In the February 15, 2017 edition of The Journal of Bone & Joint Surgery, Tischler et al. put some hard numbers on the risk of smoking for those undergoing total joint arthroplasty (TJA).
After controlling for confounding factors, the authors of the Level III prognostic study found that:
- Current smokers have a significantly increased risk of reoperation for infection within 90 days of TJA compared with nonsmokers.
- The amount one has smoked, regardless of current smoking status, significantly contributed to increased risk of unplanned nonoperative readmission.
In a commentary on the Tischler et al. study, William, G. Hamilton, MD says, “…as physicians, we should work cooperatively with our patients to enhance outcomes by attempting to reduce these modifiable risk factors. We can educate patients and can suggest smoking cessation programs and weight loss regimens that may not only improve the risk profile during the surgical episode, but also improve the patients’ overall health.”
Researchers at Vanderbilt University Medical Center have concluded that fibrin, a protein involved in blood clotting and found abundantly around the site of new bone fractures, impedes rather than supports fracture healing.
Their recent study in The Journal of Clinical Investigation looked at mice that had experimentally induced deficits in either fibrin production or fibrin clearance. Researchers found normal fracture repair in mice without fibrin and impaired vascularization and fracture healing in mice with inhibited fibrin clearance. They also saw increased heterotopic ossification in the mice unable to remove fibrin.
In a Vanderbilt press release, study coauthor Jonathan Schoenecker, MD, commented that “any condition associated with vascular disease and thrombosis will impair fracture healing.” These findings, he suggested, may explain why obesity, diabetes, smoking, and old age—all of which are associated with impaired fibrin clearance—are also associated with impaired fracture healing. Dr. Schoenecker went on to speculate that anti-clotting drugs commonly used to treat cardiovascular conditions may find new applications in enhancing fracture repair.
The July 1, 2015 JBJS contains a database-driven analysis by Duchman et al. of more than 78,000 patients who underwent primary total hip or knee arthroplasty between 2006 and 2012. The authors found that the 10% who were current smokers had a higher rate of wound complications (1.8%), compared with rates in former smokers (1.3%) and nonsmokers (1.1%). Current smokers had approximately twice the rate of deep wound infections compared with former smokers or nonsmokers. The authors note, however, that periprosthetic infections—a specific complication of great interest to orthopaedists and patients—are not captured by the National Surgical Quality Improvement Program (NSQIP) database from which the analyzed data was extracted.
These findings align with several others that associate smoking with short-term postsurgical complications. However, commentators Jeffrey Cherian, DO and Michael Mont, MD note that this study’s definitions of “current” smokers (those who smoked within one year of surgery) and “former” smokers (those who did not smoke in the year prior to surgery but did smoke a pack a day or more for at least a year before that) leave surgeons “unable to adequately define a time point at which smoking should be stopped prior to surgery…to decrease the risk of adverse outcomes.” The commentators call for trials that more strictly stratify patients by tobacco usage so that surgeons can “evaluate the optimal time point for smoking cessation as well as the best programs and options for nicotine replacement.”