Fracture Risk Rises after Gastric Bypass Surgery
This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.
Nearly 200,000 Americans have bariatric surgery each year, so it’s important to understand the long-term musculoskeletal consequences of those procedures. Gastric bypass constitutes the most common bariatric surgery and is believed to lead to bone loss. However, fracture risk in gastric-bypass patients has been insufficiently studied. Given that diabetes is an independent risk factor for fractures, any gastric bypass–fracture association should be studied in patients with and without diabetes.
That’s what Swedish researchers did in a retrospective cohort study1 of 38,971 obese patients who underwent gastric bypass—7,758 of whom had diabetes and 31,213 of whom did not. The patients in each of the two groups were propensity-score matched with controls (1 to 1). The researchers evaluated the overall risk of fracture and fall injury, along with fracture risk according to amount of weight loss and degree of calcium and vitamin D supplementation during the first year after surgery.
After a median follow-up of 3.1 years, gastric bypass was associated with an increased risk of any fracture, both in patients with diabetes (HR, 1.26) and without diabetes (HR, 1.32). Fracture risk appeared to increase with time. The risk of fall injury without fracture also increased after gastric bypass. (The increased risk of fall injury may explain some of the increased fracture risk.) Surprisingly, neither higher amounts of weight loss nor poor calcium and vitamin D supplementation during the first year after surgery were associated with increased fracture risk.
The metabolic consequences of surgically induced weight loss are significant for the obese population. Those consequences probably reach beyond bone to affect many aspects of musculoskeletal and possibly neurological homeostasis.
Reference
- Axelsson KF, Werling M, Eliasson B, Szabo E, Näslund I, Wedel H, Lundh D, Lorentzon M. Fracture Risk After Gastric Bypass Surgery: A Retrospective Cohort Study. J Bone Miner Res. 2018 Jul 16. doi: 10.1002/jbmr.3553. [Epub ahead of print] PMID: 30011091
BOG Fracture-Risk Score Combines DNA Info with Physiological Factors
This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.
During childhood and adulthood, we often put ourselves at risk for future fractures based on our activity, diet, and social habits. Many factors affect the risk of both stress fractures in younger people and fragility fractures later in life. Everyone—but especially athletes and active-duty military personnel—could benefit from an early heads-up regarding their genetic and phenotypic predisposition to stress fractures. Later in life, the FRAX index is a very useful multifactor risk score, but it is usually calculated only after a sentinel event, such as a fragility fracture.
Ultrasound is a readily available and inexpensive way to obtain an estimated heel bone mineral density (eBMD). Many common genetic variants contribute to the genetic basis for the eBMD phenotype. These variants are most commonly characterized by single nucleotide polymorphisms (SNPs, pronounced “snips”). Stanford researcher Stuart Kim developed the BMD Osteoporosis Genetic (BOG) risk score by combining 22,886 SNPs with data on height, weight, sex, and age.1 The correlation between actual eBMD and the BOG algorithm was 0.496, which was higher than the correlations achieved using the 22,886 genetic predictors or the four covariates alone.
Individuals with low BOG scores had a 17.4-fold increased risk for osteoporosis compared to those with the median BOG score. Low BOG scores were also associated with a 1.9-fold higher risk for bone fractures compared to median BOG values. However, the algorithm’s ability to discriminate cases from controls in the overall population was modest. The receiver operator area under the curve for predicting osteoporosis or fracture by the BOG algorithm was 0.78 and 0.57, respectively.
Although the effect of an individual SNP may be inconsequential, the cumulative effect from many SNPs can be large. The author stated that “an algorithm such as the BOG risk score might be useful to screen the general population…to identify individuals that warrant closer examination, such as BMD measurement via DXA [dual-energy X-ray absorptiometry].”
Reference
- Kim SK. Identification of 613 new loci associated with heel bone mineral density and a polygenic risk score for bone mineral density, osteoporosis and fracture. PLoS One. 2018 Jul 26;13(7):e0200785. doi: 10.1371/journal.pone.0200785. eCollection 2018. PMID: 30048462
JBJS 100: Talar Neck Fractures, Knee Cartilage Repair
Under 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 full-text 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:
Fractures of the Neck of the Talus
L G Hawkins: JBJS, 1970 July; 52 (5): 991
This article, richly illustrated with radiographs, reports on >1-year results from 43 patients treated after sustaining a vertical fracture of the neck of the talus. Hawkins introduced a 3-group classification system based on the initial radiographic appearance of the fracture, and he provided an in-depth discussion of the complication of avascular necrosis.
Autologous Chondrocyte Implantation and Osteochondral Cylinder Transplantation in Cartilage Repair of the Knee Joint
U Horas, D Pelinkovic, G Herr, T Aigner, R Schnettler: JBJS, 2003 February; 85 (2): 185
In the 15 years since this paper appeared in JBJS, nearly 800 articles have been published that have “autologous chondrocyte implantation” (ACI) in their title. This study—replete with histologic, biopsy-specimen, and electron microscopy images—compared 2-year results among 40 patients who had received either ACI or autologous osteochondral transplants for knee cartilage defects. Both treatments decreased symptoms, but the authors concluded that “the improvement provided by the [ACI] lagged behind that provided by the osteochondral cylinder transplantation.” For more current information on these cartilage-repair techniques, see the JBJS Clinical Summary on Knee Cartilage Injuries.
JBJS 100: Harris Hip Score, Clavicle Fractures
Under 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 full-text 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:
Traumatic Arthritis of the Hip after Dislocation and Acetabular Fractures—Treatment by Mold Arthroplasty: An End-Result Study Using a New Method of Result Evaluation
W H Harris: JBJS, 1969 June; 51 (4): 737
The most lasting legacy from this classic 1969 article from William Harris is the author’s proposed hip score. A “single, reliable figure” designed to be equally applicable to different hip problems and different treatments, the Harris Hip Score is still used worldwide today in routine evaluations before and after hip arthroplasty. Not surprisingly, this article remains the most frequently cited paper in the hip arthroplasty literature.
Nonoperative Treatment Compared with Plate Fixation of Displaced Midshaft Clavicular Fractures
Canadian Orthopaedic Trauma Society: JBJS, 2007 January; 89 (1): 1
Amid the ongoing debate about whether to operate on which type of clavicle fractures, this multicenter, randomized clinical trial stands out for its rigorous design and focus on patient-oriented outcomes. Local irritation and unsightly prominence from hardware notwithstanding, these findings support primary plate fixation of completely displaced midshaft clavicle fractures in active adult patients.
Opioid-Tapering Plan May Help Prevent Prolonged Use after Trauma/Surgery
Addressing the opioid epidemic requires a concerted effort from all sectors of society, but the role of surgeons (orthopaedic and otherwise) cannot be ignored because they determine how best to manage postoperative pain for millions of patients. OrthoBuzz recently commented on two opioid-related studies from the July 18, 2018 issue of JBJS. In the August 1, 2018 edition of The Journal, Mohamadi et al. explain findings from a meta-analysis of 37 studies involving nearly 2 million patients that pinpoint several patient-related risk factors associated with opioid use beyond 2 months following surgery or trauma.
Using careful meta-analysis methods, the authors determined that about 4% of patients continued to use prescription opioids beyond 2 months after surgery or trauma. They also identified the following risk factors as being “among the most important predictors of prolonged opioid use” in these patients:
- Prior use of opioids or benzodiazepines
- Depression
- Long-duration hospital stay
- History of back pain
Mohamadi et al. also calculated a “number needed to harm” (NNH) from their data. NNH indicates the number of patients with a certain risk factor that is necessary to result in 1 person with prolonged opioid use beyond that of a patient population without that risk factor. They found that for every 3 patients with a history of opioid use, every 23 patients with a history of back pain, every 40 with depression, or every 62 with a history of benzodiazepine use, 1 patient will continue to use prescribed opioids for an extended time period.
Because this meta-analysis was derived from observational studies, the authors caution that “causal inferences could not be drawn for the proposed risk factors.” But they do offer a practical piece of advice gleaned from prior research: Provide patients with an opioid-tapering plan at the time of discharge to significantly reduce the likelihood of prolonged opioid use.
JBJS 100: Proximal Humeral Fractures, Stem Cells
Under 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:
Displaced Proximal Humeral Fractures: Classification and Evaluation
C Neer: JBJS, 1970 September; 52 (6): 1077
Complex distal humeral fractures have long challenged orthopaedic surgeons and their patients. Often the first step in fracture-management decision-making is classification, and in this 1970 study, Dr. Neer proposed a 6-group classification based on the presence or absence of displacement of one or more of the four major proximal segments. Since then, this classification has been variably adapted by multiple authors, but its usefulness remains intact.
The Effect of Implants Loaded with Autologous Mesenchymal Stem Cells on the Healing of Canine Segmental Bone Defects
S F Bruder, K H Kraus, V M Goldberg, S Kadiyala: JBJS, 1998 July; 80 (7): 985
Research into mesenchymal stem cells (MSCs) to augment healing of tendons, chondral and bone defects, and other connective tissues has taken off since these authors used autologous MSCs to help heal 21-mm segmental femoral defects. Radiographic union occurred rapidly at the interface between host bone and porous ceramic cylinders loaded with MSCs, and a large collar of bone had formed around the cell-loaded implants after 16 weeks.
What’s New in Orthopaedic Trauma 2018
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, Niloofar Dehghan, MD, co-author of the July 5, 2018 Specialty Update on Orthopaedic Trauma, selected the five most clinically compelling findings from among the 32 studies summarized in the Specialty Update.
Clavicle Fractures
–Findings from a multicenter randomized trial comparing open reduction/internal fixation with nonoperative treatment for acute, displaced, distal-third clavicle fractures1 included the following:
- No between-group differences in DASH and Constant scores at 1 year post-injury
- Higher rates of nonunion and malunion in the nonoperative group
- Similar rates of secondary surgical procedures in the two groups
Despite no significant differences in functional outcomes between the two groups, primary fixation of these fractures reduced the risk of nonunion and malunion and decreased the magnitude of secondary procedures.
Humerus Fractures
–A retrospective cohort study of 84 patients with nonoperatively treated humerus shaft fractures2 showed fracture union in 87% of the cohort at a mean of 18 weeks. However, researchers found that if physical examination at 6 weeks after injury revealed motion at the fracture site, progression to fracture union was unlikely. They concluded that results from clinical examination of fracture motion at 6 weeks could help patients and physicians with shared decision-making regarding the appropriateness of transitioning to surgical fixation
Syndesmotic Ankle Injuries
–A randomized controlled trial compared outcomes between a suture button and 1 quadricortical syndesmotic screw in patients undergoing syndesmosis fixation. After 2 years, patients in the suture button group had higher AOFAS ankle scores, higher Olerud-Molander ankle scores, and a lower rate of tibiofibular widening of ≥2 mm than the syndesmotic screw group. Findings also favored the suture button group in terms of symptomatic recurrent syndesmotic diastasis.
–A similar randomized trial compared suture button fixation with screw fixation using two 3.5-mm cortical screws.3 There were no between-group differences in functional outcomes, but the rates of malreduction and unplanned reoperations were higher in the screw group. The suture button group had greater syndesmosis diastasis and less fibular medialization.
Blood Loss Management
–In a randomized trial comparing transfusion rates among 138 patients who underwent arthroplasty for low-energy femoral neck fractures,4 researchers found no significant differences among those treated with tranexamic acid versus those treated with placebo. However, tranexamic acid reduced the amount transfused by 305 mL. There were no between-group differences in adverse events at 30 and 90 days.
References
- Canadian Orthopaedic Trauma Society, Hall J, Dehghan N, Schemitsch EH, Nauth A, Korley R, McCormack R, Guy P, Papp S, McKee MD. Operative vs nonoperative treatment of acute displaced distal clavicle fractures: a multicenter randomized controlled trial. Read at the Orthopaedic Trauma Association 33rd Annual Meeting; 2017 Oct 11-14; Vancouver, Canada. Paper no. 4.
- Driesman AS, Fisher N, Karia R, Konda S, Egol KA. Fracture site mobility at 6 weeks after humeral shaft fracture predicts nonunion without surgery. J Orthop Trauma.2017 Dec;31(12):657-62.
- Canadian Orthopaedic Trauma Society, Sanders D, Schneider P, Tieszer C, Lawendy AR, Taylor M. Improved reduction of the tibiofibular syndesmosis with TightRope compared to screw fixation: results of a randomized controlled study. Read at the Orthopaedic Trauma Association 33rd Annual Meeting; 2017 Oct 11-14; Vancouver, Canada.
- Watts CD, Houdek MT, Sems SA, Cross WW, Pagnano MW. Tranexamic acid safely reduced blood loss in hemi- and total hip arthroplasty for acute femoral neck fracture: a randomized clinical trial. J Orthop Trauma.2017 Jul;31(7):345-51.
When Is a Fracture Good to Go?
This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.
Determining when a fracture has healed enough for functional use can be difficult. The Radiographic Union Score for Tibia fractures (RUST) assesses fracture healing on a continuous scale from 4 to 12 points. Based on an evaluation of anteroposterior and lateral radiographs, RUST accounts for callus without visible fracture line (3 points), callus with visible fracture line (2 points), or absence of any callus (1 point) for each of four cortices. The modified RUST (mRUST) score subdivides the second parameter into two categories (callus present and bridging callus), creating a score ranging from 4 to 16 points. This tool has demonstrated high intraclass correlation coefficients (ICCs). However, until now, the correlation of these scores to mechanical properties of healed bone had not been demonstrated.
Cooke et al.1 evaluated both scores against the physical properties of bone healing by using a model of closed, stabilized femur fractures in 8- to 12-week-old male mice. Control mice received a normal diet and an experimental group received a phosphate-restricted diet. The physical properties of bone healing were determined with micro-computed tomography (µCT) and torsion testing on postoperative days 14, 21, 35, and 42. There were 10 to 16 mice in each group at any given time-point.
RUST scores from five raters were determined from anteroposterior and lateral radiographic views constructed from the µCT scans. ICCs were 0.71 (mRUST) and 0.63 (RUST). Both RUST scores were positively correlated with callus bone mineral density, bone volume fraction, callus strength, and rigidity. Radiographically healed calluses with an mRUST score of ≥13 and a RUST score of ≥10 had excellent relationships to structural and biomechanical metrics.
Mechanical properties revealed the effects of delayed healing due to phosphate dietary restrictions at later time points, but no such distinctions were found in the RUST scores. Both the RUST and mRUST scores have high correlation to physical properties of bone healing, but this tool may not be reliable for detecting poor bone quality due to nutrient deficiencies.
Reference
- Cooke ME, Hussein AI, Lybrand KE, Wulff A, Simmons E, Choi JH, Litrenta J, Ricci WM, Nascone JW, O’Toole RV, Morgan EF, Gerstenfeld LC, Tornetta P 3rd. Correlation between RUST assessments of fracture healing to structural and biomechanical properties. J Orthop Res. 2018 Mar;36(3):945-953. doi: 10.1002/jor.23710. Epub 2017 Sep 20. PMID: 28833572 PMCID: PMC5823715 DOI: 10.1002/jor.23710
JBJS 100: THA Registries, Bone-Repair Growth Factors
Under 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, both from 2002:
The Swedish Total Hip Replacement Register
H Malchau, P Herberts, T Eisler, G Garellick, P Soderman: JBJS, 2002 November; 84 (Suppl 2): S2
In this 19-page analysis of data from the Swedish Total Hip Replacement Register, which was initiated in 1979, Malchau et al. pinpoint the striking clinical and socioeconomic effects of the Register’s first 20 years. The information captured by joint registries, especially in regions that provide universal health care coverage and thus maintain robust databases, has helped orthopaedic surgeons refine indications, surgical techniques, and implant choices.
The Role of Growth Factors in the Repair of Bone: Biology and Clinical Applications
J R Lieberman, A Daluiski, T A Einhorn: JBJS, 2002 June; 84 (6): 1032
Countless studies related to tissue engineering and the musculoskeletal system have been published in the 16 years since this Current Concepts Review appeared in JBJS. Yet this article remains an essential primer for understanding how growth factors affect cells and tissues—and the possible applications for using growth factors to accelerate fracture healing, treat nonunions, and enhance spinal fusion.
Sarcopenia: An Independent Predictor of Mortality in Geriatric Acetabular Fractures
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.
Fractures in the elderly are a growing problem in developed countries and generally carry a significant morbidity and mortality burden. When considering treatment strategies and making prognoses in this patient population, our ability to stratify patient frailty may be just as or more important than classifying the fracture. In a recent study in the Journal of Orthopaedic Trauma, Mitchell et al. evaluate the role of sarcopenia, an age-related loss of muscle mass, in predicting 1-year mortality among elderly patients with acetabular fractures.1
The authors performed a retrospective review of nearly 150 patients >60 years of age who sustained an acetabular fracture between 2003 and 2014. The authors used the lowest quartile of the psoas:lumbar vertebral index (PLVI) in the cohort as a surrogate for sarcopenia. The PLVI is calculated by measuring the cross-sectional area of the psoas muscle bellies at the L4 level and dividing that number by the cross-sectional area of the L4 vertebral body measured at the superior endplate (see image). Lower PLVIs represent greater loss of muscle mass.
After controlling for confounding variables, the authors found that sarcopenia was an independent risk factor for 1-year mortality. Specifically, patients with sarcopenia had a 32.4% 1-year mortality rate compared to a rate of 11.0% in patients without sarcopenia. Age and injury severity score (ISS) were also predictive of 1-year mortality, and patients with all 3 factors (age >75 years, ISS >14, and sarcopenia) had a mortality rate of 90%.
This article highlights the importance of risk-stratifying patients in ways that account for more than their presenting injuries. In the elderly population, chronologic age is only one of many indicators of frailty. Sarcopenia may be another marker that we can use to better understand the general well-being of our patients. As Mitchell et al. mention, more research must be done to precisely define a PLVI cutoff for sarcopenia to make this index a clinically useful tool. Ultimately, doing so will allow us to offer elderly patients and their families more thoughtful and evidence-based counseling regarding treatment and prognosis.
Matthew Herring, MD is a senior orthopaedic resident at the University of Minnesota and a member of the JBJS Social Media Advisory Board.
Reference
- Mitchell, Phillip M., et al., Sarcopenia is Predictive of 1-year Mortality After Acetabular Fractures in Elderly Patients.” Journal of Orthopaedic Trauma, June 2018; 32 (6) : 278-282.
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