A Survey of Musculoskeletal Disorders in the Orthopaedic Surgeon: Identifying Injuries, Exacerbating Workplace Factors, and Treatment Patterns in the Orthopaedic Community.

INTRODUCTION: As demand for orthopaedic care increases, the orthopaedic community must preserve access to skilled physicians. Workplace hazards and related injuries or conditions contribute to musculoskeletal (MSK) stress on orthopaedic surgeons, which can lead to undesirable medical leaves of absence or early retirement. The purpose of this study was to identify and characterize work-related and non-work-related MSK conditions that affect orthopaedic surgeons and differential injury patterns among male and female surgeons. This study hypothesized that MSK conditions would be exacerbated by work, correlate with age, and show gender-based disparities. Identifying MSK conditions and associated workplace hazards may ultimately help guide preventive or protective efforts. METHODS: Following IRB and society approvals, a modified 15-question physical discomfort survey was emailed to a randomized selection of American Academy of Orthopaedic Surgeons (AAOS) members and all Ruth Jackson Orthopaedic Society members. Data were deidentified and merged by AAOS; analyses were performed by the authors. RESULTS: Most surgeons reported at least one MSK condition (86%; 95% male versus 82% female, P = 0.317), with an average of two conditions per surgeon. Low back pain (56%) and neck pain (42%) were the two most common conditions reported. Male surgeons were more likely to report medial epicondylitis (P = 0.040), lateral epicondylitis (P ≤ 0.001), low back pain (P = 0.001), and lumbar radiculopathy (P = 0.001); however, male respondents were significantly older than female respondents (57 versus 43 years, P ≤ 0.0001), and some conditions were age-correlated. Most respondents reported at least one work-attributed MSK condition (64%; 68% male versus 62% female, P = 0.806). Caseload was not associated with an increased number of work-related MSK conditions; yet, 60% of surgeons reported that work worsened symptoms. Surgical treatment was sought most often for lumbar radiculopathy (6%) and carpal tunnel syndrome (6%). Sixty-nine leaves of absence were reported; most less than 1 month (55%). Exacerbating workplace factors included positioning (patient/surgeon), instruments, and personal protective equipment. DISCUSSION: Work-related MSK conditions are common among orthopaedic surgeons. Greater awareness of potential workplace-related hazards and conditions is needed to address and mitigate negative MSK health effects on orthopaedic surgeons.

How are peri-implant fractures below short versus long cephalomedullary nails different?

BACKGROUND: Cephalomedullary nails are a commonly used implant for the treatment of many pertrochanteric femur fractures and are available in short and long configurations. There is no consensus on ideal nail length. Relative advantages can be ascribed to short and long intramedullary nails, yet both implant styles share the potentially devastating complication of peri-implant fracture. Determining the clinical sequelae after fractures below nails of different lengths would provide valuable information for surgeons choosing between short or long nails. Thus, the purpose of the study was to compare injury patterns and treatment outcomes following peri-implant fractures below short or long cephalomedullary nails. METHODS: This was a multicenter retrospective cohort study that identified 33 patients referred for treatment of peri-implant fractures below short and long cephalomedullary nails (n = 19 short, n = 14 long). We compared fracture pattern, treatment strategy, complications, and outcomes between these two groups. RESULTS: Short nails were associated with more diaphyseal fractures (odds ratio [OR] 13.75, CI 2.2-57.9, p 0.002), which were treated more commonly with revision intramedullary nailing (OR, infinity; p 0.01), while long nails were associated with distal metaphyseal fractures (OR 13.75, CI 2.2-57.9, p 0.002), which were treated with plate and screw fixation (p 0.002). After peri-implant fracture, there were no differences in blood loss, operative time, weight bearing status, or complication rates based on the length of the initial nail. In patients treated with revision nailing, there was greater estimated blood loss (EBL, median 300 cc, interquartile range [IQR] 250-1200 vs median 200 cc, IQR 100-300, p 0.03), blood product utilization and complication rates (OR 11.1, CI 1.1-135.7, p 0.03), but a trend toward unrestricted post-operative weight-bearing compared to patients treated with plate and screw constructs. CONCLUSION: Understanding fracture patterns and patient outcomes after fractures below nails of different lengths will help surgeons make more informed implant choices when treating intertrochanteric hip fractures. Revision to a long nail for the treatment of fractures at the tip of a short nail may be associated with increased patient morbidity.

Metabolomic Profiling in the Characterization of Degenerative Bone and Joint Diseases.

Osteoarthritis and inflammatory arthropathies are a cause of significant morbidity globally. New research elucidating the metabolic derangements associated with a variety of bone and joint disorders implicates various local and systemic metabolites, which further elucidate the underlying molecular mechanisms associated with these destructive disease processes. In osteoarthritis, atty acid metabolism has been implicated in disease development, both locally and systemically. Several series of rheumatoid arthritis patients have demonstrated overlapping trends related to histidine and glyceric acid, while other series showed similar results of increased cholesterol and glutamic acid. Studies comparing osteoarthritis and rheumatoid arthritis reported elevated gluconic acid and glycolytic- and tricarboxylic acid-related substrates in patients with osteoarthritis, while lysosphingolipids and cardiolipins were elevated only in patients with rheumatoid arthritis. Other bone and joint disorders, including osteonecrosis, intervertebral disc degeneration, and osteoporosis, also showed significant alterations in metabolic processes. The identification of the molecular mechanisms of osteoarthritis and inflammatory arthropathies via metabolomics-based workflows may allow for the development of new therapeutic targets to improve the quality of life in these patient populations.

Extracellular Matrix-Mediated Maturation of Human Pluripotent Stem Cell-Derived Cardiac Monolayer Structure and Electrophysiological Function.

BACKGROUND: Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) monolayers generated to date display an immature embryonic-like functional and structural phenotype that limits their utility for research and cardiac regeneration. In particular, the electrophysiological function of hPSC-CM monolayers and bioengineered constructs used to date are characterized by slow electric impulse propagation velocity and immature action potential profiles. METHODS AND RESULTS: Here, we have identified an optimal extracellular matrix for significant electrophysiological and structural maturation of hPSC-CM monolayers. hPSC-CM plated in the optimal extracellular matrix combination have impulse propagation velocities ≈2× faster than previously reported (43.6±7.0 cm/s; n=9) and have mature cardiomyocyte action potential profiles, including hyperpolarized diastolic potential and rapid action potential upstroke velocity (146.5±17.7 V/s; n=5 monolayers). In addition, the optimal extracellular matrix promoted hypertrophic growth of cardiomyocytes and the expression of key mature sarcolemmal (SCN5A, Kir2.1, and connexin43) and myofilament markers (cardiac troponin I). The maturation process reported here relies on activation of integrin signaling pathways: neutralization of ß1 integrin receptors via blocking antibodies and pharmacological blockade of focal adhesion kinase activation prevented structural maturation. CONCLUSIONS: Maturation of human stem cell-derived cardiomyocyte monolayers is achieved in a 1-week period by plating cardiomyocytes on PDMS (polydimethylsiloxane) coverslips rather than on conventional 2-dimensional cell culture formats, such as glass coverslips or plastic dishes. Activation of integrin signaling and focal adhesion kinase is essential for significant maturation of human cardiac monolayers.