Faculty Bibliography

Spaceflight alters normal physiology of cells and tissues observed on Earth. The effects of spaceflight on the musculoskeletal system have been thoroughly studied, however, the effects on cartilage have not. This area is gaining more relevance as long duration missions, such as Mars, are planned. The impact on intervertebral discs and articular cartilage are of particular interest to astronauts and their physicians. This review surveys the literature and reports on the current body of knowledge regarding the effects of spaceflight on cartilage, and specifically changes to the spine and intervertebral disc integrity and physiology. A systematic literature review was conducted using PubMed, MEDLINE, and Google Scholar. Eighty-six unique papers were identified, 15 of which were included. The effect of spaceflight on cartilage is comprehensively presented due to limited research on the effect of microgravity on the spine/intervertebral discs. Cellular, animal, and human studies are discussed, focusing on human physiologic changes, cartilage histology, mineralization, biomechanics, chondrogenesis, and tissue engineering. Several common themes were found, such as decreased structural integrity of intervertebral disks and impaired osteogenesis/ossification. However, studies also presented conflicting results, rendering strong conclusions difficult. The paucity of human cartilage studies in spaceflight leaves extrapolation from other model systems the only current option for drawing conclusions despite known and unknown limitations in applicability to human physiology, especially spinal pathophysiology which is special interest. The aerospace and biomedical research communities would benefit from further human spaceflight articular cartilage and intervertebral disc studies. Further research may yield beneficial application for spaceflight, and crossover in understanding and treating terrestrial diseases like osteoarthritis and vertebral disc degeneration.

Diabetic ketoacidosis is a potentially fatal complication of diabetes mellitus that may result in hypertriglyceridemia. Rarely, the resulting hypertriglyceridemia may precipitate acute pancreatitis. We report a case of acute pancreatitis secondary to hypertriglyceridemia precipitated by diabetic ketoacidosis and postulate that this unusual presentation is due to the patient being prone to ketosis.

Serotonin syndrome (SS) is an underrecognized and potentially fatal disorder that occurs secondary to combinational use or overdose of a single serotonergic medication. The presentation may be complicated by hepatic encephalopathy in cirrhotic patients, which may also affect metabolism of these serotonergic agents. The authors report a rare case of severe SS complicated by hepatic encephalopathy secondary to cirrhosis in a 52-year-old woman after an increase in her home dosage of fluoxetine and addition of other psychiatric medications.

CASE/METHODS:A 14-year-old boy presented with a pathologic fracture of the distal aspect of the tibia and a remote history of a dog bite near the injury site. Imaging studies, biopsy, and presentation corroborated the diagnosis of chronic osteomyelitis. Multiple diagnostic methods were negative until an open biopsy identified Haemophilus parainfluenzae, a fastidious oropharyngeal bacterium, with polymerase chain reaction analysis. The patient underwent extensive debridement, placement of external fixation, and a year-long antibiotic therapy regimen. He subsequently required a tibial-fibular osteotomy at a second site with placement of an intramedullary nail for correction of a leg-length discrepancy. CONCLUSION/CONCLUSIONS:This case report illustrates the complex management of chronic osteomyelitis in pediatric patients, its sequelae, and the importance of considering treatment of atypical pathogens.

Fusion of the lumbosacral spine is a common surgical procedure to address a range of spinal pathologies. Fixation in lumbar fusion has traditionally been performed using pedicle screw (PS) augmentation. However, an alternative method of screw insertion via cortical bone trajectory (CBT) has been advocated as a less invasive approach which improves initial fixation and reduces neurovascular injury. There is a paucity of robust clinical evidence to support these claims, particularly in comparison to traditional pedicle screws. This study aims to review the available evidence to assess the merits of the CBT approach. Six electronic databases were searched for original published studies which compared CBT with traditional PS and their findings reviewed. Nine comparative studies were identified through a comprehensive literature search. Studies were classified as retrospective cohort, prospective cohort or case control studies with medium quality as assessed by the GRADE criteria. The available literature is not cohesive regarding outcomes and complications of CBT versus PT procedures. Most studies found no difference in operative time, but reported less blood loss during CBT. Radiological outcomes show no difference in slippage at one year although CBT is associated with greater bone-density compared to PT. Results for post-operative pain are inconclusive.

BACKGROUND:Anterior lumbar interbody fusion (ALIF) is a surgical technique used to treat patients with a variety of lumbar pathologies. Identification of risk factors leading to complication following ALIF surgery may allow surgeons to better judge candidacy and optimize care for high-risk patients. METHODS:A retrospective analysis was conducted on a prospectively collected database of 137 patients who all underwent ALIF surgery by a single primary spine surgeon. Patients were separated into age-based cohorts (≤49, 50-63, and ≥64 years of age). Chi-squared, Fisher exact test, and multivariate logistic regression models were used to identify independent risk factors. RESULTS:A total of 137 patients met the inclusion criteria. Patients were divided into age-based tertiles as follows: Group 1 (<49 years old, n = 45, 32.8%), Group 2 (50-63 years old, n = 46, 33.6%), and Group 3 (64 years old, n = 46, 33.6%). Univariate analysis revealed increasing age (relative to Group 1) to be an independent risk factor for postoperative hematoma and delayed subsidence at 6 weeks and 12 weeks postoperatively compared with immediately post operation (all P < 0.05). No significant differences were found among the groups in terms of clinical outcome. Multivariate analysis also demonstrated increased age to be independently associated with greater prevalence of delayed subsidence (odds ratio 9.174, P = 0.029). CONCLUSIONS:Increased age was not associated with adverse perioperative outcomes and complications of ALIF. However, there was an increased incidence of delayed subsidence in patients ≥64 years old.

INTRODUCTION/BACKGROUND:Immune-compromised subjects, especially those with underlying HIV disease, are prone to be infected with Norwegian scabies, where the cutaneous lesions are classically distributed over the extremities. CASE PRESENTATION/METHODS:We report the case of an HIV-positive 16-year-old man with severe crusted Norwegian scabies initially misdiagnosed as a dermal fungal infection. The patient had extensive, generalized, thick, hyperkeratotic, crusting, yellowish papule lesions distributed on the entire body from his scalp to his toes.The patient was started with Ivermectin and topical Permethrin, which eventually resulted in complete resolution. Interestingly, despite quarantining efforts, one of the patient's acquaintances and a healthcare worker acquired the symptoms of itching. CONCLUSION/CONCLUSIONS:This atypical presentation of Norwegian scabies emphasizes the need to include scabies in the differential diagnosis when HIV-infected patients present with crusted, generalized cutaneous lesions.