Mark Makumbi Kayanja

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Over 700,000 osteoporotic compression fractures occur each year in the United States, twice the number of hip fractures. These vertebral fractures, most of which occur in the elderly, represent significant personal and societal burdens. Percutaneous vertebroplasty (PVP) is a minimally invasive method that involves the percutaneous injection of(More)
OBJECTIVE To introduce a new miniature robot (SpineAssist; MAZOR Surgical Technologies, Caesarea, Israel) that has been developed and tested as a surgical assistant for accurate percutaneous placement of pedicle screws and translaminar facet screws. METHODS Virtual projections in three planes-axial, lateral, and anteroposterior-are reconstructed for each(More)
BACKGROUND CONTEXT Complications, such as graft subsidence and adjacent segment degeneration, are not uncommon after ventral cervical fusion. It has been theorized, but not proven, that sagittal alignment may affect this process. It is therefore hypothesized that increasing lordosis during anterior cervical fusion decreases adjacent segment motion (ASM) and(More)
OBJECTIVE To evaluate the accuracy of a novel bone-mounted miniature robotic system for percutaneous placement of pedicle and translaminar facet screws. METHODS Thirty-five spinal levels in 10 cadavers were instrumented. Each cadaver's entire torso was scanned before the procedure. Surgeons planned optimal entry points and trajectories for screws on(More)
BACKGROUND CONTEXT Osteoporotic compression fractures are an important public health concern, leading to significant morbidity, mortality and economic burden. Cement augmentation procedures used to treat these fractures alter the biomechanics of the fractured segment, which could promote adjacent failure. However, if alignment is improved or restored, there(More)
STUDY DESIGN A histological evaluation of biopsies obtained from presumed osteoporotic vertebral compression fractures (VCF) to confirm possible osteomalacia after tetracycline labeling. OBJECTIVE To describe the results of a series of biopsies obtained at the time of vertebral augmentation in presumed osteoporotic VCF, with special reference to the(More)
STUDY DESIGN Experimental biomechanics of multilevel segments with 0, 1, 2, and 3 vertebral levels of polymethylmethacrylate augmentation. OBJECTIVE To compare multilevel spinal segments with different numbers (0, 1, 2, and 3) of vertebral levels augmented with polymethylmethacrylate. SUMMARY OF BACKGROUND DATA The stiffness and strength of single-level(More)
BACKGROUND CONTEXT Vertebral compression fractures (VCFs) are a common clinical problem and may follow trauma or be pathological. Osteoporosis increases susceptibility to fracture by reducing bone mass and weakening bone architecture. Approximately 2.5 million osteoporotic fractures occur worldwide annually, usually involving the vertebrae, wrist and hip.(More)
STUDY DESIGN In vitro biomechanical comparison of transarticular facet screws to lateral mass plates in two level instrumentations of the cervical spine. OBJECTIVE Lateral mass plates are costly, and screw placement is difficult. Facet screws have never been tested as an alternative in the cervical spine. This biomechanical study compared cervical(More)
BACKGROUND CONTEXT Human cadaveric specimens are commonly used to evaluate bone-implant interface strength in osteoporotic spine fixation. Dual-energy X-ray absorptiometry (DXA) scans are usually carried out on explanted spine specimens to measure bone mineral density (BMD) before in vitro biomechanical studies are carried out. PURPOSE The purposes of(More)