Detection of posttraumatic cartilage injury using quantitative T1rho magnetic resonance imaging. A report of two cases with arthroscopic findings.
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Adult↗
Biomedical subjects
Marc Safran
Publications and source records attributed to Marc Safran.
Ulnar collateral ligament of the elbow.
Recent advances in the diagnosis and treatment of the overhead athlete's elbow has led the medical community to understand that the ulnar collateral ligament (UCL) of the elbow is more commonly injured than originally thought. Injury can result in secondary symptoms and problems in other regions of the elbow. Sports requiring an overhead motion, such as throwing a ball, hitting a ball overhead, or serving a tennis ball, imparts a valgus stress on the elbow that is resisted by the UCL. Throwing sidearm or hitting a forehand in tennis, squash, or racquetball may also impart a valgus stress to the elbow. Repeated or excessive valgus stress places a force on the UCL that may result in injury to the ligament. Injury to the UCL may result in problems in other areas of the elbow, including the ulnar nerve, the flexor-pronator musculotendinous unit, the radiocapitellar joint and the posterior compartment of the elbow, in addition to being a cause of loose bodies within the elbow. This article reviews the anatomy, biomechanics, and pathophysiology of injury to the UCL and injuries to the other structures that result from UCL injury. Also reviewed are patient history, examination techniques, tests that help confirm the diagnosis of UCL injury, and treatment of the injured UCL.
Arthroscopy↗
Computer-aided quantification of focal cartilage lesions using MRI: accuracy and initial arthroscopic comparison.
OBJECTIVE: The purpose of the study was to validate a Gradient Peak Method (GPM) by evaluating its accuracy and consistency at different magnetic field strengths. The GPM using magnetic resonance imaging (MRI) was previously proposed to quantitatively assess the morphology of focal cartilage lesions, and its feasibility was demonstrated. METHODS: GPM quantifies the morphologic properties of cartilage lesions based on their three-dimensional geometry. Twenty-two conical and cylindrical lesions were surgically created on fresh porcine knees, and the results obtained by GPM were compared with manually measured lesion dimensions. Another 15 focal lesions of various shapes were created and scanned, and the quantification results were compared at 1.5 Tesla and 3 Tesla. Additionally, cartilage lesions in three patients were scanned, quantified by GPM, and compared with arthroscopic visualization and measurements. RESULTS: The average absolute errors of GPM (depth: < or =0.4mm; diameter: < or =1.4mm) were within twice the in-plane resolution in depth estimates and within the slice thickness in diameter estimates. Analysis also suggested that the quantifications of GPM using 1.5 Tesla and 3 Tesla data were not statistically different. Moreover, the GPM results were shown to be consistent with the lesion measurements obtained arthroscopically. CONCLUSIONS: The GPM using MRI provides estimates of lesion thickness, depth, diameter, and area. With this validation, the method can be potentially used as an auxiliary tool to help radiologists and physicians assess cartilage lesions quantitatively and monitor disease progression.
Animals↗
Tennis injuries.
OBJECTIVE: The purpose of this chapter is to critically review the existing studies on the epidemiology of tennis injuries in pediatric athletes, present suggestions for the prevention of injury based on these studies, and present suggestions for future research. DATA SOURCES: Data sources included published articles on pediatric tennis injuries, a previously published review by the authors, and unpublished data from one of the authors (MS). MAIN RESULTS: Most studies of tennis injuries show that they are of microtrauma origin, develop over time, and result in short times of absence from play. They involve all joints of the body, but have a higher incidence in the shoulder, back, and knee. Intrinsic and extrinsic risk factors may be related to the incidence of injury. These factors may be evaluated by a comprehensive pre-participation exam, and preventive strategies may be implemented. CONCLUSIONS: Most injury studies in pediatric tennis players vary in the population studied, methods of injury evaluation, and risk factors studied. Consequently, few specific conclusions can be derived about the causative factors. Further longitudinal prospective studies need to be done to completely discover all the factors involved in producing tennis injuries.
Athletic Injuries↗
Caffeine consumption among adults on benzodiazepine therapy: United States 1988-1994.
The concomitant use of benzodiazepines and caffeine was studied to learn if caffeine consumption varied as a function of benzodiazepine use. Caffeine may antagonize the effects of benzodiazepine and even relatively small amounts can aggravate symptoms associated with anxiety disorders. In addition, caffeine can cause or aggravate insomnia, one of the main reasons cited for use by the subjects in this analysis. Given this, there would seem to be sufficient reason for at least some users of benzodiazepines to consider, with their physicians, avoiding or limiting caffeine consumption. Data from the Third National Health and Nutrition Examination Survey were analyzed to obtain a nationally representative sample of benzodiazepine users. Subjects included 253 individuals (64% women) whose median age was 54 yr. Approximately 88% of benzodiazepine users reported caffeine consumption in the 24-hr. Dietary Recall. 26% of benzodiazepine users and 23% of nonusers reported consuming greater than 250 mg of caffeine during the 24-hr. reference period. In regression analyses, no significant relationships were found between reported caffeine consumption and benzodiazepine use. This study suggests that users and nonusers of benzodiazepines ingest similar amounts of caffeine even though some users should probably avoid or limit caffeine use.
Aged↗