Biomedical subjects

M D Linkous

Publications and source records attributed to M D Linkous.

4 recordsLinked to original sources

PubMed2000

Characteristics of triangular fibrocartilage defects in symptomatic and contralateral asymptomatic wrists.

PURPOSE: To characterize triangular fibrocartilage (TFC) defects in symptomatic and contralateral asymptomatic wrists. MATERIALS AND METHODS: Communicating and noncommunicating defects of the TFC were depicted on bilateral wrist arthrograms in 56 patients with unilateral wrist pain and without associated lesions of the scapholunate or lunotriquetral ligaments. The exact location of each TFC lesion was noted. RESULTS: Communicating defects were noted in 36 (64%) of 56 symptomatic and in 26 (46%) of 56 asymptomatic wrists. Twenty-five (69%) of 36 communicating defects were bilateral. Except for one defect in each group of symptomatic and asymptomatic wrists, all communicating defects were noted radially. Noncommunicating defects were noted in 28 (50%) of 56 symptomatic wrists and in 15 (27%) of 56 asymptomatic wrists. Eleven (39%) of 28 noncommunicating defects were bilateral. On the symptomatic side, 28 of 36 noncommunicating defects (including eight multiple defects) were located proximally at the ulnar side. On the asymptomatic side, 11 of 17 noncommunicating defects (including two multiple defects) were at or near the ulna. CONCLUSION: Noncommunicating TFC defects, which typically are located on the proximal side of the TFC near its ulnar attachment, have a more reliable association with symptomatic wrists than do communicating defects. Radial-sided communicating defects described in the literature (Palmer type 1A and 1D) as posttraumatic commonly are seen bilaterally and in asymptomatic wrists.

Adolescent↗

PubMed2000

Scapholunate ligamentous communicating defects in symptomatic and asymptomatic wrists: characteristics.

PURPOSE: To determine whether the sizes and locations of scapholunate ligamentous communicating defects are different in symptomatic and asymptomatic cases. MATERIALS AND METHODS: Bilateral wrist arthrograms were reviewed for 30 consecutive patients with a history of wrist trauma and unilateral wrist pain who had at least one scapholunate ligamentous communicating defect and unremarkable conventional radiographs. The location and size of each ligamentous defect was recorded. Differences between symptomatic and asymptomatic wrists were analyzed with the chi(2) or Fisher exact test. RESULTS: Most communicating defects in both groups were incomplete and ranged from pinhole size to large. There was a higher frequency of complete disruption in the symptomatic wrists (nine [32%] of 28 wrists) than in the asymptomatic wrists (two [10%] of 20 wrists; P: =.092). Communicating defects involved the dorsal portion in 18 (64%) of the 28 symptomatic cases and in five (25%) of the 20 asymptomatic cases (P: =.007). CONCLUSION: The data suggest that the demonstration of a complete ligamentous disruption or involvement of the dorsal portion of the ligament may indicate a traumatic cause rather than a degenerative change.

Adult↗

PubMed1998

Wrist arthrography today.

In recent years, wrist arthrography has been criticized for having low sensitivity and low specificity. This largely has been due to widely varying and less than rigorous technique and the reliance on criteria for abnormality that are now known to be invalid. Other criticisms have included the length of time needed to perform a three-compartment arthrogram with or without comparison to the contralateral side and the radiation dose to the patient. It is our belief, however, that with the use of the patient's history, symptoms and physical examination to develop a focused examination strategy, and with the use of digital equipment, the examination can be performed quickly and with minimal radiation dose to the patient. In order to improve the accuracy of arthrography, the radiologist must abandon the concept that simply identifying a communicating defect between the carpal compartments is a criterion for abnormality. He or she must utilize a meticulous approach to determine the site of communication to evaluate the features of the defects in order to determine the significance of the defect. As more is learned about the nature of traumatic and attritional defects and with further technologic advancements in cross-sectional imaging and three-dimensional rendering, it is quite possible that arthrographic imaging of the wrist will experience a resurgence of interest in the evaluation of posttraumatic wrist pain, avoiding the fate of such examinations as pneumoencephalography and oral cholecystography as many have predicted.

Arthrography↗

PubMed1994

Noninvasive method for the detection of bowel ischemia: computed tomography detection of absorbed iodinated contrast material.

RATIONALE AND OBJECTIVES: Although systemic absorption of enterically administered iohexol and its excretion in urine has been previously documented in rats with ischemic bowel, a practical and sensitive method of detecting urinary iohexol has not been available. We proposed to detect the presence of iohexol in the urine of rats with normal and ischemic bowel by use of a computed tomography (CT) number increase in the bladder with the use of CT. METHODS: Anesthetized rats (250 g) underwent either sham laparotomy (n = 6), ligation of two vascular arcades to the proximal jejunum (n = 5), ligation of six vascular arcades to the proximal jejunum (n = 6), or ligation of the superior mesenteric artery (n = 6). Rats were hydrated with saline (3.2 ml/hr intravenously). Each received a 3-ml enteric bolus of isotonic iohexol. Serial CT scans and plain film radiographs of the bladder were performed at 2, 4, and 6 hr to detect systemic absorption of contrast from the gut. Urine iohexol concentrations were measured by capillary electrophoresis. CT number and iohexol concentration were compared with evidence from plain film radiographs of bladder opacification. Intestinal ischemia was graded histologically. RESULTS: Histologic evidence of ischemia was present in all six-arcade and five of six superior mesenteric artery (SMA)-ligated animals. No animals in the control or two-arcade group showed evidence of bowel ischemia. Statistically significant increases (P < 0.05) in bladder density were demonstrated in the six-arcade and SMA-ligated groups. No statistical difference was noted between the two-arcade ligation and control groups. CONCLUSIONS: Experimental intestinal ischemia was reliably detected by bladder opacification after administration of enteric contrast. CT detection of systemic absorption of enteric iohexol was more sensitive than plain film radiographs and may be useful in the diagnosis of intestinal ischemia, although it may not be specific for ischemia.

Animals↗