Biomedical subjects
Publications and source records attributed to S R Cannon.
The relationship between dyschondroplasia (Ollier's Disease) and the possibility of malignant change is well known. The authors describe a patient who developed four primary chondrosarcomas over 11 years. These were treated by local wide excision and, in two sites, prosthetic replacement to preserve the limb. To the authors' knowledge, no patient with more than two primary chondrosarcomas has previously been described.
Thirty patients were managed with the use of a simple means of external fixation. Ten of these patients had multiple injuries. In 18 the fractures were open. Five cases had loss of bone length and infected wounds when first seen and were treated with the aid of microvascular surgical procedures. Eight cases required skin grafting. One case required a vein graft to the popliteal artery. The method described is simple to use. It requires little previous experience and is cost effective. We recommend its use in the initial treatment of grade 2 and 3 open fractures. It may also be used on closed unstable fractures, and will maintain limb length in severe injuries with loss of bone substance while further treatment is considered or performed.
To test the relative accuracy of Doppler echocardiographic peak frequency and turbulence parameters in assessing aortic stenosis, we constructed a pulsatile flow model that simulated human left ventricular and aortic pressures, flow, and anatomy. Continuous wave-measured peak frequencies and pulsed Doppler-measured turbulence were determined in the model ascending aorta for nine stenotic valve areas for each of five different flow rates. The mean squared systolic peak frequency (MSPF) and turbulence spectral envelope area (SEA) were regressed against the mean systolic gradient (r = .94, SEE = 5.6 mm Hg; and r = .96, SEE = 1.2 mm Hg, respectively). SEA was more accurate than MSPF at moderate-to-high degrees of stenosis and exhibited a smaller standard error. MSPF was more accurate than SEA in mild stenoses, where SEA tended to overestimate gradients. When flow data were included in a multiple regression analysis, both MSPF and SEA provided fair predictions of actual effective valve areas (r = .90 and r = .94, respectively). Use of high pulse-repetition-frequency Doppler echocardiography significantly reduced aliasing problems common to pulsed Doppler techniques.
To determine the source of errors in the Gorlin formula for estimating stenotic valvular orifice area, we used a pulsatile flow model that emulated left ventricular and aortic pressures and flow and allowed control of ventricular outflow orifice area. After comparing orifice areas calculated by the Gorlin formula with actual orifice areas, the Gorlin formula constant (k) was found to be highly correlated with the square root of the mean transvalvular gradient (r = .95). A new formula was derived empirically and predicted areas more accurately and with smaller standard errors than the Gorlin formula in the model (r = .98, SEE = 0.11 and r = .87, SEE = 0.28, respectively) in a series of 19 patients with Hancock porcine xenograft valves (r = .89, SEE = 0.07 and r = .60, SEE = 0.12, respectively) and in the original series of patients reported by Gorlin and Gorlin in proposing the Gorlin formula (r = .93, SEE = 0.11 and r = .91, SEE = 0.12, respectively).
There were one hundred and ninety seven patients who presented with back pain to an Athletes Clinic over four years. Their mode of presentation, investigations, diagnoses and treatments are analysed. The majority of patients were male and below 30 years of age. The average duration of symptoms prior to presentation, despite an easy access policy, was 42 weeks. Injury was usually related to six popular sports. Radiological examination was a rewarding investigation in these patients and included an A-P view of the pelvis. The diagnostic label of prolapsed intervertebral disc appears to have been used too frequently. Physiotherapy was the most useful treatment modality regardless of age, mode of onset and duration of symptoms.
To differentiate normal from abnormal left-sided heart valves, 34 adults (6 normal and 28 abnormal) with 48 valve lesions proved at catheterization were examined using a 3 MHz duplex pulsed Doppler echocardiograph with 2-dimensional verification of sample volume position and on-line display of the Doppler audio spectrum. A uniform protocol was used to position the sample volume for each lesion and to analyze the Doppler spectral data. Intracardiac blood turbulence, manifested by an increased Doppler spectral envelope area, was the noninvasive indicator of disease. The specific lesion present was determined by documenting the intracardiac location and timing of the turbulence. Doppler spectral envelope areas in all normal valve sites were smaller than those measured at the same sites in patients with aortic stenosis, mitral stenosis, and mitral regurgitation (p less than 0.01). Except for a single patient with minimal aortic regurgitation, spectral envelope area allowed complete separation of patients with valve disease from normal subjects (p less than 0.01). High sensitivity (97%) and specificity (100%) were noted despite the presence of multiple valve lesions in 67% of the patients. The data demonstrate application of a simple, noninvasive method of acquiring and analyzing Doppler echocardiographic data which allows accurate identification or exclusion of left-sided valve disease in adults, even in the presence of multiple valve lesions.
A case is described of traumatic separation of the proximal femoral epiphysis associated with a fracture of the mid-shaft of the same femur in a two-year-old girl. The rarity of this injury is emphasized and its treatment outlined. No similar reports could be found, and the relevant literature is reviewed.
The feasibility and safety of early discharge from hospital following inguinal hernia repair in selected patients is well established. The following is an account of 104 unselected patients who presented consecutively to an Inner London hospital with inguinal hernias. The intention was to discharge all patients 48 h after operation, but for a variety of reasons a later discharge day was planned preoperatively in 50. Of the 104 patients, 62 (60 per cent) were discharged on the planned day, but only 23 per cent left hospital 48 h after operation. The factors which accounted for this are discussed. It was possible, however, to discharge over 85 per cent within 5 days of operation.
Ten patients with biliary-type pain, in whom investigations of the biliary tract were negative, are reported. All the patients were sexually active premenopausal women and all had evidence of infection with chlamydia trachomatis. Five patients submitted to laparoscopy had fibrinous adhesions between the anterior surface of the liver and the parietal peritoneum (perihepatitis). All 10 patients were diagnosed as suffering from the Curtis-Fitz-Hugh syndrome caused by Chlamydia trachomatis. The clinical similarities between the Curtis-Fitz-Hugh syndrome (right upper quadrant abdominal pain, perihepatitis and genital tract infection) and acute biliary disease are emphasized and the diagnostic implications discussed.
One hundred and twenty-two inguinal hernias were repaired in a consecutive series of 104 patients. The patients were randomly divided into two groups. In one, 66 wounds were closed by the traditional method of using interrupted non-absorbable skin sutures. In the second group, 56 wounds were closed with subcuticular Dexon sutures. The results of the two methods of skin closure were compared in the immediate postoperative period, at 2 weeks, 3 months and at more than 18 months after surgery. The final appearance of the wounds was similar in the two groups. Dexon has the advantage for short-stay patients of not requiring removal.
Pulsed Doppler echocardiography and digital Fourier analysis were utilized to examine flow distal to the aortic valve and to quantify aortic stenosis. A graphic index of parameters derived from velocity spectrum patterns generated by Fourier analysis was regressed against mean systolic pressure gradients in 21 adults with clinical evidence of aortic stenosis who underwent catheterization studies and five normal adults (r = .82). Correlation improved in the absence of regurgitation (r = .92). Sensitivity for detecting gradients greater than 30 mmHg was 86%; specificity was 90%. Doppler spectral analysis shows promise in alleviating the need for many invasive studies.
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Sequential measurements of height and weight from diagnosis to maturity in 44 children with Perthes' disease are presented. Both boys and girls have an increased growth velocity after the age of 6 years. In boys diagnosed prior to the age of 6 years, the pubertal growth spurt occurs early but is not sustained. Girls have a delayed but rapid pubertal growth spurt. Abnormal growth patterns are further evidence for the concept of "the susceptible child" and increased growth velocity may contribute to trabecular failure and subsequent epiphyseal infarction.