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Biomedical subjects

D S Tearse

Publications and source records attributed to D S Tearse.

15 recordsLinked to original sources
PubMed1997

Popliteus function in ACL-deficient patients.

Anterior cruciate ligament (ACL) injuries commonly result in anterolateral rotary instability and a 'pivot shift' phenomenon. Since popliteus muscle stimulation causes a pivot shift, some postulate the popliteus muscle plays a role in causing pivot shifts. To see if patients with pivot shifts exhibited excessive popliteus muscle activity, we studied fine-wire EMGs of the popliteus in 16 normal subjects and 10 ACL-deficient subjects. Subjects performed six activities (level walking and jogging, ascending walking and jogging, and descending walking and jogging). Except for minor timing differences in ascending treadmill and ascending jogging, the signals were similar for injured and uninjured limbs; similar variance ratios suggested similar pattern variability. Thus, we observed only minor popliteus EMG signal differences in this group of patients. We conclude that the popliteus muscle does not actively contribute to instability in the studied activities.

Anterior Cruciate Ligament Injuries↗
PubMed1996

Imaging of muscle injuries.

Although skeletal muscle is the single largest tissue in the body, there is little written about it in the radiologic literature. Indirect muscle injuries, also called strains or tears, are common in athletics, and knowing the morphology and physiology of the muscle-tendon unit is the key to the understanding of these injuries. Eccentric muscle activation produces more tension within the muscle than when it is activated concentrically, making it more susceptible to tearing. Injuries involving the muscle belly tend to occur near the myotendinous junction. In adolescents, the weakest link in the muscle-tendon-bone complex is the apophysis. Traditionally, plain radiography has been the main diagnostic modality for evaluation of these injuries; however, with the advent of MRI it has become much easier to diagnose injuries primarily affecting the soft tissues. This article reviews the anatomy and physiology of the muscle-tendon unit as they relate to indirect muscle injuries. Examples of common muscle injuries are illustrated.

Adolescent↗
PubMed1996

MRI of complete rupture of the pectoralis major muscle.

Rupture of the pectoralis major muscle is a rare clinical entity. Only few reports have discussed its MRI or CT features. We have reviewed the imaging features of four cases of complete rupture of the pectoralis major muscle. One case of acute injury underwent surgical repair. MRI is useful in delineating the site and extent of the rupture in relation to the musculotendinous junction, which will help the surgeons with possible treatment options and surgical planning. Because of the complex anatomy of the pectoralis major muscle near its insertion on the humerus and the signal characteristics of hematoma and edema in the muscle, axial T2-weighted images were most valuable for the evaluation of acute and subacute injuries. Axial T1-weighted images were helpful in delineating chronic injuries. CT is inferior to MRI for direct visualization of muscle rupture.

Adult↗
PubMed1995

Hamstring injuries: radiographic, conventional tomographic, CT, and MR imaging characteristics.

PURPOSE: To review experience with the imaging features of hamstring injuries. MATERIALS AND METHODS: Imaging findings in 18 male and four female patients with clinically proved hamstring injuries were reviewed. The patients' ages ranged from 13 to 61 years (mean, 26 years). Radiography, conventional tomography, computed tomography (CT), and magnetic resonance (MR) imaging were performed. RESULTS: Plain radiographs obtained less than 1 week after injury were normal or showed avulsion of an ischial apophysis. Plain radiographs and conventional tomograms obtained more than 1 week but less than 3 months after injury were confusing, because callus and osteolysis were present. CT helped identify a healing avulsion of an ischial apophysis. MR imaging was helpful no matter how long after the injury it was performed. It provided a means to evaluate muscle, tendon, and bone. CONCLUSION: Familiarity with the variable appearance of hamstring injuries over time and with different modalities facilitates accurate characterization.

Adolescent↗
PubMed1995

Shoulder problems in athletes. Hastening the return to full function.

Shoulder disorders in athletes initially may appear perplexing, but most can be resolved successfully with a systematic approach to clinical evaluation. Newer imaging techniques can be extremely helpful in diagnosing difficult cases or in planning surgery. Arthroscopy also can be helpful in confirming diagnoses and in treating problems resistant to nonoperative regimens.

Athletic Injuries↗
PubMed1994

Popliteus function in ACL-deficient patients.

Anterior cruciate ligament (ACL) injuries commonly result in anterolateral instability, resulting in a "pivot shift" phenomenon. Given that popliteus muscle stimulation results in a pivot shift, others have postulated that the popliteus muscle has a role in the pivot shift phenomenon. We hypothesized that patients with instability from ACL injuries may have excessive popliteus muscle activity. Therefore, we studied the EMG activity (using fine wire electrodes) of the popliteus muscle in sixteen normal subjects and ten ACL-deficient subjects. We recorded the EMG in six activities (level walking and jogging, ascending walking and jogging, and descending walking and jogging). Person's Product Moment Correlations were above 0.7, except in the case of ascending the treadmill (r = 0.427) and ascending jogging (r = 0.645), suggesting that the timing of the signals was similar for injured and uninjured limbs. Variance ratios for the injured and uninjured limbs were statistically similar, suggesting similar variability of patterns. Thus, we observed only minor popliteus EMG signal differences in this group of patients. We conclude that the popliteus muscle does not contribute to instability in the studied activities.

Anterior Cruciate Ligament Injuries↗
PubMed1987

Management of non-contiguous vertebral fractures.

Non-contiguous vertebral fractures are not common. In 78 consecutive patients with acute thoracolumbar fractures, we found that 13 patients (16.7%) had non-contiguous spinal injuries. Five patients had a combination of cervical and thoracolumbar injuries and eight had a combination of thoracic and lumbar injuries. Four of the eight patients in the thoracic and lumbar group had posterior surgical stabilisation procedures. Two patients had instrumentation of all injured, non-contiguous vertebrae and healing occurred uneventfully, and two patients had instrumentation of only the major fracture and a progressive deformity occurred at the site of the minor fracture. We concluded that: patients with a spinal fracture should have radiographic evaluation of their entire spine to rule out non-contiguous fractures; if non-contiguous fractures are evident on standard radiographs, all levels of injury should be evaluated with computerised tomography; and all unstable or potentially unstable injuries should be reduced, stabilised, and fused.

Adult↗
PubMedDate not supplied

The GORE-TEX anterior cruciate ligament prosthesis. A long-term followup.

The GORE-TEX anterior cruciate ligament prosthesis has been implanted in 268 patients at our institution since April of 1984. Follow-up for this study was available on 70% of these patients (188). Eighty-one percent (152) of these had the ligament for chronic injuries, 14% (26) for acute, and 5% (10) for subacute injuries. The patient population had an average age of 27.6 years (SD = 8.4) and a Tegner activity score of 6.05 (SD = 1.53). Prior procedures had been performed on 56% (105) of the patients. Concomitant procedures were performed in 73% (137) and included iliotibial band tenodesis, partial meniscectomy, posterior oblique ligament advancement, or meniscal repair. Followup averaged 48 months (range, 24 to 68). Evaluation included a questionnaire, physical examination, radiographs, KT-1000 arthrometer testing, and an activity score. Results were graded as excellent, good, fair, and poor. Acceptable results (good and excellent) were obtained in 83 patients (44%). Fifty-eight patients (32%) were rated excellent and 25 (13%) were rated good. Unacceptable results (fair and poor) were obtained in 105 patients (56%). Twenty-five patients (13%) were rated fair and 80 (42%) were rated poor. Subjective improvement was indicated by 166 patients (88%). Activity levels postoperatively as rated by the Tegner Scale improved in 2 (1%), remained the same in 167 (89%), and decreased in 19 patients (10%). Effusions occurred in 63 patients (34%) and caused an unacceptable result in 22 (12%). Rupture occurred in 23 patients (12%). Loosening greater than 3 mm occurred in 64 patients (34%) and led to unacceptable results in 37 (20%). Infection occurred in 5 patients (2.7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMedDate not supplied

Radiographic abnormalities of the lumbar spine in college football players. A comparative analysis.

The purpose of this study was to make a direct comparison between lumbar spine radiographs of incoming college football players and of an age-matched control group to determine whether there is a higher prevalence of lumbar spine abnormalities in football players before competing at the Division I level. We reviewed 187 lumbar spine radiographs. Of these, 104 were taken as a standard part of the preparation physical examination for incoming college football players. The remaining 83 radiographs were taken during routine preemployment physicals at a local factory. Each radiograph was read independently by three separate orthopaedic radiologists in a blinded fashion. Data were collected and statistically evaluated for 13 variables. The rate of spondylolysis was only 4.8% in our group of athletes and 6.0% in the control group (not significantly different). Only in the category of degenerative changes was a significant difference found. The control group had a 16.9% incidence of disk space narrowing and spurring and the football players had a 6.7% incidence. The remainder of the variables were not significantly different between the two groups. Our findings differ from previously published reports and indicate that football players entering college at the Division I level may have a similar prevalence of radiographic lumbar spine abnormalities, including spondylolysis and spondylolisthesis, as age-matched controls.

Adult↗
PubMedDate not supplied

Achilles tendon injuries.

As the number of persons who participate in athletic activity into their later years has increased, so has the incidence of overuse injuries to the Achilles tendon. The etiology of these problems is multifactorial and includes biomechanical factors and training errors. Use of a histopathologic scheme for classification of these injuries facilitates a logical approach to treatment. Conservative care is a mainstay of treatment for inflammatory conditions. Satisfactory outcomes may be obtained with either nonoperative or operative treatment of acute ruptures, although surgically treated patients appear to recover better functional capacity. Treatment of neglected injuries to the Achilles tendon continues to be a challenging problem.

Achilles Tendon↗