Search PubMed⌕ Search

Biomedical subjects

J S Torg

Publications and source records attributed to J S Torg.

98 records · Page 6Linked to original sources
PubMedDate not supplied

The effect of ambient temperature on the shoe-surface interface release coefficient.

Previous studies of the shoe-surface interface correlated foot fixation with cleat length, configuration, and material composition as well as turf type and surface conditions. Our study examined the effect of temperature on the rotational torsion resistance of artificial turf football shoes. Five football shoe models, a flat-soled basketball-style turf shoe, a natural grass soccer-style shoe, and three multistudded turf shoes, were studied on dry Astro Turf at five temperatures (range, 52 degrees F to 110 degrees F). An assay device, a prosthetic foot mounted on a loaded stainless steel shaft, was used to determine the force necessary to release a shoe from the turf's surface. We used a torque wrench to apply a rotational force so that each shoe was pivoted counterclockwise through an arc of 60 degrees. Our results indicated that release coefficients differ within and among the shoe models at various turf temperatures. We also found that an increase in turf temperature, in combination with cleat characteristics, affects shoe-surface interface friction and potentially places the athlete's knee and ankle at risk of injury. Based on an established risk criterion, which correlated shoe-surface interface combinations in the laboratory with documented clinical occurrences, only the flat-soled basketball-style turf shoe could be designated "safe" or "probably safe" at all five temperatures.

Ankle Injuries↗
PubMedDate not supplied

Magnetic resonance imaging of knee disorders. Clinical value and cost-effectiveness in a sports medicine practice.

To prospectively evaluate the clinical value of magnetic resonance imaging of the knee in a referral sports medicine practice, we performed a three-part study. First, we asked 72 consecutive patients a series of clinically relevant questions regarding the ordering of their magnetic resonance imaging scans. Second, we asked the treating physicians at our center if the magnetic resonance imaging findings changed the diagnosis or treatment. Third, we compared the clinical evaluation with the findings on magnetic resonance imaging scans for 37 patients who had arthroscopic confirmation. From the physician's perspective, in only three cases would the results of the scan have changed the diagnosis. Information from the scans was judged to contribute to patient treatment in only 14 of 72 patients. Finally, comparison of clinical evaluation and magnetic resonance imaging findings with findings during arthroscopic procedures showed that clinical evaluation had a sensitivity and specificity of 100% for diagnosis of anterior cruciate ligament injuries, whereas magnetic resonance imaging was 95% sensitive and 88% specific. For isolated meniscal lesions, the clinical assessment had a sensitivity and specificity of 91% compared with 82% and 87%, respectively, for magnetic resonance imaging. For evaluation of articular surface damage, the predictive value of a positive test was 100% for clinical assessment and 33% for the magnetic resonance imaging. We conclude that magnetic resonance imaging is overused in the evaluation of knee disorders and not a cost-effective method for evaluating injuries when compared with a skilled examiner. Clinical assessment equals or surpasses the magnetic resonance imaging in accuracy.

Adolescent↗
PubMedDate not supplied

Long-term evaluation of the Elmslie-Trillat-Maquet procedure for patellofemoral dysfunction.

We evaluated 55 knees in 51 patients after Elmslie-Trillat-Maquet procedures. The procedure involves medialization of the tibial tubercle on a distal pedicle and elevating the tibial tubercle anteriorly 10 mm with a local bone graft. At a mean followup of 74.2 months (range 13 to 196), all patients completed postoperative surveys and 38 underwent postoperative examinations. Subjectively, 9 knees (16%) had excellent results, 24 knees (44%) obtained good results, and 13 knees (24%) had fair results for a total of 84% improvement overall. Using Fulkerson's functional knee score, 19 knees (35%) had excellent results, 10 knees (18%) had good results, and 11 knees (20%) had fair results for a total of 73% improvement overall. A total of 24 knees (44%) required later screw removal. The most significant findings of this study include 1) an 84% overall subjective improvement in symptoms; 2) the findings that young patients without evidence of progressive osteoarthrosis and with patella instability as a primary symptom tend to have the most favorable outcome; and 3) 24 knees (44%) required later screw removal.

Bone Screws↗
PubMedDate not supplied

The pathomechanics of chronic, recurrent cervical nerve root neurapraxia. The chronic burner syndrome.

This study defined chronic recurrent cervical nerve root neurapraxia, the chronic burner syndrome, characterized the clinical findings, and described the responsible pathomechanics. We studied a subset of 55 athletes (mean age, 22 years) for evaluation of recurrent burners. Eleven subjects were professional athletes. The mechanism of injury was extension combined with ipsilateral-lateral deviation in 46 patients (83%). Spurling's sign was positive in 39 patients (70%). Twenty-nine patients (53%) had developmentally narrowed cervical canals, and 48 patients (87%) had evidence of disk disease by magnetic resonance imaging. The disk disease was in the form of a disk bulge, disk protrusion, or a frank disk herniation deforming the cord. Fifty-one patients (93%) had disk disease or narrowing of the intervertebral foramina secondary to degenerative disk disease. Although burners may be the result of a brachial plexus stretch injury in high school and collegiate football players seen with acute symptoms, nerve root compression in the intervertebral foramina secondary to disk disease is a more common cause in collegiate and professional players who have recurrent or chronic burner syndromes. There is a high incidence of cervical canal stenosis in football players with recurrent burner syndrome. The combination of disk disease and cervical spinal canal stenosis may lead to an alteration in normal cervical spine mechanics that may make these athletes more prone to chronic burner syndromes.

Brachial Plexus↗
PubMedDate not supplied

Posterior cruciate ligament insufficiency. A review of the literature.

A review of the English language literature establishes athletic mishaps as a major cause of posterior cruciate ligament injury. However, diversity of opinion exists regarding the functional significance of the lesion, its occurrence as an isolated entity, and the roles of conservative and surgical management. The posterior cruciate ligament is a composite structure, consisting of a superficial tibiofemoral and meniscofemoral portion and a deep tibiofemoral portion. The structure is intra-articular but extrasynovial, coursing from its attachment to the lateral surface of the medial femoral condyle posteriorly and inferiorly to its distal attachment into the posterior rim of the tibia, blending with the capsule and periosteum. Mechanical studies have demonstrated that abnormal posterior tibial displacement can occur only with posterior cruciate ligament laxity. The most prevalent mechanism resulting in injury to the posterior cruciate results from a blow on the anterior aspect of the flexed knee. However, both hyperflexion and hyperextension as well as deceleration and rotation have been described. Posterior cruciate ligament insufficiency may result from an avulsion fracture involving the ligament-bone insertion of the ligament, usually from the posterior aspect of the proximal tibia. Also, disruption may occur as an intersubstance tear of the ligament, either as an isolated phenomenon or in combination with multiple ligamentous injuries. The importance of distinguishing between combined injuries associated with significant collateral and/or anterior cruciate ligament injuries from the 'isolated' type lies in the fact that the prognosis for the 'isolated' injuries is much better. Careful clinical evaluation of the knee with an acute posterior cruciate ligament injury will reveal subtle, but definite, findings peculiar to the lesion. These include the posterior sag sign, the posterior drawer sign, reverse pivot shift, Godfrey's test, and the presence of varus or valgus instability with the joint in full extension. In patients with chronic posterior cruciate ligament laxity, the presenting symptom is often that of patellar pain. It is generally agreed that avulsion fractures involving the ligament-bone insertion of the posterior cruciate ligament should be treated by open reduction and internal fixation. Surgical treatment of this lesion will result in excellent functional recovery. A variety of procedures have been reported for the management of acute disruption of the posterior cruciate ligament.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMedDate not supplied

Osteoid osteoma. Distant, periarticular, and subarticular lesions as a cause of knee pain.

Osteoid osteoma, a benign osteoblastic tumour comprised of osteoid and atypical bone, is a well-known entity. However, clinical diagnosis may be delayed, especially when the pain is referred to a nearby joint. This paper reports a series of 11 cases occurring in physically active patients in whom the diagnosis was delayed because of pain referral to the knee. The mean duration from the onset of symptoms to diagnosis of osteoid osteoma was 20 months (range 3 to 48 months). Review of these 11 lesions indicates that they can be classified on the basis of their anatomical location: (a) distant to the knee; (b) periarticular; or (c) subarticular (intraarticular). It should be noted that initially only 5 of the 11 cases displayed characteristic x-ray findings; in the remaining 6 cases, diagnosis was dependent on positive 99mTc radionuclide bone scans, tomograms, and computerised tomography scans. Of the 9 patients who underwent surgical resection of their lesions, all had complete relief of symptoms and all continued to be asymptomatic at follow-up evaluations.

Adolescent↗
PubMedDate not supplied

Management and rehabilitation of ligamentous injuries to the ankle.

The management of ligamentous injuries to the ankle is controversial. Neither the methods for classification and diagnosis, or the procedures for treatment are clear cut. Ankle sprains are a common occurrence, with the majority involving the lateral ligament complex. Within this complex, the anterior talofibular ligament is injured most frequently, usually while the foot is in the plantar flexed position. Ankle injuries can be diagnosed through physical exam, including the anterior drawer test and/or a stress exam, or through roentgenographic evaluation. The purpose of the stress roentgenogram is to measure the degree of talar tilt. However, it does not always yield consistent, reliable results. This inconsistency has led to the use of arthrography. There is debate over its use as well, however, Ankle sprains can be classified into three groups, according to functional loss. Treatment for first and second degree sprains is usually non-operative. The best approach to Grade III sprains is debatable. The issues in the treatment of Grade III sprains are first, whether treatment should be operative or non-operative, and second, whether non-operative treatment should emphasise immobilisation or mobilisation. Brostrom's work is cited as noteworthy. He recommended adhesive strapping followed by mobilisation as the treatment of choice, and reserves surgery for cases of chronic instability. Results demonstrated that strapping yielded shorter disability periods, while surgery produced less instability. The prevention of functional instability is a major concern in the treatment of ankle injuries. There is no consensus for treating a lateral ligament rupture. The authors suggest immobilisation followed by a rehabilitative programme. Three methods of immobilisation are plaster casting, adhesive strapping, and the air-stirrup. The physiological mechanism of cryotherapy and thermotherapy are discussed briefly and recommendations for their use are provided. Aspiration is also discussed. Loss of motion is designated as a primary cause of chronic pain and reinjury, and exercises intended to restore range of motion are provided. Exercises aimed at restoring strength and proprioception are also presented. This allows for return to activity and serves to prevent reinjury.

Ankle Injuries↗