James A. Nicholas

Viscoelastic stress relaxation in human skeletal muscle

Viscoelastic stress relaxation refers to the decrease in tensile stress over time that occurs when a body under tensile stress is held at a fixed length. The purpose of this study was to demonstrate viscoelastic stress relaxation in human skeletal muscle. Resistance to stretch (tensile force), hip flexion range of motion (ROM), and reflex contractile activity (IEMG) of the hamstring muscle group were measured during a passive straight leg raise. The testing protocol involved a first stretch to the maximum tolerated ROM with the lower extremity held at that point for 45 s (test 1). All 15 subjects tested (9 men, 6 women) had a stretch induced EMG response. The onset of a sustained EMG response occurred at a specific hip flexion angle in 10 subjects. These 10 subjects (6 men, 4 women) underwent a second straight leg raise stretch (test 2) to a ROM 5 degrees below the ROM at which the onset of EMG activity occurred in test 1. The stretch was held at this hip flexion angle for 45 s. There was a significant decrease in force at final ROM during the 45 s in test 1 (11.35 +/- 1.75 N, P < 0.0001) and in test 2 (4.2 +/- 1.55 N, P < 0.05). The percent decrease from the force at the respective final ROM was not significantly different between the tests (14.4 +/- 2.2% in test 1 and 13 +/- 2.3% in test 2). In test 1 there was a significant decrease over time in IEMG of 59.71 +/- 16.01 microV.s (P < 0.01) which was not significantly correlated to the decrease in force.(ABSTRACT TRUNCATED AT 250 WORDS)

Double-contrast Arthrography of the Knee: Its Value In The Management Of Two Hundred And Twenty-five Knee Derangements

1. Arthrography of the knee is a valuable diagnostic procedure. In 225 consecutive knees examined and operated on by the same surgeon, the preoperative arthrograms, all performed and interpreted by the same radiologist, demonstrated meniscal tears correctly in 97.5 per cent of the 200 knees with such lesions, giving an accuracy of 99.7 per cent in the 143 lesions of the medial meniscus and of 93 per cent in the fifty-seven lesions of the lateral meniscus. Five tears found at operation were not demonstrated by arthrography, four in the lateral and one in the medial meniscus. In six patients, tears of both menisci, unsuspected on the basis of the clinical examination, were demonstrated correctly on the arthrograms. In no instance did an arthrogram indicate a tear in a meniscus which was not corroborated at surgery. In twenty-five patients with lesions other than meniscal tears, the arthrograms were helpful but not diagnostic for all types of lesions. 2. Prolonged observation and procrastination in the treatment of patients with symptomatic knees were avoided. The surgeon and patient were assured of a correct preoperative diagnosis, especially when the clinical signs were not specific and the symptoms were intermittent and not disabling. 3. Unnecessary surgery was reduced. 4. Arthrography revealed residual portions of the meniscus left after previous meniscectomy in eight patients, one of the retained fragments being itself torn. Reoperation resulted in cure in all eight patients. Osteochondral fractures were also demonstrated as well as loose fragments more than eight millimeters in diameter. 5. In this series, one-half of the thirty-four tears of the anterior cruciate ligament were demonstrated by arthrography. We are still developing the technique to demonstrate the cruciate ligaments on arthrograms. 6. Four patients with no anteroposterior instability were shown to have anterior cruciate tears by arthrography. 7. There were no complications of arthrography in this series. All patients returned to work immediately after the procedure.

ACQUIRED ABSENCE OF THE ODONTOID PROCESS: A CASE REPORT.

A case is presented of acquired absence of the odontoid process in a child, two and one-half years old, occurring most probably as the result of an ununited fracture. The roentgenographic findings were similar to those reported with congenital absence of the odontoid process.

Osteoporosis, osteomalacia, and the skeletal system.

Osteomalacia and rickets are disorders of bone mineralization. There are many causes, but all may be controlled by suitable treatment. Except in vitamin-D deficiency, treatment often must be continued for years with careful chemical and clinical control. Relatively simple investigations enable one to distinguish between the various causes.

Histological and Alkaline-Phosphatase Changes in Autogenous Transplants of Tibial Grafts in Dogs Treated with Cortisone

Cortisone treatment of dogs after transplants of autogenous tibial grafts revealed sharply reduced alkaline-phosphatase activity two and four weeks after surgery. Graft incorporation and suitable trabecular formation were not seen until four weeks after transplantation in corticosteroid-treated dogs; the trabeculae of the callus lacked the usual osteoblastic lining. Histologically and grossly, the graft site in cortisone-treated dogs exhibited a retardation in bone healing of two weeks when compared with that in control dogs.

Pathological fractures of the spine. Etiology and diagnosis. A review of one hundred and five cases.

The records were reviewed of 162 patients who had been admitted to the Hospital for Special Surgery since 1950 with compression fractures of the spine and demineralization. Fifty-seven of the patients were excluded from this study because the diagnosis was known at the time of admission, adequate trauma to cause fracture had occurred, or the diagnostic study or follow-up had been inadequate. In the remaining 105 patients, osteoporosis was thought to be responsible for the vertebral collapse in fifty-five patients, malignant bone disease in twenty-five, hypercorticism with rheumatoid arthritis in nine, and osteomalacia in six patients. Other conditions were responsible for vertebral collapse in ten patients. The chances of a patient having primary or metastatic malignant bone disease were markedly increased if fewer than three vertebrae were collapsed and the patient was less than fifty-five years of age. In the younger-age group especially, a variety of unusual conditions other than osteoporosis produced the demineralization. In order to make a final diagnosis, complete and, often, repeated studies are necessary. It is important to establish an exact diagnosis since some conditions that produce vertebral collapse respond to specific treatment.

Adrenocortical response in operative procedures upon the bones and joints.

We have presented the results of a study of eosinophil levels in 177 patients. Of these, fifty-two were healthy persons used as controls and 125 were patients who were suffering from various disabilities or injuries of the skeletal system and who underwent different surgical procedures. We have described the important metabolic effects taking place in the body, which depend chiefly upon the response of the adrenal gland to the stimulus of injury, and have pointed out the significant findings. We have employed the eosinophil count only as an indicator of these activities. Finally, it should be pointed out that the metabolic processes we are trying to observe are multiple and complicated. The study of eosinophil levels, which is the method we have employed, may be likened to the opening of one small window through which may be obtained only an imperfect glimpse of the many activities going on within. Many other avenues of approach must be explored before we can penetrate to a point where we can obtain a clearer understanding of these complex mechanisms. We believe that a greater knowledge of them is important to orthopaedic surgeons and will promote the welfare of their patients.

The New York city consultation service for orthopedically handicapped children

Summary This report describes a consultation service maintained by the official health agency in New York City for orthopedically handicapped children, operated in conjunction with a teaching hospital. Significant findings are as follows: 1. The direct cost to the official health agency is

Injuries to Knee Ligaments: Relationship to Looseness and Tightness in Football Players

3.52 per child seen. 2. At least 84 per cent of the childrenseen had an orthopedic condition, and 71 per cent had an orthopedic condition warranting further orthopedic care and rehabilitation. 3. Seventy-three per cent of the childrenseen were recommended for placement in regular classes within the public school system. 4. One-third of the children referredto the consultation service failed to keep their appointments. 5. Only 8 per cent of the children referred were infants and preschoolers referred by child health stations of the Department of Health. The implications of these findings are discussed from the viewpoint of improvement of services to orthopedically handicapped children.