Showing papers in "Bulletin of the Hospital for Joint Diseases in 1983"

The mechanical properties of articular cartilage.

Abstract: An outline of a theoretical model for the mechanical behavior of articular cartilage is presented. The model explicitly describes the pressures and flows generated in the interstitial fluid during loading and deformation. A number of experimental tests to measure the mechanical properties of cartilage are available. The interpretation of these test results in the light of this model and the important factors to consider in the design of experiments are reviewed.

Gait analysis for decision-making in cerebral palsy.

Abstract: Gait analysis offers objective assessment of complex neuromuscular conditions such as cerebral palsy. With such assessment, more predictable treatment outcomes should be possible with less "staging of surgery." This article presents prerequisites and specifications of the Newington Children's Hospital laboratory. Three cases are presented to demonstrate the clinical applications.

Error analysis of scoliosis curvature measurement.

Abstract: The Cobb angle is the recommended standard for curvature assessment of scoliotic patients. Because the errors associated with this measure are thought to be significant, we conducted a study to quantify the variability of the Cobb measure among observers, within each observer's repeated measurements, and between the traditional protractor Cobb measurement and a computer-aided technique.

Gait analysis--precise, rapid, automatic, 3-D position and orientation kinematics and dynamics

Abstract: A fully automatic optoelectronic photogrammetric technique is presented for measuring the spatial kinematics of human motion (both position and orientation) and estimating the inertial (net) dynamics. Calibration and verification showed that in a two-meter cube viewing volume, the system achieves one millimeter of accuracy and resolution in translation and 20 milliradians in rotation. Since double differentiation of generalized position data to determine accelerations amplifies noise, the frequency domain characteristics of the system were investigated. It was found that the noise and all other errors in the kinematic data contribute less than five percent error to the resulting dynamics.

Primary liposarcoma of bone. Case report and review of the literature.

Abstract: Although liposarcoma is a common tumor of the soft tissues of the body, it rarely occurs as a primary neoplasm of bone. An extensive review of the literature from 1930-1980 uncovered fewer than 35 cases. The authors discuss the diagnosis and treatment of a case of primary liposarcoma of bone in the right femur of a 34-year-old Bedouin man.

Ossifying fibroma of bone. Report of two cases.

Abstract: Two cases are reported of a hitherto undescribed type of lesion for which the term "ossifying fibroma of bone" is suggested. The lesions occurred in children aged 12 and 13 years, and involved the tibia and the humerus. Histologically they consisted of fibrous tissue containing small, partly calcified spherules: in this respect they differ from the usual types of fibro-osseous lesion such as fibrous dysplasia and osteofibrous dysplasia. The term "ossifying fibroma" is proposed for this condition, although in the past it has been applied to other types of bone lesion.

Evaluation of bonding of bone to inorganic crystal surfaces.

Abstract: It is known that bone will adhere strongly to dense hydroxyapatite Evidence is presented to show that bone will adhere to calcite as well, and a theory is proposed to explain the bonding of bone to both these materials While primarily of interest as a pedagogical tool for evaluating the bonding of bone to other materials, calcite may also be of clinical use as packing material for orthopaedic or dental defects

Cervical chordoma with intradural invasion. A case report.

Abstract: An unusual case of cervical chordoma with intradural invasion is presented. Anterior resection of the vertebral body with Kiel (calf) bone grafting was performed. Computer tomographs taken on follow-up, four-and-a-half years later, showed the bone graft to be well incorporated and the residual tumor in arrest.

Shoulder arthroscopy. Technique and indications.

Abstract: The development of shoulder arthroscopy is reviewed since its beginnings in 1931. The technique of posterior introduction of the arthroscope and positioning of the patient is presented. An additional portal for arthroscopic surgery is also described. The main indications for the procedure are reviewed, based on a survey of the literature and the author's experience, and five cases are presented illustrating some of the situations for which the technique proved beneficial.

A physiologically based criterion for muscle force predictions on locomotion.

Abstract: A quantitative method of muscle activity prediction is presented which uses a criterion of maximum endurance of musculoskeletal function and is based on the inversely nonlinear relationship of muscle force and contraction endurance. The results obtained through the use of this method agree more closely with known patterns of muscle activity, as revealed by electromyography, than do those obtained by most linear optimization techniques.

Tumoral calcinosis in an infant. A case report.

Abstract: An unusual calcified soft tissue mass in the knee of an 18-month-old black male infant proved to be tumoral calcinosis. A relatively rare disorder of unknown etiology, this is one of the few reported cases of its occurrence in the knee. The diagnosis is one of exclusion. Because of their radiographic similarity, the differential diagnosis includes intracapsular and paraarticular chondroma, traumatic myositis ossificans, and calcinosis circumscripta.

Bone remodeling in response to local mechanics.

Abstract: A brief discussion of the importance of the collaboration of engineers and surgeons in solving the many problems that continue to vex patients with orthopaedic and related diseases.

Experience with electrical stimulation of nonunions.

Abstract: The use of electrical stimulation modalities for the treatment of nonunions in the orthopaedic patient population is receiving increasing attention. The following report briefly describes the early results obtained from using three commercially available devices in 33 patients.

The relationship of paraarticular ossification and excess callus formation in fracture healing to local electric and electromagnetic fields.

Abstract: The unusual end results of fractures of the extremities in several patients with neurological problems are presented. The authors suggest a theoretical explanation for the soft tissue changes and excess callus formation that occurred, as well as a possible method of curtailing or preventing paraarticular ossification in soft parts.