Weight-bearing Stress Research Articles

The Effects of Pressure on Epiphyseal Growth

1. When a growing epiphysis is subjected to a stress, the rate or direction of the growth of that epiphysis or both are modified so as to yield to that stress. 2. Pressures applied in directions parallel to the direction of epiphyseal growth inhibit the rate of such growth. While considerable pressures are necessary to stop cartilaginous growth completely, slight or even intermittent pressures can slow or hinder it. The gravitational pressures of normal weight-bearing seem to slow cartilaginous growth in vertical weight-bearing bones; escape from normal weight-bearing stresses results in overgrowth. 3. Pressures applied in directions perpendicular to the direction of epiphyseal growth deflect the direction of such growth, resulting in lateral or spiral (torsional) displacement of the newly laid-down bone. 4. The ease with which angular or torsional deformities may be produced in a growing bone varies inversely with its diameter. The narrower the bone, the greater its plasticity.

COMMON ORTHOPEDIC PROBLEMS IN CHILDREN

Foot Problems NORMALLY the foot functions differently in stance than it does in motion. During stance, static stresses are most important. The foot may be divided at the midtarsal joints into the hindfoot which receives 60 per cent of the weight-bearing stress and the forefoot which receives 40 per cent of the stress. The spring ligament normally transmits the stresses from hindfoot to forefoot. All degrees of foot shape and size may be natural for a particular individual. Similarly, the gait pattern of a child varies considerably within the normal range. The child should be allowed to establish his own normal gait pattern. During the toddling stages the child's shoe soles should be flexible enough to bend at the toe. One should avoid the use of rigid shoes. Some of the conditions which may alter normal stance or gait follow. Simple Foot Strain Long arch strain is due to abnormal stress on the longitudinal ligament. Inflammatory repair of the ligament produces pain which can be demonstrated by finding an area tender to palpation. Some patients have a depressed longitudinal arch or long spring ligament without foot symptoms. A diagnosis of long arch strain cannot be made unless tenderness is present. A tight heel cord may produce foot strain. The foot accommodates to a tight heel cord by pronation of the forefoot. To correct a tight heel cord, the child should stand away from the wall (while facing it) with the heels flat, then lean forward count to 3. Repeat 5 times twice daily. Pronation

Giant-Cell Tumors: Radiation Therapy and Late Results

The interest of the average surgeon or radiologist in giant-cell tumors never lags because of too great familiarity. This report is based on a review of 29 cases, principally from the service of Dr. E. P. Pendergrass of the University of Pennsylvania Hospital, Drs. Geo. E. Pfahler, Karl Kornblum, and Arthur Finkelstein, of the Graduate Hospital, University of Pennsylvania, and from the author's services at the Skin and Cancer Hospital, Philadelphia, and the Newcomb Hospital, Vineland, N. J. The collection of giant-cell tumors in the X-Ray Museum of the Temple University Hospital assembled by Dr. W. E. Chamberlain was inspected with much profit, but is not included in this series for discussion. Most of the cases in the group were treated more than five years ago, one as long as thirteen years ago. There is little value in statistics based on so small a number of cases, but the experience encountered in many of this series offers some grounds for discussion. Fourteen patients treated by irradiation alone showed good long-term results, on the whole. Some suffered intercurrent fractures, but none lost time from other complications. Leucutia, Witwer, and Belanger (5) reported similar satisfactory late results with radiation therapy of giant-cell tumors. Two cases underwent malignant change, one six years and the other nine years after treatment. In 14 cases treated by surgery and irradiation good results were also obtained, but with a greater incidence of intercurrent fractures, repeated operations, and infections, and with longer periods of morbidity. One impression gained from this review is the value of fixation or splinting, whether irradiation therapy is used alone or in combination with surgery. It sometimes seemed that immobilization was almost as important as the radiotherapeutic or operative management of the case. Surprisingly good results were obtained when little radiation was employed, in some instances purposely and in other cases because of poor cooperation on the part of the patient. In one patient, who had known of the presence of a tumor in the upper end of the right humerus and had refused treatment for twenty-eight years, an organized stable-appearing giant-cell tumor was revealed by x-ray examination. If these tumors can heal spontaneously, it may be that the simple measure of preventing fractures by proper splinting and removal of weight-bearing stresses for a sufficiently long period is a more important factor than is realized in the ultimate cure, the splinting to be done to spare the part from weight-bearing, not from other active or passive use. It appeared that healing occurred more rapidly while the part was at rest than during the other phases of the therapeutic course. Healing took place faster in children than in adults and apparently with smaller amounts of radiation.