The effect of unilateral varus rotational osteotomy with or without pelvic osteotomy on the contralateral hip in patients with perinatal static encephalopathy

Forty-eight patients with perinatal static encephalopathy were treated with unilateral varus rotational femoral osteotomy for hip subluxation. Twenty-one of the 48 also had concomitant pelvic osteotomy. Twenty-seven of the patients were nonambulators. Bilateral soft-tissue releases had been performed previously in 20 patients. At the time of varus rotational osteotomy, the mean age was 8 years, 11 months. The indication for a varus rotational osteotomy was femoral head subluxation or dislocation in all cases. The preoperative center-edge angle ranged from -8 degrees to 18 degrees (mean, 4 degrees), and on the contralateral side, the center-edge angle ranged from 0 degree to 32 degrees (mean, 19 degrees). The center-edge angle on the operative side at follow-up averaged 25 degrees (-10 degrees to 78 degrees), an improvement of 21 degrees, and on the contralateral side averaged 27 degrees (range, 9 degrees-40 degrees), an improvement of 8 degrees. Forty-seven patients have had no subsequent surgery on the contralateral hip. One patient had a varus rotational osteotomy on the contralateral hip 5 years postoperatively; however, this hip was subluxated at the time of the index procedure. Twelve patients have had no surgery at any time on the contralateral side. None of these patients had deterioration of the contralateral hip. Surgery on one hip should not, in itself, be an indication for surgery on the contralateral concentrically reduced hip with adequate abduction in patients with acetabular dysplasia secondary to perinatal static encephalopathy.

Intramedullary fixation of unstable both-bone forearm fractures in children

A retrospective study was performed to evaluate the results of intramedullary fixation used in the management of unstable, diaphyseal both-bone forearm fractures in skeletally immature patients. Twenty-five patients with 25 fractures were identified whose fracture management included only intramedullary fixation. Galeazzi, Monteggia, radial head, and distal metaphyseal fractures were excluded from this analysis. Mean age at fracture was 10 + 8 years. There were 15 closed and 10 open fractures (eight grade I and two grade II). Smooth Kirschner wires or Rush rods were used for fixation. Average length of immobilization was 8 + 2 weeks; 6 + 2 in a long-arm cast and 2 + 0 weeks in a short-arm cast. All 25 regained normal elbow motion, with 17 regaining full forearm rotation. Eight patients had an average loss of 13 degrees of supination and 9 degrees of pronation. There were four minor and two major complications (one rod migration and one delayed union). No infections, malunions, or synostoses occurred in this patient group. Using the grading scheme adapted by Price there were 21 excellent results (84%), four good (16%), and no fair or poor results. In our experience, intramedullary fixation of the unstable both-bone forearm fractures is a safe, effective, and user-friendly technique when alignment jeopardizes fracture position at union and eventual forearm motion.

Distortion compensation and elimination in holographic reconstruction

We discuss the quantitative location of objects from holographic images when the reconstruction wavelength differs from the recording wavelength. The holographic image equations are interpreted in a way that clarifies the meaning of stereo pairs of holographic images and indicates how backprojection methods can be used in holography to locate objects. Alternative methods involving the production of distortion-free regions in the holographic image field during reconstruction, the use of self-calibrating objects in the object field during recording, and triangulation can be used to locate objects.

Pemberton pelvic osteotomy and varus rotational osteotomy in the treatment of acetabular dysplasia in patients who have static encephalopathy

Forty-four patients (fifty-two hips) who had static encephalopathy and acetabular dysplasia were managed with a Pemberton osteotomy as part of a comprehensive operative approach. Thirty-three patients had quadriplegia and were unable to walk; the remaining eleven patients had diplegia and could walk. The age at the time of the operation ranged from four years and five months to sixteen years and five months, as an open triradiate cartilage is a prerequisite for the Pemberton procedure. Concomitant operative procedures included a varus rotational osteotomy in fifty of the involved hips, a soft-tissue release in thirty-seven hips, and an open reduction in thirteen hips. The mean center-edge angle preoperatively was -11 degrees (range, -80 to 17 degrees), which improved to a mean of 27 degrees (range, 5 to 62 degrees) at the time of the latest follow-up. The mean duration of follow-up was four years (range, two years to eight years and eight months). At the time of writing, none of the hips had redislocated but one hip had subluxated. Eight of the hips had been painful preoperatively, but none of these was painful at the time of the most recent follow-up. One patient who had not had pain in the hip preoperatively had pain at the time of the follow-up evaluation. There were no complications attributable to posterior uncovering of the hip. The age of the patient at the time of the operation had no discernible effect on the result.

Racial misclassification of American Indians: its effect on injury rates in Oregon, 1989 through 1990

OBJECTIVES

We assessed the extent to which injury rates among American Indians in Oregon are underestimated owing to misclassification of race in a surveillance system.

METHODS

The Oregon Injury Registry, a population-based surveillance system, was linked with the Indian Health Service patient registration file from Oregon, and injury rates for American Indians were calculated before and after correcting for racial misclassification.

RESULTS

In 1989 and 1990, 301 persons in the Oregon registry were coded as American Indian. An additional 89 injured persons who were coded as a race other than American Indian in the registry were listed as American Indian in the Indian Health Service records. The age-adjusted annual injury rate for health service-registered American Indians was 6.9/1000, 68% higher than the rate calculated before data linkage. American Indian ancestry, female sex, and residence in metropolitan counties were associated with a higher likelihood of concordant racial classification in both data sets.

CONCLUSION

Injury rates among American Indians in an Oregon surveillance system are substantially underestimated owing to racial misclassification. Linkage of disease registries and vital records with Indian Health Service records in other states may improve health-related data regarding American Indians.

Closed intramedullary femoral osteotomy. Shortening and derotation procedures

Closed osteotomy and nailing were performed on 37 patients for leg-length inequality or rotational deformities. Shortening operations were performed in 31 patients, derotation in six. Preoperatively, the leg-length discrepancy ranged from 2 to 6.6 cm. All femoral shortenings resulted in correction to less than 1 cm. Preoperatively, rotational deformities averaged 58 degrees; all were corrected to within 5 degrees of normal. Follow-up observation averaged 3.3 years. There were no nonunions or infections. All patients regained preoperative joint range of motion (ROM). Thirteen patients were Cybex tested one year or more postoperatively; all had quadriceps and hamstring strength equal to or greater than the contralateral leg, except for two patients who had suffered additional trauma to the shortened femur. Closed femoral osteotomy is an effective, safe, and reproducible means to obtain lower limb length correction in patients with leg-length inequality or rotational abnormality.

Effects of bone ingrowth on the strength and non-invasive assessment of a coralline hydroxyapatite material

The dependence of strength on the amount of bone growth into a hydroxyapatite material made from coral was investigated. Block and granular forms of the material were implanted into cortical and trabecular regions of the skeletons of 16 dogs. The results were examined after 4, 8, 12 and 16 wk, with four dogs in each experimental group. When implanted into cortical bone, the bending strength of the implant material was found to be highly correlated with the amount of pore space which had become occupied by bone (r = 0.92, P less than 0.005 for the block form; r = 0.84, P less than 0.005 for the granular form). Multiple regression analysis showed that six histomorphometric measures of ingrowth accounted for 96% of the variability in bending strength of the block material, and there were no significant differences between block and granular forms of the material. On the other hand, when implanted into trabecular bone, the block form of the material achieved greater compressive strength than the granular form. While both strength and ingrowth increased with time, there were poor correlations between these two variables. Finally, when the material is implanted into trabecular bone, it becomes stronger in compression than the surrounding bone; when implanted in cortical bone, linear modelling suggests that resorption and replacement of the implant would be required to approximate the bending strength of the surrounding bone.

Compression-plate fixation of acute fractures of the diaphyses of the radius and ulna

A retrospective study was done of eighty-seven patients who had 129 diaphyseal fractures of either the radius or the ulna, or both, and who were treated with fixation using an AO dynamic-compression plate. Open fractures were internally fixed primarily, and both comminuted and open fractures routinely had bone-grafting. Ninety-eight per cent of the fractures united, and 92 per cent of the patients achieved an excellent or satisfactory functional result. The rate of infection was 2.3 per cent. Refracture occurred after removal of a 4.5-millimeter dynamic-compression plate in two patients, but there were no refractures after removal of a 3.5-millimeter plate. The 3.5-millimeter-plate system gave excellent results in patients who had a fracture of the forearm, and it minimized the risk of refracture. Our results demonstrated that immediate plate fixation of an open fracture of the forearm, with a low rate of complications, is possible.

Agricultural chemical use and congenital cleft lip and/or palate

A case-control study utilizing vital records and ecologic, surrogate exposure measures was conducted in Iowa and Michigan. The study hypothesis anticipated an excess risk of clefts among fetuses exposed during the peak agricultural chemical use period (April through November) coincident with their first trimester of gestation. To examine this hypothesis, multiple regression techniques were used to aid identification of potential confounders; additional analyses, stratified on the potential confounders, were performed using two chemical exposure indices. The major findings of these analyses suggest: (1) an agricultural chemical effect (using the multiple exposure index) controlling for season of conception; (2) no independent effect of season of conception (thus the null hypothesis is not rejected); and (3) little chemical/season interaction. These results imply that if exposures to agricultural chemicals are, in fact, risk factors for clefts, an expanded model that accounts for multiple pesticidal exposures may be more sensitive than consideration of season of exposure, as originally hypothesized.

Epidemiological insights on malnutrition: some resurrected, others restructured, a few retired

In its modern sense, epidemiology has progressed from a classical concern of causality as expressed within biological limits to recognition that a variety of social factors have proportionate significance in the origin and behavior of human nutritional disorders. Basically an analytical process, nutritional epidemiology has grown to include, among objectives for prevention and control, a synthesis of plans for intervention; the monitoring of action programs introduced; and again a parallel analytic mission to evaluate such accomplishments as programs bring forth. Nutritional epidemiology, so employed, becomes a general scientific discipline, widely purposed and incorporating objectives beyond public health: measures concerned with social welfare, economic growth, political stability, and behavioral compatibility with fellow humans and other living things. Specifically, nutritional epidemiology comprises a branch of knowledge utilizing human ecology to solve problems in three broad dimensions--a defined causality, a prescribed intervention (planning, operations) and an evaluation of results, concurrently made and terminally. The groundwork is medical ecology, the approach holistic. A population of pregnant mothers and their newborn children is accorded first priority among fields of interest, past any single disease entity or technical method of control. Community programs enlarge from that base.