Wilton H. Bunch

A biomechanical analog of curve progression and orthotic stabilization in idiopathic scoliosis

A biomechanical analog of curve progression and orthotic stabilization in idiopathic scoliosis has been developed using the classical theory of curved beam-columns. The interaction of the spinal musculature and other supporting structures is incorporated in the model using an equivalent flexural rigidity. The stability of a given scoliotic curve relative to a normal spine is described in terms of the so-called critical load ratio (Pc/Pe). This dimensionless quantity appears in the exact solution of the governing differential equation and boundary conditions. It is defined as the ratio of the load bearing capacity of a scoliotic spine (Pc) to that of a normal spine where the load bearing capacity of a normal spine is defined as Eulers buckling load (Pe). The computation of Pc/Pe is based upon a maximum allowable moment criterion. This model is used to study the effect of the degree of initial curvature and curve pattern in the frontal plane on the stability of untreated idiopathic scoliosis. Although restricted to two-dimensions, the model appears to demonstrate the synergistic effects of end support, transverse loading, and curve correction on improvement in relative stability of an orthotically supported scoliotic curve. The results of this study are in qualitative agreement with clinical findings that are based on long-term studies of natural history of idiopathic scoliosis and of patients undergoing orthotic management for scoliosis.

The stresses of the surgical residency

UNLABELLED Concern over resident work hours prompted us to study the stress of surgical residencies and determine if the experience might be associated with an increased use of alcohol and drugs. Two hundred fifty-seven surgery residents were selected from a stratified, randomized sample of residents (n = 1728) from the AMA files and were given an eight-page self-administered questionnaire. RESULTS Surgical residents reported very long hours and heavy duties and complained of loss of sleep and exhaustion, both of which correlated with nights on call. Despite the heavier work load, surgical residents showed no more emotional stress than other residents. Surgery residents were more likely to have used alcohol in the last month than other residents (P less than .05) but 70% had used it fewer than 10 times in the month. All surgical residents were less likely to have used marijuana, cocaine, or other drugs than were other residents. Surgical residents seem to cope well with the extreme stresses of surgery training programs; however, more research needs to be done if we are to fully understand the process for training surgeons.

The value' of functional independence measure scores

Functional independence measure (FIM) scores are frequently used as if the various sections are of equal importance and as if the interval between each score is equal. We tested this hypothesis by using marketing research techniques to assess the value to rehabilitation nurses and therapists of four of the six sections. Communication was valued more highly than continence, mobility and self care in that order. The interval between the scores is not equal, with difference between a FIM 2 and 3 being greater than between a FIM 5 and 6. However, when the other difficulties such as interexaminer reliability are considered, these score differences are not great. We concluded that for practical purposes FIM scores may be used as if they were of equal interval spacing, and the scores of the various sections may be added together.

Dermatomal Somatosensory Evoked Potentials: Their Use in Lumbar Radiculopathy

The accurate diagnosis of lumbar radiculopathy secondary to intervertebral disc herniation or spinal stenosis remains a significant problem. Studies have stressed that misdiagnosis of root entrapment significantly contributes to the incidence of failed back syndrome. In an attempt to aid the proper selection of surgical candidates, dermatomal somatosensory evoked potentials (DSSEP) have been used in conjunction with standard diagnostic techniques to evaluate our patients. The advantage of this technique lies in the root specificity. The authors studied the DSSEP using two methods. In Method I, using milligrams as the standard, the accuracy was 85.7%. In Method II, using surgical outcome as the standard, the accuracy was 87.5%. As a result, the authors have found the noninvasive, relatively inexpensive DSSEP to be a useful adjunct in the selection of patients undergoing lumbar spine surgery.

Moral reasoning, professionalism, and the teaching of ethics to orthopaedic surgeons.

Moral reasoning is not the only component of moral behavior, but it is an important and measurable constituent. Eighty orthopaedists, who took a standardized test of moral reasoning, showed marked heterogeneity in scores, ranging from the level of junior high students to the level of moral philosophers. This variability poses difficulty for those who plan educational courses in ethics, but is not an insurmountable difficulty.

Conversion reactions in pediatric athletes.

We report five children and adolescents who displayed a conversion reaction in response to stresses induced by athletic competition. Failure to make proper diagnosis led to additional physician referral, needless testing, rehabilitation, or orthotic management. Patients are characterized as high achievers who are frequently younger than peers in the sport. Conversation between child and physician identified the source of conflict in four patients. Physical therapy helps resolve symptoms associated with an acute episode and facilitates transition into psychotherapy. Psychotherapy is recommended only for patients with persistent maladaptive behavior.

The epidemiology of "schooliosis".

Summary: Questionnaires submitted to children subsequent to school screening for scoliosis reveal that 13% of respondents recall being referred to a physician. This rate is considerably higher than the 3% referral rate reported by school health officials. The discrepancy points to misperceptions by students and their parents as a likely cause perceptions by students and their parents as a likely cause of “schooliosis,” a condition which brings a flood of normal children into the offices of orthopaedists and pediatricians. Correcting possible communications problems, rather than blaming the screening program, should ease the over‐referral phenomenon and allow screening to continue at its present efficient levels.

Progression of unsupported curves in adolescent idiopathic scoliosis

Stability of three types of double scoliotic curves of 10 - 40 ° was analyzed using a biomechanical model: double primary (Type I), primary thoracic with compensatory lumbar (Type II), and primary lumbar with compensatory thoracic (Type III). The load-carrying capacity of each curve was analyzed as a function of magnitude of the curve, its location and flexibility. Curve magnitude was found to be the most influential parameter governing the stability of a scoliotic curve up to 30°. Results suggest that in evaluating curves of comparable magnitudes, Type I and II curves are more likely to progress and, therefore, should be braced at an earlier stage than Type III curves.

Moral decisions regarding innovation. The case method.

Little consideration has been given to the ethics of innovation in surgery despite the major role of innovation in orthopaedic practice. We propose that a series of cases of increasing ethical complexity may serve as a classification system and assist orthopaedists in thinking about the ethical dimensions of other cases.

The ethics of the introduction of gene therapy into orthopaedic practice.

Gene therapy has the potential to transform musculoskeletal medicine. Orthopaedists have been ready to incorporate innovations in medicine and engineering into their surgical practice, frequently before having full information. There is no reason to doubt the rapid acceptance of gene therapy by the orthopaedic profession. Caution is needed in incorporating gene therapy into standard practice because of the lack of knowledge and risks that are greater than for previous innovations.