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Biomedical subjects

M R Christofersen

Publications and source records attributed to M R Christofersen.

10 recordsLinked to original sources

Stenosing tenosynovitis and impingement of the peroneal tendons associated with hypertrophy of the peroneal tubercle.

We report three patients with lateral ankle and foot pain, with the diagnosis of stenosing tenosynovitis of the peroneus longus tendon associated with a markedly enlarged peroneal tubercle. Stenosing tenosynovitis of the peroneus longus tendon associated with an atraumatically enlarged peroneal tubercle has rarely been reported, and these reported cases were associated with an os peroneum. One of our patients had no demonstrable associated os peroneum but did have a bony tunnel enveloping the peroneus longus tendon. Our other two patients had an os peroneum, but were asymptomatic at the lateral outer border of the cuboid tunnel; one patient had involvement of the peroneus longus and brevis tendons.

Adult↗

Child abuse presenting as a thoracolumbar spinal fracture dislocation: a case report.

A child sustained a traumatic thoracolumbar spinal fracture--dislocation with cord compression. A court confirmed the diagnosis of child abuse. There was no history of trauma, and the diagnosis of child abuse was missed by the physicians who first saw the child. Spinal injuries in child abuse are uncommon. They may be symptomatic or asymptomatic, stable or unstable, or occur with or without bony changes on the x-rays. Injuries without a history of trauma may be overlooked if asymptomatic. Radiologic skeletal surveys in suspected abuse should include a minimum of two views of the spine even if the child has no symptoms referrable to the spine. Conversely, a traumatic cause should be considered whenever there is spinal cord injury without vertebral injury. Having a high index of suspicion for abuse while remembering that pediatric spinal injuries may occur in the context of normal x-rays will decrease the likelihood of missed diagnosis, repeated abuse, or complications from delayed immobilization of unstable injuries.

Child Abuse↗

Radiographic assessment of longitudinal growth of the rabbit femoral physes.

Using surgically implanted metal markers, serial radiographs of 17 immature femurs were evaluated for growth of the entire femur and of the distal femoral physis in rabbits 20 to 100 days of age. From these data the rate of longitudinal growth was plotted. The most rapid growth during the study period was from 20 to 40 days. Growth rates reached a plateau at 100 days of age. The increases in length for unit of time were compared for the entire femur and the distal physis. The distal physis was responsible for approximately 65-70% of the femoral growth for the study period. As an internal control of reproducibility of measurement, two means of determining distal femoral growth rates were compared. Their best fit curves proved to be almost identical. The model of evaluation of femoral growth is reproducible and can serve as a control against which variables in growth can be compared.

Animals↗

Three-dimensional computerized reconstruction of histologic serial sections for orthopedic research.

New programs in image processing and computer graphics can now render three-dimensional images from serial tissue slices. Although neuroanatomists have used these techniques most intensively, there are exciting applications of this methodology in orthopedic research and investigative embryology. Three-dimensional reconstructions of histologic sections from newborn clubfeet have been used to determine the rotational alignment of the hindfoot bones. Similar studies could be undertaken to improve understanding of the normal and pathologic perinatal development of the spine, hip, and hand.

Computer Graphics↗

Lyme arthritis in children. An orthopaedic perspective.

The cases of forty-three children with clinical and serological evidence of Lyme arthritis that was diagnosed between August 1983 and July 1985 were evaluated. The mean length of follow-up was twenty months, with a range of five to thirty months. All of the children lived in or had visited an area where the disease was known to be endemic. Arthritis was the presenting feature in more than half of the children, and half of the children had initially consulted an orthopaedic surgeon, none of whom made the correct diagnosis. Only twenty patients had a history of erythema chronicum migrans, the characteristic rash that precedes the arthritis, and for only nineteen children was there any recollection of having been bitten by a tick. Three patients had Bell palsy and one had a popliteal cyst in conjunction with the arthritis. All of the patients had oligoarticular involvement. The knee was involved in all but two patients. Recurrent attacks of synovitis were common. Effusion was the only radiographic abnormality that was observed, and it was found in thirty-two patients. The sedimentation rate was elevated in thirty of thirty-six patients. Immunofluorescent serology for Lyme disease, which is sensitive and specific, was uniformly positive. Of thirty-three patients who were treated with oral administration of penicillin or tetracycline alone, thirty-one responded, while two patients who had recurrent attacks of the disease responded to parenteral administration of antibiotics. The remaining ten patients responded to combinations of orally and parenterally administered antibiotics. Longer follow-up is needed to further document the apparently low rate of relapse after antibiotic therapy in this young population.

Adolescent↗

Circumferential growth plate fracture of the thoracolumbar spine from child abuse.

We report a unique fracture dislocation of the immature spine associated with child abuse and paraplegia. Because it occurs through growth centers, this fracture may be initially difficult to identify without special studies. The fracture patterns were isolated injuries in both children and were best shown with computer tomography. Mechanisms of injury are proposed and should suggest child abuse as a cause. Experience with these initial cases has suggested a treatment approach based on the mechanism of injury. There is no indirect means of reduction for this fracture and anterior open reduction is the treatment of choice.

Battered Child Syndrome↗

Excision and wire fixation of rigid myelomeningocele kyphosis.

The results of vertebral excision and wire fixation of rigid progressive congenital kyphotic curves in nine children with myelomeningocele are detailed. Mean follow-up was 5.4 years. Age at operation ranged from 3.3 to 13.3 years. An average correction of 41% of a mean curve of 127 degrees was achieved. In three patients, greater than 50% correction was lost by the time of follow-up. The goals of postural stability and skin ulceration control were achieved. Complications included cast ulcers, long bone fractures, and wire protrusion. An ideal age for surgery was not identified. For patients less than 12 years of age, the growth rate (kg/year) accelerated after operation.

Adolescent↗

Clubfoot analysis with three-dimensional computer modeling.

Which way are the bones rotated in a clubfoot? This question has long been debated by clubfoot surgeons. Opinions have been based on observations from surgery, radiographs, and autopsies. These methods all have pitfalls and are subject to misinterpretation. We used three-dimensional computer modeling to analyze histologic sections of a newborn clubfoot and a newborn normal foot. Relative to the bimalleolar axis in the axial plane, the normal talus demonstrated 5 degrees of internal rotation of its body and 25 degrees internal rotation of its neck. The clubfoot talus showed 14 degrees of external rotation of its body and 45 degrees of internal rotation of its neck. The calcaneus was externally rotated 5 degrees in the normal foot and internally rotated 22 degrees in the clubfoot.

Calcaneus↗

Acute osteomyelitis in children: a review of 116 cases.

We reviewed 116 cases of acute hematogenous osteomyelitis (AHO) (without septic joints) from 1979 to 1985 to establish current patterns of clinical presentation, modes of treatment, and success of therapy. We found that patients present early in the course of their disease, and many have no findings other than local tenderness and an elevated sedimentation rate. Sixty-four of the patients were treated nonoperatively. The average antibiotic treatment time was 2 weeks by intravenous (i.v.) administration followed by additional outpatient oral therapy for periods of up to 4 weeks. This treatment regimen applied specifically to acute osteomyelitis led to no known treatment failures.

Adolescent↗

Longitudinal growth from the proximal femoral growth centers in the rabbit.

We selectively ablated the proximal growth centers of the femur in 3-week-old white New Zealand rabbits to study the contribution of each physis to bone length. The results were compared with the normal growth pattern determined in our previously published study. Growth in 10 femora with ablated greater trochanteric apophyses was normal as was the rate of growth for the 11 femora in which the proximal physis and femoral head were excised. Following femoral head excision, growth of 10 greater trochanteric apophyses, transferred in situ with muscular pedicle, was delayed initially, then increased at a rate very different from the control trochanteric growth. On the basis of this animal study, we support substitution of the greater trochanteric apophysis for an injured femoral neck physis to provide growth in the length of the femur.

Animals↗