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Biomedical subjects

J A Persing

Publications and source records attributed to J A Persing.

At least 73 records · Page 4Linked to original sources

Cranial vault growth in craniosynostosis.

Skull growth after single suture closure was described in 1851 by Virchow, who noted that growth in the plane perpendicular to a fused suture was restricted. However, this observation failed to predict compensatory growth patterns that produce many of the deformities recognized as features of individual syndromes. The deformities resulting from premature closure of a coronal, sagittal, metopic, or lambdoid suture can be predicted on the basis of the following observations: 1) cranial vault bones that are prematurely fused secondary to single suture closure act as a single bone plate with decreased growth potential; 2) asymmetrical bone deposition occurs mainly at perimeter sutures, with increased bone deposition directed away from the bone plate; 3) sutures adjacent to the prematurely fused suture compensate in growth more than those sutures not contiguous with the closed suture; and 4) enhanced symmetrical bone deposition occurs along both sides of a non-perimeter suture that is a continuation of the prematurely closed suture. These observations regarding growth in craniosynostosis are illustrated with clinical material in this report.

Cranial Sutures↗

Vacuum-stiffened beanbag for cranial remodeling procedures in modified prone position. Technical note.

In surgical correction of multiple-suture synostosis, placing the patient in the modified prone position permits access to the calvarium from the supraorbital ridge to the occipital bone below the transverse sinus. The modified prone position thereby enables surgeons to perform cranial remodeling procedures at one stage under direct vision, contributing to improved surgical results. However, no satisfactory head-frame for this position has been available. The authors report the successful use of a vinyl bag filled with styrofoam beads to achieve the modified prone position in young children. This widely available, economical device provides a safe, reliable means of positioning the child's head for cranial remodeling procedures.

Child, Preschool↗

Hemimegalencephaly, hemifacial hypertrophy and intracranial lipoma: a variant of neurofibromatosis.

A case is presented of a 30-year-old, mentally retarded and epileptic patient, with a progressive hemifacial hypertrophy since birth. Repeated biopsies revealed the neurofibromatous nature of her facial lesion. Autopsy also revealed an ipsilateral hemimegalencephaly, as well as meningeal lipomas and osteomas. This combination of lesions represents an unusual variant within the spectrum of neurofibromatosis.

Adult↗

Nerve compression syndromes of the lower extremity.

Nerve compression syndromes of the lower extremity present a challenge in differential diagnosis. Compression of the common peroneal nerve occurs relatively frequently; compression of the sciatic nerve occurs infrequently. The pattern of weakness helps distinguish lumbar root entrapment from peripheral compression syndromes. Compression syndromes must also be differentiated from diabetic, alcoholic or vasculitic neuropathy. Recovery correlates with the degree and duration of nerve injury. Thus, early diagnosis and treatment are important.

Diagnosis, Differential↗

Tarsal tunnel syndrome caused by sciatic nerve schwannoma.

The clinical presentation and radiological findings of a patient with a sciatic nerve schwannoma in whom signs and symptoms of a tarsal tunnel syndrome developed are described. Additionally, this article emphasizes that the radiological appearance of an enlarged nerve distant to the tumor site does not necessarily imply either malignancy or plexiform neurofibromatous infiltration of the nerve.

Adult↗

Lambdoid synostosis: surgical considerations.

Premature closure of the lambdoid suture may result in abnormalities in skull shape not only in the parieto-occipital region, but also in the frontal region and at the vertex of the skull. Although most of these abnormalities are mild, some constitute significant abnormalities in shape and therefore require specific surgical correction. In this report, we describe our approach from five patients we have treated and followed for 6 to 24 months with abnormalities characteristic of unilateral and bilateral lambdoid synostosis. We describe our approach to the simultaneous correction of frontal, occipital, and abnormal vertical height skeletal abnormalities in one operative procedure. To date, no negative neurologic sequelae have resulted from this operative approach, but significant improvement in skull form has been appreciated.

Craniosynostoses↗

Restricted growth at the frontonasal suture: alterations in craniofacial growth in rabbits.

Apposition of bone at the sutural margin is generally thought to be a compensatory adjustment to growing soft-tissue organs such as the brain or eyes within the skull. The frontonasal suture which is located at the interface between the cranial and facial skeletons is a site of extremely active growth in the young rabbit. Recently, we showed that premature closure of a cranial suture, the coronal suture, can alter the growth not only at the adjacent frontonasal suture but also of the basicranium and midface. This study examines the effects of restricted growth at the frontonasal suture on both growth at adjacent cranial sutures and linear growth of the basicranium and midface. Thirty newborn New Zealand White rabbits were subdivided into experimental and sham-treated groups of equal size and distribution for sex and birth weight. At 9 days of age, the frontonasal suture of each experimental animal was immobilized by bilateral application of methyl-cyanoacrylate adhesive across the frontonasal suture. Growth and morphometric changes were monitored by radiocephalometric methods through 120 days of age by bilateral implantation of radiopague markers on each side of frontonasal, coronal, and anterior lambdoid sutures. Results indicate that restricted growth at the frontonasal suture results not only in a significant shortening of the midface but also in significant decreases in growth at the coronal and internasal sutures. Growth at the interfrontal and sagittal sutures is increased. Furthermore, growth at the anterior portion of the nasal bones is significantly increased, thereby offsetting a portion of the decreased nasal bone length resulting from frontonasal restriction.

Animals↗

Barrel stave osteotomy for correction of turribrachycephaly craniosynostosis deformity.

The "barrel-stave" osteotomy procedure addresses the characteristic excessive height and reduced anteroposterior projection of the turribrachycephalic skull in one operative procedure. Four quadrant craniectomies are followed by barrel stave-like osteotomies in the parietooccipital region. The parietooccipital bone undergoing osteotomy is displaced posteriorly, thereby opening up the posterior fossa and effectively increasing the potential volume of the cranial vault. This increased capacity allows for notable reduction in skull height and reshaping of the skull along the anteroposterior axis.

Child↗

Late surgical treatment of unilateral coronal synostosis using methyl methacrylate.

Three techniques combining the shaping of calvarial and facial bone with onlay of methyl methacrylate are presented for use in the late treatment of unilateral coronal synostosis deformities. The procedures described are suggested as possible alternatives to extensive bone repositioning procedures. They have the advantage of being quicker and are therefore potentially safer operations. Acrylic is malleable and does not resorb; thus, permanent superior esthetic results may be achieved. The two most serious risks when using this technique are infection and limitation of growth. The risk of infection may be reduced by attaching the acrylic implant securely to surrounding bone, under sterile conditions, beneath well-vascularized skin. Growth limitation may be obviated by not placing acrylic across sutures in children with enlarging skulls.

Adult↗

External cranial vault molding after craniofacial surgery.

Many congenital cranial vault deformities are only incompletely corrected by currently available surgical techniques. The supplementary use of external cranial vault molding devices after these surgical techniques, however, has resulted in consistently improved cranial vault from over what could be achieved by operation alone. These devices are inexpensive, easily individualized to abnormal skull shapes, and well tolerated by young patients.

Abnormalities, Multiple↗

Experimental unilateral coronal synostosis in rabbits.

Immobilization of the coronal suture was produced unilaterally in 9-day-old rabbits to determine its effect on subsequent craniofacial development. The suture was immobilized unilaterally by the topical application of methylcyanoacrylate adhesive. Subsequent growth effects on the cranial vault, base, and facial skeleton were assessed by serial radiographic cephalometry. Unilateral coronal suture immobilization resulted in significantly decreased bone growth at the coronal suture (mean 0.95 mm +/- 0.35 SE) when compared to sham-treated control animals (mean 5.06 mm +/- 0.20 SE). Frontonasal suture bone growth contralateral to the immobilized half of the coronal suture, however, was significantly increased. The anterior cranial base became significantly shortened, and orbital asymmetry developed. The pattern of induced abnormalities simulates unilateral coronal synostosis in humans.

Animals↗

Skull expansion in experimental craniosynostosis.

Bilateral coronal suture immobilization was performed in 9-day-old rabbits to simulate the brachycephaly deformity characteristic of coronal synostosis. Growth abnormalities were documented by serial radiographic cephalometry. A "corrective" linear craniectomy procedure was performed on the rabbits with an immobilized coronal suture at 60 days of age. The degree of amelioration of the induced abnormalities by the surgery in these animals was compared with a similar group of animals that had the same surgery plus supplemental implantation of a spring expansion device at the coronal suture craniectomy site. The mean marker separation at the coronal suture was significantly greater (5.61 mm +/- 0.52 SE versus 2.53 mm +/- 0.38 SE; p less than 0.05) following spring expander implantation than with linear craniectomy alone. Similarly, induced anterior cranial base shortening and distortion of craniofacial cephalometrics were more significantly improved by the additional use of the spring expansion device.

Animals↗

Use of the Philadelphia collar as an alternative to the halo vest in patients with C-2, C-3 fractures.

We analyzed retrospectively 27 individuals with C-2, C-3 fractures, 8 of whom were treated with a Philadelphia collar rather than the more commonly used halo vest. Successful fusion without neurological deficit occurred in all cases whether treatment was by Philadelphia collar (n = 8), halo apparatus (n = 16), or prolonged bed rest (n = 3). There was an increase in subluxation in 3 patients in both the Philadelphia collar group and the halo apparatus group. However, 1 of the 3 in the collar group was uncooperative and discarded his collar during treatment. If he is excluded, the subluxation rate in the Philadelphia collar group is 27%; the rate in the halo group is 19%. The Philadelphia collar seems to be an acceptable means of stabilizing the neck in C-2, C-3 fractures, but one must consider the degree of cervical movement in the collar (as detected by dynamic x-ray films), patient reliability, and patient age. The presence of subluxation did not preclude successful fusion in either the Philadelphia collar or the halo vest groups.

Adolescent↗

Surgical approaches for the correction of metopic synostosis.

Premature closure of the metopic suture results in a deformity ranging from a minor variation to a severe cosmetic deformity. The three principal abnormalities comprising metopic synostosis are trigonocephaly secondary to the restriction of growth of both frontal bones, deficient lateral supraorbital rims, and hypotelorism. Seventeen of 18 patients evaluated for metopic synostosis had surgical correction of their anomalies. For a minor degree of prominence at the metopic suture, a bicoronal flap followed by shaping at the suture with a shaping burr was sufficient and yielded favorable cosmetic results. A more extensive procedure for cosmetic resolution of trigonocephaly and hypotelorism was required for those patients with more pronounced deformities. In patients with moderate to severe metopic synostosis, the following procedures were important in achieving excellent cosmetic results: a bicoronal subgaleal flap down to the supraorbital rims with preservation of continuity of pericranium with an intact periorbita; bifrontal craniotomy with complete removal of the metopic suture; dural plication in midline to achieve an immediate aesthetically pleasing contour; removal or remodeling of the supraorbital rims and nasion with replacement of the remodeled frontal bone anteriorly in order to rebuild the orbital rim and release the supraorbital bar from the anterior cranial base; and securement of the bifrontal bones anteriorly and laterally, but not posteriorly, to allow further anterior and lateral displacement of the supralateral orbital margin.

Craniosynostoses↗

External cranioplasty: historical perspectives.

Selective external cranial vault remodeling has been practiced since antiquity. The variations, methods, and desired results of external cranioplasty are as pervasive as the practice is old.

Aged↗

The surgical treatment of fibrous dysplasia. With emphasis on recent contributions from cranio-maxillo-facial surgery.

Fibrous dysplasia is a congenital, metabolic, nonfamilial disturbance that occurs in one or more bones, at times in association with skin pigmentations or endocrine abnormalities. The authors report on a large personal series of 23 patients with fibrous dysplasia involving the craniofacial skeleton. The etiology, clinical findings, pathology, and differential diagnosis of this condition are reviewed and a working hypothesis is offered for the pathophysiology of this disorder. Approximately one-third of patients with fibrous dysplasia have involvement of the cranial or facial bones. The authors describe how new techniques in craniofacial surgery have opened up additional options for this group of patients. Deformity, diplopia, proptosis, sinus infection, deafness, and loss of vision, are some of the clinical features that may require early surgical management. Evidence is given to support more complete resection of bony lesions with immediate reconstruction by several techniques. The removal, remodeling, and replacement of the dysplastic bone is advanced as a promising new method for the management of these complex problems. Successful use of this technique in four patients is reported. In a separate group of patients, continuing good experience is reported with cranio-orbital reconstruction by means of large methyl-methacrylate implants. Both of these surgical approaches eliminate donor site morbidity that results from the grafting of large amounts of autogenous bone. Both techniques also avoid the problems associated with postoperative absorption of bone grafting. Several patients are reported in whom serious disturbances in visual function appear to have been prevented or reversed by early treatment. Factors leading to malignant change in patients with fibrous dysplasia are reviewed.

Adolescent↗