Outcome analysis for correction of single suture craniosynostosis using resorbable fixation

A retrospective review was performed on 63 patients at Childrens Healthcare of Atlanta at Scottish Rite who underwent correction of single-suture craniosynostosis using a resorbable fixation system. Included in the series were 24 patients with metopic synostosis, 15 with sagittal synostosis, and 24 with unicoronal synostosis. The average age at operation was 22.7 months (range: 2.8 months-18 years), and mean follow-up time was 30.7 months (range: 7.1-10 years). Reoperation equal to or exceeding the magnitude of the original procedure occurred in 4.76% of the patients. This was comparable to the reoperation rate observed at our institution using traditional fixation systems. Minor complications related to the use of resorbable plates were also identified, and the final outcome for single-suture synostosis was favorable. Results suggest that resorbable plates and screws are as effective as titanium-based systems in the treatment of single-suture synostosis.

Introduction by Topic Editors, Peter W. Carmel, M.D., and James M. Drake, M.D

Shunt systems with differential pressure valves are prone to the complications of overdrainage. A programmable valve permits adjustment of the opening pressure of the valve. In this paper the authors report the incidence of subdural fluid collections in a randomized trial of programmable compared with conventional valves, and they describe methodologies used in management of this complication. A multiinstitutional, prospective, randomized trial of the Codman Hakim programmable valve and conventional fixed-pressure valves was undertaken. Two classes were defined: "new" and "replacement" valves. Randomization of the type of valve in each group was performed at each study site. Clinical and radiological studies were required at fixed intervals over a 104-week period. All complications were reported. The experimental valves were required to be reprogrammed after magnetic resonance imaging studies, but all other decisions regarding pressure setting were left to each investigator. Three hundred seventy-seven patients were randomized; 194 were treated with a programmable valve and 183 with a fixed-pressure valve. The two groups were statistically similar in demographic composition, as were the "new" and "replacement" categories. The investigators made 540 valve pressure changes (five per patient; range one-41 changes). More than half of the reprogramming adjustments were made in the first 3 months postplacement; 70% were made within 6 months. More than half of all reprogramming adjustments were required in a group of 30 patients. Four treatment modalities were observed: 1) 30% of the fluid collections resolved spontaneously (25% in the patients with programmable valves and 36.3% in those with conventional valves) and were largely found to be hygromas in infants and children; 2) four subdural fluid collections were unresolved and under observation; 3) the subdural hematoma was drained and the shunt removed (in 8.3% of patients with the programmable valve and 36.3% of those with the control valve); 4) the pressure of programmable valve was raised in 58% of patients (seven of 12), and this increase in opening pressure was a feature used by investigators to affect treatment. There was no significant difference in the incidence of subdural fluid collections between the programmable and fixed-pressure valve treatment groups. The programmable feature provided a considerable advantage in treatment when subdural collections occurred.

The use of hydroxyapatite cement in secondary craniofacial reconstruction

Sixty-one patients underwent secondary craniofacial reconstruction for contour defects using hydroxyapatite cement over a 3-year period (20-month mean follow-up). There were 56 children, aged 2.2 to 18 years (mean, 10.7 years), 21 boys and 35 girls. This is the first series of pediatric patients in whom the use of hydroxyapatite cement has been reported. There were five adults aged 21 to 46 years (mean, 32 years), 3 men and 2 women. Thirty-one patients underwent reconstruction for secondary orbitocranial defects after surgery for synostosis, 7 after surgery for hypertelorism, 10 for posttraumatic skull defects, and 13 for a variety of other facial skeletal defects. There were seven complications (11 percent), ranging from a retained drain to postoperative seromas, all of which required reoperation without loss of the contour correction. All of the complications occurred in the first 18 months of our study. There has been excellent retention of implant volume with no recurrence of contour defects to date. We have not found any visible evidence of interference with craniofacial growth over the study period. We conclude that hydroxyapatite cement is a versatile and safe biomaterial when used for the correction of secondary craniofacial contour defects in children and adults. The coupling of antibiotics with this biomaterial may have applications in the treatment of osteomyelitis.

Monobloc and facial bipartition distraction with internal devices

Distraction osteogenesis (DO) permits gradual lengthening of the craniofacial skeleton. With the advent of new internal devices, monobloc (M) and facial bipartition (FB) DO are feasible. The rationale behind M and FB distraction is (1) gradual advancement of the M segment is not associated with a substantial retrofrontal dead space; (2) because 5 to 7 days elapse prior to distraction, the nasofrontal opening, in theory, is allowed to remucosalize; (3) gradual expansion of the soft tissues takes advantage of skin creep, potentially limiting relapse; (4) the procedure appears to be less invasive with decreased blood loss and operative time, enabling its use in infants; (5) overdistraction may eliminate or reduce the frequency of subsequent procedures; and (6) the procedure may be combined with FB and skull vault remodeling to provide excellent results in more complex craniofacial dysostosis problems. Five children underwent M advancement (N = 3) and M with FB (N = 2) at 9 months to 5 years of age to correct functional abnormalities such as corneal exposure, increased intracranial pressure, and apnea, as well as severe craniofacial disfigurement. Each patient underwent from 22 to 30 mm of distraction with the Modular Internal Distraction (MID) system, developed by the first author (SRC). There was one infection late in the series along the DO cable track. There were no cases of epidural abscess. In conclusion, MDO, with and without FB, appears to be a safe and effective technique for transcranial frontofacial advancement. The morbidity of the procedure appears to be less than that of conventional M advancement.

Spinal intradural cerebellar ectopia

An ectopic cerebellum, as in Chiari malformations and ectopic cerebellar dysplastic tissue, is a common finding; however, the presence of an organized ectopic cerebellum is exceedingly rare. We describe the MR imaging, surgical, and histologic appearance of an intraspinal ectopic cerebellum in an infant.

Geniculate ganglion meningioma

Primary ectopic meningiomas are rare, but may be seen in the head and neck region. The temporal bone and its neural foramen are rarely the site of a primary meningioma. This report describes the CT and MRI appearance of an ectopic meningioma arising at the anatomic location of the geniculate ganglion, and discusses the differential diagnosis as well as the possible origin of the tumor.

The use of porous granular hydroxyapatite in secondary orbitocranial reconstruction

The search for the ideal bone-graft substitute has been the focus of many research and clinical studies. Hydroxyapatite is one such material that combines osseointegration with maintenance of implant volume and excellent durability. We present our experience in 29 patients ranging in age from 3 to 22 years (mean age 10.5 years) who underwent secondary orbitocranial reconstruction of large contour defects utilizing porous granular hydroxyapatite. Follow-up ranges from 6 to 72 months (mean 30 months). Indications for secondary surgery included residual bony contour defects of the frontal bone, temporal areas, and superior orbital rims that were present 12 months or more after initial surgery. There was one infection secondary to a chronic seroma necessitating removal of the porous hydroxyapatite, and one patient required revision for underfilling and another for overfilling. Excellent permanent contour improvement was obtained with a smooth skin surface in the remainder of our patients. The contour corrections have been long lasting, without evidence of porous hydroxyapatite resorption or migration.

A longitudinal, statistical study of reoperation rates in craniosynostosis

A prospective, statistical study of reoperation rates was done in the treatment of 167 consecutive children with nonsyndromic and syndromic craniosynostosis over a 6-year period at Scottish Rite Children's Medical Center in Atlanta, Georgia. Mean length of follow-up was 2.8 years, with a range of 3 months to 6 years. Reoperation equal to or exceeding the magnitude of the original procedure occurred in 7 percent of cases. Multiple regression analysis revealed several factors associated with reoperation: Females and children with syndromic synostoses were more likely to require reoperation. Total reoperation rates for syndromic and nonsyndromic synostoses were 27.3 and 5.9 percent, respectively. Age at initial surgery, length of operation, and estimated blood loss did not predict a higher reoperation rate.

Frontal basilar trauma: classification and treatment

We report our experience with 14 consecutive cases of frontal basilar trauma occurring in children and adolescents aged 18 months to 18 years (mean 9.5 years). Brain parenchymal injury resulting in functional deficit occurred in 5 patients (36 percent), 2 patients suffered bilateral blindness, and 1 suffered unilateral loss of vision. A classification system and treatment algorithm based on the clinical fracture pattern seen by computed tomography are introduced. Type I, central, is confined to the upper nasoethmoidal complex, central frontal bone, and medial third of the superior orbital rims. Type II, unilateral, involves the entire supraorbital rim and the upper lateral orbital wall, extending into the squamosa of the temporal bone and ipsilateral frontal bone. Type III, bilateral, involves fractures of the upper nasal ethmoidal complex, bilateral supraorbital and upper lateral orbital wall fractures, and bilateral frontal bone fractures. This classification was utilized to plan elective orbital and cranial osteotomies, similar to those used for frontal orbital advancement at the time of acute fracture repair. Frontal orbital osteotomies were used to access the anterior cranial fossa, orbital apices, and nasofrontal ducts and to obtain an intact bony template for side-table reassembly of the fracture fragments. There was no significant operative morbidity, one late cerebrospinal fluid leak, and no infections. Reoperation was necessary in four patients (29 percent) for aesthetic indications.

Turribrachycephaly: a technical note

We describe a technique for early correction of the so-called towering skull deformity, or turribrachycephaly. The technique makes use of the natural elasticity and plasticity of cranial bone, and it is best applied during the first year of life. Surgery consist of routine exposure of the cranial bone via a coronal incision. The frontal bone flap is elevated and removed. On either side, a bony osteotomy is then made, commencing low down in the temporal region and running posteriorly and superiorly toward the occiput. This approach leaves a superior bone flap, which may be left attached to the occipital bone via a flexible posterior hinge region, or completely detached by continuing the osteotomy across the midline. After the osteotomy, the bone flap is elevated up to the sagittal sinus on either side of the midline. The bone flap is not removed, but pushed down, compressing the brain along the craniocaudal axis. The lateral edge of the flap overlaps the temporal bone, and it can be fixed in the desired position by means of simple positional screws or Vicryl sutures. A standard fronto-orbital advancement is performed prior to lowering the skull vault, which permits the brain to be moved down and forward, filling the dead space in the anterior cranial fossa. The frontal bone flap is then shaped appropriately and fixed by means of plates and screws to the advanced fronto-orbital bar. Posteriorly, the frontal lobe is left "floating." To date, we have performed this technique on 5 patients, and we find it both faster and simpler than other techniques. Short-term results in terms of cranial shape are good. In older infants (> 2 years of age), this technique may not prove useful because of the loss of the loss of plasticity of the bone.