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A Preliminary Investigation of Postoperative Molding to Improve the Result of Cranial Vault Remodeling

Higuera, Stephen MD; Hollier, Larry H. Jr MD; Stevens, Phillip M. CO, LO; Stal, Samuel MD

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JPO Journal of Prosthetics and Orthotics: October 2005 - Volume 17 - Issue 4 - p 125-128
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The value of helmet therapy in the treatment of dysmorphic cranial vaults has been well established.1–3 In cranial deformities secondary to positional head molding, the use of helmets to improve the flattened areas of the skull can be quite dramatic.3 However, this success is dependent on the rapidly growing brain pushing out the immature cranial vault in those areas allowed by the helmet.

More recently, helmets have been increasingly used after endoscopic cranial vault surgery.4,5 In this process, the fused suture is resected and a limited number of osteotomies performed. The patient is then placed immediately in a conforming helmet to help mold the surgically treated skull into the desired shape because no substantial reshaping is performed during surgery. When performed at a very early age, the results from this technique have been promising. However, very few authors have used helmets after surgery in patients who have undergone radical cranial vault remodeling, ostensibly because the addition of the helmet was deemed unnecessary once the osteotomized cranial vault had been shaped appropriately. The current article reviews a series of patients undergoing standard cranial vault remodeling for single suture synostosis via a coronal approach with frontal orbital advancement with cranial reshaping. All patients were placed into helmets immediately after surgery, with accurate documentation of skull shape recorded before and after treatment.

PATIENTS AND METHODS

Six patients underwent cranial remodeling with postoperative helmet therapy from 2003 to 2004. All patients had a diagnosis of nonsyndromic craniosynostosis. Two patients had metopic synostosis, two patients had left unilateral coronal synostosis, one had bilateral coronal synostosis, and one had a right unilateral coronal synostosis. The patients’ ages at the time of operation ranged from 5 months to 13 months. The patients were evaluated and measured by the same orthotist, and helmet therapy was begun 2 to 4 weeks after surgery. Measurements were recorded, and the cephalic index was calculated using the formula (head width / head length × 100). The cephalic index is a proportion of the width of the head to the length of the head. The cephalic indices were compared with the normative data described by Farkas.6,7 A cephalic index of 78% was used as the ideal value. Measurements were performed using a caliper and included cranial circumference, skull base, cranial vault, orbitotragal depth, head width, and head depth (Table 1). Patients had serial visits to the orthotist for measurements and adjustments at 3-week intervals, and helmet therapy lasted 4 to 6 months.

T1-7
Table 1:
Measurements recorded by the orthotist

Two to 4 weeks after surgery, a plaster mold was made by the orthotist. The plaster served as a template for the helmet (Figure 1). The helmet was made of 3/8″ co-polymer thermoplastic with an interface foam of ½″ closed cell pelite (Figure 2). During the orthotist follow-up visits, adjustments were made to relieve any areas of impingement. The helmet fit was closely monitored to ensure the treatment strategy was maintained. Gradual removal of the foam interface material allowed for these regular adjustments. Care was taken to ensure proper clearances of the patient’s ears and allowed the patient a reasonable visual field. The orthotist verified intimate contact of the helmet in areas where growth constraint was desired and sufficient clearance where corrective growth was desired. The family was instructed how to perform daily skin checks and other pertinent caregiver instructions. The helmet was kept on the patient for a total of 23 hours a day.

F1-7
Figure 1.:
A plaster mold is made 2–4 weeks after surgery, serving as a template for the helmet.
F2-7
Figure 2.:
Two views of the helmet.

RESULTS

All patients had an improved cephalic index compared with initial measurements taken after surgery (Table 2). In addition, all patients demonstrated an improvement in subjective skull contour when evaluated by the surgeon (Figures 3 and 4). No complications were attributed to the use of postoperative helmet therapy.

T2-7
Table 2:
Postoperative cranial indices (C.I.) before and after helmet therapy
F3-7
Figure 3.:
Preoperative (left) and postoperative (right) photographs after cranial vault remodeling.
F4-7
Figure 4.:
Skull contour after surgery (left) and after helmet therapy (right).

DISCUSSION

The efficacy of helmets in molding the immature cranial vault has been well established for the nonoperative treatment of nonsynostotic conditions.1–3 However, the success is largely dependent on beginning treatment in the first year of life, while the brain is rapidly growing. This concept has been extended to postoperative patients undergoing minimal vault surgery, usually secondary to early operation for sagittal synostosis or using endoscopic assistance.4,5 This is because typically little is done intraoperatively to reshape the cranium in these operations. Little has been written about the use of helmets after aggressive cranial vault remodeling with frontal orbital advancement.

This series evaluates just such a group of patients. As with any major craniofacial operation involving multiple osteotomies, the end result is dependent upon many variables. Among these is the viability of the repositioned bone segments. Depending upon the surrounding vascular supply and the size of the bone fragment, there is variable resorption of these grafts. In addition, despite the best surgical efforts, asymmetries persist after cranial vault remodeling.

Intuitively, providing a template for the remodeled skull to grow into should improve the results by preventing undue pressure on the recently remodeled skull and allowing the rapidly growing brain to push forward the reconstructed segments symmetrically. Promising results with this technique have been documented as have data supporting the use of postoperative cranial orthoses after endoscopic-assisted strip craniectomies. A recent survey9 revealed that at least 12 centers in the United States are using postoperative cranial orthoses after cranial vault remodeling.

Another benefit of postoperative helmet therapy concerns the patient’s family. Although the helmet is primarily constructed for molding and shaping of the skull, it can also provide the family with a “sense of security” regarding the recently remodeled skull fostering a positive and comfortable environment for the family and the patient during the postoperative course.

The results seen with this group of patients seem promising. Measurements taken after surgery and at the end of helmet treatment show remarkable improvement. All indices progress to the normative values in the patients evaluated. Unlike previous patients treated by our group, the asymmetries and irregularities were not seen with great frequency.

One of the most important issues to address in this evaluation is that of cost. Is this improvement in skull shape worth the added cost incurred by manufacturing of the helmet and regular visits to the orthotist and surgeon? To more thoroughly evaluate this, one would have to follow up patients treated with and without helmet molding and include the costs of secondary cranioplasty into the overall treatment cost. The average cost of postoperative helmet therapy is $2,500 to $4,000. This is substantially less than a second or subsequent cranial vault remodeling procedure, which can range up to $36,131, including a hospital stay and anesthesia. As helmet therapy in the postoperative patient becomes more popular, these data should be forthcoming.

REFERENCES

1. Teichgraeber JF, Seymour-Dempsey K, Baumgartner JE, et al. Molding helmet therapy in the treatment of brachycephaly and plagiocephaly. J Craniofac Surg 2004;15:118–123.
2. Littlefield TR, Beals SP, Manwaring KH, et al. Treatment of craniofacial asymmetry with dynamic orthotic cranioplasty. J Craniofac Surg 1998;9:11–19.
3. Kelly KM, Littlefield TR, Pomatto JK, et al. Importance of early recognition and treatment of deformational plagiocephaly with orthotic cranioplasty. Cleft Palate Craniofac J 1999;36:127–130.
4. Jimenez DF, Barone CM. Endoscopy-assisted wide-vertex crani-ectomy, ‘barrel-stave’ osteotomies, and postoperative helmet molding therapy in the early management of sagittal suture craniosynostosis. Neurosurg Focus 2000;9:1–6.
5. Jimenez DF, Barone CM, Cartwright CC, Baker L. Early management of craniosynostosis using endoscopic-assisted strip craniectomies and cranial orthotic molding therapy. Pediatrics 2002;1:97–104.
6. Farkas LG. Anthropometry of the Head and Face, 2nd ed. New York: Raven Press; 1994.
7. Farkas LG. Anthropometry of the Head and Face in Medicine. New York: Elsevier; 1981.
8. Persing JA, Nichter LS, Jane JA, Edgerton MT. External cranial vault molding after craniofacial surgery. Ann Plast Surg 1986;17(4):274–283.
9. Barringer WJ. The use of postoperative cranial orthoses in the management of craniosynostosis. J Prosthet Orthot 2004;16(4S):56–58.
Keywords:

cranial vault remodeling; craniosynostosis; postoperative helmet modeling

© 2005 American Academy of Orthotists & Prosthetists