Titanium mesh and hydroxyapatite cement cranioplasty: a report of 20 cases

Hydroxyapatite cement in pediatric craniofacial reconstruction

The gold standard for closing small cranial defects is autogenous bone: iliac crest, rib, or split calvarial grafts. Autogenous grafts result in donor site morbidity, increased operative time, blood loss, and additional cost, and they are limited in quantity. Hydroxyapatite cements are alternative bone substitutes that eliminate these restrictions. Although the use of hydroxyapatite is well accepted in completely developed crania, its use in the growing pediatric skull is limited. The purpose of the current study was to address the safety and long-term efficacy of this bone substitute for the repair of craniofacial bone defects in the growing pediatric skull. Safety is measured dually by resistance of bone substitute to infection and its tolerability by lack of a foreign body reaction. Efficacy is evaluated as structural skull integrity, volume stability with time, aesthetic quality, and most importantly, the ability to integrate adequately into a growing cranium without subsequent deformity or complications. This is a retrospective review of all pediatric patients at the authors' institution who underwent reconstruction of cranial defects using hydroxyapatite cement between May 1997 and March 2001. Eight patients who underwent 11 operations between the ages of 25 and 100 months (mean, 55 months) were followed up between 23 and 72 months (mean, 38 months). No mortalities or significant morbidities were encountered in the study population. It has been the authors' experience that hydroxyapatite cement is both biocompatible and resistant to infection when used in sites not contiguous with sinus mucosa; and that it is a good alternative to autogenous bone in pediatric craniofacial reconstruction.

Cranioplasty in children

OBJECTIVE

The objective was to assess the outcome and complications associated with different cranioplasty implant materials in children.

MATERIALS AND METHODS

A retrospective review was conducted of 28 consecutive cranioplasties carried out on 24 children between 1994 and 2001 (age range, 9 months to 15 years; minimum follow-up 18 months). The indications were: defect from previous craniectomy for trauma, tumour, infection or evacuation of haematoma (n=21), intradiploic dermoid cysts (n=2), growing fractures (n=4) and residual bony defect following craniofacial reconstruction (n=1). The materials used were: patient's craniectomised bone flap (n=16), split calvarial graft (n=8), acrylic (n=3) and titanium (n=1). All patients were assessed for bony fixation, cosmesis, wound healing and flap infection.

RESULTS

There was no mortality and 18% morbidity (n=5: 3 infected flaps, 1 sterile wound dehiscence and 1 sterile wound discharge; overall infection rate 10%). Out of the 14 patients who had their own craniectomised bone flaps implanted initially, 3 became infected (2 in patients with bilateral defects) necessitating flap removal. Two of these were successfully re-implanted. No donor or recipient bone flap complications were seen in the 8 split calvarial grafts, wound discharge was seen in 1, requiring wound toilet. No complications were seen with acrylic or titanium cranioplasties.

CONCLUSION

In this series, the use of the patients' own craniectomised flap had a low infection rate, and was mainly seen in patients who had bilateral flaps re-implanted soon after removal. There were no complications arising from the use of split calvarial and allograft material. Use of autologous implant material should be preferred whenever possible due to obvious resource and biological advantages, and can even be re-implanted if infected.

Clinical applications of Norian SRS (calcium phosphate cement) in craniofacial reconstruction in children: our experience at Hospital La Paz since 2001

PURPOSE

The reconstructive surgeon has been searching for an ideal material to use in the reconstruction of craniofacial deformities. Although bone graft presents most of the ideal properties, its limited availability and donor-site morbidity makes its use compromised in some patients, especially in pediatric patients. In the search of this ideal material, calcium phosphate cements have shown promising results in patients with craniofacial deformities, because of its unlimited availability, avoidance of donor-site morbidity, and long-term maintenance.

MATERIALS AND METHODS

We report our experience at the Pediatric Division of Maxillofacial Surgery Department, Hospital La Paz, Madrid, since 2001, in the use of Norian SRS (calcium phosphate cement; Norian, Cupertino, CA) for the treatment of secondary craniofacial deformities. Clinical charts are retrospectively reviewed, paying attention to gender, age, pathologic conditions, previous surgeries, and the clinical applications of this kind of calcium phosphate cement. Complications are also reviewed.

RESULTS

Five patients have been treated for different craniofacial malformations, using Norian SRS as a part of the surgical procedure. The main indication was frontal and cranial irregularities. Temporal hollowing was also reconstructed with the calcium phosphate cement. All patients, except for 1, recuperated successfully. One patient suffered a wound dehiscence with subsequent infection of the material.

CONCLUSION

Norian SRS offers craniofacial surgeons an option in the treatment of pediatric patients with diverse craniofacial malformations, although special attention must be paid to the risk of infections in selected patients.

Reconstruction of skull bone defects using the hydroxyapatite cement with calvarial split transplants

PURPOSE

We sought to present a new method for primary reconstruction of traumatic or tumor calvarial defects.

PATIENTS AND METHODS

Forty-one patients underwent reconstruction of calvarial bone defects between October 1998 and December 2001. Among them were 19 patients who needed reconstruction of the calvaria due to traumatic bone loss. Five of these trauma cases had insufficient primary reconstruction of the calvaria. Tumor resection caused calvarial defects in 22 patients. For primary reconstruction of the skull bone defects, calvarial split grafts were used to cover the defect as accurately as possible. The monocortical layers of the calvaria were fixed with titanium miniplates. Irregular defects surrounding the transplanted regions were filled with hydroxyapatite cement. In one case of posttraumatic bone loss, hydroxyapatite cement alone was sufficient to reconstruct the defect.

RESULTS

The follow-up of each patient was at least 6 months; the longest period was 38 months. Evaluated clinical and radiologic results are stable, showing no measurable side effects.

CONCLUSION

Hydroxyapatite cement alone or in combination with calvarial split grafts gave clinically and aesthetically stable results in the reconstruction of skull bone defects. The cement can be used for many reconstruction possibilities in craniofacial surgery.

Orbitozygomatic Resection of Meningiomas of the Orbit

OBJECTIVE

To review our experience with the surgical treatment of orbital meningiomas.

METHODS

A retrospective review of all patients presenting to the author for treatment of orbital meningiomas over a 5 year period with a minimum of 1 year follow-up were included in this review. Demographic data, surgical approaches, and recurrence rates were documented.

RESULTS

A total of seven patients were treated for this condition. Complete surgical resection was achieved with the outlined technique in 71% of the patients, and gross tumor removal was achieved in the remaining 29% of patients. This latter group received postoperative gamma-knife treatment, and only a single patient has evidence of persistent disease that is nonprogressive at 3-year follow-up.

CONCLUSIONS

Meningioma of the orbit, whether primary (ectopic) or secondary. should be treated as at other sites with complete surgical excision if possible. Gamma knife or intensity modulated radiotherapy may be useful for residual microscopic disease. Surgical clearance is facilitated with the broad field exposure afforded by the orbitozygomatic approach outlined in the article, with particular attention directed at positive identification of key landmarks particularly in retro-orbital and cavernous sinus extension.

Reconstrucción craneal mediante malla de titanio y cemento de apatita carbonatada

We report the case of a 45 year old patient who was affected by an infectious disease of the temporal bone, after the surgical treatment of a meningioma in the greater sphenoid wing. This infection healed after the resection of the craniotomy flap. The remaining bone defect was reconstructed using a titanium mesh covered by hydroxyapatite cement (Norian). The result was excellent due to the strength of the titanium mesh and the volume and contour offered by the hydroxyapatite cement.

Temporal bone chondroblastomas

OBJECTIVES

To review temporal bone chondroblastomas in regards to their presentation, radiographic findings, histopathology, and treatment.Study design Case report and literature review.

METHODS

A case report of a 38-year-old man is reviewed who presented with left-sided mixed hearing loss, otalgia, otorrhea, and a left external auditory canal mass. A computed tomography scan revealed a 6-cm mass involving the petrous and squamous portions of the left temporal bone.

CONCLUSIONS

Temporal bone chondroblastomas are extremely rare osseous tumors with only 35 cases previously reported in the literature. Presenting symptomatology and pathology may be confused with more common lesions seen in the temporal bone. Diagnostic radiology, including computed tomography and/or magnetic resonance imaging, as well as immunohistochemical staining with S-100 protein may assist in making the diagnosis. Treatment is complete surgical excision with preservation of vital neurovascular structures.

Lipotransfer as an adjunct in head and neck reconstruction

OBJECTIVES

To present our technique of lipotransfer and to evaluate a single center's experience in the use of lipotransfer as an adjunct to head and neck reconstruction.

STUDY DESIGN

A retrospective review of all patients undergoing lipotransfer over a 5-year period by the senior author was undertaken. A total of 23 patients with a minimum follow-up of 1 year were available for analysis.

METHODS

Patient records were retrospectively reviewed to assess functional (in the case of palate augmentation) and esthetic outcomes.

RESULTS

Twenty-three patients undergoing lipotransfer as part of their reconstructive effort included (1) eight patients undergoing temporal fossa augmentation following temporalis muscle flap reconstruction for extirpative skull base surgery, (2) six patients undergoing facial defect augmentation following traumatic atrophy, (3) three patients undergoing palatal augmentation for correction of velopharyngeal insufficiency, and (4) six patients undergoing soft tissue augmentation following flap reconstruction of the face. Twenty of the 23 patients had excellent maintenance of graft volume. An adequately vascularized recipient bed appears to be an important factor in determining ultimate graft survival using our technique.

CONCLUSIONS

Lipotransfer of the head and neck represents a simple, effective adjunctive technique providing for large amounts of readily available, well-tolerated soft tissue filler material. Patient selection is important, specifically in regard to determining that there is adequate vascularity of the recipient bed.

Correction of large (>25 cm(2)) cranial defects with "reinforced" hydroxyapatite cement: technique and complications

INTRODUCTION

Hydroxyapatite cement is both biocompatible and osteoconductive, and it lacks significant toxic or immunogenic properties, making it an ideal substrate for the repair of cranial defects. However, with its putty-like composition, the repair of large cranial defects can be difficult because significant settling occurs as the cement hardens. We describe a technique in which we use hydroxyapatite cement, reinforced with tantalum mesh and titanium miniplates, for the repair of large (>25 cm(2)) cranial defects.

METHODS

After the margins of the cranioplasty are delineated, tantalum mesh is placed under the edges of the defect. Titanium miniplate single-hole bars are used to criss-cross the defect and are then secured to the surrounding bone with screws. The mesh is secured to the bars with 28-gauge stainless steel wire. Hydroxyapatite cement is applied in the defect and contoured appropriately.

RESULTS

We performed nine cranioplasties in eight patients ranging in age from 1.5 to 35 years (mean, 12.2 +/- 10.1 yr). The reasons for cranioplasty included cranial defect from prior trauma (n = 4), fibrous dysplasia (n = 2), infected bone flaps (n = 2), and tumor (n = 1). The cranioplasties ranged in size from 40 to 196 cm(2) (mean, 128.3 +/- 56.9 cm(2)). Follow-up ranged from 2 to 33 months (mean, 11.4 +/- 12.8 mo). Two cranioplasty constructs were removed at 1 and 3 months postoperatively owing to infection.

CONCLUSION

The use of hydroxyapatite cement with mesh and miniplates provides internal structural support and increased stability of the construct. Although this technique provides an excellent cosmetic result and no evidence to date of bony resorption, the rate of infection is alarmingly high in these large constructs.