Experience in the use of calvarial bone grafts in orbital reconstruction

Experience in the use of calvarial bone grafts in orbital reconstruction V.

Ilankovan,

I. T. Jackson

Department of Orul und Maxi&facial Swgery, Cutlrriesburt~ Hospital, Beursdw. Glasgow and Institute of Cruniofucial and Rrconstructhe Surgrry, 222.50 Providence Drive, S&e 703, Southfield, Ml, USA

SUMMARY. It is now accepted that calvarial bone is a suitable material for grafting in the facial area. From an extensive experience of using calvarial grafts in all regions of the face, the orbit has been singled out for this study. A group of 222 patients who underwent 279 calvarial grafts has bc!n examined. The majority of patients had post-traumatic or congenital deformities. I&constructions were performed with split-thickness cranial bone grafts and in some cases, the full-thickness of the cranium was used. The follow-up period ranged from 3 months to 4 years with an average of 20 months. After the first operation, 86% of the sample attained most occurring during satisfactory aesthetics on clinical examination. There were 13 (4.6%) complications, harvesting full-thickness calvarial grafts. From this study it is seen that orbital reconstruction can be performed using calvarial bone to obtain satisfactory aesthetic and functional results. This can be accomplished with minimal donor site morbiditv.

Stefano (1957). and Munro and Guyron (1981). The calvarium was used as a pcdicled flap independently by Muller and Koenig as early as 1800. Later. calvarial bone chips were recommended to repair cranial defects. The use of split-thickness skull grafts was described bv Lecene in 1920. Recently. Marchac (1078) and Tessicr (1982) have popularised the USC of full-thickness and split-thickness calvarial bone grafts in craniofacial reconstruction. The advantages of using calvarial bone as a graft material arc that the scar is hidden in a hair-bearing area, there is little or no postoperative pain and no obvious donor site deformity. It is possible to harvest grafts of varying size and contour. and the operation is performed through the coronal incision which is the usual approach to major orbital reconstruction. Greater volume survival and early rcvascularisation have been reported in membranous bone grafts by Zins and Whitaker (1983). In children abundant calvarial bone can be harvested compared to other sources. The postoperative difficulties in breathing or walking associated with rib and hip grafts arc eliminated. Calvarial bone can be used in five different ways to reconstruct the orbit. These arc full-thickness, split-thickness, bone dust, bone chips and shavings, and vasculariscd grafts. Frequently these types of bone graft are used in combination. The technique of harvesting calvarial bone has been described previously (Jackson et ~1.. 1986). Our experience in orbital reconstruction using calvarial bone grafts is presented.

INTRODUCTION The orbit is an irregular conical-shaped cavity formed from seven bones including the frontal. sphenoid, zygomatic, maxillary. ethmoid. lacrimal and palatine bones. The orbital margin is rectangular in shape with a rounded edge. The margin has an average height of 40 mm, a width of 35 mm and a depth of 45 to 50 mm. The average orbital volume is 30 ml with a bony orbital volume to globe volume ratio of 4.5:1 (Doxanas & Anderson. 1084). The orbital skeleton is often involved. in or deformed by congenital or acquired disorders. The patients may present with facial deformity or asymmetry, exophthalmos or enophthalmos. orbital dystopia, diplopia and ocular motility disorders. The repair and reconstruction involves aligning and/or re-shaping the bony walls by ostcotomics and augmentation by inlay or onlay techniques: and various procedures to cover defects using alloplastic or autogcnous materials. The commonly used autogenous materials arc bone and cartilage. The use of dura mater to reconstruct the orbital floor has been reported (Waite & Clanton. 198X). Cartilage has been used successfully to correct enophthalmos (Monasterio EI al.. 10X7), but in its fresh state has a tendency to warp and is unsatisfactory to reconstruct bony orbital walls. Iliac and rib bone grafts tend to resorb unpredictably and may result in contour irregularities. In addition donor site morbidity can be troublesome and the patient may have to remain in hospital for a long period. ilium was used to reconstruct the skull by Mauclairc in 1908 and was later popularised by Converse in 1054. Kib grafts were employed by Kappis in IO15 and re-introduced by Rallin (1921). l3rown (1028), Fagarasano (1937), Longacre and de

MA’I’I’HIAIS Patients 92

AND METHODS

undergoing

orbital

wall or margin

recon-

Expcriencc

struction. singly or as a part of a major reconstruction were selected for this study. Over the last 5 years, 222 patients underwent 279 bone grafts to reconstruct orbital deformities. Not only were two or more varieties of calvarial bone graft harvested in the

in the use of calvarial bone grafts in orbital reconstruction

same patient, but some patients needed grafting on more than one occasion. There were 140 males and 82 females, whose ages ranged from 3 months to 69 years. The follow-up period ranged from 3 months to 4 years with an average of 20 months. Ilospitalisation for over 75% of the patients was less than 48 h. The majority of the patients presented with post-traumatic deformity or congenital disorders (Table 1). Craniosynostosis, hypertclorism, TreachcrCollins syndrome and lateral facial dysplasia were among the most common craniofacial disorders (Fig. 1). Sixteen patients who presented with acute trauma needed immediate bone grafting for adequate correction. The areas most frequently grafted were the lateral wall and the orbital floor (Table 2). Access to the orbital walls and margins was obtained by a coronal or hcmicoronal flap. a lower blepharoplasty or a transconjunctival incision. The most common approach in this series was the coronal flap.

Table

I -

Classification

ACUIC

‘l‘rilum;l

of the deformity

10

Post-traumatic Deformity Congenital Disorders Tumour Facial Asymmetry

76 66 30 34 222

l‘otal

Table Lateral Floor

‘wm&d Fig. I - Reconstruction of the lateral wall of the right orbit using full thickness calvarial bone graft in a ir-month-old infant with hemifacial microxomia. Arrow shows the donor site of the hone graft.

93

2 -

Rccipicnt

Wall

sites of calvarial

Medial Wall Superior Rim Inferior Rim

94 131 21 22 4x 23

‘l‘otal

309

KOOf

bone grafts

pig. 2(A)- Three dimensional surface shading display showing the tlclcct in rhc maxilla and the orbital lloor after excision of il rCcUrrCll1 amelohlastoma. Also. it shows the surgical planning of the va%rlarisctl calvarial honeacq;tft to reconstruct the orbital floor. (H) Full thickness c;tlvarial hone pcdiclcd on the tcmporalis muscle to rcconstrucl the orbital rim and !k)or.

94

British Journal of Oral and Maxillofacial

Surgcr)

The majority of the bone harvested was of splitthickness type (Table 3). The graft was taken using a contouring bur and a straight osteotome as has been described previously (Jackson et al., 1986). Three of the 24 vasculariscd grafts were used to reconstruct defects after tumour resection and the rest were used in congenital deformity surgery. The vascularised bone pediclcd on the tcmporalis muscle (Figs 2A & 13) or the superficial temporal vessels and galea (Fig. 3) was sometimes raised with the help of The surgical procedure was that a neurosurgeon. described by Bite et al. (1987). Ninety one grafts were used as onlays and the remainder were used as a combination of onlay and inlay grafts. The grafts were stabiliscd using screws. mimplates, direct wires and SurgicclR (Johnson and Johnson, 3963, Gresham Court. Oakdale. MN 55109. USA). On many occasions split-thickness bone grafts and skull shavings were placed on the orbital floor without any fixation.

Table

3 -

Classification

of calvarinl

hone gr;lfts

Vasculariscd Grafts Full ‘rhickness Cirafts Split Thickness Grafts Skull Shaving Bone Dust

24 I4 IO2 I2 37

‘fatal

270

RESULTS One hundred and ninety one (86%) patients attained facml symmetry after the first operation and did not require a second procedure. Rigid fixation was used in 92% of this group. Nine post-traumatic deformity patients required further grafting to correct residual cnophthalmos and pupillary level inequality. There were 13 (4.6%) complications (Table 4). The majority of the operative complications occurred during the harvesting of full-thickness cranial grafts. Four minor dural tears occurred while separating the dura from the inner table of the calvarium. All four patients were under 5 years old. The dural tear was closed with direct suture without further complications. The inner table was perforated three times split-thickness grafts. Postwhile harvesting operatively there were two scalp wound infections, one wound dehiscencc and two donor site haematomas. The hacmatomas formed in patients who viu a separate incision had had the bone harvested without drainage. Part of a vascularised bone graft. used to reconstruct the orbital floor and the infraorbital rim in a post-tumour resection defect, became ischaemic and was removed.

DISCUSSION The concept of surgically correcting congenital orbital bone disorders is somewhat different to the correction of acquired orbital bone disorders. Grafting the patient at an early age offers the advantage of possibly minimising secondary deformity. Further, experimental studies in animals have shown that the osteogenic potential of the cambium layer of the periosteum is at its maximum in young animals (Melcher & Accursi, 1971). In the above series, 21 vascularised grafts were used to reconstruct the orbital walls and part of the zygoma. The continued vascularity of the transferred skull in these patients was demonstrated by technetium bone scans and reported in a previous publication (Bite et ul., 1987). Another advantage of the vascularised graft is the bulk provided by the soft tissue pcdiclc. Contour irregularities of the orbital walls and margins can be reshaped, and bone dust is an ideal graft to augment small defective areas. Bone dust has been used to reconstruct full-thickness defects (Shchadi. 1970). is completely permeable to new blood vessels, and in our expcriencc, sound bone healing rather than fibrous healing occurs. In the

TIble

4 -

Complications

Opcrativc: Postoperative:

Fig. 3-Full thickness calvarial bone pediclcd on the supcrl’icial temporal artery ;md galea IO reconstruct the zyoma in a patient with Trcacher-Collins syntlromc.

following

calcarial

bone grafting

Dural Tear Inner lablc perforation Wound in(cction Wound dchisccncc ffacmatoma Ronc infection Tot;ll

4 3 2 I 2 I 13

Expcricncc

present series the bone dust harvested using a craniotomy was not only used to contour the defect, but was also used to partially r-c-fill the donor site defect (Fig. 4). Three-dimensional computcriscd scan reformation

in the USCofcalvarial

hone grafts in orbital reconstruction

9.5

was used in cases of cnophthalmos to quantify the volume discrepancy (Bite et al.. 19X.S). Ilerc splitthickness grafts and skull shavings (Fig. 5) were used to obtain volume svmmetry. The best instrument to harvest skull shavings in our expericncc is the Lambottc osteotomc (W. I,. Lorenz orthopaedic instruments, 9850 Interstate Center Drive, Jacksonville. Florida 32218. USA). In children. due to the lack of diploe, it is safer to harvest full-thickness bone than attempt to split the cranium Or situ. The 92% of the patients who attained a stable and acceptable result with the first operation support the general belief that rigid fixation plays a major role in the maintcnancc of the weight and volume of bone grafts. The main disadvantage of calvarial bone is its lack of malleability. This can be overcome by selecting the correctly contoured donor site and in young children preparing the graft as describe by Tcssier in 1982. The graft may also be contoured by differential shaping with ir bur. If the pcricranium is left 01 situ the grafts will automatically curl and will adapt more accurately to the contours of the orbit. skull graft-harvesting techniques The limitations are few. It is advisable not to harvest bone crossing the midline as the sagittal sinus may bc traumatised. Also. it is preferable to raise the bone from nondominant side; in this way, any cerebral complications may be less significant. To prevent hacmatoma formation, insertion of a drain and a suitably applied pressure dressing is essential. Lateral skull radiographs and CT scans may help to identify the thickness of the skull but are not always accurate. Tapping the skull with the same instrument in each case may allow one to gain expcriencc in relating the tone to the thickness of the skull. A large number of calvarial bone grafts were harvested to reconstruct orbital deformities. with few complications. Although the follow-up period is short, the early postoperative results are in our opinion excellent. Provided that the graft is harvested blood sinuses. a small away from the intracranial dural tear can be managed satisfactorily. In these cases, 24 h postoperative neurological observation

of

‘1full thickness graft is Fig. 4-Donor site dcfcct from harvcstin, 0 < filled with bone dust and bone chips. prior to covcrinp with Surgicel’ and pcricranium.

Fig. 5-Skull Lambottc

Table

5 -

shuving procedure

is demonstrated

and suitable antibiotic cover for 5 days is essential. In the above series the dural tears occurred while

using il

ostcotomc.

Guidelines

for the use of calwriitl

IXmC yxfts

Full thickness .~--.

r:rec

Pcdiclecl

Onlay contouring Inlay to cover defects

‘specific indications

Inlay to cover defects in orbital wyalls and rims Onlay (rarlcy)

specific indic:llion~

in orbital

rccon~truction dust

Skull

Split thichnch\ _-.

HOIlC

Not

Donor

site tlcfcct (Fig. 4)

Donor Gtc tlclCCt Onlay contouring Correction of enophthalmos

(:‘wcr

localiwd

Correction ofcnophthnlmos C‘obcr will1 dcfccts Onl;l! contouring (over donor site defect

-.

shaving

-.

Children (under 5 years) witahlc

(due to lack

ofdiploc)

Adults

.dSpccification

indication:

Only contouring inlay to cwcr Jcfcct3 Correction

01

cllo~'lltt~~lllllo~

:~b5cnt 0~ poor soft tissue co\ cr Radiation therapy prc- and postopcr:llivcly

dcfcct

Contour irrcgukbr marginx Scconclar~ and tcrtiq olll;l~

Cover

donor- hitc dclcct

96

British Journal of Oral and Maxillofacial Surgery

harvesting full-thickness bone in patients less than 5 years old. The dura tends to bc attached firmly to table in young patients. and careful the inner dissection is essential. It is strongly advised that without considerable cxperiencc full-thickness and vascularised grafts should be harvested with the help of a neurosurgeon. Before harvesting cranial bone grafts a period of cadaver training is advised. A simple quideline for the USCof various bone grafts in orbital reconstruction is given in Table 5. This study demonstrates that calvarial bone can play a major role in orbital reconstruction due to the lack of donor site morbidity, satisfactory aesthetic results. the availability of five graft types and possibly less resorption by using membranous bone with rigid fixation.

Keferences Ballin..M.

(lY21).

Gywolop.

Bite. U., Jackson. 1.I‘. , Forbes. Ci. S. X: Gchrig. D. Q. ( 1985). Orl~itaIvolumcmcasuro~ncntsinc~~ophthalmosusingthreedimensional Cfimaging. Plo.sliccr~~t//ircor~rrucrive.Sur~~ery, 75,502. Ritc.U..Jachson.l.T..W;~hncr.ll.W.CI:Marsh.R.W.(IYX7). Vascularisedskull honcgraftsin craniof;lcialsur~cry. Annals

of’l’las/ic Sur,very. lY,3. by split-ribmcthod.JournNlo~

the Cbllrge ofSu,geons qfA usrralia.

Bulletimet MemoirsdelaSocieredeChirurgiede 232.

Paris, 34,

Me1chcr.A. M.&Accursi,G. E.(1971).Osteogcnesiscapacityof pcriosteal andostcoperiostcal flapselevated from theparictal boneof rat. ArchivesofOralBiolo~y, 16,573. Monasteri0.F. O., Rodriguez, A. &Bcnavidcs, A. (1987). Asimplemcthodforthecorrectionofcnophthalmos. Clinics in Plastic Surgery, 14, 169. Mullcr. W. (1890). ZurFragedcrtemporarenSchHdclrcsektion anstellcdertrcpanation. ZerllrablalrfrtrChirlr,gie. 17,&i. Munro.1. R.&C;uyuron.R.(lY8l).Splitribcranioplasty.A~~~1a~s

0fPlasticSur~~erv. 7.341. “~

Shehadi,S.

,,

,

--

1. (1070). Skullreconstructionusinghonedust.

JournalofPlasricSur~rrv,

Briri.sh

23,227.

‘~cssier,P.(I~X2).Autog~~1o~sl~oncgraftstakenfromthc calvariumforfacialandcranialapplications. c’linic.siuPlus/ic Surger~,Y.SBl. Waitc.P. D.&Clanton.J.T.( l988).Orbitallloorrcconstruction with lyophilizeddura. JournaloJOralundMuxillofacial

Surgery. 46,727.

Anlcthodofcranioplasty.S~r~er~.

0h.slewic.s. 33,70.

Brown. R. C. (lY2X). Cranioplasty

Marchac. D. ( lY7S). Radical forehead rcmodcllingforcraniostenosis. I’lasricandRecons~ructiveSur~ary, 61,823. Mauclaire, M. (1’908). Commcntsonarticlc by RouvilloisM: Brechccranicnnerestaureeparlaprothesemetallique.

I, 23s.

Convcrse.J. M. (IYi4).Tcchniqucofboncgraftin~lorcontour rcstor;ltionofthc face. P/u.s/i~andRecon.s~r~~c/i~~c.S~rr~ery.

14.32. I>onan~~s.hl.‘f. & Anderson,

R. 1.. (1984). C‘li~~i~al0,6itcrl 1st. E.d.. pp. 22-23. Baltimoreand London: Williamsand Wilkins. Fagarasan0.J. (1937)Procedcdecranioplastiepardcsgrcffos costuax rehoubles: Procedc due ‘grillage protecteur‘.

Zins.J.E.&Whitaker,l..A.(IYX3).Membranousvcrsus endochondralhonc: fmplicationsforcraniofacial tion. Plu.sri~utldRecon.s/rucriveSurgery, 72,778.

reconstruc-

The Authors V. Ilankovan FDSRCS. FRCS Registrar DepartmcntofOralandMaxiIlofacial Cannieshurnllost~ital. Rcarsdcn. ’ GlasgowG6l I01

Surgery.

nmmnly.

TechniyueChirur~ie,

2Y,57.

Jachson.I.T’..Hclden.Ci.&Marx.R. (IYX6).Skullbonc~raftsin m~~xillolaci;tl;~ndcr;~niof;tci;~Isurger~. JounlalofOruland

MaxillofaciulSlc~cry. 44,940. Kappis. A. (19 IS). Zur I>cckungvonSchatlclefcktcn.

Zenrralhl

Chirurgie. 42, X97, Kocnig.F.

(IX%)).Dcr

1.1‘. Jackson, MD, FRCS. FAG, FRACS DircctorofCraniofacialalldReconstructivcSurjiery. 2225tJProvidcnce Drive. Suitc703. Southficld, M148075. USA

knochcrneErsatzgrohcnSchadeldefkte.

%efllr~rlDIC~l7irur,~ic. 17,367. Lcccne. P. (102t)).Cranioplastiect prothcsecranicnnc. In: C/rirrcgie Reparamriceer Orrhopediquc. vol. I p, 409 Paris: Massonet Cit. Long;lcrc.J.J.&dcStcT;lno.G. A.( 1057). Reconstructionof cxtcnsivcdelcctsoftheskullwithsplitribgrafts. P/as/i~and Recorl.str[rc,/iveSlrr,~ery.61, 186.

CorrespondcnceandrcquestsforoffprintstoMrV. Senior Registrar. I~cpartmentofOralandMaxiIlofacialSurgery. SunderlandDistrictGcncral flospital. Kayll Road. SunderlandSR47TP Papcrrcceived2SJunclYYI Acccptcd2YOctohcr lY9l

Ilankovan.