Cervical Spine Anomalies in the Craniosynostosis Syndromes KAYE

Cervical Spine Anomalies in the Craniosynostosis Syndromes

KAYE M. Hemmer, M.D. WILLIAM H. McAListER, M.D. JEFFREY L. MARSH, M.D.

Cervical spine radiographs of 34 patients with a variety of craniosynostosis syndromes were reviewed to determine the incidence and nature of skeletal anomalies and to evaluate the findings in terms of syndromal patterns. Intervertebral fusions occurred in 30 percent of Pfeiffer's, 38 percent of Crouzon's, and 71 percent of Apert's syndrome children. In Crouzon's and Pfeiffer's syndromes, isolated upper cervical fusions were most common; in Apert's syndrome, the fusions were more likely to be complex involving C5-C6. This syndromal variation, however, was not specific enough for diagnostic differentiation.

Elucidating the full spectrum of a disease space. Although variation in the nature and process assists diagnosis, prognosis, and treat- distribution of cervical spine anomalies was not- ment. Such elucidation also may assist compre- ed between Kreiborg's two syndrome groups, the hension of the etiology and underlying findings were not specific enough to allow syn- pathophysiology of the process. Skeletal anoma- drome differentiation. We, therefore, undertook lies are recognized concomitants of the various a retrospective study of our patients with craniosynostosis syndromes (Gorlin et al, 1976). craniofacial dysostosis syndromes to ascertain the Acral anomalies have been focused upon, aside nature and frequencies of cervical spine defor- from the skull findings, to assist syndrome mities and to determine whether diagnostically differentiation among affected patients. While useful syndromal variations were present. axial skeletal anomalies have been described in patients with these syndromes, they have not METHOD been documented in detailed fashion in the liter- ature. Kreiborg (1981), in his monograph on The charts of all patients with craniosynosto- Crouzon's syndrome, reported a variety of cer- sis syndromes followed in the Cleft Palate and vical spine findings affecting one-third of that Craniofacial Deformities Institute of Washing- population. The most common finding was iso- ton University Medical Center, St. Louis, Mis- lated intervertebral fusion involving the C2-C3 souri, were reviewed to verifty the authenticity interspace. Kreiborg (1987) subsequently report- of the diagnoses utilizing description of craniofa- ed a survey of the cervical spines of his patients cial and acral anomalies and genetic evaluation. with Apert's syndrome. Two-thirds of the Patients diagnosed as "upper Crouzon'"' or bi- Apert's syndrome patients displayed cervical coronal synostosis without evidence of maxillary spine abnormalities with predominance of fusions retrusion were excluded. The radiographic cer- at the C5S-C6 interspace. In contrast to the sim- vical spine images available for the remaining ple fusions found in Crouzon's, fusions in patients with the various craniosynostoses syn- Apert's syndrome patients were generally com- dromes were reviewed without knowledge of the plex or involved more than an isolated inter- diagnoses by a single pediatric radiologist. All available images of the cervical spine were used in the review. These included standard frontal All of the authors are affiliated with the Washington and lateral spine projections as well as addition- University Medical Center, St. Louis, MO. Dr. Hemmer is a Fellow in Craniofacial Surgery Division of Plastic and al views of the cervical spine as seen on skull Reconstructive Surgery. Dr. McAlister is Professor of Radi- and chest radiographs and cephalometrograms. ology, Mallinckrodt Institute of Radiology, and Head of Pedi- Some abnormalities, especially fusions, were atric Radiology at Children's Hospital. Dr. Marsh is Professor noted only on subsequent spine radiographs and of Surgery, Plastic and Reconstructive, and Medical Direc- not on earlier ones. In such cases, the later ob- tor of Cleft Palate and Craniofacial Deformities Institute, at Children's Hospital. servations were those recorded.

328 Hemmer et al, CERVICAL SPINE ANOMALIES IN CRANIOSYNOSTOSIS SYNDROME 329

RESULTS was not syndrome specific, some trends were observed. There was involvement of an isolated in- The study population consisted of 34 patients. terspace in five of six affected Crouzon's The syndromal diagnoses were: 16 Crouzon's, - syndrome, versus two of five affected Apert's 7 Apert's, 7 Pfeiffer's, 3 Carpenter's, and 1 syndrome patients. Furthermore, the majority of Saethre-Chotzen syndrome. There were 19 males fusions in the Apert's group were complex, span- and 15 females. The age at the time cervical ning more than a single interspace. Four of six spine films were obtained ranged from birth to fusions in Crouzon's syndrome patients involved 20 years, with a median age of 9 years. C2-C3; this interspace was not involved in any Four types of cervical spine abnormalities Apert's syndrome patients. All but one Apert's were encountered: fusions (N= 20), high atlas syndrome fusion included the C5-C6 interspace. (N=9), butterfly vertebrae (N=2), and over- Two Crouzon's syndrome spines had isolated in- sized odontoid (N= 1). Fusions included facet volvement of this interspace, and a third showed fusions, neural arc fusions, and block vertebrae. inclusion of the C5-C6 interspace in a complex '*Neural arch fusions'' (N= 6) referred to more fusion involving the entire cervical column. complex fusions than those just involving the facet joints (N=7). ''Block vertebra'' (N=7) DISCUSSION was used to describe partial or complete fusion, either cartilaginous or bony, of two or more ver- A variety of skeletal anomalies have been iden- tebrae. '"'High atlas" referred to an atlas that was tified in the cervical spine of patients with close to but not fused with the occiput. The dis- craniosynostosis syndromes (Uhlmann, 1952; tribution of the specific cervical anomalies Pruzansky, 1976; Kreiborg, 1981, 1987). The among the craniosynostosis syndromes was not most frequently identified abnormality was in- syndrome specific (Table 1). Nonetheless, pa- tervertebral fusion, obliterating part or all of the tients with Crouzon's and Apert's syndromes had involved intervertebral space, facets, or re- the highest proportion of anomalies. Specifical- mainder of the neural arch (Kreiborg, 1981). ly, facet fusion occurred in three of 16 Crouzon's Although such fusion may be seen in the gener- and three of seven Apert's syndrome patients al population at large, such malformations are (Figs. 1 and 2). Block vertebrae were found in infrequent (Resnick, 1981). In a review of 700 two Crouzon's, three Apert's, and two Pfeiffer's spines from patients in an orthopaedic hospital, syndrome patients (Figs. 1B and 2B). Neural the incidence of cervical fusions was 0.5 percent arch fusion was noted in two patients each of (Shands, 1956). Cervical fusions were detected Crouzon's, Apert's and Pfeiffer's syndromes. in 2.9 percent of 105 patients with cleft lip with The majority of high atlas occurred in Crouzon's or without cleft palate (Sandham, 1986). In con- syndrome patients (Fig. 1B). Butterfly vertebae trast, the frequency of fusions was 32 percent were ecountered in two Crouzon's syndrome pa- in Kreiborg's Crouzon's syndrome population tients (Fig. 3). There was an incidental finding (N= 47), 38 percent in our Crouzon's syndrome of an oversized odontoid in one of three patients set (N=16); and 67 percent in Kreiborg's with Carpenter's syndrome. There were no ab- Apert's syndrome population (N= 36), 71 per- normalities noted in the one child with Saethre- cent in our Apert's syndrome set (N=7). This Chotzen syndrome. markedly increased frequency presumably Cervical spine fusions were more common in reflects a pathophysiologic process that distin- Apert's syndrome (71 percent) than in Crouzon's guishes the craniosynostosis syndromes from the syndrome (38 percent) patients (Table 2). general population. Nonetheless, the nature of Although the anatomic distribution of fusions the cervical spine abnormalities observed in these

TABLE 1 Specific Cervical Spine Findings in the Various Craniosynostosis Syndromes

Syndromes

Cervical Spine jie Crouzon's Apert's Pfeiffer's Carpenter's Saethre-Chotzen's Findings (N= 16) (N=7) (N=7) (N=3) (N=1)

Facet fusion

Q GQ O O

Block vertebrae -

D Q NJ O

Neural arch fusion O

D b D O

High atlas O JO N &

Butterfly vertebrae O

D C- 3 &

Large odontoid &

JO O JO - &

330 Cleft Palate Journal, October 1987, Vol. 24 No. 4

FIGURE 1 Crouzon's syndrome. A, Girl, age 10 years, facet fusion of C2-C3 (arrow). B, Girl, age 12 years, showing a high atlas, block vertebra (arrowhead) with neural arch fusion of C2-C3 (arrow). Hemmer et al, CERVICAL SPINE ANOMALIES IN CRANIOSYNOSTOSIS SYNDROME 331

FIGURE 2 Apert's syndrome. A, Boy, age 11 years, with facet fusion of C5-C6 (arrow). B, Boy age 8 years, with block vertebra of CS-C6 (arrow).

FIGURE 3 Crouzon's syndrome. Four-month-old boy with butterfly vertebra of C6 and C7 (arrows).

332 Cleft Palate Journal, October 1987, Vol. 24 No. 4

TABLE 2 Cervical Spine Fusions in Crouzon's Versus ditions. Our patients could not be sorted by syn- Apert's Syndrome . drome according to cervical spine anomalies.

Conclusions cannot be drawn from our single Cervical Crouzon's Apert's case of Saethre-Chotzen syndrome. Spine Syndrome Syndrome Fusion (N=16) (N= 7) The cervical fusions in the craniosynostosis syndromes have been shown to be progressive C2-3 3 0 with aging (Schauerte and St.-Aubin, 1966; Kaye C4-5 0 1 C5S-6 2 1 et al, 1978; Pruzansky, 1976). The age of the C3-4, 5-6 0 1 study population, therefore, can affect incidence C4-5, 5-6 0 1 and distribution of data. The younger the sam- C5S-6, 6-7 0 1 C2 thru 7 1 0 ple, the greater the chance of underestimation of No fusions 10 2 the spine anomalies. The median age of our pa-

tients, 9 years, is younger than that of Kreiborg's, the majority of whom were adoles- syndromes are not specific and can be seen in cents or adults. a number of other conditions (Taybi, 1983). What are the clinical implications of these find- The cranial and facial anomalies in Crouzon's ings? Although there are variations in the cervi- and Apert's syndromes, while having many fea- cal spine anomalies among the various tures in common, are sufficiently distinct, in craniosynostosis syndromes, there is insufficient most cases, to allow separation of the two con- syndrome specificity for this information to be ditions on the basis of craniofacial features used diagnostically. Although the observed fu- without reference to their acral deformities. sions do not limit significantly the range of clin- While the most frequent cervical spine abnormal- ical cervical motion, the restricted flexion ity identified in both groups was intervertebral extension may affect placement of an endo- fusion, there were distinct differences between tracheal tube. It is important to recognize such the two syndromes in the frequency, location, cervical anomalies prior to the induction of and complexity of these fusions. Fusion in the anesthesia since they may compound the already Crouzon's syndrome group occurred only half problematic airway management of these pa- as frequently as in the Apert's syndrome group. tients. We did not find odontoid disorders in our Although the C2-C3 interspace was involved in population, as did Kreiborg (1981), which might over half of the Crouzon's syndrome patients, allow a fatal C1-C2 subluxation. The possibility this interspace was never involved in those with of this occurrence, however, has been discussed Apert's syndrome. Conversely, C5S-C6 was by others (Munro, 1986). fused in two-thirds of the Apert's syndrome cases, but in the Crouzon's syndrome popula- CONCLUSIONS tion it was involved half of the time. Although our sample is small, the findings do coincide with Cervical spine anomalies can be documented Kreiborg's (1981, 1987) finding of a radiographically in patients with a variety of predominance of C5S-C6 involvement in Apert's craniosynostosis syndromes. Intervertebral fu- syndrome, in contrast to predominance of C2-C3 sions occurred in 30 percent of Pfeiffer's, 38 per- involvement in Crouzon's syndrome. Further- cent of Crouzon's, and 71 percent of Apert's more, the majority of the Crouzon's syndrome syndrome children. In Crouzon's and Pfeiffer's fusions involved an isolated interspace, but the syndromes, isolated upper cervical fusions were Apert fusions were generally more complex, in- most common; in Apert's syndrome, the fusions volving more than one interspace both in our were more likely to be complex involving populations and Kreiborg's. High atlas was C5S-C6. These differences in fusion site and na- found primarily in our Crouzon's syndrome ture may reflect differences in underlying osse- population. The reasons for the distinct anatom- ous pathophysiology. This syndromal variation, ical regions and degrees of fusions in Crouzon's however, was not specific enough for diagnos- versus Apert's syndromes are unknown. There tic differentiation. The limitation of cervical may be fundamental differences in the underly- range of motion resultant from these anomalies ing osseous pathophysiology, which accounts for may have clinical significance with respect to the variations in acral anomalies as well. Crou- surgical airway management in these patients. zon's and Pfeiffer's syndromes tend to be essen- tially indistinguishable on the basis of craniofacial features alone. Their similarity also Acknowledgment. We are indebted to Ms. Karen Lask for is reflected in the cervical spines of the two con- manuscript preparation. Hemmer et al, CERVICAL SPINE ANOMALIES IN CRANIOSYNOSTOSIS SYNDROME 333

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