Management of severe cervical kyphosis in a patient with Larsen syndrome

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1 J Neurosurg Pediatrics 1: , 2008 Management of severe cervical kyphosis in a patient with Larsen syndrome Case report MARCI MADERA, M.D., 1 ALVIN CRAWFORD, M.D., 2 AND FRANCESCO T. MANGANO, D.O. 1,3 1 Department of Neurosurgery, University of Cincinnati College of Medicine; and Divisions of 3 Pediatric Neurosurgery and 2 Pediatric Orthopedic Surgery, Cincinnati Children s Hospital Medical Center, Cincinnati, Ohio Larsen syndrome is a rare genetic disorder of the connective tissue that is characterized by multiple joint dislocations, distinctive deformities of the hands and feet, characteristic facial features, kyphoscoliosis, and segmentation anomalies of the vertebrae. Diverse treatment options, including conservative observation and surgical correction, have been reported for patients who present with cervical spine pathophysiology. Differences in surgical approaches, timing of the correction, and pre- or postoperative bracing have been reported. According to the authors, the present case is the first report of a pediatric patient with Larsen syndrome in whom an asymptomatic cervical instability was treated before neurological deterioration with synchronous anterior decompression and fixation, posterior fusion and fixation, and halo placement. A review of the literature on similar patients reveals the variety of practices associated with a diagnosis of Larsen syndrome. (DOI: /PED/2008/1/4/320) KEY WORDS cervical fusion cervical instability Larsen syndrome pediatric cervical spine I Abbreviation used in this paper: CT = computed tomography. N 1950 Loren J. Larsen and coauthors 7 described the first series of patients with a rare inherited condition characterized by distinctive facial features (that is, forehead prominence, flattened nasal bridge, and hypertelorism), dislocations of multiple joints (usually hips, knees, and/or elbows), and spinal anomalies. The spinal deformities include scoliosis, spinal stenosis, abnormal segmentation, neural arch defects, coronal cleft vertebrae, and anteroposterior dissociation Of the spinal anomalies associated with Larsen syndrome, the most dangerous are vertebral malformations that lead to instability of the cervical spine. In some patients, the pathological entity can contribute to cervical kyphosis, dramatic cervical spinal instability, and neurological deficit. Several sudden deaths in patients with Larsen syndrome, including 1 of Larsen and colleagues 6 patients, were attributed to brainstem or spinal cord compression. 3,7,8,11 In our review of the English literature on cervical instability in patients with Larsen syndrome, multiple treatment options were described both before and after the onset of neurological symptoms. Practitioners have yet to agree on standard practices regarding surveillance, timing of correction, pre- or postoperative bracing, or surgical approach. The lack of standardization is related in part to the relative rarity of the syndrome and in part to the different degrees of syndrome severity at the time of initial clinical evaluation. To the best of our knowledge, this case is the first report of a patient with Larsen syndrome in whom asymptomatic cervical instability was treated with synchronous anterior decompression and fixation, posterior fusion and fixation, and halo placement. Case Report History and Examination. This 30-month-old boy with Larsen syndrome had been followed conservatively at our institution since the age of 6 months. His medical history was significant for subglottic stenosis. He was developmentally normal, sat up at 10 months, and walked at 17 months. He had undergone capsulotomy for bilateral skew foot deformities. During routine follow-up monitoring, dynamic radiography showed worsening cervical kyphosis and instability of the congenital cervical kyphosis (Fig. 1). At this time, he was placed in a rigid cervical collar. Cervical magnetic resonance imaging revealed thecal sac compression 320 J. Neurosurg.: Pediatrics / Volume 1 / April 2008

2 Cervical instability in Larsen syndrome FIG. 1. Preoperative lateral radiographs in neutral (A), flexion (B), and extension (C) views, showing cervical instability in a 30-month-old boy with Larsen syndrome. with an intramedullary T2-weighted signal change at C-3 (Fig. 2A). A CT scan was obtained to better evaluate the severe kyphotic deformity for surgical planning (Fig. 2B D). The patient was neurologically intact on physical examination. In discussions with the child s family about the options for treatment, surgery was recommended because of the spinal cord compression, instability, and risk of future catastrophic neurological decline. Operation. During the surgery, nasal intubation was accomplished using a flexible endoscope under direct vision to prevent any cervical extension and to facilitate passage of the endotracheal tube past the stenotic portion of the boy s trachea. Baseline spinal cord monitoring parameters were determined before starting the procedure and were evaluated continuously to the end of the operation. These parameters included brainstem, cervical, and cortical somatosensory evoked potentials; transcranial motor evoked potentials; and spontaneous electromyographic activity. Both C-3 and C-4 corpectomies were performed anteriorly, and the thecal sac was decompressed. Following fibular strut harvest, a C2 5 construct was created with the strut notched at its ends to provide a better fit (Fig. 3). An absorbable plate ( mm, Resorb-X plate, KLS Martin) was cut to fit along the anterior cervical autograft from C-2 to C-5 and secured with absorbable screw fixation ( mm, Resorb-X absorbable screws, KLS Martin) with the intent to create a temporary buttress while awaiting fusion. Posteriorly, the boy s C-1 anatomy seemed favorable to placement of bilateral isthmus screws, and thus it was possible to avoid fusion to the occiput. Therefore, C-1 screws were placed bilaterally, followed by sublaminar wires to C-5 with bilateral rod fixation. Cross-links were then placed to further strengthen the posterior construct. Fusion was completed with allograft material. After closure of the posterior wound, the child was positioned supine and a halo brace was placed. All spinal cord monitoring parameters remained stable throughout the operation and without changes. Postoperative Course. The child was transferred to the pediatric intensive care unit for observation. Subsequently, the nasal tube was removed. Postoperatively he demonstrated symptoms of Horner syndrome and transient weakness in his extremities. He was transferred to the rehabilitation unit, from which he was later discharged neurologically intact. After 18 weeks of halo immobilization, radiography studies obtained in the patient showed evidence of osseous fusion; FIG. 2. Images showing severe kyphotic deformity of the cervical spine in a child. Preoperative sagittal T2-weighted magnetic resonance image (A) reveals the apex at C3 4, hypoplastic vertebral bodies, cerebrospinal fluid effacement, and abnormal intramedullary signal extending from C3 5. Sagittal (B) and coronal (C) CT scans and oblique 3D view (D) of the CT reconstructions used for surgical planning. J. Neurosurg.: Pediatrics / Volume 1 / April

3 M. Madera, A. Crawford, and F. T. Mangano FIG. 3. Sagittal radiograph (A) demonstrating maintenance of the improved cervical alignment and evidence of solid fusion 1 year postoperatively. Sagittal 2D CT scan (B) showing C3 4 corpectomies with placement of a fibular strut graft extending from C2 5 and improved cervical alignment postoperatively. Three-dimensional CT scan (C) showing the anterior and posterior implants placed for stabilization. Posterior rod extends from C1 5; allograft material is noted adjacent to the posterior hardware. the halo vest was replaced by a Minerva brace for 4 weeks and then discontinued. At the 12-month follow-up, the patient continued to fare well with continued improved cervical alignment and no neurological deficits (Fig. 3A). Discussion Patients with Larsen syndrome represent significant surgical challenges for the spine surgeon. The cervical spine, specifically, appears to be more severely affected than the thoracic or lumbar segments and thus deserves careful attention and follow-up in this patient population. 1,2,5,11,12 Age, individual presentation, and severity of disease help determine clinical decision making. Before 1996, the only patient with Larsen syndrome who had undergone surgical fixation before neurological deterioration was a 19-year-old with C1 2 subluxation. He did not have the severe kyphosis of the lower cervical spine that is more often described in patients who have undergone surgical correction. 2 Since then, Johnston et al. 5 have described progressive kyphosis on serial imaging in a series of 4 patients who had undergone posterior cervical fusion before the onset of neurological deterioration. In one patient who suffered a postsurgical fall that rendered him quadriparetic, a pseudarthrosis was also evident; this patient subsequently underwent 2 additional procedures for decompression and stabilization. Several other authors have highlighted falls or trauma as inciting events of neurological deterioration in patients with Larsen syndrome (Table 1). After a discussion with our patient s parents, the child underwent a combined anteroposterior decompression and fusion with external fixation. Treatment goals were to improve the probability of a successful fusion, reduce the need for future surgery, and provide enhanced cervical stability should the boy subsequently experience a traumatic fall. To our knowledge, all other reported cases of initial anterior and posterior surgical treatment of cervical spine instability occurred after patients became symptomatic. Symptoms have ranged from weakness in a single or multiple extremities, to numbness, to myelopathy. We believe that the natural history of the disease underscores the importance of early correction. Forese and colleagues 3 have advocated nonsurgical treatment consisting of continuous cervical traction and total spinal column bracing in patients with severe deficits since birth. Although these authors noted improvement in ventilatory and motor functions, they hypothesized that surgical intervention might be needed later. Of the 10 cases reviewed for the present report, 3 symptomatic patients deteriorated or had no improvement postoperatively, 1 patient improved before correction, and 6 patients improved after surgery. Of these latter 6 patients, only 1 was reported to be neurologically normal. Based on the literature review and our patient s experience, we make the following recommendations. Patients in whom Larsen syndrome is diagnosed should be monitored with both static and dynamic serial radiography. Conservative management before the appearance of clinical symptoms should be avoided given the inability to predict postoperative improvement. Although improvement in neurological deficits has been seen with close monitoring, surgical correction should not be delayed given the long-term risk of neurological deterioration, especially in younger children, who are at risk for frequent falls. Surgical correction that successfully addresses both the anterior and posterior elements may obviate future procedures. Debate continues about the timing of bracing before surgical treatment in patients with progressive kyphosis. 1,5 Our patient was placed in a hard cervical collar while awaiting surgical decompression and fusion. Based on data in the literature and the traumatic risk that falls represent in these children, we advocate bracing for those with cervical instability documented on flexion and extension x-ray films until surgical correction can be performed. As postoperative bracing is important to encourage a solid fusion, we believe that halo immobilization in the patient in the present case was the best way to achieve this goal. Conclusions In children who suffer from Larsen syndrome with cervical instability, we recommend synchronous anterior and posterior procedures that are tailored to the deformity as well as the use of halo fixation postoperatively until fusion is documented radiographically. This approach should prevent children from sustaining a significant neurological deficit after a minor trauma, such as a fall. 322 J. Neurosurg.: Pediatrics / Volume 1 / April 2008

4 Cervical instability in Larsen syndrome TABLE 1 Literature review of surgically treated cervical deformity in patients with Larsen syndrome* Preop Approximate Brace/ Authors & Year Age at 1st Op Trauma Traction Condition Improvement Op Brace Condition Postop Micheli et al., mos none semirigid UE & mild LE weak- improved UE C3 T2 pst fusion Minerva jacket unknown cervical ness weakness Muzumdar et al., 13.5 yrs fall NA bilat numbness, weak- NA cervical decompression NA minimal improvement, condition de ness in all extremities teriorated later Bowen et al., yrs none NA no deficit, progression NA occiput C4 pst fusion, later Minerva jacket no deficit of kyphosis scoliosis correction Miz & Engler, mos MVA NA hyperreflexia, decreased myelopathy occiput C2 pst fusion Minerva jacket no recurrent myelopathy perineal sensation resolved Francis & Noble, 5 yrs none traction weakness, inability to NA ant cervical decompression, halo vest no deficit 1988 right self fibular strut placement Forese et al., yrs none NA arm weakness NA ant & later pst cervical fu- NA no improvement sion Johnston et al., mos fall after 1st NA no deficit initially, fall NA pst cervical fusion followed Minerva jacket & improvement to walking op after 1st op induced by 2 ant decompressions then halo vest quadriparesis & fusions 14 mos none NA no deficit NA pst cervical fusion halo vest no deficit 14 mos none NA no deficit NA pst cervical fusion Minerva jacket no deficit 16 mos none NA no deficit NA pst cervical fusion Minerva jacket no deficit 12 yrs none NA myelopathy, weakness NA ant & pst cervical fusion NA no improvement Luk & Yip, yrs none NA no deficit initially, sen- NA ant T12 L3 fusion, ant de- halo vest transient weakness in extremities after sory deficit in UE compression & fusion, 2nd op, ultimately no deficit after 1st op later pst fusion 6 yrs none halo myelopathy improved pst C1 T1 fusion, later ant halo vest myelopathy resolved after 1st ant cercervical fusion & repeat vical fusion ant fusion 2 Banks et al., yrs fall halo myelopathy, weakness NA pst C1 T1 decompression halo vest & then hard transient increased weakness postop in all extremities & fusion, ant cervical de- cervical collar w/ later improvement to better than compression & fusion 4 preop status days later Katz et al., yrs falls? NA weakness before 1st op, improved in halo 2 failed pst cervical fusions, halo vest & then col- after 4th op, transient weakness w/ inability to walk be- after 3rd op (pst pst decompression & fu- lar after 2nd op, improvement but persistent C-5 & fore 3rd op decompression sion, later ant fusion w/ halo vest through C-6 weakness pst sublaminar wires 4th op, later collar present case 2.5 yrs none rigid cervical no deficit NA synchronous ant decom- halo vest transient postop weakness & Horner collar pression & fusion/fixa- syndrome resolved tion, pst fusion/fixation * ant = anterior; LE = lower extremity; MVA = motor vehicle accident; NA = not available or not applicable (preoperative improvement in patients with no deficit); pst = posterior; UE = upper extremity. J. Neurosurg.: Pediatrics / Volume 1 / April

5 M. Madera, A. Crawford, and F. T. Mangano Acknowledgments We thank Ms. Mary Kemper and Ms. Tonya Hines for their editorial assistance. References 1. Banks JT, Wellons JC III, Tubbs RS, Blount JP, Oakes WJ, Grabb PA: Cervical spine involvement in Larsen s syndrome: a case illustration. Pediatrics 111: , Bowen JR, Ortega K, Ray S, MacEwen GD: Spinal deformities in Larsen s syndrome. Clin Orthop Relat Res 197: , Forese LL, Berdon WE, Harcke HT, Wagner ML, Lachman R, Chorney GS, et al: Severe mid-cervical kyphosis with cord compression in Larsen s syndrome and diastrophic dysplasia: unrelated syndromes with similar radiologic findings and neurosurgical implications. Pediatr Radiol 25: , Francis WR Jr, Noble DP: Treatment of cervical kyphosis in children. Spine 13: , Johnston CE II, Birch JG, Daniels JL: Cervical kyphosis in patients who have Larsen syndrome. J Bone Joint Surg Am 78: , Katz DA, Hall JE, Emans JB: Cervical kyphosis associated with anteroposterior dissociation and quadriparesis in Larsen s syndrome. J Pediatr Orthop 25: , Larsen LJ, Schottstaedt ER, Bost FC: Multiple congenital dislocations associated with characteristic facial abnormality. J Pediatr 37: , Laville JM, Lakermance P, Limouzy F: Larsen s syndrome: review of the literature and analysis of thirty-eight cases. J Pediatr Orthop 14:63 73, Luk KD, Yip DK: Congenital anteroposterior spinal dissociation in Larsen s Syndrome: report on two operated cases with long-term follow-up. Spine 27:E296 E300, Lutter LD: Larsen syndrome: clinical features and treatment a report of two cases. J Pediatr Orthop 10: , Micheli LJ, Hall JE, Watts HG: Spinal instability in Larsen s syndrome: report of three cases. J Bone Joint Surg Am 58: , Miz GS, Engler GL: Atlanto-axial subluxation in Larsen s syndrome. A case report. Spine 12: , Muzumdar AS, Lowry RB, Robinson CE: Quadriplegia in Larsen syndrome. Birth Defects Orig Artic Ser 13: , Weisenbach J, Melegh B: Vertebral anomalies in Larsen s syndrome. Pediatr Radiol 26: , 1996 Manuscript submitted November 5, Accepted December 14, Address correspondence to: Francesco T. Mangano, D.O., c/o Editorial Office, Department of Neurosurgery, ML 0515, 231 Albert Sabin Way, Cincinnati, Ohio editor@mayfield clinic.com. 324 J. Neurosurg.: Pediatrics / Volume 1 / April 2008