Cervical myelopathy caused by pseudoarthrosis between posterior arch of the atlas and lamina of the axis in Klippel-Feil syndrome: a case report

Transmandibular Cervical Corpectomy for Persistent Spinal Cord Compression in a Patient With Klippel-Feil Syndrome: A Technical Note and Systematic Review

BACKGROUND

Few studies have described a transmandibular approach for decompression in a patient with Klippel-Feil syndrome (KFS) for cervical myelopathy.

OBJECTIVE

To describe the transmandibular approach in a KFS patient with cervical myelopathy and to perform a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

METHODS

A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Embase and PubMed databases were searched from January 2002 to November 2022 for articles examining patients with KFS undergoing cervical decompression and/or fusion for cervical myelopathy and/or radiculopathy were included. Articles describing compression due to nonbony causes, lumbar/sacral surgery, nonhuman studies, or symptoms only from basilar invagination/impression were excluded. Data collected were sex, median age, Samartzis type, surgical approach, and postoperative complications.

RESULTS

A total of 27 studies were included, with 80 total patients. Thirty-three patients were female, and the median age ranged from 9 to 75 years. Forty-nine patients, 16 patients, and 13 patients were classified as Samartzis Types I, II, and III, respectively. Forty-five patients, 21 patients, and 6 patients underwent an anterior, posterior, and combined approach, respectively. Five postoperative complications were reported. One article reported a transmandibular approach for access to the cervical spine.

CONCLUSION

Patients with KFS are at risk of developing cervical myelopathy. Although KFS manifests heterogeneously and may be treated through a variety of approaches, some manifestations of KFS may preclude traditional approaches for decompression. Surgical exposure through the anterior mandible may prove an option for cervical decompression in patients with KFS.

Klippel-Feil Syndrome: Clinical Presentation and Management

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Klippel-Feil syndrome (KFS) is a rare multisystem constellation of findings with congenital cervical fusion as the hallmark. The etiology is not fully understood.

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Recent studies have indicated that KFS is more prevalent than previously described.

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Hypermobility in the nonfused segments may lead to adjacent segment disease and potential disc herniation and myelopathy after minor trauma.

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Most patients with KFS are asymptomatic and can be managed nonoperatively. Surgical treatment is reserved for patients presenting with pain refractory to medical management, instability, myelopathy or radiculopathy, or severe adjacent segment disease.

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Patients with craniocervical abnormalities and upper cervical instability should avoid contact sports as they are at increased risk for spinal cord injury after minor trauma.

Cervical vertebral malformations in 9 dogs: radiological findings, treatment options and outcomes

Background

Disregarding atlantoaxial instability in toy breed dogs associated with dens malformation and cervical spondylomyelopathy; cervical vertebral malformations are rare and poorly characterised in veterinary medicine and consequently treatment strategies and clinical outcome are sparsely documented.

Results

Electronic clinical records at our veterinary referral hospital between April 2009 and November 2018 were searched for patients presented with cervical myelopathy secondary to an underlying suspected vertebral malformation/instability. Nine dogs met the inclusion criteria. Two dogs were diagnosed with atlantoaxial pseudoarthrosis, two dogs with a syndrome similar to Klippel-Feil in humans, two dogs with congenital cervical fusion, two dogs with congenital C2-C3 canal stenosis and deficiencies of the dorsal arch of the atlas and laminae of the axis and one with axial rotatory displacement. Tetraparesis, proprioceptive deficits, cervical hyperesthesia and cervical scoliosis were the most common clinical signs. The axis was the most commonly affected vertebrae (8/9 patients). Patients diagnosed with Klippel-Feil-like Syndrome were the younger (average of 262.5 days) and patients diagnosed with fused vertebrae the oldest (average of 2896 days) in our studied population (average of 1580.8 days).

Conclusion

Cervical vertebral malformations are rare, or alternatively, being underdiagnosed in veterinary medicine. Patients diagnosed with Klippel-Feil-like Syndrome had a successful medium and long-term outcome with conservative management. Surgical treatment was often indicated for the other conditions presented in this study due to spinal instability and/or myelopathy. Stabilisations via ventral approaches were revealed to be safe. Multicentre and prospective studies are necessary in veterinary medicine to better characterise clinical outcomes in cervical vertebral malformations.

Combined ossification of the posterior longitudinal ligament at C2-3 and invagination of the posterior axis resulting in myelopathy

PURPOSE

Spinal stenosis at the C2-3 segment is a rare occurrence, and when it occurs myelopathy infrequently results. Furthermore, only a handful of cases involving congenital abnormalities of the posterior arch of the axis have been described resulting in cervical myelopathy many of which described simultaneous congenital abnormalities at adjacent levels and none of which identified ossification of the posterior longitudinal ligament (OPLL) at the same level. We report a case of a previously undescribed combination of abnormalities at the C2-3 segment resulting in clinical myelopathy.

METHODS

A 49-year-old Chinese male presented with a progressive cervical myelopathy (C-JOA score 11 immediately pre-op). Segmental OPLL at the C2-3 disk space was visible, together with invagination of the bilaterally hypoplastic C2 lamina into the spinal canal. Signal abnormalities of the spinal cord were evident on both T1 and T2 sequences.

RESULTS

The patient underwent a posterior decompression and instrumented fusion at C2-3 using pars screws at C2 and lateral mass screws at C3. Following surgery there was a rapid and significant improvement in the neurological symptoms, with the C-JOA score improving to 14 at final follow-up. A successful fusion was evident.

CONCLUSIONS

Deficiencies in the posterior arch of the axis are rare and have not previously been reported in conjunction with OPLL. Advanced imaging is helpful to define the abnormality and site of compression. In the setting of a progressive neurological dysfunction, surgical decompression and stabilization is a reasonable intervention and can be associated with neurological and symptomatic improvement.

Cervical myelopathy caused by atlas osteochondroma and pseudoarthrosis between the osteochondroma and lamina of the axis: case report

A 58-year-old man presented with a 6-month history of progressive cervical myelopathy. Magnetic resonance imaging and computed tomography of the cervical spine revealed a bone tumor arising from the posterior arch of the atlas and osteophytes at a pseudoarthrosis between the tumor and the lamina of the axis, resulting in marked spinal cord compression. The patient's symptoms resolved after en bloc resection of the tumor and removal of the osteophytes. The histological diagnosis was osteochondroma. The primary cause of myelopathy in the present case was osteochondroma arising from the posterior arch of the atlas, but the osteophyte formations appearing at the pseudoarthrosis between the atlas osteochondroma and the lamina of the axis might also have contributed to the symptoms, which appeared when the patient was in his late 50s.

Cervical myelopathy associated with congenital C2/3 canal stenosis and deficiencies of the posterior arch of the atlas and laminae of the axis: case report and review of the literature

STUDY DESIGN

A case report of a young male suffering progressive neurologic dysfunction associated with a previously unreported combination of structural bony abnormalities. A review of the literature is also presented.

OBJECTIVE

To describe a unique presentation of cervical myelopathy related to posterior deficiencies of the atlas and axis, and to report on the successful management of this case.

SUMMARY OF BACKGROUND DATA

Cervical myelopathy from congenital canal stenosis is an uncommon presentation in the adolescent age group, especially affecting the C2/3 level. Aplasia of the atlas is a rare, although well-reported phenomena. Defects of the posterior elements of the axis are similarly uncommon. A combination of the 2 defects in the 1 patient has not previously been recorded.

METHODS

A 14-year-old Caucasian male with no history of trauma or neck pain presented with progressive cervical myelopathy over a 2-year period. Plain radiograph and computed tomography revealed congenital aplasia of the posterior arch of the atlas and bilateral cleft defects of the laminae of the axis resulting in a free floating C2 spinous process. Magnetic resonance imaging showed T1 and T2 signal abnormality at the C2-C3 level, with C2/3 congenital canal stenosis and mild disc protrusion.

RESULTS

The patient underwent a posterior decompression and lateral mass fixation at the C2/3 articulation to preserve maximal motion segments. At 12-month follow-up, the patient's cervical myelopathy had improved in terms of gait dysfunction and hemiparesis. Fusion was evident across the posterior lateral mass on radiologic investigation.

CONCLUSION

Posterior deficiencies of the atlas and axis are rare occurrences in isolation, let alone in the 1 patient. This report broadens the radiographic differential diagnosis of patients presenting with cervical myelopathy, which has been associated with congenital posterior C2 anomalies in only a handful of patients. Surgery is an appropriate option for these patients faced with progressive neurologic dysfunction.