Characteristics and management of pain in patients with Klippel-Feil syndrome: analysis of a global patient-reported registry

[Research on effectiveness of occipito-odontoid angle in predicting dysphagia after occipitocervical fusion in patients with C 2, 3 Klippel-Feil syndrome]

OBJECTIVE

To introduce a new occipitocervical angle parameter, occipito-odontoid angle (O-Da), for predicting dysphagia after occipitocervical fusion (OCF) in patients with C _{2, 3} Klippel-Feil syndrome (KFS) and analyze its effectiveness.

METHODS

A total of 119 patients met selective criteria between April 2010 and November 2019 were retrospectively included as the study subjects. There were 56 males and 63 females. The age ranged from 14 to 76 years, with a median age of 51 years. There were 44 cases of basilar invagination and 75 cases of atlantoaxial subluxation. Forty patients were combined with C _{2, 3} KFS. Seven patients underwent anterior decompression combined with posterior OCF and 112 patients underwent posterior OCF. The fixed segments were O-C ₂ in 36 cases, O-C ₃ in 51 cases, O-C ₄ in 25 cases, and O-C ₅ in 7 cases. All patients were followed up 21-136 months, with a median time of 79 months. The lateral cervical X-ray films before operation and at last follow-up were used to measure the occipital to C ₂ angle (O-C ₂a), the occipital and external acoustic meatus to axis angle (O-EAa), the occipital protuberance to axial angle (Oc-Axa), the O-Da, and the narrowest oropharyngeal airway space (nPAS). The differences of the above parameters between the last follow-up and the preoperative values were calculated (represented as dO-C ₂a, dO-EAa, dOc-Axa, dO-Da, and dnPAS). Patients were divided into two groups according to whether they suffered dysphagia after operation, and the differences in clinical data and radiographic parameters were compared between the two groups. The correlation between occipitocervical angle parameters and nPAS in 40 patients with C _{2, 3} KFS was analyzed respectively. In addition, sensitivity and specificity analyses were used to assess the effectiveness of dO-Da≤-5° for the prediction of postoperative dysphagia.

RESULTS

Thirty-one patients (26.1%) suffered dysphagia after OCF (dysphagia group), including 10 patients with C _{2, 3} KFS; no dysphagia occurred in 88 patients (non-dysphagia group). There was no significant difference in age, follow-up time, fixed segment, proportion of patients with rheumatoid arthritis, proportion of patients with atlantoaxial subluxation, and proportion of patients with C _{2, 3} KFS between the two groups ( P>0.05). The proportion of female patients was significantly higher in dysphagia group than in non-dysphagia group ( χ ²=7.600, P=0.006). The difference in preoperative O-C ₂a between the two groups was significant ( t=2.528, P=0.014). No significant differences were observed in preoperative O-EAa, Oc-Axa, O-Da, and nPAS ( P>0.05). There was no significant difference in dO-C ₂a, dO-EAa, dOc-Axa, dO-Da, and dnPAS between the two groups ( P>0.05). The dO-C ₂a, dO-EAa, dOc-Axa, and dO-Da were positively correlated with dnPAS in 40 patients with C _{2, 3} KFS ( r=0.604, P<0.001; r=0.649, P<0.001; r=0.615, P<0.001; r=0.672, P<0.001). Taking dO-Da≤-5° as the standard, the sensitivity and specificity of dO-Da to predict postoperative dysphagia in patients with C _{2, 3} KFS were 80.0% (8/10) and 93.3% (28/30), respectively.

CONCLUSION

The dO-Da is a reliable indicator for predicting dysphagia after OCF in patients with C _{2, 3} KFS.

Klippel-Feil Syndrome: Pathogenesis, Diagnosis, and Management

Klippel-Feil syndrome (KFS), or congenital fusion of the cervical vertebrae, has been thought to be an extremely rare diagnosis. However, recent literature suggests an increased prevalence, with a high proportion of asymptomatic individuals. Occurring as a sporadic mutation or associated with several genes, the pathogenesis involves failure of cervical somite segmentation and differentiation during embryogenesis. Most commonly, the C2-C3 and C5-C6 levels are involved. KFS is associated with other orthopaedic conditions including Sprengel deformity, congenital scoliosis, and cervical spine abnormalities, as well as several visceral pathologies. There are several classification systems, some based on the anatomic levels of fusion and others on its genetic inheritance. Management of patients with KFS primarily involves observation for asymptomatic individuals. Surgical treatment may be for neurologic complaints, correction of deformity, concomitant spinal anomalies, or for associated conditions and varies significantly. Participation in sports is an important consideration. Recommendations for contact sports or activities depend on both the level and the number of vertebrae involved in the fusion. A multidisciplinary team should be involved in the treatment plan and recommendations for complex presentations.

Omovertebral bone causing traumatic compression of the cervical spinal cord and acute neurological deficits in a patient with Sprengel's deformity and Klippel-Feil syndrome: case report

The presence of an omovertebral bone with Sprengel's deformity and Klippel-Feil syndrome is a complex congenital anomaly that is not well understood. It most commonly manifests as cosmetic deformity, limited range of motion, and functional disability, although there are reports of the insidious development of cervical myelopathy. In this paper, the authors present the case of a 49-year-old man with acute neurological deficits after a low-energy mechanism of traumatic spinal cord compression, resulting from an impinging omovertebral bone through a traumatic laminar defect. The patient underwent resection of the omovertebral bone, laminectomy decompression of the spinal canal, and anterior stabilization. This case highlights a rarely discussed complication of undiagnosed Sprengel's deformity and its associated conditions following even low-energy traumatic mechanisms.

Congenital Fusion of Dens to T3 Vertebra in Klippel-Feil Syndrome

BACKGROUND

Patients with Klippel-Feil syndrome may present with neurologic complaints such as neck pain, radiculopathy and gait instability. Here we describe surgical management of a patient with congenital fusion of the occipital-cervical region and also block circumferential fusion of dens to T3 with spinal cord compression. This report is the first of its kind with such extensive fusion.

CASE DESCRIPTION

Our patient was a 56 year-old female, who presented with neck pain and tingling in all extremities. On exam, she had a short neck, prominent jaw with extremely limited range of motion in neck and features of myelopathy. CT showed fusion of the dens to T3 vertebrae. Patient underwent sub-occipital craniectomy, C1 laminectomy and Occiput to T5 posterior fixation and fusion with neurologic improvement.

CONCLUSION

This is the first reported case of Klippel-Feil syndrome with fusion of all cervical vertebrae down to T3. We recommend surgery for advanced cases of myelopathy or radiculopathy due to stenosis and spinal instability.