Motion preserving fixation of an unstable Jefferson fracture using C1 lateral mass screws and rods: A case report

Abstract

BACKGROUND

Jefferson fractures of the atlas (C1) are burst-type injuries commonly caused by axial loading. Fracture stability depends largely on the integrity of the transverse atlantal ligament (TAL). While stable injuries may be treated conservatively, unstable fractures often require surgical stabilization. Fusion-based techniques provide reliable stability but significantly restrict upper cervical motion. This report describes a motion-preserving posterior fixation technique for an unstable Jefferson fracture.

CASE SUMMARY

A 32-year-old man sustained an unstable C1 Jefferson fracture (Gehweiler type IIIB) following a fall from a height. Imaging demonstrated fractures of the anterior and posterior arches with associated TAL disruption. After initial cervical immobilization, the patient underwent direct posterior C1 fixation with bilateral lateral mass screws and rod constructs. Intraoperatively, the vertebral artery was found to be entrapped between posterior arch fragments, requiring careful blunt dissection. The procedure was completed without complications. Postoperative imaging confirmed satisfactory reduction and stable fixation. At 1 year and 9 months of follow-up, computed tomography demonstrated bony union, and dynamic radiographs confirmed atlantoaxial stability. Clinical assessment revealed full, pain-free cervical range of motion.

CONCLUSION

Direct C1 lateral mass screw–rod fixation provided effective stabilization of an unstable Jefferson fracture while preserving upper cervical mobility.

Key Words: C1 vertebra; Transverse atlantal ligament; Lateral mass screws; Direct fixation; Unstable fracture; Case report

Core Tip: Unstable Jefferson fractures are traditionally managed with fusion-based techniques that sacrifice atlantoaxial motion. This case report highlights a motion-preserving surgical approach using C1 (atlas) fixation with lateral mass screws and rods, achieving fracture union while maintaining cervical mobility. To our knowledge, this represents the first reported case in Saudi Arabia managed with this technique, providing regional evidence supporting motion-preserving strategies for selected unstable atlas fractures.

INTRODUCTION

Jefferson fractures of the atlas (C1) are uncommon injuries of the upper cervical spine and represent a distinct clinical entity because of the unique anatomy and biomechanics of the craniovertebral junction[1,2]. These fractures typically result from axial loading producing a burst-type fracture pattern[1]. Accurate assessment of fracture stability is essential, as inappropriate or delayed management may result in persistent pain, deformity, or late neurologic compromise.

Fracture stability is largely determined by the integrity of the TAL, and disruption of the ligament is a key factor in selecting an appropriate management strategy. Magnetic resonance imaging (MRI) is considered the most reliable modality for evaluating transverse atlantal ligament (TAL) integrity and associated soft-tissue injury[1]. Although C1-C2 fusion has traditionally been considered the standard treatment for unstable Jefferson fractures, it results in loss of atlantoaxial rotation[3]. This loss of motion may significantly affect functional outcomes and quality of life, particularly in younger or physically active patients.

Motion-preserving techniques, such as direct C1 osteosynthesis, have been used to maintain atlantoaxial mobility and reduce long-term complications[2,4,5]. This case report describes the management of an unstable Jefferson fracture (Gehweiler type IIIB) using direct posterior C1 lateral mass screw-rod fixation.

CASE PRESENTATION

Chief complaints

A 32-year-old man presented to the emergency department after a fall from approximately 2.5 m, sustaining a direct injury to the cervical spine.

History of present illness

On initial assessment, hedenied loss of consciousness, headache, nausea, vomiting, seizures, or involuntary movements. He reported localized neck pain without radicular, motor, or sensory symptoms.

History of past illness

Past medical history was unremarkable.

Personal and family history

Family history unremarkable.

Physical examination

On examination, the patient was alert and fully oriented, with a Glasgow Coma Scale score of 15/15. He was immobilized in a Philadelphia cervical collar. Palpation revealed mild localized tenderness over the upper cervical region without midline spinal tenderness. Neurologic examination demonstrated normal power, intact sensation, and preserved reflexes in all extremities. The remainder of the physical examination was unremarkable.

Laboratory examinations

Laboratory investigations were not done.

Imaging examinations

Initial computed tomography (CT) of the cervical spine demonstrated fractures involving both the anterior and posterior arches of the atlas (Figure 1A). MRI of the cervical spine revealed significant disruption of the TAL, more pronounced on the right side, confirming fracture instability and the need for surgical intervention. The injury was classified as a Gehweiler type IIIB fracture with disruption of the C1 ring.

Figure 1 Preoperative and direct postoperative computed tomography scan. A: Preoperative computed tomography (CT) scan showing the displaced fractures involving both the anterior and posterior arches of the atlas; B: Direct postoperative CT shows reduction of the fracture with appropriate positioning of the lateral mass screws and rods.

FINAL DIAGNOSIS

The injury was classified as a Gehweiler type IIIB fracture with disruption of the C1 ring.

TREATMENT

The patient underwent posterior C1 fixation using bilateral lateral mass screws (28 mm) connected with rod constructs. Intraoperatively, the vertebral artery was found to be entrapped between fragments of the posterior arch. Careful blunt dissection was performed using a Penfield dissector.

Postoperatively, the patient reported localized pain at the surgical site, which was managed with analgesics. No postoperative neurological deficits or other abnormalities were observed. Direct postoperative CT confirmed a satisfactory reduction of the fracture with appropriate positioning of the lateral mass screws and rods (Figure 1B).

OUTCOME AND FOLLOW-UP

The patient was maintained in a Philadelphia cervical collar for two months following surgery. At the two-month follow-up, he reported significant improvement in pain; however, cervical range of motion remained limited, primarily because of paraspinal muscle stiffness. A structured physiotherapy program was initiated three months postoperatively, resulting in progressive improvement in pain control and cervical mobility.

At the most recent follow-up, conducted 1 year and 9 months after surgery, repeat CT imaging (Figure 2A) demonstrated bony union of the posterior arch with satisfactory consolidation. A small residual reduction gap persisted at the anterior arch, without evidence of instability. Dynamic flexion-extension cervical radiographs confirmed atlantoaxial stability (Figure 2B). Clinical examination at that time demonstrated full, pain-free cervical range of motion without neurological deficit (Figure 3).

Figure 2 Re-examination 1 year and 9 months postoperative. A: 1 year and 9 months Postoperative computed tomography scan shows bony union of the posterior arch with satisfactory consolidation; B: 1 year and 9 months dynamic flexion-extension cervical radiographs show atlantoaxial stability.

Figure 3 One year and nine months postoperative clinical examination show full cervical range of motion to the end point.

DISCUSSION

This case demonstrates the successful management of an unstable Jefferson fracture using direct posterior C1 lateral mass screw-rod fixation, with preservation of upper cervical motion and favorable mid-term clinical and radiological outcomes. Disruption of the TAL rendered the fracture unstable and unsuitable for isolated conservative management, thereby necessitating surgical stabilization[1,2].

Fusion-based techniques have traditionally been used for unstable atlas fractures and provide reliable mechanical stability; however, they do so at the expense of atlantoaxial motion, particularly axial rotation[1,6]. Loss of atlantoaxial motion following fusion may negatively affect functional outcomes and quality of life, especially in younger or physically active patients[4,6]. In this case, fixation was selected over fusion for several reasons, including the patient’s young age and an occupation that require physical activity.

Fusion would have resulted in a restricted cervical range of motion, potentially affecting the patient’s occupation and lifestyle. In addition, fusion may require a second procedure to remove hardware which is generally not preferred by patients. These considerations have driven increasing interest in motion-preserving alternatives.

Early motion-preserving strategies for unstable atlas fractures were pioneered by Ruf et al[7], who demonstrated the feasibility of direct C1 osteosynthesis as a function-preserving treatment option for unstable Jefferson fractures[7]. Subsequent clinical series have supported the role of C1 osteosynthesis in achieving fracture union while maintaining cervical mobility[4,5]. The present case adds to this growing body of evidence by demonstrating durable fracture healing, maintained atlantoaxial stability, and full restoration of cervical range of motion at mid-term follow-up. Notably, to our knowledge, this technique has not previously been reported in Saudi Arabia, suggesting that this may represent the first documented case managed using this motion-preserving approach.

A notable intraoperative finding was entrapment of the vertebral artery between posterior arch fracture fragments, highlighting the technical complexity of C1 fixation and underscoring the importance of meticulous surgical exposure, careful preoperative imaging review, and a thorough understanding of vertebral artery anatomy when performing posterior C1 instrumentation[5].

Nonoperative treatment options, including rigid cervical collars and halo vest immobilization, remain appropriate for selected stable Jefferson fractures. However, their use in unstable injuries has been associated with prolonged immobilization, patient discomfort, variable union rates, and residual functional limitations[8,9]. Alternative surgical approaches, such as transoral anterior fixation, allow direct fracture reduction while preserving motion but are associated with a higher risk of infection and increased postoperative morbidity[10].

CONCLUSION

This case report demonstrates that direct posterior C1 lateral mass screw-rod fixation can achieve effective stabilization of an unstable Jefferson fracture while preserving upper cervical mobility. In this young, active patient with confirmed TAL disruption, the technique resulted in satisfactory fracture reduction, durable bony union, maintained atlantoaxial stability, and full restoration of cervical range of motion at mid-term follow-up. By avoiding fusion-based procedures, this motion-preserving approach maintains physiologic cervical biomechanics and may reduce the functional limitations associated with loss of atlantoaxial rotation. Although longer-term follow-up and larger studies are required, this case supports the feasibility and safety of direct C1 osteosynthesis in carefully selected patients for whom preservation of cervical motion is a priority.