Long-term outcome of adult traumatic atlantoaxial rotatory fixation: a case series

Abstract

Background

This case series presents five cases of adult atlantoaxial rotatory subluxation (AARS) following traumatic events, focusing on treatment strategies and long-term outcomes.

Case presentation

This paper includes four Iranian male patients and one Iranian female patient with ages ranging from 25 to 46 years old. Each case involved unique presentations and management approaches. Initial conservative treatments, including skull traction and orthoses, were attempted, but surgical intervention became necessary due to inadequate response. Surgical fixation significantly improved functional status and alleviated symptoms in all patients, leading to long-term relief. Radiological assessments demonstrated successful outcomes post-surgery.

Conclusions

This study underscores the importance of considering both conservative and surgical options in managing adult atlantoaxial rotatory subluxation to achieve optimal outcomes.

Introduction

Atlantoaxial rotatory subluxation (AARS) is an uncommon condition that mostly occurs in pediatric population as a result of injury to facet joints and surrounding ligaments, namely Alar and transverse ligaments, at C1–C2 level [1]. The incidence of mentioned condition in adult group is less and is caused by high-energy trauma such as motor vehicle accidents or falling down [2]. AARS is a potentially life-threatening condition that encompasses variety of symptoms ranging from limitation of range of motion and torticollis to death; in addition, diagnosis is based on physical examination and radiological findings [3, 4]. Due to rarity of the condition, treatment is controversial and both conservative and surgical treatment have been described previously [5–7]. Here we present the report of five AARS cases and investigate the treatment strategies, in addition to the long-term outcomes.

Case presentation

Case 1

A 25-year-old Iranian male presented to our tertiary trauma bay following motor vehicle accident. Primary and secondary trauma surveys exhibited no major disability except for limitation of cervical range of motion (CROM) along with abnormal neck posture (torticollis). His Glasgow Coma score (GCS) was 15 and both pupils were reactive to light. Since the patient suffered from suboccipital pain and midline tenderness at occipitocervical junction, he underwent cervical computed tomography scan and findings were in favor of AARS as well as hangman’s fracture. Magnetic resonance imaging (MRI) revealed no significant ligamentous injury and only facet joint effusion as well as paravertebral edema. After implementing skull traction and Philadelphia cervical collar, the desired improvement was not achieved; therefore, he underwent intraoperative traction, open reduction with gentle manipulation, and posterior C1/C3 fusion to release the facet and resolve the torticollis; 2-year follow-up showed significant symptom relief; visual analogue scale (VAS) was 1 and there was no crucial limitation in cervical range of motion. Additionally, radiologic findings exhibited remarkable advancement in all features.

Case 2

Following a motor vehicle accident, a 30-year-old Iranian male patient presented with cock-robin posture of the neck in addition to right-side brachial plexus injury and ipsilateral shoulder dislocation. Apart from limitation of cervical motion and suboccipital pain (VAS 8) and associated midline tenderness, primary and secondary surveys indicated no other significant findings. His GCS was 15 and both pupils were reactive to light. He underwent computed tomography (CT) scan and AARS with anterior displacement of atlas (5 mm) was detected. MRI showed transverse ligament injury along with bilateral facet joint effusion and paravertebral edema. He was classified as Fielding–Hawkins grade 2 and primarily underwent nonsurgical management using Gartner–Wall skull traction and Philadelphia cervical collar. Due to inadequacy of conservative-only management, surgical option was chosen for him with atlantoaxial fixation; 18-month follow-up showed significant pain relief (VAS 1) as well as notable progress in cervical range of motion.

Case 3

After motor vehicle accident, a 27-year-old Iranian male patient was brought to our tertiary trauma center. Trauma surveys revealed no major disability other than torticollis and limited cervical ROM. He also suffered from suboccipital headache in addition to midline tenderness in occipitocervical junction. His GCS was 15 and pupils were equally brisk in response to light. Cervical CT scan was taken and it revealed AARS along with unilateral C1–C2 facet fracture on left side. Patient underwent cervical MRI and it showed evidence of no notable ligamentous injury with joint effusion on left side as well as paravertebral soft tissue swelling. First, Gartner–Wall traction and Philadelphia collar were applied, and due to incompetence of nonsurgical management, he eventually underwent C1–C2 fixation surgery; 6 year follow-up demonstrated outstanding improvement in both clinical and radiologic parameters.

Case 4

An Iranian 46-year-old female patient presented with torticollis and limited cervical range of motion in addition to severe neck pain (VAS 8) after falling from five stairs, and was brought to our trauma hospital. Initial assessment revealed no obvious disability, and no neurological deficit was found during further evaluation. Cervical CT scan was indicative of AARS with no significant anterior displacement of atlas. Patient underwent MRI to appraise soft tissue injury, which was indicative of paravertebral soft tissue swelling with no obvious ligamentous injury. As was mentioned in previous cases, due to incompetence of conservative-only management, she underwent surgery. Subsequent follow-up findings demonstrated noticeable resolution of symptoms (VAS 0) with limitation of cervical motion in rotation to left side, exclusively.

Case 5

Following to a motor vehicle accident, a 32-year-old Iranian male patient presented with abnormal neck posture and severe pain in occipitocervical junction (VAS 9); moreover, primary and secondary surveys manifested limited cervical range of motion in every plane. No other outstanding neurological deficit was detected and patient was prepared to have further radiological evaluation. Findings of CT and MRI revealed AARS with unilateral facet fracture along with paravertebral soft tissue swelling, disruption of alar ligament, and facet edema, respectively. He had atlantoaxial fixation surgery after nonsurgical management failed. Long-term follow-up declared complete pain relief (VAS 0) along with remarkable resolution of limitation of CROM.

Discussion

AARS is rare in adults and usually results from high-energy trauma. It can be life-threatening, with symptoms ranging from limited motion and torticollis to death. Diagnosis relies on physical exams and radiological findings. This report presents five adult AARS cases, all initially managed conservatively but ultimately requiring surgical intervention due to inadequate responses. These cases often involved other complicating injuries necessitating stabilization surgery. Post-surgery, patients showed significant symptom improvement and functional recovery. Radiological assessments confirmed long-term surgical success, highlighting the benefits of atlantoaxial fixation in terms of quicker recovery and reduced hospital stays. This study’s importance lies in its detailing of comprehensive adult cases and the efficacy of surgical treatment after conservative methods failed.

There are a few cases in the literature pertaining to adult traumatic atlantoaxial fixation; therefore, to exemplify the topic on the ground of the previous studies seems inconvenient. Different classification systems for AARS have been alluded to in the literature, and among them the Fielding–Hawkins classification is the most applied [8]. It has been suggested to manage the mentioned condition in all grades conservatively at first; meanwhile, if the follow-up clinical and radiologic findings are unfavorable, surgical options could be taken into consideration [9]. Conservative therapeutic strategies, including closed reduction via skull traction as well as orthoses, were applied to all presented cases initially; however, due to inadequate response to nonsurgical management, all of them ended up undergoing fixation surgery. Other concomitant injuries associated with craniocervical junction, such as unilateral or bilateral atlantoaxial facet fracture, Jefferson fracture, and fractures of the odontoid process, may necessitate further stabilization of the involved structures yielding to failure of conservative only treatment [10]. Atlantoaxial fixation surgery of nominated patients seriously improved their functional status and caused relief of their complaints. All the patients experienced resolution of their symptoms, namely pain in suboccipital region (VAS) and limitation of cervical range of motion. As has been demonstrated thus far, atlantoaxial fixation surgery has the advantage of earlier functional recovery and less expenditure of hospital resources because of shortened hospital stay and succeeding investigations [11]. Several radiologic measures were administered in the present study by which the prosperity of surgical management in long-term follow-up was assessed. Among them, the C1–C2 rotational angle demonstrated the degree whereby the rotational subluxation was reduced; in addition, distal segment lordotic angle is the indicator of sagittal cervical alignment of distal segment in instrumented C1–C2 fixation surgeries postoperatively. Abnormal occipitoatlantal angle may indicate the instability in craniovertebral junction due to associated ligamentous and soft tissue injuries; moreover, suboccipital or craniocervical pain may lead to loss of normal cervical lordosis. All the aforementioned radiologic criteria were assessed in the present study both pre- and postoperatively, and the results showed significant long-term improvement (Fig. 1, Tables 1, 2).

Fig. 1.

Radiologic measures of case 1 before and after surgery in long-term follow-up: A (yellow lines) shows the rotational angle as an indicator of rotational atlantoaxial subluxation, which was notably improved in long-term follow-up (from 43 to 9 degrees); B reveals preoperative cervical magnetic resonance imaging; as seems obvious, no evidence of transverse ligament disruption was seen; C demonstrates occipitoaxial angle (yellow lines), which had no significant change before surgery and in long-term follow-up; D and E manifest distal segment lordosis and cervical Cobb’s angle (yellow lines) with no significant change; and F shows the fusion condition of fixed vertebrae postoperatively

Table 1.

Radiologic measures of operated AARS cases in long-term follow-up

Cases	Preoperative								Postoperative (long term follow-up)
	Clinical findings			Radiologic findings					Clinical findings			Radiologic findings
	TOR	VAS	CROM LIMIT	ROT ANG	O-C2	DISTAL SEG LOR	COB	FUS	TOR	VAS	CROM LIMIT	ROT ANG	O-C2	DISTAL SEG LOR	COB	FUS
Case 1 (2 Y)	YES	9	ROT FLEX EXT	43	18	8	23	NO	NO	1	EXT	9	23	8	23	YES
Case 2 (18 M)	YES	8	ROT FLEX EXT	30	12	1	2	NO	NO	1	LFT ROT	6	13	3	12	YES
Case 3 (6 Y)	YES	9	ROT FLEX EXT	39	16	0.5	1	NO	NO	1	RT ROT	5	14	3	14	YES
Case 4 (1 Y)	YES	8	ROT FLEX EXT	35	22	1	6	NO	NO	0	LFT ROT	8	24	3	9	YES
Case 5 (3 M)	YES	9	ROT FLEX EXT	18	9	3	5	NO	NO	0	LFT ROT	8	13	3	9	YES

TOR torticollis, VAS visual analogue scale, CROM LIMIT cervical range of motion limitation, ROT ANG C1–C2 rotational angle, O-C2 occipitoaxial angle, DISTAL SEG LOR distal segment lordotic angle, COB cervical Cobb’s angle, FUS fusion

Table 2.

Fielding–Hawkins classification of atlantoaxial rotatory fixation

Fielding–Hawkins classification of atlantoaxial rotatory fixation
• Type I: Rotatory dislocation without anterior displacement, intact transverse ligament, and the dens acting as the pivot point
• Type II: Rotatory dislocation with anterior displacement between 3 mm and 5 mm, injured transverse ligament, and the opposite facet acting as the pivot point
• Type III: Anterior rotatory dislocation of both facet joints with anterior displacement > 5 mm and injured transverse ligament and facet capsules
• Type IV: Posterior rotatory dislocation of both facet joints

Adopted from ref. [12]

Conclusions

AARS is a rare condition with few case reports in literature; hence, managing it properly is a dilemma for spine surgeons. Both conservative and surgical therapeutic strategies should be applied coherently to achieve optimal outcomes. It is worth noting that surgical modality, as has been presented in present essay, should not be avoided or postponed in patients in whom nonsurgical management has failed.

Author contributions

Investigation: KY, HJ, STK, and ASM; data gathering: HJ, ASM, and BS; writing—draft: KY, ASM, BS, STK, and SZ; and writing—revision: STK and SZ.

Funding

Not applicable.

Availability of data and materials

Further data may be made available upon reasonable request from the corresponding author.

Declarations

Ethical approval and consent to participate

Written informed consent was obtained from the patients for participation in this study.

Consent for publication

Written informed consent was obtained from the patients for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

The authors declare that there is no conflict of interests in design, execution, and drafting of this study.