Upper cervical spine instability due to pyogenic infection successfully treated by one stage posterior debridement and stabilization: Case Report and literature review

INTRODUCTION

Pyogenic infections of the spine are generally rare, representing about 3%–4% of all bone infections. Among these, only 3%–12% are confined to the cervical spine.^[1-6] Upper cervical spine pyogenic infection is not common compared to other vertebral segment infections, and it is usually associated with unfavorable clinical outcomes.^[7] Several factors have been recognized in the literature, potentially predisposing to the development of C1-C2 osteomyelitis, including the elderly population, immunocompromised patients, and patients with associated comorbidities, such as diabetes, hypertension, and end-stage renal disease.^[6,8] Besides, upper cervical pyogenic infection diagnosis can be challenging; patients usually present with vague symptoms, and the occiptocervical pain may not be severe. High clinical suspicion is needed to reach the diagnosis.^[2] The delay in diagnosing upper cervical osteomyelitis might result in undesirable management delays, which could lead to instability and neurological deficits. The reason behind this is due to its unusual location and relatively rare occurrence. We found only 15 papers about upper cervical osteomyelitis in English literature from 1995 to 2020 [Table 1]. We hereby describe the case of a middle-aged gentleman who presented with a pyogenic infection involving the occipital condyles, the atlas and the axis with severe instability to show that the posterior approach without the anterior transoral approach is a valid surgical option in these cases. Additionally, we emphasize the importance of stabilization to successfully treat spine osteomyelitis and summarize the literature available discussing upper cervical spine infection treatment options.

CASE REPORT

A 65-year-old male was transferred to our hospital with severe neck pain and stiffness for two months associated with occipital pain, which affected his quality of life. He has been bedridden for two months because any movement caused excruciating neck pain. There was no history of fever, trauma, multiple joints pain, or exposure to tuberculosis or brucellosis. He was admitted to another hospital for two months, and despite doing many investigations and imaging, no clear pathology was identified. He had a positive history of diabetes, hypertension, bronchial asthma, hypothyroidism, ischemic heart disease (post angioplasty), transient ischemic attack, and old acute kidney injury requiring temporary hemodialysis.

Upon physical examination, the patient was in an acute delirium state, and in an altered general condition, confused with a Glasgow coma scale score of 13/15. His oxygen saturation was 89% on room air, catching up to 98% on 2 L/min nasal cannula, while the remaining vital signs were within normal limits. A diffuse tenderness was noted throughout the cervical spine, and the range of motion was limited due to pain. No warmth, redness, or skin changes were noticed over the cervical region. It was difficult to assess his neurological examination due to confusion, but it was grossly intact, with no upper motor neuron signs.

Laboratory studies at admission showed a white blood count (WBC) of 16.00 cells per cubic millimeter of blood, C-reactive protein (CRP) of 115 mg\dl, erythrocyte sedimentation rate (ESR) of 120 mm\hour. Tumor markers and Brucella titer were all within normal limits, and Quantiferon-TB and purified protein derivative were negative. The cervical spine radiographs showed a destructive lesion with gross occipitocervical instability [Figure 1]. A computed tomography (CT) scan demonstrated a destructive lytic lesion involving C1 and C2 with evidence of instability [Figure 2].

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Figure 1:

Cervical spine radiographs showing a destructive lesion with gross occipitocervical instability.

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Figure 2:

A computer tomography scan demonstrating destructive lytic lesion involving C1 and C2 with evidence of instability.

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Gadolinium-enhanced magnetic resonance imaging (MRI) revealed mild cord compression, aggressive and destructive lesion predominately involving the body of C2, odontoid process, anterior and posterior arch of the C1 vertebra, with extra-osseous soft tissue component at the craniocervical junction and involvement of the prevertebral and paraspinal musculature [Figure 3].

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Figure 3:

MRI revealed mild cord compression, aggressive and destructive lesion predominately involving the body of C2, odontoid process, anterior and posterior arch of the C1 vertebra.

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Carotid angiography CT scan showed occlusion of the 2^nd segment of the left vertebral artery at the level of C1. Histological and microbiologic examinations from CT guided biopsy taken from C1–C2 paraspinal mass were all inconclusive.

The patient was scheduled to undergo a single session open biopsy from C1–C2 lesions, irrigation and debridement, and posterior cervical spine instrumentation and fusion from occiput to C6. The patient was labeled as American Society of Anesthesiologists (ASA) class 4, and he signed high-risk consent.

Surgical procedure

Under general anesthesia with endotracheal intubation, the patient was placed on Mayfield cervical management set in a prone position. Posterior cervical spine instrumentation and fusion from occiput to C6 using an intraoperative navigation system, an open biopsy from C1–C2 lesions with irrigation and debridement were performed. The left side of the C1 lateral mass was chosen to access the anterior collection based on the fact that the left vertebral artery was occluded, 5 cm³ of pus were drained. Soft tissue and bone samples were taken for histological and microbiological studies.

Bilateral C2 intralaminar screws were used due to the advanced destruction of the C2 pedicles and pars interarticularis. A third rod was added to increase the stability of the construct. At the end of the surgery, a suction drain was inserted. There were no complications during the procedure, and the patient was stable intra-operatively. Tissue, bone, and fluid samples were sent for gram stain, culture and sensitivity, TB PCR, acid-fast bacilli, TB culture, fungal culture, and histopathology.

Following the surgery, infectious disease team started the patient empirically on the following antibiotics: piperacillin/ tazobactam 4.5 g IV Q6h, vancomycin 15 mg/kg IV Q8h, rifampicin 600 mg PO once daily.

Five days later, the result of histologic and microbiologic examinations confirmed the presence of methicillin-sensitive Staphylococcus aureus. Vancomycin and piperacillin\ tazobactam were discontinued. The patient was started on cefazolin intravenously (2 g/6 hours) and rifampicin orally (600 mg once daily). Gradually and over the next four weeks, there was a clinical improvement; the patient was stable vitally and without neurological deficit, his confusion was completely resolved, his nutritional status improved, and he started mobilization with an extensive physiotherapy program. The antibiotic treatment was changed to a two-week oral course using cephalexin (650 mg\6 hours) and rifampicin (600 mg once daily). The patient was discharged from the hospital with a hard collar for a total of 12 weeks following the surgery. Laboratory studies at discharge showed a WBC of 5.32 cells/cm³ of blood, CRP of 12 mg/dl, ESR of 2 mm\hour. On follow-up visits at 3 and 6 months, one year and 2 years, the patient had completely recovered, with a normal WBC, CRP, ESR. Six months after surgery, the cervical spine radiographs revealed good alignment, stability, and reossification of the C1 and C2 vertebrae [Figure 4]. CT scan showed reformation of the odontoid process, bone healing of the C1 and C2 and fusion, stable positioning of the instrumentation with no signs of screw loosening [Figure 5].

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Figure 4:

Radiographs showing good alignment, stability, and recalcification of C1 and C2.

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Figure 5:

CT scan showed reformation of the odontoid process, bone healing of the C1 and C2 and fusion.

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DISCUSSION

In the current case, there was a two-month delay in the diagnosis despite doing many investigations, including MRI, which was inaccurately reported by the radiologist at the other hospital as degenerative changes without mentioning the infection. Consequently, when the patient presented to our clinic, there was already evidence of instability in the radiograph and CT. In the literature, we found that the delay in diagnosis time is common. In the Schimmer et al. case series,^[2] two patients with C1–2 osteomyelitis were studied. The delay between the onset of symptoms and diagnosis was 5 and 8 weeks, respectively, while in Barnes et al. literature-based review,^[6] three publications provided data on the meantime between the onset of symptoms and diagnosis; the range was between 14.4 and 17.9 weeks.

Elevation of inflammatory markers is common in cervical spine infection and methicillin-sensitive Staphylococcus aureus is the most common organism.^[9] Rezai et al.,^[10] retrospectively reviewed 57 patients with pyogenic spinal osteomyelitis. At the time of admission, for 55 patients, ESR was 65 mm/h, two patients within a normal range, the WBC was 11, and blood cultures yielded positive results for 23 of 30 (77%) patients. The organisms from these cultures included methicillin-sensitive Staphylococcus Aureus in 16 cases, methicillin-resistant Staphylococcus aureus in 4, Streptococcus pneumoniae in one, Streptococcus agalacticae in one, and Escherichia coli in one.

Several factors have been recognized in the literature, potentially predisposing to the development of C1–C2 osteomyelitis seen in the current case, including the age of the patient, immunocompromised status and his comorbidities.^[6,8]

Optimal management for upper cervical infection is debatable and should be adjusted according to the patient’s condition, presentation time, presence of instability, and neurological deficit.

In the current case, cervical spine instability was managed by posterior fusion from occiput to C6, an open biopsy from C1–C2 lesions and irrigation and debridement. Since the organism was not identified by image-guided biopsy, besides we needed to address the cervical spine instability. We accessed the lesion through the left side C1 lateral mass because the left vertebral artery was occluded. We were also able to take soft tissue and bone for histological and microbiological studies through this access. Furthermore, due to the advanced destruction of C1, screw insertion in its lateral masses was not feasible. So, we added a third rod to increase the stability of the construct. Similarly, due to the advanced disease involvement and destruction of the C2 pedicles and pars, the only option for C2 fixation was interlaminar screws. Bone graft was not used due to the active infection. Biomechanical studies have shown that constructs that incorporate C2 interlaminar screws provide adequate rigidity and reliable stability with comparable results to constructs utilizing C2 pedicles or pars screws.^[11,12] Intraoperative navigation was chosen to perform screw insertion and debridement for a safer procedure.^[13]

We chose a single session surgical approach to establish a histological and microbiologic diagnosis, prevent neurologic deterioration, eradicate the infection, achieve cervical spinal stability, and prompt early cervical fusion. Furthermore, since our patient had many medical comorbidities, he was not the ideal candidate for multiple anesthesia and surgeries. The anterior approach was an option, but due to many medical comorbidities and the patient’s condition, we preferred to manage all from the posterior, as the anterior transoral approach would have been aggressive.

Spine fusion and instrumentation in the presence of active infection represent a dilemma to the surgeons. In the last three decades, there was an increase in the number of articles supporting spinal instrumentation in the presence of active infection.^[14,15] These articles have demonstrated that instrumentation can be used safely, and it will lead to more stability that promotes infection clearance.

Screven et al. believe that the spine instrumentation and fusion in the presence of active infection should be carried out urgently and without delay to prevent neurological deterioration.^[16] In a consecutive series of 32 immunocompromised patients with pyogenic vertebral osteomyelitis treated with instrumentation in an acute setting, Carragee and Iezza found a low risk of recurrence over ten years follow-up.^[17] On a follow-up visit at two years, our patient had recovered completely. CT showed complete ossification and fusion of the upper cervical spine with no signs of screw loosening.

CONCLUSION

High index of suspicion is needed to adequately diagnose upper cervical spine infections, appropriate radiological work up is indicated in a timely fashion to avoid delay in diagnosis that may result in poor prognosis and catastrophic neurological complications. Spinal stability is integral part of spine infection treatment along with identifying the organism and appropriate antibiotics treatment. Successful treatment of upper cervical spine infection may be achieved with all posterior surgical intervention, thus avoiding the high morbidity of the upper cervical spine anterior approaches.