Delayed presentation of Candidal Vertebral Osteomyelitis following penetrating spinal injury

1. Introduction

Missile based penetrating spinal injuries (MPSI) are common in military warfare and have been extensively reported in combat zone.¹ Non missile penetrating spinal injuries (NMPSI) often occur due to stab injuries with various weapons and have been reported in both civil and military life.^2,3 We report a case of NMPSI with extensive abdominal trauma resulting in CVO and describe its successful management with a review of literature.

2. Case report

A 33-year-old fisherman had sustained an extensive penetrating injury of the abdomen due to a projectile dislodged from a boat engine, following an engine blast. The projectile had cut through the abdominal wall resulting in complete prolapse of abdominal contents. The high velocity of the projectile had caused damage to spinal musculature and even resulted in stable vertebral fracture of fourth lumbar vertebra. He underwent emergency laparotomy after immediate resuscitation and initial assessment. During surgery, multiple complete transections of the colon were noted, for which he underwent resection of contaminated and necrosed parts, followed by sigmoid-sigmoid colon and ileum –ascending colon anastomosis and repair of multiple perforations of small intestine. In addition, he required ileac colostomy and abdominal wall repair at the first stage. He also had a ureteric injury for which double J stenting (DJ) and ureteric repair was done. Due to the grievous nature of abdominal injury and the stable nature of L4 fracture, the spinal injury was treated conservatively. MRI of the lumbar spine showed transected L4 nerve root close to the neural foramen incurred by the projectile injury. Considering the extensiveness of open injury and postoperative spikes of fever, routine blood, urine, endotracheal secretions, axillary, groin and loin samples were sent for culture and sensitivity. Initially urine culture yielded Burkholderia Cepacia, known to dwell in marine environments and was managed by Meropenem for a period of 7 days.

One month after the initial injury, the patient had enormous purulent discharge from the wound over the lateral abdominal wall which yielded Candida. The patient underwent drainage and debridement of the abscess. Subsequently he was ambulatory with a lumbosacral corset and had recovered from back pain completely. However, ten weeks post-injury, he started experiencing excruciating low back ache, and difficulty in walking for which he was referred to us.

On examination the patient had severe para-spinal spasm and restriction of spinal movements. Neurological deficit was noted in his right L3 and L4 roots with Medical research council (MRC) grade 3. His MRI and CT scan of lumbar spine (Fig-1) revealed a comminuted fracture of L4 vertebra through the right lateral aspect of the vertebral body, right pedicle and lamina with subtle displacement of the fractured segment causing right foraminal and mild canal stenosis. Extensive damage to the psoas and erector spinae muscles were noted. Altered subchondral marrow signal intensity changes on either side of L3-L4 and L4-L5 disc spaces, fluid collection in the disc space was observed, along with the presence of a right paravertebral abscess raising the suspicion of infective vertebral lesion. Elevated ESR values of 53 mm/hour and CRP of 18 mg/l were further suggestive of infective spondylodiscitis. However, there were no clinical or systemic features of infection. A blood and urine culture examination, to isolate microorganism, did not yield any growth.

Fig. 1.

A) Sagittal right paracentral T2 weighted MRI images showing altered signal intensities of L3-L4 and L4-L5 adjoining endplates and disc in addition to L4 vertebral involvement suggesting infection, B) Right parietal wall involvement and paravertebral abscess seen in axial images, c) Sagittal CT image with arrow pointing towards the comminuted fracture fragments lying freely and close to the vertebral foramen and D) Axial CT image depicting the foraminal stenosis due to the large chunk of bone fragment.

Surgical debridement, washout and instrumented stabilization along with nerve root decompression, was performed using the posterior approach. Using standard surgical methods, L3-L5 posterior stabilization with intermediate pedicle screws at L4 and decompression was done. Inter-transverse fusion using local bone graft was performed on the contralateral side. Extensive scarring of soft tissues resulting in dural adhesions were noted. Unhealthy granulation tissue was observed in the right foramen below L4 pedicle encompassing the L4 nerve root. Nerve root was found to be compressed by the fracture fragment and henceforth debulking was done to free the same. After thorough debridement, the unhealthy tissue samples were sent for culture and histopathological examination. Copious saline irrigation of the debrided area was done. Wound was closed in layers after achieving hemostasis over a deep sub facial drain. The patient was started on intravenous cefaperazone and sulbactum, based on isolation of Burkholderia Cepacia from urine in his previous medical reports.

Tissue staining of the intra-operative samples showed yeast cells (Fig-2) and culture revealed Candida Albicans infection. Based on anti-fungal sensitivity, Fluconazole was started and continued for a period of 6 months. The patient was mobilized on the second day following surgery and was started on a structured rehabilitation program. Immediate postoperative MRI showed adequate nerve root decompression and follow up MRI demonstrated significant improvements in signal intensities and good healing of endplates (Fig-2). He improved symptomatically, and all serum markers of infection and inflammation returned to normal levels at 6 months. Neurologically, he improved by one grade and CT (Fig-3) was repeated by the end of one year, which showed good osseous bridging and healing.

Fig. 2.

A) Immediate postoperative MRI with arrow showing discal and marrow signal hyperintensity and B) and C) Follow up MRI at six months and 1 year shows good healing with reversal of altered intensities. D) Right paravertebral abscess and E) & F) its resolution following antibiotic treatment and debridement. G) & H) Gram stains showing budding yeast cells.

Fig. 3.

Serial radiographs A) Anteroposterior view and B) Lateral images taken preoperatively, and at 3 and 6 months following surgery showing progressive healing of the vertebral body. CT C) Axial section and D) coronal section at one year showing healing by osseous bridging and complete healing of bony defects.

3. Discussion

We report here for the first time, a case of Candidal Vertebral Osteomyelitis following Non-missile penetrating abdominal injury which resulted in multiple colonic perforations and complete prolapse of abdominal content along with comminuted spine fracture. Candidal Vertebral osteomyelitis (CVO) is a rare entity, usually found in immunocompromised patients and were never reported until 1970.^4,5 70% of Candidal osteomyelitis is believed to have hematogenous spread and 30% due to contiguous infection. The incidence of CVO is only 1% among all cases of vertebral osteomyelitis. Candida Albicans is the most common sub-species noted.^6,7 There is usually a delay between the onset of candidemia and full blown osteomyelitis, which varies from months to even 3 years.^8,9

Unlike pyogenic spondylodiscitis, CVO lacks systemic features.^10,11 In this particular case, the initial diagnosis considered was Pseudoarthosis of the lumbar fracture based on the relatively symptom free period following the injury and lack of systemic signs of spinal infection. However, on further investigations by MRI, CT and correlation with blood parameters, infective spondylodiscitis was diagnosed. Henceforth, a high index of suspicion is to be maintained especially in contaminating injuries of the spine.

The source of infection may be through retained foreign objects, direct contamination from hollow visceral intestinal contents, blood stream from another secondary foci or even the primary penetrating object. In traumatic events, concurrent injuries may delay diagnosis of vertebral infections.¹² Multiple risk factors have been reported for CVO which include immune-suppression, presence of intravenous catheter, recent abdominal surgery, parenteral nutrition and recent use of broad spectrum antibiotics. This patient had normal immunological status at presentation which was evident by the normal blood cell counts, albumin and Hemoglobin levels. Yet the severity of trauma and need for parenteral nutrition and repeated abdominal surgeries puts him at a high risk for secondary infections. Though ESR, CRP, blood and urine culture are to be done routinely in all individuals suspected to have vertebral infection, MRI remains the gold standard in diagnosing vertebral osteomyelitis.¹³ MRI also helps in identifying nerve root injury, tracking sinus if any, locating paravertebral abscess, identifying extent of infection and in monitoring response to treatment.¹⁴

Management of penetrating injuries to spine, depends on mode of injury as well as time since injury.15, 16, 17, 18 Though there is no strict consensus, acute surgical intervention has been well accepted especially in those with large retained foreign objects, neurological deficits and CSF leaks. Early decompression is said to have better neurological outcomes.^19,20 In our case, surgery was deferred at the primary center due to the initial moribund status of the patient. Administration of broad spectrum antibiotics for a minimum of 24–48 hours has been recommended in such cases to avoid secondary infections.²¹

Among all possible causes of vertebral osteomyelitis, fungi contribute only around 1–2%.²² Organisms reported in penetrating injuries of spine include mainly Gram positive bacteria –Staphylococcus Aureus and Staphylococcus Epidermidis in patients without hollow visceral injury and Gram negative bacteria such as E. coli, Enterococci, and Proteus Mirabilis in those who have transabdominal injury. However, Candidal infection following such injuries has not been reported. The ideal way to manage such infections, would be to identify the organism through tissue or pus culture, obtained either by percutaneous or open techniques. Administering appropriate antibiotics at an adequate dosage is the most important step toward managing fungal infections.²³ The duration of chemotherapy in CVO has been debated widely. However they may be extended till complete clinical and biochemical evidence of eradication of infection.²⁴ Antifungal treatment is either administered as monotherapy, sequential or combination therapy (in cases of severe candidemia and inadequate response). Though Amphotericin B was considered the first line drug of choice in the past, Azoles have been found to be equally effective and much safer.²⁵ Fluconazole has been the most common antifungal drug administered over recent years. The current consensus is to continue therapy for at least for a period of 6–12 months.²⁶

4. Conclusion

Candidal Vertebral Osteomyelitis (CVO) unlike other causes of spinal infections lacks systemic features. Delayed exacerbation of local symptoms following penetrating injuries of spine should arouse suspicion among surgeons regarding the possibility of spinal infections. Surgical debridement and instrumentation is safe in CVO. Among the anti-fungal agents, Azoles are currently preferred, due to their drug safety and efficacy and need to be administered at least for a period of six months. Our rare case of CVO was successfully managed by debridement, instrumented stabilization and antifungal therapy and the patient returned to his pre-injury functional status.

Conflicts of interest

None.

Informed consent

The patients consent was obtained to publish this material.

Financial disclosures

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