A CLINICAL CASE OF MULTI-STAGE SURGICAL TREATMENT OF A PATIENT WITH VERTEBRAL IMPLANT-ASSOCIATED INFECTION Kochnev E.Ya., Mukhtyaev S.V., Meshcheryagina I.A., Grebenyuk L.A.
Russian Ilizarov Scientific Center for Restorative Traumatology and Orthopaedics, Kurgan, Russia
The incidence of purulent infections after spinal surgery varies from 0.7 to 20 %. For polytrauma, the percentage is quite high (about 10 %). For surgery of spinal deformations, the risk of surgical site infection (SSI) varies from 1.9 to 4.4 %. There are some findings of risk of deep infection in surgical site after surgery of deformations in children at the age < 21 (3.6 %). The literature describes the dependence on location and selection of a surgical approach. So, for example, the rate of purulent complications is below 0.07 % for anterior cervical approach with discectomy and spondylodesis. However, for posterior approach, the risk increases to 2,94 %. According to various findings, surgery of oncologic diseases of the spine has the risk of purulent process from 2.4 to 7.1 %, and after radial therapy, the probability of SSI can achieve 32 %. The realization of surgery with lumbar spine fusion causes purulent complications in 8.8-12.2 % for revision surgery at the same level [1-6]. One of the first researchers ,who paid attention to high risk of SSI after spinal manipulations, was Thalgott J.S. in 1991 [7], who noted a high increase in probability of purulent process with increasing ISS (Injury Severity Score) to 18 and more. In his work, the author paid attention to correlation between factors of resistance of the body exposed to spinal surgery, and considered the risk factors of postsurgical infection. Particularly, Thalgott J.S. considered immunity as one of the most important parameters of protection of the body from purulent processes.
Subsequently, some studies with different opinions appeared. There is an opinion in scientific and practical medicine that patient's age is a burdening factor of purulent complications after spinal surgery. However, there are no findings confirming this point of view now. Moreover, concurrent diseases, which are almost always appear with body ageing, can be factors of high risk of SSI [2, 7, 8].
Diabetes mellitus (DM) gives at least 4.1-fold increase in probability of postsurgical wound purulence. The cause consists in the fact that disordered microcirculation, which is related to DM, can worsen oxygen delivery to peripheral tissues, resulting in decreasing systemic ability to resist an infection. Also hyperglycemia can disorder the leukocyte functions such as adhesion, chemotaxis and fagocitosis, resulting in decreasing immune protection of the body. Moreover, DM causes disorders of collagen synthesis and fibroblast proliferation which influence on postsurgical wound healing [8].
Currently, there are some contradictive opinions that high volume of surgical intervention, high blood loss and long duration of surgery increase the probability of purulent complications in surgery spine. However, the Second International Consensus Meeting on Musculoskeletal Infection resulted in achievement of the strong consensus towards influence of the above mentioned causes of purulent process [4, 8, 9].
The available studies show that transfusion of blood components in surgery is the independent predictor of postsurgical purulent complications. This relationship with hemotransfusion is explained by development of immune suppression by means of influence of antigens in transfused blood products on T-lymphocytes, and also by possible bacterial contamination of transfused blood products, including autoblood collected during surgery [4, 8, 9].
A previous surgical intervention for the spine can have high probability of purulent complications. The use of the combined approach for the lumbar spine is associated with higher trend to postsurgical purulent processes as compared to posterior approach. Conversely, for the thoracic spine, only the posterior approach gives higher probability of surgical wound purulence as compared to anterior one. If the combined approach is required, it is desirable to perform it with a single stage of surgical intervention [8].
According to some studies, the high body mass index (BMI) can be the risk factor of SSI. For BMI > 35, the probability of purulent infections increases almost two times [2, 4, 5, 9, 10].
Urinary tract infection also can be the risk factor of postsurgical purulent process. Installation of the urine catheter for more than five days can promote urinary tract infection [1]. Smoking causes vasoconstriction and tissue hypoxia, and decreased collagen proliferation in the surgical wound which negatively influences on healing of soft tissues of the back and is a risk factor of vertebral SSI [2, 7-10].
Malnutrition and hypoproteinemia, especially with hypoalbuminemia, are independent predictors of spinal purulent process in the postsurgical period [2, 7, 8].
Objective – to show a clinical example of the result of multi-stage surgical treatment of a patient with polytrauma, complicated by vertebral implant-associated infection and neurological deficit.
MATERIALS AND METHODS
The study corresponds to the ethical standards and norms of legislation of the Russian Federation. The patient gave the informed consent for participation in the study and for data publishing.
The patient, female, age of 45, was admitted to Ilizarov Center. There were some complaints of muscular weakness and disordered sensitivity in her lower extremities, pain in the thoracolumbar spine, a fistula in the left lumboiliac region, and periodical increase in body temperature to 38 °C.
The anamnesis data included the falling from the height 4 months ago. Immediately after trauma, she was admitted to a hospital according to her place of residence. She was examined. The fractures of the second vertebrae and both bones of the right leg were found, as well as a dislocation of the left ankle bone. Surgical treatment was carried out at that hospital: thoracophrenolumbotomy to the left, L2 resection, medullary cone decompression, interbody fusion with mesh implant and ventral screw construct. At the same time, the patient received plate fixation for the right leg, and screw fixation through the left tarsus.
The patient was discharged for outpatient treatment. Her condition was satisfactory. A fistula appeared in the late postsurgical period. It was in the site of the installation of the drain after thoracophrenolumbotomy.
After admission to Ilizarov Center, clinic of purulent osteology, the patient had some complaints of muscle weakness, disordered sensitivity in her lower extremities, pain in the lumbar spine, periodical increase in body temperature to 38 °C. Urination was through the urethral catheter.
There were abnormal changes in neurological status. Movements in the lower extremities were limited by contractures of hip, knee and ankle joints. Brisk knee reflexes D = S, decreased Achilles reflex. The tone in the legs was decreased. Muscular strength was about 3.5-4 points. Leg muscles were hypotrophied. There were no abnormal foot signs. Proprioceptive sense was normal. Abdominal reflexes were normal. The stretch symptom was positive, with higher value to the left. Sensitive disorders with conduction type with hyperesthesia and L1 dermatoma. Disordered function of pelvic organs with difficult urination.
The examination was in the dressing ward. A fistula (0.5 × 0.5 cm) with little mucopurulent discharge was found in the lumboiliac region to the left. A smear was taken for microbiological study. It found Staphylococcus aureus (10 × 5 CFU/ml), sensitive to vancomycin. The figure 1 presents a picture of the patient's back.
Figure 1
A picture of fistular passage
The laboratory analyses were performed after admission. Clinical blood analysis: leukocytes − 8.5 × 109/l, erythrocytes − 4.62 × 1012/l, hemoglobin − 102 g/l, hematocrit − 35.1 %, platelets − 588 ×109/l, ESR − 110 mm/h. Leukocytic formula: band neutrophils − 1 %, segmentonuclear neutrophils − 68 %, eosinophiles − 1 %, monocytes − 2 %, lymphocytes − 28 %. Biochemical blood analysis: increasing transaminase (alanine transaminase − 83 U/l, aspartate transaminase − 57 U/l). Total urine analysis: mild proteinuria − 0.25 g/l, single erythrocytes (8-10 per field of view) and leukocytes (15-20 per field of view).
Fistulography and computer fistulography of the lumbar spine were conducted (Fig. 2).
Figure 2
Fistulography and computer fistulography of the lumbar spine determines the condition after surgical intervention. Deformation of L2 vertebral body. Th10-L5 segments have been fixed with metal construct and L1-L3 implant.
After examination, a decision on surgical management was made.
The stage 1 of surgical management: thoracolumbar spine fusion with apparatus for external transpedicular fixation. In the postsurgical period, the antibacterial therapy was conducted with cephalosporin of 3rd generation (2 g per 100 ml of saline, i.v., drop infusion, 2 times per day) up to the stage 3 of surgical management.
The figure 3 shows X-ray imaging after surgical management.
Figure 3
The X-ray images of the thoracolumbar spine in two planes: condition after surgical treatment, deformation of L2 body. Segments Th10-L5 have been fixed with metal construct, L1-L3 – with implant.
After 1 and half of the month, the stage 2 of surgical management was conducted: removal of internal metal construct (screws and mesh implant) through lumbotomy approach to the left; ultrasonic preparation of bone cavities and retroperitoneal leaks, draining.
Vancomycin was added to previously prescribed antibiotic therapy (1 g per 400 ml of saline, i.v., drop infusion, for the whole period of hospitalization).
The figure 4 shows spondilography after surgical management.
Figure 4
The lumbar spine X-ray image in two planes: condition after surgical management of lumbar spine, stable fixing construct, partial resection of L2 vertebra; Mesh implant removed.
The stage 3 of surgical management was carried out 1 month after removal of internal metal construct: dismounting of external transpedicular fixation apparatus, ultrasonic preparation of screw channels, spondylodesis for Th10, Th11, Th12, L4, L5 and S1 with internal construct for transpedicular fixation (Stryker), draining.
Figure 5 presents spondilography of the patient after surgical management.
Figure 5
Lumbar spine X-ray images in two planes: condition after surgical treatment, stable fixing construct, destruction of bone tissue in L2, intense cystic rebuilding of bodies and arches of L1-L3.
In 3 weeks, the patient was discharged for outpatient follow-up according to place of residence. Antibiotic therapy was 6 weeks. Then, she was admitted for the next stage of surgical management.
One year after sanitation of osteomyelitis, the patient was admitted to Ilizarov Clinic of Low Invasive Spine Surgery and Oncovertebrology.
At admission, the neurological status was positive: movements in lower extremities were limited by contractures in ankle joints. Knee tendon reflexes D = S abs., Achilles reflexes D = S abs. Low tone in lower extremities. Muscle strength in distal parts to the left − 3.5-4 points, to the right − 4.5-5. Hypotrophy of leg muscles. No abnormal foot signs. Normal proprioception. Constant abdominal reflexes. Tension symptom − negative on both sides. Sensitive disorders of hyperesthesia type with L4 dermatomas on both sides. No disorders in pelvic organs functioning.
The patients received the 4th stage of surgical management: corpectomy for L2 vertebra through posterior-lateral approach; interbody corpodesis for L1-L3 with mesh titanium implant; removal of screws in S1 vertebra; additional fixation of L3; remounting of metal construct.
The figure 6 shows spondilography after surgical management.
Figure 6
Thoracolumbar spinal X-ray images in two planes: condition after surgical management, osteoporosis, deformation of L2 body, Schmorl's nodule in Th9, decrease in height of intervertebral disk in L1-L4, L5-S1; sclerosis of endplates Th8-S1; Th11-L5 segments fixed with metal construct, L1-L3 – with implant; correct position of construct and implant
On 10th day, the patient was discharged for rehabilitation course (14 days).
After 3 years, at the moment of control examination, the patient had no signs of purulent process. There were some complaints of combined contracture of the right ankle joint. The disability status was cancelled.
The figure 7 presents CT imaging of the thoracolumbar spine.
Figure 7
CT after 3 years: stable metal construct, no fractures of screws
DISCUSSION
The use of transpedicular external fixation apparatus was firstly described by Magerl F. in 1977. Despite of the fact that this construct was designed for fixation, it could be used for compression and distraction. Later, in 1994, Jeanneret B. and Magerl F. published a report on successful use of transpedicular external fixation apparatus for osteomyelitic lesion of the spine. We think that it is irrationally to refuse from external transpedicular fixation for situations where its use is substantiated: purulent vertebral process − for temporary extrafocal fixation, and, possibly, for correction of deformation with conversion to internal transpedicular system, or for gradual correction of evident spine deformations and for surgery of spondylolisthesis with high risk of neurological complications when single-stage correction is used [11, 12, 13].
CONCLUSION
The selected strategies of complex multi-stage treatment of this patient based on clinical picture of the disease, and adherence to subsequence and principles of treatment of purulent processes allowed solving all tasks: achievement of persistent remission of purulent process, improvement in life quality.
Information on financing and conflict of interest
The study was conducted without sponsorship.
The authors declare the absence of any clear and potential conflicts of interests relating to publication of this article.