unusual complications of cervical spine surgery for

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Cervical myelopathy is a recognized complication of rheumatoid arthritis and other ... We report two cases that illustrate some potential complications of cervical ...
British Journal of Rheumatology 1996;35:682-685 CASE REPORT

UNUSUAL COMPLICATIONS OF CERVICAL SPINE SURGERY FOR CERVICAL MYELOPATHY IN RHEUMATOID ARTHRITIS R. MUNRO, M. DUNCAN, H. A. CAPELL and R. JOHNSTON* Centre for Rheumatic Diseases, Glasgow Royal Infirmary and *Institute of Neurological Sciences, Southern General Hospital, Glasgow SUMMARY Cervical myelopathy is a recognized complication of rheumatoid arthritis and other inflammatory arthropathies. In a significant proportion of patients, surgical stabilization of the cervical spine offers the best opportunity for improvement of symptoms and long-term survival. We report two cases that illustrate some potential complications of cervical spine surgery and which also emphasize the need for vigilance when caring for patients in this group. KEY WORDS: Cervical myelopathy, Surgery.

CASE 1 A 64-yr-old patient with a 17 yr history of seropositivc erosive rheumatoid arthritis was referred for neurosurgical assessment for cervical myelopathy. Her main symptoms Submitted 25 July 1995;revisedversion accepted 2 February 1996. Correspondence to: R. Munro, Centre for Rheumatic Diseases, Glasgow Royal Infirmary, Castle Street, Glasgow.

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were limb weakness and difficulty in walking. Examination showed brisk reflexes with no objective evidence of muscle weakness. Prior to assessment, she had been reasonably well apart from a coxsackie virus illness 10 weeks previously. She had been treated with second- and third-line agents over the course of her disease. The most recent was chlorambucil which had been stopped during her viral illness, although her white cell count was satisfactory at that time. X-rays of her cervical spine showed subaxial disease with 4 mm stable subluxation of C3 on C4 and 5 mm of subluxation on flexion of C4 on C5. Further assessment included MRI of her cervical spine, which showed severe cord compression (Fig. 1). In view of her symptoms and radiological findings, surgical stabilization was indicated. The procedure involved anterior cervical vertebrectomy with bone graft and plate fixation. At the same procedure, she underwent transoral resection of her odontoid peg with posterior fixation with cement and wires using the Brattstrom technique. The initial post-operative period was unremarkable and she was transferred back to the rheumatology ward on the fourth post-operative day. On day 7 post-operatively, she complained of visual hallucinations and became paranoid. Similar episodes had been noted following previous joint surgery. Over the next 4 days, she had further episodes of confusion, but remained apyrexial and physical examination, including neurological assessment, was unremarkable. On day 16, she complained of unsteadiness on sitting upright and became pyrexial with truncal ataxia, although there were no other new abnormal neurological findings. Laboratory investigations showed the development of a leucocytosis (white cell count 15.3 x 10'/0 and a positive sputum culture which grew scanty Staphylococcus aureus. Other investigations, including a chest X-ray, were unremarkable. She was commenced on oral flucloxacillin for a presumed chest infection and an urgent head CT scan was performed. This showed an area of low attenuation in the left cerebellar hemisphere with ring enhancement following contrast consistent with an abscess (Fig. 2). She was immediately transferred back to the neurosurgical unit for drainage of the abscess. Although culture of the fluid was negative, she was treated withflucloxacillinfor a total of 8 weeks. The remainder of her recovery was unremarkable and she suffered no further sequelae in relation to the abscess.

INVOLVEMENT of the cervical spine is common in inflammatory arthropathies. In rheumatoid arthritis, up to 85% of those with moderate to severe disease will have X-ray changes in the cervical spine [1], although only a small proportion of these patients will be symptomatic. Symptoms range from mild discomfort in the occipito-cervical region to severe occipital pain, and from mild intermittent weakness to at worst sudden quadriparesis. Cervical spine involvement is usually defined according to the anatomical site, i.e. either atlanto-axial or subaxial, although both may co-exist in the same patient. Atlanto-axial disease is the most commonly observed type in rheumatoid arthritis and is due to damage to the transverse ligament and/or pannus formation at the synovial lined joint around the odontoid peg. Subluxation may be fixed or reducible and most often involves Cl moving forward on C2. Surgical intervention is indicated if there is progressive neurological deterioration or for intractable cervical/occipital pain. Untreated cervical spine disease with a neurological deficit carries a poor prognosis with up to 50% of patients dying in the first 6 months of follow-up [2, 3]. Surgery to the cervical spine is not without substantial risks; these have been summarized in a recent review by Casey and Crockard [4]. Post-operative morbidity and mortality appear to be related to the degree of pre-existing neurological impairment [3]. We discuss below two patients who underwent cervical spine surgery and who developed unusual post-operative complications, one early, the other late.

MUNRO ET AL:. COMPLICATIONS OF CERVICAL SPINE SURGERY

CASE 2 A 49-yr-old woman with a 40 yr history ofjuvenile arthritis of a rheumatoid type presented with intractable occipital headaches and electric shock sensations radiating to both arms and legs suggestive of L'Hermitte's sign. At the time of presentation, her arthritis was well controlled on auranofin, although previously she had required bilateral knee replacements and wrist surgery. Neurological examination revealed no objective signs of cervical myelopathy, although reflexes were brisk bilaterally. X-rays showed moderate atlanto-axial subluxation with 5 mm forward slip of Cl on C2. An MRI scan confirmed subluxation at the Cl/2 level with mild cord compression. Cervical spine stabilization was undertaken by posterior Cl/2 wire fixation and bone graft obtained from the right posterior iliac crest. In May of 1994, she had a recurrence of her neurological symptoms and cervical spine X-ray showed failure of bony fusion following her previous surgery. A further posterior cervical stabilization was performed using Cl/2 transarticular screw fixation and a further bone graft from the iliac crest. After the second operation, the patient complained of persistent pain over the right iliac crest donor site. Several months later, she presented at a routine rheumatology clinic visit with a history of intermittent abdominal cramps and a soft-tissue swelling over her right iliac crest. A plain pelvic X-ray showed a large defect in her right ileum (Fig. 3) and raised the possibility of bowel herniation through the defect. An ultrasound examination was unhelpful, but CT scanning confirmed the presence of a significant hernia containing bowel through the iliac defect (Fig. 4). In view of the risk of strangulation, it was felt that a surgical repair of the hernia was required. This was performed successfully using a wire mesh to close the defect.

DISCUSSION The complications of cerebellar abscess and iliac crest herniation following cervical spine surgery in RA are unusual, but illustrate a number of wellknown problems associated with surgery for cervical myelopathy.

Sepsis is a major cause of morbidity and mortality after neck surgery, partly due to the debilitated state of many patients who require such intervention. Sepsis may be local, but is more commonly at a distal site, e.g. chest or urinary tract. A study by Ranewat et al. [5] of 33 patients showed a mortality rate of 27% at 2 yr. Two-thirds of the patients who died did so because of infection. Unfortunately, the causative organism in case 1 was never isolated. Haematogenous spread from a chest infection is a strong possibility, particularly in view of the positive sputum culture. Another possible source is a contaminant from the patient's skin settling on the wire at the time of surgery. The most likely causative organism in this case would be a coagulase-negative Staphylococcus. The second of our cases illustrates two problems: non-union and complications at the donor site for the bone graft. Zoma et al. [6] reported a series of 32 RA patients undergoing cervical spine stabilization, of which 25% of patients required more than one procedure. In general, repeat surgery was required because of poor union or stability following the first operation. More recent studies suggest that surgery should be performed early before the development of basilar imagination or sub-axial instability, as patients with isolated atlanto-axial disease appear to have a much lower incidence of recurrent post-operative

FIG. 2.—Case 1. Computerized tomography of the brain showing a left cerebellar abscess.

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FIG. I.—Case 1. Magnetic resonance image showing cord compression at C4/5.

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FIG. 4.—Case 2. Computerized tomography of the pelvis showing a hernia containing bowel through the defect in the right iliac crest..

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FIG. 3.—Case 2. Plain pelvic radiograph with a defect of the right iliac crest.

MUNRO ET AL.: COMPLICATIONS OF CERVICAL SPINE SURGERY

ACKNOWLEDGEMENTS

We would like to acknowledge the assistance of Miss Ruth McKee, consultant surgeon in relation to case 2, Dr Alastair Forrester, consultant radiologist

for radiographic studies, and Miss Ann Tierney who typed the manuscript. REFERENCES

1. Bland JH. Rheumatoid arthritis of the cervical spine. J Rheumatol 1974;1:319-41. 2. Mark JS, Sharp J. Rheumatoid cervical myelopathy. Q J Med 1981;199:307-19. 3. Boden SD, Dodge LD, Bohlman HH, Rechtine GR. Rheumatoid arthritis of the cervical spine. A long term analysis with predictors of paralysis and recovery. J Bone Joint Surg 1993;75A:1282-97. 4. Casey ATH, Crockard A. In the rheumatoid patient: surgery to the cervical spine. Br J Rheumatol 1995;34:1078-86. 5. Ranewat CS, O'Leary P, PeUicci P, Tsairis P, Marchisello P, Dorr L. Cervical spine fusion in rheumatoid arthritis. J Bone Joint Surg 1979;61A:1001-10. 6. Zoma A, Sturrock RD, Fisher WD, Freeman P, Hamblen DL. Surgical stabilisation of the rheumatoid cervical spine. / Bone Joint Surg 1987;69B:8-12. 7. Stirrat AN, Fyfe IS. Surgery of the rheumatoid cervical spine. Correlation of pathology and prognosis. Clin Orthop 1993393:135-43. 8. Agarwal AK, Peppelman WC, Kraus DR et at. Recurrence of cervical spine instability in rheumatoid arthritis following previous fusion: can disease progression be prevented by early surgery? J Rheumatol 1992;19:1364-70. 9. Hu RW, Bohlman HH. Fracture at the iliac bone graft site after fusion of the spine. Clin Orthop 1994;309: 208-13.

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instability [7, 8]. Unfortunately, in case 2, despite early surgical intervention, the symptoms recurred due to incomplete bony fusion following resorption of the bone graft. Complications at the bone graft donor site are more unusual. There have been a number of reports of fracture at the iliac bone graft harvest [9] site, although there have been no reports of iliac bone defects leading to bowel heraiation. The harvested bone for grafting is taken from the outer cortical area with some medullary bone. It is possible, in our case, that a breach was made in the inner cortical bone with the defect subsequently enlarging due to bone resorption. In view of the obvious problems with surgery for cervical myelopathy, it is fortunate that only a small percentage of the rheumatoid population with inflammatory joint disease will require surgery. Many of these patients are frail and have a poor outlook if managed conservatively. Thus, early surgical intervention offers a significant chance of sustained improvement in terms of symptoms and overall survival. Nevertheless, constant vigilance is essential when follow-up of such patients is undertaken.

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