A study on clinicoradiological outcome of posterior and posterolateral decompression and stablisation with pedicle screws and fusion for tuberculosis of dorsal and lumber spine

Abstract

INTRODUCTION: Tuberculosis is ubiquitous in distribution. Globally, nearly 30 million people suffer from tuberculosis. 3 million deaths occur due to tuberculosis per year. India has burden of 6 million cases. Recent increase in the incidence is due to concomitant tuberculosis with HIV infection and drug resistance. Of these 1-3% constitutes skeletal system involvement. Spinal tuberculosis(50%) is the most common form of skeletal tuberculosis. The evolution of treatment of tuberculosis of spine have passed through different phases of development from Pre-antitubercular era through Postantitubercular era and from Radical surgery through Middle path regimn. Traditionally, the anterior approach is the gold standard approach because vertebral bodies and disc spaces are most commonly affected, and the anterior approach allows direct access to the diseased vertebral bodies for debridement and abscess drainage, allows wide decompression and reconstruction of the defect. A combined anterior debridement and posterior instrumentation helps to overcome stability related drawbacks of anterior approach alone. However, it entails two surgeries (single event or staged) with additional morbidity and is indicated for patients with significant deformity. In posterior or posterolateral approaches anterior and lateral column can be reached through extra pleural approach. Posterior approach provides excellent exposure for circumferential spinal cord decompression, allows multiple level posterior instrumentation above and below the level of pathology, more stable construct ,less morbid surgery, allows earlier rehabilitation and is a familiar approach. AIM OF THE STUDY: The aim of this prospective study is to analyse the clinicoradiological outcome of posterior and posterolateral decompression, stabilisation with pedicle screws and fusion for tuberculosis of dorsal and lumbar spine done in our institution from July 2010 to June 2012. OBJECTIVES : (a) To study the effectiveness of posterior and posterolateral decompression, stabilisation with pedicle screws and fusion for tuberculosis of dorsal and lumbar spine. (b) To study the improvement in the angle of kyphosis. (c) To show that posterior surgery allows early mobilisation. (d) To evaluate that posterior surgery associated with reduced morbidity and mortality. MATERIALS AND METHODS: This study was conducted in our Hospital on 15 patients with Tuberculosis of Dorsal and Lumbar spine from July 2010 to June 2012. All patients were treated with posterior or posterolateral approach and stabilised with Pedicle screw system. Selection criteria: The Inclusion criteria is age group of 12 to 70 years of age, mild to moderate amount of cold abscess. no improvement with conservative treatment and worsening of neurological deficit. Patients less than 12 years of age,huge cold abscess, severe kyphotic deformity with internal gibbus and patients not fit for anaesthesia are excluded from the study. During study age of patient, mode of presentation, Level of the lesion and associated co morbid condition are considered. Anti tuberculous therapy started. RESULTS: This study was conducted in our Hospital on 15 patients with Tuberculosis of Dorsal and Lumbar spine from July 2010 to June 2012. All patients were treated with posterior or posterolateral approach and stabilised with Pedicle screw system. The mean follow up period was 12 months (range 6-26 months). The following are the results of the study: The mean duration between surgery and onset of symptoms was 10.2 months (range 5-14 months). The mean surgical time was 3 hours 20 minutes (range 2h 20 min-4hr 10 min). The average blood loss was 800 ml (400 ml – 1500 ml). The mean preoperative Visual analog score was 8.7 (range7-10)which improved to 1.7(1-4) at final follow up implying better pain score postoperatively. The mean preoperative ESR value was 111.8 which improved to 31.7 at final follow up which indicates improvement in disease activity. Before surgery, 7 patients were classified as Frankel grade C,2 patients each with grade B,D and E& one patient with grade A.After surgery,all patients with grade C improved to one grade. Out of 2 patients with grade B,one improved to grade C and other improved to grade D.Of the patients with grade D, one improved to grade E and the other remained with grade D.One patient with grade A havenot recovered. The mean preoperative kyphosis in the thoracic and thoracolumbar spine was 27.9 degrees which was corrected to a mean of 9.5 degrees in the final follow up radiographs implying better correction and maintenance of kyphosis. CONCLUSION: The posterior/posterolateral approach (extracavitory approach) gives a reasonable access to the lateral and anterior aspects of the cord for an equally good decompression of the cord. It is a less morbid approach and avoids problems associated with thoracotomy and laprotomy. It facilitates early mobilization and avoids problems of prolonged recumbency. It provides better functional outcome and significantly better sagittal plane and kyphosis correction. Posterior approach preferred because of its familiarity, its simplicity, and its low complication rate.