Prediction of Deformity in Spinal Tuberculosis Paul Jutte, MD, PhD * ; Sander Wuite, MD * ; Bertram The, MD * ; Richard van Altena, MD † ; and Albert Veldhuizen, MD, PhD * Tuberculosis of the spine may cause kyphosis, which may in turn cause late paraplegia, respiratory compromise, and un- sightly deformity. Surgical correction therefore may be con- sidered for large or progressive deformities. We retrospec- tively analyzed clinical and radiographic parameters to pre- dict the final kyphotic angle in spinal tuberculosis and to identify patients at risk of unfavorable outcomes at an early stage of the disease when surgery may be indicated. Unfa- vorable outcome was defined as progression of 10° or greater and/or a final angle of 40° or greater. We analyzed 53 pa- tients with active spinal tuberculosis located in the thoracic (T1 to T10) and thoracolumbar spine (T11 to L2) and with initial kyphotic angles less than 40°. We calculated the in- dexed total bone height loss, a value of 1 being the equivalent of the loss of a total vertebral body. There were no indepen- dent predictors. A bone height loss greater than 0.3 on the initial radiograph in combination with a thoracolumbar lo- cation indicated a 38% chance of unfavorable outcome ver- sus only a 3% chance of unfavorable outcome when bone height loss was 0.3 or less in combination with a thoracic location. We present a simple and clinically useful algorithm for predicting kyphosis in spinal tuberculosis. Level of Evidence: Level II, prognostic study. See the Guide- lines for Authors for a complete description of levels of evi- dence. Tuberculosis of the spine demineralizes and destroys the vertebral body, causing pain and deformity (kyphosis) and sometimes spinal cord compression (Pott’s paraplegia). A persisting large kyphosis may cause several problems. Late paraplegia may develop as a result of myelopathy because of the chronically irritated and malnourished spi- nal cord at the apex of the curve. 15,19,28 An operation for late paraplegia is difficult and prone to major complica- tions without resolution of the neurologic deficit. 20 High degrees of kyphosis also may cause respiratory compro- mise because of diminished intrathoracic volume. 30 Some patients may have a cosmetically unsightly hunchback de- formity. 14 The British Medical Research Council Working Party on Tuberculosis of the Spine performed a series of trials to in- vestigate various methods for treating spinal tuberculosis and concluded chemotherapy on an outpatient basis is suf- ficient to treat the majority of patients and routine surgery is not beneficial. 2–12 This finding is important because most patients live in countries with limited resources. However, one study suggests patients with a presenting kyphosis angle greater than 30° had a mean final angle of 50° to 73° develop after 10 years. 24 Numerous authors state kyphosis greater than 30° is likely to progress. 1,17,19–22,24,29,31,36 Many authors consider large or progressive deformities indications for surgery. 1,13,17,19–22,24,28,29,34–37 Large ky- photic angles can be corrected and maintained with mod- ern instrumentation techniques. 13,20–23,29,31,35,36 Early prediction of which patients may be at risk of having large and/or progressive kyphotic angles develop could guide clinical decision making. Rajasekaran and Shanmugasundaram 26 described a predictive formula, but unfortunately they included patients with severe kyphosis who had a clear indication for surgery. The reported ac- curacy of this formula also varies widely (range, 34– 90%). 24,26 Therefore, there is still no clear guideline for clinical decision making. We sought to assess which radiographic and clinical parameters are early predictors for the final kyphotic angle in patients with spinal tuberculosis. We investigated stan- Received: November 10, 2005 Revised: May 29, 2006; August 14, 2006 Accepted: September 29, 2006 From the * Department of Orthopaedic Surgery and the † Department of Tu- berculosis and Lung Disease, University Medical Center Groningen, Gron- ingen, The Netherlands. Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrange- ments, etc) that might pose a conflict of interest in connection with the submitted article. Each author certifies that his or her institution has approved or waived approval for the human protocol for this investigation and that all investi- gations were conducted in conformity with ethical principles of research. Correspondence to: P. C. Jutte, MD, PhD, Department of Orthopaedic Sur- gery, University Medical Center Groningen, PO Box 30.001, 9700 RB Gro- ningen, The Netherlands. Phone: 31-50-3612802; Fax: 31-50-3611737; E-mail: p.c.jutte@orth.umcg.nl. DOI: 10.1097/01.blo.0000246559.27596.33 CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Number 455, pp. 196–201 © 2006 Lippincott Williams & Wilkins 196 Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.