Changing trends in duration of treatment of musculoskeletal and spinal tuberculosis- long term experience in a tertiary care teaching hospital.

Duration of antitubercular therapy (ATT) for musculoskeletal (MSK) tuberculosis (TB) is a challenge, particularly if pain persists at the end of therapy. WHO recommends 6-9 months therapy, index TB guidelines of India recommends 12 months ATT extendable to 18 months, yet many surgeons in India continue to prescribe 18-24 months ATT in all cases of MSK TB. To address this controversy, two studies were conducted to assess the adequacy of 6 months ATT for MSK TB, the third study to evaluate results of 9-12 months of ATT and fourth study to assess residual back pain in spinal TB after ATT of different duration. In the 1st study (2006-09), after 6 months of ATT, all 9 cases of spinal and all 25 cases of extraspinal MSK TB had healed clinically and with a negative ciprofloxacin-labelled technetium 99 scan and among them, even as early as 3 months, 2 spinal and 4 extra-spinal cases had negative scans. In the 2nd study (2010-2013), after 6 months ATT, Gadolinium enhanced MRI scans in 50 cases of MSK TB depicted complete resolution in 6 cases (12%), partial resolution in 36 cases (72%) and no resolution in 8 cases (16%). Irrespective of the MRI findings at 6 months, in 44 clinically healed cases ATT was stopped at 6 months and they remained healed at more than 5-year follow up. In 6 cases, who had no clinical healing, ATT was prolonged in 3 patients and the category of ATT was changed in remaining 3 patients (2 spinal TB and one Hip TB). In the 3rd study (2019-2022), all 51 patients of spinal TB who took 9-12 months of ATT had fever subsidence within 1-6 months (mean 3.52 months), appetite improvement within 1-7 months (mean 3.5 months) and weight gain by 1-8 months (mean 4.45 months). Intermittent back pain continued in 23/51 patients (41%) even after 2 years of stoppage of 9-11 months ATT, among them 20 patients (96.4%) had radiological bony fusion. Persistent back-pain (mean VAS 6.33) occurred in 3 cases who took 12 months ATT; 2 reported after 10 months of whom 1 was detected as MDR, 3rd patient reported after 7 years and recovered after 1 year of ATT. In the 4th study (2020-2023), 88 of 300 MSK TB (non-resistant cases, managed non-operatively) patients responded telephonically, 48 visited the hospital and 40 patients were telephonically interviewed regarding back pain after ATT. After various duration of ATT, 6-9 months (13.6% cases); 10-12 months (26.1% cases); 13-18 months (53.4% cases) and 19-24 months (6.8% cases) all had clinically healed with no fever, loss of appetite or weight loss. Majority (45/48) of patients (93.8%) had bony healing yet back pain was present in 28 patients (31.8%); intermittent pain in 19 patients and continuous pain in nine. Stopping ATT at 6 months may be considered in cases with complete clinical healing with normal ESR. Patients with no progressive signs of clinical healing by 6 months should be investigated for drug resistance rather than empirical extension of treatment beyond 6-9 months.