Microendoscopic discectomy (MED) for lumbar disc herniation: comparison of learning curve of the surgery and outcome with other established case studies.

BACKGROUND: To compare the results of a series of microendoscopic discectomies done at a government medical college in South India, with other published series and to analyze the learning curve for the procedure. METHODS: Microendoscopic discectomy (MED) was performed in 40 patients. The cases were in the age group between 20-50 years (mean age, 32.3 years). The period of study was 3 years. The most common level operated was L5-S1 (27 cases) followed by L4-L5 (12 cases). Double level disc herniation was observed in 1 patient, at L4-L5 and L5-S1. Patients with bilateral involvement and lumbar stenosis were excluded from the study. Diagnosis was based on clinical neurological examination, X-ray, CT and MRI. The MED was performed, following Destandau's procedure using Storz endoscopic microdiscectomy system. All patients were followed up regularly on 10th postoperative day, 1 month, 3 months and 1 year. Mean follow up of all patients were 14.1 months. The learning curve for the procedure was also analyzed. RESULTS: In our case series comprising of 40 cases, it was observed that as compared to other established studies, the mean operative duration, intraoperative blood loss, mean hospital stay and complication rate was largely reduced, with good experience and training. The outcome based upon modified Macnab criteria, showed that in maximum number of patients had excellent outcome and only 3 out of the 40 cases had poor outcome. Moreover, since the procedure was technically demanding, it took initial 20 cases to complete our learning curve and in the next 20 cases it was observed that we had improved our technique, operating time, blood loss, and outcome. CONCLUSIONS: MED in properly trained hands is an excellent technique that could replace the conventional open surgery, in the management of lumbar disc disease if the learning curve could be overcome.

Traumatic transfers: calibration is adversely affected when prediction models are transferred between trauma care contexts in India and the United States.

OBJECTIVE: We evaluated the transferability of prediction models between trauma care contexts in India and the United States and explored updating methods to adjust such models for new contexts. STUDY DESIGN AND SETTINGS: Using a combination of prospective cohort and registry data from 3,728 patients of Towards Improved Trauma Care Outcomes in India (TITCO) and from 18,756 patients of the US National Trauma Data Bank (NTDB), we derived models in one context and validated them in the other, assessing them for discrimination and calibration using systolic blood pressure, heart rate, and Glasgow coma scale as candidate predictors. RESULTS: Early mortality was 8% in the TITCO and 1-2% in the NTDB samples. Both models discriminated well, but the TITCO model overestimated the risk of mortality in NTDB patients, and the NTDB model underestimated the risk in TITCO patients. CONCLUSION: Transferability was good in terms of discrimination but poor in terms of calibration. It was possible to improve this miscalibration by updating the models' intercept. This updating method could be used in samples with as few as 25 events.

The Madras Institute of Neurology, Madras Medical College, Chennai.

The Madras Medical College and its affiliated Government General Hospital, Chennai, are among the oldest medical institutions in India. The Madras Institute of Neurology (MIN) was the second neurosciences department to be started in India. The MIN has trained several batches of illustrious neurologists and neurosurgeons. This article briefly traces the history of the MIN, its important milestones, and its current developments.