The importance of “time to surgery” in the management of lumbar disc herniation in patients without progressive neurological deficits

BACKGROUND: Prolonged sciatica symptoms may result in disability and consequently, absence from work for a longer period. Up to 10% of patients may need surgery but it is difficult to predict and determine which of these patients would improve spontaneously in comparison to those who might benefit from discectomy surgery. We aimed to determine if delay in the “time to surgery” (TTS) has any adverse effects on the patient reported outcome measures (PROMs). METHODS: Eighty-seven patients after exclusions were selected consecutively. PROMs were comprised of pre-operative, six weeks and six months post-operative back and leg pain visual analogue scores (VAS) and Oswestry disability index (ODI). The differences between these scores were correlated with TTS. Minimal clinically important difference (MCID) of 30% improvement for ODI scores and 33% for VAS scores from baseline were considered as significant improvement. Patients were grouped into TTS less than 6 months and TTS greater than 6 months from referral to TTS. The longest TTS was 18 months. Statistical analysis was done using JASP (Version 0.14.0) [computer software]. RESULTS: The TTS was on average 22.5 weeks. MCID for the leg pain VAS was achieved in 90.2% patients with TTS <6 months and in 80.8% with TTS ≥6 months. The MCID for ODI was achieved in 60.7% with TTS <6 months and in 42.0% with TTS ≥6 months. The MCID for back pain VAS was achieved in 73.8% with TTS <6 months and in 50.0% of patients with TTS ≥6 months. Those who achieved the MCID in ODI score between the two groups were analysed using chi-square test with P=0.115. Those who achieved the MCID in VAS leg pain score between the two groups were analysed using chi-square test with P=0.227. No statistical difference was found in ODI and VAS for leg for patients with TTS before or after 6 months. CONCLUSIONS: Lumbar discectomies had a positive impact on patient’s pain and function in our local district hospital. Delayed surgery of ≥6 months did not cause statistically significant worse outcomes. In the absence of worsening neurological deficit, it may be the wrong approach to define a value for the TTS.