Role of 6-minute walk distance in assessing outcomes of spine surgery: a systematic review

Abstract

Background
Functional evaluation approaches that objectively monitor post-operative recovery are becoming increasingly crucial in spine surgery, particularly for lumber spinal stenosis (LSS), where mobility is a significant result. The 6-min walk distance (6MWD) test, a simple, low-cost tool, is frequently used in cardiac rehabilitation but often unproductive in spine surgery evaluation.


Objective
The objective of this systematic review is to critically investigate the role of the 6-min walk distance in measuring functional outcomes in patients after lumber spinal surgery. It specifically investigates: (1) changes in 6MWD before and after surgery, (2) the retainership between 6MWD and clinical or patient-reported outcomes (e.g. ODI, VAS, ZCQ) and (3) the predictive utility of 6MWD for surgical success.


Methods
A complete literature search was conducted using PRISMA 2020 standards on PubMed, SCOPUS, ScienceDirect and Cochrane Library. Studies on adult patients who underwent lumber decompression or fusion surgery and reported pre- and post-operative 6MWD were included. The risk of bias was assessed using JBI cohort appraisal technique.


Results
Seven studies involving 428 patients were included. Post-operative 6MWD demonstrated continuous and clinically significant improvement (mean change range 21–183 m). Improvements in 6MWD were substantially associated with decreased pain (VAS0), disability (ODI0) and improved quality of life (ZCQ, COMI). Several studies established minimal clinically important difference (MCID) criteria ranging from 50 to 105.9 m., with predictive ROC analysis indicating that 6MWD may distinguish between responders and non-responders. The test also showed moderate-to-strong internal and external responsiveness, making it more sensitive than other functional instruments such as the Timed Up and Go (TUG) test.


Conclusion
The 6MWD is a useful, non-invasive and responsive indicator for monitoring post-operative functional recovery in lumber spine surgery patients. Integration into clinical protocols can improve outcome monitoring, risk classification and specific established standards and improve the prognostic relevance.