Evaluation of patient’s postoperative pain or inflammation can help determine hospital stay and patient satisfaction. An assessment and analysis method used to predict a patient's pain prognosis was made which found that an analysis via the pain trajectory is an appropriate method to prevent chronic post-surgical pain due to distal radius fracture.

As compared to conventional pain assessment, using the simple linear fit model can offer more precise evaluation of acute pain trajectory after surgery. But, this technique has a drawback of using only the slope and not the intercept. This study aimed to verify the modification of the pain trajectory model comprising slope and intercept and to recognize the clusters.

Post-operative pain was measured in 60 patients alongwith their pain trajectories. These patients had undergone DRFs. The linear fit of a patient’s pain intensity score describes the trajectory. Each patient’s trajectory had a slope and intercept in this linear model, (‘X’for days and ‘Y’ for pain intensity). The structural equation modeling (multiple regression analysis model) was used to predict pain following the surgery at 30 days. Lastly, the hierarchical cluster analysis was done by the pain trajectory.

The “slope and intercept model” was found to be the best out of other models. As per the outcomes of the cluster analysis, 4 pain trajectory groups (slope and intercept) were formed.

Pain trajectory via the slope and intercept is beneficial for predicting postoperative pain at 30 days. Clinicians may be able to detect the risk of prolonged pain quickly as compared to other methods by considering both the slope and intercept.