Perisurgical observation of nociceptive thresholds during total knee arthroplasty for association with persisting postsurgical pain: an explorative study

Background of the study:
Total knee arthroplasty (TKA) often produce severe persistent postsurgical
pain (PPSP), and in some cases, chronic pain. While the acute pain postpones the early recovery, the chronic pain seriously restricts an individual’s quality of life, and also increases costs of global health care and absenteeism at work. Central sensitization plays a major role in the development of PPSP. Sensitization is characterized by generalized hyperalgesia and can be detected by means of a decrease in (electrical) pain threshold. Recently, a pilot study showed that presurgical electrical pain tolerance thresholds (ePTT) have predictive value for PPSP in abdominal surgery patients. Other pilot studies suggest that, in addition to ePTTs, electrical nociceptive perception thresholds (eNPTs), when tracked over a short period of time (e.g. 25 minutes) can be expected to be able to observe changes in peripheral and/or central mechanisms in more detail than regular EPTs. Results after TKA show similar persisting pain incidences as after abdominal surgery. Therefore, these patients are a suitable population to study the generalizability of the results found in previous studies.

Objective of the study:
The main objective of this study is to investigate the predictability of persisting postsurgical pain (PPSP) after TKA using electrical quantitative sensory testing (eQST) and nociceptive perception thresholds (NPT) in combination with a presurgical conditioning pain modulation (CPM) paradigm. The secondary objectives of this study are to investigate (1) the effect of TKA on stimulus specific changes in NPT, and (2) the correlation between eQST versus NPT and PPSP.

Study design:
Monocentre prospective observational study

Preoperative: baseline measurement at -35 to -7 days

Postoperative: days 2, 42, 84, 168, and 365

Not applicable