The evolution of somatosensory processing signs after nociceptive targeted surgery in patients with musculoskeletal disorders: a systematic review.

Surgery is often advised when conservative treatment fails in musculoskeletal pain conditions, but a substantial proportion still suffers chronic pain after surgery. Somatosensory processing system (SPS) signs were previously studied as potential predictors for chronic postsurgical pain, but results are inconsistent. Therefore, studying the evolution of SPS signs could be of added value. The aim was to summarize all studies that measured how SPS signs evolved after nociceptive targeted surgery in musculoskeletal disorders, and to find pre-, peri- and postoperative predictors for the evolution of these SPS signs. Data was summarized, and risk of bias and level of evidence and recommendation were determined. Twenty-one studies were included. Five scored a low, three a moderate, and 13 a high risk of bias. In general, no consistent evolution of SPS signs comparing pre- and postoperative values and predictors for this evolution in musculoskeletal disorders could be found. In most cases, static quantitative sensory testing (QST) did not change or conflicting results were found. On the other hand, dynamic QST mostly improved after surgery. Worthfully mentioning is that worsening of SPS signs was only seen at a follow-up of < 3 months after surgery, that conclusions are stronger when evaluating dynamic QST with a follow up of ≥ 3 months after surgery, and that pain improvement postsurgery was an important predictor. Future high quality research should focus on the evolution of SPS signs after nociceptive targeted surgery, accounting for pain improvement groups and focusing on pre, peri- and postoperative predictors of this evolution.