Clinical Evaluation of Post-Surgical Scar Hyperesthesia; an Exploratory Longitudinal Study

Evidence for the objective clinical evaluation of scar hyperesthesia is lacking. This exploratory study investigated the clinical relevance and responsiveness of objective scar evaluation measures in adults following hand surgery. With ethical approval and consent, participants were enrolled from one NHS hospital. Patient reported and investigator completed scar morphology, cosmesis, pain and function were evaluated at 1- and 4-months post-surgery. Statistical analysis investigated the responsiveness of outcome measures and association of physical measures with the Palmar Pain Severity Scale (PPS). 21 participants enrolled prior to premature study closure due to the COVID-19 pandemic; 13 completed follow up. Scar pain (p=.002); scar interference (PPI [p=.009]) and Brief Pain Inventory (BPI) scores (p=.03) improved. Neuropathic Pain Symptom Inventory (NPSI) scores demonstrated heterogeneity in scar pain; evoked pain predominated. Patient Scar Assessment Questionnaire (PSAQ) indicated improvement in cosmetic dissatisfaction and consciousness (p=.03; p=.003), respectively. Baseline psychological screening scores correlated with scar pain (p=.04), and interference (p< .001). Scar morphology, pliability and inflammation were not associated with scar pain. Significant differences in scar mechanical pain sensitivity (p=.04) and cold pain threshold (p=.05) were identified. PPS and PPI scores were responsive in a heterogeneous hand surgery sample. BPI ‘worst pain’ identified severe pain, suggesting composite scar pain scores are required. The PSAQ robustly measured scar appearance and consciousness. Psychophysical tests of mechanical and thermal sensitivity are potential candidate objective measures of scar hyperesthesia. The NPSI demonstrates clinical utility for exploring scar pain symptoms and may support the elucidation of the drivers of persistent scar pain. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement DK was funded by the British Association of Hand Therapists 2017 Research Grant to conduct this study and received infrastructure support from the National Institute for Health Research (NIHR) Imperial Biomedical Research Centre (BRC) and an Imperial Clinical Academic Training Office (CATO) Postdoctoral Bridging Fellowship. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Health Research Authority (HRA) and Health and Care Research Wales (HCRW) gave ethical approval for this work on 20th December 2018 (18/LO/2161). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript.