Baseline Kinesiophobia and Pain Catastrophizing Scores Predict Prolonged Postoperative Shoulder Pain.

BACKGROUND: Chronic postsurgical pain remains a major hurdle in postoperative management, especially in patients undergoing shoulder surgery, for whom persistent pain rates are higher than for any other surgical site. Little is known about pain beliefs and attitudes as preoperative predictors of postoperative pain following nonarthroplasty shoulder surgery. OBJECTIVES: We evaluated predictors of pain following nonarthroplasty shoulder surgery, hypothesizing that preoperative kinesiophobia, pain catastrophizing, and neuropathic pain scores are predictive of greater postoperative pain. STUDY DESIGN: Case control study. SETTING: Division of Sports Medicine at the University of Wisconsin School of Medicine and Public Health. METHODS: Consecutive patients aged 18 and older undergoing a nonarthroplasty  shoulder operation were selected. At the preoperative appointment and 3 months postoperative, patients completed the Short-Form McGill Pain Questionnaire-2 to assess severity and quality of pain, the painDetect Questionnaire to screen for neuropathic pain, the Tampa Scale of Kinesiophobia to assess fear of movement and fear-avoidance beliefs, and the Pain Catastrophizing Scale  to gauge rumination, magnification, and pessimism. A univariable negative binomial regression model was used to identify associations between preoperative predictors and postoperative  scores, reporting risk ratios and 95% confidence intervals. RESULTS: Eighty-one patients completed the preoperative surveys and 43 patients completed at least one postoperative survey. The median pain score decreased from 3 out of 10 (interquartile range [IQR] = 2-5) in the preoperative group to one (IQR = 0-2) in the postoperative group (P < 0.001). Mean kinesiophobia scores decreased from 40.44 (standard deviation [SD] = 5.94) preoperatively to 35.40 (SD = 6.44) postoperatively (P < 0.001). Median pain catastrophizing scores decreased from 7 (IQR = 2-17]) preoperatively to 2 (IQR = 0-11]) postoperatively (P = 0.005). No significant changes in neuropathic pain scores were observed. Higher baseline kinesiophobia scores were associated with greater postoperative pain (risk ratio = 1.09, 95% confidence interval [CI] = 1.01 to 1.18), P = 0.03), as were higher pain catastrophizing scores (risk ratio = 1.05, 95% CI = 1.01 to 1.08), P = 0.01). No association between baseline neuropathic pain and degree of postoperative pain was identified. LIMITATIONS: Limitations of the study include a single institution with multiple surgeons and types of surgery. The study drop-out rate was relatively high. CONCLUSION: This study suggests that greater baseline kinesiophobia and pain catastrophizing are predictive of greater postoperative pain following nonarthroplasty shoulder surgery in an adult population.

Regional wall mechanics and blunt traumatic aortic rupture at the isthmus.

OBJECTIVE: Blunt traumatic aortic injury (BTAI) is part of a spectrum of diseases termed acute aortic syndrome that accounts for 20% of road traffic accident related deaths. The injury has a complex aetiology with a number of putative mechanisms accounting for the injury profile, characteristics of which include a transverse primary intimal tear located at the aortic isthmus. We hypothesised that an understanding of regional aortic wall mechanics would contribute to an understanding of the aetiology of BTAI. METHODS: Samples of porcine aorta were prepared from ascending (A), descending (D) and peri-isthmus regions (I). A histological analysis of aortic wall architecture was performed at the site of attachment of the ligamentum arteriosum. Samples were mounted in a bubble inflation clamping rig, connected via a solenoid release valve to a compressed air reservoir. Using a pressure transducer and high-speed camera (1000fps) we collected data on wall thickness, rupture pressure and radial extension, allowing calculation of ultimate tensile stress. RESULTS: Histological analysis at the point of attachment of the ligamentum arteriosum to the isthmus shows some heterogeneity in cellular architecture extending deep into the tunica media. Wall thickness was significantly different between the three sampled regions (A>I>D, p<0.05). However, we found no difference in absolute rupture pressure between the three regions (kPa), (A, 300+/-28.9; I, 287+/-48.3; D, 321+/-29.6). Radial extension (cm) was significantly greater in A vs I (p<0.05), (A, 1.85+/-0.114; I, 1.66+/-0.109; D, 1.70+/-0.138). Ultimate tensile stress (kPa), (A, 3699+/-789; I, 3248+/-1430; D, 4260+/-1626) was significantly greater in D than I (p<0.05). CONCLUSIONS: The mechanism of blunt traumatic aortic rupture is not mechanically simple but must correspond to a complex combination of both relative motion of the structures within the thorax and local loading of the tissues, either as a result of their anatomy or due to the nature of the impact. A pressure spike alone is unlikely to be the primary cause of the peri-isthmus injury but may well be a contributory prerequisite.