Patients who are more sensitive to pain have significantly worse outcomes after rotator cuff surgery
Heightened pain sensitivity has been shown to have a detrimental effect on patient outcomes after surgery for spinal stenosis. The objective of this study was to assess the impact of pain sensitivity on outcomes after rotator cuff surgery. It was hypothesized that high pain sensitivity would have a clinically significant detrimental effect on outcomes.
Eighty-one patients (age 58±10 yr, 64 men, 17 women) completed a validated pain sensitivity questionnaire prior to rotator cuff surgery. The questionnaire is composed of 17 life situations that are associated with pain. Inclusion criteria were age 18-80 yr and undergoing a rotator cuff repair. Exclusion criteria were revision rotator cuff repair, isolated subscapularis tears, partial thickness rotator cuff tears, grade 2 or higher glenohumeral OA, and intraarticular injection after surgery. Patients completed DASH and ASES questionnaires, and a visual analog score for shoulder pain (VAS) prior to surgery, and at 3, 6 and 12 months after surgery. Additionally, active forward flexion, internal rotation (IR) and external rotation (ER) range of motion (ROM) were assessed on each occasion. High pain sensitivity was defined as a score >1SD above the mean score. Patients with a
DASH score of <15 at follow-up were classified as asymptomatic. Effect of pain sensitivity on outcome scores was assessed by Time (pre-op vs 3 months, 6 months, 12 month) x Group (high vs. normal pain sensitivity) mixed model ANOVA. Based on the normal variability in DASH scores it was estimated that with a sample of 80 patients there would be 80% power to detect a 5-point difference in DASH scores between patients with high versus normal pain sensitivity.
Pain sensitivity prior to surgery averaged 4.2±2.1 (out of 10) with a trend for higher pain
sensitivity in women versus men (5.3±2.9 vs. 3.9±1.7, P=0.07). Twenty-five of 81 patients had high pain sensitivity (31%). Follow-up was completed by 71 patients at 3 months (3.3±0.7 months), 58 patients at 6 months (6.3±0.7 months) and 32 patients at 12 months (12.2±0.7). Compared to pre-op values DASH, ASES and VAS scores were significantly improved at 3, 6 and 12 months (P<0.001). Improvements in outcome scores were unaffected by pain sensitivity (P=0.11-0.99). However, all 3 scores were markedly
worse in patients with high pain sensitivity at all time points (pre-op, 3, 6, 12 months post-op; P<0.0001 to P=0.016); DASH scores were 66% worse, ASES scores 20% worse, VAS scores 63% worse in patients with high pain sensitivity. At 6 months only 6 of 21 patients with high pain sensitivity were asymptomatic (29%) compared with 25 of 37 patients with normal pain sensitivity (68%, P=0.006). Outcomes were unaffected by having a double row versus single row repair (P=0.37-0.87), having an AC joint resection (P=0.21-0.95), or having a biceps tenodesis (P=0.37-56). Postoperative range of motion was unaffected by pain sensitivity (active forward flexion P=0.19, internal rotation P=0.19, external rotation P=0.21). At follow-up patients with high pain sensitivity had less forward flexion ROM than patients with normal pain sensitivity (157±26°vs.173±8°at 6 months, P=0.014; 165±18°vs. 177±5°at 12 months, P=0.035) and less external rotation ROM (51±15°vs. 62±11°at 12 months, P=0.048).
Patients with high pain sensitivity (assessed prior to surgery) had markedly poorer outcomes after rotator cuff surgery and were 2.3 times more likely to remain symptomatic 6 months after surgery compared to patients with normal pain sensitivity.