Table 2.
Characteristics at and in Relation to Pain Development.
| Covariate | Entire Cohort No.=169 | No Surgery No.=121 | Surgery No.=48 | P – value* |
|---|---|---|---|---|
| Age at pain onset (yr), mean (SD) | 64.4 (8.9) | 65.9 (8.7) | 60.6 (8.3) | 0.0004 |
| Time between study enrollment and pain onset (yr), median [IQR] | 2.6 [2.9] | 3.0 [2.9] | 1.9 [2.8] | 0.0002 |
| Tear type at visit prior to pain onset, No. (%): | ||||
| Full-thickness | 105 (62%) | 79 (65%) | 26 (54%) | 0.13† |
| Partial-thickness | 46 (27%) | 27 (22%) | 19 (40%) | |
| Control | 18 (11%) | 15 (12%) | 3 (6%) | |
| For full tears (No.=105) at visit prior to pain onset: tear width at visit prior to pain onset (mm), median [IQR] | 13.0 [12.0] missing: 3 massive |
13.0 [9.5] missing: 3 massive |
11.0 [13.0] | 0.52 |
| For full tears (No.=105) at visit prior to pain onset: tear length at visit prior to pain onset (mm), median [IQR] | 12.5 [10.0] missing: 6 massive, 1 not measured |
13.0 [10.0] missing: 4 massive, 1 not measured |
12.0 [11.0] missing: 2 massive |
0.51 |
| Tear enlargement prior to pain development or within 2.25yr of pain development (or until surgery), No. (%) | 85 (50%) | 60 (50%) | 25 (52%) | 0.67 |
| Tear enlargement related to pain onset, No. (%): | ||||
| No enlargement before or within 2.25yr of pain development | 84 (50%) | 61 (50%) | 23 (48%) | 0.51† |
| First enlargement before pain development | 41 (24%) | 31 (26%) | 10 (21%) | |
| First enlargement precisely at pain development | 20 (12%) | 13 (11%) | 7 (15%) | |
| First enlargement after and within 2.25yr of pain development (or until surgery) | 24 (14%) | 16 (13%) | 8 (17%) | |
| Cable disruption at or within 1.25yr after pain development (or until surgery), No. (%) | 31 (23%) missing 36 |
20 (21%) missing 27 |
11 (28%) missing 9 |
0.22 |
| Muscle degeneration, sum of architecture and echogenicity (most severe of supraspinatus and infraspinatus) at or within 1.25yr after pain development (or until surgery), No. (%): | ||||
| 0 (normal) | 126 (75%) | 90 (75%) | 36 (77%) | 0.85 |
| 1 | 5 (3%) | 5 (4%) | 0 (0%) | |
| 2 | 26 (16%) | 16 (13%) | 10 (21%) | |
| 3 | 1 (1%) | 1 (1%) | 0 (0%) | |
| 4 (severe) | 9 (5%) missing 2 |
8 (7%) missing 1 |
1 (2%) missing 1 |
|
| Change‡ in ASES between enrollment and worst ASES at or within 1.25yr after pain development (or until surgery), mean (SD) | −37.5 (19.0) | −32.7 (17.2) | −49.7 (18.1) | <0.0001 |
| Change‡ in pain numeric pain scale between enrollment and worst VAS at or within 1.25yr after pain development (or until surgery), mean (SD) | +4.7 (2.3) | +4.3 (2.2) | +5.9 (2.0) | 0.0001 |
| Change‡ in RAND-12 mental component score between enrollment and worst VAS at or within 1.25yr after pain development (or until surgery), mean (SD) | −3.8 (10.0) missing 21 |
−4.2 (9.8) missing 9 |
−2.6 (10.6) missing 12 |
0.06 |
| Change‡ in RAND-12 physical component score between enrollment and worst VAS at or within 1.25yr after pain development (or until surgery), mean (SD) | −3.8 (9.6) missing 21 |
−3.3 (9.5) missing 9 |
−5.3 (9.6) missing 12 |
0.15 |
No. = number of patients; yr = year; SD = standard deviation; IQR = interquartile range; ASES = American Shoulder Elbow Surgeons; VAS = visual analog scale.
*
P-value compares patients who did and did not undergo surgery by Cox proportional hazards regression.
†
Covariate was modelled as an unordered categorical variable.
‡
Change is calculated by subtracting the value at enrollment from the value at follow-up.