Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose:
A sizeable number of patients continue to suffer from pain, functional disability and reduced quality of life after total joint arthroplasty (TJA). The etiology of post-TJA pain is not well established and the presence of chronic pain of neuropathic origin has been suggested.
Leptin has been identified as a mediator of the immuno-inflammatory response in osteoarthritis (OA), and its pro-inflammatory functions could explain its role in peripheral pain sensitization. We previously demonstrated that high synovial fluid (SF) leptin concentrations correlate with increased preoperative pain in hip and knee OA patients. In addition, animal models have suggested the involvement of leptin in the pathogenesis of pain at the spinal level and in the development of neuropathic pain.
Our objective was to assess pain, function, patient satisfaction and general health in patients undergoing TJA according to SF leptin concentration.
Methods:
Prospective cohort study of patients with primary OA undergoing total hip or knee arthroplasty between January and December 2010. On the day of intervention, SF was sampled and leptin concentrations were assessed using an ELISA kit. Exposure was SF leptin concentration (≤19.6 ng/ml vs. >19.6 ng/ml= highest quartile). Outcomes were: joint pain, function and general health measured pre- and at 1 year postoperative with WOMAC, VAS for pain, and SF-12, and patient satisfaction at 1 year measured on 5-item Likert scale.
Results:
167 TJAs were included, 88 total hip and 79 total knee arthroplasties. Mean age was 72 years, mean BMI 28 kg/m², 58% were women. High intra-operative SF leptin concentrations (>19.6 ng/ml) were found in 39 (23.4%) joints. Compared to leptin levels <19.6 ng/ml their presence was associated with significantly higher pain levels on both WOMAC and VAS pain scales, with lower function and worse physical and mental health scores both pre- and 1 year postoperative (effect sizes ranging from 0.4 to 0.7) and with lower satisfaction (see Table). Residual pain of ≥5 on the VAS was present in 33% of TJAs with high leptin concentration compared to 13% in the other group (RR 2.5, 95% CI 1.3; 4.7). The degree of improvement in all domains (difference pre- to postoperative) was not significantly modified by SF leptin levels.
Conclusion:
High intra-articular leptin were strongly associated with more residual pain and functional disability 1 year after arthroplasty. However, the degree of improvement was independent of leptin concentration. With respect to pain these results lend support to the hypothesis that high intra-articular leptin levels could favor spinal pain sensitization and the development of neuropathic pain earlier in the disease process.
Table 1. Preoperative and 1-year postoperative assessment of pain, function and general health according to leptin concentration
| |
Leptin 1-3rd quartile ≤ 19.6 ng/ml |
n |
Leptin 4th quartile > 19.6 ng/ml |
n |
4th vs. 1-3rd quartile Unadjusted mean difference (95% CI) |
4th vs. 1-3rd quartile Adjusted mean difference (95% CI)* |
|
WOMAC pain, mean (SD) |
|
116 |
|
36 |
|
|
|
Preoperative |
42.2 (±18.3) |
|
32.5 (±15.5) |
|
9.7 (3.1; 16.4) |
9.1 (2.6; 15.5) |
|
At 1 year |
71.8 (±24.1) |
|
61.5 (±21.1) |
|
10.2 (1.4; 19.1) |
9.8 (0.8; 18.8) |
|
Difference |
29.5 (±23.8) |
|
29.0 (±21.2) |
|
0.5 (-8.2; 9.2) |
0.7 (-8.2; 9.6) |
|
|
|
|
|
|
|
|
|
WOMAC function, mean (SD) |
|
116 |
|
36 |
|
|
|
Preoperative |
44.6 (±19.9) |
|
37.6 (±15.4) |
|
7.0 (0.8; 13.3) |
7.4 (0.5; 14.2) |
|
At 1 year |
71.1 (±24.4) |
|
62.5 (±20.4) |
|
8.6 (-0.3; 17.5) |
8.7 (-0.3; 17.8) |
|
Difference |
26.5 (±25.2) |
|
24.9 (±23.1) |
|
1.6 (-7.7; 10.9) |
1.3 (-8.1; 10.8) |
|
|
|
|
|
|
|
|
| |
|
122 |
|
37 |
|
|
|
Preoperative |
5.8 (±1.8) |
|
6.5 (±1.7) |
|
0.7 (0; 1.3) |
0.6 (0; 1.2) |
|
At 1 year |
1.9 (±2.1) |
|
3.3 (±2.4) |
|
1.4 (0.5; 2.1) |
1.2 (0.4; 2.0) |
|
Difference |
3.9 (±2.3) |
|
3.2 (±2.6) |
|
0.7 (-0.2; 1.6) |
0.6 (-0.3; 1.5) |
|
|
|
|
|
|
|
|
| |
|
112 |
|
34 |
|
|
|
Preoperative |
35.7 (±8.4) |
|
32.0 (±7.1) |
|
3.7 (0.5; 6.8) |
4.0 (0.8; 7.1) |
|
At 1 year |
42.3 (±9.4) |
|
36.4 (±9.2) |
|
5.9 (2.3; 9.5) |
5.9 (2.2; 9.5) |
|
Difference |
6.6 (±9.9) |
|
4.4 (±8.8) |
|
2.2 (-1.5; 6.0) |
1.9 (-1.9; 5.7) |
|
|
|
|
|
|
|
|
| |
|
112 |
|
34 |
|
|
|
Preoperative |
44.8 (±11.0) |
|
39.3 (±11.0) |
|
5.5 (1.2; 9.8) |
5.8 (1.5; 9.9) |
|
At 1 year |
47.5 (±10.1) |
|
41.0 (±9.7) |
|
6.5 (2.7; 10.4) |
6.7 (2.9: 10.5) |
|
Difference |
2.8 (±11.1) |
|
1.7 (±11.3) |
|
1.1 (-3.3.; 5.4) |
1.0 (-3.4; 5.4) |
| |
|
|
|
|
|
|
| |
|
126 |
|
39 |
|
|
| |
82 (64.1) |
|
12(30.8) |
|
|
|
| |
20 (15.6) |
|
18 (46.2) |
|
|
|
| <> Somewhat satisfied |
12 (9.4) |
|
5 (12.8) |
|
|
|
| <> Dissatisfied |
12 (9.4) |
|
4 (10.3) |
|
p=0.002 |
|
| |
|
|
|
|
|
|
*Adjusted for age, ASA score, OA site (hip vs. knee) and Charnley disability grade with use of multivariable linear regression
Disclosure:
A. Lübbeke,
None;
G. J. Puskas,
None;
A. Finckh,
None;
D. Suva,
None;
S. Bas,
None;
C. Gabay,
None;
D. Fritschy,
None;
P. Hoffmeyer,
None.
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