Discussion
supraspinatus tears, Pain, impingement, pain, ’ pain, degenerative pathologies, tenderness, abduction
REGRESSION
The regenerative effect of L-GF in SIS was tested on different outcome measures (clinical and sonographic). Pain has been considered one of the main outcome measures and has shown significantly more improvement in the L-GF group (2.9 points in mean VAS) than in the saline group (1.8 points), which represents a 42% reduction in the former versus 23% in the latter. Linear regression also showed that L-GF injection was a significant predictor of lower follow-up VAS scores, and controlling for other variables, follow-up VAS scores were significantly lower in the L-GF group than in the saline group by 1.38 points. In addition, subacromial tenderness was elicited in a significantly lower number of patients in the L-GF group at follow-up than in the saline group. This effect of L-GF on pain reduction could be explained by the anti-inflammatory effect of HGF released from platelets during the activation step [Limited ROM is caused by altered shoulder kinematics [For the painful arc sign, logistic regression showed that L-GF was a significant predictor of a negative painful arc sign at follow-up (40% in L-GF versus 3% in saline group). Furthermore, by adjusting for covariates, the L-GF group was 30 times more likely to have a negative painful arc at follow-up than the saline group. This suggests that L-GF, through its anti-inflammatory effect, may have acted by inducing considerable pain relief as well as decreasing supraspinatus tendon thickness, thus improving the impingement while passing under the coracoacromial arch during abduction. In comparison with steroid injection, a study comparing the effectiveness of steroids to local anesthetic injections for supraspinatus tears found considerable pain relief after steroid injection, yet no improvement regarding the painful arc sign [To evaluate patients’ pain during different activities and the resulting disability, SPADI-total and subscores were assessed at baseline and follow-up. The SPADI-total and SPADI-pain subscales showed a statistically significant reduction in both groups. However, the magnitude of improvement was larger in the L-GF group than in the saline group. Additionally, linear regression revealed that L-GF was a significant predictor of a lower SPADI-total score at follow-up. For the SPADI-disability subscale, only the L-GF group showed statistically significant improvement.In agreement with our results, a meta-analysis has shown significantly better SPADI scores at 3 weeks, 3 months and 6 months among patients treated with PRP than with saline, exercise therapy or dry needling [To objectively evaluate soft tissue organization, ultrasonography was used at follow-up to measure the thickness of the supraspinatus tendon. A statistically significant decrease in tendon longitudinal thickness was detected in the L-GF group only. A decrease toward normal thickness is considered a sign of successful tendon regeneration where a more organized fibrillar pattern is restored since L-GF enhances tendon remodeling [Although 17 months was the mean duration of symptoms in our patients, which poses great challenges to healing, this chronicity still did not affect the outcome measures in the L-GF group, as concluded by the regression analysis. Another challenge was the age of our patients, which is a well-known risk factor for degenerative pathologies [