Collagen and platelet-rich plasma in partial-thickness rotator cuff injuries. Friends or only indifferent neighbours? Randomised controlled trial

Abstract

Background Partial-thickness rotator cuff injuries (PTRCI) are the sum of degenerative, overload, and microtrauma processes. An external supply of collagen and platelet-rich plasma (PRP) could potentially counteract the deterioration of degenerative tendinopathy. This study aimed to compare the effectiveness of collagen with PRP, PRP alone, and collagen alone in the treatment of PTRCI. Methods Ninety patients with PTRCI were randomised and treated with ultrasound-guided injections into the shoulder bursa every consecutive week: Group A – collagen with PRP (n = 30), Group B – collagen alone (n = 30), and Group C – PRP alone (n = 30). Primary outcomes were pain intensity measured in control points on a numeric rating scale (NRS), QuickDash, and EQ-5D-5L questionnaires at the initial assessment (IA) and control assessments after 6 (T1), 12 (T2), and 24 (T3) weeks, respectively. Results No statistical differences were found between groups in primary outcomes, although there was a trend towards improvement in Groups A and C (opposite to Group B) between T2 and T3. The following parameters were also observed: rotator cuff discontinuity (n = 3, one case in each group) and rotator cuff regeneration (n = 22 in Group A, n = 20 in Group B, and n = 23 in Group C). Conclusions Combined therapy of collagen and PRP in PTRCI presents similar effectiveness to monotherapies with collagen or PRP. Trial registration The study was prospectively registered on the NCT Trial Center (identification number: NCT04492748) on 30.07.2020.

Conservative Management of Partial Thickness Rotator Cuff Tears: A Systematic Review

“…Multiple studies using tendon-like cell models have consistently shown that the combination of collagen and PRP exerts synergistic effects. The addition of various PRP products resulted in increased cell proliferation, confirming the positive impact of this combination 31 . The benefits of collagen injections are confirmed by the findings of the present systematic review, coherently with the results of a recent RCT 35 .…”

“…Regarding the Level of Evidence, 5 studies were level I RCTs 30,31,34,37,38 ; 5 level III PCC studies 7,8,32,33,42 ; and 1 level IV prospective case-series study 36 …”

“…Godek et al 31 reported the variation in the tear size with bursal-sided lesions increasing from 3.3 to 4.6 and intratendinous lesions decreasing from 4.7 to 4.4 cm.…”

“…One 35 reported VAS for pain and CMS and compared them in patients receiving 0.5 mL of collagen injections and patients receiving 1 mL of collagen injections. The second study 31 focused on the variation in tear width after collagen injections. Data for these studies are summarized in Table 2.…”

“…Regarding the Level of Evidence, 5 studies were level I RCTs 30,31,34,37,38 ; 5 level III PCC studies 7,8,32,33,42 ; and 1 level IV prospective case-series study. 36 The 11 studies reviewed included a total of 454 patients, with a minimum follow-up of 3 months.…”