Page 30 - 2020 ISAKOS Newsletter Volume I

CURRENT CONCEPTS
State of the Art for Injections in Orthopaedics
However, good results were seen in association with the use of gel PRP matrix, the application of PRP at the tendon-bone interface, the use of PRP for double-row repairs, and the use of PRP for small or medium-sized rotator cuff tears.4
Epicondylitis
PRP injections have reported good results in the treatment of the lateral epicondylitis, in cases where physiotherapy has been unsuccessful. A multicenter, double-blinded, randomized controlled trial reported increased pain relief and diminished elbow tenderness at 24 weeks suggesting that Leukocyte-rich Platelet-Rich Plasma (LR-PRP) may have beneficial long-term effects for treating lateral epicondylitis compared to steroid.5
Achilles Tendon
No difference was found in clinical outcome scores, pain relief, or neovascularization of tendon tissue with PRP compared to placebo injection with saline in a double-blind, randomized controlled trial of 54 patients with 1-year follow- up. Even after acute tendon rupture, PRP administration at the time of surgical repair has not been proven to be efficacious.
Patellar Tendon
Some studies that evaluated the injection of leukocyte-rich PRP compared with dry needling in the treatment of refractory patellar tendinopathy plus standardized eccentric exercises showed significantly more clinical improvement in the group of PRP at 12 weeks but not at 26 weeks. A systematic review of eleven studies reported the beneficial effects of PRP injection for treating patellar tendinopathy to be inconclusive and inconsistent in comparative studies. Load-based rehabilitation remains the cornerstone of tendinopathy management.
Cell Based Therapies
In the setting of rotator cuff repair, there are few studies using bone marrow cells (BMAC) to augment the healing rate. One case-control study using BMAC sourced from posterior iliac crest showed significant improvement in healing outcomes and reduced number of re-tears determined by ultrasound and MRI at ten years follow up. However, another study showed no significant difference in clinical scores at six months using BMAC sourced from the ipsilateral humeral head.6
Injections for Meniscus Tears
Platelet Rich Plasma (PRP)
PRP contains several bioactive agents that can mediate the tissue healing process after an injury through both the inflammatory and remodeling phases. Platelets are involved in homeostasis, aggregation and clot formation steps, which finally leads to the scaffold formation, necessary to enhance meniscus healing.
However, only few clinical studies have demonstrated slightly improved clinical outcomes and good rates of meniscal healing.
Cell Based Therapies
Clinical studies using cellular therapies for meniscal repair are currently limited. A RCT, found statistically significant meniscus growth on MRI at 24 weeks post-injection, as well as better functional and clinical outcomes using expanded autologous bone marrow mesenchymal stem cells injected percutaneously in knees.7 A clinical study reported the repair of a grade II meniscal tear following a percutaneous injection of autologous adipose stem cell (ASCs) along with PRP, hyaluronic acid, and CaCl2. One randomized, double-blind, controlled study, reported evidence of meniscus regeneration and an improvement in knee pain.
The use of mesenchymal stem cells seems to stimulate the regeneration of meniscal tissue and it appears to be a promising approach to restore as much meniscal tissue as possible. However, these regenerative technologies still need to be optimized. Further studies are also needed in this field to support its use.
Summary
Level 1 of evidence.
• OA: Clinical use of LP-PRP for the treatment of symptomatic mild to moderate knee OA is strongly supported in the literature.
• Tendinopathy: LR-PRP is recommended for the treatment of lateral elbow tendinopathy.
• Meniscus: Meniscal regeneration was reported in a therapeutic level 1 study with the use of injectable expanded autologous bone marrow mesenchymal stem cells but needed further study.
• Muscle: PPP should be used to stimulate myoblast differentiation, which is necessary for skeletal muscle regeneration, but stronger research is needed.
• ACL: BMAC and PRP are safe and showed good long- term results as a coadjuvant for partial tears of the ACL in a level 4 of evidence study. May be used assuming minimal risk to the patient, but future higher-quality research is recommended to create a more definitive recommendation.
28 ISAKOS NEWSLETTER 2020: VOLUME I