What do people ask about a sore tendon?

Sources

1. Tendinopathy is described in the Nature Reviews Disease Primers review as a complex, multifaceted tendon pathology - disorganised collagen fibres, increased microvasculature and sensory nerve ingrowth, dysregulated matrix homeostasis, increased immune cells and inflammatory mediators, and enhanced cell apoptosis - most commonly affecting the rotator cuff, the medial and lateral elbow epicondyles, the patellar tendon, the gluteal tendons and the Achilles. The authors state plainly that management consists of exercise and loading programmes, therapeutic modalities and surgery, and that their effectiveness 'remains ambiguous'.

   Millar NL, et al. — Tendinopathy.. Nat Rev Dis Primers, 2021. DOI: 10.1038/s41572-020-00234-1.

2. Across 41 randomised trials and 2,672 participants, corticosteroid injection reduced tendinopathy pain in the SHORT term but the effect reversed later. For lateral epicondylalgia, corticosteroid had a large short-term effect versus no intervention (SMD 1.44, 95% CI 1.17-1.71), but no intervention was FAVOURED at intermediate term (SMD -0.40, -0.67 to -0.14) and long term (-0.31, -0.61 to -0.01). Of 991 participants injected with corticosteroid in trials reporting adverse events, one (0.1%) had a tendon rupture. Platelet-rich plasma was not more efficacious than placebo for Achilles tendinopathy in the trials available at that time.

   Coombes BK, et al. — Efficacy and safety of corticosteroid injections and other injections for management of tendinopathy: a systematic review of randomised controlled trials.. Lancet, 2010. DOI: 10.1016/S0140-6736(10)61160-9.

3. Thirty-nine men with patellar tendinopathy were randomised to peritendinous corticosteroid injection, eccentric decline squats or heavy slow resistance training for 12 weeks. All three improved at 12 weeks - but at the half-year follow-up the gains were MAINTAINED in the two exercise groups and had DETERIORATED in the corticosteroid group. Heavy slow resistance also produced elevated collagen network turnover and the highest treatment satisfaction at follow-up.

   Kongsgaard M, et al. — Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy.. Scand J Med Sci Sports, 2009. DOI: 10.1111/j.1600-0838.2009.00949.x.

4. In a 165-patient, injection-blinded, placebo-controlled factorial trial of unilateral lateral epicondylalgia, corticosteroid injection produced LOWER complete recovery or much improvement at one year than placebo injection (83% vs 96%; RR 0.86, 99% CI 0.75-0.99) and far higher one-year recurrence (54% vs 12%; RR 0.23, 99% CI 0.10-0.51). At 26 weeks the gap was wider still (55% vs 85%). Physiotherapy did not change one-year outcomes but did improve the 4-week picture when given with a placebo injection (39% vs 10%).

   Coombes BK, et al. — Effect of corticosteroid injection, physiotherapy, or both on clinical outcomes in patients with unilateral lateral epicondylalgia: a randomized controlled trial.. JAMA, 2013. DOI: 10.1001/jama.2013.129.

5. In 198 people with tennis elbow randomised to eight physiotherapy sessions, corticosteroid injection or wait-and-see, corticosteroid was significantly better at six weeks and then significantly WORSE in the long term: 47 of 65 initial successes subsequently regressed. Physiotherapy beat wait-and-see in the short term, but by 52 weeks most participants in both of those groups reported a successful outcome.

   Bisset L, et al. — Mobilisation with movement and exercise, corticosteroid injection, or wait and see for tennis elbow: randomised trial.. BMJ, 2006. DOI: 10.1136/bmj.38961.584653.AE.

6. In 185 primary-care patients with lateral epicondylitis, corticosteroid injection had a 92% success rate at six weeks versus 47% for physiotherapy and 32% for wait-and-see - and then reversed. At 52 weeks the success rates were 69% for injections, 91% for physiotherapy and 83% for wait-and-see. The relative gain of physiotherapy over simply waiting was small.

   Smidt N, et al. — Corticosteroid injections, physiotherapy, or a wait-and-see policy for lateral epicondylitis: a randomised controlled trial.. Lancet, 2002. DOI: 10.1016/S0140-6736(02)07811-X.

7. A systematic review of 50 studies of locally administered glucocorticoid on tendon tissue found loss of collagen organisation, increased collagen necrosis, reduced fibroblast proliferation and viability, decreased collagen synthesis in 17 studies, and a meta-analysis of the mechanical data showing significant deterioration in tendon mechanical properties (effect size -0.67, 95% CI 0.01 to -1.33). The authors state this supports the emerging clinical evidence of long-term harm from glucocorticoid injection into tendon.

   Dean BJ, et al. — The risks and benefits of glucocorticoid treatment for tendinopathy: a systematic review of the effects of local glucocorticoid on tendon.. Semin Arthritis Rheum, 2014. DOI: 10.1016/j.semarthrit.2013.08.006.

8. In 25 randomised trials covering 26,610 participants and 3,464 injuries, STRENGTH TRAINING reduced sports injuries to less than a third (RR 0.315, 95% CI 0.207-0.480) and proprioception training roughly halved them (RR 0.550, 0.347-0.869), while STRETCHING showed no protective effect at all (RR 0.963, 0.846-1.095). Overuse injuries specifically were nearly halved by exercise programmes (RR 0.527, 0.373-0.746).

   Lauersen JB, et al. — The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials.. Br J Sports Med, 2014. DOI: 10.1136/bjsports-2013-092538.

9. FDA states verbatim that stem cells, stromal vascular fraction, umbilical cord blood, Wharton's jelly, amniotic fluid and exosome products have not been approved 'for the treatment of any orthopedic condition, such as osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain, or shoulder pain.' Tendonitis and tennis elbow are named explicitly. No exosome product holds FDA approval at all, and the only stem cell products with FDA approval in the United States are blood-forming cells derived from umbilical cord blood, cleared only for disorders of blood production. FDA also states it has received reports of blindness, tumour formation and infections following treatment with unapproved products.

   U.S. Food and Drug Administration — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. FDA (Center for Biologics Evaluation and Research), 2020.

10. The American Medical Society for Sports Medicine's position statement on regenerative medicine exists precisely because the field has 'produced widely varying opinions' and because regulators, clinicians, scientists, patient advocacy organisations and the media have raised concern about how these products are used. It sets out terminology, the basic science and clinical evidence for orthobiologics, regulatory considerations, and best practices for introducing them responsibly - describing the evidence as growing that CERTAIN products are safe and potentially efficacious, not as settled.

    Finnoff JT, et al. — American Medical Society for Sports Medicine Position Statement: Principles for the Responsible Use of Regenerative Medicine in Sports Medicine.. Clin J Sport Med, 2021. DOI: 10.1097/JSM.0000000000000973.