Efficacy of Tendon Strip Injections compared to sham following failure of conservative therapy for Achilles tendinopathy

A single TSI or sham injection will be delivered by a radiology nurse and experienced musculoskeletal radiologist.Three injection groups (i) Tendon strip injection with steroid: The TSI consists of five syringes, the first with exactly 10 mL of 0.5% bupivacaine hydrochloride and 25 mg of hydrocortisone (the syringe will be large enough to take both the local anaesthetic and steroid), followed by four syringes with 10 mL each of normal saline. The TSI will be injected into the interface between Kager’s fat and the Achilles tendon. The local anaesthetic + the steroid, followed by the four saline syringes are injected consecutively by using a connecting tube (allows consecutive syringes to be attached). The position of the needle is monitored continuously by ultrasound and the needle is moved gently across the anterior aspect of the tendon to ensure uniform effect over the pathological area. Including our preliminary trials and the prior case series on TSI there are over 175 participants who have had this procedure, with no reports of serious complications (e.g. tendon rupture, infection). (ii) Tendon strip injection without steroid: This injection is identical to the TSI with steroid, but the first syringe will only contain exactly 10 mL of 0.5% bupivacaine hydrochloride (no steroid). (iii) Sham injection: The sham injection consists of five syringes like the tendon strip injection. The first contains 2-3 mL of 0.5% bupivacaine hydrochloride. The subsequent four syringes contain 0.25mL of normal saline (i.e a few drops). Total volume is 3-4mL. The sham will be injected under image guidance by the same expert radiologist, deep to the tendon and away from the interface between Kager’s fat and the Achilles tendon (at last 5mm away). The sham injection will result in a numbing effect, like the TSI. Immediately post injection participants will be asked which injection they believe they received to assess the success of participant blinding. Post injection treatment: Immediately after the injection, participants will be asked about how logical and successful they feel the treatment they have received will be, as well as their confidence in the treatment. This will only be assessed at the baseline. After the injection, an appropriately trained researcher, who is blind to treatment allocation will deliver identical advice and a 12-week exercise program to all participants, based on our prior TSI work. This includes an evidence-based and progressively loaded exercise protocol for Achilles tendinopathy, education about physical activity modification and resumption, and advice about progressing and regressing exercise load, based on a pain monitoring model. The researcher will also provide education about Achilles tendinopathy (pathology, pain, risk factors, prognosis, treatments, recovery times). Participants will be reviewed by the researcher at 2, 6 and 12 weeks (all at at Imaging at Olympic Park (IOP), aside from week 2 over Zoom) to modify the exercise as required (e.g. progress load, modify technique), and at 12 weeks to provide evidence-based advice about continuing exercise beyond the intervention period. The researcher will also call participants at week 1, 4,8 and 10 to ask whether they have any questions or issues with the exercise or education intervention, and participants will be provided with basic online exercise videos and education and the researchers contact details that they can use at any time. Participants will be advised to refrain from using other physical therapy interventions and non-steroidal anti-inflammatory medications but will be allowed to take paracetamol (up to 4g/day) for pain relief as required. Details of the exercise program: a) who is administering the program: physiotherapist for first 12 weeks and self-administered after that. b) the mode of administration: independently at home. c) the level of intensity: will be adjusted by the participants themselves. They will be advised to do 15 repetitions x 4 sets, once a day for three times a week. If they experience less than 5/10 pain and have 2 reps in reserve, then they will be advised to add weights in 5kgs increments. d) the frequency/duration of program, 15 repetitions x 4 sets, once a day for three times a week for 52 weeks. Participants will be reviewed by the researcher at Imaging at Olympic Park (IOP) at 2, 6 and 12 weeks to modify the exercise as required (e.g. progress load, modify technique), and at 12 weeks to provide evidence-based advice about continuing exercise beyond the intervention period. Details of the education program: a) who administers the education: physiotherapist for first 12 weeks and participant self-administered after that. b) the mode of administration: videos, education leaflets. c) the frequency/duration of program: single session at the beginning of the program and then follow up calls at week 1, 4,8 and 10 to ask whether they have any questions or issues with the exercise or education intervention. Participants will also be reviewed by the researcher at Imaging at Olympic Park (IOP) at 2, 6 and 12 weeks to modify the exercise as required (e.g. progress load, modify technique), and at 12 weeks to provide evidence-based advice about continuing exercise beyond the intervention period. The education/exercise relative to the injection procedure: The education will be delivered on the same day post-injection, and participants will be advised to start the exercises 2-3 days post-injection. strategies to monitor adherence: participants will be advised to maintain an exercise diary to log their attendance every time they perform exercises. The physiotherapist/research assistants will also make follow up calls at week 1, 4,8 and 10 to ask whether they have any questions or issues with the exercise or education intervention. Participants will also be reviewed by the researcher at IOP at 2, 6 and 12 weeks to modify the exercise as required (e.g. progress load, modify technique), and at 12 weeks to provide evidence-based advice about continuing exercise beyond the intervention period.