Achilles

No magic answer for Achilles tendinopathy.

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“Although they are trendy money spinners, best evidence shows little effectiveness”—An attention grabbing subheading to an editorial by Nic Maffulli in the BMJ commenting on an intriguing randomised controlled trial (RCT) from New Zealand on the use of autologus blood injections in treating Achilles tendinopathy. It doesn’t work.

Evidence based sports medicine was radical new thinking when Tom Best and I first began to think about it. Care of the athlete had evolved empirically. Few asked questions. For example, when our university research group first began to study ice, perhaps the most commonly used treatment in soft tissue injury, there was little quality evidence to inform treatment; the duration of each application, over what period of time, the temperature of the ice (melting iced water is 0 degrees Celcius),  if it mattered if you were fat or thin etc. Clinicians then began to ask about the evidence for the tests used in clinical examination, the effectiveness of prevention, the appropriate management of common conditions. Where we thought there was certainty, there was little evidence. This RCT on Achilles tendinopathy is an important trial because it asked serious questions about a treatment that had become commonplace yet seemingly evidence free.

Much of what we think is fact in sport is hype, based often on weak science, but mostly on extrapolation from observation. People in sport are forever looking for that extra added magic ingredient to set them apart. Complicit and gullible because they want to believe.  They follow the training programme, wear the headband, chase the logo the champions wear. It is no surprise that they take the drink, buy the supplement, wear the shoe, or do the exercise endorsed by champions. Ever susceptible, suggestible—looking for an easy way, its human nature.  So, it was no surprise to see the hype surrounding yet another product on the margin. This was the next big thing—an injection to cure one of the most common and troublesome injuries.

Its great to see good quality research and more is needed. But, research is expensive and its almost impossible to justify research in sports medicine when competing for funds with cancer, cardiology, and other core medical topics.  There is an evidence vacuum and in sports medicine there is huge pressure to do something. And, always someone looking for the magic answer.

Sourc: BMJ

 

 

Impact of autologous blood injections in treatment of mid-portion Achilles tendinopathy: double blind randomised controlled trial.

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Abstract

Objective To assess the effectiveness of two peritendinous autologous blood injections in addition to a standardised eccentric calf strengthening programme in improving pain and function in patients with mid-portion Achilles tendinopathy.

Design Single centre, participant and single assessor blinded, parallel group, randomised, controlled trial.

Setting Single sports medicine clinic in New Zealand.

Participants 53 adults (mean age 49, 53% men) with symptoms of unilateral mid-portion Achilles tendinopathy for at least three months. Participants were excluded if they had a history of previous Achilles tendon rupture or surgery or had undergone previous adjuvant treatments such as injectable therapies, glyceryl trinitrate patches, or extracorporeal shockwave therapy.

Interventions All participants underwent two unguided peritendinous injections one month apart with a standardised protocol. The treatment group had 3 mL of their own whole blood injected while the control group had no substance injected (needling only). Participants in both groups carried out a standardised and monitored 12 week eccentric calf training programme. Follow-up was at one, two, three and six months.

Main outcome measures The primary outcome measure was the change in symptoms and function from baseline to six months with the Victorian Institute of Sport Assessment-Achilles (VISA-A) score. Secondary outcomes were the participant’s perceived rehabilitation and their ability to return to sport.

Results 26 participants were randomly assigned to the treatment group and 27 to the control group. In total, 50 (94%) completed the six month study, with 25 in each group. Clear and clinically worthwhile improvements in the VISA-A score were evident at six months in both the treatment (change in score 18.7, 95% confidence interval 12.3 to 25.1) and control (19.9, 13.6 to 26.2) groups. The overall effect of treatment was not significant (P=0.689) and the 95% confidence intervals at all points precluded clinically meaningful benefit or harm. There was no significant difference between groups in secondary outcomes or in the levels of compliance with the eccentric calf strengthening programme. No adverse events were reported.

Conclusion The administration of two unguided peritendinous autologous blood injections one month apart, in addition to a standardised eccentric training programme, provides no additional benefit in the treatment of mid-portion Achilles tendinopathy.

 

What is already know on this topic

  • Several studies have suggested that the injection of autologous blood can be helpful in the treatment of various tendinopathies
  • Autologous blood injections are a relatively common treatment, despite a lack of high quality evidence supporting their use in the management of Achilles tendinopathy
  • The use of peritendinous autologous blood injections does not reduce pain or improve function in those with mid-portion Achilles tendinopathy when they are combined with an eccentric training programme.

What this study adds

Discussion

Summary of principal findings

To our knowledge, this is the first double blinded, randomised, controlled trial investigating the efficacy of autologous blood injections as a treatment for mid-portion Achilles tendinopathy in addition to a standardised eccentric training programme. Both groups showed a steady and clinically meaningful improvement in the mean VISA-A scores throughout the study. The addition of two peritendinous autologous blood injections administered one month apart, however, was unlikely to have resulted in additional clinically meaningful improvements in pain or in ability to return to activity.

Comparisons with the literature

The only other available published study investigating the use of autologous blood injections to treat Achilles tendinopathy concluded that injections produced a moderate improvement in symptoms.24 This previous study lacked blinding and allocation concealment, administered a variable number of injections, included participants with unilateral and bilateral symptoms, and had a high dropout rate. The sample size recruited for our study was large enough to preclude possible clinical benefits and harm and was also similar to that in other randomised trials that used the change in VISA-A score as the primary outcome measure (40-75 participants).24 28 29 The monitoring of eccentric training was also similar to that used by some other investigators,28 30 though others did not mention steps taken to monitor compliance.29 31 Good compliance probably contributes to a participant’s clinical improvement.25 Without accurate monitoring, any benefit attributable to the intervention might actually be caused by disparity between groups in the compliance with eccentric training or would at least increase the variation of the results. It is also likely that there would be increased variation in measurement between participants.

Explanations and clinical implications

The use of autologous blood injections to treat tendinopathy has become particularly popular in recent years, despite the apparent lack of quality evidence supporting their use.19 20 24 32 33 Our findings suggest that the application of autologous blood injections as described has no clear clinically beneficial effect, and based on this finding we cannot recommend their future use. There are, however, several other possible explanations for the outcome. Firstly, the needling process itself might have created sufficient bleeding in the control participants to induce a healing response. Secondly, administering injections closer together would have enhanced any potential benefit from maintaining a steady state effect of growth factors present in the blood.17 19 The lack of ultrasound guidance, or the injections being directed peritendinously rather than intratendinously, could have affected the outcome. From our experience however, most autologous blood injections administered in New Zealand are delivered peritendinously. Several reports of benefit from unguided injections in tendinopathy support this type of administration.24 32 33 34 35 36 There are also numerous studies indicating that peritendinous injections of differing substances can provide benefit in the treatment of Achilles tendinopathy.24 36 37 38 The intratendinous injection of platelet rich plasma, a derivative of whole blood, has been investigated in the treatment of mid-portion Achilles tendinopathy with mixed results to date.39 The proposed mechanism of action of autologous blood injections and platelet rich plasma is similar, but the former is cheaper as it does not require specific preparation and a smaller volume of blood is taken from participants. The negligible clinical effect of autologous blood injections in this study, and the mixed results of platelet rich plasma, suggest that these forms of injection therapy are not useful for the treatment of mid-portion Achilles tendinopathy. Eccentric training is already recognised as a good treatment option for Achilles tendinopathy,15 25 28 and both groups showed a clinical improvement as a result of the eccentric training component. It was therefore difficult to show an additive clinically meaningful effect of autologous blood injections. We did not use any type of substance in the injections in the control group, whereas most other studies used injections of normal saline28 40 41 42or local anaesthetic.43 44 There is recent evidence to suggest that higher levels of extracellular sodium suppress transient receptor potential V1 (TRPV1) activity, a non-selective cation channel present in nociceptors that helps to integrate pain perception.45We considered that injecting normal saline could itself result in reduced pain sensation, and as such, not strictly act as a control intervention. Indeed, the group allocation prediction analysis shows that participants were unable to determine which group that they had been randomised to, suggesting that with the use of our control intervention, we were able to maintain adequate blinding.

Strengths and limitations of the study

Strengths of this study were the high participation rate (95%) and low dropout rate (6%). The participants reflected a wide range of society with ages ranging from 27 to 76 and sex being evenly matched with 53% men and 47% women. There was, however, an under-representation of minority ethnic groups, with 91% of the participants identifying themselves as European and the 9% remaining as New Zealand Maori. A further strength was the use of the validated primary outcome measure, the VISA-A questionnaire, which was completed in the presence of the single blinded assessor. We also used daily monitoring of eccentric training compliance with a written log, which could have encouraged good compliance and showed that there were no differences between the groups in the eccentric training aspect of the management.

Future research

We conclude that the administration of unguided peritendinous autologous blood injections does not confer an additional benefit to rehabilitation outcomes resulting from a standardised eccentric training programme. Follow-up studies could involve the injections being given intratendinously under ultrasound guidance, a shorter time interval between injections, or an increase in the volume of injected blood. It would also be beneficial to have a third treatment group who undertake an eccentric training programme only, without injection. While such derivations would aid in estimation of the effect of the needling itself, it would be without blinding and therefore susceptible to placebo effects. A fourth treatment with autologous blood injections in the absence of eccentric training would help to determine whether any benefit is obtained from injections in isolation.

Source: BMJ