Midportion Achilles Tendinopathy Treatment

Today we wrap up the mid portion Achilles tendinopathy CPG, but we also take things one step further by summarizing a 2015 article by Karin Silbernagel and Kay Crossley called, "A Proposed Return-to-Sport Program for Patients With Midportion Achilles Tendinopathy: Rationale and Implementation." For further reading, we also recommend taking a look at Silbernagel's "Current Clinical Concepts: Conservative Management of Achilles Tendinopathy" from 2020. If you haven't been using these principles, doing so could really level-up your Achilles tendinopathy rehab.

Transcript

Welcome back! The plan today is to wrap up midportion Achilles tendinopathy. First we’re going to cover the interventions section of the CPG, and then we’re going to talk about a great article by Karin Silbernagel and Kay Crossley that gives you really useful, practical steps for treating this condition.

First, let’s look at the CPG. I’m going to cover interventions in order of strongest evidence in favor to weakest evidence in favor, with recommendations against specific interventions at the end. Then we will cover non-PT treatments. The CPG authors also note that most of these studies are performed on chronic Achilles tendinopathy, so you have to use some clinical reasoning to decide what is appropriate for your patient. Most of the studies also exclude individuals with suspected tendon frailty (such as from systemic diseases), so keep that in mind as you apply this information. Lastly, the authors recommend modifying your treatment based on whether the patient is in an acute or nonacute stage, so we will cover their stage-based suggestions after we go through these recommendations.

Okay, so here are the interventions we should try, from strongest evidence to weakest.

There is A-level evidence for mechanical loading to decrease pain and improve function. This includes strong recommendations either for eccentric exercise or heavy-load, slow concentric-eccentric exercise—as long as we don’t suspect abnormal tissue frailty.  This recommendation also comes with an expert opinion suggestion that the exercise should be performed at least twice weekly within patient pain tolerance.

There is something important to note here. For a while, eccentrics were considered the must-do exercise for Achilles tendinopathies, because early studies on eccentrics had pretty good results. However, as we’ve continued to study tendons and tendinopathies, we have found that there’s nothing magical about eccentric contractions for tendon issues—the tendon doesn’t know whether it is being loaded concentrically or eccentrically. The reason that eccentrics worked so well is that we could load eccentrics more heavily than we typically load combined concentric/eccentric exercises. So successive studies have shown that it’s more about loading than about contraction type. Hence, our recommendation now goes beyond eccentrics to include heavy-load, slow concentric/eccentric exercise.

Continuing with our intervention recommendations, we have B-level evidence for patient education that encourages individuals with non-acute tendinopathy to continue with their recreational activities within their pain tolerance. This is based on one of Karin Silbernagel’s studies that compared an “active rest” group of patients to a group that was encouraged to continue their sport as long as their pain stayed below a 5/10. Both groups also performed an exercise program. Both groups improved, and at 5-year follow-up, both groups averaged above a 90 on the VISA-A. So continuing to perform your sport as long as pain remains below a 5/10 appears not to be detrimental to tendon recovery. (Note once more that this is specifically for nonacute tendinopathies. If a tendinopathy is acute, active rest may be more appropriate at first.) 

Next, we have a B-level recommendation for iontophoresis with dexamethasone to decrease pain and improve function in patients with acute mid portion Achilles tendinopathy. I will emphasize again: iontophoresis with dexamethasone is recommended for acute tendinopathy, not chronic tendinopathy.

Next, we have a C-level recommendation for stretching the plantarflexors to improve pain in those who have limited ankle dorsiflexion ROM.

Next, we have E-level evidence, which means foundational or theoretical evidence, for counseling patients about theories regarding why PT and mechanical loading are effective, modifiable risk factors like BMI and shoe wear, and typical recovery timeframe.

Lastly, we have F-level expert opinion to consider using manual joint and soft tissue mobilization, neuromuscular reeducation targeting impaired LE kinematics, rigid taping to alter foot posture, and combined dry needling with injection under ultrasound guidance with eccentric exercise.

That covers the interventions we should consider. Due to conflicting evidence, the CPG makes no recommendations for heel lifts, orthoses, or low level laser therapy. We can’t yet tell whether those treatments help or not.

Now here are the treatments we should not be doing: based on C-level evidence, we should not be using night splints with these patients, and with F-level evidence, we should not be using elastic taping. In other words, we are kind of confident that splinting won’t help, and we don’t really know, but we don’t think that elastic taping will help.

Next we’ll cover three interventions that are typically outside of a PT’s scope, and then we’ll wrap up the CPG with a comparison of acute vs. non acute treatments. The CPG presents evidence related to corticosteroid injections, extracorporeal shockwave therapy, and platelet-rich plasma injection, without making any specific recommendations, since they consider these to be typically outside of a PT’s scope. For corticosteroid injections, they point out that a systematic review of randomized controlled trials concluded that there is an initial short-term benefit to injections, but that benefit is not maintained at intermediate or long-term follow-up. In other words, it might help some patients at first, but it’s not an effective long-term treatment. On the other hand, a recent RCT and systematic review demonstrated that high volume corticosteroid injections coupled with eccentric exercises improved VISA-A scores more effectively than eccentric exercises alone. I think the lesson here is that if corticosteroid injections are used, they should be coupled with exercise.

For extracorporeal shockwave therapy, systematic reviews show no effect for its use in isolation. We do have some evidence that it can help in chronic tendinopathy when combined with eccentric exercise. So for now, it should only be considered in chronic cases, and only when combined with exercise.

For platelet-rich plasma, the CPG says that we have many systematic reviews that offer high-level evidence against the use of PRP for improving symptoms, function, return to sport, and for ultrasonic evidence of improvement. So don’t recommend PRP to your Achilles tendinopathy patients.

Let’s conclude the CPG by comparing acute and nonacute presentations and treatment. The CPG recommends staging the tendinopathy and considering stage and irritability when selecting interventions. In the decision tree section of the guideline, they suggest identifying a case as acute and irritable if there is redness, warmth, and swelling; if the symptoms have lasted for 3 months or less; and if there are high levels of pain that limit low-level activity, like walking. In this case, the authors recommend matching the following interventions to the following findings: if you note pain and inflammation, try iontophoresis (which has B-level evidence) or other modalities (which are based on expert opinion). If your findings include loss of ROM, try stretching (which has C-level evidence) and joint or soft tissue mobilization (which is based on expert opinion). If you note painful motion, try rigid taping or some other form of bracing—both suggested based on expert opinion. Finally, provide education on continuing to stay active within a tolerable level of pain (which has B-level evidence), and counsel the patient on modifiable risk factors (which has theoretical evidence).

Nonacute or less irritable tendinopathy will lack redness, warmth, or swelling (although tendon thickening will likely still be present). Symptoms will have persisted for at least 3 months, and pain will occur after onset of a higher-level activity or after completion of a higher-level activity. The following treatments are recommended, matched to the following findings: if you find tendon pain with palpation, treat with heavy load exercises (based on A-level evidence). If you note loss of ROM, treat with stretching (based on C-level evidence) or joint and soft tissue mobilization (based on expert opinion). If you find painful motion, you can use rigid taping or bracing (both based on expert opinion). If you note abnormal biomechanical findings, treat with neuromuscular exercises addressing whatever impairments you see (based on expert opinion). And once more, provide education on continuing to stay active within a 5/10 pain level tolerance (based on B-level evidence), and counsel the patient on modifiable risk factors (based on theoretical evidence).

To summarize: the authors suggest treating pain in acute tendinopathy with iontophoresis or other anti-inflammatory modalities, but in nonacute or less irritable tendinopathy, treat pain with heavy loading. Both groups can receive stretching and joint or soft tissue mobilization to treat loss of motion, and both groups can receive rigid taping or bracing to treat painful motion. Both groups should receive education to stay active within a tolerable amount of pain, and both groups should receive counseling on modifiable risk factors. Finally, if you note other lower quarter musculoskeletal or biomechanical impairments in those with nonacute tendinopathy, consider using neuromuscular exercises to address those problems.

That wraps up the CPG. Before we finish this episode, I want to cover some principles of Achilles tendinopathy treatment laid out by Silbernagel and Crossley. While the CPG does a good job of summarizing the general evidence we have for treating Achilles tendinopathy, Karin Silbernagel has done a great job publishing a more detailed protocol that incorporates what we know about physiology, pain science, and subjective patient experience. I highly recommend you take a look at the paper, “A Proposed Return-to-Sport Program for Patients With Midportion Achilles Tendinopathy: Rationale and Implementation” by Silbernagel and Crossley from JOSPT in 2015. More recently, Dr. Silbernagel was involved in writing a summary of evidence for Achilles tendinopathy treatment; it is titled, “Current Clinical Concepts: Conservative Management of Achilles Tendinopathy,” and it was published int he Journal of Athletic Training in 2020. I will put links to both of these papers in the show notes. But because you don’t necessarily have time to read every paper that some guy on a podcast recommends, I’ll summarize some of the key points now.

In the JOSPT article I just mentioned, Silbernagel and Crossley specify six factors that a good PT should consider when planning rehabilitation and return to sport for an individual with Achilles tendinopathy. The first factor is tendon healing. We need to be able to identify what stage of healing the individual is in; recognize that tendons heal more slowly than muscles and Achilles healing can take up to 12 months; recognize that mechanical loading is crucial to promote tendon healing; and that factors like age, genetics, medications, and hormone levels affect healing.

The second factor is tendon recovery. One simplified model of the pathophysiology of tendinopathy is that collagen degradation is occurring faster than collagen synthesis, so tendon repair cannot keep up with tendon breakdown. The authors point out that evidence shows a net decrease in collagen in the first 24 to 36 hours after exercise followed by a net increase after 36 to 78 hours. So that means we need to build recovery days into our rehab program. Silbernagel and Crossley suggest 3 recovery days in between heavy loading in the earlier stages of rehab. This can be shortened as patients progress and the tendon gains strength. Because these recovery days are going to be so important, the authors suggest grouping activities into light, medium, and high intensity and adjusting the amount of recovery accordingly. More on that in a minute.

The third factor to consider is pain and symptoms. I referenced a study a few minutes ago that seemed to show that participating in sports—as long as pain stayed at a low to moderate level—was not detrimental to recovery. Monitoring and adjusting activities in response to pain is called the “pain-monitoring model.” The authors here point out that if all activities and rehab are kept completely pain-free, then it’s unlikely that the exercises are producing enough load on the injured tendon to stimulate repair. On the other hand, tendinopathy is typically an overload condition, so maximum pain is not the goal either. So the pain-monitoring model allows patients to experience up to 5/10 pain during and after exercises and activities, and this amount of pain is considered “acceptable” and not high risk. So activities don’t need to be stopped or modified as long as pain is no greater than 5/10 during the activity, after the activity, the morning after the activity, and as long as pain and stiffness does not increase week to week. This model has a lot of strengths in that it assures tissue loading is adequate to stimulate repair, and it reframes pain as an acceptable guide to rehab, which could be particularly useful for individuals experiencing kinesiophobia or central sensitization. The pain-monitoring model has now been discussed and studied in quite a few trials, and so I think this framework is really good to know for the OCS and for your clinical practice.

Before we move on to the next factor, I want to reiterate that the pain-monitoring model does not just apply to pain experienced during the activity, but also immediately afterward, the following morning, and week-to-week. In later stages of rehabilitation, patients with tendinopathy tend to experience less pain during activities but potentially more pain the following morning. The authors recommend using a pain journal to help keep track.

Moving along, the fourth factor to consider in rehab is impairments. We know that individuals with Achilles tendinopathy tend to have other impairments, such as impaired strength, ROM, endurance, and jumping ability. We have also seen that symptoms tend to improve before all the impairments resolve. So when planning for return-to-sport, we need to be looking beyond symptom resolution and make sure we finish addressing the other impairments as well. Remember that Achilles tendinopathy reoccurrence is not uncommon, so we don’t want to set someone up for another episode a few months down the line.

The fifth factor to consider is load on the Achilles tendon. We know overload causes tendinopathy. We also know that treating tendinopathy requires load. So we need to be skilled at progressively loading the tendon within its limits all the way up to sport-specific activities for return-to-sport. We can adjust load by adjusting the magnitude of resistance—like adding more weight—or by increasing the rate of loading—like doing a quick heel raise instead of a slow heel raise. The authors summarize literature on Achilles loading that suggests the Achilles experiences a load about equal to bodyweight during cycling, 3.5 times bodyweight while walking, 5 times bodyweight while submaximally hopping (like jumping rope), and 12 times bodyweight while running—with load directly connected to speed, so running faster means more load on the tendon. So we can progress Achilles load by activity—cycling to walking to hopping to running—and by speed—normal walking to fast walking and slow jogging to fast running. The authors also point out that while running, a rearfoot striking pattern actually decreases load on the Achilles tendon compared to a forefoot striking pattern, and a shorter step length (or increased cadence) also decreases load. So running athletes may be able to modify their load by reducing forefoot landing or by shortening their stride.

Moving on, the last factor to consider is perceived rate of exertion. When classifying activities as light, medium, or high intensity, the authors recommend that patients use something like the Borg scale to rate how difficult an activity is with respect to their Achilles. This helps guide decision-making with activity progression and rest days.

Tying this all together, Silbernagel and Crossley recommend a rehab program that consists of essentially two phases. The first phase involves a lot of education on tendinopathy, tendon repair, how symptoms may resolve before the tendon is done healing, and how to use the pain-monitoring model. The exercise program consists of a progression of typical bodyweight-oriented Achilles loading both with knees straight and knees bent, such as bilateral heel raises on the floor, progressing to single leg heel raises on the floor, progressing to eccentric heel raises on the floor, progressing to heel raises off the edge of a step, and eventually progressing toward rebounding heel raises and adding more weight. (You can pull up the article if you want detailed specifics.)

Once a patient can do all ADLs with no more than 2/10 pain, they enter the second phase of the program. Here, they start to return to more sport-specific activities. At this point, the therapist and the patient will categorize activities into light, moderate, and high load based on pain during the activity, pain the next day, and the athlete’s perceived exertion with respect to the Achilles tendon. A light activity would cause only 1-2/10 pain during and after the activity and would be rated by the athlete as 0-1 on the Borg scale. Light activities can be performed every day without the need for recovery days. Moderate activities cause 2-3/10 pain during the activity, 3-4/10 pain the next day, and are rated on the Borg as a 2-4. It’s recommended that 2 recovery days be taken between bouts of moderate intensity exercises. High intensity exercises produce 4-5/10 pain during the activity, 5-6/10 pain the next day, and are rated as 5-10 on the Borg. It’s recommended that 3 recovery days be taken between bouts of high intensity exercises.

It’s expected that as the athlete improves, some high intensity activities will become moderate, and some moderate intensity activities will become light. The authors recommend revisiting the list every 3 weeks and recategorizing which activities are light, moderate, or high intensity. In this way, the athlete can continue to progress with fewer recovery days.

We just covered a lot. And I think it’s great stuff, but it’s still a lot. So I’ll reiterate the things I think are most important from the Silbernagel and Crossley article: remember your pain-monitoring model. In Achilles tendonopathy rehab, it’s okay for a patient to experience up to 5/10 pain during the exercise, after the exercise, and the next morning, and pain and stiffness should not be getting worse week to week. If pain or stiffness does get worse, or if the patient is experiencing >5/10 pain, you should know how to decrease load on the tendon by modifying amount of resistance or speed of load. Or if a patient is experiencing absolutely no pain during their rehab, you should know how to progress tendon loading. Keep in mind that modifying intensity of the activity—like walking or running—and biomechanics—like shortening a runner’s stride—are good ways to modify tendon load.

Okay, that’s it for this week. Again, I’ll post links to the two articles I mentioned in the show notes. I hope this content helps you prepare for the exam, and if you haven’t been introduced to some of these concepts before, I hope it helps you as you work with people with tendinopathy.