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Current Concepts In Treating Achilles Tendinopathy
Acknowledging the common presentation of Achilles pathology, these authors examine the literature and share their own experience with conservative and surgical treatment of insertional and non-insertional Achilles tendinopathy.
Podiatric physicians commonly diagnose and treat pathology of the Achilles tendon in the general public and athletes.1 However, Achilles tendinopathy can be challenging to treat, given the variety of possible etiologies. Extrinsic and intrinsic factors contributing to Achilles dysfunction include overuse, poor shoewear, unfavorable surface conditions, training errors, biomechanics and tendon deficiencies.2 These factors can induce repetitive trauma, resulting in microscopic injury with inadequate healing, ultimately leading to further injury and pathophysiology of the Achilles tendon.
We know Achilles tendinopathy occurs more in older people and men.3 Among athletes, tendon pathology also commonly occurs in older individuals.4 Unfortunately, the literature discussing Achilles dysfunction and terminology can be confusing and contradictory. Terms such as tendinopathy, peritendinitis, tenosynovitis, paratenonitis, achillodynia, tendinitis and tendinosis have all been associated with non-insertional Achilles pain. Researchers commonly refer to pain at the insertion of the Achilles tendon as insertional Achilles tendinopathy, tendinosis or tendinitis.5 Maffulli and colleagues labeled tendinopathy as impaired performance, swelling and tendon pain, which should include the histological findings of tendinosis and peritendinitis.6
Having an anatomic understanding of the posterior leg and calf is essential in understanding Achilles pathology (see “Pertinent Anatomical Insights With Achilles Tendinopathy” at right).
Essential Diagnostic Insights
The clinical presentation of Achilles pain differs in location between posterior heel pain at the back of the foot (insertional tendinopathy) and pain in the Achilles tendon (non-insertional tendinopathy) at the back of the leg. Patients with non-insertional tendinosis present with pain in the back of the Achilles area, usually with a “bump.” These patients often relate a history of a non-significant trauma such as a sprain, twisting or “overdoing it.” The pain typically progresses over time before patients seek medical treatment and it seems to hurt with increased activity or is asymptomatic.
Patients with insertional heel pain have pain at the posterior calcaneus. This usually hurts in shoes from the heel counter and hurts with palpation. Physical activity usually exacerbates this pain.
The patient history provides useful information to aid in the diagnosis of Achilles tendinopathy. The onset of symptoms, recent or previous injuries to the Achilles tendon, and previous treatment are keys for making a diagnosis.14 Patients in an early phase will complain of pain following strenuous activity while those who complain of pain during and after any activity are in a later phase. Those in the later phase typically do not tolerate sporting activity. Upon presentation, the most common symptom of a patient with Achilles tendinopathy is pain. It is imperative to pinpoint the precise location of pain within the tendon.14 Pain at the insertion is commonly associated with insertional tendinopathy while pain 2 to 6 cm proximal to the insertion within the watershed area is usually isolated to the tendon itself.
Palpation of a bulbous mass with the tendon or at its insertion usually indicates a more chronic pathology (tendinosis) while diffuse edema and erythema may indicate an acute onset (tendinitis).15
The differential diagnosis may include fracture, bursitis, rupture of the posterior tibial or plantaris tendon, neurologic disorders, calcaneal periostitis, Haglund’s deformity, Sever’s disease, bone disorders, compartment syndrome, plantar fasciitis, muscle strains or other soft tissue problems. One must also consider systemic diseases such as rheumatoid or inflammatory arthritis, seronegative spondyloarthropathies, Reiter’s syndrome, infection, metabolic disorders and connective tissue disease.6
What You Should Know About The Histology
On a histopathologic level, we can divide Achilles tendinopathy into two findings, peritendinous changes and intratendinous degeneration, that often coexist.16
When it comes to chronic Achilles tendinopathy, peritendinous changes will include an abundance of fibroblasts and myofibroblasts with formation of new connective tissue and adhesions. Åström and colleagues reported intratendinous degenerative changes in most lesions characterized by vascular proliferation, the presence of fibrinogen, focal hypercellularity and abnormal fiber structure in 90 percent of biopsies from symptomatic parts of the tendon.3
What Diagnostic Imaging Can Reveal
One should obtain radiographs and pay special attention to the lateral and calcaneal axial films. Enthesopathy or calcification within the tendon at its insertion is commonly present.
Ultrasonography has proven to be a quick, accurate and inexpensive modality in observing intratendinous lesions or thickening of the Achilles.17 However, this is operator dependent and less sensitive than magnetic resonance imaging (MRI).18 Fluid may be present around the tendon in the acute setting while one may note chronically hypoechoic areas within the tendon or paratenon with fibrous disruptions representing adhesions.4
Magnetic resonance imaging is the most common and reliable imaging modality to examine the Achilles tendon. Not only does MRI allow for detailed three-dimensional imaging of anatomic structures, it distinguishes between normal and abnormal tissue. Imaging will often reveal thickening of the tendon with intratendinous signal abnormalities.18 The disadvantages of MRI include its high cost and time-consuming scanning process.19
Key Pointers On Conservative Treatment
Conservative treatment for non-insertional Achilles tendinopathy initially focuses on rest and activity modification. If the patient presents with a lot of pain, utilize a tall walking boot as a first-line treatment to calm down the tendon. Patients wear the walking boot until the initial presenting symptoms decrease or resolve, usually within one to two weeks. Concomitantly start non-steroidal anti-inflammatories (NSAIDs) to help with patient discomfort. Research has shown that NSAIDs have a modest effect in treating tendinosis and authors have suggested that NSAID use is questionable due to the histological absence of inflammatory cells with chronic tendinosis.20-24 The short-term benefit with the use of NSAIDs is most likely due to the analgesic effect of these medications.25
The use of corticosteroid injections is very controversial. Reports have shown a decrease in pain and swelling but a high complication rate of 82 percent, including acute tendon rupture.5,26-27 The potential risks outweigh any benefit gained from corticosteroid injections and the senior author does not recommend corticosteroids.28
The mainstay for long-term relief of symptoms with non-insertional Achilles tendinosis centers on physical therapy with eccentric exercises of the Achilles tendon.29-31 The mechanical loading of the Achilles tendon with eccentric exercises increases the stretching of the tendon in comparison with concentric exercises. Alfredson and coworkers performed a randomized study comparing eccentric and concentric exercises over a 12-week program.32,33 The authors reported that 82 percent of patients in the eccentric exercise group returned to normal activities at 12 weeks in comparison to only 36 percent in the concentric exercise group. Patients sustained the results over a 12 month period.34 Six-week programs with eccentric stretching have also shown efficacy.35-37
Researchers have also described extracorporeal shockwave therapy (ESWT) for the treatment of non-insertional Achilles tendinopathy with conflicting results.38,39 The senior author has no direct experience with this treatment modality.
Platelet-rich plasma (PRP) has been in use to treat a wide variety of orthopedic pathologies in recent years with significant improvement of symptoms when clinicians have utilized PRP in tendon therapy.40-43 Unfortunately, researchers have not reported these same results when using PRP for Achilles tendinopathy.40,44 De Vos and colleagues performed a randomized double-blind placebo-controlled study evaluating eccentric exercises and PRP or saline injections for Achilles tendinosis.45 The study showed no difference in improvement in pain and activity at six months between the two groups. Sadoghi and coworkers recently concluded PRP may be beneficial in increased healing strength with acute Achilles tendon ruptures.46 However, there is no evidence showing benefit in using PRP in the treatment of Achilles tendinopathy.
We prefer conservative treatment consisting of initial rest, activity modification and, if necessary, walking boot mobilization. We offer NSAIDs as well. After the initial pain/discomfort calms down, initiate aggressive eccentric stretching of the Achilles tendon. Do this with a night splint, home stretching exercises and physical therapy.
The initial treatment of insertional Achilles tendinopathy is similar to non-insertional tendinopathy. The focus is on rest, protection and a decrease in pain. Patients can accomplish this via activity modification, a tall boot walker and NSAIDs. Patients with insertional heel pain often have pain with loading of the foot and ankle. Dorsiflexion at the ankle joint causes compression of the retrocalcaneal bursa and impingement of the anterior Achilles tendon fibers.47
The biomechanics of the hindfoot and ankle play a role in insertional Achilles tendinopathy. Orthotics to correct eversion and pronation of the hindfoot may be beneficial.48,49 Heel lifts have also shown benefit by plantarflexing the heel but we do not prefer this.50 Equinus or a tight heel cord is often the biomechanical cause of the symptoms, and a heel lift further shortens the muscle tendon complex. Although a heel lift can offer short-term pain relief, this does not address the etiology in the long term.
Authors have shown that eccentric loading of the Achilles tendon offers a benefit with non-insertional tendinopathy but is less effective with insertional tendinopathy.51,52 The success rates reported in these two studies respectively were 28 percent and 32 percent. The proposed reason for lack of success was that dorsiflexion compresses the retrocalcaneal bursa.
Jonsson and colleagues eliminated ankle dorsiflexion in their study and improved the outcome of conservative treatment to 67 percent of cases.53 Johnson and Alvarez reported on immobilization in a boot walker for six to eight weeks followed by a stretching regimen.54 They noted 88 percent satisfaction with this method although they could not differentiate whether the immobilization or stretching contributed the most to the success. Although there is risk, physicians have used corticosteroids for insertional Achilles tendinopathy, directing attention specifically toward the retrocalcaneal bursa. However, this approach risks rupture of the Achilles tendon and we do not recommend it.55-58
Addressing Surgical Options For Non-Insertional Achilles Tendinopathy
One should reserve surgical treatment of both non-insertional and insertional Achilles tendinopathy for cases that fail exhaustive conservative treatment. Non-insertional surgical repair focuses on debridement of all tendinosis or non-viable tendon. Authors believe this debridement initiates vascular ingrowth and a healing response.22,59
Our preferred operative treatment is an open technique with the patient in the prone position. Make a posterior medial incision over the area of the diseased tendon. Dissect through the paratenon with the medial and lateral skin flaps providing full thickness dissection. Employ a no-touch technique with minimal retraction. Identify the area of the Achilles, which is usually bulbous and slightly discolored from the surrounding tendon. Debride the devitalized tendon longitudinally with two converging semi-elliptical incisions.
After removing the full thickness of the diseased tendon, repair the remaining tendon with tubularization of the anterior portion of the tendon followed by the posterior portion. One can accomplish this with either absorbable or non-absorbable sutures. Close the subcutaneous tissue and skin accordingly, and place the limb into a gravity equinus posterior splint.
Success rates with open procedures are reportedly between 75 percent and 100 percent.59-63 Authors have recommended that if one debrides greater than 50 percent of the tendon, the surgeon should perform augmentation with a tendon transfer.61,62,64 However, this has not been our experience.
Dothan and colleagues have reported good results with gastrocnemius lengthening for non-insertional Achilles tendinosis.65 Complications reported with the open procedure are not uncommon. Paavola and coworkers have reported an overall complication rate of 11 percent with a 3 percent incidence of wound necrosis, a 2.5 percent incidence of superficial infection and a 1 percent incidence of sural nerve injury.64 They also reported a re-operation rate of 3 percent.
Key Surgical Pearls For Insertional Achilles Tendinopathy
Surgical treatment for insertional Achilles tendinopathy usually entails removal of the calcaneal spur with debridement of the retrocalcaneal bursa and debridement with repair/reattachment of the Achilles tendon. Researchers have described several approaches to accomplish this, including longitudinal tendon splitting, medially- or laterally-based incisions, and a transverse or Cincinnati incision.61,66-69 There does not appear to be a significant advantage of one approach over another.
Our primary approach is with the patient in a lateral decubitus position. Make a lateral incision between the Achilles tendon and the lateral posterior tubercle of the calcaneus. Perform full thickness dissection utilizing a no-touch technique of the tissues. Reflect the Achilles tendon off the lateral and posterior portion of the calcaneus, closely following the morphology of the posterior heel spur. Leave the medial expansion of the Achilles tendon intact. Excise the retrocalcaneal bursa. Use a sagittal saw to resect the posterior heel spur as well as the posterior superior calcaneal tubercle or dorsal projection. The angle of the saw blade is from posterior inferior to superior anterior and from lateral to medial. This removes and decompresses the posterior portion of the calcaneus.
After removing this portion of bone, smooth all bony contours with a rasp. Then debride the anterior portion of the Achilles tendon, which usually has insertional tearing. Utilize intraoperative fluoroscopy to confirm all bony prominences are removed and smoothed. Then reattach the Achilles tendon to the posterior calcaneus with either an absorbable or non-absorbable suture.
From biomechanical and clinical data, authors have reported that one can debride 50 percent of the Achilles tendon with a low risk of re-rupture.68,70 Researchers have described reattachment of the Achilles tendon using bone anchors, screws or transosseous sutures.66,68,71-74
For Achilles tendinosis, in which one debrides greater than 50 percent of the tendon, one should augment the Achilles with a neighboring tendon transfer, most commonly the flexor hallucis longus (FHL) tendon. The FHL tendon has many advantages with transfer. It fires in the same phase of gait as the Achilles, is in close proximity to the Achilles, has good vascularity and is the second strongest plantarflexor.75
DeCarbo and coworkers described a single incision short harvest with interference screw fixation.76 This obviates the need for a plantar medial foot incision. Researchers have also described the use of peroneus brevis tendon and flexor digitorum longus tendon to augment the Achilles with both having disadvantages and not being as ideal as the FHL transfer.75,77 Nunley and colleagues reported 96 percent satisfaction with good function at seven years with no augmentation.67
A Guide To Post-Op Protocol
Postoperatively, the initial protocol for both non-insertional and insertional repair is the same. Place the patient in a bulky Jones compression dressing in gravity equinus for 10 days. At the first post-op visit, remove the sutures and place the patient into a slightly plantarflexed non-weightbearing below-knee cast.
For non-insertional Achilles debridement, patients wear the cast for a total of three weeks with subsequent transition into a full weightbearing boot and initiation of an open kinetic chain range of motion. There is an additional three weeks of boot walker use and the patient subsequently wears an ankle brace with formal physical therapy for one month.
When it comes to insertional Achilles debridement with or without augmentation, patients wear the non-weightbearing boot for one month, transition into a weightbearing boot for one month and then they use an ankle brace with physical therapy. Longer periods of non-weighbearing and protected weightbearing occur with more extensive Achilles debridement/repair.
In Conclusion
One can treat both non-insertional and insertional Achilles tendinosis successfully with conservative care. If conservative care fails to provide pain relief or a functional return to activity, consider surgical intervention. Physicians should exhaust conservative treatment for two to six months before offering surgical treatment.
Dr. DeCarbo is a fellowship trained foot and ankle surgeon in private practice at the Orthopedic Group in Pittsburgh. He is a faculty member with the Monongahela Valley Foot and Ankle Reconstructive Fellowship in Monongahela, Pa. Dr. DeCarbo is a Fellow of the American College of Foot and Ankle Surgeons.
Dr. Thun is a fellow with the Monongahela Valley Foot and Ankle Reconstructive Fellowship in Monongahela, Pa. He is an Associate of the American College of Foot and Ankle Surgeons.
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