Achilles Tendinopathy

Introduction

Tendinopathy is the commonest pathological condition affecting the Achilles tendon and represents between 55% and 65% of its disorders. Achilles tendinopathy is frequently observed in athletes and physical workers whose activity is associated with major mechanical loading that exceeds the tendon's capacity.

Its exact aetiology is unknown; however, it is thought to be associated with multiple factors including intrinsic factors (impaired blood supply, gastrocnemius-soleus dysfunction, genetic predisposition, male gender, lower limb malalignment, lateral ankle instability, foot joint hypermobility, foot deformities, leg length discrepancy, high BMI, hypertension, metabolic and endocrine disorders) and extrinsic factors (overuse during volleyball, basketball, and running, training errors, inadequate footwear, unsuitable training surfaces drugs including steroids and fluoroquinolones as well as sedentary lifestyle).

In the literature, different hypotheses are described to explain the cause of pain in Achilles tendinopathy including intratendinous degeneration, neovascularisation and neurogenic inflammatory process. The existence of inflammatory process remains controversial however this concept has somewhat regained its popularity in the recent years.

Especially in the acute phase there may be an inflammatory cellular reaction in the peritendineum, with circulatory impairment and oedema. It has been shown that new nerve endings also grow into the tendon with the new vessels. Training at excessive or unaccustomed volumes can lead to a degradation of the viscoelastic characteristics of the tendon and an accumulation of dysfunctional repair tissue.

 

Non-insertional Tendinopathy

Athletes (elite or recreational) are the most common group to present with non-insertional Achilles tendinopathy. It has been described in association with many different sporting activities, but middle and long-distance runners have the highest susceptibility to it.

​Clinical findings include tendon thickening and pain on palpation. Clinical tests include painful arc test (a sensitive swelling that moves with ankle movements), Royal London Hospital test (RLH test – a swelling that is most painful on ankle dorsiflexion), and tendon loading tests (pain on passive dorsiflexion, pain on single heel raise and pain on hopping).

Maffulli et al. and Hutchinson et al. suggested that these tests were sufficiently reliable in the clinical diagnosis of non-insertional Achilles tendinopathy. However a recently published meta-analysis concluded that the most appropriate clinical reference standard for diagnosis of Achilles tendinopathy yet needed further investigation.

Imaging modalities include ultrasonography (with Doppler) and MRI. Ultrasound may be particularly useful to guide injection treatments. Various studies have compared the efficacy of ultrasound with MRI.

Early studies showed that MRI scans were better for characterising degeneration, however, later research has shown equal or better accuracy with ultrasound along with being more cost effective. Greyscale ultrasound was found to be more sensitive, whereas colour Doppler ultrasound had higher correlation with patients’ symptoms.

Newer imaging modalities include ultrasound tissue characterisation and sono-elastography, which have yielded promising initial results in improving sensitivity, specificity and accuracy in the diagnosis.

 

Conservative Treatment

The mainstay and first-line of management in non-insertional Achilles tendinopathy is conservative.

Conservative modalities include avoiding precipitating factors, modifying training regimes, eccentric exercises, orthoses, cryotherapy, NSAIDs, extracorporeal shockwave therapy (ESWT) and high volume and sclerosing injections. The authors of a recently published meta-analysis (2018) do not recommend splints and orthoses to patients with Achilles tendinopathy.

At present, eccentric strengthening has become the treatment of choice for non-insertional Achilles tendinopathy, with the greatest amount of evidence for its effectiveness. Most commonly used protocol is Alfredson’s protocol in which the exercises are performed in three sets of 15 repetitions, twice a day for 12 weeks.

This regime has shown excellent results in various studies including systematic review, meta-analysis and RCTs. Isotonic, isokinetic, and concentric loading have also been described, but found to be inferior to the eccentric exercises.

ESWT is considered to be the second line treatment depending upon its availability. An RCT has shown that a combination of ESWT and eccentric exercises improved the success rate significantly compared to eccentric exercises alone. Its effect is two-fold, on tissue healing and on pain transmission by implications on both central and peripheral nervous systems. Trials with high methodological quality ratings revealed that 4 months after completion of shock wave therapy the success rate in patients suffering from non-insertional Achilles tendinopathy was 52%.

​Out of the injection therapies in use, only ultrasound-guided sclerosing polidocanol injections have provided some promising results in a Scandinavian study. Corticosteroid injections may have some early benefit, but adverse effects were reported in up to 82% of corticosteroid trials.

Platelet-rich plasma (PRP) in the treatment is also in use for Achilles tendinopathy, however the only RCT published in this regard showed no significant difference in pain or activity level in patients with chronic Achilles tendinopathy between PRP and saline injection at 6, 12 or 24 weeks when combined with an eccentric stretching programme.

NSAIDs have been shown to have a modest effect on symptoms,9 but this was not supported in a randomised study including a placebo arm.

 

Surgical Treatment

Approximately 25% patients fail to respond to conservative treatment and require surgical intervention.

Open surgical approach involves a large incision and debridement of all of the pathological tissue and may require an FHL tendon augmentation. Studies have shown a success rate  of between 50% and 100%. However, the main concern remains the risk of wound complications. In a large series of 432 consecutive patients from a specialist centre there was an overall complication rate of 11%.

Initial results of small series are available for some other therapies including stripping the paratenon from the tendon, with or without using high-volume fluid injection, ventral scraping of the tendon through an ultrasound-guided minimally invasive technique, and ultrasound-guided multiple percutaneous longitudinal tenotomie have shown some promising results in symptomatic benefit.

 

Insertional Tendinopathy

Insertional Achilles tendon disorders account for around 20% to 25% of tendo Achillis disorders. In addition to the above mentioned factors, a postero-superior calcaneal prominence, (originally described by Haglund, 1928) has been associated with tendon attrition, pain and swelling.

However, insertional spurs are probably an adaptive process of formation rather than being due to tendon micro-tears or inflammatory changes. Patients often have heel pain on loading, which may be due to ankle dorsiflexion causing retrocalcaneal bursa compression and impingement of the anterior fibres of the tendon.

Imaging should always include radiographs of the weightbearing foot. MRI is useful in preoperative planning to determine the extent of intratendinous pathology, which can help predicting the likelihood of requiring augmentation after operative debridement. In addition, MRI can identify patients with isolated retrocalcaneal bursitis, which can be treated with less extensive surgery.

 

Conservative Treatment

Immobilisation is frequently used in the acute symptoms, but prolonged immobilisation should be avoided. Johnson et al. used an initial immobilisation for six to eight weeks and a subsequent stretching regime for patients with retrocalcaneal pain. After an average treatment duration of 163 days, 88% were satisfied with the results. However, it is difficult to ascertain whether it was the immobilisation or the stretching that contributed most to the perceived success of this treatment. In contrast, the authors of a recently published meta-analysis (2018) do not recommend splints and orthoses to patients with Achilles tendinopathy.

Alfredson’s regime for insertional tendinopathy may cause the retrocalcaneal bursa to be compressed against the tendinopathic fibres of the anterior aspect of the Achilles tendon.

Two recent systematic reviews have shown that a successful outcome following eccentric loading exercise is less likely in insertional disorders, with success rates of 28% and 32% reported. This regime was modified by Jonsson et al. who eliminated the ankle dorsiflexion by using floor-level exercises only, which subsequently improved outcomes in 67% of cases, compared with 32% for the original activities.

ESWT is commonly used for insertional tendinopathy as well. Although the available RCTs and systematic reviews report good to excellent results but do not stratify the outcomes of insertional and non-insertional tendinopathies. Furia evaluated the effectiveness of ESWT in the symptomatic treatment of Achilles tendinopathy over time and observed satisfactory results in 47.2% of cases at 2-month follow-up, 73.2% of cases at medium-term (6- to 12-month) follow-up, and 76% of cases at long-term (13- to 24-month) follow-up. These findings indicate that ESWT can effectively treat Achilles tendinopathy for a long period of time.

Trials with high methodological quality ratings revealed that 4 months after completion of shock wave therapy, 64% of the patients with chronic insertional Achilles tendinopathy confirmed complete recovery or marked improvement. Taylor et al. reported that the effects of shock wave therapy are better in patients over the age of 60 if the symptom duration is less than 12 months. Older patients with longer symptom durations are less likely to benefit from ESWT.

A study by van der Worp reported that theories about ESWT can be roughly divided into pain relief, tissue regeneration, and destruction of calcifications. Santamato et al. reported that ultrasound examinations revealed neovascularization in 91.7% of patients 1 and 2 months after focused ESWT and demonstrated the efficacy of ESWT in pain reduction with a high degree of patient satisfaction,

The available studies on the use of injections (sclerosing agents, local anaesthetics, Hyperosmolar dextrose solution and PRP) present uncertain results due to smaller number of patients and short-term follow up duration. For the use of PRP injections, of the four available trials, only one has documented a significant treatment effect of PRP at 6 months in PRP group compared to the placebo group.

Overall up to 90% patients improve with conservative treatment modalities.

 

Surgical Treatment

Appropriate selection of the patients is important as the outcomes are poor in patients with diabetes, smoking and peripheral vascular disease. Endoscopic debridement of retrocalcaneal bursa and calcaneoplaty may result in good to excellent results in 75 to 95% cases according to some published studies.

Contracture of the gastrocnemius muscle may be an aggravating factor in Achilles tendinosis. If preoperative gastrocnemius contracture is identified (a positive Silfverskiold test), a gastrocnemius lengthening procedure should also be performed in addition to debridement of the Achilles tendon, using a separate incision at the musculotendinous junction.

Open surgery includes detachment and debridement of the degenerate tendon, decompression of bursal tissue, resection of the bony prominence, reattachment of the tendon insertion, and/or augmentation with a tendon transfer or graft. Various incisions have been described, including longitudinal tendon splitting, medially or laterally based and transverse but there is no significant advantage of one over another.

Reattachment can be carried out using bone anchors or trans-osseous sutures using either single- or double-row repairs but complete detachments of the insertion are probably better restored if double-row techniques are used.

The most frequently used reconstruction technique is by using FHL (benefits include synergistic action during the same phase of gait, location, good vascularity, low lying muscle belly, and being the second strongest plantarflexor) using single incision, double incision and more recent minimally invasive and endoscopic techniques, each with its pros and cons.

Other options include Peroneus Brevis (risks ankle instability) and FDL (weaker than FHL). Autografts include the options of using Hamstrings, Patellar tendon or Quadriceps tendon. Most of the available studies report satisfaction rates from 82% to 97% and significant improvements in function scores after surgical treatment for insertional tendinopathy.

Johnson et al. published a small series of 22 cases with an average follow-up period of 34 months, and showed that the AOFAS score increased from 53 to 89, pain subscores improving from 7 to 33. Patients were better able to tolerate shoe wear after surgery, with 77% of patients reporting no pain with shoe wear postoperatively, compared to only 5% preoperatively. In addition, 91% of patients were able to work full time postoperatively compared to 45% preoperatively.

McGarvey et al. published a small series of 22 cases with an average 33-month follow-up period. Pain resolved completely in 59% of patients and 86% could tolerate shoe wear without significant difficulty. The overall patient satisfaction rate was 82% and 91% patients were able to return to full-time work or routine daily activities.

Patients undergoing simple Achilles debridement and repair undergo splinting in a neutral position immediately postoperatively and are kept non-weight-bearing for approximately 2 weeks (until wound has healed). After that the foot is placed in a walker boot and weight-bearing is allowed as tolerated. Gentle active range-of-motion exercises are started at the time of weight-bearing.

Six weeks after surgery, the patients are weaned into a shoe with a 0.5-inch heel lift, and more aggressive physical therapy is then started. Patients undergoing FHL tendon transfer are kept non-weight-bearing in a cast or splint for 4 weeks, after which they follow a similar protocol as above.

​

References​

  • Bussin ER, et al. BMJ Open 2017;7:e015126. doi:10.1136/bmjopen-2016-015126.
  • Lohrer et al. BMC Musculoskeletal Disorders (2016) 17:207; DOI 10.1186/s12891-016-1061-4.
  • Pearce CJ, Tan A. Non-insertional Achilles tendinopathy. EFORT Open Rev 2016;1:383-390. DOI:10.1302/2058-5241.1.160024.
  • Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy; Br J Sports Med. 2009;43:409–16.
  • Magnan B, Bondi M, Pierantoni S, Samaila E. The pathogenesis of Achilles tendinopathy: a systematic review. Foot Ankle Surg. 2014;20:154–9.
  • A. J. Roche, J. D. F. Calder; Achilles tendinopathy; A Review of the Current Concepts; Bone Joint J 2013;95-B:1299–1307.
  • Johnson MD, Alvarez RG. Nonoperative management of retrocalcaneal pain with AFO and stretching regimen. Foot Ankle Int 2012;33:571–581.
  • Wilson F., Walshe M., O’Dwyer T., Bennett K., Mockler D., Bleakley C. Exercise, orthoses and splinting for treating Achilles tendinopathy: a systematic review with meta-analysis. British Journal of Sports Medicine. 2018;52(24):1564–1574.
  • Hart L. Corticosteroid and other injections in the management of tendinopathies: a review. Clin J Sport Med 2011;21:540–541.
  • Warden SJ, Kiss ZS, Malara FA, et al. Comparative accuracy of magnetic resonance imagining and ultrasonography in confirming clinically diagnosed patellar tendinopathy. Am J Sports Med 2007;3:427-436.
  • van Schie HT, de Vos RJ, de Jonge S, et al. Ultrasonographic tissue characterisation of human Achilles tendons: quantification of tendon structure through a novel non-invasive approach. Br J Sports Med 2010;44:1153-1159.
  • Ooi CC, Schneider ME, Malliaras P, et al. Diagnostic performance of sonoelastography in confirming clinically diagnosed Achilles tendinopathy: comparison with B-mode ultrasound and color Doppler imaging. Ultrasound Med Biol 2015; 41:15-25.
  • Docking SI, Ooi CC, Connell D. Tendinopathy: is imaging telling us the entire story? J Orthop Sports Phys Ther 2015; 45:842-852.
  • Alfredson H, Pietilä T, Jonsson P, Lorentzon R. Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. Am J Sports Med 1998;26:360-366
  • Magnussen RA, Dunn WR, Thomson AB. Nonoperative treatment of midportion Achilles tendinopathy: a systematic review. Clin J Sport Med 2009;19:54-64.
  • Sussmilch-Leitch SP, Collins NJ, Bialocerkowski AE, Warden SJ, Crossley KM. Physical therapies for Achilles tendinopathy: systematic review and meta-analysis. J Foot Ankle Res 2012;5:15.
  • Rompe JD, Furia JP, Maffulli N. Mid-portion Achilles tendinopathy–current options for treatment. Disabil Rehabil 2008;30;22:1666-1676.
  • Rompe J. D., Nafe B., Furia J. P., Maffulli N. Eccentric loading, shock-wave treatment, or a wait- and-see policy for tendinopathy of the main body of tendo achillis. The American Journal of Sports Medicine. 2007;35(3):374–383.
  • Furia JP. High-energy extracorporeal shock wave therapy as a treatment for chronic noninsertional Achilles tendinopathy. Am J Sports Med. 2008;36(3):502–508.
  • van der Worp H, van den Akker-Scheek I, van Schie H, Zwerver J. ESWT for tendinopathy: technology and clinical implications. Knee Surg Sports Traumatol Arthrosc. 2013;21(6):1451–1458.
  • Santamato A, Beatrice R, Micello MF, et al. Power Doppler ultrasound findings before and after focused extracorporeal shock wave therapy for achilles tendinopathy: a pilot study on pain reduction and neovascularization effect. Ultrasound Med Biol. 2019;45(5):1316–1323.
  • de Vos RJ, Weir A, van Schie HT, et al. Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial. JAMA 2010;303:144-149.
  • Longo UG, Ramamurthy C, Denaro V, Maffulli N. Minimally invasive stripping for chronic Achilles tendinopathy. Disabil Rehabil 2008;30:1709-1713.
  • Taylor J., Dunkerley S., Silver D., et al. Extracorporeal shockwave therapy (ESWT) for refractory achilles tendinopathy: a prospective audit with 2-year follow up. The Foot. 2016;26:23–29. 
  • Chan O, O'Dowd D, Padhiar N, et al. High volume image guided injections in chronic Achilles tendinopathy. Disabil Rehabil 2008;30:1697-1708.
  • Boesen AP, Hansen R, Boesen MI, et al. . Effect of high-volume injection, platelet-rich plasma, and sham treatment in chronic Midportion Achilles tendinopathy: a randomized double-blinded prospective study. Am J Sports Med 2017;45:2034–43.
  • Alfredson H. Ultrasound and Doppler-guided mini-surgery to treat midportion Achilles tendinosis: results of a large material and a randomised study comparing two scraping techniques. Br J Sports Med 2011;45:407-410.
  • Johnson KW, Zalavras C, Thordarson DB: Surgical management of insertional calcific Achilles tendinosis with a central tendon splitting approach. Foot Ankle Int 27:245-250, 2006.
  • McGarvey WC, Palumbo RC, Baxter DE, et al: Insertional Achilles tendinosis: Surgical treatment through a central tendon splitting approach. Foot Ankle Int 23:19-25, 2002.
  • Calvin et al. Insertional Achilles Tendinopathy: Surgical Options; Oper Tech Orthop 18:247-253; 2008 Elsevier Inc.