Nicola Maffulli and Umile Giuseppe Longo
DEFINITION
Tendinopathy of the Achilles tendon involves clinical conditions in and around the tendon arising from overuse.1
Tendinopathy of the Achilles tendon is common both in athletic and nonathletic individuals. It can affect several regions of the tendon.
One particularly common site is the main body of the tendon, 2 to 4 cm from its insertion on the calcaneus.2
ANATOMY
The two heads of gastrocnemius (medial and lateral) arise from the condyles of the femur, the fleshy part of the muscle extending to about the midcalf. As the muscle fibers descend they insert into a broad aponeurosis that contracts and receives the tendon of the soleus on its deep surface to form the Achilles tendon.3
The Achilles tendon is the thickest and strongest tendon in the body. About 15 cm long, it originates in the midcalf and extends distally to insert into the posterior surface of the calcaneum. Throughout its length, it receives muscle fibers from the soleus on its anterior surface.4
PATHOGENESIS
To date, the etiopathogenesis of Achilles tendinopathy remains unclear.
Tendinopathy has been attributed to a variety of intrinsic and extrinsic factors.6
It has been linked to overuse vascularity, dysfunction of the gastrocnemius-soleus, age, gender, body weight and height, endocrine or metabolic factors, deformity of the pes cavus, lateral instability of the ankle, the use of quinolone antibiotics, excessive movement of the hindfoot in the frontal plane, marked forefoot varus, changes in training pattern, poor technique, previous injuries, footwear, and environmental factors such as training on hard, slippery, or slanting surfaces.1–6
Most of the above factors should be considered associative, not causative, evidence, and their role in the cause of the condition is therefore still debatable.7
NATURAL HISTORY
Although Achilles tendinopathy has been extensively studied, there is a clear lack of properly conducted scientific research to clarify its cause, pathology, natural history, and optimal management.8
The management of Achilles tendinopathy lacks evidencebased support, and tendinopathy sufferers are at risk of longterm morbidity with unpredictable clinical outcome.9
Most patients respond to conservative measures, and the symptoms can be controlled, especially if the patients accept that a decreased level of activities may be necessary.9
In 24% to 45.5% of patients with Achilles tendinopathy, conservative management is unsuccessful, and surgery is recom-
mended after exhausting conservative methods of management, often tried for 3 to 6 months. However, longstanding Achilles tendinopathy is associated with poor postoperative results, with a greater rate of reoperation before reaching an acceptable outcome.10,11
As the biology of tendinopathy is being clarified, more effective management regimens may come to light, improving the success rate of both conservative and operative management.12
PATIENT HISTORY AND PHYSICAL FINDINGS
Patients typically present with pain located 2 to 6 cm proximal to the insertion of the tendon and felt after exercise.
As the pathologic process progresses, pain may occur during exercise, and, when severe, may interfere with activities of daily living.
Runners experience pain at the beginning and at the end of a training session, with a period of diminished discomfort in between.
The foot and the heel should be inspected for malalignment, deformity, obvious asymmetry in the size of the tendon, localized thickening, a Haglund heel, and any previous scars.11–13
The tendon should be palpated to detect tenderness, heat, thickening, nodularity, and crepitation.
The “painful arc” sign helps to distinguish between lesions of the tendon and paratenon. In paratendinopathy, the area of maximum thickening and tenderness remains fixed in relation to the malleoli from full dorsiflexion to plantarflexion, whereas lesions within the tendon move with movement of the ankle.14
IMAGING AND OTHER DIAGNOSTIC STUDIES
Plain soft tissue radiography is useful in diagnosing associated or incidental bony abnormalities.9
Ultrasound is the primary imaging method, since it correlates well with the histopathologic findings despite being operatordependent.12
Ultrasound promptly identifies hypoechoic areas, which have been shown at surgery to consist of degenerated tissue, and increased thickness of the tendon.
MRI studies should be performed only if the ultrasound scan remains unclear.
MRI provides extensive information on the internal morphology of the tendon and the surrounding structures and is useful in evaluating the various stages of chronic degeneration and in differentiating between peritendinitis and tendinosis. Areas of mucoid degeneration are shown on MRI as a zone of high signal intensity on T1and T2-weighted images.13
DIFFERENTIAL DIAGNOSIS
Paratendinopathy of the Achilles tendon, acute or chronic rupture of the Achilles tendon, rerupture of the Achilles tendon, tear of the musculotendinous junction of the gastrocnemius-soleus and the Achilles tendon12
NONOPERATIVE MANAGEMENT
There is weak evidence of a modest benefit of nonsteroidal anti-inflammatory drugs (NSAIDs) for the alleviation of acute symptoms.5
Low-dose heparin, heel pads, topical laser therapy, and peritendinous steroid injection produced no difference in outcome when compared with no treatment.8
Medications shown to be effective in randomized controlled trials include peritendinous injection of aprotinin, topical application of glyceryl trinitrate, and the use of ultrasoundguided sclerosing injections in the area of neovascularization.9
Painful eccentric calf-muscle training can be an effective treatment for noninsertional Achilles tendinopathy.13
Eccentric loading and low-energy shock-wave therapy show comparable results.14
SURGICAL MANAGEMENT
Conservative management is unsuccessful in 24% to 45.5% of patients with tendinopathy of tendo Achilles.14
Surgery is recommended after at least 6 months of conservative management.11
The objective is to excise fibrotic adhesions, remove degenerated nodules, and make multiple longitudinal incisions in the tendon to detect intratendinous lesions and to restore vascularity, possibly stimulating the remaining viable cells to initiate a response in the cell matrix and healing.14
The defect can be sutured in a side-to-side fashion or left open.
Reconstruction procedures may be required if large lesions are excised.
Preoperative Planning
Preoperative imaging studies can guide the surgeon in the placement of the incision and in incising the tendon sharply in line with the tendon fiber bundles.
FIG 1 • Incision used for open surgery: it lies just posterior to the medial border of the Achilles tendon. It avoids the sural nerve and the short saphenous vein, and the scar is away from the shoe counter.
Positioning
Under locoregional anesthesia, the patient is placed prone with the ankles clear of the operating table.
The prone position allows excellent access to the affected area.
Alternatively, the patient can be positioned supine with a sandbag under the opposite hip and the affected leg positioned in a figure 4 position.
A tourniquet is applied to the limb to be operated on. The limb is exsanguinated, and the tourniquet is inflated to 250 mm Hg.4
Approach
The incision is made on the medial side of the tendon to avoid injury to the sural nerve and short saphenous vein (FIG 1).
A straight posterior incision may also be more bothersome with the edge of the heel counter pressing directly on the incision.
Maintaining thick skin flaps is vital to reduce the incidence of wound breakdown.10
TECHNIQUES
Expose the paratenon and the Achilles tendon (TECH FIG 1).
Identify and incise the paratenon (TECH FIG 2).
In patients with evidence of coexisting paratendinopathy, the scarred and thickened tissue is generally excised.
Based on preoperative imaging studies, the tendon is incised sharply in line with the tendon fiber bundles (TECH FIG 3).
TECH FIG 1 • Paratenon and the Achilles tendon exposed.
The tendinopathic tissue can be identified as it generally has lost its shiny appearance and it frequently contains disorganized fiber bundles that have more of a “crabmeat” appearance (TECH FIG 4).
Sharply excise this tissue (TECH FIG 5).
The remaining gap can be repaired using a side-to-side repair, but we leave it unsutured (TECH FIG 6).
TECH FIG 2 • The paratenon is excised.
TECH FIG 3 • Longitudinal tenotomy along the tendon fibers. Note that as the tendon fibers rotate 90 degrees, the longitudinal tenotomy has to follow them.
TECH FIG 4 • The macroscopic appearance of the tendinopathic area is visualized.
TECH FIG 5 • The tendinopathic tissue is excised.
TECH FIG 6 • Appearance at the end of the procedure.
TECH FIG 7 • The skin wound after suture of the deep tissues.
TECH FIG 8 • Steri-Strips are applied to the surgical wound before a routine compressive bandage. The limb is then immobilized in a below-knee synthetic weight-bearing cast with the foot plantigrade.
Suture the subcutaneous tissues with absorbable material (TECH FIG 7).
The skin edges are juxtaposed with Steri-Strips (TECH FIG 8) and then a routine compressive bandage. The limb is immobilized in a below-knee synthetic weightbearing cast with the foot plantigrade.
If significant loss of tendon tissue occurs during the débridement, consider a tendon augmentation or transfer.
A tendon turndown flap has been described for this purpose. With a turndown procedure, one or two strips of tendon tissue from the gastrocnemius tendon are dissected out proximally while leaving the strip attached to the main tendon distally. It is then flipped 180 degrees and sewn in to cover and bridge the weakened defect in the distal tendon.
A plantaris weave has also been reported for this purpose. The plantaris tendon can be found on the medial edge of the Achilles tendon. It can be traced proximally as far as possible and detached as close as possible to the muscle tendon junction to gain as much length as possible.
It can be left attached distally to the calcaneus, looped and woven through the proximal Achilles tendon, and sewn back onto the distal part to the tendon.
Alternatively, the plantaris can be detached distally as well and used as a free graft.
The tourniquet is deflated and the time recorded.7
POSTOPERATIVE CARE
A period of initial splinting and crutch walking is generally used to allow pain and swelling to subside. In addition, wound healing complications are difficult to manage and an initial period of immobilization may promote skin healing.
After 14 days, the wound is inspected and motion exercises are initiated. The patient is encouraged to start daily active and passive ankle range-of-motion exercises. The use of a removable walker boot can be helpful during this phase. Weight bearing is not limited according to the degree of débridement needed at surgery, and early weight bearing is encouraged. However, extensive débridements and tendon transfers may require protected weight bearing for 4 to 6 weeks postoperatively.
After 6 to 8 weeks of mostly range-of-motion and light resistive exercises, initial tendon healing will have been completed. More intensive strengthening exercises are started, gradually progressing to plyometrics and eventually running and jumping.13,14
OUTCOMES
The surgical procedure is commonly successful, but patients should be informed of the potential failure of the procedure, risk of wound complications, and at times prolonged recovery time.6
Rehabilitation is focused on early motion and avoidance of overloading the tendon in the initial healing phase.
COMPLICATIONS
Wound healing problems
Infection
Sural nerve injury
Rupture of Achilles tendon
Deep vein thrombosis
REFERENCES
1. Maffulli N. Re: Etiologic factors associated with symptomatic Achilles tendinopathy. Foot Ankle Int 2007;28:660–661.
2. Maffulli N, Kader D. Tendinopathy of tendo achilles. J Bone Joint Surg Br 2002;84B:1–8.
3. Maffulli N, Kenward MG, Testa V, et al. Clinical diagnosis of Achilles tendinopathy with tendinosis. Clin J Sport Med 2003;13: 11–15.
4. Maffulli N, Khan KM, Puddu G. Overuse tendon conditions: time to change a confusing terminology. Arthroscopy 1998;14:840–843.
5. Maffulli N, Reaper J, Ewen SW, et al. Chondral metaplasia in calcific insertional tendinopathy of the Achilles tendon. Clin J Sport Med 2006;16:329–334.
6. Maffulli N, Sharma P, Luscombe KL. Achilles tendinopathy: aetiology and management. J R Soc Med 2004;97:472–476.
7. Maffulli N, Testa V, Capasso G, et al. Results of percutaneous longitudinal tenotomy for Achilles tendinopathy in middleand longdistance runners. Am J Sports Med 1997;25:835–840.
8. Maffulli N, Testa V, Capasso G, et al. Similar histopathological picture in males with Achilles and patellar tendinopathy. Med Sci Sports Exerc 2004;36:1470–1475.
9. Maffulli N, Testa V, Capasso G, et al. Surgery for chronic Achilles tendinopathy yields worse results in nonathletic patients. Clin J Sport Med 2006;16:123–128.
10. Maffulli N, Testa V, Capasso G, et al. Calcific insertional Achilles tendinopathy: reattachment with bone anchors. Am J Sports Med 2004;32:174–182.
11. Maffulli N, Wong J. Rupture of the Achilles and patellar tendons. Clin Sports Med 2003;22:761–776.
12. Maffulli N, Wong J, Almekinders LC. Types and epidemiology of tendinopathy. Clin Sports Med 2003;22:675–692.
13. Rompe JD, Nafe B, Furia JP, et al. Eccentric loading, shock-wave treatment, or a wait-and-see policy for tendinopathy of the main body of tendo Achilles: a randomized controlled trial. Am J Sports Med 2007;35:374–383.
14. Sayana MK, Maffulli N. Eccentric calf muscle training in non-athletic patients with Achilles tendinopathy. J Sci Med Sport 2007;10:52–58.