DEFINITION

The Achilles tendon is the strongest tendon in the body and is the primary plantarflexor of the ankle joint.16

Sudden stretch of the tendon tissue can result in complete or partial rupture, with an estimated incidence of 8 to 18 per 100,000 persons.1,3

With complete rupture, the ruptured ends of the tendon may pull apart, leading to a significant plantarflexion weakness and to the creation of a gap that is palpated clinically.

A common source of confusion is that patients may continue to have active ankle plantarflexion due to the action of other flexors of the ankle.

As a result, the diagnosis is initially missed in an estimated 20% to 25% of cases.5

 

 

ANATOMY

 

Three calf muscles—the medial, lateral gastrocnemius, and soleus—converge together to form the “triceps surae” or the Achilles tendon (FIG 1).

 

The plantaris muscle originates from the lateral femoral condyle and passes obliquely between the gastrocnemius and soleus to reside medial to the Achilles tendon and inserts into it or the calcaneus. In an

anatomic study, the plantaris muscle was absent in 7.3% of specimens.16

 

 

 

FIG 1 • The triceps surae (Achilles tendon) is formed by the convergence of the medial, lateral gastrocnemius, and soleus muscles.

 

 

The Achilles tendon courses distally, rotates 90 degrees internally, the soleus contribution being medial to that of the gastrocnemius, and inserts into the middle third of the flat surface of the posterior calcaneal

tuberosity.10

 

The middle section of the tendon, 2 to 6 cm proximal to its insertion site, is a hypovascular zone.

 

 

This zone is the narrowest in cross-section and corresponds to the most common site of tendon pathology, including paratenonitis, tendinosis, and tendon rupture.10

 

The tendon is surrounded by a paratenon that has a single layer of cells with variable structure, not a true tenosynovium.

 

Webb et al17 documented the highly variable position of the sural nerve in relation to the Achilles tendon.

 

As measured from the calcaneal insertion, the sural nerve crossed the tendon from medial to lateral at a mean distance of 9.8 cm, then coursed distally to lie a mean of 18.8 mm laterally (FIG 2).

 

 

 

 

FIG 2 • Position of the sural nerve in relation to the Achilles tendon. (Adapted from Webb J, Moorjani N, Radford M. Anatomy of the sural nerve and its relation to the Achilles tendon. Foot Ankle Int 2000;21:475-477.)

 

 

 

PATHOGENESIS

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Achilles ruptures are usually caused by noncontact injuries. Common injury mechanisms leading to Achilles rupture are forceful push-off with an extended knee, sudden unexpected ankle dorsiflexion, or violent dorsiflexion of a plantarflexed foot.13

 

Achilles rupture can occur high, near the muscle-tendon juncture (9%), at the tendon midportion (72%), or at the calcaneal insertion (19%).5

 

Concomitant injuries such as ankle ligament sprains or ankle or tarsal fractures should be ruled out.

NATURAL HISTORY

 

Most Achilles ruptures do not have any antecedent symptoms.

 

 

A study of histologic scores comparing ruptured tendons with unruptured tendons, however, showed that there were significant histopathologic changes in the ruptured group that were not present in the older, asymptomatic, and unruptured group. Therefore, tendinosis may play a role, but the extent of this role

remains unknown.14

 

Achilles rupture is more common in men. Studies have shown a male-to-female ratio of up to 12:1.

 

From an epidemiologic standpoint, middle-aged men with white-collar professions and recreational athletic activity constitute most of the patients.

 

 

Other predisposing factors are leg muscle imbalance, training errors, foot pronation, and use of corticosteroids and fluoroquinolones.13

 

In a longitudinal observational study, there was a contralateral Achilles rupture in 6% of patients who had a previously repaired Achilles rupture with a median delay of 3.1 years.1

PATIENT HISTORY AND PHYSICAL FINDINGS

 

Most ruptures occur during athletic activity. Patients usually describe a sudden painful snap or shooting pain followed by sudden weakness to foot push-off.

 

Athletes will be unable to bear weight and will report distal leg swelling and stiffness.

 

 

 

 

FIG 3 • A. Ankle radiograph showing a disrupted Kager triangle. B. Normal Achilles ultrasound image. C. Ankle MRI (T1-weighted image) showing a distal Achilles tendon rupture.

 

 

Examination for ruptured Achilles tendon can include the following:

 

 

Palpable gap test. A gap present indicates complete Achilles rupture with separation of the ruptured ends. It is more reliable when done early after rupture. It is 73% sensitive.13

 

Calf squeeze test (Thompson test). With patient prone, squeeze the calf and observe foot movement. Compare with the contralateral side. It is 96% sensitive.13

 

Knee flexion test. With patient prone, patient actively flexes knee. Observe foot position and compare with other. It is 88% sensitive.13

 

Active plantarflexion. This is poorly sensitive and unreliable because powerful plantarflexion may still be possible due to the action of other ankle plantarflexors.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Anteroposterior (AP), lateral, and mortise view plain radiographs of the ankle should be obtained to rule out concomitant fractures or calcific changes of the Achilles tendon.

 

 

On a lateral view, the examiner should look for a disruption of the normal triangular fat pad seen anterior to the Achilles tendon (Kager triangle; FIG 3A).

 

Ultrasonography can provide a dynamic study of the tendon structure and accurately measure gapping of the ruptured tendon ends.

 

 

The quality of images is highly dependent on the equipment and operator (FIG 3B).

 

Magnetic resonance imaging (MRI) is highly sensitive and specific in diagnosing Achilles tendon rupture.

 

 

It provides valuable information about tendon degeneration or other associated injuries (FIG 3C).

 

MRI was found to be superior to ultrasound in diagnostic specificity of chronic Achilles tendinopathy.2

DIFFERENTIAL DIAGNOSIS

Rupture of the medial gastrocnemius Plantaris tendon rupture

Baker cyst rupture

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Acute deep venous thrombosis Leg or calf contusion

Tibia distal shaft fracture

Posterior ankle impingement or symptomatic os trigonum

 

 

NONOPERATIVE MANAGEMENT

 

Traditionally, nonoperative treatment usually entailed casting the foot in plantarflexion to allow apposition of the tendon ends, followed by casting the foot in neutral. Treatment continues for 12 weeks.

 

 

In a recent retrospective review, early recognition and initiation of nonoperative management within 48 hours of injury resulted in a successful functional outcome that was comparable to surgical repairs.18

 

Nonetheless, nonoperative treatment carries up to threefold increase in the rerupture rate and may result in weakness of push-off secondary to healing of the tendon in a lengthened position.15

 

In the past 4 years, several level 1 studies showed comparable functional results between operative repair and nonoperative treatment with an accelerated rehabilitation program.15,19,20 A systemic review of these studies clearly showed significant decrease in rerupture rate with operative treatment, albeit an increase in

complication rates.19 In addition, operative treatment provided an improvement in plantarflexion isokinetic strength as documented with Biodex testing20 and jump and hop testing.15

 

Based on the aforementioned information, it is still our practice to offer young, active individuals surgical repair with full disclosure of the possible use of nonoperative treatment.

 

In our hands, nonoperative treatment is often reserved for elderly; sedentary patients; and also for patients with diabetes, tobacco use, and steroid use who are at high risk for surgical wound healing.4

SURGICAL MANAGEMENT

 

Operative repair and early mobilization is considered the treatment of choice for younger patients with active lifestyles. In most patients, it is established that operative repair results in a favorable functional outcome with a significantly lower rerupture rate.

 

Numerous surgical techniques have been described, including open repair, percutaneous repair, limited open repair, and open repair with augmentation.

 

 

In a comprehensive review of the recent literature, Wong et al21 concluded that in terms of outcome and the complication rate, the best results could be achieved with open repair and early mobilization.

 

Preoperative Planning

 

Plain radiographs are reviewed and any displaced fractures are treated at the same surgical sitting.

 

MRIs are reviewed to evaluate the quality of tendon tissue and the level of rupture and to measure the tendon gap if present.

 

Severe tendon degeneration or a large gap may require a larger incision or tendon lengthening or augmentation; the surgeon should take this into account during preoperative patient counseling.

 

 

 

 

FIG 4 • Patient is in prone position with both legs prepared and draped for surgery.

Positioning

 

Achilles tendon repair is performed with the patient prone (FIG 4). We prefer to use a Wilson frame and commercially available foam headrest.

 

A thigh tourniquet is used for intraoperative hemostasis. A leg tourniquet is not recommended because it may tether the calf muscles and prevent intraoperative tendon apposition.

 

Some surgeons prefer to drape both legs for intraoperative comparison and accurate restoration of the resting tendon length. The operated leg should be clearly marked.

 

Approach

 

 

Open Achilles repair is usually performed through a longitudinal medial, midline, or lateral incision. Primary end-to-end repair is done with heavy nonabsorbable suture.

 

Modified Bunnell, Kessler, Krackow, and triple-bundle techniques have been described.5

 

 

In a biomechanical study, Jaakkola et al6 showed that the triple-bundle technique (FIG 5) provided the strongest

 

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suture repair. They credited its superior strength to the use of multiple strands and to tying the knots away from the repair site. However, the authors expressed concern over the large amount of suture material used and its possible negative effect on the vascularity of the tendon.

 

 

 

FIG 5 • Triple-bundle technique of Achilles repair.

 

 

At our institution, we have designed a modification of the Krackow technique in which the free ends of one suture are passed peripherally to encircle the transverse limb of the opposite suture (FIG 6).

 

 

We likened this scheme to wrapping a gift box and named it the gift box technique.

 

We have performed biomechanical pullout studies on 13 Achilles cadaveric pairs comparing the gift box technique to the standard Krackow suture and documented more than a twofold increase in suture pullout

strength.12

 

We believe that the modification is simple to perform, minimizes suture material use, and preserves the vasculature of the healing tendon.

 

 

 

FIG 6 • Our modification of Krackow suture or the gift box technique. (Copyright Sam Labib.)

 

TECHNIQUES

• Exposure

A longitudinal incision over the medial border of the tendon provides excellent exposure and access to the plantaris tendon and avoids the sural nerve (TECH FIG 1).

Mobilize the thick skin and subcutaneous layer laterally, and take great care to preserve the paratenon.

Protect the sural nerve and lesser saphenous vein as they course lateral to the paratenon. Enter the paratenon through a midline incision (away from the skin incision).

Limit dissection at the tendon-paratenon plane, especially anterior to the tendon, to preserve the vascular supply of the tendon.

 

 

 

 

TECH FIG 1 • Medial longitudinal incision centered over the rupture site.

 

• Modified Krackow Suture (Gift Box) Technique

   

  Débride the ends of the ruptured tendon in a limited manner.

   

  Two no. 2 fortified polyester sutures (FiberWire, Arthrex, Inc., Naples, FL) are used.

   

   

  Four-loop Krackow locking sutures9 are passed on the medial side and four on the lateral side, avoiding the middle third of the tendon width.

   

  Unlike the classic Krackow suture, we pass our transverse limb in the middle of the tendon as we transition from one side to the other (TECH FIG 2A).

   

  Use straight Keith needles to pass the free suture ends across the rupture site into the opposite end of the tendon.

   

  Sutures should emerge one superficial and one deep to the transverse limb of the opposite Krackow suture.

   

  Thus, four-suture strands are passed across the rupture site.

   

  Tie the surgical knots away from the rupture site—in other words, proximal and distal to the Krackow suture.

   

  Excellent apposition is usually achieved as the knots push on the transverse limbs of opposing sutures and the desired tendon length is recreated (TECH FIG 2B,C).

   

  Use epitendinous running Prolene 3-0 suture to oversew the tendon ends together.

   

  Meticulously repair the paratenon with 3-0 braided polyglycolic absorbable suture (Vicryl, Ethicon, Inc., Somerville, NJ) (TECH FIG 2D).

   

  This can be facilitated by placing the ankle in maximum plantarflexion to relax the tendon tissue.

   

  We believe that midline placement of the paratenon incision facilitates its repair and minimizes the chance of skin tethering to the repaired tendon.

   

  Perform subcuticular skin closure with 4-0 monofilament absorbable suture (Monocryl, Ethicon).

   

   

  71

   

   

   

  TECH FIG 2 • A. The transverse limb of the gift box suture is passed through tendon midsubstance. B. The gift box suture completed and tied. Note the tension created on the transverse limb of the suture, which helps tendon apposition. C. Completed gift box suture. D. Photo after closure of the Achilles paratenon. (A,B: Copyright Sam Labib.)

• Triple-Bundle Suture Technique

   

  Beskin et al6 popularized an open repair of the Achilles tendon using no. 1 nonabsorbable polyester suture (Ethibond, Ethicon).

   

  Three rows of sutures are placed, creating six strands of suture that are tied away from the rupture site.

   

  The technique provides the strongest suture repair available to date but is technically difficult to perform, requires a large amount of suture material, and may lead to vascular compromise of the tendon during

  healing.6

• Primary Repair with Augmentation

 

Multiple authors have advocated primary augmentation of Achilles repair, with some preferring plantaris tendon, flexor tendon (TECH FIG 3), or artificial tendon implants.13

 

A study by Jessing and Hansen,7 however, found no evidence that such augmentation was superior to a nonaugmented end-to-end repair.

 

TECH FIG 3 • Flexor hallucis longus tendon used to augment Achilles tendon repair.

 

 

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PEARLS AND PITFALLS
	Clinical ▪ Diagnosis of complete rupture can be missed due to other active ankle flexors. evaluation ▪ Ultrasonography or MRI may be needed to verify the diagnosis. Care is taken to evaluate concomitant bony or tendon injury.     Nonoperative ▪ Should be initiated early, with cast application in plantarflexion preferably within treatment 48 hours of injury. Tendon gapping should be looked for and corrected. Strongly considered for patients with poor skin or vascular compromise. Poorly controlled diabetes and tobacco or steroid use are relative contraindications for surgical treatment.     Approach ▪ Midline incisions may result in a painful scar. A lateral incision places the sural nerve at an added risk of injury. Poor tissue handling may result in wound slough or dehiscence.     Tendon ▪ Aggressive trimming of tendon ends may result in significant shortening and tension undue tension on the repair. Use the contralateral limb as your guide to appropriate restoration of resting

 

 

Suture

technique

• Avoid strangulating locking suture techniques, which may compromise tendon

  healing and promote scar formation.

• Paratenon preservation and repair is mandatory for tendon repair and healing.

tendon length.

 

 

POSTOPERATIVE CARE

 

Early functional mobilization was shown to yield improved tendon healing.8

 

A posterior splint holding the site in mild plantarflexion is used for 14 days. Labib et al11 showed no significant difference in tension when the repaired tendon was positioned in 30, 20, and 10 degrees of plantarflexion.

 

Wound inspection is done, a non-weight-bearing cast boot is applied with heel lifts, and daily active range of motion is started.

 

The patient is kept non-weight bearing for a total of 6 weeks, but recent evidence suggests that weight bearing can be started before 6 weeks with no added risk of rerupture or gap formation.8

 

 

The patient is allowed gradual return to full weight bearing over an additional 6 weeks. At 3 months, full weight bearing is permitted, with lowimpact activities.

At 6 months, full activities are permitted as tolerated.

OUTCOMES

Based on a literature review, there is overwhelming support for open operative repair and early functional mobilization of Achilles tendon rupture in healthy active individuals. On average, a success rate of 85% to

95% is often quoted.5

Wong et al21 conducted an extensive literature review and concluded that the best results regarding outcome and complication rate could be achieved with open repair and early mobilization.

Most authors agree that surgical repair provides a significantly lower rerupture rate and better functional outcome, but these advantages should be weighed against the possible risks of wound dehiscence or infection.

Recent studies showed a significant temporal improvement in surgical outcome coupled with a net decrease in surgical complications.5

 

 

COMPLICATIONS

Delayed or missed diagnosis

Intraoperative devitalization of tendon, leading to wound infection

Failure to preserve and repair the paratenon, leading to scarring and skin tethering Sural nerve injury and neuroma formation

Wound dehiscence

 

Tendon rerupture Loss of ankle motion Calf weakness

 

 

REFERENCES

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2. Aström M, Gentz CF, Nilsson P, et al. Imaging in chronic Achilles tendinopathy: a comparison of ultrasonography, magnetic resonance imaging and surgical findings in 27 histologically verified cases. Skeletal Radiol 1996;25:615-620.

    

    

3. Bhandari M, Guyatt GH, Siddiqui F, et al. Treatment of acute Achilles tendon ruptures: a systematic overview and meta-analysis. Clin Orthop Relat Res 2002;(400):190-200.

    

    

4. Bruggeman NB, Turner NS, Dahm DL, et al. Wound complications after open Achilles tendon repair: an analysis of risk factors. Clin Orthop Relat Res 2004;(427):63-66.

    

    

5. Coughlin MJ, Mann RA, eds. Surgery of the Foot and Ankle, ed 7. St. Louis: Mosby, 1999:835-850.

    

    

6. Jaakkola JI, Hutton WC, Beskin JL, et al. Achilles tendon rupture repair: biomechanical comparison of the triple bundle technique versus the Krackow locking loop technique. Foot Ankle Int 2000;21:14-17.

    

    

7. Jessing P, Hansen E. Surgical treatment of 102 tendo Achilles ruptures— suture or tenontoplasty? Acta Chir Scand 1975;141:370-377.

    

    

8. Kangas J, Pajala A, Ohtonen P, et al. Achilles tendon elongation after tendon repair: a randomized comparison of 2 postoperative regimens. Am J Sports Med 2007;35:59-64.

    

    

9. Krackow KA, Thomas SC, Jones LC. A new stitch for ligament-tendon fixation. Brief note. J Bone Joint Surg Am 1986;68(5):764-766.

    

    

10. Labib SA, Gould JS. Achilles tendonitis. Orthopedic Board Review Hyperguide. Available at: http://www.ortho.hyperguide.com/Sports Medicine.

     

     

11. Labib SA, Hage WD, Sutton K, et al. The effect of ankle position on the tension in the Achilles tendon before and after operative repair: a biomechanical cadaver study. Foot Ankle Int 2007;28:478-481.

     

     

12. Labib SA, Rolf R, Dacus R, et al. The “giftbox” open repair of the Achilles tendon: a modification of the traditional Krackow technique. Foot Ankle Int 2009;30:410-414.

     

     

13. Maffulli N. The clinical diagnosis of subcutaneous tear of the Achilles tendon a prospective study in 174 patients. Am J Sports Med 1998;26(2):266-270.

     

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14. Maffulli N, Barrass V, Ewen SW. Light microscopic histology of Achilles tendon ruptures. A comparison with unruptured tendons. Am J Sports Med 2000;28:857-863.

     

     

15. Olsson N, Silbernagel KG, Eriksson BI, et al. Stable surgical repair with accelerated rehabilitation versus nonsurgical treatment for acute Achilles tendon ruptures: a randomized controlled study. Am J Sports Med 2013;41(12):2867-2876.

     

     

16. Sarrafian SK. Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia: JB Lippincott, 1993.

     

     

17. Webb J, Moorjani N, Radford M. Anatomy of the sural nerve and its relation to the Achilles tendon. Foot Ankle Int 2000;21:475-477.

     

     

18. Weber M, Niemann M, Lanz R, et al. Nonoperative treatment of acute rupture of the Achilles tendon: results of a new protocol and comparison with operative treatment. Am J Sports Med 2003;31: 685-691.

     

     

19. Wilkins R, Bisson LJ. Operative versus nonoperative management of acute Achilles tendon ruptures: a quantitative systematic review of randomized controlled trials. Am J Sports Med 2012;40(9): 2154-2160.

     

     

20. Willits K, Amendola A, Bryant D, et al. Operative versus nonoperative treatment of acute Achilles tendon ruptures: a multicenter randomized trial using accelerated functional rehabilitation. J Bone Joint Surg Am 2010;92(17):2767-2775.

     

     

21. Wong J, Barrass V, Maffulli N. Quantitative review of operative and nonoperative management of Achilles tendon ruptures. Am J Sports Med 2002;30:565-575.