Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Achilles Tendon Rupture

Basics
Description
  • The Achilles tendon is the strongest tendon in the body and is subject to loads of 7 times body weight.
  • Definition: Tendon disruption in its watershed region
  • Anatomy :
    • The terminal segment of the medial and lateral gastrocnemius and the soleus muscles
    • Is 5 cm long and inserts on the posterior calcaneal tuberosity
    • Is surrounded by a paratenon, which allows it to glide freely
    • Is composed mainly of type 1 collagen
    • The blood supply to the tendon is poorest in a watershed region from 6 cm proximal to the tendon’s insertion on the calcaneus.
    • The tendon rotates 90° as it courses distally, concentrating mechanical stress in the watershed area.
  • Classification:
    • Acute versus chronic
    • Open versus closed
    • Complete versus incomplete
General Prevention
Training and stretching result in tendon adaptation, including increased cross-sectional area.
 
Epidemiology
  • Bimodal distribution:
    • Young to middle-aged athletes (40 years old)
      • 75% occur during sports activity.
      • The most common sports to cause acute Achilles tendon rupture varies from country to country, depending on which sports are most popular in that area.
    • Older nonathletes (3% of ruptures)
Incidence
  • Unclear, varying from 37.3 per 100,000 in several studies
  • Increasing incidence seen in recent decades
Prevalence
  • It predominantly affects males.
  • Left side injury is more common than right (possibly because right-hand dominant athletes push-off with the left leg).
  • More common in industrialized countries and among weekend warriors
Risk Factors
  • In 1 study, previous Achilles tendon rupture was a risk factor for future contralateral tendon rupture in up to 6% of patients.
  • Several medications are associated with an increased risk of tendon rupture.
    • Corticosteroids, either oral or injected locally into the Achilles tendon area
    • Anabolic steroids
    • Fluoroquinolone antibiotics
  • Multiple systemic diseases have been associated, but not often, with spontaneous ruptures.
    • Diabetes
    • Rheumatoid arthritis and other inflammatory arthritides
    • Gout
Pathophysiology
Histopathology from Achilles tendon ruptures almost always shows evidence of degenerative changes and chronic tendinosis.
 
Etiology
  • Most common: Indirect mechanism:
    • Pushing off with weightbearing foot while extending the knee
    • Eccentric contraction of gastrocnemius soleus complex
  • Rarely, direct trauma such as a laceration or gunshot wound can tear the Achilles tendon.
Associated Conditions
  • Achilles tendinopathy
    • Insertional: Retrocalcaneal bursitis, insertional tendinopathy
    • Noninsertional: Tendinosis, peritendinitis
Diagnosis
Signs and Symptoms
  • Usually, a sudden snap or pop is felt in the back of the ankle.
  • Patient may describe a sensation of being kicked in the back of the leg.
  • Pain may be severe.
  • Local pain, swelling with a palpable gap along the Achilles tendon near its insertion site, and weak active plantarflexion strength all strongly suggest the diagnosis.
History
In addition to a general foot and ankle history, enquire about previous pain or symptoms of tendinopathy.
 
Physical Exam
  • Perform general foot and ankle examination, concentrating on the following specific areas:
    • Examine the posterior ankle for tenderness, swelling, or a palpable gap in the tendon.
    • Check muscle strength.
      • Patient still may be able to plantarflex the ankle by compensating with other muscles, but strength will be weak.
      • Single-limb heel rise will not be possible.
    • Knee flexion test:
      • Check resting position of ankle with patient prone and knees flexed 90°.
      • Loss of normal resting gastrocnemius soleus tension will allow ankle to assume a more dorsiflexed position than that on the uninjured side.
    • Thompson test:
      • Position the patient prone with ankles clear of the table.
      • Squeezing the calf normally produces passive plantarflexion of the ankle.
      • If the Achilles tendon is not in continuity, the ankle will not passively flex with compression of calf muscles.
Tests
Lab
Obtain preoperative laboratory tests only if surgery is planned.
 
Imaging
  • Plain radiographs to evaluate bony structure
  • If evidence is present of a calcaneal tuberosity fracture and Achilles tendon avulsion, CT can help to assess the calcaneus fracture pattern.
  • Acute Achilles tendon rupture usually is a diagnosis made clinically.
    • If the diagnosis is in question, MRI or, occasionally, ultrasound can help to make the diagnosis.
Differential Diagnosis
  • Achilles tendinopathy
  • Partial Achilles tendon rupture
  • Calcaneus fracture
Treatment
Initial Stabilization
  • Once the diagnosis is made, the ankle should be splinted in equinus with a well-padded, below-the-knee, nonweightbearing splint.
  • Ice and elevation help to control swelling.
General Measures
  • Management can be operative or nonoperative, depending on the patient’s age, general health, activity level, and preferences.
    • In general, surgical treatment is preferred in young, active, healthy individuals.
  • Surgical and nonsurgical techniques are associated with treatment-specific risks and benefits that both surgeon and patient must consider .
  • Nonoperative management:
    • Immobilization protocol:
      • Below-the-knee cast with ankle in full equinus is placed initially.
      • During the following 10 weeks, the ankle is gradually brought to a plantigrade position with cast changes approximately every 2 weeks.
      • Weightbearing is allowed after 6 weeks.
      • After casting, a heel lift usually is worn for several months.
    • Functional bracing protocol:
      • Boot or brace that limits dorsiflexion but allows plantarflexion
      • The dorsiflexion block is gradually relaxed, allowing more ankle motion.
Activity
With the nonoperative treatment technique, weightbearing usually is not permitted for 6 weeks.
 
Special Therapy
Physical Therapy
  • Many rehabilitation protocols are available.
  • Generally, therapy initially involves progressive, active ankle motion and progresses to weightbearing and strengthening.
Surgery
  • Open technique :
    • Surgery is delayed ~1 week to allow for swelling diminution.
    • Prone position: Both legs should be draped into the operative field so that resting ankle position can be approximated to the normal side when sutures are tied.
    • A medial longitudinal incision along Achilles tendon often is used to decrease the risk of sural nerve injury.
    • A running locking technique with 2 suture strands in each segment of tendon produces the strongest repair .
    • The paratenon should be preserved and repaired to help prevent adhesions.
      • If present, the plantaris tendon can be unfolded and wrapped around the repair to minimize adhesion formation.
  • Percutaneous techniques: Several techniques using special instruments and multiple stab incisions have been described.
  • Surgical management of chronic ruptures:
    • The repair technique depends on the size of the gap and the presence of muscle atrophy.
      • If end-to-end repair is not possible, V–Y lengthening, turndown advancement flap, tendon transfer or augmentation (flexor hallucis longus, flexor digitorum longus), and allograft tendon are options.
Follow-up
Prognosis
  • The prognosis is good for both operatively and nonoperatively managed Achilles tendon tears.
    • In a prospective randomized trial of 112 tears treated operatively or nonoperatively, no differences were noted in return to sports, isokinetic strength, endurance, or ankle motion at 1 year .
    • A meta-analysis of 421 patients showed a nonsignificant difference in the proportion of patients who regained normal function after surgical or nonoperative management (71% versus 63%) .
Complications
  • Meta-analysis of 356 patients :
    • Rerupture rate: 3.5% in the surgical group versus 12.6% in the nonsurgical group
    • Overall incidence of complications in the surgical group: 34.1%
      • 19.7% adhesions
      • 9.8% altered sensation (sural nerve most common)
      • 4% wound infection or dehiscence
    • Overall incidence of complications in the nonsurgical group: 2.7%
      • Adhesions, excessive tendon lengthening, and DVT were the most common.
  • Compared with open techniques, percutaneous surgery has been associated with a shorter operative time, lower infection rate, higher rate of rerupture, and higher rate of sural nerve injury .
    • These results may improve with newer techniques .
Patient Monitoring
  • Sutures are removed ~2 weeks after surgery.
  • Casting/bracing and progressive therapy are instituted as described earlier.
  • Consider prophylaxis for DVT.
Miscellaneous
Codes
ICD9-CM
  • 727.67 Nontraumatic
  • 845.09 Traumatic
Patient Teaching
The patient should be actively involved in the decision-making process, with a clear understanding of the risks and benefits of surgical and nonsurgical treatments.
 
FAQ
Q: Which nerve is at greatest risk for injury during operative treatment of an Achilles tendon rupture?
A: The sural nerve runs lateral to the Achilles tendon and is at risk.
 
Q: In which situation is urgent surgical intervention required for a closed Achilles tendon injury?
A: Occasionally, the Achilles tendon will avulse a piece of the calcaneal tuberosity instead of producing an intratendinous tear. Because this area is subcutaneous, the bony fragment can place pressure on the skin, causing necrosis of the area. Calcaneal tuberosity avulsion fractures should be fixed urgently if the skin is compromised.
 
Q: Can the ankle be plantarflexed if the Achilles tendon is ruptured?
A: Yes. Other muscles, including the tibialis posterior, flexor hallucis longus, flexor digitorum longus, and peroneals, pass posterior to the center of rotation for the ankle joint. Compensation using these muscles can plantarflex the ankle, but strength will be markedly diminished.
 
Q: What is the main advantage of surgical treatment for an acute Achilles tendon tear?
A: The main advantage of operative management is the significantly lower rate of rerupture. In essence, for every 10 patients treated with surgical repair, 1 rerupture will be prevented. However, surgical repair has a higher risk of infection, wound healing problems, and sural nerve injury than nonoperative management .

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