AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Background

Achilles tendon ruptures commonly occur to otherwise healthy men between the ages of 30 and 50 years who have had no previous injury or problem reported in the affected leg. Those who suffer this injury are typically "weekend warriors" who are active intermittently.

Most Achilles tendon tears occur in the left leg in the substance of the tendoachilles, approximately 2-6 cm – the ‘watershed zone" – above the calcaneal insertion of the tendon.  That the left Achilles tendon is torn more frequently may be related to handedness; right-handed individuals ‘push off’ more frequently with the left foot.
 
The most common mechanisms of injury include sudden forced plantar flexion of the foot, unexpected dorsiflexion of the foot, and violent dorsiflexion of a plantar flexed foot. Other mechanisms include direct trauma and, less frequently, attrition of the tendon as a result of longstanding peritenonitis with or without tendinosis.^{1, 2, 3}
 
Other populations at risk for an Achilles tendon rupture include those who are poorly conditioned, those of advanced age, those who have been using fluoroquinolone antibiotics, those who have used corticosteroids, and those who overexert themselves.
 
Besides Achilles tendon rupture, which the remainder of this article will focus on, there is also a spectrum of Achilles tendon injuries, including peritenonitis, tendinosis, and peritenonitis with tendinosis.^{1, 2, 3}

Patients with peritenonitis will usually note a localized burning pain that accompanies or follows activity and tracks along the tendoachilles.

Peritenonitis with tendinosis will generally present with activity-related pain, swelling, and sometimes crepitation along the tendon sheath, with or without the presence of nodularity. More severe symptoms may include pain at rest.

Tendinosis is a late-stage manifestation of this problem, characterized by mucoid degeneration of the tendoachilles itself, with a lack of inflammatory response and symptoms characterized by a sense of fullness or nodularity in the posterior aspect of the tendoachilles.

For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center. Also, see eMedicine's patient education articles Ruptured Tendon and Achilles Tendon Rupture.

Related eMedicine topics:
Achilles Tendon Injuries and Tendonitis
Achilles Tendonitis
Overuse Injury
Tendonitis

Related Medscape topics:
Resource Center Exercise and Sports Medicine
CME Tendinopathy -- From Basic Science to Treatment
CME Tendon Problems a Possible Adverse Effect of Statin Therapy
Medscape Alerts - Fluoroquinolones Earn Black Box Warning for Tendon-Related Adverse Effects
The Medscape Medical Minute - What Is the Best Way to Treat and Rehabilitate a Ruptured Achilles Tendon?

Frequency

United States

Although the worldwide frequency of Achilles tendon ruptures is not known, data collected from Finland estimates that it occurs in 18 per 100,000 people yearly. The male-to-female ratio of rupture is estimated from 1.7:1 to 12:1. 

Functional Anatomy

The Achilles tendon is the largest and strongest tendon in the human body, and it is formed from tendinous contributions of the gastrocnemius and soleus muscles. The tendons converge approximately 15 cm proximal to the insertion at the posterior calcaneus. When viewed in cross section, the right Achilles tendon appears to spiral counterclockwise 30-150º toward its insertion at the calcaneus; the left Achilles tendon spirals clockwise analogously. The spiraling of the tendon as it reaches the calcaneus allows for elongation and elastic recoil within the tendon, facilitating storage and release of energy during locomotion. This phenomenon also allows higher shortening velocities and greater instantaneous muscle power than could be generated by the gastrocsoleus complex alone.
 
Because actin and myosin are present in tenocytes, tendons have almost ideal mechanical properties for the transmission of force from muscle to bone. Tendons are stiff but resilient, possess a high tensile strength, and have the ability to stretch up to 4% before damage occurs.^{4, 5} With stretch greater than 8%, macroscopic rupture occurs.
 
The blood supply for the Achilles tendon is derived from the posterior tibial artery and its contributions to the musculotendinous junction, as well as the mesosternal vessels which cross the paratenon, infiltrating the tendon and the bone-tendon junction at the calcaneus.⁶ The watershed zone is an area 2-6 cm proximal to the calcaneus, in which the blood supply is less abundant and becomes even sparser with age. It is in this region that most degeneration and therefore rupture of the Achilles tendon occurs. Because younger tendons have better blood supply, significantly higher tensile strength, and less stiffness, they tend to rupture less frequently.^{4, 5}

Sport-Specific Biomechanics

The peak Achilles tendon force (F) and the mechanical work (W) by the calf muscles are respectively approximately 2200N and 35J in the squat jump, 1900N and 30J in the countermove jump, and 3800N and 50J when hopping.⁷ The estimated peak load is 6-8 times the body weight during running with a tensile force of greater than 3000N. On average, Achilles tendons in women have a smaller cross-sectional area than in men. This possibly suggests that less force is generated in a woman’s Achilles tendon than the figures noted above, which may account for the lower rate of rupture in women.⁷

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

History

• Patients with an Achilles tendon rupture frequently present with complaints of a sudden snap in the lower calf associated with acute severe pain.
• The patient may be able to ambulate with a limp, but he or she is unable to run, climb stairs, or stand on their toes.
• There is a loss of plantar flexion power in the foot.
• There may be swelling of the calf.
• There may be a history of a recent increase in physical activity/training volume.
• There may be a history of recent use of fluoroquinolones, corticosteroids, or of corticosteroid injections.
• There may have been a previous rupture of the affected tendon.

Physical

• Examine the entire length of the gastrocsoleus-Achilles complex, noting any tenderness, swelling, ecchymosis, and tendon defects. A palpable gap in the Achilles tendon may be appreciated.
• The patient will be unable to stand on the toes on the affected side.
• Clinical tests
• • “Hyperdorsiflexion” sign – With the patient prone and knees flexed to 90º, maximal passive dorsiflexion of both feet may reveal excessive dorsiflexion of the affected leg.
  • Thompson test – With the patient prone, squeezing the calf of the extended leg may demonstrate no passive plantar flexion of the foot if its Achilles tendon is ruptured.
  • O’Brien needle test – Insert a needle 10 cm proximal to the calcaneal insertion of the Achilles tendon. With passive dorsiflexion of the foot, the hub of the needle will tilt rostrally when the Achilles tendon is intact.⁸

Causes

The common precipitating event that causes an Achilles tendon rupture is a sudden, eccentric force applied to a dorsiflexed foot.^{9, 10, 11} Ruptures of the Achilles tendon also may occur as the result of direct trauma or as the end result following Achilles peritenonitis, with or without tendinosis. Risk factors associated with Achilles tendon rupture include the following:

• Recreational athlete (weekend warrior)
• Relatively older age (30-50 y)
• Previous Achilles tendon injury or rupture
• Previous tendon injections or fluoroquinolone use
• Abrupt changes in training, intensity, or activity level
• Participation in a new activity

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Other Problems to Be Considered

Achilles tendinosis
Calcaneus bone injuries
Fascial tears
Gastrocnemius/soleus tear (usually a tear of the medial head of the gastrocnemius)
Inflammatory arthropathy
Inflammatory processes
Syndesmosis
Tennis leg (tear of the plantaris tendon)
Vascular injuries

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Lab Studies

• Serum and blood studies are usually unnecessary.

Related Medscape topic:
Resource Center Pathology & Lab Medicine

Imaging Studies

• Radiographs are more useful in ruling out other injuries than in ruling in Achilles tendon ruptures, and they may show findings of soft-tissue swelling, increased ankle dorsiflexion on stress views, vascular or heterotopic calcifications, accessory ossicles, calcaneal fractures, a Haglund deformity, or bony metaplasia.
• Musculoskeletal ultrasonography can be used to determine the tendon thickness, character, and presence of a tear. This imaging modality is inexpensive, involves no ionizing radiation and, in the hands of skilled ultrasonographers, may be very reliable.
• Magnetic resonance imaging (MRI) can be used to discern incomplete ruptures from degeneration of the Achilles tendon, and MRI can also distinguish between paratenonitis, tendinosis, and bursitis.

Related Medscape topic:
Specialty Site Radiology

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Acute Phase

Rehabilitation Program

Physical Therapy

An individual who ruptures his or her Achilles tendon should seek prompt medical treatment. Physical therapy is generally not indicated in the acute phase of treatment, but it later becomes a crucial part of rehabilitation once adequate healing of the tendon has occurred.

The course of treatment (nonoperative vs operative) is determined on a patient-by-patient basis. Typically, both nonoperative and operative treatment options are offered to patients, with particular emphasis on the benefits and risks of each procedure. The recommendations provided in this section regarding operative versus nonoperative treatment are guidelines only and must be personalized to each patient’s needs and condition.

Surgical Intervention

Controversy exists regarding whether to conservatively manage a first-time Achilles tendon rupture or to surgically reconstruct the ruptured tendon. There are distinct benefits and risks for each approach.^{1, 12, 13, 14, 15}

According to Kahn et al, there was a consistent finding of an approximately 33% higher rate of complications (other than rerupture) in those treated surgically¹; nonoperatively treated patients had a rerupture rate approximately 3 times higher than those treated surgically, but these patients had minimal risk for other complications. Listed complications resulting from open surgical repair included deep infections (1%), fistulae (3%), necrosis of the skin or tendon (2%), rerupture (2%), and minor complications (percentage not documented).¹

Studies indicate that patients who had a percutaneous rather than an open surgical approach had a minimal rate of infection, but it was also demonstrated that there were relatively high rates of injury to the sural nerve.^{1, 14}

Conservative repair
 
Early reports of rerupture in conservatively treated patients noted rates as high as 40%. In newer protocols with shorter immobilization periods, the rates of rerupture appear to be much less and are comparable to the rerupture rate for surgically repaired tendons. 

Twaddle and Poon reported on a protocol in which surgical and nonsurgical patients were treated with the same casting and splinting regimen.¹³ Patients in the surgical group underwent Achilles tendon repair using a Krackow procedure, followed by 10 days in a plaster-of-Paris hanging equinus cast, whereas nonsurgical patients were placed directly in the cast. After removal of the cast, patients were placed in a removable below-the-knee orthosis with the ankle at 20º of plantar flexion. They were to remove the splint for 5 minutes of every hour, and while sitting with the leg hanging, practice active dorsiflexion and passive plantar flexion, allowing the foot to fall as far as was comfortable.¹³

At the 4-week point of the study, the orthosis was brought to neutral, with the same range-of-motion protocol as the previous weeks. At 6 weeks, the patients were allowed to bear weight as tolerated while wearing the orthosis. At this time, they were also allowed to remove the orthosis at night. At 8 weeks, patients were weaned from the brace and then began physical therapy for stretching and strengthening.¹³ There were 3 cases of reruptures, 2 in the surgical and 1 in the nonsurgical group. Of the 2 surgical reruptures, 1 fell down stairs, and the other was hit by a car while trying to stop a robbery. The nonsurgical patient slipped off an embankment at 16 weeks. All reruptures were treated surgically.¹³ 
 
Other, more recent conservative protocols employ a period of nonweight-bearing casting, either above or below the knee, with the foot in equinus for approximately 2-4 weeks, and then serial casting or functional splinting with decreasing degrees of plantar flexion to neutral at 2- to 4-week intervals. 

The average time for immobilization in these protocols is 9 weeks. The success and complication rates in this longer treatment protocol appear less favorable than with protocols of shorter duration. Good functional results were reported in the shorter protocols, as were relatively low rates of rerupture. Immobilization in these studies averaged 2 weeks, and follow-up lasted an average of 22.3 months.  
 
In all conservatively treated patients, the rate of skin complications was 0.5% (3 of 578); other minor unspecified general complications accounted for problems in another 8.5% of patients, major complications in 0.6% of patients, and rerupture in 9.8% of patients. 
 
Percutaneous surgery
 
Ma and Griffith reported on 18 tendon repairs using percutaneous sutures to reapproximate the ruptured stumps.¹⁶ Through stab wounds, sutures were passed through the distal and proximal ends, which were approximated while the ankle was held in maximal equinus. The sutures were then cut short, tied off using a surgeon’s knot, and pushed subcutaneously. The 6 small wounds were cleaned and dressed with dry, sterile dressings. Afterward, the patients were placed in short leg, nonweight-bearing casts for 4 weeks, followed by 4 weeks in a weight-bearing, low-heeled cast.

In later studies, minor variations of this procedure were employed along with general or local anesthesia. High rates of sural nerve entrapment were reported in these studies, accounting for 16.7% of treated cases. Further studies analyzed outcomes of percutaneous surgery followed by either early mobilization or prolonged immobilization.¹⁷ Of those mobilized early, 6.6% reported minor wound complications, 3.3% reported major wound complications, 14.8% reported minor general complications, and 0.8% reported major general complications. Of those immobilized, 4.9% reported minor wound complications, 8.5% reported minor general complications, 0.8% reported major general complications and 6.6% reported rerupture.¹⁷
 
Open surgical repair
 
Open reconstruction is undertaken using a medial longitudinal approach. Medial incisions have the advantage of better visualization of the plantaris tendon, as well as avoidance of injury to the sural nerve. Midline incisions are rarely used because of higher rates of wound complications and adhesions.¹⁸ 
 
After application of the tourniquet and palpation of the rupture gap, the incision is made through the skin and subcutaneous fat to the paratenon. The paratenon is then divided longitudinally to expose the ruptured ends, which are irrigated and debrided. The ends are then reapproximated and sutured with a heavy nonabsorbable suture using a modified Kessler, Krackow, or Bunnell technique, while being careful not to overtighten.
 
If the repair is insecure and reinforcement is required, a pull-out wire or multiple interrupted sutures may be used. These may be augmented with a turn-down fascial graft or a woven tendon graft.
 
Following surgery, the ankle is maintained in flexion as a cast or rigid orthosis is applied. After a period of immobilization, the foot is brought into neutral or slight plantar flexion in a rigid orthosis, and the patient is allowed partial weight bearing. Immobilization is typically discontinued 4-6 weeks after repair. At that point, active and active-assisted range of motion, swimming, stationary cycling, and walking in a shoe fitted with a heel lift can be initiated. In most cases, patients can progress to full activity within 4 months of surgery.¹⁸
  
In general, surgical treatment is advocated for young and athletic individuals who frequently subject their Achilles tendon to relatively high-demand activity. Conservative approaches with lower rerupture rates are being investigated. These conservative protocols show rerupture rates approaching those of surgical rerupture rates and have the advantage of fewer complications, in particular infections of the surgical wound and other wound-related problems.

In summary, operative repair of Achilles tendon ruptures has been reported to have lower rerupture rates; increased postoperative muscle strength, power, and endurance; and an earlier return to activities compared with nonoperative treatment. Wound complications occasionally do occur after operative treatment and may include infection, drainage, sinus formation, and skin sloughing.

Related Medscape topics:
Resource Center  Sepsis
Resource Center Wound Management
Specialty Site Surgery

Other Treatment

Nonoperative treatment is usually indicated for patients who are elderly and/or inactive, as well as for those with systemic illnesses or poor skin integrity. Patients with diabetes, wound healing problems, vascular disease, neuropathies, or serious systemic comorbidities are encouraged to opt for nonoperative treatment because of the significant risks of operative treatment (eg, infection, wound breakdown, repair dehiscence, perioperative complications).

• A short-leg cast is applied to the affected leg while the ankle is placed in slight plantar flexion (gravity equinus). By keeping the foot in this position, the tendon ends are theoretically better apposed. Cast immobilization is continued for about 6-10 weeks. Forced dorsiflexion is contraindicated. The ankle may gradually be dorsiflexed to a more neutral position after a period of immobilization (~4-6 wk). This position is sustained with serial casting or adjustable ankle orthotics. Walking in the cast is allowed at this time. Following cast removal, a 2-cm heel lift in the shoe is worn for an additional 2-4 months. During this time, a rehabilitation program is initiated.
• Advantages of nonoperative treatment include no wound complications (eg, skin breakdown, infection, scar formation, neurovascular injury), decreased hospital costs and physician fees, lower morbidity, and no exposure to anesthesia.
• Disadvantages of nonoperative treatment include a higher incidence of rerupture (up to 40%) and more difficult surgical repair following rerupture. In addition, the tendon edges may heal in an elongated position because of a gap in the unapposed tendon ends, resulting in decreased plantar flexion power and endurance.

Recovery Phase

Rehabilitation Program

Physical Therapy

Following cast removal, gentle passive range of motion of the ankle and subtalar joints is initiated. After 2 weeks, progressive resistance exercises (PREs) are added to the regimen. This is followed by aggressive gait training exercises at about 10 weeks following the injury (nonoperative patients) or surgery (operative patients), leading toward activity-specific maneuvers and a return to activities at 4-6 months. The patient's recovery is largely dependent on the quality of the rehabilitation program, his/her motivation and focus, as well as his/her desired postinjury activity level.

MEDICATION

Section 7 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

No medical therapy is indicated for this condition. Medication is only prescribed for the symptomatic relief of pain. These medications may include acetaminophen, various nonsteroidal anti-inflammatory drugs (NSAIDs), or narcotics, depending on physician preference.

Related eMedicine topics:
Toxicity, Acetaminophen
Toxicity, Narcotics
Toxicity, Nonsteroidal Anti-inflammatory Agents

Related Medscape topics:
Resource Center Adverse Drug Events Reporting
Resource Center Opioids: A Guide to State Opioid Prescribing Policies
Resource Center Pain Management: Advanced Approaches to Chronic Pain Management
Resource Center Pain Management: Pharmacologic Approaches

Drug Category: Nonsteroidal Anti-inflammatory Agents (NSAIDs)

Although most NSAIDs are used primarily for their anti-inflammatory effects, they are effective analgesics and are useful for the relief of mild to moderate pain.

Drug Category: Analgesics

Pain control is essential to quality patient care. Analgesics ensure patient comfort and have sedating properties, which are beneficial for patients who have sustained trauma or who have sustained injuries.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Return to Play

Return to play following an Achilles tendon rupture is dependent on the method of treatment (operative vs nonoperative). (See Treatment.)

Complications

• Following nonoperative treatment, the incidence of rerupture is higher (up to 40%).
• Surgical repair results following rerupture are poorer when compared with the initial operative treatment of an acute tendon rupture.
• Operative treatments have several complications, including wound complications (eg, infection, skin slough, sinus formation), adhesions, and possible sural nerve injury (especially through a lateral longitudinal approach).

Related Medscape topics:
Resource Center Sepsis
Resource Center Wound Management
Resource Center Vascular Surgery
Specialty Site Neurology & Neurosurgery

Prevention

Good conditioning and proper stretching is important in the prevention of Achilles tendon injuries. Adequate warm-up is always encouraged before participation in activities that place the Achilles tendon at risk.

Related Medscape topic:
Resource Center Exercise and Sports Medicine

Prognosis

With proper treatment and rehabilitation, the prognosis following an Achilles tendon rupture is good to excellent. Most athletes are able to return to their previous activity levels with either surgical or conservative treatment. However, individuals who undergo surgical treatment are less likely to experience rerupture of their Achilles tendons. The rerupture rate for operative treatment is 0-5%, compared with nearly 40% in those who opt for conservative treatment.

Education

Individuals should be educated on the importance of stretching and proper conditioning to prevent rerupture of the Achilles tendon. Wearing appropriate and properly fitting shoes during activities also should be stressed to all athletes.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical/Legal Pitfalls

• Misdiagnosing and/or delaying treatment for an Achilles tendon rupture are potential medicolegal pitfalls. Upon presentation, patients may be able to weakly plantar flex their ankles due to the intact peroneal muscles, posterior tibialis tendon, or flexor hallucis tendons; therefore, misdiagnosis or delay in treatment may occur because the condition is believed to be just a sprain.

Related Medscape topics:
Resource Center Medical Malpractice and Legal Issues
Resource Center Trauma

ACKNOWLEDGMENTS

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author, Henry Marano, MD, to the development and writing of this article.

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

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4. Maffulli N. Rupture of the Achilles tendon. J Bone Joint Surg Am. Jul 1999;81(7):1019-36. [Medline]. [Full Text].
5. Moore KL. Clinically Oriented Anatomy. 3^rd ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 1999.
6. Carr AJ, Norris SH. The blood supply of the calcaneal tendon. J Bone Joint Surg Br. Jan 1989;71(1):100-1. [Medline]. [Full Text].
7. Kader D, Saxena A, Movin T, Maffulli N. Achilles tendinopathy: some aspects of basic science and clinical management. Br J Sports Med. Aug 2002;36(4):239-49. [Medline]. [Full Text].
8. O'Brien T. The needle test for complete rupture of the Achilles tendon. J Bone Joint Surg Am. Sep 1984;66(7):1099-101. [Medline]. [Full Text].
9. Saltzman CL, Tearse DS. Achilles tendon injuries. J Am Acad Orthop Surg. Sep-Oct 1998;6(5):316-25. [Medline].
10. Puddu G, Ippolito E, Postacchini F. A classification of Achilles tendon disease. Am J Sports Med. Jul-Aug 1976;4(4):145-50. [Medline].
11. Clement DB, Taunton JE, Smart GW. Achilles tendinitis and peritendinitis: etiology and treatment. Am J Sports Med. May-Jun 1984;12(3):179-84. [Medline].
12. Metz R, Verleisdonk EJ, van der Heijden GJ, et al. Acute Achilles tendon rupture: minimally invasive surgery versus nonoperative treatment with immediate full weightbearing--a randomized controlled trial. Am J Sports Med. Jul 21 2008;epub ahead of print. [Medline].
13. Twaddle BC, Poon P. Early motion for Achilles tendon ruptures: is surgery important? A randomized, prospective study. Am J Sports Med. Dec 2007;35(12):2033-8. [Medline].
14. Chalmers J. Review article: Treatment of Achilles tendon ruptures. J Orthop Surg (Hong Kong). Jun 2000;8(1):97-99. [Medline]. [Full Text].
15. Cetti R, Christensen SE, Ejsted R, Jensen NM, Jorgensen U. Operative versus nonoperative treatment of Achilles tendon rupture. A prospective randomized study and review of the literature. Am J Sports Med. Nov-Dec 1993;21(6):791-9. [Medline].
16. Ma GW, Griffith TG. Percutaneous repair of acute closed ruptured achilles tendon: a new technique. Clin Orthop Relat Res. Oct 1977;128:247-55. [Medline].
17. Elliot RR, Calder JD. Percutaneous and mini-open repair of acute Achilles tendon rupture. Foot Ankle Clin. Dec 2007;12(4):573-82, vi. [Medline].
18. DeLee JC, Drez D Jr, Miller MD, eds. Orthopaedic Sports Medicine. 2^nd ed. Philadelphia, Pa: WB Saunders; 2003.
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20. Bring DK, Reno C, Renstrom P, et al. Joint immobilization reduces the expression of sensory neuropeptide receptors and impairs healing after tendon rupture in a rat model. J Orthop Res. Jul 24 2008;epub ahead of print. [Medline].
21. Maffulli N, Ajis A. Management of chronic ruptures of the Achilles tendon. J Bone Joint Surg Am. Jun 2008;90(6):1348-60. [Medline]. [Full Text].
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Article Last Updated: Aug 5, 2008