Review of Achilles Tendon Injuries

Muscoskeletal injuries are most commonly sustained during sports or exercises. Some of them can be treated effectively and most victims can go back to their usual workouts while others can be forced into choosing less involving sports. This can however, be prevented if people take the necessary precautions while engaging in strenuous activities. This paper discusses a sport injury related to the musculoskeletal system, specifically Achilles tendon injuries; it reviews the injuries’ causations, diagnosis and rehabilitation concerns.

Physiology

The Achilles tendon is made up of fibrous tissues which connect the calf muscles to the heel bone. The bursae cushion the Achilles tendon at the heel. Tendons’ elasticity and flexibility enables them to over send force created by the muscles to the bone. Tendon’s strength is determined by their “thickness and collagen content”; they have a positive correlation. Their elasticity, flexibility and thickness enables them to absorb excess force hence protect the muscles from injury (Maffulli 2004). It is surrounded by peritenon, a connective tissue which provides vascular supply for surrounding blood vessels and enhances the gliding function of the tendon upon dynamic activities. Each time the calf muscles flex the Achilles tendon pulls on the heel. This facilitates movement (Hess 2010).

Aetiology        

Achilles tendon injuries mostly result from irritation or a tear on this tendon (Raleigh 2012). Tendon injuries can either be acute or chronic. They exhibit themselves in grades, the initial grades indicating acute injuries and the final ones chronic injuries. Grade one tendon injuries are characterized by pain along the Achilles tendon 1-3 hours after engaging bin physical activities. Tenderness may exist if there is no intervention within a day. Grade two tendon injuries are depicted by minimal pain in the Achilles tendon at the end of a physical activity. When the pain exists at the initial phase of a physical activity hence shortening the training duration, the injury has progressed to grade three. Grade for and five are characterized by excruciating pain and inability to engage in physical activities. The difference arises in the fifth grade whereby daily activities are also imposed (Dubin 2006). Chronic incidences are mostly caused by extrinsic/external factors while acute incidences are caused by the interaction of the extrinsic and intrinsic factors. Intrinsic factors refer to factors such as age, weight, previous injury and muscle strength while extrinsic factors refer to activities that may incite the occurrence of the incidence (Raleigh 2012). External factors include the use of fluoroquinolone antibiotics and corticosteroids and overuse of the Achilles tendon mostly during workouts. It is mostly caused by weakening of the tendons as a result athletes are poor training patterns such as lack of stretching properly before jumping/turning; previous injury and/or exercising on slippery floors. Intrinsic factors deal with the body’s inability to respond to external forces as expected. In cases of age, as one becomes more elderly, the tendon properties are altered. Muscle junctions increase in stiffness and tensile strength reduces.

Genetics is also included; an individual can inherit genes characterized with weak tendons and muscle strength. Weak tendons are therefore incapable of absorbing external forces; any strenuous activity will exert pressure on the muscles and cause them to tear. Two theories have been proposed to explain the aetiology of Achilles tendon injuries; the degenerative and mechanical theories (Egger 2017). The degenerative theory holds that Achilles tendon injuries are caused by chronic degradation of the tendon, hence does not necessarily involve strenuous activities. Arner, the founder of the theory, found that all 74 cases of Achilles tendon injuries were as a result of degenerative changes. The mechanical theory is based on the results of studies done to determine the cause of tendon ruptures. It postulates that tendon failures result from exerting excessive forces on the tendon. The risk is normally high for athletes with the inability to restrict themselves from “uncoordinated muscle contractions” (Egger 2017). This explains why tendon ruptures are common among weekend warriors.

Resultant Pathomechanics

Weakened collagen fibres can be observed using a microscope. They are wavy when relaxed and stretch when pressure is exerted on them. Damaged collagen fibres remain waved even when the tendons have loads (Hess 2009). Injured Achilles tendons are mostly inflamed. Ruptures are indicated by a space between the tendon and the calcaneus. This is the rupture site. Patients with ruptures cannot climb stairs since the Achilles tendon cannot glide against the heel bone; they have been separated. This explains why most surgical methods involve incisions which try to treat the rupture site by connecting the dislocated bone through stitching; the most preferable one involving the formation of a loop around the rupture site (Bistolfi 2017).

Prevention

The principal means is avoiding strenuous activities or training practices which cause weakening of the tendon; pressure exerted on the Achilles tendon should not exceed its tensile strength. Athletes should engage themselves in adequate warm ups prior to physical activities. This ensures that the tendon is prepared for weight-bearing through increased temperature in the cells surrounding it. Elasticity is also promoted to reduce the chances of muscle tears. Athletes should maintain their levels of workouts as they age to increase tendon hypertrophy. Individuals should also be actively involved in activities which strengthen the ankle plantar flexors, a common one is eccentric exercises. Fluoroquinolone antibiotics and cortisone shots should also be avoided since they reduce tensile strength hence increase the risk to tendon ruptures (Hess 2009).

Diagnosis

Physicians can proceed with the diagnosis after conducting at least two of the following tests; “Thompson test, Matles test, plantar flexion strength”. The Thompson and Matles tests should have positive results indicating that the Achilles tendon has been irritated. The plantar flexion strength test should be negative to indicate that the muscle cannot sustain resistance to movement hence has been damaged (Egger 2017). In cases where it is difficult to determine the type of diagnosis required, imaging studies can be used; this is mostly when the test results are insufficient and/or there is no historical information about the patients’ condition. MRIs can be used to determine the diagnosis (Carcia 2010). MRIs are preferred to ultrasounds irrespective of their higher costs and relative unavailability since they have higher sensitivity hence reduce ambiguity (Egger 2017). Tendon injuries can either be tedinitis or tendinosis.  Tenditis  is microscopic tearing of the tendon which can heal by itself if the tendon is protected from external forces that do not outweigh its strength. Tendinosis is failed healing. Tendons can be damaged by acute trauma, whereby a sudden event causes irritation to a previously normal tendon, chronic overuse whereby there is cumulative damage from activities that cause gradual weakening of the tendon and acute trauma caused by overuse of the tendon. Tendon overuse can be as a result of insufficient rests after engaging in strenuous activities. The tendon does not have enough time to regain its composure before absorbing more shock.  It is important to distinguish the both so that treatment methods can be determined for better results. The diagnosis depends on the intensity of the injury. Physicians may either use the conservative or operative approach. Chronic tendon ruptures are best treated using the operative approach.

Conservative Approach

Conservation treatment involves “cast immobilization and functional rehab”. The most common form of treatment being cast immobilization. It involves no weight-bearing exercises for a month and later on “walking cast” for another four weeks. Functional rehab involves physical therapy whereby patients are given shoes with wedges with stepwise decreasing of the plantar flexion to neutral for more than six weeks after which patients are incorporated into other forms of physical therapy. Patients, specifically athletes, prefer functional rehab to cast immobilization since the former enables them resume their activities at a relatively shorter period of time. Studies show that patients who successfully complete functional rehab have lower risks to re-rupture, indicating the effectiveness of this form of treatment (Egger 2017). Other forms of physical therapy include manual therapy, iontophoresis, stretching, eccentric loading, heel lifting, foot orthoses, laser therapy, tapping and night splints” (Carcia 2010).Manual therapy’s main focus is mobilizing soft tissue to reduce pain and increase muscle movement in patients. This is achieved through moving the toe in such a way that it influences the movement of the Achilles tendon to the direction in which it is considered to be motile. Foot orthosis functions to change the motion of the foot while running by reducing excessive movement of the foot which may create excessive force capable of tearing the tendon. Iontophoresis involves injecting medicine into the damaged tendon using electricity. It reduces inflammation of the tendon and reduces pain. Laser therapy uses low level lasers to reduce stiffness and pain. Eccentric loading is similar to functional protocol since they both involve movement of the foot/ankle with an external resistance to movement. It is more effective in pain reduction compared to night splints; patients recover quickly (Carcia 2010).Ice and massaging can also be used to reduce pain and swelling and enable the muscle to relax (Bistolfi 2017).

Operative Approach

Percutaneous operations were invented by Ma and Griffith to reduce wound infections (Thevendran 2013). It involves passing sutures in a crisscross fashion to capture the proximal and distal aspects of the tendon and cinch them together. This type of operation is beneficial since there is no full incision, there is reduced risk of infection, the surgery is shorter and less pain is inflicted on the tendon. The operation option preserves natural growth factors to facilitate healing with minimal scarring. It also ensures that the blood clot that forms around the injured tendon remains intact to encourage rapid healing. This operation however, compromises repair strength. This is due to the fact that the suture is placed transversely through the skin and the tendon and led out through the opposite side. It is then crisscrossed through the tendon and a stitch is placed with the ankle in plantar flexion so that the gap formed is filled. It strangulates the rupture site. This has led to the development of the “non-strangulating loop technique” which offers considerable effort on the rapture site to promote repair strength (Thevendran 2013). Open repair involves various suture techniques. The “open end-end repair involves a longitudinal incision of 6-8cm” (Bistolfi 2017).

The Brunnel, Kessler and Krackow techniques can be used, the best surgery option being the Krackow technique; it has lower probability to failure. The Krackow suture was modified by Mandelbaum to to involve a posteromedial incision. It is more effective if the patient is operated on within the first stages of the injury. Another approach involves the exposure of the affected Achilles tendon and the heel bone’s tuberosity through a “posterolateral longitudinal incision”. A loop is then formed through stitches that pass through the heel bone and the defected Achilles tendon. This approach is recommended for chronic tendon injuries since it is more thorough. Its main disadvantage is scarring and possibilities of infections (Bistolfi 2017).

After surgery, the patient is placed in a splint or cast from the toes to just below the knees. He/she is discouraged from walking or putting considerable weight on the affected leg.  He/she should elevate the leg above heart level to reduce pain and swelling. Mobilization is maintained through the use of crutches or a wheelchair. Approximately two weeks after surgery, the cast is removed and the incisions are evaluated. Physical therapy is started six weeks after surgery. Patients are normally able to return to full activity within six months but full recovery can be achieved for over a year (Kearney 2012). Irrespective of the treatment option used, there are chances that the injury will not heal fully. Patients may also have blood clots in the leg’s blood vessels. This is mostly common among patients who use surgical methods to treat Achilles tendon injuries; incisions promote blood clots around the rupture to reduce the recovery time. Cases of re-rupture are also high since treatment options such as functional rehab and eccentric exercises only reduce the chances of re-rupture, they do not clear the odds. The healing process may also make the tendon shorter (Kearney 2012).

Rehabilitation Concerns

Although surgery reduces the chances of re-rupture, patients that use this treatment option are susceptible to wound infections and the need for an operation making this option most favorable for younger people and athletes so that they can resume their normal activities sooner. Wound infections can be reduced by using the percutaneous surgery since it uses smaller cuts (Gulati 2015). Physicians are also advised to use a brace rather than the usual plaster to fasten the recovery process. They should also avoid cortisone shots since it may interfere with inflammation which is necessary for the healing process. The same applies to NSAIDs. Both can be used to relieve patients of pain but continuous dependence on them will slow the healing process.

Conclusion

The Achilles tendon facilitates movements along the foot-ankle region. It is made up of collagen fibre whose elastic property enables the tendon to act as a shock absorber upon performing strenuous activities. Injuries occur when the external forces exceed the tendon’s tensibility strength. This may cause ruptures. Victims are advised to seek medical attention as soon as they notice mild pain around the calf and heel bone. This ensures that the injury does not progress to other chronic stages which may limit the patient’s movement. Physicians are required to do tests before determining the type of diagnosis to be adopted. Functional rehab is more beneficial to patients since no operation is necessary and they can resume their normal activities earlier. Surgical methods of treatment have more scarring and are susceptible to wound infections. They reduce chances of re-rupture but patients are still exposed to some risk of reoccurrence of the same. For prevention, individuals are advised to avoid fluoroquinoline antibiotics and corticosteroids since they weaken collagen fibres.

References

Bistolfi, A., Zanovello, J., Lioce, E., Morino, L., Cerlon, R., Aprato, A. & Massazza, G. (2017). Achilles Tendon Injuries: Comparison of Different Conservative and Surgical Treatment and Rehabilitation. Journal of Novel Physiotherapy and Rehabilitation, 1, 39-53.

Carcia, C. M., Martin, R. L., Houck, J. & Wukich, D. K. (2010). Achilles Pain, Stiffness and Muscle Power Deficits: Achilles Tendinitis. Journal of Orthopaedic Sports Physical Therapy, 40(9).

Dubin, J. (2006). Evidence Based Treatment for Achilles Tendon Injuries.

Egger, A. & Berkowitz, M. J. (2017). Achilles tendon injuries. Current Reviews in Musculoskeletal Medicine, 10(1), 72-80. doi: 10.1007/s12178-017-9386-7 Gulati, V., Jaggard, M., Said Al-Nammari, S., Uzoigwe, C., Gulati, P., Ismail, N., Gibbons, C. & Gupte, C. (2015). Management of Achilles tendon injury: A current concepts systematic review. World of Journal Orthopedics, 6(4), 380-386. doi: 10.5312/wjo.v6.i4.380

Hess, G. W. (2009). Achilles Tendon Rupture: A Review of Etiology, Population, Anatomy, Risk Factors and Injury Prevention. Foot & Ankle Specialist, 3(1), 28-32.

Hsu, A. R., Jones, C. P., Cohen, B. P., Davis, W. H., Ellington, J. K. & Anderson, R. B. (2015). Clinical Outcomes and Complications of Percutaneous Achilles Repair System Versus Open Technique for Acute Achilles Tendon Ruptures.  Foot Ankle Int., 36(11), 1276-1286. doi: 10,1177.1071100715589632

Kearney, R. S. & Costa, M. L. (2012). Current concepts in the rehabilitation of an acute rupture of the tendo Achilles. J Bone Joint Surg Br, 94(1), 28-31.

Maffuli, N., Sharma, P. & Luscombe, K. L. Achilles tendinopathy: aetiology and management. Journal of the Royal Society of Medicine, 97(10), 472-476. doi: 10.1258/jrsm.97.10.472

Raleigh, S. M. & Collins, M. (2012). Gene Variants that Predispose to Achilles Tendon Injuries: An Update on Recent Advances. Achilles Tendon, 26-40.

Thevendran, G., Sarraf, K. M., Patel, N. K., Sadri, A. & Rosenfeld, P. (2013). The ruptured Achilles tendon: a current overview from biology of rupture to treatment. Musculoskeletal Surg, 97, 9-20.