Experimental rupture of the Achilles tendon. Comparison of various types of experimental rupture in rats

Current Concepts in Achilles Tendon Ruptures

The Achilles tendon has a high incidence of ruptures often occurring in weekend warriors and the aging population. Based on anatomic studies of the Achilles tendon, ruptures are commonly found in the watershed area proximal to the insertion site. Traditionally, treatment options included conservative therapy with immobilization and a prolonged non-weight-bearing phase versus surgical treatment. Surgical treatment can vary between open, minimally invasive, or percutaneous approaches. In more recent years, early functional rehabilitation with or without surgery has shown to have successful results.

Gross Anatomy: Achilles Tendon

The Achilles tendon is well known as the strongest tendon within the body. Its anatomic composition is unique to allow absorption of extreme loads. Historically, there has been a longstanding belief that rupture of the Achilles tendon occurs within a "watershed" region of ischemia. However, experimental data have demonstrated uniform hemodynamic flow throughout the tendon to challenge this widespread notion.

Anatomical and Functional Considerations in Achilles Tendon Lesions

The pathologic conditions of the Achilles tendon are best understood in the context of its unique anatomy and functional demands. Some of these unique considerations include its high physiologic load demands, microscopic tissue composition, muscular origin spanning the knee joint, intimate insertional relationship with the plantar fascia, sensory innervation, and vascular supply with watershed areas. Risks of both acute rupture and chronic tendinopathy are affected by the tendon's anatomy and its functional demands. The tendon's functional anatomy changes with advancing age, notably in its collagen composition and vascular supply.

Acute Achilles Tendon Rupture: Clinical Evaluation, Conservative Management, and Early Active Rehabilitation

The Achilles tendon (AT) is the strongest, largest, and most commonly ruptured tendon in the human body. Physical examination provides high sensitivity and specificity. Imaging studies are not recommended unless there are equivocal findings in the physical examination. Recent studies have shown that the risk of re-rupture is negated with implementation of functional rehabilitation protocols. Heterogeneity in study design makes conclusions on the specifics of functional rehabilitation protocols difficult; however, it is clear that early weight bearing and early controlled mobilization lead to better patient outcome and satisfaction in both surgically and conservatively treated populations.

Acute achilles tendon rupture in athletes

The incidence of AT rupture has increased in recent decades. AT ruptures frequently occur in the third or fourth decade of life in sedentary individuals who play sport occasionally. Ruptures also occur in elite athletes. Clinical examination must be followed by imaging. Conservative management and early mobilization can achieve excellent results, but the rerupture rate is not acceptable for the management of young, active, or athletic individuals. Open surgery is the most common option for AT ruptures, but there are risks of superficial skin breakdown and wound problems. These problems can be prevented with percutaneous repair.

The ruptured Achilles tendon: a current overview from biology of rupture to treatment

The Achilles tendon (AT) is the most frequently ruptured tendon in the human body yet the aetiology remains poorly understood. Despite the extensively published literature, controversy still surrounds the optimum treatment of complete rupture. Both non-operative management and percutaneous repair are attractive alternatives to open surgery, which carries the highest complication and cost profile. However, the lack of a universally accepted scoring system has limited any evaluation of treatment options. A typical UK district general hospital treats approximately 3 cases of AT rupture a month. It is therefore important for orthopaedic surgeons to correctly diagnose and treat these injuries with respect to the best current evidence-based practice. In this review article, we discuss the relevant pathophysiology and diagnosis of the ruptured AT and summarize the current evidence for treatment.

A case of "fresh rupture" after open repair of a ruptured Achilles tendon

We present the case of Achilles tendon rupture in a 54-year-old man while rehabilitating after end-to-end open repair of an acute Achilles tendon rupture. Re-rupture after surgical repair of Achilles tendon is well known. The present case, however, is atypical, because the second rupture occurred significantly proximal to the first rupture. To our knowledge, this is the first time this has been described in English language studies. We have termed this incident a fresh rupture. A gastrocnemius turndown flap was used to repair the fresh rupture, which led to a satisfactory recovery. This case report serves to inform surgeons of the existence of this type of Achilles tendon rupture, while considering the possible etiologies and suggesting a technique that has been shown to be successful in the present case.

An anatomical and radiological study of the fascia cruris and paratenon of the Achilles tendon

BACKGROUND

The Achillon jig permits the placement of sutures deep to the fascia cruris and the paratenon through the substance of the ruptured tendon, permitting a safe minimally invasive repair. Our experience has suggested that these two layers may not be as clearly delineated as first thought or may merge at an, as yet, undefined level.

METHODS

We performed an anatomical and radiological (US and MRI) study of the layers of tissue superficial to the Achilles tendon in cadaveric specimens.

RESULTS

The mean distance for the confluence of the fascia cruris and paratenon from the postero-superior calcaneal tubercle (PSCT) was found to be 37.3mm (range 17-58mm). Ultrasound examination was found to be less distinct than MRI scanning.

CONCLUSIONS

We recommend careful identification of the fascia cruris and paratenon and insertion of the central branches of the jig adjacent to the tendon substance when using this method for repair.

A case of 'second rupture' following open repair of a ruptured Achilles tendon

We present a case of Achilles tendon rupture in a 54-year-old man whilst rehabilitating following end-to-end open repair of an acute Achilles tendon rupture. Re-rupture following surgical repair of Achilles tendon is well known. This case however, is atypical as the second rupture occurred significantly proximal to the first rupture. To our knowledge this is the first time this has been described in the English literature. We have termed this incident a 'second rupture'. We describe the surgical technique used by the operating surgeon during open repair of this 'second rupture', involving a gastrocnemius flap turndown. This has lead to the patient making a good recovery, despite complications. This case report serves to inform surgeons of the existence of this type of Achilles tendon rupture, whilst considering possible aetiologies and suggesting a technique for repair of the injury.

Anatomy and biomechanical aspects of the gastrocsoleus complex

The complexity of its anatomy coupled with the biomechanics of the Achilles tendon may explain the frequency of injury to this structure. Its unique characteristic of the muscle crossing three joints (knee, ankle, and subtalar joints) makes it more susceptible to injury than muscles that span a single joint. A better understanding of the contributing pathologic conditions associated with functional shortening of the gastroc-soleus complex and its effects on the normal biomechanics of the foot and ankle may improve the treatment of the many and varied pathologies that occur within the tendon itself and the associated abnormalities that occur with a tight Achilles tendon.

Acute ruptures of the achilles tendon

The Achilles tendon (AT) is the most frequently ruptured tendon in the human body, but the etiology of AT ruptures is still not completely understood. Percutaneous repair and conservative management are viable alternatives to open surgery, which carries higher complication rates and is the most costly of the 3 management options. Individual patients will have different needs due to their age, occupation, or level of sporting activity. If the studies reporting a rising incidence of AT rupture are accurate, the field of AT surgery will become an increasingly important one for orthopedic surgeons. A major problem in the evaluation of the outcome of management of AT ruptures has been the lack of a universally accepted scoring system for the evaluation of results of management of AT rupture. The AT Total Rupture Score is a self-administered instrument with high clinical utility, and it can be used for measuring the outcome, related to symptoms and physical activity, after treatment in patients with a total AT rupture. Future developments may include the use of adhesives in tendon surgery. An understanding of the role, which cytokines play in tendon healing may also lead to the advent of new treatments, possibly based on gene therapy. However, such novel interventions are unlikely to be in routine clinical use for some time.

Noninsertional Achilles tendinopathy

The treatment of noninsertional Achilles tendinopathy remains, to a large extent, empirical. Neither different operative techniques nor nonoperative regimes have been subjected to controlled trials. Rather, the condition is still treated on the basis of anecdotal evidence combined with personal experience. However, increased knowledge of the basic science of tendinopathy and tendon healing has directed therapeutic regimens and will continue to do so. Manipulation of proteolytic enzymes and control of neovascularization are probably the two areas that show most promise.

The anatomy of the Achilles tendon

The Achilles tendon is the strongest and largest tendon in the body. It is the conjoined tendon of the gastrocnemius and the soleus muscles, and may have a small contribution from the plantaris. The muscles and the Achilles tendon are in the posterior, superficial compartment of the calf. Through the Achilles tendon, they are the main plantar flexors of the ankle. The Achilles tendon is subjected to the highest loads in the body, with tensile loads up to ten times body weight during running, jumping, hopping, and skipping. This article discusses the anatomy of the Achilles tendon.

Tendon injury and tendinopathy: healing and repair

Tendon disorders are frequent and are responsible for substantial morbidity both in sports and in the workplace. Tendinopathy, as opposed to tendinitis or tendinosis, is the best generic descriptive term for the clinical conditions in and around tendons arising from overuse. Tendinopathy is a difficult problem requiring lengthy management, and patients often respond poorly to treatment. Preexisting degeneration has been implicated as a risk factor for acute tendon rupture. Several physical modalities have been developed to treat tendinopathy. There is limited and mixed high-level evidence to support the, albeit common, clinical use of these modalities. Further research and scientific evaluation are required before biological solutions become realistic options.

Achilles tendon rupture: surgical versus non-surgical treatment

OBJECTIVE

To ascertain the treatment method of choice for Achilles tendon rupture, which results in the most favourable functional outcome.

METHODS

A comprehensive literature search was performed to retrieve relevant English language articles comparing surgical with non-surgical treatment.

RESULTS

The literature search identified five prospective randomised controlled trials, three of which compare surgical with non-surgical treatment, one which compares functional early mobilisation with cast immobilisation after surgical repair and one which compares functional and cast immobilisation in non-surgical management of Achilles tendon rupture.

CONCLUSION

Surgical treatment of Achilles tendon rupture is associated with a significantly lower incidence of re-rupture and therefore is the treatment method of choice. Non-surgical treatment may be acceptable for patients who refuse surgery or who are unfit for surgery. Functional early mobilisation appears to be associated with an improved functional outcome and should be considered in preference to plaster cast immobilisation where appropriate.

Subcutaneous rupture of the Achilles tendon: basic science and some aspects of clinical practice

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Effects of training, immobilization and remobilization on tendons

Since a tendon is a living tissue, it is not a surprise that tendon shows the capacity to adapt its structure and mechanical properties to the functional demands of the entire muscle-tendon unit. However, compared with muscle, the experimental knowledge of the effects of strength or endurance-type training on tendon tissue is scarce and clinical human experiments are completely lacking (1). Research should, however, be able to improve the true understanding of the biomechanical, functional, morphological and biochemical changes that occur in tendons due to training and physical activity, since understanding of the basic physiology of a tissue is the key to understanding its pathological processes (1, 2). Compared with muscle tissue, the metabolic turnover of tendon tissue is many times slower due to poorer vascularity and circulation (1, 3). The adaptive responses of tendons to training are therefore also slower than those in muscles, but they may finally be considerable if the time frame is long enough (3, 4).

Overuse injuries of the lower extremity in runners

The purpose of this article is to review the literature on overuse injuries of the lower extremity in runners and to discuss briefly today's knowledge concerning etiology, diagnosis and treatment. Running is a natural entity in many sports and a majority of runners will sustain one or more overuse injuries throughout the career, in most cases affecting the lower extremity. A runner may be regarded as an athlete who regularly runs as the predominant physical activity. From that point, we should subdivide the definition "runner" considering the character of different sports or recreational activities performed. Overuse injuries are often described merely from symptoms, including several different etiological and pathoanatomic correlates covering a variety of ailments. The clinical approach should be focused on a thorough history and physical examination. Analysis of possible injury mechanisms, correction of associated extrinsic and intrinsic factors and advice on alternative training should be given. A knowledge of specific demands from the type of running performed is necessary to evaluate the symptoms presented. Overuse etiology has to be considered multifactorial with a yet unsolved exact pathophysiology needing further research. The definition of a "runner", of "running" and of "overuse injury" should be established and agreed upon. This review attempts to draw attention to the huge multidisciplinary work that has to be done to better understand the mechanisms causing an overuse injury in a runner and to define diagnoses on a scientific base, whether or not excentric or intrinsic factors predispose or trigger.

Prevention and treatment of overuse tendon injuries

Overuse injuries are common in recreational and competitive sports as well as in day-to-day activities. The musculotendinous unit comprises the tissue most frequently involved: structural damage to the tendon occurs from repetitive strain and loading, from either endurance or skill activities that require technique and power. The potential for injury is enhanced by a great variety of predisposing intrinsic or extrinsic factors. Tendinous tissue will become fatigued as its basal reparative ability is overwhelmed by repetitive dysfunctional and microtraumatic processes. Tendinitis is the earliest recognisable manifestation of overuse injury: as damage progresses, partial tears and complete ruptures may ensue. The diagnosis of overuse injury rests with identification not only of the affected tendinous unit, but also of the underlying predisposing condition or conditions. Treatment can then proceed with elimination or correction, if possible, of these conditions, together with control of inflammation and programmes of modalities designed to restore the structural and functional integrity of the tendon. Knowledge of overuse problems has grown exponentially in the past 3 decades, as evidenced by the outpouring of scientific and medical literature. Sophisticated analytical techniques, supplementing a sound history and physical examination, have greatly facilitated the diagnosis of overuse problems and allowed the application of scientific therapeutic principles. As the number of participants in recreational activities continues to grow, the application of these techniques in ever more innovative ways holds the greatest promise for the prevention of overuse tendon injuries.

Overuse injuries in sports. A review

Because knowledge of overuse syndromes is limited, the diagnosis and treatment of these conditions are a challenge to sports medicine physicians. Trial and error methods of treatment and too little attention to basic research have resulted in less than optimum solutions. We do know that these maladies most frequently result from overload or repetitive microtrauma stemming from extrinsic factors such as training errors, poor performance, poor techniques and inappropriate surfaces or intrinsic factors including malalignment and muscle imbalance. Overuse injuries involving the muscles include compartment syndromes and muscle soreness; while those involving the tendons result from a variety of degenerative and inflammatory processes. Overstress of bone results in stress fractures, apophysitis and periostitis. Bursitis and joint overstress problems are also discussed briefly. General guidelines for establishing the appropriate diagnosis are: the initial stages of therapy require rest, often a modification or scaled down exposure to the athlete's usual performance rather than complete abstinence; in acutely symptomatic cases pain medications and various measures to control inflammation may be necessary; an exercise programme should start early with range of motion exercises and isometric muscle contractions; when pain allows, dynamic muscle and flexibility exercises can resume together with a conditioning programme; if possible, eccentric exercises should be performed. The treatment may also include other conservative treatment modalities and surgery in special cases. Overuse injuries constitute a great diagnostic and therapeutic problem because the symptoms are often diffuse and uncharacteristic. An appropriate diagnosis followed by adequate treatment can improve or eliminate most of these conditions, but perhaps even more importantly a proper understanding of overuse syndromes should allow physicians to assist athletes, trainers, and coaches in preventing them.