Nonoperative management of acute ruptures

Abstract

The rapidly growing trend for participation in recreational and competitive sports is accompanied by an increase of overuse syndromes. In the foot and ankle, the incidence of Achilles tendon ruptures and tendon-related disorders has increased significantly in the last decades. In Germany alone, the incidence of acute Achilles tendon rupture is estimated to be 15,000 cases a year. The classic Achilles rupture usually does not occur at times of the highest level of sports activities, but rather shows a peak incidence between the ages of 30 and 45 years. This patient population is made up of a remarkably large portion of leisure athletes and patients with sedentary occupations. In the athletic population, the portion of injuries among track-and-field athletes is cited as only 10%, and these are mostly young patients who have sustained a tendon rupture as a result of an incompletely treated Achilles tendinopathy or after an enormous training workload. In the future, an increasing number of older patients (over 50 years) will sustain acute Achilles tendon ruptures, as strenuous sports activities become more and more normal in this age group, and since the Achilles tendon seems to be one of the tendons that is most susceptible to degenerative changes within the human body. The male-to-female ratio of Achilles tendon ruptures ranges between 5:1 and 10:1 in most series, and, on average, the men are older than the women. According to the literature and the authors' experience, an Achilles tendon rupture most frequently (80% to 90% of cases) occurs 2 to 6 cm proximal to its calcaneal insertion. The incidence of proximal ruptures at the musculotendinous junction is 10% to 15%, and the ruptures are usually caused by degenerative changes. Ruptures at or near the calcaneal insertion are rare and are mostly found in patients who are hyperpronators and who have a large Haglund's deformity or in individuals who have received a steroid injection for the treatment of tendinopathy. Most typical intratendinous ruptures occur because of a rapid loading of the tendon, but bony avulsions are caused by continuously increasing tension and strength on the heel or by direct impact. The classic rupture mechanism is usually a consequence of an indirect loading and traction mechanism such as during push-off with the foot in plantarflexion with simultaneous knee extension, or with a sudden, unexpected dorsiflexion of the ankle with powerful contraction of the calf muscles. 9 Direct impact, such as a kick or hit on the tensed tendon, accounts for only 1% to 10% of ruptures. The degenerative and the mechanical theories of the pathogenesis of Achilles tendon rupture are continually debated. Aseptic inflammations (tendinitis, paratendinosis) and reduced vascular supply lead to degenerative changes with cell loss and disorders of mucopolysaccharide content, even progressing to fatty, mucoid, or calcifying degeneration of the tendon. Repetitive or single stresses result in minor microtrauma. Low temperature and fatigue of athletes leads to a decreased maximal load resistance of the tendon, causing injury. If the regenerative healing processes cannot keep pace with injury, the sum of microtrauma leads to rupture. © Springer Science+Business Media, LLC 2009.