Rupture of the patellar tendon is usually preceded by a reduction in the mechanical strength of the tendon tissue as a result of diabetes mellitus, microtrauma, and similar weakening. Tissue is also frequently removed from the patellar tendon for reconstruction of the anterior cruciate ligament. A patellar tendon rupture is noticeable by a noticeably upward displacement of the kneecap and the inability to extend the knee joint through.
What is a patellar tendon rupture?
More like a band of tissue, the patellar tendon (ligamentum patellae) connects the kneecap (patella) to the tibia. Due to its short lever arm, it must endure enormous forces of sometimes more than 1,000 kiloponds per square centimeter when extended from extreme knee flexion. Above the kneecap, the ligament continues as the quadriceps tendon and connects to the powerful quadriceps femoris muscle. When the knee is flexed, the patella is used as a bell crank, so to speak. In the case of a complete patellar tendon rupture, power can no longer be transmitted from the quadriceps to the tibia. When the thigh muscle is tensed, only the patella is then pulled upwards. The upward displacement of the patella is also one of the main indicators pointing to a patellar tendon rupture. Complete rupture of the ligament due to selective overuse is rare. Rupture is usually preceded by certain pre-existing conditions that have led to gradual weakening of the patellar tendon. It is not uncommon for some of the patellar tendon tissue to be used for reconstruction of the anterior cruciate ligament, resulting in temporary weakening.
Causes
In principle, a patellar tendon rupture can occur as a result of a punctual overload-especially in an extreme knee flexion position-or as a result of an externally inflicted injury. Preliminary damage to the patellar tendon tissue, which favors a rupture or makes it possible in the first place, often exists in the form of degenerative changes. Specifically, these include diabetes mellitus or arterial occlusive disease (shop window disease) or a metabolic disease that chronically undersupplies and weakens the tendon tissue. A patellar tendon rupture is also promoted by anatomical malpositions such as knock knees or different leg lengths. A patellar tendon rupture mainly occurs in people in the “second half of life”, when the elasticity of the ligaments has decreased somewhat overall due to the natural aging process. Lack of exercise can also promote the condition, as the ligaments are insufficiently challenged over a long period of time. However, too much sport with chronic overloading of the patellar tendon also has an unfavorable effect because microtears occur, which promote chronic tendinitis, an inflammation of the patellar tendon. Athletes who frequently have to make abrupt changes of direction or who also frequently overload the patellar tendon statically, as is the case with weightlifters, are particularly at risk.
Symptoms, complaints and signs
A patellar tendon rupture is accompanied by severe pain and a swollen knee, making a clear diagnosis difficult. The upward displacement of the patella can be considered an important leading symptom. However, a differential diagnosis should be made to determine whether there may be a patella fracture, which also leads to an upward displacement of parts of the patella. An equally important symptom is the inability to actively extend the lower leg against the slightest resistance. This stems from the fact that if the tendon of the quadriceps is completely torn, there is no connection to the tibia and thus no force can be transmitted toward extension of the lower leg. The strong swelling is caused by reactions of the immune system. This has all available forces ramped up to repair the rupture, which of course cannot work in the case of a complete tear. The two ends at the ruptured site gape far apart and cannot reconnect “on their own”. As a result of the swelling, the knee appears red and warmer than the surrounding tissue.
Diagnosis and course of the disease
If the leading symptoms of a patellar tendon rupture described above do not provide sufficient certainty about the nature of the injury, imaging techniques such as X-rays or, better yet, magnetic resonance imaging (MRI) may be consulted.This is often necessary if, for example, it is not certain whether the tendon is torn or completely ruptured. The further course of the disease depends very much on whether it is a tear, a partial rupture, or a complete tear of the tendon. In some cases, the exact diagnosis is difficult because the ligament usually does not show a smooth tear, but frays and a few fibers may still be connected. In the case of a partial rupture, the patellar tendon can partially regenerate under favorable conditions, which is impossible in the case of a total rupture. There is virtually no force to bring the two torn ends back together and fuse them together.
Complications
In most cases, patellar tendon rupture results in very severe pain. These occur mainly at the knees and can lead to significant restrictions in the life and daily routine of the affected person. In most cases, the knee can no longer be fully extended. The pain itself often spreads to other regions of the leg and can lead to considerable restrictions there. Furthermore, in the worst case, a complete tear in the tendon can occur. The knee itself is usually swollen and reddened. The affected person may also be dependent on walking aids in his daily life due to the patellar tendon rupture. The knee is also heated and the affected person often suffers from fever. As a rule, the patellar tendon rupture is treated with physiotherapy. Complications do not occur in this process. However, the patient may also require surgical intervention to restore full joint mobility. The life expectancy of the affected person is not affected by patellar tendon rupture.
When should you see a doctor?
If pain occurs around the knee after a fall or accident, there is cause for concern. If there are irregularities in the knee joint due to heavy physical exertion, this is also unusual and needs to be investigated. If there is swelling of the knee, changes in the appearance of the skin, and a decrease in physical exertion, a doctor is needed. An examination is advisable as soon as gait unsteadiness, impaired locomotion as well as restrictions in general mobility occur. If the leg can no longer be loaded with its own weight as usual, a medical diagnosis is needed. Until a doctor is consulted, the affected knee should be relieved and pain medication should be avoided. If the affected person suffers from dizziness, palpitations, disturbances in consciousness or a loss of consciousness, there is a need for rapid action. In these cases, the complaints lead to secondary symptoms. These must receive immediate medical attention to prevent a life-threatening condition from setting in. In acute cases, an ambulance service should be alerted. Sudden changes in behavior, redness of the knee and an internal warmth are further signs of a health disorder. If the pain extends into the lower leg, an injury is present and should be presented to a physician as soon as possible. If there is a displaced patella or other visual changes in the skeletal system, a physician is needed.
Treatment and therapy
Treatment of patellar tendon rupture also depends on whether it is a complete tear or an avulsion. In the case of a tear, depending on the severity of the tear, specialized physical therapy is recommended, usually combined with aquatic exercise to allow movement without weight-bearing. In parallel with physiotherapy, decongestants and pain therapy are also used as needed. In the event of a complete tear, surgery must be performed. Various procedures are available to reconnect the two torn ends of the patellar tendon or to implant a replacement tendon from the patient’s own or donor material. To prevent degeneration of the quadriceps, the suture site can be relieved by certain surgical procedures so that functional physical therapy can be started early after surgery.
Outlook and prognosis
The prognosis of patellar tendon rupture depends on the cause as well as the patient’s cooperation within the healing process. In principle, the condition is curable.Complete and permanent recovery is also possible. If there is a complete tear of the tendon, surgical intervention is required. Otherwise, irreversible damage may develop and lifelong discomfort and pain may result. If the operation proceeds without further complications, the patient is then given physiotherapeutic support. In this, the patient learns how to perform optimal movements and can gradually achieve an improvement in his or her health. Under optimal conditions, healing is achieved in this way. If the tendon is torn, there is usually no need for surgery. Nevertheless, physiotherapy is scheduled to improve movement patterns and support the healing process. Better results are achieved if the affected person also performs exercises learned independently outside of the therapy sessions. In addition, lifestyle is crucial for long-term development. With an unhealthy lifestyle, overweight as well as incorrect exercise, the risks for permanent disorders are increased. Likewise, the risk for the development of secondary diseases increases. Even if healing is achieved, patellar tendon rupture can recur throughout life. The prognosis is unchanged if symptoms recur.
Prevention
Active measures to prevent patellar tendon rupture consist of maintaining fitness through light exercise training and through light to moderate endurance sports. All stressed tendons and ligaments are thus stimulated to maintain strength and elasticity. Passive measures consist of avoiding selective overloading of the knee joint, especially from severe flexion. Similarly, sports such as handball, field hockey and volleyball should be practiced at an advanced age only with the necessary forethought and caution.
Aftercare
In most cases of patellar tendon rupture, there are limited or few aftercare measures available to the affected person. The affected individual should therefore seek medical attention for this condition ideally at the first signs and symptoms to avoid further complications or discomfort that would reduce the affected individual’s quality of life. Self-healing cannot occur with patellar tendon rupture, so a visit to a doctor is always necessary. Most patients rely on the measures of physiotherapy or physical therapy for this condition. In this case, the affected person can also repeat many of the exercises themselves in their own home in order to continue to alleviate the discomfort and to advance the mobility of the body. However, in some cases, surgical intervention is necessary to alleviate the discomfort of patellar tendon rupture. After such a procedure, the affected person should rest and take it easy on the body. Efforts or stressful and physical activities should be refrained from in order not to put unnecessary strain on the body. As a rule, this disease does not reduce the life expectancy of the affected person.
This is what you can do yourself
To reduce the symptoms, the affected person can pay more attention to his own health. Weight gain or excess weight should be avoided as a matter of principle, so that the joints, bones and tendons are not unnecessarily stressed. The body weight should be within the recommended BMI. In addition, light physiotherapeutic exercises are recommended after medical or professional consultation. One-sided physical stress should be refrained from so that no further muscle or bone complaints develop. The affected region should be relieved and sufficiently rested so that the healing process is not interrupted. Exerting force or carrying heavy objects should be avoided, as they contribute to a worsening of well-being. Until the knee has regenerated, sporting activities should be limited or stopped completely. Strong strains of the knee joint as well as the extensor muscles in the thigh can intensify the complaints and have a negative effect on healing. Likewise, the footwear used should be optimized and adapted to the current physical needs. Wearing shoes with high heels should be refrained from in order to avoid further symptoms. The organism needs sufficient vitamins, trace elements and enough fluids for a quick recovery.To strengthen the immune system, a healthy diet is recommended and consumption of nicotine or alcohol is discouraged.
