Femur, tibia and patella (kneecap) are the three bones that make up the knee joint. Because of its location, the patella is the bone, which, in case of direct trauma, is more exposed to fracture risk: A contusive trauma, such as the one that can result from a “dry” fall on the front of the knee, perhaps bent, for example by slipping as you climb the stairs, can certainly cause a fracture of the knee”, recalls Dr. Andrea Bruno, orthopedist and traumatologist at Humanitas.
A particular case is the so-called “dashboard trauma”,”in a road accident – continues the specialist – the driver goes to beat the knee bent against the inner structure of the car suffering the fracture of the patella”.
The fracture is often transversal, with a line that runs horizontally on the anterior part of the bone, or it may be comminuted, that is, multi-fragmentary, “star-shaped”, with a central point of impact and the parts of fracture that radiate on the surface. Longitudinal ones are more rare. In any case, it is a serious injury that limits or completely prevents movement.
A simple X-ray can diagnose the fracture and its characteristics: whether it is composed, with bone fragments that keep contact or that are only spaced by one or two millimeters, or broken down if the contact between bone fragments is not maintained. A fracture of the patella often leads to skin injury, swelling and significant spillage of blood inside.
The results of the instrumental examination will be followed by indications for treatment: “Usually, in the case of fracture of the patella, surgery is performed, particularly when the fracture is complete, i.e. it affects the entire thickness of the bone. Let us not forget, – the specialist points out – that the kneecap is joined by patellar and quadricipital tendons that make up the extensor apparatus of the knee. This leads the proximal bone fragment to the top, while the distal bone fragment remains fixed to the tibia thanks to the patellar ligament. Hence the subject’s inability to maintain the upright position derives from this condition”.
Surgery is required for displaced fractures, which are the most frequent outcome of trauma, while in compound fractures it is possible to define a conservative intervention with plaster; this will help to maintain the contact between bone fragments during healing.
Trauma may also lead to another type of injury: “In particular, car accident traumas – adds the expert – may also result in injury to ligaments, especially the cross ligaments. However, these lesions will be treated later on as the cure of the patellar fracture takes priority.
After the surgery or treatment, it is necessary to define a rehabilitation path with the objective of recovering joint mobility, muscular reinforcement that may have been compromised by forced immobility and the reduction of joint rigidity: “It takes at least two to three months to return to daily activities, for example to start doing physical activity again”. After surgery or conservative treatment, the doctor will ensure that the patient can gradually place the body weight on the affected leg of the fracture.
Finally, the fracture of the patella may lead to some complications: “A form of post-traumatic arthrosis may develop due to the involvement of patello-femoral cartilage, especially if the fracture is multi-fragmental. In addition, the patient will be able to experience a form of chronic pain and inflammation, stiffness and feel “scratches in the joints”, concludes Dr. Bruno.