Rehabilitation
Irrespective of surgical or non-surgical resolution to the fracture, a physical therapist can advise on progressive weight-bearing exercises and help with strengthening muscles of the leg, improving range of motion of the knee and in reducing stiffness. Prognosis
Outcomes with treatment are generally good, unless there is involvement of the articular surface or the quadriceps mechanism. There is an increased risk of developing osteoarthritis in people who have broken their patella.There is limited evidence supporting the different surgical interventions for treating fractures of the patella in adults. There is also no evidence of trials that could evaluate the effects of surgical treatment compared with the conservative treatment or other different types of conservative interventions. Epidemiology
Patella fractures make up about 1% of all broken bones. Males are affected more often than females. Those of middle age are most often affected. 6% to 9% of patellar fractures are of the open type. An ageing population and global increase in the number of TKAs has led to an increasing number of periprosthetic fractures of which a patella fracture is one type. History
Prior to the 19th century most patella fractures were treated non-surgically with extension splinting, frequently resulting in poorly joined fragments of bone and long-term pain and disability. Incomplete understanding of the importance of the patella led to the trend of removing the whole patella, also resulting in pain, disability and dissatisfaction. The first open reduction and internal fixation for a patella fracture was performed in 1877 by Scottish surgeon Sir Hector Cameron.
A painful defect may be felt in the knee and there may be blood in the joint. Complications
Complications may include injury to the tibia, femur, or knee ligaments. In the longer term, the knee may not regain full movement, pain may persist and there is an increased likelihood of osteoarthritis of the knee. If there is an associated open wound as in an open fracture, complications also include risk of infection, inability of the broken bones to reunite and osteonecrosis. Diagnosis
Diagnosis is based on symptoms and confirmed with X-rays. In children an MRI may be required. Differential diagnosis
Some people have a normal bipartite patella or two-part patella which can appear as a fracture. The fragment is usually seen in the top outer corner of the patella and can be distinguished from a fracture by being present in both knees. Types
The patella can break in various ways depending on the way it is injured, and into two or more pieces. Types include transverse, with one fracture line and is the most common type, marginal, osteochondral and the rare vertical type, or stellate, where a direct compression force gives rise to a comminuted pattern. Patella fractures can be further classified as displaced, where the broken ends of bone do not line up correctly and separate by more than 2mm, or undisplaced and stable where pieces of bone remain in contact with each other.