Patellar tendon rupture

Patellar tendon rupture
Other names	Patellar tendon tear
Patellar tendon rupture showing a marked distance between the tibial tuberosity and the bottom of the knee cap.
Specialty	Orthopedics
Symptoms	Pain, trouble walking, inability to straighten the knee[1]
Usual onset	Sudden[2]
Types	Partial, complete[1]
Causes	Falling directly on the knee, jumping from a height[1]
Risk factors	Patellar tendinitis, kidney failure, diabetes, steroid use[1]
Diagnostic method	Based on symptoms, examination, medical imaging[1]
Differential diagnosis	Patellar fracture, patella dislocation, quadriceps tendon rupture, muscle strain[2][3]
Treatment	Rest, physiotherapy, surgery[1]
Prognosis	Good[1]
Frequency	Up to 1 in 10,000 per year[2]

Patellar tendon rupture is a tear of the tendon that connects the knee cap (patella) to the tibia.^[1] Often there is sudden onset of pain and walking is difficult.^[1] In a complete rupture, the ability to extend that knee is decreased.^[1] A pop may be felt when it occurs.^[2]

Injury to the patellar tendon generally requires a significant force such as falling directly on the knee or jumping from a height.^[1] Risk factors include patellar tendinitis, kidney failure, diabetes, and steroid or fluoroquinolone use.^[1][2] There are two main types of ruptures: partial and complete.^[1] In most cases, the patellar tendon tears at the point where it attaches to the knee cap.^[1] Diagnosis is based on symptoms, examination, and medical imaging.^[1]

Small tears may be treated with rest and splinting, followed by physiotherapy.^[1][2] Larger tears typically require surgery within a couple of weeks.^[1][2] Outcomes are generally good.^[1] Rates in the general population are not clear; however, in certain high-risk groups it occurs about 1 in 10,000 per year.^[2] They occur most often in those under the age of 40.^[2]