What happens when you get hurt
At the moment of impact, soft tissue is compressed between the external object and the bone. Small vessels rupture, blood and interstitial fluid escape into the tissue - this is how swelling and bruising are formed. The bruise may not appear immediately, but after a day, and gradually changes color from purple to greenish and yellow as it resolves. If the blow falls on the front surface of the knee, the prepatellar bursa often suffers, then a soft swelling forms above the patella. Sometimes blood enters the joint cavity - this is hemarthrosis, requiring examination by a doctor.
- Soft tissue injury without fracture
- Rupture of small vessels, bruising
- Swelling around the joint
- Inflammation of the prepatellar bursa
- Hemarthrosis with bleeding into the joint
- Gradual change in bruise color
First aid
In the first hours, the main thing is to reduce swelling and hemorrhage. The leg needs to be unloaded, cold applied through the cloth for 15–20 minutes, repeating several times during the day, a loose elastic bandage applied and the leg elevated. Hot compresses, rubbing and warming ointments are contraindicated in the first two days because they dilate blood vessels and increase swelling. Alcohol worsens the condition for the same reason. After two or three days, when acute inflammation subsides, heat and light massage of the surrounding muscles are already acceptable.
- Unloading the legs and rest
- Cold through fabric 15–20 minutes
- Elastic bandage without compression
- Elevated leg position
- Avoid heat and rubbing for the first 48 hours
- Pain medication if necessary
When it's not just a bruise
There are signs that must necessarily rule out a more serious injury. A rapid increase in swelling during the first hour usually means blood in the joint, and this happens with a ligament rupture, fracture or meniscal injury. Inability to put weight on the leg and walk several steps, point tenderness over the patella or head of the fibula, limited extension and a feeling of blocking also require examination. In children, an injury in the area of the growth plate may look like a bruise, but result in a fracture, so they are examined especially carefully.
- Swelling in the first hour - suspicion of hemarthrosis
- Inability to stand and walk
- Joint block
- Point pain over the bone
- Trauma in a child with pain in the growth plate
- Symptoms persist for more than a week
Survey
The traumatologist examines the knee, checking the range of motion, the stability of the ligaments, the presence of effusion and the point of maximum pain. An X-ray of the knee joint is prescribed if a fracture is suspected: in case of inability to support, severe pain over the bone, limited flexion, and in elderly patients. Ultrasound shows well the fluid in the joint, the condition of the bursae and superficial ligaments. If pain persists longer than two to three weeks, there is blockage or a feeling of instability, an MRI is ordered to evaluate the menisci, ligaments and cartilage.
- Examination by a traumatologist
- X-ray of the knee joint according to indications
- Ultrasound of the joint and periarticular bursae
- MRI for persistent pain and blockages
- Puncture for intense hemarthrosis
- Repeated examination after 7–10 days if complaints persist
Treatment and recovery
An uncomplicated bruise is treated with rest in the first days, cold, fixation and painkillers as needed. There is no need to completely immobilize the knee: as soon as the pain allows, light movements and tension of the thigh muscles begin so as not to lose strength. After a few days, exercises are added to restore range of motion and strengthen the quadriceps muscle. For inflammation of the prepatellar bursa, the doctor selects treatment and recommends avoiding prolonged kneeling. They return to sports when movements are painless and strength is restored.
- Rest in the first days, then early activation
- Isometric exercises for thigh muscles
- Gradual restoration of range of motion
- Anti-inflammatory drugs as prescribed by a doctor
- Knee pads for kneeling work
- Return to sport without pain and with restored strength