Patella fracture

Disease Description (Causes and Symptoms)

• Definition: A condition in which the patella (the dish-shaped bone at the front of the knee) is cracked or broken, which may affect the articular surface of the knee joint and the extensor mechanism.
• Causes: Trauma is common, including traffic accidents, falls (from a height), and direct impact or strong contraction forces during jumping or running (e.g., forceful limb contraction during a fall).
• Pathophysiology: Depending on the fracture pattern (transverse fracture, comminuted fracture, and whether the articular surface is involved), articular surface incongruity and damage to the patellar extensor mechanism (the connection between the patellar tendon and quadriceps tendon) may occur. Involvement of the articular surface increases the risk of arthritis.
• Main symptoms: Severe localized tenderness, pain at the front of the knee, swelling (from immediately after the injury), inability or difficulty bearing weight or extending the knee, and a depression or sense of instability when the fracture site is palpated.

Treatment Methods

• Diagnosis and Initial Care
  • Diagnosis: Medical history and physical examination (evaluation of the extensor mechanism), and radiographic examinations (anteroposterior [AP] and lateral views of the knee, sunrise/tangential view). CT may be needed to assess comminuted fractures and the articular surface, and MRI to assess soft tissues and articular cartilage.
  • First aid: Keep the injured leg straight and immobilize it with a splint (from the thigh to the heel), apply ice and elevation, and provide pain relief; do not wrap the bandage too tightly. If a splint is unavailable, use a pillow or blanket. Monitor for nerve and vascular symptoms (tingling, pallor, loss of sensation, or a weakened pulse).
• Conservative Treatment
  • Indications: When the articular surface is relatively well aligned and there is no or only minor displacement (with the extensor mechanism preserved).
  • Methods: Immobilization of the knee in an extended position (with a cast or knee support/brace), pain control, and close follow-up radiographic examinations. Gradual joint motion and strengthening are started according to the course of treatment. Non-weight-bearing or restricted weight-bearing ambulation.
• Surgical Treatment
  • Indications: Articular surface incongruity (marked displacement), comminuted (multifragmentary) patellar fractures, damage to the extensor mechanism, open fractures, unstable fractures, and similar conditions.
  • Examples of surgical methods: Tension-band wiring and screw fixation may be used for transverse fractures; for comminuted fractures, reduction and internal fixation (plates and screws) according to the findings, or partial patellectomy, may be used.
  • After surgery: Early joint motion may be started depending on the fixation status, or protected immobilization may be maintained for a certain period followed by rehabilitation.
• Rehabilitation and Lifestyle Management
  • Goals: Maintain alignment of the articular surface, restore the range of knee flexion and extension, and recover thigh muscle strength, especially quadriceps strength.
  • General recommendations: Control pain and swelling, perform gradual range-of-motion (ROM) exercises, receive physical therapy (strength and balance training), and adjust weight-bearing. Return to sports is determined after bone union and recovery of strength and function (usually over several weeks to several months).
• Complications and Prognosis
  • Complications: Post-traumatic arthritis (when the articular surface is involved), knee stiffness (restricted motion), nonunion or delayed union, infection (with surgery), metalwork irritation (or the need for removal), and, rarely, chronic pain.
  • Prognosis: Varies according to the fracture pattern, involvement of the articular surface, and whether the extensor mechanism is damaged. Functional recovery is possible with appropriate reduction, fixation, and rehabilitation, but articular surface damage increases the possibility of long-term arthritis.

Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)

• Items to bring (for the appointment and examinations)
  • List of currently used medications and supplements (including anticoagulants)
  • History of allergies (medications, latex, etc.)
  • Records of previous surgeries and hospitalizations, previous images (X-ray/CT/MRI of the affected area), or test results (if possible, these are essential)
  • Record of when symptoms began and the details of the incident (how the injury occurred), pain severity and changes, knee function (whether extension is impossible), and walking status
  • Photos (if there is swelling, a wound, or deformity) or a record of the first-aid measures performed
• Self-check before the outpatient visit
  • Check for bleeding or wounds, skin discoloration (bluish or pale skin), decreased sensation, weakness, or inability to move
  • Determine whether an emergency-room visit is needed because of fever, chills (suspected infection), or severe pain
• Main points the doctor may ask about during the appointment (preparing these can help with diagnosis and treatment)
  • Exact mechanism of injury (direct impact, fall, etc.) and when the pain began
  • Any previous knee conditions (arthritis, patellar tendinitis, etc.)
  • Whether you can currently walk and which movements provoke pain
  • Whether you are using anticoagulants (warfarin, DOACs, etc.)

Examples of General Questions to Ask the Doctor

• "Does this fracture require surgery? If not, how long will conservative treatment last, and what restrictions will apply?"
• "What prognosis and recovery period should I expect? When can I begin weight-bearing and exercise, especially sports?"
• "What rehabilitation (physical therapy) program do you recommend, and what should I do to reduce the risk of complications such as arthritis and stiffness?"
• "What complications are expected with surgery, and what is the plan for pain management, antibiotics, and anticoagulation management after surgery?"

Examples of Condition-Specific Questions

• "Is there articular surface incongruity in my patellar fracture? Depending on the extent of articular surface involvement, how high is my long-term risk of arthritis?"
• "How do you determine whether the extensor mechanism (the function that straightens the knee) is damaged? If it is damaged, how likely is complete recovery with surgery?"

(Additional Reference — What to Do in an Emergency)

• Cases requiring an immediate visit to the emergency room: Severe bleeding, loss of sensation or inability to move, pale or cool skin or a weakened pulse (suspected vascular injury), progressively worsening pain or swelling, high fever, and similar symptoms.
• Summary of initial home care: Keep the leg straight and immobilize it with a splint (thigh → heel), apply ice and elevate the leg, do not make the bandage too tight, control pain, and visit a medical facility promptly.