Cruciate ligament injury

Disease Description (Causes and Symptoms)

• Definition: A condition in which the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), or other ligaments of the knee joint are partially or completely torn by trauma or excessive force, resulting in reduced anterior-posterior and rotational stability of the knee.
• Causes/Pathophysiology: When abnormal anterior-posterior, rotational, and lateral forces are applied to the knee due to sudden stopping or changes in direction, landing after a jump, collisions between athletes, traffic accidents, and other causes, the cruciate ligaments become stretched or torn. When the ACL is torn, the knee shifts forward, and repetitive instability may lead to meniscal injury and wear of the articular cartilage (degenerative arthritis).
• Main symptoms: Sudden knee pain, a “pop” or sensation of rupture, immediate swelling (intra-articular bleeding/hemarthrosis and swelling), a slipping or giving-way sensation in the knee when standing or walking (instability), joint noises, and, in severe cases, inability to walk.

Treatment Methods

• Initial (acute-phase) first aid: Control pain and swelling with RICE (rest, ice, compression, and elevation), restrict weight-bearing by using a brace and crutches, and manage pain with nonsteroidal anti-inflammatory drugs (NSAIDs).
• Conservative treatment (when surgery is not indicated or in cases of partial tears or mild instability): Physical therapy (strengthening, especially balancing the quadriceps and hamstrings), use of a functional brace, and gradual weight-bearing and rehabilitation programs (maintaining joint mobility and training strength, posture, and proprioception).
• Surgical treatment (when instability is severe, the ligament is completely torn, or the patient has a high activity level): Cruciate ligament reconstruction is the standard treatment. Common graft materials include autografts (bone–patellar tendon–bone (BTB) and hamstring tendons [semitendinosus and gracilis]) and allografts (such as the Achilles tendon). Surgical technique: arthroscopic grafting (graft placement and fixation through bone tunnels). For PCL tears, conservative treatment or reconstruction is selected depending on the extent of injury, associated injuries, and clinical instability.
• Medications/other: NSAIDs and, if necessary, analgesics for pain control; postoperative antibiotics to prevent infection and thrombosis prevention when risk factors are present may be considered.
• Rehabilitation and precautions: Staged rehabilitation after surgery (early joint exercises and load control → recovery of strength and function → training for return to sports). In general, a full return to sports takes 6–12 months after surgery, with variations depending on the individual and the surgical method. Avoid excessive rotation or pivoting movements and excessive loading in the early stages.
• Complications/Prognosis: Although reconstruction can restore stability in most cases, possible complications include re-tear, graft problems, joint stiffness, infection, thrombosis, and, over the long term, meniscal cartilage injury and degenerative arthritis. Consistent rehabilitation is important for the prognosis.

Checklist Before an Outpatient Visit (Items to Prepare and Things to Check Before the Visit)

• Items/documents to bring: A list of current medications (including anticoagulants), allergy history, history of previous surgery or trauma, results or images from previous examinations (knee X-rays, MRI, joint ultrasound, etc.; CD/USB if possible), and notes on exercise and occupational history (types of sports and required level).
• Symptom record: When and how the symptoms began (when and in what situation they occurred), pain intensity, presence of swelling and bleeding (bruising), ability to bear weight, frequency of the knee “giving way,” presence or absence of locking symptoms (joint catching), and factors that improve or worsen the symptoms.
• Lifestyle/Goals: Desired timing and level for returning to daily activities, work, and sports, and whether you are currently exercising or undergoing rehabilitation.
• Examinations that may be performed at the outpatient visit: Physical examination (anterior and posterior drawer tests, Lachman test, pivot shift test, etc.), and, if necessary, X-ray or MRI, or interpretation of images already submitted.
• Precautions before the visit: Wear comfortable clothing that allows the knee to be exposed during the visit, and inform the medical staff in advance if you are already taking anticoagulants.
• Example questions (questions the patient may prepare in advance for the doctor):
  • "What is the extent of my knee injury now (partial or complete tear)?"
  • "Based on the MRI results and clinical findings together, will I need surgery?"

Examples of General Questions to Ask the Doctor

• What are the main side effects of this medication (the analgesic/anti-inflammatory medication that will be prescribed)? Are there any foods or medications I should avoid while taking it?
• If you recommend surgery, what are the surgical methods (autograft vs. allograft), and what are their advantages and disadvantages?
• If I receive only conservative treatment without surgery, what is the prognosis (knee stability and risk of reinjury)?
• How long will rehabilitation take, and when can I resume light exercise and sports?
• What are the risks of complications (infection, thrombosis, re-tear, etc.), and how can they be prevented?

Examples of Condition-Specific Questions

• ACL-related: "For my ACL tear, which would be more suitable: an autologous hamstring tendon graft or a patellar tendon (BTB) graft? How do the two methods differ in recovery speed, re-tear rate, and their effects on anterior knee pain?"
• PCL-related: "In the case of a PCL injury, please explain whether knee stability is likely to be maintained long term with conservative treatment alone, or in what situations early reconstruction is recommended, such as with associated injuries or severe instability."