Knee Injury
Case Studies
A 15-year-old gymnast has noted knee pain that has become progressively worse during the
past several months of intensive training for a statewide meet. Her physical examination
indicated swelling in and around the left knee. She had some decreased range of motion and
a clicking sound on flexion of the knee. The knee was otherwise stable.
Studies Results
Routine laboratory values Within normal limits (WNL)
Long bone (femur, fibula, and tibia) X-ray No fracture
Arthrocentesis with synovial fluid analysis
Appearance Bloody (normal: clear and straw-colored)
Mucin clot Good (normal: good)
Fibrin clot Small (normal: none)
White blood cells (WBCs) <200 WBC/mm3 (normal: <200 WBC/mm3)
Neutrophils <25% (WNL)
Glucose 100 mg/dL (normal: within 10 mg/dL of serum
glucose level)
Magnetic resonance imaging (MRI) of the knee Blood in the joint space. Tear in the posterior
aspect of the medial meniscus. No cruciate
or other ligament tears
Arthroscopy Tear in posterior aspect of medial meniscus
Diagnostic Analysis
The radiographic studies of the long bones eliminated any possibility of fracture.
Arthrocentesis indicated a bloody effusion, which was probably a result of trauma. The fibrin
clot was further evidence of bleeding within the joint. Arthrography indicated a tear of the
medial meniscus of the knee, a common injury for gymnasts. Arthroscopy corroborated that
finding. Transarthroscopic medial meniscectomy was performed. Her postoperative course
was uneventful.
Critical Thinking Questions
1. One of the potential complications of arthroscopy is infection. What signs and symptoms of joint infection would you emphasize in your patient teaching?
2. Why is glucose evaluated in the synovial fluid analysis? 3. What are special tests used to differentiate type of Tendon tears in the knee ? Explain
how they are performed (Always on boards)
