Locked knee due to fat pad adhesion.

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Knee Biomechanics

Background:

• A locked knee, characterized by restricted movement post-injury, is typically caused by meniscal tears, anterior cruciate ligament (ACL) injuries, or chondral lesions.
• While common causes are well-documented, intra-articular blockades can arise from less frequent pathologies.

Observation:

• A 23-year-old male experienced a locked right knee following a fall one month prior.
• Magnetic Resonance Imaging revealed an ACL discontinuity, intact posterior cruciate ligament, and a posterior horn meniscal tear.
• Arthroscopic examination identified significant fat pad adhesion as the cause of knee rotation immobilization.

Findings:

• Arthroscopic debridement of the inflamed fat pad adhesion successfully resolved the knee lock.
• Post-operative assessment confirmed the restoration of free knee movement.

Implications:

• Fat pad adhesion represents a rare but treatable cause of locked knee syndrome.
• Early diagnosis through clinical, radiographic, and definitive arthroscopic evaluation is crucial for effective management.
• This case expands the differential diagnosis for locked knee, emphasizing the importance of thorough arthroscopic assessment.