Knee – Pseudothrombophlebitis

CASE HISTORY

Chronic knee pain for years getting worse. Prior right knee surgery. Evaluate for internal derangement.

TECHNICAL FACTORS

Long- and short-axis fat- and water-weighted images were performed. 

KEY IMAGES

This case has no key images.

CASE FINDINGS

• Lateral retinaculum and MPFL are normal. Mild lateral tilt of the patella without subluxation. No high-grade chondromalacia of the patellar cartilage. Focal 1 x 1cm partial-thickness chondral erosion in the midbody medial trochlea. 
• Quadriceps tendon patellar tendon and flexor mechanism are unremarkable. 
• Chronic tear of the ACL without anterior tibial translation; suspect scarring of the ACL remnant to the PCL. Inflammation of the intercondylar notch. No traumatic tear of the PCL MCL or lateral collateral complex. Blunting of the medial meniscus posterior horn suggestive of prior partial meniscectomy without traumatic tear of the remnant. No traumatic lateral meniscus tear. 
• No effusion or intraarticular bodies. 
• Femorotibial shift present. Full-thickness chondral loss of the medial femoral condyle and tibial plateau weightbearing surface with focal osteochondral erosion of the central weightbearing aspect. Partial-thickness chondral fissuring of the central weightbearing surface of the lateral femoral condyle. 
• Musculature and marrow signal are normal. Pseudothrombophlebitis of the posterior capsule extending through the capsule into the popliteal space without venous thrombosis. The neurovascular bundle is intact.

CASE CONCLUSION

• Medial compartment failure with femorotibial shift full-thickness chondral loss of the femoral condyle and tibial plateau and multifocal osteochondral erosions of the medial femoral condyle and medial tibial plateau. Medial meniscus is status post partial meniscectomy with no traumatic tear of the remnant. 
• Chronic tear of the ACL without anterior tibial translation. 
• Grade 2 to 3 chondromalacia of the medial trochlea with focal 1 x 1cm partial-thickness chondral erosion of the midbody. 
• Grade 2 to 3 chondromalacia of the lateral femoral condyle with partial-thickness chondral fissuring in the central weightbearing aspect. 
• Pseudothrombophlebitis of the posterior capsule extending through the capsule into the popliteal space without venous thrombosis.