Every KNEE Must Bend MI Zucker, MD

A dr Z Lecture

On Injuries of the KNEE

The KNEE Series Lateral (cross-table) Anterior-posterior (AP) Obliques: internal/external Patella (“sunrise”) Notch

Lateral, AP, Obliques

Patella and Notch Patella or “sunrise” is tangential Notch is a bended knee AP

Anatomy Lateral

Anatomy AP

Anatomy Patella

Soft Tissue Swelling Loss of tissue planes

Joint Effusion Distension of SUPRAPATELLA BURSA Normal

Joint Effusion NOT predictive of fracture. Can be due to ligament, meniscus or bone injury.

Lipohemarthrosis IS predictive of fracture: 100% Need cross-table lateral to see it

Patella Fracture Direct blow Fragments not very distracted

CAVEAT Bipartite patella: developmental variant of the superior-lateral corner, often bilateral

The EXTENSOR APPARATUS Quadriceps muscles Common ext. tendon Patella and retinaculum Patella ligament Ant. tibia tubercle

Patella Fracture: Indirect Fragments are distracted ORIF

Extensor Apparatus Injuries Common extensor tendon injury Patella ligament injury

KID Extensor Injury Anterior tibia tubercle: Injury of the PHYSIS

Tibia Plateau Fractures Lateral 80% Medial 10% Lateral and medial 10%

Tibia Plateau Fractures Vertical, with or without depressed articular surface Impacted type can be very subtle

Tibia Spine Fracture Can occur at any age, but common in kids especially after fall onto flexed knee from bicycle: “Bicycle Fracture”

Segond’s Fracture At attachment of lat cap lig to lat margin of tibia Same mechanism as ACL injury 95% predictive of ACL tear

Collateral Ligament Injuries Usually, nonspecific: joint effusion, soft tissue swelling Torn lig occasionally calcifies later

Fibula Head Fracture Usually, direct blow Can be associated with PCL tear

Osteochondral Fracture Articular surface of femur, lat aspect of medial condyle Acute Stress: osteochondritis dissicans

Distal Femur Fractures Big mechanism Intercondylar, supracondylar. ORIF

Patella Dislocation Almost always LATERAL Can fracture edge of patella/femur Acute management is closed reduction

Knee Dislocation Big mechanism Big risk of arterial injury So, big emergency!

Tibia-Fibula Fractures Serious injuries Poor blood supply to tibia, so delayed healing frequent. ORIF

Exception: Stress Fracture of Tibia Repetitive injury causing microfractures Usually, FATIGUE type Non-operative management

Toddler’s Fracture Child just learning to walk Twisting injury NOT predictive of child abuse Non-operative management

Corner/Bucket Handle Fracture Twisting of joint Intentional injury Pathognomonic of child abuse

GOODBYE Copyright 2004 MI Zucker