see: [Emergency radiology - tibial plateau fracture](x-devonthink-item://2A71AF1A-4715-4D5F-9841-03401D8E6C4E?page=312), [Hayes' tibial plateau fracture](x-devonthink-item://2F009CDB-2100-4C5A-A542-3413DBB3BA48), [Core Radiology - Knee trauma](x-devonthink-item://C1EF00FD-576C-4C41-AE08-CA966611F572?page=1024), [Dunn - Knee and leg fractures](x-devonthink-item://0EB25783-F802-4295-A212-76B92AFCA28C) - lateral tibial pleateau is weaker than medial TP; therefore lateral is involved in 85-90% of cases - a valgus (medially-directed) force to lateral side of knee drives lateral femoral condyle into lateral tibial plateau - can be difficult to see on XR because fracture is in oblique plane and therefore not parallel to the x-ray beam > Lateral tibial plateau fracture associated with: > - ACL > - medial collateral ligament injury > [[Neurovascular assessment|common peroneal nerve]] most often affected ![[Pasted image 20240322223833.png]] ![[Pasted image 20241016200041.png]] # Schatzker classification ![[Pasted image 20241021182040.png]] I. split fracture of lateral tibial plateau II. split depression of lateral tibial plateau III. central depression of lateral plateau IV. split of the medial tibial plateau V. bicondylar tibial plateau fracture VI. dissociation btwn metaphysis and diaphysis # normal knee XR ![[Pasted image 20240322224852.png| the trabeculae are normally more dense on the medial side (arrow) than lateral side]] ![[Pasted image 20240322225149.png]] ==↓ not normal below!!== *abnormal* lateral for comparison ![[Pasted image 20240322225242.png]] # Findings - increased trabecular density (aka *sclerosis*) of the lateral tibial plateau relative to the medial plateau is a sign of compression fracture of the lateral tibial plateau (normally medial has more density than lateral ) - interrupted or deformed tibial plateau surface - lateral displacement of tibial plateau relative ot femoral condyle - widening of joint space of injured side - lipohaemarthrosis # examples ![[Pasted image 20240322223728.png| subtle non-displaced medial tibial plateau fracture]] ![[Pasted image 20240322224931.png|compression fracture of the lateral tibial plateau causes increased trabecular density ("sclerosis")]] ![[Pasted image 20240322225016.png| irregularity of the cortical surface and increased trabecular density with lateral displacement relative to femoral condyle (look at the lines)]] ![[Pasted image 20240322225511.png| initial XR interpreted as normal, although there is a moderately displaced lateral tibial plateau fracture]] ![[Pasted image 20240322225603.png| same patient as case above, recalled and now fracture is markedly displaced and needed surgery!]] ![[Pasted image 20240322225714.png]] ## lipohaemarthrosis - the presence of a linear interface between two different densities within an effusion suggests *lipohemarthrosis*, in which the effusion contains not only blood, but also fat - results from entry of marrow fat into the joint cavity and is suggestive of fracture. - indicative of an intra-articular fracture with blood and fat entering the joint from the bone marrow. ![[Pasted image 20240322223400.png|a large lipohaemarthrosis in the suprapatellar bursa]] ![[Pasted image 20240322223519.png| a knee effusion wiht a fat-fluid level in the supra-patellar bursa]] ![[Pasted image 20240322224230.png| this is a lateral lipohaearthrosis from non-displaced patella fracture]] ## ED Case lipohaemarthrosis 21 yo twisted right knee felt pop while dirt biking. ![[image.jpg]] Lipohaemarthrosis from medial tibial plateau fracture ![[image 2.jpg]] AP XR is NAD ![[image 1.jpg]] CT for above case; would not have seen on XR. Impacted mildly displaced fracture posterior lip of medial tibial plateau ## medial tibial plateau fracture ![[Pasted image 20241016200140.png|injury to the medial plateau (arrow) from a blow to the medial side of the joint.]]