Intercondylar fossa: Béclère, Camp-Coventry, and Holmblad

Where is the intercondylar fossa located?

On the posterior distal femur, between the femoral condyles.

How does the intercondylar fossa differ from the intercondylar eminence?

Fossa: depression in the femur. Eminence: raised area on the proximal tibia.

Which intercondylar-fossa method uses an AP axial projection?

Béclère.

Which intercondylar-fossa methods use PA axial projections?

Camp-Coventry and Holmblad.

What is the main image-evaluation requirement for an intercondylar-fossa projection?

An open intercondylar fossa, clear of the patellar apex.

Which femoral surfaces are demonstrated by intercondylar-fossa projections?

The posteroinferior articular surfaces of the femoral condyles.

Which findings indicate absence of rotation on an intercondylar-fossa image?

A centered intercondylar eminence and slight proximal tibiofibular overlap.

How should the tibial plateaus appear on Camp-Coventry and Holmblad images?

One or both in profile, with anterior and posterior surfaces superimposed.

What patient position is used for the Béclère method?

Supine.

What femur-to-tibia long-axis angle is used for Béclère in the material reviewed?

60° in your Merrill page; your review quiz accepts 40–60°.

How is the CR directed for the Béclère method?

Perpendicular to the long axis of the lower leg/tibia.

Where does the CR enter for the Béclère method?

½ inch (1.3 cm) inferior to the patellar apex.

How is the knee supported for the Béclère method?

Support the flexed knee with sandbags and stabilize the foot.

How is rotation avoided when positioning for Béclère?

Keep the femoral condyles equidistant from the IR.

A supine patient has a flexed knee, with the CR perpendicular to the tibia and entering ½ inch below the patellar apex. Which method is being performed?

Béclère; AP axial intercondylar fossa.

What patient position is used for Camp-Coventry?

Prone, with no body rotation.

How much knee flexion is used for Camp-Coventry in Merrill?

40° or 50°.

How is the foot supported for Camp-Coventry?

Rest it on a suitable support to maintain the selected knee flexion.

What CR angle and direction are used for Camp-Coventry with 40° knee flexion?

40° caudad.

What CR angle and direction are used for Camp-Coventry with 50° knee flexion?

50° caudad.

What CR relationship must be maintained for Camp-Coventry?

Perpendicular to the long axis of the lower leg/tibia.

Where does the CR enter and exit for Camp-Coventry?

Enters the popliteal fossa and exits at the patellar apex.

What is the popliteal fossa?

The hollow at the back of the knee.

A prone patient has the knee flexed 50° and the CR angled 50° caudad into the popliteal fossa. Which method is being performed?

Camp-Coventry; PA axial intercondylar fossa.

What patient position is used for the original Holmblad method?

Kneeling on the table, with the affected knee over the IR and the upper body supported.

What three patient positions does Merrill describe for Holmblad?

Kneeling on the table; standing with the affected knee on a stool; standing with the flexed knee against a vertical IR.

How much knee flexion does Merrill specify for Holmblad?

70° from full extension.

In Holmblad positioning, how does the femur’s long axis relate to the CR?

Approximately 20° from the CR.

What CR direction is used for the original kneeling Holmblad setup?

Perpendicular to the lower leg and IR; no tube angulation relative to the IR.

What CR relationship is maintained in all Holmblad variations?

Perpendicular to the long axis of the lower leg/tibia.

Where does the CR enter for Holmblad?

The popliteal fossa, at the level of the patellar apex.

Which Holmblad modification uses a horizontal CR?

Standing with the flexed affected knee against a vertical IR.

A patient kneels over the IR, flexes the knee 70° from extension, and receives a perpendicular CR through the popliteal fossa. Which method is being performed?

Holmblad; PA axial intercondylar fossa.

How do Camp-Coventry and the original Holmblad method differ?

Camp-Coventry: prone, 40° or 50° flexion with matching caudad CR. Holmblad: kneeling, 70° flexion with a perpendicular CR.

How does CR entrance differ between Béclère and the PA axial fossa methods?

Béclère: anteriorly, ½ inch below the patellar apex. PA methods: posteriorly through the popliteal fossa.

Which condition affecting the femoral condylar surfaces may be evaluated with an intercondylar-fossa projection?

Osteochondritis dissecans.