MCQs-sports knee 1
– the posterolateral corner refers mostly to the arcuate complex – consists of LCL, lateral head of gastrocs, popliteus tendon, and arcuate ligament.
– the posterolateral corner does not include the oblique popliteal ligament – this is on the other side of the knee!
– in the neuropathic knee (post-syphilis), you would expect to find peril-articular new bone formation.
– for high tibial osteotomy, pre-op arthroscopy does not accurately predict the outcome from HTO; over 15 degrees of varus is getting to be too much for an HTO to correct (you have to take away so much bone from the lateral side); the patient should ideally have no restrictions in ROM, but invariably have 10-90.
– for the discoid meniscus, there is the complete, incomplete, and Wrisberg – the Wrisberg is like a normal looking meniscus, but it lacks the coronary ligament attachments to the tibia and just has the ligament of Wrisberg at the back. These are the unstable ones and are often more symptomatic than the complete or incomplete
– the position of the femoral tunnel for ACL reconstruction of the right knee is 11:00, (1:00 in the left knee) 5 to 7 mm anterior to the over the top position. If you drill an 8 mm tunnel, this would leave 1-3 mm of bone posteriorly. Most people use a 10 mm tunnel, in which case start the drill 7 mm anterior. Use a 9 mm interference screw.
– with respect to ACL reconstruction with bony tunnels:
– On the FEMUR: too anterior placement (resident ridge) – too tight in flexion
too far posterior (over the top) – too tight in extension
– On the TIBIA: too anterior placement – too tight in flexion, AND it impinges in extension
too far posterior – too loose in flexion
– these also have to do with where you tension the ligament (in flexion or extension)
– at 45 degrees of flexion, the medial and lateral facets of the patella are in contact with the intratrochlear notch. The odd facet is on the medial side and engages the condyle only in maximal flexion.
– in a football player who sustains a valgus external rotation injury to his knee with lateral joint line tenderness – think about ACL injury with Segond fracture (avulsion injury of the lateral capsule)
– Lachmann testing probably creates the highest strain forces within the ACL
– for the young patient with valgus knee – do distal femoral varus osteotomy
– in football players, the most likely mechanism for PCL injury is probably direct trauma to the front of the knee. Not entirely sure about that. Definitely in MVA, it is direct trauma. Look out for femoral peel-off more commonly with hyperextension injury. Look out for midsubstance tears more commonly in direct trauma.
– quadriceps active test is a diagnostic test for PCL
– standard MCL grade 3 injury rehab consists of hinge brace and early range of motion. If too painful, then immobilize in extension (Zimmer splint or cast)
– ACL injury may occur from contact force, but more commonly is noncontact deceleration secondary to valgus and external rotation, or varus internal rotation, or hyperextension. A direct blow to the anterior proximal tibia will not cause an ACL injury – it’ll cause a PCL injury!
– in the ACUTE ACL – Lachman test is probably most accurate; it is often too difficult to do a pivot shift.
– the presence of a pivot shift phenomenon, regardless of grade, is indicative of ACL injury
– the natural history of PCL insufficiency is hard to know, but in some it leads to arthritis, beginning in patellofemoral joint; most are asymptomatic though. It has been shown to have a higher incidence of MEDIAL OA also.
– for tibial spine fractures, you can try a closed reduction by bringing the knee into extension – you cannot cast it in full extension though; you need to flex it slightly. If the fragment reduces (to within 2 mm), then cast
– for recurrent dislocation of the patella – IF YOU ARE TO OPERATE – do proximal realignment first (try to avoid doing any sort of distal realignment); this consists of