JAAOS Questions

Question 1

When should you do nonsurgical management for PLC

Answer 1

isolated grade I or II PLC injuries that have no bony involvement.

Question 2

when should you do surgical management for PLC

Answer 2

surgical management is preferred in grade III injuries or high-demand patients with grade II injuries.

Question 3

when should you do primary repair of PLC

Answer 3

bony avulsion injuries in the acute setting <3 weeks

Question 4

main constituents of PLC

Answer 4

he lateral collateral ligament (LCL), popliteus muscle-tendon unit, and popliteofibular ligament (PFL), which is subdivided into an anterior and posterior arm

Question 5

secondary stabilizers of the PLC

Answer 5

lateral capsular thickening also described as the lateral patellofemoral ligament, the fabellofibular ligament, the coronary ligament of the lateral meniscus, the lateral head of the gastrocnemius, and the long head of the biceps femoris

Question 6

what is the arcuate ligamentous complex

Answer 6

Y-shaped thickening of the posterolateral capsule extending to the posterior aspect of the fibular styloid

Question 7

where does the common peroneal nerve emerge from beneath biceps femoris tendon

Answer 7

45 mm proximal to the posterior border of the fibular head

Question 8

what is the function of the PLC

Answer 8

serves as the primary restraint to varus stress and external rotation of the tibia at the knee

Question 9

what serves as the primary restraint to varus stress at the knee jt

Answer 9

LCL

Question 10

what is the function of popliteus

Answer 10

across the knee joint to assist with knee flexion and “unlocks” the knee joint by internal rotation of the tibia; however, it also has ligamentous qualities that allow it to function as a secondary stabilizer to varus stress

Question 11

most common modes of injury of PLC

Answer 11

direct varus stress at the knee or noncontact hyperextension and external rotation injury.

Question 12

% of peroneal nerve injury in PLC knee injuries

Answer 12

26.2%

Question 13

provocative tests of PLC

Answer 13

varus stress test, dial test, reverse pivot shift test, ER recurvatum test

Question 14

what are standard AP and lateral radiographics of knee useful for in PLC

Answer 14

identifying fractures, soft-tissue swelling, and joint space widening or narrowing. In particular, lateral joint space widening, fibular head avulsion fractures, and anteromedial tibial fractures can be suggestive of PLC injuries

Question 15

what is the arcuate sign

Answer 15

avulsion fracture of the styloid process of the fibula that represents an injury to the arcuate complex of the PLC

Question 16

what kind of imaging has demonstrated high interobserver and intraobserver reliabilities and can reproducibly show lateral compartment widening in PLC injuries.

Answer 16

varus stress xrays

Question 17

MRI is less sensitive to identify which ligamentous structure in PLC

Answer 17

In a study conducted in 2000, LaPrade et al demonstrated MRI sensitivity for LCL (94.4%) and popliteus origin (93.3%) signal irregularities in PLC injuries to be quite high; however, MRI was less sensitive for PFL (68.8%) injury

Question 18

what does the evidence show for arthroscopic vs open PLC reconstruction procedures

Answer 18

although comparable with the open procedure, there is no current evidence to suggest superior clinical outcomes using an arthroscopic technique.

Question 19

Evidence for reconstruction techniques for PLC

Answer 19

There are several techniques described to reconstruct the PLC, with no clear superiority of one over the other

Question 20

chronic PLC injuries generally asocciated with…

Answer 20

varus malalignment

Question 21

what additional procedure should you consider for chronic PLC injuries with malalignment

Answer 21

• If associated with malalignment, commonly a valgus-producing high tibial osteotomy is necessary, before or at the time of PLC reconstruction.
• A medial opening wedge osteotomy allows better control of the slope and is preferred in combined PLC/PCL injuries

Question 22

Recommendation for post-operative rehabilitation course

Answer 22

Chahla et alrecommended non–weight-bearing for the first 6 weeks postoperatively, with 0° to 90° of flexion for the first 2 weeks, followed by range of motion as tolerated. After 6 weeks, they recommended gradual weaning of crutches and progression to muscular endurance, followed by muscular strength and power development.
Return to sports should be recommended no earlier than 6 months after surgery and more commonly closer to 9 months.

Question 23

What is recommended during procedure for PLC reconstruction regarding the nerve

Answer 23

The surgical recommendation is to visualize and protect the nerve at all times, especially before deep dissection and while drilling through the fibula head for graft reconstruction.