JAAOS Questions Flashcards
When should you do nonsurgical management for PLC
isolated grade I or II PLC injuries that have no bony involvement.
when should you do surgical management for PLC
surgical management is preferred in grade III injuries or high-demand patients with grade II injuries.
when should you do primary repair of PLC
bony avulsion injuries in the acute setting <3 weeks
main constituents of PLC
he lateral collateral ligament (LCL), popliteus muscle-tendon unit, and popliteofibular ligament (PFL), which is subdivided into an anterior and posterior arm
secondary stabilizers of the PLC
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
what is the arcuate ligamentous complex
Y-shaped thickening of the posterolateral capsule extending to the posterior aspect of the fibular styloid
where does the common peroneal nerve emerge from beneath biceps femoris tendon
45 mm proximal to the posterior border of the fibular head
what is the function of the PLC
serves as the primary restraint to varus stress and external rotation of the tibia at the knee
what serves as the primary restraint to varus stress at the knee jt
LCL
what is the function of popliteus
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
most common modes of injury of PLC
direct varus stress at the knee or noncontact hyperextension and external rotation injury.
% of peroneal nerve injury in PLC knee injuries
26.2%
provocative tests of PLC
varus stress test, dial test, reverse pivot shift test, ER recurvatum test
what are standard AP and lateral radiographics of knee useful for in PLC
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
what is the arcuate sign
avulsion fracture of the styloid process of the fibula that represents an injury to the arcuate complex of the PLC
what kind of imaging has demonstrated high interobserver and intraobserver reliabilities and can reproducibly show lateral compartment widening in PLC injuries.
varus stress xrays
MRI is less sensitive to identify which ligamentous structure in PLC
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
what does the evidence show for arthroscopic vs open PLC reconstruction procedures
although comparable with the open procedure, there is no current evidence to suggest superior clinical outcomes using an arthroscopic technique.
Evidence for reconstruction techniques for PLC
There are several techniques described to reconstruct the PLC, with no clear superiority of one over the other
chronic PLC injuries generally asocciated with…
varus malalignment
what additional procedure should you consider for chronic PLC injuries with malalignment
- 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
Recommendation for post-operative rehabilitation course
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.
What is recommended during procedure for PLC reconstruction regarding the nerve
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.
