Chronic PLC Management

Issues

 

Limb alignment

 

Risk that late posterolateral corner reconstruction will fail in the setting of the varus knee

- varus knee alignment and varus thrust in stance phase

- consider osteotomy first in this setting

 

Options

 

1. Posterolateral Corner Reconstruction

 

Moulton et al. Am J Sports Med 2016

- systematic review of posterolateral corner reconstruction for chronic injuries

- 450 patients

- 90% rate of objective stability, 10% failure

 

2. High tibial osteotomy

 

Arthur et al Am J Sports Med 2007

- opening wedge high tibial osteotomy for patients with varus knee and chronic posterolateral corner

- 21 patients

- 8/21 (38%) did not require subsequent reconstruction

- 4/6 with isolated posterolateral corner did not require subsequent reconstruction

- 10/14 with multiligament injuries did require subsequent reconstruction

 

Examination

 

LCL

- grade 3 laxity in extension

 

Dial test

- confirm PLC instability

- > 10 - 15o compared with other side

 

Increased Dial Test 30 degrees

 

PCL / ACL

 

Xray

 

Stress radiographs useful

- Telos

- confirm PCL / LCL

 

Long leg views

- assess for varus malalignment

 

MRI

 

MRI Chronic Posterolateral CornerMRI Chronic Posterolateral Corner Reconstruction 2

Chronic proximal avulsion LCL / Popliteus

 

LCL Chronic Distal Avulsion MRI

Chronic distal avulsion LCL

 

Limb alignment

 

Chronic PLC Long leg ViewLong leg

Mild varus of right knee

 

Definition Varus Malalignment

 

Mechanical axis passes medial to tip of medial tibial spine on long leg view

 

Surgical Technique - Medial Opening Wedge High Tibial Osteotomy

 

Advantages Opening wedge HTO

- avoids disruption of proximal tibio-fibular joint (for lateral PLC reconstruction)

- tighten the posterior capsule

- allows variation of the posterior slope (in setting of ACL / PCL)

 

Must be very careful not to overcorrect

- chronic posterolateral corner instability

- in a standing long leg view, the measured femoro-tibial angle is abnormally large

- the joint line is opened up laterally due to ligament insufficiency

- with correction, the joint line will close with standing

- the amount of valgus obtained will be more than that calculated at surgery

- one solution is to subtract the opening angle in the knee joint

- the other solution is to calculate the alignment of the other limb and calculate correction to normal valgus alignment

 

Technique

- medial opening wedge with plate and allograft bone

- correct so that mechanical axis passes through down slope of lateral tibial spine

- decrease posterior tibial slope with ACL deficiency

- increase posterior tibial slope with PCL deficiency

 

ACL + High tibial osteotomy for ACL + chronic posterolateral corner

 

ACL / Posterolateral corner / patient in varus

 

ACL LCL MRIACL LCL MRI 2

Sagittal MRI showing torn ACL                             Coronal MRI demonstrating chronic avulsion LCL fibula head

 

ACL PLC Alignment

Varus malalignment left knee

 

ACL HTO IntraoperativeACL HTO

ACL + high tibial osteotomy

 

Surgical technique