Knee Dislocation— ACL/PCL/PLC

Jarret M. Woodmass

Bruce A. Levy

Michael J. Stuart

Chronic ACL/PCL/PLC Injuries

• A thorough physical examination is performed to assess knee range of motion, ligament laxity, limb alignment, gait, and neurovascular status.¹,²,³

• Anteroposterior, lateral, patellar, and full-length standing (hip-knee-ankle) radiographs along with magnetic resonance imaging are essential to confirm the clinical examination findings and rule out concomitant pathology (eg, malalignment, meniscus, articular cartilage, subchondral bone injuries).

• Multiple reconstruction techniques exist for posterolateral corner injuries (PLC).⁴

• Author’s approach:⁵

• All-inside anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) allograft reconstructions with suspensory fixation.

• PLC reconstruction using an anatomic single graft technique.⁶

▪ Note: Stress radiographs showing asymmetric varus instability of 10 mm (at 30 degrees of knee flexion) represent disruption of the lateral collateral ligament (LCL), popliteofibular ligament, popliteus tendon, and lateral capsular avulsion.⁷ In this circumstance, a dual graft reconstruction is performed as described by Laprade (not shown here).⁸

Sterile Instruments/Equipment

• Standard arthroscopy setup

• Spider limb positioner (Tenat Medical, Smith & Nephew, Calgary, AB)

• Allograft tissue: 3 or 4 tendons

• RetroConstruction Drill Guide Set (Arthrex, Naples, FL)

• FiberTape (Arthrex, Naples, FL)

• TightRope (Arthrex, Naples, FL)

• TightRope Attachable Button System (ABS) (Arthrex, Naples, FL)

• BioComposite screws (Arthrex, Naples, FL)

• Passport cannula (Arthrex, Naples, FL)

• Vessel loop

Patient Preparation/Positioning

• The patient is positioned supine with a tourniquet applied to the upper thigh.

• Both knees are examined under anesthesia to confirm the instability pattern.

• Fluoroscopic imaging is used to measure the amount of medial and lateral joint space opening (grade of instability) compared to the contralateral knee.

• The operative leg is stabilized in a Spider knee positioner.

• This allows stable knee positioning at various flexion angles and decreases reliance on assistants.

Graft Selection/Preparation

• All-inside ACL—quadrupled semitendinosus allograft (Fig. 50-1)

• Length: >260 mm total (65-70 mm quadrupled graft); width: 8-10 mm

• FiberTape passed through femoral button and incorporated into (but not sutured to) the graft (internal brace)

• Femoral fixation—TightRope; tibial fixation—TightRope ABS; 5.5-mm SwiveLock anchors (1—GraftLink supplementary fixation; 2—internal brace)

Figure 50-1 | All-inside ACL graft preparation using semitendinosus allograft and an internal brace. A. Semitendinosus allograft tendon. B. Quadrupled semitendinosus allograft with TightRope ABS tibial fixation and TightRope femoral fixation. C. Final construct demonstrating the internal brace (FiberTape) being loosely apposed to the allograft with Monocryl suture allowing independent tensioning.

• All-inside PCL—quadrupled anterior tibial tendon allograft

• Length: >320 mm total (80-90 mm quadrupled graft); width: 10-12 mm

• FiberTape passed through femoral button and incorporated into (but not sutured to) the graft (internal brace)

• Femoral fixation—TightRope; tibial fixation—TightRope ABS, 5.5-mm SwiveLock anchors (1—GraftLink supplementary fixation; 2—internal brace)

• PLC reconstruction: anatomic single-graft transfibular reconstruction

• Achilles tendon allograft (minimum of 20 cm length) with bone block

▪ Bone block is contoured to press fit into a 9-× 25-mm femoral socket

All-inside ACL Reconstruction Socket Preparation

• A superomedial outflow portal, both standard and low inferomedial portals, and an inferolateral working portal are established.

• Femoral tunnel creation

• The knee is flexed 100-120 degrees to prevent injury to the peroneal nerve.

• A spade-tipped pin is advanced through femoral footprint.