Repair of Acute Grade-3 Combined Posterolateral Corner Avulsion Injuries Using a Transosseous Krackow Suture Pull-Through Technique.

Background: For complete disruption of the posterolateral corner (PLC) structures, operative treatment is most commonly advocated, as nonoperative treatment has higher rates of persistent lateral laxity and posttraumatic arthritis^1-5. Some studies have shown that acute direct repair results in revision rates upwards of 37% to 40% compared with 6% to 9% for initial reconstruction^3,6. In a recent study assessing the outcomes of acute repair of PLC avulsion injuries with 2 to 7 years of follow-up, patients with adequate tissue were shown to have a much lower failure rate than previously documented⁷. In the present video article, we demonstrate a transosseous Krackow pull-through technique for repair of acute avulsion-type PLC multiligamentous knee injuries with no midsubstance injury.

Description: An incision is made along the lateral aspect of the knee from the epicondyle to the fibular shaft. The soft-tissue avulsion injury is identified and tagged with suture. Locking Krackow sutures are placed into the injured structures without separating the soft-tissue sleeve avulsion. With fibular avulsions, fibular and tibial transosseous tunnels are drilled with 2 Beath pins through the fibular head and tibia, exiting through the anteromedial tibial cortex. Lateral collateral ligament (LCL) and anterior biceps sutures are passed through the anterior tunnel, and popliteofibular ligament (PFL) and posterior biceps sutures are passed through the posterior tunnel. A small incision is made over the anteromedial tibial cortex in order to tie the sutures over the same metallic button. In fibular head avulsion fractures, high-strength suture placed through the fibular neck can provide additional compression. For proximal PLC injuries, the iliotibial band is incised at the lateral epicondyle, and the proximal attachment sites of the LCL and popliteus are localized. Krackow locking sutures are placed within the LCL and popliteus tendon. Transosseous tunnels are drilled with Beath pins through the native attachment sites of the LCL and popliteus on the lateral condyle and are directed anteriorly to avoid convergence with a potential anterior cruciate ligament (ACL) femoral tunnel. Sutures are pulled through the femoral attachment sites and tied over the same metallic button.

Alternatives: For acute PLC injuries, nonoperative treatment is not endorsed for the majority of cases. Surgical options include direct repair, repair with augmentation, or reconstruction.

Rationale: The transosseous Krackow pull-through technique allows for an enhanced and secure soft-tissue repair while avoiding suture anchor pull-out from the metaphyseal fibular head bone, which can also be compromised by cortical avulsion fractures. This procedure avoids the cost of an allograft and the donor-site morbidity of an autograft that are associated with a reconstruction. For patients with midsubstance tears, chronic injuries, and/or inadequate tissue quality, reconstructions or augmentations are more appropriate. According to Moran et al., this technique can result in a similar failure rate (10.7%) to initial reconstruction and a far lower failure rate than seen in other PLC repair techniques⁸. The present technique has a comparatively more reliable fixation method, as the suture is secured to dense tibial cortical bone, avoiding the suture anchor dislodgement that can occur with solely fibular fixation⁸. This is advantageous when the fibular bone is fragile or fractured. Suture pull-out may be further prevented with multiple locking Krackow sutures.

Expected outcomes: At a mean follow-up of 2 years (range, 3 to 90 months), Moran et al. reported a failure rate of 10.7%, which was significantly lower than the failure rate of 38% reported in a 2016 systematic review of PLC repairs^8,9. On clinical examination, the procedure yielded a significant decrease in lateral compartment opening, from 9 mm preoperatively to 0 mm postoperatively⁸.

Important tips: For distal PLC injuries, perform a peroneal neurolysis to identify and decompress the peroneal nerve.Carefully evaluate the soft tissue proximal to the avulsed portion to determine if any midsubstance tearing is present.

Acronyms and abbreviations: PLC = posterolateral cornerLCL = lateral collateral ligamentPFL = popliteofibular ligamentACL = anterior cruciate ligamentALL = anterolateral ligamentMRI = magnetic resonance imagingAM = anteromedialPCL = posterior cruciate ligamentFU = follow-upPROM = patient-reported outcome measureTDWB = touch-down weight-bearing.