Single‐Stage Anatomic Reconstruction of Anterior Cruciate Ligament, Posterior Cruciate Ligament, Medial Collateral Ligament, and Posterolateral Corner for Multiligament Knee Injury

Abstract

Multiligament knee injuries represent rare and challenging injuries that require complex surgical management to restore stability and function. Current evidence supports anatomic single‐stage reconstructions when feasible in order to re‐establish knee kinematics and enable early rehabilitation. This technique paper describes single‐stage anterior cruciate ligament reconstruction with a bone–patellar tendon–bone allograft, double‐bundle posterior cruciate ligament reconstruction with Achilles tendon allograft for the anterolateral bundle and tibialis anterior allograft for the posteromedial bundle, medial collateral ligament reconstruction with hamstring autograft, and anatomic posterolateral corner reconstruction with Achilles tendon allograft. Key aspects emphasized include identification and protection of the common peroneal nerve, accurate anatomic tunnel placement to avoid convergence, and a graft tensioning sequence prioritizing the posterior cruciate ligament, followed by the anterior cruciate ligament, medial collateral ligament, and then the posterolateral corner. This technique provides a reproducible single‐stage strategy to address multiligament knee injuries, restoring stability across all planes and supporting functional recovery.

Multiligament knee injuries (MLKIs) involve disruption of 2 or more of the 4 principal knee stabilizers (anterior cruciate ligament [ACL], posterior cruciate ligament [PCL], medial collateral ligament [MCL], and posterolateral corner [PLC]) and often arise from an acute knee dislocation. ¹ These injuries are highly complex and frequently associated with concomitant intra‐articular fractures as well as nerve, vascular, chondral, and/or meniscal pathology. ¹ , ² , ³ , ⁴ In the long term, MLKIs can lead to significant morbidity, including pain, instability, and functional limitation. ⁵ , ⁶ Accordingly, timely and comprehensive management of these severe injuries is critical to optimizing long‐term knee function.

Reported management strategies include immobilization as well as repair or reconstruction performed according to different staging and timing protocols. Over time, evidence has favored operative intervention, which results in better clinical outcomes, improved function, and higher rate of return to activity when compared to nonoperative management. ⁷ , ⁸ , ⁹ Historically, early repair techniques were commonly employed, but outcomes were often unpredictable and showed a high rate of failure. ¹⁰ , ¹¹ , ¹² This has led to a gradual shift toward anatomic reconstructions, which have shown superior biomechanical stability and more reliable restoration of knee kinematics. ¹³ Advances in surgical instrumentation, imaging, and graft fixation have clarified prior controversies, and contemporary consensus now generally favors anatomic, single‐stage reconstruction when possible as this has been associated with improved stability, earlier rehabilitation, and lower rates of residual laxity and postoperative stiffness. ¹¹ , ¹³ , ¹⁴ , ¹⁵ To the authors’ knowledge, there is a lack of published techniques related to single‐stage anatomic reconstruction of the ACL, PCL, PLC, and MCL. Therefore, we are presenting this technique to serve as a surgical guide when confronted with this challenging case.

SURGICAL TECHNIQUE

Indications

Recent expert consensus suggests surgical intervention is warranted for MLKI, given significantly higher functional outcomes and rate of return to work over nonoperative management. ¹⁵ This technique is indicated for reconstruction of Schenck classification KD‐IV or V MLKIs (Figures 1a‐e and 2). ¹⁶ Single‐stage reconstruction is warranted whenever possible in order to facilitate early rehabilitation and to help prevent iatrogenic stretching of the grafts. ¹⁷

FIGURE 1.

Preoperative radiographs of the patient's right knee were obtained after the injury due to suspicion of a knee dislocation. Pre‐reduction films (a,b) display a dislocation of the tibiofemoral joint on both the AP and lateral views. Postreduction films (c,d) display successful reduction of the tibiofemoral joint. A valgus stress radiograph (e) obtained postreduction displays medial joint widening measured to approximately 20 mm. Due to the nature of the injury and significant joint widening on the stress radiographs, an MRI scan was planned for further evaluation for associated soft tissue injuries. (AP, anteroposterior; MRI, magnetic resonance imaging; R, right.)

FIGURE 2.

Preoperative MRI of the patient's right knee was obtained after the injury due to suspicion of a MLKI due to the reported knee dislocation. The sagittal T2 view (a) shows a rupture of the FCL at the proximal insertion point (blue arrow). The first coronal T2 view (b) shows a midsubstance rupture of the ACL (green arrow) and a rupture of the PCL (orange arrow). The second coronal T2 view (c) shows a midsubstance rupture of the MCL (purple arrow). Due to the concerning imaging findings and associated clinical findings associated with the knee dislocation, a plan was made to perform a single‐stage anatomic surgical reconstruction of the ACL, PCL, PLC, and MCL. This allowed for significant restoration of ligamentous stability. (ACL, anterior cruciate ligament; FCL, fibular collateral ligament; MCL, medial collateral ligament; MLKI, multiligament knee injury; MRI, magnetic resonance imaging; PCL, posterior cruciate ligament; PLC, posterolateral corner.)

Contraindications

This technique is contraindicated in patients with extremely low functional demand, severe polytrauma preventing surgical management of the injured limb, and severe vascular injury and subsequent ischemia in which amputation is required for limb salvage.

Patient Positioning and Examination Under Anesthesia

The patient is brought to the operating room and placed in the supine position. The ipsilateral thigh is placed into a leg holder, and a nonsterile thigh tourniquet is placed. The contralateral limb is placed into a well‐padded stirrup. The patient is prepped and draped in standard sterile fashion.

PLC Reconstruction

A lateral approach with a hockey‐stick incision is used for the anatomic PLC reconstruction. ¹⁸ The full‐thickness flap is elevated to identify and neurolyze the common peroneal nerve (Figure 3). The fibular collateral ligament (FCL) is identified and tag‐stitched, and the iliotibial band is incised at its femoral insertion. Using an extra‐articular (ACUFEX, Smith & Nephew, Memphis, TN) and 18 mm offset guides (Smith & Nephew), femoral tunnels for the FCL and popliteus are drilled distal and anterior to one another, aimed 35° anteriorly, and reamed to 25 mm. Passing sutures are placed. The fibular FCL insertion is exposed by opening the biceps bursa, and the champagne‐glass drop‐off is identified. A Beath pin is drilled (Smith & Nephew) anterolateral (AL) to posteromedial (PM) and reamed to 7 mm. For the popliteus, a tibial tunnel is drilled from the flat spot between Gerdy's tubercle and the tibial tubercle to the anatomic posterior point under fluoroscopic guidance and reamed to 10 mm. Passing sutures are left in place, completing PLC tunnel preparation.

FIGURE 3.

Intraoperative view of the right knee showing identification and protection of the CPN during posterolateral corner exposure. The patient is positioned supine with the right knee flexed to 90°. The CPN (blue arrow) is visualized deep to the biceps femoris muscle (green arrow). Prompt and meticulous identification of the CPN is essential prior to further dissection, tunnel drilling, or graft passage, as iatrogenic injury to this structure can result in significant motor and sensory deficits. Once identified, the nerve is carefully mobilized and protected throughout the procedure using vessel loops or retractors. The FCL is also visualized (yellow arrow). (CPN, common peroneal nerve; FCL, fibular collateral ligament.)

MCL Reconstruction

A medial incision is made from just proximal/anterior to the medial epicondyle to 7 cm distal to the joint line. The infrapatellar branch of the saphenous nerve is protected. Semitendinosus and gracilis tendons are harvested with distal insertions preserved (Figure 4). The distal superficial MCL insertion 6 cm below the joint line is secured with an all‐suture anchor (Q‐fix, Smith & Nephew). Proximally, the adductor tendon identified the MCL origin 12 mm distal and 8 mm anterior; a guide pin is placed, isometry confirmed, and a 7 mm socket reamed to 30 mm. A passing stitch is inserted, and both grafts are passed deep to the sartorial fascia from distal to proximal to complete MCL preparation.

FIGURE 4.

Intraoperative view of the right knee showing key steps of MCL reconstruction. The patient is positioned supine with the right knee flexed to 30°. The hamstring tendon autograft is harvested through a medial incision (blue arrow) and the Beath pin is drilled for subsequent tunnel creation. (MCL, medial collateral ligament.)

Portal Placement and Diagnostic Arthroscopy After Open Approaches

Standard high AL and anteromedial parapatellar portals are created, and a diagnostic arthroscopy is performed.

PCL Reconstruction

A radiofrequency probe is used to mark the AL and PM PCL bundle footprints. The AL bundle lies between the medial arch and trochlear points near the articular cartilage, and the PM bundle is located 8 mm posterior to this (Figure 5a). Closed femoral sockets (11 mm AL, 7 mm PM) are reamed to 25 mm and passing sutures placed. A PM portal is created for remnant debridement and tibial footprint identification. Using a PCL guide (Smith & Nephew), a Beath pin is drilled from the anteromedial tibia to the PCL facet and confirmed fluoroscopically just proximal to the champagne‐glass drop‐off. A 12 mm tibial tunnel is reamed, protecting posterior neurovascular structures with a curette. Passing sutures are placed, and the tunnel is smoothed by cycling a large smoother introduced proximally and retrieved through the anteromedial portal (Figure 5b).

FIGURE 5.

Arthroscopic views of the right knee from the anterolateral portal showing key steps of anatomic double‐bundle PCL reconstruction. The patient is positioned supine with the right knee flexed to 90°. The femoral tunnels for the AL and PL PCL bundles are visualized after anatomic drilling, showing their distinct orientations within the native PCL footprint (a). The trochlea point and the medial arch point serve as key landmarks for accurate tunnel placement, with the drill guide positioned under direct visualization. The tibial tunnel was smoothed by cycling a large smoother (Gore Smoother Crucial Tool, Smith & Nephew) passed proximally through the tibial tunnel and pulled out the anteromedial arthroscopic portal (b). The debrided tibial PCL footprint and newly created tibial tunnels are seen before graft fixation (c). Care is taken to avoid tunnel convergence and preserve the posterior cortical wall during tibial tunnel preparation. This configuration restores the native double‐bundle anatomy and tension pattern of the PCL. (AL, anterolateral; PCL, posterior cruciate ligament; PL, posteromedial.)

ACL Reconstruction

Attention is returned to the intercondylar notch where a shaver and radiofrequency cautery device are used to debride the lateral aspect of the notch along the native ACL origin on the lateral femoral condyle. A radiofrequency probe and awl are used to mark the center of the femoral tunnel. A 7 mm over‐the‐top drill guide (Smith & Nephew) is placed through the medial portal, and a pin is drilled through the guide exiting the distal lateral femur. A 10‐mm reamer is placed over the pin and reamed to 25 mm of depth, and careful inspection of tunnel trajectory is confirmed proper placement. A passing suture is placed through the pin. A tibial guide set at 65° is placed flush with the proximal tibia at the marked spot and at the anatomic tibial footprint of the ACL. The guide pin is then drilled followed by reaming to 11 mm.

Graft Passage and Tensioning

The PM bundle graft of the PCL is pulled through the passing stitch, positioned in the femoral tunnel, and fixed with a 7 × 20 mm PEEK screw. The bone plug over the AL bundle is similarly passed into the femoral tunnel and fixed with an 8 × 20 mm titanium screw. The grafts are pulled down the tibia and are both fixed in the tibia (Figure 5c). The AL bundle at 90° knee flexion with a staple and the PM bundle in full extension with an all‐soft tissue anchor (Q‐fix, Smith & Nephew) as the second staple did not have appropriate purchase due to soft bone. Posterior drawer examination confirmed restoration of posterior tibial stability.

The previously placed femoral passing suture is pulled into the joint and out through the tibial tunnel. The ACL bone plug sutures are shuttled through this suture and delivered out the lateral thigh. With the knee maximally flexed, a blunt guide pin is inserted through the accessory medial portal into the superior femoral tunnel‐bone plug junction (Figure 6), and the graft is fixed with a 7 × 20 mm cannulated titanium screw. After cycling the knee 20 times, tibial fixation is performed in full extension using a 9 × 20 mm cannulated screw placed at the anteromedial aspect of the tibial tunnel (Figure 7). Clinical and arthroscopic assessment confirmed stable anterior translation and absence of notch impingement.

FIGURE 6.

Arthroscopic view of the right knee from the anterolateral portal showing the BPTB allograft in position following passage for ACL reconstruction. The femoral bone block is well seated within the anatomic ACL footprint, with the tendon portion of the graft oriented along the native ACL trajectory (blue arrow). The graft is appropriately tensioned and free of impingement against the intercondylar notch. This view confirms anatomic tunnel placement and secure positioning of the BTB graft prior to final fixation. (ACL, anterior cruciate ligament; BPTB, bone–patellar tendon–bone.)

FIGURE 7.

Arthroscopic view of the right knee from the anterolateral portal showing the final appearance and orientation of the reconstructed cruciate ligaments following graft passage. The BPTB allograft for ACL reconstruction is appropriately tensioned and positioned in line with the native femoral and tibial footprints (blue arrow). The PCL reconstruction is visualized posterior to the ACL (green arrow), confirming an anatomic relationship between the 2 grafts without impingement or tunnel convergence. This view verifies restoration of normal intra‐articular alignment and tension balance between the ACL and PCL reconstructions. (ACL, anterior cruciate ligament; BPTB, bone–patellar tendon–bone; PCL, posterior cruciate ligament.)

The hamstring tendon grafts that are previously passed under the sartorial fascia for the MCL reconstruction are fixed on the femur with a 7 mm PEEK screw at 30° of flexion and neutral rotation. The proximal tibial MCL insertion is recreated 12 mm distal to the joint line with an all‐soft tissue anchor (Q‐fix, Smith & Nephew) (Figure 8).

FIGURE 8.

Intraoperative view of the right knee showing the anatomically reconstructed MCL (blue arrow) following successful graft passage and fixation. The patient is positioned supine with the knee flexed to 90°, showing the graft coursing along the native MCL trajectory from the medial femoral epicondyle to the tibial insertion. Proper tensioning and alignment of the graft are confirmed intraoperatively to restore medial stability while avoiding overconstraint. The saphenous nerve and vein are protected throughout the exposure. This view confirms anatomic restoration of the MCL and completion of the medial‐side reconstruction. (MCL, medial collateral ligament.)

FCL and popliteus grafts are inserted into their femoral tunnels and fixed with 7 × 20 mm screws. The popliteus graft is routed posteriorly, and the FCL graft passed through the fibular tunnel AL to PM and then fixed at 30° with a 6 × 20 mm PEEK screw (Figure 9, Video 1). Both grafts are advanced through the tibial tunnel and fixed at 60°. Final assessment should confirm restored varus and rotational stability with a negative dial test.

FIGURE 9.

Intraoperative view of the right knee showing FCL (blue arrow) graft fixation to the fibula with a screw. The patient is positioned supine with the right knee flexed to 30°. After the FCL graft is fixed, the same graft will be used to reconstruct the PFL (green arrow). The graft for the popliteus tendon reconstruction is also visualized (orange arrow) and will be fixed concurrently with the PFL. Proper identification of the individual graft limbs and their orientation is critical for anatomic restoration of the PLC structures and prevention of tunnel convergence. (FCL, fibular collateral ligament; PCL, posterior cruciate ligament; PFL, popliteofibular ligament.)

VIDEO 1.

Download video file ^{(77.6MB, mp4)}

This video shows a surgical technique describes the management of a 50‐year‐old female with an acute knee dislocation and complete rupture of the anterior cruciate ligament, posterior cruciate ligament, posterolateral corner, and medial collateral ligament. After initial evaluation confirmed no vascular or neurologic injury but showed significant instability and effusion, surgical management was undertaken. The procedure included right knee arthroscopy, anterior cruciate ligament reconstruction with patellar bone–patellar tendon–bone allograft, posterior cruciate ligament reconstruction with Achilles tendon allograft, posterolateral corner reconstruction with Achilles tendon allograft, medial collateral ligament reconstruction with hamstring autograft, medial meniscus debridement, and lysis of adhesions. Following surgical preparation of the medial and lateral sides, diagnostic arthroscopy, and careful graft harvest, sequential reconstructions were performed: the LaPrade technique for posterolateral corner, standard medial approach for medial collateral ligament, arthroscopic double‐bundle reconstruction for posterior cruciate ligament, and bone–patellar tendon–bone graft fixation for anterior cruciate ligament. Stability was restored with appropriate screw and anchor fixation, loose bodies were removed, adhesions were addressed, and mild meniscal fraying was debrided. The procedure concluded with layered closure and application of a hinged knee brace locked in slight hyperextension. Video content can be viewed at https://doi.org/10.1002/atn2.70079.

The subcutaneous tissue is closed with 2.0 Monocryl suture, and the skin layer is closed in standard fashion. A sterile dressing is then applied. A hinged knee brace locked in negative 10° of extension is applied to the operative knee (Figure 10).

FIGURE 10.

Postoperative radiographs of the right knee obtained 2 weeks after anatomic multiligament reconstruction. Anteroposterior view showing appropriate tunnel placement and fixation for the reconstructed ACL, PCL, and collateral grafts (a). Lateral view showing proper graft trajectory and hardware positioning without evidence of tunnel convergence or hardware complications (b). These images confirm stable fixation and restoration of anatomic alignment following reconstruction. (ACL, anterior cruciate ligament; PCL, posterior cruciate ligament.)

Rehabilitation

Rehabilitation focuses on protecting the reconstruction while gradually restoring motion and weight bearing. For the first 6 weeks, patients remain nonweight‐bearing in a brace locked in full extension, with early range of motion to 0° to 90° emphasizing full extension. From 6 to 12 weeks, weight‐bearing progresses as tolerated, the brace is unlocked, and therapy advances to strengthening and balance training. After 12 weeks, patients typically regain full weight bearing and near‐full range of motion, with continued strengthening and neuromuscular work. Return to running and sport is allowed only after strength symmetry and functional criteria are met, usually around 9 months.

DISCUSSION

MLKIs are rare but severe injuries best treated with anatomic reconstruction to restore stability and function. This technique uses single‐stage reconstruction with LaPrade PLC ¹⁸ using Achilles allograft, anatomic MCL with semitendinosus/gracilis autografts, ACL with patellar bone–patellar tendon–bone allograft, and double‐bundle PCL with Achilles and tibialis anterior allografts. Key principles include careful neurovascular identification, accurate anatomic landmarking, drilling all tunnels before graft passage to avoid convergence, and fixing grafts in the proper sequence (PCL, ACL, MCL, and PLC) (Tables 1 and 2). The main limitation is the technical complexity required to avoid tunnel interference.

TABLE 1.

Pearls and Pitfalls in Multiligament Knee Reconstruction

Pearls	Pitfalls
Perform anatomic reconstruction of ACL, PCL, MCL, and PLC in a single stage when feasible	Failure to protect the common peroneal nerve can result in permanent neurologic injury
Use LaPrade technique for PLC reconstruction to anatomically restore all 3 primary stabilizers	Improper tunnel placement may lead to tunnel convergence or graft impingement
Identify and protect the common peroneal nerve early during PLC dissection	Nonanatomic reconstructions risk residual laxity and poor functional outcomes
Prepare PLC, MCL, PCL, and ACL tunnels (in this order) before graft passage to improve efficiency and avoid tunnel convergence	Inadequate graft tensioning sequence can increase posterior translation and rotational instability
Sequence graft tensioning as PCL first, ACL second, MCL third, and PLC last to optimize biomechanics	Neglecting to confirm tunnel orientation under fluoroscopy risks inaccurate tunnel placement
Utilize double‐bundle PCL reconstruction for greater stiffness and reduced posterior laxity	Harvesting insufficient hamstring autograft length may compromise MCL reconstruction
Employ semitendinosus and gracilis autografts for MCL to address both superficial and deep components	Overly aggressive meniscal or soft tissue debridement can reduce joint stability
Confirm stability intraoperatively with drawer, pivot shift, and dial tests	Inadequate postoperative rehabilitation progression may impair recovery and delay return to sport

ACL, anterior cruciate ligament; MCL, medial collateral ligament; PCL, posterior cruciate ligament; PLC, posterolateral corner.

TABLE 2.

Advantages and Disadvantages of Multiligament Knee Reconstruction

Advantages	Disadvantages
Restores stability across all major planes through anatomic reconstruction of ACL, PCL, MCL, and PLC	Technically demanding procedure requiring advanced surgical expertise
Single‐stage approach enables earlier rehabilitation and reduces total operative burden	Risk of tunnel convergence due to multiple reconstructions performed in a single stage
LaPrade technique provides comprehensive anatomic restoration of the PLC	Prolonged operative time compared with isolated ligament reconstructions
Double‐bundle PCL reconstruction improves stiffness and reduces posterior laxity	Increased complexity may raise risk of intraoperative complications
Use of both autograft and allograft allows tailored graft selection based on patient profile	Greater demand on rehabilitation protocols to protect multiple reconstructions simultaneously
Clear graft tensioning sequence optimizes biomechanical stability	Potential for higher graft requirement, necessitating availability of both allograft and autograft sources
Reduces likelihood of residual laxity compared with nonanatomic or staged approaches	Not suitable for patients with severe comorbidities, poor bone quality, or low functional demand

ACL, anterior cruciate ligament; MCL, medial collateral ligament; PCL, posterior cruciate ligament; PLC, posterolateral corner.

With current advancements in defining the key structures involved in the PLC, the LaPrade technique anatomically reconstructs the 3 primary contributors to static stability of the posterolateral knee: the FCL, popliteus tendon, and the popliteofibular ligament which differs from other PLC reconstruction techniques that focus more on reconstructing or repairing one of the PLC contributors. ¹¹ , ¹⁸ , ¹⁹ Accordingly, the LaPrade technique is favored by the senior author due to its ability to achieve a more anatomically precise reconstruction of all 3 PLC contributors. ¹⁸ , ²⁰ Furthermore, this technique utilizes anatomic reconstructions of the ACL, PCL, and MCL which have all shown to properly restore biomechanical function of the knee with significant reductions of laxity in their respective load planes. ²¹ , ²² , ²³ Specifically, the MCL technique explained uses the tendons of the semitendinosus and gracilis which has shown to provide significantly superior stability in external rotation and anteromedial rotatory instability compared with single strand short constructs as it addresses both the superficial and deep MCLs. ²³ Moreover, the double‐bundle PCL reconstruction used in this technique has shown significantly better biomechanical stability and improved clinical outcomes when compared with single‐bundle reconstructions. ²⁴ , ²⁵

Additionally, this technique included preparation of all tunnels (e.g., PLC, MCL, PCL, and ACL) prior to passing and securing the grafts to minimize the risk of tunnel convergence. The preferred order of graft passage and tensioning (e.g., PCL, ACL, MCL, and PLC) was used in this technique as it provides the greatest biomechanical advantage to avoid excess posterior translation and internal rotation. ²⁶ Overall, this technique provides anatomic reconstructions of the 4 major ligaments in the knee.

DISCLOSURES

The author (J.C.) declares the following financial interests/personal relationships which may be considered as potential competing interests: J.C. reports a relationship with Smith & Nephew that includes consulting or advisory, speaking and lecture fees, and travel reimbursement. The other authors (L.D.M., J.C.B., F.C., N.T., J.T.M., T.F.V.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.