DEFINITION

Multiligament knee injuries result from both high-energy (eg, motor vehicle collisions) and low-energy (eg, athletic injuries, falls) events. Ultra-low velocity dislocations are those described in obese patients with minimal trauma. Dislocation of the tibiofemoral joint is common, with or without spontaneous reduction.

 

 

ANATOMY

 

Put very simply, knee dislocations can be viewed as injuries to one or both cruciate ligaments (ie, anterior cruciate ligament [ACL] or posterior cruciate ligament [PCL]), with variable involvement of the collateral ligaments (ie, the medial collateral ligament [MCL] and the fibular collateral ligament [FCL]) along with the popliteofibular ligament (PFL)/arcuate complex posterolaterally and the posterior oblique ligament (POL) medially. There are also important musculotendinous stabilizers—the biceps femoris and popliteus posterolaterally and the pes anserine complex medially, all of which must be considered in restoring knee function. Palpable bony landmarks about the knee are crucial to aid in orientation for examination and when planning subsequent surgical approaches.

 

The lateral femoral epicondyle, Gerdy tubercle, and the fibular head are critical to identify the placement of lateral incisions, as are anatomic structures such as the FCL and peroneal nerve. Medially, the femoral epicondyle, tibial tubercle, pes insertion site, and posteromedial tibial edge are crucial landmarks for medial surgical exposures for inlay and MCL reconstruction.

 

The intrinsic structure of the vascular system of the knee consists of an anastomotic ring of five geniculates: the superomedial, superolateral, inferomedial, inferolateral, and middle geniculates as well as muscular and articular branches.

 

 

The extrinsic system plays a crucial role when parallel medial or lateral incisions are made about the knee in the sagittal plane.

 

Proper planning should allow 7 to 10 cm between superficial parallel incisions to greatly lessen the risk of skin bridge loss, but it has been our experience that such incisions should be avoided if possible. This anastomotic network alone cannot support vascularity distal to the knee with popliteal vessel occlusion.

 

The surgical anatomy of the knee usually is described in layers, going from the superficial structures to the deep structures.42

 

Layer I is commonly described as consisting of the Marshall layer (arciform) anteriorly, the sartorius medially, and the iliotibial (IT) band and biceps femoris fascia laterally.

 

Layer II includes the FCL, patellar tendon, and superficial MCL.

 

Layer III includes the posterior oblique, arcuate ligament, and deep portion of the MCL. Layer III is thin anteriorly and has distinct, structurally important thickenings posteromedially (POL) and posterolaterally (arcuate ligament). A Segond fracture is caused by avulsion of the thickened middle third of the lateral knee capsule in this layer. Layer III is simplistically described as variations in the joint capsule.

 

 

Posterolateral reconstructions are complex because of this anatomy and variability and require restoration of both the FCL and PFL as well as the proximity of the peroneal nerve. Because the lateral aspect of the knee is less commonly explored, some authors have described it as “the dark side of the knee.”

 

 

The surgeon should understand the important anatomic relationships of the posterior structures of the knee, especially in regard to the popliteal neurovascular bundle.

 

 

The medial and lateral heads of the gastrocnemius are the borders of the popliteal fossa distally, the pes anserinus tendons medially, and the biceps femoris tendon laterally. The popliteus, posterior joint capsule, oblique popliteal ligament, and posterior femoral cortex form the floor of the fossa. Through this fossa run the plantaris muscle and the neurovascular structures. The popliteal artery enters through the adductor magnus superiorly as it leaves Hunter canal, courses through the fossa, and exits through the soleal arch. The popliteal vein enters superolateral to the artery and continues superficial to the artery but is located deep to the tibial and common peroneal nerves, leaving the fossa medial to the popliteal artery.

 

The vascular structures are located directly behind the posterior horns of the medial and lateral menisci. The vascular structures are protected during posteromedial and posterolateral approaches if the surgeon remains anterior to the medial and lateral heads of the gastrocnemius during dissection and careful retraction; the surgeon should be cautioned that further dissection toward the midline can injure the neurovascular bundle with either approach.

 

With the advent of posterior procedures to the tibial side of the PCL, it is critical to understand the posterior neurovascular anatomy. The posteromedial approach also is useful to gain access to the tibial insertion of the PCL.

 

 

Deep dissection along the posterior tibial surface and femoral condyles provides additional safety for this approach. Use of a tourniquet during dissection provides improved visualization of the surgical planes.

 

Unlike the vascular surgeon, who uses a posteromedial approach for the neurovascular (popliteal) bundle, the

 

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orthopaedic surgeon dissecting posteromedially should avoid the neurovascular bundle. Staying anterior to the medial gastrocnemius and hugging the posterior aspect of the knee joint protects the bundle in the orthopaedic approach.

 

It is important to stop the dissection at the PCL because further dissection laterally with this approach eventually will reach and potentially injure the bundle.

 

NATURAL HISTORY

 

Before the development of modern surgical techniques for management of multiligament injuries, scores of patients were left with stiff, unstable, or even amputated limbs. Today, even with aggressive evaluation and treatment, patients ultimately may have residual instability with a lower level of activity, decreased range of motion (ROM), osteoarthritis, and even amputation. The use of allografts in multiligamentinjured knees is a

recent advance, although occasionally, it is complicated by deep infection or rejection.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

During the initial evaluation of a patient with a suspected multiligament knee injury, the clinician should be cognizant of the potential for concomitant injuries. High- or lowenergy knee trauma can have potentially life- or limbthreatening injuries, which must be identified acutely.

 

Once any life-threatening injuries have been treated, a careful injury history should be obtained if possible, including prehospital neurovascular status of the limb, time of injury, and mechanism. Patients often relate a history of hyperextension of the knee in sporting events or a flexed knee that struck the dashboard during a motor vehicle accident.

 

 

Complete examination of the injured limb focuses both above and below the knee to evaluate for fracture as well as continuity of the extensor mechanism. In suspected knee dislocations, a complete ligamentous examination is crucial. Increased varus or valgus laxity in full extension as compared to 30 degrees of flexion may indicate collateral and concomitant cruciate disruption. The dial test in the prone position is useful for evaluating posterolateral corner (PLC) and PCL injuries. A posterior Lachman maneuver can also be used to evaluate PCL continuity. For the obese, swollen, or painful patient, a stabilized Lachman maneuver can be performed in which the examiner places his/her thigh behind the patient's thigh to bolster and stabilize the femur.

 

Any evidence of current dislocation of the tibiofemoral joint should be addressed emergently, with attempted reduction under sedation, splinting, careful neurovascular examination pre- and postreduction, and high-quality radiographic evaluation following reduction.

 

 

The radiographic evaluation should include an anteroposterior and a lateral radiograph of the knee with the limb in a long-leg splint to demonstrate that a successful reduction has been achieved.

 

Medial furrowing of the soft tissues of the knee along the joint line usually suggests a posterolateral dislocation with buttonholing of the medial femoral condyle through the joint capsule, MCL incarceration into the joint, and irreducibility with closed methods of reduction (an irreducible or complex

dislocation).12,41

 

 

Any asymmetry in the vascular examination from the uninjured extremity, even prehospital, necessitates further evaluation, with the specifics often dictated by vascular surgery protocols and regional preference.37

 

Many clinicians routinely obtain angiograms regardless of the vascular examination findings with

multiligament injured knees.4 Nonetheless, the current trend toward using sequential clinical examinations in reduced dislocation with normal pulses (including normal neurovascular examination) is becoming more popular and is considered safe. FIG 1 describes the Stannard protocol for selective arteriography.

 

Use of Doppler or other noninvasive vascular laboratory studies in conjunction with an ankle-brachial index is very useful because these studies can provide objective information (rather than the subjective findings of

pulses) and also avoid the invasiveness of angiography.27

 

Multislice computed tomographic angiography (MCTA) is a noninvasive imaging modality that is an alternative to the traditional gold standard of catheter-based angiography. It has been shown to be both

sensitive and specific for arterial evaluation in the injured lower extremity.17

 

The surgeon must be aggressive in the management of any abnormal vascular findings, with immediate vascular consultation and immediate surgical exploration of ischemia in the reduced knee dislocation.

Ischemia in the dislocated knee requires reduction and pulse or vascularity reevaluation. Continued ischemia from a popliteal artery injury for more than 6 to 8 hours results in amputation rates of up to 80%.15

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

An integral part of evaluation of the multiligamentously injured knee is plain radiographs before and after reduction to confirm congruity of the joint, evaluate for associated fractures, and detect ligament avulsion injuries that may aid in timing of the treatment plan. Note that 50% of patients with a dislocated knee will have a reduced tibiofemoral joint on plain radiographs at the time of initial evaluation.

 

Magnetic resonance imaging (MRI) is an excellent adjunct to delineation of the extent of injury and pattern of ligament injury and musculotendinous and osteoarticular injuries. These studies are combined with a careful examination of the ligamentous structures, with and without anesthesia, which are compared with those in the uninjured extremity.

 

MRI cannot replace a careful clinical examination under anesthesia (EUA), which can determine functional ligamentous injury and the need for ligament reconstruction. EUA is particularly useful in these patients given the severity of injury and associated pain.

 

Arthroscopic EUA can be helpful to further evaluate injury to the medial and lateral structures in addition to MRI and physical exam findings at the time of definitive ligamentous reconstruction.

 

CLASSIFICATION

 

Multiple classification systems have been used to describe dislocations of the knee.

 

 

Historically, the most commonly used system has been based on a positional description of the tibial position

 

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with respect to the femur when the knee is dislocated.14 However, this system is not without limitations.

 

 

 

FIG 1 • Stannard protocol for selective arteriography.

 

 

First, up to 50% of knee dislocations present spontaneously reduced, making classification based on position at the time of injury difficult, if not impossible.43

 

Second, this system does not provide information regarding the energy of the injury, the ligaments injured, or associated neurovascular injuries, all of which play a part in the overall treatment plan.

 

 

Classifying dislocations based on the anatomic injury pattern (ie, ligaments torn and associated neurovascular injuries) allows for adequate physician communication (especially for future reconstructions) and preoperative

planning.5 The anatomic classification is shown in Table 1.

 

Fracture-dislocation of the knee as described by Moore29 in 1981 involves a ligamentous injury in association with a fracture of the tibial or femoral condyles. This entity should be distinguished from the purely ligamentous definition of the dislocated knee as outlined in Table 1. Avulsion injuries such as the Segond fracture, fibular head avulsion fractures, patellar tendon or biceps femoris tendon avulsions, and cruciate avulsions may occur in knee dislocations, but they should be considered ligamentous or tendinous injuries and not condylar injuries that destabilize the bony architecture of the knee.

 

Table 1 Anatomic Classification of Knee Dislocations

Class

Description

KD I

Single cruciate torn and knee dislocated, ACL/collateral ligament usually torn, PCL intact

 

or

PCL/collateral ligament torn, ACL intact

KD II

Both cruciates torn, collaterals intact

KD III

Both cruciates torn, one collateral torn

Subset KD III M (M = ACL, PCL, MCL torn)

or

KD III L (L = ACL, PCL, LCL torn)

KD IV

All four ligaments torn

KD V

Periarticular fracture-dislocation (Fx-Dx, as modified by Stannard)

KDV.1 Fx-Dx, ACL or PCL intact KDV.2 Fx-Dx, with a bicruciate injury

KDV.3 Fx-Dx, bicruciate injury, one corner KDV.4 Fx-Dx, all four ligaments injured

C and N may be added to include arterial (C) and nerve (N) injury. KD, knee dislocation; ACL, anterior

cruciate ligament; PCL, posterior cruciate ligament; MCL, medial collateral ligament; M, medial; L, lateral; LCL, lateral collateral ligament.

 

 

 

 

DIFFERENTIAL DIAGNOSIS

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Knee dislocations can be difficult to assess in the presence of gross knee swelling or with the presentation of multitrauma or associated fractures.

 

Accurate detection of associated neurovascular injuries is critical.

 

Identification of the ligaments injured is based on the initial examination, imaging studies, and EUA.

 

NONOPERATIVE MANAGEMENT

 

Many patients today are treated with surgical management of some type; however, depending on their injury pattern, there are still subsets who are treated nonoperatively. These include patients with severe comorbidities that increase the risks of surgery or those with open dislocations or greatly damaged soft tissue envelopes, where the focus is on restoring the envelope and treating infection.

 

Cast Immobilization

 

Although the cast immobilization technique was used for many years to treat multiligament injuries to the knee before modern reconstructive procedures were available, closed treatment as definitive management rarely is indicated.

 

Immobilization in extension/slight flexion for 6 weeks, as described by Taylor et al,39 can result in a stable knee but, in our experience, should be used only in circumstances where the preferred technique of ligamentous reconstruction is not applicable or feasible (arterial injury, open knee dislocation with severe soft tissue envelope injury).

External Fixation

 

External fixation may be used to span the knee joint with fixation in the tibia and femur and is useful in patients who have poor rehabilitation potential. It also may be used as a temporary stabilizing measure in open knee dislocations, severe soft tissue injuries, unstable reductions (especially KD IV injuries), and vascular reconstructions while awaiting optimal conditions for operative ligamentous reconstructions.

 

Advantages include adequate maintenance of reduction, access to soft tissue wounds, patient mobilization, and protection of maturing reverse saphenous vein grafts.

 

However, the potential for loss of knee motion, arthrofibrosis, and heterotopic ossification in greater than 40% of knees exists.21 These often require later manipulation under anesthesia and lysis of adhesions.

Hinged Knee Brace

 

The patient is placed in a hinged knee brace and reduction of the knee joint confirmed radiographically. Supervised ROM exercises are initiated in the first few weeks following the injury.

 

This treatment method is ineffective in creating a stable knee but is an extremely important step in the process to a successful multiligamentous reconstruction.

 

Gaining extension, a more normal gait pattern, full flexion, and decreased swelling (resolution of inflammation) add to an easier postoperative course, with avoidance of postoperative stiffness and heterotopic ossification with multiligamentous reconstruction. In our experience, multiligamentous reconstruction within 10 days of injury can have significant risks of stiffness and a clinically inferior outcome.

 

The work of Shelbourne34 and others with ACL/MCL injuries with preoperative rehabilitation is even more applicable to multiligament knee injuries. Obtaining preoperative ROM before PCL, ACL, and collateral ligament reconstruction is extremely useful in obtaining a stable, pain-free knee after dislocation.

 

 

SURGICAL MANAGEMENT

Indications

Surgical intervention produces better clinical outcomes than nonoperative management of the multiligament injured knee.21

Operative reconstruction is recommended to most patients with multiligament knee injuries. In some cases, an external fixator is used temporarily, followed by surgical reconstruction; in most cases, early braced knee motion is instituted with delay of reconstruction of ligament injuries undertaken only after motion is restored and inflammation is resolved.

Ligamentous repair (ie, suture repair) is now only occasionally used. Failure rates of up to 40% have been reported with primary repair of the FCL/PLC,20 whereas loss of flexion and inferior return to

preinjury levels of activity have been documented with cruciate repairs.23 It is noteworthy, however, that revision reconstructions after failed repair of collateral structures may yield results similar to those of primary reconstructions.

Crucial to the immediate care of these injuries is a meticulous neurovascular examination. Any vascular deficit necessitates emergent vascular surgery consultation and consideration for an open popliteal artery exploration and reverse saphenous vein graft reconstruction.

The optimal timing for surgical intervention is not clearly defined. Multiple investigators have advocated acute (within 3 weeks) surgical management of knee dislocations.9,34 However, these findings are not

universal and caution should be used in selecting early surgical candidates because higher energy

injuries, concomitant vascular insult, and soft tissue integrity all play a role in optimizing the timing of surgery. Generally, the authors advocate waiting for several weeks after the injury before performing surgical reconstruction of these multiligamentous injuries in order to regain motion, decrease inflammation, and allow maturation of vascular grafts or repairs when performed.

Both single procedure and staged reconstructions are described for multiligamentous injuries. The decision is based on surgeon experience as well as the pattern and severity of the collateral injuries. If

staged reconstruction is undertaken, collateral reconstruction precedes cruciate reconstruction.21

 

 

Authors' Preference

 

In our experience, it is best to wait for preoperative motion, gait, and swelling to improve. Over 22 years of experience with knee dislocations has led to the following guidelines:

 

 

Delayed reconstruction is better than immediate surgery.

 

Preoperative rehabilitation is useful to regain motion, and resolution of swelling and inflammation is critical to surgical success.

 

Reconstruction is done with allo- and autografts, avoiding surgical repairs unless combined with reconstruction.

 

Both cruciates and involved collateral(s) are reconstructed simultaneously.

 

 

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Approach

Graft Choice

 

Many graft choices are available for ACL reconstruction in the multiligament-injured knee. We prefer a bone-patellar tendon-bone (BTB) or soft tissue allograft.

 

Although a BTB autograft is the gold standard in an isolated ACL reconstruction, the comorbidities of ipsilateral graft harvest in combined ACL-PCL injuries can result in stiffness, especially in simultaneous cruciate reconstruction.

 

The ipsilateral hamstring autograft should not be considered for a cruciate graft in a type III knee dislocation (KD IIIM) because the hamstrings provide a secondary restraint to valgus load and are preferentially used for MCL reconstruction.

 

Allografts are ideal for the multiligamentous knee injury. Allograft Achilles tendon and quadriceps tendon with bone blocks work well for PCL and PLC reconstructions, respectively, whereas hamstring allografts can be useful for ACL and MCL reconstructions.

 

The following graft selections represent autograft options for patients who decline the use of allograft tissue:

 

 

 

PCL reconstruction: ipsilateral or contralateral quadriceps tendon autograft ACL reconstruction: ipsilateral or contralateral patella BTB tendon autograft

 

KD IIIM: contralateral semitendinosus and gracilis (ACL), ipsilateral quadriceps (PCL), and ipsilateral semitendinosus (MCL)

 

KD IIIL or KD IV: Arciero-type lateral reconstruction using ipsilateral or contralateral semitendinosus or

biceps femoris tenodesis procedure

 

Posterior Cruciate Ligament Reconstruction

 

A number of approaches to modern PCL reconstruction are available, including (1) transtibial and femoral tunnels (with or without dual femoral socket) and (2) tibial inlay using a single or dual femoral tunnel in which tibial fixation is achieved by securing a bone plug into a trough positioned at the anatomic insertion of the PCL.

 

 

Significant differences in graft thinning and elongation, as well as differences in failure rates (32% transtibial, 0% inlay), have been shown in a biomechanical model of the two techniques, favoring the inlay technique. However, significant clinical differences have not been demonstrated between tibial tunnel and inlay PCL reconstructions and indeed transtibial PCL reconstructions have excellent long-term clinical

stability.26

 

There is no consensus on single versus double-bundle reconstruction of the PCL. Although many investigators have demonstrated decreased residual laxity with doublebundle reconstructions,46,48 clinical and functional superiority has not been definitively established.6

 

One of the senior authors prefers a single femoral socket and tibial inlay PCL reconstruction through a posteromedial approach for the KD IIIM injury pattern. The inlay technique places the bone-tendon junction of the graft at the joint line of the proximal tibia and may avoid the risk of the “killer curve” graft impingement seen experimentally with the transtibial tunnel technique. Both senior authors, regardless of the approach to the tibial side of a PCL reconstruction, use a single femoral tunnel reconstruction of the anterolateral bundle of the PCL.

 

 

Nonetheless, the Achilles tendon allograft is ideal for a double-bundle femoral reconstruction of the PCL. The calcaneal bone plug is fashioned for the tibial inlay, and the tendon portion is split into 6- and 8-mm graft bundles for posteromedial and anterolateral PCL bundle reconstruction, respectively. Cannulated, fully threaded 4.0-mm screws are used for the tibial inlay fixation, and soft tissue interference screw fixation (7- and 9-mm) is used in double-bundle femoral fixation.

 

 

PCL reconstructions often have failed to reestablish normal posterior translation at long-term follow-up.

 

 

Authors have proposed multiple factors that are responsible for late loosening and resultant residual posterior tibial translation following this surgical reconstruction.

 

 

The first factor is the acute angle the graft must make to round the posterior lip of the tibia when exiting the transtibial tunnel. This has been described as the “killer turn” or killer curve, which may cause graft abrasion and subsequent failure.22

 

The second factor involves the distinct anatomic bundles of the PCL, which function at different degrees

of knee flexion.3 Reconstructing the specific PCL bundles may produce more normal function than the single femoral tunnel technique (anterolateral PCL bundle).

 

The third factor is that the method of tunnel fixation may influence stiffness and elongation of grafts, with aperture fixation favored over extracortical fixation.45

 

Finally, failure to reconstruct the lateral structures in a PLC deficient knee leads to increased loads on the reconstructed PCL.1,25

 

Although tibial inlay techniques may appear cumbersome, advances have been made that reduce the technical difficulties encountered during these procedures. We believe the posteromedial approach to PCL

reconstruction described here simplifies this technique by maintaining the patient in the supine position during ACL and PCL reconstruction, avoiding the prone position altogether, preserving the origin of the medial head of the gastrocnemius, and simplifying graft passage.

 

Medial Collateral and Posteromedial Corner Reconstruction

 

Injury to the MCL in the setting of multiligamentous knee injury may be successfully treated nonoperatively in conjunction with delayed cruciate reconstruction.7

 

Decisions regarding reconstruction should be individualized and based on EUA and, in our experience, arthroscopic EUA.

 

Persistent valgus or external rotation laxity in full extension should prompt the surgeon to consider imbrication or anterior advancement posteromedial corner (POL).

 

Loop graft reconstruction of the MCL such as the modified Bosworth is preferred by the senior authors. However, based on biomechanical data, anatomic double-bundle techniques may be superior to single-bundle techniques in restoring valgus and external rotation laxity in biomechanical evaluation of the MCL deficient

knee.8

 

 

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The native superficial MCL femoral insertion is proximal and posterior to the medial epicondyle, and the tibial insertion is broad but preferentially posterior to the midportion of the medial tibia.

 

Tensioning of the MCL graft should be done at 30 degrees. Tensioning of the POL should be done in no more than 0 to 15 degrees of knee flexion to avoid flexion contracture.

 

Posterolateral Corner Reconstruction

 

The key components of the deep PLC are the popliteus, the PFL, and the FCL. The PLC plays a pivotal role in varus stability and also resisting excessive external rotation and posterior tibial translation.

 

Identification of the common peroneal nerve and protection during the exposure should precede any ligamentous reconstruction. The nerve can be found reliably behind the fibular neck or more proximally at the inferior edge of the biceps femoris. It is easily palpated and must be isolated as the first step in a PLC approach/reconstruction.

 

Historically, techniques such as primary repair, arcuate complex advancement,16 and biceps tenodesis44 were described to resist excessive varus instability in the lateral complex deficient knee.

 

Current practice supports performing anatomic reconstructions of the PLC with free allograft tissue, thereby accounting for the FCL, popliteus, and PFL.

 

LaPrade et al10,18 describe a technique using a split Achilles tendon allograft with separate bone blocks (minimum length 22 cm) anchored to anatomic femoral FCL and popliteal insertions via bone sockets placed an average of 18.5 mm apart. A tibial tunnel starting medial to the Gerdy tubercle and exiting at the presumed level of the musculotendinous junction of the native popliteus is created. An anterolateral to posteromedial fibular tunnel is created. The FCL graft is fixed to its femoral insertion and passed deep to the IT band and superficial to the popliteus tendon, entering into the fibular tunnel anterior to posterior, where it is secured with an interference screw at 30 degrees of flexion and slight valgus. The popliteal graft is tunneled deep through the hiatus and passed posterior to anterior through the tibial tunnel along with the posteriorly exiting limb of the FCL graft. The popliteus limb is passed deep to the FCL limb as described earlier. Both limbs are tensioned together through the tibial tunnel at 60 degrees of flexion and slight internal rotation with an interference screw

used in the tibia to secure the grafts. The short limb between the fixed fibular FCL and posterior tibia recreates the PFL.

 

 

Alternatively, Bicos and Arciero2 describe a technique using a single free graft with a minimum length of 24 cm and with an anterior and posterior limb as referenced from the fibular tunnel. The fibular tunnel is directed in an anterolateral to posteromedial direction. Once the graft is fastened in the fibular tunnel with interference fixation, the posterior limb can be tunneled along the popliteal hiatus and into a femoral socket created at the anterior aspect of the popliteal hiatus. The anterior limb of the graft is then passed under the biceps femoris and IT band and into a femoral socket at the FCL femoral insertion. Both grafts are tensioned at 30 degrees of flexion, internal rotation, and slight valgus and secured with interference

fixation.2

 

Multiligament Reconstructions

 

Knee Dislocation Type I (KD I): Anterior Cruciate and Collateral Ligaments Torn

 

The integrity of the ACL determines the timing of reconstruction for a type I knee dislocation.

 

 

ACL reconstruction is best delayed until ROM is restored for two reasons:

 

 

 

Collateral ligament healing usually occurs nonoperatively. Postoperative stiffness often is avoided.

 

We prefer to regain complete ROM and delay reconstruction for this type of injury. Patients usually regain knee motion within 6 weeks of the injury.

 

Graft choice is based on surgeon experience and patient preference and usually involves an ipsilateral bone-tendon-bone autograft.

 

Collateral ligament injury associated with only one torn cruciate ligament usually can be treated nonoperatively.

 

Note that PCL collateral ligament injuries with an intact ACL, although less common, do occur and are also classified as a KD I.

 

Knee Dislocation Type II (KD II): Anterior and Posterior Cruciate Ligaments Torn, Examination under Anesthesia Intact Corners

 

The integrity of the collateral ligaments allows for early ROM and a delayed reconstruction of the cruciate ligaments.

 

We prefer allografts for cruciate reconstructions performed simultaneously, but the decision is based on surgeon experience, patient preference, and risk tolerance.

 

Our graft of choice for bicruciate injuries is BTB allograft for the ACL and an Achilles tendon allograft for the PCL.

 

The patient is positioned supine with the injured extremity draped free. A lateral post is used to assist with arthroscopy.

 

Diagnostic arthroscopy is performed through standard portals, and associated injuries are treated as required.

 

The remnants of the cruciate ligaments are débrided. A small stump remnant may be retained to identify the anatomic footprints of the ACL and PCL. The detailed technique for ACL and PCL reconstructions is described in the Techniques section of this chapter.

 

The ACL tibial and femoral tunnels are prepared first, and the guide pin or passing suture advanced into the femoral tunnel to be used later for graft passage. The femoral tunnel may be drilled under dry visualization.

 

The PCL femoral tunnel(s), either single socket (preferred) or double socket, is prepared next under dry visualization. A single tunnel aims to replicate the anterolateral bundle, whereas double-bundle attempts restoration of anterolateral and posteromedial bundles of the PCL.

 

In a tibial tunnel PCL reconstruction technique, arthroscopic elevation of the posterior capsule and tibial PCL stump allows the surgeon to place a guide pin in the facet of the tibial footprint and verify this with direct visualization. The senior authors recommend intraoperative plain or fluoroscopic images as an adjunct in determining proper placement of the tibial PCL pin prior to reaming the tunnel.

 

 

Using this technique, secure your tibial PCL bone plug with interference fixation followed by manual tensioning of the graft in the femoral aperture and fixation prior to passage of the ACL graft.

 

 

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The ACL BTB allograft is passed from the tibial tunnel to the femoral tunnel and secured endoscopically with interference fixation to the femur with the knee hyperflexed or with a button on the femoral side of a soft tissue ACL graft reconstruction. The tibial side of the graft is not fixed until after the PCL fixation is complete.

 

Using the tibial inlay PCL technique, the posteromedial approach is used to gain access to the tibial attachment of the PCL and inlay reconstruction is carried out as described in the Techniques section of this chapter. Care must be taken to avoid placement of the bone block fixation screws in the ACL tibial tunnel.

 

 

The PCL graft is tensioned through the femoral side, and the knee is put through its ROM multiple times in an effort to remove a laxity from the graft construct.

 

 

 

The PCL femoral side is fixed endoscopically or cortically with the knee positioned at 20 degrees. Fixing the PCL graft before final ACL tensioning avoids posterior subluxation of the tibia on the femur. The ACL graft is fixed to the tibial side with the knee in extension.

 

Again, the ACL must be tensioned after the PCL fixation. Performing ACL tension and fixation before PCL

reconstruction could create posterior subluxation of the tibia on the femur.

 

Knee Dislocation Type IIIM: Tears of the Anterior Cruciate Ligament, Posterior Cruciate Ligament, and Medial Collateral Ligament

 

The steps for addressing a combined bicruciate injury with a collateral injury are similar to those described for the bicruciate reconstruction.

 

A more extensile posteromedial approach is used to expose the femoral MCL attachment site that is proximal and posterior to the medial femoral epicondyle. Division of medial layer 1 (sartorius fascia) or tunneling under this layer are both acceptable methods for graft passage across the joint line.

 

 

After fixation of the PCL to the femur, the MCL graft is tensioned and secured to the femur and the tibia. The tibial side of the ACL graft is then tensioned in extension and secured to the tibia.

Knee Dislocation Type IIIL: Torn Anterior and Posterior Cruciate Ligaments and Lateral Complex

 

As for the Type IIIM reconstruction, the reconstruction of a Type IIIL injury proceeds through bicruciate reconstruction.

 

After the PCL is tensioned, the lateral approach to the knee is performed, and the FCL and PLC reconstructed using the technique described later in this chapter (LaPrade Reconstruction).

 

The ACL graft is then tensioned in extension and secured to the tibia.

 

Knee Dislocation Type IV: Torn Anterior Cruciate Ligament, Posterior Cruciate Ligament, Medial Collateral Ligament, and Lateral Complex

 

This pattern most often is associated with a high-energy injury and represents a complex reconstruction. Use of initial external fixation is occasionally required in those patients with a KDIV that subluxates in a brace.

 

Careful attention to knee position during tensioning of the grafts is required to achieve a stable and concentric reconstruction in which the tibiofemoral joint is not subluxated.

 

 

The initial reconstruction follows bicruciate ligament reconstruction and includes exposure of the MCL. A lateral approach is used to expose the PLC as described later in the Techniques section.

 

 

The MCL and PLC grafts are prepared. The MCL graft is tensioned and fixed.

 

The posterolateral graft is tensioned and fixed.

 

The ACL graft is tensioned in extension and fixed to the tibia.

 

 

TECHNIQUES

• Bone-Patellar Tendon Graft for Bone-Anterior Cruciate Ligament Reconstruction

  The patient is positioned supine with a lateral post or leg holder in place.

  Standard arthroscopy portals are used, and a systematic examination of the knee is performed.

  Tibial and femoral tunnels 10 to 11 mm in diameter are drilled using standard methods. We prefer to use an accessory anteromedial portal for femoral tunnel preparation. A passing stitch is pulled into the femoral tunnel when removing the guide pin to later pass the graft.

  The allograft BTB bone plugs for the ACL are fashioned to match the tunnel diameter, and the femoral plug is fashioned to a length of 20 to 25 mm. Note that use of an accessory medial portal for femoral tunnel placement often requires a shorter patellar bone plug to allow graft passage into a low femoral wall socket.

  A small drill is used to place a hole in the femoral bone plug of the graft and a no. 2 braided composite suture (FiberWire, Arthrex, Naples, FL) is passed through the hole for graft passage.

  Two holes are drilled in the tibial bone plug and a no. 2 suture is passed to aid in graft passage and even potential post or staple fixation in case of graft length mismatch.

  A critical step in planning the depth of the femoral tunnel is factoring in the length of the allograft.

  The femoral tunnel should be reamed to a length of 20 to 25 mm. Most patients require an intra-articular graft length of 25 mm.

  Sixty millimeters (35 mm for the femoral tunnel plus 25 mm for the intra-articular portion) should be subtracted from the length of the entire graft to yield the ideal tibial tunnel length.

  This method ensures that optimal fixation of the bone plug in the tibial tunnel will be possible.

  P.524

  The loop of the passing suture is retrieved from the femoral tunnel through the tibial tunnel, and the no. 2

  braided composite suture on the femoral bone plug is brought out of the lateral skin.

   

  Fixation on the femoral side is performed using an interference screw through the accessory anteromedial portal with a protective sleeve in knee hyperflexion.

   

  Fixation and tensioning of the tibial side of the ACL graft are delayed until after PCL reconstruction.

   

  If graft tunnel mismatch occurs and the ACL tibial bone plug is not completely within the tibial tunnel, tibial interference fixation can be performed with an oversized soft tissue interference screw, or staple-post fixation can be performed externally on the tibial surface.

   

  In our experience, simultaneous bicruciate reconstruction, although complex, can be simplified by the following steps performed in this order:

   

  Tibial inlay using a posteromedial approach: ACL femoral and tibial tunnel preparation; femoral PCL tunnel preparation; ACL graft passage with fixation of the femoral side only; tibial inlay via the posteromedial approach; PCL graft passage and fixation; collateral reconstruction; and, lastly, ACL tibial fixation

   

  Alternatively, if a transtibial tunnel PCL technique is used, tibial tunnel preparation and PCL graft passage and fixation should be used prior to passing the ACL graft.

• Double-Bundle Posterior Cruciate Ligament Reconstruction

Positioning and Preparation

 

The patient is positioned supine on the operating table with the use of a lateral post. A careful EUA is performed to confirm the ligament injury and diagnosis.

 

Standard inferomedial and inferolateral arthroscopy portals are used.

 

A 30-degree arthroscope is inserted and diagnostic arthroscopy performed to confirm the PCL tear.

 

The PCL remnant is removed and the anatomic origins of the anterolateral and posteromedial bundles are identified.

Double-Bundle Tunnel Preparation

 

A long drill-tip guidewire is placed through the inferolateral portal with the knee positioned at 90 degrees, viewing the pin placement from an inferomedial portal. This allows sequential femoral bundle pin placement and reaming for the anterolateral bundle of the PCL (8-mm tunnel) followed by posteromedial tunnel creation (6 mm).

 

The guidewire is inserted in the anatomic site of the anterolateral bundle (usually high in the notch, near the articular surface), drilled into the condyle, and exiting out of the skin overlying the distal medial thigh.

 

The slotted end of the guidewire is used to pass a suture into the tunnel, with the loop remaining in the tunnel.

 

At our institution, both tunnels are reamed endoscopically through the medial cortex to allow for adequate graft tensioning.

 

At this point, both femoral sockets have been reamed, passing sutures are in place (exiting the inferomedial portal), and the posteromedial approach is performed.

Posteromedial Approach and Tibial Inlay Site Preparation

 

The leg is placed in the figure-4 position and the primary surgeon is positioned on the contralateral side of the operating table.

 

A posteromedial approach to the knee is used, with a 6- to 10-cm incision centered over the posterior joint line. The incision should follow the posterior cortex of the proximal tibia and the medial femoral epicondyle.

 

The sartorius fascia is exposed and incised in line with the skin incision. The gracilis and semitendinosus tendons are retracted posteriorly and distally. The fascia between the medial head of the gastrocnemius muscle and the posterior border of the semimembranosus muscle is divided in line with the incision. The semimembranosus tendon is incised, tagged, and reflected for later repair with nonabsorbable sutures.

 

The remainder of the exposure is performed by blunt dissection following the posterior border of the joint line and remaining anterior to the medial head of the gastrocnemius muscle at all times to protect the popliteal neurovascular structures.

 

The popliteus muscle is elevated with Bovie cautery, and a blunt Hohmann retractor is placed just lateral to the PCL insertion onto the tibia. This provides excellent visualization of the posterior tibia to create the trough.

 

The remnant of the PCL, the posterolateral edge of the medial femoral condyle, the joint surface, and the lateral meniscus are palpable anatomic landmarks that are used to position the trough in the center of the posterior tibia.

 

A burr is used to cut a trough 10 mm wide × 10 mm deep × 25 mm long extending from the joint line and centered over the midline posterior tibia depending on bone block size of the Achilles or quadriceps tendon inlay graft.

 

The trough should correspond to the size and shape of the allograft bone block. The previously fashioned inlay bone block is fixed to the tibia with 4.0-mm cannulated screws.

 

A posterior capsulotomy is made at the mid-joint line, and a curved Kelly clamp is used to identify the site for the posterior capsulotomy, through the notch medial to the ACL graft (lateral to the medial femoral condylar notch). Once the capsulotomy is formed, the Kelly clamp is used to grab the previously placed femoral socket passing sutures and transfer them out of the back of the knee.

 

We routinely use dry arthroscopy to ensure that the sutures are on the correct side of the ACL as well as to aid in grasping the sutures when reaching from the posterior approach.

 

At this time, the tourniquet is released and hemostasis is evaluated.

Graft Preparation

 

As noted earlier, our preferred graft for PCL reconstruction is an Achilles tendon allograft.

 

This graft allows for either a single- or double-bundle femoral technique, depending on surgeon preference and experience.

 

The ends are prepared by placing a traction stitch with a no. 2 FiberWire suture to facilitate graft tubulization and eventual passage.

 

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The calcaneal bone plug can be fashioned to maintain doublebundle tendons and can vary in size (often, it is 15 mm wide × 15 mm deep × 35 mm long). Hence, graft preparation must be performed before tibial trough creation. The senior author prefers a single-bundle femoral tunnel.

Tibial Graft Passage and Fixation

 

The tibial inlay graft is positioned into the tibial trough with care taken to ensure that the bone-tendon junction is positioned at the joint line to avoid abrasion or the killer turn effect.

 

The inlay is secured with two 4.0-mm cannulated screws over a guidewire, positioned 1 cm apart.

 

The screws are placed from posterior to anterior and parallel to the joint line in an anterolateral trajectory to avoid inadvertent capture of the ACL graft in the tibia.

Femoral Graft Fixation

 

Once the inlay is secured, the double-bundle graft ends are sequentially passed, beginning with the posteromedial bundle followed by the anterolateral bundle. This sequence allows for optimal visualization.

 

 

 

TECH FIG 1 • AP and lateral views of a right knee that has undergone a PCL reconstruction using the tibial inlay technique for the tibial side of the graft and with a soft tissue interference screw on the femoral side. Staples visible medially are from a simultaneous modified Bosworth MCL reconstruction with semitendinosus autograft and double-bundle ACL reconstruction with suspensory femoral fixation.

 

 

The knee is positioned at 20 degrees of flexion during tensioning of the 6-mm posteromedial bundle graft, and a 7 × 30-mm soft tissue interference screw is placed arthroscopically, viewing from the inferomedial portal.

 

Next, the anterolateral bundle is passed (8-mm graft). The knee is then ranged for 20 cycles and placed in 70 degrees of flexion where the graft is fixed with a 9 × 30-mm soft tissue interference screw.

 

Lastly, the tibial side of the ACL allograft reconstruction is identified and ranged. The ACL graft is fixed with the knee in full extension.

Collateral Reconstruction

 

At this point, the ACL and PCL reconstructions are complete, and the associated collateral reconstruction is performed.

 

Although it is tempting to delay the collateral reconstruction, it is the senior authors' opinion that the bicruciate reconstruction is at risk for failure or loosening by staging the collateral reconstruction.

 

We try to limit the number of other procedures scheduled the day of a bicruciate reconstruction to minimize the pressure from those other cases that may tempt the surgeon to delay the collateral reconstruction (TECH FIG 1).

• Single-Loop Posteromedial Complex Reconstruction

   

  An incision is made from the medial femoral epicondyle to the posterior aspect of the insertion of the pes anserinus tendon on the tibia. Incisions should be planned preoperatively to facilitate ACL, PCL, and MCL reconstruction through the same skin incisions if necessary.

   

  The sartorius fascia is incised in line with the semitendinosus tendon from distal to proximal, and semitendinosus graft harvest is performed, leaving the tibial Sharpey fibers attachment in place.

   

  The proximal end of the semitendinosus is cleared of remaining muscle, and a Krackow suture is placed in its free end.

   

  A subretinacular tunnel is made from distal to proximal deep to layer 1, and the graft is passed using a Kelly clamp to retrieve the free tendon end.

   

  Using a high-speed burr, a U-shaped trough is made around the isometric point of the MCL (approximately 3 mm proximal and 4 mm posterior to the medial femoral epicondyle).

   

   

  The graft is laid into this trough and is secured with either a staple or screw-washer construct. The graft is passed back through the fascial tunnel, and the knee is cycled through a ROM.

   

  P.526

   

  Under manual tension at 30 degrees of knee flexion, the graft is then stapled to the tibia at the insertion of the MCL on the posterior half of the tibia. Of note, the insertion of the semitendinosus is slightly anterior to the MCL insertion and, hence, when looped back down, should be fixed to the tibia at its posterior edge.

   

  If residual valgus laxity is evident in full extension, consideration should be given to making a vertical capsulotomy posterior to the superior MCL, advancing the POL, and imbricating this capsule at the posterior edge of the MCL reconstruction. This should be performed in near full extension.

   

  The wound is closed in layers including repair of sartorius fascia.

   

  The tibial side of the ACL graft can then be tensioned and fixed in extension.

• Anatomic Double Graft Reconstruction of the Posterolateral Corner (LaPrade Reconstruction)

   

  The key components of the deep PLC are the popliteus, the PFL, and the FCL. The anatomic, dual allograft reconstruction described by LaPrade et al18 addresses each of these three critical components.

   

  A transtibial and transfibular tunnel will be used, and two femoral sockets measuring 25 mm will be used to dock the bony ends of the grafts at the FCL and popliteus insertion sites.

   

  We routinely use an Achilles tendon allograft because it provides adequate tendon length, calcaneal bone block for femoral fixation, and the ability to split the graft into two grafts. A minimum length of 22 cm is desired.

  Posterolateral Approach

   

  The patient is positioned supine on the operating table, with the injured extremity draped free. The leg is carefully positioned on the operative table, with the foot resting in the seated surgeon's lap.

   

  The knee is flexed to 90 degrees to relax the peroneal nerve, and a skin incision is made beginning at the lateral epicondyle of the femur toward the Gerdy tubercle. Full-thickness anterior and posterior skin/fat flaps can be developed to broaden the exposure, particularly posteriorly.

   

  The common peroneal nerve is identified as it courses from the inferior border of the biceps femoris proximally through the perineural fat to the fibular neck. The nerve is fully exposed until it safely falls away from the reconstructive field. A vessel loop may be used with caution to avoid excessive traction. The senior authors simply use the vessel loop without a clamp to avoid undue tension on the peroneal nerve resulting from the weight of the clamp.

   

  Once the nerve is exposed and protected, the interval between the lateral gastrocnemius and soleus is bluntly developed posterior to the fibular head. The surgeon should not dissect posterior to the lateral gastrocnemius muscle because this places the popliteal neurovascular structures at risk.

   

  Adequate palpation of the posteromedial facet of the fibular head and the posterolateral aspect of the tibia with a finger or specifically designed guides (LaPrade, Arthrex) will allow safe guide pin placement for fibular and tibial tunnels.

  Tunnel Preparation

   

  Once the exposure is complete and protection of the peroneal nerve is verified, a guide pin is placed from the fibular insertion of the FCL anterolaterally to the posteromedial facet on the fibular styloid. This should be approximately a 45-degree angle from the coronal plane and aimed slightly distal to proximal.

  The surgeon's finger should be on the posteromedial fibular facet, protecting the peroneal nerve and neurovascular bundle even if using specifically designed guides (LaPrade). Usually, a 7-mm tunnel is drilled over the guide pin.

   

  A 9-mm tibial tunnel is reamed over a guide pin that is placed from the distal and medial aspect of the Gerdy tubercle to the popliteal sulcus on the posterolateral aspect of the tibia. A tissue protector and specifically designed guide are used again to protect the neurovascular structures. Surgeon safety is equally critical, and if using the technique of a surgeon's finger to guide the drill pin, care should be taken to avoid injury to the surgeon.

   

  The IT band is then split in line with its fibers such that the popliteal tendon and FCL femoral insertions are identified, and the lateral capsule is split to expose the lateral femur.

   

  The FCL attachment is proximal and posterior to the lateral epicondyle.

   

  The anterior aspect of the popliteal sulcus is identified. It should be slightly anterior to the FCL and approximately 18.5 mm from the FCL.19

   

  Parallel guide pins are placed exiting the anteromedial femoral cortex, and 9-mm tunnels are reamed to a depth of 20 mm. Care must be taken to avoid damage to the lateral femoral articular surface (popliteal tunnel) as well as injury to the ACL tunnel (fibular collateral tunnel).

  Graft Placement

   

  Eyelets on the guide pins are used to pass the calcaneal portions of the grafts into the popliteus and FCL femoral origins. These are fixed with metallic interference screws.

   

  The popliteal graft is tunneled along its anatomic course to the popliteal hiatus, and with help of a suture passer or passing stitch, is delivered from posterior to anterior through the tibial tunnel.

   

  The second graft fastened at the FCL origin will reconstruct both the FCL and PFL.

   

  The graft is passed deep to the IT band and anterior arm of the biceps femoris and through the fibular tunnel anterolateral to posteromedial.

   

  The residual free end is then pulled through the tibial tunnel (posterior to anterior) next to the first (popliteus) graft, thereby reconstructing the PFL.

   

  The knee is cycled and an interference screw (7 mm) is placed in the fibular tunnel with the knee at 30

  degrees and slight valgus.

  Manual traction is placed on both grafts exiting the anterior tibial tunnel. With the knee at 60 degrees of flexion and slight internal rotation, the grafts are fixed with a soft tissue interference screw (9 mm).

   

   

   

  P.527

   

  PEARLS AND PITFALLS

   

  Neurovascular status

• Carefully evaluate pulses and the neurologic examination. Use noninvasive studies to objectively document the findings of a normal vascular examination. Aggressively (emergently) evaluate asymmetry or ischemia on vascular examination with vascular consultation, computed tomography (CT) angiography, and as indicated, intraoperative arteriography, exploration, or reverse saphenous vein grafting of the injured popliteal artery segment.

   

  Planning ▪ Determine the impact of ligamentous reconstructions on the patient as a whole.

  Delay reconstructions for multitrauma, and consider external fixation for such patients to assist in transfers and mobilization. Treat the patient.

  • Obtain preoperative ROM with normalized gait prior to reconstruction. This will maximize the final result. The PCL often will heal to a grade 1 or 2, thereby making it possible to perform only an ACL/collateral reconstruction.

  • Use allografts over autografts, depending on patient preference and religious beliefs.

     

    Diagnosis ▪ Clearly diagnose the ligaments involved. EUA combined with MRI can give an accurate picture of the needed reconstructions. Remember, MRI may overdiagnose ligamentous injuries, which will be found on EUA not to need reconstruction.

     

    Surgery ▪ Use reconstructions over repairs. If using repairs, delay postoperative ROM.

  • Perform bicruciate and collateral reconstructions at the same sitting (simultaneously), if possible.

     

    Simultaneous bicruciate reconstruction

• Drill the ACL femoral and tibial tunnels first.

• Drill PCL femoral tunnel(s) second.

• Pass the ACL graft and fix on the femoral side first if performing tibial inlay PCL.

• Pass the PCL first and fix on the tibial side if performing tibial tunnel PCL.

• Perform a posteromedial approach for the tibial inlay.

• Fix tibial side of ACL reconstruction/perform collateral reconstruction.

 

POSTOPERATIVE MANAGEMENT

 

A thorough understanding of the reconstruction and tailoring the treatment plan to each individual patient are crucial to all rehabilitation protocols.

 

Patients who undergo early repair or reconstruction of multiligament knee injuries should begin supervised knee motion exercises within the first 3 days after surgery to decrease the risk of arthrofibrosis.

 

A hinged knee brace is used after bicruciate reconstructions, with non-weight bearing of the extremity recommended for 3 to 4 weeks.

 

Weight bearing is progressed to full, usually at 6 weeks, with a brace and crutches.

 

With medial or lateral procedures, consideration is given to a slower return to full weight bearing owing to poor quadriceps tone and potential unfavorable mechanics.

 

Early postoperative therapy focuses on control of edema and pain to facilitate return of quadriceps function.

 

 

Following PCL reconstruction, early return of full extension is paramount.

 

Supervised passive extension exercises are performed with a simultaneous, anteriorly directed force on the proximal tibia twice daily.36

 

 

The knee is kept in a postoperative brace from 0 to 90 degrees for the first 6 weeks. Closed kinetic chain active exercises are allowed in this arc of motion.

 

The goal is to regain full ROM by 3 months.

 

If 90 degrees of flexion is not achieved by 8 to 12 weeks, manipulation under anesthesia (MUA) and arthroscopic lysis of adhesions, release of the anterior interval, and evaluation of reconstructed structures are strongly recommended. The presence of a flexion contracture is extremely worrisome and should be

aggressively managed.4,28

 

Straight-line jogging usually is begun at 5 to 6 months, depending on quadriceps function.

 

Patients may return to full activity in 9 to 12 months.

OUTCOMES

The trend in recent years of increased surgical management of ligamentous injuries, coupled with earlier motion and a more aggressive approach to the management of stiffness (eg, MUA, arthroscopic lysis of adhesions), has yielded more favorable results than those previously reported regarding function, pain, and the incidence of debilitating instability.

Studies using Lysholm scores for outcomes favor surgical treatment of these injuries over nonoperative treatment, with an average increase of 20 points reported with operative intervention.23,31,33,36,38,47

Generally speaking, 93% of patients are able to return to some type of occupation but may not be able to work at a highly demanding job. In seven studies, approximately 70% of patients returned to their previous occupation.23,24,30,32,33,38,40

With surgical intervention, many patients ultimately have knees that function well for activities of daily living, and some are able to participate in recreational sports, but only 40% are able to return to their previous level of activity.30,33,35

 

 

COMPLICATIONS

 

 

One of the most devastating problems encountered in multiligament knee injuries is failure to identify and appropriately manage vascular injuries in the acute phase.

Another common problem is failure to recognize the full extent of the ligamentous injury, including collateral/capsular involvement at the time of surgical management.

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There also is potential for nerve injury, with peroneal nerve involvement more common than tibial nerve injury.

Complete nerve dysfunction carries a much worse prognosis than a partial injury, especially regarding the tibial nerve. Fewer than half of these patients have complete functional recovery of the nerve.9,11,13

The necessity of creating multiple femoral and tibial tunnels brings with it the potential risk of tibial plateau fracture, medial femoral condyle avascular necrosis, and subchondral fracture.

The potential also exists for intraoperative neurovascular injury, especially with lateral side reconstructions (peroneal nerve) and PCL reconstructions (popliteal neurovascular bundle).

Postoperatively, the risks include infection (especially with open injuries), wound healing problems with multiple incisions, and arthrofibrosis (with or without heterotopic ossification).

On average, 38% of multiligament knee injuries require at least one surgical intervention to regain motion.24,28,30,32,35,38,40,43

There also is concern for posttraumatic arthritis (especially of the patellofemoral joint), potential loss of graft or repair fixation, and deep venous thrombosis with pulmonary embolus.

 

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