ACL/PCL reconstruction: the role of double-bundle PCL reconstruction

ACL/PCL RECONSTRUCTION: THE ROLE OFDOUBLE-BUNDLE PCL RECONSTRUCTION

HUSSEIN A. ELKOUSY, MD and CHRISTOPHER D. HARNER, MD

Our approach to combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuriesdepends on the timing of the injury and concomitant ligament and bony pathology. In the acute setting (within 3weeks), we prefer to perform single-bundle ACL and PCL reconstruction because we have seen consistently goodresults. However, chronic combined injuries do not fare as well because single-bundle PCL reconstruction in theseinjuries has not consistently corrected posterior laxity. Because of this clinical data, we now utilize a double-bundle PCL technique for knees with chronic, combined ligament deficiency with instability. This particularpatient population has significant anterior, posterior, and, in many cases, posterior lateral laxity. Once the decisionhas been made to proceed with this procedure, attention to the technical details is critical to achieving goodresults. In this article, we will outline important general and specific technical details that will facilitate theprocedure and optimize the clinical outcome.KEY WORDS: anterior cruciate ligament, posterior cruciate ligament, double-bundle reconstruction© 2003 Elsevier Inc. All rights reserved.

Perhaps the most important feature of combined ante-rior cruciate ligament (ACL) reconstruction and double-bundle posterior cruciate ligament (PCL) reconstruction isthat it is rarely indicated. Most isolated PCL injuries maybe treated successfully nonoperatively and most combinedinjuries may be treated with combined ACL reconstruc-tion with a single-bundle PCL reconstruction.1-11 How-ever, a small subset of patients with combined injuriesmay benefit from a double-bundle PCL reconstruction.

Double-bundle PCL reconstruction has been advocatedto restore posterior tibiofemoral stability in the full rangeof flexion and extension in patients with grade 3 injuries.12

In addition, it has been shown that reconstructing bothcomponents of the PCL decreases posterior laxity com-pared with a single-bundle reconstruction.13 The largeranterolateral bundle confers stability in the mid-ranges offlexion, and the smaller posteromedial bundle confers sta-bility in extension but also in extreme flexion.14,15 There-fore, in theory, by reconstructing both bundles in patientswith chronic instability, posterior stability can be restoredin the full range of motion.

Few patients are candidates for a double-bundle PCLreconstruction in the presence of an associated ACL tear.When the 2 injuries occur simultaneously, many authors,ourselves included, prefer to operate within the first 3weeks after the injury.8,11,16-19 In this setting, we managethese injuries with combined ACL and single-bundle PCL

reconstruction. However, it is not always possible to per-form surgery in this initial window of time due to associ-ated ligament and bony pathology to the knee, as well astrauma to other parts of the body. Though some of thesepatients will follow up with complaints of stiffness, asubset of patients will complain of instability, includingposterior instability. In our experience, a single-bundlePCL reconstruction often leaves these patients with resid-ual posterior laxity; therefore, we have treated them withdouble-bundle PCL reconstruction to reduce this posteriorlaxity.

Examination findings are consistent with ACL and PCLinsufficiency and include a positive Lachman, positiveanterior and posterior drawer examinations, positive pivotshift, and positive reverse-pivot shift maneuvers. The find-ings of significant posterior translation and a profoundreverse pivot as compared with the contralateral limbsupport the decision to proceed with the combined ACLand double-bundle PCL. The history provides the moreimportant information in that if the patient presents witha chronic injury and complains of posterior instability inflexion as well as extension, then a combined ACL withdouble-bundle PCL reconstruction may provide morebenefit than a single-bundle PCL reconstruction. The goalof the procedure is to maintain range of motion whileconferring posterior tibiofemoral stability in the full rangeof motion.

PREOPERATIVE EVALUATION

Any patient who presents with a chronic combined ACLand PCL injury has sustained a high-energy injury in thepast and care should be taken to fully evaluate both theoperative extremity and other injuries. Often, an associ-ated injury prevented an acute or subacute reconstruction.These injuries may include spinal column injuries, thoracicinjuries, and vascular, nervous, or ligamentous injuries of

From the Fondren Orthopaedic Group, Sugar Land, TX; and theCenterfor Sports Medicine, University of Pittsburgh Medical Center, Pittsburgh,PA.

Address reprint requests to Hussein A. Elkousy, MD, Fondren Ortho-paedic Group, 15200 Southwest Freeway, Suite 290, Sugar Land, TX77478.

© 2003 Elsevier Inc. All rights reserved.1060-1872/03/1104-0006$30.00/0doi:10.1053/otsm.2003.50027

286 Operative Techniques in Sports Medicine, Vol 11, No 4 (October), 2003: pp 286-293

the involved extremity. Therefore, a broad preoperativeclinical assessment should focus on the risks of anesthesiaand take special care in patient positioning. A more tar-geted examination of the extremity should focus on vas-cular status, nerve function, and the status of other kneeligaments. Radiographs should be obtained to rule out oldfractures or to assess the tibiofemoral relationship. Finally,a magnetic resonance image is helpful in these cases tofully evaluate other soft-tissue structures of the knee, in-cluding the menisci and the collateral ligaments.

GRAFTS

Because of the extensive existing damage to the knee, weprefer to use allograft tissue to reconstruct most of theinjured structures in a combined ACL and PCL injury.Patellar tendon allograft is used for the ACL reconstruc-tion, an Achilles allograft for the anterolateral bundle ofthe PCL, and a semitendinosus autograft for the postero-medial bundle of the PCL.

Once the allograft tissue has been thawed in saline on aseparate designated table, the grafts are prepared. Thepatellar tendon bone plugs are fashioned into 11-mm mil-limeter diameters by 20- to 25-mm-long plugs. The inter-posed tendon is slightly wider than 11 mm to maximizecollagen bulk of the graft. Two drill holes are placed on thetibial bone plug and one drill hole is placed on the end ofthe femoral bone plug furthest from the tendon. Number5 braided nonabsorbable sutures are looped through eachof these drill holes.

The Achilles bone plug is fashioned into an 11-mmdiameter by 20- to 25-mm-long bone plug. The soft-tissuelimb is trimmed to a width approximately double thewidth of the bone plug. This soft-tissue limb is foldedlongitudinally and stitched with a number 5 braided non-absorbable crossing whipstitch from the midsubstance,and extends distally so that the 2 limbs of the sutureextend from the end of the graft. A drill hole is place in theend of the bone plug furthest from the tendon and a loopof number 5 braided nonabsorbable suture is passedthrough this hole (Fig 1).

The semitendinosus tendon is harvested in standardfashion early in the case before making the tibial bonetunnels. Once the semitendinosus tendon is harvested, it isprepared by placing a running number 2 nonabsorbablebraided whipstitches in each end of the graft. As muchhealthy graft length is preserved as possible. The graft isfolded into a double loop and the looped end is sewn toitself with a 0 vicryl suture. For all grafts, a blue markingpen demarcates the tendon side of the bone plugs, and thelooped end of the semitendinosus graft is marked at 25 or30 mm, depending on the femoral tunnel length (Fig 1).

EXAMINATION UNDER ANESTHESIA

After anesthesia has been administered, an examination isperformed. All ligaments are tested, particularly the pos-terolateral corner to insure that the appropriate procedureis performed. The ACL is tested with a Lachman, a pivotshift, and an anterior drawer. The PCL is tested by com-paring the femorotibial step-off with the contralaterallower limb followed by a posterior drawer. Reverse pivotshift and Godfrey tests may also be tested. The PCL andposterolateral corner are tested by comparing externalrotation of the affected leg with the contralateral leg at 30°and 90°.

OPERATIVE SETUP

Once the knee has been examined, the table is set up. Asandbag is taped to the table in a position to hold the footwith the knee at 90° of flexion. A side post is placed justdistal to the level of the greater trochanter. No tourniquetis used unless autograft patellar tendon is harvested,which is generally not the case for these multiligamentreconstructions. The contralateral extremity is placed infull extension on a soft egg crate pad that extends beneaththe heel. A foley catheter is placed because of the antici-pated 3- to 5-hour length of the case.

Once the surgeon is satisfied that the injury is confinedto the ACL and PCL only, the portal and incision sites aremarked. The portal sites are a superolateral outflow portal,

Fig 1. Double-bundle PCL grafts. Double-loop semitendinosus autograft above is used to reconstruct the posteromedialbundle, and the Achilles allograft below is used to reconstruct the anterolateral bundle.

ACL/PCL RECONSTRUCTION: THE ROLE OF DOUBLE-BUNDLE PCL RECONSTRUCTION 287

and anterolateral and anteromedial working portals. Afourth posteromedial portal is used, but it is not marked atthe beginning of the case because it will be localized witha spinal needle during the case. A vertical anteromedialincision is marked for the entry sites of the tibial tunnelsfor the grafts and for the semitendinosus graft harvest.This is marked from the level of the superior aspect of thetibial tubercle midway between the tibial crest and theposteromedial border of the tibia, and it extends distally 2to 3 cm. Each portal site and the incision site are injectedwith a marcaine and epinephrine mixture. The joint isinjected through the portal sites.

SURGICAL TECHNIQUE

ARTHROSCOPY AND PRELIMINARYPREPARATION

The knee is washed with alcohol and betadine beforedraping. Arthroscopy portals are established, beginningwith the superolateral portal with the knee in full exten-sion. An outflow cannula is placed to gravity in this portal.The knee is flexed to 90° by using the previously placedbump to hold the position. A roll of towels is placedbetween the side post and the thigh to prevent the hipfrom externally rotating. Anterolateral and anteromedialportals are established. The ACL, PCL, and menisci arevisualized to confirm the physical examination findings.Once this is done, the ACL is debrided first, followed bythe PCL. Care is taken to leave sufficient stump of the ACLon the tibial side and of the PCL on both the tibial and

femoral sides to insure that the anatomy is not obscuredfor tunnel placement. This may not be as critical if oneligament is preserved, but it is essential for combinedligament reconstructions because no reference point maybe available. A notchplasty of the medial wall of the lateralfemoral condyle allows for accurate placement of the ACLfemoral tunnel and will help with passing the 2 grafts. Theentire PCL usually cannot be fully debrided unless a pos-teromedial portal is established as a working portal and a70° arthroscope is placed in the anterolateral portal. The30° arthroscope is also placed in the posteromedial portalto identify the tibial origin of the PCL and completethe debridement with a shaver in the anteromedial portal(Fig 2).

The hamstring tendons are palpated to insure goodposition of the anteromedial incision. The incision is madeand the soft tissue is dissected to the level of the sartoriusfascia. The sartorius is incised above and parallel to theunderlying semitendinosus. The semitendinosus is har-vested while keeping the gracilis intact. This same incisionwill serve as the tibial tunnel entry sites for the ACL andPCL grafts.

TUNNEL PREPARATION

The PCL guide is placed through the anteromedial portaland set at the origin of the PCL on the posteromedialborder of the lateral tibial plateau (Fig 3A). The appropri-ate site is between 1 and 2 cm distal to the articularmargin. The PCL footprint serves as a landmark. Thecannula for the guide is placed in the anteromedial inci-

Fig 2. Operative setup demonstrating the arthroscope in the posteromedial portal. The anterolateral portal, anteromedialportal, and the anteromedial incision are also apparent in this photograph.

288 ELKOUSY AND HARNER

sion to insure that there is sufficient room for an ACLtunnel guide wire 2 cm proximal and posterior to the PCLtunnel. This will insure an approximately 1-cm bonebridge between the final tunnels. A guide wire is drilledthrough the cannula under direct arthroscopic vision viathe posteromedial portal with the knee in 90° of flexion(Fig 3B). The last few millimeters are completed by tap-ping the guide wire with a mallet rather than drilling toavoid injury to the popliteal vessels. The guide is removed

and a lateral radiograph is taken to insure good position ofthe guide wire.

The ACL guide is place through the anteromedial por-tal. The guide is set between 45° and 50° to allow sufficientlength of the tibial tunnel. The intra-articular entry site ofthe tibial tunnel is chosen based on the position of theanterior horn of the lateral meniscus, the tibial spines, andthe native ACL footprint. The cannula for the guide isplaced against the tibial cortex through the anteromedial

Fig 3. (A) The PCL guide is placed through the anteromedial portal and set at the origin of the PCL on the medial posteriorborder of the lateral tibial plateau. (B) A guide wire is drilled through the cannula under direct arthroscopic vision via theposteromedial portal with the knee in 90° of flexion.


incision. Once again, care is taken to insure that the entrysite for the guide wire is 2 cm from the PCL entry site (Fig4). The guide wire is drilled under direct vision via theanterolateral portal. The ACL tunnel is placed proximaland posterior to the PCL tunnel because the PCL will befixed with a screw and washer distal to the tunnel,whereas the ACL will be fixed with an interference screw.Although the PCL tunnel is more anterior than the ACLtunnel, it should still lie at least 1 cm from the tibial crestto minimize prominence of the hardware.

Once the ACL guide wire has been placed, the radio-graph has usually been developed and the final tunnelscan be drilled. If the guide wire is not adequate based onthe radiograph, then a 3- or 5-mm offset guide can gener-ally be used to make minor modifications in the position ofthe wire. However, this is not usually necessary if the PCLorigin has been adequately visualized arthroscopically. Acautery is used to incise the periosteum in a vertical lineflanking each guide wire. A three-eighths-inch curvedosteotome is used to reflect the periosteum to allow fortunnel placement. The PCL tibial tunnel is drilled firstwith a compaction drill under direct vision from the pos-teromedial portal. A specialized double-curved curette isplaced through the anteromedial portal to prevent migra-tion of the guide wire during drilling. The last few milli-meters of drilling are advanced by hand to avoid poplitealvessel injury. The compaction drill size matches the finalsize of the anterolateral bundle of the graft, which isgenerally 11 mm.

A plug is placed in the PCL tunnel entry site to mini-mize outflow of arthroscopic fluid. A drill is then chosenthe same size as the final ACL graft size (11 mm) and theACL tunnel is drilled. A plug is also placed in this tunnel

to minimize outflow of fluid and maintain arthroscopicpressure.

The ACL femoral entry site is selected at the 10 or 2o’clock positions depending on whether it is a right kneeor a left knee, respectively. The arthroscope is placed in theanterolateral portal. A Steadman awl is used to mark thesite 6 to 7 mm anterior to the posterior wall of the notch.This is performed manually, without a guide for assis-tance. A guide pin is placed through the anteromedialportal and tapped into the femoral tunnel mark with theknee first hyperflexed maximally. An acorn reamer isplaced over the guide pin and drilled by hand. The size ofthe reamer selected is one size below the final size of thefemoral tunnel; therefore, often, a 10-mm acorn reamer isused for an 11-mm tunnel. The depth of the tunnel isbetween 25 and 30 mm, depending on the length of thefemoral bone plug (generally 2 to 4 mm longer than thefemoral plug). Sequential dilators starting with the size ofthe original acorn reamer are used to dilate the tunnel. If a10-mm acorn reamer is used, the dilators start at 10 mmand increase in size in 0.5-mm increments to the finaltunnel size of 11 mm.

The PCL femoral tunnel sites are marked through theanterolateral portal with the camera in the anteromedialportal. The anterolateral femoral tunnel site is marked atthe 1 or 11 o’clock position for right and left knees, respec-tively. The center of the tunnel is marked with a Steadmanawl approximately 6 to 7 millimeters from the articularsurface. This will allow the 11-mm tunnel to abut thearticular surface. The posteromedial tunnel is marked 3 to4 millimeters from the articular surface at the 2:30 to 4o’clock position for a right knee and at the 8 o’clock to 9:30position for a left knee. The graft is generally 5 to 7

Fig 4. The ACL and PCL guide wires have been drilled through the anteromedial incision. Care is taken to insure that the guidewires are at least 2 cm apart to maintain an adequate bone bridge between the tunnels.


millimeters in size; therefore, the tunnel will abut thearticular surface. The actual sites for the tunnels will varybased on the footprints of the native bundles of the PCL.Once the tunnels are marked, sequential guide pins areplaced and tapped into the marked sites. Acorn reamers 1size below the tunnel size are hand-drilled to a 25 to 30mm depth. Each tunnel is sequentially dilated in 0.5-mmincrements to the final tunnel size (Fig 5).

GRAFT PLACEMENT: PCL

The anterolateral bundle of the PCL is passed first. A3.2-mm drill bit is used to drill the far cortex of the femoraltunnels of both bundles of the PCL via the anterolateralportal. The sutures of the 2 tibial limbs of the PCL graftsare then tied together to allow simultaneous passage ofthese 2 grafts through the tibial tunnel. A hewson suturepasser is placed up through the PCL tibial tunnel, and theloop is grasped with a grasper to bring it into view in thejoint. The sutures of the tibial limbs are passed through theanterolateral portal and through the hewson suture passerloop. The hewson suture passer is then used to pull thesutures out the tibial tunnel. Alternatively, an 18-gaugewire may be used to pass the sutures by passing the wirethrough the tibial tunnel and out the anterolateral portal.Once the sutures have been passed, the grafts are pulledthrough the tibial tunnel with care taken to leave sufficientgraft on the femoral side to pull each limb into the femoraltunnels.

A beath needle is passed from the anterolateral portalthrough the femoral tunnel of the anterolateral bundlefrom inside to outside. The suture from the anterolateralbundle bone plug is threaded through the eyelet of thebeath needle and pulled up through the femoral tunnel.

The plug is pulled into the femoral tunnel and fixed witha metal interference screw. The screw is placed from insidethe joint and behind the graft, away from the articularsurface. The same procedure is used to pass the postero-medial graft; however, this graft is fixed with a bioscrew.Alternatively, the anterolateral bundle may be fixed with ametal screw from the outer cortex placed through a smallincision, and the posteromedial bundle may be fixed overa button on the outer cortex. Once the femoral limbs havebeen fixed, the graft is pulled taught through the tibialtunnel.

GRAFT PLACEMENT: ACL

A 3.2-mm drill bit is used to drill the far cortex of the ACLfemoral tunnel via the anteromedial portal. This is per-formed with the knee in a hyperflexed position. A beathneedle with a suture loop in the eyelet is passed by handthrough the femoral tunnel via the anteromedial portal. Apituitary rongeur or other grasping device is used to feedthe sutures of the femoral bone plug through the tibialtunnel. A second grasper is placed through the suture loopof the beath needle and through the anteromedial portal.This second grasper is used to grasp the suture of the boneplug and pull it through the loop in the anteromedialportal. The beath needle is pulled through the joint, pull-ing the femoral bone-plug sutures. This series of maneu-vers is performed because the position of the femoraltunnel at 10 or 2 o’clock requires passage of the beathneedle from the anteromedial portal. Once the femoralbone plug is pulled into the femoral tunnel, the bone plugis secured with a metal interference screw placed via theanteromedial portal.

Fig 5. Final PCL femoral tunnel positions in a left knee. The tunnel for the anterolateral bundle is on top and the posteromedialtunnel is being dilated.


TIBIAL FIXATION OF GRAFTS

The PCL components are secured before the ACL on thetibial side. The anterolateral bundle of the PCL is fixedwith a soft-tissue washer and a post with the knee in 90° offlexion and with the tibiofemoral step-off reduced with amild anterior drawer force. Mild tension to keep the grafttaut is placed on the graft as it being fixed. The postero-medial bundle is also fixed with a post and washer, but theknee is placed in 15° to 30° of flexion.

The knee is placed in full extension to fix the ACL grafton the tibial side. A metal interference screw is placedwhile tension is applied to the graft. No force is applied inthe sagittal plane. All wounds are irrigated with saline andclosed in multiple layers.

POTENTIAL PITFALLS AND MANAGEMENT

To avoid catastrophic vascular complications, the vascularstatus of the limb is constantly monitored. The distalpulses are checked before the case and marked with a pen.These pulses should be checked periodically throughoutthe case. In addition, the soft-tissue tension of the calf isnoted before the case and monitored periodically to avoidmissing the development of a compartment syndrome.

The intra-articular site of the PCL tibial tunnel is themost difficult tunnel to place. Care should be taken to clearthe hypertrophic synovium and scar tissue that resultsfrom a chronic PCL tear to allow adequate visualization ofthe PCL insertion site. This not only allows accurate place-ment of the tunnel, but it also affords protection of thevascular structures that may be adherent to the posteriorcapsule. A well-placed posteromedial portal facilitates thistask.

The PCL grafts may be difficult to pass; however, me-ticulous technique and a couple of tricks can ease passageof the grafts. The free suture ends of the grafts can be tiedtogether so that all 4 strands are pulled through the tibialtunnel with the hewson suture passer or with the 18-gaugewire. In addition, the larger anterolateral graft may ob-struct passage of the smaller posteromedial bundle. Thiscan be prevented by insuring that the leading edge of thesmaller graft enters the tibial tunnel at the same time as orslightly before the larger graft and by keeping both graftstaut during passage. A probe placed in the anteromedialportal can help coax the grafts into the tunnel while visu-alizing the grafts from the posteromedial portal.

POSTOPERATIVE MANAGEMENT

The knee is placed in a knee brace and locked in fullextension for 7 days until the first postoperative visit.20

The patient may perform straight-leg raises and quad setsand may bear partial weight on the extremity in the in-terim period.20 After the first postoperative visit, gentlepassive range of motion is initiated from full extension to45° of flexion. This is gradually increased to a goal of 90°of flexion by 6 to 8 weeks. Full range of motion is achievedbetween 3 and 6 months.

Strengthening is initiated immediately, but exercisesthat allow unopposed hamstring function are avoided.20

Quadriceps strengthening is encouraged with open-chain

extension exercises near full extension only and withclosed-chain kinetic exercises that allow co-contraction ofthe hamstrings and the quadriceps. Once sufficientstrength is attained, full weight bearing is allowed.

CONCLUSIONS

Combined ACL and double-bundle PCL reconstruction isa procedure with limited indications. Although combinedinjuries are not rare, we prefer to treat them within 2 to 3weeks; therefore, each ligament is reconstructed with asingle-bundle graft. We reserve double-bundle PCL graftsfor patients with chronic ACL and PCL deficiency. Thegoal is to restore the anatomic function of the PCL asclosely as possible and to minimize the residual posteriorlaxity seen with single-bundle PCL reconstructions in thechronic setting.

The procedure requires a regimented series of stepswith meticulous attention to surgical technique. The tibialtunnels are created first with careful attention to leavesufficient bone between the ACL and PCL tunnels to avoida fracture of the bone bridge. The PCL tibial tunnel istechnically the most challenging tunnel to place and drilldue to its articular outlet in the posterior aspect of thelateral tibial plateau. The task of placing this tunnel ismade easier by placing a posteromedial portal and ade-quately exposing the PCL tibial origin. This allows accu-rate placement of the guide wire, which should also bechecked with a radiograph. Meticulous technique and con-stant vigilance helps to avoid a vascular injury whiledrilling this tunnel.

The femoral tunnels for the ACL and PCL are drilledthrough the anterior working portals. The position of thesetunnels is somewhat predictable; however, the femoralinsertion of the PCL should be preserved to allow for moreaccurate placement of the PCL tunnels. The PCL graft isthe most difficult to pass; therefore, it is passed first fromthe articular side through the tibial tunnel. The grafts areall fixed on the femoral side before fixation on the tibialside. The final important consideration is that the graftsmust be fixed in place with the knee in the appropriateposition. The anterolateral bundle of the PCL functionswith the knee in the mid-range of flexion; therefore, it isfixed with the knee at 90° and the posteromedial bundle isfixed closer to extension between 15° and 30°.

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ACL/PCL reconstruction: the role of double-bundle PCL reconstruction