ARTHROSCOPICALLY ASSISTED ANTERIORCRUCIATE LIGAMENT RECONSTRUCTIONUSING A CENTRAL-THIRD PATELLARTENDON AUTOGRAFT AND TWO INCISIONS

MICHAEL T. DIMENT, MD, WAYNE J. SEBASTIANELLI, MD, andKENNETH E. DEHAVEN, MD

The following article is a discussion of the technique currently used by the senior author (KED) forreconstruction of the anterior cruciate ligament using two incisions and a central one-third patellar tendonautograft. The reconstructive procedure is performed arthroscopically using standard portals andinstrumentation. An incision over the patellar tendon is used to harvest the patellar tendon, and a lateralincision is used for femoral tunnel placement and fixation. The technique has allowed us to achieve good andexcellent results over the past 6 years.KEY WORDS: arthroscopic setup, bone tunnel placement, graft fixation, graft harvest, patient positioning

Over the past 6 years the senior author (KED) has con­sistently used the following technique when replacementof the anterior cruciate ligament (ACL) is indicated. Itinvolves the use of two incisions and the central one thirdof the patellar tendon as an autograft. A midline, verticalincision over the patellar tendon is used to harvest thepatellar tendon graft, and a lateral incision over the il­iotibial band (ITB) is used for femoral tunnel placementand fixation. There has been one major change in thetechnique over time. Originally, a miniarthrotomy wasmade through the patellar tendon defect created by har­vesting the graft. The subsequent intra-articular workwas then done under direct vision by the operating sur­geon. Currently, no arthrotomy is used, and all of theintra-articular work is done arthroscopically.

In this article we will describe operative preparationand patient positioning, arthroscopic setup, notch prep­aration, graft harvest, bone tunnel placement, graft in­sertion, and graft fixation. This technique has givengood, predictable results in our hands. We feel thatthis technique is straightforward and can be accom­plished by most surgeons who have advanced arthro­scopic skills.

From the Section of Athletic Medicine, Department of Orthopae­dics, University of Rochester School of Medicine and Dentistry,Rochester, NY.

Address reprint requests to Kenneth E. DeHaven, MD, University ofRochester School of Medicine and Dentistry, Department of Ortho­paedics, 601 Elmwood Ave, Box 665, Rochester, NY 14642.

Copyright © 1993 by W. B. Saunders Company1060-1872/93/0101-0007$05.00/0

OPERATIVE PREPARATION ANDPATIENT POSITIONING

We prefer an epidural anesthetic because it usually pro­vides the necessary relaxation and anesthesia needed forsurgery and can be used postoperatively for analgesia.After adequate relaxation is achieved, a careful examina­tion of the knee is carried out to document the degree oflaxity in the knee before beginning the surgical proce­dure. The Lachman, anterior drawer, pivot shift, andanteromedial rotatory instability tests are checked andgraded.

The application of the tourniquet should not be takenfor granted. A snug fit in a proximal position wiII makethe placement of the leg holder and the drapes easier andwill provide greater distal exposure. We use a leg holderpositioned over the tourniquet that is nearly, but notcompletely, circumferential. This position provides ex­cellent distal exposure and stability without acting as atourniquet. The foot of the table is then flexed to allowaccess to the knee.

Care must also be taken in positioning the nonopera­tive leg. A pillow is placed under the thigh to keep thehip slightly flexed to prevent a stretch injury to the fem­oral or lateral femoral cutaneous nerves. An above-kneeelastic stocking is placed on the leg to help prevent ve­nous engorgement and stasis.

Before initiating the procedure we inject approximately20 mL 0.5% Marcaine (bupivicaine hydrochloride, Win­throp, New York, NY) with epinephrine, 1:200,000, intothe knee and the proposed portal sites. This serves todecrease bleeding and to allow more of the procedure tobe performed before a tourniquet is necessary': it can alsoserve to augment slow onset of the epidural block.

Operative Techniques in Sports Medicine, Vol 1, No 1 (January), 1993: pp 45·49 45

ARTHROSCOPY

The use of the arthroscope allows us to thoroughly in­spect the joint and to document any associated pathol­ogy. At this time we proceed with any necessary menis­calor chondral work. Our goal is to complete as much ofthe procedure as possible without using the tourniquet.However, we do inflate the tourniquet before making theposterior exposure for a meniscal repair, if that is neces­sary. We have found that an arthroscopic pump is alsouseful when trying to avoid the use of the tourniquet.Our starting pressure of 35 mm Hg will generally allow usto accomplish the majority of our procedure. As bleedingis encountered, elevating the pump pressure to 50 mmHg is usually all that is necessary to allow us to continue.

When choosing portals, either a superomedial or a su­perolateral portal may be used for the outflow. The su­peromedial portal has the advantage of being positionedout of the way of the lateral exposure and usually func­tions well with the canula lying in the medial gutter, butit has the disadvantage of being placed through the vas­tus medialis obliques (VMO). The superolateral portaldoes not violate the VMO, but it must be positionedslightly anterior to avoid interfering with the lateral ex­posure. The standard inferolateral scope portal is posi­tioned near the patellar tendon to visualize the entirenotch, especially the posterior notch. The inferomedialportal placement is chosen by using an 18-gauge spinalneedle as a guide. This allows for optimal placement toaccomplish any necessary meniscal work and still be ableto prepare the notch for the placement of the graft.

INTERCONDYLARNOTCH PREPARATION

The intra-articular portion of the reconstruction beginswith obtaining adequate visualization of the notch andsubsequent resection of the incompetent ACL. At times,anterior synovium may obscure visualization. In this in­stance, we use a synovial resector blade on our shaverand begin debriding medially and gradually proceed lat­erally. Release of the ligamentum mucosum generallyaids visualization by allowing the fat pad to fall awayfrom the notch. After we can visualize the anterior hornsof both menisci, we begin resecting the remaining ACL.We are careful not to injure the posterior cruciate liga­ment (PCL) during this step. We routinely expose thelateral border of the PCL, which allows us to use this asa landmark throughout the remainder of the ·procedure.Usually, we use a basket forceps and a curette to removethe soft tissue from the lateral wall of the intercondylarnotch. We believe that it is important to visualize theposterior outlet of the notch and to confirm this with theprobe. A ridge of bone is usually encountered anterior tothe true posterior aspect of the notch, the "resident's"ridge, and this must not be mistaken for the true outlet.

We find that a notchplasty is necessary in the majorityof our patients, with the amount of resection based on thewidth of the notch. Enough bone is removed to allow

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room for the graft to lie between the PCL and the lateralwall of the notch. Slightly more bone is removed anteri­orly than posteriorly to avoid lateralizing the femoral or­igin of our reconstructed ligament. A motorized burr isused to perform the majority of the notchplasty. After anadequate notchplasty has been performed, a burr is usedto make a dimple indentation at our chosen "isometricpoint." This dimple is placed 5 to 7 mm anterior to theposterior outlet of the notch at the junction of the roofand the sidewall of the notch, and it serves as our chosensite to seat the tip of the femoral drill guide. We areusually able to reach this point in the procedure withouthaving to use the tourniquet. Next we drain the fluidfrom the knee, remove the arthroscopic instrumentsexcept for the outflow cannula, exsanguinate the legwith an Esmark bandage, and elevate the tourniquetto a pressure of 150 mm Hg above the systolic bloodpressure.

GRAFT HARVEST

The patellar tendon graft is harvested through a midlineincision that extends from the inferior one third of thepatella to just below the tibial tubercle. The paratenon isidentified over the tendon and incised in line with theincision. The medial and lateral borders of the tendonare exposed as the para tenon is reflected. With the kneeslightly flexed, the width of the proximal one third of thetendon is measured. We use one third of this width forour graft, and using a no. 10 blade we incise the centralone third of the patellar tendon (usually 9 to 11 mmwide), being careful to stay parallel to the fibers of thetendon.

We use patellar and tibial bone blocks of 25 mrn. Anoscillating saw is used to make the initial bone cuts, tak­ing care to avoid extending the proximal cuts into theinsertion fibers of the quadriceps tendon. This avoidsweakening the soft tissue and boney bridge in the prox­imal third of the patella and decreases the liklihood offracture when removing the graft. The bone blocks areremoved by completing the saw cuts with a J/4-inchstraight and/or curved osteotome with the goal of remov­ing bone blocks that are as rectangular in shape as pos­sible.

After removal of the graft, a two-team approach isused, with one team preparing the graft while the secondteam exposes the lateral femur. A rongeur is used tocontour each bone block into a cylindrical form. Thebone that is removed is saved for later bone grafting ofthe patellar defect. A short chucked K-wire is used todrill two holes through each bone block. A no. 5 Ethi­bond (Ethicon, Sommerville, NJ) suture is passedthrough each hole, and the graft and sutures are passedthrough a sizer to confirm the exact diameter of the boneplugs. If one bone block is smaller, it is used in the tibia.This allows us to drill the smallest hole possible in theproximal tibia, which will create a smaller stress riser inthe relatively weak cortical bone in the proximal tibia.We also believe that a smaller hole will provide bettergraft fixation after the interference screw is inserted.

DIMENT, SEBASTIANELLI, AND DEHAVEN

LATERAL EXPOSURE

The lateral skin incision is centered over the midportionof the ITB and extends proximally about 6 cm from thelateral epicondyle in line with the ITB. The ITB is incisedin line with its fibers, 2 cm anterior to its posterior edge.The vastus lateralis is dissected off of the ITBdown to thelateral intermuscular septum and retracted anteriorly toexpose the lateral shaft of the femur. At the level of theproximal metaphysis, a Metzanbaum scissor is used tomake an opening in the lateral intermuscular septumnear its insertion into the shaft of the femur. By placingthe index finger through this opening one can bluntlyexpose the posterior aspect of the intercondylar notch.

BONE TUNNEL PLACEMENT

The arthroscope is reinserted into the knee via the infe­rolateral portal, and the knee is irrigated to remove anyclotted blood. A no. 1 nylon suture is loosely tied to ahole in the tip of the blunt-tipped gaff. The gaff is thenplaced· through the inferomedial portal, through thenotch, and palpated posteriorly at the "over-the-top" po­sition. Using both hands, the gaff is advanced posteri­orly through the posterior capsule, the hole in the sep­tum, and into the lateral incision. The nylon suture isuntied, passed through a hole in the tip of the DyonicsKinernetric femoral drill guide (Smith & Nephew DyonicsInc, Andover, MA), and secured with one knot (Fig 1).2The rear entry femoral drill guide with the zero offsetsleeve is coupled to the gaff. Using both hands, we drawthe gaff and the tip of the femoral drill guide back into thenotch through the posterior capsule. The tip of the fem­oral drill guide is then seated in the previously mademarker dimple and held in place with light manual ten­sion.

The gaff is removed, and the free end of the suture isthreaded through the tibial guide. The tibial guide is

. i ..

Fig 1. Free the suture from the gaff and affix It to the femoralguide's almer arm as shown. The single-throw knot shouldbe tightly set, leaving a 5 to 7-in proximal tail. Interlock thefemoral guide's aimer arm (with affixed suture) Into the endof the gaff, and draw It Into the Intercondylar notch via theover-the-top route by withdrawing the gaff from the front.

ACL RECONSTRUCTION: PATELLAR TENDON AUTOGRAFT

Fig 2. The tips of the femoral and tibial guides are seated intheir chosen locations, and the isometry is checked.

inserted through the inferomedial portal, and the tip isplaced just lateral to the medial tibial plateau at the pos­terior edge of the tibial stump of the ACL (Fig 2).2 Theoffset on the tibial guide is set at one half the size of thetibial tunnel to be drilled, which places our K-wire andthe center of our subsequent tunnel approximately in thecenter of the ACL insertion. This location is one that wecan find predictably, and it will closely approximate thetrue isometric point. The knee can be brought into ex­tension to see if the chosen location will result in the graftimpinging in the notch. The isometer is the tibial drillguide is observed as the knee is put through a full rangeof motion. Our goal is to accept no more than 2 m ofexcursion when going from full flexion to extension. Ifexcursion is greater than 2 rnm, the chosen sites for eithertunnel can be changed before making any drill holes.

The lateral entry site for the femoral tunnel is posi­tioned on the flare of the metaphysis just anterior anddistal to where the posterior lateral femoral condyle joinsthe posterior shaft of the femur. The entry site for thetibial tunnel is chosen just medial to the tibial tubercleand proximal to the pes anserine insertion. After appro­priately positioning the drill guides, K-wires are ad­vanced into the joint under direct vision, and the drillguides are removed. The knee is brought into full exten­sion to verify the course of the K-wires and to ensure thatgraft impingement will be avoided. When drilling overthe K-wires to make the bone tunnels, we place a largecurette through the inferomedial portal into the notch toprotect the PCL (Fig 3).

After drilling the tibial tunnel, there is usually someadditional soft tissue around the edges of the tunnel thatmay make graft placement difficult. We remove this withthe shaver and a 45° angled basket. Tunnel preparationis completed by placing a GoreTex smoother (W.L. Goreand Associates, Inc, Flagstaff, AZ) through both tunnelsfrom proximal to distal. If the tip of the smoother will notpass directly into the tibial tunnel, we place a nerve hookup the tibial tunnel and hook the end of the smoother anddirect it into the tibial tunnel. It is important to place aposteriorly directed force on the smoother while raspingthe tunnels as the knee is slowly taken through a fullrange of motion. This posterior force will reduce the tibia

47

Fig 3. The femoral tunnel is drilled over the K-wire, and thecurette is used to protect the peL.

and prevent inadvertent anterior tunnel migration. Freemovement of the smoother with the knee in full exten­sion assures us that an adequate notchplasty has beenperformed. If impingement does occur, additionalnotchplasty is performed before placing the graft.

GRAFT INSERTION AND FIXATIONThe sutures from the tibial end of the graft are thenplaced through the loop in the proximal end of thesmoother, and the smoother is removed. This places the

/

Fig 4. (A) The patellar tendon graft is passed. The tendinousportion of the graft should be oriented in the posterior aspectof the bony tunnels. (B) The graft is secured In the tibialtunnel with an interference screw.

48

lead sutures through both tunnels. Using two hands, wepass the graft from proximal to distal; the graft generallypasses best with the knee slightly flexed (Fig 4). To allowgraft passage into the tibial tunnel, we make sure that thebone block and sutures will fit through the size tunnelthat has been drilled before attempting passage. It is alsoimportant to make sure that the graft is not blocked bysoft tissue at the opening of either tunnel. A nerve hookcan be used to direct the tip of the graft into the tunnel ifnecessary.

During graft passage we position the bone block in thefemoral tunnel such that the tendon faces posteriorly andthe cancellous surface faces anteriorly, which keeps thetendon positioned posteriorly. Before passing the graft,the bone-tendon junction of the femoral bone block ismarked with methylene blue. We use this mark to posi­tion the graft in the femoral tunnel such that the boneblock is flush with the intra-articular opening of the tun­nel but does not protrude into the notch. We believe thatthis minimizes the stress riser effect on the graft againstthe anterior edge of the femoral tunnel as the knee goesthrough its normal range of motion. We place both thetibial bone block and the femoral bone block with thetendon facing posteriorly and the cancellous surface fac­ing anteriorly. If the tibial bone block is entirely withinits tunnel, we secure the bone block with a headless,cannulated, interference screw (Fig 4). In a patient witha longer patellar tendon, the tibial bone block may pro­trude out of the tibial tunnel. When this occurs, we makea small groove in the tibia just distal to the tunnel to allowthe bone block to lie flat on the tibia, and we secure thetibial bone block with a staple just wide enough to spanthe graft. An alternate method of fixation is to place alarge fragment cancellous screw and washer just distal tothe groove and to tie the sutures around this post. Withthe graft fixed distally, we manually place tension on thegraft sutures proximally and check the stability of theknee.

"

DIMENT, SEBASTfANELLI, AND DEHAVEN

.'

Fig 5. The graft is secured and tensioned proximally usingan obliquely directed malleolar screw.

Proximal fixation is achieved by tying the suturesaround the head of a malleolar screw and washer that isdirected obliquely from distal to proximal (Fig 5).3,4 Thescrew is placed 1.5 ern proximal and slightly anterior tothe lateral opening of the femoral tunnel. This type offixation allows the tension in the graft to be adjusted afterit has been fixed at both ends. We put the knee througha range of motion and recheck the stability. By using thescope and a probe, we recheck the tension in the graftunder direct vision. If necessary, we can increase the

ACL RECONSTRUCTION: PATELLAR TENDON AUTOGRAFT

tension in the graft simply by advancing the malleolarscrew. As the screw advances, the sutures and the boneblock advance slightly, and tension in the graft is in­creased. The final check for stability is performed beforethe arthroscopic instruments are removed.

The tourniquet is then released, and hemostasis isachieved. The lateral incision is closed in a standardfashion. The ITB and the subcutaneous tissue are closedseparately. The excess bone that was trimmed from thebone blocks is now placed in the defect in the patella.The para tenon is closed over the tendon as much as pos­sible, but no sutures are placed in the tendon. A drain isplaced in the subcutaneous tissue of both incisions, andthe skin is closed with a subcuticular pullout wire. Theknee is then immobilized in a hinged, long-leg splint infull extension, and motion is initiated the following day.

COMMENT

We have found that the use of the arthroscope has al­lowed us to make a natural progression from our originalminiarthrotomy technique. We believe that the arthro­scopically assisted technique with two incisions allows usto achieve proper graft placement and fixation. In ourhands, we have achieved good and excellent reproduc­ible results in the treatment of the unstable, ACL­deficient knee.

REFERENCES

1. Furia JP, Zanbettu GJ: An injection technique to create a bloodlessfield in arthroscopically assisted anterior cruciate ligament recon­struction. Am J Sports Med 20:406-409, 1992

2. Sapega AA, Moyer RA: Surgical technique for arthroscopically­assisted anterior cruciate ligament reconstruction with the DyonicsKinemetric" guide system. Kinematic" Guide System for ACL Re­construction Surgical Technique:4-7, 10-11, 1988

3. Acker JH, Drez 0: Angulation of fixation screw in knee ligamentprocedures. Orthopaedics 12:823-826, 1989

4. Jakob R: Personal communication, April 1984.

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