ARTHROSCOPICALLY ASSISTED POSTERIORCRUCIATE LIGAMENT RECONSTRUCTION

RUSSELL F. WARREN, MD and DANIEL M. VELTRI, MD

Arthroscopic posterior cruciate ligament (PCL) reconstruction is a technically demanding procedure. However,not all patients with PCL injury require reconstruction. We reconstruct the PCL when there is significantposterior instability or associated ligamentous injury . Bone-patellar tendon-bone autograft or allograft orAchilles tendon allograft can be used for PCL reconstruction. Here we outline our arthroscopic technique forreconstruction. Posterior cruciate ligament-specific drill guides and the use of accessory arthroscopy portalsassist in reconstruction. Fluoroscopic guidance is useful in tibial tunnel placement. An isometer is used todetermine correct femoral tunnel placement. The graft passage is eased by the use of a Steinman pin as apulley. Finally, the graft is fixed in full extension. Attention to the technical surgical details of peLreconstruction will increase the probability of success.KEY WORDS: arthroscopy, posterior cruciate ligament, posteromedial portal, reconstruction

Arthroscopic posterior cruciate ligament (PCL) recon­struction offers some advantages over open techniques,but it is a technically demanding procedure. 1 When me­dial or posterolateral ligamentous injury is present, wehave combined an arthroscopic approach to the femoralorigin of the PCL with a posteromedial or posterolateralapproach for the tibial PCL attachment and associatedligamentous repairs.?

In treating acute PCL injury we presently believe thatroutine reconstruction is not required for isolated PCLinjuries. 2

-5 In evaluating patients, our goal is to deter­mine if the injury is restricted to the PCL or if there areassociated ligamentous injuries. Also, the degree of pos­terior displacement and the presence of associated intra­articular injury may determine if reconstruction is war­ranted . Thus, the presence of posterolateral instability orgrade 3 medial instability in association with PCL injuryrepresent indications to perform early PCL reconstructioncombined with medial or posterolateral repair.?

If medial, posterior, or posterolateral instability is sus­pected but not apparent from the office examination,then an examination under anesthesia would be appro­priate . One must be sure whether isolated PCL injury oradditional medial or posterolateral injury has occurrcd.f

The degree of posterior translation is important whendealing with an isolated PCL injury. If it is less than 10mm, then a nonoperative program would be used. If thedisplacement is greater than 10 to 15 mrn, jhen recon­struction is advised because it is likely that additionalsecondary restraints have been comprornised.v"

In evaluating our patients, if we are planning on a non-

From the Sports Medicine Service at The Hospital for Special Sur­gery. New York. NY.

Address reprint requests to Russell F. Warren, MD, Sports Medi­cine Service, Hospital for Special Surgery, 535 E 70th St, New York,NY 10021.

Copyright © 1993 by W. B. Saunders Company1060-1872193/0102-0009$05.00/0

operative program, a magnetic resonance imaging scan isobtained noting the location and degree of PCL injury.In particular, the presence of increased signal on the T2images suggesting osseous and possibly chondral injuryis important. If significant chrondral injury is suspected,one should perform arthroscopy to evaluate for loose os­teochondral fragments. Meniscus injury is relatively in­frequent in acute isolated PCL ruptures. If a torn med ialmeniscus is present, repair should be performed, if pos­sible, because the pressure in the medial compartmentwill increase with quadriceps loading after PCL injury.6

Removing the medial meniscus will only compound thepotential for degeneration in the medial compartment.

In the chronic setting, a careful assessment of previousattempts at PCL reconstruction is needed. In addition, itis important to note the mechanical alignment, patello­femoral function, and presence of a degenerative medialcompartment. If the patient's main complaint is pain,and the symptoms suggest patellofemoral or medial com­partment disease, a bone scan is performed. This scanmay indicate early articular degeneration and the needfor reconstruction in an isolated PCL injury. In chroniccases the mere presence of marked posterior laxity hasnot been an indication for reconstruction.f'' More impor­tant, the patient's subjective symptoms of pain and/orinstability are critical to note.

When patellofemoral pain is present and there is sig­nificant degeneration of the patellar articular cartilage, anallograft has the advantage of avoiding alterations in thepatellofemoral mechanism. It is particularly important inthe postoperative period where strengthening the quad­riceps will be critical because it represents the main com­ponent of the PCL rehabilitation program.v"

The patient's own patellar tendon may be used if therehas been no previous surgery and if it is of sufficientlength and width. In placing a graft it is important toplace the tibial hole well distal to the joint line. Thus,patellar tendons that are less than 4 em in length maypresent difficulty in performing complete arthroscopic

136 Operative Techniques in Sports Medic ine, Vol 1, No 2 (April), 1993 : pp 136,142

placement. An alternative is to insert the femoral portionof the graft arthroscopically and the tibial portion usingan open posterior approach" (Fig 1). Similarly, if thereare multiple ligament deficiencies, such as anterior cruci­ate ligament (ACL)/PCL or posterolateral injury, an al­lograft wiII provide necessary graft material without ex­tensive dissection.

In using allografts, surgeons have been concernedabout possible decreased allograft strength relative to au­tograft and the possibility of human immunodeficiencyvirus (HIV) contamination from the allograft. It appearsthat fresh frozen allografts have strengths consistent withthose of fresh autografts because freezing does not de­crease the tissues' ultimate tensile strength.9

,10 Somesurgeons recommend allografts such as the Achilles ten­don because such a graft is stronger than standard bone­patellar tendon-bone (BTB) graft. The greater strength ofan Achilles allograft is not necessary because the PCLstrength of 2,000 N, although low, is more than ade­quately reproduced by a BTB graft of 10 to 12 mm.l!Cooper et al have found that a BTB of 10 mm has astrength of 3,000 NY Thus, using a 12-mm graft willresult in an ultimate tensile strength of approximately3,600N.

Although of great potential concern, HIV contamina­tion to date has fortunately been rare. Only one case ofviral transmission after ACL reconstruction has been re­ported. Buck has estimated that by careful donor assess­ment, including autopsy and HIV testing, the risk can bereduced to 1 in 1.5 million.P The use of irradiation tofurther decrease the risk has been suggested, although

Fig 1. Intraoperative photograph demonstrating a posteriorapproach to the tibial attachment of the peL.

PCl RECONSTRUCTION

the exact amount necessary to kill the virus is unclear.l"Irradiation levels of 2.5 Mrad may be sufficient and havelimited effects on the soft tissue strength. Higher levelsundoubtedly will adversely affect this strength.!? Al­lograft PCL reconstruction with BTB or Achilles tendonprovides significant advantages but is not risk free.

The Achilles tendon allograft provides excellent lengthand a large volume of collagen for graft strength. Thefree tendon portion of the allograft also passes throughthe graft tunnels easier than the BTB bone blocks. How­ever, graft fixation is compromised at the free tendonportion of the graft. The BTB graft will allow excellentimmediate interference screw fixation at both ends, but itmay be limited by its length and possibly by its width.Our personal preference is to obtain a complete BTB thathas a patellar tendon component of 5 ern or more inlength. Although we have previously used allografts forPCL reconstruction, we currently use autograft BTB ifthere is adequate patellar tendon length, no significantpatellofemoral arthritis, and no associated chronic liga­mentous instabilities.

ARTHROSCOPIC APPROACH

When performing a complete arthroscopic PCL recon­struction using allograft, the standard equipment plus a70°arthroscope is of value. In addition, a second arthro­scope for viewing from the posteromedial corner is help­ful. A specific guide system for PCL reconstruction(Acufex [Acufex Microsurgical, Norwood, MAl) is impor­tant to provide protection during drilling of the tibial tun­nel. Additional instruments to act as a pully for graftpassage are helpful. We use an isometer to determinethe point of least graft excursion on the femoral condyle.This allows for proper femoral tunnel placement. Mostimportantly, radiographic control with a spot fluoroscanis quite helpful to ensure proper tibial tunnel placementand to decrease the risk of iatrogenic neurovascular in­jury.

Proper positioning for reconstruction requires that thepatient be placed supine with the potential to flex theknee to 90°. A standard 30° arthroscope is inserted in ananterolateral portal. A high medial portal is used for aworking portal, and at times a central portal will improvethe view or access to the PCL. Inflow is through thearthroscope, outflow is through a superomedial portal,and a pump is used. No tourniquet is used, although itis applied and left uninflated. An electric cautery with aninsulated tip is helpful in dissecting the soft tissues off ofthe tibial PCL insertion. The pump is used to control anybleeding encountered.

The joint is viewed in a standard fashion noting thedegree of articular disease in each compartment (Fig 2).If a medial meniscus tear is encountered, a repair is per­formed if anatomically feasible. In dealing with PCL re­construction where the ACL is intact, it is important toavoid injury to the ACL during the procedure. If theACL is also injured, then the drill holes for the PCL andACL are placed followed by the PCL graft. The PCL graftis not secured until the ACL graft has been placed.

The PCL is evaluated and the tissue from the medial

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Fig 2. Arthroscopic view of a chondral lesion of the medialfemoral condyle associated with a chronic PCL injury.

femoral condyle removed (Fig 3). This will improveviewing of the tibial attachment. A ligament of Hum­phrey, if present, may be large and could be confusedwith a PCL. Stressing the suspect ligament while observ­ing the lateral meniscus will identify whether the tissue isthe PCL or ligament of Humphrey. If the lateral menis­cus moves with ligament stress, then this tissue is theligament of Humphrey. If the lateral meniscus does notmove with ligament stress, then this tissue is the PCL.

After debriding the femoral condyle, a posteromedialportal is created (Fig 4). This will be used for removingremaining tibial PCL attachments and viewing the areaduring drilling and graft placement. In addition, thisportal is used to create a pulley as the graft is passed fromthe tibia to the femur. A Steinman pin V4 inch in diameteris placed through this portal and passed under the graft

Fig 3. Arthroscopic view of an acute PCL tear off the medialfemoral condyle.

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Fig 4. An arthroscopic posteromedial portal is established toassist in viewing and debriding the PCL tibial attachment.Debridement is performed with rasps and a 5.5 shaver. (Re­printed with permission from Bowen M, Warren RF, CooperDE: Posterior cruciate ligament and related injuries, in InsallJ (ed): Surgery of the Knee (ed 2). New York, NY, ChurchillLivingstone [in press]).

to be inserted. As the graft is advanced, the rod acts as apulley to prevent the graft from catching on the edge ofthe tibial drill hole.

Drilling the tibial tunnel is the most difficult aspect ofthe procedure. The tibial attachment site is viewed bypassing the arthroscope medial to the ACL and viewingdistally. If this view is unsatisfactory a 700 arthroscope

Fig 5. Proper tibial guide placement Is demonstrated on acadaver knee. The guide wire should enter the tibial cortexdistal and medial to the tibial tubercle.

WARREN AND VELTRI

may be used, or the arthroscope can be moved to a mid­patella portal, the medial portal, or the posteromedialportal. Using two camera heads provides the option ofswitching from one camera to the other without movinga well positioned arthroscope.

The tibial attachment site is debrided using a 5.5 shaverand rasps. The main debriding instrument will be a 5.5shaver that is passed posteriorly from the medial portaland then from the posteromedial portal. The PCL attach­ment site is cleared for a distance of 2 to 3 ern distal to thejoint line.

The tibial drill hole is drilled under fluoroscopic con­trol. The Acufex tibial guide is placed on the tibial cortexso that guide wire entrance will be distal to the tibialtubercle (Fig 5). Normally the tunnel is started medial tothe tubercle, but it can be placed lateral to the tuberclewhen an ACL reconstruction is also being performed.The PCL tibial tunnel is placed inferior to the ACL tibialtunnel when simultaneous reconstructions are per­formed. The tibial guide is inserted first before drillingthe wire to determine proper tibial tunnel placement.The tip of the guide is placed over the posterior edge ofthe tibia, and the guide wire assembly is fixed to the tibia(Fig 6). Position of the tip of the guide can be verifiedfluoroscopically (Fig 7). The width of the tibia should benoted before drilling, and a drill stop is placed on theguide wire to prevent excess posterior penetration of thewire.

The guide wire is placed by manually noting the pen­etration of the posterior tibial cortex and by viewing thepenetration with the arthroscope and fluoroscope. Thenthe wire is grasped from the posteromedial portal to pre­vent inadvertent further penetration when drilling overthe wire with a cannulated drill. A 12-mm cannulateddrill is then placed over the guide wire, and the tibialtunnel is drilled. A drill stop is again placed over the drillat a correct depth to prevent excessive penetration of thedrill. The drill should be noted to pass in a poste­rior/superior direction toward the proximal posterior cor-

Fig 6. Posterior position of the tibial guide is demonstratedon a cadaver knee via a posterior approach to the knee. Thetip of the tibial guide should be well distal to the articularsurface of the posterior tibia.

PCl RECONSTRUCTION

Fig 7. Fluoroscopic view of guide wire placement. This dem­onstrates improper positioning of the tibial guide andguidewire. The guide tip is positioned on the tibial articularsurface forcing the guidewire Into an inappropriate superiorposition. The tip of the tibial guide should be well distal to theposterior tibial articular surface.

tex. The objective is to place the tunnel exit distal to thesuperior surface of the tibia. If the superior edge is pen­etrated, the graft may progressively erode through thesoft bone creating laxity with the passage of time. Thiswill result in functional graft failure.

Once the tibial tunnel is completed, attention is di­rected towards femoral tunnel preparation. The femoralhole is placed at a point to minimize graft excursion.Generally this is in the posterior portion of the middlethird of the femoral surface. Our preference is to place adrill hole such that the posterior edge will be at the junc­tion of the mid third and posterior third of the medialcondyle. Grood has noted that the area of least motion isbullet-shaped with its base proximal.P The drill holeshould be about 1 em proximal to the articular margin.An isometer may be used to assess excursion, but thegraft excursion at the posterior edge of the hole will bedifferent from that measured with a suture and isometer(Fig 8). Medially, over the femoral condyle, an exposureis made down to the epicondyle. The fascia over thevastus medialus oblique is incised longitudinally and themuscle retracted proximally. The femoral drill guide en­trance is placed on the cortical surface of the medial fem­oral condyle 3 em from the edge of the articular surface(Fig 9). Closer placement to the articular surface, al­though decreasing the angle for the graft passage, mayweaken the remaining subchondral bone distal to the drill

139

hole and possibly playa role in the development of avas­cular necrosis. After inserting the guide wire, the femo­ral drill hole is completed using the appropriate cannu­lated drill (Fig 10).

The previously prepared BTB allograft is examined.The tendon should be more than 4.5 ern, and a 12 mmgraft is used if possible. The bone blocks are 2.5 cm inlength and approximate the drillhole size. Making thetibial drill hole 12 mm and the femur drill hole 11 mm willfacilitate eventual graft passage. The tendon is tubedwith an interlocking suture to prevent damage to thegraft by impingement during placement. In preparingthe bone blocks, the femoral component is decreased to 2cm in length to aid in turning the posterior tibial corner.We prefer to pass their graft from distal to proximal. Thisis facilitated by initially placing a Yankhauer suction tubethrough the tibial tunnel. A looped wire is then passed

Fig 8. This drawing represents the use of an Isometer aftertibial tunnel preparation. The femoral hole Is located with thefemoral drill guide. Positioning Is then checked with theIsometer. Guldewire position can then be adjusted asneeded. (Reprinted with permission from Bowen M, WarrenRF, Cooper DE: Posterior cruciate ligament and related Inju­ries, In Insall J (ed): Surgery of the Knee (ed 2). New York, NY,Churchill livingstone [in press].)

140

Fig 9. This drawing demonstrates proper placement of thefemoral drill guide. The femoral drill guide entrance Is placedon the medial femoral condyle cortex 3 em from the edge ofthe articular surface. (Reprinted with permission from BowenM, Warren RF, Cooper DE: Posterior cruciate ligament andrelated Injuries, In Insall J (ed): Surgery of the Knee (ed 2).New York, NY, Churchill Livingstone [in press].)

through the tube into the joint where it is then advancedinto the femoral tunnel. A second looped wire is placedinto the first wire, then pulled through the femoral tunneland out the tibial tunnel. The sutures previously placedin the femoral bone block are placed into the looped wire.The wire is then advanced through the tibial tunnel,joint, and into the femoral tunnel along with the suturesand accornpaning graft. As noted earlier, a pulley fromthe posteromedial portal, using a Steinman pin placedunder the sutures, will aid in the passage of the graft.The bone block may catch as it enters the joint, but thepulley arrangement creates a posterior vector as the boneblock is pulled into the joint. The graft will then be di­rected toward the femoral tunnel allowing an easier en­trance to the tunnel. The length of the graft is adjustedby tapping the tibial bone block posteriorly. If the graft isshort, the tibial bone block may have to be advanced asignificant distance. The femoral bone block should com­pletely enter the medial femoral condyle. Ideally, inter­ference screw fixation is used at both ends of the graft.In placing the tibial screw, fluoroscopic control is helpfulif the tibial bone block is near the posterior tibial cortex.The sutures through the bone blocks are then tied overbuttons overlying the tunnels (Fig 11).

When fixing the graft, place the knee through a rangeof motion (ROM) to ensure that the graft is not caught onthe posterior edge of the tibia. The tibial screw is insertedfirst. The knee is then put in full extension and the fem­oral screw is inserted. The tibia should not be pulled

WARREN AND VELTRI

excessively anterior relative to the femur. The tibial pla­teaus should conform to the condyles of the femur whenfixing the graft. Placing the knee at 0° wiII accomplishthis best, particularly if there has been some degree ofACL injury.1,2,16,17 Once the knee is placed in full exten­sion, the femoral screw is inserted. If a combined ACLand PCL reconstruction is performed, the PCL femoralscrew is not inserted until the ACL graft is placed. Theknee is put in full extension, and the PCL femoral screwis placed followed by the ACL tibial screw securing bothgrafts.

If the AchiIIes tendon allograft is used, the tendon com­ponent must be tapered for passage. This is accom­plished by cutting it at an angle and then rolling the edgeinto a tube. A Bunnell suture and a running interlockingstitch are placed into the free tendon end of the graft.The bone attachment is made into a plug that is trapezoidin shape to increase fixation. It wiII measure 25 mm x 12mm in length.

I""-

Fig 10. Drawing demonstrating completion of the tibial andfemoral tunnels. (Reprinted with permission from Bowen M,Warren RF, Cooper DE: Posterior cruciate ligament and re­lated Injuries, In Insall J (ed): Surgery of the Knee (ed 2). NewYork, NY, Churchill Livingstone [in press].)

PCl RECONSTRUCTION

Fig 11. Drawing demonstrating bone-patellar-bone graftplacement. The bone blocks are fixed in their respective tun­nels with Interference screws. The bone block sutures arethen tied over buttons overlying the tunnels. (Reprinted withpermission from Bowen M, Warren RF, Cooper DE: Posteriorcruciate ligament and related Injuries, in Insall J (ed): Sur­gery of the Knee (ed 2). New York, NY, Churchill Livingstone[in press].)

The free tendon end is locked with a running stich sothat it will not unravel. Passage is in a manner similar tothat for the BIB graft (Fig 12). Fixation to the femur dif­fers from the BIB graft in that a 6.5-mm cancellous screwand ligament washer are used. The edge of the femoralhole is chamfered to allow the graft to slide proximallywithout damaging it. The knee is reduced and placedthrough an arc of motion, and the screw is placed into adrill hole proximally with the knee at 0°. It is importantto decrease the prominence of the screw because medialhardware is poorly tolerated. The rehabilitation programhas been similar to that for the BTB.

In essence, a ROM program of 0° to 90° is initiated.Limited weight bearing using crutches is allowed with aknee brace locked in full extension. Postoperatively,quadriceps exercises are started immediately with active

141

Fig 12. Intraoperative photograph showing Achilles allograftpassage from the distal tibial tunnel to the proximal femoraltunnel. The free tendon portion of the Achilles allograft isfixed to the femur with a 6.5-mm cancellous screw and liga­ment washer.

knee extension from 90°to 0° and straight leg raises. 1,2,16,17

Passive knee flexion exercises are used to gain knee flex­ion. Hamstring exercises are avoided. The return ofhamstring strength has been relatively spontaneous, andwe prefer to decrease the posterior translation exacerbat­ed by hamstring isokinetic exercise. Running will start atthe 5th month followed by sport-specific agility drills at 6to 7 months. Full return to sports is allowed when ade­quate quadriceps and hamstring strength is achieved andsport-specific agility and proprioreceptive skills are mas­tered.

SUMMARY

Arthroscopic PCL reconstruction is a technically demand­ing procedure. Patient selection is important in achiev­ing successful reconstruction. In the absence of signifi­cant posterior translation, acute osteochondral injury, oradditional ligamentous injuries, the patient with isolatedPCL injury generally can function quite well with appro­priate quadriceps rehabilitation.2-s,7 Surgery is reservedfor patients with significant posterior instability, osteo­chondral injury, or associated ligamentous injuries.2,s ,7

142

The authors have outlined their arthroscopic techniquefor PCL reconstruction using a BTB autograft, BTB al­lograft, or Achilles allograft. As stressed previously, flu­oroscopy is useful in preparing the tibial tunnel. Successin PCL reconstruction is not dependent on an all­arthroscopic technique. Certainly one can perform a pos­terior, posteromedial, or posterolateral arthrotomy to as­sist in tibial tunnel preparation. This is also especiallyuseful when repairing the MCL or posterolateral corner.Proper femoral tunnel placement is the key to achievingproper PCL function . The details to proper graft place­ment have been outlined. Finally, graft fixation shouldbe done with the knee at full extension to prevent poste­rior tibial sag and excessive anterior tibial displacement.Proper patient selection as well as attention to the surgi­cal det ails will assist the surgeon in obtaining the desiredstable knee and functional success in PCL reconstruction.

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6. Skyhar MJ, Warren RF, Ortiz GJ, et al: The effects of posteriorcruciate and posterol ateral complex laxity on articular contact pres­sures within the knee. Presented at the AAOS 56th Annual Meet­ing, Las Vegas, NV, February 1989

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8. Burks RT, Schaffer JJ:A simplified approach to the tibial attachmentof the posterior cruciate ligament. Clin Orthop 254:216·219, 1990

9. Nickolaou PK, Seaber AV, Glisson RR, et al: Anterior cruciate lig­ament aIlograft transplantation. Am J Sports Med 14:348·360, 1986

10. Arnoczky SP, Warren RF, Ashlock MA: Replacement of the anteriorcruciate ligament using a pateIlar tendon aIlograft. J Bone Joint Surg[AmI 68:376-385, 1986

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14. Gibbons MJ, Bartolozzi AR: Anterior cruciate ligament reconstruc­tion using aIlografts: A review of the important issues. Op TechOrthop 2:76-85, 1992

IS. Grood ES, Hefzy MS, Lindenfield TN: Factors affecting the region ofmost isometric femoral attachments. Am J Sports Med 17:197-207,1989

16. Ogata K, McCarthy JA, Dunlap A, et al: Pathomechanics of poste­rior sag of the tibia in posterior cruciate deficient knees . Am J SportsMed 16:630-636, 1988

17. Ogata K: Posterior Cruciate Ligament Reconstruction: A compara­tive study of two different methods. BuIl Hosp [t Dis Orthop Inst51:186-198, 1991

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