StreszczenieWiæzadÆo krzyºowe tylne (WKT) jest strukturå ana-tomicznå stanowiåcå gÆówny ogranicznik tylnegoprzemieszczenia ko¥ci piszczelowej wzglædem ko¥ciudowej. Funkcjonalnie moºna je podzieliì na kilkaczæ¥ci, z których najwaºniejsze så: pæczek przed-nio-boczny i pæczek tylno-przy¥rodkowy. Pæczekprzednio-boczny napina siæ przy kolanie zgiætym do90°, tylno-przy¥rodkowy przy kolanie zgiætym do30°. WKT ma 38 mm dÆugo¥ci, okoÆo 13 mm ¥red-nicy, jest poÆoºone wewnåtrzstawowo, ale na ze-wnåtrz bÆony maziowej, którå wpukla od tyÆu dostawu tak, ºe tworzy ona grubå warstwæ synowialnåprzykrywajåcå WKT z trzech stron.Dodatkowymi elementami tylnego kompleksuwiæzadÆowo-torebkowego stawu kolanowego så wiæ-zadÆa Æåkotkowo-udowe przednie (Humphreya)i tylne (Wrisberga). WiæzadÆo Wrisberga rozpoczy-na siæ na rogu tylnym Æåkotki bocznej, tylnym brze-gu ko¥ci piszczelowej, przechodzi sko¥nie i ku tyÆo-wi od WKT i ma swój osobny koñcowy przyczep nako¥ci udowej, moºe mieì grubo¥ì do 50% WKT,przeciætnie 20%. WiæzadÆo przednie Humphreyazaczyna siæ na rogu tylnym Æåkotki bocznej, prze-biega wzdÆuº przedniego brzegu WKT i przyczepiado kÆykcia przy¥rodkowego ko¥ci udowej. Przyuszkodzonym WKT wiæzadÆa te majå pewne zna-czenie w redukowaniu objawu szuflady tylnej.WKT jest grubsze od WKP, ale jego parametry me-chaniczne u ludzi mÆodych obciåºenia koñcowe —1627 ± 491N i sztywno¥ì liniowa — 204 ± 66 N såzbliºone do WKP, wg Harnera påczek przed-nio-boczny ma 2,5x wiækszå wytrzymaÆo¥ì niº tyl-no-przy¥rodkowy i 5x wiækszå od wiæzadeÆ Æåkotko-wo-udowych.Wg Butlera WKT odpowiada za 95% siÆy blokujåcejtylnå transpozycjæ ko¥ci piszczelowej w szufladzietylnej. Uszkodzenie elementów kompleksu tylnegopowoduje narastanie niestabilno¥ci szpotawiåceji zwiækszenie rotacji zewnætrznej piszczeli, co zabu-rza tzw. „screw-home mechanism”, w którym pi-szczel rotuje siæ na zewnåtrz, gdy kolano zbliºa siædo peÆnego wyprostu. Wg Skyhara bardzo zwiæksza

to obciåºenie styczne w stawie rzepkowo-udowymi przednio-przy¥rodkowym przedziale stawu kola-nowego powodujåc jego stopniowe uszkodzenie.W WKT jest do¥ì trudno ustaliì punkty izomet-ryczne, wydaje siæ, ºe najbliºszy izometrii przyczepudowy stanowi punkt w miejscu przeciæcia siæ liniiw 1/3 pomiædzy dalszym brzegiem chrzåstki stawo-wej i brzegu bliºszego bruzdy miædzykÆykciowej nagodzinie 2 dla kolana prawego i 10 dla kolanalewego.Doniesienia na temat czæsto¥ci wystæpowaniauszkodzenia WKT bardzo siæ róºni, od 1 – 40% os-trych urazów stawu kolanowego. Fanelli obserwo-waÆ uszkodzenia WKT u 38,3% pacjentów z ostrymurazem kolana, tylko 3% miædzy nimi stanowiÆyuszkodzenia izolowane, pozostaÆe to byÆy urazywielowiæzadÆowe. Shelbourne obserwowaÆ tylko 8%uszkodzeñ WKT w urazach ostrych. Do uszkodze-nia WKT dochodzi najczæ¥ciej przy urazach o du-ºej intensywno¥ci — sportowych, motocyklowych itp.Najczæstszym mechanizmem urazowym jest przy-Æoºenie skierowanej ku tyÆowi siÆy do nasadybliºszej piszczeli, niekontrolowany przeprost itp.W badaniu klinicznym najistotniejszy objaw stano-wi test szuflady tylnej w zgiæciu kolana do 90°,zwracajåc szczególnå uwagæ na to, by zawsze po-równywaì badanie kliniczne obu nóg i przed bada-niem doprowadziì koñczynæ do pozycji neutralnejuwzglædniajåc fizjologiczne wysuniæcie piszczeli1 cm ku przodowi spod ko¥ci udowej. Zwiækszenierotacji zewnætrznej stopy ponad 10 – 15°, w porów-naniu z nogå zdrowå, jest patognomoniczne dlauszkodzenia struktur „rogu tylnego”.Urazy WKT mogå byì ostre lub zastarzaÆe, przed-stawiono 4-stopniowy podziaÆ wg Coopera.Ze wzglædu na grube pokrycie maziówkowe WKTma znacznie wiækszy potencjaÆ do samoistnego go-jenia, niº WKP i w znacznej czæ¥ci przypadkówulega wygojeniu. Ze wzglædu na ten fakt, jak i oba-wæ przed zwóÆknieniem stawu w przypadku opera-cji „na ostro” zaleca siæ przyjæcie postawy wyczeku-jåcej i przez 6 tygodni raczej nie ma wskazañ do re-

62 • Wiosna 2002

Posterior cruciate ligament injuriesand its treatment

Uszkodzenia wiæzadÆa krzyºowego tylnego i jego leczenie

Grzegorz Adamczyk

Carolina Medical Center, Warszawa

konstrukcji WKT. Wyjåtek mogå stanowiì zÆoºoneurazy z uszkodzeniem struktur „rogu tylnego”, któ-re szybko bliznowaciejå i po 2 – 3 tygodniach pro-blem stanowi ich identyfikacja i skuteczna reinser-cja. Czæ¥ì autorów uwaºa to za wskazanie do przy-spieszenia decyzji operacyjnej.MateriaÆem do przeszczepu mogå byì zarówno allo-jak i autoprzeszczepy. Zastosowanie znajdujå allo-przeszczepy ¥ciægna Achillesa z blokiem kostnym,przeszczepy wiæzadÆa wÆasnego rzepki z dwomablokami kostnymi, zÆoºone ¥ciægna miæ¥ni smukÆe-go i póÆ¥ciægnistego oraz miæ¥nia prostego uda.Czæsto stosowane autoprzeszczepy to: przeszczepywiæzadÆa wÆasnego rzepki z dwoma blokami kostny-mi, zÆoºone ¥ciægna miæ¥ni smukÆego i póÆ¥ciægni-stego oraz miæ¥nia prostego uda.Zaletå alloprzeszczepów jest nie uszkadzanie chorejkoñczyny, znaczne rozmiary, wadami moºliwo¥ìtransmisji chorób (ostatnio praktycznie wyelimino-wana), wysoki koszt, moºliwo¥ì indukowania odpo-wiedzi immunologicznej. W rekonstrukcjach WKPbardzo dobre i dobre wyniki w autoprzeszczepachstwierdza siæ w okoÆo 94% przypadków, w alloprze-szczepach w 86%.Przez caÆe lata za zÆoty standard uwaºana byÆa art-roskopowa technika operacyjna z uºyciem pojedyn-czego pasma rekonstruujåca jedynie pæczek przed-nio-boczny. Opisano technikæ tego zabiegu zeszczególnym naciskiem podkre¥lajåc konieczno¥ìstaÆej kontroli zarówno artroskopowej jak i radiolo-gicznej miejsca wyprowadzenia kanaÆu piszczelowe-go w tylnym aspekcie ko¥ci piszczelowej, zewzglædu na moºliwo¥ì uszkodzenia pæczka naczy-niowo-nerwowego goleni. Ostatnio, coraz po-wszechniejsza staje siæ rekonstrukcja WKT z uºy-ciem dwu pasm, odtwarzajåcych dwa pæczki wiæ-zadÆa — przednio-boczny napinany w zgiæciu 90°i tylno-przy¥rodkowy napinany w zgiæciu 30°, gdyºtylko takie postæpowanie przybliºa nas do biome-chaniki oryginalnego wiæzadÆa.W pracy omówiono szczegóÆowo technikæ operacyj-nå artroskopowej rekonstrukcji WKT z uºyciemuformowanego w literæ „V” zdwojonego pasma¥ciægna miæ¥nia prostego uda, która jest preferowanaw CMC. Przedstawiono takºe moºliwe, opisanew literaturze powikÆania — takie jak ograniczeniezakresu ruchu, pooperacyjna niestabilno¥ì, przedniból kolana, martwica kÆykcia przy¥rodkowego ko¥ciudowej, powikÆania naczyniowe i nerwowe i pokrót-ce — ich przyczyny i moºliwo¥ci leczenia.[Acta Clinica 2002 2:62-76]

SÆowa kluczowe: wiæzadÆo krzyºowe tylne stawukolanowego, rekonstrukcja wiæzadÆa krzyºowegotylnego, artroskopia stawu kolanowego, technika„dwóch pæczków”

SummaryPosterior cruciate ligament is a main restraint of po-sterior translation of tibia. PCL acts primarily as twofunctional separate bundles, with anterolateral por-tion acting predominantly in flexion and a postero-medial acting predominantly in extension. The lin-ear stiffness of the anterolateral bundle is 2,5 timesgreater than that of the posteromedial bundle andmenisco-femoral ligaments. The strength and stiff-ness of the anterolateral component of PCL has sig-nificant implication for ligament reconstruction.PCL is a main component of functional entity ofposterolateral anatomical structures of the knee jointcomposed of two parts: posterolateral complex of theknee in terms of the superficial lateral collateral lig-ament and „deep ligament complex”, which includethe arcuate ligament, popliteus tendon, fabellofibu-lar ligament and the posterolateral capsule — so cal-led posterior complex ligaments. The main mecha-nisms are high velocity injuries, e.g. hyperextensionor fall on flexed knee and direct trauma of proximaltibia. Incidence of PCL injury is reported to be from1 – 40% of acute knee injuries, in 42% of patientswith haemarthrosis occurs PCL lesion. A total of45,9% of PCL injuries were combined ACL/PCLtears, 41,2 PCL/PLC tears and only 3% were isola-ted PCL tears. The base of diagnosis is a clinical in-vestigation, and the most accurate clinical test toevaluate the PCL injury is the posterior drawer at90° of flexion performed with the patient supine. In-creased external rotation of 15° or more at 30° ofknee injury is considered diagnostic for posterior la-teral complex injury.Main classification of PCL injury and simplifiedschema of decision-making used in CMC are pre-sented. Graft selection options available are com-mented. Two basic operative techniques have beendescribed in details: an arthroscopic single bundle(that might be simplified by a mini-open posteriorapproach inlay proposed by Clancy) and an arthro-scopic double-bundle method with the use of „V”shaped rectus femoris ligament graft — preferred inCMC.Complications and pitfalls were also commented,including loss of motion, persistent instability, ante-rior knee pain, osteonecrosis of medial femoral con-dyle, infection, vascular and neurological problemsand a brief comment, how to avoid them was given.[Acta Clinica 2002 2:62-76]

Key words: posterior cruciate ligament reconstruc-tion, knee arthroscopy, double bundle technique

Tom 2, Numer 1 • 63

Posterior cruciate ligament injuries

The posterior cruciate ligament (PCL)has been a subject of many controversies.Basic research and clinical studies have ex-ploded in recent years, many new operativetechniques have been described, followedby rehabilitation protocols and a basicquestion — whether and when we shouldreconstruct an injured PCL — has not beenyet solved. Opinions differ from Hughston(1, 2), who found PCL „the fundamentalstabilizer of the knee” to Shelbourne whostated, that „knee function is independentof the grade of PCL laxity”. Probably thekey is a careful clinical investigation,a good qualification based on both: degreeof instability and a level of patients activityand expectations. Surgery should be reser-ved for active, young patients with a severe,III grade instability of a „posterior cornertype” (PLC).

Functional anatomy

The posterior cruciate ligament origi-nates from lateral aspect of the medial fem-oral condyle and passes posteriorly and lat-erally to the anterior cruciate ligament(ACL) to insertion on the posterior aspectof the tibia in posterior tibial fovea ~ 1 cmbelow the medial tibial condyle. PCL is in-tracapsular but extraarticular, because it re-flects synovium from posterior capsule ofthe knee joint and it’s anterior, medial andlateral aspects are covered by a synovialfold, and its posterior aspect connects withposterior capsule and periosteum distally(4,16). The synovial covering is evidentlythicker and more complete than that ofACL, but there’s no evidence that vascularsupply of PCL is more effective than ofACL.

The average length of PCL is 38mm,width 13 mm (16). Cross sectional area ofPCL increases from the tibial to femoralinsertion and is approximately 1,5 timesthat of the ACL. The orientation of the lig-

ament depends on the angle of the kneeflexion — it is vertical in the frontal planeand angles forward 30 – 45° in the sagittalplane and is located just medial to the cen-ter of the knee near the longitudinal axis oftibial rotation. Fibers are more horizontalin flexion and more vertical with knee ex-tension.

PCL consists of different functional re-gions of which the anterolateral and poste-romedial bands are two of the largest (3, 4).The anterolateral component runs from theanterior aspect of the intercondylar surfaceof the medial femoral condyle posterolate-rally to insert on the lateral aspect of theposterior tibial fossa. The posteromedialbundle arises from the posterior portion ofthe femoral insertion site and extends obli-quely to insert on the medial aspect of theposterior tibial fossa. The anterolateralbundle tightens with a knee flexion, whe-reas the posteromedial component tightenswith knee extension (3, 4, 16).

Meniscofemoral

ligaments (MFLs).

MFLs represent accessory knee liga-ment that attach to the medial femoral con-dyle in the region of PCL, present in 71%to 100% of the dissected knees consist ofthe anterior ligament of Humphrey and theposterior ligament of Wrisberg (3, 19).

The posterior MFL of Wrisberg origi-nates from the posterior horn of the lateralmeniscus, posterior tibia or posterior capsu-le and crosses obliquely, posterior to the PLto a separated insertion site on the medialfemoral condyle, maybe as large as 50% ofdiameter of the PCL (15, 18), and a domi-nant posterior MFL was found in 36% ofspecimens dissected by Heller and Lan-gman (19), averaged 20% (7 – 35%) size ofPCL (3).

The anterior MFL of Humphrey arisesfrom the posterior horn of the lateral me-

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64 • Wiosna 2002

niscus, passes along the anterior aspect ofthe PCL to insert on the medial femoralcondyle.

MFLs serve as a minor restraint to pos-terior translation of the tibia when the PCLis cut, but they are believed to play an im-portant role in meniscal kinematics.

Functional

biomechamincs

Tensile properties are function of age,ligament orientation and the direction ofapplied load. For a long time after Kenne-dy’s study (22) PCL was taught to be al-most twice as strong as ACL and the tibialcollateral ligaments (MCL) respectively atthe same strain rates. Prieto (27) tested ca-davers 19 – 25 years old with the knee 45°and obtained an ultimate load of1627 ± 491 Newtons and linear stiffness of204 ± 66 Newtons — similar to values ofACL. Harner (3) performed a more deta-iled study and has found that the ultimateload to failure of the anterolateral band was~2,5 times greater than the posteromedialband and ~5 times greater than the MFL.The linear stiffness of the anterolateralbundle was ~2,5 times greater than that ofthe posteromedial bundle and MFL. Thestrength and stiffness of the anterolateralcomponent of PCL has significant implica-tion for ligament reconstruction.

Knee kinematics

Butler (7) assessed total restraining for-ce in the stressed knee and then selectivecutted individual ligaments and measuredreduction in the restraining force, indepen-dently of ligament cutting order. He deter-minates, that the PCL provided 95% of thetotal restraining force to a straight posteriordraw. Grood and Gollehon (17, 18) inde-pendently performed selective cutting stud-ies of the PCL and posterolateral structu-

res. Gollehon (17) defined the posterolate-ral complex of the knee in terms of the su-perficial lateral collateral ligament and„deep ligament complex”, which includethe arcuate ligament, popliteus tendon, fa-bellofibular ligament and the posterolateralcapsule. As knee flexion increased from 0°to 90° isolated sectioning of PCL causeda progressive increase in posterior tibialtranslation which was greatest at 90° fle-xion. Isolated sectioning of lateral collateralligament caused increased varus rotation atall angles of flexion, with relatively smallincreases in external rotation at 0°, 30° and90° of knee flexion. Isolated sectioning of„deep ligament complex” produced increa-sed external rotation at 90° of flexion witha concomitant increase in varus rotation.

This findings suggested, that the poste-rior draw test at 75°-90° of flexion is the

Tom 2, Numer 1 • 65

Posterior cruciate ligament injuries

Fig. 1 a, b. A drawer test

a

b

best way to asses stability of PCL. Combi-ned injuries of PCL and PLC demonstratesignificant increase in posterior translation,varus angulation and external rotation atall angles of the knee flexion when compa-red to the normal knee. Lesion of PCL se-verely disturbs a so-called „screw-homemechanism” of external rotation of the tibiaas the limit of extension is approached.

Skyhar (29) measured articular contactpressure in cadaveric knees after sectioningligaments and they have found, that contactpressures in the medial and patellofemoralcompartments were significantly increasedafter isolated or combined sectioning ofPCL, in lateral compartment pressure wasincreased only after combined PCL andPLC sectioning.

The PCL is so complex structure, thatis very difficult to define the points of iso-metric placement of the graft, hence ten-sion on the ligament remains constant dur-ing range of motion of the knee. Isometricplacement restores normal knee kinematicsand minimizes stress on the graft. Only 5%of PCL is isometric (11). Ogata andMcCarty (24) recommended anatomicguidelines for isometric placement of thePCL, the most isometric and isotonic posi-tion for the femoral insertion was at the in-tersection of a line, one third the distancebetween the distal articular surface and theproximal edge of the intercondylar notch,and the two or ten o’clock position on thenotch for a right or left knee respectively.

Incidence

Incidence of PCL injury is reported tobe from 1 – 40% of acute knee injuries, ap-proximately 3% in general population and38% in reports from regional trauma centers.Fanelli (13) reports in he’s practice 38,3%incidence of PCL tears in acute knee inju-ries, 56,5% of these injuries occurs in pa-tients wit multiple trauma. A total of 45,9%

of PCL injuries were combined ACL/PCLtears, 41,2 PCL/PLC tears and only 3% we-re isolated PCL tears. He stated 42% ofPCL injury in patients with haemarthrosis.Shelbourne and Jari (21) in a multicenterstudy estimated for 5164 isolated ACL inju-ry 352 isolated PCL, 61 PCL/MCL, 49ACL/PCL/MCL, 28PCL/PLC — but it is anextremely low ratio of combined injuries,that has been reported.

Mechanism

Most PCL injuries occurs secondarilyto sports or motor vehicle trauma. A poste-riorly directed force at the level of tibial tu-bercle is a common mechanism, e.g. fall onthe flexed knee with a foot plantarflexed.Other mechanism is an external rotation ofthe tibia or posteromedial varus directedforce. Other mechanism might be hyperex-tension.

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Fig. 2 a, b. Mechanism of injury

a

b

Patients experience severe pain andswelling and usually describe gross defor-mity of the knee, but majority of these dis-locations spontaneously reduces and major-ity of victims present reduced.

Evaluation

of PCL injuries

The most accurate clinical test to evalu-ate the PCL injury is the posterior drawerat 90° of flexion (1, 26), performed with the

patient supine. Usually exist a 10 mm stepoff between the medial tibial plateau and themedial femoral condyle. One should alwayscompare the contralateral leg. Fu, Harnerand Kashiwagushi subdivided posterior dra-wer into III categories: Grade I injuries usu-ally lose 0,5 cm of step off, Grade II injurieslose the entire step-off, but still cannot besubluxated beyond the condyle. In grade IIIinjuries the proximal tibia could be subluxa-ted posteriorly 10 mm beyond the medial fe-moral condyle, creating a reverse step off.

Because in Grade III injury tibia at 90°of flexion is always posteriorly subluxated,when testing PCL tibia should be reducedinto „neutral position” with an anteriorlydirected force. Testing should be performedin both 30° and 90°. This is the most easilyperformed with one hand behind the proxi-mal tibia, reducing the joint, and the otherat the ankle, creating an external rotation

Tom 2, Numer 1 • 67

Posterior cruciate ligament injuries

Fig. 3 a. A positive „step-off”

Fig. 3 b. „Step-off reduce

Fig. 3 c. „Negative step-off” Fig. 4 b. A decrease external rotation

Fig. 4 a. An external rotation assessment in proneposition

force. It should be always compared withan uninjured side. Increased external rota-tion of 15° or more at 30° of knee injury isconsidered diagnostic for PLC injury.

The „reverse pivot-shift” may also de-tect a PLC or PCL/PLC injury. Testingbegins with the knee flexed at 90°, with ti-bia posteriorly flexed. As the knee is bro-ught into extension, relocates.

PCL acts as an important secondary re-straint to external rotation, more importantat 90° than at 30° of knee flexion. Increasedexternal rotation at 90° suggest a combinedPCL/PLC (but not LCL) injury.

Classification

of PCL injuries

(after Cooper, 10)

Level I — isolated injuries to either thePCL or PLC, yields mm posterior drawer,

trace asymmetry in external rotation andvarus laxity at 30°.

Level II — 2-ligament injury, knee stab-le to varus and valgus at full extension byhaving ++ varus or valgus laxity at 30° offlexion, posterior drawer 11 – 15mm, withthe PLC — extensive external rotation.

Level III — 3 ligament injury, varus-val-gus unstable in full extension, always PCLand PLC, knee with severe hyperextension,drawer 15 mm, knee reduced.

Level IV — dislocation.Subclassify: Acute or chronic (A or C).

Full thickness chondral injury or menis-cectomy.

Ligament healig

potential of PCL

The PCL has an intrinsic ability to healunlike the ACL — maybe due to better sy-novial coverage (17). In the acute settingMRI has been reported to be 99% sensitiveand specific. With a chronic injury resultsof MRI studies suggest that torn PCL mayheal and 77% of torn ligaments regain con-tinuity although with an abnormal appear-ance. Often MRI show a „normal” PCLdespite obvious clinical posterior laxity andso reduces the accuracy of this investigationas a predictor for treatment. Clinical deci-sion should be than based on results of cli-nical investigation and patients complaintsthan on MRI studies.

Decision making

Natural history of a PCL deficient kneehas been well described (12) and in a pop-ulation of active patients less than 45 yearsof life it leads to a progressive knee deterio-ration and 5 years after an injury majorityof PCL deficient patients complaints of in-stability and functional disability and pres-ents signs of early degenerative changes onX-ray examination.

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68 • Wiosna 2002

Fig. 5 a, b. Reversed „pivot-shift” phenomenon

a

b

Patients with high-energy knee disloca-tion may have remote injuries that takeprecedent over the knee, but an immediatereduction of the joint is required to preventamputation and to allow the best chancefor functional recovery of the injured knee.Urgent reduction of dislocation should beperformed once a neurovascular examina-tion is documented. If a surgeon is unableto do it manually, a closed or open reduc-tion under anesthesia should be performedas soon as possible in order to restore a blo-od flow within 6 – 8 hours of injury. Anysuspicious leg compartments should havefasciotomies performed when indicated.Open injuries requires urgent irrigationand debridement. An external fixator in re-duced position that spans the knee jointwithout distraction might be used in pa-tients with polytrauma, vascular repair,open dislocation or dislocation highly un-stable after reduction. The knee should bebraced or splinted in 20° flexion.

In patients with less severe, isolatedPCL or PCL/PLC injuries patient mightbe immobilized in extension to minimizeposterior subluxation by the hamstrings

(26). Quadriceps sets, straight leg raisesand weight bearing are allowed.

An acute surgery is rather not indicatedfor isolated PCL injury. This is primarilydue to of the high incidence of stiffness andarthrofibrosis if acute reconstructions areperformed within first six weeks. On theother hand the PCL could heal and for pa-tient with less than ++ posterior drawerlaxity, the PCL injury might be managedconservatively.

There’s a doubt considering PLC inju-ry — these structures are often amendable toprimary repair, because scar formation oc-curs quickly, obscuring details and makingprimary repair and anatomical positioningnearly impossible. According to Harner andPetrie (26) it may indicate a „subacute” re-pair within 2 – 3 weeks.

If a diagnostic arthroscopy is perfor-med, a very careful attention should be pa-id to pressure of a fluid in order to avoida liquid leakage through torn capsule topopliteal fossa and possible venous com-pression and complications.

Surgery should be performed on electi-ve basis, once the knee is fully rehabilitated

Tom 2, Numer 1 • 69

Posterior cruciate ligament injuries

Tab. 1. Schema of decision

to include full range of motion, minimalswelling, good leg control. The patient sho-uld be educated regarding rehabilitationgoals like proprioception, cocontraction,quadriceps strengthening and surgical pro-cedure.

In chronic PCL injuries surgery shouldbe carefully indicated and any effort to im-prove joint function and stability by a pro-per rehabilitation program should be made.

So a simplified schema (Tab. 1 and 2)of decision might be proposed (acc. to Har-ner and Petrie, 26).

Graft selection:

Many materials have been proposed,because the ideal graft should be strong,provide secure fixation, be easy to pass, bereadily available and have low donor sitemorbidity. On the other hand there shouldbe some technical opportunities, becausemany of these patients have been previous-ly operated or have a multiligamental inju-ry and many sources of graft materialsmight be needed at the time of operation.

The available options are autograftsand allograft sources: Achilles tendon allo-

graft, autograft bone-patellar tendon-bone(BPTB), split quadriceps tendon autograft,quadruple semitendinosus and gracilis au-

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70 • Wiosna 2002

Fig. 6 a, b. Graft sources: central part of patellartendon

b

a

Tab. 2. Schema of decision

to- and allografts, autograft BPTB and splitbiceps tendon autograft. Synthetics are notapproved by the Food and Drug Adminis-tration (10), but in Europe still are used socalled „hot-dog” combined autografts andsynthetic augmentation (15).

Allograft tissues have well-known ad-vantages — no morbidity, significant bulk,disadvantages are: expense, the possibilityof disease transmission, histocompatibilitymismatch with immune response (presentin up to 60% of patients) and even a slightrisk of acute rejection or failure to incorpo-rate. The risk of viral transmission has beencurrently so reduced, that is nearly negligi-ble, there were no such a studies performedin PCL surgery, but in ACL reconstructionan overall success ratio is 86%, when com-pared with 94% in autografting.

Operative techniques:

There are in general two methods:a single bundle and a double bundle oneand three techniques: by an open ap-proach, arthroscopically assisted and a truearthroscopic technique.

Tom 2, Numer 1 • 71

Posterior cruciate ligament injuries

Fig. 6 e. Graft sources: hamstrings gracillis andsemitendinosus graft

Fig. 6 c, d. Graft sources: a rectus femoris graft

c

d

Fig. 7 a, b. Allograft of Achilles tendon

a

b

e

Single bundle technique

Traditionally, reconstruction involvedreplacing only the anterolateral bundle ofthe posterior cruciate ligament. This type ofreconstruction has been termed „singlebundle reconstruction” and persist low-gra-de posterior cruciate graft laxity. Clancy op-erated PCL with a BPTB with a two inci-sion approach (8), Fulkerson (14) added anipsilateral autogenous central quadricepstendon with proximal patellar bone plug, toavoid a disruption of an extensor mecha-nism. Nowadays a pure arthroscopic tech-nique, e.g. a so-called Pittsburgh approachhas been widely accepted (23).

Patient positioning: Patient is positio-ned supine with a tourniquet over the up-per thigh. Flexion of the knee should bemaintained 90° without assistance through-out the entire procedure. The dorsal pedisand posterior tibial pulses should be chec-ked before and after the procedure. Antibi-otics are given routinely.

Examination under anesthesia and di-agnostic arthroscopy are carried out ina systematic manner, tourniquet use is avo-ided if possible. The arthroscope is placedthrough a lateral, a motorized shaver thro-ugh medial.

Debridement of the PCL femoral andtibial insertion: The intercondylar notch isdebrided of the remnant PCL, sometimesis good to leave some fibers of femoral at-tachment to serve as a landmark for femo-ral tunnel pins placement. The 30° arthro-scope is passed through the notch anda posteromedial portal is made under di-rect visualisation. A shaver is placed thro-ugh the posteromedial portal with the mo-uth pointed anteriorly to avoid inadvertentinjury to the neurovascular bundle and ti-bial insertion is debrided under vision. Itis facilitated by use of 70° scope. Debride-ment is performed to 1,5 cm below the jo-int line.

Tibial tunnel: The PCL tibial guide isplaced through the medial portal and its anset is an orientation parallel to the proximaltibiofibular joint. A 2 cm longitudinal inci-sion is made to periosteum on the antero-medial aspect of the tibia 1 fingertip belowthe level of tibial tubercle and it’s positionshould be checked by intraoperative X-raybefore drilling. Guide pin should exit onthe distal third of the PCL foot print seenon X-ray as a posteriorly sloped corticalshadow just anterior to the medial tibialplateau shadow. When pin or drill are dril-led a special curette is placed over theguide to prevent pin migration. 11 mmPCL tibial tunnel is made, great attentionis paid when exciting the posterior cortex,last step might be done by hand drilling.

Femoral tunnel — should be centered8 – 9 mm proximal to the articular surfaceof the medial femoral condyle in the ante-rior half of the native femoral insertion site(approximately 2 o’clock for the rightknee). Through a anterolateral portal a 35mm blind femoral tunnel is the createdwith a cannulated drill.

Graft preparation — a bone plug is sha-ped a round 11 mm plug corresponding to

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Fig. 8. An X-ray intraoperative control of a tibialtunnel positioning

the femoral tunnel and one 5# Suture isplaced through the bone. The tendinousportion of graft is trimmed, tubulerized us-ing a baseball type stitch to correspondwith the 10 mm tibial tunnel.

Graft passage is facilitated by use of lo-oped, 18-gauge wire that is inserted thro-ugh the tibial tunnel, great care is exercisedwhen passing wire posteriorly around thetibial insertion to prevent a vascular injury.When the looped wire is visible inside thejoint, the suture attached to the soft tissueend of Achilles allograft is threaded thro-ugh the loop. The wire is then pulled outthe distal end of the tunnel carrying the su-ture with it. The entire graft is pulled intothe joint. The suture attached to the boneblock is then threaded through the eye ofthe needle and pulled out of the anterome-dial thigh allowing placement of bony pluginto the femoral tunnel from within the jo-int. We fix it with a bioresorbable interfer-ence screw or through a separate incisionanteromedially, midway between the me-dial patellar facet and the medial epicondy-le through the vastus medialis obliquemuscle.

Tibial fixation is performed with theknee in 90° of flexion. The normal 1 cm ti-bial step-off of the medial tibial plateau inrelation to femoral condyle should be resto-red and another interference screw instal-led. The graft should be pretensioned befo-re installation.

Immediately after surgery the patient isplaced in a hinged knee brace that is lockedinto extension with a particular care to en-sure that no posterior translation occurswhile putting on the brace.

Tibial fixation may by facilitated andsecured by a tibial inlay procedure with onmini-open approach described by Berg (6),with the posterior opening of knee jointand a direct fixation of a bony plug intoposterior proximal tibia, however it needsa two-stage procedure.

Our preferred method are double tun-nel, because PCL acts primarily as twofunctional separate bundles, with anterola-teral and anterocentral portion acting pre-dominantly in flexion and a posteromedialacting predominantly in extension. As itwas mentioned, single bundle graft repre-sents only the anterolateral part and is ten-sioned at 90° of flexion. Because majority offunctional activities are performed at lessthan 70° of flexion, the graft is subjected toposterior stresses at flexion angles that aresignificantly less those at which it was ten-sioned what results in a cyclic fatigue andlengthening of the graft.

Double tunnel

technique

Positioning of the patient, examinationof the knee under anesthesia and systema-tic arthroscopic of the knee without a tou-rniquet, debridement of the PCL femoraland tibial insertions, tibial tunnel creationas mentioned above. Differences beginwhen drilling the femoral tunnels. To fa-cilitate that procedure a lateral portal isenlarged, arthroscope switched to medialportal and irrigation stopped. The antero-lateral bundle origin an the medial femo-ral condyle is seen inside the PCL foot-print, guide wire is placed approximately9 – 10 mm from articular surface and ad-vanced. 11mm tunnel, 25 – 30 mm ofdepth is drilled, bone debris removed. Po-steromedial bundle femoral tunnel size issmaller, about 6 – 8 mm in diameter accor-ding to the graft size a minimum 3 – 4mm bony bridge should separate thesetunnels. An anterior proximal guide pinshould enter an intercondylar notch at10.30 position in a left knee or 1.30 posi-tion in a right, approximately 6mm poste-rior to the articular surface of the medialfemoral condyle. The posterior-distal tun-nel is drilled 5 mm posterior and 5 mm

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distal to the anterior, still within the anato-mic site of origin of PCL.

Next steps depends on the graft choice— if a rectus femoris graft is chosen — mas-sive Ethibond sutures are installed on threeends of a V-shaped graft — 5# on bonyblock from patella and a 2# baseball stit-ches placed on tendinous endings.

Graft passage through a tibial tunnel isfacilitated by an elastic curved device, tun-nel is large enough for a bony block. Theentire graft is pulled into the joint. The su-ture attached to tendinous endings separa-tely are then threaded through the eye ofthe needle and pulled out of the anterome-dial thigh allowing placement of preparedtendons into the femoral tunnels from wi-thin the joint. We fix it with a bioresorbab-le interference screw or through a separateincision anteromedially, midway betweenthe medial patellar facet and the medialepicondyle through the vastus medialis ob-lique muscle.

An anterolateral bundle is tensioned at90° of flexion with an anterior drawer test,a posteromedial at 30° of flexion.

Immediately after surgery the patient isplaced in a hinged knee brace that is lockedinto extension with a particular careto en-sure that no posterior translation occurswhile putting on the brace.

Complications

The most common is persistent laxityas noted by a positive posterior drawer test.This is mainly due to not sufficient correc-tion of other accompanying ligamentousinjuries or underestimation of malaligne-ment of a limb axis and might need a revi-sion surgery among symptomatic patients.Loss of range of motion may also occurand often of some degree of flexion. Loss ofextension is minimized by avoiding immo-bilization in flexion immediately aftera surgery. It maybe treated arthroscopically

by debridement of medial and lateral para-patellar gutters and retinacular release.Neurologic injuries can be present ina form of neurapraxia if the tourniquet isprolonged. Due to a fear of vascular,thrombotic or neurologic problems an useof tourniquet should be strictly limited andcontrolled. Many surgeons (25) use a poste-romedial safety incision — 2 cm incisionmade just inferior to the posterior joint li-ne. The crural fascia is carefully incised,the interval developed between the poste-rior capsule of the tibio-femoral joint ante-riorly and to medial head of gastrocnemiusmuscle and neurovascular structures poste-riorly. The surgeon can place his fingertipin this extracapsular position to monitorthe position of tools, thus protecting theneurovascular structures. It has an additio-nal advantage as a way to escape pathwayfor extravasating arthroscopic irrigation flu-id if a capsular tear occurs.

Infection after PCL reconstruction isunusual, there are no reported series in lite-rature, a risk factor might be a previoussurgery and meniscal repair (9, 25).

An osteonecrosis of the medial femoralcondyle has been reported (5, 25) andmight occur from increased pressure in thebone causing a vascular insufficiency. Itmight be also due to drilling a femoral tun-nel too close to the articular surface, whichmight disturb the single nutrient vesselproviding the intraosseus blood supply tofemoral condyle.

Anterior knee pain due to synovitis,harvest of bone-patellar tendon-bone grafts,prominent hardware and degenerative pa-tello-femoral joint disease has been re-ported.

References

1. Adamczyk G., Antolak –., Skrok T., ÿmigielskiR.: Uszkodzenia chrzåstki stawów kolanowychstwierdzane w czasie artroskopii stawów kolano-wych u chorych z ostrymi i zastarzaÆymi uszkodze-

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niami wiæzadÆa krzyºowego przedniego — na pod-stawie zapisów video 144 operacji. Acta ClinicaTom I, 2001, 2: 138 – 144.2. Adamczyk G.: Diagnostyka kliniczna uszkodzeñwiæzadeÆ krzyºowych. Acta Clinica Tom I, 2001, 4:294 – 306.3. Allen A.A., Harner Ch.D., Fu F.H.: Anatomyand Biomechanics of the Posterior Cruciate Liga-ment, Sports Medicine and Arthroscopy Review1994, 2: 81 – 87.4. Arnoczky S.P., Warren R.F.: Anatomy of the cru-ciate ligaments. I: Feagin J.A. ed. The crucial liga-ments. New York: Churchill Livingstone. 1988;179 – 195.5. Athanasian E.A., Wickiewicz T.L., Warren R.F.:Osteonecrosis of the femoral condyle after arthro-scopic reconstruction of a cruciate ligament. A re-port of two cases. JBJS (Am), 1995, 77: 1418 – 1422.6. Berg E.E.: Posterior cruciate ligament tibial inlayreconstruction; Arthroscopy, 1995, 11: 69 – 76.7. Butler D.L., Noyes F.R., Grood E.S.: Ligamento-us restraints to anterior-posterior drawer in the hu-man knee. A biomechanical study. J.B.J.S. (Am)1980, 62: 259 – 270.8. Clancy W.G., Shelbourne K.D., Zoellner G.B.,Keene J.S., Reider B., Rosenberg T.D.: Treatment ofknee joint instability secondary to rupture of the po-sterior cruciate ligament, JBJS (Am) 1983, 65:310 – 322.9. Clancy W.G., Bisson L.J.: Double Tunnel tech-nique for reconstruction of the posterior cruciate lig-ament, Operative Techniques in Sports Medicine,Vol. l7, 1999, 3: 110 – 117.10. Cooper D.E.: Classification of posterior crucia-te ligament injury patterns. Presented at Interna-tional PCL Study Group Meeting. Dijon, France1995.11. Covey D.C., Sapega A.A., Martin R.C.: Arthro-scope assisted allograft reconstruction of the poste-rior cruciate ligament. Technique and biomechani-cal consideration. J. Orthop, Techniques 1993, 1:91 – 97.12. Dejour H., Walch G., Peyrot P.: The naturalhistory of rupture of the posterior cruciate ligament.Fr. J. Orthop. Surg. 1988, 2: 112 – 120.13. Fanelli G.C., Feldmann D.D.: Management ofcombined anterior cruciate ligament (posterior cru-ciate ligament) posterolateral complex injuries of theknee. Operative Techniques in Sports Medicine,Vol. l7, 1999, 3:143 – 149.14. Fulkerson J.P., Langeland R.: An alternativecruciate reconstruction graft: The central quadricepstendon. Arthroscopy 1995, 11: 252 – 254.

15. Gächter A.: Plastic aus einem transligamentärenIn: Jakob R.P., Stäubli H.-U., eds. Kniegelenk undKreuzbänder. Berlin; Springer Verlag; 1990,393 – 398.16. Girgis F.G., Marshall J.L., Al Monajem A.R.S.:The cruciate ligaments of the knee joint. Anatomi-cal, functional and experimental analysis. Clin. Or-thop. 1975, 106: 216 – 231.17. Gollehon D.L., Torzilli P.A., Warren R.F.: Therole of posterolateral and cruciate ligaments in thestability of the human knee. A biomechanical study.J.B.J.S. (Am) 1987, 69: 233 – 242.18. Grood E.S., Stowers S.F., Noyes F.R.: Limits ofmovement in the human knee. Effect of sectioningthe posterior cruciate ligament and posterolateralstructures. J.B.J.S. (Am) 1988, 70: 88 – 97.19. Heller L., Langman J.: The menisco-femoral li-gaments of the human knee, J.B.J.S. (Br) 1964, 46:307 – 313.20. Hughston J.C., Bowden J.A., Andrews J.R.,Norwood L.A.: Acute tears of the posterior cruciateligament: Results of operative treatment. J.B.J.S.(Am) 1980, 62: 438 – 450.21. Jari S., Shelbourne K.D.: Nonoperative or Dela-yed Surgical Treatment of Combined Cruciate Lig-aments and Medial Side Knee Injuries. Sports Med-icine and Arthroscopy Rev. 2001, 9: 185 – 192.22. Kennedy J.C., Hawkins R.J., Willis R.B.: Ten-sion studies of human knee ligaments. J.B.J.S. (Am)1976; 58; 350 – 5.23. Klimkiewicz J.J., Harner Ch.D.: Single bundleposterior cruciate ligament reconstruction: Universi-ty of Pittsburgh approach. Operative Techniques inSports Medicine, Vol. l7, No 3, 105 – 109, 1999.24. Ogata K., McCarty J.A.: Measurements oflength and tension patterns during reconstruction ofthe posterior cruciate ligament. Am. J. Sports Medi-cine 1992, 20: 351 – 355.25. Petrie R., Harner Ch.D.: Double bundle poste-rior cruciate ligament reconstruction: University ofPittsburgh approach, Operative Techniques inSports Medicine, Vol. l7, No 3, 118 – 126, 1999.26. Petrie R., Harner Ch.D.: Evaluation and Mana-gement of the posterior cruciate injured knee Oper-ative Techniques in Sports Medicine, Vol. l7, 1999,3: 93 – 103.27. Prieto M.P., Bain J.R., Stonebrook S.N.: Tensi-le strength of the human posterior cruciate Liga-ment (PCL). Transpl. Orthop. Res. Society 1988,17; 195.28. Shelbourne K.D., Davis T.J., Patel D.V.: Thenatural history of acute, isolated, nonoperativelytreated posterior cruciate ligament injuries: A pro-

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spective study. Am. J. Sports Med. 1999, 27:276 – 283.29. Skyhar M.J., Warren R.F., Oritz G.J., SchwartzE., Otis J.C. The effects of sectioning of the poste-rior cruciate ligament and the posterolateral comp-lex on the articular contact pressure within the knee.J.B.J.S. (Am) 1993, 75: 694 – 699.30. Wascher C.D., Schenck R.C.: Surgical Treat-ment of Acute and Chronic Anterior Cruciate Liga-

ment (Posterior Cruciate Ligament) Lateral SidedInjuries of the Knee Sports Medicine and Arthro-scopy Rev. 2001, 9: 199 – 207.

Adres do korespondencji / Address for correspon-

dence: Grzegorz Adamczyk, Carolina Medical Cen-ter, ul. Broniewskiego 89, 01 – 876 Warszawa.e-mail: grzegorz.adamczyk@carolina.pl

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