Advances in Posterior Cruciate Ligament Reconstruction
Embed Size (px)
Text of Advances in Posterior Cruciate Ligament Reconstruction
Current advances in posterior cruciate ligament (PCL) reconstruction have achieved excellent clinical and function- al outcomes.1-8 Anatomy, cadaver sec- tioning studies, biomechanical studies, and clinical outcome data are reviewed in this chapter. Current controversies, including transtibial versus inlay, auto- graft versus allograft, and single-bundle versus double-bundle reconstructions,
are highlighted. Novel surgical tech- niques, including the all- inside PCL reconstruction, are discussed.
Anatomy The anatomy of the PCL has been recently revisited and highlighted by Kennedy et al.9 The PCL complex is divided into the anterolateral bundle, the posteromedial bundle, and the
meniscal femoral ligaments. The menis- cal femoral ligaments are divided into the anterior meniscofemoral ligament (otherwise known as the ligament of Humphrey) and the posteromedial fem- oral ligament (otherwise known as the ligament of Wrisberg). The anterolateral bundle is primarily responsible for re- straining posterior tibial translation at 90° of knee fl exion, and this bundle has been traditionally reconstructed in single-bundle reconstructions. The posteromedial bundle acts as a re- straint to posterior tibial translation at approximately 30° of knee fl exion, and this bundle is reconstructed in double- bundle reconstructions. The femoral and tibial insertions are shown in Fig- ures 1 and 2.
A key element in the anatomy of the PCL is the insertion at the base of the tibial PCL facet. Understanding this anatomy is essential to restoring normal PCL function during reconstruction. Whether this insertion site is obtained by using a transtibial approach ar- throscopically or an open inlay approach through a posteromedial incision, an
Advances in Posterior Cruciate Ligament Reconstruction
Bruce A. Levy, MD Gregory C. Fanelli, MD
Mark D. Miller, MD Michael J. Stuart, MD
Dr. Levy or an immediate family member has received royalties from VOT Solutions and Arthrex; serves as a paid con- sultant to or is an employee of Arthrex; has received research or institutional support from Arthrex, Biomet, and Stryker; and serves as a board member, owner, offi cer, or committee member of the Arthroscopy Association of North America (representative to the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine) and Knee Surgery Sports Traumatolog y and Arthroscopy; and is a deputy editor for Clinical Orthopedics and Related Research. Dr. Fanelli or an immediate family member is a member of a speakers’ bureau or has made paid presentations on behalf of Biomet and CONMED Linvatec. Dr. Miller or an immediate family member serves as a board member, owner, offi cer, or committee member of the American Orthopaedic Society for Sports Medicine and Miller Orthopaedic Review Enterprises. Dr. Stuart or an immediate family member has received royalties from Arthrex; serves as a paid consultant to or is an employee of Arthrex; and has received research or institutional support from Stryker.
Abstract Current advances in posterior cruciate ligament reconstruction have led to excellent clinical and functional outcomes. It is helpful to review anatomy, cadaver sectioning studies, biome- chanical studies, clinical outcome data, and novel surgical techniques for posterior cruciate ligament reconstruction, including all-inside reconstructions. Surgeons also should be aware of current controversies regarding transtibial versus inlay, autograft versus allograft, and single-bundle versus double-bundle reconstructions.
Instr Course Lect 2015;64:543–554.
544 © 2015 AAOS Instructional Course Lectures, Volume 64
understanding of the insertion sites of this particular attachment site is criti- cal for a successful PCL reconstruction. More recently, the anatomy of the in- tercondylar notch and its reference to the PCL bundles were delineated. The top of the notch is referred to as the intercondylar notch apex, and several other points are described. The troch- lear point and the medial arch point are the boundaries of the anterolateral bundle and also are used as reference marks for the posteromedial bundle. Also, there is the so-called arch of the cartilage and an area referred to as the straight cartilage, which delineates areas of the anterolateral and posteromedial bundles on the medial femoral condylar
wall (Figure 3). As a general rule, the PCL is a much larger ligament than the anterior cruciate ligament (ACL), with an average dimension of 33 × 13 mm. Because it has a crescent-shaped inser- tion on the femur, it is often diffi cult to fi nd the so-called isometric point when performing single-bundle PCL reconstructions.
Surgical Technique Options The two traditional ways of recon- structing the PCL are the open inlay and the arthroscopic transtibial tun- nel techniques. Other options include single- bundle (anterolateral bundle) and double-bundle (anterolateral and posteromedial bundle) reconstructions.
The graft choices include a wide variety of autograft and allograft options.
Open Inlay Versus Arthroscopic Transtibial Reconstructions Biomechanical Evidence McAllister et al10 performed a cadaver cyclic loading study and compared tran- stibial tunnel and tibial inlay PCL graft reconstructions. The reconstructions were brought through cyclic loading to failure. The authors found no important advantage of one technique versus the other.
Clinical Evidence May et al11 performed a systematic clin- ical review of the literature comparing transtibial with inlay PCL reconstruc- tion. Similar to the biomechanical data, the authors reported no important ad- vantage of one technique versus the other.
Single- Versus Double- bundle Reconstructions Biomechanical Evidence Markolf et al12 performed a cadaver study of single-bundle versus dou- ble-bundle reconstructions and found that the single-bundle anterolateral PCL reconstruction graft best reproduced normal PCL force profi les, whereas the double-bundle reconstruction slightly reduced laxity at 0° to 30°. Whiddon et al13 performed a cadaver study com- paring single- versus double-bundle reconstructions using an open inlay PCL reconstruction cadaver model. The authors looked at 10 cadaver knees that used bone-patellar tendon-bone al- lografts and tested these knees in a sim- ilar way as the knees would be clinically tested (that is, they used the posterior drawer test, the dial test, and posterior
Illustration of the anterior view of a right knee fl exed to 90° with the posterior cruciate ligament (PCL) intact, demonstrating the characteristic morphology of the cartilage margin of the femoral intercondylar notch. The illustration also shows the trochlear point, the medial arch point, and the pos- terior point, as well as the intercondylar notch apex and the trochlear groove. ACL = anterior cruciate ligament, ALB = anterolateral bundle, aMFL = anterior meniscofemoral ligament, PMB = posteromedial bundle. (Reproduced with permission from Anderson, CJ, Connor G, Ziegler, MD, et al: Arthroscopically pertinent anatomy of the anterolateral and posteromedial bundles of the pos- terior cruciate ligament. J Bone Joint Surg Am 2012;94:1936-1945.)
Advances in Posterior Cruciate Ligament Reconstruction Chapter 48
© 2015 AAOS Instructional Course Lectures, Volume 64 545
stress radiography). The knees were tested intact and then retested after se- quential resection of both the PCL and the posterolateral corner structures. The authors found that if they resected the PCL and the posterolateral corner but did not restore the posterolateral corner structures, the double- bundle PCL re- construction had better rota tional stabil- ity. However, if they sectioned the PCL and the posterolateral corner and then reconstructed the posterolateral corner, they found no difference between the single- and double-bundle techniques.
Clinical Evidence Single-bundle versus double-bundle re- constructions were compared in a recent systematic clinical review by Kohen and Sekiya.8 The authors stated the follow- ing: “The superiority of single-bundle or double-bundle posterior cruciate ligament reconstruction remains un- certain.” In a comparative study by Wang et al,14 the authors performed a prospective study of 35 patients, 19 with single-bundle reconstructions and 16 with double-bundle reconstructions. They used hamstring autografts and followed this group of patients for 2 years and found no signifi cant differ- ences in functional scores, ligament lax- ity, and radiographic changes. Fanelli et al15 reported on a series of 90 con- secutive PCL reconstructions, where the fi rst 45 were performed using a sin- gle-bundle technique and the next 45 were performed using a double-bundle technique. Each reconstruction used a transtibial approach and a fresh- frozen allograft. Follow-up was between 24 and 72 months. When comparing stress radiography, KT-1000 arthrom- eter (MEDmetric) results, the Tegner Lysholm Knee Scoring Scale, and Hos- pital for Special Surgery functional knee
scores, the authors were unable to fi nd any signifi cant differences between the two groups.
Autograft Versus Allograft Hudgens et al16 also performed a sys- tematic review comparing allograft ver- sus autograft in PCL reconstruction and found satisfactory clinical and func- tional results from both graft types. Other authors have reported excellent long-term outcomes with the transtibial
technique, the open inlay technique, autograft reconstruction, allograft re- construction, and single-bundle and double-bundle PCL reconstructions.1-8 As with any surgical technique, under- standing the anatomy of the PCL is the fi rst step in successful surgery.
Transtibial Tunnel Surgical Technique This chapter’s authors prefer an Achil- les tendon allograft for single-bundle
Illustration of the posterior aspect of a right knee with the poste- rior cruciate ligament (PCL) intact, demonstrating the fi ber orientation. ALB = anterolateral bundle, PMB = posteromedial bundle, pMFL = posterior menis- cofemoral ligament. (Reproduced with permission from Anderson, CJ, Connor G, Ziegler, MD, et al: Arthroscopically pertinent anatomy of the anterolateral and posteromedial bundles of the posterior cruciate ligament. J Bone Joint Surg Am 2012;94:1936-1945.)
546 © 2015 AAOS Instructional Course Lectures, Volume 64
PCL reconstructions, and Achilles ten- don and tibialis anterior allografts for double-bundle PCL reconstructions.17 Allograft tissue is prepared, and arthro- scopic instruments are placed with the infl ow in the superior lateral portal, the arthroscope in the inferior lateral patellar portal, and instruments in the inferior medial patellar portal. An ac- cessory extracapsular, extra-articular posteromedial safety incision is used to protect the neurovascular structures and confi rm the accuracy of tibial tun- nel placement (Figure 4). The incision is made along the posteromedial tibial crest at 4 to 5 cm distal to the joint line. Dissection is carried down to the fas- cia, and a plane is created between the medial head of the gastrocnemius and the semimembranosus tendon. Blunt fi nger dissection is then used to sweep
anterior to the gastrocnemius tendon, allowing extra-articular palpation of the mammillary bodies on either side of the PCL facet.
To prepare for a combined PCL- ACL reconstruction, notch preparation is performed fi rst and consists of ACL and PCL stump débridement, bone re- moval, and contouring of the medial and lateral walls and the roof of the in- tercondylar notch. Specially designed 90° curets and rasps placed through the notch to the posterior aspect of the tibia are used to elevate the capsule and clearly identify the PCL-tibial footprint.
The arm of the PCL-ACL guide is inserted through the inferior medi- al patellar portal to begin creation of the PCL-tibial tunnel. The tip of the guide is positioned at the inferior lateral aspect of the PCL anatomic insertion
site. The bullet portion of the guide contacts the anteromedial surface of the proximal tibia at a point midway between the posteromedial border of the tibia and the anterior tibial crest, approximately 1 cm below the tibial tu- bercle. This provides an angle of graft orientation such that the graft will turn two very smooth 45° angles on the pos- terior aspect of the tibia and will not have an acute 90°-angle turn that may cause pressure necrosis on the graft. The tip of the guide, in the posterior aspect of the tibia, is confi rmed with the surgeon’s fi nger through the extra- capsular, extra-articular posteromedial safety incision. Intraoperative AP and lateral radiographs also may be used. As a double safety check, the surgeon uses his or her fi nger to confi rm the position of the guidewire through the posterior medial safety incision.
An appropriately sized, standard cannulated reamer is used to create the tibial tunnel. The surgeon uses his or her fi nger placed through the extracap- sular, extra-articular posteromedial in- cision to monitor the position of the guidewire. The drill is advanced until it comes to the posterior cortex of the tibia. The chuck is disengaged from the drill, and completion of the tibial tunnel is performed by hand. This provides an additional margin of safety for comple- tion of the tibial tunnel.
The PCL single- or double-bundle femoral tunnels are made from the inside out. Inserting an appropriately sized, double-bundle aimer through a low anterior lateral patellar arthro- scopic portal creates the PCL antero- lateral bundle femoral tunnel. The double-bundle aimer is positioned di- rectly on the footprint of the femoral anterolateral bundle PCL insertion site. The appropriately sized guidewire is
Anterior photograph of a right knee fl exed to 90° with a probe (from posterior) separating the anterolateral bundle (ALB) and the posterome- dial bundle (PMB) of the posterior cruciate ligament and demonstrating the landmarks surrounding the trochlear point and the medial arch point along the cartilage margin of the femoral intercondylar notch. (Reproduced with permission from Anderson, CJ, Connor G, Ziegler, MD, et al: Arthroscopically pertinent anatomy of the anterolateral and posteromedial bundles of the pos- terior cruciate ligament. J Bone Joint Surg Am 2012;94:1936-1945.)
Advances in Posterior Cruciate Ligament Reconstruction Chapter 48
© 2015 AAOS Instructional Course Lectures, Volume 64 547
drilled through the aimer, through the bone, and out a small skin incision. The double-bundle aimer is removed, and an acorn reamer is used to endoscopically drill from inside out the anterolateral PCL femoral tunnel. When performing a double-bundle double femoral tunnel PCL reconstruction, the same process is repeated for the posteromedial bundle of the PCL. There should be at least 5 mm of bone between the two PCL femoral tunnels.
The cyclic dynamic method of graft tensioning is used to tension the PCL and ACL grafts (Figure 5). During this surgical technique, the PCL and/or ACL grafts are secured on the femoral side fi rst with the surgeon’s pre- ferred fi xation method. The technique described is a tibial-sided tensioning method. Polyethylene ligament fi xa- tion buttons are used for cortical sus- pensory fi xation, and aperture opening interference fi xation with bioabsorbable interference screws are used for femoral side PCL and ACL fi xation. In com- bined PCL-ACL reconstructions, the PCL graft is tensioned fi rst, followed by fi nal PCL graft tibial fi xation. ACL graft tensioning and fi xation follows that of the PCL.
The tensioning boot is applied to the foot and the leg of the surgical limb, and tension is placed on the PCL graft(s) distally using a device such as the Biomet graft-tensioning boot (Biomet). Tension is gradually applied with the knee in 0° of fl exion (full extension), thus reducing the tibia on the femur. This restores the anatomic tibial step- off. The knee is cycled through a full range of motion multiple times to allow pretensioning and settling of the graft. The process is repeated until there is no further change on the torque setting of the graft tensioner with the knee at 0°
of fl exion. When no further changes or adjustments are necessary in the tension applied to the graft, the knee is placed in 70° to 90° of fl exion, and fi xation is achieved on the tibial side of the PCL graft with a bioabsorbable interference screw for interference fi t fi xation and backup cortical suspensory fi xation with a bicortical screw and a spiked liga- ment washer or a polyethylene ligament fi xation button.
It is very important to use primary and backup fi xation. During PCL-ACL reconstruction, primary aperture fi xa- tion is achieved with bioabsorbable in- terference screws, and backup fi xation is performed with a screw and a spiked ligament washer and ligament fi xation buttons. Secure fi xation is critical to the success of this surgical procedure. In
the experience of this chapter’s authors, mechanical tensioning of the cruciate ligaments at 0° of knee fl exion and res- toration of the normal anatomic tibial step-off at 70° to 90° of fl exion has pro- vided the most reproducible method of establishing the neutral point of the tibial-femoral relationship. Full range of motion is confi rmed on the operating table to ensure the knee is not “cap- tured” by the reconstruction.
Tibial Inlay Surgical Technique Berg18 fi rst introduced a tibial inlay technique for PCL reconstruction in 1995.18 This chapter’s authors adapted this technique shortly after its publica- tion and have modifi ed it over the years. The Berg technique has been combined
Intraoperative photograph of the transtibial tunnel surgical tech- nique. The 2-cm extracapsular extra-articular posteromedial safety incision allows the surgeon to position his or her fi nger posterior to the capsule of the knee joint and anterior to the medial head of the gastrocnemius and the neu- rovascular structures. This enables the surgeon to protect the neurovascular structures, monitor instruments working in the posterior aspect of the knee, confi rm the accuracy of the posterior cruciate ligament (PCL) reconstruction tibial tunnel, and facilitate the fl ow of the surgical procedure. The PCL rasp ele- vator is shown in use. (Reproduced with permission from Fanelli GC, Giannotti B, Edson CJ: Current concepts review: The posterior cruciate ligament. Arthroscopic evaluation and treatment. Arthroscopy 1994;10:673-688.)
548 © 2015 AAOS Instructional Course Lectures, Volume 64
with the posterior approach described previously by Burks and Shaffer,19 and it has subsequently been modifi ed as described later in this chapter.
The advantage of the inlay technique is that it eliminates graft abrasion and attrition associated with the traditional transtibial PCL technique.20 The PCL
graft can be fi xed directly into a trough at its tibial origin, and an anatomic PCL reconstruction can be accomplished. The approach is safe because the pop- liteal artery is retracted by the medial head of the gastrocnemius and is well outside the surgical fi eld.21,22 This chap- ter’s authors also have eliminated the problems associated with reposition- ing the patient during this procedure by placing the patient in the lateral decubitus position and simply rotating the leg at the hip to access the front of the knee.23
Patient Selection In the experience of this chapter’s au- thors, PCL injuries are rarely isolated. They commonly occur as a result of a motor vehicle crash (the so-called dashboard injury) and usually involve disruption of the posterolateral corner. The posterior drawer test, the preferred test for PCL injuries, can be quantifi ed with stress radiographs. Research has shown that isolated PCL injuries have a side-to-side difference of 10 mm or less on stress radiographs, but a combined PCL- and posterolateral corner–injured knee has a side-to-side difference of 20 mm or more.24 This chapter’s au- thors address these injuries within the fi rst 2 weeks and repair and/or recon- struct all the injured structures at that time. The repair and reconstruction of the posterolateral corner yields the best long-term outcomes.25
Patient Positioning As indicated earlier, after the comple- tion of an examination under anes- thesia, the patient is positioned in the lateral decubitus position with the in- jured leg up (Figure 6). It is important to pad the contralateral leg and all other extremities and use an axillary roll. A
Intraoperative photograph of the mechanical graft tensioning boot, which is used to tension both the posterior cruciate ligament (PCL) and the anterior cruciate ligament (ACL) reconstructions. It aids in reducing the tibia on the femur, pretensioning the PCL and ACL grafts, and maintaining reduc- tion during cycling and cruciate ligament graft fi xation.
Intraoperative photograph of a patient in the lateral decubitus position. Note that the surgical (right) leg is up and the nonoperative leg is well padded and down. A bean bag positioner is used, and the surgical leg can be rotated when necessary.
Advances in Posterior Cruciate Ligament Reconstruction Chapter 48
© 2015 AAOS Instructional Course Lectures, Volume 64 549
bean bag is used…