Examination is performed with the patient under anesthesia and supine on
the operating table. The dial test is performed at 30° and 90° of knee
flexion to assess the integrity of the posterolateral corner. A posterior
drawer test is carried out with concurrent fluoroscopic evaluation to assess
the degree of posterior laxity (Figs. 6-A
and 6-B).
Incisions are marked and are injected with 0.25% Marcaine (bupivacaine)
with epinephrine before sterile preparation of the patient. Medial and lateral
parapatellar portals as well as a superolateral outflow portal are
established. Finally, a posteromedial portal is placed under direct
arthroscopic visualization. Diagnostic arthroscopy is performed
(Fig. 7), and, once the bundle
rupture patterns are identified, the femoral insertions are marked with use of
a radiofrequency device. The meniscofemoral ligaments are preserved. The
medial intercondylar and bifurcate ridges are carefully probed, outlined, and
preserved (Fig. 8), with the
surgeon noting the concavity of the insertion sites and their differential
slopes. The length and width of the bundle insertion sites are then measured
with respect to the tunnel and graft diameters
(Fig. 9).
The tibial insertion sites are then addressed. A posterior cruciate
ligament curet is placed through the anteromedial portal to dissect the
posterior tibial insertions, and a 70° arthroscope is used to visualize
the posterior aspect of the tibia as well as the posterior tibial space. The
posterior cruciate ligament remnant and soft tissue are cleared approximately
2 to 3 cm distal to the joint line with use of a radiofrequency device and an
arthroscopic shaver placed through the posteromedial portal. Care is taken to
preserve any remaining intact posterior cruciate ligament fibers (when
present) and the meniscofemoral ligaments (which are almost always
present).
The posterior cruciate ligament curet is again used through the
anteromedial portal, to clear the remainder of the tibial insertions for the
two bundles; adequate visualization is obtained through the posteromedial
portal (Fig. 10).
The posterior cruciate ligament guide is then set at 45° to 50° and
positioned through the anterolateral portal. The tip of the guide is placed
proximally and laterally on the tibial footprint, the position is confirmed
with a lateral fluoroscopic view, and the guide pin is inserted through an
anterolateral incision on the tibia, which is extended to address concomitant
posterolateral corner injuries as necessary.
The tip of the posterior cruciate ligament guide is then repositioned more
medially and distally to recreate the tibial insertion of the posteromedial
bundle, and placement is again confirmed with a lateral fluoroscopic view
(Fig. 11). The guide pin is
advanced through an anteromedial incision, and pin placements are confirmed
with an anteroposterior fluoroscopic view
(Fig. 12).
The tibial tunnels are drilled to match the previously measured dimensions
of the femoral insertions. The anterolateral bundle usually sizes to an 8 to
9-mm-diameter graft and the posteromedial bundle, to a 6 to 7-mm-diameter
graft. Tunnels are established with cannulated compaction drills and then are
dilated to their respective sizes (Fig.
13). The guide pin is protected from advancing with the posterior
cruciate ligament curet, and the posterior cortex of the tibia is always
drilled by hand, not by power.
The femoral footprint is then viewed with a 30° arthroscope through the
anteromedial portal, and a Steadman awl is utilized to mark the center points
of the two insertions. With the knee in 110° of flexion, a guide pin is
placed on the awl site on the anterolateral bundle, tapped into place with a
mallet, and subsequently advanced. The posteromedial guide pin is placed in a
similar manner. The pin placement is then evaluated with use of fluoroscopy
(Figs. 11 and 12).
The anterolateral femoral tunnel is drilled with an acorn reamer to a depth
of 30 to 40 mm, with the knee in 110° of flexion, and is dilated to its
final diameter. Care must be taken not to injure the patella or the lateral
femoral condyle. A Beath drill-bit is utilized to perforate the medial cortex.
The posteromedial tunnel is drilled in a similar manner to a depth of 25 mm
(Figs. 14-A and 14-B).
We utilize two tibialis anterior tendon allografts to match the patient's
native bundle diameters (Figs. 15 and
16). The grafts are whip-stitched with number-2 Tycron (polyester
fiber) suture on both ends.
To facilitate graft passage, two number-8 French pediatric feeding tubes
are placed in a retrograde fashion through each tibial tunnel and pulled
anteriorly to exit through the anterolateral portal. If the meniscofemoral
ligament is intact, the anterolateral bundle should pass over the ligament and
the posteromedial bundle should pass below the ligament.
A suture is shuttled through both pediatric feeding tubes, and the
whip-stitched anterolateral graft is passed through the anterolateral portal
into the notch and subsequently pulled through the tibial tunnel
(Fig. 17). The femoral end of
the graft is then passed through the femoral tunnel, with use of a Beath pin
and a 40-mm Endoloop (Smith and Nephew, Andover, Massachusetts) with the
button removed. The graft is then secured over a post to provide femoral
fixation. The posteromedial bundle graft is passed in a similar manner with
use of a 50-mm Endoloop.
The grafts are then provisionally fixed over posts on the femoral side. Two
AO 6.5-mm cancellous screws and washers are placed for the Endoloops. If a
concomitant posterolateral reconstruction or collateral ligament repair is
necessary, as is often the case, it is performed after femoral and before
tibial fixation of the posterior cruciate ligament grafts.
The knee is then cycled. First, the anterolateral bundle of the posterior
cruciate ligament is tensioned with the knee at 90° of flexion with the
application of an anterior drawer force. The graft is tied over a 4.5-mm
bicortical screw with a washer. The posteromedial graft is then tensioned and
fixed with the knee at 30° of flexion with the application of an anterior
drawer force.
For the first postoperative month, a hinged brace is worn and the
rehabilitation is focused on protecting the healing of the osseous and
soft-tissue structures and minimizing the effects of immobilization through an
early protected range of motion. At one week, the brace is unlocked and
closed-kinetic-chain mini-squat exercises, quadriceps sets, and straight-leg
raises are performed with the assistance of a physical therapist or an
athletic trainer. Between six and eight weeks, once good quadriceps control is
achieved, the brace is unlocked for all activities, and use of the brace is
discontinued entirely at eight weeks. Flexion is limited to 90° during
exercise. Between three and nine months, the patient focuses on more
concentrated closed-kinetic-chain progression, while adding treadmill, pool
jogging, and swimming (no breaststroke) to the regimen. At nine months,
sport-specific training, work hardening (a highly structured goal-oriented,
individualized treatment program designed to return a person to work), or job
restructuring is initiated.
CRITICAL CONCEPTSINDICATIONS:The majority of patients with a grade-I or II posterior cruciate ligament
injury do well with nonoperative management. However, young athletic patients
with an isolated grade-III injury sometimes require operative
management9. We
perform reconstruction in patients with posterior cruciate ligament deficiency
if they become symptomatic despite maximized conservative treatment,
especially when the articular compartments of the knee are well preserved.While injuries of the posterior cruciate ligament can occur in isolation,
an increasing number are being recognized as being part of a combined ligament
injury pattern. Treatment of these complex injuries has typically been
operative10. A
common injury pattern involves damage to the posterior cruciate ligament and
the structures of the posterolateral
corner11. Most of
these patients with combined injuries benefit from surgery, which has been
shown to provide a more predictable clinical outcome. An early and accurate
diagnosis of all concomitant ligamentous injuries is essential. In cases
requiring combined anterior cruciate and posterior cruciate ligament
reconstruction, a single-bundle (anterolateral bundle) reconstruction
technique is used because of concern about widening, and subsequent
coalescence, of the tibial tunnels.CONTRAINDICATIONS: Isolated grade-I and grade-II injuries of the
posterior cruciate ligament usually do not require surgical
intervention12. The
favorable outcomes seen after nonoperative treatment of these injuries are
most likely related to the integrity of the posterior cruciate ligament
remnant in those with partial injuries, other secondary restraints such as the
meniscofemoral ligaments, and the intrinsic healing capabilities of the
posterior cruciate ligament.Patients in whom the posterior cruciate ligament injury is associated with
arthritis in the medial and patellofemoral compartments typically do not
respond well to an isolated reconstruction of the posterior cruciate ligament.
We have utilized a biplanar osteotomy in these patients to reduce contact
forces in the medial compartment by decreasing varus and increasing the
posterior slope of the tibia.PITFALLS:Technical Pearls and PitfallsReconstruction of the posterior cruciate ligament should not be performed
in an ambulatory surgery center. Furthermore, a vascular surgeon should be
immediately available in the event of injury to a major vascular
structure.The following technical points are aimed at reducing the risk to
neurovascular structures.A posterior cruciate ligament curet should be used to protect the tip of
the guide pin from advancing into the popliteal fossa while drilling.The tourniquet should be left down, or a tourniquet should not be used, to
facilitate immediate identification of a vascular injury.Fluoroscopy should be used when pins are passed and during drilling of the
tibial tunnel.The tibial tunnel should be finished by manual drilling rather than by
power drilling.The arthroscopic shaver blade should face anteriorly when tissue is being
débrided from the posterior part of the tibia. Suction should be used
carefully as popliteal fat and neurovascular structures are easily sucked into
the shaver blades.An anterior drawer force should be applied to the knee to avoid
débriding the anterior cruciate ligament.Fluoroscopic guidance for pin placement is critical to achieve anatomical
placement of the tibial tunnels. An osseous bridge, of a minimum of 2 mm,
should be maintained between the two tunnels to prevent tunnel
coalescence.A radiofrequency device set to its lowest energy level will facilitate
identification of the medial intercondylar and bifurcate ridges during
dissection of the femoral bundle insertions of the posterior cruciate
ligament.With respect to the orientation of tibial and femoral footprints,
double-bundle reconstructions may be optimized by avoiding a mismatch
phenomenon (Figs. 18-A and
18-B). A more functional and anatomical reconstruction may be
achieved by correctly positioning each tunnel on both the tibial and the
femoral side (Figs. 19-A and
19-B). This may result in improved reciprocal tensioning behavior
and avoid graft elongation.AUTHOR UPDATE:In this paper, we have described the use of topographical osseous landmarks
to more accurately position the femoral and tibial insertions of a
double-bundle reconstruction of the posterior cruciate ligament. The femoral
insertions of the posterior cruciate ligament are delineated by osseous
landmarks—i.e., the medial intercondylar and bifurcate ridges.
Recognition of these landmarks is critical to accurate placement of the
femoral tunnels.Our understanding of the orientation of the tibial insertions of the
posterior cruciate ligament has evolved. The anterolateral insertion is
actually located more proximally than the posteromedial insertion. Also,
measurements from our previous
study1 suggest that
the average areas of the distinctive anterolateral and posteromedial
footprints, totaling 209 mm2, are larger than those reported in the
literature13,14.
Furthermore, our three-dimensional analysis utilizing a laser scan technique
has more accurately captured the concave insertion-site topography of the
posterior cruciate ligament (Figs.
3 and
20). We currently employ all
of this information to guide an anatomical reconstruction of the injured
posterior cruciate ligament.Double-bundle anatomy can also be restored through augmentation procedures
when only one of the two bundles is injured. In our experience, this has been
the case in up to one-third of cases of acute and chronic posterior cruciate
ligament injury. Typically, patients present with a torn anterolateral bundle.
Augmentation techniques, with preservation of the posteromedial bundle and
reconstruction of the anterolateral bundle, have been used with good
results.
CRITICAL CONCEPTS
INDICATIONS:
The majority of patients with a grade-I or II posterior cruciate ligament
injury do well with nonoperative management. However, young athletic patients
with an isolated grade-III injury sometimes require operative
management9. We
perform reconstruction in patients with posterior cruciate ligament deficiency
if they become symptomatic despite maximized conservative treatment,
especially when the articular compartments of the knee are well preserved.
While injuries of the posterior cruciate ligament can occur in isolation,
an increasing number are being recognized as being part of a combined ligament
injury pattern. Treatment of these complex injuries has typically been
operative10. A
common injury pattern involves damage to the posterior cruciate ligament and
the structures of the posterolateral
corner11. Most of
these patients with combined injuries benefit from surgery, which has been
shown to provide a more predictable clinical outcome. An early and accurate
diagnosis of all concomitant ligamentous injuries is essential. In cases
requiring combined anterior cruciate and posterior cruciate ligament
reconstruction, a single-bundle (anterolateral bundle) reconstruction
technique is used because of concern about widening, and subsequent
coalescence, of the tibial tunnels.
CONTRAINDICATIONS: Isolated grade-I and grade-II injuries of the
posterior cruciate ligament usually do not require surgical
intervention12. The
favorable outcomes seen after nonoperative treatment of these injuries are
most likely related to the integrity of the posterior cruciate ligament
remnant in those with partial injuries, other secondary restraints such as the
meniscofemoral ligaments, and the intrinsic healing capabilities of the
posterior cruciate ligament.
Patients in whom the posterior cruciate ligament injury is associated with
arthritis in the medial and patellofemoral compartments typically do not
respond well to an isolated reconstruction of the posterior cruciate ligament.
We have utilized a biplanar osteotomy in these patients to reduce contact
forces in the medial compartment by decreasing varus and increasing the
posterior slope of the tibia.
PITFALLS:
Technical Pearls and Pitfalls
Reconstruction of the posterior cruciate ligament should not be performed
in an ambulatory surgery center. Furthermore, a vascular surgeon should be
immediately available in the event of injury to a major vascular
structure.The following technical points are aimed at reducing the risk to
neurovascular structures.A posterior cruciate ligament curet should be used to protect the tip of
the guide pin from advancing into the popliteal fossa while drilling.The tourniquet should be left down, or a tourniquet should not be used, to
facilitate immediate identification of a vascular injury.Fluoroscopy should be used when pins are passed and during drilling of the
tibial tunnel.The tibial tunnel should be finished by manual drilling rather than by
power drilling.The arthroscopic shaver blade should face anteriorly when tissue is being
débrided from the posterior part of the tibia. Suction should be used
carefully as popliteal fat and neurovascular structures are easily sucked into
the shaver blades.An anterior drawer force should be applied to the knee to avoid
débriding the anterior cruciate ligament.Fluoroscopic guidance for pin placement is critical to achieve anatomical
placement of the tibial tunnels. An osseous bridge, of a minimum of 2 mm,
should be maintained between the two tunnels to prevent tunnel
coalescence.A radiofrequency device set to its lowest energy level will facilitate
identification of the medial intercondylar and bifurcate ridges during
dissection of the femoral bundle insertions of the posterior cruciate
ligament.With respect to the orientation of tibial and femoral footprints,
double-bundle reconstructions may be optimized by avoiding a mismatch
phenomenon (Figs. 18-A and
18-B). A more functional and anatomical reconstruction may be
achieved by correctly positioning each tunnel on both the tibial and the
femoral side (Figs. 19-A and
19-B). This may result in improved reciprocal tensioning behavior
and avoid graft elongation.
Reconstruction of the posterior cruciate ligament should not be performed
in an ambulatory surgery center. Furthermore, a vascular surgeon should be
immediately available in the event of injury to a major vascular
structure.
The following technical points are aimed at reducing the risk to
neurovascular structures.
A posterior cruciate ligament curet should be used to protect the tip of
the guide pin from advancing into the popliteal fossa while drilling.
The tourniquet should be left down, or a tourniquet should not be used, to
facilitate immediate identification of a vascular injury.
Fluoroscopy should be used when pins are passed and during drilling of the
tibial tunnel.
The tibial tunnel should be finished by manual drilling rather than by
power drilling.
The arthroscopic shaver blade should face anteriorly when tissue is being
débrided from the posterior part of the tibia. Suction should be used
carefully as popliteal fat and neurovascular structures are easily sucked into
the shaver blades.
An anterior drawer force should be applied to the knee to avoid
débriding the anterior cruciate ligament.
Fluoroscopic guidance for pin placement is critical to achieve anatomical
placement of the tibial tunnels. An osseous bridge, of a minimum of 2 mm,
should be maintained between the two tunnels to prevent tunnel
coalescence.
A radiofrequency device set to its lowest energy level will facilitate
identification of the medial intercondylar and bifurcate ridges during
dissection of the femoral bundle insertions of the posterior cruciate
ligament.
With respect to the orientation of tibial and femoral footprints,
double-bundle reconstructions may be optimized by avoiding a mismatch
phenomenon (Figs. 18-A and
18-B). A more functional and anatomical reconstruction may be
achieved by correctly positioning each tunnel on both the tibial and the
femoral side (Figs. 19-A and
19-B). This may result in improved reciprocal tensioning behavior
and avoid graft elongation.
AUTHOR UPDATE:
In this paper, we have described the use of topographical osseous landmarks
to more accurately position the femoral and tibial insertions of a
double-bundle reconstruction of the posterior cruciate ligament. The femoral
insertions of the posterior cruciate ligament are delineated by osseous
landmarks—i.e., the medial intercondylar and bifurcate ridges.
Recognition of these landmarks is critical to accurate placement of the
femoral tunnels.
Our understanding of the orientation of the tibial insertions of the
posterior cruciate ligament has evolved. The anterolateral insertion is
actually located more proximally than the posteromedial insertion. Also,
measurements from our previous
study1 suggest that
the average areas of the distinctive anterolateral and posteromedial
footprints, totaling 209 mm2, are larger than those reported in the
literature13,14.
Furthermore, our three-dimensional analysis utilizing a laser scan technique
has more accurately captured the concave insertion-site topography of the
posterior cruciate ligament (Figs.
3 and
20). We currently employ all
of this information to guide an anatomical reconstruction of the injured
posterior cruciate ligament.
Double-bundle anatomy can also be restored through augmentation procedures
when only one of the two bundles is injured. In our experience, this has been
the case in up to one-third of cases of acute and chronic posterior cruciate
ligament injury. Typically, patients present with a torn anterolateral bundle.
Augmentation techniques, with preservation of the posteromedial bundle and
reconstruction of the anterolateral bundle, have been used with good
results.