Posterior Cruciate Ligament Pathology Treatment & Management

Updated: Oct 19, 2021
  • Author: Matthew Lawless, MD; Chief Editor: Thomas M DeBerardino, MD  more...
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Approach Considerations

The long-term outcome of posterior cruciate ligament (PCL) insufficiency is difficult to predict, as is the outcome of PCL reconstruction. [55] Current reconstruction techniques (ie, the tibial inlay and double-tunnel methods) are promising with regard to their ability to create more normal knee responses to a posterior tibial force. However, the value of restoring knee posterior-tibial stability has not yet been correlated with patient function and outcome.

Many also believe that PCL reconstruction cannot prevent or delay the onset of degenerative changes in patients who have had a PCL injury. [29]  One certainty is that isolated PCL tears are not benign injuries. Reconstruction is advocated for patients with grade 3 PCL injuries. The natural history of isolated grade 1 and grade 2 PCL injuries has been established, and the outcome following PCL reconstruction must prove to be better to warrant the procedure and lengthy rehabilitation.


Medical Therapy

The natural history of PCL insufficiency has been a subject of controversy. Several reports with small cohorts have reported good outcomes with conservative treatment. These reports include patients with acute and chronic PCL insufficiency, as well as isolated and combined PCL injuries. [56, 57, 58] Several authors have reported late chondrosis of the medial femoral condyle and the patellofemoral compartment in patients with PCL insufficiency. [39, 59, 60, 61, 62] The development of meniscus tears and abnormal contact pressures have been reported. [61, 63, 64]

Geissler et al evaluated patients with PCL injuries treated conservatively with arthroscopy at a mean of 2.2 years. They reported that 49% had grade 2 or higher articular cartilage lesions, and 36% had meniscal tears. [61]

Keller et al monitored 40 patients with isolated PCL injuries treated conservatively an average of 6 years. Among the patients, 90% complained of knee pain, 65% had activity limitations secondary to the knee, and 43% had difficulty walking. The patient complaints were correlated with objective measures of posterior laxity. In addition, the incidence of radiographic abnormalities increased in relation to the duration of follow-up. [60]

Boynton et al reported findings in 38 patients at a mean of 13.4 years after an isolated PCL injury treated conservatively. Among the patients, 81% complained of occasional knee pain, and 56% reported occasional knee swelling. Radiographic analysis also correlated the degree of degenerative changes to the duration of follow-up. [62]

Shelbourne et al reported that of 133 athletic patients treated conservatively for isolated acute PCL tears, 68 patients returned for clinical follow-up at a mean of 5.4 years. The other 65 patients complete a modified Noyes Knee Questionnaire. The mean questionnaire score was 84.2. A score of 94 has been found to be normal for athletes of the same age. [65]

Findings in this cohort led to the following conclusions:

  • Healing of PCL injuries occurs, and residual laxity does not increase over time
  • Subjective scores are poorly correlated with the degree of posterior knee laxity
  • Objective and subjective knee function is independent of the grade of posterior knee laxity
  • A trend toward medial compartment arthrosis exists but does not correlate with the degree of posterior knee laxity
  • Meniscus tears are rare
  • Independent of laxity, one half of patients can return to the same sport at the same level, one third can return to the same sport at a lower level, and one sixth cannot return to the same sport

Although these results are comparable to those reported after PCL reconstruction, this cohort had laxity of grade 2 or less, and no distinction between partial and complete PCL tears was made in this study. [26, 65]


Surgical Therapy

PCL reconstruction begins with an examination with the patient under anesthesia to rule out concomitant ligament injuries. [66] Diagnostic arthroscopy should be performed, and any meniscus or cartilage procedures should be performed. Findings such as abnormal lateral joint opening at 25° of knee flexion during knee arthroscopy are also suggestive of posterolateral corner insufficiency. [40, 67] Arthroscopic findings consistent with an isolated PCL injury are as follows [30, 68] :

  • Anterior cruciate ligament (ACL) pseudolaxity
  • Medial femoral condyle and patellofemoral compartment chondrosis
  • Abnormal relation of the medial femoral condyle to the medial meniscus

Arthroscopic debridement of the PCL should be performed, leaving any fibers in continuity to lie over the graft and leaving enough remnants to identify the PCL footprints. A limited notchplasty (see the image below) can be performed for visualization; notch impingement is not a factor for PCL reconstruction, unlike ACL reconstruction. [69]

A right knee pending posterior cruciate ligament ( A right knee pending posterior cruciate ligament (PCL) reconstruction. A minimal notchplasty is completed. Two guide pins are advanced into the medial femoral condyle for tunnel placement to reconstruct the two bundles of the PCL. Image courtesy of Janos P. Ertl, MD.

Tibial graft fixation can utilize a tunnel or an inlay technique. The tunnel technique is simpler, avoiding posterior knee dissection. However, the angle the graft must make at the back of the tibial articular surface has been termed the killer turn. [40, 54, 69]  A cadaveric study demonstrated that the PCL graft has increased laxity and evidence of degradation after 72 cyclic loads, after tibial tunnel PCL reconstruction. [70]

The tibial inlay technique can be performed with the patient in a lateral position or else requires the patient to be turned from supine to prone and back to supine. [71] Decreased posterior tibial translation has been demonstrated after the tibial inlay technique. [70, 72]

Femoral graft placement has been performed with single-tunnel and, subsequently, double-tunnel techniques. Single-tunnel techniques were designed to recreate the stabilizing effect of the anterolateral bundle of the PCL. This was based on the belief that the anterolateral bundle of the PCL is dominant. [73] The inability of single-tunnel techniques to restore posterior tibial translation throughout knee range of motion (ROM) led to further studies. [39, 74, 75, 76]

Isometric PCL reconstruction has been advocated to recreate normal PCL function. Studies have shown that the isometric region of the PCL is a small portion of the ligament. [40, 69] Isometric reconstructions restored normal posterior translation only at low angles of knee flexion, not at knee flexion greater than 60°. [77] Nonisometric reconstruction with the femoral tunnel placed distal to the isometric region, in the anterior aspect of the PCL footprint, 7-10 mm proximal to the articular surface better restores posterior translational stability throughout knee range of motion (ROM) than isometric reconstruction. [40, 69, 77]

Codominance of the anterolateral bundle (larger aspect of the PCL) is taut in flexion (also becomes tighter in internal rotation), and the smaller posteromedial bundle is taut in extension. The two bundles are inseparable. Subsequently, double-tunnel or double-bundle techniques have been developed with the goal of restoring normal knee kinematics. [25, 39, 74, 75, 76, 77, 78] Split- or Y-graft may be used, or else two separate grafts are needed. (See the images below.)

The two femoral tunnels are created by reaming fro The two femoral tunnels are created by reaming from outside in; 8- to 9-mm tunnels are made depending on the patient size and graft used. Image courtesy of Janos P. Ertl, MD.
Two red Robinson catheters are advanced through th Two red Robinson catheters are advanced through the femoral tunnels. Image courtesy of Janos P. Ertl, MD.
The catheters have premade holes that are used for The catheters have premade holes that are used for suture retrieval. Image courtesy of Janos P. Ertl, MD.
The catheters are advanced and threaded out the po The catheters are advanced and threaded out the posterior knee. In this case, a posterior tibial inlay graft from an Achilles tendon allograft is used. The two bundles are secured to the catheters and advanced into the joint through the tunnels. Image courtesy of Janos P. Ertl, MD.
The two Achilles tendon bundles are secured with a The two Achilles tendon bundles are secured with a baseball whipstitch, threaded through the catheter holes, and advanced into the femoral condyle tunnels. Image courtesy of Janos P. Ertl, MD.
Additional view of the placement and advancement o Additional view of the placement and advancement of the Achilles allograft. Image courtesy of Janos P. Ertl, MD.
Completion and seating of the femoral allograft re Completion and seating of the femoral allograft reconstruction. The two bundles are secured or stabilized by suturing over a post and washer. Note the re-establishment of the broad surface area for the reconstructed posterior cruciate ligament (PCL) origin. Image courtesy of Janos P. Ertl, MD.
Completion of the tibial inlay two-bundle Achilles Completion of the tibial inlay two-bundle Achilles tendon allograft/posterior cruciate ligament (PCL) reconstruction. The bony calcaneus remnant is secured to the posterior tibia with one or two interfragmentary compression screws into a trough into the posterior tibia at the level of the PCL insertion. Care is taken not to penetrate the anterior tibial cortex with these screws. Note the intact original anterior cruciate ligament (ACL). Image courtesy of Janos P. Ertl, MD.

With the double-tunnel technique, the anterolateral bundle graft should be tensioned in 90° of knee flexion with anterior tibial translation. [69, 71] Tension of the posteromedial bundle graft has been advocated with the knee in extension and with the knee in 30° of flexion with the tibia anteriorly translated. [69, 71] Debate also persists as to whether a bone bridge is needed at the articular surface between the two femoral tunnels.

In-vitro studies support the double-bundle technique over the single-bundle technique. [74, 77, 78] The double-bundle technique has been shown to restore results of the posterior drawer test to normal. [78, 79, 80]

All other ligament laxities, especially the lateral side, should be addressed. Contraindications for PCL reconstruction include active infection and lack of full motion.


Postoperative Care

Postoperative management should include a wound drain and neurovascular examination in the recovery room. Neurapraxia is the most common complication of PCL reconstruction. [69] Passive ROM from 0º to 90° and quadriceps-strengthening exercises should be initiated immediately after surgery.

Patients should be restricted to toe-touch weightbearing with an extension brace for the first 2 weeks after surgery. The brace is kept locked in extension for a total of 4 weeks, then 0-90° motion is allowed for the next 4 weeks. Full extension must be achieved by postoperative weeks 3-6, or else intervention is required.

Patients are restricted from squatting, downhill walking, or sudden deceleration for 6 months. At 6 months, patients may begin straight run-walking if quadriceps and hamstring deficits are less than 20%. Once patients can run straight ahead at full speed, they may progress to lateral running, crossovers, cutting drills, and figure-eight exercises. [40]