A twenty-nine-year-old female professional athlete, who had played handball from the age of twelve years and had competed in the premier league from the age of sixteen years, sustained a twisting injury to the right knee while landing. Seven days later, examination revealed a minimal right knee effusion and a positive Lachman test with a soft end point. The posterior drawer sign had a hard stop, and the posterior sag sign was negative. No lateral or medial instability was observed. Active and passive knee motion was intact. The patient denied any family history of skeletal congenital abnormalities; no abnormalities had been noted during pregnancy, childbirth, or childhood. Five years prior to this event, she had given birth to a healthy girl who had normal physical and mental development.
Magnetic resonance imaging (MRI) of the right knee (Figs. 1-A, 1-B, and 1-C) demonstrated a recent ACL tear with a fully disorganized and partially retracted ligament as well as associated intra/periligamentous edema. The PCL did not have a normal appearance; there was only a thin, hypointense bandlike structure, consistent with a rudimentary, extremely hypoplastic ligament. There were no visible signs of an old PCL tear, such as ligament discontinuity or retraction, bands with abnormal orientation, or insertional surface irregularity. The presence of a well-developed hyperplastic posterior meniscofemoral ligament of Wrisberg (with a thickness of up to 5 mm) was noted. “Kissing” osteochondral contusions were present in the lateral compartment, on the weight-bearing surface of the femoral condyle, and on the posterior tibial plateau margin. Grade-II chondromalacia of the patellofemoral joint and an osteochondral lesion on the medial trochlear ridge, with a partial chondral defect and focal irregularity of the subchondral bone, were also present.
Because of the unusual MRI findings in the right knee, an MRI of the left knee was also obtained (Figs. 2-A, 2-B, and 2-C). It revealed a hypoplastic PCL with a well-developed relatively hyperplastic ligament of Wrisberg. The ACL was intact and normal. There was an 11-mm intraosseous ganglion cyst in the tibial insertion of the posterior root of the medial meniscus, grade-II/III patellar chondromalacia predominantly on the medial facet, and an old osteochondral lesion on the medial trochlear ridge, with a partial-thickness chondral defect.
The patient initially underwent physical therapy for four weeks. Once the knee effusion subsided, arthroscopic ACL reconstruction with a single-bundle bone-tendon-bone technique was performed. Prior to surgery, there was an 8-mm difference in the Lachman test (with a soft end point) between the right knee and the uninjured left knee. The pivot shift test on the right was positive (grade I with glide pivot). The posterior drawer sign was symmetrical with a hard stop on both knees.
The surgery was performed under general anesthesia with the use of a tourniquet. The bone-tendon-bone graft was harvested and prepared. A standard anterolateral portal was used for viewing, and an anteromedial portal was used as a working portal. The ACL stump was debrided; instead of a normal PCL, there was a hyperplastic posterior meniscofemoral ligament of Wrisberg (Fig. 3). Tugging on the ligament of Wrisberg with a hook induced movement at the posterior horn of the lateral meniscus. The knee was placed in flexion between 110° and 120°. The femoral guide was introduced into the joint through the anteromedial portal, and a drill wire was placed into the center of the anatomic ACL insertion at the 10 o’clock position and was overdrilled with a 10-mm-diameter reamer. A suture was then retrieved, and a guide pin was drilled into the joint, followed by a cannulated reamer with an equal diameter to the graft in order to create the tibial tunnel. A grasper was placed through the tibial tunnel to retrieve the suture. The graft was passed through the tibia into the femoral socket, and once properly positioned in the tunnel, it was fixed with round cannulated interference screws. Firm traction was applied to the tibial bone block and the graft was fixed into the tibial tunnel with round cannulated interference screws (Fig. 4). Knee stability was checked with the Lachman and anterior drawer tests. Two drains were placed, and the operative wound was closed in the usual fashion. Postoperative radiographs showed that there were no signs of hypoplastic tibial eminences; the correct position of the interference screws was also evident (Figs. 5-A and 5-B). Six months later, the patient had a stable knee with a full range of motion, and both the Lachman and pivot shift tests were negative. She had continued playing handball professionally.
Two years after the surgery, the patient had full range of motion in the operated knee and good strength in the quadriceps femoris muscle. There was a 2-mm difference in the Lachman test (with a firm end point) between the operated and healthy knee. The pivot shift test on the right was negative. The patient had continued playing professional handball without any limitations.
Note: The authors thank Dr. Boris Petrovic for consultation and assistance with the MRI interpretations.