Appendix 1
Case Reports
Patient 1
A 33-year-old man presented at our Level 1 trauma center after injuries to both lower extremities in a work accident. His right knee suffered hyperextension and varus injury, resulting in a KD-5 knee fracture dislocation without neurovascular injury [1]. MRI confirmed soft tissue avulsion of the posterior cruciate ligament (PCL) from the femur (Fig. 1A). Additionally, we noted lateral collateral ligament and biceps femoris avulsions from the fibular head, a reverse-Segond fracture, and a radial tear of the posterior horn of the medial meniscus.
In light of the reverse-Segond fracture and the potential risk of fracture propagation with the creation of a PCL tibial reconstruction tunnel, we considered PCL repair. Two weeks after injury, we performed an arthroscopic primary repair of the PCL. In addition, we débrided the meniscus, internally fixed the reverse-Segond fracture, and performed open primary repair of the lateral side using suture anchors.
At 6 years’ followup, he reported unlimited, pain-free ambulatory capacity. He works 12-hour shifts although he electively abandoned athletics. Examination revealed ROM of 0° to 125°, negative posterior drawer test with a solid end point, and slight increase in varus laxity at 30° compared to the opposite knee with a solid end point. At 75 months’ followup, his Lysholm score was 92 and his modified Cincinnati score was 90. Recent MRI confirmed anatomic appearance of the PCL (Fig. 1B).
Patient 2
A 17-year-old boy injured his right knee while jumping on a trampoline. An outside institution originally treated the patient, where they closed reduced his KD-2 [1] anterior knee dislocation. There was no neurovascular injury. MRI revealed a soft tissue avulsion of the PCL from the femur and a complete midsubstance anterior cruciate ligament (ACL) rupture. They then transferred the patient to our facility for definitive care.
Two weeks after injury, we planned for an allograft bicruciate reconstruction; however, he had limited motion on examination under anesthesia and we noted substantial hemorrhagic synovitis on arthroscopic examination. Due to a heightened concern for postoperative arthrofibrosis, we adjusted the plan; surgery was limited to arthroscopic repair of the PCL. We never performed a planned staged repair of the ACL because the patient achieved excellent stability and function postoperatively.
At 64 months’ followup, he had symmetric full ROM of 0° to 120°, negative posterior drawer test, and Grade 1A Lachman. His Lysholm score was 95 and his modified Cincinnati score was 96. He competed in recreational athletics without limitation. Recent MRI confirmed anatomic appearance of the PCL.
Patient 3
We treated an 18-year-old woman, struck by a motor vehicle, at our Level 1 trauma center for right knee trauma. She suffered a KD-5 [1] fracture dislocation of the knee that spontaneously reduced in the field. There was no neurovascular injury. MRI revealed a soft tissue PCL avulsion from the femur (Fig. 2A), an ACL rupture, a medial collateral ligament rupture, a medial meniscal root avulsion, and a reverse-Segond fracture.
In light of her reverse-Segond fracture, as in Patient 1, we opted for PCL repair. Three weeks after injury, she underwent an arthroscopic primary PCL repair. Her tissue quality permitted separate sutures for each bundle of the PCL. Additionally, we performed an arthroscopic medial meniscal root repair to a suture anchor, as well as an open medial collateral ligament repair, and internal fixation of her fracture. We never performed a planned staged reconstruction of her ACL because the patient achieved acceptable postoperative stability and function to meet the demands of her lifestyle.
At 64 months’ followup, she had symmetric full ROM of 0° to 135°, negative posterior drawer test, Grade 2A Lachman, 1+ opening to valgus at full extension, and 30° with a firm end point. Her Lysholm score was 90 and her modified Cincinnati score was 96. Recent MRI confirmed almost anatomic appearance of the PCL (Fig. 2B).
References
1. Wascher DC, Dvirnak PC, DeCoster TA. Knee dislocation: initial assessment and implications for treatment. J Orthop Trauma. 1997;11:525-529.
Legends
Fig. 1A–B (A) A sagittal view MR image from Patient 1 shows the PCL avulsed from the medial femoral condyle (arrow). (B) A sagittal view MR image from Patient 1 at 6-year followup shows the PCL inserting into the medial femoral condyle (arrow).
Fig. 2A–B (A) A coronal view MR image from Patient 3 shows the PCL avulsed from the medial femoral condyle (arrow). (B) A coronal view MR image from Patient 3 at 5-year followup shows the PCL inserting into the medial femoral condyle (arrow).