Arthroscopic Posterior Cruciate Ligament Reconstruction: The Achilles Tendon Allograft versus the Quadriceps Tendon Allograft.

We aimed to compare and analyze the outcomes of arthroscopic posterior cruciate ligament (PCL) reconstruction with the Achilles tendon allograft and the quadriceps tendon allograft. Twenty-nine patients who received the same procedure of arthroscopic PCL reconstruction within our inclusion criteria were reviewed retrospectively. There were 13 patients in the Achilles tendon allograft group and 16 patients in the quadriceps tendon allograft group. At least in 2 years of follow-up period, we evaluated the patients using the posterior drawer test, KT 2000 test, Lysholm knee scoring scale, Tegner activity scale score, International Knee Documentation Committee (IKDC) subjective knee form score, and Telos stress radiography. Between the two groups, no differences were found in preoperative patient demographic factors (age, gender, mean time of surgery, average follow-up period, cause of injury, and combined injury) (p > 0.05). Results of the posterior drawer test, KT 2000 test, Telos stress radiography, Lysholm score, Tegner activity score, and IKDC subjective score were not significantly different between the two groups at preoperative evaluation and after surgery (p > 0.05). On comparing preoperative evaluation and follow-up after surgery, the Achilles tendon allograft group showed significant improvement in the results of the KT 2000 test, Telos stress radiology, and Lysholm score, whereas the quadriceps tendon allograft group showed significant improvement in the results of the KT 2000 test, Telos stress radiology, Lysholm score, Tegner activity score, and IKDC subjective score (p < 0.05). The quadriceps tendon for arthroscopic PCL reconstruction is good alternative allograft for the Achilles tendon for arthroscopic PCL reconstruction. This is a retrospective comparative study.

The Bow Tie Shape of the Anterior Cruciate Ligament as Visualized by High-Resolution Magnetic Resonance Imaging.

BACKGROUND: Although numerous studies have examined the anatomic characteristics of the anterior cruciate ligament (ACL), its actual shape remains unclear. PURPOSE: To determine the average shape of the ACL by analyzing its cross section through the use of high-resolution magnetic resonance imaging (MRI) data. STUDY DESIGN: Descriptive laboratory study. METHODS: The study included 96 MRIs, conducted using a 3.0-T magnet, to analyze the shape of the ACL. Three-dimensional, curved multiplanar reconstruction was used to obtain cross sections at 7 points (femoral insertion; midsubstance 1, 2, 3, 4, and 5 from the femoral side to the tibial side; and tibial insertion). The width and thickness of cross sections were measured by 2 independent observers, and the ratio of width to thickness was calculated to determine the proportions of each cross section. The 7 cross sections were accumulated and standardized to generate an average model through the use of image analysis software developed by the authors. RESULTS: The mean ± SD width (femoral insertion, 17.02 ± 2.17 mm; tibial insertion, 17.33 ± 2.03 mm) and thickness (femoral insertion, 11.03 ± 1.75 mm; tibial insertion, 10.09 ± 1.70 mm) of both insertions were significantly larger than those of midsubstance 4 (width, 9.99 ± 1.87 mm; thickness, 6.53 ± 1.25 mm) ( P < .001). The mean ratios of width to thickness of the 7 cross sections from femoral insertion to tibial insertion were 1.57 ± 0.23, 3.36 ± 0.57, 3.07 ± 0.81, 2.18 ± 0.54, 1.56 ± 0.32, 2.16 ± 0.48, and 1.75 ± 0.28, respectively. The shape of the cross section at midsubstance 4 was an oval isthmus, which was the most narrow and well-balanced shape. It was transformed into a wide band at midsubstance 1 and 5. The shape of the femoral insertion was semicircular, with its anterior side slightly straight and its posterior side convex. The tibial insertion was kidney bean-shaped. CONCLUSION: On 3.0-T MRI, the ACL has a "bow tie" shape, including an oval isthmus, with a semicircular femoral insertion and kidney bean-shaped tibial insertion. CLINICAL RELEVANCE: The measurement method will allow surgeons to quantitatively diagnose partial injuries of the ACL using a noninvasive system in actual patients.