Prospective Randomized Study of Objective and Subjective Clinical Results Between Double-Bundle and Single-Bundle Anterior Cruciate Ligament Reconstruction.

BACKGROUND: There is controversy as to whether double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring tendon graft (DB-HT) or single-bundle ACL reconstruction with patellar tendon graft (SB-PT) obtains the best clinical outcomes. PURPOSE: To compare the short-term clinical outcomes of DB-HT with those of rectangular-tunnel SB-PT (RTSB-PT) at 2-year follow-up and to identify the factors that affect subjective knee functional score. STUDY DESIGN: Randomized controlled trial. Level of evidence, 1. METHODS: Sixty-three male patients (mean age, 26.1 years) and 87 female patients (mean age, 25.8 years) were included in this study and were randomly distributed to either the DB-HT (n = 76) or RTSB-PT (n = 74) group. Clinical outcomes (knee flexion range of motion [ROM], heel-height difference, side-to-side difference in anterior laxity, rotational laxity, and Tegner activity score) were compared between the DB-HT and RTSB-PT groups, and examination of factors affecting subjective outcomes (Knee Injury and Osteoarthritis and Outcome Score [KOOS] results) was performed by multiple linear regression analysis. RESULTS: Fourteen patients (9 DB-HT, 5 RTSB-PT) had secondary ACL injury within 2 years after primary ACL reconstruction and were excluded from analysis. In the examination of 136 patients at the 24-month follow-up, there was no significant difference between the 2 groups in clinical or subjective outcomes. The normalized knee extensor strength of the RTSB-PT group showed negative surgical technique effect in the early postoperative phase (P = .005), but there was no significant difference between the 2 groups at the 24-month follow-up (P = .114). There was no significant difference in change of normalized knee flexor strength between the 2 groups (P = .493). Age, sex, body mass index (BMI), and presence of meniscus injury were the factors that affected KOOS subscale scores. CONCLUSION: In this prospective randomized controlled study, there was no significant difference in the incidence of secondary ACL injury and no difference in objective or subjective outcomes between the DB-HT and RTSB-PT reconstruction at 24-month follow-up. Age, sex, presence of meniscus injury, and BMI affected subjective KOOS subscale scores, while surgical technique did not.

Intraoperative laxity measurements using a navigation system in anatomical double-bundle posterior cruciate ligament reconstruction.

PURPOSE: The objective of this study was to evaluate knee kinematics during double-bundle posterior cruciate ligament reconstruction (DB-PCLR) intraoperatively using a navigation system, and especially assess biomechanical behaviour of the anterolateral bundle (ALB) and posteromedial bundle (PMB) graft in DB-PCLR. Also, clinical results of minimum 2-year follow-up were investigated. METHODS: Nine patients received DB-PCLR with hamstring graft. Before reconstruction, knee laxities, including posterior tibial translation (PTT) in neutral rotation at 15°, 30°, 45°, 60°, 75° and 90° of knee flexion, were measured using a kinematic-based navigation system. After the PMB or ALB was temporally fixed, the knee laxities were measured in the same manner. Each patient was evaluated pre- and post-operatively with side-to-side difference of tibial position in gravity sag view and Lysholm score. RESULTS: Both ALB and PMB fixation restrained the PTT compared to  PCL deficiency throughout all knee flexion angles. At 90° of knee flexion, ALB fixation significantly decreased PTT compare to PMB fixation (p = 0.014) and DB-PCLR significantly decreased PTT compare to ALB fixation (p = 0.045). The mean side-to-side difference of tibial position in gravity sag view was 12.0 ± 1.7 mm preoperatively and 2.3 ± 1.8 mm at final follow-up, and the mean Lysholm scores were 68.9 ± 20.9 and 96.3 ± 2.9, respectively. CONCLUSIONS: There were no significant differences in the PTT between ALB and PMB fixations at 0° to 75° of knee flexion, and both ALB and PMB reconstructions are important for restraining PTT. At 90° of knee flexion, the ALB grafts may be more important to control PTT compared to PMB grafts; however, neither single-bundle reconstruction with ALB nor PMB could function as DB-PCLR did. In addition, PTT after DB-PCLR was strongly correlated side-to-side difference in posterior sag view at the final follow-up. The results from this study indicated that both ALB and PMB are important to stabilize PCL-deficient knees. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Biomechanical comparison of posterior cruciate ligament reconstruction techniques using cyclic loading tests.

Posterior tibial translation (PTT) of the posterior cruciate ligament (PCL) reconstructed-knee under cyclic loading of 1,000 cycles with a 100-N load was compared between four different procedures, including two reconstructions with patellar tendon graft (transtunnel and inlay techniques) and two reconstructions with hamstring tendon graft (Endobutton and EndoPearl techniques) in twelve fresh-frozen human knees. The EndoPearl technique is a direct tendon fixation using biodegradable interference screws and an anchoring device, while the Endobutton technique is an indirect tendon fixation using a titanium button and surgical tape. The change of PTT after cyclic loading in the Endobutton technique was significantly greater than in the other reconstruction technique. No graft rupture at the killer turn or complete pullout from the bone tunnel was found. The advantage of the inlay technique compared to the transtunnel technique with respect to the posterior stability could not be shown in the current study. Posterior laxity of PCL reconstructed-knees with hamstring tendon graft using the Endobutton technique increased more easily than that with patellar tendon graft. For PCL reconstruction using the hamstring tendon graft, anatomical fixation may be preferable to prevent excessive posterior laxity in the early phase of the rehabilitation protocol.

A biomechanical comparison of repair techniques for anterior cruciate ligament tibial avulsion fracture under cyclic loading.

PURPOSE: Although several technical developments for arthroscopic treatment of anterior cruciate ligament (ACL) avulsion fracture have been reported, it remains unclear which fixation technique is most effective to obtain the best initial fixation strength. The objectives of this study were to compare the initial fixation strength in response to a cyclic tensile load between different fixation techniques for ACL avulsion fractures. TYPE OF STUDY: Cadaveric biomechanical evaluation. METHODS: Using 15 fresh-frozen cadaveric human knees, 3 different fixation techniques for noncomminuted ACL avulsion fractures were compared by measuring the anterior tibial translation (ATT) under 500 cycles of 0 to 100 N of anterior tibial load: (1) antegrade screw fixation, (2) retrograde screw fixation, and (3) pullout suture fixation. RESULTS: The increase in the ATT after the cyclic loading for the pullout suture fixation (2.2 +/- 0.8 mm) was significantly larger than that for the antegrade screw fixation (1.0 +/- 0.2 mm). The ATT increase in the retrograde fixation group (2.0 +/- 0.6 mm) was not significantly different compared with the other groups. CONCLUSIONS: All methods were effective and there was a slight biomechanical advantage to antegrade screw fixation over pullout suture fixation. CLINICAL RELEVANCE: Antegrade screw fixation is more effective in obtaining initial rigid fixation than pullout suture fixation for ACL avulsion fractures.