Three single loops enhance the biomechanical behavior of the transtibial pull-out technique for posterior meniscal root repair.

PURPOSE: To investigate the effect of applying an additional suture to enhance the biomechanical behavior of the suture-meniscus construct used during the transtibial pull-out repair technique. METHODS: A total of 20 fresh-frozen porcine tibiae with intact medial menisci were used. In one half of all specimens (N = 10), two non-absorbable sutures were passed directly over the meniscal root from the tibia side of the meniscus to the femoral side (2SS). In other ten specimens, three sutures were passed over the meniscal root (3SS). All specimens were subjected to cyclic loading followed by load-to-failure testing. Displacement of the construct was recorded at 100, 500, and 1000 cycles. Further, stiffness (500-1000 cycles) and ultimate load and modes of failure of the suture-meniscus construct were also recorded. RESULTS: There was no statistically significant difference between the Group 2SS and Group 3SS at the 1st (1.6 ± 0.7 vs 1.4 ± 0.4 mm) and the 100th cycle (2 ± 0.7 vs 1.8 ± 0.4 mm). At 500 and 1000 cycles, the 2SS fixation technique resulted in significantly more displacement than the 3SS fixation technique (2.8 ± 0.6 vs 2.3 ± 0.5 mm; 3.1 ± 0.7 vs 2.5 ± 0.5 mm) (p < 0.05). No differences between two groups were noted concerning ultimate load to failure and stiffness (500-1000 cycles). CONCLUSION: Three single sutures technique provided superior biomechanical properties compared with the two single sutures technique during the conducted fatigue tests. CLINICAL RELEVANCE: Applying three simple stitches during meniscal root repair might be beneficial for healing of the posterior meniscal root, potentially reducing the post-operative immobilization time.

Biomechanical comparison between the modified rolling-hitch and the modified finger-trap suture techniques.

PURPOSE: The purpose of this study was to characterize the biomechanical effect of two grasping suture techniques used during ligament reconstruction: the modified rolling-hitch (MRH) and the modified finger-trap (MFT). METHODS: Flexor profundus tendons were harvested from fresh pig hind-leg trotters. Each specimen was mounted on an electro-mechanic universal testing machine (Instron 3367). In half of all tendons (15 specimens), the suture was passed around the tendon following the MRH knot (Group 1). In the remaining half of all tendons (15 specimens), the suture was passed over a distance of 30 mm according to the MFT suture technique (Group 2). As per standard intra-operative technique, a 1 cm residual tendon stub was left free from suture in all samples. All specimens were preconditioned to a load of 50 N for 10 min, followed by three cycles loading between 50 and 120 N. At this point, each sample was cyclically tensioned between 35 and 240 N, at 1 Hz for 200 cycles. Load-to-failure test was then carried out at a rate of 200 mm/min. RESULTS: Rupture of the suture material at the knot was the mode of failure in all specimens during the loaded to failure test. Significant difference was found between Group 1 vs Group 2 for the elongation between the 0th cycle and 10th cycle, the elongation between the 10th cycle and 200th cycle, the mean stiffness at the 10th cycle, and the mean stiffness at the 190th cycle. No significant differences were noted between Group 1 and Group 2 concerning the ultimate load-to-failure. CONCLUSION: This study showed that both suture methods appear to be biomechanically effective in a porcine tendon model. However, the single-knot grasping technique (MRH) provided superior biomechanical properties compared with the MFT technique.