Biomedical subjects

Edoardo Monaco

Publications and source records attributed to Edoardo Monaco.

4 recordsLinked to original sources

PubMed2006

Revision anterior cruciate ligament reconstruction with doubled semitendinosus and gracilis tendons and lateral extra-articular reconstruction.

BACKGROUND: The outcome of revision anterior cruciate ligament reconstruction has only rarely been reported. The purpose of this study was to evaluate the results of revision anterior cruciate ligament surgery with use of an autogenous doubled semitendinosus and gracilis graft in association with an extra-articular procedure. METHODS: Between 1997 and 2003, thirty patients underwent a repeat reconstruction of a previously reconstructed torn anterior cruciate ligament with use of a doubled semitendinosus and gracilis graft combined with an extra-articular reconstruction. Primary reconstruction had been done with an autogenous patellar tendon graft in twenty-six patients and with a prosthetic ligament in four patients; the average time from the primary reconstruction to the revision was five years. Functional outcomes, graft survival, and radiographic outcomes were evaluated at a mean of five years. A graft was considered to have failed when a revision was done or when the side-to-side difference on KT-1000 arthrometer testing was >5 mm and/or the pivot-shift test grade was greater than a trace. RESULTS: One patient underwent another revision reconstruction because of graft failure at three years postoperatively. The mean International Knee Documentation Committee (IKDC) subjective knee score for the remaining twenty-nine patients was 84 +/- 12 points, and the mean Lysholm knee score was 90 +/- 10 points. The side-to-side difference as measured with the KT-1000 arthrometer with maximum manual force was <3 mm in twenty patients (of the twenty-eight who returned for follow-up), between 3 and 5 mm in six patients, and >5 mm in two patients. The result of the pivot shift examination was normal in fifteen patients, slightly positive in eleven patients, and positive in two patients. Twenty-five percent of the patients showed no radiographic signs of degenerative joint disease. CONCLUSIONS: Revision anterior cruciate ligament reconstruction with use of an autogenous doubled semitendinosus and gracilis graft combined with an extra-articular procedure provided satisfactory functional outcomes, with a failure rate of 10%.

Adult↗

PubMed2005

Effect of cyclic loading on new polyblend suture coupled with different anchors.

BACKGROUND: Secure tendon-to-bone fixation is essential for successful rotator cuff repair. Biomechanical properties of devices used in rotator cuff repair should be better understood. PURPOSE: To evaluate the response to incremental cyclic loading of 6 different anchor-suture complexes commonly used in rotator cuff repair. STUDY DESIGN: Controlled laboratory study. METHODS: Two absorbable anchors 5 mm and 6.5 mm in diameter and 1 metallic anchor, coupled with Ethibond or FiberWire, were tested on 5 pairs of fresh-frozen human cadaveric shoulders. An incremental cyclic load was applied until failure using a Zwich-Roell Z010 electromechanical testing machine. The ultimate failure load and mode of failure were recorded. An analysis of variance model was used for statistical analysis. RESULTS: The FiberWire suture coupled with both absorbable and metallic anchors provided statistically significantly stronger fixation. However, although the metallic anchors in most cases failed because of slippage of the anchor, absorbable anchors failed because of rupture of the eyelet. CONCLUSIONS: The FiberWire seems to increase the strength of fixation devices under cyclic load using both absorbable and metallic anchors, with relevant differences in failure mode (slippage of the metallic anchor and eyelet failure in the absorbable anchor). CLINICAL RELEVANCE: Use of the FiberWire suture might change the mode of failure of the suture-anchor complexes.

Aged↗

PubMed2005

Evolgate fixation of doubled flexor graft in anterior cruciate ligament reconstruction: biomechanical evaluation with cyclic loading.

BACKGROUND: The weakest points in hamstrings anterior cruciate ligament reconstruction are its points of fixation, especially on the tibial side. Methods for graft fixation to bone should be strong enough to avoid failure, stiff enough to restore load-displacement response, and secure enough to resist slippage under cyclic loading. HYPOTHESIS: Biomechanical properties of the interference screw can be improved by reinforcing the walls of the tunnel with a metal spiral (Evolgate fixation). STUDY DESIGN: Controlled laboratory study. METHODS: Three paired tests were performed using common digital extensor bovine tendons fixed to porcine tibias with interference screw, Intrafix, and Evolgate; critical graft fixation conditions were simulated by applying subsequent cycles to the graft before loading the graft until failure. RESULTS: The strength, stiffness, and resistance to slippage of the Evolgate were significantly higher than those of the interference screw; the ultimate failure load of the Evolgate was significantly higher than that of the Intrafix (1058+/-130 N and 832+/-156 N, respectively; P=.02). No statistically significant differences were found between Evolgate and Intrafix regarding the stiffness and slippage under cyclic load. CONCLUSION: Evolgate fixation seems to be stronger, stiffer, and more resistant to slippage than is interference screw fixation of similar length, and it is stronger but not stiffer than Intrafix. CLINICAL RELEVANCE: The Evolgate provides structural properties that seem to be appropriate for an intensive rehabilitation after anterior cruciate ligament reconstruction using a doubled semitendinosus and gracilis graft.

Alloys↗

PubMed2003

The Evolgate: a method to improve the pullout strength of interference screws in tibial fixation of anterior cruciate ligament reconstruction with doubled gracilis and semitendinosus tendons.

PURPOSE: The goal of the study was to investigate the biomechanical properties of a new device for tibial fixation in arthroscopic anterior cruciate ligament reconstruction using doubled semitendinosus and gracilis tendons. TYPE OF STUDY: Biomechanical study. METHODS: This study compares the initial pullout strength, stiffness, and failure modes of 7 pairs of 4-strand human semitendinosus and gracilis grafts fixed to porcine tibias using either the Evolgate (Citieffe, Bologna, Italy) or 1 round threaded titanium interference screw. Structural tests of the graft fixation method tibia complexes were performed using a materials testing machine (MTS Bionix 855, Minneapolis, MN) at a strain rate of 50 mm/second. RESULTS: The mean failure load was 1,237 +/- 191 N for the Evolgate and 537 +/- 65 N for the interference screw (P <.05) and the mean stiffness was 168 +/- 37 N/m for the Evolgate and 105 +/- 17 N/m for the interference screws (P < or =.05). Although in all the cases fixed with the Evolgate failure occurred because of tendon rupture inside the tibial tunnel close to the fixation device, in 4 of the 7 cases fixed with interference screws, failure occurred because of tendon slippage at the fixation site. CONCLUSIONS: These results indicate that initial pullout strength of hamstring tendon graft interference screw fixation can be significantly increased using the Evolgate. In fact, because the screws purchase only in the cancellous bone, the Evolgate reinforces the walls of the tibial tunnel with a titanium involute, avoiding the loss of fixation strength related to the low density of the cancellous bone of the proximal metaphysis of the tibia.

Adult↗