Biomedical subjects

P W Krauss

Publications and source records attributed to P W Krauss.

3 recordsLinked to original sources

PubMed1997

Fixation strength of a biodegradable interference screw and a press-fit technique in anterior cruciate ligament reconstruction with a BPTB graft.

The objective of this study was to evaluate the fixation strength of a biodegradable interference screw (Arthrex, Naples, FL) compared with press fit fixation and a titanium interference screw in anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BPTB) graft. Porcine lower limbs were used. Ultimate failure loads of the biodegradable screw (805.2 N; range 680 to 995 N) did not differ significantly from ultimate failure loads of titanium interference screws (768.6 N; range 544 to 1094 N). Press fit fixation provided significant (P < .01) lower fixation strength (462.5 N; range 80 to 825 N). These results support the conclusion that biodegradable interference screws are a reasonable alternative in terms of primary fixation strength.

Animals↗

PubMedDate not supplied

Cortical versus cancellous interference fixation for bone-patellar tendon-bone grafts.

The objective of this study was to evaluate the initial fixation strength of a metal interference screw (9 x 25 mm; Arthrex, Naples, FL) with respect to its position relative to the bone plug in anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft. Porcine lower limbs were used. In group 1 (n = 20) the screw was placed adjacent to the cortex of the bone plug. In group 2 (n = 20) the screw was placed between the cancellous surfaces of the tibial tunnel and the bone plug. Specimens were loaded to failure using an universal material testing machine. Failure mode was defined by visual analysis of the specimens after loading. Primary fixation strength was not significantly different for both groups. Maximum force was 779 +/- 179 N (group 1, cortical side) and 743 +/- 143 N (group 2, cancellous side). There was a difference in failure modes. In group 1, testing resulted predominantly in tendon ruptures and bone plug fractures (70%). In group 2, bone plug pullouts were predominant (75%). From these data we conclude that the position of the screw relative to the bone plug influences failure mode but not the initial fixation strength.

Animals↗

PubMedDate not supplied

Comparison of initial fixation strength between biodegradable and metallic interference screws and a press-fit fixation technique in a porcine model.

The objective of this study was to evaluate the initial fixation strength of a biodegradable interference screw compared with press-fit fixation and a titanium interference screw in anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft. Porcine lower limbs were used. The specimens underwent 500 loading cycles between 60 and 250 N. This corresponds to loads in the graft during aggressive rehabilitation. Thereafter, intact specimens were loaded to failure. Failure mode was defined by visual analysis. Under cyclic loads none of the interference screw fixations failed. In the press-fit group (angle between load axis and tunnel axis 80 degrees), five specimens failed. The mean maximal load to failure was 945 N (+/- 87) for the titanium screw, 797 N (+/- 60) for the biodegradable screw, and 708 N (+/- 211) for the five press-fit specimens that did not fail during cyclic loading. With respect to primary fixation strength, biodegradable screws are a reasonable alternative to titanium interference screws. The press-fit fixation did not provide a secure fixation in all cases. Five press-fit specimens failed under cyclic loads comparable with those seen under conditions of accelerated rehabilitation.

Absorbable Implants↗