Tibial press-fit fixation of the hamstring tendons for ACL-reconstruction

Abstract

Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary to achieve fixation. Up till the present point, there is no biomechanical data available for the tibial press-fit fixation of the hamstring tendons. Hamstring tendons of 21 human cadavers (age: 41.9 +/- 13.1 years) were used. A press-fit fixation with looped semitendinosus and gracilis tendons secured by a tape (T) over a bone bridge, or by a baseball-stitched suture (S), was compared with degradable interference screw fixation (I) in 21 porcine tibiae. The constructs were cyclically strained and subsequently loaded to failure. The maximum load to failure, stiffness, and elongation during cyclical loading were measured. The maximum load to failure was highest for the T-fixation at 970 +/- 83 N, followed by the I-fixation with 544 +/- 109 N, and the S-fixation with 402 +/- 78 N (P < 0.03). Stiffness of the constructs averaged 78 +/- 13 N/mm for T, 108 +/- 18 N/mm for S, and 162 +/- 27 N/mm for I (P < 0.03). Elongation during initial cyclical loading was 2.0 +/- 0.6 mm for T, 3.3 +/- 1.1 mm for S, and 1.4 +/- 0.5 mm for I (S inferior to I and T, P<0.05). Elongation between the 20th and 1,500th loading cycle was lower for T (2.2 +/- 0.7 mm) compared with I (4.1 +/- 2.7 mm) and S (4.8 +/- 0.7 mm; P < 0.001). The T-fixation technique exhibited a significantly higher failure load than the S-, and I- techniques. All techniques exhibited larger elongation during initial cyclical loading than is reported in the literature for grafts with bone blocks. Only one technique (T) showed satisfactory elongation behavior during long-term cyclic loading. Interference screw fixation demonstrated significantly higher stiffness. Only one of the investigated techniques (T) seemed to exhibit adequate mechanical properties necessary for early aggressive rehabilitation programs.

A novel implant-free tibial pull-press-fixation for ACL reconstruction

“…Our results for the interference screw fixation show maximum failure loads comparable to the results of other studies [10,14,24]. The load-to-failure of the pull-press suture showed a significantly higher result than a conventional baseball-stitched suture and the interference screw fixation.…”

“…Comparable studies using a 1 mm oversized interference screw [24] showed a higher stiffness than found in our setup [10]. The stiffness of the pull-press group showed results that came close to the results of oversized interference screws (162 ± 27 N/mm Sysorb; Centerpulse Medical AG, Winterthur, Switzerland and 115 ± 34 N/ mm for Smart Screw ACL [10,14]).…”

“…The stiffness of the pull-press group showed results that came close to the results of oversized interference screws (162 ± 27 N/mm Sysorb; Centerpulse Medical AG, Winterthur, Switzerland and 115 ± 34 N/ mm for Smart Screw ACL [10,14]). …”

“…Since the cortical bone of the porcine tibiae is similar to human cadavers [19], the results of the P-and the S-fixation are better comparable with the results obtained in human specimen. We chose our set-up to be able to compare our results with other similar studies [2,10,14,17,21] and because the bone structure of the porcine tibiae is more homogenous than it is in human cadaveric tibiae. In addition, we used a strain rate of 1 mm per according to previous research and the results of similar studies [2,7,9,10,13].…”

RETRACTED ARTICLE: Graft fixation alternatives in anterior cruciate ligament reconstruction

“…Yet, the stability results are excellent. Some surgeons, in particular Dargel et al [18] and Jagodzinski et al [19], used a press-fit technique with no fixation and have achieved good results.…”