[RIGIDfix tibial and femur cross pin system used for hamstring grafted anterior cruciate ligament reconstruction].

OBJECTIVE: To evaluate the curative effect of RIGIDfix tibial and femur cross pin system used for hamstring grafted reconstruction of anterior cruciate ligament (ACL) in arthroscopy.

METHODS: Thirty two cases with ACL ruptures were reconstructed arthroscopically with hamstring grafts and the grafts fixed with RIGIDfix cross-pin on both femoral and tibial sides. They included 18 males and 14 females with a mean age of 28 (20-45) years old; the mean time from injury to operation was 3.6 (2.5-6) months. And each knee was checked by MRI and X-ray preoperatively. Through arthroscopy, we found 19 ACL ruptured from femoral attachment point, 13 from tibial point, 3 cases combined with medial meniscus injury and 4 cases with articular cartilage injury of medial femoral condyle. After semitendinosus or gracilis harvesting, the hamstring grafts were pre-tensioned and woven, the diameter of 4 or 5 strands grafts was 7-8 mm. To position and drill tibial tunnel on ACL stump of tibial crest, and to drill femoral tunnel at 10:00 to 11 o'clock of femoral intercondylar fossa transtibial with knee flexed to 90 degree, the depth of femoral tunnel was 30 mm. The RIGIDfix guide was inserted through tibial tunnel up into the femoral tunnel to drill the sleeve and interlocking Trocar across the lateral femur and keep the two sleeves fixed to the lateral femur. Insert RIGIDfix guide into the tibial tunnel, keeping the top of guide 2-3 mm beneath the endostoma of tibial tunnel, drill the sleeve and interlocking Trocar across the lateral tibia and keep the two sleeve fixed to the lateral tibia. The graft was pulled into the tunnel (the 30 mm mark on the graft should be at the edge of femoral hole) to insert the RIGIDfix cross pins from femoral tunnel to tibial tunnel, while inserting the second, third, fourth cross pin, the graft should be kept under tension. Then a knot was tied through tibial bony bridge using the Enthibond thread switched to the end of tendon grafts. We finally observed the tension of tendon grafts and the impingement of fossa intercondylic under arthroscopy.

RESULTS: With a 16-month follow-up evaluation, all of the patients' injured knees were stable and the average Lysholm knee score increased from 62.5 to 94.5. Rulermetr device values were less than 2 mm of sagittal displacement in 28 patients and 4 mm in 4. Postoperative Lachman was negative in 30 patients and weakly positive in 2. According to the IKDC scores, 30 patients reported normal function, 2 reported nearly normal function and none reported abnormal or severely abnormal function.

CONCLUSION: The grafting method of fixing both femur and tibia sides with absorbable cross pins is feasible. In this way, the graft is stabilized to allow for reconstruction. A surgeon should refrain from dissecting the tendon and enlarging the tunnel so as to promote the healing of tendon and bone.