Biomechanical evaluation of different anterior cruciate ligament fixation techniques for hamstring graft.

BACKGROUND: A number of anterior cruciate ligament (ACL) fixation techniques are currently in use. Slippage or failure of the graft by excessive loading or aggressive rehabilitation may result in an unstable knee. Load and slippage of the ACL graft varies according to the fixation technique used. METHODS: Graft slippage, load to failure, and stiffness were evaluated using an animal model. Six soft tissue ACL fixation techniques and bone cement as a fixation device were tested: group A, Endo Button CL-Bio RCI; group B, Swing Bridge-Evolgate; group C, Rigidfix-Intrafix; group D, Bone Mulch-Washer Lock; group E, Transfix-Retroscrew; group F, Transfix-Deltascrew; group G, Kryptonite bone cement. Maximum failure load, stiffness, and slippage at the 1st and 1000th cycles and mode of failure were evaluated. RESULTS: The maximum failure load was significantly higher in group B (1030 N) and significantly lower in group E (483 N) than in the others. The stiffness of group B (270 N/mm) was significantly higher than the others. As for the mode of failure, group C showed failure in the femoral side in all tests (four device ruptures and two tendon ruptures on the femoral side). All failures of the other groups occurred on the tibial side except one test in group A. All failures in group G were due to slippage of the tendons. CONCLUSION: Load to failure and stiffness was significantly different between the ACL fixation techniques. All but one of the fixation techniques showed sufficient properties for adequate postoperative rehabilitation. Bone cement used as a fixation device in soft tissue grafts did not seem to provide adequate initial fixation suitable for early rehabilitation after ACL reconstruction.

C-reactive protein and erythrocyte sedimentation rate changes following arthroscopically assisted anterior cruciate ligament reconstruction.

We studied changes in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) to establish normal values after uncomplicated anterior cruciate ligament (ACL) reconstruction. The levels of CRP and ESR were determined by serial measurements in 45 consecutively treated patients. Blood samples were collected before surgery and on postoperative days 1, 3, 7, 15, and 30. Both ESR and CRP showed a marked increase postoperatively, peaking between the 3rd and 7th postoperative days, the latter showing a faster return to normal ( P=0.286). These data show that CRP can be used as a more accurate predictor than ESR of postoperative complications if the blood level remains elevated or unexpectedly rises.

One-stage arthroscopically assisted anterior and posterior cruciate ligament reconstruction.

PURPOSE: To retrospectively evaluate 15 consecutive patients who underwent simultaneous isolated, arthroscopically assisted anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction. TYPE OF STUDY: Case series. METHODS: A bone-patellar tendon-bone autograft was used as the PCL substitute and doubled hamstring tendons were used as the ACL graft. The IKDC evaluation form and the HSS, Lysholm, and Tegner clinical rating scales were used to make clinical evaluations. Anteroposterior translation was measured with the KT-2000 arthrometer and stress view radiography. RESULTS: At final IKDC evaluation, 3 patients (20%) were graded A, 7 (46.7%) were graded B, 3 (20%) were graded C, and 1 patient (6.7%) was graded D. One patient underwent revision surgery in another hospital for severe postoperative residual laxity. Two C-graded patients had an unsatisfactory outcome as a result of serious complications related to knee injuries. All patients with a grade A or B returned to sports activity. At stress view examination, mean posterior side-to-side translation measured at the lateral tibial plateau was 5.8 +/- 1.1 mm and the mean translation at the medial tibial plateau was 7.3 +/- 1.5 mm; the mean anterior dislocation was 3.3 +/- 0.4 mm. The preoperative HSS score rated an average of 32 +/- 9. Postoperatively, the average score reached was 89.6 +/- 8.3. The preoperative Lysholm score was 65.5 +/- 9.1 (range, 48 to 78) in patients with chronic lesions and at follow-up was 95.1 +/- 4.5 (range, 88 to 100). The average Tegner activity score decreased in patients with chronic lesions from 6.9 +/- 1.7 (range, 4 to 9) before injury to 5.5 +/- 1.6 (range, 2 to 9) at follow-up (P =.053 ). At follow-up, 7 patients (50%) returned to their preinjury level after surgery. CONCLUSIONS: These results show the effectiveness and safety of simultaneous arthroscopic reconstruction of both cruciate ligaments using autografts that can adequately restore satisfactory stability, even in the presence of minimal peripheral laxity (1 degrees or 2 degrees ). We conclude that the use of autografts can restore ligament function with good patient compliance and without significant surgical complications.

Transcondylar screw fixation in anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to investigate the outcomes of 2 different methods of femoral fixation for arthroscopically assisted anterior cruciate ligament (ACL) reconstruction. TYPE OF STUDY: Double-blind prospective study. METHODS: Fifty-five patients were prospectively evaluated at 2-year follow-up. In group A, 24 patients underwent arthroscopic ACL reconstruction with bone-patellar tendon-bone and interference screw fixation. In group B, 31 patients underwent arthroscopic ACL reconstruction with bone-patellar tendon-bone and transcondylar screw fixation. Patients were evaluated by using the IKDC form, Lysholm-II form, Tegner scoring system, and KT-2000 arthrometer. RESULTS: In group A, final IKDC clinical evaluation achieved 0% grade A, 62.5% grade B, 25% grade C, and 12.5% grade D. In group B, 29.1% achieved grade A, 54.8% grade B, 12.9% grade C, and 3.2% grade D. The difference was statistically significant (P <.05). The injured versus normal side-to-side KT-2000 difference at maximum manual loading was 3.68 mm (SD, 1.71) in group A and 1.64 (SD, 2.05) in group B (P <.0001). CONCLUSIONS: This prospective study could not provide significant data suggesting that 1 method of fixation is superior to the other. Therefore, we consider both methods comparable in terms of stability and functional outcome at short-term follow-up. Transcondylar fixation offers the following advantages: fixation without intra-articular hardware, greater bone-to-bone fixation, and the possibility of fixation with breakage of the posterior femoral tunnel wall. Moreover, this method may be a useful alternative in revision ACL surgery.

Postoperative bleeding following notchplasty in anterior cruciate ligament reconstruction: thermal radio frequency versus powered instrumentation.

This study compared postoperative bleeding during anterior cruciate ligament (ACL) reconstruction following notchplasty by power instrumentation with that following radiofrequency. Between January 1998 and April 1998 we prospectively divided 24 consecutive patients undergoing arthroscopic ACL reconstruction with bone-patellar tendon-bone autograft into two groups. Notchplasty was performed by powered instrumentation in group A (n=12) and by radiofrequency in group B (n=12). Two Redi-Vac suction drains were placed, one intra-articularly and the other subcutaneously at the harvest site and tibial tunnel. All drains were removed 48 h postoperatively. The first drainage measurement (end of surgery, 6 a.m. postoperative day 1) showed average total bleeding of 124.16 cc in group A and 65.41 cc in group B (P<0.001); per hour this was 10.21 cc in group A and 5.49 cc in group B (P<0.001). The second drainage measurement (6 a.m. postoperative day 2) showed average total bleeding of 44.55 cc in group A and 17.78 cc in group B (P<0.01); per hour this was 1.85 cc in group A and 0.74 cc in group B (P<0.001). Radiofrequency technology can be used when performing intercondylar notchplasty in ACL reconstruction. As a result of this technique postoperative intra-articular bleeding was significantly reduced.

[Synovial healing in reconstructed cruciate ligaments. Our personal experience compared in single interventions and combined reconstructions]. / La maturazione sinoviale dei legamenti crociati ricostruiti. Esperienza personale a confronto negli interventi isolati e nelle ricostruzioni combinate.

INTRODUCTION: The healing process of tendon grafts used in cruciate ligament reconstruction is called ligamentization. The tendon structural architecture changes progressively into the histological appearance of normal ligament. Amiel and Clancy have demonstrated that this process is time-dependent in anterior cruciate ligament (ACL) reconstruction, the tendon graft taking one year to become similar to a normal cruciate ligament. Three different maturation phases of anterior cruciate graft ligamentization can be seen at MRI: periligamentous proliferation, intraligamentous proliferation and definitive healing. We report our MR findings in the reconstruction of single ACL, posterior cruciate ligament (PCL), and of both ACL and PCL. MATERIAL AND METHODS: January 1995 to January 1999 we selected 60 patients submitted to arthroscopic cruciate ligament reconstruction. The ACL was reconstructed with the patellar tendon in 22 cases and the PCL in 23; fifteen patients underwent double reconstruction of ACL, with hamstring tendons, and PCL, with patellar tendons. Fifty-five patients were followed-up with MRI: 45 with a dedicated permanent magnet (Artroscan, Esaote Biomedica, Genoa, Italy) and 10 with a permanent low-field unit (AIRIS, Hitachi, Japan); the same technical parameters were used in all cases. Forty of 55 patients were examined at 1, 3, 6, 9 and 12 postoperative months, while 15 were followed-up longer (12 to 36 months postoperatively). At the first follow-up MR examination, 5 patients (2 ACL and 3 PCL) were excluded for incorrect tunnel position (1 case), hypertrophic scarring (2 cases) and new trauma (2 cases). MR findings were compared with clinical data of joint stability. RESULTS: MRI showed the different stages of the healing process in 20 ACL patients: proliferating soft tissue around the graft with the low signal intensity typical of tendons (stage I, 1-3 months postoperatively), the graft becomes progressively hyperintense (stage II, 3-9 months postoperatively), and finally the low signal intensity indicating completed ligamentization (stage III, 12 months postoperatively). As for PCL reconstructions, MR findings were similar but the process took longer, even 24 months. Finally, in the 15 cases of double reconstruction, both grafts were difficult to distinguish on T1-weighted images for a very long time (24-36 months postoperatively). DISCUSSION AND CONCLUSIONS: Relative to the ACL, ligamentization takes longer for PCL and combined ACL and PCL reconstructions, probably because the morphological changes in PCL and double grafts may be impaired by many factors, such as gravity, long bone tunnels, hemarthrosis, hyperplastic synovial reaction in the intercondylar notch; also, rehabilitation protocols differ in ACL from PCL patients. No signs of instability were found at physical or arthrometric examinations. MRI demonstrates the different stages of ligamentization and thus proves a useful tool for postoperative follow-up in cruciate ligament reconstructions. Contrast-enhanced (Gd) studies are reserved to the cases of graft impingement or if other abnormalities are suspected.