Luca Labianca

Double-Bundle Anterior Cruciate Ligament Reconstruction A Computer-Assisted Orthopaedic Surgery Study

Background The biomechanical function of single-bundle anterior cruciate ligament reconstruction, in cadaveric studies, is successful in limiting anterior tibial translation in response to an anterior tibial load but seems to be insufficient to control a combined rotator load of internal and valgus torque. Anatomical double-bundle anterior cruciate ligament reconstruction might produce a better biomechanical outcome. Hypothesis The addition of the posterolateral bundle to the anteromedial bundle, in an in vivo double-bundle computer-assisted anterior cruciate ligament reconstruction, is able to reduce internal rotation of the tibia at 30° of knee flexion, compared with a standard single-bundle reconstruction. Study Design Controlled laboratory study. Methods Twenty consecutive anterior cruciate ligament reconstructions were performed in male patients in April and May 2006 with double-bundle gracilis and semitendinosus tendon grafts using the 2.0 OrthoPilot navigation system. Group A (10 patients) underwent standard single-bundle anterior cruciate ligament reconstruction with doubled gracilis and semitendinosus tendon graft; group B (10 patients) underwent double-bundle reconstruction with doubled gracilis and semitendinosus tendon graft. Anteroposterior displacement and internal and external rotation at 30° of knee flexion were evaluated before and after reconstruction, using manual maximum force. Results Both techniques significantly reduced anteroposterior displacement and internal and external rotation of the tibia with respect to preoperative anterior cruciate ligament–deficient condition (P < .05). Comparing groups, no differences in anteroposterior tibial displacement and internal and external rotation of the tibia were found (anteroposterior, 3.7 mm and 5.2 mm; internal rotation, 16.3° and 16.6°; external rotation, 15.7° and 15.1°, respectively) in group A and B (P = .06, .90, and .72, respectively). Conclusion The hypothesis that addition of the posterolateral bundle to the anteromedial bundle is able to reduce internal rotation of the tibia at 30° of knee flexion is not confirmed. Clinical Relevance The effective role of the anatomical double-bundle procedure in better restoring knee kinematics should be questioned in an in vivo model.

Double-Bundle Anterior Cruciate Ligament Reconstruction: A Comprehensive Kinematic Study Using Navigation

Background Single-bundle anterior cruciate ligament reconstruction seems to be insufficient to control a combined rotatory load of internal and valgus torque, whereas anatomical double-bundle reconstruction might produce a better biomechanical outcome, especially during rotatory loads. Hypothesis The addition of the posterolateral bundle to the anteromedial bundle, in an in vivo double-bundle computer-assisted anterior cruciate ligament reconstruction, is able to reduce the internal rotation of the tibia at different degrees of flexion. Study Design Controlled laboratory study. Methods Ten consecutive anterior cruciate ligament reconstruction procedures were performed in male patients using double-bundle gracilis and semitendinosus tendon graft with the 2.0 OrthoPilot anterior cruciate ligament navigation system. Anteroposterior displacement at 30°, 60°, and 90° as well as internal and external rotation at 0°, 15°, 30°, 45°, 60°, and 90° of knee flexion were evaluated before reconstruction, after fixation of the anteromedial bundle, and then after fixation of the posterolateral bundle. Results Fixation of the anteromedial bundle significantly (P <. 05) reduced the anteroposterior displacement at 30°, 60°, and 90° of knee flexion; the internal rotation at 15°, 30°, 45°, and 60°; and the external rotation at 0°, 30°, 60°, and 90°. The addition of the posterolateral bundle to the anteromedial bundle did not significantly reduce internal and external rotation of the tibia at degrees of flexion measured (P >. 05). Conclusion The hypothesis that the addition of the posterolateral bundle to the anteromedial bundle is able to reduce internal rotation of the tibia, minimizing the pivot-shift phenomenon, was not confirmed. Clinical Relevance The effective role of the anatomical double-bundle procedure in better restoring knee kinematics and allowing better clinical outcomes should be questioned in an in vivo model of anterior cruciate ligament reconstruction using doubled semitendinosus and gracilis graft.

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.

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

BackgroundA 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.MethodsGraft 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.ResultsThe 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.ConclusionLoad 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.

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.

Navigated knee kinematics after tear of the ACL and its secondary restraints: preliminary results.

In this study we evaluated the role of the anterior cruciate ligament (ACL) and its secondary restraint in controlling knee stability using a navigation system. The purpose of this study was to evaluate the kinematics of the knee in different conditions of instability: ACL intact, after transection of the posterolateral (PL) bundle, after transection of the anteromedial (AM) bundle, and after lesion of the anterolateral femorotibial ligament (ALFTL). Anterior tibial translation and rotation were measured with a computer navigation system in 6 knees in whole fresh-frozen human cadavers by use of a manual maximum load. Anterior translation was evaluated at 30°, 60°, and 90° of flexion; rotation at 0°, 15°, 30°, 45°, 60°, and 90° of flexion. Cutting the PL bundle does not increase anterior translation and rotation of the knee. Cutting the AM bundle significantly increased the anteroposterior (AP) translation at 30° and 60° of flexion (P=.01), but does not increase rotation of the knee. Cutting the ALFTL increased anterior translation at 60° of flexion (P=.04) and rotation at 30°, 45°, and 60° of flexion (P=.03). The PL bundle does not affect anterior translation and rotation of the knee. The AM bundle is the primary restraint of the anterior translation but does not affect rotation of the knee. The lateral compartment becomes the primary restraint of rotation after ACL cut. The primary kinematic effect of an ACL injury is an increase in anterior tibial translation, but there is no significant change in maximum internal or external rotation. The lesion of the ALFTL increases tibial rotation and could be correlated to the pivot shift phenomenon.

Clinical and radiological outcomes of postoperative septic arthritis after anterior cruciate ligament reconstruction

BackgroundSeptic arthritis after arthroscopic anterior cruciate ligament (ACL) reconstruction is a rare complication. In the literature, several treatments have been proposed. The aim of the study was to report our results using ambulatory irrigation of the knee and parenteral and oral antibiotics.MethodsFrom January 2001 to December 2008, a total of 12 patients were treated for postoperative septic arthritis of the knee after ACL reconstruction in our hospital. The average age at trauma was 24 years (range 16–43 years). The treatment protocol included irrigation of the knee (for 2 days) and parenteral antibiotics and oral antibiotics subsequently. Repetitive irrigation was performed if necessary. The average duration of follow-up for our series was 38 months (range 6–54 months). Follow-up included International Knee Documentation Committee (IKDC) forms, radiography, Tegner and Lysholm scores, and KT-1000 arthrometric evaluation.ResultsIn all cases treatment of infection was successful. Neither graft nor hardware removal was needed in any of the cases. At final examination, the pivot shift was negative in 10 of 12 patients, and it was 1+ in the other 2 patients; the Lachman was negative in all cases. The mean postoperative Tegner score was 7.2, and the mean Lysholm score was 98.3. In all, 10 of the 12 patients were graded as group A and the other 2 as group B using the IKDC form. The mean postoperative manual maximum KT-1000 side-to-side difference was 2.3. No significant bone tunnel enlargement was found at radiographic evaluation.ConclusionsThe described treatment regimen gives reliable results for this complication. There were no recurrences of septic arthritis or bone infection. No further surgeries were required, and the graft was retained during the treatment of septic arthritis.

Osteomyelitis Caused by Pantoea agglomerans in a Closed Fracture in a Child

Development of osteomyelitis in a closed fracture is rare. Although it has been reported that trivial trauma may be associated with the subsequent development of acute osteomyelitis, no evidence has been found that fractures are involved in the etiology of osteomyelitis. Only 25 cases (11 in adolescents) of osteomyelitis after closed fracture have been reported in literature. The authors report a case of osteomyelitis in an 8-year-old girl after a forearm fracture involving the diaphysis of the radius and ulna. Radiographic examinations were performed 5, 14, and 30 days after trauma. At last examination, the forearm appeared swollen and red. Blood culture and radiographs confirmed the clinical suspicion of osteomyelitis. The cultures grew Pantoea agglomerans, a saprophytic gram-negative bacterium commonly isolated from plants, flowers, seeds, water, and soil and sensitive to all of the most common antibiotics. After the arm was immobilized, high doses of intravenous antibiotics were administered for 4 weeks, and oral antibiotics were prescribed for an additional 4 weeks. The patient responded well to treatment. Twelve months after the initial injury, the patient regained full elbow and wrist flexion-extension range of motion. Based on their experience and a review of the literature, the authors suggest that bone infection be considered for patients with closed fractures complicated by excessive or prolonged pain and swelling with evident signs of inflammation where no other obvious infection is apparent. Moreover, in children, bacterial infection may cause osteomyelitis more frequently than in adults, but no evidence exists that a closed fracture increases the incidence of osteomyelitis in children with a systemic infection.

Biomechanical evaluation of six femurgraft-tibia complexes in ACL reconstruction

Soft tissue graft-tibial tunnel fixation is considered the weak point in reconstruction of the anterior cruciate ligament (ACL). We hypothesized that the biomechanical properties of fixation devices used in ACL reconstruction can be better evaluated by testing complete constructs (femoral tunnel fixation-graft-tibial tunnel fixation). Porcine knees were reconstructed with bovine digital extensor tendons using 6 different commercially available fixation device combinations, and biomechanically tested with cyclic loads (1000 cycles, 0–150 N, 0.5 Hz) and until failure (crosshead speed, 250 mm/min). The device combinations tested (in groups of 6) were EndoButton CL-BioRCI, Swing Bridge-Evolgate, Rifidfix-Intrafix, Bone Mulch- Washerlock, Transfix-Retroscrew, and Transfix-Deltascrew. Ultimate failure load, stiffness, slippage at cycles 1, 100, 500 and 1000 and mode of failure were evaluated. The statistical differences between pairs of groups were assessed with Student’s unpaired t test. The ultimate failure load of complexes made with the Swing Bridge- Evolgate was significantly higher than any other device (968 N; p<0.05), while that of devices made with Transfix-Retrofix was significantly lower than the others (483 N, p<0.05). The stiffness of Swing Bridge-Evolgate complexes was significantly higher than the others (270 N/mm, p<0.05). Regarding mode of failure, Rigidfix-Intrafix complexes showed a failure of the femoral fixation in all specimens. All failures of the other specimens occurred at the tibial side, except one specimen in the EndoButton CL-BioRCI group. Many commercially available tibial fixation devices showed biomechanically appreciable properties, sometimes better than femoral devices.

Biomechanical comparison of four coupled fixation systems for ACL reconstruction with bone socket or full-tunnel on the tibial side

BACKGROUND To compare in an animal model the biomechanical properties of four coupled fixation devices currently used in ACL reconstruction. Three out of four devices used a full tibial tunnel with an interference screw, while the other one system used a tibial socket and an adjustable loop suspension device. The null hypothesis is that there are no biomechanical differences between all the techniques tested. METHODS Thirty two femur-graft-tibia complexes were mounted on a tensile machine using bovine digital extensor tendons, porcine knees and four different fixation device combinations: After a preconditioning with a tensile load of 90N for five minutes, 1000cycles between 0 and 150N were applied to the complex before the final pulled to failure. Stiffness and strength were evaluated at the final pullout, as was the displacement (slippage) at one, 100, 500, and 1000cycles. RESULTS The multiple mean comparison led to a significant difference for the case of stiffness, with worse results in group C compared to group A (p=0.037). Conversely, no differences were found in UFL and slippage between all groups (p>0.05). CONCLUSION All the tested systems demonstrated in an animal model sufficient properties for a safe postoperative rehabilitation both for strength and for stiffness and slippage under cyclic loading.