Computer-assisted Anterior Cruciate Ligament Reconstruction Research Articles

Computer-assisted Anterior Cruciate Ligament Reconstruction. Four Generations of Development and Usage

The purpose of this paper is to review the literature about the contribution of navigation in anterior cruciate ligament (ACL) reconstruction. The evolution of computer-assisted surgery (CAS) for ACL reconstruction has undergone several steps. These steps were divided into 4 subsequent developments: (1) positioning of ACL graft placement; (2) laxity measurement of ACL reconstruction (quality control); (3) kinematic evaluation during ACL reconstruction (navigated pivot shift); (4) case-specific individual ACL reconstruction with adjustments and additional reconstruction options. CAS has shown to improve femoral tunnel positioning, even if clinical outcomes do not improve results of manual techniques. CAS technology has helped researchers better understand the effects of different ACL reconstruction techniques and bundles replacements on joint laxity and to describe tunnel positioning in relation to native ACL insertion. CAS in ACL surgery can improve results at time zero and can improve knowledge in this field.

Adolescent differences in knee stability following computer-assisted anterior cruciate ligament reconstruction.

Anterior cruciate ligament (ACL) surgery is being increasingly performed in the adolescent population. Computer navigation offers a reliable way to quantitatively measure knee stability during ACL reconstruction. A retrospective review of all adolescent patients (<18 years old) who underwent computer-assisted primary single bundle ACL reconstruction by a single surgeon from 2007 to 2012 was performed. The average age was 15.8 years (SD 3.3). Female adolescents were found to have higher internal rotation than male adolescents both pre- (25.6° vs 21.7°, P=0.026) and post-reconstruction (20.1° vs 15.1°, P=0.005). Compared to adults, adolescents demonstrated significantly higher internal rotation both pre- (23.3° vs 21.5°, P=0.047) and post-reconstruction (17.1° vs 14.4°, P=0.003). They also had higher total rotation both pre- (40.9° vs 38.4°, P=0.02) and post-reconstruction when compared to adults (31.56° vs 28.67°, P=0.005). In adolescent patients, anterior translation was corrected more than rotation. Females had higher pre- and residual post-reconstruction internal rotation compared to males. When compared to adults, adolescents had increased internal rotation and total rotation both pre-and post-reconstruction.

Application of a computerised navigation technique to assist arthroscopic anterior cruciate ligament reconstruction

Based on biomechanical cadaver studies, anatomical double-bundle reconstruction of the anterior cruciate ligament (ACL) was introduced to achieve better stability in the knee, particularly in respect of rotatory loads. Previously, the success of ACL reconstruction was believed to be mainly dependent on correct positioning of the graft, irrespective of the number of bundles for which computer-assisted surgery was developed to avoid malpositioning of the tunnel. The aim of this study was to compare rotational and translational stability after computer-navigated standard single-bundle and anatomical double-bundle ACL reconstruction. The authors investigated 42 consecutive patients who had undergone the single-bundle or double-bundle ACL reconstruction procedure using autogenous hamstring tendon grafts and ENDOBUTTON fixation in patients who had been followed up for a minimum of 24 months. Post-operative anteroposterior and rotational laxity was measured with the KT3000 and compared between groups. Both surgical procedures significantly improve rotational and translational stability compared to the preoperative ACL-deficient knee (P<0.05). No significant differences were registered between groups with regard to anteroposterior displacement of the tibia. The International Knee Documentation Committee (IKDC) and Lysholm scores were significantly higher in the double-bundle group. However, the results were excellent in both groups. The use of computer-assisted ACL reconstruction, which is a highly accurate method of graft placement, could be useful for inexperienced surgeons to avoid malposition. Long-term results of at least five years are needed to determine whether double-bundle ACL reconstruction, which was associated with improved rotational laxity and significantly better IKDC and Lysholm scores compared to the standard single-bundle ACL reconstruction procedure, exerts an influence in terms of avoiding osteoarthritis or meniscus degeneration.

Computer-Assisted Surgery Is Not More Accurate or Precise Than Conventional Arthroscopic ACL Reconstruction

Accurate and precise tunnel placement is critical to the success of anterior cruciate ligament (ACL) reconstruction. A new development, computer-assisted surgery, aids in placement of the ACL bone tunnels during surgery. Our hypothesis was that computer-assisted ACL reconstruction would allow more accurate and precise tunnel placement compared with conventional surgery. In a prospective, double-blind, randomized clinical study, 100 patients eligible for ACL reconstruction with a transtibial technique were stratified by surgeon and randomized to either conventional or computer-assisted surgery. Measurement of femoral and tibial tunnel placement with use of three-dimensional computed tomography (CT) was used as the primary outcome to compare conventional ACL surgery with computer-assisted surgery. The placement of the femoral tunnel did not differ between groups (mean, 39.7% of the proximal-distal distance on the intracondylar axis [Blumensaat line] in the conventional group compared with 39.0% in the computer-assisted surgery group; p = 0.70). The anterior-posterior positioning of the tibial tunnel on the tibial plateau also did not differ significantly (38.9% in the conventional group compared with 38.2% in the computer-assisted surgery group; p = 0.58). There was no significant difference in the precision of either the femoral or the tibial tunnel placement between the two groups. There was no significant difference in either the accuracy or the precision of tunnel placement between conventional and computer-assisted ACL reconstruction.

Rotational and translational laxity after computer-navigated single- and double-bundle anterior cruciate ligament reconstruction

Based on biomechanical cadaver studies, anatomic double-bundle reconstruction of the anterior cruciate ligament (ACL) was introduced to achieve better stability in the knee, particularly in respect of rotatory loads. Previously, the success of ACL reconstruction was believed to be mainly dependent on correct positioning of the graft, irrespective of the number of reconstructed bundles for which computer-assisted surgery was developed to avoid malpositioning of the tunnel. The aim of the present study is to compare rotational and translational stability after computer-navigated standard single-bundle, and anatomic double-bundle ACL reconstruction. The authors investigated 55 consecutive patients who had undergone the single-bundle or double-bundle ACL reconstruction procedure with the use of autogenous hamstring tendon grafts and EndoButton fixation, and the patients had been followed for a minimum period of 24 months. Intraoperative, anteroposterior and rotational laxity was measured with the computer navigation system, and compared between groups. Both surgical procedures significantly reduced anteroposterior displacement (AP) and internal rotation (IR) of the tibia compared to the pre-operative ACL-deficient knee (P < 0.05). No significant differences were registered between groups with regard to anteroposterior displacement of the tibia. A significantly greater reduction in internal rotation was noted in the double-bundle group (15.6 degrees) compared to the single-bundle group (7.1 degrees). The IKDC and Lysholm score were significantly higher in the double-bundle group. However, the results were excellent in both groups. The use of a computer-assisted ACL reconstruction, which is a highly accurate method of graft placement, could be useful for inexperienced surgeons to avoid malposition. Whether double-bundle ACL reconstruction, which was associated with improved rotational laxity and significantly better IKDC and Lysholm scores compared to the standard single-bundle ACL reconstruction procedure, provide an influence in terms of avoiding osteoarthritis or meniscus degeneration, long-term results of at least 5 years are needed.

Double-Bundle Anterior Cruciate Ligament Reconstruction

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.

Current Trends in Anterior Cruciate Ligament Reconstruction

In 2006, a survey regarding anterior cruciate ligament (ACL) reconstruction was mailed to physician members of the American Orthopaedic Society for Sports Medicine. A total of 993 responses were received from 1747 possible respondents (57%). The number of ACL reconstructions per year ranged from 1 to 275 (mean=55). The most important factors in the timing of surgery were knee range of motion and effusion. Bone-patellar tendon-bone (BPTB) autograft was most commonly preferred (46%), followed by hamstring tendon autograft (32%) and allografts (22%). Five years earlier, BPTB grafts were more frequent and hamstring tendon and allografts were less frequent (63%, 25%, and 12%, respectively). A single-incision arthroscopic technique was used by 90%. Most allowed return to full activity at 5 to 6 months, with a trend toward earlier return for BPTB grafts; quadriceps strength was an important factor in the decision. There was limited experience (4%) with double-bundle and computer-assisted ACL reconstruction. Arthroscopic-assisted, single-incision reconstruction using a BPTB autograft fixed with metal interference screws remains the most common technique used for primary ACL reconstruction. In the past 5 years, the use of alternative graft sources and methods of fixation has increased. Consensus regarding the best graft type, fixation method, and postoperative protocol is still lacking.

Double-Bundle Anterior Cruciate Ligament Reconstruction

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 or single bundle plus extraarticular tenodesis in ACL reconstruction?

Anatomic reconstructions of anterior cruciate ligament (ACL) with double bundle gracilis and semitendonosus tendons graft, reproducing AM and PL bundles, have been introduced to offer a better biomechanical outcome, especially during rotatory loads. On the other hand, many methods of tenodesing the lateral aspect of the tibia to the femur to reduce internal rotation (IR) of the tibia and minimize anterior translation of the tibia relative to the femur as a backup for intra-articular reconstruction, have been also suggested. The goal of this study is to evaluate the effect, on the IR of the tibia, of a lateral reconstruction in addition to a standard single bundle ACL reconstruction as compared with an anatomic double bundle ACL reconstruction. Computer assisted ACL reconstruction has been used because it could be very effective in evaluating the global kinematic performance of the reconstructed knee. We selected 20 consecutive ACL reconstruction procedures to be performed in males in our hospital. Patients were alternately assigned to one of the two groups--group A: standard single bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique and a lateral extraarticular reconstruction; group B: double bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique. In all ACL reconstruction procedures navigation process was performed. Both surgical techniques reduced significantly AP displacement, IR and external rotation (ER) of the tibia respect to pre-operative ACL deficient condition (p<0.05). Comparing the group A after the single bundle reconstruction and the group B after the AM bundle fixation, non differences were found in AP displacement, IR and ER of the tibia (p=0.75, p=0.07 and p=0.07 respectively; power: 0.94). Comparing the group A after the addition of the lateral tenodesis and group B after the PL bundle fixation (AM+PL) no differences in AP tibial displacement and in ER of tibia were found (p=0.9 and 0.15, respectively; power: 0.99); however a significant reduction in IR of the tibia was found in group A after the addition of the lateral tenodesis respect to the group B after the addition of the PL bundle (p=0.0001; power: 0.26). On the basis of our study, the addition of a lateral extraarticular reconstruction to a standard single bundle ACL reconstruction with hamstrings tendons graft in an "in vivo" reconstruction, is more effective in reducing the IR of the tibia at 30 degrees of knee flexion, as compared with a standard single bundle ACL reconstruction and with an anatomic double bundle reconstruction is confirmed.