Visualization of postoperative anterior cruciate ligament reconstruction bone tunnels: Reliability of standard radiographs, CT scans, and 3D virtual reality images

Background and purpose: Non-anatomic bone tunnel placement is the most common cause of a failed ACL reconstruction. Accurate and reproducible methods to visualize and document bone tunnel placement are therefore important. We evaluated the reliability of standard radiographs, CT scans, and a 3-dimensional (3D) virtual reality (VR) approach in visualizing and measuring ACL reconstruction bone tunnel placement. Methods: 50 consecutive patients who underwent single-bundle ACL reconstructions were evaluated postoperatively by standard radiographs, CT scans, and 3D VR images. Tibial and femoral tunnel positions were measured by 2 observers using the traditional methods of Amis, Aglietti, Hoser, Stubli, and the method of Benereau for the VR approach. Results: The tunnel was visualized in 50-82% of the standard radiographs and in 100% of the CT scans and 3D VR images. Using the intraclass correlation coefficient (ICC), the inter- and intraobserver agreement was between 0.39 and 0.83 for the standard femoral and tibial radiographs. CT scans showed an ICC range of 0.49-0.76 for the inter- and intraobserver agreement. The agreement in 3D VR was almost perfect, with an ICC of 0.83 for the femur and 0.95 for the tibia. Interpretation: CT scans and 3D VR images are more reliable in assessing postoperative bone tunnel placement following ACL reconstruction than standard radiographs. Copyright

The attachments of the anteromedial and posterolateral fibre bundles of the anterior cruciate ligament. Part 2: femoral attachment.

Accepted versio

The morphometry of soft tissue insertions on the tibial plateau: Data acquisition and statistical shape analysis

This study characterized the soft tissue insertion morphometrics on the tibial plateau and their inter-relationships as well as variabilities. The outlines of the cruciate ligament and meniscal root insertions along with the medial and lateral cartilage on 20 cadaveric tibias (10 left and 10 right knees) were digitized and co-registered with corresponding CT-based 3D bone models. Generalized Procrustes Analysis was employed in conjunction with Principal Components Analysis to first create a geometric consensus based on tibial cartilage and then determine the means and variations of insertion morphometrics including shape, size, location, and inter-relationship measures. Step-wise regression analysis was conducted in search of parsimonious models relating the morphometric measures to the tibial plateau width and depth, and basic anthropometric and gender factors. The analyses resulted in statistical morphometric representations for Procrustes-superimposed cruciate ligament and meniscus insertions, and identified only a few moderate correlations (R 2: 0.37-0.49). The study provided evidence challenging the isometric scaling based on a single dimension frequently employed in related morphometric studies, and data for evaluating cruciate ligament reconstruction strategies in terms of re-creating the native anatomy and minimizing the risk of iatrogenic injury. It paved the way for future development of computer-aided personalized orthopaedic surgery applications improving the quality of care and patient safety, and biomechanical models with a better population or average representation

Computer-assisted anterior cruciate ligament reconstruction: an evidence-based approach of the first 15 years.

In the last 15 years, computer-assisted surgery (CAS) has been used for many purposes during anterior cruciate ligament (ACL) reconstruction, such as tunnel positioning, joint laxity evaluation, and biomechanical studies. This article is an evidence-based literature review of the contribution of such technology to ACL surgery. A search of the PubMed and Medline databases was performed. Articles were classified according to the study design and to the research topic: anatomy, laxity, kinematics, and comparison of surgical techniques. An evidence-based approach was used to verify the clinical usefulness of CAS to ACL surgery. The use of CAS for research purposes was also evaluated. CAS was shown to improve femoral tunnel positioning, even if clinical outcomes showed no differences compared with manual techniques. CAS technology was found to be useful for research purposes in terms of providing a better comprehension of the effect of different ACL reconstructions and of the different bundles on joint laxity, as well as describing tunnel positioning in relation to native ACL insertion. CAS in ACL surgery can improve results at time 0 and can improve knowledge about ACL anatomy and kinematics. Its application remains limited mostly to research purposes because of the invasiveness of the system and the absence of improved clinical results at follow-up

Comparative study of knee anterior cruciate ligament reconstruction with or without Xuoroscopic assistance : a prospective study of 73 cases

Introduction Correct placement of both tibial and femoral tunnels is one of the main factors for a favorable clinical outcome after anterior cruciate ligament (ACL) reconstruction. We used an original system of computer assisted surgery (CAS). The system, based on Xuoroscopic guidance combined with special graphical software of image analyzing, showed to the surgeon, before drilling, the recommended placement of tibial and femoral tunnel centers. We compared the Wrst anatomical and clinical results of this procedure to the usual one single incision technique. Materials and methods We conducted a prospective study on 73 patients; 37 patients were operated on with CAS and 36 without CAS, by the same senior surgeon. The mean age was 27 years for both groups. Every patient was reviewed at an average of 2.2 years (range 1–4.5) by an independent observer, using IKDC scoring system, KT-1000, and passive stress radiographs. Results Time between ACL rupture and reconstruction averaged 30 months for both groups. CAS needed 9.3 min extra surgery time. Clinical evaluation was graded from A to C as per the IKDC scoring system: 67.6% A, 29.7% B, 2.7% C with CAS; and 60% A, 37.1% B, 2.9% C without CAS. IKDC subjective knee evaluation score averaged 89.7 with CAS and 89.5 without CAS. Pre operative KT-1000 maxi manual diVerential laxity averaged 7. At revision time, all the patients after CAS had a diVerential laxity less than 2 and 97.7% without CAS. Stress X-rays diVerential laxity averaged 2.4 mm with CAS and 3 mm without CAS. The area of dispersion of the tunnels’ center was smaller on the femoral side using the CAS method. There was no statistically signiWcant diVerence between both groups using IKDC score, KT-1000 and passive stress radiographs. Conclusions The CAS method provided a more accurate and reproducible tunnels placement without clinical signiWcant eVect. Introduction Correct placement of both tibial and femoral tunnels is one of the main factors for a favorable clinical outcome after anterior cruciate ligament (ACL) reconstruction. We used an original system of computer assisted surgery (CAS). The system, based on Xuoroscopic guidance combined with special graphical software of image analyzing, showed to the surgeon, before drilling, the recommended placement of tibial and femoral tunnel centers. We compared the Wrst anatomical and clinical results of this procedure to the usual one single incision technique. Materials and methods We conducted a prospective study on 73 patients; 37 patients were operated on with CAS and 36 without CAS, by the same senior surgeon. The mean age was 27 years for both groups. Every patient was reviewed at an average of 2.2 years (range 1–4.5) by an independent observer, using IKDC scoring system, KT-1000, and passive stress radiographs. Results Time between ACL rupture and reconstruction averaged 30 months for both groups. CAS needed 9.3 min extra surgery time. Clinical evaluation was graded from A to C as per the IKDC scoring system: 67.6% A, 29.7% B, 2.7% C with CAS; and 60% A, 37.1% B, 2.9% C without CAS. IKDC subjective knee evaluation score averaged 89.7 with CAS and 89.5 without CAS. Pre operative KT-1000 maxi manual diVerential laxity averaged 7. At revision time, all the patients after CAS had a diVerential laxity less than 2 and 97.7% without CAS. Stress X-rays diVerential laxity averaged 2.4 mm with CAS and 3 mm without CAS. The area of dispersion of the tunnels’ center was smaller on the femoral side using the CAS method. There was no statistically signiWcant diVerence between both groups using IKDC score, KT-1000 and passive stress radiographs. Conclusions The CAS method provided a more accurate and reproducible tunnels placement without clinical signiWcant eVect

Instrumented measurements of knee laxity: KT-1000 versus navigation

The KT-1000 is widely accepted as a tool for the instrumented measurement of the antero-posterior (AP) tibial translation. The aim of this study is to compare the data obtained with the KT-1000 in ACL deficient knees with the data obtained using a navigation system during "in vivo" ACL reconstruction procedures and to validate the accuracy of the KT-1000. An ACL reconstruction was performed using computer aided surgical navigation (Orthopilot, B-Braun, Aesculap, Tuttlingen, Germany) in 30 patients. AP laxity measurements were obtained for all patients using KT-1000 arthrometer (in a conscious state and under general anaesthesia) and during surgery using the navigation system, always at 30A degrees of knee flexion. The mean AP translation was 14 +/- A 4 and 15.6 +/- A 3.8 mm using the KT-1000 in conscious and under general anaesthesia, respectively (P = 0.02) and 16.1 +/- A 3.7 mm using navigation. Measurements obtained with the KT-1000 under general anaesthesia were no different from those obtained "in vivo" with the navigation system (P = 0.37). In conclusion this study validates the accuracy of the KT-1000 to exactly calculate AP translation of the tibia, in comparison with the more accurate measurements obtained using a navigation system

Stability comparison of anterior cruciate ligament between double- and single-bundle reconstructions

The purpose of this study was to evaluate the intra-operative stability during double-bundle anterior cruciate ligament (ACL) reconstructions (20 knees) using a navigation system and compare the results with those obtained from single-bundle reconstructions (20 knees). After registering the reference points during ACL reconstruction, antero-posterior and rotational stability tests with 30° knee flexion using a navigation system were measured before and after reconstructions on both groups. The change of antero-posterior translation after and before reconstruction was 12.5 mm in the double-bundle group and 10.5 mm in the single-bundle group, showing significant inter-group difference (p=0.014, from 17.5 mm to 5.1 mm in the double-bundle and from 16.6 mm to 6.1 mm in the single-bundle group). The mean rotational stability of the double-bundle group also showed more significant improvement after reconstruction compared to that of the single-bundle group (9.8° in the double- and 5.6° in the single-bundle groups, p<0.001). These findings suggest that a double-bundle ACL reconstruction restores greater knee stability with respect to the antero-posterior and rotational stability than a single-bundle reconstruction