Andrea Redler

Computer-assisted surgery: A teacher of TKAs

INTRODUCTION The hypothesis of this study is that computer-aided navigation experience could improve the ability to better place components in the coronal plane and to improve visual/spatial awareness based on the ability of navigation to provide instant feedback. The purpose of this study is to demonstrate the educational role of the navigation system to obtain a better alignment of the prosthetic components with standard instrumentation after a computer-aided navigation experience. MATERIALS AND METHODS One hundred fifty patients were operated by the same surgeon, with more than 5 years experience with TKA. They were equally divided in three groups: group A (operated with non-navigated technique by surgeon without computer-assisted experience); group B (operated with computer-assisted surgery by the same surgeon); group C (operated with non-navigated technique by the same surgeon after the computer-navigated experience). We evaluated by full-length weight-bearing radiographs the overall alignment of the lower limb in the coronal plane. The optimum placement of the components was considered when the angle was within the limits of ±3° varus/valgus on the coronal x-rays. Comparison between groups was done using one-way ANOVA followed by post hoc Bonferroni test and Pearson chi-square statistics for proportions of optimum placement (P<0.05). RESULTS In the group A 34 patients (68%) had the optimum placement on the coronal x-rays; in the group B they were 46 (92%) and in the group 41 (82%). The difference is statistically significant in comparing group A and Group B (<0.001), group A and group C (P=0.04), but not for group B and C (P=0.2). CONCLUSION We believe that the navigation system has an educational role to improve the ability of surgeon of positioning prosthetic components precisely in the coronal plane.

Isokinetic flexion strength recovery after ACL reconstruction: a comparison between all inside graft-link technique and full tibial tunnel technique

ABSTRACT Introduction: Recently, a new minimally invasive single bundle technique for anatomic ACL reconstruction has been described, called the ‘All-Inside graft-link technique’. One of the advantages of this procedure is the reduced morbidity at the donor site as the graft choice is the quadrupled semitendinosus, thus sparing the gracilis tendon. The aim of this study was to evaluate isokinetic flexion strength recovery in patients who underwent a gracilis sparing technique compared to those with a full-tibial tunnel technique using a doubled gracilis and semitendinosus tendons (DGST) graft. Methods: Patients were divided into two groups: Group A (22 patients) who underwent ACL reconstruction performed with an All-Inside graft-link technique; Group B (22 patients) who underwent ACL reconstruction with an Out-In technique and DGST graft. At a mean follow-up of 13 months, quadriceps and hamstring isokinetic peak torque deficits were recorded. Results: In group A, the mean side to side peak torque flexion difference between the operated and non-operated limbs was −3% and the mean torque at 30° was −7.5% at high angular velocity (180°/sec); the mean peak flexion torque was 7.2% and the mean torque at 30° was 3.1% at low angular velocity (60°/sec). In group B, the mean side to side peak flexion torque was −3.5% and the mean torque at 30° was −7.6% at high angular velocity (180°/sec); the mean peak flexion torque was −7.2% and the mean torque at 30° was −11% at low angular velocity (60°/sec). A statistically significant difference was found between the two groups at lower angular velocity both for the mean peak flexion torque and the mean torque at 30° (p = 0.009), with better results in the study group. Discussion/conclusion: Gracilis sparing technique is a minimally invasive technique for ACL reconstruction and yielded a significantly better flexion strength recovery at lower angular velocity compared to a full tibial tunnel technique with DGST for ACL reconstruction.

Anatomic and Histological Study of the Anterolateral Aspect of the Knee: A SANTI Group Investigation

Background: The structure and function of the anterolateral aspect of the knee have been significantly debated, with renewed interest in this topic since the description of the anterolateral ligament (ALL). Purpose: To define and describe the distinct structures of the lateral knee and to correlate the macroscopic and histologic anatomic features. Study Design: Descriptive laboratory study. Methods: Twelve fresh-frozen human cadavers were used for anatomic analysis. In the left knee, a layer-by-layer dissection and macroscopic analysis were performed. In the right knee, an en bloc specimen was obtained encompassing an area from the Gerdy tubercle to the posterior fibular head and extending proximally from the anterior aspect to the posterior aspect of the lateral femoral epicondyle. The en bloc resection was then frozen, sliced at the level of the joint line, and reviewed by a musculoskeletal pathologist. Results: Macroscopically, the lateral knee has 4 main layers overlying the capsule of the knee: the aponeurotic layer, the superficial layer including the iliotibial band (ITB), the deep fascial layer, and the ALL. Histologically, 8 of 12 specimens demonstrated 4 consistent, distinct structures: the ITB, the ALL, the lateral collateral ligament, and the meniscus. Conclusion: The lateral knee has a complex orientation of layers and fibers. The ALL is a distinct structure from the ITB and is synonymous to the previously described capsulo-osseous layer of the ITB. Clinical Relevance: Increasingly, lateral extra-articular procedures are performed at the time of anterior cruciate ligament reconstruction. Understanding the anatomic features of the anterolateral aspect of the knee is necessary to understand the biomechanics and function of the structures present and allows surgeons to attempt to replicate those anatomic characteristics when performing extra-articular reconstruction.

Anterior Cruciate Ligament Reconstruction With Suture Tape Augmentation

The advent of suture tape augmentation has led to increased use in knee, elbow, and ankle ligament repairs and reconstructions. Recent biomechanical analysis of the use of suture tape augmentation have shown superior strength characteristics compared with repair or reconstruction alone. Despite its increased use in extra-articular ligament procedures, its use as an augment to anterior cruciate ligament reconstruction has not been widely described. This article details a simple technique to incorporate the use of suture tape augmentation during concurrent anterior cruciate ligament reconstruction using hamstring autograft.

Anterolateral ligament reconstruction with autologous grafting: A biomechanical study.

Background To evaluate the reliability of the Iliotibial band compared to gracilis tendon as a graft to be used in anterolateral ligament reconstruction. Methods Gracilis tendon and a strip of Iliotibial band compared were harvested from 8 fresh human cadaveric knees. The gracilis tendon was prepared to obtain a graft of 10 cm in length (Group 1). Iliotibial band compared was prepared to obtain a graft of 10 cm in length and 0.5 cm in width from the middle portion (Group 2). All the specimens were fixed on a servo hydraulic tensile machine with dedicated cryo‐clamp. The loading protocol, used to compare the previously published results of ultimate failure load and Stiffness of the anterolateral ligament (Group 3), included a cyclic preconditioning between 10 and 25 N at 0.1 Hz for 10 cycles and then a load to failure test at 20 mm/min. Findings Gracilis tendon showed higher Ultimante Failure Load and stiffness when compared to a strip of Iliotibial band. Gracilis tendon and a strip of Iliotibial band compared showed higher Ultimante Failure Load and stiffness when compared with native anterolateral ligament as reported by Kennedy. Interpretation Both grafts tested in the present studies are suitable for an anatomical anterolateral ligament reconstruction. HighlightsGracilis and Iliotibial‐band are the most used graft for the ALL reconstruction.Gracilis and Iliotibial‐band showed higher UFl than native ALL.Gracilis and Iliotibial‐band showed higher stiffness than native ALL.Gracilis and Iliotibial‐band are suitable graft for ALL reconstruction.