Technical pitfalls of anterior cruciate ligament surgery

Clinical results comparing transtibial technique and outside in technique in single bundle anterior cruciate ligament reconstruction

Purpose

To compare the clinical results of single-bundle anterior cruciate ligament (ACL) reconstruction using the conventional transtibial technique and the anatomical outside-in technique for femoral tunneling.

Materials and Methods

From 2007 to 2011, 89 patients who received ACL reconstruction were followed for ≥1 year were enrolled in the study. The conventional transtibial technique was used in 41 patients and the outside-in technique, in 48 patients. Femoral tunnel angle measurement and three-dimensional computed tomography (3D CT) were used for radiologic assessment of the location of femoral tunnel and Lysholm score and other tests were used for clinical assessment.

Results

Both techniques did not reveal statistical differences in the clinical assessment. However, in International Knee Documentation Committee subjective knee evaluation, the sum of two questionnaire items regarding instability showed a statistically significant difference (p=0.01). In the pivot shift test, the anatomical outside-in technique showed outstanding rotational stability over the transtibial technique (p=0.04). The mean femoral tunnel inclination in coronal plane were 69.2° and 30.3°, respectively, for both techniques, and 21.6° and 50.8°, respectively in sagittal plane, showing statistically significant differences on simple radiography (p=0.04, 0.05). A 3D CT was performed in 17 patients with the conventional transtibial technique and 25 patients with the outside-in technique. Coefficients of variation were 0.33 and 0.13, respectively, from dorsal border of the condyle and 0.67 and 0.24, respectively, from the roof of intercondylar notch.

Conclusions

Femoral tunnels created with the outside-in technique have superior knee joint rotational stability compare to the transtibial technique. Therefore, the outside-in technique could be considered as a valuable technique in single-bundle ACL reconstruction.

Ligament repair: a molecular and immunohistological characterization

The anterior cruciate ligament (ACL) is the most commonly injured tissue of the human knee. Its poor ability to regenerate after injury represents a challenge to ligament tissue engineering. An understanding of the molecular composition of the structures used for its repair is essential for clinical assessments and for the implementation of tissue engineering strategies. The objective of this study was to evaluate, both at gene and protein levels, the expression of characteristic molecules in human ACL, patellar, semitendinosus and gracilis tendons and in the ligament reconstructed with patellar or semitendinosus and gracilis tendons. We demonstrated that primary ACL and tendon tissues all express collagen I, II, Sox-9, tenascin-C and aggrecan. Collagen X expression was detected at very low levels or undetectable. Cathepsin B, MMP-1 and MMP-13 were expressed at higher levels in the ACL reconstructed by the two tendons, showing that a remodeling process occurs during "ligamentization". Both our molecular and immunohistochemical evaluations did not reveal significative differences between the tendons and ligaments analyzed. However, ACL reconstructed with semitendinosus and gracilis tendon seems to present a higher expression of collagen type II when compared to that reconstructed with patellar tendon. This study could give a reasonable identification of genetic and protein markers specific to tendon/ligament tissues and be helpful in testing tissue engineering approaches for ACL reconstruction.

Complications of anterior cruciate ligament reconstruction with bone-patellar tendon-bone constructs: care and prevention

Rupture of the anterior cruciate ligament is a common injury. Correct diagnosis and patient selection, along with proper surgical technique, with careful attention to anatomic graft placement, followed by attention to proper rehabilitation, leads to predictably good to excellent results. This article reviews the recognition and avoidance of complications associated with bone-patellar tendon-bone constructs of anterior cruciate ligament reconstruction.

How to overcome severed sutures of the tibial bone peg in anterior cruciate ligament reconstruction

We report a case of severed sutures of the tibial bone peg during anterior cruciate ligament reconstruction. The graft retracted proximally in the bone tunnel. We describe a simple and aesthetically acceptable method to salvage this rare complication by use of a small arthrotomy through the defect in the remaining patellar tendon.