Converting round tendons to flat tendon constructs: Does the preparation process have an influence on the structural properties?

PURPOSE: The structural properties of hamstring tendon grafts were evaluated in a porcine model, after processing it to a flat shape, to better replace or augment anatomic flat structures (e.g. ACL, MPFL or MCL). METHODS: In this biomechanical study, porcine flexor tendons were used which have a comparable shape to semitendinosus and gracilis tendons. One part of the tendon was prepared to a flat tendon construct by splitting the tendon longitudinally with a knife to half of the diameter of the tendon. The semi-split tendon was scratched out to a flat shape. The other matched part was tested in its original round shape. The tendons (n = 40) have been fixed in a uniaxial testing machine (Zwick/Roell) by cryo-clamps after preparing the fixed ends by 2-0 polyester sutures (2-0 Ethibond® EXCEL, Ethicon, Somerville, NJ). In every specimen, there was a free 60-mm tendon part between both clamps. The tendons have been loaded to failure to evaluate typical biomechanical parameters such as stiffness, yield load and maximum load. RESULTS: No statistically significant differences (n.s.) regarding stiffness, yield load and maximum load between natively round and processed flat tendons could be detected. CONCLUSION: A prepared flat-shaped tendon does not show any different structural properties compared with an original round tendon. Therefore, a flat tendon seems to be a biomechanical stable graft option for anatomic reconstruction or augmentation of injured natively flat-shaped structures such as MCL, MPFL or ACL.

The anatomy of the anterior cruciate ligament and its relevance to the technique of reconstruction.

Anterior cruciate ligament (ACL) reconstruction is commonly performed and has been for many years. Despite this, the technical details related to ACL anatomy, such as tunnel placement, are still a topic for debate. In this paper, we introduce the flat ribbon concept of the anatomy of the ACL, and its relevance to clinical practice. Cite this article: Bone Joint J 2016;98-B:1020-6.

Atypical sequelae of knee arthroscopy and reactive arthritis.

Aim. To evaluate the reasons for atypical sequelae of knee arthroscopy.
Material. A group of 11 patients (6 women and 5 men), age 17-56 (mean 33.4), referred for rheumatological consulation because of persistent exudates and/or pain in the operated joint. Infectious arthritis, rheumatoid arthritis, psoriatic arthritis and gout were excluded. Immunological diagnostics were performed on all patients, testing for the presence of anti-Chlamydia trachomatis, anti-Yersinia enterocolitica, anti-Salmonella enteritidis and typhimurium antibodies.
Results. In 10/11 patients various antibodies were detected (most often anti-Chlamydia trachomatis antibodies). Other reasons for atypical sequelae of knee arthroscopy included pigmentous villo-nodular synovitis and chondrocalcinosis. The Discussion presents those clinical symptoms and signs appearing in orthopedic examinations that serve as indications for rheumatological consultation.
Conclusion. The most common reason for atypical sequelae of knee arthroscopy is reactive arthritis caused by Chlamydia trachomatis and G(-) enteric bacteria infections.