[Prevention of hemorrhagic complications in the lateral retinacular section of the patella. A study of the lateral arteries of the knee applied to the prevention of knee hemarthrosis].

PURPOSE OF THE STUDY

Arthroscopic lateral retinacular release is one of the most employed procedures for patellar chondromalacia. A literature review show a complication rate of 10 to 18 p. 100 of postoperative hemarthrosis. This work aims to study the vessels anatomy of the lateral side of the knee in order to find anatomical landmarks allowing to avoid or coagulate them.

MATERIAL AND METHODS

Thirty-three cadaver knees were dissected. Measures were made related to the lateral superior genicular artery and the lateral inferior genicular artery. A study using tracing-paper was also carried out. The main part of the work was more descriptive, studying anastomosis between the different arteries and veins location.

RESULTS

Concerning the lateral superior genicular artery, measure analysis showed that this artery was always cut in lateral patellar retinaculum. This artery never runs more than one centimeter proximally to the base of patella, which is too insufficient to escape from lateral retinacular release. We noted the possibility of locating 90 p. 100 of lateral superior genicular arteries in a minimal distance of 15 mm, in front of the lateral proximal angle of the patella. Concerning the lateral inferior genicular artery, only a few arteries, protected in the meniscal wall in its early course, can remain intact. Two thirds of these arteries are very vulnerable running across the lateral side of the knee. The study of the tracing-papers confirmed topographic study measurements. The descriptive study emphasized the number and the importance of anastomoses between these different arteries. Each artery is flanked by two large satellite veins, which also attribute a veinous origin to a possible bleeding.

DISCUSSION

The topographic study of the lateral inferior genicular vessels shows that their course varies. It seems necessary to avoid their division by performing the standard anterior lateral inferior arthroscopic portal proximally to these vessels. This can be realized at the beginning of the procedure through cutaneous transillumination. The lateral superior genicular vessels are always cut. They are nevertheless reachable through a small lateral incision of about 10 mm, distally to the lateral superior angle of the patella. 90 p. 100 at least of these arteries could be coagulated in such a way. We also emphasize the use of classical methods for the prevention of excessive venous bleeding, such as a compression dressing.

CONCLUSION

Following this anatomical study, we suggest, as a supplementary precaution, a selective hemostasis of the lateral superior genicular vessels through a small incision associated with the location of the lateral inferior genicular vessels by cutaneous transillumination.