PREVENTING LATERAL SKIN NUMBNESS AFTER KNEE ARTHROPLASTY

Abstract

As a result of lateral skin numbness that quite commonly occurs after knee joint operation, injury of the Infrapatellar branch of Saphenous nerve is often underestimated and regarded as a trivial complications. However, there are many complaints and worries from the patients in relation to the injury of this nerve never seems to stop.

The authors wanted to report the results of preserving this nerve during the unicompartmental knee arthroplasty for preventing lateral skin numbness.

The targets of this study were 100 cases of the unicompartmental knee arthroplasty by a single surgeon. All of the cases were medial compartmental osteoarthritis and in which a minimally invasive technique was used, with the average follow up of two years and eight months (range 24 to 42 months). The results were recorded in terms of classification of the nerve by location, preservation after surgery, sensory changes of the lateral skin flap, and complications. The classification by the location of this nerve was observed as either Mochida Type I with 76 people (76%), Type II with 16 people (16%), and unclassified types with eight people(8%). In Type I, this nerve was saved in 62 cases (82%). However in Type II, it could not be preserved in any cases because of the surgical procedure. The results of our study showed that while most of the nerve (76%) on average had a distance of 9.13mm (range 2 to 19mm) from the medial joint line to the nerve and passed inferiorly. This results allowed us to predict ahead of the location of this nerve and careful incision during the operation can preserve this nerve.

The authors discovered that in cases of unicompartmental knee arthroplasty, the nerve can be easily preserved, as 62 people(82%) of type I had this nerve completely preserved. Even if five extra minutes is necessary in order to preserve this nerve, when we think of the patient’s satisfaction it is thought of as a meaningful procedure.