A comparative study of Infra patellar branch of saphenous nerve injury between vertical and horizontal portal incisions in knee arthroscopy.

ABSTRACT

Background: An Infrapatellar Branch of Saphenous Nerve (IPBSN) injury is one of the complications leading to sensory loss in the operated knee. A high incidence of IPBSN injury was reported during hamstring harvest, but there are only a few studies analyzing IPBSN injury during arthroscopy portals. However, there was a lack of randomized comparative studies comparing the incidence of IPBSN injury in horizontal and vertical portals. This study aimed to identify the overall incidence of IPBSN injury and compare the difference between vertical and horizontal portal incisions. We also aimed to observe the recovery pattern of IPBSN injuries in both groups. We hypothesize that since the portal incisions are very small, the incidence of IPBSN injury will be very low, and it will occur more in the vertical incision. Methods: After obtaining IRC approval from B&B Hospital IRC, this prospective comparative study was conducted at the AKB center for arthroscopy, sports injury, and regenerative medicine, B&B Hospital. The calculated sample size of 128 consecutive patients was included and divided into groups by the block randomization method. A total of 64 patients were allocated to both groups. Demographic data was recorded. The sensory loss along the IPBSN was examined and documented on the first postoperative day. Their recovery was documented during two weeks and three months of follow-up visits. Parametric and non-parametric tests were applied to analyze the variables. Results: IPBSN injury was seen in 12 patients (9.37 %) among 128 study participants. Five patients (7.81 %) had IPBSN injuries in the vertical group compared to seven (10.93 %) in the horizontal group. Recovery was earlier in the horizontal incision group. Conclusion: The overall incidence of IPBSN injury during the arthroscopy portal is low. They occur equally in vertical and horizontal portal incisions. The recovery of the IPBSN injury was better and earlier in the horizontal incision group.