title: Does patellar rim electrocautery have deleterious effects on patellar cartilage?
abstract: BACKGROUND
  Circumpatellar electrocauterization to destroy pain receptors during total knee arthroplasty without patellar resurfacing is commonly used to decrease postoperative knee pain. We aimed to evaluate the effect of denervation with electrocauterization on patellar cartilage.
  
  
  METHODS
  Twenty rabbits were randomly assigned to two equally sized case and control groups. The rabbits in the case group underwent surgery via the anterior midline skin incision and medial parapatellar arthrotomy, followed by denervation electrocauterization at a depth of 1 mm and a distance of 3 mm from the outer border of the patella. In the control group, surgery was identical to that performed in the case group, but without patellar denervation. Twelve weeks after surgery, all rabbits were sacrificed. Range of motion, macroscopic evaluation of cartilage using modified Outerbridge scoring, and histopathological assessment using a modified histologic scoring system for cartilage were evaluated.
  
  
  RESULTS
  Three rabbits died during the study. Nine cases and eight animals from the control group were included in the final evaluation. All rabbits had passive full range of motion. Mean Outerbridge score was 2.0 in the case group and 0.37 in the control group (p=0.002). There were statistically significant differences in cellularity (p=0.016), loss of matrix (p=0.004), and clustering of chondrocytes (p=0.008) between the two groups. Microscopic variables as a whole were statistically significant (p=0.001).
  
  
  CONCLUSIONS
  Circumpatellar electrocauterization may result in cartilage destruction. So, we encourage caution in using routine electrocauterization in patients undergoing total knee arthroplasty.
  
  
  METHODS
  level II.
authors: Bone and Joint Disease Research Center, Department of Orthopedic Surgery, Chamran Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Niloofar
authors: N
authors: Namazi
authors: Bone and Joint Disease Research Center, Department of Orthopedic Surgery, Chamran Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Fereidoon Mojtahed
authors: FM
authors: Jaberi
authors: Department of Pathology, Chamran Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Sara
authors: S
authors: Pakbaz
authors: Bone and Joint Disease Research Center, Department of Orthopedic Surgery, Chamran Hospital, Shiraz University of Medical Sciences, Shiraz, Iran. Electronic address: vosoughiar@hotmail.com.
authors: Amir Reza
authors: AR
authors: Vosoughi
authors: McGill University, Montreal, Quebec, Canada.
authors: Mahrad Mojtahed
authors: MM
authors: Jaberi
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology*; D019902:Chondrocytes / Q000473:pathology; D003714:Denervation / Q000379:methods*; D004564:Electrocoagulation; D008297:Male; D008853:Microscopy; D010329:Patella / Q000294:innervation* / Q000601:surgery*; D017847:Patellar Ligament / Q000473:pathology; D011817:Rabbits; D011897:Random Allocation; D016059:Range of Motion, Articular / Q000502:physiology; D013194:Staining and Labeling; D013264:Stifle / Q000502:physiology
keywords: Arthroplasty; Cartilage; Electrocauterization; Knee; Patella