Microdrilling Resulted in Less Subchondral Bone Destruction Than a Traditional Microfracture Awl for Articular Cartilage Defect Bone Marrow Stimulation
Lucy E. Meyer, Richard M. Danilkowicz, Zoe W. Hinton, Bryan S. Crook, Bijan Abar, Nicholas B. Allen, Mitchell Negus, Eoghan T. Hurley, Alison P. Toth, Annunziato Amendola, Samuel B. Adams
Abstract
Purpose The purpose of this study was to compare bone marrow stimulation using micro‐computed tomography (micro‐CT) analysis of an abrasion arthroplasty technique, drilling k‐wire technique, traditional microfacture awl, or a microdrill instrument for subchondral bone defects. Methods Eleven cadaveric distal femoral specimens were obtained and divided into 3 common areas of osteochondral defect: trochlea and weightbearing portions of the medial and lateral femoral condyles. Each area of interest was then denuded of cartilage using a PoweRasp and divided into quadrants. Each quadrant was assigned either a 1.6 mm Kirschner wire (k‐wire), 1.25 mm microfracture awl, 1.5 mm fluted microdrill, PowerPick, or a curette (abrasion arthroplasty) to create 4 channels into the subchondral bone sing the same instrument. Subchondral bone and adjacent tissue areas were then evaluated using micro‐CT to analyze adjacent bone destruction and extension into the bone marrow. Results Overall, there was a significantly decreased area of bone destruction or compression using the microdrill (0.030 mm) as compared to the microfracture awl (0.072 mm) and k‐wire (0.062 mm) ( P < .05). Within the trochlea and the medial femoral condyle, there was significantly decreased bony compression with the microdrill as compared to the awl and k‐wire ( P < .05); however, when stratified, this was not significant among the lateral femoral condylar samples ( P = .08). Conclusions Decreased subchondral bony defects were seen with the microdrill versus the traditional microfracture awl indicating that when performing bone marrow stimulation, thus the microdrill may cause less damage to the subchondral bone. Clinical Relevance Bone marrow stimulation causes bony compression that may negatively impact subchondral bone and trabecular alignment. It is important to understand which tools used for bone marrow stimulation cause the least amount of damage to the subchondral bone.