Original Research High-Grade Patellar Chondral Defects Promising Results From Management With Osteochondral Autografts David Figueroa,* MD, Rafael Calvo Rodriguez,* MD, Rodrigo Donoso,* † MD, MS, Jaime Espinoza,* MD, Alex Vaisman,* MD, and Claudio Yan ˜ ez,* MD Investigation performed at Cl´ ınica Alemana de Santiago, Santiago, Chile Background: Patellar chondral defects represent up to 34.6% of defects found during routine arthroscopy. Surgical management has evolved during the past 20 years in an effort to develop techniques to replace hyaline cartilage. Currently, the only technique that achieves this is osteochondral autologous transfer (OAT). Although good and excellent results have often been reported at midterm and long-term follow-up for femoral lesions, little is known about isolated patellar defects. Purpose: To assess clinical and imaging results of patients treated with OAT for high-grade patellar defects. Study Design: Case series; Level of evidence, 4. Methods: This was a retrospective study on all patients who received OAT for high-grade symptomatic patellar chondral defects between 2010 and 2018 at our institution. The study included patients younger than 40 years of age with anterior knee pain and a grade 4 International Cartilage Repair Society patellar chondral defect between 1 and 2.5 cm 2 . Patients with surgery in other knee compartments, concomitant anterior cruciate ligament ruptures, infection, rheumatoid arthritis, and degenerative lesions were excluded. Six months postoperatively, all patients underwent magnetic resonance imaging (MRI) to allow assessment of graft integrity via the MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score to evaluate morphologic features and integration. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Kujala scores were used to assess functional outcomes at final follow-up. Results: A total of 26 patients who received a patellar OAT were included. Most patients were male (88.4%), and the mean ± SD age was 28.5 ± 9.7 years. Patellar chondral defects had a median size of 180 mm 2 (range, 64-250 mm 2 ), and patients received a median of 1 autograft (range, 1-3). Functional outcomes assessed at a minimum of 1 year after surgery showed a mean Kujala score of 90.42 ± 6.7 and a mean WOMAC score of 95 ± 3.6. MRI revealed a median MOCART score of 75 points (range, 20-90 points). Conclusion: To our knowledge, this is the largest series to date regarding isolated patellar OAT. At midterm follow-up, most patients reported good and excellent results regarding symptoms and activity levels. Most autografts showed good osseous integration and excellent filling of the chondral surface, as evidenced on MRI. OAT is a good alternative to treat high-grade patellar chondral defects, especially among young patients. Keywords: patella; autologous; transplantation; osteochondral; chondral; cartilage Knee chondral defects are frequent findings in routine arthroscopy, representing a challenge for the orthopaedic surgeon. This is especially true in young athletes due to high demands on returning to previous levels of sports activity. 12 These defects usually cause pain and articular effusion and eventually lead to the development of early osteoarthritis. 6 The patella is a sesamoid bone that presents the thickest articular cartilage in the body, with a mean thickness of 6 to 7 mm. This allows the patella to bear the load to which the patellofemoral joint is exposed, which can be 6 to 7 times the total body weight. 17 Thus, any defect on the patella reduces the normal distribution of forces on its surface, which can lead to defect enlargement, increased pain, and further functional deterioration. It is well known that articular cartilage has a low regen- eration capacity given its avascular and hypocellular char- acteristics. 19,22 Special concern exists regarding chondral defects on the patella given the treatment difficulty that these pose. 22 Furthermore, patellar chondral defects can be evidenced in approximately 34.6% of defects found during routine arthroscopy. 10 The Orthopaedic Journal of Sports Medicine, 8(7), 2325967120933138 DOI: 10.1177/2325967120933138 ª The Author(s) 2020 1 This open-access article is published and distributed under the Creative Commons Attribution - NonCommercial - No Derivatives License (https://creativecommons.org/ licenses/by-nc-nd/4.0/), which permits the noncommercial use, distribution, and reproduction of the article in any medium, provided the original author and source are credited. You may not alter, transform, or build upon this article without the permission of the Author(s). For article reuse guidelines, please visit SAGE’s website at http://www.sagepub.com/journals-permissions.