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Revision Rates of Knee Cartilage Restoration Surgeries and Conversion to Total Knee Arthroplasty Within Five Years Ravand Khazai MD, Harout Boyajian MD, Olumuyiwa Idowu, Lewis Shi MD, Aravind Athiviraham, MD University of Chicago, Department of Orthopaedic Surgery and Rehabilitation Medicine Conclusion Objectives Results Introduction Materials & Methods • To examine the rates of complications and re- operation for common knee cartilage reconstruction procedures performed in the United States, and subsequent conversion to total knee arthroplasty (TKA). • Previous studies have examined outcomes of osteoarthritis patients, as well as rates of conversion to total joint arthroplasty following general knee arthroscopy. • Few studies have examined outcomes or conversion rates for patients who have undergone specific cartilage restoration procedures. • Institutional Review Board approval obtained • Retrospective review of the Truven Health Marketscan® Research Database (de-identified records for 55 million US patients with private or employer provided coverage) • Microfracture and OATS are associated with lower rates of conversion to TKA within 5 years compared to previous reports for general knee arthroscopic procedures. • Patients undergoing ACI were more likely to require a subsequent surgical procedure or conversion to arthroplasty, while those undergoing microfracture were least likely. Revision Surgery Codes Inclusion Criteria • Patients treated between 2003 and 2014, tracked at least 2 years post primary operation for revision/complication data and 5 years for TKA data • Microfracture/abrasion chondroplasty (CPT 29879), osteochondral auto- or allo- grafting (OATS) (CPT 27415, 27416, 29866, 29867), and autologous chondrocyte implantation (ACI) (CPT 27412). • For TKA conversion, age limited to >50. Complication Codes CPT Definition 27415 Osteochondral allograft, knee, open 27416 Osteochondral autograft, knee, open 29846 Arthroscopy with debridement 29867 Arthroscopic Osteochondral Allograft 27412 Autologous Chondrocyte Implantation 29879 Microfracture/Abrasion arthroplasty 29877 Chondroplasty/Debridement CPT Definition 27301 Incision & drainage, deep abscess, bursa, hematoma 27303 Incision & drainage, with involvement of bone 27310 Arthrotomy , knee, with exploration, drainage, or removal of foreign body 27520 Closed treatment of patellar fracture, without manipulation 27524 Open treatment of patellar fracture, with internal fixation 27570 Manipulation of knee joint under general anesthesia 29871 Arthroscopy, knee, surgical; for infection, lavage and drainage 29884 Arthroscopy, knee, surgical; with lysis of adhesions, with or without manipulation • Microfracture▲- most common -76,304 patients • Incidence decreased every year starting in 2009, from approximately 600 cases per million in 2009, to approximately 450 per million in 2014. • OATS ♦, relatively stable incidence of between 2009- 2014, with 20-25 cases per year per million. • 2,151 patients were enrolled throughout the encompassed time period. • ACI ◼ was the least common, 868 patients enrolled 0 100 200 300 400 500 600 700 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Rate/million Year Rates Figure 1. INCIDENCE OF CARTILAGE RESTORATION SURGERY 2003-2014 • Patients s/p microfracture tended to be older than those who underwent either osteochondral grafting or ACI, with an average age of 48.3 years (p < .001). • No statistically significant difference between OATS and ACI (average 34.5 years for both). Microfracture OATS ACI total n 76,304 2,151 868 Mean Age 48.3 (SD 13.6) 34.5 (SD 14.1) 34.5 (SD 13.5) Adolescents (10-19) 4,184 (5.5%) 491 (22.8%) 168 (19.4%) Young adults (20-34) 6,738 (8.8%) 550 (25.6%) 263 (30.3%) Adults (>35) 65,371 (85.7%) 1,110 (51.6%) 437 (50.3%) males 38,084 (49.9%) 1,230 (57.2%) 451 (52%) females 38,220 (50.1%) 921 (42.8%) 417 (48%) TABLE 1. DEMOGRAPHIC INFORMATION Microfracture OATS ACI n at 2y 76,304 2,151 868 n at 5y 24,892 741 233 Rate of revision 6,403 (8.4%)* 331 (15.4%) 183 (21.1%) Most common revision revision microfracture (57.1%) chondroplasty (52.6%) chondroplasty (63.5%) N days to revision 349 272 370 Rate of complication 1,065 (1.4%)* 107 patients (5%) 46 (2.1%) Most common complication manipulation under anesthesia (49.8%) lysis of adhesions (43.3%) lysis of adhesions (61%) # of TKA within 5y 428 (1.7%) 16 (2.2%) 16 (6.9%)* Mean days to TKA 780 918 867 Mean age 48.3y* 34.5y 34.5y Mean age of TKA pts 56.2y 48.9y 49.2y * indicates significant difference among row (p < 0.01) TABLE 2. RATES OF FOLLOW UP, REVISION, COMPLICATION, AND ARTHROPLASTY FOLLOWING CARTILAGE RESTORATION PROCEDURES • Microfracture patients, 6,403 (8.4%) underwent at least one revision surgery • microfracture (4,383; 57.1%), chondroplasty (2,815; 36.7%), and open osteochondral grafting (173; 2.3%). • 1,065 (1.4%) patients sustained a complication • manipulation under anesthesia (MUA) (626; 49.8%), arthroscopic lysis of adhesions (LOA) (341; 27.1%), arthroscopic lavage and drainage (I&D) (130, 10.3%), and incision and drainage (68, 5.4%). • OATS: 331 (15.4%) underwent at least one revision procedure • chondroplasty (229; 52.6%), microfracture (98, 22.5%), and open OATS (50, 11.5%). • 107 patients (5%) sustained a complication • LOA (55; 43.3%), MUA (47; 37.0%), open I&D (9; 7.1%), and arthroscopic I&D (7; 5.5%). • ACI was the least common; 868 patients • 183 (21.1%) underwent revision surgeries • chondroplasty (151; 63.5%), revision ACI (44, 18.5%), and microfracture (36, 15.1%) were most commonly performed. • 46 (2.1%) patients sustained a complication • LOA (36; 61%) and MUA (22; 37.3%). Microfracture OATS ACI n at 5y 13,236 115 25 # of TKA within 5y 308 (2.3%)* 5 (4.3%) 6 (24%) Mean days to TKA 731 893 532* TABLE 3. RATES OF ARTHROPLASTY FOLLOWING CARTILAGE RESTORATION PROCEDURES IN PATIENTS OLDER THAN 50 YEARS • 13,236 Microfracture patients (age >50) remained enrolled for 5 years • 308 (2.3%) underwent TKA at an average 731 days (2.1 years) • OATS cohort, 115 patients (age >50) remained enrolled for 5 years • 5 patients (4.3%) underwent TKA at an average of 893 days • Of the ACI cohort, 25 patients (age>50) remained enrolled for 5 years • 6 (24%) underwent TKA at an average of 532 days * indicates significant difference among row (p < 0.01)
