The trouble with rare conditions is that they are “rare”. In the accompanying manuscript, Abularrage et al seek to identify predictors of vascular injury associated with total knee or total hip arthroplasty. They have been able to identify only 34 possible arterial injuries from a pool of more than 41,000 lower extremity total joint arthroplasties performed from 1996 to 2003 at VA Hospitals and contained in the NSQIP database. With an incidence similar to the risk of a lightning strike, individual orthopedic and vascular surgeons will likely never have sufficient personal experience to greatly expand our current understanding of the factors that lead to arterial injury. Thus, there is a compelling argument favoring the use of large, multi-institutional databases, like NSQIP, in the investigation of rare conditions. The National Surgical Quality Improvement Program originated in the Veterans Health Administration in 1991, prompted by a 1987 Congressional mandate that required the VA to report outcomes of major surgery as per national average, and risk-adjusted for severity of patient illness. During the decade after the inception of the NSQIP, the 30-day mortality rate in the VA after major surgery decreased by 31%, and 30-day postoperative morbidity rate decreased by 45%. A 2002 Institute of Medicine report cited the VA Health System as “best in the nation” in part because of the impact of NSQIP on surgical outcomes.1Khuri S.F. Safety, quality, and the national surgical quality improvement program.Am Surg. 2006; 72: 994-998PubMed Google Scholar Despite its successes, the NSQIP database has significant limitations. In the present study, the authors have inferred the presence of arterial injury associated with total joint arthroplasty by identifying any vascular surgery CPT code occurring within 30 days of the index orthopedic procedure. No chart review was performed and no patient was examined. Based on CPT codes, NSQIP does not differentiate direct repair of artery from vein. The database does not indicate if the vascular insult resulted in hemorrhage or ischemia. Furthermore, since the NSQIP database does not record laterality, the orthopedic procedure and the vascular procedure might not have involved the same extremity. Similarly, a femoral thrombectomy for peripheral embolism unrelated to the index orthopedic procedure might be misconstrued as a complication of orthopedic surgery. It is curious that eight of the thirty-four vascular procedures occurred between 6 and 30 days following the index orthopedic procedure leaving one to wonder if the “injury” was simply missed, late in onset or completely unrelated to the orthopedic procedure. Given the small number of vascular injuries, the misclassification of even a few cases could have significant impact on the statistical analysis. This study confirms previous reports that reoperative total joint surgery is associated with a higher risk of vascular injury. A novel finding is the apparent association of arterial injury with African-American race particularly following total knee arthroplasty. Interestingly, a history of prior vascular surgery was not associated with an increased risk of vascular injury during orthopedic procedures. Unfortunately, the database does not provide any information regarding prior vascular symptoms, preoperative non-invasive testing or vascular imaging. Thus, despite the authors admonition to orthopedic surgeons to “obtain a thorough vascular history”, it is not clear from the evidence in this manuscript that preoperative vascular assessment will reduce the already rare incidence or severity of vascular injuries associated with lower extremity total joint arthroplasty. Predictors of lower extremity arterial injury after total knee or total hip arthroplastyJournal of Vascular SurgeryVol. 47Issue 4PreviewLower extremity arterial injury is a rare complication following total knee (TKA) or total hip arthroplasty (THA). To date, no multi-institutional study has identified preoperative factors that may portend increased risk for these injuries. We queried a large clinical database for the incidence and predictors of arterial injury and/or compromise following lower extremity arthroplasty. Full-Text PDF Open Archive