This study evaluated whether or not a morphologic predisposition exists to the development of primary osteoarthritis and establishes a classification tool to predict outcome in surgical treatment of elbow osteoarthritis. Detailed radiographic morphologic analysis of the ulnotrochlear and radio-capitellar joints in 90 normal and 24 osteoarthritic elbows showed few differences. Based upon commonly demonstrated radiographic features of degenerative changes, joint space narrowing, and marginal osteophytes, a classification system for rating the severity of primary osteoarthritis of the elbow was developed and applied retrospectively classified the preoperative radiographs of 18 patients (21 elbows) who had undergone elbow debridement and capsular release through a lateral collateral ligament preserving approach. Clinical and radiographic outcomes were assessed at an average 65 months postoperative. Total elbow motion and Mayo elbow performance scores were best in those who had been classified as class I preoperatively and worst in those in class III. This newly developed radiographic classification system is a useful tool in predicting surgical outcome following debridement of primary elbow osteoarthritis.