Objective: To assess and score the progression of osteoarthritis (OA) of the distal and proximal interphalangeal (DIP and PIP) and metacarpophalangeal (MCP) joints.
Methods: Forty-six patients with OA of the finger joints were followed up for 3 years; 36 of them were followed up for 5 years. Posteroanterior radiographs of the hands were obtained at the start of this prospective study and at yearly intervals. The scoring systems used were based on the increased incidence of OA during consecutive years in previously normal joints, the radiologic progression of anatomic lesions in the affected finger joints, and the consecutive pathologic phases recognized in the course of the disease.
Results: Significant increases both in the numbers of affected DIP, PIP and MCP joints per subject and in the anatomic progression of the disease (changes in osteophyte growth, loss of joint space, and subchondral cysts or sclerosis) in the different finger joints of each patient were recorded during the 3 and 5 years of followup. In approximately 40% of the patients, the classic picture of OA was complicated by erosive changes, which preceded a period in which repair phenomena in the "eroded" finger joints led to the generation of a new subchondral plate covered by cartilaginous tissue. Huge osteophytes were then responsible for the nodular aspect of the affected finger joints.
Conclusion: OA of the finger joints is progressive in nature and passes through predictable phases. The recognition of and the attribution of a score to these respective phases made assessing the progression of OA less time-consuming and led to the same conclusions as when the anatomic progression was scored.