We are writing to reconcile the seemingly contradictory findings of two recent articles published by our groups in Arthritis and Rheumatism, on differences between men and women undergoing surgery for osteoarthritis (OA) (1,2). The Brigham and Women's ]Hospital study showed that women reported substantially, significantly worse functional status than men at the time of total hip and knee arthroplasty and of laminectomy for degenerative lumbar spinal stenosis. Women undergoing total knee replacement also had more limited range of knee motion than men, while there were no gender differences in physical examination findings in the laminectomy and hip arthroplasty cohorts. Radiographs were not evaluated.
The Mayo Clinic study also revealed a trend (of borderline statistical significance) toward worse selfreported preoperative functional status in women. However, men had significantly more severe radiographic hip OA and more limited range of hip motion than women, although the latter difference did not reach statistical significance. Since women were no worse than men on 17 of 19 clinical variables and women had less severe radiographic involvement, the Mayo group reported that women did not have more severe OA than men prior to hip arthroplasty.
The two studies difixed methodologically. The Brigham and Women's Hospital study was conducted in referral centers; the Mayo Clinic study was population based. The Brigham and Women's Hospital study had detailed functional status information obtained with validated instruments, but limited data on objective impairment; the Mayo Clinic group had access to a broader array of impairment data (physical and radiographic), but limited information on functional status (single unscaled items were abstracted from medical records). In the Brigham and Women's Hospital study, preoperative functional status data were obtained by patient recall 6 months after surgery for OA of the hip or knee, while data on lumbar spinal stenosis were collected prospectively, all of the Mayo data were obtained prospectively. It is difficult to determine whether and how much these methodologic differences influenced the principal findings of the studies. In particular, we do not know whether determinants of the decision to undergo surgery are the same for community patients and those who travel to a tertiary referral center. Despite these differences, similar themes emerged from the two studies. The Brigham and Women's Hospital study showed that women hiad worse self-reported functional status than men; the Mayo Clinic findings lend modest support to this conclusion. Tlhe Mayo Clinic study showed that women had less severe radiographic involvement than men and similar physical exatmination features of hip OA; the Brigham and Women's Hospital data support this result.
We suggest that the difiicult quandary posed by these