In Reply.—The differential diagnosis of osteomyelitis v septic arthritis is not as obvious or absolute as Dr Green perceives it to be.
The patients described in my study were initially seen and followed up by staff physicians in the Divisions of Pediatric Orthopedics and Pediatric Infectious Disease, Louisiana State University School of Medicine, Shreveport. After examining all clinical and laboratory data, plus personally performing the shoulder taps, their specific diagnosis was primary osteomyelitis. I have no reason to question their diagnostic ability.
Some of the factors used in the diagnosis included the following: the lack of pain on joint movement, the lack of initial local swelling or erythema, a positive blood culture, an insignificant leukocytosis, positive bone scans on day 2 of the illness, and abnormal roentgenographic findings between days 7 and 11 of the clinical illness. These criteria are all compatible with a "benign form" of osteomyelitis in