Reason: rule out L SF osteomyelitis History: Contracture. There is deformity of the phalanges of the little finger. The distal phalanx is dislocated volarly relative to the middle phalanx. The base of the distal phalanx is not well defined on this study, which could be due to prior trauma or erosion. There is abnormal low signal intensity on T1-weighted images within the remaining distal phalanx. There appears to be angular deformity of the middle phalanx possibly representing a healing fracture; there is low signal intensity on T1-weighted images and high signal intensity on fat saturated T2 weighted images with mild enhancement following contrast administration. The PIP joint ankylosis suspected on the patient's recent radiographs is not clearly evident on this MRI study, but the PIP joint is held in approximately 50 degrees of flexion. There is abnormal signal intensity and enhancement of the head of the proximal phalanx with poor definition of the articular surface of the head of the proximal phalanx. There is mild edema type signal seen on the fluid sensitive sequences within the remainder of the proximal phalanx with relative preservation of fatty marrow signal intensity on T1-weighted images. The fifth metacarpal appears normal. The extensor tendon can be followed to the level of the PIP joint, after which it is not clearly defined. There is prominence of the soft tissues dorsal to the middle phalanx with low signal intensity of the soft tissues which presumably represents scarring. We see no fluid collection to suggest abscess formation. There is also bowstringing of the flexor tendon volar to the middle phalanx and distal half of the proximal phalanx suggesting disruption of the A3 and A4 pulleys. There is a small 5th MCP joint effusion.
1. Deformity and abnormal signal intensity of the distal, middle, and proximal phalanges of the fifth digit as described above. We cannot determine to what extent this signal abnormality is related to infection, prior trauma, or postsurgical changes.2. The extensor tendon can be followed to the level of the PIP joint, distal to which there appears to be scar tissue. Again we are uncertain if this is related to prior surgery or trauma.3. Bowstringing of the flexor tendon suggesting disruption of the A3 and A4 pulleys.