Codman, writing shortly after Roentgen's discovery of X-rays, set out to define the normal X-ray anatomy of joints. Using cadaveric skiagraphs, he documented the geometric distortions of radiography and analyzed wrist and ankle kinematics. He also demonstrated early contrast and stereoscopic techniques.
Every radiograph you read tomorrow obeys the geometry Codman laid out here. The joint space you measure is cartilage and fluid, not bare bone, because cartilage is radiolucent. That single fact underlies how we grade osteoarthritis by joint space narrowing.
His distortion rules still guide positioning: keep the part of interest against the cassette and the tube far away to minimize magnification. This is why a knee shot through thick tissue distorts the far condyle. The inverse square law he cites governs the dose and exposure trade-offs behind every technique setting.
His wrist analysis, splitting motion between the radiocarpal and midcarpal rows, remains the mental model for understanding carpal instability and why the ulna and pisiform sit outside the true joint.
Codman, writing shortly after Roentgen's discovery of X-rays, set out to define the normal X-ray anatomy of joints. Using cadaveric skiagraphs, he documented the geometric distortions of radiography and analyzed wrist and ankle kinematics. He also demonstrated early contrast and stereoscopic techniques.
Every radiograph you read tomorrow obeys the geometry Codman laid out here. The joint space you measure is cartilage and fluid, not bare bone, because cartilage is radiolucent. That single fact underlies how we grade osteoarthritis by joint space narrowing.
His distortion rules still guide positioning: keep the part of interest against the cassette and the tube far away to minimize magnification. This is why a knee shot through thick tissue distorts the far condyle. The inverse square law he cites governs the dose and exposure trade-offs behind every technique setting.
His wrist analysis, splitting motion between the radiocarpal and midcarpal rows, remains the mental model for understanding carpal instability and why the ulna and pisiform sit outside the true joint.