Etiology and pathogenesis] Hematogenous purulent infections of the bones and joints of the hand are extremely rare, and are mostly secondary to infection of adjacent soft tissues. The most common is septic phalangitis secondary to osteomyelitis of the end phalanges, or infection following injury to the nail bed and phalanges due to crushing injuries to the end phalanges. It can also be secondary to purulent tenosynovitis, interstitial infections, and subcutaneous infections. It is also not uncommon for open bone and joint injuries to be followed by bone and joint infections. Diagnostic points】 Clinical manifestations In general, systemic symptoms are mild, but local symptoms are obvious. Redness, swelling, heat, pain and pressure pain, often dorsal side is more important. If the infected wound does not heal for a long time or the granulation is outgrown, the possibility of bone and joint infection should be noted, and X-ray is needed to make a clear diagnosis. Bone and joint infection secondary to soft tissue inflammation differs from the pathological changes of typical hematogenous osteomyelitis in that the infection is localized, with worm-like changes in the bone and a periosteal reaction, and the dead bone is often fragmented or in small pieces. In septic arthritis, local redness, swelling, heat and pain are more pronounced, the joint is in a slightly flexed position, active and passive activities are restricted, and severe pain is experienced when moving. X-rays show soft tissue swelling, narrowing of the joint space, joint surface destruction and periosteal reaction in advanced stages, and finally bony fusion of the joint. Treatment overview】 For septic osteoarthritis with significant pus accumulation or significant bone necrosis, incision and drainage and lesion removal surgery should be performed, along with braking, physical therapy and antibiotic treatment. In cases of severe osteomyelitis of the finger bone that does not heal over time, amputation of the finger may be considered in addition to the thumb. Early septic arthritis can be treated with puncture and pus aspiration, irrigation, and injection of antibacterial drugs, which may preserve some degree of joint function. If the infection cannot be controlled by puncture and drainage of the finger joint, arthrocentesis may be considered to fix the joint in a functional position. In cases of severe knuckle infections that do not heal over time, amputation of the thumb is also feasible in addition to the thumb.