Tuberculosis of the wrist causes a variety of conditions such as skin lesions, tenosynovitis, bursitis, osteomyelitis, arthritis, and tuberculous allergic reaction [10]. Early manifestations of tuberculosis of the wrist joint, however, are not typical as they may start gradually and advance over a long time [11]. During the early stage of simple tuberculosis of the wrist, the lesions are mostly confined to the synovium of the wrist, joint capsule, and other surrounding soft tissues. The patient experiences pain and swelling of the wrist without exhibiting any manifestation characteristics of tuberculosis such as hot flashes, night sweats, and poor appetite. As the infection advances, the wrist mobility becomes limited, the pain and swelling aggravate, and the abscesses and sinus tract may form locally. With an increasing exudation of the focus, the wrist pressure increases causing ischemia and necrosis of the adjacent tendons and nerves. Further development of these pathological changes results in the destruction of the periosteum, followed by necrosis and degeneration of the bones. When pathologies develop to the edge of the articular surface, the articular cartilage erodes and the subchondral bone is destroyed. With the destruction of the carpal bones, the spaces are filled by necrotic tissue resulting in arthritis and deformity of the affected carpal joint [12]. Chandrasekharan et al. believe that tuberculosis of the wrist joint can be histologically divided into three stages. During the early stage, granuloma infiltration is present in the tendon sheath, followed by fiber tissue destruction and caseation of the tendon sheath. During the last stage, the tendon is replaced by infiltrating granuloma and ruptures [7], and the wrist deformity is increased.
Early diagnosis of this disease is difficult and therefore the misdiagnosis rate is quite high. It takes an average of 16–19 months from the onset of carpal symptoms for a clear diagnosis [11]. In our patients, the course of the disease was (15.1 ± 11.3) months. Tuberculosis of the wrist can originate from trauma-related infection or through the pathogen transport by blood circulation from the other organs. It can also be caused by an infection of wrist joint by Mycobacterium tuberculosis after a trauma. In our case, four (22%) patients had a history of wrist trauma. However, upon the occurrence of bone and joint tuberculosis, the proportion of patients with previous tuberculosis was 1 / 3 − 1 / 2 [13], and the proportion of patients with active tuberculosis was lower. In our series, only 2 (11%) patients had a previous diagnosis of tuberculosis. Therefore, it is important to determine whether the patients have tuberculosis or had a previous history of tuberculosis so that it may be used for the diagnosis of wrist tuberculosis. Blood tests of patients with wrist tuberculosis revealed increased levels of ESR and CRP and decreased levels of albumin. Radiographically, the majority of the lesions showed wrist masses with unclear boundaries, bone destruction, narrowing of the carpal joint space, and involvement of the distal radius and ulna. With disease progression, the invasion of the carpal bones by the lesion became more advanced, forming extensive periostitis [14]. However, in the case of simple synovial tuberculosis, there was no clear radiographical sign of osteoporosis or bone destruction. During the early stage of wrist tuberculosis, it is difficult to radiographically diagnose the lesion. In case of evident radiographical signs of joint destruction and calcification, further imaging examinations are warranted [15]. MRI is an effective tool for identifying carpal tuberculosis [16]. It can clearly show the soft tissue of the wrist, offering a clearer understanding of the tendon injury, blood vessel, and articular cartilage. It can also detect early effusion in the wrist as well as the inflammatory changes of bone. The carpal tuberculosis MRI showed rice bodies in the carpal mass and abnormal thickening of the synovium. On T2WI, the low-density lesions, low-density synovium with central erosion and surrounding abscess are important markers that distinguish tuberculosis from other types of arthritis [17, 18]. MRI examination allows for an early diagnosis of wrist tuberculosis. In recent years, color Doppler ultrasonography had also commonly been used for the diagnosis of wrist diseases. For example, during effusion and empyema in the wrist, ultrasonography can clearly identify their location and volume and reveal the involvement of blood vessels, nerves, and tendons in the wrist joint [15]. When rice bodies are observed intraoperatively in the wrist joint, it is highly indicated to be tuberculosis. There are two opinions regarding the formation of rice bodies. One is that the synovium is necrotic and exfoliated, and is wrapped by fibrin. The other states that they are the formation of mature collagen, reticular protein, and elastin, similar to connective tissue[15]. Histopathology is the gold standard for the diagnosis of tuberculosis [13]. Earlier studies divided pathological manifestations of wrist tuberculosis into three stages. Stage 1 is tissue hyperemia and edema, infiltration and exudation of inflammatory cells, accompanied by purulent secretion. Stage 2 is the synovial infarct shedding, fibrin wrapping, formation of rice granules [15]. During Stage 3, the patient develops synovial thickening with nodular granuloma. Tuberculosis of the wrist is often differentiated from suppurative infection, tenosynovitis, giant cell tumor of the tendon sheath, sarcoidosis, pigmented villonodular synovitis, gouty arthritis, and rheumatoid arthritis [7].
Early use of anti-tuberculosis drugs is key to successful treatment [19]. During the early stage, if the soft tissue and adjacent bones are not affected, the disease can be conservatively managed with drugs. If the conservative treatment proves ineffective, an operation must be considered. When the patient develops bone destruction, the infected tissues should be surgically thoroughly removed [20]. The operation procedures undertaken are based on the patient’s conditions. However, no matter what procedures, the general principle is to provide sufficient, combined chemotherapy, and complete focus removal, appropriate fixation after the operation, and strengthening of the physique. These are key to prevent the recurrence of joint tuberculosis. A combination of operation and chemotherapy can preferably alleviate the symptoms, and chemotherapy should be delivered preoperatively as it can reduce bone destruction and expansion of the infection [21]. In our study, five patients received antecedent surgical clearance of the focus of the wrist. However, they were not given anti-tuberculous postoperatively, a factor that likely contributed to the recurrence of wrist tuberculosis. Surgical debridement without prescription of chemotherapeutic agents may lead to the recurrence of wrist tuberculosis [7]. Chemotherapy should follow the basic principles of "early, regular, whole process, appropriate amount, and combination". For drug-sensitive tuberculosis with a definite diagnosis, the first choice of drug treatment scheme has been the same since the 1970s [22]. During operation, advisable not to excessively pursue small incision. Instead, it is essential to fully expose the focus, protecting the blood vessels and nerves of the wrist, and thoroughly remove the focus tissue, especially the caseous substance and rice bodies, including the necrotic carpal bone, tendon, tendon sheath, and the surrounding soft tissue, and to fully scrape the focus tissue with a curette until the normal bone surface and tissue ooze blood. In case of a severely erosion of the carpal bones, the wrist function of cannot be restored after removing the necrotic bone, joint fusion can be performed. Arthrodesis can be performed with steel plates or Kirschner wires. The steel plate should be used for internal fixation if there are more necrotic carpal bones and if the wrist joint is unstable after more carpal bones are removed. Compared to the Kirschner wire, the fixation is more reliable; however, the cost is higher. If there is less amount of wrist bone removal and if the Kirschner wire can be fixed firmly, the patient and their guardian should be consulted. Kirschner wire fixation may fix the wrist in a deformed position. Among the three cases of wrist fusion, 2 were fixed with a steel plate and the fixation position of wrist joint was good. One case was fixed with Kirschner wire and resulted in a slightly deformed wrist joint. Recently, it has been reported that patients with a tuberculosis-related bone defect can be implanted with a 3D-printed porous composite scaffold. Isoniazid and rifampicin can be modified and added to the implant. Through 3D printing, bone defects can be repaired and bone regeneration is promoted. The scaffold slowly releases antituberculosis drugs, allowing for a high drug concentration around the focus while keeping the systemic concentration below the safety limit [23]. Some studies have reported a vacuum suction drainage combined with external fixation for a safe, reliable, and effective treatment for severe wrist tuberculosis. This modality also effectively reduces the incidence of infection, promotes the functional reconstruction, shortens the wound healing time, and reduces the recurrence of tuberculosis [24].