Radiographic distribution and clinical determinants of hand bone cysts in hemodialysis-related carpal tunnel syndrome

The aim of this study was to investigate the radiographic characteristics and distribution of bone cysts in the hands of patients with dialysis-related amyloidosis (DRA) undergoing surgery for carpal tunnel syndrome (CTS) and to identify factors associated with cyst formation using hand radiography.

We analyzed preoperative hand radiographs of 50 hands (mean age: 70 years) from hemodialysis patients and a 1:2 age- and sex-matched control group (100 hands). Bone cysts (≥ 2 mm) with sclerotic margins were evaluated across 15 sites per hand (radius, ulna, 8 carpal bones, and 5 metacarpals). Multivariate linear regression analysis incorporating clinical, biochemical, and localized parameters was performed to identify factors affecting the number of cysts in dialysis patients. Additionally, the presence of bone cysts in bones associated with osteoarthritis (OA) was assessed.

The prevalence of bone cysts was significantly higher in the hemodialysis group than in the controls (94% vs. 74%), with a higher mean number of involved bones (5.2 vs. 2.9). The total area of bone cysts in the hemodialysis group (84.7mm²) was significantly larger than that in the controls (39.5mm²). Cysts were most frequent in the scaphoid and lunate (60%). Multivariate analysis identified only dialysis vintage and OA as independent factors associated with cyst number. Dialysis vintage showed a strong positive correlation with cyst count (r = 0.69). OA was significantly more frequent in the hemodialysis group (44% vs. 25%). Among 64 OA joints, 89.1% exhibited concomitant bone cysts, most commonly at the thumb carpometacarpal joint.

Bone cysts were nearly ubiquitous in hemodialysis-related CTS patients, particularly in the scaphoid and lunate. The strong correlation between dialysis vintage and cyst count, along with a significantly larger total cyst area and a high association with OA, suggests that plain radiography remains a valuable and accessible clinical tool for assessing the cumulative burden of amyloidosis and joint degeneration.