Osteonecrosis (ON) is typically viewed as an isolated condition stemming from vascular compromise. We present a three-case series demonstrating that MRI, performed to confirm the diagnosis of ON, incidentally revealed features consistent with underlying, previously undiagnosed inflammatory arthritis (IA). Even in the absence of typical clinical features, the presence of imaging findings such as synovitis, tenosynovitis, and erosions should prompt a thorough clinical and serological evaluation for coexisting IA. An interesting point to note is that none of the three patients reported a history of steroid use. This manuscript aims to highlight a possible pathophysiological link between IA and ON.

Background/Objectives: Mueller-Weiss syndrome (MWS) is a rare condition characterized by spontaneous adult-onset osteonecrosis of the navicular bone. This study aimed to assess the diagnostic value of quantitative and semi-quantitative standardized uptake value (SUV) measurements on Tc-99m MDP SPECT/CT for differentiating MWS from other foot pathologies. Methods: We retrospectively reviewed 21 MWS patients who underwent SPECT/CT and compared them with 10 feet from 5 non-MWS patients as controls. MWS severity was staged using the Maceira classification. Volumes of interest (VOIs) were defined in the lateral navicular and distal tibia. SUVmax values were measured for the navicular bone (N), tibial metaphysis (Tm), and diaphysis (Td). Uptake ratios (N/Tm and N/Td) were calculated for semi-quantitative comparison. Results: MWS patients showed significantly higher SUVmax in the navicular compared with controls (9.2 vs. 1.5, p < 0.001). Both N/Tm and N/Td ratios were also significantly elevated (p < 0.001). SUVmax and uptake ratios positively correlated with Maceira stage and visual navicular uptake intensity. Diagnostic thresholds of N SUVmax > 3.77 (AUC = 0.93), N/Tm > 1.139 (AUC = 0.95), and N/Td > 0.93 (AUC = 0.93) effectively distinguished MWS from non-MWS cases. Conclusions: Quantitative and semi-quantitative SUV analysis on SPECT/CT offers a reliable tool for diagnosing MWS and evaluating disease severity. Semi-quantitative ratios, by normalizing metabolic variability, provide a practical and reproducible alternative to absolute SUV measurements for early detection and treatment planning in MWS.

Mueller-Weiss syndrome is a rare condition seen in adults due to spontaneous osteonecrosis of tarsal navicular bone unlike Koehler's disease which is quite common in paediatric population. We report a single case of Mueller-Weiss syndrome in an adult female. After a trail of conservative treatment, operative management was done with excision of necrotic fragment and arthrodesis of mid-foot joints augmented with tricortical iliac crest graft. Good fusion and significant reduction of pain on weight-bearing was observed after a duration of 6 weeks. Mueller-Weiss syndrome is relatively rare differential for mid-foot pain in adult population. Early recognition and management of the condition prevents arthritic changes and disability.

There are numerous causes of flatfoot, among them osteonecrosis of the navicular bone, a rare disease known as Mueller-Weiss syndrome, also leads to deformity. A 53-year-old male presented to our Outpatient Department with pain and swelling over bilateral foot for 3 years with increased severity in the left. Physical examination as well as footprint revealed a bilateral flat foot, and there was tenderness as well as swelling over the dorsomedial aspect of bilateral foot. After a detailed physical examination and radiological assessment, the case was diagnosed as Mueller-Weiss syndrome. He was treated with non-steroidal anti-inflammatory drugs, custom ankle-foot orthotic brace for 6 weeks, and activity modification and symptoms were relieved and he was able to do daily activities without any discomfort. MW syndrome is a rare condition, where conservative treatment provides better results if it is diagnosed and treated early, whereas late cases require surgical intervention.

Mueller-Weiss Syndrome (MWS), characterized by spontaneous adult-onset tarsal navicular osteonecrosis, is an uncommon cause of chronic midfoot pain that can lead to functional impairment and progressive deformities. This study aimed to present clinical and radiological outcomes of talonavicular-cuneiform (TNC) arthrodesis in the treatment of patients with MWS. A retrospective study was performed on 8 consecutive patients (6 female, 2 male; mean age = 50 years; range = 33-64) who underwent TNC arthrodesis using plate fixation with autologous bone grafting for the treatment of MWS. To evaluate clinical status, the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Midfoot Score was performed immediately preoperatively and at the final follow-up. In radiographic evaluation, talus-first metatarsal angle (Meary's angle) was measured preoperatively and at the final follow-up. Solid fusion was also examined on postoperative radiographs and computerised tomography. The mean follow-up was 35 months (range = 24-52). The mean AOFAS improved from 37 (range = 24-53) preoperatively to 85 (range = 80-93) at the final follow-up (p < 0.001). No major intra- operative complications were observed in any of the patients. According to the Maceira and Rochera radiological staging system, 5 feet was stage 3, and 3 feet was stage 4. The mean union time was 10 months (range = 5-15). Radiographic solid fusion was achieved in all but one foot that developed talonavicular non-union. TNC arthrodesis using plate fixation with autologous bone grafting seems to be an effective surgical method for reconstruction of MWS.