Defining the imaging diagnostic criteria for adult chronic non-bacterial osteitis.

Osteitis of the sternocostoclavicular (SCC) region, referred to as sternocostoclavicular hyperostosis (SCCH), is the clinical expression of chronic non-bacterial osteitis (CNO) in adults with this rare chronic auto-inflammatory disorder of the axial skeleton. The diagnosis is based on distinctive computerized tomography (CT) features of sclerosis and hyperostosis of the SCC region, and local increases in osteoid formation visualized by high radiopharmacon uptake on skeletal scintigraphy but clear radiologic diagnostic criteria are lacking. In a cross-sectional study, CT scans and whole-body skeletal scintigraphy images obtained in 169 patients seen at the Center for Bone Quality of the Leiden University Medical Center between 2008 and 2018 with a suspected diagnosis of CNO of the SCC region were re-evaluated by 2 skeletal radiologists and 2 nuclear physicians. The diagnosis was confirmed in 118 (70%) predominantly female patients (n = 103, 89.2%); median age at first symptoms 45 years (range 20-73). The diagnosis was excluded in the remaining 51 "non-CNO" patients. Increased radiopharmacon uptake at the SCC region was observed in 82% CNO patients, with the manubrium sterni having the highest predictive ability to discriminate on both imaging modalities. The prevalence of sclerosis of the clavicles, manubrium and first ribs was significantly higher in CNO patients (P < 0.001). Hyperostosis was not observed in non-CNO patients. 46 CNO versus only 2 non-CNO patients had costoclavicular ligament calcification. Our findings identify CT scan features of sclerosis and hyperostosis of manubrium sterni, medial end of clavicles and first ribs, and calcification of costoclavicular ligaments, associated with increased tracer uptake on skeletal scintigraphy at the SCC region, specifically manubrium sterni, as well-defined imaging diagnostic criteria for adult CNO. Pitfalls encountered in the diagnosis of CNO are highlighted. These defined imaging diagnostic criteria for adult CNO should facilitate the diagnosis of this rare auto-inflammatory bone disease across the spectrum of its early to late stages.

Determinants of Quality of Life in Adult Patients with Chronic Non-Bacterial Osteomyelitis (CNO) of the Sternocostoclavicular Region (SCCH): A Dutch Single Center Study.

Sternocostoclavicular hyperostosis (SCCH), the main clinical manifestation of chronic non-bacterial osteomyelitis (CNO) in adults, is associated with various degrees of chronic pain and restricted shoulder girdle function. We evaluated the impact of CNO/SCCH on quality of life (QoL) and its determinants in 136 adult patients with this rare auto-inflammatory bone disorder using the Short Form 36, Brief Pain Inventory, Brief Illness Perception, Utrecht Coping List, and Shoulder Rating questionnaires. Data were compared with those of the general Dutch population, patients with chronic pain, fibrous dysplasia, or osteoarthritis. Eighty-six (64%) predominantly female (85%) patients with completed questionnaires were included in the study. Sixty-four (75%) had isolated CNO/SCCH. Mean delay in diagnosis was 3.0 ± 5.5 (SD) years, 90% had variable pain, and 84% limited shoulder function. Compared to healthy and chronically diseased reference populations, CNO/SCCH patients demonstrated significant impairments in almost all aspects of QoL, maladaptive illness perceptions, and ineffective coping strategies. For patients with >5-year delay in diagnosis, higher pain scores and limited shoulder function were identified as determinants for impaired QoL. Patients with CNO/SCCH reported significant impairments in QoL associated with clinical and psychological determinants. Clinical measures such as shortening delay in diagnosis, effective pain management, and psychosocial interventions targeting these factors should help minimize the negative impact of CNO/SCCH on QoL.

Sternocostoclavicular Hyperostosis: Positive Clinical and Radiological Response on Pamidronate.

Background: Sternocostoclavicular hyperostosis (SCCH) is a rare disease, constituting a chronic sterile osteomyelitis with elevated bone turnover in the axial skeleton, causing pain and shoulder dysfunction. SCCH severely interferes with daily activities, work, and quality of life. SCCH has a relapse-remitting disease course, but inflammatory-induced sclerotic transformation in the affected area is slowly progressive. Here we present two patients with clinical and radiological diagnosis of SCCH treated with intravenous pamidronate, leading to clinical remission in both, but complete resolution of sclerosis in one of them, which is a novel finding in our experience. Case Presentation: Two adult female SCCH-patients presented with longstanding pain, swelling of the anterior chest wall, and compromised shoulder function. Subsequent single photon emission computed tomography-computed tomography (SPECT/CT) illustrated elevated bone activity and sclerosis in the SC region, with hyperostosis, confirming the diagnosis of SCCH. As symptoms in both patients were eventually refractory to standard painkillers such as non-steroidal anti-inflammatory drugs (NSAIDs), intravenous pamidronate treatment in 3-month cycles was started. Pamidronate was effective in reducing pain and improving shoulder function and also led to decreased bone turnover on skeletal scintigraphy. Sclerosis in the first patient persisted. In the second patient, however, a complete resolution of sclerosis was observed. Conclusions: SCCH remains a rare bone disorder for which no evidence-based therapies are yet available. While disease burden is high, SCCH lacks recognition and is often diagnosed long after symptomatic presentation. As for the cases in this report, pamidronate was successful in reducing symptoms, and in the second case even led to regression of sclerotic changes on CT-imaging.