Radiological features and formation mechanisms of periosteal proliferation in osteogenesis imperfecta type V

This study investigates the radiological features and formation mechanisms of periosteal proliferation caused by disordered osteogenesis and mineralisation in osteogenesis imperfecta (OI) type V.

A total of 24 patients (mean age: 6.3 ± 5.2 years; 62.5% females) underwent X-ray and dual-energy X-ray absorptiometry, yielding 134 images of 180 long bones. Bones were categorised into fracture and nonfracture groups. Fracture patterns and the subsequent healing process during follow-up were assessed. Periosteal proliferation morphology (thin, lamellated, solid, thick, circular, butterfly, shell, spindle, and irregular), boundary (well defined or ill defined), distribution (focal or diffuse), thickness, bone enlargement, bone cortex, and soft-tissue mass were assessed. Relevant clinical and laboratory data on bone metabolism and inflammation were also recorded.

Fractures healed gradually through callus formation (median follow-up: 2 years). All periosteal proliferations showed intact cortex and no soft-tissue mass; the solid type accounted for 63.8%. Ill-defined proliferation thickness was 2.3 times greater than well-defined (10.7 [5.1, 46.4] and 4.6 [3.5, 7.7], respectively; P = 0.003). Diffuse proliferation more often accompanied bone enlargement than focal (36.7% vs. 7.8%, P = 0.001) and progressed more frequently (73.7% vs. 42.9%, P = 0.030). The patients with elevated C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) are more likely to exhibit diffuse periosteal proliferation than the normal inflammatory markers (66.7% vs 0%), although not statistically significant (P = 0.147).

OI type V shows delayed fracture healing or nonunion. Nonfracture cases present unique periosteal proliferation. Diffuse type correlates with bone enlargement and progression. Inflammatory markers' role needs further confirmation.