Osteopetrosis - A Case Series Exploring Complications and Multidisciplinary Management

Abstract Background: Osteopetrosis is a group of rare inherited skeletal dysplasias, with each variant sharing the hallmark of increased bone mineral density (BMD). Abnormal osteoclast activity produces overly dense bone predisposing to fracture and skeletal deformities. Whilst no cure for these disorders exists, endocrinologists play an important role in surveillance and management of complications. Clinical Cases: A 43-year-old female had findings suggestive of increased BMD on radiographic imaging performed to investigate shoulder and back pain. X-ray of lumbar spine demonstrated a ‘rugger jersey’ spine appearance, while shoulder X-ray revealed mixed lucency and sclerosis of the humeral head. DXA scan showed T-scores of +11 at the hip and +12.5 at the lumbar spine. MRI of head displayed bilateral narrowing and elongation of the internal acoustic meatus and narrowing of the orbital foramina. Genetic assessment confirmed autosomal dominant osteopetrosis with a CLCN7 variant. Oral colecalciferol supplementation was commenced and multi-disciplinary management instigated with referral to ophthalmology and ENT teams. A 25-year-old male presented with a seven-year history of low back pain and prominent bony swelling around the tibial tuberosities and nape of neck. Past medical history included repeated left scaphoid fracture in 2008 and 2018. Recovery from his scaphoid fracture was complicated by non-union requiring bone grafting with open reduction and fixation. Plain X-rays of the spine again demonstrated ‘rugger jersey’ spine. DXA scan was notable for elevated T scores; +2.9 at hip and +5.8 lumbar spine. MRI spine showed vertebral endplate cortical thickening and sclerosis at multiple levels. The patient declined genetic testing and is under clinical review. A 62-year-old male was referred to the bone metabolism service following a DXA scan showing T scores of +11. 7 at the hip and +13 at the lumbar spine. His primary complaint was of neck pain and on MRI there was multi-level nerve root impingement secondary to facet joint hypertrophy. Past medical history was significant for a long history of widespread joint pains; previous X-ray reports described generalized bony sclerosis up to 11 years previously. Clinical and radiological monitoring continues. Conclusion: Individuals with osteopetrosis require a multidisciplinary approach to management. There is no curative treatment and mainstay of therapy is supportive with active surveillance for complications.