Paget's disease of the lumbar spine: decompressive surgery following 17 years of bisphosphonate treatment.

Background: We present a rare case of Paget's disease (PD) with involvement of the lumbar spine over a period of 19 years. We discuss the diagnostic process to rule out alternative diagnoses and medical and surgical treatment strategies.
Case Description: A 58-year-old man first diagnosed with PD in 1998 with solid involvement of the 4th lumbar vertebra has been undergoing periodic examinations over a period of 18 years. Since then, the patient has been treated conservatively with bisphosphonates. When conservative treatment options have been exhausted, surgery was indicated due to a progressively reduced ability to walk. Surgery with undercutting decompression via laminotomy was performed. PD was confirmed by biopsy. Bisphosphonate treatment was continued pre- and postoperatively. Follow-up examinations showed an improvement in clinical outcome measures.
Conclusions: Conservative treatment remains the gold standard for PD with spinal involvement. This patient had been asymptomatic on bisphosphonate therapy for almost 17 years, but presented with new onset back pain. In such cases, fracture and rare conversion into sarcoma must be ruled out, and biopsy should be performed even in the absence of signs of malignancy. Currently, there are no clear treatment recommendations available in the literature regarding cases of PD with expansive growth and involvement of the spinal canal causing neurologic deficits. Furthermore, laminectomy has been shown to cause complications in up to 27% of cases with the risk of early postoperative death. In contrast, extended laminotomy and undercutting decompression should be considered.