Purpose: Bony exostosis has been identified in Dupuytren’s disease previously and there has been debate as to whether this process is due to spurs or heterotopic ossification, the formation of ectopic lamellar bone in soft tissues. Previous case series of bony spurs suggested that this was a response to tensile stresses, however more recent reports have identified ossification that was discontinuous with skeletal bone and included histological analysis suggesting that the pathological process is consistent with heterotopic ossification. Methodology: A case series of 3 patients, with severe and recurrent Dupuytren’s disease with bony exostosis. 2 patients exhibited more severe disease with positive features of Dupuytren’s diathesis, while the third case did not exhibit early onset of disease, a family history or ectopic fibromatosis. The bony spurs were resected and sent for histological analysis. Results: Intraoperatively, extraskeletal bony growth was identified growing in a spur like fashion from the shaft of the middle phalanx into the fibrous band. In the more severe cases, this extended further along the band with islands of ectopic bone within and affected the A3 pulley. Histological examination revealed mature lamellar bone with fibrocartilaginous metaplasia surrounded by palmarfibromatotic tissue as well as ectopic bone formation. Meanwhile the third case demonstrated normal bone with no atypical features. Conclusion: The findings of this series support previous reports of heterotopic ossification in severe Dupuytren's disease such as Dupuytren’s diathesis. Therefore, appropriate surgical planning and pre-operative X-rays should be considered in such cases and intraoperative access to bone nibblers when required.