Anterior Congenital Radial Head Dislocation in an Adult with Associated Posterior Interosseous Nerve Palsy

Introduction: Anterior congenital radial head dislocation (CRHD) is a rare abnormality that is less commonly seen in the adult population. Most of the time, adult-onset symptoms are due to the prolonged dislocation of the radiocapitellar joint that has been present since birth. One of the possible complications of having a prolonged radial head dislocation is the presence of neuropathies such as posterior interosseous nerve (PIN) palsy. There has been, however, no literature published regarding the relationship of CRHD with PIN palsy. Case Report: We here report a 66-year-old male incidentally diagnosed with anterior CRHD with concomitant PIN palsy after acquiring a fracture of the lateral humeral condyle. Open reduction internal fixation of the lateral condyle was done along with decompression of the said nerve. PIN palsy was completely recovered 2 months after surgery. Conclusion: Surgeons must be aware that PIN palsies can occur in the presence of a chronic radial head dislocation, even if asymptomatic. Prompt nerve decompression as well as removal of the mechanical block is pertinent to avoid the perilous effects of an irreversible PIN palsy. Keywords: Congenital radial head dislocation, posterior interosseous nerve palsy, neurolysis, fracture.