Flexible dropped head deformity following laminectomy for cervical spondylotic myelopathy: a case series and review of literature

Background Context Flexible dropped head deformity (FDHD) following laminectomy for cervical spondylotic myelopathy (CSM) is a debilitating entity. Patients need to support their head manually to look forward in standing or sitting position. Flexible dropped head deformity is different from rigid dropped head deformity in patients with post-laminectomy kyphosis or ankylosing spondylitis and has only once been described after surgery to the cervical spine. Purpose This case report aimed to report a rare, but severe complication of cervical posterior decompressive surgery, to describe its possible etiology, and to review the literature on the management of FDHD in order to provide recommendations for its treatment. Study Design This is a retrospective clinical case series. Patient Sample This sample comprises four patients with FDHD. Methods We retrospectively reviewed the charts with clinical follow-up data of all patients who underwent posteriorly directed spinal interventions and concomitantly developed FDHD and were admitted between January 1998 and September 2015. Results Cervical decompressive laminectomy is regularly performed in our institution. Four patients with FDHD were identified (3 men and 1 woman). The overall prevalence was less than 1% (=4 of 460 total estimated CSM surgeries). Flexible dropped head deformity developed within weeks or months after surgery. One patient was treated conservatively, whereas the other three received surgery to reconstruct stability of the cervical spine. Two of the surgically corrected patients eventually required revision surgery as a result of failure of the hardware and because of skin erosion. Conclusions Flexible dropped head deformity is a rare, but serious complication of posterior decompressive surgery. Its etiology appears multifactorial. Its management needs to be directed toward early surgical intervention.