Clinical Study Recovery of ankle dorsiflexion weakness following lumbar decompressive surgery Ali Ghahreman a, * , Richard D. Ferch a , Preshanth Rao b , Nadana Chandran b , Bruce Shadbolt c a Department of Neurosurgery, John Hunter Hospital and University of Newcastle, New Lambton, New South Wales 2305, Australia b Department of Neurosurgery, The Canberra Hospital, Woden, Australian Capital Territory, Australia c Department of Epidemiology and Community Health, The Canberra Hospital, Woden, Australian Capital Territory, Australia article info Article history: Received 1 July 2008 Accepted 31 October 2008 Keywords: Ankle dorsiflexion weakness Foot drop Lumbar decompressive surgery Recovery abstract This retrospective study evaluated the recovery of ankle dorsiflexion (ADF) weakness following decom- pressive surgery in order to identify factors indicative of a better outcome. Fifty-six consecutive patients with ADF weakness secondary to nerve root compression underwent lumbar decompressive surgery. The demographic features, duration and severity of preoperative ADF weakness, associated radicular pain, as well as the radiological and intraoperative findings were recorded. ADF weakness at the time of initial follow-up at 6 weeks following surgery, and the latest follow-up at a median of 24 months was recorded. The patients had a mean age of 50.5 years with equal numbers of men and women. Acute disc prolapse was the compressive pathology in 88%. Clinical foot drop, defined as an ADF power of <3 by manual testing according to the Medical Research Council classification, was present in 66% of patients on presentation. Grade 3 power was present in 27% of patients and 7% had grade 4 power on presentation. The mean ADF power on presentation was 1.8. This improved to a mean of 3.2 at 6 weeks following surgery (p < 0.0001). A further small improvement in ADF power occurred after 6 weeks following surgery to a power of 3.5 at the latest follow-up (p < 0.0001). The degree of ADF weakness at latest follow-up correlates with the deficit at presentation (p < 0.001). Younger patients made a better recovery (p = 0.03). No other significant associations between the demographic or clinical features and the recovery of the weakness could be identified. Thus, decompressive surgery was associ- ated with an early improvement in ADF weakness. Only small improvements take place beyond 6 weeks following surgery. The degree of deficit at presentation is predictive of the extent of r ecovery. Recovery in ADF strength is more evident in younger patients. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Weakness of ankle dorsiflexion (ADF), which in its more severe form is known as foot-drop, is a disabling manifestation of neural compression due to disc prolapse or other degenerative compres- sive factors. Foot-drop is associated with considerable difficulty in ambulation and an orthosis may be needed to assist with the gait problem associated with this deficit. Associated radicular or neuropathic pain and numbness can exacerbate the discomfort and disability associated with ADF weakness and further deduct from the quality of life. Numerous case reports describe foot-drop in association with unusual aetiology, 1–18 and the outcomes of operative management or rehabilitation for this disabling deficit have been described. 19–22 Some publications describe the natural history and patterns of neural compression in patients with ADF weakness due to lumbar compressive pathology and only a few articles specifically evaluate the recovery of ADF weakness after decompressive surgical inter- vention. 23–27 In the current study we aimed to assess the rate and extent of the recovery of ADF weakness after surgical decom- pression. We reviewed demographic and clinical factors to identify those factors that predicted a better outcome. 2. Patients and methods A retrospective review was undertaken of 56 consecutive pa- tients with ADF weakness who underwent surgical decompression for lumbar degenerative pathology, between January 2001 to July 2007, at two public teaching hospitals in Australia. The clinical re- cords, radiological reports and operative notes were reviewed. Pa- tients were included if they had weakness or paralysis of ADF that was believed to result from acute or chronic lumbar degenerative pathology for which surgical decompression had been undertaken. Patients with cauda equina syndrome were not included. Fifty-two patients completed follow-up requirements. 0967-5868/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2008.10.017 * Corresponding author. Present address: 5 Aldor Green, Conder ACT 2906, Australia. Tel./fax: +61 2 62949324. E-mail address: aghahreman@bigpond.com (A. Ghahreman). Journal of Clinical Neuroscience 16 (2009) 1024–1027 Contents lists available at ScienceDirect Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn