The Journal of Hand Surgery (European Volume) 2015, Vol. 40E(7) 682–694 © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1753193414553162 jhs.sagepub.com JHS(E) Introduction Outcomes in Zone II flexor tendon repair are not always satisfactory and potentially can be improved (Elliot and Harris, 2003). The adoption of multi-strand repairs (Savage and Risitano, 1989; Wu and Tang, 2014) and modification of rehabilitation regimens have yet to achieve dramatic improvements in outcomes. Another approach for better results is to prevent adhesion for- mation between the newly repaired tendon and the tendon sheath. Anti-adhesion therapies have gener- ally not progressed beyond preclinical studies, despite the development of innovative applications. These include anti-inflammatory agents such as steroids and non-steroidal anti-inflammatory drugs (Ketchum, 1971; Kulick et al., 1984); natural polymers such as hyaluronic acid (Amiel et al., 1989), collagen solution (Nyska et al., 1987), amniotic fluid (Ozgenel et al., 2001); anti-metabolites such as 5-fluorouracil (Akali et al., 1999; Karaaltin et al., 2013) and barrier methods such as Teflon™ (Bartle et al., 1992). The chief investi- gator (VCL) in the present study had previously reported on the use of ADCON ® T/N (purified porcine gelatine, AAP bio implants, Nijmegan, Netherlands) in tendon adhesions, with failure to show benefit in a A multicentre, randomized, double- blind trial of the safety and efficacy of mannose-6-phosphate in patients having Zone II flexor tendon repairs V. C. Lees 1 , D. Warwick 2 , P. Gillespie 3 , A. Brown 4 , M. Akhavani 5 , D. Dewer 5 , D. Boyce 6 , S. Papanastasiou 7 , R. Ragoowansi 8 and J. Wong 1 Abstract The safety, tolerability and preliminary efficacy of mannose 6-phosphate in enhancing the outcome in Zone II flexor tendon repair was studied in a multicentre parallel double-blinded randomized controlled trial. Eight UK teaching hospitals were involved in treating repaired flexor tendons with a single intraoperative intrathecal dose of 600 mM mannose 6-phosphate, with follow-up over 26 weeks. A total of 39 patients (mannose 6-phosphate, n = 20; standard care, n = 19) were randomized. Seven were excluded from the safety and tolerability analysis because of intraoperative findings and eight were excluded due to early dropout (n = 4) or tendon rupture (n = 4), leaving 24 (mannose 6-phosphate, n = 13; standard care, n = 11) for assessment of total active motion. The safety, tolerability and other side effects were comparable between the groups. There was no significant difference between the two groups in the total active motion at Week 26. We concluded that mannose 6-phosphate, although safe and tolerable, had no beneficial effect on finger range of motion after Zone II tendon division. Level of evidence 1b Keywords Mannose 6-phosphate, flexor tendon repair, adhesions, Phase I/II clinical trial) Date received: 20th April 2013; revised: 3rd August 2014; accepted: 4th August 2014 1 University Hospital South Manchester, Manchester, UK 2 Southampton General Hospital, Southampton, UK 3 Addenbrookes Hospital, Cambridge, UK 4 Ulster Hospital, Belfast, UK 5 Royal Free Hospital, London, UK 6 Morriston Hospital, Swansea, UK 7 Lister Hospital, Stevenage, UK 8 Royal London Hospital, London, UK Corresponding author: J. Wong, University Hospital South Manchester, Manchester, M13 9PT, UK. Email: jason.k.wong@manchester.ac.uk 553162JHS 0 0 10.1177/1753193414553162Journal of Hand SurgeryLees et al. research-article 2014 Full Length Article