Micronerves in Dupuytren and the Impact of Its Dissection on Recurrence

Dupuytren disease (DD) is a highly prevalent disabling hand disease. Spontaneous fibrosis nodules and strands in the palms of the hand cause finger contractures in disturbing positions and movement restricitions. Finger movement can be restored by surgery (removing the fibrosis tissue), but recurrence is a major problem (reports of \>70%) and this is difficult to treat.

Through microfasciectomy, the presence of small nerve bundles (micronerves) were observed in the finger (other than the digital nerves) through microsurgical enlargement. These nerves are possibly related to the hand fascia, which is the origin of DD. Palmaris fascia innervation was recently elucidated in 16 cadavers and recent research had demonstrated that the palmar aponeurosis is densely innervated and contains a variety of sensory corpuscles as wall as free nerve endings.

These micronerves and their dissection could play a role in the recurrence of DD. This thought is substantiated by the fact neuromas (formed by transection of nerves) were found in recurrence DD and nerve damage is generally known to cause fibrosis (as seen in chronic reactive pain syndrome). This study will investigate the role of these micronerves in DD, the impact of its dissection on formation of neuromas and on recurrence.

It's an observational study, investigation 2 groups of patients. Group 1 being patients with primary DD and group 2 patients with recurrence DD. The nerves and possible neuromas will be documented (presence, location, numbers and (unavoidable) micronerve transections) on a standard map and by digital photomicrography in both groups. The first aim is to confirm their presence and their proximity to the DD fibrosis tissue. Secondly, these allocations will be statistically correlated with clinical outcome and compared between the 2 groups. The ultimate goal of these mappings is to develop new surgical techniques that avoid cutting there nerves and/or cut them at preferable locations (away from recurrence, most likely more proximal at a distance to the proximal interphalangeal joints). Hereby an improved surgical technique (microfasciectomy) can possible reduce/avoid neuroma formation, pain and possibly recurrence.

Also, the presence of nerve growth factor (NGF) will be evaluated. The purpose is to provide information on potential neuro-induced fibrosis. NGF is a cell signalling cytokine that was demonstrated earlier to be associated with nerve tissue, neuromas and pain level. It is linked to the alpha-smooth actin expressing myofibroblast, 'activated' connective tissue cells with contractile properties producing collagen strands that cause the finger contractures. Therefore, the presence of NGF and myofibroblast cells crowd around NGF foci will be studied in a biopsy taken per-operatively. Focus will be on the direct environment of the neuromas. The presence of NGF will also be quantified and compared between both groups. It there is a higher amount of NGF in recurrence, there is a possible role for neuro-induced fibrosis and this creates opportunities to select this protein as a target of treatment to improve clinical outcome.

• Presence of micronerves [Срок оценки: During surgery/microfasciectomy]
• Correlate clinical outcome (motion, pain, recurrence) with these findings (micronerve dissection, presence of neuromas, NGF and αSMA) in both groups [Срок оценки: pre-operative, post-operative (10 days, 3 months, 12 months)]