Assessment of somatosensory rehabilitation for neuropathic and chronic pains after knee injury or surgery

Abstract

One of the complications after trauma or knee surgery is neuropathic pain associated with epicritic sensitive disorders, such as hypoesthesia, hyperesthesia or mechanical allodynia (MA). Different sensory rehabilitation techniques are proposed to relieve pain. After a first somatosensory and pain evaluation, we used vibro-tactile in situ or remote stimulation, respectively for hypoesthesia and allodynia, and desensitization for hyperesthesia or low MA. These techniques are essentially based on auto-exercises. The main objective is to evaluate the effect of this somatosensory rehabilitation protocol on neuropathic pain. In a retrospective study, we included patients admitted for neuropathic pain and sensitive disorders after surgery or knee injury treated by this somatosensory rehabilitation protocol between 2012 and 2016. For 47 patients, we evaluated, before and after rehabilitation pain and sensitive disorders. Pain was assessed with maximal numerical scale at rest (NSmax) and McGill questionnaire (MGQ). First, the sensitive disorder was qualified and mapped. Second, hypoesthesia was quantified through the pressure and vibration perception (respectively PPT, VPT), and allodynia through a rainbow color (RC) code using the monofilaments of Semmes-Weinstein. Thirty-three patients had hypoesthesia treated with tactile and or vibratory stimulation of the site. Twenty patients had MA: 14 of them treated with remote vibro-tactile rehabilitation, and 8 with desensitization in case of low MA, or both methods successively. Five patients had hyperesthesia, treated with desensitization. After rehabilitation, the MCQ decreased significantly of 29.9% ( P < 0.0001) and NSmax of 40.7% ( P = 0.002). We observed a significant improvement of the PPT (diminution of 69.3%, P < 0.0001) and RC (improvement of 84.7%, P = 0.03) between first and last evaluations. Fifteen patients did not achieve the protocol. In 32 patients who finished the protocol, the median duration of rehabilitation was 4 months (sd = 2.72). This protocol allows an improvement of sensitive disorders associated with pain decrease. Despite the duration of protocol (several successive methods, necessity of intermediate evaluations), adherence to this method, based on self-exercises, is good. Efficiency could be improved by identifying patients who are likely to cooperate with the method.