The human trapeziometacarpal (TMC) joint has a crucial evolutionary importance as it permits rotation and opposition of the thumb to the other fingers. In chronic TMC joint osteoarthritis (i.e., rhizarthrosis), this motor ability, essential for pinching, grasping, and manipulating objects, may become difficult or impossible due to intolerable pain. Here, we assess whether patients with rhizarthrosis show signs of abnormal brain representation of hand movements. To this end, we studied 35 patients with rhizarthrosis, affecting predominantly one of the two hands, and 35 healthy subjects who underwent both behavioural and fMRI measures of brain activity during overtly executed or imagined thumb-to-finger-opposition movements. The patients with rhizarthrosis were slower than controls both in motor execution and imagination. In the patients, correlation between the motor execution and imagination times was preserved, even though such correlation was less strong than in normal controls. The fMRI measures showed reduced activation in the hand primary motor and dorsal premotor cortex for the patients only during explicit movements. This was true for both hands, yet more so for the most affected hand. No significant differences were seen for the motor imagery task. These results show that an orthopaedic disorder that reduces patients' motoric repertoire in the absence of any neurological impairment is sufficient to induce neurofunctional changes in the cortical representation of hand movements. The substantial preservation of motor imagery with its neural counterparts distinguishes the neurological patterns of rhizarthrosis from those of complete immobilization or amputation suggesting that motor imagery may be used to boost motor recovery in rhizarthrosis after surgical treatment.

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Motor imagery (M.I.) training has been widely used to enhance motor behavior. To characterize the neural foundations of its rehabilitative effects in a pathological population we studied twenty-two patients with rhizarthrosis, a chronic degenerative articular disease in which thumb-to-fingers opposition becomes difficult due to increasing pain while the brain is typically intact. Before and after surgery, patients underwent behavioral tests to measure pain and motor performance and fMRI measurements of brain motor activity. After surgery, the affected hand was immobilized, and patients were enrolled in a M.I. training. The sample was split in those who had a high compliance with the program of scheduled exercises (T+, average compliance: 84%) and those with low compliance (T−, average compliance: 20%; cut-off point: 55%). We found that more intense M.I. training counteracts the adverse effects of immobilization reducing pain and expediting motor recovery. fMRI data from the post-surgery session showed that T+ patients had decreased brain activation in the premotor cortex and the supplementary motor area (SMA); meanwhile, for the same movements, the T− patients exhibited a reversed pattern. Furthermore, in the post-surgery fMRI session, pain intensity was correlated with activity in the ipsilateral precentral gyrus and, notably, in the insular cortex, a node of the pain matrix. These findings indicate that the motor simulations of M.I. have a facilitative effect on recovery by cortical plasticity mechanisms and optimization of motor control, thereby establishing the rationale for incorporating the systematic use of M.I. into standard rehabilitation for the management of post-immobilization syndromes characteristic of hand surgery.

A case is presented of an unusual complication of shoulder arthroscopy, which was caused by incorrect location of the posterior portal, inducing neurapraxia of both the axillary and radial nerves, with significant clinical and functional sequelae. A subsequent open surgical neurolysis was required to restore normal nerve function. This type of lesion has not been reported previously. Level of evidence V.

BackgroundSyphilis is a chronic infection that is classified into three stages. In its tertiary stage, syphilis spreads to the brain, heart and other organs; the lesions may involve the skin, mucous membranes and bones. Neuropathic arthropathy associated with tertiary syphilis has rarely been described in Europe and its association with HIV-HCV co-infection has not been reported so far.This article reports the case of a man with tertiary syphilis presenting with rapidly evolving neuropathic arthropathy of the hip and extensive bone destruction.Case presentationOn initial presentation, the patient complained of progressively worsening left-sided coxalgia without localized or generalized inflammation. The patient reported to have no history of previous infections, trauma or cancer. Plain x-ray films of the left coxofemoral joint showed marked degeneration with necrosis of the proximal epiphysis of femur and morphological alterations of the acetabulum without protrusion. Primary coxarthrosis was diagnosed and hip arthroplasty was offered, but the patient declined treatment. Three months later, the patient presented a marked deterioration of his general condition. He disclosed that he was seropositive for HCV and HIV, as confirmed by serology. Syphilis serology testing was also positive. A Girdlestone's procedure was performed and samples were collected for routine cultures for bacteria and acid fast bacilli, all resulting negative.Although histological findings were inconclusive, confirmed positive serology for syphilis associated with progressive arthropathy was strongly suggestive of tertiary syphilis, probably exacerbated by HIV-HCV co-infection. The patient partially recovered the ability to walk.ConclusionsDue to the resurgence of syphilis, this disease should be considered as a possible cause of neuropathic arthropathy when other infectious causes have been ruled out, particularly in patients with HIV and/or HCV co-infection.