The functional organization of adult cerebral cortex is characterized by the presence of highly ordered sensory and motor maps. Despite their archetypical organization, the maps maintain the capacity to rapidly reorganize, suggesting that the neural circuitry underlying cortical representations is inherently plastic. Here we show that the circuitry supporting motor maps is dependent upon continued protein synthesis. Injections of two different protein synthesis inhibitors into adult rat forelimb motor cortex caused an immediate and enduring loss of movement representations. The disappearance of the motor map was accompanied by a significant reduction in synapse number, synapse size, and cortical field potentials and caused skilled forelimb movement impairments. Further, motor skill training led to a reappearance of movement representations. We propose that the circuitry of adult motor cortex is perpetually labile and requires continued protein synthesis in order to maintain its functional organization.

Thumb carpometacarpal osteoarthritis (CMC OA) is a common disease, affecting up to 11% and 33% of men and women in their 50s and 60s, respectively, which leads to pain, laxity and weakness of the CMC joint. Based on the staging of the CMC OA, different forms of treatment can be used, including both conservative and surgical measures. Surgical options include osteotomy, trapezial excision, ligament reconstruction with or without tendon interposition, and various prosthetic interpositional implants with or without trapezial excision. The present article reviews the staging of CMC OA, the evaluation of hand function using patientreported questionnaires, and outcomes of both conservative and surgical treatments. The present review also introduces a commercially available interpositional spacer surgical technique for CMC OA and the early evidence that the literature has shown for improving hand function, strength and stability of the thumb CMC joint postoperatively.

Thumb carpometacarpal osteoarthritis (CMC OA) is a common disease, affecting up to 11% and 33% of men and women in their 50s and 60s, respectively, which leads to pain, laxity and weakness of the CMC joint. Based on the staging of the CMC OA, different forms of treatment can be used, including both conservative and surgical measures. Surgical options include osteotomy, trapezial excision, ligament reconstruction with or without tendon interposition, and various prosthetic interpositional implants with or without trapezial excision. The present article reviews the staging of CMC OA, the evaluation of hand function using patient-reported questionnaires, and outcomes of both conservative and surgical treatments. The present review also introduces a commercially available interpositional spacer surgical technique for CMC OA and the early evidence that the literature has shown for improving hand function, strength and stability of the thumb CMC joint postoperatively.

Therapeutic, I.