Somatosensory and motor representations following bilateral transplants of the hands: A 6-year longitudinal case report on the first pediatric bilateral hand transplant patient.

A vascularized composite tissue allotransplantation (VCA) was performed at the Children's Hospital of Philadelphia (CHOP), on an 8-year-old patient in 2015, six years after bilateral hand and foot amputation. Hand VCA resulted in reafferentation of the medial, ulnar, and radial nerves serving hand somatosensation and motor function. We used magnetoencephalography (MEG) to assess somatosensory cortical plasticity following the post-transplantation recovery of the peripheral sensory nerves of the hands. Our 2-year postoperative MEG showed that somatosensory lip representations, initially observed at "hand areas", reverted to canonical, orthotopic lip locations with recovery of post-transplant hand function. Here, we continue the assessment of motor and somatosensory responses up to 6-years post-transplant. Magnetoencephalographic somatosensory responses were recorded eight times over a six-year period following hand transplantation, using a 275-channel MEG system. Somatosensory tactile stimuli were presented to the right lower lip (all 8 visits) as well as right and left index fingers (visits 3-8) and fifth digits (visits 4-8). In addition, left and right-hand motor responses were also recorded for left index finger and right thumb (visit 8 only).During the acute recovery phase (visits 3 and 4), somatosensory responses of the digits were observed to be significantly larger and more phasic (i.e., smoother) than controls. Subsequent measures showed that digit responses maintain this atypical response profile (evoked-response magnitudes typically exceed 1 picoTesla). Orthotopic somatosensory localization of the lip, D2, and D5 was preserved. Motor beta-band desynchrony was age-typical in localization and response magnitude; however, the motor gamma-band response was significantly larger than that observed in a reference population.These novel findings show that the restoration of somatosensory input of the hands resulted in persistent and atypically large cortical responses to digit stimulation, which remain atypically large at 6 years post-transplant; there is no known perceptual correlate, and no reports of phantom pain. Normal somatosensory organization of the lip, D2, and D5 representation remain stable following post-recovery reorganization of the lip's somatosensory response.

Upper and lower extremity reconstructive applications utilizing free flaps from the medial genicular arterial system: A systematic review.

BACKGROUND: Free flaps derived from the medial genicular artery (MGA) system, including the medial femoral condyle (MFC) and medial femoral trochlear (MFT) flaps, are potential reconstructive options to address upper and lower extremity bony pathology. Our primary aim was to comprehensively search the literature to describe the spectrum of pathology treated with these flaps, and to assess patient outcomes to improve our understanding of expected union and complication rates. METHODS: Following PRISMA guidelines, a systematic review using Pubmed and Embase databases with citation cross-referencing was performed to identify all original clinical articles characterizing MGA flap treatment of upper and lower extremity pathology. RESULTS: The initial search identified 173 articles which was narrowed down to 40 meeting inclusion criteria, representing a total of 248 cases: 174 and 74 in the upper and lower extremities, respectively. Sixteen distinct recipient sites were identified with union rates ranging from 66 to 100% (98.7% overall). The majority (83.9%) of patients had undergone prior failed surgery. Major complications (those with limb/flap loss or requiring unplanned reoperation) were more frequent for lower versus upper extremity applications (17.1% vs. 6.2%, respectively). Donor site femoral fracture or persistent knee dysfunction occurred in 0.8% and 0.4% of patients, respectively. CONCLUSIONS: MGA free flaps are a versatile option for upper and lower extremity osseous reconstruction, offering high rates of union with minimal complications for a complex patient population. This study furthers our understanding of patient outcomes following MGA flap reconstruction, which previously was limited to case reports and small case series.

Osteoblasts express the inflammatory cytokine interleukin-6 in a murine model of Staphylococcus aureus osteomyelitis and infected human bone tissue.

Staphylococcus aureus is the single most common cause of osteomyelitis in humans. Incidences of osteomyelitis caused by S. aureus have increased dramatically in recent years, in part due to the appearance of community-acquired antibiotic resistant strains. Therefore, understanding the pathogenesis of this organism has become imperative. Recently, we have described the surprising ability of bone-forming osteoblasts to secrete a number of important immune mediators when exposed to S. aureus in vitro. In the present study, we provide the first evidence for the in vivo production of such molecules by osteoblasts during bacterial infection of bone. These studies demonstrate the expression of the key inflammatory cytokine interleukin-6 by osteoblasts in organ cultures of neonatal mouse calvaria, and in vivo using a mouse model that closely resembles the pathology of trauma-induced staphylococcal osteomyelitis, as determined by confocal microscopic analysis. Importantly, we have established the clinical relevancy of these findings in infected human bone tissue from patients with S. aureus-associated osteomyelitis. As such, these studies demonstrate that bacterial challenge of osteoblasts during bone diseases, such as osteomyelitis, induces cells to produce inflammatory molecules that can direct appropriate host responses or contribute to progressive inflammatory damage.