Periarticular Proprioception: Analyzing the Three-Dimensional Structure of Corpuscular Mechanosensors in the Dorsal Part of the Scapholunate Ligament.

INTRODUCTION: Sensory nerve endings transmit mechanical stimuli into afferent neural signals and form the basis of proprioception, giving rise to the self-perception of dynamic stability of joints. We aimed to analyze the three-dimensional structure of periarticular corpuscular sensory nerve endings in a carpal ligament to enhance our understanding of their microstructure. METHODS: Two dorsal parts of the scapholunate ligament were excised from two human cadaveric wrist specimens. Consecutive cryosections were stained with immunofluorescence markers protein S100B, neurotrophin receptor p75, protein gene product 9.5 (PGP 9.5), and 4',6-diamidino-2-phenylindole. Three-dimensional images of sensory nerve endings were obtained using confocal laser scanning microscopy, and subsequent analysis was performed using Imaris software. RESULTS: Ruffini endings were characterized by a PGP 9.5-positive central axon, with a median diameter of 4.63 µm and a median of 25 cells. The p75-positive capsule had a range in thickness of 0.94 µm and 15.5 µm, consisting of single to three layers of lamellar cells. Ruffini endings were significantly smaller in volume than Pacini corpuscles or Golgi-like endings. The latter contained a median of three intracorpuscular structures. Ruffini endings and Golgi-like endings presented a similar structural composition of their capsule and subscapular space. The central axon of Pacini corpuscles was surrounded by S100-positive cells forming the inner core which was significantly smaller than the outer core, which was immunoreactive for p75 and PGP 9.5. CONCLUSION: This study reports new data regarding the intricate outer and intracorpuscular three-dimensional morphology of periarticular sensory nerve endings, including the volume, number of cells, and structural composition. These results may form a basis to differ between normal and pathological morphological changes in periarticular sensory nerve endings in future studies.

[Acute and post-acute soft tissue reconstruction]. / Weichteilplastik in der Akut- und Postakutsituation.

BACKGROUND: The precise analysis of the injured structures requiring reconstruction in complex wound defects is a prerequisite for successful restoration. OBJECTIVE: The fundamental reconstructive strategies for soft tissue defects of the extremities including injuries to vessels, nerves and burn wounds in the context of the acute and post-acute trauma phases are presented. MATERIAL AND METHODS: The different phases of soft tissue reconstruction are described. Recommendations for action with respect to the reconstruction of the functional structures are described. Two clinical case examples illustrate the approach. RESULTS: The acute reconstruction phase is defined as the period 0-72 h after the traumatic event and includes surgical debridement, primary reconstruction of nerves and vessels using interpositional grafts if necessary and temporary soft tissue reconstruction. Combined thermomechanical trauma requires early debridement combined with internal fixation of open fractures. In the post-acute reconstruction phase, which is generally defined as a period of up to 6 weeks after the traumatic event, definitive soft tissue reconstruction is performed. In the case of long reinnervation distances, nerve transfer or motor replacement plastic surgery is performed in the post-acute phase. CONCLUSION: The reconstruction of soft tissue after trauma necessitates a stage-dependent approach. In the acute phase procedures aim at the immediate preservation of the limb. In the post-acute phase, definitive soft tissue reconstruction is performed to enable maximum functional preservation. Combined thermomechanical injuries require early surgical treatment in order to prevent infections.

Prospective analysis of glucose metabolism in patients with hand infection.

BACKGROUND: Type-2 diabetes influences the course and severity of hand infections. METHODS: We prospectively examined glucose metabolism in 90 patients with hand infection, distinguishing between normal, prediabetic and diabetic states. HbA1c-levels were evaluated prior to surgery. Patients with normal levels took an oral glucose tolerance test and those diagnosed with prediabetes were retested after the infection subsided. Hospital stay, number of surgical interventions and inflammatory markers were examined per group. RESULTS: Sixty-two patients (68.8%) had abnormal glucose metabolism: 17 (18.9%) with history of diabetes and 11 (12.2%) newly diagnosed. Prediabetes was observed in 34 patients (37.8%). At follow-up, prediabetes and diabetes were diagnosed in 7 cases each, and physiological glucose metabolism was observed in 3 patients. For the 11 patients unable to undergo a second oral glucose tolerance test, detailed phone calls confirmed absence of diabetes. C-reactive protein levels were significantly elevated in diabetic patients compared to those with normal glucose metabolism (p = 0.001) or prediabetes (p = 0.034). Patients with history of diabetes were significantly older than those with normal glucose tolerance (p = 0.001) or prediabetes (p = 0.017). There were no significant intergroup differences in thrombocyte count, length of hospital stay, interval from injury to admission or the number surgical interventions. CONCLUSION: Glucose metabolism should be assessed in patients with hand infections and reassessed after the infection has subsided in prediabetic cases.