Hongyi Zhu

Pre-operative predictive factors for the survival of replanted digits

PurposeThe primary objective of this study was to evaluate factors that influence the survival rate after digit replantation.MethodsA total of 291 digits of 200 patients who received digital replantation after complete amputation from 1 January 2014 to 31 December 2015 were included in this study. Univariate and multivariate analysis were performed to evaluate the correlation between potential risk factors and the failure rate. Age, gender, smoking status, Tamai level of amputation, causes of injury and ischemia time were recorded before replantation.ResultsAge, smoking, causes of injury and ischemia time were pre-operative predictors for survival. On the contrary, gender and Tamai level did not alter the survival rate significantly. We divided patients into four groups according their smoking status: none, mild (<10 cigarettes per day), moderate (10–20 cigarettes per day) and heavy (>20 cigarettes per day). Our data demonstrated that the risks of failure only increased in heavy group.ConclusionsMild and moderate cigarette consumption (<20 cigarettes per day) did not increase the risk for replant failure of digits. Heavy (>20 cigarettes per day) cigarette consumption, increased age (>45xa0years), non-cut injury and prolonged ischemia time (>12 hours) were risk factors for replant failure.

Nerve wrap after end-to-end and tension-free neurorrhaphy attenuates neuropathic pain: A prospective study based on cohorts of digit replantation

The repair of injured peripheral nerve is still challenging for surgeons. The end-to-end and tension-free neurorrhaphy is the current gold standard for reconstruction after complete nerve transection without significant defect. The main objective of this study neurorrhaphy in digit replantation affects the sensory recovery and neuropathic pain in replanted digit. Total 101 patients who received replantation of single completely amputated digit were included for analysis in this study. In group I (nu2009=u200949), the digital nerves were repaired with end-to-end and tension-free neurorrhaphy and then wrapped into a tendon-derived collagen nerve conduit. In group II (nu2009=u200952), the digital nerves were repaired with end-to-end and tension-free neurorrhaphy only. The static two-point discrimination (s2PD) was performed to evaluate sensory recovery. Visual analog scale (VAS) scores of pain at rest and with exertion were measured respectively. The s2PD tests at three and six months after surgery did not show any significant difference between the two groups. The VAS scores at rest and with exertion of group I were significantly reduced compared with those of group II at three and six months after surgery. Thus, we concluded that nerve wrap into a collagen conduit after end-to-end and tension-free neurorrhaphy could attenuate neuropathic pain after digit replantation but have no benefit for sensory recovery.

Locking Plate Alone versus in Combination with Two Crossed Kirschner Wires for Fifth Metacarpal Neck Fracture

Fracture of fifth metacarpal neck commonly requires open reduction and internal fixation. However, the current methods of internal fixation in fifth metacarpal neck fractures remain unsatisfactory. Patients with fractures of fifth metacarpal neck received open reduction and internal fixation with either locking plate in combination with two crossed Kirschner wires (K-wires) or locking plate alone were evaluated for the clinical outcomes. Clinical outcomes included grip strength, Michigan hand outcomes questionnaire (MHQ), final angulation and range of motion (ROM) one year after treatment. The averages of MHQ scores, final angulation and ROM of fifth metacarpophalangeal joint of plate with K-wire group were more superior to those of plate group (MHQ 96.7 versus 86.6, final angulation 11.8 versus 23.6, ROM 83.3 versus 72.2). The grip strength had no significant difference between two groups. Locking plate in combination with two crossed K-wires is a more optimal method of fixation compared with locking plate alone.

Brain remodeling after chronic median nerve compression in a rat model

Carpal tunnel syndrome is the most common compressive neuropathy, presenting with sensorimotor dysfunction. In carpal tunnel syndrome patients, irregular afferent signals on functional magnetic resonance imaging are associated with changes in neural plasticity during peripheral nerve injury. However, it is difficult to obtain multi-point neuroimaging data of the brain in the clinic. In the present study, a rat model of median nerve compression was established by median nerve ligation, i.e., carpal tunnel syndrome model. Sensory cortex remodeling was determined by functional magnetic resonance imaging between normal rats and carpal tunnel syndrome models at 2 weeks and 2 months after operation. Stimulation of bilateral paws by electricity for 30 seconds, alternating with 30 seconds of rest period (repeatedly 3 times), resulted in activation of the contralateral sensorimotor cortex in normal rats. When carpal tunnel syndrome rats received this stimulation, the contralateral cerebral hemisphere was markedly activated at 2 weeks after operation, including the primary motor cortex, cerebellum, and thalamus. Moreover, this activation was not visible at 2 months after operation. These findings suggest that significant remodeling of the cerebral cortex appears at 2 weeks and 2 months after median nerve compression.

Novel method for restoration of anorectal function following spinal cord injury via nerve transfer in rats

Objectives Nerve transfer has been developed to restore partial function after serious nerve injuries, for example, restoring bladder control after spinal cord injury (SCI). Our aim here was to establish a preclinical proof-of-concept model using nerve transfer for restoring anorectal function after SCI. Setting We used laminectomy to model SCI, and bilateral spinal ventral and dorsal nerve root anastomosis to re-establish connectivity to the anorectal musculature. Methods Multidisciplinary methods were used to assess the anatomical and functional integrity of the alternative spinal-to-anorectal nerve circuit. Adult rats were used to establish the model. Bilateral anterior and posterior L5 nerve roots were surgically matched with anterior and posterior of S1 nerve roots by microscopic anastomosis to establish an artificial rectal reflex arc with complete sensory and motor pathways. Twelve weeks later, we used retrograde nerve tracing and neurohistomorphological analysis to assess anatomical integrity of the new artificial rectal reflex arc. Anorectal manometry was used to assess the function of the new nerve circuit. Results Retrograde tracing with recombinant attenuated pseudo rabies virus indicated that the new neural pathway was successfully established to the anorectal musculature after experimental SCI. Toluidine blue-stained sections of the anastomosis site revealed normal-appearing nerve fiber morphology and regeneration, and transmission electron microscopy revealed myelinated axons. Anorectal manometry revealed significant anorectal functional recovery. Conclusion These results suggest that our model is a feasible first step in developing an alternative reflex pathway after laminectomy at L4 to S2 and shows promise for effective restoration of anorectal function.

Plate versus Kirschner wire fixation in treatment of fourth and fifth carpometacarpal fracture-dislocations: A retrospective cohort study

BACKGROUNDnFourth and fifth carpometacarpal fracture-dislocations with unsatisfactory closed reduction commonly require later open reduction and internal fixation. However, the optimal method of internal fixation for these is unknown. The purpose of this study was to determine through objective clinical measures which method is superior for fourth and fifth carpometacarpal fracture-dislocations: a K-wire or a plate.nnnMETHODSnWe conducted a retrospective review of hospital records of patients who had received treatment for fourth and fifth carpometacarpal fracture-dislocations at one hospital between May 2007 and May 2015. A total of 86 patients who had received open reduction either with plate or K-wire fixation were included. Demographic and clinical characteristics of the two groups of patients were collected. Patients received standardised clinical tests one year after fixation. Clinical outcomes included tests of grip strength and scores on the Michigan Hand Outcomes Questionnaire and Disabilities of Arm, Shoulder, and Hand. Students t tests and Chi-square tests were used to statistically evaluate whether plate or K-wire fixation was superior on the clinical variables.nnnRESULTSnThe two groups were statistically indistinguishable on their demographic and clinical characteristics. Generally, the clinical outcomes of internal fixation were satisfactory. The average DASH and MHQ scores of the K-wire group were superior to those of the plate group (DASH 2.3 versus 9.8, Pu202f=u202f0.01; MHQ 96.7 versus 86.6, Pu202f=u202f0.02). Grip strength was not significantly different between the two groups (89.5u202f±u202f5.8% versus 90.1u202f±u202f4.9%, Pu202f=u202f0.36).nnnCONCLUSIONSnThis non-randomly controlled, retrospective study suggests that clinical outcomes after K-wire fixation is superior to plate fixation for fourth and fifth carpometacarpal fracture-dislocations. This is especially the case for hand functions related to work. The present results suggest that K-wire fixation is the gold-standard technique for the treatment of fourth and fifth CMC fracture-dislocations.

Is NS-EDTA Effective in Clearing Bacteria From Infected Wounds in a Rat Model?

Background Irrigation is one of the key procedures in open fracture management to eliminate pathogens and prevent infection. Metal ion deprivation could inhibit bacterial adhesins and weaken adhesion to the host tissue. EDTA in solution can competitively bind to a metal ion and thus might be able to inhibit bacterial adhesins. Questions/purposes (1) Is normal saline-EDTA toxic to fibroblasts and endothelial cells? (2) In a contaminated wound rat model, does irrigation with normal saline-EDTA solution decrease the risk of positive bacterial cultures and infection when compared with normal saline and soap solutions? (3) In an infected wound rat model, are fewer surgical débridements and irrigations with normal saline-EDTA solution required to obtain culture-free wounds when compared with normal saline and soap controls? Methods Normal saline-EDTA solution refers to 1 mmol/L EDTA dissolved in normal saline (pH adjusted to 7.4). Normal saline and soap solutions acted as controls. The toxicity of these solutions to fibroblasts and endothelial cells was assessed in vitro by Annexin V/propidium iodide staining and flow cytometer counting (a well-established method to quantitatively measure the number of dead cells). We established contaminated and infected wound models (bone-exposed or not) with either Staphylococcus aureus or Escherichia coli in rats to investigate the efficacy of normal saline-EDTA solution (n = 30 for the contaminated model and n = 50 for the infected model). For contaminated wounds, the proportion of positive bacterial cultures and infections was compared after irrigation and débridement among the three groups. For infected wounds, we performed irrigation and débridement every 48 hours until the cultures were negative and compared the number of débridements required to achieve a negative culture with survival analysis. Results Normal saline-EDTA showed no additional toxicity to fibroblasts and endothelial cells when compared with normal saline (normal saline [97%] versus EDTA [98%] on fibroblasts, p = 0.654; normal saline [97%] versus EDTA [98%] on endothelial cells, p = 0.711). When bone was exposed in the contaminated models, EDTA irrigation resulted in fewer positive bacterial cultures with S aureus (EDTA: 23%, normal saline: 67%, soap: 40%, p = 0.003) and with E coli (EDTA: 27%, normal saline: 57%, soap: 30%, p = 0.032); however, infection risk was only lower with EDTA irrigation (S aureus with EDTA: 10%, normal saline: 33%, soap: 37%, p = 0.039; E coli with EDTA: 3%, normal saline: 27%, soap: 23%, p = 0.038). In the infected wound model, EDTA irrigation resulted in earlier culture-negative wounds (fewer surgical sessions) compared with normal saline and soap solutions (nonbone-exposed wounds infected by S aureus: p = 0.003, infected by E coli: p = 0.001; bone-exposed wounds infected by S aureus: p = 0.012, infected by E coli: p = 0.022). Conclusions After in vitro assessment of toxicity and in vivo evaluation of efficacy, we concluded that normal saline-EDTA is superior to normal saline and soap solution in our laboratory models. Clinical Relevance The use of normal-saline EDTA as an irrigation solution may reduce the infection rate of wounds. Future studies in large animals and humans might prove our observation in rat models that normal saline-EDTA has an advantage over normal saline as an irrigation solution.

Glucocorticoid-activated IRE1α/XBP-1s Signaling: An Autophagy-Associated Protective Pathway Against Endotheliocyte Damage

Glucocorticoid-induced endothelial injury has been reported in several diseases. Although there are several theories, the exact mechanism underlying the role of glucocorticoids in this process remains unclear. Autophagy has been reported to occur as a response to different stimuli and can affect cell survival and function. In this study, we found that glucocorticoids induced apoptosis and endoplasmic reticulum (ER) stress in endotheliocytes. Furthermore, we discovered that glucocorticoids induced autophagy in these cells and the inositol requiring protein 1 (IRE1α)/X-box binding protein 1s (XBP-1s) axis, one of the downstream signaling pathways of ER stress, was associated with the glucocorticoid-induced autophagy. The autophagy partly protected endotheliocytes from glucocorticoid-induced apoptosis and inhibition of proliferation. In conclusion, glucocorticoid-induced endoplasmic reticulum stress activated the IRE1α/XBP-1s signaling and induced autophagy, which, in turn, played a protective role in endotheliocyte survival and proliferation, avoiding further cellular damage caused by glucocorticoids.

Risk Factors of Acute Hand Injuries in Manual Workers: A Case-control study

The purpose of this study was to identify the risk factors of hand injuries in manual workers. Total 1672 manual workers with acute hand injuries who visited our emergency department accompanied by their colleagues from 1 March 2014 to 1 March 2017 were included in this study. One accompanied colleague with identical work task was chosen randomly as control for each patient. The personal characteristics including gender, age, work experience, acute hand injury history, smoking and alcohol consumption were recorded and compared. Finally, we found the history of severe and multiple times of acute hand injuries, high and very high daily alcohol consumption, working experience from one to two years were risk factors for acute hand injuries in manual workers.

Timing for Surgical Stabilization with K-wires after Open Fractures of Proximal and Middle Phalangeal Shaft

The optimal timing for surgical stabilization after open fractures of proximal and middle phalangeal shaft remained unclear. Total 147 patients with single open fracture in proximal or middle phalangeal shaft (arrived within 8u2009hours) who received K-wire fixation from June 2012 to June 2015 were included for analysis. The timing for surgical stabilization of fractures (immediate or delayed) was decided according to the surgeons’ preferences. The Michigan hand outcomes questionnaire (MHQ) scores, grip strength and total active motion (TAM) one year after the initial surgery were similar between the two groups. There was no significant difference in the incidence of tenosynovitis, bone nonunion. The overall infection rate in immediate fixation group was slightly but not significantly higher compared with the delayed fixation group (29.2% versus 20.7% Pu2009=u20090.212). However, patients with both palmar and dorsal wounds who received immediate fixation had much higher infection rate compared with delayed fixation (52.6% versus 22.7%, Pu2009=u20090.047). The immediate fixation could reduce costs and the period of hospitalization. Open fractures with both palmar and dorsal wounds should be treated with delayed fixation of K-wires otherwise stabilized immediately after injury.