Anesthesia for the Experimental Rats

Rats and mice are commonly used in experimental laboratories and anesthetic drugs are important for researchers to understand the details. Administration of fluids helps to stabilize the experimental animals before anesthesia via intravenously through the lateral vein in rats and in case of difficulty in catheterization and maintenance, fluids are usually administered as boluses. Large volumes of cool fluids will rapidly lead to hypothermia and all parenteral fluids must be warmed to body temperature before administration. Premedication with a sedative may ease induction with volatile anesthetic drugs. The first choice for rodent anesthesia is complete inhalational anesthesia. The second option is using injectable anesthesia. Recovery from the volatile agents that have been used rapid when the agent is no longer administered. Anesthetic monitoring equipment is an infant-size bell sthethoscope that can be used to ausculate the heart and lungs. Supplemental heating should be provided to reduce the heat loss supply and maintain core body temperature. The kinds of drugs, characteristics, route of administration and care after surgery were reviewed and summarized from the references. Anesthetic drugs, maintenance, monitoring and aftercare are important in the laboratories to keep the animal safe in all experimental procedures.

Ipsilateral Dorsalis Pedis Vascularized Pedicle Flap in the Distal Leg and Foot

PURPOSE: We had proceeded seven iIpsilateral dorsalis pedis vascularized pedicle flaps in the distal leg and foot to cover the restricted size defects and followed-up average for 5 years and 9 months to evaluate the survival rate, neurosensory function and cosmesis in final results. MATERIALS AND METHODS: From January 1999 through October 2012, we have performed iIpsilateral dorsalis pedis vascularized pedicle flaps in the distal leg and foot to cover the restricted size defect (average around 3.6x2.4 cm) in 7 cases and average age was 41.6 years (21.5 to 59.0 years). Lesion site was posterior heel in 4 cases, distal anterior leg in 3 cases. Donor structure was the dorsalis pedis artery and the first dorsal metatarsal vessel and deep peroneal nerve in 3 cases and the dorsalis pedis artery and the first dorsal metatarsal vessel in 4 cases. RESULTS: Seven cases (100%) were survived and defect area was healed with continuous dressing without skin graft. The sensory function in the neurovascular flap was restored to normal in 3 cases. Cosmesis was good and fair in 7 cases (85.7%). CONCLUSION: Ipsilateral dorsalis pedis vascularized pedicle flap in the distal leg and foot is one of the choice to cover the exposed bone and soft tissues without microsurgical procedure.

Comparison of Floating Knee according to Presence of Knee Joint Injury

PURPOSE: To compare the clinical outcomes of floating knee according to the presence of knee joint injury. MATERIALS AND METHODS: Between March 2004 and March 2009, we investigated 36 patients, who underwent surgical treatment for floating knee injuries. We classified the floating knee into two groups as type I (12 cases) has no knee joint injury and type II (24 cases) has knee joint injury. We compared two groups about combined injury (orthopedics or other part), open fracture or not, neurovascular injury,union time, range of motion, and complication rate. RESULTS: There is statistically no significant difference between two groups as type I (6 cases, 50%) and type II (13 cases, 54.2%) in orthopedic combined injury (p=0.813), and also same as type I (3 cases, 25%) and type II (12 cases, 50%) in combined injury on the other department (p=0.151), and in floating knee with open fracture as 4 type I (33%) and 12 type II (50%) of 16 cases (44%), and Gustilo-Anderson 3 type I, 4 type II, 1 IIIA, 4 IIIB, and 4 IIIC (p=0.423). There is statistically no significant difference between two groups in neurovascular injury as 1 type I (8.3%), and 3 type II (12.5%) (p=0.708). There is a statistically significant difference between two groups in the mean bone union time as 18.2+/-5.37 weeks (12~24 weeks) for type I and 24.95+/-9.85 weeks (16~33 weeks) for type II (p=0.045), and in the mean range of knee joint motion as 133+/-12.74 degree (120~150 degree) for type I and 105+/-19.00 degree (80~135 degree) for type II (p=0.012). CONCLUSION: Floating knee with knee joint injury is severe itself and related with severe combined injuries, subsequent range of knee joint motion limitation, the delay of union time, and high complication rate. Therefore, we should take care in surgical treatment for this trauma entity.

Open Repair of Acute Tibial Avulsion Injury of Posterior Cruciate Ligament: Clinical Outcomes and Usefulness of Preoperative 3-D CT / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical outcome of open repair of acute tibial posterior cruciate ligament (PCL) tibial avulsion injury using the posteromedial approach, and to examine the usefulness of pre-operative 3D-computed tomography (CT) imaging. MATERIALS AND METHODS: From July 2004 onwards, among the 33 patients with acute tibial avulsion injury of the PCL, 22 patients were available for a 1-year follow-up. Patients underwent internal fixation using screws, pullout sutures or staples through the posteromedial approach. Clinical evaluations were performed using the posterior drawer test, posterior drawer stress x-ray, range of motion and Tegner score. In addition, size of the fragment, visibility, comminution, displacement and presence of extension were studied and were compared to the pre-operative X-ray and 3D-CT imaging. RESULTS: Four cases demonstrated 10-degree restriction in flexion and 1 case demonstrated 10-degree restriction in extension compared to the unaffected side. Except for the 2 cases which had Grade I posterior instability on the posterior drawer test, the results of the post-operative joint stability were negative and the posterior drawer stress X-ray using the Telos device showed an average of 0.57+/-0.4 mm. Like the average pre-operative Tegner score of 6.7+/-0.9, the Tegner score was restored to 6.2+/-0.7 (p>0.05) at the last follow-up. 3D-CT showed an improved accuracy in visibility (55.6%), comminution (50%) and displacement (44.4%) compared to the simple X-ray. CONCLUSION: The acute tibial avulsion injury treated with the appropriate internal fixation through the posteromedial approach based on the fracture size demonstrated exellent outcomes. The pre-operative 3D-CT was useful for identifying the fracture pattern and choosing the appropriate internal fixation.