The impact of a post-operative clinical care pathway on head and neck microvascular free tissue transfer outcomes.

OBJECTIVE: To study the impact of a clinical care pathway and computerised order set on short-term post-operative outcomes for patients undergoing head and neck free tissue transfer. METHODS: In this retrospective cohort study, patients who underwent head and neck free tissue transfer by a single reconstructive surgeon between January 2007 and July 2009 were assigned to one of two cohorts based on the timing of their surgery: pre- or post-clinical care pathway implementation. Measured outcomes included peri-operative complications and mortality, length of hospital stay and costs, unplanned reoperations, and readmissions within 30 days of discharge. RESULTS: The pre-clinical care pathway cohort included 81 patients and the post-clinical care pathway cohort comprised 46. Implementation of the clinical care pathway was associated with decreased variability in length of hospital stay (median (interquartile range) = 8 (6, 11) vs 7 (6, 9) days). The post-clinical care pathway cohort also had a significantly lower unplanned reoperation rate (15.2 vs 35.8 per cent, p = 0.01). CONCLUSION: A clinical care pathway is a successful means of standardising and improving complex patient care. In this study, care pathway implementation in head and neck free tissue transfer patients improved efficiency and the quality of patient care.

Axisymmetric scalable magneto-gravitational trap for diamagnetic particle levitation.

We report on the design, construction, and use of axisymmetric magnetic traps for levitating diamagnetic particles. The magnetic traps each consist of two pole pieces passively driven by a neodymium iron boron (NdFeB) permanent magnet. The magnetic field configuration between the pole pieces combined with the earth's gravitational field forms a 3D confining potential capable of levitating a range of diamagnetic substances, e.g., graphite powder, silica microspheres, and gallium nitride (GaN) powder and nanowires. Particles trap stably at atmosphere and in high-vacuum for periods up to weeks with lifetimes largely determined by choices made to actively destabilize the trap. We describe the principles of operation, finite element design, approximate closed-form results for design rules, and examples of operation of such traps.

A survey of gundog lameness and injuries in Great Britain in the shooting seasons 2005/2006 and 2006/2007.

The aim of this paper was to record the types of injuries and causes of lameness exhibited by dogs involved in game shooting. The study investigated gundogs that worked in the seasons 2005/2006 and 2006/2007. Information was acquired by owner questionnaires. The dogs were classified as working in the beating line, as peg dogs or as picking up dogs. A further group comprised Setters and Pointers that worked the grouse moors. A secondary objective was to assess the incidence of injuries that were treated by owners without seeking the assistance of their veterinarian, and to identify those that may have been underestimated. Depending on whether a dog was injured or went lame, and, if so, the nature of the injury, was correlated with the number of days worked, where it worked, its breed and the type of work it did. A mildly positive association between the Spaniel breed group and injuries was seen in 2005/2006 but not in 2006/2007. However, the relationship between the type of work and injuries was very significant for both seasons with dogs working in the beating line being at greatest risk and Setters and Pointers having the least number of injuries. The dogs in the beating line were also at a significantly greater risk of injury in both years when the type of injury was investigated. Fifty-three percent of all injuries were deemed to be sufficiently minor, that veterinary attention was not sought. However, those dogs with proximal thoracic limb lameness may have been under-investigated. There was a highly significant association between tail injuries and undocked Springer and Cocker Spaniels.

Metacarpal fractures associated with pancarpal arthrodesis in dogs.

OBJECTIVE: To report the prevalence of third metacarpal bone fractures after dorsal plating for pancarpal arthrodeses in dogs and to identify predisposing factors. STUDY DESIGN: Retrospective clinical study. ANIMALS: Fifty-four client-owned dogs. METHODS: Pancarpal arthrodesis was performed using dorsally applied 2.7- or 3.5-mm bone plates. Medical records and radiographs were retrospectively evaluated to identify those dogs with metacarpal bone fractures after pancarpal arthrodesis and to determine the angle of arthrodesis, the percentage of the third metacarpal bone covered by the bone plate, and the percentage width of the bone occupied by the screw. Radiological evidence of arthrodesis at follow-up examination 6 weeks postoperatively was recorded. Long-term results were obtained by telephone follow-up with the owners. All lame dogs were evaluated clinically and radiographically. RESULTS: Metacarpal fractures occurred in 6 of 54 dogs. One of these dogs had a stress fracture of the third metacarpal 10 months after implant removal and was not included in the statistical analysis. Fractures occurred through the distal screw hole in four dogs and involved two metacarpal bones (III and IV) in two dogs. The median ratio of bone screw diameter-to-metacarpal bone diameter was the same for dogs with metacarpal bone fractures and those with no fractures (44%), and the median angles of arthrodesis were 8 degrees and 7 degrees. These values were not statistically significant. The percentage length of the metacarpal bone covered by the plate was 53% (no fracture) compared with 46% (fracture), and this difference was statistically significant (P = .035). CONCLUSIONS: Screw diameter was not implicated as a predisposing factor for metacarpal bone fracture in dogs undergoing pancarpal arthrodesis using a dorsally applied dynamic compression plate. The length of the metacarpal bone covered by the bone plate did affect the frequency of metacarpal fracture, with fewer fractures occurring when greater than 53% of the bone length was covered by the dynamic compression plate. CLINICAL RELEVANCE: When performing pancarpal arthrodesis with a dorsally applied bone plate, it is recommended that at least 50% of the length of the third metacarpal bone should be covered by the plate.

The surgical anatomy of the stifle joint in sheep.

OBJECTIVE: To provide a detailed description of the surgical anatomy of the stifle joint in sheep. STUDY DESIGN: The results from analysis of cadaveric dissections (14 stifle joints) and stifle radiographs (8 sets of mediolateral and craniocaudal radiographs) are presented. ANIMALS: Skeletally mature ewes of mixed breeds. CONCLUSIONS: Although the anatomy of the ovine stifle joint is similar to that of the human knee joint, a number of unique features were identified. These included the presence of the tendon of the m. extensor digitorum longus on the craniolateral aspect of the stifle joint, the absence of a cranial meniscofemoral ligament (ligament of Humphrey) in the caudal joint space, and attachment of the patellar tendon to the cranial pole of the patella (rather than to the distal pole, as in humans). The implications of these differences are discussed with reference to the suitability of the ovine stifle as a surgical model for the human knee joint.

Arthrodesis of the tarsometatarsal joint using a laterally applied plate in 10 dogs.

The efficacy of tarsometatarsal arthrodesis using a laterally applied plate was evaluated retrospectively in 10 dogs (11 joints). Arthrodesis was performed to manage a tarsometatarsal subluxation in two hocks; in the other cases, the tarsometatarsal subluxation was accompanied by tarsal or metatarsal fractures. The average period to referral was 15 days and all dogs had been managed with previous external coaptation of the affected limb. Arthrodesis was achieved in all the joints following initial surgery. Implant removal was indicated in three dogs which remained intermittently lame. Implants were left in situ in the remaining seven dogs. After an average follow-up period of 28 months, all dogs had resumed normal activity. Seven dogs were reported to be completely sound, one was stiff after rest following vigorous exercise and two had an intermittent mild lameness following strenuous exercise.

Repair of femoral trochanteric osteotomy in the dog.

The records and radiographs of 24 dogs that underwent femoral trochanteric osteotomy repair were reviewed. Osteotomy repair was performed with either a pin and tension band wire or a lag screw technique. Significant clinical complications associated with the osteotomy were identified in one dog (4 per cent) six weeks after surgery, although abnormal radiographic changes were evident in 15 dogs (62 per cent). The method of repair did not influence healing and there were comparable radiographic complication rates. It is concluded that femoral trochanteric osteotomy is not associated with significant clinical problems, despite a high incidence of abnormal radiographic findings.

Suspected mitochondrial myopathy in a Jack Russell terrier.

A Jack Russell terrier with a history of progressive exercise intolerance was examined at the age of four months and again 10 months later. Clinical examination revealed a stunted, thin dog with a stilted gait. The dog had raised lactate levels before and after feeding and a raised lactate/pyruvate ratio after feeding, indicating a metabolic abnormality. Histochemical evaluation of muscle biopsies revealed subsarcolemmal accumulation of oxidative activity when stained with nicotinamide adenine dinucleotide tetrazollum reductase and ragged red fibres when stained with modified Gomori trichrome; all fibre types were involved. Ultrastructural examination of the muscle confirmed the presence of subsarcolemmal accumulations of mitochondria. Histochemical staining for the activity of enzymes of the Krebs cycle, oxidative phosphorylation and other metabolic cytosolic enzymes failed to demonstrate an abnormality. In view of the clinical picture and the biochemical and histological findings, a tentative diagnosis of mitochondrial myopathy was made. The difficulties associated with diagnosing mitochondrial disorders are discussed.

A morphological assessment of vein allografts preserved in glycerol and used for arterial replacement.

There is an increasing need for alternatives to reversed autogenous saphenous vein in the treatment of first-time and recurrent arterial occlusions. Vein grafts taken from rats and goats and from humans were preserved in glycerol, reconstituted in saline and compared morphologically with fresh veins of similar origin. In rats and goats, autograft, allograft and glycerol-preserved allograft veins were used to replace lengths of common iliac and carotid arteries. After various periods of time these were retrieved and examined using light microscopy and scanning electron microscopy. Appearances were found to correlate well with function. All allograft vessels were found to have failed. Over 70% of autografts were functional in both species and all of these had re-endothelialised. In rats, all of the glycerol-preserved grafts had failed but in goats 64% were patent at 6 months but did not show signs of a neointima. In larger animals, glycerol-preserved vein allografts appear to offer an acceptable form of arterial replacement where fresh vein autograft is unavailable.

A clinical trial of three anaesthetic regimens for the castration of ponies.

After premedication with intravenous xylazine 30 ponies were anaesthetised for castration under field conditions with intravenous ketamine, thiopentone or methohexitone. The duration of anaesthesia was adequate for surgery and the times taken to stand were similar in each group. The recovery of the ponies after ketamine was quieter than after either of the barbiturates and this may be an advantage when skilled assistance is lacking. However, all the anaesthetics appeared to be suitable for performing minor surgery in the field.