Complications of lateral plate fixation compared with tension band wiring and pin or lag screw fixation for calcaneoquartal arthrodesis. Treatment of proximal intertarsal subluxation occurring secondary to non-traumatic plantar tarsal ligament disruption in dogs.

OBJECTIVE: To compare complication rates and the outcomes of these complications after lateral plate fixation with figure-of-eight tension-band-wire and pin or lag screw fixation for arthrodesis of the calcaneoquartal joint, following non-traumatic disruption of the plantar tarsal ligament in dogs. METHODS: Data were collected retrospectively from five UK referral centres. Diplomate specialists and their residents performed all procedures. Referring veterinarians were contacted for long-term follow-up. RESULTS: Seventy-four procedures were undertaken in 61 dogs. There were 58 arthrodeses in the lateral plate group (Plate), nine in the pin and tension-band-wire group (Pin), and seven in the lag screw and tension-band wire-group (Screw). Compared to Plate (17%), further surgical intervention was required more frequently following Pin (56%, OR = 3.2) or Screw (43%, OR = 2.5) fixation. Clinical failure of arthrodesis occurred less frequently with Plate (5%) compared with Screw (43%, OR = 8.6) and Pin fixation (22%, OR = 4.4). Cases managed with external coaptation postoperatively were more likely to suffer from postoperative complications (OR = 2.2). CLINICAL SIGNIFICANCE: Lateral plating was associated with fewer postoperative complications than pin and tension-band-wire fixation for arthrodesis of the calcaneoquartal joint in dogs with non-traumatic disruption of the plantar tarsal ligament.

Feline talocrural luxation: a cadaveric study of repair using ligament prostheses.

Currently recommended surgical techniques to treat severe biaxial feline talocrural soft-tissue injuries commonly lead to unsatisfactory outcome. Data relating to canine talocrural stabilisation may not be useful in cats due to major differences in tarsal anatomy between the species. This experimental biomechanical cadaveric study used specimens (n = 10) prepared from the distal pelvic limbs of five adult cats. The aim was to design a technique for treating talocrural luxation using suture prostheses and bone tunnels, and to investigate its suitability for use in clinical cases. Four prosthetic ligaments were placed through a series of five 1.5 mm bone tunnels. Two prostheses, the caudoproximal pair, were taut in talocrural flexion and two prostheses, the craniodistal pair, were taut in extension. The intact specimens had their range-of-motion (ROM) and stability tested, after which they were transected at the talocrural joint (simulated luxation) and repaired using the technique described. The ROM and stability of the repaired specimens were tested and compared to the intact specimens. The repaired specimens had comparable stability to the intact specimens, although the ROM was different (p <0.05) in six of 16 positions (p <0.003125). These corresponded to the positions where the lateral prostheses were taut. The repair technique described may be useful in the treatment of talocrural luxation, as it is low-profile in an area of limited soft-tissue cover, allows anatomic reduction, restores normal talocrural joint stability and near-normal tarsal ROM.

Modification of the cranial closing wedge ostectomy technique for the treatment of canine cruciate disease. Description and comparison with standard technique.

OBJECTIVE: To describe a modification of the cranial closing wedge ostectomy (CCWO) technique and to compare its efficacy to the standard technique on cadaveric specimens. METHODS: The standard and modified CCWO technique were applied to eight pairs of cadaveric tibiae. The following parameters were compared following the ostectomy: degrees of plateau levelling achieved (degrees), tibial long axis shift (degrees), reduction in tibial length (mm), area of bone wedge removed (cm²), and the area of proximal fragment (cm²). RESULTS: The size of the removed wedge of bone and the reduction in tibial length were significantly less with the modified CCWO technique. CLINICAL SIGNIFICANCE: The modified CCWO has two main advantages. Firstly a smaller wedge is removed, allowing a greater preservation of bone stock in the proximal tibia, which is advantageous for implant placement. Secondly, the tibia is shortened to a lesser degree, which might reduce the risk of recurvatum, fibular fracture and patella desmitis. These factors are particularly propitious for the application of this technique to Terrier breeds with excessive tibial plateau angle, where large angular corrections are required. The modified CCWO is equally effective for plateau levelling and results in an equivalent tibial long-axis shift. A disadvantage with the modified technique is that not all of the cross sectional area of the distal fragment contributes to load sharing at the osteotomy.

Salter-Harris type III fractures of the distal humerus in two dogs.

Salter-Harris type III fractures of the distal humerus in a four-month-old male Labrador Retriever and a male crossbreed dog (estimated to be 3.5-months-old) are reported. Both fractures were treated with open reduction and interfragmentary compression by lag screw fixation. Both fractures healed and full limb use was regained at four weeks postoperatively. The occurrence of this unusual fracture type may be related to the physeal closure pattern of the distal humeral physis, and a different mechanism of injury compared to the more common Salter-Harris type IV fracture seen in this region.

Early kinematic outcome after treatment of cranial cruciate ligament rupture by tibial plateau levelling osteotomy in the dog.

OBJECTIVES: To establish the effect of tibial plateau levelling osteotomy (TPLO) on two selected pelvic limb kinematic variables in dogs treated for clinical cranial cruciate ligament rupture (CCLR). METHODS: Thirteen dogs that had incurred CCLR and were treated by TPLO walked on a treadmill whilst kinematic data on pelvic limb paw motion were acquired using motion capture equipment. Data were subject to secondary processing using matrix analysis software and statistical analysis. RESULTS: Pelvic limb stance duration significantly increased during the 12 week study period, recovering to near-normal values. Range of pelvic limb paw velocity also significantly increased but did not reach normal values by 12 weeks postoperatively. CLINICAL SIGNIFICANCE: The improvement in stance duration to near normality may aid in explaining the widely-held subjective impression that TPLO frequently provides an excellent outcome in the early stages after repair of the cruciate deficient canine stifle joint. Both stance length and range of paw velocity provide useful objective measures to compare outcome following surgery for CCLR.

Treatment of caudal mandibular fracture and temporomandibular joint fracture-luxation using a bi-gnathic encircling and retaining device.

Fractures of the caudal portion of the mandible and temporomandibular joint (TMJ) fracture-luxation can be challenging to treat with direct fixation methods. This paper describes a simple technique for the indirect treatment of caudal mandibular fracture and TMJ fracture-luxation using a subcutaneous loop of nylon leader line tunnelled around the maxilla, incisive and nasal bones, and under the mandible, placed just caudal to the canine teeth, and crimped ventral to the mandibular skin: a bignathic encircling and retaining device (BEARD). A BEARD was used to treat two immature dogs with simple, unilateral caudal mandibular fractures, six cats with unilateral injury (two with TMJ luxation, three with TMJ fracture-luxation, one with caudal mandibular fracture), and two cats with bilateral injury (comminuted caudal mandibular fracture with contralateral TMJ luxation; bilateral condylar neck fracture). The BEARD treatment failed short-term due to poor tolerance in one cat, and concurrent injuries and poor initial reduction in another cat. One cat was lost to long-term follow-up. Rostral dental occlusion was normal in six out of seven cases, and reported jaw function was normal in seven out of seven cases. The case with poor occlusion had imperfect initial reduction. Complications included dorsal nasal skin swelling or discharge, oesophagostomy tube dislodgement or blockage, BEARD loosening, and regurgitation. Treatment of uni- or bilateral caudal mandibular trauma using a BEARD can lead to clinical union, and normal rostral occlusion, provided that case selection is appropriate and immediate-post-surgical occlusion has been corrected.

Treatment of tibial fractures with plates using minimally invasive percutaneous osteosynthesis in dogs and cats.

OBJECTIVES: The aim of the here described case series was to develop and evaluate the minimally invasive percutaneous osteosynthesis for the plate fixation of tibial fractures in dogs and cats. METHODS: Six dogs and four cats with shaft fractures of the tibia were treated using minimally invasive percutaneous osteosynthesis. Follow-up radiographs four to six weeks after fracture fixation were evaluated for fracture healing. For the long-term follow-up (minimum 2.4 years), owners were contacted by phone to complete a questionnaire. RESULTS: All fractures healed without the need for a second procedure. Follow-up radiographs obtained after four to six weeks in seven cases showed advanced bony healing with callus formation and filling of the fracture gaps with calcified tissue in all seven. All the patients had a good to excellent long-term result with full limb function. The time needed for regaining full limb use was two to three months. CLINICAL SIGNIFICANCE: Minimally invasive percutaneous osteosynthesis seems to be a useful technique for the treatment of tibial shaft fractures in dogs and cats.

Acute compartment syndrome complicating an intramuscular haemangiosarcoma in a dog.

Acute compartment syndrome in dogs is a rare complication of muscle trauma, but it has not been previously reported as a consequence of neoplasia in dogs. This case report describes the occurrence of a compartment syndrome of the femoral compartment in an 11-year-old, male, mixed-breed dog caused by acute bleeding of an intramuscular haemangiosarcoma. The compartment syndrome was relieved by immediate fasciotomy. The dog was euthanased following acute recurrence of clinical signs seven weeks after surgery.

Modulation of gating of cloned rat and human K+ channels by micromolar Zn2+.

The actions of zinc ions on three species of K+ channels were studied using mouse fibroblasts stably transfected with a plasmid containing both the appropriate K+ channel gene and a steroid-inducible promotor. The channels studied were rKv1.1 and hKv1.5, delayed rectifiers cloned from rat and human tissue, respectively, and hKv1.4, an inactivating human K+ channel. Zn2+ shifted the activation curves for all three K+ currents in the depolarizing direction and also shifted the steady state inactivation curve for hKv1.4 in the depolarizing direction. The effect of Zn2+ was concentration dependent between 2 and 1000 microM. As a consequence of the modulation of gating, the activation kinetics of the K+ currents were slowed by Zn2+, an effect likely to delay repolarization of the neuronal action potential. The action of Zn2+ on these diverse K+ channels suggests the existence of a common Zn2+ binding domain, the occupation of which influences the voltage sensor. The resulting modulation of gating of hKv1.4 by Zn2+ may well be of physiological significance, in view of the localization of this channel in mossy fiber nerve terminals in the hippocampus, where Zn2+ is found in abundance.

Zinc modulates transient outward current gating in hippocampal neurons.

The actions of zinc ions (Zn2+) on transient outward current (TOC) were studied in cultured embryonic rat hippocampal neurons and adult guinea pig CA1 neurons acutely isolated from hippocampal slices. Zn2+ (1-1000 microM) shifted both the activation and inactivation curves for the TOC in the depolarizing direction. These effects of Zn2+ were modeled, assuming a single class of binding sites for Zn2+, yielding apparent dissociation constants for Zn2+ between 10 and 35 microM. In addition, the activation kinetics of the TOC were significantly slowed by Zn2+; deactivation was slowed at the highest concentrations of Zn2. These complex actions of Zn2+ on the TOC are likely to delay repolarization and promote spontaneous activity, resulting in action potential prolongation and hyperexcitability of hippocampal neurons.

Gangrenous cholecystitis: new observations on sonography.

We studied 25 patients with gangrenous cholecystitis and observed a new sonographic finding--striated thickening of the gallbladder wall--and three patterns of pericholecystic fluid collections. Heterogeneous thickening of the gallbladder wall was characterized by either multiple striations (alternating hypoechoic and hyperechoic layers) or irregular mass-like protrusions projecting into the gallbladder lumen. We observed striated thickening far more frequently (in 10 of 25 patients) than other findings reported previously as being associated with gangrenous cholecystitis, such as intraluminal membranes (1 in 25 patients) and masslike protrusions into the gallbladder lumen (1 in 25 patients). Although the sensitivity and specificity of this finding cannot be determined by our study, we believe that mural striations in cases of acute cholecystitis should raise the question of gangrenous changes. Additionally, we found that two subtypes of pericholecystic fluid collections (types II and III) were associated with gallbladder wall perforation and abscess formation more frequently than type I collections.

Reoperative carotid surgery.

Fourteen patients underwent carotid reoperation for symptomatic recurrent carotid stenosis after previous ipsilateral carotid endarterectomy. Eight of these patients presented with focal transient ischemic attacks, two with strokes, and four with vertebrobasilar insufficiency. Recurrent symptoms in eight patients were similar to those prompting the initial carotid endarterectomy. Symptoms recurred early after previous carotid endarterectomy in 2 patients and late in 12 patients. Eleven patients underwent repeat endarterectomy and carotid patch angioplasty, two patients underwent patch angioplasty alone, and one patient underwent carotid artery replacement with a vein graft. Persistent or recurrent focal symptoms referable to the reoperated carotid artery were not present during follow-up (mean 27.4 months, range 4 to 79 months). Vertebrobasilar symptoms were relieved by carotid reoperation in each patient. Although the natural history of asymptomatic postoperative carotid restenosis is unknown, reluctance to reoperate on symptomatic patients is unwarranted, since carotid reoperation can be performed safely with the expectation that recurrent focal and nonfocal vertebrobasilar symptoms will be relieved.

Participants in prospective, randomized clinical trials for resected non-small cell lung cancer have improved survival compared with nonparticipants in such trials.

The survival of 78 patients with resected non-small cell lung cancer entered in prospective, randomized investigational trials is compared to that of a population-based group of control patients not included in such trials. The survival of trial patients is significantly better than that of controls (P less than 0.001). This survival advantage for trial participants is most apparent among late Stage I patients, and is observed after matching for known prognostic factors (i.e., primary tumor size, nodal status, tumor histology) and after adjusting in the analysis for age, sex, and the administration of radiation therapy. Several explanations for the improved outcome for trial patients are explored, including differences in preoperative evaluation, staging, surgical technique, placebo effects, and patient motivation. These results suggest the possibility that inclusion in these controlled cancer trials may have had an inherent advantage for all participants.

The significance of hydronephrosis after aortofemoral reconstruction.

Hydronephrosis due to ureteral obstruction is a rarely reported complication of aortic bypass grafting. Patients who had undergone aortic reconstruction were screened using serial real-time ultrasound examination to detect ureteral obstruction. The clinical course and incidence of graft complications, renal impairment, amputation, and death were determined for hydronephrotic patients and compared with the incidence of similar complications in a control group. Hydronephrotic patients had an extremely high incidence of graft infection, anastomotic aneurysm, graft thrombosis, and amputation. Obstructed ureters were at high risk for intraoperative injury during removal of infected aortic grafts. A subgroup of hydronephrotic patients who developed multiple anastomotic aneurysms without graft infection was identified. Hydronephrosis was frequently silent, and detection required active investigation. After aortic reconstruction, routine screening with real-time ultrasound examination appears warranted to identify a high-risk subset of patients.

Upper-extremity emboli secondary to axillofemoral graft thrombosis.

Four episodes of upper-extremity arterial emboli following axillofemoral bypass graft thrombosis are described. The source of the embolus was the blind stump of the proximal portion of the graft limb that remained patent after graft occlusion. With axillofemoral graft thrombosis, management requires treatment of the lower-limb ischemia and an awareness of the embolic potential of the acutely thrombotic graft limb. Patient evaluation and the surgical management of axillofemoral graft thrombosis with and without the complication of upper-extremity ischemia are discussed, as well as the etiology and prevention of this complication.