Single institution retrospective study evaluating the frequency of implant removal and associated risk factors following open fracture fixation in 80 cases (2010-2020).

BACKGROUND: Open fractures occur commonly in small animals and are characterised by contamination of the fracture site. While never quantified, it is believed that open fractures stabilised with internal implants are at a higher risk for requiring explantation. This retrospective study determines the frequency and risk factors for explantation following use of internal fixation. Medical records of client-owned dogs and cats with an open fracture, between 2010 and 2020 stabilised using internal implants, were included. Data retrieved included signalment, cause and characterisation of the fracture, comorbidities, preexisting infections, and all details related to anesthesia and surgery. Pre-, Peri- and post-operative antibiotic use were detailed. All cases were followed to clinical union. Postoperative complications, including requirement for implant removal were recorded and classified as major or minor. Associations between potential risk factors and need for explantation were assessed. RESULTS: Of 80 cases, 72 (90%) were dogs and eight (10%) cats. Major complications were encountered in 23 (28.75%) cases and minor complications in 16 (20%) cases. Explantation was performed in 17 cases (21.25%). Out of 72 dogs, 13 required explantation (18%) whereas four of the eight cats needed implants removed (50%). Only diagnosis of postoperative infection was associated with an increased risk of explantation (RR 2.77; 95% CI 1.25; 6.15; p = 0.045). CONCLUSION: Approximately 1 in 5 open fractures stabilised using internal fixation can be anticipated to require explantation, with cats potentially being at a higher risk than dogs. Cases diagnosed with postoperative infection are at a higher risk for requiring implant removal.

Management of insufficiency fractures associated with long-term bisphosphonate therapy in a cat.

Case summary: A 10-year-old spayed female domestic medium hair cat presented after sustaining atraumatic insufficiency fractures of the right calcaneus and the left tibia approximately 6 weeks apart. Chronic alendronate therapy had been ongoing for 9 years for the management of previously diagnosed idiopathic hypercalcemia. The right calcaneal fracture was managed non-operatively due to minimal functional impairment. The left tibial fracture was managed via open reduction and internal fixation with orthogonal plating. Alendronate therapy was discontinued at the time of the fracture repair with prednisolone being used to manage the hypercalcemia. Despite rapid clinical improvement, the tibial fracture had a protracted healing course, with clinical union only being achieved 22 weeks postoperatively. At 17 months postoperatively, the idiopathic hypercalcemia remained well controlled. Gait assessment, orthopedic examination and orthogonal radiographs performed at this time revealed resolution of left pelvic limb lameness, a normal orthopedic examination of the left pelvic limb and no evidence of implant-associated complications. Monitoring is ongoing but at the time of publication, no further fractures have occurred. Relevance and novel information: As reported in humans, this case report gathers evidence of associations between bisphosphonate treatment and the occurrence of insufficiency fractures in cats, and provides evidence that stress reactions may precede their development. If bisphosphonate therapy is utilized in the long term, serial radiographic monitoring for signs of impending fracture may be warranted. Fracture repair can be successful in cats that have received long-term bisphosphonate therapy, but delayed healing should be anticipated and implant choices made accordingly.

Accuracy of anatomic 3-dimensionally printed canine humeral models.

OBJECTIVE: To evaluate the accuracy of various three-dimensional print (3DP) technologies using morphometric measurements. STUDY DESIGN: Experimental. SAMPLE POPULATION: Cadaveric canine humeri and size-matched 3DP models. METHODS: Fiduciary radiopaque markers were affixed to canine humeri of three different sizes (4, 13, 29 kg) at predetermined anatomical landmarks. 3DP models were created using one of three printers; desktop printers Form 3L and Ultimaker 5S, and industrial printer Objet Connex (n = 5/group/printer). Marker based morphometric dimensions between cadavers and 3DP models were statistically compared using 2-factor repeated measures ANOVA followed by Tukey's post-hoc test (p < .05). RESULTS: Bone size and printer type both significantly affected 3DP accuracy, with size having the larger effect (p < .0001 and p < .02, respectively). Regardless of printing technology, model size was smaller than native bone in most cases. At the humeral condylar level, the best accuracy was seen in the medium-sized humerus with the Ultimaker printer ([0.09 mm], p < .03). Accuracy was reduced in the proximal humerus in all groups. CONCLUSION: Desktop printers were overall more accurate than the industrial printer. Although significant differences were identified between models of different sizes, the submillimetric magnitude of these differences is unlikely to be clinically relevant. CLINICAL SIGNIFICANCE: While preoperative planning using 3DP models is becoming mainstream, accurate representation of the actual bone is critical. This study demonstrates that common desktop printers are suitable for this purpose.

Tibial tuberosity transposition advancement for treatment of concomitant cranial cruciate ligament rupture and medial patellar luxation in four feline stifles.

CASE SERIES SUMMARY: Three cats (four stifles) were diagnosed with varying grades of medial patellar luxation and stifle instability in cranial tibial thrust. Radiographs showed periarticular osteophytosis, intra-articular mineralization and opacification encroachment of the infrapatellar fat pad. Stifle exploration revealed either partial (n = 2) or complete (n = 2) cranial cruciate ligament tear and medial meniscal injury in all cases. Medial meniscectomy, partial parasagittal patellectomy, femoral trochleoplasty and tibial tuberosity transposition advancement using a 6 mm cage, two-fork plate and 4 mm spacer were performed in four stifles. Screws (2.0 mm) and washers were used in the cranial cage ears rather than conventional 2.4 mm screws. By the 2-week recheck, lameness was minimal and stifles were stable. Radiographic follow-up at 8 weeks showed appropriate progression of osseous union in all cases. One cat experienced a major complication, suffering tibial fracture following a lapse in exercise restriction, and revision surgery was performed successfully with subsequent osseus union of the osteotomy site. At the mid-term follow-up, all cats had a return to previous level of function, as assessed by both owner questionnaire and clinical evaluation. RELEVANCE AND NOVEL INFORMATION: Tibial tuberosity transposition and advancement has been shown to be successful in dogs for the treatment of concomitant medial patellar luxation and cranial cruciate ligament rupture. To date, there have been no reports of tibial tuberosity transposition and advancement in cats. A benefit of this approach is concomitant alignment of the extensor mechanism and neutralization of the femorotibial shear force. Our case series describes successful use of tibial tuberosity transposition advancement in cats.

Clinical application of the small I-Loc interlocking nail in 30 feline fractures: A prospective study.

OBJECTIVE: To describe medium-term functional outcome after nail osteosynthesis in feline traumatology and report clinically relevant recommendations for I-Loc angle-stable interlocking nail use in cats. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Client-owned cats (n = 29). METHODS: Consecutive cases with femoral, tibial, or humeral fractures were included. Outcome measures included fracture and surgical procedure description, limb alignment, nail size vs body weight (BW), percentage of nail medullary canal (MC) fill, time to limb function at clinical union (CU), and complications. Descriptive statistics were reported and compared with historical data. RESULTS: Bone distribution was 53.3% femora, 30% tibiae, and 16.7% humeri. There were six epimetaphyseal and 24 diaphyseal fractures. Overall, 67% of fractures were comminuted. Open reduction and minimally invasive techniques were used in 73% and 27% of cases, respectively. Seventeen I-Loc 3 (cat mean BW 4.4 ± 2.2 kg) and 13 I-Loc 4 (cat mean BW 5.2 ± 1.2 kg) nails were placed with mean MC fill of ≤50%. Average time to CU was 7.2 weeks. At CU, lameness had resolved or was mild in every cat, and all cats ultimately regained full limb function. No major complications were encountered. CONCLUSION: Because of improved CU times, excellent functional outcomes, and low complication rate, our results provide evidence that I-Loc nails are safe and effective for feline traumatology. CLINICAL SIGNIFICANCE: The I-Loc may be advantageous for fixation of epimetaphyseal fractures. Because of feline bone specific dimensional constraints, I-Loc 3 is likely appropriate for all feline humeri and most tibiae, while I-Loc 4 is well sized for feline femora.

Design Considerations to Facilitate Clinical Radiological Evaluation of Implantable Biomedical Structures.

Clinical effectiveness of implantable medical devices would be improved with in situ monitoring to ensure device positioning, determine subsequent damage, measure biodegradation, and follow healing. While standard clinical imaging protocols are appropriate for diagnosing disease and injury, these protocols have not been vetted for imaging devices. This study investigated how radiologists use clinical imaging to detect the location and integrity of implanted devices and whether embedding nanoparticle contrast agents into devices can improve assessment. To mimic the variety of devices available, phantoms from hydrophobic polymer films and hydrophilic gels were constructed, with and without computed tomography (CT)-visible TaOx and magnetic resonance imaging (MRI)-visible Fe3O4 nanoparticles. Some phantoms were purposely damaged by nick or transection. Phantoms were implanted in vitro into tissue and imaged with clinical CT, MRI, and ultrasound. In a blinded study, radiologists independently evaluated whether phantoms were present, assessed the type, and diagnosed whether phantoms were damaged or intact. Radiologists identified the location of phantoms 80% of the time. However, without incorporated nanoparticles, radiologists correctly assessed damage in only 54% of cases. With an incorporated imaging agent, the percentage jumped to 86%. The imaging technique which was most useful to radiologists varied with the properties of phantoms. With benefits and drawbacks to all three imaging modalities, future implanted devices should be engineered for visibility in the modality which best fits the treated tissue, the implanted device's physical location, and the type of required information. Imaging protocols should also be tailored to best exploit the properties of the imaging agents.

Interlocking Nails and Minimally Invasive Osteosynthesis.

Reviews of clinical outcomes led to the foundation of a new approach in fracture management known as biological osteosynthesis. As intramedullary rods featuring cannulations and locking devices at both extremities, interlocking nails are well suited for bridging osteosynthesis. Unique biological and mechanical benefits make them ideal for minimally invasive nail osteosynthesis and an attractive, effective alternative to plating, particularly in revisions of failed plate osteosynthesis. Thanks to a new angle-stable locking design, interlocking nailing indications have been expanded to osteosynthesis of epi-metaphyseal fractures, including those with articular involvement and angular deformities such as distal femoral varus and associated patellar luxations.

Bilateral radial and ulnar fractures in a red kangaroo (Macropus rufus).

CASE DESCRIPTION: An 11-month-old sexually intact male red kangaroo (Macropus rufus) was examined because of bilateral radial and ulnar fractures. CLINICAL FINDINGS: Radiography of the forelimbs revealed bilateral, short oblique fractures in the proximal to mid diaphyses of the radii and ulnae. Fractures were overriding and moderately displaced. Wider than expected gaps were evident in the humeroulnar and humeroradial joints bilaterally. Although several physes remained open, no proximal radial physis was radiographically evident. TREATMENT AND OUTCOME: Dual bone fixation was performed bilaterally, and dynamic luxation of the left radial head was identified and stabilized intraoperatively. Although satisfactory function of both forelimbs was evident at 8 weeks and 26 months after surgery, a persistent gait abnormality affecting the right forelimb was noted. Twenty-six months after surgery, radiography revealed bilateral proximal radial physes and resolution of the abnormally wide gaps in the humeroradial and humeroulnar joints. Despite dual bone fixation, synostoses formed bilaterally and may have contributed to the persistent lameness in the kangaroo's right forelimb. CLINICAL RELEVANCE: Veterinarians treating kangaroos should be aware of difficulties in determining skeletal maturity and planning fracture stabilization because of potential differences in skeletal growth and fracture healing, compared with other species. We described critical issues observed in the treatment and outcome of the kangaroo of the present report and provided lessons learned as well as potential explanations of these issues to facilitate future treatment of kangaroos with forelimb fractures.

Outcome of Supraglenoid Tubercle Fractures in 12 Dogs.

OBJECTIVE: The aim of this study was to report the outcome and complications of surgical stabilization following fracture of the supraglenoid tubercle in dogs. MATERIALS AND METHODS: Data from three referral centres (Queen Mother Hospital for Animals, Michigan State University and Veterinary Referral Hospital Hallam) were reviewed retrospectively for cases of supraglenoid tubercle fracture (n = 12). RESULTS: Overall success rate was 9/12. Major complication rate was 2/12 and minor complication rate was 9/12. All fractures that had major complications were comminuted. Methods of stabilization included pin and tension band wire (n = 5), lag screw (n = 2), plate fixation (n = 2), fragment removal (n = 2) and conservative management (n = 1). CLINICAL SIGNIFICANCE: Good outcomes can be achieved following fractures of the supraglenoid tubercle, although cases with comminution have a higher complication rate. Further research into the optimal method of fixation and postoperative management is required.

Injuries involving the central tarsal bone in nonracing dogs: Short-term outcomes and prognostic factors.

OBJECTIVE: To describe traumatic injuries involving the central tarsal bone (Tc) in nonracing dogs. STUDY DESIGN: Retrospective multicenter study. ANIMALS: Thirty-two client-owned dogs. METHODS: Medical records from January 2010 to December 2016 were searched for dogs with Tc injury. Fracture classification, concurrent tarsal fractures, treatment, and perioperative management were tested for association with postoperative complications and short-term outcome. Outcome measures consisted of the latest lameness score reported in the record. RESULTS: The most common injuries consisted of type V fractures (22) and luxation of the Tc (8). Other injuries included 1 case each of type III and type IV fractures. Twenty-two concurrent fractures involved other tarsal bones. Complications were diagnosed in 18 (62.1%) dogs, consisting of 13 minor, 4 major, and 1 catastrophic complication. Lameness at final follow-up (median 7 weeks) in 28 dogs was scored as 0 of 5 in 14 (50.0%) dogs, 1 of 5 in 7 (25.0%) dogs, 2 of 5 in 4 (14.3%) dogs, 4 of 5 in 1 (3.5%) dogs, and 5 of 5 in 2 (7.1%) dogs. Major complications were associated with the presence of multiple tarsal fractures (risk ratio [RR] 3.94, 95% CI 0.80-19.37, P = .13), specifically when the calcaneus was involved (RR 5.78, 95% CI 1.53-21.88, P = .05). CONCLUSION: The most common diagnosis in this population of nonracing dogs consisted of type V Tc fractures. Fractures affecting other tarsal bones were common and were associated with a higher risk of major complications, especially those affecting the calcaneus. CLINICAL SIGNIFICANCE: Short-term outcomes seem favorable in nonracing dogs with isolated Tc fractures, but dogs with concomitant tarsal fractures are predisposed to major complications.

Impact of femoral varus on complications and outcome associated with corrective surgery for medial patellar luxation.

OBJECTIVES: To evaluate the association of femoral varus with postoperative complications and outcome following standard corrective surgery for medial patellar luxation (MPL) without distal femoral osteotomy (DFO) in dogs. METHODS: In a retrospective study spanning a 12 year period, 87 stifles with MPL that were treated by standard surgical techniques were included. Inclination angle (ICA), femoral varus angle (FVA), anatomical lateral distal femoral angle (aLDFA), and mechanical lateral distal femoral angle (mLDFA) were measured. Postoperative complications were noted and outcome evaluated. Associations between potential risk factors and both complication rate and outcome were assessed. RESULTS: Postoperative complications occurred in 19 stifles, five of which were major. There was no evidence of an association between FVA (p = 0.41) or aLDFA (p = 0.38) and any complication. There was also no evidence of an association between FVA (p = 0.31) or aLDFA (p = 0.38) and any major complication. Dogs with a larger aLDFA had increased odds of a poorer outcome (p = 0.01) as did dogs that suffered a major complication (p = 0.0001). CLINICAL SIGNIFICANCE: Based on radiographic measurements, there is no evidence of an association between FVA and the incidence of postoperative complications following standard MPL correction. Traditional surgical techniques appear to be appropriate for most cases of MPL and further work is required to better define selection criteria for including DFO in the treatment of these cases.

Surgical management of medial humeral epicondylitis, cubital synovial osteochondromatosis and humeroradial subluxation in a cat.

CASE SUMMARY: A 13-year-old domestic shorthair cat presented for evaluation of pain and difficulty ambulating. Orthopedic examination and CT facilitated a diagnosis of bilateral elbow synovial osteochondromatosis with medial humeral epicondylitis and concurrent osteoarthritis. Right humeroradial subluxation was evident on CT images, but no instability was evident preoperatively. Surgical treatment was elected, including external neurolysis of the ulnar nerve, removal of the areas of mineralization within the flexor carpi ulnaris muscle and medial arthrotomy to remove intra-articular mineralized bodies. Following closure, instability of the right elbow was noted with humeroradial subluxation necessitating placement of circumferential suture prostheses to provide satisfactory stability. Reassessment was performed 2, 6, 12, 24 and 40 weeks postoperatively and revealed maintenance of elbow stability and substantial improvement in mobility and comfort. RELEVANCE AND NOVEL INFORMATION: While humeroradial subluxation has been reported in association with medial humeral epicondylitis on post-mortem examination, associated clinically significant instability has not been documented previously. Surgeons should be aware of the potential for this complication and check elbow stability following surgery. Despite this complication, a favorable medium-term outcome was achieved for this cat.

Surgical stabilization of concomitant canine medial patellar luxation and cranial cruciate ligament disease. Effect of fixation method on postoperative complication rate and clinical outcome.

OBJECTIVES: To compare complication rates and outcomes between cases of concomitant cranial cruciate ligament (CrCL) disease and medial patellar luxation (MPL) treated using extracapsular stabilization and tibial tuberosity transposition (ECS+TTT) and tibial tuberosity transposition and advancement (TTTA). METHODS: In a multicentre retrospective study, records from four referral hospitals were reviewed for dogs with concomitant CrCL pathology and MPL treated using ECS+TTT or TTTA. Data retrieved included signalment, partial/complete CrCL tear, MPL grade, treatment performed, occurrence of postoperative complications, and postoperative outcome grade. Associations between surgical procedure and risk of complication and surgical procedure and outcome were investigated using univariable logistic regression and proportional odds logistic regression respectively. Multiple logistic regression was used to explore confounding factors. RESULTS: A total of 72 stifles were evaluated in 66 dogs; 32 stifles were stabilized using ECS+TTT and 40 using TTTA. Overall complications were 2.7 times more frequent in the ECS+TTT group and major complications occurred only in this group. The TTTA group was less likely to suffer complications (17.5%) compared to the ECS+TTT group (46.9%) (p = 0.009) and TTTA cases had lower odds of a poorer clinical outcome (p = 0.047). CLINICAL SIGNIFICANCE: Stifles stabilized using ECS+TTT are more likely to suffer from postoperative complications and a poorer clinical outcome when compared to TTTA.

Calcaneal Fractures in Non-Racing Dogs and Cats: Complications, Outcome, and Associated Risk Factors.

OBJECTIVE: To estimate the prevalence of complications and describe the outcome associated with calcaneal fractures in non-racing dogs and in cats. STUDY DESIGN: Retrospective multicenter clinical cohort study. ANIMALS: Medical records of client-owned dogs and cats (2004-2013). METHODS: Medical records were searched and 50 animals with calcaneal fractures were included for analysis. Complications were recorded and an outcome score applied to each fracture. Associations between putative risk factors and both major complications, and final outcome scores were explored. RESULTS: Complications occurred in 27/50 fractures (61%) including 23 major and 4 minor complications. At final follow-up, 4 animals (10%) were sound, 27 (64%) had either intermittent or consistent mild weight-bearing lameness, 7 (17%) had moderate weight-bearing lameness, and 1 (2%) had severe weight-bearing lameness. Fractures managed using plates and screws had a lower risk of complications than fractures managed using pin and tension band wire, lag or positional screws or a combination of these techniques (Relative risk 0.16, 95% CI 0.02-1.02, P=.052). Non-sighthounds had reduced odds of a poorer outcome score than sighthounds (Odds ratio 0.11, 95% CI 0.02-0.50, P=.005) and fractures with major complications had 13 times the odds of a poorer outcome score (Odds ratio 13.4, 95% CI 3.6-59.5, P<.001). CONCLUSION: This study reports a high occurrence of complications associated with calcaneal fracture stabilization in non-racing dogs and in cats, and a poorer outcome score was more likely in animals with complications. A more guarded prognosis should be given to owners of non-racing dogs or cats with calcaneal fractures than previously applied to racing Greyhounds with calcaneal fractures.

A preliminary study of the effect of closed incision management with negative pressure wound therapy over high-risk incisions.

BACKGROUND: Certain postoperative wounds are recognised to be associated with more complications than others and may be termed high-risk. Wound healing can be particularly challenging following high-energy trauma where wound necrosis and infection rates are high. Surgical incision for joint arthrodesis can also be considered high-risk as it requires extensive and invasive surgery and postoperative distal limb swelling and wound dehiscence are common. Recent human literature has investigated the use of negative pressure wound therapy (NPWT) over high-risk closed surgical incisions and beneficial effects have been noted including decreased drainage, decreased dehiscence and decreased infection rates. In a randomised, controlled study twenty cases undergoing distal limb high-energy fracture stabilisation or arthrodesis were randomised to NPWT or control groups. All cases had a modified Robert-Jones dressing applied for 72 h postoperatively and NPWT was applied for 24 h in the NPWT group. Morphometric assessment of limb circumference was performed at six sites preoperatively, 24 and 72 h postoperatively. Wound discharge was assessed at 24 and 72 h. Postoperative analgesia protocol was standardised and a Glasgow Composite Measure Pain Score (GCPS) carried out at 24, 48 and 72 h. Complications were noted and differences between groups were assessed. RESULTS: Percentage change in limb circumference between preoperative and 24 and 72 h postoperative measurements was significantly less at all sites for the NPWT group with exception of the joint proximal to the surgical site and the centre of the operated bone at 72 h. Median discharge score was lower in the NPWT group than the control group at 24 h. No significant differences in GCPS or complication rates were noted. CONCLUSIONS: Digital swelling and wound discharge were reduced when NPWT was employed for closed incision management. Larger studies are required to evaluate whether this will result in reduced discomfort and complication rates postoperatively.

Patellar ligament rupture in the cat: repair methods and patient outcomes in seven cases.

The medical records of cats receiving surgical treatment for unilateral patellar ligament rupture between 1999 and 2012 at 12 referral centres in the UK and Ireland were reviewed. Seven cases were identified: six were caused by trauma and one was iatrogenic, occurring as a complication following surgical stabilisation of a tibial fracture. All cases were treated by sutured anastomosis of the ruptured ligament, with six of the repairs protected by a circumpatellar and/or transpatellar loop of suture. The stifle was immobilised by transarticular external skeletal fixation in three cases. No cases required revision surgery. No complications were reported. Final evaluation, performed at a median time of 31 days, determined five patients to have returned to acceptable or good limb function; two cases were lost to follow-up. The data suggest that, in cats, the current surgical techniques extrapolated from their canine counterparts for repair of a completely or partially ruptured patellar ligament are successfully used and result in acceptable limb function.

Effect of fixation method on postoperative complication rates after surgical stabilization of lateral humeral condylar fractures in dogs.

OBJECTIVES: To assess the impact of stabilization method on the complication rate after lateral humeral condylar fracture (LHCF) repair. STUDY DESIGN: Retrospective multicenter clinical cohort study. ANIMALS: Dogs (n = 151) with LHCF. METHODS: Medical records (2004-2012) were reviewed for dogs that had surgical repair of LHCF. Data retrieved included signalment, cause of fracture, evidence of incomplete ossification of the humeral condyle, occurrence of postoperative complications, presence of supracondylar comminution preoperatively, and persistence of an intracondylar fissure postoperatively. Outcome was assessed based on the most recent data available and graded as excellent, good, fair, or poor. RESULTS: LHCF (n = 135) were evaluated in 132 dogs; 61 fractures were stabilized using a transcondylar screw and supracondylar K-wire, 13 using a transcondylar screw and supracondylar screw, and 61 using a transcondylar screw and lateral epicondylar plate. Major complications were significantly (P = .01) more common after stabilization using a transcondylar screw and supracondylar K-wire (28%) than in dogs where a supracondylar screw or lateral epicondylar plate were used (11%). Cases that had postoperative complications were significantly (P = .02) more likely to have a poor outcome. CONCLUSIONS: LHCF stabilized using a transcondylar screw and supracondylar K-wire are more likely to have major complications resulting in a poorer outcome than cases stabilized using a supracondylar screw or lateral epicondylar plate.

Effect of neutering and breed on femoral and tibial physeal closure times in male and female domestic cats.

The timing of physeal closure is dependent upon many factors, including gonadal steroids, and previous studies have shown that early neutering delays physeal closure. Pelvic and femoral radiographs of 808 cats were analysed and physes at the greater trochanter, proximal femur, distal femur and proximal tibia were recorded as being open or closed. Date of birth, gender, neuter status and breed of cases were recorded. Each physis was analysed individually at a specific age. The number of male entire (ME), male neutered (MN), female entire (FE), female neutered (FN), pedigree and non-pedigree cases at each of these ages was recorded. The number of cases that were open or closed at each stated age were compared between the neutered and entire, the female and male, and the pedigree and non-pedigree groups using a Fischer's exact test, with P <0.05 being considered significant. Seven hundred and eighty-three radiographs were included: 359 MN, 95 ME, 237 FN and 92 FE. Ninety-six cats were pedigree and 687 were non-pedigree. A statistically significant effect was shown with physes closing later in MN than in ME cats for the greater trochanter (P = 0.0037), distal femur (P = 0.0205) and tibial tuberosity (P = 0.0003). No effect was shown for the proximal tibial or proximal femoral physes, nor for any physis when comparing FE with FN cats. No statistically significant effect of breed or sex was noted. Physeal closure will occur later in MN cats than in ME cats for the greater trochanteric, distal femoral and tibial tuberosity physes, and the potential clinical consequences of this should be evaluated further.

Use of vacuum-assisted closure to maintain viability of a skin flap in a dog.

CASE DESCRIPTION: A 4-year-old sexually intact male Labrador Retriever-Poodle mix was admitted to the hospital for treatment of a wound in the left thoracic region. The wound had been debrided and primary closure had been performed by the referring veterinarian 4 days previously. CLINICAL FINDINGS: The dog had a 20-cm-long wound covered by a large flap of skin that extended caudally from the scapula over the left side of the thorax. A 3-cm defect was evident at the cranioventral aspect of the wound, from which purulent material was being discharged. The skin flap was necrotic, and the skin surrounding the flap was bruised. Signs of pain were elicited when the wound and surrounding region were palpated. Other findings, including those of thoracic radiography, were unremarkable. TREATMENT AND OUTCOME: The wound was debrided, and vacuum-assisted closure (VAC) was initiated for 3 days until a healthy bed of granulation tissue developed. A reconstructive procedure was performed with a rotation flap 3 days after VAC dressing removal. The VAC process was reinitiated 2 days following reconstruction because of an apparent failing of the skin flap viability. After 5 days of VAC, the flap had markedly improved in color and consistency and VAC was discontinued. Successful healing of the flap occurred without the need for debridement or additional intervention. CLINICAL RELEVANCE: Use of VAC led to a good overall outcome for the dog, with complete healing achieved. Additional evaluation of this technique for salvaging failing skin flaps is warranted in dogs, particularly considering that no reliable method for flap salvage in veterinary species has been reported to date.