Effect of Plate Type on Tibial Plateau Levelling and Medialization Osteotomy for Treatment of Cranial Cruciate Ligament Rupture and Concomitant Medial Patellar Luxation in Small Breed Dogs: An In Vitro Study.

OBJECTIVE: The main aim of this study was to determine the effective magnitude of proximal tibial segment medialization achievable during tibial plateau levelling and medialization osteotomy (TPLO-M) with Fixin 1.9-2.5 mm pre-contoured T plates with three different offsets. METHODS: In this in vitro study, 36 tibia bone models reconstructed using stereolithography from hindlimb CT scans of a 5 kg dog and a 10 kg dog without orthopaedic disease were used. TPLO-M was performed using plates with three different offsets (2, 4 and 6 mm). Post-osteotomy radiographic and bone models measurements were performed. RESULTS: Regardless of patient weight, the +4 mm offset plates provided a translation of 2.93mm (± 0.51) while the +6 mm offset plates provided a translation of 5.03mm (± 0.47). In the 5kg dog bone model group limited bone contact at the osteotomy site was documented when using the +6mm offset plate. CONCLUSION: The +4mm and +6mm offset Fixin plates may be considered for TPLO-M in dogs weighing between 5 and 10 kg. The +6mm offset plate should be used cautiously in dogs weighing less than 10 kg since this plate may result in insufficient postoperative bone apposition at the osteotomy site.

Surgical Treatment of Nonmineralized Supraspinatus Tendinopathy in Dogs: A Retrospective Long-Term Follow-Up.

(1) Background: two forms of supraspinatus tendinopathy (ST) have been reported in dogs: mineralized and non-mineralized. Surgical treatment consists of longitudinal incisions (splitting) in the tendon of insertion of the supraspinatus muscle. The purpose of this retrospective study is to describe the diagnostic workout, the surgical procedure and the short and long term follow up of dogs treated for non-mineralized ST. (2) Methods: medical records (2010-2017) of dogs diagnosed with non-mineralized ST that underwent surgical treatment were reviewed. Data retrieved were: signalment, history, clinical signs, orthopaedic examination findings, diagnostic imaging findings, surgical treatment, histopathologic diagnosis and clinical outcome. (3) Results: A total of 27 dogs met the inclusion criteria. The most consistent clinical findings were intermittent lameness accompanied by pain on palpation of the insertion of the supraspinatus. Magnetic resonance imaging (MRI) of 27 shoulders distended sheaths of the biceps tendon (10/27), compression of the biceps brachii tendon sheaths (5/27) and enlargement of the supraspinatus tendon (3/27) were observed. The most prominent histologic finding was severe myxomatous degeneration in all 27 samples. Resolution of lameness was achieved in 80% of the cases surgically treated without any further lameness episodes in the long-term follow-up. (4) Conclusions: the surgical splitting of the non-mineralized supraspinatus tendon is an effective procedure with no intra-operative complications and a low incidence of minor (18%) and major (4%) complications.

Biomolecular, Histological, Clinical, and Radiological Analyses of Dental Implant Bone Sites Prepared Using Magnetic Mallet Technology: A Pilot Study in Animals.

BACKGROUND: A new instrumentation exploiting magneto-dynamic technology (mallet) proposed for implant site preparation was investigated. METHODS: In the tibias of three minipigs, two sites were prepared by mallet and two by drill technique. Primary stability (ISQ) was detected after implant positioning (T0) and at 14 days (T14). X-rays and computed tomography were performed. At T14, bone samples were utilized for histological and biomolecular analyses. RESULTS: In mallet sites, histological evaluations evidenced a significant increase in the newly formed bone, osteoblast number, and a smaller quantity of fibrous tissue. These results agree with the significant BMP-4 augmentation and the positive trend in other osteogenic factors (biological and radiological investigations). Major, albeit IL-10-controlled, inflammation was present. For both techniques, at T14 a significant ISQ increase was evidenced, but no significant difference was observed at T0 and T14 between the mallet and drill techniques. In mallet sites, lateral bone condensation was observed on computed tomography. CONCLUSIONS: Using biological, histological, clinical, and radiological analyses, this study first shows that the mallet technique is effective for implant site preparation. Based on its ability to cause osseocondensation and improve newly formed bone, mallet technology should be chosen in all clinical cases of poor bone quality.

Use of a Transarticular Calcaneo-Tibial Locking Plate for Temporary Immobilization of the Tarsocrural Joint following Surgical Repair of Common Calcaneal Tendon Rupture in Eight Dogs.

OBJECTIVE: The purpose of this clinical communication is to report the management of common calcaneal tendon rupture in dogs using a transarticular calcaneo-tibial locking plate as a method of temporary immobilization of the tarsocrural joint to support primary repair of the common calcaneal tendon. STUDY DESIGN: Dogs presented with partial or complete common calcaneal tendon rupture treated with primary tendon repair supported by the transarticular calcaneo-tibial locking plate technique from July 2016 to December 2019 were included. The tarsus was placed at a standing angle of 150 degrees and the pre-contoured Fixin locking 'L' or 'T' plate was medially applied with two locking screws inserted in the calcaneus and two screws inserted in the distal tibia. Tendon healing judgement was mostly based on clinical palpation and ultrasound examination was not performed in all the cases. Plates were removed in all dogs 6 weeks postoperatively. RESULTS: All tendons healed and no complications at the level of the tenorrhaphy were noted in the postoperative period. All dogs returned to hunting activity with full function of the affected limb. No major complications requiring revision surgery were observed. Minor complications occurred in two cases; osteomyelitis and screw pull-out. CONCLUSION: The use of a transarticular calcaneo-tibial locking plate for temporary immobilization of the tarsocrural joint after surgical repair of common calcaneal tendon rupture appears to be an effective technique with comparable results to other reported techniques.

Role of rhBMP-7, Fibronectin, And Type I Collagen in Dental Implant Osseointegration Process: An Initial Pilot Study on Minipig Animals.

BACKGROUND: The biological factors involved in dental implant osseointegration need to be investigated to improve implant success. METHODS: Twenty-four implants were inserted into the tibias of six minipigs. Bone samples were obtained at 7, 14, and 56 days. Biomolecular analyses evaluated mRNA of BMP-4, -7, Transforming Growth Factor-ß2, Interleukin-1ß, and Osteocalcin in sites treated with rhBMP-7, Type 1 Collagen, or Fibronectin (FN). Inflammation and osteogenesis were evaluated by histological analyses. RESULTS: At 7 and 14 days, BMP-4 and BMP-7 increased in the sites prepared with rhBMP-7 and FN. BMP-7 remained greater at 56 days in rhBMP-7 and FN sites. BPM-4 at 7 and 14 days increased in Type 1 Collagen sites; BMP-7 increased from day 14. FN increased the TGF-ß2 at all experimental times, whilst the rhBMP-7 only did so up to 7 days. IL-1ß increased only in collagen-treated sites from 14 days. Osteocalcin was high in FN-treated sites. Neutrophilic granulocytes characterized the inflammatory infiltrate at 7 days, and mononuclear cells at 14 and 56 days. CONCLUSIONS: This initial pilot study, in a novel way, evidenced that Type 1 Collagen induced inflammation and did not stimulate bone production; conversely FN or rhBMP-7 showed neo-osteogenetic and anti-inflammatory properties when directly added into implant bone site.

Fracture Repair in Cats Using a Conical Coupling Mini 1.9 to 2.5 mm Locking Plate System.

OBJECTIVE: The aim of this study was to retrospectively evaluate the clinical application of the Fixin mini 1.9 to 2.5 system for the treatment of long bone fractures in cats. We proposed that the Fixin mini system would successfully stabilize long bone fractures in cats with a healing time and complication rate similar to those previously reported for feline fractures using other locking bone plate systems. MATERIALS AND METHODS: Medical records and radiographs of cats with long bone fractures stabilized with the Fixin mini 1.9 to 2.5 system were retrospectively reviewed. Signalment, body weight, bone(s) fractured, region of bone fractured, fracture classification, concurrent orthopaedic injuries, complications, time to functional union, if minimally invasive plate osteosynthesis techniques were used, plate size, number of plates, bone graft use and ancillary methods of fixation were recorded. RESULTS: Fifty-six fractures in 54 cats were included. Mean time to radiographic union was 8.8 weeks. Complications were recorded in 8 out of 56 fractures. Major complications occurred in 4 of 56 fractures and minor complications occurred in 4 of 56 fractures. CONCLUSION: The Fixin mini 1.9 to 2.5 system had an overall complication rate and time to functional union similar to that of other implant systems used to treat feline long bone fractures and it appears suitable for repair of a wide variety of long bone fracture configurations in cats.

Antebrachial Angular Deformities Using Computer-Assisted Hexapod External Fixator Systems in Dogs.

OBJECTIVE: The aim of this study was to investigate the applicability of computer-assisted hexapod fixators in dogs and to consider the advantages and disadvantages during implementation. MATERIALS AND METHODS: This was a prospective study. The study material consisted of 11 deformed extremities of 6 dogs. The correction plans were defined according to multiple extremity radiographs of the dog and the clinical evaluation of deformities. All measurements were uploaded to Click2Correct software program. Latent, correction and consolidation periods of each dog were recorded. The hexapod external fixators were removed after completion of the correction. RESULTS: Data were adapted to the radiographic navigation software to be used during operation and postoperative period. The latent period ranged from 3 to 20 days, the correction period ranged from 7 to 20 days and the consolidation period ranged from 39 to 81 days. It was concluded that special fixators can be used in dogs with complex antebrachial deformities. CLINICAL SIGNIFICANCE: The ability to perform six axes correction at the same time has a considerable advantage, especially in dogs with complex antebrachial deformities. It is practical to use this fixation system in dogs with antebrachial deformities.

Minimally Invasive Plate Osteosynthesis Fracture Reduction Techniques in Small Animals.

Indirect fracture reduction is used to align diaphyseal fractures when using minimally invasive fracture repair. Indirect reduction achieves functional fracture reduction without opening the fracture site. The limb is restored to length and spatial alignment is achieved to ensure proper angular and rotational alignment. Fracture reduction can be accomplished using a variety of techniques and devices, including hanging the limb, manual traction, distraction table, external fixators, and fracture distractors.

The effectiveness of marine based fatty acid compound (PCSO-524) and firocoxib in the treatment of canine osteoarthritis.

BACKGROUND: NSAIDs are accepted as the most predictably efficacious medical treatment of the clinical signs of osteoarthritis (OA). The marine-based fatty-acid compound PCSO-524 has been proposed as an adjunctive treatment for canine OA, however benefits of this agent is still controversial. The purpose of this study was to evaluate and compare the effectiveness of PCSO-524 combined with the NSAID firocoxib using force plate gait analysis, orthopedic assessment score (OAS) and canine brief pain inventory score (CBPI) in dogs with OA. A prospective, randomized, double-blinded study was conducted. Seventy-nine dogs that had hip and/or stifle OA were assigned randomly into three treatment groups: firocoxib, PCSO-524 and combination of firocoxib and PCSO-524, orally for 4 weeks. Peak vertical force (PVF, expressed as a percentage of bodyweight), OAS, CBPI, serum prostaglandin E2 concentration, hematology and blood chemistry values were evaluated before treatment (Day0), as well as at the second (Day14) and fourth week (Day28) during treatment. RESULTS: Within group analysis revealed significant increases in PVF over the 4-week treatment period for firocoxib, PCSO-524 and the combination (p < 0.05). Mean increases in PVF were 3.25 ± 4.13, 2.01 ± 3.86, 4.11 ± 4.69%BW (mean ± SD) respectively. The OAS showed non-significant change in all treatment groups. There were significant decreases in CBPI pain severity score (PSS) and CBPI pain interference scores (PIS) within some groups over time, however no significant differences were found between the groups. Significantly decreased serum PGE2 concentration (p < 0.05) was found in the combination group. Significant increases in BUN and creatinine (p < 0.05) compared to pre-treatment values were found in the firocoxib and combination groups but not in the PCSO-524 group at day28, but all values in all dogs remained within the normal ranges. CONCLUSIONS: The results of this study suggested combination of both PCSO-524 and firocoxib is more effective in alleviation of inflammation and improvement of weight bearing ability when compared to the uses of either PCSO-524 or firocoxib alone. Further clinical studies are needed to confirm this, and to determine if there is any benefit of PCSO-524 over placebo.

Combination of magnesium sulphate and ropivacaine epidural analgesia for hip arthroplasty in dogs.

OBJECTIVE: The aim of this study was to determine whether lumbosacral epidural administration of magnesium sulphate added to ropivacaine prolongs and improves perioperative analgesia, without adverse effects on motor block duration or hind limb neurological function, in dogs undergoing hip arthroplasty. STUDY DESIGN: Investigator-blind, controlled, randomized, prospective clinical trial. ANIMALS: A group of 20 client-owned dogs undergoing hip arthroplasty were allocated randomly to either group C (control, 1 mg kg-1epidural ropivacaine) or group M (magnesium, epidural injection of 1 mg kg-1 ropivacaine and 2 mg kg-1magnesium sulphate). METHODS: All dogs were premedicated with intramuscular acepromazine. General anaesthesia was induced with propofol and maintained with isoflurane in oxygen. Intraoperatively, nociception was assessed based on changes in heart rate, respiratory rate and mean arterial pressure above baseline values. Postoperatively, pain was evaluated with a Sammarco pain score, a Glasgow pain scale and a visual analogue scale (VAS). Tarlov's scale was used to quantify motor block. All dogs were evaluated at recovery and then 1, 2, 3, 4, 5 and 24 hours after that. Rescue analgesia was provided during surgery with fentanyl and, postoperatively, with buprenorphine. Groups were compared using one-way repeated-measure analysis of variance followed by the Holm-Sidak method for multiple comparison or nonparametric tests when appropriate. RESULTS: The two treatment groups did not differ (p > 0.05) with respect to intraoperative physiological variables, rescue analgesia, postoperative pain scores (Sammarco q = 1.00; Glasgow q = 3.10; VAS q = 0.50) and duration of the motor block (Tarlov's q = 2.40). CONCLUSIONS AND CLINICAL RELEVANCE: The addition of epidural magnesium to ropivacaine did not improve or prolong the analgesia provided by ropivacaine alone. Further studies are needed to determine whether an epidural magnesium dose of >2 mg kg-1 would exert better analgesia, without causing adverse effects, in dogs undergoing orthopaedic surgery.

Prevalence, treatment and outcome of patellar luxation in dogs in Italy. A retrospective multicentric study (2009-2014).

OBJECTIVE: To determine the prevalence of patellar luxation in dogs in Italy and its relation to signalment, the frequency and the type of postoperative complications and the outcome of treatment, and to compare the findings with those of other studies. MATERIALS AND METHODS: The medical records from four referral clinics were searched for dogs with orthopaedic disorders referred from 2009 to 2014. From these data, the records of dogs with patellar luxation were identified, and the signalment, age and body weight, grade, side and direction of patellar luxation, treatment, postoperative complications, and outcome were retrieved. Univariate and multivariate statistical analyses were used to evaluate the data. RESULTS: Of 8,694 canine orthopaedic cases, fractures not included, patellar luxation was diagnosed in 559 dogs (801 stifles). Mixed breed dogs were most commonly affected (18%), 85% of the luxations were medial, and 52% of the dogs were female. Of the 559 dogs examined, 400 (574 stifles) met the inclusion criteria for treatment evaluation. Minor complications occurred in five percent of the dogs, and major complications in 16%, including recurrence of patellar luxation in seven percent of the dogs. The outcome was good in 88% of stifles, fair in two percent, and poor in 10%. CLINICAL SIGNIFICANCE: Although patellar luxation was more common in small breed dogs, it also was diagnosed in a significant number of large breed dogs, which included medial patellar luxation in 73% and lateral patellar luxation in 27% of stifles. Body weight and grade of luxation were the only variables statistically correlated with surgical complications.

Comparison of osteotomy technique and jig type in completion of distal femoral osteotomies for correction of medial patellar luxation. An in vitro study.

OBJECTIVES: Femoral osteotomies are frequently completed to correct malalignment associated with patellar luxation. The objectives of this study were to compare the use of: 1) two different types of jig; and 2) different types of osteotomy in the realignment of canine femoral bone models which possessed various iterations of angular deformity. METHODS: Models of canine femora possessing distal varus, external torsion and a combination of varus and torsion underwent correction utilizing two alignment jigs (Slocum jig and Deformity Reduction Device) and either a closing wedge ostectomy (CWO) or an opening wedge osteotomy (OWO). Post-correctional alignment was evaluated by radiographic assessment and compared between groups. RESULTS: The use of the Slocum jig resulted in frontal plane overcorrection when used with CWO in models of femoral varus, and when used with OWO in models of femoral varus and external torsion when compared to other techniques. The Deformity Reduction Device tended to realign the frontal plane closer to the post-correction target value in all angulation types. The use of both jigs resulted in undercorrection in the transverse plane in models with varus and torsion. CLINICAL SIGNIFICANCE: Jig selection and osteotomy type may lead to different post-correctional alignment results when performing distal femoral osteotomies. Whereas OWO allows accurate correction when used with either jig to address frontal plane deformities, the Deformity Reduction Device can be utilized with both CWO and OWO to correct torsion-angulation femoral deformities to optimize frontal plane alignment.

Kirschner wire fixation of Salter-Harris type IV fracture of the lateral aspect of the humeral condyle in growing dogs. A retrospective study of 35 fractures.

OBJECTIVES: To evaluate the use of Kirschner wires for treatment of fractures of the lateral aspect of the humeral condyle in growing dogs. METHODS: Retrospective analysis of 35 elbow fractures (33 dogs) of the lateral aspect of the humeral condyle treated by insertion of multiple transcondylar and one anti-rotational Kirschner wires. Radiographic and clinical re-evaluations were carried out immediately after surgery, at four weeks and, when required, at eight weeks postoperatively. Long-term follow-up was planned after a minimum of six months. The relationship between different implant configurations and clinical outcome was analysed statistically. RESULTS: Complete functional recovery was seen in 31 elbows (30 dogs), three elbows (2 dogs) had reduction in the range of motion, and one elbow (1 dog) had persistent grade 1 lameness two months postoperatively. Major complications occurred in eight elbows (8 dogs) and all were resolved by implant removal. Implant configuration did not affect outcome. Long-term evaluation in 12 cases with a mean follow-up of four years showed absence of lameness, normal function and no or mild radiographic evidence of osteoarthritis in 11 cases. CLINICAL SIGNIFICANCE: Fracture of the lateral aspect of the humeral condyle in growing dogs can be successfully treated by multiple transcondylar convergent or parallel Kirschner wires, resulting in adequate fracture healing.

Distal femoral osteotomy using a novel deformity reduction device.

Distal femoral osteotomy is a surgical procedure used to correct patellar luxation, secondary to a femoral deformity. A distal femoral osteotomy using the tibial plateau levelling osteotomy-jig to temporarily provide stability of the distal femoral osteotomy, maintaining limb alignment in the frontal and axial planes prior to internal plate fixation of the osteotomy, has been described. This report describes a novel jig named Deformity Reduction Device (DRD). This device was developed with the specific aim of increasing precision and predictability during corrective osteotomy execution in order to be consistent with the preoperative planning. The distal femoral osteotomy DRD-assisted procedure is described in detail, discussing the theoretical and practical principles of the application.

Pelvic limb alignment in small breed dogs: a comparison between affected and free subjects from medial patellar luxation.

Small breed dogs are 12 times more likely to develop medial patellar luxation (MPL) than large breed dogs and breed predisposition has been reported. Many surgical techniques are available for correction of patellar luxation in dogs. However, recent studies reported an 8% incidence of reluxation when traditional techniques are used. The relatively high frequency of major complications and patellar reluxation may be partially caused by inadequate appreciation of the underlying skeletal deformity and subsequent incorrect selection and application of traditional techniques. The aims of this study were to report the normal values of the anatomic and mechanical joint angles of the femur and tibia in small breed dogs and to compare these data to a population of small breed dogs affected by different degrees of MPL. Normal values of the anatomic and mechanical angles of the femur are similar to the ones reported in literature in Pomeranian dogs. Normal values of the anatomic and mechanical angles of the tibia have been described for the first time. Significant differences were found between normal population and dogs affected by grade 4 MPL in relation to anatomical Lateral Distal Femoral Angle (aLDFA), mechanical Medial Proximal Tibial Angle (mMPTA), and mechanical Caudal Proximal Tibial Angle (mCaPTA).

An alumina toughened zirconia composite for dental implant application: in vivo animal results.

Ceramic materials are widely used for biomedical applications because of their remarkable biological and mechanical properties. Composites made of alumina and zirconia are particularly interesting owing to their higher toughness with respect to the monolithic materials. On this basis, the present study is focused on the in vivo behavior of alumina toughened zirconia (ATZ) dental implants treated with a hydrothermal process. A minipig model was implemented to assess the bone healing through histology and mRNA expression at different time points (8, 14, 28, and 56 days). The novel ATZ implant was compared to a titanium clinical standard. The implants were analyzed in terms of microstructure and surface roughness before in vivo tests. The most interesting result deals with a statistically significant higher digital histology index for ATZ implants with respect to titanium standard at 56 days, which is an unprecedented finding, to the authors' knowledge. Even if further investigations are needed before proposing the clinical use in humans, the tested material proved to be a promising candidate among the possible ceramic dental implants.

Effect of screw insertion torque on push-out and cantilever bending properties of five different angle-stable systems.

OBJECTIVE: To compare the screw push-out strength and resistance to cantilever bending of 5 different angle-stable systems using 4 different insertion torque values to tighten locking screws. STUDY DESIGN: In vitro mechanical testing of 5 screw-plate constructs. SAMPLE POPULATION: Screw plate constructs (n = 60) were tested; 12 of each design, 3 for each torque value. METHODS: To compare push-out strength, screws were loaded in axial direction on the screw tip until loosening of the locking mechanism was recorded. For cantilever bending test, screws were loaded perpendicularly to their longitudinal axis at 2 mm of distance from the under surface of the plate. Load was applied in displacement control at 1 mm/min. RESULTS: There was a significant difference between the 5 different angle-stable systems regarding both push-out and cantilever bending strength. There was an influence of insertion torque value on push-out strength for 2 systems and insertion torque value influenced cantilever bending behavior only in 1 locking system. CONCLUSIONS: Locking mechanisms using "thread in thread" principle provided a stronger screw push-out behavior. Screws materials and core diameter of the different screws were directly related to cantilever bending strength.

Minimally invasive plate osteosynthesis fracture reduction techniques in small animals.

Indirect fracture reduction is used to align diaphyseal fractures in small animals when using minimally-invasive fracture repair. Indirect reduction achieves functional fracture reduction without opening the fracture site. The limb is restored to length and spatial alignment is achieved to ensure proper angular and rotational alignment. Fracture reduction can be accomplished using a variety of techniques and devices, including hanging the limb, manual traction, distraction table, external fixators, and a fracture distractor.

Cytokines and growth factors involved in the osseointegration of oral titanium implants positioned using piezoelectric bone surgery versus a drill technique: a pilot study in minipigs.

BACKGROUND: Most dental implants are positioned using a drilling surgery technique. However, dentistry recently experienced the implementation of piezoelectric surgery. This technique was introduced to overcome some of the limitations involving rotating instruments in bone surgery. This study used biomolecular and histologic analyses to compare the osseointegration of porous implants positioned using traditional drills versus the piezoelectric bone surgery technique. METHODS: Porous titanium implants were inserted into minipig tibias. Histomorphology and levels of bone morphogenetic protein (BMP)-4, transforming growth factor (TGF)-beta2, tumor necrosis factor-alpha, and interleukin-1beta and -10 were evaluated in the peri-implant osseous samples. RESULTS: Histomorphological analyses demonstrated that more inflammatory cells were present in samples from drilled sites. Also, neo-osteogenesis was consistently more active in bone samples from the implant sites that were prepared using piezoelectric bone surgery. Moreover, bone around the implants treated with the piezoelectric bone surgery technique showed an earlier increase in BMP-4 and TGF-beta2 proteins as well as a reduction in proinflammatory cytokines. CONCLUSION: Piezoelectric bone surgery appears to be more efficient in the first phases of bone healing; it induced an earlier increase in BMPs, controlled the inflammatory process better, and stimulated bone remodeling as early as 56 days post-treatment.