Preoperative computed tomography, surgical treatment and long-term outcomes of dogs with abscesses on migrating vegetal foreign bodies and oropharyngeal stick injuries: 39 cases (2010-2021).

OBJECTIVES: This study evaluated success rates of surgical treatment of head and neck abscesses and draining tracts for suspected migrating vegetal foreign body and oropharyngeal penetrating injuries, and compared the outcomes according to whether a vegetal foreign body was identified in preoperative computed tomography (CT) examination. MATERIALS AND METHODS: This retrospective study involved 39 dogs that underwent CT and subsequent surgical exploration of abscesses and/or draining tracts in the head and neck, in a single institution between 2010 and 2021. Recorded data included signalment, history, physical examination, CT and surgical findings. The postoperative follow-up period was at least 8 months. Cases were classified according to whether a foreign body was identified on CT or was only suspected because of the presence of cavities and/or draining tracts on CT. RESULTS: A vegetal foreign body was identified on CT in 11 of 39 cases and later confirmed at surgery in 10 cases. In 28 of 39 cases, a vegetal foreign body was not identified on CT, but in seven of these 28 cases it was found at surgery. Resolution of clinical signs was achieved in 11 of 11 cases when a vegetal foreign body was identified on CT and in 26 of 28 cases without a foreign body identified on CT. Two cases of recurrence were observed in animals in which no foreign body was detected. CLINICAL SIGNIFICANCE: In this population of dogs undergoing surgery after preoperative CT scan, we observed resolution of clinical signs after a single surgical procedure in 95% of the cases. All animals in which a foreign body was identified were cured.

Evaluation of a small-bore needle arthroscope for diagnosis and treatment of medial coronoid disease in dogs: a pilot study with short-term assessment.

CASE HISTORY: Dogs (n = 15) that were presented to a single veterinary teaching hospital with elbow dysplasia-associated lameness between September 2021 and May 2022, and were determined to require arthroscopy based on imaging results, were prospectively recruited into the study. The median duration of lameness was 4 (min 1, max 24) months. CLINICAL FINDINGS: Various breeds were represented with a median body weight of 31.6 (min 15, max 46.4) kg and median age at presentation of 14 (min 8, max 83) months. Results of imaging modalities (CT) were consistent with medial coronoid disease with fissured or fragmented medial coronoid process in all dogs. ARTHROSCOPIC FINDINGS: Feasibility of the needle arthroscopy (NA) procedure was firstly assessed in a preliminary cadaveric study in forelimbs (n = 10) collected from 10 adult dogs euthanised for reasons unrelated to the study. Elbow exploration was performed through a medial approach beginning with NA (1.9 mm 0° angle scope) followed by standard arthroscopy (SA; 2.4 mm 30° angle scope). The quality and extent of visualisation (scored through the number of anatomical structures visualised) were recorded and statistically compared. As the cadaver study indicated that NA allowed safe inspection of all structures in medial/caudal compartments, this procedure was then used in the dogs requiring treatment. In the clinical setting, elbow exploration was successful in all dogs and the treatment (removal of osteochondral fragments) was performed without requiring conversion into SA. One month after surgery, all dogs had an improvement in their lameness score (0-5) and 12/15 dogs were no longer lame. There was a reduction in Canine Orthopaedic Index scores measured a median of 99 (min 47, max 180) days after surgery (24 (IQR 19.5-31.5)) compared to the pre-operative period (49 (IQR 46.5-57); p < 0.001). CLINICAL RELEVANCE: Needle arthroscopy-assisted removal of osteochondral fragments was performed in all dogs with satisfactory short-term clinical outcome. NA is a feasible technique for diagnosis and lesion assessment in dogs with a fissured or fragmented coronoid process. Larger clinical studies with longer follow-up are necessary to validate the NanoScope operative arthroscopy system as an alternative strategy to SA for video-assisted treatment of medial coronoid disease.

Feline ureteral rupture with para-ureteral urinomas following blunt trauma: clinical presentation and long-term outcome after treatment by urinary diversion for five cases from 2012 to 2019.

CASE HISTORY: Medical records were reviewed for cats that underwent surgical treatment of traumatic ureteral rupture (TUR) using urinary diversion procedures between 2012 and 2019. CLINICAL FINDINGS AND TREATMENT: Five cats had presented with injuries associated with road traffic accidents. These included three cats with abdominal hernias that required surgical management. At a median of 15 days after the accident, cats represented with lethargy, the presence of an abdominal mass or with lower urinary tract symptoms and in all cats contrast diagnostic imaging showed proximal unilateral TUR with associated para-ureteral urinoma. Four cats received subcutaneous ureteral bypass (SUB) device placement and one had ureteral anastomosis over a stent. Unilateral cyst-like retroperitoneal fluid consistent with para-ureteral urinoma was observed in all cats and a diffuse retroperitoneal haematoma was noticed in four cats. No immediate major complications occurred, and all cats had post-operative serum creatinine concentration within the reference interval. The cat that had received a ureteral stent subsequently required placement of a SUB following stent encrustation 15 months after surgery. Median follow-up time was 34 (min 28, max 58) months and renal function was normal in all cats at the last follow-up. CLINICAL RELEVANCE: Urinary diversion procedures provided long-term stable renal function following proximal TUR in these five cats. Delayed, subtle non-specific clinical signs subsequent to high-energy blunt trauma causing abdominal hernia and associated diffuse retroperitoneal haematoma, should raise suspicion of TUR. ABBREVIATIONS: AFAST: Abdominal focused assessment with sonography for trauma; SUB: Subcutaneous ureteral bypass; TUR: Traumatic ureteral rupture.

Needle arthroscopy for exploration of the elbow joint: a case series of six dogs with preliminary cadaveric study.

CASE HISTORY: Dogs (n = 6) suffering from elbow-associated lameness for a median of 3.5 (min 2, max 12) months duration requiring arthroscopic exploration according to imaging results were prospectively included in this study. CLINICAL FINDINGS: Dogs that met the inclusion criteria were of various breeds with a median body weight of 18 (min 13.2, max 34.5) kg and median age at presentation of 11 (min 6, max 96) months. Results of imaging modalities (radiographs and/or computed tomography (CT)) were consistent with developmental elbow disease in all of the dogs. ARTHROSCOPIC FINDINGS: Feasibility of the needle arthroscopy procedure was first assessed in a preliminary cadaveric study. Disease-free cadaveric forelimbs (n = 12) were collected from adult dogs (n = 6) euthanised for reasons unrelated to the present study. Elbow exploration was performed, beginning with needle arthroscopy (1 mm, 0° angle scope) followed by standard arthroscopy (2.4 mm, 30° angle scope) through a medial approach. The ease of introduction, range of motion and the quality of visualisation were assessed subjectively and the presence of iatrogenic introduction lesions and extent of field of vision (assessed by the number of anatomical structures visualised) were scored and statistically compared. Needle arthroscopy allowed inspection of all structures at risk for medial/caudal compartment disease in all joints considering the occasional need for multiple portals. In the clinical setting, elbow exploration was found to be similar to that in cadaver joints in 4/6 dogs. The lower quality of vision provided by needle arthroscopy was a limitation of the technique, and 2/6 clinical cases required conversion to standard arthroscopy for full visualisation of the joint. No introduction lesions were noted with needle arthroscopy in either the cadaveric or clinical studies. CONCLUSIONS AND CLINICAL RELEVANCE: Needle arthroscopy allowed safe visualisation of all of the structures of the medial and caudal compartment in disease-free cadaveric elbows, suggesting that needle arthroscopy is an appropriate technique for diagnosis and assessment of lesions of developmental elbow disease. However, the low quality of vision provided by the 1 mm scope, and the small diameter of the sleeve, which limited fluid inflow, combined with fragility of the device were major drawbacks that prevented consistent full exploration of the joint and detailed lesion assessment in clinical situations. Improvement of the device is thus necessary before use of the technique in clinical practice can be recommended. ABBREVIATIONS: CCD: Caudal compartment disease; CT: Computed tomography; DED: Developmental elbow disease; DJD: Degenerative joint disease; LCL: Lateral collateral ligament; LCP: Lateral coronoid process; LHC: Lateral part of the humeral condyle; MCD: Medial compartment disease; MCL: Medial collateral ligament; MCP: Medial coronoid process; MHC: Medial part of the humeral condyle; MRI: Magnetic resonance imaging.

Treatment of urinary incontinence in a cat with genitourinary dysplasia using an urethral sphincter occluder.

A 2-year-old spayed female Maine Coon presented with urinary incontinence and recurrent urinary tract infection since 2 months of age. Clinical examination was unremarkable. Ultrasonography, CT and cystourethroscopy revealed urogenital abnormalities consistent with genitourinary dysplasia. Urethral pressure profilometry suggested urethral sphincter mechanism incompetence. Surgical placement of an artificial urethral sphincter occluder was performed. Mild decrease of urinary incontinence was observed 6 weeks postoperatively. Inflation of the occluder under urethral pressure profilometry was subsequently performed and resolved the incontinence. This is the first report to describe the use of urodynamic testing at the time of inflation of an artificial urethral sphincter occluder to adjust the degree of urethral occlusion.

Effects of a viscosupplementation therapy on rabbit menisci in an anterior cruciate ligament transection model of osteoarthritis.

The aim of this study was to evaluate the morphological, microstructural, and mechanical effects of a viscosupplementation therapy on rabbit menisci at an early stage of osteoarthritis (OA). Anterior cruciate ligament transection (ACLT) was performed in twelve male New-Zealand White rabbits on the right knee joint. Six of these twelve rabbits received a mono intra-articular injection of high molecular weight hyaluronic acid (HA) two weeks after ACLT. Six additional healthy rabbits served as controls. Medial menisci were removed from all right knees (n=18) six weeks after ACLT and were graded macroscopically. Indentation-relaxation tests were performed in the anterior and posterior regions of the menisci. Collagen fiber organization and glycosaminoglycan (GAG) content were assessed by biphotonic confocal microscopy and histology, respectively. Viscosupplementation significantly (p=0.002) improved the surface integrity of the medial menisci compared to the operated non-treated group. Moreover, the injection seems to have an effect on the GAG distribution in the anterior region of the menisci. However, the viscoelastic properties of both operated groups were similar and significantly lower than those of the healthy group, which was explained by their modified collagen fiber organization. They displayed disruption of the tie fibers due to structural alterations of the superficial layers from which they emanate, leading to modifications in the deep zone. To conclude, the viscosupplementation therapy prevents macroscopic lesions of the menisci, but it fails to restore their collagen fiber organization and their viscoelastic properties. This finding supports the role of this treatment in improving the lubrication over the knee.

A comparative study of tissue-engineered constructs from Acropora and Porites coral in a large animal bone defect model.

OBJECTIVES: To compare the therapeutic potential of tissue-engineered constructs (TECs) combining mesenchymal stem cells (MSCs) and coral granules from either Acropora or Porites to repair large bone defects. MATERIALS AND METHODS: Bone marrow-derived, autologous MSCs were seeded on Acropora or Porites coral granules in a perfusion bioreactor. Acropora-TECs (n = 7), Porites-TECs (n = 6) and bone autografts (n = 2) were then implanted into 25 mm long metatarsal diaphyseal defects in sheep. Bimonthly radiographic follow-up was completed until killing four months post-operatively. Explants were subsequently processed for microCT and histology to assess bone formation and coral bioresorption. Statistical analyses comprised Mann-Whitney, t-test and Kruskal-Wallis tests. Data were expressed as mean and standard deviation. RESULTS: A two-fold increaseof newly formed bone volume was observed for Acropora-TECs when compared with Porites-TECs (14 sd 1089 mm3versus 782 sd 507 mm3; p = 0.09). Bone union was consistent with autograft (1960 sd 518 mm3). The kinetics of bioresorption and bioresorption rates at four months were different for Acropora-TECs and Porites-TECs (81% sd 5% versus 94% sd 6%; p = 0.04). In comparing the defects that healed with those that did not, we observed that, when major bioresorption of coral at two months occurs and a scaffold material bioresorption rate superior to 90% at four months is achieved, bone nonunion consistently occurred using coral-based TECs. DISCUSSION: Bone regeneration in critical-size defects could be obtained with full bioresorption of the scaffold using coral-based TECs in a large animal model. The superior performance of Acropora-TECs brings us closer to a clinical application, probably because of more suitable bioresorption kinetics. However, nonunion still occurred in nearly half of the bone defects.Cite this article: A. Decambron, M. Manassero, M. Bensidhoum, B. Lecuelle, D. Logeart-Avramoglou, H. Petite, V. Viateau. A comparative study of tissue-engineered constructs from Acropora and Porites coral in a large animal bone defect model. Bone Joint Res 2017;6:208-215. DOI: 10.1302/2046-3758.64.BJR-2016-0236.R1.

Viscoelastic properties of rabbit osteoarthritic menisci: A correlation with matrix alterations.

The aim of this study was to evaluate the effect of early osteoarthritis (OA) on the viscoelastic properties of rabbit menisci and to correlate the mechanical alterations with the microstructural changes. Anterior Cruciate Ligament Transection (ACLT) was performed in six male New-Zealand White rabbits on the right knee joint. Six healthy rabbits served as controls. Menisci were removed six weeks after ACLT and were graded macroscopically. Indentation-relaxation tests were performed in the anterior and posterior regions of the medial menisci. The collagen fibre organization and glycosaminoglycan (GAG) content were assessed by biphotonic confocal microscopy and histology, respectively. OA menisci displayed severe macroscopic lesions compared with healthy menisci (p=0.009). Moreover, the instantaneous and equilibrium moduli, which were 2.9±1.0MPa and 0.60±0.18MPa in the anterior region of healthy menisci, respectively, decreased significantly (p=0.03 and p=0.004, respectively) in OA menisci by 55% and 57%, respectively, indicating a global decrease in meniscal stiffness in this region. The equilibrium modulus alone decreased significantly (p=0.04) in the posterior region, going from 0.60±0.18MPa to 0.26±012MPa. This induced a loss of tissue elasticity. These mechanical changes were associated in the posterior region with a structural disruption of the superficial layers, from which the tie fibres emanate, and with a decrease in the GAG content in the anterior region. Consequently, the circumferential collagen fibres of the deep zone were dissociated and the collagen bundles were less compact. Our results demonstrate the strong meniscal modifications induced by ACLT at an early stage of OA and highlight the relationship between structural and chemical matrix alterations and mechanical properties.

Surgical repair of thoraco-lumbar vertebral fracture-luxations in eight cats using screws and polymethylmethacrylate fixation.

OBJECTIVE: To report our clinical experience in the surgical treatment of feline thoraco-lumbar vertebral fracture-luxations using optimal safe implantation corridors as previously described in vitro. STUDY DESIGN: Retrospective clinical study. MATERIALS AND METHODS: Medical records and radiographs of cats with vertebral fracture-luxations stabilized by screws and polymethylmethacrylate (PMMA) using optimal safe implantation corridors between 2009 and 2011 were reviewed. For each patient the data included: signalment, cause of vertebral fracture-luxations, presence of concurrent injuries, pre- and postoperative neurological grade, surgical treatment, imaging findings, and clinical outcome with short-term (2 weeks) and long-term (12 months) follow-up. RESULTS: Eight cats with vertebral fracture-luxations involving the lumbar (L)(n = 5), the thoracic (T) spinal segments (n = 2), or the thoraco-lumbar junction (n = 1) were included in the study. Screws and PMMA were used bilaterally in five cats and unilaterally in three cats. No surgical intra-operative complications using the defined corridors were recorded. Implant failure followed by spontaneous recovery was recorded in one case. Two cats died in the postoperative period (≤ 4 days). The short-term and long-term clinical outcome was excellent in four out of eight cats and satisfactory in two out of eight cats. CONCLUSION AND CLINICAL RELEVANCE: This pilot study demonstrates the clinical applicability of optimal safe implantation corridors for stabilization of feline thoraco-lumbar vertebral fracture-luxations with screws and PMMA. This technique can be used with limited risks of iatrogenic injuries for stabilization of vertebral fracture-luxation localized between T11-L4.

Use of preoperative computed tomography for surgical treatment of recurrent draining tracts.

OBJECTIVES: To evaluate a rational decision-making approach based on preoperative computed tomography for surgical planning in dogs and cats with recurrent draining tracts. METHODS: Retrospective evaluation of case records of animals that underwent preoperative computed tomography for surgical treatment of thoracic/abdominal recurrent draining tracts. Cases were classified according to whether a source of inflammation and/or infection, in particular foreign bodies, was identified (group 1), suspected (group 2) or neither identified nor suspected (group 3) at computed tomography. Surgery consisted of removal of the source of inflammation and/or infection (group 1), debridement or abscess drainage (group 2) or en bloc resection of diseased tissues (group 3). Clinical outcome was evaluated at least 12 months after surgery. RESULTS: A source of inflammation and/or infection was found in 100% (8 of 8), 41% (7 of 17) and 25% (3 of 12) of cases in groups 1, 2 and 3, respectively. Recurrent draining tracts resolved in 100% (8 of 8), 94% (16 of 17) and 92% (11 of 12) of cases in groups 1, 2 and 3, respectively. CLINICAL SIGNIFICANCE: The proposed strategy provided a 95% (35 of 37) cure rate, after a single procedure in 81% (30 of 37) of cases. Recovery of a foreign body at surgery was not a prerequisite for the resolution of the recurrent draining tracts.

Computed tomographic study of the optimal safe implantation corridors in feline thoraco-lumbar vertebrae.

OBJECTIVE: To define the implantation corridors in feline thoraco-lumbar vertebrae (T10-L7) using computed tomography (CT) for optimal safe placement of the implants (screws/pins) in spinal column stabilization. STUDY DESIGN: Computed tomographic study. MATERIALS AND METHODS: Computed tomography images of feline spinal column (n = 10) were used to define the optimal safe implantation corridors (OSIC) in the transverse plane. The OSIC were defined as corridors allowing the greatest amount of bone purchase with safe margins for implantation of the bicortical implants. They were characterized by their insertion point, optimal angle (from the midsagital plane), maximum and minimum safe angles (from the same insertion points), length, and width. RESULTS: The OSIC are located within the vertebral bodies. Insertion points were situated at the level of the vertebro-costal joint or the base of the transverse process of the vertebral body for thoracic and lumbar vertebrae, respectively. The mean optimal angle of the OSIC was 90.2° with a maximum deviation angle from optimal angle of 10° dorsally and 8.8° ventrally in thoracic vertebrae, and 90.5° with a maximum deviation angle from the optimal angle of 8.4° dorsally and 7.6° ventrally in lumbar vertebrae. CONCLUSION AND CLINICAL RELEVANCE: Corridors drilled in the vertebral body perpendicular to the midsagital plane (90°) or with a small angle (≤10°) of deviation from the optimal angle provide an optimal safe placement of bicortical implants. However, perpendicular implant placement may not always be feasible due to surrounding soft tissue structures.

Laparoscopic ovariectomy in dogs using a single-port multiple-access device.

The aim of this case series was to describe a novel technique of single-incision laparoscopic ovariectomy in dogs using the SILS Port (Covidien), a single-port multiple-access device, in 40 client-owned dogs. A single 3 cm incision was made caudal to the umbilicus and the SILS Port device was bluntly introduced. Three cannulae were inserted in the SILS Port through the access channels. In the first 20 cases, a transabdominal suspension suture was used to transfix the ovaries. In all cases, ovariectomy was performed using a standard straight non-roticulated laparoscopic grasper and a vessel sealer/divider device. Mean (sd) duration of the ovarian resection was 25.1 (6.1) minutes (range 16 to 39 minutes). In five dogs (with transabdominal suspension suture), minor bleeding in the mesovarium or in the spleen was observed. Since the SILS Port allows simultaneous use of two instruments and a telescope through a single incision, the suspension suture is not mandatory. The lack of a transabdominal suspension suture increased collision between instruments and the telescope, but triangulation capabilities remained sufficient to achieve visualisation, sufficient manoeuvrability and safe vessel sealer/divider device application. The time to perform ovarian resection remained unaltered with or without suspension suture and regardless of the fat score of the ovarian ligament. Complications were less frequent without a suspension suture.

Minimally invasive video-assisted cervical ventral slot in dogs. A cadaveric study and report of 10 clinical cases.

OBJECTIVES: To investigate the feasibility of a minimally invasive video-assisted (MIVA) cervical ventral slot (VS) in dogs without the use of fluoroscopy, and to report our initial clinical experiences in dogs. METHODS: Two surgical approaches to an intervertebral disk space (IVDS) were performed in eight intact canine cadavers to determine the feasibility of MIVA-VS using the Destandau Endospine™ Devicea (DED) without fluoroscopic guidance. In a subsequent clinical study, 10 client-owned dogs admitted for a Hansen type 1 disk extrusion underwent a MIVA-VS. Recorded data in both studies included: incision lengths, correct targeting of the IVDS, technical problems encountered during the procedure, and potential damage to major anatomical structures. In the 10 clinical cases, duration of the procedure and clinical outcome at five and 12 days, and after a minimum of three months were also recorded. RESULTS: Correct exposure of the targeted IVDS was achieved in all cases. There was no major iatrogenic damage. Mean skin incision length was 39 mm and mean surgery time was 52 minutes. The technique provided increased illumination and magnification of the surgical field. Recovery was uneventful in all cases. CLINICAL RELEVANCE: The present study provided evidence that MIVA-VS using the DED was feasible and a relatively fast and safe procedure for the treatment of cervical disk herniation. Advantages of the technique seemed to include shorter incisions, less dissection and improved visibility.

Anatomical and safety considerations in establishing portals used for canine elbow arthroscopy.

OBJECTIVES: To describe the relationship of the major muscular, ligamentous and neurovascular structures in relation to standard medial elbow arthroscopic portals used in dogs, and to evaluate their potential iatrogenic lesions. DESIGN: Anatomical study using 20 canine cadaveric elbows. METHODS: Arthroscopic explorations were performed using medial portals. Three 4 mm orthopaedic pins were introduced in place of the arthroscope, egress canula and instrumental portals. Limbs were dissected. Distances between pins and neurovascular structures were measured. Muscle, ligament and cartilage lesions were recorded. RESULTS: Minimal muscular lesions were observed. No ligament injury was evidenced. Superficial iatrogenic cartilage lesions were observed in three joints. The arthroscopic portal was 23.1 mm (range: 16 to 28.5 mm) caudal to the brachial artery, 21.0 mm (13-30.5 mm) caudal to the median nerve, and 4.0 mm (1-7 mm) cranial to the ulnar nerve. The instrumental portal was 16.3 (9-24 mm) caudal to the brachial artery, 13.5 mm (7-24.5 mm) caudal to the median nerve, and 11.8 (8-18 mm) cranial to the ulnar nerve. The egress portal was 21.4 mm (12-37 mm) caudal to the ulnar nerve. CONCLUSIONS AND CLINICAL RELEVANCE: The study confirmed the safety of elbow medial arthroscopic portals. Care must be taken when placing the camera portal so as to avoid injury of the ulnar nerve. Should extensive intra-articular procedures be needed, manipulation of instruments should be done cautiously in the cranio-medial compartment of the joint due to the proximity of the median nerve to the capsule.

Rectovaginal fistula following colectomy with an end-to-end anastomosis stapler for a colorectal adenocarcinoma.

An 11-year-old, female neutered Labrador retriever was presented with a micro-invasive differentiated papillar adenocarcinoma at the colorectal junction. A colorectal end-to-end anastomosis stapler device was used to perform resection and anastomosis using a transanal technique. A rectovaginal fistula was diagnosed two days later. An exploratory laparotomy was conducted and the fistula was identified and closed. Early dehiscence of the colon was also suspected and another colorectal anastomosis was performed using a manual technique. Comparison to a conventional manual technique of intestinal surgery showed that the use of an automatic staple device was quicker and easier. To the authors' knowledge, this is the first report of a rectovaginal fistula occurring after end-to-end anastomosis stapler colorectal resection-anastomosis in the dog. To minimise the risk of this potential complication associated with the limited surgical visibility, adequate tissue retraction and inspection of the anastomosis site are essential.

De novo reconstruction of functional bone by tissue engineering in the metatarsal sheep model.

Large bone defects are still a challenge to orthopedic surgeons. In this study, a massive bone defect with a clinically relevant volume was efficiently reconstructed by transplanting an engineered bone in which mesenchymal stem cells (MSCs) expanded in autologous serum (AS) were combined with a porous scaffold. In the first step, we established that the way in which the MSCs are distributed over the scaffold affects the ultimate bone-forming ability of the transplant: constructs consisting of a natural coral scaffold and a pseudo-periosteal layer of MSCs surrounding the implant (coral-MSC3D) formed significantly more bone than constructs in which the MSCs were distributed throughout the implant (p = 0.01). However, bone healing occurred in only one sheep, owing to the high resorption rate of natural coral scaffold. To overcome this problem, constructs in which MSCs were combined with a porous coralline-based hydroxyapatite (CHA) scaffold having the same architecture as natural coral but a lower resorption rate were prepared. After their implantation, these constructs were found to have the same osteogenic potential as autologous bone grafts in terms of the amount of newly formed bone present at 4 months (p = 0.89) and to have been completely replaced by newly formed, structurally competent bone within 14 months. Nevertheless, although the rate of bone healing was strikingly improved when CHA-MSC3D constructs were used (five of seven animals healed) as compared with the coral-MSC3D construct (one of seven healed), it was still less satisfactory than that obtained with autografts (five of five healed).

Cervical expanding hematomas in dogs: five cases.

Five puppies were presented to the Alfort National Veterinary School for a rapidly expanding, well-demarcated, subcutaneous cervical mass of a few days' duration. In all cases, previous trauma was reported. Fine-needle aspiration of the mass in each case revealed a serosanguineous fluid containing mainly erythrocytes, with a total protein concentration ranging from 3.5 to 5.2 g/dL. Coagulation tests failed to reveal any coagulation disorder. En-bloc surgical removal of the fluid-filled mass associated with short-term postoperative drainage was curative in all cases. Histopathological examination of the mass revealed encapsulated hematoma. The disease resembles chronic expanding hematoma in humans.

Tissue-engineered bone regeneration.

Bone lesions above a critical size become scarred rather than regenerated, leading to nonunion. We have attempted to obtain a greater degree of regeneration by using a resorbable scaffold with regeneration-competent cells to recreate an embryonic environment in injured adult tissues, and thus improve clinical outcome. We have used a combination of a coral scaffold with in vitro-expanded marrow stromal cells (MSC) to increase osteogenesis more than that obtained with the scaffold alone or the scaffold plus fresh bone marrow. The efficiency of the various combinations was assessed in a large segmental defect model in sheep. The tissue-engineered artificial bone underwent morphogenesis leading to complete recorticalization and the formation of a medullary canal with mature lamellar cortical bone in the most favorable cases. Clinical union never occurred when the defects were left empty or filled with the scaffold alone. In contrast, clinical union was obtained in three out of seven operated limbs when the defects were filled with the tissue-engineered bone.

[Characterization of biomechanical behavior of the lumbosacral spine in dogs. Characteristics related to spondylosis and disk degeneration]. / Caractérisation du comportement biomécanique du rachis lombo-sacré chez le chien. Particularités associées à la spondylose et à la dégénérescence discale.

The in vitro and static biomechanical behaviour of vertebrae with spondylosis were compared with that of healthy vertebrae. In the dog, spondylosis predominates in the lombo-sacral spine which was chosen as an animal model for spontaneous spondylosis. Fourteen surgical specimens were take from German shepherd dogs which had been submitted to right and left lateral flexion, saggital flexion and dorsal flexion. Angular displacements were recorded with an analyser of spinal movement. Our results demonstrated diseased vertebrae have more flexibility than healthy vertebrae in the sagittal and frontal planes than but less so for dorsal flexion. In Addition, diseased vertebrae tend to move upward during lateral flexion. Exeresis of ligament and capsular structures has allowed us to demonstrate the importance of these structures in maintaining spine stability in the sagittal plane and in joint coaptation. Exeresis of the facet joints led to the demonstration of the role of these structures in the maintenance of spine stability in the transverse plane in cases of disc degeneration.