M. Manassero

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

OBJECTIVESnTo 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.nnnMETHODSnTwo 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.nnnRESULTSnCorrect 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.nnnCLINICAL RELEVANCEnThe 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.

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 mm3 versus 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.

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

OBJECTIVEnTo 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.nnnSTUDY DESIGNnComputed tomographic study.nnnMATERIALS AND METHODSnComputed 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.nnnRESULTSnThe 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.nnnCONCLUSION AND CLINICAL RELEVANCEnCorridors 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.

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

OBJECTIVEnTo 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.nnnSTUDY DESIGNnRetrospective clinical study.nnnMATERIALS AND METHODSnMedical 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.nnnRESULTSnEight 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.nnnCONCLUSION AND CLINICAL RELEVANCEnThis 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.

Stabilization of Olecranon Fractures by Tension Band Wiring or Plate Osteosynthesis: A Retrospective Study of 41 Cases

OBJECTIVESnu2003This article aimed to describe olecranon fracture in dogs and cats and their stabilization with tension band wiring or plate osteosynthesis, and to evaluate complications associated with each technique.nnnMETHODSnu2003Medical records of cats and dogs that had been surgically treated for olecranon fractures with either tension band wiring or plate osteosynthesis were retrospectively reviewed. The surgical technique, complications and long-term outcomes were assessed.nnnRESULTSnu2003Forty-one olecranon fractures were included. Fractures were articular, comminuted and open in 90, 31 and 27% of cases, respectively. Tension band wiring and plate osteosynthesis were performed in 22 and 19 fractures, respectively. Complications occurred more commonly after tension band wiring (74%) compared with plate osteosynthesis (27%) (pu2009=u20090.002) and these were probably related to it being used in comminuted fractures (pu2009=u20090.01) or to errors in technique. Minor complications included Kirschner wires migration (nu2009=u20095), pain (nu2009=u20093), osteomyelitis (nu2009=u20093), skin breakdown (nu2009=u20093) and seroma (nu2009=u20091). Implant failure requiring further fixation (nu2009=u20094) was observed only in the tension band wiring group. Other major complications included skin wound debridement and closure (nu2009=u20091) and chronic lameness requiring implant removal (nu2009=u20097). Long-term functional outcomes were excellent regardless of the technique used.nnnCLINICAL SIGNIFICANCEnu2003Plate osteosynthesis should be performed for olecranon fracture repair if technically feasible.

Reproducibility, Accuracy and Effect of Autoclave Sterilization on a Thermoplastic Three-Dimensional Model Printed by a Desktop Fused Deposition Modelling Three-Dimensional Printer

OBJECTIVESnu2003The main purpose of this study was to determine the reproducibility and accuracy of a three-dimensional (3D) bone model printed on a desktop 3D-printer based on fused deposition modelling (FDM) technology with polylactic acid (PLA) and the effect of autoclave sterilization on the printed models.nnnMETHODSnu2003Computed tomographic images of the tibia were obtained from 10 feline cadavers, used to create a bone surface-rendering file and sent to the 3D printing software. Right and left tibias were each printed five times with the FDM desktop 3D printer using PLA plastic material. Plastic models and cadaveric bones were measured with a profile projector device at six predetermined landmarks. Plastic bones were then sterilized using an autoclave before being re-measured applying the same method. Analyses of printed model size reliability were conducted using intra-class correlation coefficients (ICC) and Bland-Altman plots.nnnRESULTSnu2003The ICC always showed an almost perfect agreement when comparing 3D-printed models issued from the same cadaveric bone. The ICC showed moderate agreement for one measurement and strong/perfect agreement for others when comparing a cadaveric bone with the corresponding 3D model. Concerning the comparison of the same 3D-printed model, before and after sterilization, ICC showed either strong or perfect agreement.nnnCLINICAL SIGNIFICANCEnu2003Rapid-prototyping with our FDM desktop 3D-printer using PLA was an accurate, a reproducible and a sterilization-compliant way to obtain 3D plastic models.

Ultrasonography is more accurate than percutaneous palpation for identifying targeted thoracolumbar intervertebral disc spaces in dogs

During minimally invasive spinal surgery, correct identification of the affected intervertebral disc space is critical. Percutaneous palpation is commonly used, but results may be unreliable. Fluoroscopy is the gold standard but can be cumbersome and exposes operators to ionizing radiation. Spinal ultrasound has been described in veterinary medicine and could be a feasible alternative. This prospective, methods comparison study mimicked a minimally invasive spinal surgery in 10 canine cadavers and compared the accuracy of ultrasound and percutaneous palpation for thoracolumbar intervertebral disc space identification, using fluoroscopy as the reference standard. For each experiment, a disc space was randomly chosen. Identification was then attempted using both percutaneous palpation and ultrasound. For ultrasound, a linear probe was used to guide the operator to the correct location. The time necessary to perform each method was recorded. Accuracies for each method were calculated and statistically compared. Effects of body condition score, location of the targeted thoracolumbar intervertebral disc space and learning curve for each method were also evaluated. Ultrasonographic identification was more accurate (96.7%xa0vs. 76.7%; Pxa0<xa00.03) but took longer (147 s vs. 29 s; Pxa0<xa00.0001) than percutaneous palpation. Findings from this cadaver study indicated that percutaneous palpation alone had low accuracy for correctly identifying a targeted thoracolumbar intervertebral disc space and supported the use of ultrasound as a method for improving the accuracy. Future studies are needed to assess the method in clinical cases, especially in obese dogs and/or those in which the targeted site is distant from palpable anatomical landmarks.

Bone haemophilic pseudotumour of the ulna: A rare complication of haemophilia in a dog

OBJECTIVESnThis case report describes for the first time a bone haemophilic pseudotumour in a dog.nnnCASE DESCRIPTIONnA seven-month-old German Shepherd male dog was presented with the complaint of a forelimb weight-bearing lameness with major swelling that expanded dramatically after fine needle aspiration. Radiographs showed a large, well-defined ulnar diaphyseal cystic-like osteolytic lesion. Based on prolonged activated partial thromboplastin time (aPTT) and low factor VIII activity, haemophilia A was diagnosed. Bone scintigraphy, computed tomography, magnetic resonance imaging, and histological findings definitely ruled out malignant neoplasia or inflammation and strongly supported a bone haemophilic pseudotumour over an aneurysmal bone cyst. Segmental ulnar resectionu200a and replacement by a polymethylmethacrylate spacer combined with perioperative bleeding management resulted in a successful outcome.nnnDISCUSSIONnThis case provided evidence that a bone haemophilic pseudotumour may be the sole presenting clinical sign of haemophilia A in dogs. Early diagnosis, based on history and magnetic resonance imaging findings, is imperative for prompt treatment leading to successful outcome. It is challenging as fine needle aspiration or biopsy is contraindicated. As described in humans, surgical excision of the lesion combined with management of severe postoperative bleeding was associated with successful outcome in the present case.nnnCLINICAL SIGNIFICANCEnA bone haemophilic pseudotumour should be considered in the differential diagnosis of expanding mass associated with osteolysis, especially in young male dogs. Perioperative monitoring of the bleeding disorder and subsequent FVIII replacement therapy was of paramount importance in the present case.