Case summary A 4-month-old female domestic shorthair kitten was presented for a congenital cleft palate causing nasal discharge and sneezing episodes. CT revealed a palatal bone defect involving 20% ...of the palatal area. Surgical correction of both the hard and soft palate defects was performed using the overlapping and medially positioned flap techniques, respectively. Complete healing of the wound and full resolution of the clinical signs occurred within a 1-month period. At 2 months postoperatively, two punctiform oronasal fistulae were observed rostrally without associated clinical signs. Control CT, performed 6 months postoperatively, revealed a 50% enlargement of the palatal bone defect. At 12 months postoperatively, the cat was still in good general condition without any clinical signs. Relevance and novel information To the best of our knowledge, this is the first report to describe the treatment of a congenital cleft palate in a kitten using the overlapping flap technique with a successful medium-term clinical outcome, despite the formation of two oronasal fistulae. This suggests that, as in dogs, full restoration of oronasal compartmentation is not mandatory to achieve functional outcome. The increase of the palatal bone defect over time may play a role in late oronasal fistulae formation and should be considered for surgical planning.
Purpose The purposes of this study were to assess tissue ingrowth within the Ligament Advanced Reinforcement System (LARS) artificial ligament (LARS AC; LARS, Arc sur Tille, France) and to study the ...biomechanical characteristics of the reconstructed knees in a sheep model of anterior cruciate ligament (ACL) replacement. Methods Twenty-five female sheep underwent excision of the proximal third of the left ACL and intra-articular joint stabilization with a 44-strand polyethylene terephthalate ligament (mean ultimate tensile failure load, 2,500 N). Animals were killed either 3 or 12 months after surgery. Explanted knees were processed for histology (n = 10) or mechanical tests including tests of laxity and loading to failure in tension (n = 15). Results Well-vascularized tissue ingrowth within the artificial ligament was only observed in the portions of the ligament in contact with the host's tissues (native ligament and bone tunnels). Ligament wear was observed in 40% of explanted knees. The ultimate tensile failure loads of the operated knees at both time points were inferior to those of the contralateral, intact knees (144 ± 69 N at 3 months and 260 ± 126 N at 12 months versus 1,241 ± 270 N and 1,218 ± 189 N, respectively) ( P < .01). In specimens with intact artificial ligaments, failure occurred by slippage from the bone tunnels in all specimens explanted 3 months postoperatively and in half of the specimens explanted 12 months postoperatively. Conclusions This study provides evidence that the LARS AC has a satisfactory biointegration but that it is not suitable for ACL replacement if uniform tissue ingrowth is contemplated. Despite good clinical performance up to 1 year after implantation, none of the reconstructions approached the mechanical performance of the normal ACL in the ovine model. Partial tearing of the artificial ligament, which led to a significant decrease in ultimate tensile strength, was observed in 40% of cases in the ovine model. Clinical Relevance The LARS is not a suitable scaffold for ACL replacement. Further animal studies are needed to evaluate its potential for augmentation of ligament repair.
Objective
To report outcomes after the correction of ectopic ureter (EU) by open surgery or cystoscopic‐guided laser ablation (CLA) in female dogs.
Study design
Retrospective study from 2011 to 2018.
...Animals
Twenty‐five female dogs.
Methods
Data collected included signalment, clinicopathologic data, procedural data, complications, and short‐term and long‐term outcomes. Complications were graded as minor or major if a surgical revision was required. Continence status was scored subjectively (1 = completely incontinent to 10 = fully continent).
Results
Fifteen dogs had bilateral EU and 24 had intramural EU (iEU). Open surgical correction included 13 neoureterostomies, 2 neocystoureterostomies, and a combination of these in 2 dogs. Eight dogs underwent CLA. Eighteen dogs experienced minor complications (72%), and 2 experienced major complications (8%). One‐month postoperative continence was achieved in 20/25 (80%) dogs (median score of 10). Incontinence recurred at a median time of 24.9 months in 5 dogs but responded to medical treatment. Overall, dogs remained continent for 66 months (median) and 22/25 (88%) dogs achieved continence with adjunction of medical/surgical treatment in incontinent ones. Fewer minor complications and postoperative recurrences of incontinence were documented after CLA than neoureterostomy (P < .01 and P < .05).
Conclusion
Ectopic ureter correction by open surgery or CLA resulted in a subjectively good prognosis, most dogs reaching continence within a month of surgery, although incontinence occasionally recurred in the long term. CLA was associated with fewer complications and incontinence recurrences than neoureterostomy.
Clinical significance
Cystoscopic‐guided laser ablation should be preferred to correct iEU to prevent short‐term complications and the recurrence of incontinence. Further studies should investigate the cause of postoperative recurrence of urinary incontinence.
The present study aimed at elucidating the effect of local pH in the extracellular microenvironment of tissue-engineered (TE) constructs on bone cell functions pertinent to new tissue formation. To ...this aim, we evaluated the osteogenicity process associated with bone constructs prepared from human Bone marrow-derived mesenchymal stem cells (hBMSC) combined with 45S5 bioactive glass (BG), a material that induces alkalinization of the external medium. The pH measured in cell-containing BG constructs was around 8.0, that is, 0.5 U more alkaline than that in two other cell-containing materials (hydroxyapatite/tricalcium phosphate HA/TCP and coral) constructs tested. When implanted ectopically in mice, there was no de novo bone tissue in the BG cell-containing constructs, in contrast to results obtained with either HA/TCP or coral ceramics, which consistently promoted the formation of ectopic bone. In addition, the implanted 50:50 composites of both HA/TCP:BG and coral:BG constructs, which displayed a pH of around 7.8, promoted 20-30-fold less amount of bone tissue. Interestingly, hBMSC viability in BG constructs was not affected compared with the other two types of material constructs tested both in vitro and in vivo. Osteogenic differentiation (specifically, the alkaline phosphatase ALP activity and gene expression of RUNX2, ALP, and BSP) was not affected when hBMSC were maintained in moderate alkaline pH (≤7.90) external milieu in vitro, but was dramatically inhibited at higher pH values. The formation of mineralized nodules in the extracellular matrix of hBMSC was fully inhibited at alkaline (>7.54) pH values. Most importantly, there is a pH range (specifically, 7.9-8.27) at which hBMSC proliferation was not affected, but the osteogenic differentiation of these cells was inhibited. Altogether, these findings provided evidence that excessive alkalinization in the microenvironment of TE constructs (resulting, for example, from material degradation) affects adversely the osteogenic differentiation of osteoprogenitor cells.
Abstract This study investigates the impact of polystyrene sodium sulfonate (PolyNaSS) grafting onto the osseo-integration of a polyethylene terephthalate artificial ligament (Ligament Advanced ...Reinforcement System, LARS™) used for Anterior Cruciate Ligament (ACL). The performance of grafted and non-grafted ligaments was assessed in vitro by culturing human osteoblasts under osteogenic induction and this demonstrated that the surface modification was capable of up-regulating the secretion of ALP and induced higher level of mineralisation as measured 6 weeks post-seeding by Micro-Computed Tomography. Grafted and non-grafted LARS™ were subsequently implanted in an ovine model for ACL reconstruction and the ligament-to-bone interface was evaluated by histology and biomechanical testings 3 and 12 months post-implantation. The grafted ligaments exhibited more frequent direct ligament-to-bone contact and bone formation in the core of the ligament at the later time point than the non-grafted specimens, the grafting also significantly reduced the fibrous encapsulation of the ligament 12 months post-implantation. However, this improved osseo-integration was not translated into a significant increase in the biomechanical pull-out loads. These results provide evidences that PolyNaSS grafting improved the osseo-integration of the artificial ligament within the bone tunnels. This might positively influence the outcome of the surgical reconstructions, as higher ligament stability is believed to limit micro-movement and therefore permits earlier and enhanced healing.
A strategy for improving the efficacy of stem cell-based bone tissue engineering (TE) constructs is to combine bone morphogenetic protein-2 (BMP-2) with multipotent stromal cells (MSC). Previous ...studies on the potential cooperative effect of BMP-2 with human multipotent stromal cells (hMSCs) on bone formation
have, however, shown contradictory results likely due to the various and/or inappropriate BMP-2 doses. Our results provided evidence that the addition of BMP-2 at low dose only was beneficial to improve the osteogenic potential of hMSCs-containing TE constructs, whereas BMP-2 delivered at high dose overcame the advantage of combining this growth factor with hMSCs. This new knowledge will help in designing improved combination strategies for tissue regeneration with better clinical outcomes.
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Ti6Al4V is commonly used for orthopedic applications. This study was designed to test the potentially added benefit of Ti6Al4V functionalized with a bioactive polymer poly(sodium ...styrene sulfonate) both in vitro and in vivo. Cell-based assays with MC3T3-E1 osteoblast-like cells were used to measure the cell adhesion strength, cell spreading, focal contact formation, cell differentiation and the mineralization of extracellular matrix on grafted and ungrafted Ti6Al4V discs in combination with FBS and collagen type I. Bone morphogenetic protein-2 (BMP-2) was also included in the cell differentiation assay. Results showed that the grafted surface combined with collagen I gave superior levels in every parameter tested with cell-based assays and was almost equivalent to BMP-2 for cell differentiation. In vivo testing was conducted in rabbits (n=42) with cylinders of grafted and ungrafted Ti6Al4V implanted in defects made to the femoral and lateral condyles and animals that were maintained to 1, 3 and 12months. Hydroxyapatite coated Ti6Al4V cylinders were included as a clinical reference control. Osseointegration was assessed post-mortem using histomorphometric analysis conducted on resin sections of explanted undecalcified bone. Two histomorphometric parameters, that of bone-to-implant contact and the bone area, were analyzed by a trained observer blinded to sample identity. Results showed osseointegration on grafted Ti6Al4V was marginally better than both ungrafted and hydroxyapatite coated Ti6Al4V. Overall, the study found that the grafted Ti6Al4V significantly promoted all aspects of osteogenesis tested in vitro and, although in vivo outcomes were less compelling, histomorphometry showed osseointegration of grafted Ti6Al4V implants was equivalent or better than controls.
Anterior cruciate ligament (ACL) repair techniques are new emerging strategies prevailing, in selected cases, over standard reconstruction of the ACL with excision of its remnants. Mid-substance ACL ...tears represent a challenge for ACL repair techniques, and remnants-preserving ACL reconstruction (rp-ACLR) using an autograft remains the recommended treatment in this situation. However, morbidity associated with the autograft harvesting prompts the need for alternative surgical strategies based on the use of synthetic scaffolds. Relevant small animal models of mid-substance tears with ACL remnants preservation and reconstruction are necessary to establish the preliminary proof of concept of these new strategies.
A rat model of rp-ACLR using a tendinous autograft after complete mid-substance ACL transection was established. Twelve weeks following surgery, clinical outcomes and knee joints were assessed through visual gait analysis, Lachman tests, thigh perimeter measurements, magnetic resonance imaging, micro-computed tomography, and histology, to evaluate the morbidity of the procedure, accuracy of bone tunnel positioning, ACL remnants fate, osteoarthritis, and autograft bony integration. Results were compared with those obtained with isolated ACL transection without reconstruction and to right non-operated knees.
Most operated animals were weight-bearing the day following surgery, and no adverse inflammatory reaction has been observed for the whole duration of the study. Autograft fixation with cortical screws provided effective graft anchorage until sacrifice. Healing of the transected ACL was not observed in the animals in which no graft reconstruction was performed. rp-ACLR was associated with a reduced degeneration of the ACL remnants (p = 0.004) and cartilages (p = 0.0437). Joint effusion and synovitis were significantly lower in the reconstructed group compared to the transected ACL group (p = 0.004). Most of the bone tunnel apertures were anatomically positioned in the coronal and/or sagittal plane. The most deviated bone tunnel apertures were the tibial ones, located in median less than 1 mm posteriorly to anatomical ACL footprint center.
This study presents a cost-effective, new relevant and objective rat model associated with low morbidity for the preliminary study of bio-implantable materials designed for remnants-preserving ACL surgery after mid-substance ACL tear.
CASE DESCRIPTION 7 privately owned female African lions (Panthera leo) that had been bred for public exhibition and were housed in outdoor pens were evaluated prior to undergoing elective ...ovariectomy. CLINICAL FINDINGS All animals were healthy. Median age was 15 months (range, 9 to 34 months), and median body weight was 71 kg (156 lb; range, 48 to 145 kg 106 to 319 lb). TREATMENT AND OUTCOME Surgical sterilization by means of single-incision laparoscopic ovariectomy was elected. A 2- to 3-cm-long skin incision was made just caudal to the umbilicus, and a single-port multiple-access device was bluntly inserted through the incision. Traction was maintained with stay sutures to provide counterpressure, and three 5-mm-diameter cannulae were introduced through the device's access channels with a blunt trocar. The abdomen was insufflated to a pressure of 12 mm Hg with CO
. Each ovary was grasped and suspended with a standard 36-cm-long laparoscopic grasper, and ovariectomy was performed with a 5-mm vessel sealer and divider device. Because of the depth of subcutaneous fat, extensive subcutaneous dissection was necessary to insert the single-port device. In contrast, fat content of the mesovarium was minimal and did not vary markedly among animals. Subjectively, single-incision laparoscopic ovariectomy was easily performed, but all surgeons had experience in laparoscopic surgery. Median duration of the surgical procedure was 29 minutes (range, 21 to 49 minutes). No perioperative complications were encountered. CLINICAL RELEVANCE Findings suggested that the single-incision laparoscopic technique may be an acceptable, minimally invasive option for ovariectomy of large felids.
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