Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objective:  The aim of this study was to assess the protective effect of transecting a partially ruptured cranial cruciate ligament (CCL) during tibial plateau levelling osteotomy (TPLO) surgery on postoperative patellar ligament thickness (PLT) and shortening.

Study design:  Dogs with partial CCL rupture that underwent a unilateral TPLO were included. The population was divided into two groups: remnant CCL transected (study group) and left in situ (control group). Preoperative and 6-week postoperative measurements of PLT, in three specific locations, and patellar ligament length (PLL) were collected. Risk factors for PLT and shortening were also included.

Results:  Fifty-two dogs (56 stifles) with partial CCL rupture were retrospectively included. Twenty-nine stifles (51.8%) had the remnant CCL transected (study group) and 27 stifles (48.2%) had the remnant CCL left in situ (control group). Significant differences were found on PLT measurements between pre- and 6-week post-surgery for all three ligament locations with greatest difference at the middle region. Median PLL was significantly shorter 6-week post-surgery for both groups. No significant differences in PLT nor PLL were identified between procedures where the remnant was transected or not.

Conclusion:  This study did not identify a protective effect of transecting the CCL remnant on PLT or patellar ligament shortening, contrary to other reports within the literature. Further investigation is needed in the form of prospective studies with higher number of cases to understand the clinical implications of patellar ligament thickening and shortening in dogs.

Objective:  Medial patellar luxation (MPL) is prevalent in small dogs; however, the causes vary, and few studies have reported tibial deformities. We aimed to conduct a detailed morphological investigation of internal tibial torsion and internal foot rotation and compare the results between MPL grades to better understand the pathogenesis of MPL.

Study design:  We performed a morphological study of the tibia and comparison with MPL grade, and established a new parameter, metatarsal orientation relative to the orientation of the tibial tuberosity, the proximal tibia metatarsal angle (PTMTA). The distal tibia metatarsal angle was also established, and tibial torsion angle (TTA), mechanical medial proximal tibial angle, medial distance of the tibial tuberosity/proximal tibial width, and crural rotation angle were compared among the grades of MPL.

Results:  The PTMTA was significantly higher in grades 3 and 4 than in the normal group. TTA, medial distance of the tibial tuberosity/proximal tibial width, and mechanical medial proximal tibial angle were significantly higher in grade 4 than in the other grades, which is consistent with previous reports. A correlation was also observed between the PTMTA and the TTA.

Conclusion:  The PTMTA functioned as a parameter that included elements of the distal tibia metatarsal angle, TTA, and medial distance of the tibial tuberosity/proximal tibial width, and is considered clinically useful because it can be visually ascertained during palpation. Our results may play a major role in surgical decision-making in the treatment of MPL.

Objectives:  To evaluate the outcome and complications in dogs with medial patellar luxation (MPL) undergoing tibial tuberosity transposition (TTT) with a locking plate and pin fixation (Plate-Pin).

Methods:  This retrospective multicenter study included 65 consecutive MPL stifle surgeries using tibial tuberosity (TT) fixation with a 5-hole locking plate and a pin. The median weight of the dogs was 6.2 kg. The grade of luxation was 2/4 in 50 stifles and 3/4 in 15 stifles. Outcomes were assessed during follow-up examinations 33 to 648 days after surgery with clinical examination and radiography. Canine Orthopedic Index questionnaires were sent to owners 6 to 39 months after surgery.

Results:  Complications were reported in 14/65 stifles, of which 8/14 were minor and 6/14 were major. After treatment of the major complications, lameness was resolved in all cases and the MPL was resolved in 64/65 stifles.

Clinical significance:  When the surgery was performed as described in this article, Plate-Pin fixation for TT during MPL surgery is a feasible technique with a lower incidence of luxation recurrence, TT avulsion, and fractures compared with recent retrospective studies with pin and tension band wire TT fixation. Further development of the locking plate TT fixation is indicated to resolve pin-related complications and to determine if fixation including a pin is necessary.

Objective:  The aim of this cadaveric study was to compare the biomechanical outcomes of three methods of stabilization for tibial tuberosity transposition to treat medial patellar luxation: a complete osteotomy with a two-pin and tension band wire (TBW) fixation (TBW group), a partial osteotomy with a two-pin fixation (2 Pin group), and a partial osteotomy with a spacer pin fixation (Spacer Pin group).

Study design:  Thirty medium to large-sized canine cadaveric tibiae were dissected and randomly assigned to one of three groups: TBW, 2 Pin, and Spacer Pin groups. The patellar ligaments were loaded in tension until ultimate failure. Ultimate failure force and mode of failure were documented, stiffness was calculated, and the results were compared statistically between the three treatment groups.

Results:  There were not any significant differences in ultimate failure force or stiffness between groups. All groups predominantly failed by patellar ligament failure, with distal tibial crest fracture/displacement being the second-most common mode in the 2 Pin and Spacer Pin groups.

Conclusion:  The mechanical properties of the spacer pin stabilization were not different from the TBW and 2 Pin groups. The spacer pin technique could be an alternative way to stabilize tibial tuberosity following tibial tuberosity transposition with a partial osteotomy based on this cadaveric load-to-failure model.

Objective:  The aim of this study was to describe the development of a total elbow replacement (TER) technique in swine and report the outcome of TER in a Kunekune sow (61 kg) with severe elbow osteoarthritis.

Methods:  The technique was developed by operating on three pig cadavers (Yorkshire 40-50 kg). The TATE Elbow implant fit was confirmed with modeling to the patient's computed tomography imaging. Patient-specific instrumentation was printed for attempted use. Total elbow replacement was performed using a lateral approach, including lateral epicondylar osteotomy, careful retraction of the radial nerve, and preservation of the lateral collateral ligament. Postoperative care included controlled exercise and physical therapy.

Results:  A lateral approach to the pig elbow for TATE TER was successfully developed. The bulk of the lateral head of the triceps muscle precluded use of the patient-specific instrumentation; the procedure was performed using standard instrumentation. Radiographic evidence up to 9 months postoperatively showed adequate implant alignment and satisfactory osteointegration of humeral and radioulnar components. There were not any postoperative complications and the patient's comfort was improved by 6 months and sustained at 18 months.

Conclusion:  A lateral approach for TATE TER in a pig with advanced elbow osteoarthritis proved feasible and effective. With the expansion of the TATE Elbow line, it is possible that a larger range of pigs could be treated. This report suggests that a lateral approach for TATE TER in dogs could represent a suitable alternative to the medial approach currently used.

Objective:  To assess the biomechanical parameters of intact tibiotarsi (INT) and tibiotarsi with a 5-mm segmental diaphyseal defect repaired using four osteosynthesis techniques: a locking plate (LP), a plate-rod combination, an external skeletal fixator (one end-threaded positive-profile pin per fragment) with an intramedullary pin tie-in (TIF 1), and an external skeletal fixator (two end-threaded positive-profile pins per fragment) with an intramedullary pin tie-in (TIF 2).

Study design:  Sixty tibiotarsi from 30 adult laying hens were allocated into five groups for nondestructive dynamic torsion and four-point bending tests, followed by failure tests. Nondestructive dynamic tests evaluated stiffness over time in torsion and bending. Torsion destructive tests provided maximum torque and rotation values, whereas the four-point bending tests provided the yield load, maximum bending load, and maximum displacement.

Results:  The INT group showed higher torsional stiffness and maximum torque but similar bending stiffness, torsional strength, and bending strength in one or more groups. LP and TIF 2 exhibited the highest similarity frequencies among the treatment groups, whereas the TIF 1 group displayed lower stiffness and strength for most of the evaluated parameters.

Conclusion:  Similar results for LP and TIF-2 groups suggest the biomechanical equivalence of these methods for tibiotarsal osteosynthesis in adult hens.

Objectives:  Gracilis myopathy is a well-recognized syndrome of weight-bearing gait abnormality; however, detailed description of computed tomography (CT) and magnetic resonance imaging (MRI) features of gracilis myopathy is lacking in the literature. This study aims to describe in detail CT and MRI features of gracilis myopathy.

Study design:  This is a retrospective study. Medical records of dogs with characteristic gait and available pelvic limb MRI or CT, presenting to four referral institutions, were reviewed.

Results:  Seven cases with MRI (3/7) or CT (4/7) were included, all German Shepherd dogs. MRI findings in all cases included a well-defined, T1-/T2-/proton density-weighted hypointense band along the axial margin of the gracilis muscle, shorter affected muscles, thickening and T2W/STIR hyperintensity with contrast enhancement at the symphyseal tendon, and concurrent focal indentation of the axial border of the gracilis muscle. CT findings included a hyperattenuating band (4/4), single instances of contrast enhancement at the origin of the muscle, thickening of the tendon at the origin and insertion, and concurrent thickening at the musculotendinous muscle.

Conclusion:  CT and MRI can present advantages in correctly identifying the specific muscles affected within the gracilis-semitendinosus muscle complex. Both modalities can localize anatomically lesions in detail, for instance at the origin or insertion of the muscle, which could present advantages in novel treatment strategies for this condition.

A hip luxation 3 years following a cementless total hip replacement was diagnosed in a 4.7-year-old neutered male Lagotto Romagnolo that presented with a non-weight-bearing left pelvic limb lameness. Orthogonal radiographs revealed a left hip luxation and an osteolytic fracture of the greater trochanter. A mass consistent with an inflammatory granuloma was identified on preoperative computed tomography scan. Surgical revision consisted of granuloma excision, replacement of the loose acetabular cup, and repair of the femoral fracture with a locking plate. Fracture biology was augmented with the use of recombinant human bone morphogenetic protein 2 (rhBMP2) impregnated collagen sponge applied around the acetabulum and femoral fracture site. Osteointegration of the prosthetics and fracture healing were documented within 3 months of revision. Long-term follow-up at 3 years postrevision showed normal limb usage and no further evidence of total hip replacement complication.

Intramedullary nails are specialized metal rods inserted into the medullary cavity of a fractured bone and secured to reduce load on the fracture site, provide stability, and permit healing. The purpose of this review is to highlight the biomechanics of orthopaedic intramedullary nailing, as well as discuss the biomechanical considerations that have shaped implant design and fixation technique in veterinary and human medicine. Relevant studies were included from the PubMed database and Google Scholar for discussion on the basic science and nail design of intramedullary nails. Implant design and implementation continues to progress, with new innovative designs currently under investigation. A lack of consensus remains on the superior implant material. Recent studies, particularly in human populations, have supported the use of reaming based on reoperation rates, nonunion rates, and dynamization. Design modifications, such as the expandable intramedullary nails and angle-stable interlocking designs, have been investigated as methods of improving cortical contact and resisting torsional stress. Intramedullary nailing is a valuable stabilization technique for long bone fractures across a variety of species. The technology continues to undergo design improvements in both veterinary and human medicine.

Objective:  The main aim of this pilot study was to assess the feasibility of spinal neuronavigation for plate fixation of lumbar vertebrae in miniature breed dogs using a surgical navigation system in combination with a custom-made reference array.

Study design:  This was an experimental cadaveric study in five miniature breed dogs.

Methods:  A 4-hole locking plate with four 2.0-mm locking screws was placed on two adjacent lumbar vertebrae using a neuronavigation system consisting of a mobile cone beam computed tomography linked to a navigation system. The procedure was performed by a novice surgeon. The plate and screw positions were assessed for surgical safety using predefined criteria. Surgical accuracy was determined by the deviation of entry and exit points between pre- and postoperative images.

Results:  A total of five plates and 20 screws were placed. In 85% (17/20), screws were placed appropriately. The median entry point deviation was 1.8 mm (range: 0.3-3.7) and the median exit point deviation was 1.6 mm (range: 0.6-5).

Conclusion:  Achievement of surgical accuracy in the placement of screws for fixation of lumbar vertebral plates in small breed dogs using neuronavigation with a custom-made reference array by a novice surgeon resulted in surgical safe plate placement in four of the five cadavers. Therefore, we judge the method as promising, however, further studies are necessary to allow the transfer of image-guided navigation for lumbar plate fixation into the clinic.