Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objectives:  The goal of this study was to compare the accuracy and safety of a transcondylar screw (TCS) placed using a 3D-printed patient-specific guide (PSG) or a generic aiming device (AD). We hypothesized that PSG is more accurate (i.e., positioning and orientation closer to the optimal trajectory) and safer (reduced incidence of joint violation) than the AD.

Methods:  A total of seven pairs of forelimbs were allocated to PSG and AD groups. After CT scanning, the optimal TCS orientation was planned in silico by a surgical specialist, and guides were printed. Using the PSG or AD, a 2.5-mm drill hole was drilled from medial to lateral across the humeral condyle. The positioning of the "planned" and "achieved" drill holes was defined on postoperative CT. The accuracy of TCS positioning and the risk of joint penetration were then calculated for the two groups.

Results:  Positioning of the entry and exit holes was significantly more accurate in the PSG group. Differences in screw angulation were not significantly different between groups. Despite the presence of an outlier (caused by incomplete seating of the PSG against the bone), 7 out of 7 screws positioned with PSG were "safe," while 3 out of 7 from the AD group would have violated the joint.

Conclusion:  Our data confirm the technical superiority of PSG over the AD for placement of a TCS in the humeral condyle.

Objective:  To characterize central tarsal bone fractures and associated tarsal fractures in a cohort of racing and ex-racing greyhounds using computed tomography (CT).

Study design:  Retrospective observational study including 66 client-owned greyhounds (67 limbs) presented for central tarsal bone fracture between 2017 and 2024. Collected data included signalment, racing history, and laterality of tarsal injury. Central tarsal bone fractures were characterized using a previously described grading system, and concomitant tarsal injuries were recorded.

Results:  Of 67 central tarsal bone fractures, 59 showed moderate to severe comminution. Six fractures were dorsal slab fractures, one was a combined dorsal and medial slab fracture, and one was a luxation. Consistent with the findings of prior studies, the majority of central tarsal bone fractures affected the right limb (58/67 limbs). The most common concomitant tarsal injuries were fractures of the fourth tarsal bone (30/67 limbs), fractures of the calcaneus (25/67 limbs), and proximal intertarsal instability or luxation (6/67 limbs).

Conclusion:  CT reveals a substantially higher number of highly comminuted fractures than have been reported in prior studies that characterized central tarsal bone fractures using orthogonal radiography. Concurrent injury to other tarsal structures is a common finding and is an accurate predictor of severe comminution of the central tarsal bone.

Objectives:  This case series aims to explore the application of 3D-printed patient-specific guides (PSG) in feline shoulder arthrodesis, addressing the scarcity of literature on this procedure in cats. The primary objectives include assessing the feasibility, accuracy, and outcomes of the procedure in four feline cases.

Methods:  The study employed a retrospective analysis of cases involving feline shoulder arthrodesis performed using PSG. Surgical planning utilized CAD-based techniques, and 3D-printed guides were created for precise osteotomies and implant placement. Follow-ups included radiographic assessments, re-examinations, and owner-reported outcomes.

Results:  Four feline cases with distinct shoulder issues were successfully treated using PSG. Postoperative management, radiographic evaluations, and long-term follow-ups revealed positive outcomes in terms of limb function and patient activity. The study demonstrates the potential of PSG in achieving accurate humeroscapular alignment in feline shoulder arthrodesis.

Clinical significance:  This case series highlights the clinical significance of PSG in enhancing the precision of humeroscapular alignment during feline shoulder arthrodesis. The positive outcomes observed in various shoulder pathologies suggest that this technique could contribute to improved surgical outcomes.

Objective:  This study aimed to report clinical and radiographic outcomes of dogs that underwent radial and ulnar fracture repair using 1.5-mm locking plate systems.

Study design:  Dogs that had radial and ulnar fractures repaired using 1.5-mm locking compression plate systems at four referral hospitals were retrospectively included. Signalment, body weight, fracture aetiology, fracture location and configuration, radius diameter, plate-bone ratio, repair method, clinical and radiographic outcomes, complications, and time to last follow-up were recorded.

Results:  Thirty fractures in 28 dogs were included. Median body weight was 2.4 kg (range 1.3-5.5 kg). The mean length of the proximal segment relative to the total length of the radius was 67% (range 33-93%). The mean diameter of the radius at its isthmus was 4.9 mm (range 3.1-6.1 mm). The mean plate-bone ratio was 64% (range 48-89%). Radiographic union was documented in 29/30 fractures at a median of 8 weeks postoperatively. Of the cases with long-term follow-up available, 21/24 had a full function and 3/24 had an acceptable function. Five complications occurred, including infection (n = 2), screw migration (n = 1), bandage sores (n = 1), and peri-plate fracture (n = 1).

Conclusion:  In this population of miniature and toy-breed dogs, 1.5-mm locking plates provided effective fixation for radial and ulnar fractures. Despite complications in 5/30 fractures, radial union occurred in 29/30, and no dog had an unacceptable function at the last follow-up.

Objective:  To determine (1) whether the tibial plateau angle (TPA) in dogs with Salter-Harris type 1 (SH-1) or type 2 (SH-2) fractures of the proximal tibial physis significantly decreases in the time between diagnosis and reevaluation following surgical repair and (2) whether the method of surgical repair influences the change in TPA over time.

Study design:  This study was a retrospective study. Medical records from 2017 to 2022 were reviewed to identify dogs with SH-1 or SH-2 fractures of the proximal tibial physis that had undergone surgical repair with Kirschner wires (K-wires), with or without a tibial tuberosity tension band. The TPA of the affected limb was measured by four investigators on radiographs taken prior to surgery, immediately postoperatively and at 4-8 weeks follow-up, with the average values recorded.

Results:  A total of 32 dogs, 22 fractures repaired with K-wires and a tension band, and 10 with K-wires only. There was a mean decrease in TPA from injury to first reevaluation of 5.89 degrees (p < 0.001) and from immediately postoperatively to first reevaluation of 2.2 degrees (p = 0.018); however, no significant decrease in TPA was observed when comparing fractures repaired with or without a tension band.

Conclusion:  The TPA of dogs with SH-1 and SH-2 fractures of the proximal tibial physis decreased in the reevaluation interim following repair with K-wires with or without a tension band. Despite initial imperfect reduction, the risk of cranial cruciate ligament rupture may not be increased, potentially reducing the need for additional surgery if high TPA is observed postoperatively. This study was overrepresented by small breeds, and future studies on large and giant breeds with extended follow-up would be indicated.

Objective:  The objectives of this study were (1) to evaluate the need for flexed radiographs of the proximal medial trochlear ridge (PMTR) after trauma involving medial tarsus; (2) to evaluate outcome following arthroscopic removal of traumatic osteochondral fragments (TOCF) resulting from direct injury to PMTR.

Methods:  Records of patients with wounds to the medial tarsus were searched and those with TOCF of the PMTR included. Patient history, fracture etiology, preoperative diagnostics, and intraoperative findings were documented. Postoperative performance data were collected using Thoroughbred Racing database or a telephone questionnaire.

Results:  All cases had wounds with concurrent synovial sepsis of the tarsocrural joint. Standard weight-bearing radiographs were performed preoperatively (n = 15), but most (n = 13) failed to identify PMTR pathology. When acquired (n = 8), flexed radiographs (including a uniquely described flexed plantaroproximolateral dorsodistomedial Pl30Pr45Lat-DoDiM oblique) identified PMTR lesions. PMTR TOCF were removed during the initial surgery (n = 15) or subsequent (n = 3) arthroscopy, performed due to unresolved synovial sepsis. Fifteen out of 16 horses with >6-month follow-up resumed full exercise.

Conclusion:  Flexed tarsal radiographs should be performed as part of a standard protocol for traumatic wounds involving the medial tarsus. Horses had excellent prognosis following arthroscopic removal of TOCF of the PMTR. Failure to recognize and remove TOCF resulted in refractory synovial sepsis for horses in this study.

Objective:  To determine the effect of locking head inserts (LHI) on plate strain, stiffness, and deformation when applied to a 3.5-mm broad locking compression plate (LCP) in an open fracture-gap model.

Study design:  Six, 13-hole, 3.5-mm broad LCP were secured to epoxy bone models with a 10 mm central defect and 1 mm plate offset. Two peripheral locking screws were placed in each segment, with the remaining screw holes left unfilled. Three strain gauges were glued to each LCP at anticipated regions of maximum strain. Constructs underwent cyclic uniaxial loading at a rate of 20 mm/min to 400 N in three different configurations (Configuration 1: no LHI, Configuration 2: 3 LHI, Configuration 3: 9 LHI). LHI were tightened to 4 Nm of torque. A data acquisition system was used to collect implant strain during testing. Construct stiffness and deformation were recorded by the biomechanical testing machine.

Results:  Maximum implant strain was recorded at the central screw hole directly over the simulated fracture gap in all configurations (Mdn 1,837.3 µε [interquartile range: 1,805.1-1,862.0]). There was no difference in implant peak-to-peak strain with addition of LHI at all three gauges (Gauge 1 [p = 0.847], Gauge 2 [p = 0.847], Gauge 3 [p = 0.311]). Similarly, peak-to-peak displacement (p = 0.069) and axial construct stiffness (p = 0.311) did not change with the addition of LHI.

Conclusion:  The addition of LHI to a 3.5-mm broad LCP construct was not shown to have an effect on plate strain, stiffness, or deformation.

Objective:  This study aimed to report the clinical, radiographic, and computed tomography results of supracutaneous locking plate (SLP) application in radial-ulnar and tibial fractures.

Study design:  In this clinical prospective study, cats and dogs with nonarticular radial, ulnar, and tibial fractures were managed with SLP. Surgical records, fracture healing, complications, and lameness were reviewed during scheduled rechecks. Fracture healing was assessed by clinical, radiographic, and tomographic reexaminations.

Results:  All cases were reevaluated during clinical and radiological follow-up examinations for 13 weeks. Supracutaneous locking plates were used in 8 radial-ulnar and 25 tibial fractures. Closed reduction was used in 10 cases, and the minimally invasive osteosynthesis approach technique was used in 20 cases. The median fracture healing time was 50.5 days (range: 27-88). Callus area, the Hounsfield units value of callus tissue, and three-dimensional bone volume gradually increased during fracture healing (p < 0.05).

Conclusion:  Using SLPs to manage nonarticular diaphyseal radial-ulnar and tibial fractures in cats and dogs resulted in acceptable clinical outcomes. Cats and dogs tolerated SLPs well, and no complications related to structural integrity were encountered in most cases.

Objective:  To evaluate the in vitro mechanical properties of basilar fractures of the femoral neck stabilized with two or three titanium-cannulated screws in dogs.

Study design:  Ex vivo study.

Sample population:  Cadaveric canine femur (n = 21).

Methods:  The bones were divided as follows: Group 1: control (no osteotomy); Group 2: osteotomy and stabilization with two cannulated screws; and Group 3: osteotomy and stabilization with three cannulated screws. All groups were tested with destructive axial compression with load applied to the femoral head. The stiffness, load, and displacement were evaluated at the failure of Group 1, and the yield load and displacement of Groups 2 and 3.

Results:  The placement of the three cannulated screws was more demanding than two cannulated screws because of the risk of cortical perforation, especially in the trochanteric fossa area. The smaller the width of the femoral neck, the higher the risk of cortical bone wall perforation. The intact control bones were stiffer (674 N/mm) than both the two-screw repair (90 N/mm) and three-screw repair (120 N/mm) groups (p < 0.05). The failure load was greatest for Group 1 (2692 N). The yield loads for Groups 3 and 2 were 586 and 303 N, respectively. There was no difference between groups for displacement.

Conclusion:  In vitro cadaveric models of femoral neck basilar fractures repaired with three cannulated screws were significantly stronger than two cannulated screws, but the clinical efficacy must be evaluated by comparing them in vitro with noncannulated stainless steel screws.