Stabilisation of femoral capital physeal fractures using transcervical pinning in cats: 19 cases (2014-2022).

OBJECTIVES: To report the short-term clinical and radiographic outcomes in cats with femoral capital physeal fractures stabilised with transcervical pinning. MATERIALS AND METHODS: Medical records of cats diagnosed with femoral capital physeal fractures and treated with transcervical pinning were reviewed. The collected data included signalment, weight, time from lameness to surgery, reported trauma, affected side, concomitant orthopaedic injuries, radiographs, osteoarthritis, femoral neck osteolysis, proximal femoral epiphysis to femoral neck ratio, fracture reduction, implants, complications and clinical evaluation results. An owner questionnaire was used for long-term follow-up. RESULTS: Nineteen cats with a total of 21 fractures met the inclusion criteria. Fifteen of the 19 cats showed no signs of lameness at the 1-month follow-up. Major and catastrophic complications occurred in 9.5% and 23.8% of the fractures, respectively. All catastrophic complications occurred in fractures with a high preoperative osteolysis grade (2 or 3). CLINICAL SIGNIFICANCE: In our study, transcervical pinning was found to be a reliable fixation method for the treatment of femoral capital physeal fractures in cats with minimal preoperative femoral neck osteolysis. High rates of implant failure with loss of fracture reduction were observed in cats with high-grade preoperative osteolysis.

Repair of femoral fractures in calves via external skeletal fixator with intramedullary pin tie-in.

OBJECTIVE: To describe the success rate and associated complications of external skeletal fixator/intramedullary pin tie-in for calf femoral fracture fixation. STUDY DESIGN: Clinical retrospective. ANIMALS: Ten calves, less than 30 days old, with diaphyseal/metaphyseal femoral fractures. METHODS: Medical records were reviewed from the University of Wisconsin from 2000 to 2020. Fractures were repaired using open reduction and fixation. An intramedullary Steinman pin was placed, exiting near the greater trochanter, and utilized for fracture reduction. Bicortical transfixation pins were placed distal and proximal to the fracture site. Poly(methyl methacrylate) (PMMA)-filled tubing connected the transfixation pins and proximal intramedullary pin, creating a Type 1a external skeletal fixator (ESF) tie-in. Follow up was obtained via medical records and phone interviews. RESULTS: Short-term survival rate was 7/10 (70%). Postanesthetic death occurred once. Postoperative complications occurred in all remaining cases. The most common findings were transfixation pin tract lucency and lameness (6/9 cases), implant dysfunction (5/9 cases), and infection (4/9 cases). Three of five cases with long-term follow up survived; all went on to productive careers. CONCLUSION: Although patients were prone to postoperative complications, short-term survival was comparable to previous reports. CLINICAL SIGNIFICANCE: The external skeletal fixator/intramedullary (ESF/IM) pin tie-in is less expensive and offers comparable success rates to other methods, providing a lower cost option for calf femoral fracture repair.

Closed reduction and fluoroscopic-guided percutaneous pinning of femoral capital physeal or neck fractures: Thirteen fractures in 11 dogs.

OBJECTIVES: To report the short-term clinical outcome and complications in dogs that underwent surgical repair of femoral capital physeal or neck fractures via fluoroscopic-guided percutaneous pinning (FGPP). STUDY DESIGN: Retrospective case series. ANIMALS: Client owned dogs (n = 11) with femoral capital physeal or neck fractures (n = 13). METHODS: Records (July 2018-July 2021) of dogs that underwent surgery for femoral capital physeal or neck fracture repair with FGPP from two hospitals were reviewed. Data collected included signalment, age, weight, preoperative lameness severity, fracture factors (etiology, Salter-Harris classification, time from injury to surgery, radiographic displacement), surgical factors (surgery time, number/size of implants, reduction quality) and outcome (follow-up examination findings, radiographic findings, complications). RESULTS: Most fractures (11/13) occurred secondary to trauma. The median time from injury to surgery was 5.5 days. There was mild radiographic displacement preoperatively in 10/13 fractures. Satisfactory fracture healing and limb function was achieved in 10/13 femurs. Complications occurred in 5/11 cases and included intra-articular implants, implant failure/nonunion, implant migration (2), and malunion. Of these five complications, two resolved with implant removal, and a salvage procedure was recommended in the remaining cases. Of the three cases requiring salvage procedures, two originally presented with radiographic evidence of fracture chronicity. CONCLUSIONS: FGPP can be used to successfully treat femoral head and neck fractures with appropriate case selection and precise surgical technique.

Minimally invasive plate osteosynthesis of femoral fractures with 3D-printed bone models and custom surgical guides: A cadaveric study in dogs.

OBJECTIVE: Assess the accuracy and efficiency of reduction provided by application of plates precontoured to 3-dimensional (3D)-printed femoral bone models using a custom fracture reduction system (FRS) or intramedullary pin (IMP) to facilitate femoral minimally invasive plate osteosynthesis (MIPO) in dogs. STUDY DESIGN: Experimental cadaveric study. SAMPLE POPULATION: Seven dog cadavers. METHODS: Virtual 3D femoral models were created using computed tomographic images. Simulated, virtual mid-diaphyseal femoral fractures were created and reduced. Reduced femoral models were 3D-printed and a plate was contoured. Custom drill guides for plate screw placement were designed and 3D-printed for the FRS. Mid-diaphyseal simulated comminuted fractures were created in cadavers, and fractures were aligned using FRS or IMP and stabilized with the precontoured plates. Number of fluoroscopic images acquired per procedure and surgical duration were recorded. Computed tomographic scans were repeated to assess femoral length and alignment. RESULTS: Compared to the preoperative virtual plan, median change in femoral length and frontal, sagittal, and axial alignment was less than 3 mm, 2°, 3°, and 3° postoperatively, respectively, in both reduction groups. There was no difference in length or alignment between reduction groups (P > .05). During FRS, fewer fluoroscopic images were taken (P = .001), however, surgical duration was longer than IMP procedures (P = .011). CONCLUSION: Femoral alignment was accurate when using plates precontoured to 3D printed models, regardless of reduction method. CLINICAL SIGNIFICANCE: Accurate plate contouring using anatomically accurate models may improve fracture reduction accuracy during MIPO applications. Custom surgical guides may reduce fluoroscopy use associated with MIPO.

Clinical outcomes of canine total hip replacement utilizing a BFX lateral bolt femoral stem: 195 consecutive cases (2013-2019).

OBJECTIVE: To evaluate the clinical outcomes of total hip replacements (THR) utilizing a BFX lateral bolt stem in dogs with coxofemoral joint disease. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: A total of 149 dogs representing 195 THR. METHODS: Consecutive THRs utilizing a BFX lateral bolt stem were studied. Preoperative, immediate postoperative, 1-, 2-, 3-, 4-, and 12-month postoperative radiographs were performed. All major and minor complications, revisions, outcomes, subsidence, canal flare index (CFI) were recorded. RESULTS: An intraoperative complication rate of 11.8% was observed. The postoperative complication rate was 13.6%, with 9.2% major and 4.4% minor complications. Complications included: postoperative femur fractures (3.6%), coxofemoral luxation (3.6%), stem failure (0.5%), septic loosening (0.5%), aseptic loosening (0.5%), and acetabular fracture (0.5%). Three dogs underwent prophylactic plating after subjective assessment of cortical thickness. Five of 195 (2.6%) cases underwent explant of their prostheses (median = 3 months). Mean stem subsidence at 1 month postoperatively was 1.22 ± 0.16 mm. An increased CFI was associated with postoperative femur fractures (p < .05). A total of 190 of 195 (97.4%) cases returned to normal function in the long-term follow-up period. CONCLUSION: Use of the BFX lateral bolt stem resulted in minimal postoperative subsidence, a low femoral stem complication rate, and a high rate of achieving normal limb function. CLINICAL SIGNIFICANCE: The BFX lateral bolt stem should be considered in canine THR as the femoral failure rate is low and the long-term success rate is high.

Management of Feline Femoral, Tibial and Humeral Fractures Using a 3.5 mm Titanium Interlocking Nail.

OBJECTIVE: Our objectives were to report complications associated with stabilization of long-bone fractures in cats using a 3.5-mm titanium interlocking nail and to examine the influences of signalment, fracture type and fixation evaluations on the occurrence of complications. STUDY DESIGN: Retrospective clinical study. MATERIAL AND METHODS: Medical and radiographic records of cats with long-bone fractures treated with an interlocking nail were reviewed. Data included age, sex, weight, cause of the fracture, fractured bone(s) and fracture type. Complications were classified as minor and major complications. Fisher's exact tests and logistic regression analysis were used to test whether certain variables of signalment and interlocking nail configuration had an effect on the occurrence of complications. RESULTS: Sixty-seven fractures of 67 cats were examined in this study. Forty-eight femora, sixteen tibiae and three humeri were included. Complications occurred in 11/67 fractures. Major complications occurred in 8/67 fractures and included screw breakage (n = 3), nail breakage (n = 2), nail bending (n = 1), screw loosening (n = 1), non-union (n = 1). Statistical analysis showed a significant difference between fracture types and the occurrence of major complications (p = 0.02). CONCLUSION: In conclusion, use of this commercially available standard 3.5-mm titanium interlocking nail for stabilization of comminuted and oblique humeral, femoral and tibial fractures in cats is feasible.

Short-Term Clinical and Radiographic Outcome after Stabilization of Femoral Capital Physeal Fractures with Cortical Positional Screws in 39 Cats.

OBJECTIVE: The aim of this study was to report the short-term clinical and radiographic outcome for the treatment of femoral capital physeal fractures with cortical positional screws in cats. STUDY DESIGN: Medical records and radiographs of cats with femoral capital physeal fractures stabilized with cortical positional screws were retrospectively reviewed. Signalment, bodyweight, femoral head affected, fracture classification, fracture reduction, implants, concurrent orthopaedic injuries, osteoarthritis, femoral neck osteolysis, complications and 6-week follow-up clinical results were recorded. A short- to long-term follow-up was performed by telephone questionnaire with the owners. RESULTS: Forty-six fractures in 39 cats met the inclusion criteria. In 45/46 fractures, radiographic signs of bone healing were present and 35/39 cats were assessed as walking normally by a veterinarian at 6-week follow-up. There was a significant increase in radiographic signs of osteoarthritis (p=0.037) and femoral neck osteolysis (p=0.001) on 6-week follow-up radiographs. Pre- and postoperative osteoarthritis and femoral neck osteolysis were not associated with clinical outcome. The mean follow-up period for the telephone questionnaire was 48 months (range, 5-147 months). Seven out of 25 owners reported a gait abnormality in the short- to long-term. CONCLUSION: Femoral capital physeal fractures in cats can be treated successfully with the use of cortical positional screws. This technique may be considered as an alternative to other primary fixation techniques and salvage procedures for the treatment of femoral capital physeal injuries in cats. This technique seemed successful in cats with a low-grade preoperative femoral neck osteolysis.

Ultrasonographic diagnosis of femoral fractures in large animals.

OBJECTIVE: Femoral fractures are often catastrophic in large animals. Radiographic diagnosis is limited by patient size and feasibility, especially in ambulatory settings. Ultrasonography is widely available and may provide an alternative to radiography for definitive diagnosis. ANIMALS: 12 large animals (6 horses, 5 cattle, and 1 elephant). PROCEDURES: Retrospective analysis of large animal patients diagnosed with femoral fracture by use of femoropelvic ultrasonography (2000 to 2019). RESULTS: 5 of 12 cases were ≤ 1 year of age. The remaining 7 cases were 2 to 33 years of age (median, 13 years). All patients developed severe acute lameness after falling (n = 4), limb entrapment (2), dystocia (1), vehicular collision (1), ipsilateral full limb casting (1), or unknown events (3). All were non-weight-bearing or lame at the walk, including 2 recumbent cattle. Ten cases showed upper limb swelling that was variable in location, and 3 had nonspecific upper limb crepitus. Ultrasonography revealed evidence of diaphyseal (n = 6), greater trochanteric (2), capital physeal (2), and distal femoral (2) fractures. Fracture movement during limb manipulation or weight shifting was sonographically visualized in 5 animals. Radiography confirmed fractures in 3 of 8 animals: 2 bovines with distal femoral fractures detected on standing projections and 1 capital physeal fracture that required ventrodorsal projections under general anesthesia. All animals were euthanized (11) or slaughtered (1 bovine). Postmortem examination confirmed ultrasonographic findings in 10 of 10 necropsied animals. CLINICAL RELEVANCE: Femoral fractures were not localized nor confirmed in any case prior to ultrasonography. Study findings supported the use of ultrasonography for rapid patient-side diagnosis, prognostication, and decision-making in suspect cases.

Feline Femoral Fracture Fixation: What are the options?

PRACTICAL RELEVANCE: The femur is the most commonly fractured bone in cats. Femoral fractures usually result from high-velocity trauma such as a road traffic accident or fall from a height and, as such, are associated with a wide variety of concurrent injuries. The initial focus of treatment should always be on assessment and stabilisation of the major body systems. Once any concurrent injuries have been addressed, all femoral fractures need surgical stabilisation, with the notable exception of greenstick fractures in very young cats, which can heal with cage rest alone. A number of different surgical options are available depending on the fracture type, location, equipment, surgeon experience and owner finances. CLINICAL CHALLENGES: Femoral fractures can vary hugely in complexity and the small size of feline bones can limit the choice of implants. Furthermore, cats can present unique challenges in the postoperative period due to their active nature and the limited means to control their exercise level. AUDIENCE: This review is aimed at general and feline-specific practitioners who have some experience of feline orthopaedics, as well as those simply wishing to expand their knowledge. AIMS: The aim of this review is to help clinicians assess, plan and manage feline femoral fractures. It provides an overview of diagnostic imaging and a discussion of a range of suitable surgical options, including the principles of different types of fixation. It also highlights cat-specific issues, approaches and implants pertinent to the management of these cases. EVIDENCE BASE: A number of original articles and textbook chapters covering many aspects of femoral fractures in cats and dogs have been published. Where possible, this review draws on information from key feline research and, where necessary, extrapolates from relevant canine literature. The authors also offer practical guidance based on their own clinical experience.

Limb Gait Score of Femur Fracture Fixated by Intramedullary Pinning in Dogs.

Animal posture, limb gait, and body weight-bearing in dogs can be evaluated by limb gait score. In this study, nine adult male dogs of local breed were used to induce a complete transverse femoral mid-shaft fracture fixed internally by intramedullary pining under general anesthesia with the aseptic technique and followed for 60 days postoperative. The data were analyzed, including five degrees that indicate the correlation among animals' posture, limbs, and body weight tolerance per day. The results demonstrated that in grade 5, the animals completely hold the affected limb during standing position 1st-3rd day postoperative. From the 4th-10th day postoperative, in grade 4, the animals supported the body weight on the affected limb in the standing position and hold it during waking. In grade 3, from 11th-21th day postoperative, the operated animals supported body weight on the affected limb in slow waking and hold it in speed waking and running. From the 22nd-28th day postoperative, in grade 2, the animals used the limb in speed walking, from the 29th-35th day postoperative. In grade1, the animals could use the limb in running from the 36th-2nd day postoperative. In grade 0, the animals used the limb normally in walking, running, and jumping until the end of experimental periods (60th day postoperative). The results indicated that limb gait scores in dogs can be used for the evaluation of the relationships among animals' posture, limb gait, and body-weight bearing per day during bone regeneration processing of femur fracture fixed by intramedullary pining.

Femoral condylar fractures in four continental giant breed rabbits.

Four male neutered continental giant rabbits aged between 10 and 30 months were presented with femoral condylar fractures, which developed without an observed traumatic injury. Stabilisation of the condylar fracture was achieved with screw fixation in all cases, which was supplemented with additional fixation in three cases. Complications consequent to the surgical intervention occurred in two cases: a femoral fracture and loss of fixation. Three rabbits were reported to have recovered normal limb function, and the rabbit that developed a femoral fracture as a consequence of its surgical intervention was treated with amputation.

Outcome of canine cementless collared stem total hip replacement with proximal femoral periprosthetic cerclage application: 184 consecutive cases.

OBJECTIVE: To report outcomes of cementless collared stem total hip replacement (THR) with proximal femoral periprosthetic cerclage application in dogs. STUDY DESIGN: Retrospective case series. ANIMALS: Client-owned dogs (n = 150) with THR (n = 184). METHODS: Serial postoperative radiographs and medical records of dogs that underwent consecutive index cementless THR, with a single full cerclage wire placed distal to the femoral neck osteotomy line and proximal to the lesser trochanter, were reviewed for intraoperative and postoperative complications. RESULTS: No proximal femoral fractures occurred. No complications associated with the use of the cerclage wire were encountered. A fissure (n = 1) or fractures (n = 2) occurred near the tip of the femoral stem in three cases postoperatively. All three cases required plate and screw fixation. All dogs returned to subjectively normal function at home and all owners were satisfied with the outcome. CONCLUSION: A single full cerclage wire may minimize the risk of a proximal femur fracture following cementless collared stem total hip replacement in dogs. No complications were encountered with the cerclage wire. CLINICAL SIGNIFICANCE: Application of a cerclage wire is a simple and economically feasible procedure that requires minimal additional instrumentation, takes little time, and may decrease the risk of proximal femur fractures after cementless press-fit THR.

Determination of the insertion position of implants for the cross-pin fixation of distal femoral physis fractures.

The cross-pin technique for the treatment of distal femoral physis fractures (specifically, Salter-Harris Type I fractures) was investigated using femurs collected from beagle cadavers. The pin was inserted from the medial surface of the femur at an inclination of approximately 30 to 45° relative to the long axis of the femur in the anteroposterior direction; the pin exit was set proximal to the origin of the long digital extensor tendon. Digital and radiographic images of the femur in the anteroposterior and lateral directions were obtained. In both types of images, the insertion angle of the pin relative to the long axis was measured. Results suggest that when inserting a pin proximal to the fracture line, the ideal position can be achieved by inclining the pin approximately 20° cranially relative to the long axis of the lateral direction of the femur, in addition to the previously described criteria.

La technique des tiges croisées pour le traitement des fractures de la physe fémorale distale (en particulier, les fractures de Salter-Harris de type I) a été étudiée à l'aide de fémurs prélevés sur des cadavres de beagle. La tige a été insérée à partir de la surface médiale du fémur à une inclinaison d'environ 30 à 45° par rapport au grand axe du fémur dans la direction antéropostérieure; la sortie de la tige était localisée en amont de l'origine du tendon extenseur digital long. Des images numériques et radiographiques du fémur dans les directions antéropostérieure et latérale ont été obtenues. Dans les deux types d'images, l'angle d'insertion de la tige par rapport au grand axe a été mesuré. Les résultats suggèrent que lors de l'insertion d'une tige proximale au trait de fracture, la position idéale peut être obtenue en inclinant la tige d'environ 20° crânialement par rapport au grand axe de la direction latérale du fémur, en plus des critères décrits précédemment.(Traduit par Docteur Serge Messier).

Arthroscopic removal of an intra-articular screw causing joint impingement after distal femoral fracture repair in a dog.

The use of lag screws to treat femoral condyle fractures is common, and their placement in surgery is technically demanding. Intra-articular screw impingement is a serious complication that may occur during surgical treatment of femoral condyle fractures. Here, we describe the case of a 3-year-old 40-kg dog which experienced recurrent lameness 6 mo after successful surgical treatment of a comminuted medial femoral condyle fracture due to an intra-articular non-loosening screw causing joint impingement. Removal of the conflicting screw was performed arthroscopically, based on its ability to offer minimally invasive access to the stifle joint. Six months after removal of the screw, the dog had full recovery without limitations to range of motion or stifle pain. To our knowledge, this is the first report on the use of arthroscopy to remove an intra-articular screw causing joint impingement after distal femoral fracture repair in a dog.

Retrait par arthroscopie d'une vis causant un empiètement intra-articulaire après une ostéosynthèse du fémur distal chez un chien. Les fractures fémorales condyliennes sont communément stabilisées au moyen de vis de traction dont le placement peut s'avérer techniquement difficile. L'empiètement intra-articulaire induit par une vis est une complication sérieuse du traitement des fractures fémorales condyliennes. Nous décrivons dans le présent article le cas d'un chien de 3 ans et de 40 kg présenté pour une boiterie récidivante, 6 mois après le traitement d'une fracture comminutive du condyle fémoral médial, due à une vis causant un empiètement intraarticulaire. Le retrait de la vis est effectuée par arthroscopie étant donné que cela permettait un accès minimalement invasif au grasset. Six mois après l'arthroscopie, le chien présente une récupération orthopédique pleine sans douleur ni diminution de l'amplitude articulaire du grasset. Il s'agit du premier cas de retrait par arthroscopie d'une vis causant un empiètement intra-articulaire après une ostéosynthèse d'une fracture fémorale distale chez un chien.(Traduit par l'auteur).

A RETROSPECTIVE STUDY OF FEMORAL FRACTURES IN WILD BIRDS OF PREY: 119 CASES.

A retrospective study was performed to describe patient and fracture characteristics, treatments, complications, and outcomes associated with femoral fractures in free-ranging birds of prey. Cases were identified from the electronic database and included raptors admitted with femoral fractures at the Bird of Prey Clinic of the Université de Montréal, from 1986 to 2018. In total, 119 individuals from 24 species, with 123 femoral fractures, were included in the study. Twenty-seven birds (23%) were declared dead upon arrival. Ninety-two birds (77%) were admitted alive; 80 with acute fractures and 12 with a fracture that had already healed. A conservative treatment (cage rest) was used to manage eight fractures. Surgical repair was attempted on 34 femoral fractures in 33 birds. An intramedullary pin alone was used in 28 cases (82%), and an external skeletal fixator-intramedullary pin tie-in fixator was used in 6 cases (18%). For surgically treated fractures, 19 healed (in 18 birds), 4 did not heal, and 11 birds died or were euthanized before healing could be achieved. Of the 23/34 fractures where the healing process could be assessed, healing rate for comminuted fractures (11/23) was 91% (10/11). Surgical complications occurred in 10 cases (including 7 cases of migration and loosening of the pin, and 1 case of osteomyelitis), leading to euthanasia in 4 cases. Out of the 21 birds with acute femoral fracture upon presentation that were released, 14 had received a surgical treatment and 7 had received a conservative treatment. Nine of the 21 released birds (43%) had at least one other fractured bone. The majority of deaths and euthanasia occurred within 2 wk after admission (51/59; 86%). Thirteen birds were euthanized primarily because of their femoral fracture. Thirteen birds died in treatment and 33 were deemed nonreleasable and euthanized because of a comorbidity not related to the femoral fracture.

Use of a circular fixator construct to facilitate closed reduction and percutaneous stabilization of a distal femoral physeal fracture in a dog.

Background: Fractures of the distal femoral physis are the most common physeal fracture sustained by skeletally immature dogs. Reduction and stabilization of these fractures can sometimes be achieved through closed reduction, primarily in fractures that are nominally displaced. Circular external fixator constructs have been used to assist in indirect, closed reduction of fractures at other anatomic locations in dogs and this report describes application of this method to reduce a displaced Salter-Harris type II fracture of the distal femur in a 1-year-old dog. Case Description: A 1-year-old female spayed Akita was referred for treatment of a Salter-Harris type II fracture of the right distal femur. The epiphyseal segment was laterally and slightly caudally displaced. Multiple attempts to manually reduce the fracture during surgery were unsuccessful, so a two-ring circular external fixator construct was applied to facilitate distraction and reduction. The construct was applied by placing a medial-to-lateral Kirschner wire in both the mid-femoral diaphysis and in the distal femoral epiphysis. Distraction of the construct provided sufficient separation of the fracture segments to facilitate near anatomic reduction. The fracture was stabilized with two percutaneously placed Steinmann pins placed in Rush fashion. Radiographic union was confirmed 5 weeks after surgery. The dog was not lame and was bearing more weight on the right pelvic limb, as assessed using force plate analysis, 9 months following surgery. Goniometric measurements of stifle range of motion and thigh muscle circumference were similar between the pelvic limbs. Conclusion: Application of a two-ring circular construct would appear to be useful to facilitate closed reduction and percutaneous stabilization of distal femoral physeal fractures.

Zürich cementless total hip arthroplasty as a treatment option for capital physeal fractures in dogs: Outcome in 53 cases.

OBJECTIVE: To review the outcome of dogs that underwent Zürich cementless total hip arthroplasty (Z-THA) for the repair of acute and chronic capital physeal fractures (CPF) and document the CPF-related hip remodeling. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Fifty-three Z-THA in 53 dogs. METHODS: Medical records of dogs (2006-2019) that underwent Z-THA for CPF management were reviewed. Dogs were divided into two groups on the basis of the days elapsed between CPF diagnosis and Z-THA, acute (≤30 days) and chronic (>30 days). Hip remodeling variables were determined from preoperative radiographs or intraoperatively. Descriptive statistics were performed, and the complication rates, outcome, and coxofemoral remodeling were recorded. Comparisons of remodeling variables and rates between groups were performed by using Fisher's exact test. RESULTS: In total, 23 of 53 (43.4%) cases were acute, and 30 of 53 (56.6%) cases were chronic. There was no difference in the femoral remodeling rates between the acute and chronic groups (P = .184), whereas acetabular remodeling was more prevalent in the chronic group (P < .001). Intraoperative complications occurred in four of 53 (7.5% [1/23 acute, 3/30 chronic]) cases, and postoperative complications occurred in six of 53 (11.3% [2/23 acute, 4/30 chronic]) cases. Good clinical outcomes were achieved in 51 of 53 (96.2% [21 acute, 30 chronic]) cases. CONCLUSION: Complication rates of Z-THA for CPF repair were similar to the complication rates reported for Z-THA of dysplastic hips. Hip remodeling was common regardless of CPF chronicity. CLINICAL SIGNIFICANCE: Zürich cementless total hip arthroplasty is viable for surgical management of CPF. There is a high likelihood that hip remodeling will be encountered, even in fractures treated within 30 days of presenting for hind limb lameness.

Clinical application of the small I-Loc interlocking nail in 30 feline fractures: A prospective study.

OBJECTIVE: To describe medium-term functional outcome after nail osteosynthesis in feline traumatology and report clinically relevant recommendations for I-Loc angle-stable interlocking nail use in cats. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Client-owned cats (n = 29). METHODS: Consecutive cases with femoral, tibial, or humeral fractures were included. Outcome measures included fracture and surgical procedure description, limb alignment, nail size vs body weight (BW), percentage of nail medullary canal (MC) fill, time to limb function at clinical union (CU), and complications. Descriptive statistics were reported and compared with historical data. RESULTS: Bone distribution was 53.3% femora, 30% tibiae, and 16.7% humeri. There were six epimetaphyseal and 24 diaphyseal fractures. Overall, 67% of fractures were comminuted. Open reduction and minimally invasive techniques were used in 73% and 27% of cases, respectively. Seventeen I-Loc 3 (cat mean BW 4.4 ± 2.2 kg) and 13 I-Loc 4 (cat mean BW 5.2 ± 1.2 kg) nails were placed with mean MC fill of ≤50%. Average time to CU was 7.2 weeks. At CU, lameness had resolved or was mild in every cat, and all cats ultimately regained full limb function. No major complications were encountered. CONCLUSION: Because of improved CU times, excellent functional outcomes, and low complication rate, our results provide evidence that I-Loc nails are safe and effective for feline traumatology. CLINICAL SIGNIFICANCE: The I-Loc may be advantageous for fixation of epimetaphyseal fractures. Because of feline bone specific dimensional constraints, I-Loc 3 is likely appropriate for all feline humeri and most tibiae, while I-Loc 4 is well sized for feline femora.