Closed reduction and fluoroscopic-assisted percutaneous pinning of 42 physeal fractures in 37 dogs and 4 cats*

Outcomes of 15 dogs and two cats with metabone fractures treated with fluoroscopically guided normograde metabone pinning

OBJECTIVE

To report the outcomes of 15 dogs and two cats with metabone fractures treated with fluoroscopically guided normograde metabone pinning (FGNMP).

STUDY DESIGN

Retrospective case series.

ANIMALS

A total of 15 client owned dogs and two cats with 57 metabone fractures.

METHODS

Description of FGNMP and reporting of the following data: signalment, pre- and postoperative radiographs, intramedullary pin diameter used, anesthesia, surgery and coaptation times, duration to normal weightbearing and bone union, postoperative care and complications.

RESULTS

Median surgery time was 54 min (range: 26-99), median duration of coaptation was 14 days (range: 1-5 weeks), median time to normal weightbearing was 16 days (range: 2-45) and median time to bone union was 6 weeks (range: 4-12). All cases had at least 12 months of post-surgical follow-up with a median follow-up of 18 months (range: 12-70). No major complications occurred. Mild radiographic changes associated with subchondral bone sclerosis were noted on follow-up radiographs in 13/57 fractures. All cases returned to normal gait and full (15) or acceptable (2) function.

CONCLUSION

In this study, FGNMP was an effective and safe technique for metabone fracture repair, requiring only short-term external coaptation in most patients. Time to bone union and return to normal function compared favorably to previously reported techniques.

CLINICAL RELEVANCE

Fluoroscopically guided normograde metabone pinning provides an alternative technique for treatment of metabone fractures.

Use of a Modified Intramedullary Pinning Technique for Distal Femoral Physeal Salter-Harris Type I and II Fracture Management: A Retrospective Study of 31 Cats

OBJECTIVE

 To report a modified intramedullary pinning technique, and associated outcomes, for distal femoral physeal Salter-Harris type I and II fracture management in cats.

STUDY DESIGN

 Retrospective study including client-owned cats presented between November 2014 and February 2022 with distal femoral physeal fractures treated with an intramedullary pin and one antirotational pin inserted in the lateral femoral condyle. Collected data included signalment, fracture characteristics according to the Salter-Harris classification, surgical data (intramedullary and antirotational pin sizes), and outcome data (radiographic and functional outcomes and complications).

RESULTS

 Thirty-one cats were included in this study. Bone healing was radiographically confirmed 6 to 8 weeks postoperatively in all cases. The majority of cats (30/31) were classified as full functional outcomes at mid-term follow-up. The overall mid-term complication rate was 3% (1/31). Implant migration was not observed and implant removal was not needed in any case.

CONCLUSION

 The modified intramedullary pinning technique for distal femoral Salter-Harris I and II fracture management in cats was associated with an full functional outcome.

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.

Appendicular skeletal muscle mass assessment in dogs: a scoping literature review

BACKGROUND

Monitoring changes in appendicular skeletal muscle mass is frequently used as a surrogate marker for limb function. The primary objective of this study was to review scientific information related to the assessment of appendicular skeletal muscle mass in dogs. The secondary objective was to develop practical recommendations for serial evaluation of muscle mass.

METHODS

A scoping review was conducted with a systematic search of PubMed, Web of Science, CAB abstract, and Cochrane from inception to June 2021. The following modalities were included in the search: limb circumference, diagnostic ultrasound, computed tomography, magnetic resonance imaging, and dual-energy x-ray absorptiometry.

RESULTS

A total of 62 articles that measured appendicular skeletal muscle mass in dogs were identified. Limb circumference (55 articles) was the most commonly used modality. Its reliability was investigated in five studies. Several factors, including measuring tape type, body position, joint angles, and the presence of hair coat, were reported as variables that can affect measurements. Diagnostic ultrasound (five articles) was validated in three articles, but there is scarce information about observer reliability and variables affecting the measurement. Computed tomography (four articles) and magnetic resonance imaging (one article) have been used to validate other modalities at a single time point rather than as a clinical tool for serial muscle mass monitoring. Dual-energy x-ray absorptiometry (two articles) has been used to quantify specific skeletal muscle mass but was mainly used to evaluate body composition in dogs.

CONCLUSION

Limb circumference and ultrasound are likely the main modalities that will continue to be used for serial muscle mass measurement in the clinical setting unless a new technology is developed. The reliability of limb circumference is questionable. Several key factors, including measuring tape type, body position, joint angles, and coat clipping, need to be controlled to improve the reliability of limb circumference measurements. Ultrasound may provide a reasonable alternative, but further studies are required to evaluate the reliability of this modality and identify factors that influence ultrasound measurements.

Surgical and medical management in the treatment of proximal tibial metaphyseal fracture in immature dogs

The purpose of this study was to report approaches to surgical and medical management of proximal tibial metaphyseal fractures (PTMF) and short-term case outcome. Medical records of immature dogs with PTMF were reviewed and data were collected including history, signalment and side affected. Data pertaining to surgical and medical management including radiographic evaluation and short-term complications were recorded. Forty-five dogs with a total of 47 PTMF identified and treated between 2007–2019 were included in this study. Six cases were managed with external coaptation alone. Forty-one cases were treated surgically with constructs including K-wires in different configurations, bone plate and screws, and external skeletal fixation. Of the cases managed conservatively, 4 developed complications, including bandage sores, diffuse osteopenia of the tarsus/metatarsus, and angular limb deformities. Surgical complications including pin migration necessitating removal, osteopenia, and screw placement in the proximal tibial growth plate or into the stifle joint were found in 16 cases. PTMF treated with surgery had a subjectively more predictable outcome compared to those treated with external coaptation alone. Conservative management may result in complications including development of excessive tibial plateau angle (TPA) as well as distal tibial valgus.

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.

A review of minimally invasive fracture stabilization in dogs and cats

OBJECTIVE

To summarize and discuss peer-reviewed studies on minimally invasive osteosynthesis (MIO) of long bone, physeal, and articular fractures in dogs and cats.

STUDY DESIGN

Invited review.

METHODS

A critique of literature was performed to assess MIO feasibility, outcomes, and complications through PubMed, Scopus, and CAB abstracts research databases (2000-2020).

RESULTS

More than 40 MIO articles have been published in the last 15 years, but most studies had small numbers, lacked control groups, and used limited outcome measures. Studies generally showed that MIO was feasible in dogs and cats with low complication rates. The current evidence does not demonstrate superior bone healing or functional outcomes with MIO when compared to standard methods. Although treatment principles, case selection, and techniques varied depending on the anatomical location, there were no salient differences in complication rates among long bones, physeal, and articular fractures treated by MIO.

CONCLUSION

The current available evidence and the personal experience of the authors support MIO as a promising fracture management modality. MIO can yield excellent outcomes when applied in carefully selected cases, performed by surgeons experienced in the technique. We cannot, however, conclude that MIO is superior to open fracture stabilization based on the available evidence in veterinary literature. Randomized controlled studies are warranted to prospectively compare MIO with other osteosynthesis techniques and thereby validate its role in fracture management for dogs and cats.

Biomechanical Comparison of Three Stabilization Methods for Tibial Tuberosity Fractures in Dogs: A Cadaveric Study

OBJECTIVE

 The aim of this study was to compare the biomechanical properties of a hybrid external skeletal fixator (HESF) construct to the placement of paired interfragmentary Kirschner wires alone, and pin and tension band wire (PTBW) fixation for the stabilization of simulated tibial tuberosity fractures in dogs.

STUDY DESIGN

 Tibias were harvested from 12 skeletally mature dog cadavers weighing 20 to 30 kg. An osteotomy was made through the base of the tibial tuberosity, which was subsequently repaired with either paired Kirschner wires, PTBW fixation or a HESF. A tensile load was applied to the tibial tuberosity until failure occurred. Mode of failure was described and biomechanical parameters obtained were compared between fixation groups.

RESULTS

 The PTBW fixation and HESF construct afforded greater stiffness and load at 3 mm of axial displacement compared with fixation with Kirschner wires alone. There was no significant difference in stiffness and load at 3 mm displacement between PTBW and HESF fixation. Failure occurred by bending and pullout of the Kirschner wires for all fixation groups, preceded by untwisting of the knot in PTBW specimens.

CONCLUSION

 The HESF may provide a favourable alternative to PTBW fixation for tibial tuberosity avulsion fracture stabilization in dogs with substantial remaining growth potential.

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.

Tibial Apophyseal Percutaneous Pinning in Skeletally Immature Dogs: 25 Cases (2016-2019)

OBJECTIVE

 The aim of this study was to report the clinical experience with fluoroscopically guided tibial apophyseal percutaneous pinning (TAPP) for tibial tuberosity avulsion fractures (TTAF).

STUDY DESIGN

 This is a retrospective case series.

MATERIALS AND METHODS

 Medical records of skeletally immature dogs (n = 25) were reviewed. The association of pin design [smooth (SP); negatively threaded (NTP)], pin insertion angles, TTAF-type, age and breed with various outcome variables was statistically evaluated. Long-term follow-up was assessed via direct examination, radiographs, questionnaires and videos.

RESULTS

 Mean age, weight and surgery times were 6.2 months, 9.6 kg and 21 minutes respectively. No major complications occurred among the 19 SP and 6 NTP; no pin broke. Seromas and patellar desmitis rates were higher with SP (11/19; 16/19) versus NTP (0/6; 2/6) (p = 0.02; 0.03). The median horizontal pin cross angles for cases without and with desmitis were 40 and 26 degrees respectively (p = 0.047). Explantation was needed in 5/19 SP and 0/6 NTP cases. The mean tibial plateau angle (TPA) changed significantly between initial (25.6 degrees) and follow-up (18.8 degrees) radiographs (p = 0.0002). Long-term outcome, obtained at a mean of 19.9 months, was excellent in all cases.

CONCLUSION

 Tibial apophyseal percutaneous pinning can be considered to treat TTAF. Divergent pin placement and using NTP might reduce complications. Tibial plateau angle should be monitored until skeletal maturity has been reached. Long-term outcome post TAPP can be expected to be excellent.

Percutaneous Pinning for Fracture Repair in Dogs and Cats

This article describes the technique of percutaneous pinning in dogs and cats. Only acute fractures evaluated within the first 48 hours after trauma are selected for percutaneous pinning. Reduction is performed with careful manipulation of the fracture to minimize the trauma to the growth plate. After ensuring the fracture is reduced anatomically, smooth pins of appropriate size are inserted through stab incisions or through large-gauge needles. Depending on the anatomic location, the pins are cut flush with the bone or bent over. The main advantages of this technique are the minimal surgical trauma and lower perioperative morbidity.

Comparative functional outcome of supracondylar femoral fracture stabilized with cross and end threaded intramedullary pinning in dogs

The study was conducted on 24 clinical cases of dogs (with 26 fractures) suffering from supracondylar fractures of femur which were stabilized using cancellous negative intramedullary (IM) end-threaded pin with 5 screws (Group I, n=8), cross-pinning (Group II, n=8, 9 fractures) and cancellous negative end threaded IM pin having 10– 18 threads (Group III, n=8, 9 fractures). Data collected included signalment, fracture characteristics (etiology, duration, Salter-Harris classification, pre-operative and post-operative displacement), surgical information (implant size, surgical duration) and outcome assessment (functional outcome and complications). Cross pinning technique used to stabilize supracondylar fracture of femur adversely affects flexion angles of stifle joint leading to joint stiffness compared to either of the end threaded pinning techniques; however, extension angles remain unaffected. Early weight bearing in group II suggested that crossing pinning is a rigid fixation technique compared to either end threaded pinning techniques. Minor implant related complications were recorded in group II (3) followed by group 3 (2) and group 1(1) which were managed successfully. Though fixation of supracondylar fractures using double armed end threaded pin with 5 cancellous negative threads was associated with shorter duration of surgery, and fewer postoperative complications; however, based on formation of minimal and smooth callus and better functional outcome, conventional end threaded pin with 10–18 cancellous negative threads was assessed to be a better fixation technique and was recommended for the repair of supracondylar fractures of femur in dogs.