Computed Tomography Topographical Analysis of Incomplete Humeral Intracondylar Fissures in English Springer Spaniel Dogs

OBJECTIVE

 The aim of this study was to use computed tomography (CT) images obtained from English springer spaniels (ESS) with different sizes of humeral intracondylar fissure (HIF) to describe the typical shape, origin and a possible propagation pattern of HIF in this breed.

STUDY DESIGN

 It is a retrospective analysis of 32 elbow CT from 27 ESS with incomplete HIF. Measurements included HIF articular surface length, centre of HIF at articular surface relative to the caudal edge of the supratrochlear foramen (CHIF), HIF depth and sagittal area of fissure. Measurement of isthmus area and diameter was obtained for each elbow. Humeral intracondylar fissure measurements were analysed as proportions of the isthmus. For parts of analysis, elbows were grouped by HIF area as a percentage of isthmus area (%HIF) into less than 20% (n = 10), 20 to less than 40% (n = 8), 40 to less than 60% (n = 9) and 60 to less than 90% (n = 5).

RESULTS

 The mean isthmus diameter was 12.31 mm (range: 10.96-13.69 mm). Mean CHIF for %HIF groups less than 20%, 20 to less than 40%, 40 to less than 60% and 60 to less than 90% were 57, 74, 86 and 96 degrees, respectively. The less than 20% group was significantly lower than 20 to less than 40% group (p = 0.035) and 40 to less than 60% and 60 to less than 90% groups (p < 0.001); the 20 to less than 40% group was significantly lower than the 60 to less than 90% group (p = 0.015). Humeral intracondylar fissure articular surface length increased in a sigmoidal fashion relative to %HIF, corresponding to segmental enlargement of the fissure as %HIF increases.

CONCLUSION

 In ESS, HIF typically originates approximately 57 degrees caudal to the supratrochlear foramen in the sagittal plane and may propagate in a segmental fashion with lesser propagation through the proximal intracondylar region.

Influence of oblique proximal ulnar osteotomy on humeral intracondylar fissures in 35 spaniel breed dogs

OBJECTIVE

To investigate the effects of oblique proximal ulnar osteotomy (PUO) on the healing of humeral intracondylar fissure (HIF) in spaniel breed dogs.

STUDY DESIGN

Clinical retrospective study.

SAMPLE POPULATION

A total of 51 elbows from 35 spaniel dogs.

METHODS

An oblique PUO was performed in dogs diagnosed with HIF. The degree of healing of HIF was subjectively and objectively assessed on preoperative and long-term follow-up CT imaging. Objective assessment was performed by measuring the bone density in Hounsfield units (HU) of a rectangular region of interest (ROI) encompassing the entire hypoattenuated humeral fissure. Major and minor complications were recorded.

RESULTS

A total of 24 partial and 27 complete HIFs were diagnosed. The follow-up CT scan was performed at a median 18.5 months (range 10-49 months). Subjective assessment confirmed partial or complete healing of the HIF in 41 elbows (80.3%). Objective assessment confirmed a difference in mean HU of the HIF's ROI between preoperative (HU 640) and last follow-up CT images (HU 835) (p = .001). Young dogs (<14 months) had the highest increase in HU of the HIF's ROI. Major complications occurred in five dogs (6 limbs) of which four were related to the lack of healing of the fissure (7.8%).

CONCLUSION

Oblique PUO resulted in partial or complete healing of HIF and pain resolution in the majority of dogs.

CLINICAL SIGNIFICANCE

This study introduces an innovative approach to achieve healing of the HIF in the dog, which may help reduce the high complication rate traditionally associated with the use of transcondylar screws.

Long term outcomes of the Humeral Intracondylar Repair System for management of canine humeral intracondylar fissures and humeral condylar fractures

Objective

To document long-term client-reported clinical outcomes and complications for the Humeral Intracondylar Repair System (HIRS) for treatment of humeral intracondylar fissures (HIF) and humeral condylar fractures (HCF) in dogs.

Method

Data collection involved the review of clinical records and analysis of an owner questionnaire regarding complication occurrence and client-reported outcome. The "Liverpool Osteoarthritis in Dogs" (LOAD) instrument was incorporated into the questionnaire.

Results

Twenty-six cases of HIF and 14 cases of HCF were included in the study, with follow-up times of over 12 months (range 13-97 months). Thirty-seven out of 40 cases reached long-term follow up: 25 out of 26 HIF cases, 11 out of 11 lateral condylar fracture cases and one out of three dicondylar fracture cases. Two cases of HIF suffered a gradual return of lameness in the long term; both dogs had concomitant medial coronoid disease. No other complications were reported in the long term. Excluding cases with concurrent issues affecting exercise, the median LOAD score at follow-up was 4 and 5 (out of 52) for HIF and HCF cases, respectively. At long-term follow-up, 36 out of 37 cases were reported to have regained "full function of the limb."

Clinical significance

The results of this study, together with previously reported short and medium-term outcomes, support the use of HIRS for management of humeral intracondylar fissures and humeral condylar fractures.

Prevalence of incidental humeral intracondylar fissures in brachycephalic breed dogs in CT studies

Humeral intracondylar fissures (HIF) have been predominantly reported in spaniel breeds and proposed to be possible risk factors for humeral condyle fractures (HCF). We hypothesized that the prevalence of incidental HIF in French Bulldogs may be greater than that of other brachycephalic breeds. A retrospective, observational, prevalence study was performed using CT examinations of French bulldogs and other brachycephalic breed dogs presenting for an unrelated condition. Two European College of Veterinary Diagnostic and Imaging-certified radiologists reviewed the images of the humeral condyles of these dogs. A classification system was devised to grade the findings. We considered a Score 1 to be normal, Score 2 to have centralised sclerosis, Score 3 to have a partial fissure and Score 4 to have a complete fissure. A total of 228 elbows were reviewed from 122 dogs. Of this population, 145 elbows were from French Bulldogs, 54 were from Pugs, and the remainder were from a mix of other brachycephalic breeds. The prevalence of HIF (score 3 or 4) in elbows of the French bulldog, pug and other breed groups was 6.9% (CI 2.8-11%), 5.6% (CI 0-11.7%), and 3.4% (CI 0-10.15%), respectively. At a dog level, the prevalence of HIF (score 3 or 4 present in at least one elbow) was found to be 11.8% (CI 4.6-19%) in French Bulldogs, 11.1% (CI 0-22.9%) in Pugs, and 5.26% (CI 0-15%) in the other breed group. There was no significant difference between the breed groups. The inter-reviewer reliability for CT scoring of HIF based on Cohen's weighted kappa was low at 0.19.

Proximal Ulnar Osteotomy as a Treatment for Humeral Intracondylar Fissure in a Shetland Sheepdog

A seven-month-old male Shetland Sheepdog was presented for assessment of thoracic limb lameness of 3 weeks duration. Orthopaedic examination revealed severe discomfort in elbow extension, bilaterally. CT-scan confirmed presence of a complete humeral intracondylar fissure (HIF), bilaterally, and arthroscopic examination of both elbows confirmed the presence of the cartilaginous lesion previously reported in dogs suffering from HIF. A staged oblique proximal ulnar osteotomy was performed to address the humero-anconeal incongruency believed to be the cause of HIF formation. Orthopaedic examination performed 5 weeks after each surgical procedure confirmed that pain previously present on elbow manipulation had subsided. Follow-up examination performed 8 months after the second surgery revealed the dog to be sound at walking on the thoracic limbs with no discomfort present on elbow manipulation. Repeated CT scan confirmed complete healing of both HIFs. This is the first report documenting the presence of HIF in a Shetland sheepdog and complete healing of both HIFs following a proximal ulnar osteotomy.

Development of Real-Time Kinematic Magnetic Resonance Imaging (kMRI) Techniques for Studying the Kinematics of the Spine and Joints in Dogs-Preliminary Study on Cadavers

Simple Summary

Many orthopedic and neurological pathologic conditions can potentially lead to or be affected by joint instability. Standard magnetic resonance imaging, as a static technique that examine joints and body parts in functional rest, can underestimate or overlook key diagnostic findings. As a result, kinematic magnetic resonance imaging techniques were developed to evaluate joints and body parts under stress and load conditions or during movement. In human medicine, the real-time acquisition technique is one of the modalities for acquiring kinematic magnetic resonance imaging, and has gained popularity in recent years. This proof-of-concept study was designed to test the feasibility of real-time acquisition techniques in veterinary medicine for the first time. Based on the results of this preliminary cadaveric study, real-time kinematic magnetic resonance imaging may be a feasible and valuable procedure to be applied to the canine cervical spine and stifle joints. Moreover, given the ease of execution and the concise duration of acquisitions, it could be applied in a regular standard protocol MRI with little additional effort, risk, and cost. In this proof-of-concept study, a good visualization of the canine cervical spine and stifle joint was achieved, showing the potential of real-time acquisition techniques for clinical and research applications.

Abstract

Kinematic MRI (kMRI) is a novel human imaging technique that couples the excellent soft tissue contrast and multiplanar capabilities of traditional MRI with kinematic potential. The study’s goals are: (1) testing the feasibility of spinal cord and joints real-time kMRI; and (2) evaluating the quality of these kinematic studies as a new diagnostic option in veterinary medicine. Standard and real-time kinematic MRI were performed on cervical spine, elbow, and stifle joints of seven cadavers. Studies were repeated after a surgical insult aimed to create a certain degree of joint instability. A total of 56 MRI were performed—7 cervical spinal tracts, 3 elbow joints, and 4 stifle joints were examined. The technique was feasible in all the three regions examined. The images were considered of excellent quality for the stifle joint, good to fair for the cervical spine, whereas two of three elbow studies were considered to have unacceptable image quality. Additionally, real-time kMRI provided good to excellent information about stifle instability. Therefore we consider kMRI a promising technique in veterinary medicine. Further studies and an in vivo setting are needed to increase the quality of the kMRI images, and to fully evaluate clinical usefulness.

Medial epicondylar fissure fracture as a complication of transcondylar screw placement for the treatment of humeral intracondylar fissure

OBJECTIVE

To report the incidence of medial epicondylar fissure fracture (MEFF) after medial-to-lateral transcondylar screw placement in dogs with humeral intracondylar fissure (HIF) and to identify risk factors for MEFF.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Seventy-four client-owned dogs (88 elbows).

METHODS

Medical records of dogs surgically treated for HIF, and postoperative imaging studies were reviewed for demographics, fracture characteristics, and repair techniques. The width of the transcondylar screw was expressed relative to the height of the condyle. Screw angle and degree of countersinking were recorded. Information from case records and follow-up radiographs were used to identify complications.

RESULTS

Medial epicondylar fissure fracture was identified in 10 elbows (11.4%) following medial-to-lateral transcondylar screw placement: 4 cases were detected intraoperatively, 2 on immediate postoperative radiographs, 1 during routine radiographic follow up, and 3 when radiographs were reviewed for this study. A larger relative screw size was found to increase the risk of MEFF (P = .004, OR = 1.5). Fifteen additional complications were identified in 13/80 elbows at a median of 6 weeks postoperatively (range 1-56 weeks). Screw loosening was the most frequent complication (n = 9) and was the only complication in dogs with MEFF (n = 3); MEFF tended to increase the risk of perioperative screw loosening (P = .06).

CONCLUSION

Medial epicondylar fissure fracture occurred in 10/88 elbows treated for HIF and was more common in elbows treated with a larger screw size relative to the height of the condyle.

CLINICAL SIGNIFICANCE

Placing transcondylar screws with a diameter inferior to 41% of the height of the condyle is recommended to avoid MEFF. Medial epicondylar fissure fracture appears to have a low clinical significance in the perioperative period, although its effect on long-term outcome remains unknown.

Biomechanical comparison of humeral condyles with experimental intracondylar fissures immobilized with a transcondylar positional or a lag screw: An ex-vivo study in dogs

OBJECTIVE

To compare the axial biomechanical properties of intracondylar humeral osteotomies fixed with 4.5 mm transcondylar positional or cortical lag screws.

STUDY DESIGN

Ex vivo study.

SAMPLE POPULATION

Paired humeri from 21 canine cadavers.

MATERIALS AND METHODS

An intracondylar osteotomy was created on each humerus to mimic an intracondylar fissure. Paired humeri were randomly assigned to fixation with a positional or a lag screw. All specimens were radiographed postinstrumentation to document proper screw placement. Axial load was applied to the distal articular surface of the trochlea at a rate of 1 mm/s until a 40% decrease in load was measured. Specimens were assessed for mode of failure with visual inspection and radiographs.

RESULTS

Stiffness (1236.7 ± 181 N/mm vs. 1050.8 ± 265 N/mm), yield load (3284.3 ± 1703 N vs. 2071.1 ± 740 N), and maximum load (7378.0 ± 1288 vs. 5793.7 ± 2373 N) were greater in constructs fixed with a positional rather than a lag screw (p = .0008, .044, and .040, respectively).

CONCLUSION

In our model, mechanical properties were improved when the transcondylar osteotomy was stabilized with a 4.5 mm positional screw rather than a lag screw.

CLINICAL SIGNIFICANCE

This ex vivo study suggests that a transcondylar lag screw and positional screw are not biomechanically equal. Additional in vivo studies are need to help with clinical decision making when prophylactically treating HIF.

Accuracy of medial-to-lateral transcondylar screw placement using an aiming device and preoperative computer tomography planning for the treatment of humeral intracondylar fissure

OBJECTIVE

To determine the accuracy of transcondylar screws placed from medial-to-lateral using preoperative planning on computed tomography (CT) and an aiming device in elbows with humeral intracondylar fissures (HIFs).

STUDY DESIGN

Retrospective case series.

ANIMALS

Twenty-five client-owned dogs with HIF.

METHODS

A 4.5-mm transcondylar screw was placed in 34 elbows with HIF. humeral condylar diameter (HCD) was measured at the humeral condylar isthmus on CT. Entry and exit points were planned at 0.3 × HCD cranial and 0.2 × HCD distal to the medial epicondyle and 0.3 × HCD cranial and 0.3 × HCD distal to the lateral epicondyle. An aiming device was used to guide drilling from the medial entry point to the lateral exit point. The difference between planned and actual screw entry and exit points, and the angular deviation of the actual screw axis from the planned screw axis, was assessed on the postoperative CT scans.

RESULTS

Thirty-three out of 34 screws were completely within the humeral condyle. Thirteen out of 34 screws were placed less than 2 mm from planned entry and exit points in both the transverse and the frontal plane. The axis of the screw deviated by a mean of 3.2° (transverse plane) and 3.5° (frontal plane) from the planned axis.

CONCLUSION

Humeral transcondylar screws placed with the technique tested here were entirely within the humeral condyle in 33 out of 34 elbows.

CLINICAL SIGNIFICANCE

Use of CT planning and an aiming device allows accurate placement of transcondylar screws from medial-to-lateral in dogs with HIF.

Humeral Intracondylar Fissure in Dogs

Humeral intracondylar fissure (HIF) was first described as incomplete ossification of the humeral condyle. It is now known that the fissure is a stress fracture in some dogs. The descriptive term HIF is therefore preferred. In young dogs an incomplete ossification cause may still be valid. Symptomatic HIF is treated surgically with a transcondylar implant. The aim is to alleviate lameness and avoid condylar fracture. Choosing an appropriate surgical approach and implant can reduce complications. HIF is not always symptomatic and, in these cases, surgical management is more controversial, because a minority of such cases become lame or fracture.

Effect of Induced Incomplete Ossification of the Humeral Condyle on Ex Vivo Humeral Condylar Biomechanics

OBJECTIVE

 The aim of this study was to investigate the effects of an induced incomplete ossification of the humeral condyle (IOHC) lesion on ex vivo canine humeral condylar biomechanics.

STUDY DESIGN

 Nine paired cadaveric elbows were collected from mature dogs weighing between 20 and 25 kg. Left and right limbs were randomized to IOHC or normal groups. Limbs were prepared for mechanical testing; ligaments were preserved and an IOHC lesion was created. Elbows were potted, positioned into a biomaterials testing system at an angle of 135 degrees and axially loaded to failure at a rate of 30 mm/minute.

RESULTS

 Induced IOHC lesions reduced peak load (p = 0.02) when compared with an intact humerus. There was no difference between stiffness (p = 0.36) of intact humeri or humeri with an induced IOHC lesion. An induced IOHC lesion increased (p = 0.012) the probability of intracondylar fracture under load.

CONCLUSION

 Cadaveric humeri are weakened by the creation of an intracondylar osteotomy and fractures secondary to induced IOHC are similar to spontaneous humeral condylar fractures. These findings support the hypothesis that naturally occurring IOHC weakens the humeral condyle and may predispose to humeral condylar fracture.

A humeral intracondylar repair system for the management of humeral intracondylar fissure and humeral condylar fracture

OBJECTIVES

To report complications, clinical outcomes and CT-imaging outcomes of a surgical system designed for the management of humeral intracondylar fissures and humeral condylar fractures.

MATERIALS AND METHODS

Retrospective review of fracture healing from medical records, direct owner contact and an online data-submission service. Follow-up included CT scans and a calculated "bone-opacity continuity index" to quantify bone healing.

RESULTS

There was one major surgical complication and one major medical complication out of 34 fissure cases, and two major surgical and one major medical complication out of 14 fractures. Follow-up times ranged from 29 to 1268 days. All cases with CT follow-up had some continuity of bone opacity across the condyle.

CLINICAL SIGNIFICANCE

In the cases included in this study, this repair system was associated with low complication rates and favourable healing rates, particularly for humeral intracondylar fissure.

Treatment of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome

OBJECTIVES

The aim of this study is to describe the treatment and outcome of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome (PADS) and to provide advice on how to manage these cases in practice.

METHODS

Data were collated on cats with PADS that were reported to have sustained humeral fractures or had fractures or fissures of the humerus identified on radiographs. The details of the fractures were recorded in addition to any treatment and outcome information.

RESULTS

Of the 207 cases reported with PADS, 18 cats (8.7%) were found to have humeral condylar fractures, none of which was known to have resulted from significant trauma. Where treatment occurred, it involved the placement of transcondylar positional or lag screws. In some cases additional implants, including supracondylar bone plates and screws or Kirschner wires (K-wires), were used. Follow-up data revealed that only two cats were euthanased owing to the presence of the humeral fractures, with at least eight achieving some degree of recovery of function.

CONCLUSIONS AND RELEVANCE

These humeral fractures all have the characteristics of stress insufficiency fractures, being simple isolated fractures that are short oblique, with increased radio-density at the fracture line and occurring following minimal or no trauma. Humeral intracondylar fissures were identified in two cats and it is possible that some of the other fractures may have occurred secondary to pre-existing fissures. To our knowledge, no prior reports exist of fissures in cats that do not meet the criteria for PADS. Surgical repair primarily consisted of the placement of transcondylar lag or positional screws with, in some cases, adjunct implants such as bone plates and screws or K-wires. Though there were insufficient data to determine the prognosis for these fractures in the long term, unlike patellar fractures, many of these fractures will heal if treated appropriately.

Anatomic Study of the Elbow Joint in a Bengal Tiger (Panthera tigris tigris) Using Magnetic Resonance Imaging and Gross Dissections

The objective of our research was to describe the normal appearance of the bony and soft tissue structures of the elbow joint in a cadaver of a male mature Bengal tiger (Panthera tigris tigris) scanned via MRI. Using a 0.2 Tesla magnet, Spin-echo (SE) T1-weighting, and Gradient-echo short tau inversion recovery (GE-STIR), T2-weighting pulse sequences were selected to generate sagittal, transverse, and dorsal planes. In addition, gross dissections of the forelimb and its elbow joint were made. On anatomic dissections, all bony, articular, and muscular structures could be identified. The MRI images allowed us to observe the bony and many soft tissues of the tiger elbow joint. The SE T1-weighted MR images provided good anatomic detail of this joint, whereas the GE-STIR T2-weighted MR pulse sequence was best for synovial cavities. Detailed information is provided that may be used as initial anatomic reference for interpretation of MR images of the Bengal tiger (Panthera tigris tigris) elbow joint and in the diagnosis of disorders of this region.

Long-term outcome following management of canine humeral intracondylar fissure using a medial approach and a cannulated drill system

This study evaluated the feasibility, complications and long-term outcomes of using a cannulated drill system combined with intraoperative imaging to place a transcondylar screw for the management of canine humeral intracondylar fissure. Thirteen dogs were enrolled, with one dog undergoing staged bilateral surgery. No intraoperative complications occurred. Five minor (36%) and three major (21%) postoperative complications occurred, giving an overall complication rate of 57%. None of the screws placed penetrated the articular surface. The mean duration of surgery was 28 min (SD ±3.5) for dogs that developed a major complication versus 46 min (SD ±18.1) for those that did not (p=0.015). The duration of preoperative lameness was significantly shorter for cases which suffered a major complication (2 days; SD ±2.8) than those that did not (34 days; SD ±31.7, p=0.008). None of the variables assessed were significantly associated with minor complications. Median time from surgery to last follow-up was 5.8 years (range 3.5-8.5 years). Median Liverpool Osteoarthritis in Dogs questionnaire score at the final point of follow-up was 16 (range 7-27). A significant number of patients were found to require analgesia at long-term follow-up.

Assessment of medial coronoid disease in 180 canine lame elbow joints: a sensitivity and specificity comparison of radiographic, computed tomographic and arthroscopic findings

Background

Diagnostic imaging is essential to assess the lame patient; lesions of the elbow joint have traditionally been evaluated radiographically, however computed tomography (CT) has been suggested as a useful technique to diagnose various elbow pathologies. The primary objective of this study was to determine the sensitivity and specificity of CT to assess medial coronoid disease (MCD), using arthroscopy as gold standard. The secondary objective was to ascertain the radiographic sensitivity and specificity for MCD compared with CT.

Methods

For this study 180 elbow joints were assessed, of which 141 had been examined with radiography, CT and arthroscopy; and 39 joints, had radiographic and CT assessment. Sensitivity and specificity were calculated for CT and radiographic findings using available statistical software.

Results

Sensitivity and specificity of CT using arthroscopy as gold standard resulted in high values for sensitivity (100 %) and specificity (93 %) for the assessment of MCD. For the radiographic evaluation, a sensitivity of 98 % and specificity of 64 - 69 % using CT as the technique of reference, were found.

Discussion

These results suggest that in case of doubt during radiographic assessment, CT could be used as a non-invasive technique to assess the presence of MCD.

Conclusion

Based on the high sensitivity and specificity obtained in this study it has been considered that CT, rather than arthroscopy, is the preferred noninvasive technique to assess MCD lesions of the canine elbow joint.