Computed Tomographic Features of Incomplete Ossification of the Canine Humeral Condyle

Long-Term Outcome and Complications after Transcondylar Screw Placement for Canine Humeral Intracondylar Fissure

OBJECTIVE

 The aim of this study was to report postoperative complications and long-term outcomes following transcondylar screw placement for humeral intracondylar fissure (HIF).

STUDY DESIGN

 It was a retrospective single-centre case series. Medical records (2018-2022) were reviewed for dogs with HIF treated with transcondylar screw placement. Data collected included signalment, concurrent orthopaedic disease, partial or complete HIF, surgeon, surgical approach, surgical technique and implant type, transcondylar screw angulation, postoperative complications and outcomes. Long-term outcome was assessed with owner questionnaire, orthopaedic examination and follow-up radiography. Statistical analysis was performed to identify risk factors predisposing to a complication or a poor outcome.

RESULTS

 Forty-seven dogs (57 elbows) met the inclusion criteria; long-term follow-up was available in 41 dogs (50 elbows). Minor and major medical complications were noted in seven and three elbows respectively. The total complication rate was 17.5%. Increasing age was significantly associated with a reduced risk of postoperative complications (p = 0.0051). No other risk factors were identified. A postoperative complication was not associated with a less than full outcome (p = 0.5698).

CONCLUSION

 Transcondylar screw placement for HIF is associated with a low complication rate and good outcome.

Impaired endochondral ossification in a skeletally immature dog: implications for femoral cleft formation and suspected incomplete femoral ossification

Historically, knowledge regarding congenital skeletal malformations in canines is poor. The Nomina Embryologica Veterinaria does not currently list any dysmorphia related to distal femoral fusion, and there is a significant absence of comprehensive descriptions of congenital defects in the veterinary literature. This paper reports on the radiographic and computed tomography (CT) characteristics of a skeletal abnormality in a seven-month-old crossbreed dog that presented for chronic right pelvic limb lameness as a result of secondary developmental patella luxation. Successful resolution of the lameness was achieved through concurrent surgical correction of the patella luxation and distal femoral cleft.

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.

Medial versus lateral transcondylar screw placement for canine humeral intracondylar fissures: A randomized clinical trial

OBJECTIVE

To determine the influence of screw direction on complications following transcondylar screw placement for the treatment of canine humeral intracondylar fissures (HIFs).

STUDY DESIGN

Equivalence, parallel group, randomized clinical trial.

SAMPLE POPULATION

Fifty-two client owned dogs (73 elbows).

METHODS

Transcondylar screw placement was randomized to either a medial or lateral approach. The primary outcome was the incidence of postoperative complications.

RESULTS

There were 37 cases in the lateral approach group and 36 cases in the medial approach group. There was a significantly greater proportion of postoperative complications following placement of transcondylar screws from a lateral to medial direction (p = .001). There were seven cases with complications (19%) in the medial approach group versus 23 cases with complications (62%) in the lateral approach group. The majority of complications were seromas (n = 13) and surgical site infections (n = 16) with 4 complications requiring further surgery. Implant area moment of inertia (AMI), normalized to bodyweight, was lower in dogs with a major complication (p = .037).

CONCLUSION

Transcondylar screws placed from lateral to medial for canine HIFs had a greater proportion of postoperative complications in this randomized clinical trial design. Implants with a lower AMI, relative to bodyweight, were more likely to lead to major complications.

CLINICAL SIGNIFICANCE

We recommend placing transcondylar screws from medial to lateral for canine HIFs to reduce the risk of postoperative complications. Relatively small diameter implants had an increased risk of major complications.

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.

Extended Computed Tomography Scale Images Provide a Detailed Assessment of Metal Screws and Are Superior to Standard Computed Tomography Scale Images and Digital Radiography at Detecting Experimentally Induced Screw Fractures In Vitro

OBJECTIVES

 (1) To compare the ability of standard computed tomography (CT) scale (SCTS) and extended CT scale (ECTS) images, produced using conventional CT technology, to provide detailed assessment of metal screws in vitro. (2) To assess how screw size, type, and orientation relative to the Z-axis of the gantry affect implant assessment. (3) To test the ability of SCTS, ECTS, and radiography to diagnose screw failure when there is negligible screw fragment displacement.

STUDY DESIGN

 Part 1: 12 screws of different size, type, and composition were scanned in three orientations (parallel or 0°; oblique or 45°; and perpendicular or 90°) relative to the Z-axis of the gantry. SCTS and ECTS reconstructions were made for each screw, in each plane, to assess implant shape, structure, and diameter. Part 2: fatigue-failure was induced in four screws commonly used to stabilize canine humeral intracondylar fissures. Screws were then reassembled achieving grossly perfect apposition and alignment of the fragments. Ability to detect implant failure was tested using SCTS, ECTS, and radiography.

RESULTS

 ECTS provided better screw assessment compared with SCTS resulting in clear visualization of the structure in 8/12 versus 0/12 screws and shape in 12/12 versus 11/12 screws; however, results were affected by screw size, type, and orientation. ECTS identified all in vitro screw fractures with negligible screw fragment displacement; however, success was affected by screw orientation: 4/4 fractures identified with a 90° angle, 1/4 for 45°, and 0/4 for 0°. SCTS and radiography did not identify any of them.

CONCLUSION

 The results indicate that ECTS reconstructions are useful for assessment of metal screws and for detection of nondisplaced screw fractures.

Computed Tomographic Features of Non-Lame French Bulldog Elbows

OBJECTIVE

 French Bulldogs are predisposed to humeral condylar fractures. Computed tomography (CT) in English Springer Spaniel elbows has allowed identification of humeral intracondylar fissures (HIF), which can cause lameness and predispose to condylar fractures. This study aimed to evaluate CT characteristics of non-lame French Bulldog elbows, to determine the presence of underlying elbow disease.

STUDY DESIGN

 Retrospective evaluation of CT images from elbows of non-lame French Bulldogs from scans obtained for soft tissue or neurological evaluation was performed. Images were evaluated for the presence of HIF and other elbow abnormalities: condylar and supracondylar remodelling, humeral condylar sclerosis, elbow incongruency, medial coronoid process disease and elbow osteoarthritis. Descriptive statistics were performed.

RESULTS

 Computed tomographic scans from 37 dogs (74 elbows) were reviewed. No HIF were identified, although 28/74 elbows had an intracondylar sclerotic band. Medial coronoid process disease was noted in 16/74 elbows, and small osteophytes were present in 21/74 elbows, suggesting a degree of subclinical elbow disease. Widening of the caudolateral aspect of the radial incisure was identified (37/74) as a breed normal. Elbow incongruency was otherwise rare.

CONCLUSION

 Non-lame French Bulldogs showed a low prevalence of occult elbow disease but a proportion had radial incisure widening. Although humeral intracondylar sclerosis was present in over a third of dogs, no HIF were identified and therefore no clear cause for their increased risk of humeral condylar fracture was identified.

Epicondylar plate fixation of humeral condylar fractures in immature French bulldogs: 45 cases (2014-2020)

OBJECTIVES

The objective of this study was to report outcome and postoperative complications following stabilisation of humeral condylar fractures in skeletally immature French bulldogs with a transcondylar screw combined with locking or hybrid locking plates.

MATERIALS AND METHODS

Medical records from one referral hospital were reviewed to identify skeletally immature French bulldogs with humeral condylar fractures treated with a transcondylar screw and epicondylar locking or hybrid locking plates crossing the distal humeral physis.

RESULTS

Forty-five fractures in 41 different dogs with a mean age of 4 months (range 3.5 to 5) were identified. Six cases had complications: two (4.4%) minor and four (8.9%) major. Short-term clinical outcome was excellent in 35 (77.8%), good in nine (20%) and poor in one (2.2%) case. Forty-one of 45 fractures reached radiographic union without further surgical intervention; the remaining four cases reached union following revision surgery. Long-term owner assessed outcome by telephone interview was graded as excellent in all available cases (26 of 41 dogs).

CLINICAL SIGNIFICANCE

This study suggests that the stabilisation of humeral condylar fractures in skeletally immature French bulldogs with combinations of a transcondylar screw and epicondylar locking or hybrid locking plates crossing the distal humeral physis was safe and led comparable outcomes and complication rates to previous reports.

Management of Canine Y-T Humeral Fractures Using Titanium Polyaxial Locking Plates in 17 Dogs

The objective of this study was to document the short- and medium-to-long-term outcomes and complication rates of Y-T humeral condylar fractures fixed using titanium polyaxial locking plate (T-PLP). A retrospective review was performed of the medical records and radiographs of dogs with a Y-T humeral condylar fracture treated with T-PLP at a single veterinary referral center (2012–2018). Seventeen cases met the inclusion criteria. Medium- to long-term follow-up (.6 mo) information was derived using the Liverpool Osteoarthritis in Dogs (LOAD) questionnaire. Recorded complications were catastrophic (1/17) and minor (2/17). Gait at 10–12 wk following surgery was subjectively assessed as good or excellent for 13 cases. Radiographic bone union was achieved in 7/12 cases at 4–6 wk. LOAD scores obtained a mean of 15 mo (range 6–29 mo) following surgery and indicated no or mild impairment in 15/16 and moderate functional impairment in 1. The application of T-PLP for the treatment of Y-T humeral condylar fractures resulted in adequate stabilization allowing successful fracture healing and medium- to long-term outcomes comparable to previous reports. According to results of LOAD testing, the medium- to long-term follow-up suggests that clients were aware of mild to moderate functional impairment in all cases.

Visibility of Transcondylar Screw Fractures in Standard and Extended Scale Computed Tomography Images

OBJECTIVE

 Application of extended computed tomography scale (ECTS) reconstruction to diagnose metal implant failure has been described in a single case report. The purpose of this study was to compare the features and visibility of humeral transcondylar screw fractures in standard CT scale (SCTS) and ECTS images.

STUDY DESIGN

 Case series: CT images of dogs with fractured transcondylar screws were retrospectively reviewed and described in both SCTS and ECTS images.

RESULTS

 Five dogs with a total of six transcondylar screw failures (five right and one bilateral) were reviewed. All cases had an ongoing humeral intercondylar fissure with varying degrees of stress remodelling. The fracture was seen in all screws on ECTS images, however only in three implants on SCTS images. The measured fracture gap was larger in ECTS images in all cases (range: + 0.14 mm to + 0.28mm). The three smallest fracture gaps were not seen on SCTS images. A subtle hypoattenuating streak (artefact) was visible adjacent to the screw fracture in 5/6 of cases using SCTS images. All screw fractures occurred parallel and often slightly medial to the humeral intercondylar fissure.

CONCLUSION

 Implant failure is only seen with larger fracture gaps in SCTS images, with 3/6 screw fractures not visible in SCTS compared with ECTS. A hypoattenuating streak extending perpendicular to the implant in SCTS images is suggestive of screw fracture even if this is not directly visible.

Repair of Fractures of the Lateral Aspect of the Humeral Condyle in Skeletally Mature Dogs with Locking and Non-Locking Plates

OBJECTIVE

 The aim of this study was to report the functional outcome and complications following transcondylar screw and epicondylar plate fixation of skeletally mature dogs with fractures of the lateral aspect of the humeral condyle using a string of pearls, limited contact dynamic compression plate (LC-DCP) or locking compression plate (LCP).

STUDY DESIGN

 This study was a retrospective review of clinical records, radiographic images and canine brief pain inventory evaluation with a supplementary non-validated questionnaire.

RESULTS

 Thirty-one fractures in 29 dogs were included. The majority of dogs were Spaniels (23/29). Thirty fractures had evidence of humeral intracondylar fissure. Sixteen fractures had string of pearls, eight LCP and seven LC-DCP. There were two minor complications and three major complications. Perioperative (median: 6 weeks, range: 6-12) outcome was considered fully functional for 24 fractures and acceptable for 6 fractures. One dog had an unacceptable outcome due to the failure of an LCP that healed following revision surgery. Fractures with radiographic follow-up had a persistent visible intracondylar fracture line in 20/26. Twenty-six of twenty-seven owners perceived an excellent outcome (median: 135 weeks, range: 25-246).

CONCLUSION

 Repair of fractures of the lateral aspect of the humeral condyle with a transcondylar screw and epicondylar plate has a good perioperative, mid- and long-term outcome with 10% major complication rate, despite incomplete or non-union of the intracondylar fracture in 20/26 elbows.

Humero-anconeal elbow incongruity in spaniel breed dogs with humeral intracondylar fissure: Arthroscopic findings

Objective

To report arthroscopic findings in dogs with humeral intracondylar fissure (HIF) and compare these findings in joints of dogs not affected by HIF on preoperative CT images.

Study design

Controlled clinical study.

Animals

Dogs with HIF (14 dogs, 21 elbows) and dogs without HIF (20 dogs, 31 elbows).

Methods

A caudo‐medial arthroscope portal was used to inspect all elbow joints. Arthroscopic features of 21 joints of dogs with HIF were compared with 31 control elbows of HIF‐ negative dogs.

Results

All elbows with HIF showed a focal cartilage lesion on the caudal aspect of the humeral condyle. The lesions ranged from a simple indentation into the articular surface to a full thickness cartilage erosion. Humero‐anconeal incongruity was identified in all elbows with HIF as absence of joint space at the point of contact between the tip of the anconeal process and the cartilage lesion, with a wider joint space distally within the ulnar trochlear notch. None of the elbows without HIF showed the cartilage lesion or evidence of humero‐anconeal incongruity.

Conclusion

Use of a novel arthroscope portal allowed description of a previously unreported cartilage lesion on the caudal humeral condyle of dogs with HIF. The lesion was found in all dogs with HIF but in no dogs without HIF.

Clinical significance

Humero‐anconeal incongruity and an associated cartilage lesion appear to be present in dogs with HIF. We propose that this lesion may be associated with humero‐anconeal incongruity. This may be considered as a possible future therapeutic target for 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 fissures in French bulldogs

BACKGROUND

French bulldogs have previously been reported to be at an increased risk of developing humeral condylar fractures (HCF). Humeral intracondylar fissures (HIF) are thought to be a predisposing factor for HCF occurrence in skeletally mature dogs particularly when the fracture occurs during normal activity. We hypothesised that HIF may be a predisposing factor for HCF in French bulldogs.

METHODS

A retrospective case series of nine French bulldogs that had sustained HCF and where CT was performed prior to surgery.

RESULTS

Five of the fractured humeri had sclerosis adjacent to the fracture site. Six of the contralateral intact humeri were diagnosed with HIF on the basis of a partial (2/6) or complete (4/6) hypoattenuating area extending between the distal articular surface and the supratrochlear foramen in the sagittal plane, with adjacent sclerosis (6/6).

CONCLUSIONS

Recognition of sclerosis at the intracondylar fracture surface on CT can prompt suspicion that HIF preceded HCF. A predisposing HIF has potentially great clinical significance for this breed if we draw parallels with breeds such as the springer spaniel for whom HIF and HIF-associated condylar fracture is well documented.

Outcomes, complications and risk factors following fluoroscopically guided transcondylar screw placement for humeral intracondylar fissure

OBJECTIVES

To describe the surgical technique and complications for fluoroscopically guided transcondylar screw placement for humeral intracondylar fissure in dogs.

MATERIALS AND METHODS

A retrospective review was undertaken of cases from two hospitals where identical surgical technique was employed. Factors were analysed for any association with postoperative complications.

RESULTS

Sixty-two dogs (82 elbows) were reviewed for which the postoperative complication rate was 45%; a total of 15% of cases required revision surgery. Complications were more likely in cases operated on earlier in the case series and with increasing dog bodyweight. Both increasing surgical time and being a neutered female were protective against postoperative complications.

CLINICAL SIGNIFICANCE

Fluoroscopically guided transcondylar screw placement for humeral intracondylar fissure is associated with a high postoperative complication rate (45%) with 15% of cases requiring revision surgery.

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.

Lateral condylar fracture secondary to humeral intracondylar fissure in a cat

OBJECTIVE

To report the progression of a humeral intracondylar fissure (HIF) into a lateral humeral condylar fracture and successful treatment in a cat.

STUDY DESIGN

Case report.

ANIMALS

One 8-year-old, male, neutered, Maine coon crossbreed cat.

METHODS

A lateral humeral condylar fracture occurred in a cat with no history of trauma. A partial HIF was identified by computed tomography of the contralateral elbow, progressing to fracture 279 days later. Both fractures were repaired surgically at the time of their diagnoses.

RESULTS

Both lateral humeral condylar fractures were repaired with a transcondylar lag screw and caudolaterally applied locking plate. These repairs led to bone union and full return to function of surgically treated limbs. Eight hundred thirty-six days after initial presentation, a nontraumatic transverse patella fracture was diagnosed, which combined with a clinical history of extraction of retained deciduous canines supports a diagnosis of patellar fracture and dental anomaly syndrome (PADS).

CONCLUSION

Evidence of progression of HIF to fracture in a cat with PADS has implications for management of elbow-related lameness in this species. In this report, we seek to alert practitioners to the potential for HIF to be seen in cats and that cats presenting for humeral condylar fracture should undergo further assessment for patella and other fractures as well as dental anomalies. Key features of PADS may not be present at the time of initial assessment.

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.

Computed tomographic findings in three Pinschers affected by incomplete ossification of the humeral condyle

Incomplete ossification of the humeral condyle is a cause of forelimb lameness in dogs. Affected dogs are predisposed to humeral condylar fractures. Incomplete ossification of the humeral condyle has been reported in breeds such as Spaniel, Rottweiler, Labrador and Pug. Diagnosis is made by a radiographic or computed tomographic study of the elbow, while treatment includes the placement of a bone screw across the humeral condyle. This paper discusses the computed tomography findings of incomplete ossification of the humeral condyle in three Pinschers.

Use of an extended CT scale reconstruction to diagnose metal implant failure in a canine elbow

A Cocker Spaniel presented for recurrence of right forelimb lameness 33 months following transcondylar screw placement for a humeral intracondylar fissure. Elbow radiographs showed no evidence of implant-related complications. Standard CT scale reconstruction images failed to demonstrate implant failure. Extended CT scale reconstruction images revealed a fracture through the mid-portion of the screw. Revision surgery confirmed the implant failure; the screw was replaced and the lameness subsequently resolved. Extended CT scale reconstruction images allow detailed assessment of metal implants and should be considered when implant failure is suspected.

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.

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.

Incidence and types of preceding and subsequent fractures in cats with patellar fracture and dental anomaly syndrome

OBJECTIVES

The aim of this study was to document the incidence of preceding and subsequent fractures to the patellar fractures in cats with patellar fractures and dental anomaly syndrome.

METHODS

Records of cats with patellar fracture and dental anomaly syndrome were retrieved from the combined databases at the University of Bristol, UK, and Exclusively Cats Veterinary Hospital, USA. A request was made to complete a questionnaire to obtain long-term follow-up of these cats with respect to their current status and fractures to other bones; radiographs and histories were requested and were reviewed for treatment of ongoing fractures and outcome.

RESULTS

Of the 191 cases reported with this syndrome, 92 cats (48.2%) had dental anomalies and 78 (40.8%) had fractures to other bones; 21 cats sustained the fractures preceding the patellar fractures and 57 subsequently. In total, there were 175 fractures: acetabulum (25%), tibia (22%), ischium (15.4%), humeral condyle (13.7%), calcaneus (5.1%), ilium (5.1%), pubis (3.4%) and other bones (10.2%). The majority of these fractures were characteristic of insufficiency (stress) fractures with a very similar configuration in each bone.

CONCLUSIONS AND RELEVANCE

A high proportion of cats with patellar fracture and dental anomaly syndrome will have preceding or subsequent fractures to their patellar fractures. In this study, >10% of cats suffered characteristic fractures preceding the patellar fractures. The presence of these fractures should alert the veterinarian to the possibility that the cat is affected by patellar fracture and dental anomaly syndrome.

Kirschner wire fixation of Salter-Harris type IV fracture of the lateral aspect of the humeral condyle in growing dogs

Objectives: To evaluate the use of Kirschner wires for treatment of fractures of the lateral aspect of the humeral condyle in growing dogs.

Methods: Retrospective analysis of 35 elbow fractures (33 dogs) of the lateral aspect of the humeral condyle treated by insertion of multiple transcondylar and one anti-rotational Kirschner wires. Radiographic and clinical re-evaluations were carried out immediately after surgery, at four weeks and, when required, at eight weeks postoperatively. Long-term follow-up was planned after a minimum of six months. The relationship between different implant configurations and clinical outcome was analysed statistically.

Results: Complete functional recovery was seen in 31 elbows (30 dogs), three elbows (2 dogs) had reduction in the range of motion, and one elbow (1 dog) had persistent grade 1 lameness two months postoperatively. Major complications occurred in eight elbows (8 dogs) and all were resolved by implant removal. Implant configuration did not affect outcome. Long-term evaluation in 12 cases with a mean follow-up of four years showed absence of lameness, normal function and no or mild radiographic evidence of osteoarthritis in 11 cases.

Clinical significance: Fracture of the lateral aspect of the humeral condyle in growing dogs can be successfully treated by multiple transcondylar convergent or parallel Kirschner wires, resulting in adequate fracture healing.

Computerized measurements of radiographic anatomical parameters of the elbow joint in Bernese Mountain Dogs

Objective: Comparison of two methods for evaluation of anatomical parameters of elbow joints in Bernese Mountain Dogs.

Study design: Radiographic analysis.

Animals: Nine hundred and thirty-one radiographs of elbow joints from 305 Bernese Mountain Dogs.

Material and methods: The angles OL, PA, RA and UL were measured according to the Mues method and the Radius of the humeral condyle, Opening angle beta, Quotient Q and Ae, Area X, Step 1 and Step 2 according to the Viehmann method. The radiographs were divided according to their angle of flexion into five groups: 0–30°, 31–60°, 61–90°, 91–120° and >120°. The difference and the correlation between measured values and the elbow dysplasia (ED) score was calculated and compared.

Results: The average values of angle OL, PA and RA, Area X, Step 1 and Step 2 were significantly different within the different elbow flexion angle groups. The values of Opening angle beta, Quotients Q and Ae as well as Radius of the humeral condyle varied independently from the degree of the elbow flexion on the radiograph. The angles OL, PA and RA and the Radius of the humeral condyle, the Opening angle beta, the Quotients Q and Ae, Step 1 and Step 2 correlated with the ED score.

Conclusion: In contrast to the method of Mues, the majority of the measured parameters of the method of Viehmann were not influenced by the degree of flexion of the elbow joint and correlated with the ED score. Clinical relevance: The method of Viehmann warrants consideration for the evaluation of radiographs of elbow joints in the Bernese Mountain Dog for ED.

This article is based on a study first reported in S. Stein's doctoral thesis, which was presented on 08.05.2007 and published thereafter in full by Mensch & Buch Verlag. This abridged and translated version is now being published with the kind permission of Mensch & Buch Verlag.

Prevalence of incomplete ossification of the humeral condyle and other abnormalities of the elbow in English Springer Spaniels

Objectives: To determine the prevalence of incomplete ossification of the humeral condyle (IOHC) and other osseous abnormalities of the elbow in English Springer Spaniels with no history of lameness.

Methods: Prospective observational study of English Springer Spaniels with no recent history of lameness. Computed tomography scans of both elbows were obtained from dogs older than six months of age which were anaesthetized or sedated for reasons unrelated to this study. Computed tomography scans were reviewed for the presence of IOHC and other abnormalities of the elbow. Radioulnar incongruity (RUI) measurements from normal elbows were compared to elbows with IOHC and elbows with medial coronoid process (MCP) abnormalities.

Results: Computed tomography scans from 50 dogs (100 elbows) were reviewed. The prevalence of IOHC was 14% (8 elbows in 7 dogs). All condylar fissures were incomplete with a mean length of 2.6 mm. Fifty percent of the dogs (44% of elbows) had abnormalities of the medial coronoid process and 60% of the elbows had periarticular osteophytes. Group RUI meansurements for IOHC and MCP were not significantly different from normal elbows.

Clinical significance: Small IOHC fissures, periarticular osteophytes and MCP abnormalities may be identified in English Springer Spaniels without forelimb lameness. Abnormalities of the MCP are more common than IOHC.

Presented in part at the BVOA Spring Meeting, Birmingham, UK, March 2011.

Percutaneous Screw Fixation of Incomplete Ossification of the Humeral Condyle in Three Dogs (Four Elbows)

Transcondylar screw fixation was performed using a minimally invasive percutaneous technique on three dogs (four elbows) diagnosed with incomplete ossification of the humeral condyle. The technique was performed using an aiming device in all four elbow joints and assisted by intraoperative fluoroscopy in one. All screws were successfully placed on first attempt and no elbow joint required repositioning of the transcondylar screw. On immediate postoperative radiographs, median transcondylar screw angulation was 2.9° and median percentage of screw eccentricity relative to the theoretical center of the humeral condyle was 14%. No short-term postoperative complications (&lt;1 mo) were observed. The surgical technique described is a feasible option for surgical management of incomplete ossification of the humeral condyle in dogs that allowed accurate transcondylar screw placement and orientation.

Defining a safe corridor for transcondylar screw insertion across the canine humeral condyle: a comparison of medial and lateral surgical approaches

OBJECTIVES

To (1) develop guidelines for the location of drill entry and exit points when inserting a transcondylar screw across the canine humerus; (2) compare the safe corridor for transcondylar screw insertion when drilling medial-to-lateral with drilling lateral-to-medial.

STUDY DESIGN

Anatomic study.

ANIMALS

Dogs (n = 43).

METHODS

The optimum position of a transcondylar screw in 84 elbows was determined using CT multiplanar reconstructions. The positions of drill entry and exit points were defined relative to the epicondyles. Differences in elbow size were accounted for by dividing the measurements by the humeral condylar diameter (HCD), to give normalized measurements. Mean values of normalized measurements were used to develop universal guidelines for the location of drill entry and exit points. These guidelines were then applied to the 84 elbow CT reconstructions. The size of the safe corridor around this calculated drill line was determined, and expressed as tolerance angles in the frontal and transverse planes. The size of the safe corridors for medial-to-lateral and lateral-to-medial drilling were compared.

RESULTS

The lateral entry/exit point was 0.3 × HCD cranial and 0.3 × HCD distal to the lateral epicondyle. The medial entry/exit point was 0.3 × HCD cranial and 0.2 × HCD distal to the medial epicondyle. Using these guidelines resulted in safe virtual screw placement in all 84 elbows. The tolerance angle in the frontal plane was significantly smaller when drilling medial-to-lateral compared with drilling lateral-to-medial (P < .001).

CONCLUSIONS

Medial-to-lateral drilling for transcondylar screw placement carries a higher risk of inadvertently penetrating the joint compared with lateral-to-medial drilling.