Propagation of a partial incomplete ossification of the humeral condyle in an American cocker spaniel

Computed tomographic re-evaluation of skeletally immature French bulldogs previously diagnosed with humeral intracondylar fissure: 12 cases (2018-2022)

OBJECTIVES

The objective of this study was to present the follow-up findings obtained through computed tomography in skeletally immature French bulldogs previously diagnosed with humeral intracondylar fissures.

MATERIALS AND METHODS

Medical records from a surgical referral centre between January 2018 and September 2022 were evaluated for all dogs with a humeral condylar fracture where preoperative CT of both humeri was performed. French bulldogs between the age of 12 weeks and 12 months were identified and evaluated for the presence of contralateral humeral intracondylar fissure. The dogs with follow-up CT were evaluated for humeral intracondylar fissure resolution.

RESULTS

A total of 137 humeral condylar fractures were operated on within the study period, 58 of which were in French bulldogs. Twenty-seven French bulldogs had a contralateral humeral intracondylar fissure with 12 dogs matching the inclusion criteria. Follow-up CT demonstrated resolution of the humeral intracondylar fissure in 11 (91.7%) of 12 cases.

CLINICAL SIGNIFICANCE

Contralateral humeral intracondylar fissures are common in skeletally immature French bulldogs sustaining humeral condylar fractures and the majority of these fissures tend to fuse within the follow-up period. Due to the potential for breed variation in ossification of the humeral condyle, follow-up CT may be warranted in skeletally immature French bulldogs before considering prophylactic transcondylar screw placement.

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.

Clinical Assessment of a Lateral Epicondylar Anatomical Plate for the Stabilization of Humeral Condylar Fractures in Dogs

OBJECTIVE

 To report the use of a Lateral Epicondylar Anatomical Plate for the management of humeral condylar fractures (HCF) in dogs.

STUDY DESIGN

 Medical records of dogs with HCF stabilized using the Lateral Epicondylar Anatomical Plate at six UK veterinary referral centres between April 2018 and February 2021 were reviewed. Long-term follow-up (>6 months) was obtained via owner questionnaire, which incorporated the Liverpool Osteoarthritis in Dogs clinical metrology instrument.

RESULTS

 Sixty-two HCF were treated in 61 dogs (44 lateral condylar fractures [LCF] and 18 intracondylar (T/Y) fractures [ICF]). Fifty-one dogs were Spaniels or Spaniel crossbreeds. Intraoperative contouring of the plate was required for one dog-a French Bulldog. Postoperative complications occurred in 14/42 LCF and 6/18 ICF; overall there were 14 minor, 8 major, and 2 catastrophic complications. On final follow-up imaging, there was evidence of partial or complete osseous continuity of the condylar part of the fracture 32/53 HCF (24/39 LCF and 8/14 ICF) and lateral epicondylar part of the fracture in 53/53 HCF (39/39 LCF and 14/14 ICF). At final reexamination, 20/28 dogs with LCF and 5/13 dogs with ICF were not lame and the remaining dogs demonstrated mild lameness. According to the owner questionnaire, 17/17 dogs with LCF and 8/10 dogs with ICF returned to full limb use and median Liverpool Osteoarthritis in Dogs scores were 2/52 for LCF and 6.5/52 for ICF.

CONCLUSION

 The Lateral Epicondylar Anatomical Plate can be used successfully for the surgical stabilization of HCF in dogs.

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.

Correlation between the Insertion Side of a Transcondylar Screw for the Surgical Management of Humeral Intracondylar Fissures in Dogs and the Incidence of Postoperative Surgical Site Infection

OBJECTIVE

 An increased rate of surgical site infection (SSI) following treatment of canine humeral intracondylar fissure (HIF) with a lateromedially (LM) placed transcondylar screw (TCS) compared with a mediolateral (ML) TCS has been previously postulated. We hypothesized that the direction of insertion of the TCS would not affect the incidence of postoperative SSI.

STUDY DESIGN

 It was single-centre retrospective study. Dogs with HIF confirmed by computerized tomography, treated by TCS placement (between 2008 and 2019) and with a minimum follow-up of 12 weeks, were included. The following data were recorded: signalment, presenting clinical signs, direction of placement and size of the utilized TCS, surgical and anaesthetic times, concurrent surgical procedures, presence of concomitant elbow pathology, perioperative and postoperative antibiotic usage and postoperative complications. Recorded data were analysed with a multinomial logistic regression model with a p-value less than or equal to 0.05.

RESULTS

 Thirty-five dogs (46 elbows) met the inclusion criteria. Median clinical follow-up interval was 52 weeks. Seven of thirty-one elbows with a ML TCS, and 4/15 elbows with a LM TCS developed SSI. Four of nine dogs that underwent bilateral single-surgery TCS placement developed SSI unilaterally.

CONCLUSION

 No significant difference was shown in short-term SSI occurrence between the ML and the LM direction of placement of the TCS.

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.

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.

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.

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.

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.

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.

Influence of interlocking thread screws to repair simulated adult canine humeral condylar fractures

OBJECTIVE

To determine the influence of interlocking screw threads on the biomechanical properties of repaired canine humeral condylar fractures.

STUDY DESIGN

Ex vivo biomechanical study.

SAMPLE POPULATION

Thirty-six humeral condyles.

METHODS

Simulated fractures of the lateral aspect of the humeral condyle were stabilized by a 3.5 mm interlocking thread screw (ITS) or 3.5 mm buttress thread screw placed in lag (BTS-L) or positional fashion (BTS-P) and axially loaded at a walk, trot, 2-mm displacement, and failure cycles. Compact flute drill bits (CFBs) were used for ITS constructs and standard flute drill bits (SFB) for BTS constructs. The effects of bit type on drilling parameters and screw type on screw insertion properties and fragment stability were assessed.

RESULTS

CFB produced a 6°C greater temperature increase (p = .042) and required 20 N higher torque (p = .003) than SFB. Insertional torque was greater for ITS than BTS-P (p = .001) and BTS-L (p = .001). Condylar fragment rotation at failure was lower in ITS (lsmean ± SE, 8.3° ± 1.9°) than BTS-L constructs (14.5° ± 2.3°, p = .011). ITS resisted greater loads (1503 ± 105 N) than BTS-P (1189 ± 99 N, p = .038) but not BTS-L (1249 ± 123 N, p = .121) constructs.

CONCLUSION

Biomechanical performance of constructs was improved with ITS rather than BTS fixation.

CLINICAL SIGNIFICANCE

ITS can be considered for stabilization of humeral condylar fractures in adult dogs.

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.

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.

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.

Effect of breed as a risk factor for humeral condylar fracture in skeletally immature dogs

OBJECTIVES

To investigate the effect of breed as a risk factor associated with humeral condylar fracture in skeletally immature dogs in the UK.

MATERIALS AND METHODS

Retrospective study of dogs under 12 months of age that were presented with humeral condylar fracture to three specialist referral centres between 2015 and 2018. Data retrieved from medical records included breed, age, gender, neuter status, affected limb, fracture configuration and aetiology of the fracture. Breed population percentages were compared with those recorded by the UK Kennel Club.

RESULTS

Of the 115 dogs with 118 fractures, French bulldogs (41%) and English springer spaniels (15%) were overrepresented: humeral condylar fractures were more commonly diagnosed in French bulldogs (odds ratio = 5.86) and English springer spaniels (odds ratio = 5.66) compared with mixed-breed dogs. Lateral condylar fractures occurred in 70% of cases, with medial condylar fractures and Y/T fractures accounting for 9% and 21%, respectively. Median age at the time of fracture was 4 months (range 2 to 10 months).

CLINICAL SIGNIFICANCE

French bulldogs and English springer spaniels were identified as being at potentially increased risk of humeral condylar fracture in skeletally immature dogs.

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.

Healing of patellar fractures in two kittens

Two kittens aged between four and five months were presented having sustained patellar fractures. In both cases, healing was subsequently documented radiographically; this has not been reported previously in the literature.

One kitten had bilateral patellar fractures – the symptomatic right stifle was treated with a pin and tension-band-wire which later failed, at which point partial patellectomy was performed. The fracture of the left patella was minimally displaced and was treated conservatively. A radiograph of the left patella taken eleven months after initial presentation showed complete healing of the fracture. The second case was treated surgically with a circumferential wire; healing of the fracture was demonstrated radiographically at twelve weeks postoperatively. Radiographic images taken five weeks postoperatively had shown some narrowing of the fracture gap.

These two cases demonstrate that bony union of patellar fractures can be documented, given a long enough duration of radiographic follow-up; circumferential wire was an effective treatment in a displaced fracture, and conservative treatment resulted in complete healing of a minimally displaced fracture.

Clinical assessment of a shaft screw for stabilization of the humeral condyle in dogs

Objective: To report the use of a 4.5 mm shaft screw for the management of humeral condylar fractures (HCF) and incomplete ossification of the humeral condyle (IOHC) in dogs, and to assess risk factors for complications.

Methods: Dogs with HCF or IOHC that were managed with a 4.5 mm shaft screw with a minimum follow-up of six months from surgery were included. Data from the case records were used to identify risk factors for complications. Long-term follow-up was provided by an owner questionnaire and veterinary re-examination.

Results: Forty-three elbows were treated in 40 dogs (14 IOHC, 29 HCF). Minor complications were seen in four cases (9%) and major complications in 10 cases (23%). There were no statistically significant risk factors for major complication. Infection resulted in shaft screw removal from three IOHC cases. Four of eight IOHC cases that had a lateral approach had a major complication compared with zero out of six dogs that had a medial approach, but this difference was not significant (p = 0.085). Nine of 12 IOHC cases and 20/23 HCF cases had excellent or good limb use at the time of long-term follow- up (median of 106 weeks, range 26–227 weeks). All fractures healed but IOHC fissure healing was inconsistent. Fatigue failure of shaft screws was not seen.

Clinical significance: The use of shaft screws for the management of IOHC and HCF is associated with a relatively low rate of complications (compared to previous reports) and a good long-term outcome.

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.

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.