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

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.

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.

The effect of an aiming device on the accuracy of humeral transcondylar screw placement

OBJECTIVES

(1) To evaluate the accuracy of an aiming device on placement of humeral transcondylar screws compared to fluoroscopic methods. (2) To compare experience level on outcome.

STUDY DESIGN

Randomized, match pair, prospective ex-vivo study.

SAMPLE POPULATION

A total of 68 dogs.

METHODS

Canine cadaveric forelimbs were randomly assigned to either aiming device or fluoroscopic-guided groups, and to diplomate or resident. Digital radiography was used to evaluate screw trajectory deviation and eccentricity on the humeral condyle. Procedure time, outcome based on experience, and complications were recorded.

RESULTS

The aiming device screw trajectory angle was decreased in the right limb (1.9 ± 1.1°) compared with the left (3.6 ± 1.1°, p = .0178), and compared to fluoroscopy (3.4 ± 1.1° p = .0128). There was no difference between leg laterality with fluoroscopy (p = .9979). Trajectory angle was increased with resident versus diplomate (3.4 ± 1.1° and 2.5 ± 1.1° respectively, p = .0366). Eccentricity deviation was decreased using fluoroscopy versus aiming device (3.1 ± 0.36 mm, 4.2 ± 0.36 mm, respectively, p = .0017). The risk of joint involvement was 8 times greater in aiming device groups, though not significant (p = .0575). Significant complications included increased drill attempts in fluoroscopic groups (p = .0237).

CONCLUSION

The aiming device provided accurate placement of transcondylar screws, in terms of both position on the condyle and trajectory angle. Results were similar to fluoroscopic-guided method.

CLINICAL SIGNIFICANCE

An aiming device is an acceptable means of placing humeral transcondylar screws. The use of the aiming device had an eight times increased risk of joint involvement compared to fluoroscopy.

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.

Defining the safe corridor for transcondylar screw placement in the feline humeral condyle

OBJECTIVES

The aim of this study was to develop guidelines for the optimal location of drill entry and exit points for insertion of a transcondylar screw across the feline humeral condyle.

METHODS

Multiplanar reconstruction of feline elbow CT scans performed between 2016 and 2021 at one referral institution were reviewed. The optimum medial and lateral epicondylar entry and exit points for transcondylar screw placement were determined. These values were normalised to the humeral condylar diameter (HCD) for each elbow to determine the transcondylar screw placement guidelines. These guidelines were applied to each elbow and tolerance angles were determined in the transverse and frontal plane CT images to determine the safe corridor for screw placement.

RESULTS

Twenty elbows from 12 cats were evaluated in this study. The guidelines for transcondylar screw placement were as follows: the medial entry/exit point was 0.38 × HCD cranial and 0.16 × HCD distal to the medial epicondyle, and the lateral entry/exit point was 0.3 × HCD cranial and 0.16 × HCD distal to the lateral epicondyle. Tolerance angles were statistically significantly (P <0.05) larger in both frontal (34.5% larger) and transverse (21.1% larger) planes when drilled from a lateral to medial direction compared with drilling from a medial to lateral direction.

CONCLUSIONS AND RELEVANCE

The guidelines determined from this study may aid clinicians in the placement of humeral transcondylar screws in cats. Where possible, drilling from a lateral to medial direction is recommended owing to the higher tolerance angles reducing the likelihood of articular surface damage. Further studies are warranted to determine whether these guidelines are clinically useful and result in the safe insertion of a transcondylar screw in the clinical setting.

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.

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.

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.

Comparing the accuracy of freehand, fluoroscopically guided and aiming device-assisted drilling in veterinary orthopaedic surgery

BACKGROUND

Drilling accuracy is essential in the correct positioning of implants and avoidance of iatrogenic damage to surrounding tissues. The use of augmented drilling methods has been documented as an approach to improving the accuracy of drilling. The aim of this study was to compare the accuracy of two augmented drilling methods (fluoroscopically guided and aiming device) to freehand (FH) drilling.

METHODS

Three experienced specialist surgeons and three veterinary surgeons without primary orthopaedic experience drilled into synthetic bone towards a target using the three different methods at three different angles (0°, 10° and 20°). The duration of drilling was recorded, and the accuracy of drilling was measured using photographs before and after drilling.

RESULTS

The two augmented methods were more accurate than FH drilling in synthetic bone, with the aiming device producing the greatest accuracy. Increased angulation of drilling decreased the drilling accuracy. Surgeon experience did not impact on drilling accuracy. Surgeon inexperience and augmented drilling methods both increased the time taken to drill.

CONCLUSION

The use of augmented drilling methods improved the accuracy of drilling, and surgeons should consider their use when drilling in anatomical regions where the margin of error is small.