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.

Lower body weight and increasing age are significant risk factors for complications following bi-oblique proximal ulnar osteotomy in dogs.

OBJECTIVE: To report and evaluate the risk factors for complications following bi-oblique proximal ulnar osteotomy (PUO) in dogs. ANIMALS: 82 client-owned dogs (93 limbs). METHODS: Clinical records of dogs treated with bi-oblique PUO over a 5-year period were reviewed. Postoperative radiographs were analyzed, and osteotomy location and angles were recorded; follow-up radiographs were reviewed to assess the degree of osteotomy healing. Complications were classified as minor, major, and catastrophic. Logistic regression analysis was performed to investigate possible associations between the predictor variables and occurrence of complications. RESULTS: 82 dogs (93 limbs) were included. Postoperative complications were documented in 39 limbs (13 major and 26 minor). The most common major complication was osteotomy nonunion (8 limbs), while the most common minor complication was delayed union (21 limbs). Statistical analysis revealed that lower body weight (P = .01) and older age (P = .04) were significantly associated with the development of postoperative complications. CLINICAL RELEVANCE: In this study, lighter and older dogs were more likely to develop complications following bi-oblique proximal ulnar osteotomy. We did not identify an association between osteotomy angle and location on complication rate. Careful patient selection is therefore required to reduce the incidence of postoperative complications after bi-oblique PUO.

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.

The Effect of Femur Positioning on Measurement of Tibial Plateau Angle: An In Vitro Study.

Five canine cadaveric pelvic limbs with intact cranial cruciate ligaments were used to quantify the effect of variation in limb positioning on the radiographic measurement of the tibial plateau angle (TPA) with reference to the degree of femoral condyle superimposition. Intra-osseous pin placement and a custom jig design allowed the controlled three-dimensional manipulation of limbs. Medio-lateral digital radiographic projections were taken with perfect femoral hemicondylar superimposition to establish a "reference" TPA (difference in position = 0 mm), and subsequently in varying degrees of supination/pronation and abduction/adduction. The lack of femoral hemicondylar superimposition for each radiograph was quantified using a tangential line technique with reference to the long tibial axis. A total of 176 radiographs were each assessed by three observers. "True" TPA was measured and it ranged within 17-25° across all limbs assessed. Variation in femoral condylar positioning ranged from -13 mm to +13 mm proximo-distally, and -11 mm to +11 mm cranio-caudally. Moreover, 3 mm non-superimposition of the femoral condyles produced 90.6% of measurements with 1° difference between measured and "true" TPA, and a sensitivity of 97.9% for a 2° difference. Further reduction in femoral condylar superimposition to 4 mm reduced the frequency of 1° difference between measured and "true" TPA to 84.9%, and to 94.8% for a 2° difference. In conclusion, measurement of TPA in large breed dogs from radiographs with greater than 3 mm variation in femoral condylar superimposition should be interpreted with caution.

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.

Complications after proximal abducting ulnar osteotomy and prognostic factors in 66 dogs.

OBJECTIVE: To report complications and prognostic factors in dogs undergoing proximal abducting ulnar osteotomy (PAUL). To evaluate the ability to predict complications on the basis of post-operative radiographic examination. STUDY DESIGN: Retrospective cohort study. ANIMALS: Sixty-six dogs. METHODS: Medical records of dogs treated with PAUL between 2014 and 2019 were reviewed for demographics, intraoperative findings, and post-operative complications. Post-operative radiographs were reviewed by two masked expert orthopedic surgeons, who were asked to predict the likelihood of major mechanical complications. The prognostic value of variables was tested with univariate and multivariable logistic regression. Inter-investigator agreement to predict complications was evaluated with two-by-two tables and kappa coefficient. RESULTS: Seventy-four PAULs in 66 dogs were included. Duration of follow-up ranged from 12 to 75 months (median: 53 months). Post-operative complications were documented in 19/74 limbs (16 dogs), including major complications in 13 limbs. These complications consisted mainly of non-union (six limbs), implant failure (two limbs), and infection (two limbs) requiring revision surgery in nine limbs. Body weight was the only variable associated with an increased risk of post-operative complications (p = .04). Agreement between expert predictions was low (respectively k = -0.08 and k = 0.11). CONCLUSION: Major complications were reported in one fourth of limbs treated with PAUL and were more likely as body weight increased. Suboptimal plate and screw placement or osteotomy reduction on post-operative radiographs were poorly predictive of complications. CLINICAL SIGNIFICANCE: Complications are fairly common after PAUL, particularly in heavier dogs, and post-operative radiographic examination seems unreliable to predict those.

Risk of infection after double locking plate and screw fixation of tibial plateau leveling osteotomies in dogs weighing greater than 50 kilograms.

OBJECTIVE: To compare surgical site infection (SSI) rates after double locking plate and screw fixation (DLP), standard locking plate and screw fixation (LP), and conventional nonlocking plate and screw fixation (NLP) in dogs weighing >50 kg undergoing tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Retrospective study (January 2003-October 2017). ANIMALS: Two hundred seventy-five dogs weighing >50 kg with cranial cruciate ligament disease treated with TPLO. METHODS: Medical records of dogs weighing >50 kg that underwent TPLO by DLP, LP, and NLP with a minimum follow-up period of 12 months were included. Data collected included signalment, details of any concurrent surgical procedure, type of implant used, use of postoperative antibiotic therapy, occurrence of perioperative complications, and presence of postoperative infection. The probability, risk difference, and relative risk of SSI were estimated for each fixation with a marginal model. RESULTS: Nonlocking plate and screw fixation was used in 114 (41.5%) dogs, LP was used in 128 (46.5%) dogs, and DLP was used in 33 (12%) dogs. Surgical site infection was diagnosed in 48 of 275 (17.5%) dogs. Postoperative antibiotic therapy was used in 74 (64.9%) dogs, 62 (48.4%) dogs, and 32 (97.0%) dogs in the NLP, LP, and DLP groups, respectively. Dogs with NLP, LP, and DLP had postoperative infection rates of 24.5%, 13.3%, and 9.1%, respectively. There were no risk differences for the three groups (Holm-adjusted P > .05). CONCLUSION: No difference in infection rates was detected between DLP, LP, or NLP for TPLO in these dogs weighing >50 kg. CLINICAL SIGNIFICANCE: Fixation of TPLO with DLP in dogs weighing >50 kg does not seem to increase the risk of SSI compared with LP and NLP.

Use of Synthetic Osteochondral Implants to Treat Bilateral Shoulder Osteochondritis Dissecans in a Dog.

CASE DESCRIPTION: An 8-month-old American Bulldog was presented for assessment of bilateral thoracic limb lameness. Computed tomographic imaging revealed large, deep osteochondritis dissecans lesions in both humeral heads. TREATMENT AND OUTCOME: The osteochondritis dissecans lesions were debrided and the exposed subchondral defects were prepared to receive synthetic grafts. Circular implants consisting of a surface layer of polycarbonate urethane and a deep layer of lattice-type titanium were implanted into the osteochondral defects to reconstruct the articular surface topography. Follow-up clinical examination 1.5, 3 and 9months postoperatively revealed a lack of signs of shoulder pain and resolution of thoracic limb lameness. Nine-month follow-up radiographs showed radiographic evidence of osteointegration of both implants. CLINICAL RELEVANCE: Synthetic osteochondral implantation in the caudocentral aspect of the humeral head appeared technically feasible and effective in resolving lameness caused by humeral head osteochondritis dissecans.

Long-term complications following tibial plateau levelling osteotomy in small dogs with tibial plateau angles > 30°.

Tibial plateau levelling osteotomy (TPLO) is commonly performed for surgical management of cranial cruciate ligament (CCL) disease. It has been suggested that small dogs may have steeper tibial plateau angles (TPAs) than large dogs, which has been associated with increased complication rates after TPLO. A retrospective study was performed to assess the rate and nature of long-term complications following TPLO in small dogs with TPAs>30°. Medical records were reviewed for dogs with TPAs>30° treated for CCL rupture by TPLO with a 2.0 mm plate over a five-year period. Radiographs were assessed to determine TPA, postoperative tibial tuberosity width and to identify any complication. Up-to-date medical records were obtained from the referring veterinary surgeon and any complications in the year after surgery were recorded. The effects of different variables on complication rate were assessed using logistic regression analysis. Minor complications were reported in 22.7 per cent of cases. This is similar to or lower than previously reported complication rates for osteotomy techniques in small dogs and dogs with steep TPAs. A smaller postoperative TPA was the only variable significantly associated with an increased complication rate. No major complications were identified.

Surgical management of pivot-shift phenomenon in a dog.

CASE DESCRIPTION A 6.8-year-old neutered male Labrador Retriever-Poodle mix was evaluated because of continued left pelvic limb lameness unresponsive to conservative management 1 year after undergoing tibial plateau leveling osteotomy (TPLO). CLINICAL FINDINGS A jerking lateral movement of the left stifle joint was detected during walking. Orthopedic examination revealed a pivot-shift phenomenon (PSP). Palpation elicited no signs of discomfort over the TPLO plate or caudomedial aspect of the stifle joint. Radiography revealed complete bone fusion at the osteotomy site and only mild joint effusion. TREATMENT AND OUTCOME Arthrotomy was performed at the medial aspect of the stifle joint, revealing no meniscal tears. The previously applied plate was removed, and an extracapsular, synthetic, ligament-like biomaterial was placed to counteract internal tibial rotation, thereby eliminating the PSP. Six weeks later, lameness had improved considerably with no evidence of PSP; 8 weeks after surgery, the dog was assessed for sudden-onset lameness in the right pelvic limb. Cranial cruciate ligament rupture was suspected, and TPLO was performed. The PSP was identified intraoperatively, so an extracapsular implant was placed. Six weeks later, the dog had only mild lameness and no evidence of PSP in either pelvic limb. In a follow-up telephone conversation 1 year later, the owner reported no obvious lameness or gait abnormalities. CLINICAL RELEVANCE Use of an extracapsular implant effectively eliminated the PSP following TPLO in the dog of this report and can be considered as an intra- or postoperative option for dogs with PSP that responds poorly to conservative management.

Use of a subdermal plexus flap to reconstruct an upper eyelid following radical tumor resection in a cat.

CASE DESCRIPTION A 15-year-old neutered male domestic shorthair cat was examined for treatment of a recurrent neoplastic mass in the left upper eyelid that had been excised 6 months earlier by the referring veterinarian. CLINICAL FINDINGS An apparently nonpainful firm cutaneous mass (approx 2 × 2 mm) was located on the lateral third of the left upper eyelid near the scar from the previous surgical excision. TREATMENT AND OUTCOME Approximately one-third of the left upper lip was used as a subdermal plexus (lip-to-lid) flap to cover the defect created by en bloc excision of the eyelid mass. A bridge incision between the donor and recipient sites was used so that the eyelid could be reconstructed in 1 procedure. Histologic evaluation confirmed that the mass had been completely excised. Both the donor and recipient flap sites healed well without complications. The procedure resulted in excellent functional and cosmetic results with no recurrence of the mass at 14 months after surgery. CLINICAL RELEVANCE The described lip-to-lid technique was a simple 1-stage method for reconstructing an upper eyelid of a cat following radical tumor resection that provided excellent functional and cosmetic results.

Evaluation of an Axial Pattern Flap Based on the Cranial Cutaneous Branch of the Saphenous Artery: A Cadaveric Perfusion Study.

OBJECTIVES: To confirm the anatomic location of the cranial cutaneous branch of the saphenous artery (CCSA), delineate the angiosome of the CCSA, and provide guidelines for clinical use of an axial pattern flap based on the CCSA. STUDY DESIGN: Anatomic study. ANIMALS: Greyhound cadavers (n=10). METHODS: Shortly after euthanasia, the CCSA was identified and isolated in each hindlimb. Methylene blue and radiographic perfusion studies were performed. The skin was freed from the thigh for photographic and radiographic images. The dimensions of the skin area suitable for use as an axial pattern flap were related to anatomical landmarks. Mock surgical elevation and transposition of the flap in 2 dogs allowed assessment of flap mobility and ease of donor site closure for clinical use. RESULTS: The CCSA was reliably identified in all dogs branching from the saphenous artery as it became superficial to the sartorius muscle, immediately distal to the caudal cutaneous branch and proximal to the genicular branches. Genicular branches were variably paired or singular. Perfusion studies defined the CCSA angiosome as the area cranial to the saphenous artery and caudal to the cranial border of the thigh, extending proximally from the level of the medial tibial condyle to two-thirds of the distance to the inguinal ring. CONCLUSION: An axial pattern flap based on the CCSA could be expected to cover skin defects of the cranial aspect of the distal thigh and stifle, the popliteal region caudal to the stifle, and the proximal medial crus.

Locking plate and screw fixation after tibial plateau leveling osteotomy reduces postoperative infection rate in dogs over 50 kg.

OBJECTIVE: To assess the influence of locking plate and screw implants on postoperative infection rate in dogs >50 kg undergoing tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Retrospective case series. ANIMALS: Dogs >50 kg (n = 208) that had TPLO. METHODS: Medical records (January 2003-September 2011) were reviewed for dogs that had TPLO. Type of implant used (locking plate and screw fixation [LP] and dynamic compression plate and screw fixation [NLP]), use of postoperative antibiotics and presence of postoperative infection were recorded. Multivariate analysis was performed. RESULTS: Forty dogs (21.3%) had clinical signs compatible with postoperative infection. A positive microbiology swab was available in 16/40 cases (40%). Administration of postoperative antibiotics was associated with a lower incidence of infection (P = .006) and the use of NLP was associated with a higher incidence of infection (P = .01). CONCLUSIONS: Use of LP construct and postoperative antibiotic therapy significantly decreased infection rate in dogs >50 kg that have TPLO.