Management of proximal metaphyseal curvilinear tibial fractures in 25 skeletally immature dogs (2009 to 2020).

OBJECTIVES: To describe the occurrence, management and outcome of proximal metaphyseal curvilinear tibial fractures in skeletally immature dogs. MATERIALS AND METHODS: A multi-centre retrospective review was conducted, searching for skeletally immature dogs presenting with proximal metaphyseal curvilinear tibial fractures between January 2009 and September 2020. Signalment, fracture description and case management data were retrieved. Outcome was assessed by retrospectively evaluating follow-up radiographs, hospital records and an owner questionnaire. RESULTS: Twenty-five dogs met the inclusion criteria. All but one fracture was a result of minimal trauma. Twenty fractures were managed with internal fixation, two with external fixation and three conservatively. All 25 fractures healed. Eight major complications occurred in seven of 25 (28%) dogs. Twelve minor complications occurred in 10 of 25 (40%) dogs. Owner questionnaire data were available for 12 of 25 dogs; 11 of 12 were reported as having full function and one of 12 as having acceptable function at the time of questioning (median 34.5 months following presentation). At final follow-up, either by clinical examination or owner questionnaire, full function was achieved in 22 of 25 patients and acceptable function in three of 25. CLINICAL SIGNIFICANCE: This study reported a series of proximal metaphyseal tibial fractures in skeletally immature dogs. The most common fixation method was internal fixation, which frequently resulted in full limb function at final follow-up. Owners reported outcome as fully functional in all dogs that underwent surgery at first presentation and had owner follow-up available, though positive outcomes may have been affected by participation bias.

Salter-Harris type III fractures of the distal humerus in two dogs.

Salter-Harris type III fractures of the distal humerus in a four-month-old male Labrador Retriever and a male crossbreed dog (estimated to be 3.5-months-old) are reported. Both fractures were treated with open reduction and interfragmentary compression by lag screw fixation. Both fractures healed and full limb use was regained at four weeks postoperatively. The occurrence of this unusual fracture type may be related to the physeal closure pattern of the distal humeral physis, and a different mechanism of injury compared to the more common Salter-Harris type IV fracture seen in this region.

Early kinematic outcome after treatment of cranial cruciate ligament rupture by tibial plateau levelling osteotomy in the dog.

OBJECTIVES: To establish the effect of tibial plateau levelling osteotomy (TPLO) on two selected pelvic limb kinematic variables in dogs treated for clinical cranial cruciate ligament rupture (CCLR). METHODS: Thirteen dogs that had incurred CCLR and were treated by TPLO walked on a treadmill whilst kinematic data on pelvic limb paw motion were acquired using motion capture equipment. Data were subject to secondary processing using matrix analysis software and statistical analysis. RESULTS: Pelvic limb stance duration significantly increased during the 12 week study period, recovering to near-normal values. Range of pelvic limb paw velocity also significantly increased but did not reach normal values by 12 weeks postoperatively. CLINICAL SIGNIFICANCE: The improvement in stance duration to near normality may aid in explaining the widely-held subjective impression that TPLO frequently provides an excellent outcome in the early stages after repair of the cruciate deficient canine stifle joint. Both stance length and range of paw velocity provide useful objective measures to compare outcome following surgery for CCLR.

Stabilization of sacroiliac luxation in 40 cats using screws inserted in lag fashion.

OBJECTIVE: To (1) identify prognostic indicators for stability after stabilization of sacroiliac luxation with screws inserted in lag fashion and (2) report dorsoventral dimensions of the sacrum in cats. STUDY DESIGN: Multicenter retrospective study. SAMPLE POPULATION: Cats (n=40) with sacroiliac luxation. METHODS: Case records and radiographs of cats presented at the Queen's Veterinary School Hospital Cambridge and the Royal Veterinary College Hatfield for screw fixation of sacroiliac luxation were reviewed. Dorsoventral dimensions of 15 feline cadaveric sacral bodies were measured to identify the appropriate implant size for use in fixation with screws inserted in lag fashion. RESULTS: Of 40 cats, 13 had left, 14 right, and 13 bilateral sacroiliac luxations. Of 48 screws analyzed, 42 (87.5%) were placed within the sacral body or exited ventrally and 6 (12.5%) were considered malpositioned. Screw purchase within the sacrum was statistically different between unstable and stable repairs (P=.001). Using confidence intervals for screw length within the sacrum and effect on stability, the lowest screw depth that contained 95% of the screws that did not loosen was approximately 60% of the sacral width. Mean dorsoventral sacral dimension at its narrowest point was 5.9+/-1.14 mm. There was no significant difference in the incidence of implant loosening between those luxations that were 100% reduced and those that were <100% reduced (P=.7837). CONCLUSIONS: Screw purchase within the feline sacrum of at least 60% of the sacral width significantly reduces the risk of loosening. CLINICAL RELEVANCE: Screw placement to a depth of 60% of the width of the feline sacrum is recommended.

Treatment of caudal mandibular fracture and temporomandibular joint fracture-luxation using a bi-gnathic encircling and retaining device.

Fractures of the caudal portion of the mandible and temporomandibular joint (TMJ) fracture-luxation can be challenging to treat with direct fixation methods. This paper describes a simple technique for the indirect treatment of caudal mandibular fracture and TMJ fracture-luxation using a subcutaneous loop of nylon leader line tunnelled around the maxilla, incisive and nasal bones, and under the mandible, placed just caudal to the canine teeth, and crimped ventral to the mandibular skin: a bignathic encircling and retaining device (BEARD). A BEARD was used to treat two immature dogs with simple, unilateral caudal mandibular fractures, six cats with unilateral injury (two with TMJ luxation, three with TMJ fracture-luxation, one with caudal mandibular fracture), and two cats with bilateral injury (comminuted caudal mandibular fracture with contralateral TMJ luxation; bilateral condylar neck fracture). The BEARD treatment failed short-term due to poor tolerance in one cat, and concurrent injuries and poor initial reduction in another cat. One cat was lost to long-term follow-up. Rostral dental occlusion was normal in six out of seven cases, and reported jaw function was normal in seven out of seven cases. The case with poor occlusion had imperfect initial reduction. Complications included dorsal nasal skin swelling or discharge, oesophagostomy tube dislodgement or blockage, BEARD loosening, and regurgitation. Treatment of uni- or bilateral caudal mandibular trauma using a BEARD can lead to clinical union, and normal rostral occlusion, provided that case selection is appropriate and immediate-post-surgical occlusion has been corrected.

Survey of 52 fractures of the patella in 34 cats.

Stress fractures of the patella were diagnosed in 34 cats with a mean age of two years and five months. Eighteen of the cats had bilateral fractures with a median interval of three months between fractures. All the fractures were transverse and occurred in the proximal aspect or base of the patella with no evidence of trauma. In 43 of the patellae there was radiographic evidence of sclerosis. Repairs with a pin and tension band in 18 cats resulted in a further fracture or failure of fixation in 86 per cent of the cases that were followed up. Ten of the cats had suffered fractures of other bones at different times to the patellae fractures. In the majority of the cats the fracture formed a functional non-union but some cats remained stiff and lame.

Transverse stress fractures of the proximal tibia in 10 cats with non-union patellar fractures.

Ten cats with a mean age of eight years and five months had suffered proximal transverse tibial fractures; in four of them both tibiae had fractured at different times. All the cats also had bilateral non-union patellar fractures, and nine of them had evidence of fractures elsewhere, including acetabular, ischial, humeral condylar and rib fractures, which had occurred before or after the tibial fractures. All the tibial fractures were proximal and transverse. Radiographically, there was thickening and sclerosis of the cranial cortex adjacent to and at the level of the fracture, changes that were compatible with stress fractures. The outcome of repair of the tibial fracture was known in nine of the cats; eight of them healed and one resulted in a non-union. Two of the cats were euthanased as a direct result of the fracture or complications with the repair.

Feline combined diaphyseal radial and ulnar fractures. A retrospective study of 28 cases.

Feline combined diaphyseal radial and ulnar fractures were reviewed in a retrospective study of cases that were admitted to two university teaching hospitals. A high incidence of complications was noted, with 6/26 (23.1%) of cases requiring revision surgery. Open fractures were significantly more likely to require revision surgery. The two main repair methods were external skeletal fixation (ESF) or radial plating. The success rate was greater for radial plating, with only 1/10 (10%) cases requiring revision versus 4/14 (28.6%) for ESF. However, ESF tended to be applied to the more complicated fractures. Stabilisation of both bones proved to be an effective repair strategy with only 1/8 cases (12.5%) requiring revision versus 5/18 cases (27.8%) where only one bone was stabilised. Synostoses and radiohumeral luxation were noted as complications associated with the fractures stabilised by ESF. Final limb function following recovery was assessed as 'good' or 'excellent' in 93.3% of cases.

Feline shoulder luxation: a cadaveric study of injury and repair using ligament prostheses.

OBJECTIVES: To describe the range of motion and clinical stability of the feline shoulder following experimental injury and repair using a prosthetic suture technique. MATERIALS AND METHODS: Eighteen feline cadaveric thoracic limbs were randomly allocated into three groups: medial injury, lateral injury or bilateral injury. Joint range of motion and clinical stability in all directions was recorded before and after specific anatomic structures were sectioned and following surgical repair using a prosthetic suture technique. Results were compared between intact, injured and repaired limbs for each injury type. RESULTS: There was a significant difference in joint range of motion in specific limb directions between intact and injured joints and between injured and repaired joints. There was no difference in joint range of motion between intact and repaired joints. Four of six medially injured joints were deemed clinically stable and five of six laterally injured joints were deemed clinically stable. All bilaterally injured joints were deemed unstable. CLINICAL SIGNIFICANCE: The relative contributions of shoulder stabilisers to joint range of motion and clinical stability provide a reference for clinical cases with suspected shoulder instability. The prosthetic suture repair technique described was effective at returning the shoulder joint to a normal range of motion in this ex vivo model.

Traumatic fracture of the patella in 11 cats.

Traumatic patellar fracture in cats mainly occurred in male neutered cats with an average age of four years, six months and a mean weight of 4.8 kg. Patellar fractures were concurrent with long bone fractures and cruciate ligament rupture or occurred after gunshot. The patella luxated medially or laterally in four cats. Fracture fragments were usually small, either from the proximal pole (base) or distal pole (apex) or longitudinal fragments. Treatment was by fragment excision when the fragment was small or by reconstruction with pins and wires when fractures were comminuted. The outcome in six cats was reported as 'good' to 'normal' and three cats were 'improving' or had 'mild' intermittent lameness at the last follow up.

A biomechanical comparison of six different double loop configurations for use in the lateral fabella suture technique.

Six different double loop configurations which could be applied to the lateral fabella suture (LFS) technique were subjected to in vitro mechanical testing. Three double loop, single strand and three double loop, double strand configurations were tested. The strongest configuration, with a significantly higher mean ultimate load and load at yield, was the interlocking loop configuration. This is a novel configuration which has not previously been reported. The three double loop, single strand configurations all had higher mean ultimate loads than the double loop, double strand configurations. The double strand group with uneven loop length performed very poorly, with significantly lower mean stiffness and ultimate load than all of the single strand groups. This group also developed unacceptably high levels of elongation during high level cyclic loading.

Tension band stabilisation of acetabular physeal fractures in four kittens.

The surgical repair of acetabular physeal fractures in four kittens using a screw and tension band technique is reported. This was an appropriate method for restoring articular congruency and improving pelvic alignment. All cases had an excellent outcome and full limb use following fracture repair. In kittens younger than 12 weeks, there is a possibility of premature fusion of the acetabular bone resulting in development of a deformed, shallow acetabulum and hip subluxation. However, surgery is still justified when there is pelvic canal narrowing to decrease the risk of future defecatory problems. Early implant removal in such young kittens may decrease the severity of deformity caused by premature physeal closure. In kittens of 16 weeks or older, the prognosis is good for normal acetabular development and implant removal is not necessary.

Patellar luxation as a complication of surgical intervention for the management of cranial cruciate ligament rupture in dogs. A retrospective study of 32 cases.

This retrospective study identified 32 cases of patellar luxation which occurred as a complication of surgical intervention for cranial cruciate ligament rupture (CCLR). The complication was recorded mostly in larger (>/=20 kg) dogs with the Labrador Retriever being the most common breed. The complication followed extra-capsular, intra-capsular and tibial plateau levelling surgery. The mean time from CCLR surgery to the diagnosis of patellar luxation was 14 weeks. The incidence of patellar luxation occurring as a complication of surgical intervention for CCLR was 0.18% of all CCLR corrective procedures. Corrective surgery for patellar luxation was successful in 79% of stifles. The patellar reluxation rate was significantly lower (p = 0.0007) when at least one corrective osteotomy (tibial tuberosity transposition, femoral trochlear sulcoplasty or tibial plateau levelling osteotomy with tibial axial re-alignment) was performed (35%), compared to when corrective osteotomy was not performed (100% patellar reluxation rate). When performing corrective surgery for patellar luxation following CCLR surgery, at least one corrective osteotomy should be performed in order to reduce the patellar reluxation rate. The correction of patellar luxation following surgery for CCLR is challenging and carries a significant rate of failure.

Radiographic and clinical features of carpal varus associated with chronic sprain of the lateral collateral ligament complex in 10 dogs.

Lameness associated with carpal varus deformity was recognised in 10 dogs, eight of which were Dobermann Pinschers. The dogs had a mean age of seven years and nine months. Carpal varus was usually bilateral with concurrent carpal hyperflexion and pronation. Carpal varus was present prior to the onset of lameness in four cases. With stress radiography the median angle of varus deviation in all carpi was 14.6 degrees , and an increase in the size of the ulnar /ulnar carpal bone joint space was seen in six of the seven dogs. Radiographic changes included: enthesophyte formation at the proximolateral aspect of metacarpal V, periarticular soft tissue swelling, especially lateral, bone proliferation at the carpometacarpal joint I and enthesophyte formation at metacarpophalangeal joint V. Four dogs were admitted for problems other than carpal varus and lameness was not treated. Five dogs were treated with nonsteroidal anti-inflammatory drugs, but lameness was not completely resolved and became exacerbated with exercise. One dog was successfully treated by pancarpal arthrodesis.

Radiographic assessment of the skeletons of Dolly and other clones finds no abnormal osteoarthritis.

Our recent report detailing the health status of cloned sheep concluded that the animals had aged normally. This is in stark contrast to reports on Dolly (first animal cloned from adult cells) whose diagnoses of osteoarthritis (OA) at 5½ years of age led to considerable scientific concern and media debate over the possibility of early-onset age-related diseases in cloned animals. Our study included four 8-year old ewes derived from the cell line that gave rise to Dolly, yet none of our aged sheep showed clinical signs of OA, and they had radiographic evidence of only mild or, in one case, moderate OA. Given that the only formal record of OA in Dolly is a brief mention of a single joint in a conference abstract, this led us to question whether the original concerns about Dolly's OA were justified. As none of the original clinical or radiographic records were preserved, we undertook radiographic examination of the skeletons of Dolly and her contemporary clones. We report a prevalence and distribution of radiographic-OA similar to that observed in naturally conceived sheep, and our healthy aged cloned sheep. We conclude that the original concerns that cloning had caused early-onset OA in Dolly were unfounded.

Panniculitis, polyarthritis and osteomyelitis associated with pancreatic neoplasia in two dogs.

A 12-year-old crossbred dog (case 1) and a 12-year-old Shetland sheepdog (case 2) were presented with a history of lameness and distal limb swelling. Physical examination revealed joint effusions and asymmetrical swellings of the extremities. In case 1, a diagnosis of arthritis and cellulitis was made on fine-needle aspiration biopsy of the synovium and subcutis. In case 2, bone biopsies and synovial aspirates diagnosed osteomyelitis and arthritis. A diagnosis of pancreatic disease was made on the findings of marked elevations of serum lipase concentrations and ultrasonographic identification of pancreatic masses in both cases. Both the cases were non-responsive to symptomatic management and were subsequently euthanased. Postmortem examination confirmed the diagnosis of panniculitis, arthritis and osteomyelitis in both cases. A pancreatic exocrine adenoma was identified in case 1 and a pancreatic adenocarcinoma with widespread metastases in case 2. To the authors' knowledge the association of panniculitis, polyarthritis and osteomyelitis with pancreatic disorders has not been reported previously in canine clinical cases.

Plate failure by bending following tibial fracture stabilisation in 10 cats.

OBJECTIVE: To describe the clinical findings and management of tibial fractures in cats in which osteosynthesis failed due to plate bending. METHODS: Case records and radiographs of cat tibial fracture repairs from five referral centres were reviewed for signalment and to assess incidence of plate failure by bending. Cats that sustained plate bending following plate or plate-rod fixation were reviewed for fracture configuration, repair method, initial postoperative and postfailure tibial alignment, revision treatment and outcome. RESULTS: The incidence of plate bending in cat fractures managed with plate and plate-rod fixation in the four referral centres where the overall number could be established was 13% (8/60). In the 10 cats in which plates bent, initial fractures were generally oblique or spiral with mild comminution and located in the middle or distal third of the tibia. Mean time to implant failure was 24 days (range 2 to 56 days). Mean tibial valgus angle increased from 12·9° to 30·9° following bending of the plate. Short-term outcome following revision surgery using orthogonal plating or stacked medial plates was favourable with improvement in tibial valgus in all five fractures with follow-up data. CLINICAL SIGNIFICANCE: Plate bending following tibial fracture stabilisation in these 10 cats resulted in tibial valgus deformation. Consideration of plate and/or intramedullary rod selection and application should be given to avoid a plate strain environment that exceeds the yield point of the plate.

A Salter Harris type II fracture of the distal ulna in a fourteen month female neutered Great Dane.

A displaced Salter Harris type II fracture of the distal ulna and a minimally displaced Salter Harris type II fracture of the distal radius were diagnosed in a fourteen month female neutered Great Dane dog. Fracture reduction was challenging but treatment was successful. Aetiology of the unusual fracture is discussed. Long bone physes may close later in giant breeds, early neutering can cause a further delay.

The feline humerus. An anatomical study with relevance to external skeletal fixator and intramedullary pin placement.

The humeri of eleven feline cadavers were dissected and safe anatomical areas for placing external skeletal fixator pins were determined. Relevant measurements taken of the humeral condyle enabled a determination of a safe pin diameter range of 1.5 to 2.2 mm for transcondylar pins. Further anatomical measurements allowed recommendations to be made to angle pins in the distal humerus in a distolateral proximomedial direction so that the ESF pin penetrates the for cortex at least 20 mm proximal to the medial epicondyle in order to avoid pin penetration of the supracondylar foramen. Cross sections taken of the distal humerus revealed that passage of an IM pin into the medial aspect of the humeral condyle was possible in less than half the cases.

Effects of three intramedullary pinning techniques on pin location and articular damage in the canine humerus.

The purpose of this study was to compare the pin location and articular damage for intramedullary (IM) pins inserted into the humerus in a directed retrograde, non-directed retrograde, and normograde fashion. Proximal pin positioning in the humerus was significantly more cranial (p < 0.05) using both retrograde techniques when compared to the normograde technique, although this did not cause significant interference with anatomical structures. The distance to the biceps tendon, transverse humeral ligament, and the distal pin location was similar with all insertion techniques, however two of ten pins passed in a non-directed retrograde fashion penetrated the shoulder joint. The results of this study suggest that although non-directed retrograde pinning cannot be recommended, either normograde or retrograde pins directed craniolaterally provide acceptable techniques for insertion of IM pins during distal humeral fracture repair.