A Bilateral Acetabular Physeal Fracture Treated with External Fixation in an Immature Cat

This study aimed to assess the outcome of a bilateral acetabular physeal fracture treated with external fixation in an immature cat, a surgical technique not usually employed in immature patients. The fixator took 40 days, and it was removed after radiographic bone healing was achieved. No significant complications related to the technique were identified, and the outcome was classified as good based on the functional assessment and pain scales employed. The use of external fixation for stabilising acetabular fractures in immature cats should be considered a viable technical option, especially for minimally invasive stabilisation.

Characterization of Oral Pathology in Cats Affected by Patellar Fracture and Dental Anomaly Syndrome (PADS)

Patellar fracture and dental anomaly syndrome (PADS) is a congenital bone disease of cats that is characterized by atraumatic bone fractures (most commonly the patella), the persistence of deciduous teeth, and impaction of permanent teeth. Jaw swelling due to osteomyelitis is often the reason that cats with PADS are presented for veterinary dental care. The clinical history, oral examination findings, dental radiological findings, and histopathology were evaluated for 13 cats with dental and skeletal pathology consistent with PADS, including 9 with osteomyelitis. Cats in this study were predominantly domestic shorthair (12 of 13 cats), and there was no apparent sex predilection. All cats had multiple persistent deciduous teeth and multiple impacted permanent teeth, although the number of persistent and impacted teeth varied. Osteomyelitis of the jaw typically occurred within the first 4 years of life. Osteomyelitis of the mandible was 4 times more common than osteomyelitis of the maxilla. Histologically, osteomyelitis was chronic, neutrophilic, and osteoproliferative. Necrotic bone was confirmed in 67% of osteomyelitis lesions. Histological evaluation of jaws without inflammation demonstrated abnormal amounts of unmodeled bone, abnormally dense bone, and retention of cartilage in the caudal mandible. Three cats in the study had mandibular distoclusion and 2 had concurrent paronychia. To obtain a favorable clinical outcome in PADS cats with jaw swelling, prompt and aggressive surgical treatment of osteomyelitis is required. Extraction of persistent deciduous teeth and impacted permanent teeth is recommended when there is associated periodontitis or osteomyelitis.

Management of insufficiency fractures associated with long-term bisphosphonate therapy in a cat

Case summary

A 10-year-old spayed female domestic medium hair cat presented after sustaining atraumatic insufficiency fractures of the right calcaneus and the left tibia approximately 6 weeks apart. Chronic alendronate therapy had been ongoing for 9 years for the management of previously diagnosed idiopathic hypercalcemia. The right calcaneal fracture was managed non-operatively due to minimal functional impairment. The left tibial fracture was managed via open reduction and internal fixation with orthogonal plating. Alendronate therapy was discontinued at the time of the fracture repair with prednisolone being used to manage the hypercalcemia. Despite rapid clinical improvement, the tibial fracture had a protracted healing course, with clinical union only being achieved 22 weeks postoperatively. At 17 months postoperatively, the idiopathic hypercalcemia remained well controlled. Gait assessment, orthopedic examination and orthogonal radiographs performed at this time revealed resolution of left pelvic limb lameness, a normal orthopedic examination of the left pelvic limb and no evidence of implant-associated complications. Monitoring is ongoing but at the time of publication, no further fractures have occurred.

Relevance and novel information

As reported in humans, this case report gathers evidence of associations between bisphosphonate treatment and the occurrence of insufficiency fractures in cats, and provides evidence that stress reactions may precede their development. If bisphosphonate therapy is utilized in the long term, serial radiographic monitoring for signs of impending fracture may be warranted. Fracture repair can be successful in cats that have received long-term bisphosphonate therapy, but delayed healing should be anticipated and implant choices made accordingly.

A rare case of transverse patellar fracture in a cat

A case of transverse patellar fracture in a cat with preserved patellar ligament integrity and no history of traumatic injury is described. The patient is presented with grade 3 weight-bearing lameness and pain after palpation. Osteosynthesis with two Kirschner wires and figure-of-eight wiring was performed. The postoperative period was without complications. Three months post surgery, radiography demonstrated relatively good bone bridging at the fracture site and a very good clinical result.

Patellar fractures in cats: Repair techniques and treatment decision-making

PRACTICAL RELEVANCE

While feline patellar fractures are not commonly encountered in practice, they tend to be found more often in younger cats; no breed or sex predispositions are recognised. If there is no evidence of a traumatic aetiology, the cat may be suspected of having patellar fracture and dental anomaly syndrome (PADS). Patellar fractures are easy to diagnose on lateral radiographs and there are several different fracture types. The type of fracture, the age of the cat at fracture occurrence and whether there is suspicion of a pathological aetiology are all relevant when considering treatment technique.

CLINICAL CHALLENGES

While some cats with patellar fractures will do well with conservative management, surgical treatment is often indicated and decision-making can be challenging.

EVIDENCE BASE

Information and recommendations provided in this review are based on the literature and the author's own clinical experience. There are several publications on PADS, but there is limited evidence as to what the underlying cause of this condition is, and the best method for managing patellar fractures is still an area where more research is needed.

AIM

This review aims to gather the papers, case series and case reports published over the past few decades in order to discuss how best to manage different types of patellar fractures.

Chronic paronychia in cats with patellar fracture and dental anomaly syndrome

CASE SERIES SUMMARY

The aim of this case series was to describe the clinical features and treatment of paronychia in cats diagnosed with patellar fracture and dental anomaly syndrome (PADS). Clinical records, photographs, microbiology, cytology and histopathology reports were collected, and follow-up was obtained. Five cats with paronychia were included. All five cats had multiple digits of multiple limbs affected and eventually underwent amputation of the third phalanx of one or multiple digits. A total of 36 digits were affected, 17% (n = 6/36) resolved with medical management and 83% (n = 30/36) were eventually treated successfully by amputation. The cats had treatment with numerous courses of antibiotics (range 7-20; mean 11 courses) over periods of time ranging from 10 to 67 months (mean 32 months).

RELEVANCE AND NOVEL INFORMATION

Chronic paronychia may be an additional clinical feature of PADS and the probable mechanism involves poor integrity of osteopetrotic bone, loss of normal nailbed anatomy and secondary osteomyelitis of the distal phalanx. Medical management with antibiotics, anti-inflammatory therapy and steroid treatment may improve the clinical signs in the short term; however, in severe instances, amputation of the third phalanx of the affected digit seems to be necessary to resolve repeated recurrences and discomfort. Additional information on the long-term outcome is required. In any cat with atraumatic patellar fractures and/or retained deciduous teeth, paronychia may require surgical management if medical management is unsuccessful.

Management of severe stifle trauma: 2. Periarticular fractures

PRACTICAL RELEVANCE

Periarticular stifle fractures are uncommon but challenging injuries to treat. There may be concurrent damage to the ligaments and stabilising structures of the stifle joint itself, which should also be evaluated (see Part 1 of this article series). Improved knowledge of the fixation options and biomechanical challenges of these injuries will aid clinical decision-making and effective repair.

CLINICAL CHALLENGES

Due to their nature, periarticular fractures may have small juxta-articular fragments, which require additional thought to address during stabilisation. In juvenile animals, these fractures typically involve the physis and often can be managed with cross pin fixation. In adult cats, locking fixation, specialised plates or external skeletal fixators can be utilised to address the juxta-articular fragments. Readers should also be aware of patellar fracture and dental anomaly syndrome (PADS), where cats develop insufficiency fractures affecting the patella and proximal tibia. A careful oral examination should be performed in affected patients, as these cats may have persistent deciduous teeth. Close attention should be paid to preoperative radiographs for evidence of chronicity of the injury including sclerosis of the patella, remodelling and blunting of the fracture lines.

AIMS

The aims of the article are to review the current literature surrounding periarticular fractures of the stifle joint and to summarise the diagnosis, treatment, outcome and complications of each fracture type. As well as discussing general fracture fixation and biomechanical principles applicable to both dogs and cats, information is provided on specific issues facing cats, such as PADS.

EVIDENCE BASE

Published data is limited, with reports including only a small number of cats. The information and recommendations in this article have therefore been drawn from a combination of the available literature and the authors' clinical experience.

Treatment of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome

OBJECTIVES

The aim of this study is to describe the treatment and outcome of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome (PADS) and to provide advice on how to manage these cases in practice.

METHODS

Data were collated on cats with PADS that were reported to have sustained humeral fractures or had fractures or fissures of the humerus identified on radiographs. The details of the fractures were recorded in addition to any treatment and outcome information.

RESULTS

Of the 207 cases reported with PADS, 18 cats (8.7%) were found to have humeral condylar fractures, none of which was known to have resulted from significant trauma. Where treatment occurred, it involved the placement of transcondylar positional or lag screws. In some cases additional implants, including supracondylar bone plates and screws or Kirschner wires (K-wires), were used. Follow-up data revealed that only two cats were euthanased owing to the presence of the humeral fractures, with at least eight achieving some degree of recovery of function.

CONCLUSIONS AND RELEVANCE

These humeral fractures all have the characteristics of stress insufficiency fractures, being simple isolated fractures that are short oblique, with increased radio-density at the fracture line and occurring following minimal or no trauma. Humeral intracondylar fissures were identified in two cats and it is possible that some of the other fractures may have occurred secondary to pre-existing fissures. To our knowledge, no prior reports exist of fissures in cats that do not meet the criteria for PADS. Surgical repair primarily consisted of the placement of transcondylar lag or positional screws with, in some cases, adjunct implants such as bone plates and screws or K-wires. Though there were insufficient data to determine the prognosis for these fractures in the long term, unlike patellar fractures, many of these fractures will heal if treated appropriately.

A Clinical, Radiographic and Histological Study of Unerupted Teeth in Dogs and Cats: 73 Cases (2001-2018)

Lack of dental eruption may be accompanied by development of dentigerous cysts and has also been rarely associated with neoplasia. However, little information is available on prevalence of unerupted teeth and associated lesions in dogs and cats. The main objective of this study was to describe the epidemiologic data of canine and feline dental patients with unerupted teeth, and assess the prevalence of associated dentigerous cysts and tumors. Secondary aims included the evaluation of possible factors implicated in cystic development, and description of the histological features of dentigerous cysts. Medical and dental records, intraoral photographs, intraoral radiographs of client-owned dogs and cats with clinically missing teeth examined between 2001 and March 2018 were reviewed. Collected data included signalment, reason for presentation, number, type, depth of inclusion and angulation of unerupted teeth, presence of cystic lesions or tumors, abnormalities affecting involved teeth, histopathological findings, performed treatment and outcome. Seventy-three animals (69 dogs and 4 cats) with 113 unerupted teeth were included. The most frequent unerupted tooth in dogs was the first premolar teeth (78%), followed by the canine and third molar teeth. Dentigerous cysts were diagnosed associated with 48 (44.4%) teeth in dogs and one out of five unerupted teeth in cats. The affected teeth in dogs were predominantly in horizontal inclination (40%) and in soft tissue inclusion (77%). Brachycephalic canine breeds were overrepresented. The only unerupted tooth in boxer dogs was the first premolar tooth (32 teeth). Ninety percentage of boxers with unerupted teeth developed associated lesions (25 dentigerous cysts and one tumor). Two ameloblastomas (one in a dog and one in a cat) and one osteosarcoma (in a dog) were diagnosed in association with three unerupted teeth. Histology was essential in diagnosing two odontogenic cysts not evident on radiographs. In all cases that were followed-up, treatment (i.e., extraction, extraction and surgical curettage, or operculectomy) appeared successful. Untreated dentigerous cysts showed progression at re-examination. None of the unerupted teeth without evidence of cyst at the time of diagnosis showed incipient cystic development. None of the evaluated factors were associated with lack of eruption and/or development of associated lesions.

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

Objectives

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

Methods

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

Results

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

Conclusions and relevance

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