Curtis W. Probst

Vertical position of the patella in the stifle joint of clinically normal large-breed dogs

OBJECTIVE To define the vertical position of the patella in clinically normal large-breed dogs. SAMPLE POPULATION Cadavers of 13 clinically normal large-breed dog. PROCEDURE Both hind limbs were harvested with intact stifle joints and mounted on a positioning device that allowed full range of motion of the stifle joint. Lateral radiographic views were obtained with the stifle joints positioned at each of 5 angles (148 degrees, 130 degrees, 113 degrees, 96 degrees, and 75 degrees). Vertical position of the patella through a range of motion was depicted on a graph of mean stifle angle versus corresponding mean proximal patellar position (PPP) and distal patellar position (DPP) relative to the femoral trochlea for each dog. Ratio of length of the patellar ligament to length of the patella (L:P) was determined for each dog. Overall mean, SD, and 95% confidence intervals for L:P were calculated for all dogs. RESULTS Evaluation of vertical position of the patella through a range of motion revealed a nearly linear relationship between joint angle and PPP and joint angle and DPPF Evaluation of L:P results did not reveal significant differences between limbs (left or right) or among joint angles. Overall mean +/- SD L:P for all dogs was 1.68 +/- 0.18 (95% confidence interval, 1.33 to 2.03). CONCLUSIONS AND CLINICAL RELEVANCE The L:P proved to be a repeatable measurement of vertical patellar position, which is independent of stifle angles from 75 degrees to 148 degrees. This measurement could be used as a quantitative method for diagnosing patella alta and patella baja in large-breed dogs.

Does Osgood-Schlatter Disease exist in the dog? Review of human and canine literature and proposed classification system for tibial tuberosity avulsions in the immature dog.

Osgood-Schlatter disease (OSD) is a condition affecting human adolescents in which there is partial separation of bone fragments from the tibial tuberosity at the site of insertion of the patellar ligament to the tibial tuberosity. Tensile trauma seems to be the most likely aetiology. Clinical signs in people consist of swelling and pain at the proximal part of the tibial tuberosity and around the distal end of patellar ligament. Radiographs frequently show small ossicles at the patellar ligament insertion. Conservative treatment is usually curative. The term OSD has also been used for the canine patient. However, radiographs of these patients typically show an enlarged radiolucent line at the apophyseal plate of the tibial tuberosity. This finding is consistent with a mild avulsion fracture of the canine tibial tuberosity. Based on the radiographic differences between the two species, it seems more appropriate to use the term OSD only for people. The purpose of this paper is to review the literature on OSD in people and the reports of injuries to the proximal tibial tuberosity in dogs. In addition, a new classification system for tibial tuberosity avulsion injuries in the immature dog is proposed, with an algorithm for management of this injury.

Evaluation of plasma diazepam and nordiazepam concentrations following administration of diazepam intravenously or via suppository per rectum in dogs

OBJECTIVE To evaluate the pharmacokinetics of diazepam administered per rectum via compounded (ie, not commercially available) suppositories and determine whether a dose of 2 mg/kg in this formulation would result in plasma concentrations shown to be effective for control of status epilepticus or cluster seizures (ie, 150 to 300 ng/mL) in dogs within a clinically useful interval (10 to 15 minutes). ANIMALS 6 healthy mixed-breed dogs. PROCEDURES Dogs were randomly assigned to 2 groups of 3 dogs each in a crossover-design study. Diazepam (2 mg/kg) was administered IV or via suppository per rectum, and blood samples were collected at predetermined time points. Following a 6- or 7-day washout period, each group received the alternate treatment. Plasma concentrations of diazepam and nordiazepam were analyzed via reversed phase high-performance liquid chromatography. RESULTS Plasma concentrations of diazepam and nordiazepam exceeded the targeted range ≤ 3 minutes after IV administration in all dogs. After suppository administration, targeted concentrations of diazepam were not detected in any dogs, and targeted concentrations of nordiazepam were detected after 90 minutes (n = 2 dogs) or 120 minutes (3) or were not achieved (1). CONCLUSIONS AND CLINICAL RELEVANCE On the basis of these results, administration of 2 mg of diazepam/kg via the compounded suppositories used in the present study cannot be recommended for emergency treatment of seizures in dogs.

Minimally displaced tibial tuberosity avulsion fracture in nine skeletally immature large breed dogs

OBJECTIVE The objective of this study was to describe the clinical and radiographic features, as well as the treatment and outcome of minimally displaced tibial-tuberosity-avulsion-fractures (MDTTAF). MATERIALS AND METHODS Signalment, history, diagnostics, therapy, and outcome were recorded. Follow-up was documented as re-examination, radiographic assessment or telephone conversation. RESULTS Nine large breed dogs that were presented with lameness originating from the proximal tibia were included. All showed signs of pain when pressure was applied to the tibial tuberosity. There was no stifle instability or intra-articular disease. The main feature on mediolateral radiographs was a widened tibial-tuberosity-physis with reactive new bone and loss of edge definition of the epiphyseal and metaphyseal margins. Non-surgical treatment was chosen in eight dogs, and surgery in one dog. Radiographic follow-up showed progressive closure of the tibial-tuberosity-physis and healing. Clinical signs resolved at a median of 28 days (range: 14-120). DISCUSSION Minimally displaced tibial-tuberosity-avulsion-fractures should be a differential diagnosis in skeletally immature large breed dogs older than nine months of age with signs of subtle pelvic-limb lameness, and signs of proximal tibial pain, but no evidence of stifle joint disease. Thorough clinical examination and critical review of bilateral radiographs are important to diagnose MDTTAF. The outcome in these cases suggests that the prognosis for MDTTAF is excellent. Age and size of the affected dogs in this study differ from an earlier publication that illustrated more severely displaced tibial tuberosity avulsion fractures, occurring mainly in terriers around five months of age.

Archive (2006–2016)

Correspondence to: Dr. Dirsko von Pfeil Veterinary Specialists of Alaska 3330 Fairbanks Street Anchorage 99503, Alaska United States Phone: +1 907 274 0645 E-mail: drvonpfeil.vsoa@ak.net Dear Doctors Stigen and Mikalsen, We appreciate your contribution to the intriguing subject of tibial tuberosity injuries (1). Indeed, the case you saw recently in the Norwegian School of Veterinary Science appears to be very similar to Osgood-Schlatter disease in people. As stated in our publication, at the time of its writing, no case similar to the one you describe was reported in the available veterinary literature (2). We sincerely appreciate you sharing this case with the veterinary community. Based on the provided history of your patient, it is most likely that this dog suffered from a type – III tibial tuberosity avulsion fracture when it was five-months old. Over time, fusion with malunion of the proximally displaced and avulsed tibial tuberosity to the proximal tibia occurred. It is interesting that you state that “The most obvious pain response was provoked by maximally extending the right stifle joint” as with Osgood-Schlatter disease or tibial tuberosity avulsion, pain can usually be localized at the insertion of the patellar ligament, and elicited upon flexion of the knee. It would be interesting to follow this case and, if indicated see if shockwave treatment or resection of the ununited ossicles may help to decrease discomfort. In case of treatment, histopathology of the ossified particles may also provide additional information. Again, thank you for your contribution and helping to increase the knowledge base on tibial tuberosity injuries. Sincerely, Dirsko J. F. von Pfeil1,2; Charles E. DeCamp2; Curtis W. Probst2; Loic M. Dejardin2 1Veterinary Specialists of Alaska, Anchorage, Alaska, USA; 2Department of Small Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, Michigan, USA

A Response to “Osgood-Schlatter Disease in an English Setter”

Correspondence to: Dr. Dirsko von Pfeil Veterinary Specialists of Alaska 3330 Fairbanks Street Anchorage 99503, Alaska United States Phone: +1 907 274 0645 E-mail: drvonpfeil.vsoa@ak.net Dear Doctors Stigen and Mikalsen, We appreciate your contribution to the intriguing subject of tibial tuberosity injuries (1). Indeed, the case you saw recently in the Norwegian School of Veterinary Science appears to be very similar to Osgood-Schlatter disease in people. As stated in our publication, at the time of its writing, no case similar to the one you describe was reported in the available veterinary literature (2). We sincerely appreciate you sharing this case with the veterinary community. Based on the provided history of your patient, it is most likely that this dog suffered from a type – III tibial tuberosity avulsion fracture when it was five-months old. Over time, fusion with malunion of the proximally displaced and avulsed tibial tuberosity to the proximal tibia occurred. It is interesting that you state that “The most obvious pain response was provoked by maximally extending the right stifle joint” as with Osgood-Schlatter disease or tibial tuberosity avulsion, pain can usually be localized at the insertion of the patellar ligament, and elicited upon flexion of the knee. It would be interesting to follow this case and, if indicated see if shockwave treatment or resection of the ununited ossicles may help to decrease discomfort. In case of treatment, histopathology of the ossified particles may also provide additional information. Again, thank you for your contribution and helping to increase the knowledge base on tibial tuberosity injuries. Sincerely, Dirsko J. F. von Pfeil1,2; Charles E. DeCamp2; Curtis W. Probst2; Loic M. Dejardin2 1Veterinary Specialists of Alaska, Anchorage, Alaska, USA; 2Department of Small Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, Michigan, USA

Archive (2007–2017)

Correspondence to: Dr. Dirsko von Pfeil Veterinary Specialists of Alaska 3330 Fairbanks Street Anchorage 99503, Alaska United States Phone: +1 907 274 0645 E-mail: drvonpfeil.vsoa@ak.net Dear Doctors Stigen and Mikalsen, We appreciate your contribution to the intriguing subject of tibial tuberosity injuries (1). Indeed, the case you saw recently in the Norwegian School of Veterinary Science appears to be very similar to Osgood-Schlatter disease in people. As stated in our publication, at the time of its writing, no case similar to the one you describe was reported in the available veterinary literature (2). We sincerely appreciate you sharing this case with the veterinary community. Based on the provided history of your patient, it is most likely that this dog suffered from a type – III tibial tuberosity avulsion fracture when it was five-months old. Over time, fusion with malunion of the proximally displaced and avulsed tibial tuberosity to the proximal tibia occurred. It is interesting that you state that “The most obvious pain response was provoked by maximally extending the right stifle joint” as with Osgood-Schlatter disease or tibial tuberosity avulsion, pain can usually be localized at the insertion of the patellar ligament, and elicited upon flexion of the knee. It would be interesting to follow this case and, if indicated see if shockwave treatment or resection of the ununited ossicles may help to decrease discomfort. In case of treatment, histopathology of the ossified particles may also provide additional information. Again, thank you for your contribution and helping to increase the knowledge base on tibial tuberosity injuries. Sincerely, Dirsko J. F. von Pfeil1,2; Charles E. DeCamp2; Curtis W. Probst2; Loic M. Dejardin2 1Veterinary Specialists of Alaska, Anchorage, Alaska, USA; 2Department of Small Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, Michigan, USA