Osteochondritis dissecans-like lesions of the occipital condyle and cervical articular process joints in a Saddlebred colt horse

Arthroscopic removal of osteochondral fragments of the cervical articular process joints in three horses

OBJECTIVE

To report arthroscopic osteochondral fragment removal from the equine cervical spine articular process joints (APJs) including long-term follow-up.

STUDY DESIGN

Case series.

ANIMALS

Three Warmblood horses with forelimb lameness and/or reduced range of motion of the cervical spine with osteochondral fragments between the cervical vertebrae C5 /C6 or C6 /C7 .

METHOD

Arthroscopy of the APJs of C5 /C6 and C6 /C7 was performed under general anesthesia. Following endoscopic evaluation of the joints, osteochondral fragments were removed using a rongeur.

RESULTS

All horses recovered from anesthesia with no anesthetic or minor postanesthetic complications. One horse needed a second procedure for fragment removal. Fourteen to 31 months post-surgery the horses were sound for their intended use and neurological examination revealed no abnormalities.

CONCLUSION

Arthroscopic removal of osteochondral fragments can be performed safely in the equine cervical APJs of C5 /C6 and C6 /C7 resulting in a favorable long-term outcome.

CLINICAL SIGNIFICANCE

Arthroscopic removal is a valid option for horses showing clinical signs that can be attributed to osteochondral fragments in the APJs of the neck.

Influence of osteochondrosis on the longevity and racing performance of standardbred trotters and pacers

OBJECTIVE

To determine the influence of clinical osteochondrosis (OC) on the short-term (2, 3, and 4-year-old) and long-term racing performance and longevity of standardbred racehorses.

STUDY DESIGN

Retrospective case-control study.

SAMPLE POPULATION

Standardbred racehorses from a single breeding farm born between 2009 and 2017 that survived to racing age (n = 2711). Three hundred eighty-two (14%) horses were OC-affected (829 lesions confirmed arthroscopically during surgical treatment), and 2329 (86%) horses were nonaffected.

METHODS

Racing performance data were obtained from an online database and evaluated with multiple linear regression models.

RESULTS

Trotters were more likely than pacers to be affected by OC (odds ratio [OR] = 1.4, 95% CI = 1.1-1.9, P = .006). Compared with nonaffected horses, long-term OC-affected horses had 8.8 fewer starts (95% CI = -14.4 to -3.2, P = .002), 1.0 fewer wins (95% CI = -1.9 to -0.1, P = .030), and 3.8 fewer total number of first through third place finishes (95% CI = -6.2 to -1.4, P < .0001). Nonaffected horses had longer careers compared with OC-affected horses, racing 0.32 years longer (95% CI = -0.52 to -0.12, P = .002). Osteochondrosis had no impact on short-term racing performance. Horses with lesions at the distal intermediate ridge of the tibia or lateral trochlear ridge of the talus had decreased performance compared with horses without these lesions.

CONCLUSION

Pacers were less likely than trotters to be affected by OC. Affected horses had fewer starts and shorter careers, despite early surgical intervention.

CLINICAL SIGNIFICANCE

Osteochondrosis decreases long-term racing performance in racing standardbreds.

Osteochondral fragmentation of the cervical articular process joints; prevalence in horses undergoing CT for investigation of cervical dysfunction

BACKGROUND

Computed tomography (CT) imaging of the cervical spine of mature horses under general anaesthesia is becoming increasingly accessible. Osteochondral fragmentation (OF) of the cervical articular process joints (APJs) has been identified on CT imaging; the prevalence, clinical features and significance of this finding are currently unknown.

OBJECTIVES

To describe the prevalence and clinical features of a population of horses with CT evidence of OF within the cervical APJs.

STUDY DESIGN

Retrospective, descriptive case series.

METHODS

The study population consisted of all horses undergoing CT imaging of the entire cervical spine between April 2016 and December 2019 at Liphook Equine Hospital for investigation of clinical signs localised to this region. CT scans were examined for evidence of OF within the APJs and additional case features were recorded.

RESULTS

A total of 55 horses underwent CT imaging during the study period. OF was identified in 13 horses, giving a CT prevalence of 24% in the study population. OF occurred in a range of ages, breeds and uses of equine, presenting with varied clinical signs. It was identified at every level of the neck. Additional cervical pathology was identified in 11/13 OF cases.

MAIN LIMITATIONS

Retrospective analysis of a clinical caseload with a lack of clinically normal controls or post mortem confirmation of imaging findings. Low case numbers.

CONCLUSIONS

OF within the cervical APJs is recognised on CT imaging in horses with cervical dysfunction. Fragments are commonly identified in combination with additional cervical pathology. Further investigation is required to confirm their clinical significance and develop potential treatment options where necessary.

Occipital condyle defects assessed by radiography or CT can be a normal finding in foals

Age of complete ossification of equine occipital condyles has not been published. Consequently, clinical significance of occipital condyle defects on radiographs or CT scans of young horses remains unknown. The goals of this single-center, retrospective, cross-sectional study were to characterize incidental occipital condyle defects and to define the age of complete ossification. The margin of occipital condyles was classified as regular or with defect(s). Analyses were made on 121 horses, including 106 radiographic and 19 CT studies showing the occipital condyles of horses less than 5 years of age obtained over 6 years in a referral hospital. Neurological signs and outcome were not associated with occipital defects. Horses with regular occipital condyles on radiographs had a median age of 974 days (median interquartile range = 707) compared with 47 days (interquartile range = 106) in the defect group. The odds of finding radiographically regular occipital condyles were 2.6% higher for each additional day of age (P = .011, 95% CI, 0.6-4.7%). In the CT group, univariate analyses demonstrated a significant effect of age on the aspect of occipital condyles (P = .016). Horses with regular occipital condyles were older (median age = 881 days; interquartile range = 1054) than horses with a defect (median age = 109 days, interquartile range = 318). All horses above 156 days (5.1 months) of age and 550 days (18.1 months) of age had regular occipital condyles on radiographic and CT images, respectively. This study describes occipital condyle defects as a potential normal finding in young horses and provides guidelines for interpretation of the occipital condyle ossification process.