Ultrasonographic Diagnosis of Coxofemoral Subluxation in Horses

Abstract

The clinical and ultrasonographic features of seven horses with coxofemoral subluxation are presented. Affected horses included five adult geldings (11-20 years), one large pony (6 years) and a 3-month-old filly. All were lame at the walk except for the pony with grade 3/5 lameness. Lameness was acute in all horses, but three horses progressed after initial improvement. Crepitus, muscle atrophy, and pelvic asymmetry were inconsistent findings. Ultrasonographic diagnosis of subluxation required dynamic visualization of femoral head displacement from the acetabulum while placing weight on the affected limb and subsequent replacement into its normal position upon limb resting. Acetabular rim fractures and joint effusion were visible regardless of weight bearing status in six horses each. No fractures were identified in the pony; the only patient with a good outcome. Six horses had a poor outcome with severe chronic lameness, four of which were euthanized. Postmortem ventrodorsal radiographs obtained in two horses confirmed subluxation only on extended limb projections, but not on hip-flexed projections. Acetabular rim fractures were not visible radiographically in either horse but were confirmed at necropsy. Subluxation was due to an elongated but intact ligament of the head of the femur in both horses. Osteoarthrosis was evident ultrasonographically, radiographically, and at necropsy. Dynamic ultrasonography was readily performed in the standing horse and produced diagnostic images with a low frequency curvilinear transducer. The apparent poor prognosis for horses with subluxation and acetabular fracture illustrate the importance of this imaging technique to identify affected horses.

Ultrasound‐guided Injections in Horses With Cranioventral Distension of the Coxofemoral Joint Capsule: Feasibility for a Cranioventral Approach

“…Additionally, no live horse underwent confirmation of intrasynovial placement via contrast radiography as has been reported in normal horses; however, synovial fluid was retrieved in all instances, all injections were ultrasonographically monitored in real‐time and both euthanized horses underwent necropsy and/or radiographic validation of intrasynovial placement. Finally, the cranioventral injection technique was not validated in normal or control horses; however, distention of the cranioventral recess is an infrequent finding in horses without coxofemoral pathology based on our experience with this and a previous study on coxofemoral subluxation where 6/7 horses showed cranioventral distention . Furthermore, descriptions of this recess are not found in the anatomic literature.…”

“…In fact, two horses with cranioventral distention were excluded from analysis in this study because a dorsal approach had been used for injection. Furthermore, one previously reported horse with cranioventral distention due to coxofemoral subluxation from our institution underwent two ultrasound‐guided injections using a dorsal approach . Dorsal injections were performed in these instances despite known cranioventral distention and a lack of visible effusion along the dorsal joint margins.…”

“…Additionally, ultrasound has no personnel exposure risks and is the only modality able to assess effusion and synovitis within the CFJ in the standing horse. Ultrasonographic detection of cranioventral distention within the CFJ was reported in 6/7 horses with coxofemoral subluxation; however, intrasynovial access at this location has not been described …”

Radiographic diagnosis of craniodorsal coxofemoral luxation in standing equids

“…Ultrasonography can be useful to identify injuries of the pelvis and coxofemoral joint in horses (Brenner and Whitcomb ; Geburek et al . ).…”

Osteochondral dysplasia of the coxofemoral joints in a Friesian foal: Clinical findings and methods of diagnosis

“…Once ossification has progressed and the complete acetabulum cannot be assessed accurately, pelvic radiography becomes the primary imaging modality. Ultrasonography can also be a useful technique to diagnose coxofemoral joint disease in horses under practical, field conditions, but it is limited to the detection of irregularities of bony surfaces and soft tissue changes on the outer parts of the coxofemoral joint only (Brenner and Whitcomb 2009;Geburek et al 2009). Recently, a study of ultrasonographic examination of the coxofemoral joints of young foals yielded reliable images of the joint (Rottensteiner et al 2012).…”