Radiographic diagnosis of craniodorsal coxofemoral luxation in standing equids

Osteoarthritis of the coxofemoral joint in 24 horses: Evaluation of radiography, ultrasonography, intra-articular anaesthesia, treatment and outcome

BACKGROUND

Few case reports describe equine coxofemoral joint osteoarthritis (CFJOA).

OBJECTIVES

To evaluate diagnostic findings and outcome of horses with CFJOA and to provide a score facilitating radiographic assessment.

STUDY DESIGN

Retrospective case series.

METHODS

History, clinical signs, ultrasonographic, radiographic and intra-articular anaesthesia findings, treatments, outcome, and necropsy results of horses with CFJOA presented between 2002 and 2023 were collated. Radiographic findings were categorised to develop a radiographic score which was applied by two masked examiners. Intra- and inter-observer reliability was determined using weighted Cohen's kappa (Cκ) and the correlation between radiographic and ultrasound findings via Spearman correlation coefficient.

RESULTS

The study included 24 horses (median age 14 years). Most of them (20/24) were chronically lame. Frequent clinical signs included unilateral gluteal muscle atrophy (18/21), lengthening of the stride of the affected limb (13/19) and locomotion on three tracks (13/20). Both imaging modalities enabled evaluation of periarticular osteophytes (correlation coefficient r = 0.64; p = 0.003). Additionally, radiography allowed detection of irregular joint spaces, subchondral bone opacity changes and femoral head flattening/tapering. Inter-observer (Cκ = 0.846) and intra-observer (Cκ = 0.853 and Cκ = 0.842) agreement was excellent. If treated, mostly intra-articular corticosteroids were administered (16/18). Nine horses were euthanised immediately or during follow-up examination. Post-mortem, the Ligamentum capitis ossis femoris was commonly found ruptured. All surviving horses remained lame.

MAIN LIMITATIONS

Retrospective analysis of clinical records and subjective outcome assessment based on owner follow-up with potential recall bias. Due to overall disease severity, associations between different grades of clinical findings, radiographic abnormalities and outcome could not be evaluated.

CONCLUSIONS

Typical clinical signs may indicate CFJOA. Standardised evaluation of ventrodorsal radiographs allows a comprehensive diagnosis. Postmortem findings suggest joint instability as a possible causative factor that may contribute to the poor prognosis and resistance to medical therapy of the disorder.

Computer-assisted surgery for placing toggle constructs across the coxofemoral joints of small equids using a minimally invasive approach-A proof-of-concept cadaveric study

OBJECTIVE

To develop a minimally invasive technique for placing a toggle construct across the coxofemoral joint of small equids using computer-assisted surgery.

STUDY DESIGN

Experimental cadaveric study.

SAMPLE POPULATION

Three pilot specimens: One donkey, one Shetland pony and one Warmblood foal. Six main study specimens: Three Shetland ponies, one American Miniature Horse, one Warmblood foal and one donkey.

METHODS

Experimental surgeries were performed on both coxofemoral joints of each cadaver. Using a minimally invasive surgical approach, 5.5 mm bone canals were drilled through the femur and acetabulum, traversing the coxofemoral joint. Intraoperative guidance was provided by a cone-beam computed tomography (CBCT)-coupled surgical navigation system. A toggle construct was introduced through the bone canals. Surgical accuracy aberrations (SAA) were measured at the femoral entry and exit points and at the acetabular entry point on merged pre- and postoperative CBCT scans. The coxofemoral joint was assessed for articular cartilage damage by gross dissection.

RESULTS

A toggle construct was placed across all 18 coxofemoral joints. The overall median SAA in the main study was 2.8 mm (range: 0.4-8.0 mm). No cartilage damage was found in the cadaveric specimens of the main study.

CONCLUSION

The described technique allowed for the placement of a toggle construct across the coxofemoral joint of small equid cadaveric specimens without prior coxofemoral luxation.

CLINICAL RELEVANCE

This technique may serve as an option for surgical stabilization of coxofemoral joints in small equids. Further biomechanical investigations are required to assess optimal implant positioning and toggle constructs.

Modified toggle pin technique combined with prosthetic capsular reconstruction for surgical stabilization of coxofemoral luxation in a Shetland pony

OBJECTIVE

To describe open reduction and surgical stabilization of a coxofemoral luxation in a pony using a modified toggle pin technique and prosthetic joint capsule reconstruction without osteotomy of the greater trochanter.

ANIMAL

A 2-year-old Shetland pony with a bodyweight of 167 kg.

STUDY DESIGN

Case report.

METHODS

Radiographic examination confirmed craniodorsal luxation of the left coxofemoral joint. An open reduction with the aid of a pulley system was performed. A toggle pin was inserted through a bone tunnel extending from the level of the femoral shaft through the femoral head and the center of the acetabulum for the pin to be positioned on the medial wall of the acetabulum. FiberWire was subsequently passed through the cranial and caudal aspects of the acetabulum as well as a transverse tunnel in the femoral neck in a figure of 8 to facilitate capsular reconstruction. The pony was placed in a sling for 8 weeks and gradually returned to normal activity over 2 months.

RESULTS

Postoperative radiographic examination confirmed the position of the femoral head in the acetabulum with the implants in place. On 2-year follow-up the pony was sound at walk and trot.

CONCLUSION

A combined intra- and extra-articular stabilization technique for coxofemoral luxation in a pony resulted in successful long-term reduction and excellent outcome.

Successful Treatment of Acute Craniodorsal Coxofemoral Luxation in a Scarlet Ibis (Eudocimus ruber) Using Closed Reduction and a Modified Ehmer Sling

Whereas craniodorsal displacement of the coxofemoral joint is the most common luxation reported in small and large mammals, it occurs less often in avian species. Closed reduction and external coaptation with a modified Ehmer sling is the initial treatment, in most cases, for small animals (eg, dogs, cats) that present with a coxofemoral luxation. However, the Ehmer sling is reported to have a low success rate in treating coxofemoral luxations in these animals. Intractable coxofemoral luxations require an open surgical reduction. A few successful closed reductions of coxofemoral luxations have been reported in avian patients, as well as open reduction surgical techniques to repair avian coxofemoral luxations. The successful treatment of an acute craniodorsal coxofemoral luxation in a scarlet ibis (Eudocimus ruber) with a closed reduction and a modified Ehmer sling is described in this clinical report. The specific characteristics of both the patient and the injury are thought to have contributed to the success in this case.

Successful Treatment of a Coxofemoral Luxation in a Shetland Pony by Closed Reduction and Prolonged Immobilization Using a Full-Body Animal Rescue Sling

A 12-year-old, 170 kg, Shetland pony mare was presented with an acute severe right pelvic limb lameness and concurrent upward fixation of the right patella. The affected limb was rotated externally and adducted with a prominent greater trochanter and the right calcaneal tuber being more proximal than its left counterpart. Radiographic examination revealed complete dislocation of the right femoral head from the acetabular cavity in a dorsal and caudal direction. A closed reduction of the coxofemoral luxation was performed successfully under general anaesthesia. A full-body animal rescue and transportation sling (ARTS) was applied for the recovery. The reduction was followed by a right-sided medial patellar desmotomy. The pony was supported in the ARTS for a total of eight weeks combined with crossties for the first six weeks. Subsequently, the mare was discharged with instructions to slowly increase walking exercise over a period of two months before returning to her intended use. A follow-up after 22 months attested the successful treatment of a coxofemoral luxation by closed reduction and prolonged immobilization resulting in a regularly exercised pony without any residual lameness.

Donkey Internal Medicine—Part II: Cardiovascular, Respiratory, Neurologic, Urinary, Ophthalmic, Dermatology, and Musculoskeletal Disorders

Cardiovascular diseases are scarcely reported in donkeys, probably linked to their limited athletic attitude and low frequency of poor performance-related examinations. Reports on treatments for cardiovascular pathologies are anecdotal in donkeys. Respiratory tract anatomy shows important differences between horses and donkeys. Donkeys and mules can act as reservoirs spreading many viral, bacterial, and parasitic infectious respiratory diseases. Mosquito and tick-borne encephalitis have been reported in these species in the later years, and even donkeys are being used as sentinels in some areas to detect these emerging diseases. Management and treatment of lithiases can be transferable from horses; however, the same assumption must still be demonstrated for acute and chronic renal diseases. Ocular pathologies are similar to horses, with corneal ulcers frequently observed. Lameness is a common problem in donkeys, with laminitis as the most reported cause followed by pedal abscess.

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Donkeys are different to horses.

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Numerous physiological and clinicopathologic idiosyncrasies are reported in horses.

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Data published for horses should not be extrapolated for donkeys.

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Specific reference ranges, doses, and protocols have to be used for donkeys.