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JUVENILE PUBIC SYMPHYSIODESISDaniel R James, BVSc MANZCVS (Radiology/ Surgery)
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JPS- The premise
• Identification of HD in juveniles– Distraction radiography – Clinical examination/ palpation (ortolani)
• Pre-emptive/ prophylactic procedure – Non/ pre-clinical dogs
• Minimally invasive/ low morbidity
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JPS Rationale
• Derived from the work of Mathews on altering pelvic conformation through early intervention in a guinea pig model
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Rationale
Normalpelvic growth is concentric
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Rationale
JPS surgery arrestsPubic growth
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Rationale
Continued dorsal growth
Bilateral ventro-lateral rotation of acetabula
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Improved hip coverage-> Dynamic Stability
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SurgeryPhyseal closure via thermal destruction
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Surgical Technique
• Midline Approach to pubis• Cauterization of symphysis with monopolar cautery
– 40W– 10-30 seconds at each point– Repeated every 2-3mm– Cranial 1/3->1/2 of symphysis
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Surgical Technique
• Pelvic structures, particularly urethra, must be protected from excessive heat– Trans-rectal retraction
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Surgical Technique
• Pelvic structures, particularly urethra, must be protected from excessive heat– Trans-rectal retraction – Malleable retractor or tongue depressor through pre-pubic incision
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Surgical Technique
• Pelvic structures, particularly urethra, must be protected from excessive heat– Trans-rectal retraction – Retractor/ tongue depressor – Surgeon’s digit through pre-pubic incision
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Radiographic changes after JPS
• XXXXX
JPS Group
Radiographic changes of the pelvis in Labrador and Golden Retrievers after juvenile pubic symphysiodesis Objective and subjective evaluation S. Boiocchi et al Vet Comp Orthop Traumatol 2013
Control group(good hip conformation)
Comparison of radiographic evaluation: +Partial or complete closure of the cranial part of the pubic symphysis- 2
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Radiographic changes after JPS
• XXXXX
JPS Group
Radiographic changes of the pelvis in Labrador and Golden Retrievers after juvenile pubic symphysiodesis Objective and subjective evaluation S. Boiocchi et al Vet Comp Orthop Traumatol 2013
Control group(good hip conformation)
Comparison of radiographic evaluation: +Shortening and broadening of the pubic ramus- 4
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Radiographic changes after JPS
• XXXXX
JPS Group
Radiographic changes of the pelvis in Labrador and Golden Retrievers after juvenile pubic symphysiodesis Objective and subjective evaluation S. Boiocchi et al Vet Comp Orthop Traumatol 2013
Control group(good hip conformation)
Comparison of radiographic evaluation: +Widening of the obturator foramen- 5
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CT changes- Acetabular Angle
• XXXXX
R. T. Dueland et al.: Pt. I – Canine hip dysplasia treated by juvenile pubic symphysiodesisVCOT 2010
15 weeks 2 years
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CT changes- Acetabular Angle
• XXXXX
R. T. Dueland et al.: Pt. I – Canine hip dysplasia treated by juvenile pubic symphysiodesisVCOT 2010
15 weeks 2 years
JPSControl
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Ortolani
• 77% of ortolani + hips treated by JPS became ortolani – by 2 yrs• 8% of ortolani + hips not treated by JPS became ortolani – by 2 yrs
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Osteoarthritis- Percentage change
26% JPS dogs had decrease in OA score
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Osteoarthritis grade- severe laxity (>0.7)
Osteoarthritis score increased by 57% and 83% at one and 2 yearsMost dogs with DI>0.7 had OA by 2 years
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DI and osteoarthritisPr
obab
ility
of D
JD b
y 24
mon
ths
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Birth 12 weeks 17 weeks 24 weeks 52 weeks0
10
20
30
40
50
60
70
80
90
100
When to perform JPS
• Pelvic growth capacity
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When to perform JPS
8-12% loss of AA improvement for each week of delay between 12 and 24 weeks
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Window of opportunity
Birth 12 weeks 17 weeks 24 weeks 52 weeks0
10
20
30
40
50
60
70
80
90
100
Distraction radiography not considered accurate < 16 weeks
JPS efficacy dropping rapidly >20 weeks
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In summary
• JPS is minimally invasive
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In summary
• JPS is minimally invasive
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In summary
• JPS is minimally invasive
• Changes pelvic conformation
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In summary
• JPS is minimally invasive
• Changes pelvic conformation– Large body of literature documenting the capacity of JPS to
alter pelvic growth and acetabular orientation
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In summary
• JPS is minimally invasive
• Changes pelvic conformation
• Decreases development of DJD
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In summary
• JPS is minimally invasive
• Does change pelvic conformation
• Can decrease development of DJD in a SELECT group of dysplastic patients– Age 16 (12?) to 20 weeks– DI 0.4 – 0.7
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