Aim
Prevent head deformity & secondary OA
- interfere as little as possible with child's development
Goals
1. Restore & maintain ROM
- allow abduction which covers anterolateral extruded head
- important range is abduction in extension
- aim 30o abduction or 75% of contralateral side
- can consider adductor tenotomy
2. Head containment i.e >80 % coverage of the femoral head
3. Relief of symptoms
Options
1. Observe
- normal ROM
2. Symptomatic treatment
- physio for decreased abduction
3. Definitive early treatment
- Herring B & B/C > 8 years old
- femoral varising osteotomy / containment
4. Late surgical treatment of deformity / degeneration
- Shelf osteotomy
- Valgus osteotomy
- GT osteotomy
Containment
Concept ~ Petrie
- location of capital femoral epiphysis within acetabulum
Mechanism
- molding action
- subjects head to molding action of acetabulum
- leads to more spherical head / more congruous joint
- if the head remains in the acetabulum it usually remains spherical
- subluxed head associated with deformity
Herring et al JBJS Am 2004
Methods
- 337 patients with 345 affected hips in a prospective multicenter study
- all patients were between 6.0 and 12.0 years of age at the onset of the disease
- none had had prior treatment
- followed up until skeletal maturity
- no treatment / brace treatment / range-of-motion exercises / femoral osteotomy / innominate osteotomy
Results
- no differences in outcome in hips with no treatment / bracing / range-of-motion therapy
- no differences between the hips treated with a femoral varus osteotomy / innominate osteotomy
- no effect on children with a chronologic age of 8.0 years or less / skeletal age of 6.0 years or less at the onset of the disease
- > 8 at time of disease onset with lateral pillar B group and B/C border group did better with operative
- 8.0 years old or less at the onset of the disease in lateral pillar group B did equally well with nonoperative and operative treatment
- hips in lateral pillar group C had the least favorable outcomes with no differences between the operative and nonoperative groups
- female patients > 8 at onset did significantly worse than male patients
Summary
Age onset < 8 (chronological ; skeletal age 6) - no treatment
Ages onset > 8 and B or BC - containment surgery
Class C - salvage / Shelf
Varsing osteotomy as good as Salter
Non-operative Containment
Bracing
Concept
- placing hip in abduction whilst allowing hip motion & ambulation
- worn until reossification phase of lateral epiphysis
- usually 6-18 / 12
- no evidence for effect
Petrie Abduction Casts
- two long leg casts with abduction bar
- 30o abduction & 5o IR
Scottish Rite Brace
- two thigh cuffs with abduction bar
Physio
Concept
- if can maintain good abduction, then no need for varising ostetomy
- see child every 6 weeks to 3 months
- ensure no adduction contracture
- hydrotherapy
Operative Containment
Advantage
Permanent containment enhances remodeling
Disadvantage
Risks of surgery
Options
Femoral varising osteotomy
Acetabular osteotomy
Indications
> 8 at onset and B or B/C
No hinge abduction
Hinge abduction
Concept
- abducted hip does not obtain full coverage of cartilage / full containment
- hinging on abucted portion of femoral head
- a varising osteotomy with increase point loading and worsen symtoms
Diagnosis
1. MRI with hip in abduction
2. MUA pre varising osteotomy
- hinging / rose thorn appearance
- medial pooling
- i.e. whole cartilaginous head not entering acetabulum
Treatment
1. Trial adductor tenotomy / physio +++
- if hinge abduction resolves can proceed to operative intervention
2. Valgus osteotomy
- salvage
Lloyd-Roberts Varising Femoral Osteotomy
Concept
- seat head deep in acetabulum
- remove vulnerable anterolateral portion from acetabular edge
- decrease JRF on head
Aim
- sufficient varus to permit entire ossified epiphysis to be covered by ossified acetabulum
- derotation can be added to reduce anteversion and increases cover
Indications
- Herring grade B or B/C
- > 8 years at age on onset
- must be able to obtain full containment of cartilaginous head
Technique
Patient supine on radiolucent table
- preop antibiotics
- frog leg laterals when needed
Lateral approach
- elevate vastus lateralis
- incise and reflect periosteum, then protect with homanns before osteotomy
- "be good to the periosteum and it will be good to you"
- drill holes in femur proximal and distal to osteotomy site in line with each other
- allows guide to rotation after osteotomy
- place cannulated wires into femoral head now
- leave short of physis, check AP and lateral
- subtrochanteric osteotomy with saw / osteotome
- ER distal fragment (no more than 15o)
- apply Synthes proximal locking plate
- has offset otherwise have to step cut femur
- multiple angles available
- aim for 115o of varus
- avoid excessive varus < 100o to keep GT distal to femoral neck
Advantage
- operates on affected side of joint
- less demanding than acetabular surgery
- results equivocal
Disadvantage
- LLD increased
- coxa vara
- trendelenberg gait / may require GT fusion or advancement in future
- have to remove metal in future with risk refracture
- potential difficulty of THR in future / insertion of femoral stem
Salter Innominate Osteotomy
Concept
- redirects acetabulum to provide coverage for anterolateral head
Pre-requisites
- full or almost full ROM
- reasonable congruence on abduction / X-ray in full abduction confirms containment
- fragmentation stage
Advantages
- avoids shortening, coxa vara
- nil trendelenberg
Disadvantage
- more difficult
- lengthens leg
- operate on normal side of joint
- increase joint pressure
Late Salvage
Indications
- failure of containment techniques
- significant femoral head deformity with hinge abduction
Options
1. Shelf Arthroplasty
- laterally subluxed femoral head in older child
- allows some continued remodeling of the femoral head
2. Cheilectomy femoral head
- wait till physis closed
- extruded rim of bone & cartilage excised
- poor results
3. Valgus Osteotomy
- hinge abduction > 12 years
- redirect normal portion of head to acetabulum
4. GT osteotomy
- distal & lateral transfer of GT
- aim to decrease JRF
- may relieve trendelenberg gait