Issues
1. More common recently
- more high level sport
2. High risk of reinjuring knee from instability
- can suffer permanent severe chondral and meniscal damage
3. Risk of physeal arrest high if bone block across physis
- risk is growth arrest with ACL reconstruction
Epidemiology
Hemarthrosis
- 60% children have ACL tear
ACL tear
- 20% have mensical injuries
Most occur within 6-12 months of skeletal maturity
Management
Non operative
Issues
1. Non complicance children / young adolescents high
- high risk of chondral and meniscal damage
2. Best to delay surgery if able til close to maturity
- avoid growth arrests
Technique
No sport / ACL brace / ACL rehabilitation
- until 2 years from skeletal maturity
Results
Aichroth et al JBJS Br 2002
- 60 children with ACL deficient knees 1980-1990
- average age 12.5 years
- 23 patients treated conservatively, NHx was severe instability & poor knee function
- 15 knees had meniscal tear, 3 osteochondral fractures, 10 knees developed OA changes
- 37 knees with Hamstring ACL reconstruction average age 13 years
- no physeal arrest and satisfactory results in 80%
Operative
Indications
1. Meniscal tear / displaced / blocking extension
2. Failure non operative treatment
- continued instability
- high risk of chondral damage
3. Within 2 years of maturity
Problems
Growth arrest / angular deformity / LLD
Predicting growth potential
Skeletal age with Greulich-Pyle atlas
Anderson table predict growth remaining using height and growth potential
Options
Extra-articular / over the top
Intra-articular
- physeal sparing
- partial transphyseal
- transphyseal
Extra-articular / Over the Top
Indications
- > 5 years to maturity
- avoid physeal injury
Procedures
McIntosh procedures
- ITB over the top
- combined intra-articular and extra-articular reconstruction
Technique Kocher JBJS Am 2005
Harvest
- lateral incision
- entire ITB taken
- left attached distally, detached proximally
- tubularised with no 5
Arthroscopy performed
- removal of ACL stump
- minimal notchplasty to avoid injury perichondral ring distal femur
Femur
- ITB passed extra-articular around lateral femoral condyle
- over the top position
- passed out anteromedial portal
Tibia
- 4 cm incision over anteromedial tibia
- clamp passed into knee under intermeniscal ligament
- groove for tendon made in epiphysis in this area
- graft passed through
Fixation femur
- knee 90o and foot ER 15o
- sutured to lateral intermuscular septum / extra-articular
Fixation tibia
- 20o flexion
- II used to assess location of growth plates
- groove made in proximal tibia
- graft sutured in place
Post op
- TWB 6/52
- restricted ROM 0 - 90o first 2 weeks
Results
Kocher et al JBJS Am 2005
- 44 patients average age 10
- ITB extra-articular physeal sparing / McIntosh modification
- 2 revisions for graft failure at 5 and 8 years
- no angular or leg length deformity
- excellent IKDC and Lysholm scores
- pivot shift normal in 31 and nearly normal in 11
Intra-articular reconstruction
Indications
- < 5 years to maturity
Assessment of Bone Age
Xray right hand / Greulich-Pyle atlas
- estimate bone age
- estimate amount of growth from femur and tibia
Theory
4 strand hamstring graft
Tunnels < 5% physeal area do not cause growth disturbance
- i.e. 6 - 8 mm drill hole
- need to keep vertical to minimise area
Tunnels 7 - 9% of growth area
- if leave transphyseal tunnels empty or have bone inside
- will form physeal bars
- if place soft tissue across (i.e. graft) will not form physeal bar
Options
1. Physeal sparing
2. Partial transphyseal
3. Transphyseal
A. Physeal sparing / transepiphyseal
Technique
Avoiding tibial physis
- tunnel anterior tibial epiphysis / trans epiphyseal
- graft secured with screw post / staple into tibial metaphysis
Avoiding femoral physis
- femoral tunnel horizontal and remains in femoral epiphysis
- transphyseal
- entrance in ACL origin
- use II guidance to spare the physis
- tunnel at 90o
- secured with endobutton
- 'over the top' position
Results
Anderson et al JBJS Am 2003
- 12 immature patients
- no LLD, stable knees
B. Partial transphyseal
Technique
Tibial tunnel transphyseal
- keep small (6 mm)
- keep vertical
Femoral tunnel as above
- over the top
- physeal sparing
C. Transphyseal
Technique
Analogous to adult reconstruction
Preventing growth arrest
- tunnels < 7% physeal area (7mm tunnels)
- soft tissue interposition across physis
- tunnels are vertical as possible
- central in the physis to avoid angular deformity
- single pass, wash +++
- anchorage away from physis
- endobutton for femur
- short screw / staple / post for tibia
- graft only across physis
Results
Kocher et al JBJS Am 2007
- 61 knees in patient average age 14
- 3% / 2 patients revision for graft failure at 14 and 21 months postoperatively
- pivot shift normal in 51 and nearly normal in 3
- no angular or LLD
- 3 cases of arthrofibrosis requiring MUA