1. ACL Injuries In the Skeletally Immature
Jason W. Folk, MD
Steadman Hawkins Clinic of the Carolinas
February 2012

2. Consultant Smith & Nephew Endoscopy
Disclosures
Consultant Smith & Nephew Endoscopy

3. Objectives
Describe the epidemiology, pathophysiology, and treatment principles of ACL injuries in skeletally immature patients

4. ACL Injuries: Introduction
Epidemiology:
Intrasubstance tears once considered rare in pediatric population
Tibial eminence fx considered pediatric ACL equivalent
Typically under 12yo
Increasing numbers over past decade
Increased attention
ACL Injuries in children were previously considered a rare event. However, the number has been increasing over the past few decades. This is mostly because kids are more active in sports and are adhering to more vigorous training regiments and schedules.

5. ACL Injuries: Introduction
Reasons for increased incidence:
Increased participation in sports
Higher competitive levels early on
Increased awareness of injury
Decreased conditioning

6. ACL Injuries: Introduction
ACL Injuries in Soccer Players 5-18 (Shea, et al. JPO 2004.)
Based on insurance data from 6 million player-years
6.7% of total injury claims
30.8% of all knee injury claims
True incidence unknown

7. ACL Injuries: Introduction
Differences in pediatric population
Often lack fully developed complex motor skills
May have temporary decline in motor and balance during puberty
Open physes
Higher strength of ligaments vs. bone- ligament interface

8. ACL Injuries: Diagnosis
History:
Patient describes a characteristic “Pop”
Effusion forms quickly after injury
47% of patient’s aged with traumatic effusion had ACL disruption
65% in year old group. (Stanitski et al. 1993)
Approximately 60% partial tears

9. ACL Injuries: Diagnosis
Physical Exam
Often more difficult in kids than adults
Acute pain
Frightened
Unable to relax
Examine uninjured leg for baseline laxity or congenital absence of ACL

10. ACL Injuries: Imaging Plain Radiographs (4 views)
For anyone suspected of having an ACL injury
Bony avulsions
Osteochondral fractures
Physeal fractures
Patellar dislocation/subluxation
Degree of physeal closure
CT scan also used for evaluation of physeal closure.

11. Tibial Eminence Fracture
In skeletally immature, chondroepiphysis is weaker than the ligament.
Mechanism of injury typically hyperflexion
Most commonly 8-12yo
Present w/ pain and limited ROM
Dx on x-ray and CT

12. Tibial Eminence Fracture
Type I: LLC x 3-6 weeks in 20degrees flexion
Type II/III: Attempted closed reduction, +aspiration of hemarthrosis (may help reduction), LLC in extension x 4-6 weeks
Irreducible Type II/III or IV: arthrocopic vs open ORIF with suture, retrograde wire, or screw fixation
Some argue all Types II-IV should be fixed anatomically with countersinking of fragment because of residual laxity
Results of fixation usually excellent

13. ACL Injuries: Imaging MRI
Should not be used as replacement for physical exam and routine radiographs
Look for ACL tear, meniscal injury, chondral injury
Indications
Failing to improve ROM
Persistent effusion
Physical exam difficult to interpret.
Help define anatomy of physis

14. ACL Injuries: Etiology
Can occur with fractures
Distal femoral physeal fractures (25-45%)
Salter-Harris III fxs at increased risk because frequently exits intra-articularly at notch
Proximal tibial physeal fractures

15. The Physis
Concern about iatrogenic injury to physis is what drives the debate about treatment strategies

16. The Physis Distal femoral and prox tibial physis
Contribute more to limb length than hip and ankle
DF 1.2 cm/yr
PT 0.9 cm/yr
Overall 65% of length contributed to knee
Closure typically occurs
M=16
F=14

17. Anatomy of Physis MRI closure of Physis 0% at 11 years 5% at 12 years
Central tibial physis closes prior to peripheral physis
?More central tunnel
?Smaller tunnel
Sasaki et al., J Knee Surg 2002

18. ACL Injuries: Treatment
Concern for possible growth abnormality fuels debate on treatment
Non-operative
Operative
Direct Repair
Extra-articular
Intra-articular
Intra/Extra articular reconstructions
Physeal sparing
Partial Transphyseal
Complete transphyseal
Trans epiphyseal

19. ACL Injuries Nonoperative Management
Avoids risk of physeal damage
Sometimes used as a temporizing measure until skeletal maturity
Very difficult to reasonably limit young patient’s activities

20. ACL Injuries: Nonoperative management
So what if we don’t treat these injuries?
Angel et al. Arthroscopy 1989
27 children with arthroscopically documented ACL tears
22 patients at 51mo f/u
None able to return to sports at preinjury level

21. Non-op ACL Open Physis 40 pts under 14 y/o open physis 16 conservative
6 scope for meniscal tears
Only 7 return to sports
All recur giving way, swelling, pain
McCarroll et al., AJSM 1988

22. Non-op ACL Open Physis 18 pts ACL injury open physis
Only one returned to preinjury level of sports
Initial scope 13 meniscal tears
Later secondary meniscal tears in 9
Degen changes 11 of 18 pts by Xray
Mizuta et al., JBJS Br 1995

23. Non-op ACL Open Physis 60 children with ACL tear 23 nonop
Nat Hx continued instability, further meniscal and chondral damage
25 % secondary meniscal tears
Few able to participate in sports
Aichroth et al., JBJS BR, 2002

24. Non-op ACL Open Physis ? Effect of delay in treatment
39 pt < 14 y/o
Sig increase in MMT with delay in treatment > 6 weeks
36% chronic vs 11% in acute Rx
No diff in rate of LMT
Millett et al., Arthroscopy 2002

25. ACL Injuries Nonoperative Management
Graf et al:
12 skeletally immature patients with ACL tears
8 patients underwent non-op and no restriction management.
7 of the 8 had new meniscal tear at follow up

26. ACL Injury: Long Term Results
Kannus et al. JBJS-B. 1988
8 year F/U – 4/7 Pediatric Patients that had Untreated ACL Tears showed Advancing OA radiographically

27. Nonoperative Rx in Children
Non-op treatment has not resulted in good outcomes

28. ACL Injuries: Physeal Concerns
Fear disruption of open physes
Risk of epiphysiodesis, LLD, angular deformity
Caused by crossing physis with bone plug and/or fixation devices

29. ACL Injuries: Physeal Concerns
History
Campbell et al. (1959)
Large holes drilled through the physis have maximal retardation of growth plate
Insertion of cortical bone across physis causes arrest
Makel et al (1988)
Destruction of >7% of physis causes growth arrest
Destruction of 3% or less…no arrest
Stadelmeir et al (1995)
Soft tissue graft placed in drill hole did not cause physeal bar.

30. Factors Influencing Physeal Arrest
Diameter of drill hole
Soft tissue graft within tunnel
Tension of graft across physis
Tunnel location? (Central and vertical)

31. ACL Injuries: Operative Managment
Direct Repair:
A historic treatment modality
Inflammatory changes and degeneration begins within 48 hours after injury
Metalloproteases and cytokine inflammatory factors affect healing potential of direct repair
Poor results
Delee and Curtis, CORR 1983
Engebretsen, et al. Acta Orthop Scand 1988

32. ACL Injuries: Operative Management
Extra-Articular repair
Temporizing method
Non-anatomic reconstruction
Poor results
Dahlstedt , et al. Acta Orthop Scand 1988
McCarroll et al. AJSM 1998
Graf, et al. Arthrsocopy 1992

33. ACL Injuries: Assessment of maturity
Tanner et al. :
Adolescent growth spurt begins at years in boys and 10.5 years in girls.
Peak Growth velocity 1 year later
Menarche is good indication of maturity in girls
In athletic girls, menarche may be delayed.
Axillary and pubic hair appear in boys after growth spurt
Bone age: Most accurate method to determine skeletal maturity

34. General Guidelines Think about physis if: Male Female
Tanner stage 1 or 2
Not shaving
Not reached growth spurt
14 y/o or less
Female
Premenarchal
12 y/o or less

35. ACL Reconstruction Techniques

36. ACL Injury: Physeal Sparing Reconstruction
Intra-articular, non-anatomic, extra-physeal
Stanitski. JAAOS 1985

37. ACL Injury: Kocher Technique
Physeal-Sparring Combined Intra- and Extra-articular Reconstruction

38. ACL Injury: Partial Transphyseal
Hybrid of physeal sparing and adult-type reconstruction
Femoral physis left intact
Graft: Hamstring or patella
Passed through 6-8mm tunnel
<5% physeal X-sectional area
Fixed in over the top position

39. ACL Injury: Transepiphyseal

40. ACL Injury: Transphyseal

41. Thank You