1. Common Paediatric & Adolescent
Knee Problems
Dr. Lyall J. Ashberg, MD
Specialising in Paediatric and Adolescent Orthopaedics
Offices at Netcare Blaauwberg & Sea Point Medical Centre
Cape Town, South Africa
Ph: 021 554 2055 Fax: 021 554 2065
Email: Ashbergortho@gmail.com
2. Growth and Development
✤ Why do young children who fall so frequently not get injured more
often?
✤ Young tissues are more pliable and energy absorbing
✤ Stage of growth and development is essential when evaluating
paediatric knee problems
✤ Physis (growth plate) is weakest part of child skeleton
✤ Most of growth of lower limb occurs at knee (2/3)
3. General Principles
✤ Kids are not little adults
✤ Adolescent knee problems are similar to adults unless they are still growing-
Preadolescent
✤ There is a spectrum of pathology significantly dependent on stage of
development
✤ One needs to distinguish what is physiologic vs pathologic
✤ Males and females have different biomechanics which leads to different injury
profiles (ACL epidemic in females)
✤ Preseason training/Strength and conditioning programmes are safe and effective
in preventing injuries and improving performance in kids
5. Epidemiology
✤ M>F
✤ Adolescent females are approaching males
✤ In the US, there has been a 4 fold increase in female ACL (1:8) injuries
✤ Q angle, ligament laxity, genu valgum, ext tib torsion, fem
Anteversion , inter condylar notch shape, ACL size,
biomechanics, hormonal influences.
✤ Highest incidence in adolescence 2 to sport
7. Overuse Problems: Apophsitis
✤ Apophysis: specialized growth centre/cartilage attached to a tendon
or muscle
✤ Much weaker than attached tendon.
✤ Thus the terms tendinitis often doesn't apply
✤ Examples: tibial tuberosity, olecranon apophysis, Calcaneal
apophysis
8. Overuse Problems: Apophsitis
Traction apophysitis is very common around the knee
Osgood Schlatter's: tibial tuberosity
Sindig-Larsen-Johannsen: Inferior pole patella
Occurs around age 10-15, earlier in girls
✤
Often very active in sports
✤
✤ More common in boys
+/- growth spurt
✤
Relative extensor mechanism inflexibility
✤
Associated with jumping squatting, cutting sports
✤
10. Overuse Problems: Apophsitis
✤ Usually self-limiting
✤ Resolves after skeletal maturity
✤ Improved with Extensor Mechanism stretches/physio
✤ Modification of activities
✤ Anti-inflammatories
✤ Rarely surgery is necessary to remove ossicles after skeletal
maturity
✤ Pain with kneeling
17. Acute Patella
Instability/Dislocation
Often results from direct blow or valgus load
✤
Results from disruption of MPFL
✤
✤ Primary stabilizer of the patella
✤ Most often avulses off femur
✤In otherwise normal knee, frequently
associated with chondral injury
18. Acute Patella
Instability/Dislocation
✤ Pt usually describes hearing or feeling a "pop"
✤ Immediate, large haemarthrosis
✤ Knee collapsing and unable to bear weight
✤ Tender over course of MPFL & LFC
✤ Often have "Apprehension" with lateral glide test
19.
20. Patella Dislocation-Treatment
✤ First Time Dislocator
✤ Acute Care
✤ +/- evacuate haematoma for comfort
✤ Knee immobilizer
✤ Xrays/MRI looking for intrarticular loose body
✤ Family given option of non-operative tx
✤ Up to 30% fail conservative tx.
21. Patella Dislocation-Treatment
✤ Conservative Treatment
✤ Immobilization until quad inhibition resolves (2-4 wks)
✤ Physio for Quad (?VMO) strengthening/proprioception
✤ Return to sports no sooner than 3 months or until they
have protective quad/hamstring strength.
22.
23. Operative Treatment
✤ Very complex decision making
✤ Need to consider
✤ Limb alignment and rotation
✤ Valgus limbs/Excessive femoral anteversion
✤ Q angle
✤ Trochlear depth
✤ Ligamentous integrity
✤ Both generally and MPFL
25. Operative Treatment
✤ Mainstay is MPFL repair or reconstruction
✤ Many different techniques
✤ Roux-Goldwaith procedure in skeletally immature or medialization
of tibial tubercle in skeletally mature
✤ Insall proximal realignment
✤ Trochlear deepening procedure
✤ Femoral/Tibial derotation
26.
27. Meniscus Problems
✤ Other than articular cartilage, the meniscus is probably the most
important structure in the knee
✤ C-Shaped, biconcave wedge shaped structures made of fibrocartilage in
lateral and medial joint compartments
✤ Functions:
✤ Load sharing and shock absorption
✤ Protects articular cartilage
✤ Complete meniscectomy results in up to 350% increase in contact pressures!
✤ Secondary Stabiliser
✤ Proprioception
✤ Synergistic role in joint lubrication
28. Meniscus Problems
✤ Vascularity and Healing
✤ In the neonate, meniscus is extensively vascularised
✤ Persists until age 2 at which point begins to recede
✤ Only 10-30% of meniscus has blood supply
✤ Red-red
✤ Red-white
✤ White-white
29. Epidemiology
✤ Traumatic injuries in children younger than 10 are rare
✤ Congenital malformations (Discoid Meniscus) may predispose to
injury
✤ As children approach adolescence, potential for injury increases
✤ Increase in organised sports has increased the number of serious
intrarticular knee injuries
30. Meniscus Problems
✤ History
✤ Often sustain either twisting injury or varus/valgus load on fixed limb
✤ +/- "pop"
✤ Swelling/effusion (51%)
✤ Chronic tears may present with intermittent, activity related swelling
✤ Clicking/Popping/locking (bucket handle tear)
✤ Stiffness and pain
31. Meniscus Problems
✤ Physical
✤ Effusion
✤ Decreased ROM
✤ JOINT LINE TENDERNESS
✤ VALGUS/VARUS ROTATION and STRESS TEST
✤ SQUAT TEST
✤ McMurray's/Apley's: only around 58% reliable
33. Meniscus Problems
✤ Treatment
✤ Indicated in acute tears and chronic tears with
mechanical symptoms
✤ In child or adolescent, make every effort to retain child's
own parts
✤ Partial excision
✤ (Total Excision)
✤ In ACL deficient/unstable knee, MUST address ACL at
same time or repair will fail
34.
35. Meniscus Problems
Rehab
Post Menisectomy
✤
✤ WBAT
✤ ROM
✤ Quad-Hamstring rehab
Post Repair
✤
✤ Non-weightbearing at least 6 weeks
✤ ROM
✤ Quad-Hamstring rehab
✤ No competitive sports at least 3-6 months
36. Discoid Meniscus
✤ Congenital variant present at birth
✤ Three types
✤ Most often assymtomatic
✤ In the young child may present as dramatic snapping, either
audible or palpable
✤ May result in abnormal biomechanics of knee
37. Discoid Meniscus
✤ Treatment
✤ Assymptomatic children do not require treatment
✤ Will occasionally tear in older child or adolescent
✤ Symptoms of swelling and lateral joint line pain
✤ Saucerization of meniscus and repair/stabilisation
✤ Occasionally associated with OCD of LFC
✤ Addressed as per OCDs
39. Osteochondritis Dissecans
✤ "Bone-cartilage separation/dissection"
✤ Occurs in Juvenile (5-15) and adult forms (16-50)
✤ More common in males
✤ After skeletal maturity prognosis is much worse
✤ Most often affects lateral aspect of medial femoral condyle
✤ Felt to result from repetitive microtrauma although other
factors probably contribute
✤ Separation of osteochondral fragment highly likely to result
in DJD
40. OCD
✤ Presentation
✤ Depends on lesion stability
✤ Stable lesions
✤ Aching activity related pain
✤ No effusion
✤ Point tenderness over lesion
✤ Unstable Lesions
✤ More likely to have mechanical symptoms
✤ Effusion
✤ More painful
41. OCD
✤ Treatment
✤ Depends on age of patient and lesion characteristics
✤ Nonoperative
✤ Usually involves initial period of immobilisation
✤ Rehab
✤ Gradual return to sports under close observation
✤ Repeat MRI
42. OCD
✤ Factors associated with failure of non-op treatment
✤ Larger sized lesion
✤ Greater Skeletal maturity
✤ High signal behind lesion on MRI
45. ACL Injuries
✤ Embryologic development is intimately related to that of
menisci
✤ Congenital absence can occur but usually associated with other
lower limb anomalies
✤ It is an intrarticular-extrasynovial structure
✤ This has implications for healing
✤ The relationships of its insertion site on the femur and tibia
remain constant throughout growth
✤ Origin on the femur is all epiphyseal and very close to the
distal femoral growth plate
46. ACL Injuries
✤ Biomechanics
✤ Primary restraint to anterior translation of the tibia and
femur
✤ Primary stabiliser during jump, cut and twist sports
✤ Comprised of anteromedial and posterolateral bundles
✤ In the growing knee it is the “middle component” of a
complex viscoelastic chain
47.
48. ACL Injuries
✤ Biomechanics
✤ Failure mode depends on a myriad of loading and host characteristics
✤ Age of the child
✤ Sex
✤ Hormonal influences
✤ Structural factors
49. ACL Injuries
✤ Epidemiology and Risk factors
✤ Increasing frequency secondary to participation in organised sports
✤ Major risk factors include
✤ High knee-demand sports
✤ Female gender
✤ Immature neuromuscular development
✤ Concurrent meniscal injury is common
✤ ACL injury is a common cause of haemarthrosis
50. ACL Injuries
✤ Injury Patterns
✤ Midsubstance tears more common after age 12
✤ Bony avulsion most common at tibial spine and in kids <12
✤ Partial tears are more common in pre-adolescent
✤ Partial tears which are associated with instability are
“functionally complete” and should be addressed as such
51. ACL Injuries
✤ Natural History
✤ Developmental and behavioral issues may predispose children with
ACL-deficient knee to become “non-copers”
✤ Non operative treatment is associated with
✤ Recurrent instability
✤ Cumulative meniscal and cartilage damage
✤ Sports related disability
52. ACL Injury
✤ History usually reveals a non-contact, rapid deceleration mechanism
often with a valgus load and rotation of the tibia on femur
✤ Often feel a “pop” and rapid knee swelling and pain
✤ Children’s symptoms tend to resolve quickly and often return to
activities
✤ Need to distinguish between patellofemoral and ACL type instability
✤ Lachman maneuver is easiest and most sensitive exam
✤ Routine xrays for bony avulsions
✤ MRI to document concurrent injuries to menisci and cartilage
53. QuickTime™ and a
decompressor
are needed to see this picture.
ACL rupture in female basketball player
54. Lachman Anterior Drawer
QuickTime™ and a
decompressor
are needed to see this picture.
Pivot Shift Test
55. ACL Injury
✤ Treatment Considerations
✤ Distal femoral and proximal tibial growth plates are
responsible for majority of lower extremity growth
✤ Although rare, angular deformities have been described
following reconstruction
✤ Mostly secondary to inappropriately placed fixation or
bone placed across the physis
✤ Is is better to cause a growth disturbance or allow for
arthritis?
56. ACL Injury
✤ Treatment Considerations
✤ When approaching treatment in a child I consider
✤ Tanner stage/sexual maturity
✤ Bone age
✤ Activity level and type of sport
✤ Symptomatology during ADLs
✤ Family desires
57. ACL Injury
✤ Treatment Considerations
✤ Nonoperative:
✤ Decrease pain and swelling
✤ Regain quad function and normal gait
✤ Comprehensive lower extremity strengthening and proprioception
✤ Knee brace
✤ Avoidance of cutting sports
✤ Recurrent instability is not an option!
58. ACL Injury
✤ Treatment Options
✤ Direct Repair
✤ Not typically an option as this has a very high failure rate
✤ Extrarticular procedures
✤ Avoids physis
✤ Fixation is outside the knee
59.
60. ACL Injury
✤ Physeal Sparing procedures
✤ Fixation either in epiphysis or across one physis
✤ Transphyseal all soft tissue with extraphyseal fixation
✤ Adult type reconstruction
✤ Bone-patella tendon-Bone
✤ Hamstrings
✤ Allograft
✤ Quad Tendon
61.
62. Other Ligaments
✤ “Children are not small adults”
✤ Again, in pre-adolescent child need to consider the growth
plate as the “weakest link”
✤ Ligaments are more likely to fail at lower rate of load
✤ Physis fails at higher rate of load
✤ Beware the PCL/PLC injury in ACL deficient knee
✤ Posterolateral rotatory instability
✤ Children’s knees in these injuries tend to be more “forgiving
and usually amenable to non-operative management
63. Fractures
✤ Becoming more common and more severe in children
✤ Greater level of sports participation
✤ High energy sports
✤ motorized sports
✤ High level contact sports
✤ MVAs and unbuckled children in SA!!
64. Fractures
✤ Fracture related growth problems are seen most frequently after
injuries about the knee
✤ Can have life and limb threatening consequences
✤ Need to have a high index of suspicion in growing child
✤ Not a sprain/strain unless proven otherwise
✤ Should almost always get at least an xray in knee injured child
✤ Have a low threshold for advanced imaging
✤ Don’t normally recommend “stress views”
66. Fractures
✤ Distal Femoral and Proximal Tibial Physeal fractures
✤ Most common fractures mistaken for ligament injury
✤ Need a high index of suspicion
✤ Treat as such until proven otherwise
✤ Can be most devastating to growth and life/limb
✤ Non-displaced fractures can usually be treated in a cast
✤ Displaced or intrarticular fractures frequently require
surgery
67.
68.
69. Fractures
Tibial Eminence fractures
✤ ACL equivalent in pre-adolescent child
✤ Most common in children 8-14 years old
✤ 3 types-Meyers and Mckeever
✤ Type I-II usually amenable to cast immobilisation
✤ Type III always operative
✤ Not uncommon to have residual, post fixation laxity on objective testing
✤ Indicates ACL “stretch”
✤ Usually not clinically significant
70.
71. Fractures
✤ Tibial Tubercle and Patella Sleeve Fractures
✤ Mostly sports related
✤ Typically occur between 12-17 y/o
✤ Usually secondary to violent contraction of quad
✤ eg. Landing a jump
✤ At tubercle, fracture occurs at junction of ossified and cartilage growth plate
✤ Sleeve fractures occur because of cartilagenous attachment at inferior pole of
the patella
✤ Difficult to diagnose, but can result in complete disruption of extensor
mechanism.
72.
73. Infections
✤ Relatively common in younger children
✤ Can occur from direct injury, haematogenous spread or concurrent
osteomyelitis
✤ Growth plates are intrarticular
✤ Distinguished from
✤ Toxic Synovitis - self limiting
✤ Septic Prepatellar Bursitis - Extrarticular infection
✤ JIA
74. Infection
✤ Septic Arthritis
✤ Often ill looking child
✤ Will not bear weight
✤ Definitely won’t let you move their knee
✤ + Effusion
✤ Warm and sometimes red
✤ Intrarticular bacterial infection is a surgical emergency!
75. Take Home Points
✤ Children are not little adults
✤ Need to consider the growth plate and child’s stage of development
✤ “The weakest link”
✤ Effusions tend to mean unhappiness is brewing
✤ Beware the occult fracture
✤ Don’t forget about the hip and referred pain
77. References
1. Micheli, Lyle J. and Kocher, M S: The pediatric and Adolescent Knee. Saunders Elsevier, 2006.
2. Davids JR: Pediatric knee: cliinical assessment and common disorders. Pediatric Clinics North Am 43: 1067-1090, 1996.
3. Arnoczky SP, Warren RF: Microvasculature of the human meniscus. Am J Sports Med 10:90-95,1982.
4. DeLee JC: Ligamentous injury of the knee. In: Drez D (ed): Pediatric and Adolescent Sports Medicine. Philadelphia: WB Saunders
Company, 1994, pp 406-407.
5. American Academy of Pediatrics: Strength and Resistance training by children and adolescents. Pediatrics 107:1470-1472, 2001.
6. Guy J, Micheli L: Strength training for Children and Adolescents. J Am Acad of Orthopaedic Surgery 9:29-35,2001.
7. Barber-Westin SD, Noyes FR, Andrews M: A rigorous comparison between the sexes or results and complications after anterior
cruciate ligament reconstruction. Am J Sport Med 25: 514-526, 1997.
8. Dimeglio A: Growth in pediatric orthopedics. J Pediatr Orthop 21 (4): 549-555, 2001.