orthopaedics and trauma

1. Fractures and Dislocations
about the Knee
in Pediatric Patients
Steven Frick, MD

2. Anatomy
• Distal femoral physis- large, undulating-
irregular
• Proximal tibial physis- contiguous with
tibial tubercle apophysis
• Ligament and muscular attachments may
lead to avulsion injuries, fracture angulation

3. Anatomy- Neurologic and
Vascular Structures
• Popliteal artery tethered above and below
knee
• Common peroneal nerve vulnerable at
fibular neck/head

4. Growth about the Knee
• 70% of lower extremity length
• Distal femur- average 10mm/year
• Proximal tibia- average 6mm/year
• Tibial tubercle apophysis- premature growth arrest
can lead to recurvatum
• Proximal fibular physis- important for fibular
growth relative to tibia and ankle alignment

5. Fractures of the Distal Femoral
and the Proximal Tibial Physis
• Account for only a small percentage of the
total number of physeal fractures
• Are responsible for the majority of
complications due to partial physeal arrest
• High incidence of growth arrest based on
anatomy, energy of injuries
• Specific treatment recommendations to
minimize the incidence of growth arrest

6. Peterson, et.al. JOP ‘94
“Olmstead County Study”
• Experience of the Mayo clinic 1979 - 1988
• 951 physeal fractures
• 2.2% involved the physis of the distal femur
or the proximal tibia
• Fractures of the distal femoral and proximal
tibial physis account for 51% of partial
growth plate arrest

7. Anatomy Predisposing
to Growth Arrest
• Peterson ‘94 noted that the distal femoral
and proximal tibial physes are large and
multiplanar (irregular in contour) and
account for 70 and 60% of the growth of
their respective bones

8. Anatomy, continued
• Ogden, JOP ‘82 - “undulations of the
physis, which may include small
mammillary processes extending into the
metaphysis, or larger curves such as the
quadrinodal contour of the distal femoral
physis, may cause propagation of the
fracture into regions of the germinal and
resting zones of the physis”

9. Anatomy, continued
• Ogden JPO, ‘82 - distal femur develops
binodal curves in coronal and sagital planes
with central conical region - susceptible to
damage during varus/valgus injury
• Peripheral growth arrest related to damage
to zone of Ranvier stripping it away from
physis and periosteum

10. Distal Femoral Physeal Fractures
• direct blow
mechanism
• Salter I or II
common
• check neurologic /
vascular status

11. Treatment Recommendations
• Anatomic reduction is key
• Propensity for losing reduction
• Hold reduction with pins and casting

12. Thompson et.al. JPO ‘95
• 30 consecutive fractures of the distal
femoral epiphysis
• No displacement of fx treated with
anatomic reduction and pin fixation
• Three of seven patients treated closed lost
reduction
• proved maintenance of reduction, but not
prevention of growth disturbances

13. Graham & Gross, CORR ‘90
• Ten patients with distal femoral physeal
fractures retrospectively reviewed
• All treated from ‘77 - ‘87 with closed
reduction and casting or skeletal traction
• Most SHII
• Resulted in seven losing reduction and nine
eventually developing deformities

14. Graham & Gross, cont.
• Angular deformity and LLD related to the
amount of initial deformity and the quality
of reduction
• Recommended rigid internal fixation

15. Riseborough, et.al., JBJS ‘83
• Retrospective study of 66 distal femoral
physeal fracture-separations
• Only 16 seen primarily, others referred at
different stages of treatment/complications
• Noted improved results with anatomic
reduction and internal fixation in types II,III
and IV, and early detection and mgmnt of
growth arrest

16. Lombardo & Harvey, JBJS ‘’77
• 34 distal femoral physeal fx. Followed avg.
four years
• >2cm LLD in 36%
• Varus/valgus deformity in 33%
• Osteotomy, epiphyseodesis or both in 20%
• Development of deformity related to
amount of initial displacement and anatomic
reduction rather than fracture type

17. Be Wary of Fixation Only in
Thurston-Holland Fragment
Loss of reduction at 2 weeks

18. Distal Femoral Physeal Fractures
• closed reduction
and pinning for
displaced fractures
• long leg cast

19. Distal Femoral Physeal Fractures
• high rate of premature growth arrest
rare < 2 yo
80% 2 - 11 yo
50% > 11 yo
• angular deformity
• leg length discrepancy

20. Salter IV Distal Femur Fracture –
Lateral Growth Arrest

21. Salter IV Distal Femur Fracture

22. Distal Femur Physeal Bar

23. Patella Fractures in Children
• Largest sesamoid bone, gives extensor
mechanism improved lever arm
• Uncommon fracture in skeletally immature
patients
• May have bipartite (superolateral) patella-
avoid misdiagnosis

24. Physeal Bars
• male : female - 2 : 1
• distal femur, distal
tibia, proximal tibia,
distal radius

25. Patellar Sleeve Fracture
• 8-12 year old
• Inferior pole sleeve of cartilage may
displace
• May have small ossified portion
• <2mm displaced, intact extensor
mechanism- treat non-operatively

26. Patella Fractures
• much less common
than adults
• avulsion mechanism
• patellar sleeve fracture
• management same as
adults
• Restore articular
surface and knee
extensor mechanism

27. Osteochondral Fractures
• Usually secondary to patellar dislocation
• Off medial patella or lateral femoral
condyle
• Size often under appreciated on plain films
• Arthroscopic excision vs. open repair if
large

28. Acute Hemarthrosis in Children-
without Obvious Fracture
• Anterior Cruciate Tear
• Meniscal tear
• Patellar dislocation +/- osteochondral
fracture

29. Knee Injuries
Acute Hemarthrosis
• ACL 50%
• Meniscal tear 40%
• Fracture 10%

30. Tibial Eminence Fractures
• Usually 8-14 year old children
• Mechanism- hypertension or direct blow to
flexed knee
• Frequently mechanism is fall from bicycle

31. Myers- McKeever Classification
• Type I- nondisplaced
• Type II- hinged with posterior attachment
• Type III- complete, displaced

32. Tibial Eminence Fracture-
Treatment
• Attempt reduction with hypertension
• Above knee cast immobilization
• Operative treatment for block to extension,
displacement, entrapped meniscus
• Arthroscopic-assisted versus open
arthrotomy
• Consider more aggressive treatment in
patients 12 and older

33. Tibial Spine Fracture
• 8 to 14 yo
• often bicycle
accident
• Myer-McKeever
classification

34. Tibial Spine Fracture
Treatment
• Reduction in extension
• Immobilize in extension or slight knee
flexion
• Operative treatment for failed reduction or
extension block

35. Tibial Spine Closed Reduction
Follow closely – get full extension

36. Tibial Spine Malunion-
Loss of Extension
Injury Film – no reduction 2 years post-injury- lacks extension

37. Tibial Spine Fracture
• 50% still have ACL laxity
• loss of extension very debilitating

38. Tibial Spine Fx-
Arthroscopic ORIF

39. Tibial Eminence Fracture-
Results
• Generally good if full knee extension
regained
• Most have residual objective ACL laxity
regardless of treatment technique
• Most do not have symptomatic instability
and can return to sport

40. Tibial Tubercle Fractures
• Primary insertion of patellar tendon into
secondary ossification center of proximal
tibia
• Mechanism- jumping or landing, quadriceps
resisted contraction
• Common just before completion of growth
(around 15 years in males)

41. Tibial Tubercle Fracture
Classification- Ogden
• Type I- fracture through secondary
ossification center
• Type II- fracture at junction of primary &
secondary ossification centers
• Type III- fracture extends into primary
ossification center, intraarticular

42. Tibial Tubercle Fractures-
Treatment
• Nondisplaced, intact extensor mechanism-
above knee immobilization for 6 weeks in
extension
• Displaced, loss of extensor mechanism
integrity- operative fixation

43. Tibial Tubercle Fracture
• 10 - 14 year old
• often during
basketball
• surgery for
displaced fractures,
inability to extend
knee

44. Proximal Tibial Physeal
Fractures
• Usually Salter II fractures.
• Occasionally Salter I or IV
• Posterior displacement of epiphysis or
metaphysis can cause vascular compromise

45. Proximal Tibia Fracture

46. Proximal Tibial Physeal
Fractures- Salter I or II
• Often hyperextension mechanism
• Thus flexion needed to reduce
• If unstable fracture or hyperflexion needed
to maintain reduction, use percutaneous
fixation
• Above knee cast for 6 weeks

47. Proximal Tibia Salter I Fracture

48. Proximal Tibia Physeal Fractures
• Open reduction for irreducible Salter I and
II, displaced Salter IV
• Observe closely for vascular compromise or
compartment syndrome in first 24 hours
• Follow for growth disturbance, angular
deformity

49. Complications
• angular deformity
• malunion
• physeal bar
• leg length
discrepancy

50. Proximal Tibial Metaphyseal
Fractures
• Younger patients, less than 6 years
• Often nondisplaced, nonangulated
• Later progressive valgus deformity can
result from medial tibial overgrowth
(Cozen Phenomenon)

51. Proximal Tibial Metaphyseal
Fractures
• Initial treatment- try to mold into varus to
close any medial fracture gap
• Notify parents initially of possible valgus
deformity development
• Follow 2-4 years

52. Valgus Deformity after Proximal
Tibial Metaphyseal Fracture
• Observe, do not rush to corrective
osteotomy
• Typically remodels, may take years
• Not all will remodel
• Consider staple epiphyseodesis, osteotomy
if severe

53. Genu Valgum following Proximal
Tibia Metaphyseal Fracture

54. Patellar Dislocations
• Almost always lateral
• Younger age at initial dislocation, increased
risk of recurrent dislocation
• Often reduce spontaneously with knee
extension and present with hemarthrosis
• Immobilize in extension for 4 weeks

55. Patellar Dislocation
Note Medial Avulsion off Patella
and Laxity in Medial Retinaculum

56. Patellar Dislocations
• Predisposing factors to recurrence-
ligamentous laxity, increased genu valgum,
torsional malalignment
• Consider surgical treatment for recurrent
dislocation/subluxation if fail extensive
rehabilitation/exercises

57. Knee Dislocations
• Unusual in children
• More common in older teenagers
• Indicator of severe trauma
• Evaluate for possible vascular injury
• Usually require operative treatment –
capsular repair, ligamentous reconstruction
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