- See:
-
Intercondylar Eminence Frx
- Discussion:
- avulsion frx of tibial tuberosity along w/ a Salter Harris type-III frx of
proximal tibial physis;
- need to distinguish tibial tubercle avulsion from
Osgood-Schlatter disease (which has no physeal involvement);
- where as Osgood Schlatter disease involves the anteiror surface of the tubercle, the true tubercle frx
is an avulsion of the apophysis;
- avulsion fractures tend to occur between ages 12-16 years;
-
developmental anatomy:
- cartilaginous stage occurs before a secondary ossification center appears in the tubercle
- in fetus, tibial tuberosity develops from anterior aspect of proxtimal epiphysis;
- apophyseal stage: secondary ossification center appears: in girls (8–12 years of age) and in boys (9–14 years of age);
- epiphyseal stage:
- secondary ossification centers of the proximal tibia and the tubercle merge into a bony tubercle adjacent to proximal tibial epiphysis;
- this ossification center expands proximally
& by age 17, it blends in w/ ossification center of
tibial epiphysis;
- Clinical Presentation:
- swelling, pain, & tenderness directly over tuberosity;
- knee is held in 20-40 deg of flexion because of spasm of hamstrings;
- pts may or may not be able to extend knee against resistance;
- may sense a freely movable triangular fragment of bone;
-
compartment syndrome may occur in some cases;
- Radiographs:
-
lateral view: patella alta (degree depends on displacement of tuberosity)
- Classification (Watson Jones) & Treatment:
- Type I: (most common)
- type 1A: incomplete separation of fragment from metaphysis;
- type 1B: complete separation;
- additional findings:
- frx thru secondary ossification center;
- fragment of the tuberosity is avulsed & is displaced proximally;
- exam:
- pts usually can actively extend knee - but not against resistance;
- treatment:
-
lateral radiograph of knee in full extension allows evaluation of reduction;
- adequacy of reduction can be determined by position of patella compared with that in the unaffected limb;
- when residual displacement is < 5 mm, treat in cyclinder cast w/ knee extended for 6 weeks
- ORIF is indicated if > 5 mm of displacement persists;
- Type II:
- tubercle epiphysis lifted anteriorly & proximally, separating tubercle ossification center as well as
partially separating the non articular portion of the
proximal tibial epiphysis;
- hence, the frx occurs thru a cartilagenous bridge between the proximal
tibial physis and the tubercle apophysis;
- type 2A: complete tubercle frx w/o comminution
- type 2B: complete tubercle frx w/ comminution;
- exam:
- pts usually cannot extend knee against resistance;
- treatment:
- displaced grade II and III frx usually require ORIF;
- need to identify any intra-articular involvement since this always requires anatomic reconstruction;
- treated w/ ORIF w/ cancellous-bone screw placed horizontally thru tuberosity into metaphysis;
- post op:
- 4-6 weeks of immobilization in cyclinder cast;
- no unprotected activities for 6 months;
- Type III:
- frx propagates from tuberosity in a proximal and posterior direction so that it involves the articular portion
of the
proximal tibial epiphysis;
-
type 3A: single displaced fragment;
-
type 3B: comminuted displaced fragments;
- treatment:
- displaced grade II and III frx usually require ORIF;
- articular incongruenty must be restored;
- ORIF w/ cancellous-bone screw placed horizontally thru tibial tuberosity into tibial metaphysis;
- post op:
- 4-6 weeks of immobilization in a cylinder cast;
- no unprotected activity for 6 months;
Compartment syndrome complicating tibial tubercle avulsion.
Tension band wires of displaced tibial tuberosity fractures in adolescents.
Clin Orthop 1986;209:161-165. Polakopf DR, Bucholz RW, Ogden JA:
Fractures of the tibial tuberosity in adolescents.
Ogden JA, Gross RB, Murphy MJ: J Bone Joint Surg 1980;62A:205-215.
