- Discussion:
- frx of proximal tibial metaphysis are rare;
- valgus greenstick fractures usually occur between 3-6 yrs of age;
- cortex is slightly opened on the medial side;
- distal fragment is angulated lateralward;
- Non Operative Treatment:
- usually treated with closed methods;
- frx is reduced before immobilization in cast;
- place leg in long leg cast in extension for 6 weeks;
- ensure that valgus angulation is not present w/ knee in extension (either clinically or radiographically);
- any valgus angulation must be corrected by closed manipulation under anesthesia and a long leg
cast w/ knee in extension for 6 weeks;
- inform patient's family of possibility of delayed vaglus angulation;
- Operative Treatment:
- if closed reduction is impossible because of soft-tissue interposition, open anatomical reduction rarely may be indicated.
- Complications:
- Delayed Valgus Angulation:
- one complication unique to frxs of proximal metaphysis is valgus angulation;
- frx may appear benign, with little or no angulation, but after healing occurrs, limb may drift into progressive valgus angulation;
-
natural history:
- in the report by
Muller et al (Arch Orthop Trauma Surg 2002 Jul;122(6):331-3), the authors determining the extent of the two typical
outcomes (valgus deformity and leg overgrowth) following proximal tibial fractures in children;
- 7 children were retrospectively re-examined by their medical records and roentgenograms;
- ages ranged from from 1 year 10 months to 10 years 2 months;
- all the patients experienced a subjective recovery, with the exception of one child who had minor functional problems;
- 6 patients developed a genu valgum (proximal tibia angle between 6 degrees and 16 degrees) and each of them was treated conservatively;
- only two patients - both under the age of 5 - experienced a partial spontaneous correction;
- overgrowth on the side of the fracture was observed in four cases, varying from 0.5 cm to 1.5 cm, most pronounced after
complete reduction and stable osteosynthesis;
- the authors concluded that surgical correction and osteosynthesis as the preferred method of treatment, even with the
increased likelihood of overgrowth;
-
proposed causes of this angulation:
- unrecognized valgus at time of original injury or overgrowth;
- angulation may result from overgrowth of tibia w/o overgrowth of fibula;
- presence greenstick fracture of proximal tibia w/ slight medial opening may contribute to progressive valgus deformity;
- interposition of flap of fibrous tissue consisting of periosteum,
MCL, &
pes anserinus results in failure of medial gap to close;
- normal growth may occur after removal of offending tissue;
- increased vascular response resulting in asymmetrical growth stimulation of medial portion of the proximal tibial physis;
-
treatment of delayed valgus angulation:
- spontaneous correction usually occurs with time;
- therefore, it is generally advised to continue w/ non operative treatment, until natural history is clear;
- increase in valgus angulation may occur for as long as 17 mo followed by spontaneous improvement w/ in 1-2 years;
- deformity may improve over 5-10 years;
- in the study by HR Tuten et al (JBJS 81-A Jun 1999), 7 patients w/ post traumatic tibia valga were followed until deformity resolution;
- average age of injury was 4 years;
- the deformity typically occurred with 12 months of injury;
- resolution of the defomrity took, on average, 39 months;
- once the deformity had corrected, the affected limb was an average of 9 mm longer than the opposite;
-
surgical treatment:
- indications:
- failure to reduce fully any medial tibial cortical gap mandates surgical exploration and removal of interposed soft-tissue flap;
- if deformity is not sufficiently corrected by age of ten to twelve yrs, tibial osteotomy or hemiepiphyseodesis can then be performed if necessary;
- surgical treatment:
- stapling of medial portion of physis or proximal tibial osteotomy;
- note that recurrence of valgus deformity is frequent after osteotomy in skeletally immature patients;
Physeal arrest about the knee associated with non-physeal fractures in the lower extremity.
Fibrous interposition causing valgus deformity after fracture of the upper tibial metaphysis in children.
Weber B:
J Bone Joint Surg 1977;59B:290-292.
Spontaneous improvement in post traumatic valga.
Zionts LE, MacEwen GD:
J Bone Joint Surg 1986;68A:680.
Acquired valgus deformity of the tibia in children.
Balthazar D, Pappas A:
J Pediatr Orthop 1984;4:538-541.
Genu valgum following fractures of the proximal tibial metaphyseal in children.
DH Bahnson and WW Lovell.
Orthop Trans. Vol 4. 1980. p 306.
