Osteotomy around the knee in children: when and why? F. Moungondo ,R. Elbaum Service d’orthopédie Hôpital Erasme
Osteotomy around the knee in children: when and why?
F. Moungondo ,R. ElbaumService d’orthopédie
Hôpital Erasme
Introduction• In young children or
adolescent,most of frontal knee defformity can be correct without osteotomy only by simple epiphysiodesis (staple,scews or growth plate).
• In some cases when the deformity is too complex or when the patient is too old , knee osteotomy is the only solution to restaure anatomy.
Just a little remind
The variation of the normal pattern
Physiologic evolution in the frontal plane
ligament laxity
weight-bearing
Variation of the measurements
10 cm 4 cm
VARIATIONS Obese adolescents = False knock-knee
Abnormal fat distribution
10cm
Axe diaphysaire F et T en charge
Use of the metaphyseal-diaphyseal angle in the evaluation of bowed legs.J Bone and Joint surg. 1993 Nov;75(11):1602-9.Feldman MD1, Schoenecker PL.
- 5°
0°
+ 5°
2 Y 4 Y 12 Y 15 Y
G. Varum
G. Valgum
M
EVOLUTION OF THE TF ANGLE IN THE FRONTAL PLANE
F
Normal femoral and tibial torsion
Torsion :
Is the turning of a bone on its longitudinal axes.
As a result the upper andthe lower epiphysis are not in the same plane
Femoral anteversion angle :
Fabry (1973)
Tibial torsion angle :
Dupuis ( 1951)
Jend (1981)
ROTATIONAL NORMS IN HEALTHY CHILDREN
Rotational angles vary with age
5 Y 1O Y 15 Y
30°
15°
10°
5°
40°
20°
10°
FA
Lat. T.T.
EVOLUTION OF THE NORMAL FEMORAL AND TIBIAL TORSION /
AGE
Consequences of constitutional angular deformities
Do severe angular deformities induce osteoarthritis of the knee ?Modifications of TF angle
Alteration of distribution of loads on the knee
Osteoarthritis
No prospective study on the long term
of angular deformities
However
Consequences of constitutional rotational deformities
Do severe rotational deformities induce osteoarthritis of the knee and hip ?
Exaggerated torsion
Alteration of the loads on hip or knee
osteoarthritis
No prospective and longitudinal study
on the long term of rotational deformities
However
Knee growth potential
Indication of osteotomy around the knee in children and adolescent
FEMORAL OSTEOTOMY• Post acquired epiphysiodesis
(septic,traumatic…)• Posttraumatic deformity• Idiopathic malalignement (Genu
Valgum,Genu Varum; Femoral hyperantetorsion)
• Flexion contracture arthrogryppotic,IMOC,Polio
• Congenital deformity (PFFD,neurofibromatosis,OI…)
• Acquired deformity (Rickets,blount disease…)
• ….
TIBIAL OSTEOTOMY• Tibia vara (Blount disease)• Postraumatic deformity• Idiopathic Malalignement
(Excessive tibial torsion, genu varum or valgum)
• Congenital (Tibial hypoplasia, hemielia,OI, CPT…)
• Aquired Genu varum (Rickets,Blont disease…)
• Postraumatic • Focal chondrodyspalsia• ….
Mechanical axis
But we know that mechanical axis is a little bit medial to center of the knee
Normal : 9±7mm (Paley et al 2004)
4±4mm (Bhave et al)
Anatomical Axis (Paley 1994)
What about the frontal plane?
« Pathological » constitutional frontal deformities
« Pathological » constitutional angular deformities :
Should be related to the natural history
Frequently found in other members of family
They can be corrected in late chilhood
They must be differentiated from secondary deformities
TF angle exceeding 2 SD around the mean for age and sex
Constitutional angular deformityPatients < 3 years old
24 months
Constitutional genu varum
ITT
Bow legs
Spontaneous correction
Boy 16 years oldBilat genu varum
Girl 12 years oldGenu valgum I M D : 12 cm
Constitutional angular deformities in preadolescents
Rickets :Nutritional Vitamin D resistantHypophosphatasia
Infantile tibia vara (Blount)
Metaphyseal chondrodysplasia
Focal fibrocartilaginous dysplasia
Secondary angular deformities in patients less than 3 Y
Focal Chondrofibrodysplasia
Blount disease • Black ,carribean• infantile bilat• adolescent unilat
Rickets
Genu varum
X ray : widening of the physis+++
3 YGenu varum
ICd = 9cm
Metaphyseal chondrodysplasia
Secondary to :
Trauma
Infection
M.. l. 15 YFemoral Epiphysiodesis
Unilateral genu valgum or varum
Secondary angular deformities in patients more than 10 Y
Secondary to
CarentielNeuroPolyepiphyseal dysplasiaBone Tumor…
Late onset tibia vara (12Y)
Courtesy PL Docquier
AND WHAT ABOUT THE ROTATIONNAL PLANE??
Relationships between rotational malalignment and the patella
Eckhoff (1997) : « the patellar tracking pattern is determinedby the femoral and tibial torsion ».
The patella is subjected to increased stress due to malalignment syndrome.
Anterior knee pain is associated with triple deformity sd :Delgado (1996)Bruce (2004)
Patella instability is related to torsional problems :Turner ( 1994)Cameron (1996)
TreatmentOutward femoral osteotomy
+ Inward tibial osteotomy
(Delgado 1996)
AND WHAT ABOUT THE SAGITTAL PLANE??
flessum defformity
Extension deformity (genu recurvatum)
Iatrogenic (post épiphysiodèse TTA) Post trauma Post septic
Technique de l’ostéotomie tibiale de flexionpour le recurvatum d’origine tibiale
LECUIRE F, LERAT JL et al.Le genu recurvatum et son traitement par ostéotomie tibiale Revue de Chirurgie Orthopédique, 198O
Complications of osteotomies about the knee in children.
“On Sixty-five procedures were performed by a variety of techniques with the majority being on the proximal tibia.Postoperative complications were numerous with 63% of the patients having one or more. These complications included loss of alignment, vascular complications, pathologic fractures, wound infection, anterior and posterior angulation at the osteotomy site, tibial tubercle prominence and patellofemoral malalignment.”
Myckosie J.P. Orthopedics 1981 Sep 1;4(9):1005-15.
CONCLUSION
• In children ,most of pathological knee deformity can be corrected by simple procedure if some principles are respect
• If a knee osteotomy is planned ,it has to be decide after a good explanation to the child and his parents.
• Type of procedure depends on the surgeon habits• Be very carefull because complications rate are
not so rare.
THANK YOU