Infantile Tibia Vara Research Articles

Slipped upper tibial epiphysis in infantile tibia vara

We describe three cases of infantile tibia vara resulting from an atraumatic slip of the proximal tibial epiphysis upon the metaphysis. There appears to be an association between this condition and severe obesity. Radiologically, the condition is characterised by a dome-shaped metaphysis, an open growth plate and disruption of the continuity between the lateral borders of the epiphysis and metaphysis, with inferomedial translation of the proximal tibial epiphysis. All patients were treated by realignment of the proximal tibia by distraction osteogenesis with an external circulator fixator, and it is suggested that this is the optimal method for correction of this complex deformity. There are differences in the radiological features and management between conventional infantile Blount's disease and this 'slipped upper tibial epiphysis' variant.

Can Blount's disease heal spontaneously?

In stage1 of all currently accepted classifications for infantile tibia vara, the diagnosis is difficult between physiological bowing and true Blount's disease. There is no evidence of prognosis criteria for surgical treatment at this stage. We retrospectively studied a series of 26 patients born in the Indian Ocean area, presenting at stage1 of the disease, in order to determine whether any of them were likely to heal without treatment. It was found that children seen at stage1 of infantile tibia vara have a one-in-three chance of healing spontaneously. An alternative classification in three stages could then provide more suitable therapeutic indications: stage0: possible Blount's disease (patient older than 2.5 years); stage1: certain Blount's disease, active physis (+) (progressive varus, age >3 years, typical image with no epiphysiodesis bridging); stage2: certain Blount's disease, inactive physis (-) (superomedial tibial bony bridge). Level IV. Retrospective study.

A safer technique for the double elevation osteotomy in severe infantile tibia vara

Infantile tibia vara is a deformity of abrupt angulation into varus due to an affection of the postromedial aspect of the proximal tibial physis. The deformity often includes internal tibial torsion and limb length discrepancy. Gradual correction of the deformity is currently the treatment of choice for these challenging cases as it requires less invasive surgery, allows progressive and adjustable correction, permits bone lengthening if needed and achieves a more accurate correction compared to acute correction. Elevation of the depressed medial tibial condyle allows restoration of the joint architecture. Different techniques described to elevate the depressed medial tibial plateau are all technically demanding and carry potential risks of unsalvageable intra-operative complications. The aim of this study is to report the results of a safer technique for the double elevation osteotomy combined with gradual correction using the Ilizarov frame, allowing it to be more reproducible, less technically demanding and avoid those potential complications. This study included 12 limbs in 8 patients (mean age 9 years), all were classified as stage V or VI according to the Langenskiold classification. All osteotomies healed completely in all patients. The mean time in the frame was 23 weeks. The mean preoperative femoral shaft-tibial shaft angle was 36° of varus. This improved to 5° of varus. The mean preoperative femoral condyle-tibial shaft angle was 58°. This improved to 84°. The mean preoperative angle of depressed medial tibial plateau was 63°. This improved to 8°. All patients were maintaining full extension of the knee at the final follow-up, and all patients noticed a significant improvement in their gait pattern. We believe that this technique is safer and less invasive compared to traditional and even newly described techniques for elevating the depressed medial tibial plateau and correcting the deformity in severe infantile tibia vara, which will allow it to be more reproducible.

Infantile Tibia Vara: Correction of Recurrent Varus Deformity Following Epiphyseolysis

Infantile tibia vara (infantile Blount's disease) is a condition in which progressive varus of the knee develops due to diminished physeal growth of the medial aspect of the proximal tibia. A 6-year-old boy with severe bilateral infantile tibia vara (Langenskiold stage V) underwent operative correction of his deformities. Surgery consisted of epiphyseolyses of the medial proximal tibiae and valgus-producing corrective tibial osteotomies. Nearly 5 years after symmetric growth, he again developed progressive varus involving his left knee. Usually, a repeat proximal tibial osteotomy is required along with consideration for completion of epiphyseodesis. In this case report, a simpler approach using staples was taken to successfully regain correction in a patient with recurrent deformity who was treated previously by a combination of epiphyseolysis and proximal tibial osteotomy. Stapling of the lateral aspect of the physis allowed the limited remaining growth potential within the abnormal medial physeal region to correct the angular deformity. A small overcorrection into valgus corrected after subsequent removal of the staple. At 14 years, with clinical and radiologic alignment normal, bilateral proximal tibial epiphysiodeses were performed. The patient returned to playing football at a high school level and had no functional limitations. To our knowledge, this is the first report of growth modulation (physeal stapling) resulting in successful correction of recurring genu varum in a knee that had previously undergone epiphyseolysis of the medial proximal tibial physis in advanced infantile tibia vara.

Medial Epiphysiolysis in Severe Infantile Tibia Vara

Recurrent varus deformity and shortening frequently result following valgus osteotomy alone for advanced stage infantile tibia vara (ITV), due to the proximal medial physeal dysfunction which resembles a complete growth arrest in Langenskiöld grade III or greater lesions. Epiphysiolysis is a possible treatment alternative which, if successful, can restore symmetric proximal tibial growth and obviate the need for additional complex treatments to address recurrent angular deformity and limb length inequality. We reviewed 24 patients, ages 5-10 years, with 27 affected tibiae, who underwent epiphysiolysis of the proximal medial tibia combined with valgus osteotomy. The procedure was >80% successful in restoring growth and avoiding varus recurrence in children <7 years old. Patients >age 7, patients with relative undercorrection of their mechanical axis at the time of surgery, and patients with previous failed surgical treatment were more likely not to benefit from epiphysiolysis, and consequently alternative methods may be more appropriate.

Femoral Deformity in Tibia Vara

Previous studies have suggested that compensatory valgus deformity of the femur is common in patients with tibia vara, or Blount disease. The availability and routine use of standing long-cassette radiographs of the lower extremities to assess angular deformities has allowed quantitative evaluation of this hypothesis. The cases of all patients with tibia vara, two years of age or older, seen at our institution prior to treatment, over a thirteen-year period, were reviewed. Seventy-three patients with a total of 109 involved lower limbs were identified and were classified as having either infantile tibia vara (thirty-seven patients with fifty-six involved limbs) or late-onset tibia vara (thirty-six patients with fifty-three involved limbs). Standardized standing radiographs of the lower extremity were examined to assess the deformity at the distal part of the femur and the proximal part of the tibia by measuring the lateral distal femoral angle and the medial proximal tibial angle. The distal part of the femur in the children with infantile tibia vara either was normal or had mild varus deformity, with a mean lateral distal femoral angle of 97 degrees (range, 82 degrees to 129 degrees). The mean medial proximal tibial angle in these children was 72 degrees (range, 32 degrees to 84 degrees). Older children with infantile tibia vara were noted to have little distal femoral deformity, with no more than 4 degrees of valgus compared with either normal values or the contralateral, normal limb. Children with late-onset tibia vara had a mean lateral distal femoral angle of 93 degrees (range, 82 degrees to 110 degrees) and a mean medial proximal tibial angle of 73 degrees (range, 52 degrees to 84 degrees). On the average, the varus deformity of the distal part of the femur constituted 30% (6 degrees of 20 degrees) of the genu varum deformity in these patients. Patients with infantile tibia vara most commonly had normal alignment of the distal parts of the femora; substantial valgus deformity was not observed. Distal femoral varus constituted a substantial portion of the genu varum in children with late-onset disease. When correction of late-onset tibia vara is planned, the surgeon should be aware of the possibility that distal femoral varus is a substantial component of the deformity.

Tibia vara: results of hemiepiphyseodesis

Tibia vara is a condition characterized by progressive deformity of the proximal tibia resulting in varus malalignment of the lower extremity. An alternative treatment strategy involving lateral hemiepiphyseodesis of the proximal tibia in the skeletally immature has been utilized at our institution for the last 10 years. The study group consisted of 23 patients (16 male, seven female) with 33 involved extremities. The median age at surgery was 11.8 years (range, 7.0-17.3). The median follow-up was 3.1 years (range, 0.8-6.2). Of the patients, 82.6% had a weight greater than the 95th percentile. The preoperative mechanical axis had a median value of 18.0 degrees (range, 5.0-31.0) and at the most recent follow up, a median value of 7.0 degrees (range, -12.0 to 46.0). In 18 (54.5%) extremities, the mechanical axis improved by more than 5 degrees . There was no progression of the overall deformity in 11 (33.3%) extremities. Four (12.1%) extremities had worsening of the deformity. At the time of latest follow up, nine (27.2%) extremities had required corrective osteotomy. Twenty-four (72.7%) were skeletally mature and had not required any further treatment. Goals of hemiepiphyseodesis in adolescent tibia vara or late sequelae of infantile tibia vara include (1) correction of deformity to avoid need for osteotomy, and (2) prevention of progression of the deformity to facilitate subsequent surgery. In this series of patients, 87.8% had either improvement or stabilization of the degree of their deformity.

One-Step Treatment for Evolved Blount's Disease

In infantile tibia vara, the presence of superomedial bridge and sloped plateau requires several problems to be addressed: correction of varus deformity and internal tibial torsion, prevention of recurrences, restoration of normal joint congruity, and prevention and correction of limb length discrepancy. Four patients were treated as follows: percutaneous epiphysiodesis of the superolateral tibia and proximal fibula, elevation osteotomy of the medial tibial plateau, osteotomy of the fibula, and dome-shaped metaphyseal osteotomy of the tibia, followed by progressive lengthening. Osteosynthesis was achieved by an Ilizarov frame (average 6 months). Latest follow-up (average 6 years 10 months) showed that all patients were satisfied, with normal limb length and alignment and correct articular surface congruence. Correction of limb alignment, restoration of joint surface congruity, prevention of recurrence, and treatment of limb length discrepancy are all dealt with in the same procedure.

One-Step Treatment for Evolved Blount's Disease

In infantile tibia vara, the presence of superomedial bridge and sloped plateau requires several problems to be addressed: correction of varus deformity and internal tibial torsion, prevention of recurrences, restoration of normal joint congruity, and prevention and correction of limb length discrepancy. Four patients were treated as follows: percutaneous epiphysiodesis of the superolateral tibia and proximal fibula, elevation osteotomy of the medial tibial plateau, osteotomy of the fibula, and dome-shaped metaphyseal osteotomy of the tibia, followed by progressive lengthening. Osteosynthesis was achieved by an Ilizarov frame (average 6 months). Latest follow-up (average 6 years 10 months) showed that all patients were satisfied, with normal limb length and alignment and correct articular surface congruence. Correction of limb alignment, restoration of joint surface congruity, prevention of recurrence, and treatment of limb length discrepancy are all dealt with in the same procedure.

Natural history of infantile tibia vara.

We have observed the natural history without treatment of 46 limbs in 29 patients with infantile tibia vara and a metaphyseal-diaphyseal angle (MDA) of more than 11 degrees. The femorotibial angle (FTA) and MDA were measured, and Langenskiöld's classification of radiological changes in the proximal medial metaphysis of the tibia was used. In 22 limbs which were not in Langenskiöld stages II to III the condition resolved spontaneously without treatment. Of the remaining 24 which were in stages II to III, in 18 it resolved spontaneously by the age of six years, but six showed little or no improvement at the latest follow-up. It was impossible to differentiate by measuring the FTA or MDA whether spontaneous resolution could be expected before the age of four years. There was no difference in the rate of resolution of the deformity between those patients who had been treated by a brace and those who had received no treatment. We advise no initial treatment but review at six-monthly intervals until the age of four years, even in patients with Langenskiöld stage-II to stage-III deformity. When a deformity persisted or progressed we carried out a corrective osteotomy after the age of four years.

Natural history of infantile tibia vara

We have observed the natural history without treatment of 46 limbs in 29 patients with infantile tibia vara and a metaphyseal-diaphyseal angle (MDA) of more than 11°. The femorotibial angle (FTA) and MDA were measured, and Langenskiöld’s classification of radiological changes in the proximal medial metaphysis of the tibia was used. In 22 limbs which were not in Langenskiöld stages II to III the condition resolved spontaneously without treatment. Of the remaining 24 which were in stages II to III, in 18 it resolved spontaneously by the age of six years, but six showed little or no improvement at the latest follow-up. It was impossible to differentiate by measuring the FTA or MDA whether spontaneous resolution could be expected before the age of four years. There was no difference in the rate of resolution of the deformity between those patients who had been treated by a brace and those who had received no treatment. We advise no initial treatment but review at six-monthly intervals until the age of four years, even in patients with Langenskiöld stage-II to stage-III deformity. When a deformity persisted or progressed we carried out a corrective osteotomy after the age of four years.

Radiographic evaluation of bowed legs in children.

Radiographic screening is widely used to distinguish between Blount disease (infantile tibia vara) and physiologic bowing. Thirteen children with Blount disease, evaluated before 3 years of age, with initial radiographs showing no sign of Langenskiold changes, were compared with 50 children with physiologic bowing, also evaluated before 3 years of age with similar radiographic studies. Screening test accuracy was determined retrospectively for measurement of the mechanical axis, the tibial metaphyseal-diaphyseal angle (TDMA), and the epiphyseal-metaphyseal angle (EMA). A radiographic screening method combining the TMDA and the EMA, using cutoff values of 10 degrees and 20 degrees respectively, exhibited the best combination of sensitivity, specificity, and positive predictive value, correctly identifying all cases of Blount disease and 40 of 50 cases of physiologic bowing. Our data suggest that children between 1 and 3 years of age with TMDA <10 degrees, or TMDA > or =10 degrees and EMA < or =20 degrees, are at less risk for development of Blount disease. Children with TMDA > or =10 degrees and EMA >20 degrees are at greater risk for development of Blount disease and should be followed closely.

Clinical evaluation of bowed legs in children.

Early radiographic screening and/or referral to a clinical specialist are often used to distinguish between physiologic bow leg deformity and infantile tibia vara disease in young children. These practices are a consequence of the clinician's inability (based upon the clinical examination) to distinguish between the deformities associated with physiologic and pathologic bow legs. Because the great majority of these children have physiologic bowing, routine radiographic screening and referral are not cost effective and expose children to unnecessary radiation. This study describes and evaluates the efficacy of a simple clinical examination technique, the 'cover up' test, to identify young children with bow legs who are at high risk for having infantile tibia vara. The 'cover up' test qualitatively assesses the alignment of the proximal portion of the shank or lower leg relative to the thigh or upper leg. Obvious valgus alignment is considered a negative test and is indicative of physiologic bowing. Neutral or varus alignment is considered a positive test and suggests that the child is at greater risk for having infantile tibia vara. Eighteen children with infantile tibia vara, evaluated initially prior to 3 years of age, and followed to the time of surgical correction, were compared with 50 children with physiologic bowing, also evaluated initially prior to 3 years of age and followed to resolution (mean follow-up 3 years and 10 months). All of the children with infantile tibia vara had a positive 'cover up' test (sensitivity = 1.00). Eighteen of 25 children with a positive 'cover up' test actually had or developed infantile tibia vara (positive predictive value = 0.72). Forty-three of 50 children with physiologic bowing had a negative 'cover up' test (specificity = 0.86). All of the children with a negative 'cover up' test actually had physiologic bowing (negative predictive value = 1.00). We conclude that the 'cover up' test is an effective screening tool for the assessment of bow legs in children between 1 and 3 years of age. Children with a negative 'cover up' test do not require radiographic evaluation and should be followed clinically for resolution of the bowing. Children with a positive 'cover up' test should have radiographic evaluation of the lower extremities or be referred to a specialist for further evaluation and treatment.

Serrated W/M osteotomy. Results using a new technique for the correction of infantile tibia vara.

The conventional osteotomies used to treat infantile tibia vara (Blount's disease) may require internal fixation and its subsequent removal. These techniques, which carry the risk of traction injury, and potential problems of stability and consolidation, do not always succeed in correcting the rotational deformity which accompanies the angular deformity. We have used a new surgical approach, the serrated W/M osteotomy of the proximal tibia, to correct infantile tibia vara in 15 knees of 11 patients. We present the results in 13 knees of nine patients who have been followed up for a mean of eight years. The mean angular correction achieved after operation was 18 +/- 5.8 degrees. The mean femorotibial shaft angle was corrected from 14.2 +/- 3.7 degrees of varus to 4.6 +/- 4.4 degrees of valgus. At the last follow-up, the mean angular correction had reduced to 1.3 +/- 4.9 degrees of valgus without compromising the rotational correction and the overall good clinical results. All the patients and parents were satisfied, rating the result as excellent or good. There were no major postoperative complications and no reoperations. Eight patients were free from pain and able to perform physical activities suitable for their age. One complained of occasional pain. This procedure has the advantage of allowing both angular and rotational correction with a high degree of success without the need for internal fixation.

Serrated W/M osteotomy

The conventional osteotomies used to treat infantile tibia vara (Blount’s disease) may require internal fixation and its subsequent removal. These techniques, which carry the risk of traction injury, and potential problems of stability and consolidation, do not always succeed in correcting the rotational deformity which accompanies the angular deformity. We have used a new surgical approach, the serrated W/M osteotomy of the proximal tibia, to correct infantile tibia vara in 15 knees of 11 patients. We present the results in 13 knees of nine patients who have been followed up for a mean of eight years. The mean angular correction achieved after operation was 18 ± 5.8°. The mean femorotibial shaft angle was corrected from 14.2 ± 3.7° of varus to 4.6 ± 4.4° of valgus. At the last follow-up, the mean angular correction had reduced to 1.3 ± 4.9° of valgus without compromising the rotational correction and the overall good clinical results. All the patients and parents were satisfied, rating the result as excellent or good. There were no major postoperative complications and no reoperations. Eight patients were free from pain and able to perform physical activities suitable for their age. One complained of occasional pain. This procedure has the advantage of allowing both angular and rotational correction with a high degree of success without the need for internal fixation.

Brace Treatment of Early Infantile Tibia Vara

We reviewed 24 children (42 extremities) who had a diagnosis of early infantile tibia vara treated by using a brace. The indication for bracing was either a varus deformity that was not improving by age 18-24 months, or a persistent varus deformity seen in a patient older than 24 months. We prescribed an above-the-knee brace with a free ankle, single medial upright with valgus-producing straps, and either no hinged joint or a locked hinge joint at the knee. The braces were worn during the day and were removed for bedtime. The patients were followed up for an average of 27.2 months (range, 12-72) from the initiation of brace treatment, and the outcome at latest follow-up was determined by using radiographic criteria. Before treatment, 29 extremities were Langenskiöld stage I, II were stage II, and two were stage III. Before treatment, the metaphyseal-diaphyseal angle averaged 16.4 degrees. Forty of the 42 extremities had metaphyseal-diaphyseal angles of > 11 degrees, and 20 were > 16 degrees. Based on our criteria, we rated 29 extremities good, nine fair, and four poor. We conclude that daytime, ambulatory brace treatment may favorably alter the natural history of tibia vara in patients who are younger than 3 years and who have Langenskiöld stage I or II deformity.

A dynamic biomechanical analysis of the etiology of adolescent tibia vara.

Biomechanical overload of the proximal tibial physis due to static varus alignment and excessive body weight has been implicated in the etiology of infantile tibia vara. Whether a similar pathophysiologic process applies to adolescent tibia vara is controversial, with poor consensus concerning the nature and significance of static knee alignment early in the course of the disease. This study examines the hypothesis that dynamic gait deviations to compensate for increased thigh girth associated with obesity (fat-thigh gait) could result in increased loading of the medial compartment of the knee during the gait cycle. Three-dimensional motion analysis was used to identify the kinematic/kinetic profile associated with fat-thigh gait. Gait deviations identified were dynamic stance-limb knee varus, increased stance-limb knee rotation, and swing-limb circumduction. Pathologic compressive forces were generated in an anthropometric model by using recorded fat-thigh gait deviations and clinically appropriate excessive body weight. This analysis supports the clinical observation that underlying static varus malalignment of the knee is not a prerequisite for the development of adolescent tibia vara and illustrates the significance of dynamic gait deviations when considering knee-joint loading.

A Dynamic Biomechanical Analysis of the Etiology of Adolescent Tibia Vara

Summary Biomechanical overload of the proximal tibial physis due to static varus alignment and excessive body weight has been implicated in the etiology of infantile tibia vara. Whether a similar pathophysiologic process applies to adolescent tibia vara is controversial, with poor consensus concerning the nature and significance of static knee alignment early in the course of the disease. This study examines the hypothesis that dynamic gait deviations to compensate for increased thigh girth associated with obesity (fat-thigh gait) could result in increased loading of the medial compartment of the knee during the gait cycle. Three-dimensional motion analysis was used to identify the kinematic/kinetic profile associated with fatthigh gait. Gait deviations identified were dynamic stance-limb knee varus, increased stance-limb knee rotation, and swing-limb circumduction. Pathologic compressive forces were generated in an anthropometric model by using recorded fat-thigh gait deviations and clinically appropriate excessive body weight. This analysis supports the clinical observation that underlying static varus malalignment of the knee is not a prerequisite for the development of adolescent tibia vara and illustrates the significance of dynamic gait deviations when considering knee-joint loading.

Physiological bowlegs or infantile Blount's disease. Some new aspects on an old problem.

The differentiation between physiological bowlegs and infantile Blount's disease in patients aged 11-30 months is very difficult. Nevertheless, diagnosis is deemed important because treatment of infantile Blount's disease is recommended. Fourteen patients with severe bowing of the legs seen in our outpatient clinic were investigated retrospectively. We examined them and measured the tibiofemoral and metaphyseal/diaphyseal angles in radiographs taken at their first presentation. The finding that the tibiofemoral angle is not helpful in differential diagnosis could be confirmed but, contrary to reports by other authors, neither was the metaphyseal/diaphyseal angle. In view of the spontaneous recovery of all investigated patients, it must be doubted whether a diagnosis of infantile tibia vara can be made in early infancy, and whether infantile Blount's disease is a diagnosis in its own right.

Langenskiöld classification of tibia vara: an assessment of interobserver variability.

Six pediatric orthopaedic specialists and six senior orthopaedic residents independently classified 60 radiographs of infantile tibia vara according to the six-stage Langenskiöld classification. Correlation coefficients and percentage agreement were similar in both groups. Interobserver agreement was good for early and late stages, but was poor for intermediate stages. We caution clinicians that small but frequent discrepancies in radiographic staging impart a dubious prognostic value to the Langenskiöld classification.