Comprehensive treatment of late-onset tibia vara

BACKGROUND: Late-onset tibia vara (Blount disease) can be difficult to treat because of frequent morbid obesity and associated deformities, including distal femoral varus, proximal tibial procurvatum, and distal tibial valgus, that contribute to lower extremity malalignment. We present a comprehensive approach that addresses all components of the deformity and allows restoration of the anatomic and mechanical axes. METHODS: Fifteen consecutive patients (nineteen lower extremities) with late-onset tibia vara were managed with this comprehensive approach. The mean age of the patients at the time of surgery was 14.9 years, and the mean weight was 113 kg. Standing anteroposterior and lateral radiographs were made preoperatively and at the time of the final follow-up. Preoperatively, the mean mechanical axis deviation was 108 mm, the mean lateral distal femoral angle was 95 degrees , and the mean mechanical medial proximal tibial angle was 71 degrees . In all nineteen extremities, the proximal tibial varus deformity was corrected by means of a valgus osteotomy and application of an Ilizarov ring external fixator. Distal femoral varus was corrected by means of either hemiepiphyseal stapling or valgus osteotomy with blade-plate fixation in thirteen of the nineteen extremities. Distal tibial valgus was treated either with hemiepiphyseal stapling or with varus osteotomy and gradual correction with use of the Ilizarov external fixator in eleven of the nineteen extremities. RESULTS: After a mean duration of follow-up of 5.0 years, the mean mechanical axis deviation had improved to 1 mm (range, 20 to -30 mm), the lateral distal femoral angle had improved to 87 degrees (range, 83 degrees to 98 degrees), and the mechanical medial proximal tibial angle had improved to 88 degrees (range, 83 degrees to 98 degrees ). The mean time required for correction of the proximal tibial varus deformity was thirty-one days, and the external fixator was removed at a mean of 4.5 months postoperatively. All patients had development of one or more superficial pin-track infections (mean, 1.9 pin-site infections per patient). No wound infections, nonunions, or neurovascular complications occurred. Eighteen of the nineteen extremities were pain-free at the time of the final follow-up. CONCLUSIONS: This comprehensive approach allowed restoration of the mechanical and anatomic axes of the lower extremity in patients with late-onset tibia vara, resulting in a resolution of symptoms as a result of normalization of the weight-bearing forces across the knee and ankle. We believe that this approach will decrease the risk of early degenerative arthritis of the knee.     

Magnetic resonance imaging of the growth plate in late-onset tibia vara

We used Magnetic resonance imaging (MRI) in five patients (six knees), mean age 13.2 (12-15) years, with late-onset tibia vara (Blount's disease), to study the growth plate and its abnormalities. The MRI study was classified for severity of disease and compared with a radiographic classification. In severely involved knees, MRI indicated severe growth-plate changes on both sides of the knee joint. Widening in the entire proximal tibial growth plate, involvement of the distal femoral growth plate, as well as cartilage invaginations into the metaphyses, were constant findings. Three knees were treated operatively with oblique tibial osteotomy and three with lateral hemiepiphysiodesis. Two severely involved patients treated initially with hemiepiphysiodesis required additional surgery. The three patients with mild disease treated with tibial osteotomy had good clinical and functional results. This study suggests that extensive growth-plate changes in severe, late-onset tibia vara preclude successful treatment by tibial hemiepiphysiodesis. In addition, oblique osteotomy, which was successful in mild cases, was problematic in severe cases.     

Magnetic resonance imaging findings and treatment outcome in late-onset tibia vara.

Several retrospective studies have shown the usefulness of magnetic resonance imaging (MRI) in the evaluation of tibia vara. With respect to the late-onset type, however, there have been no English-language reports on MRI findings. In this article, the authors report on the MRI features of three patients with late-onset tibia vara, the results of treatment that was chosen on the basis of the findings, and the histologic characteristics of the disease. Fat-suppressed MRI revealed partial closure of the tibial physis in one patient and near-closure in another patient. They underwent osteotomy with resection of the bone bridge and have shown no evidence of recurrence. In the third patient, only irregularity of the physis was found on MRI, and she was treated conservatively. Her varus deformity subsequently improved, although it persisted. Histologic examination revealed disorganization and misalignment of the physeal zone and transverse alignment of the trabeculae. The patient with a bony bridge also had discrete ossification centers in the physeal zone.     

Treatment of late-onset tibia vara using afghan percutaneous osteotomy and orthofix external fixation

The Afghan osteotomy was combined with external fixation on 19 patients (23 extremities) with late-onset tibia vara. The average weight was 258 lb and all patients weighed >95th percentile. The average preoperative deformity was 28.2 degrees. The average intraoperative correction was 27.6 degrees. Average healing time was 141 days. The mean follow-up was 2.7 years. Based on radiographic correction, at long-term follow-up, there were 15 excellent, two fair, and six poor results. The quality of the initial correction was the only significant variable, and it was borderline (p = 0.0587). Complications included loss of alignment, peroneal nerve palsy, superficial pin tract infection, deep infection, and fracture. This method offers a technically simple procedure with a relatively low complication rate. It allows early mobilization and provides the ability to manipulate the correction postoperatively. An excellent long-term outcome is predicated on achieving an acceptable initial correction as determined by intraoperative mechanical axis radiographs.     

Infantile tibia vara

Infantile tibia vara is a developmental condition producing progressive varus deformity of the knee in young children. It appears to have a worse prognosis in the predominantly nonwhite population seen with this condition in the United States than previous studies from Scandinavia would suggest. Early roentgenographic diagnosis is critical, since toddlers can have infantile tibia vara at an early stage instead of physiologic genu varum. Aggressive bracing is appropriate treatment until age three years. Correction to valgus alignment with upper tibial osteotomy predictably can produce complete resolution of the condition if performed by age four years. After that age, the procedure becomes less effective. Prognosis for Langenskiold Grade IV disease is guarded at best, regardless of age, because the physis behaves as if effective growth arrest has already occurred. Young patients with Grade IV or greater lesions should have corrective osteotomy combined with a physeal procedure to attempt restoration of growth in the medial physis. Early effective treatment can prevent permanent intraarticular incongruity.     

Infantile tibia vara

We studied the applicability of Langenski?ld's classification to a predominantly nonwhite population with infantile tibia vara. Age at presentation was younger than that in previously published studies. Forty-seven tibiae averaging 6 years 7 months of follow-up had 66% good results. Poor results increased in proportion to stage at presentation. Brace treatment for early lesions was only 50% effective. Single tibial osteotomy before 4 years of age gave good results in 85% of tibiae, and multiple osteotomies gave good results between 4 and 8 years of age. One-half of tibiae treated with osteotomy developed recurrent varus. This review documents earlier stages at presentation, a more malignant course, and poorer results than Langenski?ld's series would suggest. We question the accuracy of Langenski?ld's estimate of prognosis when applied to this patient group.     

Adolescent tibia vara

Adolescent tibia vara is less common and less well described when compared to infantile tibia vara. Yet, the two share a significant number of features related to their epidemiology and histology. The two diseases differ most in their radiographic appearance. It does not, however, necessarily follow that their etiologies cannot be similar. By its epidemiology and histology, adolescent tibia vara appears to be related to repetitive trauma in the form of abnormal force directed on the medial tibial growth plate due to obesity, the adolescent growth spurt, or residual, incompletely corrected physiologic varus. Such forces may give growth plate suppression by the Heuter Volkman principle similar to what is thought to occur in infantile tibia vara. In the infant, this results in typical radiologic findings related to an epiphyseal ossification center which is cartilagenous and moldable and results in progressive medial wedging. In the adolescent, however, this ossification center is bony and, therefore, will not deform under stress. The growth plate, however, still responds with decreased growth resulting in varus deformity. Thus, adolescent tibia vara, by definition not related to trauma or infection, may in fact reflect the same pathologic process at work as in infantile tibia vara.     

Late-onset tibia vara

Fifteen children with late-onset tibia vara were studied. There were seven unilateral and eight bilateral cases. Eleven children were male, four were female and 13 were black; 14 were obese. All had a history of gradually progressive genu varus (average onset 11 years); 12 had preoperative knee pain. The average age at surgery was 12 years, with a preoperative tibiofemoral angle of 14 degree varus. The average follow-up was 4 years 4 months. The average tibiofemoral angle at follow-up was 0 degrees. There were 15 good, two fair, and six poor final results.     

Femoral deformity in tibia vara

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.     

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 Langenski?ld's classification of radiological changes in the proximal medial metaphysis of the tibia was used. In 22 limbs which were not in Langenski?ld 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 Langenski?ld 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 measurement of infantile tibia vara

The reproducibility of the radiographic measurement of 30 pairs of tibiae being treated for bowing was evaluated. Two methods of measurement were used. The first was the metaphyseal-diaphyseal angle of Levine and Drennan; the second, a metaphyseal-metaphyseal angle based on Cobb's angle for measuring scoliosis. Statistical analysis comparing the two methods showed no significant differences except for an increase in the angle in more severe cases measured by the metaphyseal-metaphyseal method, indicating distal tibial as well as proximal involvement. Computer digitization correlated extremely well with manual measurements. The metaphyseal-diaphyseal measurement is quite reproducible, and may allow early diagnosis and treatment of tibia vara.     

Elevation of medial tibial condyle for severe tibia vara

Clinical and radiological evidence of knee instability was used as criteria for elevation of medial tibial condyle in severe tibia vara. Restoration of tension to the exposed medial collateral ligament was used as a guide for the required amount of elevation. A second-stage proximal tibial osteotomy was performed later for correction of the remaining varus deformity. External fixators were used in all instances. Elevation of the medial tibial condyle is indicated in severe tibia vara with arrest of the medial tibial physis, in which more than a 10 degrees difference exists between valgus and varus stress radiographs with the knee in extension as compared with an opposite normal knee.     

Adolescent tibia vara: alternatives for operative treatment.

We reviewed the cases of fifteen obese patients (twenty-one extremities) who had had adolescent tibia vara and had been followed for at least two years. Of the nine patients (eleven extremities) who had been initially managed with lateral tibial hemiepiphyseodesis, eight (ten extremities) were skeletally mature at the time of the review (mean duration of follow-up, five years). The mechanical alignment was judged to be excellent in three of these ten extremities, fair in three, and poor in four. Excellent mechanical alignment was defined as a value within the reported normal range of 5 degrees of varus to 2 degrees of valgus. A poor result was defined as alignment that was more than 5 degrees outside the normal range. After secondary operative procedures, three of the extremities for which the result had been poor and one for which it had been fair had excellent alignment. Five of the nine patients had bilateral involvement. Two of them were managed with bilateral tibial hemiepiphyseodesis; two, with contralateral proximal tibial osteotomy; and one had a mild deformity on the contralateral side that was not treated. Six extremities in six patients (two of whom had a contralateral hemiepiphyseodesis) were managed primarily with proximal tibial osteotomy and were evaluated an average of seven years postoperatively. Two additional patients were managed with proximal tibial osteotomy because of residual varus deformity after the hemiepiphyseodesis.(ABSTRACT TRUNCATED AT 250 WORDS)     

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 Langenski?ld 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.     

The evolution and histopathology of adolescent tibia vara

This clinical, radiographic, and histologic study clarifies the evolution of the distinct clinical and radiographic disorder known as adolescent tibia vara (Blount's disease). Although previous reports have suggested that the disorder occurs in a limb that has been normally aligned until adolescence, we have found that most children with adolescent tibia vara maintain a mild degree of infantile physiologic genu varum. Then, concurrent with the adolescent growth spurt, certain children with predisposing factors, such as obesity, extreme activity, or rapid growth, injure the posteromedial physis as a result of repetitive trauma due to normal use of a limb already in mild varus. The result is growth suppression, further varus, and a classic radiographic presentation. Histologic examination in two cases suggests injury to the growth plate as demonstrated by fissuring and clefts in the physis as well as fibrovascular and cartilaginous repair tissue at the physeal-metaphyseal junction. Transverse trabeculae, resembling growth arrest lines, were noted in the adjacent metaphysis; however, true bony bridging of the growth plate was not seen. Recommended treatment is corrective osteotomy below the growth plate.     

Inverted arcuate osteotomy and external fixation for adolescent tibia vara

The purpose of our review is to describe and report results of a surgical technique for the treatment of adolescent Blount's disease. We retrospectively reviewed the results of 15 inverted arcuate osteotomies combined with external fixation. The inverted arc provides a proximal and stable osteotomy that can correct deformity in three planes. External fixation provides stable fixation, access to surgical wounds, and postoperative adjustment. According to the criteria of Schoenecker, we had 80% good results. Two patients with poor results were the most overcorrected, suggesting that overcorrection may not be so desirable as once suggested. We conclude that the inverted arcuate osteotomy with external fixation is an effective, reliable, and simple technique for treating adolescent tibia vara.     

Oblique tibial osteotomy for Blount's disease (tibia vara)

Nine oblique proximal tibial osteotomies were performed on six children with genu varum, all but one of whom had Blount's disease. The osteotomy was a single-plane cut allowing simultaneous correction of varus and internal rotation and permitting postoperative cast wedging if necessary to improve position. All osteotomies healed within 10 weeks. The major complications were three episodes of weakness of the extensor hallucis longus, two of which resolved in 4 days and one of which resolved only partially. We were able to combine the osteotomy with other procedures, such as epiphyseal bar resection. All nine osteotomies achieved the desired correction of deformity.     

Treatment of tibia vara by the Ilizarov method

Sixty-nine lower extremities of 45 patients (mean age, 10 years 8 months) with tibia vara were treated with the Ilizarov circular external fixator and distraction osteogenesis. Twenty-four of the patients had bilateral involvement, six of whom had simultaneous surgery and the remaining 18 had staged operations 8 to 12 months apart. In 11 limbs with femoral valgus deformity greater than 10 degrees simultaneous corrections were done. Active movements of the joints of the extremity were encouraged the day after surgery and partial weightbearing began 2 days later. All patients were followed up 27 to 178 months (mean, 80 months) after surgery. No neurovascular complications, delayed union, or nonunions were observed. The mean 28.6 degrees varus tibiofemoral angle preoperatively (range, 15 degrees -45 degrees ) improved to 7.5 degrees valgus (range, 0 degrees -18 degrees ) postoperatively. The preoperative internal torsion angle also improved from 20.7 degrees (range, 0 degrees -48 degrees ) to 3.5 degrees external torsion (range, 0 degrees -9 degrees ) postoperatively. Residual deformity was seen in six patients, and they had successful revision surgery using the same technique. The Ilizarov method allows early weightbearing and motion and allows all components of the deformity to be corrected.     

A histomorphometric study of cellular layers after hemiepiphyseal stapling on the physeal plate in rabbits

Background

Epiphyseal stapling has been widely used to correct angular deformity. The mechanism, however, has not been well determined. To determine the effect of temporary hemiepiphyseal stapling on the cellular layers of the physis, a histomorphometric study was performed using immature rabbits.

Methods

Distal lateral epiphyseal stapling of the right femur was performed on 6-week-old New Zealand white rabbits. Thirty rabbits were randomly assigned to five groups, and six rabbits in each group were analyzed weekly for up to 5 weeks.

Results

The distal femur was deformed into the valgus, and the anatomical lateral distal femoral angle decreased with the passage of time. In the sequential histomorphometry of the operated physeal plate, the area ratio of each layer, compared to the control side, decreased every week. The total area of the physeal plate had decreased up to 60 % at the 5th week compared to the area of the 1st week, and the area of the proliferative layer decreased by the greatest amount among the three layers.

Conclusions

Our findings suggest that the proliferation of chondrocytes seemed to be more suppressed by the compression of the stapling, thereby slowing the growth rate, although hypertrophy of the chondrocytes was also suppressed.