Use of Orthofix T-Garche Fixator in Late-Onset Tibia Vara:

Gradual Deformity Correction in Blount Disease

BACKGROUND

Blount disease is a disorder of the posteromedial proximal tibial physis which causes a progressive varus, procurvatum, and internal rotation deformity of the tibia. Untreated, it can cause significant limb malalignment. The goal of this study is to evaluate the results of correction of Blount disease using types of external fixation.

METHODS

We conducted a retrospective review of 41 patients (51 limbs) who underwent correction of Blount disease with an Ilizarov external fixator or a Taylor spatial frame (TSF) by a single surgeon. The medial proximal tibial angle (MPTA), mean axis deviation (MAD), posterior proximal tibial angle, and joint line congruence angle (JLCA) were measured on radiographs preoperatively, at frame removal and at final follow-up.

RESULTS

The average age at treatment was 9.6 years old, with a mean follow-up time of 34 months. Mean preoperative MPTA, MAD, and JLCA were significantly improved at the time of frame removal as well as at final follow-up with no significant changes in correction between the time of frame removal and final follow-up. There was no difference in MPTA and MAD in patients treated with an Ilizarov frame versus a TSF. MPTA, MAD, and JLCA all significantly improved regardless of the underlying diagnosis (infantile vs. adolescent Blount disease) or history of prior surgical intervention. The most common complication was superficial pin-site infection.

CONCLUSIONS

Both Iliazarov and TSF are viable treatment options for infantile and adolescent Blount disease, with the ability to significantly improve both the limb mechanical axis and the mechanical axis of the affected tibia. Correction can be attained regardless of whether patients have previously failed surgical intervention.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Evaluation of complications of treatment of severe Blount's disease by circular external fixation using a novel classification scheme

Corrective osteotomy for recalcitrant varus deformity secondary to adolescent and infantile Blount's disease can be challenging because of a combination of severity of deformity, complexity of deformity, and frequent association with patient obesity. We present here the outcome of treatment by osteotomy and gradual deformity correction by circular external fixation in 31 patients with either infantile or adolescent Blount's disease. We used a unique classification scheme to quantify and qualify complications in this patient group: category I, complications not requiring an alteration in the treatment plan, not involving unplanned return to surgery, and not influencing outcome; category II, complications requiring an alteration in the treatment plan, including unplanned returns to surgery, but that did not influence outcome; category IIIA, complications that resulted in a failure to achieve treatment goals; and category IIIB, complications that resulted in a failure to achieve treatment goals and the development of a new pathology or worsening of patient condition. All but one patient in this group incurred at least one complication. However, despite the complex nature of this patient population, 88% achieved satisfactory correction without developing category IIIA or IIIB complications. Careful selection of patients and vigilant postoperative management can result in excellent outcomes with circular external fixation and gradual correction in this challenging patient population.

Does Langenskiold staging have a good prognostic value in late onset tibia vara?

BACKGROUND

Although many literature studied the effect of many factors on the prognosis of the early-onset Blount disease, studies that were written on the prognostic factors affecting late onset tibia vara are still limited.

PURPOSE

The aim of this study is to evaluate the prognostic value of the Langenskiold classification system for late onset tibia vara.

METHODS

Twenty children from the Sporting Health Insurance Student Reference Hospital-Alexandria, with a diagnosis of late onset tibia vara were evaluated for the effect of the Langenskiold staging system on the prognosis after they all had been treated by gradual correction by Ilizarov technique using the so called "juxta-articular hinge assembly" after a mean follow-up period of 4.9 years (range : 4-6, SD 0.75).

RESULTS

The difference in varus recurrence rates between the "low grade group" and "high grade group" was found to be statistically significant (p = 0.008) as will be discussed later. There was no statistically significant relation between the age of the patients at the time of operation, sex, length of the follow up period and the degree of pre-operative varus deformity angle (DA) and the recurrence (p > 0.05).

CONCLUSION

We concluded that Langenskiold staging system is a reliable, reproducible and a good prognostic factor for late onset tibia vara.

Hemicallotasis for correction of varus deformity of the proximal tibia using a unilateral external fixator

BACKGROUND

Gradual correction of varus deformity of the proximal tibia is generally accepted and produces good results. However, most studies have used circular external fixators, which are complex and cause patient discomfort. This study was undertaken to determine the efficacy of hemicallotasis with a unilateral external fixator for correction of varus deformity of the proximal tibia.

METHODS

Thirteen patients (21 legs, 8 bilateral) were included in this study: 6 with constitutional bowing, 3 with a malunion, 2 with Blount's disease, and 2 with Turner syndrome. There were 7 males and 6 females of mean age 21 years (range 13-40). With an oblique osteotomy on the proximal tibia, a unilateral external fixator was placed on the medial side. Using a distraction of 1 mm/day, the external fixator was removed after consolidation of the callus.

RESULTS

Surgery corrected medial proximal tibia angle from a preoperative average of 75.1° (64°-81°) to 88.6° (86°-90°) at final follow-up. Average tibiofemoral angle improved from -7° to 6.8°. The duration of external fixation averaged 101.3 days and the external fixation index was 70 days/cm. No patient had a limited ambulation, and all recovered preoperative range of knee motion (mean 130.1°) at final follow-up. Seven minor complications (pin tract infection, clamp loosening) and 1 major complication (uncorrected genu procurvatum) were observed.

CONCLUSIONS

Hemicallotasis using a unilateral external fixator was found to be a safe and simple corrective procedure for varus deformity of the proximal tibia, with few complications.

Blount disease

Two clinically distinct forms of Blount disease (early-onset and late-onset), based on whether the lower-limb deformity develops before or after the age of four years, have been described. Although the etiology of Blount disease may be multifactorial, the strong association with childhood obesity suggests a mechanical basis. A comprehensive analysis of multiplanar deformities in the lower extremity reveals tibial varus, procurvatum, and internal torsion along with limb shortening. Additionally, distal femoral varus is commonly noted in the late-onset form. When a patient has early-onset disease, a realignment tibial osteotomy before the age of four years decreases the risk of recurrent deformity. Gradual correction with distraction osteogenesis is an effective means of achieving an accurate multiplanar correction, especially in patients with late-onset disease.

Acute versus gradual correction of idiopathic tibia vara in children: a systematic review

BACKGROUND

Idiopathic tibia vara (Blount disease) is an acquired form of tibial deformity found mainly in children who are Afro-Caribbean and obese. It is uncommon. Several methods have been described for the surgical treatment of this condition, which can be categorized as either acute or gradual correction. The aim of this study is to review the evidence comparing the outcome of acute versus gradual correction of childhood tibia vara using accuracy of reduction as the primary outcome measure.

METHODS

A systematic search was made of the literature across multiple databases to find all studies describing acute or gradual correction of this condition that reported radiographic correction as an outcome measure.

RESULTS

One retrospective comparative series was found that provided weak evidence of an improvement in mechanical axis deviation using gradual correction with a Taylor Spatial Frame compared with acute correction. Seventeen other case series were found, from which, there was no evidence of an advantage for either form of treatment.

CONCLUSIONS

There is very little evidence to recommend one form of correction over the other.

LEVEL OF EVIDENCE

Systematic review of case series (level IV).

Treatment of Blount disease: a comparison between the multiaxial correction system and other external fixators

BACKGROUND

Many surgical procedures have been proposed for treatment of Blount disease (tibia vara). Gradual correction of Blount disease has been described with both unilateral and circular external fixators. The purpose of this study was to compare the clinical and radiographic results of gradual correction for severe or recurrent Blount disease using the Biomet Multi-Axial Correction (MAC; Biomet Trauma, Parsippany, NJ) external fixator to our historical controls using other devices (such as the Ilizarov and Garche T-clamp).

METHODS

A total of 58 corrections were performed on the 54 limbs in 38 patients. Charts were analyzed to evaluate the presence of complications during the course of external fixator treatment. The tibiofemoral, anatomic medial proximal tibial, and proximal posterior tibial angles were measured on radiographs taken before application of the external fixator and after removal to compare the correction achieved by the MAC fixator and the other fixators.

RESULTS

The mean values for the tibiofemoral angle, anatomic medial proximal tibial angle, and proximal posterior tibial angle were similar between the 2 groups after treatment and at follow up. The rate of complications between the 2 groups was also not significantly different.

CONCLUSIONS

The MAC external fixator provides an acceptable alternative for gradual correction of Blount disease.

LEVEL OF EVIDENCE

Level III.

A retrospective analysis of treatment and outcomes in patients with late onset tibia vara

This retrospective analysis included 36 patients who presented with late-onset tibia vara during a 15-year period. Mean patient age at presentation was 12.8 years. Seventy-eight percent of patients were male, 78% were black, and 72% presented with unilateral deformity. Mean initial varus was 21 degrees with 5.8 degrees at the femur and 12.3 degrees at the tibia. Surgical correction was performed in 31 patients; 5 patients refused surgery. Patients who had osteotomies had a higher rate of complications than those treated with stapling. Epiphyseal stapling has unpredictable results in patients with late-onset tibia vara and is only a temporizing procedure in approximately half of cases. None of the treatments resulted in optimal knee function or alignment, and the long-term prognosis for late-onset tibia vara is guarded at best.

Accuracy of correction of tibia vara: acute versus gradual correction

The purpose was to assess the accuracy of deformity correction achieved in patients with tibia vara using acute intraoperative correction compared with gradual postoperative correction. Acute correction (AC) group consisted of 14 patients (14 tibiae) with a mean age of 11.4 years and whose tibia vara was corrected acutely and held using an EBI external fixator. Gradual correction (GC) group consisted of 18 patients (18 tibiae) with a mean age of 10.2 years and whose tibia vara was corrected gradually using 6-axis deformity analysis and Taylor Spatial Frame. Deformity measurements were compared preoperatively, postoperatively, and at latest follow-up. At latest follow-up, medial proximal tibial angle deviation from normal was similar for the 2 groups; posterior proximal tibial angle was significantly greater in the AC group (5.6 degrees) than in the GC group (1.9 degrees). Mechanical axis deviation was significantly greater in the AC group (17.1 mm) than in the GC group (3.1 mm). Postoperatively, frequency of accurate translation corrections (achieved translation within 5 mm of preoperative required translation) was significantly greater in the GC group (18/18) than in the AC group (7/14). Frequency of accurate angulation corrections (medial proximal tibial angle within 3 degrees of normal and posterior proximal tibial angle within 5 degrees of normal) was significantly greater in the GC group (17/18) than in the AC group (7/14). For both groups, all tibiae with preoperative internal rotation deformity had accurate rotation correction. Correction of preoperative limb-length inequality was achieved in 5 of the 7 patients in the AC group and 11 of the 11 patients in the GC group. Gradual deformity correction is a more accurate treatment method of tibia vara than acute correction.

Length changes in tibial osteotomy with angular correction

Twelve boys, aged 11-17 years, who underwent percutaneus proximal tibial osteotomy with acute angular correction and application of external fixator for unilateral Blount's disease were retrospectively reviewed. Preoperative radiographs were compared with radiographs at healing to evaluate changes in tibial length and overall limb length. Angular correction increased overall limb length by a mean of 1.4 cm (range -0.4 cm to 3.2 cm). This increase was a mean 0.7 cm less than was predicted by adding the preoperative tibial and femoral lengths. This failure to achieve the predicted limb length occurs due to shortening in the tibia and should be considered when planning an osteotomy.

Juvenile Blount's disease: bilateral case with asynchronous onset

We encountered a rare case of bilateral juvenile Blount's disease diagnosed as unilateral at the onset. The patient was a 9-year-old girl who visited our outpatient clinic with pain and deformity in the left knee. Examination of the left knee showed severe varus deformity. Correction of the varus deformity and tibial shortness was carried out at the same time by the callotasis method using an Orthofix external fixator. During follow-up the varus deformity in her right knee gradually progressed. At 18 months after the initial surgery, the right varus deformity and tibial shortness were corrected at the same time by the callotasis method using an Orthofix external fixator; proximal epiphysiodesis was also performed. The coronal-plane alignment of both knees remains good. In cases with bilateral involvement of Blount's disease, the onset of the deformity is usually nearly synchronous. In some cases, however, it begins unilaterally, as with this patient, so it is essential to check both sides by means of tomography or magnetic resonance imaging and not just radiography. Moreover, we must be careful to plan the treatment in such a case so as to anticipate possible leg-length discrepancy problems.

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.

Recurrence of varus deformity after proximal tibial osteotomy in Blount disease: long-term follow-up

In a retrospective review of 74 tibial osteotomies performed for Blount disease, the patients were divided into three groups based on age and treatment. Group A (26 osteotomies), 4 years old or younger, and group B (34 osteotomies), older than 4 years, were treated the same with osteotomy and crossed pins. Group C (14 osteotomies), older than 4 years, was treated with osteotomy and external fixator. At 6 years of follow-up, the recurrence of varus deformity was 46%, 94%, and 72% in groups A, B, and C, respectively. There was no correlation between recurrence of varus deformity and preoperative deformity angle or degree of surgical correction. Fixation with crossed pins or external fixator was not a factor. Surgery at 4 years old or younger and correction of the postoperative deformity angle in valgus may obviate recurrence of varus deformity in Blount disease at long-term follow-up.

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.