The Medial Elevation Osteotomy for Late-presenting and Recurrent Infantile Blount Disease

The transphyseal osteotomy for the slipped proximal tibial epiphysis in tibia vara

This study aimed to describe a novel transphyseal osteotomy (TPO) for acute deformity correction in children with bilateral tibia vara and the atraumatic 'slipped proximal tibial epiphysis' (SPTE) entity. We described the clinical and radiological findings in five children (10 limbs) with tibia vara that were treated with the TPO. The criteria for the SPTE were met in nine (9/10) cases. The surgical technique and short-term results of the TPO are reported. The median age was 9 years (range, 6-9), with obesity (BMI > 95th centile) present in all children. The medial tibial plateau was not significantly depressed (the median angle of depression of the medial plateau measured 30° (range, 20°-32°). The mean medial proximal tibial angle of 33° (range, 8°-71°) was corrected to 82° (range, 77°-86°), the mean anatomic posterior proximal tibial angle of 48° (range, 32°-70°) was corrected to 72° (range, 61°-86°), and the median internal tibial rotation of 45° (range, 20°-50° internal rotation) was corrected to neutral rotation (range, 10° internal-10° external rotation). There were two complications: one case of recurrent deformity and one case of intra-articular extension of the osteotomy. We describe a novel TPO that aims to simultaneously correct all aspects of the deformity, stabilise the physis, and prevent recurrence through epiphysiodesis. Further research is required to determine its efficacy and safety. The atraumatic SPTE appears to represent a specific morphological presentation in tibia vara. Level of evidence: 4.

Recurrence and Complication Rates of Surgical Treatment for Blount's Disease in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Blount's disease is a growth disorder of the proximal tibia that causes progressive genu varum in children. Surgical treatment is recommended if the deformity worsens, but which intervention is best remains controversial. This study aims to identify factors influencing outcomes and determine the most effective surgical approach.

METHODS

A systematic review was conducted of studies published before January 2022.

RESULTS

In total, 63 retrospective studies with CEBM IIIb/IV levels were included (1672 knees in 1234 patients). The most commonly reported treatment was acute correction via osteotomy (47%), followed by hemiepiphysiodesis (22%) and gradual correction (18%). Combined procedures were reported in 13% of cases. The overall recurrence rate was 18%, with a significant difference when comparing the recurrence rates after gradual correction with those after hemiepiphysiodesis (7% and 29%, respectively). Major complications beyond recurrence were observed in 5% of cases. A meta-analysis of the available raw data showed a significantly increased recurrence rate (39%) among treated children who were between 4.5 and 11.25 years of age and were followed for a minimum follow-up of 2.5 years.

CONCLUSIONS

Overall, poor evidence with which to establish an optimal treatment for Blount's disease was found. This study remarked on the need for early diagnosis, classification, and treatment of infantile tibia vara, since a significant rate of recurrence was found in neglected cases.

Guided Growth for Varus Deformity Following Early Tibial Osteotomy in Infantile Tibia Vara-A Multi-Center Study

BACKGROUND

Despite early osteotomy, many patients with infantile tibia vara (ITV) have persistent or recurrent varus deformity and disordered growth at the medial proximal tibial physis. Our hypothesis was that lateral tibial tension band plating (LTTBP) could guide correction.

METHODS

A retrospective review at 6 centers of 15 patients (16 extremities) was performed of LTTBP for varus deformity following early osteotomy in ITV, diagnosed≤4years of age. Correction of deformity parameters on digital standing anteroposterior lower extremity radiographs determined outcome.

RESULTS

Twenty-two LTTBP procedures were performed at mean age of 7.5 years, including 4 revisions for implant failure and 2 reimplantations for recurrence. Single event LLTBP, improved the medial proximal tibial angle with a mean change of 13.4 degrees (0.39 degrees/month). Eleven limbs had preoperative mechanical lateral distal femoral angle (mLDFA)>90 degrees. While n degree femoral procedures were performed, at study end, 11 femurs had mechanical lateral distal femoral angle≤90°. Pretreatment, 13 extremities had mechanical axis zone (MAZone) III varus (81%) and 3 had MAZone II varus (19%). LTTBP's were able to initially correct 13 limbs to MAZone I or valgus but 4 limbs rebounded to MAZone II varus after implant removal. Final limb alignment, after all surgeries and rebound, included 9 in MAZone I, 5 in MAZone II varus and 2 in MAZone III varus. Average follow-up was 3.0 years at mean 10.7 years of age. Fifteen procedures resulted in improvement in MAZone and 7 had no change. On average, those that improved were younger (7.3 vs. 8.0 y), weighed less (45.5 kg with body mass index 26.5 kg/m 2 vs. 67.8 kg and body mass index 35.7 kg/m 2 ), had lower mechanical axis deviation (37.1 mm vs. 43.9 mm), lower medial physeal slope (61.7 vs. 68.7 degrees) and had a higher percentage of open triradiate phases (87 vs. 57%).

CONCLUSIONS

LTTBP for residual varus, after initial osteotomy in ITV, resulted in 81% of limbs initially achieving MAZone I or valgus with implant failure revisions and femoral remodeling. Rebound after implant removal reduced the corrected rate to 56%. Ninety-four percent avoided osteotomy during the study period.

LEVEL OF EVIDENCE

IV.

Gradual Deformity Correction with a Computer-assisted Hexapod External Fixator in Blount\'s Disease

Aim

To evaluate the results in terms of correction and complications from gradual correction with a computer-assisted hexapod circular external fixator in a mixed cohort of children with Blount's disease.

Materials and methods

A retrospective review was performed of the correction and complications of 19 children (25 limbs) with recurrent infantile (IBD) and late-onset Blount's disease (LOBD) treated by gradual correction with a hexapod external fixator. The correction was measured by the medial proximal tibial angle (MPTA), anatomic posterior proximal tibial angle (aPPTA) and anatomic tibio-femoral angle (TFA). Obesity was present in 76% (19/25) of cases. Fifteen limbs were classified as infantile Blount's disease and 10 limbs as late-onset Blount's disease. The mean age was 12.5 years (range 7–17 years).

Results

The mean pre-operative MPTA of 59° (SD 13°, range 33–79°) was corrected to a mean of 86° (SD 5°, range 77–93°). The mean pre-operative aPPTA of 64° (SD 14°, range 33–84°) was corrected to 79° (SD 6°, range 70–90°). The median pre-operative rotation of 15° internal rotation was corrected to normal (0–15° of external rotation). Eight out of 25 limbs had severe deformities with varus or procurvatum greater than 40° or both. The mean pre-operative TFA of 28° varus (SD 13°, range 4–53°) was corrected to 1.8° valgus (SD 6°, range 14° varus to 13° valgus). The median follow-up was 19 months (range 6–67 months). The alignment after correction was “good” in 55% (11/20), “acceptable” in 35% (7/20) and “poor” in 10% (2/20).

The median duration for correction was 16 days (IQR 11–31 days, range 7–71 days). The median number of prescribed correction programmes was 1 (IQR 1–2, range 1–5). The mean total time in the frame was 136 days (SD 34 days, range 85–201 days).

All patients developed minor pin track infections that resolved with oral antibiotics (Category 1 complications). Four patients developed complications that necessitated modification of the treatment plan (Category 2 complications). In two cases, treatment objectives could not be achieved (Category 3 complications). Two patients treated before skeletal maturity developed recurrent genu varum.

Conclusion

Gradual correction with a computer-assisted hexapod external fixator may be a useful technique for correcting recurrent IBD or LOBD even in children with severe deformities. The results of gradual correction were similar in the two groups. While complications occur, most can be mitigated by timely intervention during the correction phase of treatment. Recurrence remains a concern if correction is performed before skeletal maturity.

Level of evidence

4.

How to cite this article

Mare PH, Marais LC. Gradual Deformity Correction with a Computer-assisted Hexapod External Fixator in Blount's Disease. Strategies Trauma Limb Reconstr 2022;17(1):32–37.

Recurrence in infantile tibia vara (Blount disease) after high tibia and fibula osteotomy

Infantile Tibia Vara (ITV or Blount disease) often recurs after surgical correction of the deformity. Vastly different recurrence rates have been reported in the literature. The main objective of this study was to identify any risk factors for the recurrence of ITV following high tibia and fibula valgus osteotomy. This was a retrospective cohort comparative study of 44 patients with ITV (16 with bilateral involvement) who underwent a total of 60 high tibia and fibula osteotomies. Demographics, family history, BMI, walking age and age at surgery were recorded. Pre-, post- and follow-up weight-bearing anatomic femorotibial angles, were measured from X-rays. The limbs were divided into Langenskiöld stages based on preoperative X-rays. The study found an overall recurrence rate of 63.3% for children who had a high tibia and fibula osteotomy for ITV. Surgery after the age of 4 years, advanced Langenskiöld stages (stages 3-5) and overcorrection of less than 15 degrees of valgus were identified as risk factors for recurrence. This study recommends performing a high tibia and fibula valgus osteotomy before the age of 4 years in ITV to avoid recurrence. Overcorrection of the high tibia and fibula osteotomy to 15 degrees of valgus should be considered in older patients with high Langenskiöld stages at time of presentation.