Proximal tibial osteotomy and Taylor Spatial Frame application for correction of tibia vara in morbidly obese adolescents

Annual Trends of High Tibial Osteotomy: Analysis of an Official Registry in Italy

Background and Objectives: Knee osteoarthritis is a serious burden for modern countries. Timing of surgery and treatment choice are still a matter of controversy in the orthopedic literature. The purpose of this study was to ascertain the incidence and hospitalization trends of high tibial osteotomy in Italy from 2001 to 2016. Materials and Methods: Data are sourced from the National Hospital Discharge Reports (SDO) of the Italian Ministry of Health between 2001 and 2016. Results: A total of 34,402 high tibial osteotomies were performed over the study period in Italy. The cumulative incidence was 3.6 cases per 100,000 residents. The age classes 50-54, 55-59 showed the higher number of procedures. In pediatric patients (0-19 years), high tibial osteotomies are also largely performed. The majority of patients having surgery were men with a M/F ratio of 1.5. The mean age of patients was 44.2 ± 19.2 years. Males were significantly younger than females (43.3 ± 20.7 vs. 45.6 ± 17.7). The average length of hospitalization was 6.1 ± 7.3 days. Over the course of the analysis, a declining trend in hospital stay length was seen. The main primary diagnosis codes were "Varus knee" (736.42 ICD-9-CM code, 33.9%), "Osteoarthrosis, localized, primary, leg region" (715.16 ICD-9-CM code, 9.5%). Conclusions: Over the study period, high tibial osteotomies in Italy almost halved. Varus deformity and knee osteoarthritis are the leading causes requiring high tibial osteotomy. Except for the pediatric setting, results showed that from the 20-24 age class to the 50-54 age class, there was an increasing request for knee osteotomy, whereas in those aged >60 years, the incidence progressively decreased. The evident decline in HTO performed over the years in Italy seems to reflect a minor role for knee osteotomy in the management of knee OA, as it seems to be primarily reserved for younger male patients.

Correction of severe lower extremity deformity with digital hexapod external fixator based on CT data

Purpose

Our goal was to examine the therapeutic effect of a self-designed digital six-axis external fixator technique for the correction of severe lower extremity deformities.

Patients and methods

Between January 2017 and December 2020, our institution employed self-developed digital hexapod external fixator technology (QSF), based on CT data, to gradually correct 28 severe tibial deformities, and 15 femurs underwent osteotomy and internal fixation. The mean patient age was 32.6 ± 14.3 years, and the mean follow-up duration was 27.4 ± 16.1 months. We also recoded and analyzed the values of preoperative and final follow-up MAD, mFTA, MPTA, LLD, mLDFA, LEFS, KSS, and functional score.

Results

The QSF adjustment duration was 21.4 ± 10.8 days, and the healing duration of the tibial osteotomy site was 17.6 ± 7.0 weeks. The preoperative MAD, mFTA, and MPTA were 54.1 ± 26.2 mm, 167.7 ± 15.7°, and 75.2 ± 12.0°, respectively. At the last follow-up, the MAD was 8.2 ± 9.9 mm, mFTA was 177.6 ± 3.4°, and MPTA was 87.6 ± 2.4°. Based on these data, we achieved significant improvement post operation. The preoperative LLD and mLDFA values were 13.8 ± 18 mm and 83.7 ± 10.8°, respectively, and the values were 7.6 ± 7.6 mm and 87.8 ± 2.6°, respectively, at the last follow-up. This indicated no significant difference in these values before and after the operation. Finally, the LEFS, KSS, and functional scores improved from preoperative 51.6 ± 11.2, 68.5 ± 11.7, and 67.8 ± 11.2 to postoperative 72.3 ± 6.1, 92.9 ± 3.4, and 94.2 ± 6.3, respectively.

Conclusions

Based on our analyses, the QSF technique accurately corrected severe multiplanar tibial deformities in adults. When combined with femoral osteotomy, satisfactory lower extremity alignment was obtained while correcting for femoral deformity. This technology has the advantages of simple operation, reliable fixation, less trauma, and less complications.

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.

Controlled Double Gradual Opening Osteotomy for the Treatment of Severe Varus of the Knee-Blount's Disease

Varus deformity of the knee can lead to early degeneration of the medial tibiofemoral joint. Pediatric patients can be pathologically affected with this deformity known as Blount disease. The cause of this pathology is still uncertain, but some risk factors are well established, such as obesity and family history. The diagnosis is made through clinical history, physical examination, and the radiographic analysis after the age of 2.5 years. The analysis of the metaphyseal-diaphyseal angle, described by Levine and Drennan, is also commonly used for prognosis. When this angle is greater than 16°, it is considered to be grossly abnormal. Possible options for correcting the generated angular deformity are epiphysiodesis, osteotomy (acute or gradual correction), and gradual correction by distraction of the physis. In this surgical technique, we performed a double tibial osteotomy with controlled gradual opening using monolateral external fixator (Orthofix, Verona, Italy). Our technique proved to be an effective way to correct the adolescent tibia vara and is practical and reproducible. Moreover, the use of gradual opening osteotomy allowed a more accurate outcome.

Acute correction of severe complex adolescent late-onset tibia vara by minimally invasive osteotomy and simple circular fixation: a case series with 2-year minimum follow-up

Background

Despite multiple published reviews, the optimum method of correction and stabilisation of Blount’s disease remains controversial. The purpose of this study is to evaluate the clinical and radiological outcomes of acute correction of late-onset tibial vara by percutaneous proximal tibial osteotomy with circular external fixation using two simple rings. Weighing up the pros and cons and to establish if this method would be the method of choice in similar severe cases especially in a context of limited resources.

Methods

This study was conducted between November 2016 and July 2020. We retrospectively reviewed the clinical notes and radiographs of 30 patients (32 tibiae) who had correction of severe late-onset tibia vara by proximal tibial osteotomy and Ilizarov external fixator. The mean age at the time of the operation was 16.6 (± 2.7) years (range 13–22).

Results

The mean proximal tibial angle was 65.7° (± 7.8) preoperatively and 89.8° (± 1.7) postoperatively (p < 0.001). The mean mechanical axis deviation improved from 56.2 (± 8.3) preoperatively to 2.8 (± 1.6) mm postoperatively (p < 0.001). The mean femoral-tibial shaft angle was changed from –34.3° (± 6.7) preoperatively to 5.7° (± 2.8) after correction, with degree of correction ranging from 25° to 45°. Complications included overcorrection (three cases 9%) and pin tract infection (eight cases 25%). The mean Hospital for Special Surgery knee scoring system (HSS) improved from 51.03 (± 11.24) preoperatively to 94.2 (± 6.8) postoperatively (p < 0.001). The mean length of follow up period 33.22 (± 6.77) months, (rang: 25–46 months). At final follow up, all patients had full knee range of motion and normal function. All cases progressed to union and there were no cases of recurrence of deformity.

Conclusion

This simple procedure provides secure fixation allowing early weight bearing and early return to function. It can be used in the context of health care systems with limited resources. It has a relatively low complication rate. Our results suggest that acute correction and simple circular frame fixation is an excellent treatment choice for cases of late-onset tibia vara, especially in severe deformities.

Update on premature physeal closure. Diagnosis and treatment

PURPOSE OF REVIEW

Premature Physeal Closure (PPC) is the most common consequence of a mostly posttraumatic, physeal injury. They are of utmost importance because they can significantly alter physeal function and lead to disorders such as limb length discrepancies and angular deformities.

RECENT FINDINGS

The type of physeal fracture has not demonstrated a solid predictive value in the formation of PPC, especially in the knee where almost any type of fracture can produce it. The detection of physeal damage with imaging tests (simple radiology and MRI) is very accurate; however, their predictive capacity to foretell which injury will generate a physeal bridge is still poor. For this reason, it is not advisable to make surgical decisions at the first medical assessment. Direct surgical management of PPC's (resection-interposition technique) has generally shown high unpredictability. Nevertheless, the latest interposition materials (chondrocytes and mesenchymal stem cells) showed promising results.

SUMMARY

PPC is an often devastating consequence of physeal injury and as such deserves further research. To date little is known about etiopathogenesis, risk factors and natural history among other aspects. Until direct surgery offers more consistent results, acute osteotomies and bone distraction for progressive correction continue to be the most widespread treatments for PPCs.

Gradual correction of proximal tibia deformity for Blount disease in adolescent and young adults

PURPOSE

Management of Blount disease in adolescents and young adults is complex and associated with high risk of morbidities. Gradual correction with external fixator can minimize soft tissue injury and allow subsequent adjustment in degree of correction. This study investigates the surgical outcome and complication rate of gradual correction of neglected Blount disease through single-level extra-articular corticotomy.

METHODS

Patients treated for Blount disease using external fixator from 2002 to 2016 were recruited for the study. We used Ilizarov and Taylor Spatial Frame (TSF) external fixator to perform simultaneous correction of all the metaphyseal deformities without elevating the tibia plateau. Surgical outcome was evaluated using mechanical axis deviation (MAD), tibial femoral angle (TFA), and femoral condyle tibial shaft angle (FCTSA).

RESULTS

A total of 22 patients with 32 tibias have been recruited for the study. The mean MAD improved from 95 ± 51.4 mm to 9.0 ± 37.7 mm (medial to midpoint of the knee), mean TFA improved from 31 ± 15° varus to 2 ± 14° valgus, and mean FCTSA improved from 53 ± 14° to 86 ± 14°. Mean duration of frame application is 9.4 months. Two patients developed pathological fractures over the distracted bones, one developed delayed consolidation and other developed overcorrection.

CONCLUSIONS

Correction of Blount disease can be achieved by gradual correction using Ilizarov or TSF external fixator with low risk of soft tissue complication. Longer duration of frame application should be considered to reduce the risk of pathological fracture or subsequent deformation of the corrected bone.

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.

Simultaneous bilateral correction of genu varum with Smart frame

PURPOSE

The aim of this study is to evaluate clinical and radiological results of simultaneous bilateral correction of genu varum with Smart frame.

METHODS

Between 2011 and 2015, a total of 25 patients (10 females, 15 males) who had bilateral genu varum deformity were operated bilaterally with tibial and fibular osteotomy in the same session, using Smart frame. The mean follow-up period was 28.7 (range, 13-45) months. All patients had bilateral tibial varus deformity. Femoral deformity was corrected in an earlier session in nine patients. Mechanical axis deviation (MAD), mechanical lateral distal femoral angle, mechanical medial proximal tibial angle (mMPTA) and posterior proximal tibial angle (PPTA) were measured preoperatively and postoperatively. Short Form-36 questionnaire was filled by the patients preoperatively and during the last follow-up.

RESULTS

The mean preoperative MAD was 37.6 mm (range, 9-98 mm), which improved to 8.4 mm (range, 3-44 mm) postoperatively ( p < 0.05). The mean preoperative mMPTA was 76°, which improved to 89° ( p < 0.05). The mean preoperative PPTA was 75.5°, which improved to 80.3 ( p < 0.05). Ten problems (20%), two obstacles (4%) and no sequelae occurred in 50 legs of 25 patients.

CONCLUSIONS

In conclusion, Smart frame is an accurate and reliable method for performing bilateral simultaneous deformity correction in patients with bilateral genu varum deformity. It can be applied for various childhood-induced severe tibial deformities such as achondroplasia, rickets, skeletal dysplasia and Blount's disease.

Update on treatment of adolescent Blount disease

PURPOSE OF REVIEW

Treatments available to correct adolescent Blount disease deformities differ in terms of features, advantages, and disadvantages. Each is indicated, therefore, for different scenarios of severity, physeal condition, and maturity. The purpose of this review is to update basic concepts, surgical treatments, and controversies concerning this disorder.

RECENT FINDINGS

The cause of Blount disease is unknown although etiologic factors as morbid obesity and hypovitaminosis D are thought to be associated with it. Recently, semiinvasive techniques (guided growth) have been proposed for mild deformities but remain controversial. Osteotomies with external fixation (hexapodes) are still the most recommended corrective treatment in this condition.

SUMMARY

Little is known about the origin and natural history of Blount disease. Treatment is always surgical and, given their complexity, should be preceded by a thorough analysis and planning regarding all deformities. Treatment principles are to correct the three-dimensional deformity and avoid recurrence. The choice of technique mainly depends on patient maturity and severity. Guided growth is a good choice for more immature patients with moderate deformities. Progressive correction using osteotomy or physeal distraction is indicated for patients with severe deformities and low remaining growth. The Taylor spatial frame is currently the most popular progressive correction device.

The challenges of a comprehensive surgical approach to Blount's disease

PURPOSE

The purpose of this study is to evaluate a surgical technique that aims to address the multi-planar deformities occurring in early onset Blount's disease.

METHODS

Seven patients (eight lower limbs) with early onset Blount's disease were treated with a surgical technique that used an external fixator to simultaneously address all aspects of deformity. Presenting radiographic parameters including mechanical axis deviation (MAD), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA) and medial plateau angle (MPA) were compared with final follow-up and the unaffected limb. Data was also collected on surgical complications and functional outcomes.

RESULTS

After a mean interval of 4.6 years (2.2 to 9), the MAD of the affected limb improved from 4.85 cm to 1.88 cm, MPTA from 43.58° to 75.46° and MPA from 43.41° to 20.71°. The mean time in the external fixator was 5.6 months (3.5 to 10.4). Recurrence was noted in three patients; two had evidence of nerve injury and one patient had premature fibular consolidation.

CONCLUSION

The surgical technique described in this study has attempted to address the complex multiaxial deformity that is encountered in Blount's disease. It identifies difficulties and limitations in developing a comprehensive surgical protocol and highlights complications associated with this approach.

Guided growth for tibia vara (Blount's disease)

Blount's disease is commonly attributed to an intrinsic, idiopathic defect in the posteromedial proximal tibial physis resulting in progressive bowing of the leg, intoeing, and lateral knee thrust. Treatment has historically included bracing, physeal stapling, or corrective osteotomy, and was determined primarily by age at presentation. As we feel the pathology is not necessarily age dependent, we have elected to use the technique of guided growth using a lateral tension band plate to correct limb alignment as a first-line treatment in all patients presenting to our clinic as long as they had growth remaining and no evidence of a physeal bar.We identified 17 patients with tibia vara (27 limbs) who were managed by means of guided growth of the proximal tibia, from age 1.8 years to 15.1 years. Clinical and radiographic parameters were followed pre- and postoperatively. The response to guided growth was documented as were any related complications.Twenty-one (78%) limbs had complete normalization of their mechanical axis (middle 50% of knee). Time to correction averaged 13.5 months (8-19 months). There were no peri-operative complications. We observed hardware failure in 3 patients; 2 with screw breakage and 1 patient with hardware migration, none requiring subsequent osteotomy or further treatment. Two patients had rebound varus: one is being observed and another has undergone a repeat procedure.Patients with pathologic tibia vara present at various ages and have historically undergone various treatments ranging from bracing to tibial osteotomy based on age at presentation. We have found that guided growth utilizing tethering plates can be used effectively as first-line treatment in all patients with growth remaining. This minimally invasive method is predictable and well tolerated. Recurrent deformity, though unlikely, is easily remedied by repeating the process and does not preclude osteotomy if eventually needed. Concomitant resolution of ligamentous laxity and inward torsion can be anticipated as the mechanical axis is restored to neutral. The only contraindications for guided growth include an unresectable physeal bar or skeletal maturity.

Treatment of Adolescent Blount Disease Using Taylor Spatial Frame With and Without Fibular Osteotomy: Is There any Difference?

BACKGROUND

In adolescents, Tibia Vara (Blount disease) patients usually present with combination of marked genu varum, procurvatum, and internal tibial torsion. When no growth remaining, standard treatment protocol for correction is osteotomy of the proximal tibia and fibula. In our study we compared 2 groups of patients: group A was treated with fibular osteotomy and group B was treated without fibular osteotomy.

METHODS

Twenty-three patients (25 tibias), 21 males and 2 females, mean age of 14.7 years (range, 13 to 21 y) were included in our study. All patients underwent correction with Taylor spatial frame. Group A (with fibular osteotomy) included 11 tibias and group B (no fibular osteotomy) included 14 tibias. Group A underwent correction by proximal tibial and fibular osteotomies (fibula was fixed distally by 2 ilizarov wires to the distal ring). Group B was treated by proximal tibial osteotomy only (fibula was not osteotomized and was not fixed to the tibia).

RESULTS

Correction goal was achieved in 9 cases in group A and 12 in group B. Mean time in frame was 15.9 weeks in group A and 14.14 in group B. Mean lengthening was 16.5 mm in group A and 12.8 mm in group B. Mean proximal tibia-fibula distance was 21.1 mm (group A) and 14.9 mm (group B). Mean distal tibia-fibula distance was 9.8 mm (group A) and 9.6 mm (group B). There was no ankle malalignment in both the groups. Complications included pin-tract infection in 11 patients and delayed union in 2 patients (1 in each group).

CONCLUSION

We believe that in patients with minimal lengthening as needed in patients with adolescent Tibia Vara correction might be performed safely without osteotomy and fixation of the fibula.

LEVEL OF EVIDENCE

Level III.

Blount disease: an update

Blount disease is a developmental disorder associated with childhood obesity. Based on whether the deformity is first noted before or after 4 years of age, early-onset and late-onset forms of Blount disease have been described. Besides physeal abnormalities of the proximal tibia, compensatory changes in the intra-articular morphology of the medial compartment of the affected knee are often noted on MRI scan. Both guided growth and acute and gradual correction via a proximal tibial osteotomy have roles in the surgical management of these patients. In order to optimize clinical outcome, frequent follow-up until skeletal maturity is recommended.

Deformity correction in Haiti with the Taylor Spatial Frame

The Taylor Spatial Frame (TSF) is an external-fixator that corrects deformities in 6 axes, and can successfully manage disorders involving multiplanar deformities. In the developing-world, orthopaedic surgeons are often faced with deformities from neglected trauma and birth defects more severe than those typically seen in developed-countries. This article evaluates the applicability of TSF in the challenging medical environment of Haiti. At Haiti Adventist Hospital, the authors treated 80 cases using the TSF with a minimum follow-up of 1-year. Good results were observed in 99% of the cases (79 out of 80), approaching similar outcomes than those described in literature.