Hemiepiphysiodesis for the correction of angular deformity about the knee

The Effect of Guided Growth Surgery on Langenskiold Stage and Mechanical Axis in Early-Onset Blount Disease: A Retrospective Case Series

INTRODUCTION

Our understanding of the efficacy of guided growth surgery with tension-band plating (TBP) in early-onset Blount disease is evolving. Preliminary work has demonstrated that TBP can normalize the mechanical axis, yet its effect on Langenskiöld stage (LS) has not previously been reported. The primary outcome of this study was improvement in LS after TBP. Secondary outcomes were improvement in LS at most recent follow-up and improvement in mechanical axis deviation (MAD), mechanical medial proximal tibial angle, and mechanical lateral distal femoral angle at treatment completion and most recent follow-up.

METHODS

A retrospective review was done of patients with early-onset Blount disease treated with TBP between January 1, 2010, and December 31, 2019, across two institutions. Inclusion criteria were a radiographic diagnosis of early-onset Blount disease (LS changes present), surgery with TBP, and follow-up beyond implant removal. Radiographs before surgery, at removal of hardware (ROH), and at most recent follow-up were evaluated.

RESULTS

Twenty-five limbs in 16 children who underwent TBP at a mean age of 5.8 ± 2.3 years were included. Implants were in situ a mean of 1.9 ± 0.7 years. The mean follow-up after ROH was 3.6 ± 1.4 years. LS ranged from 1 to 5 preoperatively with 14 of 25 limbs (56%) staged ≥3. LS improved in 15 of 25 limbs (60%) at ROH and in 21 of 25 limbs (84%) at most recent follow-up. Langenskiöld changes resolved in 7 of 25 limbs (28%) at most recent follow-up. Preoperatively, the MAD was varus in all limbs, but at ROH, the MAD had improved in 22 of 23 limbs with neutral or valgus alignment in 20 of 23 limbs (87%). At most recent follow-up, 16 of 23 limbs (70%) maintained improved alignment.

DISCUSSION

There was improvement/resolution of LS and varus deformity in early-onset Blount disease in most patients who underwent TBP. Based on these results, TBP for early-onset Blount disease should be the first-line surgical treatment.

LEVEL OF EVIDENCE

IV.

Effective time, correction speed and termination time of hemi-epiphysiodesis in children

In children with asymmetric growth on the medial and lateral side of limbs, if there still remains growth potential, the guided growth technique of hemi-epiphysiodesis on one side of the epiphysis is recognized as a safe and effective method. However, when the hemi-epiphysiodesis start to correct the deformities, how many degrees could hemi-epiphysiodesis bring every month and when to remove the hemi-epiphysiodesis implant without rebound phenomenon are still on debate. This article reviews the current studies focus on the effective time, correction speed and termination time of hemi-epiphysiodesis.

Can acute correction with simultaneous hemiepiphysiodesis of lateral proximal tibia physis prevent recurrence in neglected infantile Blount's disease?

PURPOSE

The treatment of infantile Blount's disease usually includes surgical correction, but high recurrence is still a problem regardless of the procedure. We conducted a cross-sectional study of severely neglected infantile Blount's disease treated with acute correction and simultaneous hemiepiphysiodesis of lateral proximal tibia physis. In this study, we aimed to observe the complication and recurrence.

METHODS

This research is an analytical study with a cross-sectional design using retrospective data collection and total sampling. The subjects were patients with neglected infantile Blount's disease treated from 2018 to 2023 in our institution. Follow-up was conducted in 6, 12, 24, and 36 months.

RESULTS

A total of 25 legs from twenty patients were recorded. We observed three legs (12.0%) had recurrence. No neurovascular complications and infections were observed. All subjects had significant postoperative improvement of TFA (mean 6.8 ± 0.730 valgus), Drennan angle, MPTA, MTPD, JLCA, and ligamentous laxity grading (p < 0.001). Lower than 5° postoperative valgus overcorrections and preoperative physeal bar were significant factors in patients with recurrence (p = 0.020 and p = 0.010). There was no significant increase in leg-length discrepancy during follow-up (p = 0.052). There were no significant differences between age, BMI, preoperative TFA, pre- and postoperative Drennan angle, MPTA, MTPD, JLCA, Langenskiöld stages, and length of follow-up in patients with recurrence and not.

CONCLUSION

Acute correction with simultaneous hemiepiphysiodesis of lateral proximal tibia physis is an effective technique to prevent deformity recurrence in neglected infantile Blount's disease, provided that the postoperative TFA is more than 5° of valgus and no evidence of physeal bar in the preoperative radiograph.

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.

Predicting Rates of Angular Correction After Hemiepiphysiodesis in Patients With X-Linked Hypophosphatemic Rickets

PURPOSE

Patients with X-linked hypophosphatemic rickets (XLH) often develop coronal plane knee deformities despite medical treatment. Hemiepiphysiodesis is an effective way to correct coronal plane knee deformities in skeletally immature patients, but a full understanding of the rate of angular correction after hemiepiphysiodesis in XLH patients, compared with idiopathic cases is lacking.

METHODS

We retrospectively reviewed charts of 24 XLH patients and 37 control patients without metabolic bone disease who underwent hemiepiphysiodesis. All patients were treated with standard-of-care medical therapy (SOC=active vitamin D and phosphate salt supplementation) in our clinical research center and had a minimum of 2-year follow-up after hemiepiphysiodesis. Demographic data as well as complications, repeat procedures, or recurrence/overcorrection were recorded. Standing lower extremity radiographs were evaluated before the surgical intervention and at subsequent hardware removal or skeletal maturity, whichever came first. Mean axis deviation, knee zone, mechanical lateral distal femoral angle (mLDFA), and medial proximal tibial angle were measured on each radiograph. The rate of angular correction was calculated as the change in mLDFA and medial proximal tibial angle over the duration of treatment.

RESULTS

The magnitude of the initial deformity of the distal femur was greater in XLH patients as compared with control for varus (XLH mLDFA 97.7 +/- 4.9 vs. Control mLDFA 92.0 +/- 2.0 degrees) and valgus (XLH mLDFA 78.7 +/- 6.2 vs. Controls mLDFA 83.6 +/- 3.2 degrees). The rate of correction was dependent on age. When correcting for age, XLH patients corrected femoral deformity at a 15% to 36% slower rate than control patients for the mLDFA (>3 y growth remaining XLH 0.71 +/- 0.46 vs. control 0.84 +/- 0.27 degrees/month, <3 y growth remaining XLH 0.37 +/- 0.33 vs. control 0.58 +/- 0.41 degrees/month). No significant differences were seen in the rate of proximal tibia correction. XLH patients were less likely to end treatment in zone 1 (55.0% XLH vs. 77.8% control). XLH patients had longer treatment times than controls (19.5 +/- 10.7 vs. 12.6 +/- 7.0 mu, P value <0.001), a higher average number of secondary procedures than controls (1.33 +/- 1.44 vs. 0.62 +/- 0.92 number of procedures), a higher rate of overcorrection than controls (29.2% vs. 5.4%), and a higher rate of subsequent corrective osteotomy than controls (37.5% vs. 8.1%). There was no significant difference in the rate of complications between groups (8.3% vs. 5.4%).

CONCLUSIONS

Patients with XLH undergoing hemiepiphysiodesis have a 15% to 36% slower rate of femoral deformity correction that results in longer treatment times, a higher likelihood to undergo more secondary procedures, and a lower likelihood to reach neutral mechanical alignment.

SIGNIFICANCE

This study provides important information to guide the timing and treatment of patients with XLH and coronal plane knee deformities. In addition, results from this study can be educational for families and patients with respect to anticipated treatment times, success rates of the procedure, complication rate, and likelihood of needing repeat procedures.

Predicting Deformity Correction of Growth Modulation in Late-onset Tibia Vara

BACKGROUND

Growth modulation in late-onset tibia vara (LOTV) has been reported to yield variable results. We hypothesized that parameters of deformity severity, skeletal maturity, and body weight could predict the odds of a successful outcome.

METHODS

A retrospective review of tension band growth modulation for LOTV (onset ≥8 y) was performed at 7 centers. Tibial/overall limb deformity and hip/knee physeal maturity were assessed on preoperative anteroposterior standing lower-extremity digital radiographs. Tibial deformity change with first-time lateral tibial tension band plating (first LTTBP) was assessed by medial proximal tibia angle (MPTA). Effects of a growth modulation series (GMS) on overall limb alignment were assessed by mechanical tibiofemoral angle (mTFA) and included changes from implant removal, revision, reimplantation, subsequent growth, and femoral procedures during the study period. The successful outcome was defined as radiographic resolution of varus deformity or valgus overcorrection. Patient demographics, characteristics, maturity, deformity, and implant selections were assessed as outcome predictors using multiple logistic regression.

RESULTS

Fifty-four patients (76 limbs) had 84 LTTBP procedures and 29 femoral tension band procedures. For each 1-degree decrease in preoperative MPTA or 1-degree increase in preoperative mTFA the odds of their successful correction decreased by 26% in the first LTTBP and 6% by GMS, respectively, controlling for maturity. The change in odds of success for GMS assessed by mTFA was similar when controlling for weight. Closure of a proximal femoral physis decreased the odds of success for postoperative-MPTA by 91% with first LTTBP and for final-mTFA by 90% with GMS, controlling for preoperative deformity. Preoperative weight ≥100 kg decreased the odds of success for final-mTFA with GMS by 82%, controlling for preoperative mTFA. Age, sex, race/ethnicity, type of implant, and knee center peak value adjusted age (a method for bone age) were not predictive of outcome.

CONCLUSIONS

Resolution of varus alignment in LOTV using first LTTBP and GMS, as quantified by MPTA and mTFA, respectively, is negatively impacted by deformity magnitude, hip physeal closure, and/or body weight ≥100 kg. The presented table, utilizing these variables, is helpful in the prediction of the outcome of the first LTTBP and GMS. Even if complete correction is not predicted, growth modulation may still be appropriate to reduce deformity in high-risk patients.

LEVEL OF EVIDENCE

Level III.

Guided growth: angular deformity correction through temporary hemiepiphysiodesis with a novel flexible staple (FlexTack)

Temporary hemiepiphysiodesis (HED) is applied to children and adolescents to correct angular deformities (ADs) in long bones through guided growth. Traditional Blount staples or two-hole plates are mainly used for this indication. Despite precise surgical techniques and attentive postoperative follow-up, implant-associated complications are frequently described. To address these pitfalls, a flexible staple was developed to combine the advantages of the established implants. This study provides the first results of guided growth using the new implant and compares these with the established two-hole plates and Blount staples. Between January 2013 and December 2016, 138 patients (22 children, 116 adolescents) with genu valgum or genu varum were treated with 285 flexible staples. The minimum follow-up was 24 months. These results were compared with 98 patients treated with 205 two-hole plates and 92 patients treated with 535 Blount staples. In long-standing anteroposterior radiographs, mechanical axis deviations (MADs) were measured before and during treatment to analyze treatment efficiency. The evaluation of the new flexible staple was performed according to the idea, development, evaluation, assessment, long-term (IDEAL) study framework (Stage 2a). Overall, 79% (109/138) of patients treated with flexible staples achieved sufficient deformity correction. The median treatment duration was 16 months (interquartile range (IQR) 8 to 21). The flexible staples achieved a median MAD correction of 1.2 mm/month/HED site (IQR 0.6 to 2.0) in valgus deformities and 0.6 mm/month/HED site (IQR 0.2 to 1.5) in varus deformities. Wound infections occurred in 1%, haematomas and joint effusions in 4%, and implant-associated complications in 1% of patients treated with flexible staples. Valgus AD were corrected faster using flexible staples than two-hole plates and Blount staples. Furthermore, the median MAD after treatment was lower in varus and valgus AD, fewer implant-associated complications were detected, and reduced implantation times were recorded using flexible staples. The flexible staple seems to be a viable option for guided growth, showing comparable or possibly better results regarding correction speed and reducing implant-associated complications. Further comparative studies are required to substantiate these findings.

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.

Use of Implant-Mediated Guided Growth With Tension Band Plate in Skeletally Immature Patients With Knee Pathology: A Retrospective Review

Background: Skeletally immature patients with coronal plane angular deformity (CPAD) may be at increased risk for intra-articular pathology and patellofemoral instability (PFI). These patients may be candidates for implant-mediated guided growth (IMGG) procedures with tension band plates to address CPAD in addition to procedures for concomitant knee pathology. However, there are limited data on performing these procedures simultaneously. Questions/Purpose: We sought to demonstrate the feasibility of combined procedures to address both knee pathology and concomitant CPAD using IMGG in skeletally immature patients. Methods: We conducted a retrospective review of skeletally immature patients who underwent IMGG and concomitant surgery for anterior cruciate ligament reconstruction, osteochondritis dissecans repair, meniscus pathology, or PFI at a single institution by 2 surgeons between 2008 and 2019. Data on demographics, surgical details, follow-up, and complications were recorded. Deformity correction was assessed in a subset of eligible patients. Results: Of 29 patients meeting inclusion criteria, deformity correction was assessed in a subset of 17 patients (15 valgus, 2 varus). At final follow-up, 16 of 17 patients had mechanical tibiofemoral (mTFA) angles of <5° of varus or valgus. One patient developed "rebound" valgus >5° after plate removal. Conclusions: The IMGG performed in the setting of treating intra-articular knee pathology is feasible and should be considered for skeletally immature patients with CPAD undergoing surgery for concomitant knee pathology.

Percutaneous hemiepiphysiodesis using transphyseal screws for adolescent tibia vara

Hemiepiphysiodesis around the knee is becoming the mainstay procedure in adolescents for a wide range of aetiological deformities, when considering adolescent tibia vara (ATV), the published series have variable results. The purpose of this study was to review our experience with the percutaneous transphyseal screw (PETS) in these patients followed until bone maturity. We analysed the charts from 13 patients (20 knees) that underwent lateral tibial hemiepiphysiodesis using PETS. The radiographs were accessed before surgery, at implant removal, when occurred, and at the final follow-up. The clinical evaluation noted if there were complaints regarding pain or range of motion, and the radiographic assessment included: the femorotibial angle, the mechanical axis zone, the anatomic lateral distal femoral angle, and medial mechanical proximal tibial angle. There was one overcorrection, and after the screw removal (14 knees), rebound was observed in two knees modifying the result from excellent to good in all three knees. No bone bars and no implant breakage were observed. At the last appointment, all patients had normal knee range of motion, and two patients had unilateral alignment complaints, one of whom referred to occasional pain. Overall, the surgery was excellent in 12 knees (60%), good in six knees (30%), and poor in two knees (10%). This technique is indicated to be well tolerated and effective for treating ATV. When a complete correction cannot be obtained, in our opinion, it is advantageous to at least stabilise the deformity and postpone osteotomies until after skeletal maturity. Level of Evidence: Level IV - Case Series, Therapeutic Study.

Medial Patellofemoral Ligament Reconstruction with Open Physes

Through this article, the authors aim to summarize the techniques performed on both first time and recurrent skeletally immature patients experiencing patellar dislocation. This article focuses on several key points, such as the importance of medial patellofemoral ligament femoral insertions being distal to the growth plate and performing extensive lateral release and quadricep tendon lengthening in cases of obligatory dislocation. Although acknowledging the procedures discussed cannot be considered for all patients, as individuals with open growth plates may require additional operative time, in many cases these techniques yield high rates of success.

Change of limb alignment in Korean children and adolescents with idiopathic genu valgum

There has been no study evaluating the change of limb alignment for patients with genu valgum. The purpose of this study was to investigate the change of limb alignments in children and adolescents with idiopathic genu valgum through evaluating distal femur, proximal tibia, and knee joint line.Consecutive children and adolescents, under the age of 18, with genu valgum were included. Mechanical tibiofemoral angle, mechanical lateral distal femoral angle, mechanical medial proximal tibia angle, and joint line convergence angle were measured. The rate of changes for each radiographic measurement were analyzed using a linear mixed model.A total of 1539 teleroentgenograms from 518 limbs of 273 individuals were included in this study. Linear mixed model showed that the change of limb alignment was significantly associated with age, but not associated with gender and laterality. The mechanical tibiofemoral angle was most valgus initially, decreasing until reaching its lowest value of 2.8° at 10 years old. The mechanical lateral distal femoral angle decreases from initial neutral alignment and increases in valgus continuously. The mechanical medial proximal tibia angle decreases from initial valgus and progresses to be neutral at around the age of 10. The joint line convergence angle decreases sharply from initial valgus alignment to 0° at the age of 5.Valgus alignment in children with idiopathic genu valgum decreases until approximately the age of 10. In younger children, the tibia and joint line contribute most to overall valgus alignment; in older children, the femur contributes the most. Based on our results, we recommend monitoring patient limb alignment until it stabilizes around the age of 10, and then carefully planning and performing corrective surgery with complete consideration of the changing bony alignment.

Angular Deformities of the Knee in Children Treated with Guided Growth

Introduction:

The guided growth technique is an alternative to corrective osteotomy for treating angular deformities of the extremities. It has the advantage of being minimally invasive and is effective in a growing child. This study reports on the outcome of guided growth technique using a plate in correcting knee angular deformities.

Material and Methods:

We conducted a retrospective study of children with angular deformity of the knee treated by the guided growth technique from January 2010 to December 2015 in a tertiary centre. The guided growth technique was done using either the flexible titanium plate (8-plate) or the 2-hole reconstruction plate. Correction of deformity was assessed on radiographs by evaluating the mechanical axis deviation and tibiofemoral angle. The implants were removed once deformity correction was achieved.

Results:

A total of 17 patients (27 knees) were evaluated. Twenty-two knees (81.5%) achieved complete correction of the deformity. The median age was 4.0 (interquartile range 3.0-6.0) years and the median Body Mass Index (BMI) was 26.0 (25.0-28.0). There were 7 unilateral and 10 bilateral deformities with different pathologies (14 tibia vara, 3 genu valgus). The median rate of correction was 0.71° per month. One patient (1 knee) had screw pull-out and two patients (4 knees) had broken screws in the proximal tibia. Three patients (5 knees) failed to achieve complete correction and were subsequently treated with corrective osteotomies. Out of five patients (8 knees) who were followed-up for at least 12 months after removal of hardware, two had rebound deformities. No permanent growth retardation occurred in our patients.

Conclusion:

Our outcome for guided growth to correct knee angular deformity was similar to other studies. Guided growth is safe to perform in children below 12 years old and has good outcome in idiopathic genu valgus and Langeskiold II for tibia vara. Patients should be observed for recurrence until skeletal maturity following implant removal.

Comparison of two types of fixation for proximal tibial epiphysiodesis: An experimental study in a rabbit model

Objectives

In this study, we describe a novel hemiepiphysiodesis technique to prevent implant-related perichondrial ring injury in a rabbit model.

Materials and methods

Proximal tibial epiphyseal plates of a total of 16 white New Zealand rabbits were used for this animal model. The subjects were divided into three equal groups as follows: Group 1 (Kirschner wire [K-wire]/cerclage), Group 2 (8-plate) right-hind legs, Group 3 (Control) left hind legs. Using anteroposterior radiography, the medial slope angle (MSA), articular line-diaphyseal angle (ALDA), and the angle between screws of 8-plate in lateral X-ray tibial slope angle (TSA) were measured. The radiographs were taken early postoperative (Day 1) and on sacrification day (Week 8). The histological evaluation of the perichondrial ring was made on a 7-mm axial section that stained with Safranin O/fast green at X10 magnification.

Results

In both K-wire and 8-plate groups, the early postoperative ALDA and TSA were greater than the sacrification ALDA and TSA (p=0.028 and p<0.001, respectively). The early postoperative MSA was lower than the sacrification MSA in groups, (p<0.001). The MSA in the control group was lower than the K-wire and 8-plate groups (p<0.001 and p=0.009; respectively). The perichondrial ring thickness of the K-wire group was greater than the 8-plate group in histological evaluation (p<0.001).

Conclusion

Both of the K-wire and 8-plate groups showed similar angulation effects in the proximal tibia, although histologically less damage to the perichondrial ring was observed in the K-wire group, compared to the 8-plate group.

Acute correction of proximal tibial coronal plane deformity in small children using a small monolateral external fixator with or without cross-pinning

PURPOSE

Surgical correction of proximal tibia deformity in small children can be challenging. We present the surgical technique and outcome of proximal tibia osteotomy fixed with small monolateral external fixator in this patient group.

METHODS

A total of 17 cases in eight patients younger than nine years of age were study subjects. A proximal tibia osteotomy was fixed with a small monolateral external fixator with or without cross-pinning. Outcome was evaluated by changes of radiographic parameters such as medial proximal tibia angle (MPTA), metaphyseal diaphyseal angle (MDA) and clinical findings of complications, time interval until weight bearing and fixator removal time.

RESULTS

MPTA improved from a preoperative mean of 73° (sd 4°; 66° to 78°) to an immediate postoperative mean of 90° (sd 3°; 85° to 96°) in varus tibiae, and from 104° (sd 1°; 103° to 105°) to 89° (sd 1°; 88° to 89°) in valgus tibiae. In all, 15 of the 17 cases (88.3 %) achieved postoperative MPTA within the normal range (85° to 90°). MDA improved from a preoperative mean of 19° (sd 5°; 11° to 24°) to an immediate postoperative mean of 0° (sd 4°; -6° to 7°) in varus tibiae, and from -25° (sd 2°; -22° to -24°) to 2° (SD 1°; 1° to 3°) in valgus tibiae. Full weight bearing was possible at mean 1.7 months (0.5 to 3.0). Mean follow-up period was 6.5 years (sd 5.4; 1.0 to 16.0). No complications developed during the follow-up.

CONCLUSION

Proximal tibia osteotomy fixed with small monolateral external fixator provides accurate, safe and efficient correction in the management of coronal plane angular deformity in small children.

LEVEL OF EVIDENCE

Level IV.

A retrospective study of treatment of genu valgum/varum with guided growth: Risk factors for a lower rate of angular correction

The rate of angular correction (ROAC) is very unpredictable and may be affected by various factors in the treatment of genu valgum and varum by means of guided growth. The purpose of this study was to assess the ROAC in cases from our institution and to identify risk factors associated with the occurrence of lower ROAC.We retrospectively reviewed the chart records of 68 patients undergoing guided growth with figure-eight plate for the correction of genu valgum and varum. Based on the data from these patients, the annual increment of physeal growth was calculated and compared with data from the Anderson chart. The associations between patient characteristics and ROAC were evaluated with the use of univariate logistic regression.The mean rate of femoral angular correction was 10.29 degrees/year, while the mean rate of tibial angular correction was 7.92 degrees/year. In a univariate logistic regression analysis, the variables associated with a higher risk of lower ROAC included non-idiopathic coronal deformity of the knee (odds ratio = 13.58, p < 0.001) and body weight at or above the 95th percentile for children (odds ratio = 2.69, p = 0.020).Obesity and non-idiopathic coronal deformity of the knee are risk factors for lower ROAC. It is still uncertain whether severity of deformity, race, and operative procedure have a substantial effect on the rate of correction.Level III evidence.

Affecting Factors and Correction Ratio in Genu Valgum or Varum Treated with Percutaneous Epiphysiodesis Using Transphyseal Screws

This study evaluated the correction rates of idiopathic genu valgum or varum after percutaneous epiphysiodesis using transphyseal screws (PETS) and analyzed the affecting factors. A total of 35 children without underlying diseases were enrolled containing 64 physes (44 distal femoral (DT), 20 proximal tibial (PT)). Anatomic tibiofemoral angle (aTFA) and the mechanical axis deviation (MAD) were taken from teleroentgenograms before PETS surgery and screw removal. The correction rates of the valgus and varus deformities for patients treated with PETS were 1.146°/month and 0.639°/month using aTFA while using MAD showed rates of 4.884%/month and 3.094%/month. After aTFA (p < 0.001) and MAD (p < 0.001) analyses, the correction rate of DF was significantly faster than that of PT. Under multivariable analysis, the aTFA correction rate was significantly faster in younger patients (p < 0.001), in males (p < 0.001), in patients with lower weights (p < 0.001), and in the group that was screwed at DF (p < 0.001). Meanwhile, the MAD correction rate was significantly faster in patients with lower heights (p = 0.003). PETS is an effective treatment method for valgus and varus deformities in growing children and clinical characters should be considered to estimate the correction rate.

Tension Band Plate (TBP)-guided Hemiepiphysiodesis in Blount Disease: 10-Year Single-center Experience With a Systematic Review of Literature

BACKGROUND

Primary treatment for Blount disease has changed in the last decade from osteotomies or staples to tension band plate (TBP)-guided hemiepiphysiodesis. However, implant-related issues have been frequently reported with Blount cases. The purpose of our study is to evaluate the surgical failure rates of TBP in Blount disease and characterize predictors for failure.

METHODS

We performed an Institutional Review Board-approved retrospective chart-review of pediatric patients with Blount disease to evaluate the results of TBP from 2008 to 2017 and a systematic literature review. Blount cases defined as pathologic tibia-vara with HKA (hip-knee-ankle) axis and MDA (metaphyseal-diaphyseal angle) deviations ≥11 degrees were included in the analysis. Surgical failure was categorized as mechanical and functional failure. We studied both patient and implant-related characteristics and compared our results with a systematic review.

RESULTS

In 61 limbs of 40 patients with mean follow-up of 38 months, we found 41% (25/61) overall surgical failure rate and 11% (7/61) mechanical failure rate corresponding to 11% to 100% (range) and 0% to 50% (range) in 8 other studies. Statistical comparison between our surgical failure and nonfailure groups showed significant differences in deformity (P=0.001), plate material (P=0.042), and obesity (P=0.044) in univariate analysis. The odds of surgical failure increased by 1.2 times with severe deformity and 5.9 times with titanium TBP in the multivariate analysis after individual risk-factor adjustment. All 7 mechanical failures involved breakage of cannulated screws on the metaphyseal side.

CONCLUSIONS

Most of the studies have reported high failure rates of TBP in Blount cases. Besides patient-related risk factors like obesity and deformity, titanium TBP seems to be an independent risk factor for failure. Solid screws were protective for mechanical failure, but not for functional failure. In conclusion, efficacy of TBP still needs to be proven in Blount disease and implant design may warrant reassessment.

LEVEL OF EVIDENCE

Level III-retrospective comparative study with a systematic review.

Risk factors for failure of temporary hemiepiphysiodesis in Blount disease: a systematic review

There is limited information regarding the use of temporary hemiepiphysiodesis for Blount disease. We performed a systematic review of patients treated for Blount disease using either extraperiosteal staples or plates to identify characteristics affecting clinical outcome, including the need for unplanned procedures. A total of 53 patients (63 bone segments) underwent temporary hemiepiphysiodesis at a mean age of 8.8 years (1.8-14.7 years). Overall, 32/63 (51%) segments achieved neutral mechanical axis and 31/63 (49%) underwent unplanned subsequent procedures, with or without a subsequent osteotomy. On the basis of the available heterogeneous data, neither age at index surgery nor the type of implant correlated with the need for unplanned additional surgeries.

Comparison of plate and screw constructs versus screws only for anterior distal femoral hemiepiphysiodesis in children

The study aim was to compare methods of anterior distal femoral hemiepiphysiodesis (ADFH) for treatment of fixed knee flexion deformities in ambulatory children with neuromuscular conditions and flexed knee gait. This is a retrospective review of 47 children (14 female, 33 male, age at surgery: 12.1 ± 2.7 years) who underwent ADFH between 2009 and 2016. Subjects were grouped by ADFH construct: one transphyseal screw (N = 11), two transphyseal screws (N = 28) or plates and screws (P/S group, N = 8). Clinical/radiographic variables were analyzed using paired t tests, χ tests, multiple regression and analysis of covariance. Participants experienced significant reduction in knee flexion contractures (Δ12°, P < 0.006), with no difference among groups (P = 0.43). Postoperative knee pain was significantly more prevalent in the P/S group (5/8, 63%) than the 1-SCR group (0/11, 0%) and the 2-SCR group (2/28, 7%) (P = 0.002). ADFH results in significant reduction of knee flexion deformity and improved knee extension during gait. Plate and screw constructs, the 1 and 2 transphyseal screw techniques are equally effective, but plate and screw constructs may be associated with a higher risk of persistent postoperative knee pain.

Concomitant Anterior Cruciate Ligament Reconstruction and Temporary Hemiepiphysiodesis in the Skeletally Immature: A Combined Technique

BACKGROUND

Young athletes with an anterior cruciate ligament (ACL) disruption and limb malalignment pose a treatment dilemma. Little has been published regarding limb malalignment in this population. Our aim is to review the results of combined treatment of an ACL deficient knee and genu valgum in skeletally immature patients.

METHODS

A retrospective review of skeletally immature patients who underwent transphyseal ACL reconstruction and concomitant hemiepiphysiodesis between 2004 and 2015 by 1 surgeon at a single institution was performed. Included patients had at least a year of growth remaining and were followed to skeletal maturity. Patients with a diagnosis of a connective tissue disorder were excluded. Knee stability, rate of retear, the rate of mechanical axis correction, and time to full correction were determined.

RESULTS

Ninety skeletally immature patients underwent transphyseal ACL reconstruction, 8 of which met inclusion criteria. Mean time to correction of the valgus deformity was 13 months (0.4 degree/mo). No patient required additional surgeries for malalignment. All patients had improvement in knee stability. One patient had a retear of their ACL reconstruction, for a failure rate of 13%. Preoperative mechanical lateral distal femoral angle and mechanical axis deviation corrected to near-neutral alignment for all treated limbs and were significantly different (P=0.001) than those measured preoperatively.

CONCLUSIONS

Promising results were seen for simultaneous correction of genu valgum and transphyseal ACL reconstruction. Treatment of both pathologies in a concomitant surgery can be considered in the appropriate population, with expected results comparable to each procedure in isolation.

LEVEL OF EVIDENCE

Level IV-case series.

Effects of Tibial Rotational-guided Growth on the Geometries of Tibial Plateaus and Menisci in Rabbits

BACKGROUND

There are studies on the use of oblique plate over epiphyses for rotational deformities but the effects of this method on bone are not yet known. The purpose of this study was to determine the effect and rebound effect of rotational-guided growth on the geometries of the tibial plateaus and menisci in a rabbit model of tibial axial rotation.

METHODS

Thirty male rabbits were 6 weeks old when medial and lateral plates were applied to the proximal tibias of the left side. After 4 weeks, 15 rabbits were euthanized (group 1), and the plates from the tibias of the remaining 15 rabbits (group 2) were removed. The rabbits in group 2 were euthanized 4 weeks later.

RESULTS

In the rabbits of group 1, the most striking differences were a decrease in the lateral tibial slope (from 28.3 to 10.8 degrees) and decrease in the ratio of the lateral plateau covered by the meniscus (from 71.9% to 61.3%). After removing the plates (group 2), the observed values of the rebound effects were 25.9 and 29.8 degrees for the lateral tibial slope, and 76.5% and 77.2% for the ratio of the lateral plateau covered by the meniscus. However, the meniscal geometries continued to change.

CONCLUSIONS

The rotational-guided growth provided by using plates caused a change in the tibial plateau geometry, and the rebound effect, except in the meniscal geometry, was observed after removing the plates in the growing period of the rabbits. Rotational-guided growth for the restoration of tibial axial rotation deformities may be suggested after determining the clinical effects of the increasing meniscal variables.

LEVEL OF EVIDENCE

Clinical relevance: the rotational-guided growth needs close follow-up because of possible changes in anatomy of the bone.

Distal femoral hemiepiphysiodesis with screws and suture versus 8-plate for the treatment of genu valgum in children

INTRODUCTION

There are different techniques for gradual correction of angular deformities in lower limbs. The use of screws and non-absorbable filament have been described as an effective alternative for transitory hemiepiphysiodesis in pediatric population.

HYPOTHESIS

In pediatric population with genu valgum there are no differences in outcome between hemiepiphysiodesis, using screws and non-absorbable filament (SNAF) versus 8-plate.

METHODS

Retrospective evaluation, 44 knees in 22 patients younger than 15 years, with idiopathic genu valgum, were operated on. One group (20 knees) was operated on with 8-plate technique and another group (24 knees) was operated on with SNAF technique. Initial and final intermalleolar distance (IMD) and mechanical lateral distal femoral angle (mLDFA) were compared, registering complications for each group. Mann-Whitney test was used for statistics, with significance value <0.05.

RESULTS

All patients achieved the expected mechanical axis correction. IMD and mLDFA significatively improved. There were no significant differences in magnitude and speed of correction when comparing the two techniques. Only one SNAF patient had a minor perioperative complication.

DISCUSSION

This report compares postoperative results between SNAF and 8-plate technique for correction of angular deformities in lower limbs. In this series of patients, significant clinical and radiological changes were observed between the initial and final values using both techniques, with no significant differences between them. Our group proposes the SNAF technique as an efficient, simple and cost-effective alternative to the traditional 8-plate technique, for the treatment of idiopathic genu valgum in children.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Simultaneous treatment for patellar instability and genu valgum in skeletally immature patients: a preliminary study

Genu valgum is a risk factor for patellar instability. The study purpose was to report on preliminary results of medial patellofemoral ligament (MPFL) reconstruction and simultaneous growth modulation, in patients with patellar instability and genu valgum. A total of seven patients (eight knees) with MPFL reconstruction and medial transphyseal screw insertion for genu valgum correction were assessed using full-length radiographs. Genu valgum corrected from 13.1° to 3.7° at mean 11.7 months, without compromising patellar stability. One patient each had 6° overcorrection and 5° rebound valgus. Guided growth using transphyseal screw during MPFL reconstruction could achieve deformity correction without interference with MPFL graft placement.

Treatment failures and complications in patients with Blount disease treated with temporary hemiepiphysiodesis: a critical systematic literature review

This systematic review sums up the state of knowledge about complications and reasons for failure when children with Blount disease are treated with temporary hemiepiphysiodesis. Twelve studies meet the inclusion criteria. The main reported obstacles were under correction and the poor predictability of the amount of correction that was obtainable. Obese patients with severe deformity are the most challenging groups of patients in the treatment of angular deformities. Patients with Blount disease require a careful evaluation regarding the deformity, age, body weight, and social background to reach the optimal treatment strategy. If hemiepiphysiodesis fails, osteotomy remains the preferred salvage procedure.

LEVEL OF EVIDENCE

IV.

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.

Multiplier method may be unreliable to predict the timing of temporary hemiepiphysiodesis for coronal angular deformity

Background and purposes

The multiplier method was introduced by Paley to calculate the timing for temporary hemiepiphysiodesis. However, this method has not been verified in terms of clinical outcome measure. We aimed to (1) predict the rate of angular correction per year (ACPY) at the various corresponding ages by means of multiplier method and verify the reliability based on the data from the published studies and (2) screen out risk factors for deviation of prediction.

Methods

A comprehensive search was performed in the following electronic databases: Cochrane, PubMed, and EMBASE™. A total of 22 studies met the inclusion criteria. If the actual value of ACPY from the collected date was located out of the range of the predicted value based on the multiplier method, it was considered as the deviation of prediction (DOP). The associations of patient characteristics with DOP were assessed with the use of univariate logistic regression.

Results

Only one article was evaluated as moderate evidence; the remaining articles were evaluated as poor quality. The rate of DOP was 31.82%. In the detailed individual data of included studies, the rate of DOP was 55.44%.

Conclusion

The multiplier method is not reliable in predicting the timing for temporary hemiepiphysiodesis, even though it is prone to be more reliable for the younger patients with idiopathic genu coronal deformity.

Radiographic Assessment of Guided Growth: The Correlation Between Screw Divergence and Change in Anatomic Alignment

BACKGROUND

Assessment of changes in anatomic alignment following guided growth traditionally utilizes full-length standing radiographs which subjects patients to larger radiation doses than does a single anteroposterior radiograph of the knee. In an effort to minimize radiation exposure, the present study sought to determine whether changes in screw divergence (SD) of the 2-hole tension band plate used for hemiepiphysiodesis reliably predicts change in alignment.

METHODS

A retrospective review was conducted involving all patients with genu varum or genu valgum treated with hemiepiphysiodesis at a single institution. Preoperative anatomic alignment of the femur, using anatomic lateral distal femoral angle (aLDFA) and anatomic femoral-tibial angle (aTFA), and intraoperative divergence of hemiepiphysiodesis screws were compared with postoperative imaging. Linear regression analysis determined the relationship between changes in SD and changes in alignment, and multivariate regression analysis explored the relationship between the angular changes being measured and various demographic factors.

RESULTS

Linear regression analysis revealed that for every 1 degree change in SD there was a resultant 1.80 degrees of change in aTFA and 2.11 degrees of change in aLDFA. Change in aTFA is predicted by the equation: [INCREMENT]aTFA=0.41×|[INCREMENT]SD|+1.39. The change in aLDFA was predicted by the equation [INCREMENT]aLDFA=0.27×[INCREMENT]SD+1.84 with a R2 of 0.31. [INCREMENT]aTFA and [INCREMENT]SD had a correlation coefficient of 0.68 (95% confidence interval, 0.54-0.78.) [INCREMENT]aLDFA and [INCREMENT]SD had a correlation coefficient of 0.56 (95% confidence interval, 0.42-0.68). [INCREMENT]SD and sex were the only 2 independent predictors for [INCREMENT]aLDFA and [INCREMENT]aTFA as determined by multivariate regression analysis.

CONCLUSION

Change in coronal plane anatomic alignment in patients being treated for genu valgum or genu varum with hemiepiphysiodesis can be reasonably estimated by measuring the change in SD. Therefore, when following patients postoperatively, focal radiographic imaging of the knee can be utilized in lieu of standing full-length limb radiographs to limit radiation to the pelvis in this sensitive patient population.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Distal femoral hemiepiphysiodesis using screw and non-absorbable filament for the treatment of idiopathic genu valgum. Preliminary results of 12 knees

INTRODUCTION

Different techniques for gradual correction of angular deformities of lower limbs exist. Screws and nonabsorbable filament has been described as an effective alternative for transitory hemiepiphysiodesis in New Zealand rabbits.

HYPOTHESIS

Hemiepiphysiodesis using screws and non-absorbable filament is effective in pediatric population, for correction of genu valgum.

METHODS

Retrospective evaluation, 12 knees in 6 patients younger than 15 years (3 female), operated because of genu valgum. An anchoring system with two 4.0mm cancellous screw with metal washer joined by FiberWire #2.0 filament. Initial and final intermalleolar distance (IMD) and mechanical lateral distal femoral angle were compared, recording complications. Mann-Whitney test was used for statistics, with significance value <0.05.

RESULTS

All patients achieved the expected correction. IMD and mLDFA were significatively improved. Only one patient presents a minor perioperative complication.

DISCUSSION

Lateral distal femoral hemiepiphysiodesis with screws and nonabsorbable filament resulted to be an effective alternative for genu valgum gradual correction in pediatric population. This is the first article that proposes this model, as an efficient and simple alternative for the treatment of genu valgum in pediatric patients.

LEVEL OF EVIDENCE

Retrospective study, Level IV.

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.

Rotational deformities of the long bones can be corrected with rotationally guided growth during the growth phase

Background and purpose - Coronal and sagittal plane long bone deformities can be corrected with guided growth, whereas transverse plane rotational deformities require osteotomy and internal or external fixation. We investigated whether rotational changes can be introduced with the plating technique. Methods - 45 rabbits (6 weeks old) were divided into 3 groups. The unoperated right tibia was used as control. In groups 1 and 3, two plates were placed obliquely to the long axis and in different directions. In group 2, a sham operation was performed with screws. Animals in groups 1 and 2 were followed for 4 weeks. In group 3 the implants were removed 4 weeks after the operation to observe rebound effect, and the animals were followed for another 4 weeks. The tibial torsion was assessed on computed tomography (CT). External rotation was accepted as a negative value. Results - In group 1, mean torsion was -20° (SD 7.9) in the right tibia and -2.9° (SD 7.2) in the left tibia (p < 0.001). In group 2, mean torsion was -23° (SD 4.9) in the right tibia and -26° (SD 6.5) in the left tibia (p = 0.2). In group 3, mean torsion was -21° (SD 6.3) in the right tibia and -9.5° (SD 5.3) in the left tibia (p < 0.001). Intergroup evaluation for left torsion showed a significant difference between group 2 and the other groups (p < 0.001). When the rebound effect was evaluated, there was no statistically significant difference between groups 1 and 3 (p = 0.08). Interpretation - A rotational change was attained with this technique. Although a rebound effect was seen after implant removal, it did not reach statistical significance. The final rotational change remained constant.

Hemiepiphysiodesis Implants for Late-onset Tibia Vara: A Comparison of Cost, Surgical Success, and Implant Failure

BACKGROUND

The purpose of this study was to compare hemiepiphysiodesis implants for late-onset tibia vara and to evaluate patient characteristics that may predict surgical failure.

METHODS

This is a retrospective review of late-onset tibia vara patients treated with temporary hemiepiphysiodesis from 1998 to 2012. Mechanical axis deviation (MAD), mechanical axis angle, mechanical lateral distal femoral angle, and medial proximal tibial angle were measured on standing bone length radiographs. Surgical failure was defined as residual deformity requiring osteotomy, revision surgery, or MAD exceeding 40 mm at the time of final follow-up. Implant failure was recorded. Costs included implants and disposables required for construct placement. Staple constructs included 2 or 3 staples. Plate constructs included the plate, screws, guide wires, and drill bits.

RESULTS

A total of 25 patients with 38 temporary lateral proximal tibia hemiepiphysiodeses met the inclusion criteria. The average body mass index (BMI) was 39.1 kg/m with an average follow-up of 3.0 years (minimum 1 y). Surgical failure occurred in 57.9% of patients. Greater BMI (P=0.05) and more severe deformity (MAD, mechanical axis angle, and medial proximal tibial angle; P<0.01) predicted higher rates of surgical failure. Younger age predicted higher rates of implant failure (P<0.01). There were no differences in surgical or implant failure between staple and plate systems. Hospital costs of plate constructs ($781 to $1244) were 1.5 to 3.5 times greater than the staple constructs ($332 to $498).

CONCLUSIONS

Greater BMI, more severe deformity, and younger age were predictive of surgical or implant failure. There was no difference in success between implant types, whereas the cost of plate constructs was 1.5 to 3.5 times greater than staples. The rate of surgical failure was high (58%) and consideration should be given to reserving hemiepiphysiodesis for patients with lower BMI and less severe deformity. In our population, if hemiepiphysiodesis was not offered to patients with BMI>35 or MAD>80 mm varus, the surgical failure rate would diminish to 28%. The failure rate outside these parameters would be 88%.

LEVEL OF EVIDENCE

Level II—Prognostic.

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.

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.

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.

Determining the best treatment for coronal angular deformity of the knee joint in growing children: a decision analysis

This study aimed to determine the best treatment modality for coronal angular deformity of the knee joint in growing children using decision analysis. A decision tree was created to evaluate 3 treatment modalities for coronal angular deformity in growing children: temporary hemiepiphysiodesis using staples, percutaneous screws, or a tension band plate. A decision analysis model was constructed containing the final outcome score, probability of metal failure, and incomplete correction of deformity. The final outcome was defined as health-related quality of life and was used as a utility in the decision tree. The probabilities associated with each case were obtained by literature review, and health-related quality of life was evaluated by a questionnaire completed by 25 pediatric orthopedic experts. Our decision analysis model favored temporary hemiepiphysiodesis using a tension band plate over temporary hemiepiphysiodesis using percutaneous screws or stapling, with utilities of 0.969, 0.957, and 0.962, respectively. One-way sensitivity analysis showed that hemiepiphysiodesis using a tension band plate was better than temporary hemiepiphysiodesis using percutaneous screws, when the overall complication rate of hemiepiphysiodesis using a tension band plate was lower than 15.7%. Two-way sensitivity analysis showed that hemiepiphysiodesis using a tension band plate was more beneficial than temporary hemiepiphysiodesis using percutaneous screws.

Growth guidance of angular lower limb deformities using a one-third two-hole tubular plate

PURPOSE

The eight-plate system for angular deformity correction is well known, reliable and effective at any age during growth. Due to high implant costs, we sought to evaluate the effectiveness and safety of a less expensive alternative.

METHODS

Between 2006 and 2011, 41 children with angular deformities were managed using a two-hole one-third tubular plate in cases where an eight plate would normally be indicated. Inclusion criteria in this retrospective study were: genu valgum and genu varum. X-ray documentation was performed before and after surgery and patients were followed clinically every 3 months after surgery. The cost per implant was 361.40 Sfr (Swiss Francs) compared to the eight plate at 737 Sfr.

RESULTS

Mean time for correction was 13 months. A mean LDFA/MPTA after correction of 89.9°/86.8° was recorded, as well as a mean correction angle of 6.8°/6.6°. The complication rate was 6.6 % (one superficial wound infection and one insufficient correction in an older child). These results compare favourably with published data on the eight plate.

CONCLUSION

The two hole one-third tubular plate seems to be a clinically and also cost effective alternative to the eight plate. Full deformity correction is gained for a fraction of the cost.

LEVEL OF EVIDENCE

Level III.

Combined distal tibial rotational osteotomy and proximal growth plate modulation for treatment of infantile Blount’s disease

Infantile Blount’s disease is a condition that causes genu varum and internal tibial torsion. Treatment options include observation, orthotics, corrective osteotomy, elevation of the medial tibial plateau, resection of a physeal bar, lateral hemi-epiphysiodesis, and guided growth of the proximal tibial physis. Each of these treatment options has its disadvantages. Treating the coronal deformity alone (genu varum) will result in persistence of the internal tibial torsion (the axial deformity). In this report, we describe the combination of lateral growth modulation and distal tibial external rotation osteotomy to correct all the elements of the disease. This has not been described before for treatment of Blount’s disease. Both coronal and axial deformities were corrected in this patient. We propose this combination (rather than the lateral growth modulation alone) as the method of treatment for early stages of Blount’s disease as it corrects both elements of the disease and in the same time avoids the complications of proximal tibial osteotomy.

Guided growth: the importance of a single tether. An experimental study

BACKGROUND

During the last few years, the use of the 8-plate as a technique for hemiepiphysiodesis has gained wide acceptance, as it has been shown that it works in a more physiological way than other methods such as staples or transphyseal screws. It has mechanically been compared with a tension band plate, and for this reason, only a single plate is needed. The following study was undertaken to test the 8-plate against the staples and assess factors that can influence the difference in results.

METHODS

A prospective experimental study was designed to compare the ability of 2 hemiepiphysiodesis methods, the 8-plate and the double staple, to produce angular deformity in the rabbit's tibia (group I). The variable studied was the variations in the articular line-diaphysis angle at 6 weeks. As the results showed that the 8-plate produced a bigger deformity, a second group was designed (group II) comparing single against double staple, under the hypothesis that the differences observed in the first group could be related to the number of anchors put across the physis and consequently depend on the volume of physis involved by the staples.

RESULTS

In group I, the 8-plate produced a bigger angulation at 6 weeks' time than the 2 staples (a difference of 6.5 degrees, P = 0.03). Similarly, in group II, the single staple produced a greater angulation than the 2 staples (difference 6 degrees, P = 0.08). When both groups were compared, no differences in the angulation produced by the 8-plate and the single staple with respect to the 2 staples were found.

CONCLUSIONS

These results suggest that one of the reasons why the 8-plate may act in a more "physiological way" (vs. the traditional 2-staple or 3-staple hemiepiphysiodesis) could be the fact that the growth plate is tethered only at a single point. Therefore, the physis retains a major potential for growth and deformity.

CLINICAL RELEVANCE

The 8-plate is superior in producing/correcting angular deformity when compared with the traditionally used staples (2 or more) but not when compared with a single staple.

Rate of correction after asymmetrical physeal suppression in valgus deformity: analysis using a linear mixed model application

BACKGROUND

This study was performed to estimate the rate of angular correction after asymmetrical physeal suppression and analyze the factors that influence the rate of correction by using a linear mixed model application.

METHODS

A total of 175 physes (72 distal femoral, 70 proximal tibial, and 33 distal tibial) from 78 consecutive patients with valgus angular deformity of the lower limb who underwent asymmetrical physeal suppression were included. The anatomic lateral distal femoral angle, the anatomic lateral proximal tibial angle, and the anatomic lateral distal tibial angle were measured from the teleroentgenograms of the patients' preoperative visit and periodic follow-ups. The rate of angular correction was adjusted by multiple factors by using a linear mixed model with age, sex, and surgical method as the fixed effects and each subject as the random effect. The final model included the age-specific and surgical method-specific rate and sex-specific and surgical method-specific intercept. Multivariate analysis was performed for this model.

RESULTS

In younger children (boys 14 y or younger and girls 12 y or younger), the rate of correction of valgus deformity at the distal femur, proximal tibia, and distal tibia was 0.71 degrees/month (8.5 degrees/y), 0.40 degrees/month (4.8 degrees/y), and 0.48 degrees/month (5.8 degrees/y), respectively. In older children, the rate of correction of valgus deformity at the distal femur, proximal tibia, and distal tibia was 0.39 degrees/month (4.7 degrees/y), 0.29 degrees/month (3.5 degrees/y), and 0.48 degrees/month (5.8 degrees/y), respectively. The rate of correction at the distal femur was significantly lower in older children (P = 0.025). The rate of angular correction at the proximal tibia was significantly faster in the screw group than in the staple group (P = 0.046).

CONCLUSIONS

Asymmetrical physeal suppression with staples, percutaneous transphyseal screws, and permanent method all are effective methods for treating valgus deformity in growing children. When we treat valgus deformity in growing children, we should take into consideration the fact that the rate of correction at the distal femur is lower in older children, and that at the proximal tibia is faster in the screw group.

LEVEL OF EVIDENCE

Therapeutic level III.

Screw length in the guided growth method

BACKGROUND

The appearance of the 8-plate as a method for hemiepiphysiodesis has renewed the interest for the use of this technique. However, many questions remain unanswered about the way of action of the guided growth method. Although screw length has been said to play no role, to our knowledge, no clinical or experimental evidence exists.

METHODS

An experimental prospective randomized study with 40 WNZ Rabbits aged 8 weeks was conducted. Four experimental groups were established. Each tibia was randomly allocated to one of the following groups: Staples (group 1), 8-plate either using self-taping screws of 9 mm (group 2), or 5 mm lengths (groups 3) and control (group 4). Radiological assessment of the tibial deformity was done in a weekly fashion, and ALDA (articular line-diaphyseal angle) variations at 6 weeks were used as the control variable.

RESULTS

The 8-plate as a whole produced a significant bigger deformity than the staples (10°). No significant differences between the two models of the 8-plate were found along the study (3.7°).

CONCLUSIONS

The 8-plate has shown to be more efficient in producing angular deformity than staples. However, the length of the screw has showed no role in the 8-plate function.

Angular deformities of the lower limb in children

Angular deformities of the lower limbs are common during childhood. In most cases this represents a variation in the normal growth pattern and is an entirely benign condition. Presence of symmetrical deformities and absence of symptoms, joint stiffness, systemic disorders or syndromes indicates a benign condition with excellent long-term outcome. In contrast, deformities which are asymmetrical and associated with pain, joint stiffness, systemic disorders or syndromes may indicate a serious underlying cause and require treatment.

Little is known about the relationship between sport participation and body adaptations during growth. Intense soccer participation increases the degree of genu varum in males from the age of 16. Since, according to some investigations, genu varum predisposes individuals to more injuries, efforts to reduce the development of genu varum in soccer players are warranted. In this article major topics of angular deformities of the knees in pediatric population are practically reviewed.

Treatment of infantile Blount disease with lateral tension band plating

BACKGROUND

Growth manipulation has had increasing popularity in the treatment of lower extremity angular deformities in children. This paper discusses the use of growth manipulation for the treatment of infantile Blount disease as an alternative to proximal tibial osteotomy.

METHODS

A retrospective chart and radiographic review was carried out for 12 children (18 limbs) who had treatment of infantile Blount disease with application of lateral proximal tibial tension band plates. Some children also had distal femoral lateral plates applied. Serial radiographs were measured to show response to growth manipulation.

RESULTS

The success rate of growth manipulation in this group was 89%. Failures and delayed correction were attributed to wound infection that required plate removal and broken screws. Some recurrence of varus has occurred in a few patients.

CONCLUSIONS

Growth manipulation is an effective means of treating infantile Blount disease in appropriate patients. Patients must be monitored for screw breakage after surgery. After removal of the plates, the risk of recurrent varus is attributed to the poor growth potential of the proximal medial tibial physis.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

The 8-plate versus physeal stapling for temporary hemiepiphyseodesis correcting genu valgum and genu varum: a retrospective analysis of thirty five patients

PURPOSE

In skeletally immature patients, treatment of malalignment about the knee is possible by performing temporary hemi-epiphyseodesis. Following the well-established procedure of physeal stapling, the 8-plate was introduced as a new device. The purpose of this study was to compare physeal stapling with 8-plate hemi-epiphyseodesis. We focused on evaluating deformity correction, complication rate and duration of the procedures.

METHODS

We retrospectively analysed 35 patients (61 extremities, age 2.9-16.0 years) who were treated by temporary hemi-epiphyseodesis about the knee for correction of genu varum or genu valgum by using Blount staples (32 extremities) or the 8-plate (29 extremities). Plain radiographs were analysed at the time of operation and at hardware removal that included measurement of mechanical axis deviation, mechanical lateral distal femoral angle and mechanical medial proximal tibial angle. Time until hardware removal, operation time and complications were recorded.

RESULTS

A statistically significant improvement of all radiographic measurements could be achieved with comparable results in both groups. Complications were similar in both groups with no relevant differences in amount and severity. In the 8-plate group, however, the surgical time was significantly shorter by an average of ten minutes for implantation and 12 minutes for explantation.

CONCLUSIONS

Both Blount stapling and the 8-plate technique are methods for correction of genu varum and valgum deformity in skeletally immature patients; however, a shorter operating time for implantation and explantation was noted for the 8-plate technique.

Early experience with medial femoral tension band plating in idiopathic genu valgum

PURPOSE

For correction of angular deformity, tension band plating has been proposed as a safe and minimally invasive technique. The purpose of this study was to assess the experiences and report the rate of correction obtained with this procedure in patients with idiopathic genu valgum.

METHODS

This study was a retrospective review of 47 valgus deformities of the knee treated with medial hemiepiphysiodesis using a tension band plate. The tibiofemoral angle (TFA) and the anatomic lateral distal femoral angle (aLDFA) were assessed on anteroposterior (AP) radiographs of the lower extremity taken at multiple time intervals. The values were charted to determine the change in orientation of the joint surface over time. Pearson's correlation was used to analyze the correction over time. A subanalysis was performed evaluating the effect of age and the number of plates utilized.

RESULTS

A total of 47 deformities in 25 patients were reviewed. The average time of follow-up from index surgery was 12.7 months, with an average correction of 0.96° every 3 months or 3.8° per year. The aLDFA corrected at a faster rate in knees with two plates per hemiepiphysiodesis than those with one plate, 4.2° and 3.3° per year, respectively (P = 0.035). Girls <11 years of age and boys <13 years of age corrected at a rate of 4.5°, while older children corrected at a rate of 3.4° per year (P = 0.39). There were no complications or instrumentation breakages.

CONCLUSION

Hemiepiphysiodesis with tension band plating provides an effective and predictable correction of idiopathic genu valgum. Two plates appear to provide a greater rate of correction. There is also a trend toward faster correction in younger patients as well.

Surgical epiphysiodesis indications and techniques: update

PURPOSE OF REVIEW

To present a summary of epiphysiodesis indications and to report most recent advances in the field, along with their clinical relevance.

RECENT FINDINGS

Percutaneous epiphysiodesis using transphyseal screws (PETS) and guided growth using eight plates represent the most recent techniques used for hemiepiphysiodesis.

SUMMARY

PETS and guided growth have yielded very good results and low rates of complications and are the current standard for the management of angular deformities of the lower extremities in children. Permanent percutaneous epiphysiodesis remains the preferred method for the treatment of limb length discrepancies.

Guided growth for the correction of pediatric lower limb angular deformity

Guided growth is useful in correcting pediatric angular deformities. Although growth manipulation has been applied to various deformities, it is most commonly used to correct coronal plane deformity about the knee. Temporary hemiepiphysiodesis is performed using staples, percutaneous transphyseal screws, or a tension band plate. Permanent hemiepiphysiodesis can be done using either an open Phemister or a percutaneous approach. These techniques function by tethering one side of a growing physis, thereby allowing differential growth. Applied correctly, this can also result in angular deformity correction. Undercorrection and overcorrection are common problems with guided growth. However, careful preoperative planning and appropriate follow-up can minimize complications and allow for excellent deformity correction with minimal morbidity.

A reciprocating ledge technique in closing wedge osteotomy for genu valgum in adolescents

PURPOSE

To describe a technique that preserves anterior and posterior alternate ledges in a closing wedge osteotomy.

METHODS

Five patients aged 14 to 19 years underwent a closing wedge osteotomy for genu valgum in 8 limbs using a reciprocating ledge technique. A unicortical wedge of bone was removed, with the anterior and posterior cortices spared. The anterior cortex at the proximal level and the posterior cortex at the distal level were cut through. With a wobbling action, the osteotomy site was rotated, and the distal fragment externally rotated. Manual force was applied to close the osteotomy site ensuring overlapping of the reciprocal ledges. The distal fragment was translated laterally to prevent club deformity. The osteotomy site was held with one or 2 staples. Stability was tested by flexion and extension of knee.

RESULTS

All 8 limbs attained bone union within 12 weeks, and full range of motion within a mean of 13 (range, 12-15) weeks. The mean correction of the tibiofemoral angle was 13 degrees. At a mean follow-up of 12 months, all patients were pain-free and none developed club deformity.

CONCLUSION

Sparing reciprocal ledges in a closing wedge osteotomy for genu valgum may increase stability in the flexion-extension axis, enable early range-of-motion exercises, and facilitate early bone union.