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Mechanical axis deviation correction rate using TBP and PETS in different age groups: 7-to-10 years old (a), 11-to-13 years old (b) and 14-to-16 years old (c)
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Introduction:
Pediatric coronal plane knee deformities can be treated surgically using hemiepiphysiodesis. The two leading techniques used for hemiepiphysiodesis are: tension-band plates (TBP) and percutaneous transphyseal screws (PETS). We hypothesized that PETS would lead to faster guided correction of angular knee deformities than TBP.
Materia...
Citations
... Для порівняльної оцінки значущості різниці між групами p < 0,05 вважався статистично значущим, тоді як p > 0,05 -незначущим (NS). *-p < 0,05, **-p < 0,01, ***-p < 0,001, ****-p < 0,0001 [14]. ...
Background. The classic method of surgical treatment of knee joint deformity in the coronal plane is fixation of the epimetaphyseal area using an eight-shaped 2-screw plate according to the concept of guided growth. To improve this technique, we developed, patented and applied a butterfly-like 4-screw quad plate. We also hypothesized that the 4-screw plate would result in faster controlled correction of angular knee deformities than the 2-screw plate. Objective: to improve surgical treatment of children with axial deformity of the knee area, whose growth continues. Materials and Methods. A retrospective analysis of the treatment of 37 children with deformity of the knee in the coronal plane, who were implanted with a 2-screw or 4-screw bone plate, was carried out. The study cohort included both genu varum and genu valgum of both primary and secondary etiology. In dynamics, a comparative analysis of X-ray morphometric parameters obtained from panoramic radiographs of the lower extremities was carried out. Also, depending on the type of implant, the rate of deformity correction and the incidence of complications were compared. Results. We found that the use of a 4-screw plate compared with a 2-screw plate was associated with a shorter interval between implantation and removal, i.e., faster correction. This was confirmed by the indicators of correction of mechanical axis deviation, lateral distal femoral angle and medial proximal tibial angle. No statistically significant difference between the two types of implants was found in the incidence of complications of surgical treatment. Conclusions. Analysis of the rate of correction of clinical and radiomorphometric indicators of deformation of the knee joint in the coronal plane depending on the age periodization of the child’s ontogenesis showed an advantage in the surgical use of a 4-screw quad plate compared to the use of a 2-screw quad plate for fixation of the epimetaphyseal area.
... In their study group composed of 35 patients they concluded that in the tension band plate cohort the MAD correction rate progressively increases from the younger group (7-10 years old) to the oldest (14-16 years old). 9 However, they did not consider sex-related differences, which are paramount to consider in skeletal maturity and bone development. ...
Purpose
Hemi-epiphysiodesis procedures in skeletally immature patients are commonly done to correct genu valgum over time. This study seeks to demonstrate the average rate of deformity correction for genu valgum using hinged tension band plates, while examining different age groups and sex-related differences.
Methods
A retrospective chart review of patients who underwent hemi-epiphysiodesis with hinged tension band plates for valgus knee deformity from 2012 to 2022 by one pediatric orthopaedic surgeon was performed. Expected time of growth remaining was calculated as the difference between age of skeletal maturity and bone age at time of surgery. The mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, mechanical femoral tibia angle, screw divergence angle, and hinge angle were measured immediately after implant placement and prior to implant removal.
Results
54 skeletally immature patients were treated for pathologic genu valgum. The mean age at time of surgery was 12.5 ± 1.9 years. The radiographic measurement of the valgus deformity between the beginning and end of treatment showed significant correction ( p = 0.002). The lower limb axis of the younger cohort corrected significantly faster (7.5 ± 4.6°/year) than the older cohort (5.3 ± 2.8°/year) ( p = 0.030). The mechanical lateral distal femoral angle correction rate was also significantly different between the two cohorts (7.0 ± 4.7°/year vs. 4.8 ± 2.8°/year, respectively ( p = 0.002)). The group with greater expected time of growth remaining demonstrated a significantly faster rate of correction than the group with less than 2 years of growth remaining ( p < 0.001).
Conclusion
This study reaffirms the finding that timing is essential when performing temporary hemi-epiphysiodesis for valgus knee deformity in skeletally immature patients.
... 58 Shapiro et al. also reported faster overall rates of correction in PETS, and the surgical time for implant placement was shorter compared with TBP. 59 Incision-related complications occurred in 3% of PETS and 18% of TBP patients, although this difference was not statistically significant. Hypertrophic scarring and incisional pain only occurred in the TPB group. ...
Guided growth is one of the most utilized surgical techniques for managing limb deformity in skeletally immature patients. Our understanding of this technique and the types of implants utilized have evolved over the past century. Many of the known risks of this surgery, such as over-correction, under-correction, and rebound deformity, are the same risks initially described when hemiepiphysiodesis and guided growth techniques were first published. The staple has been a powerful tool for deformity correction but its high rates of implant backout and breakage as well as unpredictable rates of premature physeal closure after removal have contributed to this implant being used less frequently today. Many studies on percutaneous transepiphyseal screws (PETS) are promising but have little follow-up, so the risks of this technique with regard to premature physeal closure are not well understood. Tension band plating is currently the most utilized method. However, in specific patient subgroups, the perioperative complication and failure of correction rates are high. Despite the abundance of literature on these techniques, our understanding of guided growth is still quite limited, as most studies are small and do not follow patients to skeletal maturity. Guided growth surgery also can restore the mechanical axis of the limb while leaving patients with significant residual diaphyseal or peri-articular deformity and the implications of these secondary deformities have not been studied. Key Concepts • An understanding of the patient's skeletal maturity and predicted growth remaining is essential prior to performing guided growth surgery. • Regular patient follow-up is critical to prevent over-correction of deformity. • Staples are an effective implant for angular deformity correction but have higher rates of implant backout, breakage, and premature physeal arrest compared to other devices.
... An alternative technique to tether the growth plate is to use transphyseal screws (Figure 7). This technique has a faster correction rate than the tension band principle [56,57]. Hence, this technique may better serve patients that are near skeletal maturity. ...
Osseous deformities in children arise due to progressive angular growth or complete physeal arrest. Clinical and radiological alignment measurements help to provide an impression of the deformity, which can be corrected using guided growth techniques. However, little is known about timing and techniques for the upper extremity. Treatment options for deformity correction include monitoring of the deformity, (hemi-)epiphysiodesis, physeal bar resection, and correction osteotomy. Treatment is dependent on the extent and location of the deformity, physeal involvement, presence of a physeal bar, patient age, and predicted length inequality at skeletal maturity. An accurate estimation of the projected limb or bone length inequality is crucial for optimal timing of the intervention. The Paley multiplier method remains the most accurate and simple method for calculating limb growth. While the multiplier method is accurate for calculating growth prior to the growth spurt, measuring peak height velocity (PHV) is superior to chronological age after the onset of the growth spurt. PHV is closely related to skeletal age in children. The Sauvegrain method of skeletal age assessment using elbow radiographs is possibly a simpler and more reliable method than the method by Greulich and Pyle using hand radiographs. PHV-derived multipliers need to be developed for the Sauvegrain method for a more accurate calculation of limb growth during the growth spurt. This paper provides a review of the current literature on the clinical and radiological evaluation of normal upper extremity alignment and aims to provide state-of-the-art directions on deformity evaluation, treatment options, and optimal timing of these options during growth.
... Most genu valgum in young children resolve spontaneously; however, deformities beyond the physiological limits can lead to cosmetic problems and produce an uneven mechanical load to the lateral compartment of the knee joint and instability of the patellofemoral joint [1][2][3][4][5][6]. The genu valgum in skeletally immature patients could be corrected by simple and minimally invasive guided growth such as permanent or temporary hemiepiphysiodesis. ...
... Previous studies have shown high success rates of temporary hemiepiphysiodesis using PETS or TBP to correct genu valgum [3][4][5][12][13][14][15]. Two previous studies reported more rapid correction with PETS than with TBP [4,5], and this depends on the direct penetration of the physis. ...
... Previous studies have shown high success rates of temporary hemiepiphysiodesis using PETS or TBP to correct genu valgum [3][4][5][12][13][14][15]. Two previous studies reported more rapid correction with PETS than with TBP [4,5], and this depends on the direct penetration of the physis. The different mechanisms between PETS and TBP for inhibition of growth may also affect the physeal behaviour even after the guided growth implant is removed [2,4,15]. ...
Background
Percutaneous epiphysiodesis using a transphyseal screw (PETS) or tension-band plating (TBP) has shown favourable correction results; however, the physeal behaviours in terms of rebound, stable correction, or overcorrection after guided growth have not been completely understood. In patients with idiopathic genu valgum, we therefore asked: (1) How is the correction maintained after implant removal of guided growth? (2) Is there any difference in the natural behaviours after PETS or TBP removal at the femur and tibia?
Methods
We retrospectively reviewed 73 skeletally immature limbs with idiopathic genu valgum treated with PETS or TBP. PETS was performed in 23 distal femurs and 13 proximal tibias, and TBP was performed in 27 distal femurs and ten proximal tibias. Mechanical axis deviation (MAD), mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle were measured at pre-correction, implant removal, and final follow-up. Changes of ≤ 3° in mechanical angles after implant removal were considered stable. Comparisons between the implant, anatomical site, and existence of rebound were performed.
Results
The mean MAD improved from − 18.8 mm to 11.3 mm at implant removal and decreased to -0.2 mm at the final follow-up. At the final follow-up, 39 limbs (53.4%) remained stable and only 12 (16.4%) were overcorrected. However, 22 limbs (30.1%) showed rebound. TBP was more common, and the correction period was longer in the rebound group ( p < 0.001 and 0.013, respectively). In femurs treated with PETS, the mean mLDFA increased from 86.9° at implant removal to 88.4° at the final follow-up ( p = 0.031), demonstrating overcorrection. However, a significant rebound from 89.7° to 87.1° was noted at the femur in the TBP group ( p < 0.001). The correction of the proximal tibia did not change after implant removal.
Conclusion
The rebound was more common than overcorrection after guided growth; however, approximately half the cases demonstrated stable correction. The overcorrection occurred after PETS in the distal femur, while cases with TBP had a higher probability of rebound. The proximal tibia was stable after implant removal. The subsequent physeal behaviours after each implant removal should be considered in the guided growth.
... Permanent hemiepiphysiodesis by medial femoral or lateral tibial epiphyseal ablation in coronal knee deformities is controversial due to its irreversible physeal damage and conceivable asymmetrical growth arrest, the need for accurate planning, and close follow-up of the patient [5]. Percutaneous epiphysiodesis with transphyseal screws (PETS) has gained wide popularity due to its ease and minimally invasive nature [6][7][8][9]. ...
Purpose:
To evaluate the outcomes of a novel percutaneous medial supracondylar femoral osteotomy and above-knee cast technique in children and adolescents as a minimally invasive surgical intervention for treatment of genu valgum.
Methods:
In this prospective study, 60 patients (70 knees) with a tibiofemoral angle more than 15° were treated with a novel medial percutaneous supracondylar femoral osteotomy and above-knee cast and followed-up for an average of 29 months. The radiological outcome was measured with MAD, TFA, and mLDFA. The functional outcome was evaluated by a modified Böstman score.
Results:
The preoperative mean MAD, TFA, and mLDFA were 2.9 cm, 16.3°, and 79.2° respectively. The Böstmann score averaged preoperatively 23.1. There was a significant improvement of all radiological and clinical outcome measures (P < 0.001). Per Böstman score, 2 knees in one patient (3%) showed an unsatisfactory result while 14 (20%) and 54 (77 %) knees had a good or excellent result, respectively. Two patients (three limbs) needed early re-casting. Other complications were not encountered.
Conclusion:
In experienced hands, percutaneous transverse metaphyseal supracondylar femoral osteotomy and above knee casting appear to be a safe, cost-effective, and reliable minimally invasive acute correction technique in genu valgum in children and adolescents.
Level of Evidence: Level IV- therapeutic
Keywords: Genu valgum in children and adolescents; novel mini open femoral supracondylar osteotomy technique; early mobilization in cast; casting in genu valgum; minimal invasive surgery MIS in limb deformity correction; fast recovery and fast track surgery
... To avoid the aforementioned complications of plates and staples, Kay et al. [17] proposed the use of percutaneous transphyseal screws following the concept of the Métaizeau technique used in the correction of limb length discrepancy [18,19]. To treat flexion deformities, screws were placed across the anterior distal femoral physis. ...
Introduction
Anterior distal femoral hemiepiphysiodesis using intra-articular plates for correction of pediatric fixed knee flexion deformities (FKFD) has two documented complications: postoperative knee pain and implant loosening. The aim of this study is to investigate the mechanical properties of a novel extra-articular technique for anterior distal femoral hemiepiphysiodesis in patients with FKFD and to compare them to the conventional technique.
Materials and methods
Sixteen femoral sawbones were osteotomized at the level of the distal femoral physis and fixed by rail frames to allow linear distraction simulating longitudinal growth. Each sawbone was tested twice: first using the conventional technique with eight plates placed anteriorly just medial and lateral to the femoral sulcus (group A) and then with plates inserted in the proposed novel location at the most anterior part of the medial and lateral surfaces of the femoral condyles with screws in the coronal plane (group B). Gradual linear distraction was performed, and the resulting angular correction was measured. Strain gauges were attached to the plates, and the amount of strain (and equivalent stress) over the plates in response to linear distraction was recorded. The two groups were compared using the Wilcoxon signed-rank test.
Results
The amount of angular correction was statistically higher in group B (extra-articular plates) at 5, 10-, and 15-mm of distraction (p < 0.001). As regards stress over the plates, the maximum stress and the area under the curve (sum of all stresses measured throughout the distraction process) were significantly higher when the plates were inserted at the conventional position (group A) (p < 0.001).
Conclusions
During anterior distal femoral hemiepiphysiodesis, the fixation of the eight plates in the coronal plane at the anterior part of the femoral condyles may produce a greater amount of correction and a lower degree of stress over the implants as compared to the conventional technique.
The aim of this study was to appraise various factors influencing the correction rate in temporary hemiepiphysiodesis (THE) around the knee joint. Specifically, the study analysed the relationship of correction rate with age, gender, aetiology, type and location of deformity.
The retrospective study included children who underwent THE for a coronal plane deformity (genu valgus or varum) around the knee joint (distal femur or proximal tibia) over a ten year period (2010–2020). The primary outcome of interest was the correction rate of the deformity.
Thirty-three children (27 females and 6 males) with a mean age of 8.1 years involving 86 plates were included in the study. The mean correction achieved was 12.2° over a treatment period of 13.3 months. Subgroup analysis showed significant differences between the type (varus (0.8° per month), valgus (1.1° per month)) and the location of deformity femur (1.2° per month) and tibia (0.7° per month)]. On multivariate analysis, the location and the duration of treatment showed significant associations with the correction rate.
The correction of coronal deformities following temporary hemiepiphysiodesis is influenced by several factors. Valgus, femoral and deformities in younger children correct at a faster rate. Location of deformity and duration of treatment emerged as potential factors affecting the correction rate.
Background:
Hemiepiphysiodesis (guided-growth) procedures have become the primary method of treatment for coronal-plane knee deformities in skeletally immature patients. Two leading techniques involve the use of a transphyseal screw or a growth modulation plate. However, clinical references for the estimation of correction are lacking, and no consensus has been reached regarding the superiority of one technique over the other. Therefore, the purpose of this study was to compare the rates of correction for distal femoral transphyseal screws and growth modulation plates in age- and sex-matched cohorts with coronal deformities.
Methods:
Thirty-one knees were included in each cohort on the basis of propensity scoring by chronological age and sex, and radiographic images were retrospectively reviewed preoperatively and postoperatively. Each case was measured for limb length, mechanical axis deviation (MAD), mechanical lateral distal femoral angle (LDFA), and bone age.
Results:
Both the MAD and LDFA rate of correction significantly differed between the screw and plate cohorts. The MAD rate of correction was observed to be 0.42 ± 0.37 mm/week (1.69 mm/month) in the plate cohort and 0.66 ± 0.51 mm/week (2.64 mm/month) in the screw cohort. The LDFA rate of correction was observed to be 0.12° ± 0.13°/week (0.50°/month) in the plate cohort and 0.19° ± 0.19°/week (0.77°/month) in the screw cohort.
Conclusions:
The current study provides simple clinical references for the rate of correction of MAD and the LDFA for 2 methods of hemiepiphysiodesis. The results suggest that transphyseal screws may correct coronal knee deformities during the initial treatment stage more quickly than growth modulation plates in distal femoral guided growth.
Level of evidence:
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Purpose of review:
This study aimed to review the established concepts and advances related to growth modulation for treating knee angular deformities. Although they are considered well tolerated procedures, careful indications and accurate techniques are necessary to ensure good results.
Recent findings:
In addition to general clinical and radiographic evaluations, new tools such as two-dimensional low-dose radiography and gait analysis have been used to clarify angular and torsional combinations and the impact of mild angulations on the knee joint. Temporary epiphysiodesis is commonly the choice, and it can be performed with different implants such as staples, tension band plates (TBP), percutaneous transphyseal screws (PETS), sutures, and screws.
Summary:
Considering its principles, TBP has been preferred for younger children. Cost can be a limitation, and research for alternative implants such as screws and nonabsorbable sutures indicate they might be an alternative in the future. In adolescents, PETS becomes an attractive alternative; however, its reversible character has been controversial, and further studies are needed to establish limits in younger patients.
