Angular deformity correction by asymmetrical physeal suppression in growing children: stapling versus percutaneous transphyseal screw

PETS (Percutaneous Epiphysiodesis Using Transphyseal Screws) in the Proximal Tibia: Deep Peroneal Nerve Proximity

BACKGROUND

Percutaneous epiphysiodesis with transphyseal screws (PETS) is commonly used to treat limb-length discrepancy and angular knee deformity in children. PETS carries a small but serious risk of nerve injury from mechanical and/or thermal damage caused by instrumentation near the deep peroneal nerve (DPN). Our goals were to (1) characterize the location of the DPN to an ideally placed PETS screw in pediatric patients undergoing medial proximal tibia hemiepiphysiodesis; and (2) describe the optimal PETS screw trajectory in this location.

METHODS

This was a retrospective study of lower-extremity magnetic resonance imaging (MRI) of pediatric patients at our institution between January 2017 and July 2024. MRIs were excluded for incomplete visualization of the proximal tibia or the presence of tumors or fractures. Multiplanar reformations were generated to simulate the ideal medial proximal tibia PETS trajectory, defined as a screw crossing the medial 1/6 of the proximal tibia physis at a 55 degrees angle relative to the physis. Distances between the DPN and the ideal PETS trajectory were measured at the lateral cortical entry site on the proximal tibia, the point nearest the nerve, and the superficial fascia.

RESULTS

Of the 56 MRIs identified, 19 were included (mean patient age, 10.8 y, 68% female). Mean±SD distance from the DPN to the lateral cortical entry site of the tibia was 1.4±0.4 cm. The closest mean distance between the screw and DPN was 1.0±0.5 cm. Mean distance between the DPN and the superficial fascia was 2.4±0.7 cm. The screw trajectory was always anterior to the DPN.

CONCLUSIONS

Given the proximity of transphyseal screws to the DPN during percutaneous epiphysiodesis of the medial proximal tibia, correct screw trajectory and a thorough understanding of the neurovascular anatomy in relation to bony landmarks is crucial to prevent nerve injury. In addition, biasing the screw path anteriorly can assist in maintaining a "safe zone" between the instrumentation and the DPN.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

'Retrograde Guidewire and Antegrade Screw Technique' in Performing Percutaneous Epiphysiodesis Using Transphyseal Screws (PETS): A Technical Report

Percutaneous epiphysiodesis using transphyseal screws (PETS) is a well-established method for managing limb deformities and length discrepancies in growing children. This technical report presents a modified approach to PETS. It emphasizes the use of a retrograde guidewire for precise screw trajectory and an antegrade screw placement technique. The procedure is performed under fluoroscopic guidance without a tourniquet, allowing immediate post-operative weight bearing. Key steps include meticulous patient positioning, fluoroscopic imaging to ensure accurate screw placement, and careful attention to anatomical landmarks. This technique offers advantages, such as minimal blood loss, shorter operative times, and preservation of joint function. By detailing our approach, we aim to enhance surgical efficiency and facilitate broader adoption of this minimally invasive procedure in orthopedic practice.

Factors influencing the speed of correction speed of distal tibial valgus deformity in children with percutaneous epiphyseodesis using transphyseal screw

INTRODUCTION

The distal tibial valgus deformity in children mimics a hindfoot valgus and is observed in several conditions of both non-neurogenic and neurogenic origin. The deformity can only be detected with radiological examination and can be safely and effectively corrected in children with medial percutaneous epiphysiodesis using transphyseal screws (PETS). The aims of the study are: 1. to determine the correction rates of the distal tibial valgus deformity due to different pathologies, 2. to examine the correction rate in relation to the age at implantation, severity of the initial deformity and the duration of implantation, 3. and types of foot deformities associated with the deformity.

MATERIALS AND METHODS

A retrospective study was done on children who underwent a PETS for a distal tibial valgus deformity. The lateral distal tibia angle 89° ± 3° on ankle mortice x-rays was taken as normal. An analysis of variance and covariance was done to investigate differences in parameters between aetiologies and relations between parameters respectively.

RESULTS

Following exclusion of 191 limbs, 155 limbs in 104 children were included the study, 5 groups could be identified: Idiopathic, ICP (cerebral palsy), MMC (Meningomyelocele), Dysmelia, MHE (multiple hereditary exostosis). The mean age at implantation of all patients was 10.9 ± 1.4 years. The average correction of 0.45° ± 0.08°/month with no significant differences in the correction rates between groups. However, the correction rates were dependent on the age, the initial deformity and the duration of treatment. The incidence of a valgus foot deformity was 86.4 %.

CONCLUSION

The correction rates of the distal tibial valgus deformity following PETS are variable and depend, on the age at implantation, duration of treatment and initial deformity. The spectrum of foot deformities associated with distal tibial valgus deformity, especially a high prevalence of valgus foot deformity warrants an ankle mortice x-ray.

LEVEL OF EVIDENCE

Level III, retrospective study.

Hemi-Percutaneous Epiphysiodesis Using Transphyseal Screws at Lateral Proximal Tibias After Epiphyseal Fusion of Distal Phalanges in the Hand Results in Undercorrection of Genu Varum

Background and Objectives: To investigate postoperative courses after hemi-percutaneous epiphysiodesis using transphyseal screws (PETS) for genu varum. We especially focused on the degree of skeletal maturation that results in undercorrection. Materials and Methods: We identified patients with idiopathic genu varum treated with hemi-PETS at the proximal tibia and followed-up to the completion of skeletal maturation. The acceptable correction was defined as the (1) final deformity < varus 1.0° or (2) final correction angle obtained by surgery (f-CA) > mean value of preoperative deformity. Results: In our cohort of 29 patients and their 29 lower limbs (one side was randomly selected in bilateral cases), the mean hip-knee-ankle (HKA) alignment was varus 6.5 ± 1.3° at the time of hemi-PETS. The mean f-CA was 5.8 ± 2.0° with a rebound of 0.3 ± 1.0°. Ten patients showed the finding of partial or complete fusion of the epiphysis of distal phalanges in the hand at the time of hemi-PETS (the fusion group, FG). Their f-CA was 4.0 ± 1.9° (with preoperative deformity of 6.9 ± 1.4°), which was significantly smaller than that (6.7 ± 1.3°, p = 0.001) of remaining 19 patients (the open group, OG). The acceptable correction was obtained in all 19 patients of the OG. Otherwise, it was obtained in two patients in the FG (p < 0.001). The other two patients in the FG preoperatively showed a complete epiphyseal fusion of the distal phalanges in the hand, and their f-CA was 0.7 and 1.1°, respectively. Conclusions: The degree of skeletal maturation corresponding to epiphyseal fusion of distal phalanges in the hand results in undercorrection after the hemi-PETS performed at the proximal tibia for genu varum.

Transphyseal Hemiepiphysiodesis: Is it Truly Reversible?

BACKGROUND

Although numerous studies reported the efficacy of percutaneous epiphysiodesis using transphyseal screws (PETS) in correcting angular knee deformities, many surgeons refrained from using it in younger children because of a lack of objective evidence of reversibility. Our hypothesis is that PETS is both truly reversible and effective.

METHODS

Twenty-one patients aged 8 to 13 years (36 lower limbs LL) with coronal plane knee deformity were enrolled into this prospective case series from January 2021 to September 2023. Besides the routine monitoring of PETS efficacy, low dose CT knee of 32 treated physes was done 6 months after screw removal. In addition, lower limb length, mechanical lateral distal femur angle (mLDFA), and medial proximal tibial angle (MPTA) were recorded preoperatively and 6 to 17 months after screw removal for 24 LL to investigate physis behavior, technique reversibility, and resumption of bone growth after screw removal.

RESULTS

The mean mechanical axis deviation (MAD) correction rate was 3.46 mm/mo and 1.78 mm/mo for genu valgum and genu varum patients, respectively. No physeal bony bars could be detected 6 months after screw removal for all patients. Out of 24 physis that underwent computerized radiography (CR) of the whole lower limb, 12 LL resumed their growth, 4 were stationary, while 8 were excluded due to inadequate calibration. A single physis showed rebound deformity, and another showed overcorrection in the genu valgum group.

CONCLUSIONS

In addition to being a highly effective method of hemiepiphysiodesis, PETS was found to be reproducible, safe, and reversible when used in the juvenile and early adolescent pediatric population.

LEVEL OF EVIDENCE

IV-Prospective case series.

Guided Growth With Minifragment Plates for Angular Deformities in the Distal Radius in Skeletally Immature Patients. Preliminary Results

INTRODUCTION

Growth modulation allows correction of progressive ulnar deviation of the distal radius in skeletally immature patients, which may occur as a consequence of various pathologies. The aim of this study is to evaluate the radiographic results and complication rate in a series of patients treated with minifragment plates.

METHODS

The medical records of 12 patients who underwent guided growth with a minifragment plate on the radial aspect of the distal radius as a consequence of angular deformities in the distal radius were retrospectively reviewed. Demographic data, radiographic changes, and complication rate were analyzed.

RESULTS

A total of 14 wrists and forearms were evaluated. The mean age at which surgery was performed was 10.5 years (interquartile range: 9.0 to 11.3). The average time between placement and removal of the material was 28.7 months (SD: 8,89). In each case, a general improvement of the radiographic parameters was obtained. There were 3 postoperative complications, but only 1 of them required reintervention (broken metaphyseal screw).

CONCLUSIONS

Hemiepiphysiodesis using a minifragment plate is a treatment that respects the surgical anatomy and offers an alternative surgical option for angular deformities of the distal radius in children.

LEVEL OF EVIDENCE

Level IV.

Factors Affecting Postoperative Courses After Removal of Transphyseal Screws Inserted for Correction of Genu Valgum

BACKGROUND

The aim of this study was to investigate factors determining the final outcomes of hemipercutaneous epiphysiodesis using transphyseal screw (PETS) for the genu valgum, especially focusing on postoperative courses after screw removal.

METHODS

Fifty-five patients with idiopathic genu valgum treated with hemi-PETS were included. The mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA) were measured to calculate the degree of correction and rebound. Regarding factors related to surgical techniques, the number of screw threads beyond the physis, the moment arm of the screw, and screw insertion angles were measured.

RESULTS

In 54 femoral segments (randomly selected in bilateral cases), hemi-PETS was performed with a growth remaining of 2.0±0.6 years. The screw was removed after 6.5±2.1 months, and the degree of correction was 5.0±1.5 degrees. The mean rebound angle was -0.4±2.4 (the negative value means further correction after screw removal). A late time of surgery and an extreme peripheral position of a screw were associated with the growth inhibition. In 50 tibial segments (also randomly selected in bilateral cases), a screw was inserted with a growth remaining of 2.0±0.6 years and removed after 6.3±1.9 months. The degree of correction was 2.9±1.7 degrees during the interval, and the rebound angle was 0.8±1.7 degrees. An earlier time of surgery and a greater correction angle before screw removal were associated with the rebound phenomenon.

CONCLUSIONS

Growth inhibition of >1.6 degrees was observed in about one-fourth of femoral segments. An extreme peripheral position of a screw should be avoided when performing hemi-PETS at the distal femur. We also recommend not performing hemi-PETS at distal femur with too short a period of growth remaining.

LEVEL OF EVIDENCE

Level III-retrospective comparative series.

Surgical approach to correction of severe knee malalignment in a pediatric population in Tanzania

AIM

Severe knee malalignment in children usually needs surgery with different options available in surgical approaches. The aim of this study was to report the results of the surgical correction of severe knee malalignment in children treated with femoral and tibial osteotomy, temporarily fixed with percutaneous Kirschner wires, in a low- and middle-income country (LMIC), with limited medical resources.

Faster Rate of Correction with Distal Femoral Transphyseal Screws Versus Plates in Hemiepiphysiodesis for Coronal-Plane Knee Deformity: Age- and Sex-Matched Cohorts of Skeletally Immature Patients

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.

The efficacy of hemiepiphysiodesis for idiopathic knee coronal angular deformity by reconstruction plate and screw: A pilot study

Background

Angular deformities of the lower extremities are among the most common findings in pediatric orthopedics. Alteration of the mechanical axis in the lower extremity affects the cosmetic appearance and may lead to gait disturbances, knee discomfort, patellar maltracking with or without pain, and early joint osteoarthritis. In the current study, we aimed to investigate the efficacy of 3-hole 3.5 mm reconstruction plates in tension-band temporary hemiepiphysiodesis for correcting idiopathic knee coronal angular deformities.

Methods

The surgical procedure was performed using an extraperiosteal tension band plate (a 3-hole reconstruction plate) and two 3.5 mm cortical screws to treat idiopathic knee coronal angular deformity in children. The location of the hemiepiphysiodesis was determined based on the type of angular deformity present. Postoperative follow-ups were conducted through x-rays to measure the medial proximal tibial angle and lateral distal femoral angle of the limbs. Statistical analysis was then performed to evaluate the efficacy of the surgical treatment based on the rate of alignment change exhibited.

Results

The study included 14 patients (25 limbs) with genu valgum deformity who underwent temporary hemiepiphysiodesis on both the distal femur and proximal tibia, with 16 proximal tibias and 15 distal femurs being corrected. The correction rate for genu valgum was found to be 0.59° per month for both proximal tibial and distal femoral hemiepiphysiodesis. Six patients (12 limbs) were also identified with genu varum deformity, and the correction rates for proximal tibial lateral hemiepiphysiodesis and distal femoral lateral hemiepiphysiodesis were 0.85° and 0.15° per month, respectively. During a mean follow-up duration of 11 ± 5.7 months, only one case of physeal plate closure was observed, and there were no other significant complications.

Conclusion

Temporary hemiepiphysiodesis with a 3-hole R-plate and two cortical screws takes advantage of physiological physeal growth to successfully treat idiopathic angular deformities with low complication rates.

Natural behaviours after guided growth for idiopathic genu valgum correction: comparison between percutaneous transphyseal screw and tension-band plate

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.

Factors Affecting Rebound Phenomenon After Temporary Hemiepiphysiodesis and Implant Removal for Idiopathic Genu Valgum in Adolescent Patients

BACKGROUND

The aim of this study was to investigate factors determining postoperative courses, especially focusing on the rebound phenomenon, in adolescent patients with idiopathic genu valgum who underwent temporary hemiepiphysiodesis and implant removal.

METHODS

We identified and reviewed patients with idiopathic genu valgum treated with temporary hemiepiphysiodesis [using tension-band plates (plate group, PG) or transphyseal screws (screw group, SG)] and followed-up to skeletal maturity.

RESULTS

In our cohort [68 patients and their 68 limbs (randomly selected in bilateral cases)], the mean hip-knee-ankle alignment was -5.4±1.8 degrees at the time of temporary hemiepiphysiodesis (negative means valgus), 2.6±2.1 degrees at the time of implant removal, and 0.7±2.6 degrees at the last follow-up, respectively. Regarding the implants, the correction speed was not significantly different (P=0.192-0.315) between the PG (total 1.29±0.37 degrees/mo, 0.71±0.23 degrees/mo at distal femur, 0.59±0.16 degrees/mo at proximal tibia, n=19) and the SG (total 1.22±0.49 degrees/mo, 0.65±0.25 degrees/mo at distal femur, 0.57±0.23 degrees/mo at proximal tibia, n=49). The magnitude of rebound phenomenon in the PG (4.1±1.9 degrees) was greater (P<0.001) than that in the SG (1.1±3.1 degrees). The use of plates and faster correction speed, rather than more severe preoperative deformity or greater correction angle, were positively associated with the rebound phenomenon in regression analyses. Among the 68 knees, 1 showed valgus alignment ≥5 degrees and 5 showed varus alignment ≥5 degrees at the last follow-up. All the 6 cases were observed in the SG. Surgical wound dehiscence was observed in 1 patient in the PG.

CONCLUSIONS

The use of plates and faster correction speed were positively associated with the rebound phenomenon. Careful attention will be needed with the corresponding conditions for optimal results. Progressive genu varum after transphyseal screw removal, which was observed in this study, should be explored in future research.

LEVEL OF EVIDENCE

Level III-retrospective comparative series.

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.

Hemiepiphysiodesis for coronal angular knee deformities: tension-band plate versus percutaneous transphyseal screw

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.

MATERIALS AND METHODS

A retrospective cohort of 35 patients treated with either TBP or PETS in one medical institution was established. The cohort included both genu varum and genu valgum of both primary and secondary etiologies. We first compared the treatment groups for differences in demographic and malalignment characteristics. Then, we compared the treatment groups for differences in operation-related outcomes, radiological mechanical correction and complication rates.

RESULTS

We found that the use of PETS, compared to TBP, was associated with a faster implantation surgery and a shorter interval between implantation and removal, i.e., faster correction. Furthermore, PETS were associated with faster correction rates of the mechanical axis deviation, lateral distal femoral angle and medial proximal tibial angle. No significant differences in complication rates were found between the two treatments.

CONCLUSION

PETS provided a faster correction of angular knee deformities compared to TBP at similar complication rates. Hence, PETS could be considered a superior technique for hemiepiphysiodesis.

Efficacy of Percutaneous Retrograde Transphyseal Guided Growth Screw in Distal Femoral Angular Deformity Correction: A New Technique

BACKGROUND

We modified the original technique for percutaneous transphyseal screw which was described in 1998 by Metaizeau and colleagues for distal femoral coronal angular deformity correction; the modification is related to the screw direction, whereas the screw is administered in a retrograde pattern, starting from the epiphysis and directed toward the metaphysis. This technique opposes the original technique that was started with a metaphyseal entry point which aimed toward the epiphysis. This study evaluates the efficacy of the newly suggested surgical technique regarding the rate of correction and growth resumption after screw removal.

METHODS

This prospective study looked at 40 patients (65 distal femoral physes), who underwent a percutaneous retrograde transphyseal guided growth screw procedure, from October 2017 to September 2019. All the patients included had distal femoral coronal angular deformities; 52 in valgus and 13 in varus deformities. The study included 17 females with an average age of 11.75 (range: 8.4 to 14.5 y) for 29 femurs and 23 males with an average age of 13.75 (range: 11.75 to 15.6 y) for 36 femurs. The mechanical lateral distal femoral angle was measured initially, and then again was measured after reaching the desired corrected orientation. The patients were then followed up after the screw removal and followed up to maturity, if the physis had continued to grow postcorrection. The degree of correction per month was calculated, and the consequence of screw removal was detected. Follow-up average time was 12.6 months (range: 30 to 6 mo).

RESULTS

The average correction in the distal femur was 1.3 degrees per month (range: 0.5 to 1.857 degrees/mo). In all of the 65 segments (61 femurs had significant growth remaining and 4 femurs had reached skeletal maturity with suboptimal mechanical lateral distal femoral angle correction), the screws were removed at the time of angular correction. Rebound growth was observed in 15 physes with an average of 1.8 degrees (range: 2 to 3 degrees); they were stable in 42 physes and progressed in 4 physes with an average of 1.6 degrees (range: 1 to 2 degrees). Complications were minor and related to entrapment of soft tissue under the screw washer.

CONCLUSION

Percutaneous retrograde transphyseal guided growth screw for distal femur coronal angular deformity is a minimally invasive procedure, with a statistically significant correction rate when compared with the original transphyseal screw technique. The new technique has proven to have growth resumption after screw removal with minimal complication risk.

LEVEL OF EVIDENCE

Level III-prospective observational study.

Temporary hemiepiphysiodesis using an eight-plate implant for coronal angular deformity around the knee in children aged less than 10 years: efficacy, complications, occurrence of rebound and risk factors

BACKGROUND

Temporary hemiepiphysiodesis (TH) using an eight-Plate implant is one of the most common surgeries used for the correction of coronal angular deformities around the knee in adolescents. However, few studies have focused on children aged less than 10 years treated with TH using an eight-Plate implant. The purpose of this study was to investigate the efficacy, correction velocity, and complications of TH with an eight-Plate implant as well as the occurrence of rebound and risk factors in this population.

METHODS

This retrospective study included a total of 135 physes (101 knees) from 66 children (mean age of 4.69 years old, range from 1 to 10 years old) who underwent TH with an eight-Plate implant to correct coronal genu angular deformities in our hospital. Related clinical factors were recorded and analysed by multivariable linear and logistic regression models.

RESULTS

The mean deformity correction period was 13.26 months, and the mean follow-up after eight-Plate removal was 12.71 months. In all, 94.06% (95/101 knees) of the genu angular deformities were completely corrected. Non-idiopathic genu angular deformity was found to be an independent risk factor for deformity correction failure (odds ratio (OR) = 2.47). The femoral correction velocity was significantly higher than the tibial correction velocity (1.28° vs. 0.83° per month, p < 0.001). After adjustment for other factors, younger children had higher correction velocities in the distal femur; however, genu valgum and idiopathic deformities were associated with higher correction velocities in the proximal tibia. In addition, we found three (3/101, 2.97%) knees with genu valgum that experienced rebound after removal of the eight-Plate, while five (5/101, 4.95%) knees with non-idiopathic genu angular deformity experienced screw loosening. No other complications were found, and non-idiopathic deformity was the only risk factor for complications (OR = 3.96). No risk factor was found for rebound in our study.

CONCLUSIONS

TH using an eight-Plate implant is an effective procedure for coronal genu angular deformities with a low incidence of complications and rebound in patients younger than 10 years old. For this population, TH using an eight-Plate should be considered as soon as the deformity stops responding to conservative treatments. The parents of children younger than 10 years of age with non-idiopathic deformities should be informed preoperatively that the deformity may be prone to correction failure or screw loosening after eight-Plate implantation.

Correction of coronal plane deformities around knee in children with two-hole tension band plates

Objectives

This study aims to present the 10-year results and complications of two-hole tension band plate hemiepiphysiodesis for coronal deformities around knee in a large population from a single center.

Patients and methods

Seventy-seven patients (46 boys, 31 girls; mean age 93±36 months; range, 22 to 181 months) who underwent temporary hemiepiphysiodesis around knee between January 2009 and January 2019 with two-hole tension band plates were retrospectively evaluated. Improvement of joint orientation angles and mechanical axis deviations, deformity correction rates, etiology groups, and complications were noted.

Results

A total of 166 bone segments (93 femurs, 73 tibias) were included in the study. Mean follow-up duration after the implantation was 36±17 (range, 12 to 88) months. Plates were removed at mean 18±8 (range, 7 to 47) months of implantation. Of the bone segments, 95.2% (n=158) responded successfully to the plates. Mean correction rate of mechanical lateral distal femoral angle in femoral valgum deformity was 0.94±0.43° (range, 0.17 to 2.22)/month and mean correction rate of mechanical medial proximal tibial angle in tibial valgum deformity was 0.62±0.36° (range, 0.11 to 1.55)/month. Mean correction rate of mechanical lateral distal femoral angle in femoral varum deformity was 1.3±0.8° (range, 0.48 to 2.92)/month and mean correction rate of mechanical medial proximal tibial angle in tibial varum deformity was 0.94±0.49° (range, 0.26 to 1.67)/month. The most common complication observed was rebound deformity seen in 41.2% (n=70) of the bone segments. Nine bone segments had persistent hemiepiphysiodesis despite plate removal. Four screw breakages (three metaphysial and one epiphysial) were observed.

Conclusion

Two-hole tension band plate hemiepiphysiodesis appears to be an effective and safe method for the correction of coronal deformities around knee.

Growth modulation for fixed flexion contracture of the knee: a comparison of two techniques

Growth modulation has become a mainstream treatment for frontal plane angular lower extremity deformities in children. Few articles address the effect of growth modulation on sagittal deformity. Our aim is to compare two anterior distal femoral growth modulation techniques for fixed knee flexion contracture. Electronic medical records were reviewed for patients who underwent anterior femoral growth modulation for fixed flexion contracture. Patients were excluded if adequate preoperative/postoperative radiographs were unavailable. A cohort was subdivided based on surgical technique: screws alone versus dual tension-band plates. Complications were recorded; radiographs were evaluated preoperatively and at hardware removal. Posterior distal femoral angle (PDFA), posterior proximal tibial angle (PPTA), and anterior cortical line (ACL) angle were evaluated. Of 35 patients identified, 20 patients (29 knees) were included. Thirteen knees were treated with dual anterior tension-band plates; 16 knees had transphyseal screws. Sagittal alignment improved in both groups. Statistically significant PDFA changes were observed in the tension-band plate group (P = 0.0095); a trend was noted toward improvement in ACL angle (P = 0.08). PPTA did not change. No changes reached significance in the transphyseal screw group (PDFA: P = 0.181, ACL: P = 0.64). Tension-band plate migration was noted in one (7.7%) of 13 knees, and transphyseal screw migration in nine (56.3%) of 16 knees (P < 0.01). Anterior distal femoral growth modulation improves sagittal alignment without significant remodeling at the proximal tibia. Hardware migration occurred more often with transphyseal screws (P < 0.01). We recommend dual anterior tension-band plating over placement of paired screws for sagittal growth modulation to treat knee flexion contracture.

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.

Correction of the knee coronal plane deformity using the screws plus reconstruction plate versus cannulated screws

INTRODUCTION

Knee angular deformity is a common finding occurring in the childhood that can cause gait disturbances and early compartment osteoarthritis. Despite various surgical approaches presented to correct the angular deformities of the knee, there is still a search for the best approach. Thus, the present study was conducted to compare the results of using cannulated screw (CS) versus screw plus reconstruction plate (SpRP) for correction of angular deformities through a two-year follow-up study.

HYPOTHESIS

Percutaneous CS implantation is as efficacious as SpRP implantation for the correction of angular deformities of the knee.

MATERIAL AND METHODS

This randomised clinical trial (RCT) was conducted on 63 patients with angular deformities who were randomly divided into two groups including treatment with cannulated screw (CS) (n=32) and treatment with screw plus reconstruction plate (SpRP) (n=31). All the patients underwent the alignment view radiography of both lower limbs before surgical procedure and then within 3, 6, 12, 18 months and 2 years following the surgery. Afterwards, the patients' mechanical axis of the knees, medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), and varus/valgus angles were assessed and compared.

RESULTS

Results of the study showed that MPTA and LDFA significantly turned to the normal range during the 18 months follow-up in both treatment groups (p-value<0.001). Varus and valgus angles were corrected in both techniques as well postoperatively (p-value<0.001). Ultimate correction was achieved earlier in the CS treated group (12 months versus 18 months later).

DISCUSSION

Findings of the study revealed that the percutaneous CS implantation was successful similar to the SpRP implantation for correction of the angular deformity, while earlier ultimate angular correction and less pain complaint were among the superiorities of the CS.

LEVEL OF THE STUDY

II, comparative prospective study.

Hemiepiphyseodesis for Juvenile and Adolescent Tibia Vara Utilizing Percutaneous Transphyseal Screws

BACKGROUND

In juvenile and adolescent tibia vara patients with sufficient growth remaining, implant-controlled hemiepiphyseodesis, or guided growth, can be used to correct deformity. Recent reports have described hardware failure of certain hemiepiphyseodesis implants in overweight patients with tibia vara. We describe our experience using transphyseal screws to correct deformity in this patient population.

METHODS

A retrospective chart and radiograph review was conducted on all juvenile and adolescent tibia vara patients who underwent lateral proximal tibial hemiepiphyseodesis using a single transphyseal screw. Charts were queried for preoperative and postoperative mechanical axis deviation, medial proximal tibial angle, lateral distal femoral angle, and postoperative complications or need for further surgery.

RESULTS

In total, 14 affected limbs in 9 patients (6 males) who underwent lateral proximal tibial transphyseal screw hemiepiphyseodesis were considered. Average chronologic age at implantation was 10.4 years and average body mass index was 31.7 kg/m. At average 23-month follow-up, the average mechanical axis deviation improved from 46 to 0 mm (P<0.001), and the average medial proximal tibial angle improved from 81 to 92 degrees (P<0.001). No limbs underwent further surgery to correct residual deformity. There were no complications or instances of implant failure associated with the transphyseal screws.

CONCLUSIONS

Hemiepiphyseodesis using transphyseal screws is an effective technique to correct deformity in juvenile and adolescent tibia vara patients with sufficient growth remaining. This method can be used safely with few complications and with minimal risk of mechanical failure, even in overweight patients.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Rebound Deformity After Growth Modulation in Patients With Coronal Plane Angular Deformities About the Knee: Who Gets It and How Much?

BACKGROUND

With observed success and increased popularity of growth modulation techniques, there has been a trend toward use in progressively younger patients. Younger age at growth modulation increases the likelihood of complete deformity correction and need for implant removal before skeletal maturity introducing the risk of rebound deformity. The purpose of this study was to quantify magnitude and identify risk factors for rebound deformity after growth modulation.

METHODS

We performed a retrospective review of all patients undergoing growth modulation with a tension band plate for coronal plane deformity about the knee with subsequent implant removal. Exclusion criteria included completion epiphysiodesis or osteotomy at implant removal, ongoing growth modulation, and <1 year radiographic follow-up without rebound deformity. Mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, hip-knee-ankle angle (HKA), and mechanical axis station were measured before growth modulation, before implant removal, and at final follow-up.

RESULTS

In total, 67 limbs in 45 patients met the inclusion criteria. Mean age at growth modulation was 9.8 years (range, 3.4 to 15.4 y) and mean age at implant removal was 11.4 years (range, 5.3 to 16.4 y). Mean change in HKA after implant removal was 6.9 degrees (range, 0 to 23 degrees). In total, 52% of patients had >5 degrees rebound and 30% had >10 degrees rebound in HKA after implant removal. Females below 10 years and males below 12 years at time of growth modulation had greater mean change in HKA after implant removal compared with older patients (8.4 vs. 4.7 degrees, P=0.012). Patients with initial deformity >20 degrees had an increased frequency of rebound >10 degrees compared with patients with less severe initial deformity (78% vs. 22%, P=0.002).

CONCLUSIONS

Rebound deformity after growth modulation is common. Growth modulation at a young age and large initial deformity increases risk of rebound. However, rebound does not occur in all at risk patients, therefore, we recommend against routine overcorrection.

LEVEL OF EVIDENCE

Level IV-retrospective study.

Hemiepiphysiodesis for Idiopathic Genu Valgum: Percutaneous Transphyseal Screw Versus Tension-band Plate

BACKGROUND

The aim of this study was to compare the outcomes of angular deformity correction by percutaneous hemiepiphysiodesis using transphyseal screw (PETS) or tension-band plating (TBP) in growing children with idiopathic genu valgum with emphasis on the rate of deformity correction.

METHODS

We retrospectively reviewed cases of hemiepiphysiodesis for angular deformity in lower extremities between 2009 and 2014. A total of 90 limbs in 33 patients received PETS and 60 limbs in 24 patients received TBP. Angular measurements were compared preoperatively and at the time of hardware removal. The amount and rate of angular deformity correction were compared between the 2 groups. Potential factors affecting correction velocity were investigated using multivariate analysis.

RESULTS

Angular correction was achieved in all patients. The mean rate of correction was more rapid with PETS than with TBP at both the distal femur (0.92 vs. 0.64 deg./mo, respectively; P<0.001) and proximal tibia (0.72 vs. 0.55 deg./mo, respectively; P=0.019). Multivariate analysis showed that the used implant significantly affected the rate of correction: PETS demonstrated faster correction velocity than TBP (-0.26, 95% confidence interval, -0.35 to -0.17, P<0.001).

CONCLUSIONS

Both PETS and TBP techniques result in satisfactory correction of coronal angular deformity in patients with idiopathic genu valgum. However, the observed rate of correction was faster with PETS than TBP. Correction with PETS, rather than TBP, may better serve patients near skeletal maturity.

LEVEL OF EVIDENCE

Level III-retrospective comparative series.

Angular deformity correction by guided growth in growing children: Eight-plate versus 3.5-mm reconstruction plate

BACKGROUND

Guided growth using the eight-plate (8-plate) is the most commonly used method to correct angular deformities in children; however, implant failure has been reported. Recently, the 3.5-mm reconstruction plate (R-plate) has been used as an alternative option for guided growth; however, hardware prominence has been problematic. This study aimed to compare the coronal angular deformity correction results of guided growth between relatively thin 8-plates with cannulated screws and thick R-plates with solid screws.

METHODS

Thirty-nine physes (24 distal femoral, 15 proximal tibial) in 20 patients underwent hemiepiphysiodesis using 8-plates, and 61 physes (40 distal femoral, 21 proximal tibial) in 35 patients underwent hemiepiphysiodesis using R-plates. Coronal angular corrections were measured and compared preoperatively, and after the completion of corrections. Amounts and rates of correction and complications were compared between the groups.

RESULTS

Mean body mass index was 18.7 kg/m2 in the 8-plate group, and 22.7 kg/m2 in the R-plate group. Angular correction was achieved in all deformities at a mean of 13.7 months and 19.7 months in the 8-plate and the R-plate group, respectively. The mean corrected mechanical lateral distal femoral angle was 9.0° in the 8-plate group, and 9.9° in the R-plate group (P = 0.55). The mean corrected medial proximal tibial angle was 7.1° in the 8-plate group, and 9.0° in the R-plate group (P = 0.07). The mean rates of angular correction were also not significantly different in the distal femur (1.03°/month vs. 0.77°/month, P = 0.2) and the proximal tibia (0.66°/month vs. 0.63°/month, P = 0.77). There was one superficial infection in each group, and one case of implant failure in the R-plate group. Two rebound deformities were observed and needed repeat hemiepiphysiodesis. Permanent physeal arrest was not observed in this series.

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.

Prediction of rebound phenomenon after removal of hemiepiphyseal staples in patients with idiopathic genu valgum deformity

AIMS

Our aim was to investigate the predictive factors for the development of a rebound phenomenon after temporary hemiepiphysiodesis in children with genu valgum.

PATIENTS AND METHODS

We studied 37 limbs with idiopathic genu valgum who were treated with hemiepiphyseal stapling, and with more than six months remaining growth at removal of the staples. All children were followed until skeletal maturity or for more than two years after removal of the staples.

RESULTS

On multivariate logistic regression analysis, the rate of correction, body mass index (BMI), age, and initial valgus angle were significantly associated with a rebound phenomenon. With those characteristics, a predictive model for rebound was generated using recursive partitioning analysis. Children with a rapid rate of correction had the most frequent and severe rebound phenomenon (incidence 79%, mean 4°), whereas those with a slow rate of correction had less rebound when they had low BMI (43%, 2°) and none when the BMI was ≥ 21 kg/m(2).

CONCLUSION

This is the first study to evaluate a predictive model for a rebound phenomenon after temporary hemiepiphysiodesis in children with idiopathic genu valgum. Cite this article: Bone Joint J 2016;98-B:1270-5.

The Efficacy of Percutaneous Lateral Hemiepiphysiodesis on Angular Correction in Idiopathic Adolescent Genu Varum

Background

Percutaneous lateral hemiepiphysiodesis of the lower extremity is a simple and excellent method to correct the angular and length problems cosmetically. However, the efficacy of percutaneous lateral hemiepiphysiodesis is not well established in the literature. The purpose of this study was to evaluate the efficacy of percutaneous lateral hemiepiphysiodesis for angular corrections in adolescent idiopathic genu varum patients with proximal tibia vara and identify the factors affecting the amount of deformity correction of the lower limb in the coronal plane.

Methods

We retrospectively reviewed 20 patients (40 lower limbs) who had percutaneous lateral hemiepiphysiodesis on the proximal lateral tibia between 1997 and 2010. Radiographic evaluations were made using (1) the hip-knee-ankle angle and (2) the length of the tibia. Furthermore, the intercondylar distance was evaluated at the level of the knee joint. Preoperative factors (gender, age, body mass index, intercondylar distance, preoperative hip-knee-ankle angle, remaining growth of tibia, and calculated correctable angle) were analyzed, as well as their correlation with the degree of the actual correction angle.

Results

The amount of coronal deformity of the lower limb was improved from its preoperative state. The median average of hip-knee-ankle angle improved from 8.0° (interquartile range [IQR], 7.0° to 10.0°) preoperatively to 3.0° (IQR, 2.5° to 4.0°) at the final follow-up (p < 0.001). The median percent ratio of the angular correction was 60% (IQR, 50% to 71.3%). The correlation coefficients were –0.537, 0.832, 0.791, and 0.685 for the bone age, preoperative hip-knee-ankle angle, the remaining growth of tibia, and calculated correctable angle, respectively.

Conclusions

Despite the excellent cosmetic outcome of percutaneous lateral hemiepiphysiodesis on the proximal lateral tibia in adolescent idiopathic genu varum, the effect was limited in most cases. For optimum results, surgery a few months earlier is recommended, rather than at the calculated operation time.

Anterior Percutaneous Hemiepiphysiodesis of the Distal Aspect of the Femur: A New Technique: A Case Report

CASE

Anterior distal femoral hemiepiphysiodesis for knee flexion deformity in children is typically done using staples or plate-and-screw constructs. Staple migration and postoperative knee pain are common complications associated with these procedures. The authors describe a new technique of percutaneous epiphysiodesis using transphyseal screws (PETS) for anterior hemiepiphysiodesis of the distal aspect of the femur that was used to treat recurrent knee flexion deformity in a child with cerebral palsy who had recurrent crouch gait after hamstring lengthening.

CONCLUSION

The technique has the advantage of being less expensive than plate-and-screw constructs, and it has the potential for causing less postoperative knee pain.

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.

Comparison of orthopaedic manifestations of multiple epiphyseal dysplasia caused by MATN3 versus COMP mutations: a case control study

Background

Multiple epiphyseal dysplasia (MED) is a relatively common skeletal dysplasia mainly involving the epiphyses of the long bones. However, it is a genetically heterogeneous group of diseases sharing certain aspects of the radiologic phenotype. In surveys conducted in East Asia, MATN3 was the most common causative gene, followed by COMP. In this study, the authors compared clinical manifestation of MED patients caused by MATN3 and COMP gene mutations, as well as subsequent orthopaedic interventions.

Methods

Fifty nine molecularly-confirmed MED patients were subjects of this study. The MATN3 gene mutation group comprised of 37 patients (9 female, 28 male). The COMP gene mutation consisted of 22 cases (15 females, 7 males). Medical records and radiographs were reviewed, and questionnaire surveys or telephone interviews were conducted.

Results

At the first presentation, the mean age was 8.8 ± 2.8 years (mean ± standard deviation) in the MATN3 group, and 8.5 ± 3.5 years in the COMP group (p = 0.670). The height in the COMP group was significantly shorter than those in the MATN3 group (p < 0.001). Gait abnormality at the first visit (p = 0.041) and the lastest follow-up (p = 0.037) were statistically significant difference. Hip pain (p = 0.084), limitation of daily activity (p = 0.075) at the latest follow-up tended to be more frequent in the COMP group. Hip dysplasia was more common in the COMP group, having significantly larger acetabular angle (p = 0.037), smaller center-edge angle (p = 0.002), severe Stulberg classification (p < 0.001), and smaller femoral head coverage (p < 0.001).

Conclusions

Clinical manifestations of MED caused by MATN3 were milder than manifestations of the COMP mutation group. These differences in clinical manifestation and prognosis justify molecular differentiation between the two genotypes.

Correction and recurrence of ankle valgus in skeletally immature patients with multiple hereditary exostoses

BACKGROUND

Ankle valgus is encountered in children with a variety of congenital musculoskeletal disorders, including multiple hereditary exostoses (MHE). Guided growth with temporary distal tibial medial hemiepiphysiodesis (DTMH) may correct the deformity; however, exostoses about the ankle commonly observed in MHE patients may hinder correction and increase the risk of recurrence. Thus, the purpose of this study was to review the outcomes of DTMH in treatment of ankle valgus in MHE versus other diagnosis (non-MHE).

METHODS

Medical records and radiographs of patients undergoing DTMH for ankle valgus between January 1, 2005, and November 1, 2010, at a single pediatric orthopedic hospital were retrospectively analyzed. Radiographs obtained preoperatively and at 6-month intervals postoperatively were reviewed and the tibiotalar angle was measured.

RESULTS

Fifty-eight ankles in 41 patients met inclusion criteria, with minimum follow-up of 12 months (mean, 34 months). Mean age was 10 years (range, 4-14 years). MHE was the most common underlying diagnosis (19 ankles, 33%). The rate of tibiotalar angle correction (mean ± standard deviation) with hardware in place was 0.37 ± 0.28 deg/mo in MHE ankles and 0.51 ± 0.42 deg/mo in non-MHE ankles (P = .161). Following hardware removal, the rate of recurrence was faster in MHE (0.29 ± 0.25 deg/mo) compared with non-MHE ankles (0.12 ± 0.19 deg/mo) (P = .059), and more total recurrent valgus deformity was observed in MHE (7.8 ± 8.2 degrees) than non-MHE ankles (3.4 ± 4.6 degrees) (P = .08) over a similar follow-up period (mean 23.4 vs 23.6 months, respectively), with differences approaching statistical significance.

CONCLUSION

MHE is a common cause of ankle valgus in children. Guided growth interventions in this population can be successful but require special consideration given the potential for relatively gradual deformity correction and rapid recurrence following hardware removal in the skeletally immature.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Guided growth for the treatment of limb length discrepancy: a comparative study of the three most commonly used surgical techniques

The purpose of this study was to compare the safety and effectiveness of three mechanical devices (percutaneous transphyseal screws, tension band plates, and staples) for the correction of limb length discrepancies in growing children and adolescents. Thirty-nine consecutive patients treated with epiphysiodesis for limb length discrepancy were retrospectively reviewed. No significant difference was recorded between the three devices in postoperative limb length discrepancy or the rate of correction between the plating and stapling groups and between plating and percutaneous transphyseal screws groups. Epiphysiodesis for length discrepancies can be performed effectively using staples, tension band plates, or percutaneous transphyseal screws.

Guided growth by a stainless-steel tubular plate

Guided growth using titanium tension band plates is an advancement in the correction of angular deformity. We applied two-hole stainless-steel one-third tubular plates for the same purpose. There were 14 deformities around the knees in eight children, mean age 10.8 years at operation. The success rate was 92.9% (13/14). The average correction rate per month was 0.59° in the femur and 0.65° in the tibia. No premature physeal arrest, overcorrection, or rebound phenomenon was observed. A stainless-steel plate is a safe and effective option for guided growth surgery in countries where only stainless-steel plates are available.

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.