Outcomes of Hemiepiphyseal Stapling for Genu Valgum Deformities in Patients With Multiple Hereditary Exostoses: A Comparative Study of Patients With Deformities of Idiopathic Cause

Hemiepiphysiodesis for Genu Valgum in Patients With Multiple Hereditary Exostoses

BACKGROUND

Genu valgum is a well-known feature of multiple hereditary exostoses (MHE). Though prior reports have demonstrated successful treatment with hemiepiphysiodesis, details regarding the correction rate and comparison to an idiopathic population are lacking. This study aimed to detail our institution's experience with guided growth of the knee in patients with MHE and compare this to an idiopathic population.

METHODS

All pediatric patients (age 18 and younger) with MHE who underwent lower extremity hemiepiphysiodesis at a tertiary care medical center between January 2016 and December 2022 were retrospectively reviewed. Preoperative and postoperative mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA, the primary outcomes) were measured in addition to mechanical axis deviation (MAD) and hip-knee-ankle angle (HKA). Patients were 1:2 matched based on age, sex, and physes instrumented to a cohort with idiopathic genu valgum.

RESULTS

A total of 21 extremities in 16 patients with MHE underwent hemiepiphysiodesis of the distal femur, proximal tibia, and/or distal tibia. The mean age at surgery was 11.7±2.2 years. Mean MAD corrected from zone 1.9±0.7 to -0.3±1.5, while mLDFA corrected from 83.4±2.9 to 91.7±5.2 degrees and MPTA corrected from 95.3±3.6 to 90.5±4.0 degrees in distal femurs and proximal tibias undergoing guided growth, respectively. Three extremities (14.3%) experienced overcorrection ≥5 degrees managed with observation. There were no differences in correction rates per month for mLDFA (0.54±0.34 vs. 0.51±0.29 degrees, P =0.738) or MPTA (0.31±0.26 vs. 0.50±0.59 degrees, P =0.453) between MHE and idiopathic groups. For 11 extremities in the MHE group with open physes at hardware removal, they experienced a mean recurrence of HKA of 4.0±3.4 degrees at 19-month follow-up.

CONCLUSION

Hemiepiphysiodesis corrects lower extremity malalignment in patients with MHE at a similar rate compared with an idiopathic coronal plane deformity population. Rebound deformity of 4 degrees at 19 months after hardware removal in patients with remaining open growth plates should make surgeons conscious of the remaining growth potential when planning deformity correction.

LEVEL OF EVIDENCE

Level III.

Effect of Solitary Osteochondroma on Alignment and Length in the Lower Extremities

BACKGROUND

There is a lack of information about the effects of untreated solitary osteochondroma (SO) on longitudinal growth of the lower extremities in children and adolescents. This study aimed to assess the coronal alignment and length of the lower extremity in patients with SO around the knee and to identify the factors related to the development of deformities.

METHODS

We retrospectively reviewed 111 patients diagnosed with SO around the knee. The patients were classified into 2 groups depending on the location of the SO: 51 in the distal femur and 60 in the proximal tibia. Characteristics of the lesions, such as type, location, size, and distance from the joint line, were determined. Radiographic analysis of the lower limbs included mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, whole-leg length, femoral length, and tibial length.

RESULTS

The mean age at the time of diagnosis was 12.3±3.4 years. No statistically significant differences were found between the affected and contralateral sides for mechanical lateral distal femoral angle and mechanical medial proximal tibial angle in either the distal femur or the proximal tibia groups. In patients with femoral lesions, the femoral and whole-leg lengths were significantly shorter on the affected side than on the unaffected side ( P <0.001 and 0.002, respectively), and the mean differences were 2.1±3.6 and 2.1±4.4 mm, respectively. Univariate logistic regression analysis did not reveal any factors associated with limb length discrepancy (LLD). In patients with tibial lesions, no statistically significant differences were found in LLD.

CONCLUSIONS

SOs around the knee did not cause clinically significant deformity of the lower extremity. However, in contrast to proximal tibia lesions, SO in the distal femur was associated with the shortening of the affected limb. Consideration should be given to the development of LLD in skeletally immature children with SO in the distal femur.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

The Perils of Sleeper Plates in Multiple Hereditary Exostosis: Tibial Deformity Overcorrection Due to Tether at Empty Metaphyseal Hole

BACKGROUND

Hemi-epiphysiodesis is the mainstay of treatment for angular deformities at the knee in children with multiple hereditary exostosis (MHE). Upon deformity correction, the metaphyseal screw may be removed from the hemi-epiphysiodesis plate, the sleeper plate technique, with anticipated reimplantation of the metaphyseal screw should the original deformity recur. The aim of the present study is to compare the incidence of complications with the sleeper plate technique with complete plate removal in an MHE cohort.

METHODS

Patients under the age of 18 with MHE who underwent hemi-epiphysiodesis of the proximal tibia and/or distal femur between February 1, 2016, and February 6, 2022 with a minimum 2-year follow-up or follow-up to skeletal maturity were identified via ICD-10 codes. Patient charts and radiographic images were reviewed to assess for the bone(s) treated, the use of sleeper plates, and whether any complication occurred, including overcorrection from bony ingrowth at the empty holes or deformity recurrence.

RESULTS

In 13 patients, 19 knees underwent hemi-epiphysiodesis at 30 sites; 13 distal femoral and 17 proximal tibial. Of 30 plates, 18 (60%) were removed completely upon deformity correction and 3 (10%) did not require removal due to skeletal maturity. Four of 13 (30.8%) femoral plates and 5 of 17 (29.4%) tibial plates were left as sleeper plates. All 5 tibial sleeper plates developed bony ingrowth into the empty metaphyseal screw hole, which led to unintended progressive deformity overcorrection. In the majority of cases, the deformity was addressed by the removal of the plate and exophytic bone and hemi-epiphysiodesis on the other side of the affected proximal tibia with subsequent resolution of the deformity.

CONCLUSIONS

All tibial sleeper plates developed bony ingrowth into the screwless metaphyseal hole. The bony ingrowth functioned as a tether, resulting in progressive deformity overcorrection. Sleeper plates should be avoided at the proximal tibia in patients with MHE, and extreme caution should be exercised when considering this technique at the distal femur or other sites.

LEVELS OF EVIDENCE

Level III-retrospective comparative study.

Indications and timing in isolated medial femoral hemiepiphysiodesis for idiopathic genu valgum: A systematic review

INTRODUCTION

Temporary isolated medial femoral hemiepiphysiodesis (TIMFH) represents a safe and effective technique widely used to treat idiopathic genu valgum. Recent studies mainly concentrated on comparing outcomes of different implants, while less attention has been reserved to the proper indications and timing for surgery. The aim of this systematic review was to provide evidence-based guidelines about indications for device implant and removal and postoperative management.

METHODS

A comprehensive literature search was performed across three databases to select articles concerning TIMFH in the treatment of idiopathic genu valgum. Studies involving other etiologies or concomitant surgical procedures were excluded. Quality assessment of the included studies was conducted through the Newcastle-Ottawa Scale.

RESULTS

Ten studies involving 237 patients for a total of 446 knees were included in the analysis. Mean age at surgery was 11,4 years. Patients were considered for surgery using various clinical and radiological parameters. Intermalleolar distance (IMD) and mechanical lateral distal femoral angle (mLDFA) were the most common evaluated. Mean treatment time was 12 months. Rebound of the deformity occurred in 6,7% of cases.

CONCLUSION

Results of this review showed good consensus among authors. Patients undergoing TIMFH for IGV should be minimum 8 years old, with an IMD greater than 8 cm and a mLDFA lower than 87°. Postoperative management should comprise of quarterly clinic evaluations, and follow-up should last until skeletal maturity. The application of more uniform parameters in clinical practice may improve the establishment of the optimal timing for implant removal.

Design of a New "U"-shaped Staple and Its Clinical Application in Postoperative Ankle Valgus of Congenital Pseudarthrosis of the Tibia in Children

Objective

There has been a lack of suitable epiphysis blocking materials due to the characteristics of less tissue coverage and narrow epiphysis in children's distal tibial medial malleolus. Therefore, this study is to investigate the clinical efficacy and safety of a new “U”‐shaped staple in the treatment of postoperative ankle valgus of congenital pseudarthrosis of the tibia (CPT).

Method

According to the inclusion and exclusion criteria, 33 patients with postoperative ankle valgus of CPT were treated with new “U”‐shaped staples from May 2013 to September 2019. The deformity of ankle valgus was gradually corrected by implanting a new “U”‐shaped staple on the medial side of the distal tibia. Clinical indexes such as the operation time, intraoperative bleeding and hospital stay were observed. Tibiotalar angle was selected as the evaluation index of ankle valgus. American Orthopedic Foot & Ankle Society (AOFAS) scale was used for clinical evaluation of ankle function. The tibiotalar angle, deformity correction rate and complications were evaluated by preoperative, postoperative and last follow‐up imaging data. Student's t‐test was used for statistical analysis.

Results

Thirty‐three patients, including 12 males and 21 females were included. All the patients were followed up for at least 14 months, with an average of 35 months. The average operation time was 23 (15–40) min, the average amount of intraoperative bleeding was 7.5 (4–10) mL, and the average hospital stay was 4.2 (3–6) days. The intraoperative tibiotalar angles of all patients were 74.2° ± 4.6°, the tibiotalar angle were 86.8° ± 4.9° when internal fixation was removed, and the tibiotalar angles at the last follow‐up were 84.3° ± 5.9°. The average orthopedic rate was 0.68° per month. No patients suffered from serious complications such as screw prolapse, osteomyelitis, wound infection, etc. Postoperative wound pain complications occurred in two patients, which were relieved after conservative treatment. The AOFAS score improved from 46.2 ± 9.4 before the operation to 74.6 ± 5.7 at the last follow‐up (P < 0.01). The ankle movement was good without joint stiffness. There was no epiphyseal plate injury after the removal of internal fixation.

Conclusion

The new “U”‐shaped staple is characterized by simple implantation, low notch, lower risk of fixation failure and close fitting with cortical bone. It is a safe and effective internal fixation system for the treatment of ankle valgus in children.

Potential influence of factors for genu valgus with hereditary multiple exostoses

Genu valgus is one of the most common limb deformities in hereditary multiple exostoses (HME). However, it is easily concealed and may account for subsequent osteoarthritis of the knee. The knees of 56 patients (33 men and 23 women) with HME were investigated bilaterally. Knee valgus was described by the mechanical axis deviation (MAD), mechanical lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA). We investigated sex, age, BMI, total number of palpable osteochondromas, number of radiographic osteochondromas around the knee, forearm deformities, morphology and distribution of lesions, and correlations between these factors and genu valgus. The measurement of LDFA and MPTA was performed to identify the sources of genu valgus deformity. Based on the measurement of the mechanical axis, limbs were classified as genu valgus (n = 22) or normal mechanical axis groups (n = 90). The different severities of the genu valgus patients were classified by MAD. By bivariate logistic regression, genu valgus was significantly associated with more sessile and flared metaphyseal lesions. However, only the number of flared metaphyseal lesions had a significant influence on the severity of genu valgus. By analyzing the LDFA and MPTA, it was found that abnormalities of both proximal tibia and distal femur play important roles in genu valgus. Early detection of sessile and flared metaphyseal knee lesions in patients with HME can contribute to early intervention of genu valgus. Level of relevance: Level 2.

Guided growth: indications and techniques for correction of knock knees and bowlegs

PURPOSE OF REVIEW

Lower extremities axis alterations are a frequent cause for consultation in the medical practice of the care of paediatric patients. When it corresponds to pathological situations, guided growth surgery has been positioned as a possibility of well tolerated, reproducible and predictable resolution. For this reason, its use has increased significantly in recent years. In this review, its current indications, preoperative study, results and complications described in the updated literature will be discussed.

RECENT FINDINGS

The success of the technique remains high in the current literature, expanding the technique to other segments and disorders, and describing new ways of performing tension band with sutures. In addition, there is an increase in its incidence and a decrease in the associated hospitalized days, which can associate with techniques of lower morbidity.

SUMMARY

As guided growth surgery allows for successful correction of axis alterations, to achieve this, it is important to know the main indications, preoperative analysis and theoretical bases on which this technique is based, to carry it out in an adequate and timely manner, seeking an adequate resolution of the child's problem.

Rapidly acquired valgus deformity of the knee after osteochondroma resection in multiple hereditary exostoses pediatric patients: A report of two cases

Patients with multiple hereditary exostoses (MHE) often develop leg length discrepancies and limb alignment deformity around the knee as part of the natural course of the disease. Limb alignment deformity occurring post-resection of an osteochondroma has been described in one case report and only pertaining to the proximal medial tibia location. Here we describe the case of 2 patients with MHE, a 7-year-old female who underwent resection of distal femur and proximal tibia osteochondromas and a 9-year-old female who had a distal femur osteochondroma resected. Both patients developed rapidly progressive valgus knee deformity requiring surgical intervention. Excision of osteochondromas near the physis of a skeletally immature patient can cause overgrowth from the involved side of the growth plate resulting in a rapidly progressing unilateral coronal plane deformity. Surgeons should be aware of this potential complication and closely follow growing patients with serial alignment radiographs and counsel the family regarding the potential of acquired limb deformity and subsequent surgeries.

Risk factors for ankle valgus in children with hereditary multiple exostoses: a retrospective cross-sectional study

PURPOSE

The aim of this study was to identify risk factors for ankle valgus in children with hereditary multiple exostoses (HME).

METHODS

We retrospectively reviewed the medical records of patients with HME who were examined at our hospital between 2010 and 2020. Patients' age and sex were recorded along with radiographic variables including mechanical axis deviation (MAD), mechanical lateral distal tibia angle (LDTA), fibula/tibia length ratio (F/T); distal fibula station according to Malhotra's classification, location of exostoses at the ankle joint and fibular neck/physis width (N/P) ratio, which were measured from radiographs. Binary logistic regression analysis was performed to identify significant independent risk factors for ankle valgus.

RESULTS

There were 61 children (20 girls and 41 boys; 122 ankles) who met the inclusion criteria. The mean age was 10.4 years (sd 3.4) and mean LDTA was 83° (sd 7°). Ankle valgus was found in 64 ankles (52%). In addition to younger age, exostoses involving the lateral aspects of the distal tibial and the medial aspect of the distal fibula (odds ratio (OR) = 4.091; 95% confidence interval (CI) 1.065 to 15.712; p = 0.040), F/T ratio < 0.96 (OR = 4.457; 95% CI 1.498 to 13.261; p = 0.007) and N/P ratio > 1.6 (OR = 2.855; 95% CI 1.031 to 7.907; p = 0.043) were associated with an increased risk of developing ankle valgus, while sex and MAD were unrelated to its occurrence.

CONCLUSION

Young age, exostoses involving both the distal tibia and fibula, the F/T ratio < 0.96 and fibular N/P width ratio > 1.6 seemed to be risk factors of developing ankle valgus.

LEVELS OF EVIDENCE

Prognostic studies, IV.

Outcomes of Temporary Hemiepiphyseal Stapling for Correcting Genu Valgum in Children with Multiple Osteochondromas: A Single Institution Study

Background: Multiple osteochondromas is a rare skeletal disorder characterized by the presence of osteocartilaginous protrusions causing bony deformities, especially around the knee. Guided growth by temporary hemiepiphyseal stapling is the treatment of choice to correct the deformity by modulating the residual physeal growth of the lower limbs. Although this procedure is increasingly practiced, inconclusive evidence exists regarding its effectiveness in children with multiple osteochondromas. The study aims to compare the outcomes of temporary hemiepiphyseal stapling for correcting genu valgum in children with multiple osteochondromas vs. idiopathic cases. Methods: In this retrospective cohort study, we included patients admitted at a single institution from 2008 to 2018. A total of 97 children (77 idiopathic, 20 multiple osteochondromas) were enclosed, accounting for 184 limbs treated by temporary hemiepiphyseal stapling. We investigated if children with multiple osteochondromas had a similar successful rate of correction, rate of complications, and correction velocity compared to children with idiopathic genu valgum. Results: Overall, 151 limbs (82%) achieved complete correction or overcorrection, with idiopathic cases having a significantly higher rate of success compared to pathologic cases (88% vs. 55%; p < 0.001). In addition, multiple osteochondromas children sustained a higher rate of major complications (p = 0.021) and showed significantly lower correction velocity (p = 0.029). Conclusion: Temporary hemiepiphyseal stapling is effective in both idiopathic and multiple osteochondromas children, although the latter often achieved incomplete correction, had a higher risk of complications, and required a longer time of stapling. We suggest to anticipate the timing of intervention; otherwise, children with multiple osteochondromas and severe valgus deformity, approaching skeletal maturity, could undergo combined femoral and tibial stapling.

Monomelic Maffucci syndrome

Maffucci syndrome is a rare congenital, non-hereditary condition characterised by presence of multiple enchondromas and haemangiomas. Enchondromatous lesions affecting epiphysial growth plates can lead to angular deformities and leg-length discrepancy in the lower limb. We describe a 12-year-old girl with monomelic Maffucci syndrome affecting her left lower limb. She presented with progressive genu valgus deformity of her left knee. This caused her to limp during her gait and was a cosmetic dissatisfaction. The deformity affected her quality of life. She underwent a supracondylar distal femoral corrective osteotomy with a successful clinical outcome and restoration of her gait and cosmetic deformity.

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.

Hereditary Multiple Exostoses: Current Insights

Hereditary multiple exostoses (HME), also called hereditary multiple osteochondromas, is a rare genetic disorder characterized by multiple osteochondromas that grow near the growth plates of bones such as the ribs, pelvis, vertebrae and especially long bones. The disease presents with various clinical manifestations including chronic pain syndromes, restricted range of motion, limb deformity, short stature, scoliosis and neurovascular alteration. Malignant transformation of exostosis is rarely seen. The disease has no medical treatment and surgery is only recommended in symptomatic exostoses or in cases where a malignant transformation is suspected. HME is mainly caused by mutations and functional loss of the EXT1 and EXT2 genes which encode glycosyltransferases, an enzyme family involved in heparan sulfate (HS) synthesis. However, the peculiar molecular mechanism that leads to the structural changes of the cartilage and to osteochondroma formation is still being studied. Basic science studies have recently shown new insights about altering the molecular and cellular mechanism caused by HS deficiency. Pediatricians, geneticists and orthopedic surgeons play an important role in the study and treatment of this severe pathology. Despite the recent significant advances, we still need novel insights to better specify the role of HS in signal transduction. The purpose of this review was to analyze the most relevant aspects of HME from the literature review, give readers an important tool to understand its clinical features and metabolic-pathogenetic mechanism, and to identify an effective treatment method. We focused on the aspects of the disease related to clinical management and surgical treatment in order to give up-to-date information that could be useful for following best clinical practice.

Guided Growth of the Proximal Femur for the Management of Hip Dysplasia in Children With Cerebral Palsy

BACKGROUND

Progressive hip displacement is one of the most common and debilitating deformities seen in children with cerebral palsy (CP). The aim of this study was to evaluate the results of temporary medial hemiepiphysiodesis of the proximal femur (TMH-PF) using a transphyseal screw to control hip migration during growth in children with CP.

METHODS

This was a retrospective study of children with CP and hip dysplasia, age 4 to 11 years and GMFCS levels III-V. There were 28 patients with 56 hips that underwent TMH-PF surgery between 2007 and 2010. Clinical and radiologic evaluation was performed preoperatively, at 6, 12, and 60 months following the index surgery. Acetabular index (AI), neck-shaft angle (NSA) and migration percentage (MP) were measured. All complications were recorded.

RESULTS

All radiographic measurements were significantly improved at the final follow-up. Positive correlations were found between NSA, MP, and AI. Multiple regression analysis revealed that MP, time from surgery, and age were influenced by the decrease of the NSA. The femoral physis grew off the screw in 9 hips within 36 months. The screw head broke during attempted screw exchange in 1 hip. The remain cases (4 hips) were treated by placing a second screw parallel to the existing one. Finally, progressive subluxation occurred in 3 hips when the physis grew off the screw and were treated by skeletal reconstruction.

CONCLUSIONS

TMH-PF was effective in controlling progressive subluxation of the hip in the majority of cases, obviating the need for major reconstructive surgery in these children with CP.

LEVEL OF EVIDENCE

Level IV.

Effect of multiple hereditary exostoses on sports activity in children

Objective

The purpose of this clinical case-control study was to assess the level of sports activity in children with hereditary multiple exostoses (HME) and to compare with the degree of physical activity in children of the same age without pathology.

Methods

A case-control study was designed. Cases were drawn from children with HME diagnosed on the basis of clinical and radiographic evaluation with an age less then 12 years. Controls were chosen from a group of children with the same age and a negative family history for HME. All patients and controls were completed with the help of parents using the following evaluations: Tegner Activity Level Scale and University of California Los Angeles (UCLA) activity scale.

Results

A total of 154 individuals participated (54 cases and 100 controls). In the case groups, the mean age was 9.07; the mean number of exostoses resulted 29.51, while the mean value of UCLA and Tegner score resulted respectively 6.04 and 5.09. In the controls, the mean age was 8.88; mean UCLA and Tegner resulted respectively 7.17 and 5.64. Comparing the two groups, the only difference was between UCLA score (p = 0.0053). Moreover, comparing the results between female children affected by HME and female controls, we found a significant difference as regards UCLA score (p = 0.0045).

Conclusion

Children affected by HME reported lower sports activity, in particular as regards female patients. Moreover, physical activity is not correlated with any other independent factor leading different patients to a similar level of ability in performing sport.

Study design

Level III - Case Control Study.

Correction of ankle valgus by hemiepiphysiodesis using the tension band principle in patients with multiple hereditary exostosis

BACKGROUND

Ankle valgus is a common deformity in patients with multiple hereditary exostoses (MHE) and a potential risk factor for early degenerative arthritis. In children, medial hemiepiphysiodesis of the distal tibia is a relatively simple surgical technique used to correct this deformity. We present here the first results of applying this procedure using the eight-Plate guided growth system (eight-Plate) for growth guidance.

METHODS

Between 2006 and 2011 we performed hemiepiphysiodesis of the distal medial tibia in 30 ankles of 18 children with MHE using the eight-Plate. Weight-bearing total leg radiographs were obtained preoperatively, during follow-up and at the time of implant removal or when the distal tibial physis had closed. The lateral distal tibia angle (LDTA) was measured and fibular shortening assessed using the Malhotra classification. To evaluate the effect of hemiepiphysiodesis, we correlated the LDTA with age.

RESULTS

The mean age at time of surgery was 12.6 (range 9.5-15.0) years, and the mean preoperative LDTA was 76.9° (range 68.5°-83.5°). During follow-up, the implant was removed in 12 extremities and the physis had closed in 18 extremities. The mean LDTA at the time of implant removal or at closure of the physis was 83.6° (range 76.5°-90.0°). Mean correction of LDTA was 6.9° after a mean follow-up period of 22 (range 3-43) months. During follow-up, no changes in the Malhotra classification were found in any of the patients. Correction of the valgus deformity of the ankle was significantly correlated (r = -0.506) (p = 0.004) with age in all patients.

CONCLUSION

Temporary medial hemiepiphyseodesis of the distal tibia seems to be an effective strategy for correcting ankle valgus in children with MHE. Timing of the intervention is, however, of importance. Hemiepiphyseodesis alone has no effect on the Malhotra classification.

LEVEL OF EVIDENCE

IV, retrospective review.