Surgical epiphysiodesis indications and techniques: update

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.

Gait Analysis in Patients After Hemiepiphysiodesis Due to Valgus or Varus Knee Deformity

Background: Developmental knee joint deformities are a common problem in pediatric orthopedics. Children with a valgus or varus deformity of the distal femur or the proximal tibia are commonly treated with hemiepiphysiodesis. Gait analysis in patients with lower limb deformities plays an important role in clinical practice. The purpose of our study was to assess gait parameters in patients who underwent hemiepiphysiodesis procedures of the distal femur or proximal tibia due to a knee deformity and to compare them with those in healthy controls. Methods: We prospectively evaluated 35 patients (14 females and 21 males) after hemiepiphysiodesis and compared the results with a healthy control group (26 participants). Gait was analyzed with a G-Sensor device (BTS Bioengineering Corp., Quincy, MA, USA). We assessed the following gait parameters: gait cycle duration, step length, support phase duration, swing phase duration, double support duration, single support duration, cadence, velocity, and step length. We assessed these gait parameters in a group of patients before and after treatment with hemiepiphysiodesis. We compared the patients' results before and after treatment to those of a healthy control group. The level of significance was set at p < 0.05. Results: The mean follow-up period was 13 months. There was no difference in the results of gait assessments in patients prior to and after treatment. The median step length was 47.09% in the treated limb after treatment and 54.01% in the intact limb (p = 0.018). There were no other differences in gait parameters in the treated limbs and the healthy, intact limbs in the patient group after treatment. There were no significant differences in the patients before and after treatment compared with those in the healthy control group in all gait parameters. Conclusions: Valgus or varus knee deformity correction with the use of hemiepiphysiodesis does not significantly improve preoperative gait parameters. The biomechanical outcomes of hemiepiphysiodesis in the treatment of valgus or varus knee deformity are good. We observed no differences in gait cycle duration, step length, support phase duration, swing phase duration, double support duration, single support duration, gait velocity, cadence, or step length between the experimental and healthy control groups.

[Angular and torsional malalignments of the paediatric knee joint]

BACKGROUND

Abnormal angular and torsional alignment of the lower extremities during growth are a common reason for consultation of a paediatrician or orthopaedist. There is often uncertainty about the pathological value of these abnormalities and the need for treatment, even among specialists. In the course of physiological growth and development processes, the axial and torsional alignment of the legs sometimes change considerably and in characteristic patterns.

DIAGNOSTICS

The ability to assess whether abnormal angular or torsional alignments of the lower limb in the course of growth should still be regarded as normal or already as pathological, depending on age and gender, is essential for the treating physician and requires precise knowledge of the physiological development processes and the tolerable limits in all three spatial dimensions.

TREATMENT

After careful explanation to the frequently concerned parents, a restrictive approach with observation of the spontaneous course of correction on the basis of regular clinical check-ups makes sense in the majority of cases. Pathological deviations from the physiological conditions are rare overall, can be idiopathic or of secondary origin and should be further clarified diagnostically using imaging procedures. As conservative measures are ineffective, pronounced angular and/or torsional deformities of the legs requiring treatment can only be corrected by surgical intervention, even in children and adolescents. The surgical treatment modalities available are varied and differ in terms of their invasiveness and complication profile, depending on the localization, type and severity of the deformity, as well as the age and possible concomitant diseases of the affected child or adolescent.

Deep learning generated lower extremity radiographic measurements are adequate for quick assessment of knee angular alignment and leg length determination

PURPOSE

Angular and longitudinal deformities of leg alignment create excessive stresses across joints, leading to pain and impaired function. Multiple measurements are used to assess these deformities on anteroposterior (AP) full-length radiographs. An artificial intelligence (AI) software automatically locates anatomical landmarks on AP full-length radiographs and performs 13 measurements to assess knee angular alignment and leg length. The primary aim of this study was to evaluate the agreements in LLD and knee alignment measurements between an AI software and two board-certified radiologists in patients without metal implants. The secondary aim was to assess time savings achieved by AI.

METHODS

The measurements assessed in the study were hip-knee-angle (HKA), anatomical-tibiofemoral angle (aTFA), anatomical-mechanical-axis angle (AMA), joint-line-convergence angle (JLCA), mechanical-lateral-proximal-femur-angle (mLPFA), mechanical-lateral-distal-femur-angle (mLDFA), mechanical-medial-proximal-tibia-angle (mMPTA), mechanical-lateral-distal-tibia- angle (mLDTA), femur length, tibia length, full leg length, leg length discrepancy (LLD), and mechanical axis deviation (MAD). These measurements were performed by two radiologists and the AI software on 164 legs. Intraclass-correlation-coefficients (ICC) and Bland-Altman analyses were used to assess the AI's performance.

RESULTS

The AI software set incorrect landmarks for 11/164 legs. Excluding these cases, ICCs between the software and radiologists were excellent for 12/13 variables (11/13 with outliers included), and the AI software met performance targets for 11/13 variables (9/13 with outliers included). The mean reading time for the AI algorithm and two readers, respectively, was 38.3, 435.0, and 625.0 s.

CONCLUSION

This study demonstrated that, with few exceptions, this AI-based software reliably generated measurements for most variables in the study and provided substantial time savings.

Morphology of the knee after guided growth using tension-band devices: a retrospective multicenter study of 222 limbs and 285 implants

BACKGROUND AND PURPOSE

Temporary hemiepiphysiodesis by tension-band devices is commonly applied to correct angular limb deformities in children. We aimed to evaluate knee joint morphology after guided growth using these devices.

PATIENTS AND METHODS

In a retrospective multicenter study we analyzed standardized anteroposterior long-leg radiographs of 222 limbs (285 implants) of patients treated by temporary hemiepiphysiodesis with either eight-Plates or FlexTacks for coronal angular deformities of the knee joint between 2013 and 2019. Femoral floor angle (FFA), femoral notch-intercondylar distance (FNID), and tibial roof angle (TRA) were measured pre- and postoperatively to assess the central knee joint morphology. Statistical exploratory analyses were performed using linear mixed models, t-tests, Wilcoxon signed-rank test, and Mann-Whitney U test.

RESULTS

217 FlexTacks (femur 106, tibia 111) in 104 children and 68 eight-Plates (femur 61, tibia 7) in 35 children were identified. Median time period under growth guidance was 11 months (range 4-42). No statistically significant change in the FFA was detected (eight-Plate: P = 0.2; FlexTack: P = 0.3). A statistically significant difference of the FNID was found in the eight-Plate group (P = 0.02), but not in the FlexTack group (P = 0.3). While TRA increased in both groups, a statistical significance was observed only in the FlexTack group (P < 0.01).

CONCLUSION

We found minor but clinically irrelevant changes in knee morphology after the treatment.

[Options and limits of leg length correction in paediatric orthopaedics]

For paediatric orthopaedic surgeons treating leg length discrepancy, knowledge of the available procedures and their options and limits is just as important as mastery of the very different surgical methods and implants, as well as the possible complications, in order to be able to advise and treat the children and adolescents and their parents comprehensively and in the best interests. Both the growth inhibiting procedures and the complex bone lengthening procedures require a great deal of experience to successfully guide patients and families through what is often a lengthy and sometimes complicated treatment process. Careful preoperative indications and planning, precise surgical techniques with suitable instruments and implants, and attentive postoperative check-ups are mandatory prerequisites for the desired therapeutic success.

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.

Radiographic reference values of the central knee anatomy in 8-16-year-old children

BACKGROUND AND PURPOSE

For correction of leg-length discrepancy or angular deformity of the lower limb in skeletally immature patients temporary or permanent (hemi-)epiphysiodesis can be employed. These are reliable treatments with few complications. Recently, radiographic analysis of treatment-related alterations of the central knee anatomy gained interest among pediatric orthopedic surgeons. To date the comparison and adequate interpretation of potential changes of the central knee anatomy is limited due to the lack of defined standardized radiographic references. We aimed to establish new reference values of the central knee anatomy.

PATIENTS AND METHODS

A retrospective analysis of calibrated longstanding anteroposterior radiographs of 254 skeletally immature patients with a chronological age ranging from 8 to 16 years was conducted. The following radiographic parameters were assessed: (1) femoral floor angle, (2) tibial roof angle, (3) width at femoral physis, and (4) femoral notch-intercondylar distance.

RESULTS

All observed radiographic parameters were normally distributed with a mean age of 12.4 years (standard deviation [SD] 2, 95% confidence interval [CI] 12.2-12.6). Mean femoral floor angle was 142° (SD 6, CI 141.8-142.9), mean tibial roof angle was 144° (SD 5, CI 143.7-144.1), mean width at femoral physis was 73 mm (SD 6, CI 72.8-73.9), and mean femoral notch-intercondylar distance was 8 mm (SD 1, CI 7.5-7.7). The estimated intraclass correlation coefficient values were excellent for all measurements.

CONCLUSION

This study provides new radiographic reference values of the central knee anatomy for children between 8 and 16 years and we suggest considering values within the range of 2 SD as the physiological range.

Supplementary Fibular-guided Growth in Treatment of Late-onset Blount Disease

Purpose:

Blount disease is due to an idiopathic defect in the posteromedial proximal tibial physis resulting in increasing bowing of the leg in addition to lateral knee thrust with lateral collateral ligament laxity. Our rationale is that Blount disease has a bony and ligamentous laxity element of the lateral collateral ligament that can be corrected simultaneously through hemiepiphysiodesis of the tibia and epiphysiodesis of proximal fibula physis by cannulated screws.

Patients and Methods:

This is a retrospective study conducted on 23 limbs with tibia vara treated between 2010 and 2017 followed up for 2 to 6 years. Ages ranged from 9 to 13 years with a late-onset type of Blount disease. We used a percutaneous transphyseal fully threaded screws traversing the proximal tibial lateral hemiepiphysis, and another screw inserted traversing the proximal fibular epiphysis.

Results:

There was a statistically significant improvement of the radiographic parameters, especially in the form of joint line congruence angle in both supine and standing positions. All patients were clinically and radiographically completely corrected without complications, except 1 patient with a surgical site superficial infection, treated medically.

Conclusion:

Fibular-guided growth surgery with lateral proximal tibia epiphysiodesis is a minimally invasive technique that improves the corrective power of hemiepyphysiodesis of the posterolateral compartment of the knee.

Level of Evidence:

Level IV, retrospective case series.

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

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

Single-Stage Tibial Osteotomy for Correction of Genu Varum Deformity in Children

Conservative and operative treatments with gradual or acute correction of severe varus deformities of the leg have been described. We evaluated whether the corrective osteotomy used within the NGO Mercy Ships is an effective treatment for genu varum deformity of different etiologies in children and which patient specific factors have an influence on the radiographic outcome. In total, 208 tibial valgisation osteotomies were performed in 124 patients between 2013 and 2017. The patients' mean age at the time of surgery was 8.4 (2.9 to 16.9 (min/max)) years. Seven radiographically measured angles were used to assess the deformity. Clinical photographs taken pre- and postoperatively were assessed. The mean time between the surgery and the end of physiotherapeutic treatment was 13.5 (7.3 to 28) weeks. Complications were monitored and classified according to the modified Clavien-Dindo-classification system. The mean preoperative mechanical tibiofemoral angle was 42.1° varus (range: 85°-12° varus). The mean postoperative mechanical tibiofemoral angle was 4.3° varus (range: 30° varus-13° valgus). The factors predicting a residual varus deformity were higher age, greater preoperative varus deformity and the diagnosis of Blount disease. The tibiofemoral angle measured on routine clinical photographs correlated well with the radiographic measurements. The single-stage tibial osteotomy described is a simple, safe and cost-effective technique to correct three-dimensional deformities of the tibia. Our study shows very good mean postoperative results, but with a higher variability than in other studies published. Nevertheless, considering the severity of preoperative deformities and the limited opportunities for aftercare, this method is excellent for the correction of varus deformities.

Crossed Congenital Hemihyperplasia: A Case Report

Overgrowth syndromes generally present with inherent health concerns and, in some instances, an increased risk of malignant intra-abdominal tumors, such as Wilms tumor or hepatoblastoma. There are various types of hyperplasia, but the crossed type is reported to be the rarest. We present a rare, crossed type of congenital hemihyperplasia. A six-year-old girl was referred to our clinic for leg length discrepancy and was diagnosed with congenital hemihyperplasia of the right lower limb and left upper limb. The leg length discrepancy had begun to affect the patient’s gait and stair climbing. We regularly monitored her leg length and checked for functional and cosmetic problems for 24 months. However, the hyperplasia progressed and caused severe gait impairment. Leg length discrepancy at the last check-up was 30 mm. She underwent femoral lengthening surgery using a monolateral external fixator. At the 14th month follow-up, her gait and stair climbing had greatly improved, and a scanogram revealed that the leg length discrepancy had been successfully treated with a mild varus angulation of the femur. We present a rare, crossed congenital hemihyperplasia. We recommend limb lengthening surgery for treating patients with idiopathic hemihyperplasia.

Coronal plane deformity around the knee in the skeletally immature population: A review of principles of evaluation and treatment

Coronal plane deformity around the knee, also known as genu varum or genu valgum, is a common finding in clinical practice for pediatricians and orthopedists. These deformities can be physiological or pathological. If untreated, pathological deformities can lead to abnormal joint loading and a consequent risk of premature osteoarthritis. The aim of this review is to provide a framework for the diagnosis and management of genu varum and genu valgum in skeletally immature patients.

The single portal percutaneous epiphysiodesis technique for treatment of leg length inequality stops growth as expected

One technique for distal femur and proximal tibia epiphysiodesis to treat leg length inequality is a single-incision percutaneous technique using reamers and curettes. The purpose of this study is to demonstrate the efficacy and reliability of this technique by quantifying the growth arrest produced from this method. Patients who underwent distal femur and proximal tibia epiphysiodesis with a single-incision percutaneous technique were retrospectively reviewed. Using scanogram data, derivative formulas of both the multiplier and arithmetic methods were used to predict bone length after physeal arrest at maturity. Patients included had at least 2-year follow-up after surgery. Predicted bone lengths were then compared to actual bone lengths obtained via scanogram at final follow-up. A total of 46 patients were included in the study (27 males; 19 females). Average age at surgery was: males 14.5 years, females 12.4 years. Surgery was performed on 40 distal femurs and 25 proximal tibias. Postoperative femurs demonstrated an actual mean length of 44.75 cm. Predicted femur bone lengths utilizing the multiplier and arithmetic methods were 45.08 and 44.08 cm, respectively. Postoperative tibias demonstrated an actual mean length of 38.12 cm. Predicted tibia lengths utilizing the multiplier and arithmetic method were 38.30 and 38.02 cm. No significance was found between actual and predicted bone lengths for both tibias and femurs. This study demonstrates that a single-incision percutaneous epiphysiodesis technique reliably arrests the growth as expected. Surgeons can confidently and accurately employ this technique to successfully treat leg length inequality.

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.

Guided Growth in Leg Length Discrepancy in Beckwith-Wiedemann Syndrome: A Consecutive Case Series

Beckwith-Wiedemann Syndrome (BWS) is a rare genetic disorder characterized by overgrowth, macroglossia, abdominal wall defects, neonatal hypoglycemia, predisposition to embryonal tumor, lateralized overgrowth, and leg length discrepancy (LLD), which can affect normal posture and gait. Aim of this study was to evaluate the effects of guided growth (temporary epiphysiodesis technique) as LLD management in BWS patients. Between 2007 and 2021, 22 BWS patients (15 F, 7 M) with a mean age of 7.9 years (2.9–14.4) and a mean LLD at first surgery of 3.65 cm (2–10), underwent temporary proximal tibial (PTE) and distal femur epiphysiodesis (DFE). In 18 patients the first surgical procedure was PTE, in one, DFE, and in 3 cases, PTE and DFE at the same time, respectively. Eleven patients reached equality of leg length after a mean follow-up of 7.7 years (3.7–13.0) and mean age of 13.3 years (12.7–27.5); 10 patients underwent 3 surgical procedures, one 7 procedures. Fifteen patients had no complications. No severe complications, infection, articular stiffness, or neuro-vascular lesions occurred in remaining patients; complications included secondary varus or valgus axial deviation in a total of 6 patients, and two screw breakages in two patients. Guided growth as a minimally invasive procedure seems efficient for LLD treatment with low complication rate in BWS patients.

Growth arrest: leg length correction through temporary epiphysiodesis with a novel rigid staple (RigidTack)

AIMS

Temporary epiphysiodesis (ED) is commonly applied in children and adolescents to treat leg length discrepancies (LLDs) and tall stature. Traditional Blount staples or modern two-hole plates are used in clinical practice. However, they require accurate planning, precise surgical techniques, and attentive follow-up to achieve the desired outcome without complications. This study reports the results of ED using a novel rigid staple (RigidTack) incorporating safety, as well as technical and procedural success according to the idea, development, evaluation, assessment, long-term (IDEAL) study framework.

METHODS

A cohort of 56 patients, including 45 unilateral EDs for LLD and 11 bilateral EDs for tall stature, were prospectively analyzed. ED was performed with 222 rigid staples with a mean follow-up of 24.4 months (8 to 49). Patients with a predicted LLD of ≥ 2 cm at skeletal maturity were included. Mean age at surgery was 12.1 years (8 to 14). Correction and complication rates including implant-associated problems, and secondary deformities as well as perioperative parameters, were recorded (IDEAL stage 2a). These results were compared to historical cohorts treated for correction of LLD with two-hole plates or Blount staples.

RESULTS

The mean LLD was reduced from 25.2 mm (15 to 45) before surgery to 9.3 mm (6 to 25) at skeletal maturity. Implant-associated complications occurred in 4/56 treatments (7%), and secondary frontal plane deformities were detected in 5/45 legs (11%) of the LLD cohort. Including tall stature patients, the rate increased to 12/67 legs (18%). Sagittal plane deformities were observed during 1/45 LLD treatments (2%). Compared to two-hole plates and Blount staples, similar correction rates were observed in all devices. Lower rates of frontal and sagittal plane deformities were observed using rigid staples.

CONCLUSION

Treatment of LLD using novel rigid staples appears a feasible and promising strategy. Secondary frontal and sagittal plane deformities remain a potential complication, although the rate seems to be lower in patients treated with rigid staples. Further comparative studies are needed to investigate this issue. Cite this article: Bone Joint J 2021;103-B(8):1428-1437.

[Growth modulation through hemiepiphysiodesis : Novel surgical techniques: risks and progress]

The correction of angular deformities of the lower limb is a key task in paediatric orthopaedic surgery. The growth potential of the physis can be employed for the correction of these malalignments in childhood and adolescence. Hemiepiphysiodesis (HED) is a surgical technique used for growth modulation by permanent or temporary asymmetrical arrest of the growth plate. In permanent HED, exact timing of the procedure is mandatory to achieve optimal correction. Temporary HED through tension band devices such as two-hole-plates or flexible staples has been established as the treatment of choice for growth guidance with excellent results. Implant-associated complications have been significantly reduced through implant modifications. Several experimental procedures have the potential to achieve growth modulation even without the requirement of surgical intervention.

Growth modulation of angular deformities with a novel constant force implant concept-preclinical results

PURPOSE

Varus-valgus deformities in children and adolescents are often corrected by temporary hemi-epiphysiodesis, in which the physis is bridged by an implant to inhibit growth. With standard implant solutions, the acting forces cannot be regulated, rendering the correction difficult to control. Furthermore, the implant load steadily increases with ongoing growth potentially leading to implant-related failures. A novel implant concept was developed applying a controlled constant force to the physis, which carries the potential to avoid these complications. The study aim was to proof the concept in vivo by analyzing the effect of three distinct force levels on the creation of varus deformities.

METHODS

The proposed implant is made of a conventional cerclage wire and features a twisted coil that unwinds with growth resulting in an implant-specific constant force level. The proximal medial tibial physes of 18 lambs were treated with the implant and assigned to three groups distinct by the force level of the implant (200 N, 120 N, 60 N).

RESULTS

The treatment appeared safe without implant-related failures. Deformity creation was statistically different between the groups and yielded on average 10.6° (200 N), 4.8° (120 N) and 0.4° (60 N) over the treatment period. Modulation rates were 0.51°/mm (200 N), 0.23°/mm (120 N) and 0.05°/mm (60 N) and were constant throughout the treatment.

CONCLUSION

By means of the constant force concept, controlled growth modulation appeared feasible in this preclinical experiment. However, clinical trials are necessary to confirm whether the results are translatable to the human pathological situation.

Tension band plates have greater risks of complications in temporary epiphysiodesis

PURPOSE

This study aimed to compare the efficacy of decreasing leg-length discrepancy (LLD) and postoperative complications between tension band plates (TBP) and percutaneous transphyseal screws (PETS).

METHODS

This retrospective study reviewed LLD patients who underwent temporary epiphysiodesis at the distal femur and/or proximal tibia from 2010 to 2017 (minimum two years follow-up). Efficacy of decreasing LLD was assessed one and two years postoperatively. Complications were classified with the modified Clavien-Dindo-Sink complication classification system. Knee deformities were assessed by percentile and zone of mechanical axis across the tibial plateau.

RESULTS

In total, 53 patients (25 boys, 28 girls) underwent temporary epiphysiodesis (mean age, 11.4 years). The efficacy of decreasing LLD at two years between the TBP (n = 38) and PETS (n = 15) groups was comparable. Seven grade III complications were recorded in six TBP patients and in one PETS patient who underwent revision surgeries for knee deformities and physis impingement. Four grade I and two grade II complications occurred in the TBP group. The mechanical axis of the leg shifted laterally in the PETS group and medially in the TBP groups (+7.1 percentile versus -4.2 percentile; p < 0.05). Shifting of the mechanical axis by two zones was noted medially in four TBP patients and laterally in two PETS patients.

CONCLUSION

More implant-related complications and revision surgeries for angular deformities were associated with TBP. A tendency of varus and valgus deformity after epiphysiodesis using TBP and PETS was observed, respectively. Patients and families should be informed of the risks and regular postoperative follow-up is recommended.

LEVEL OF EVIDENCE

Level III.

Epiphysiodesis for the treatment of tall stature and leg length discrepancy

Painful orthopedic conditions associated with extreme tall stature and leg length discrepancy (LLD) include back pain and adopting bad posture. After failure of conservative treatment options, blocking of the growth plates (epiphysiodesis) around the knee emerged as gold standard in patients with tall stature and LLD in the growing skeleton. Surgical planning includes growth prediction and evaluation of bone age. Since growth prediction is associated with a certain potential error, adequate planning and timing of epiphysiodesis are the key for success of the treatment. LLD corrections up to 5 cm can be achieved, and predicted extreme tall stature can be limited. Percutaneous epiphysiodesis techniques are minimally invasive, safe and efficient methods with low complication rates. In general, a multidisciplinary approach should be pursued when treating children and adolescents with tall stature.

Temporary Proximal Tibial Epiphysiodesis for Correction of Leg Length Discrepancy in Children-Should Proximal Fibular Epiphysiodesis Be Performed Concomitantly?

The need for concomitant proximal fibular epiphysiodesis (PFE) when correcting leg length discrepancy (LLD) with temporary proximal tibial epiphysiodesis (PTE) in children is controversially discussed. This single center, retrospective cohort study analyzes proximal fibular growth in patients treated by PTE with and without concomitant PFE. Radiographic measurements were conducted before implantation and at implant removal. The position of the fibular head in relation to the tibia was assessed with recently established radiographic reference values. All patients (n = 58, 19 females) received PTE to treat LLD at a mean age of 12.2 years (range 7 to 15). In 27/58 (47%) concomitant PFE was performed. Mean follow-up was 36.2 months (range 14.2 to 78.0). The position of the proximal fibula at implant removal was within physiological range in 21/26 patients (81%) with PFE and in 21/30 patients (70%) without PFE. Proximal fibular overgrowth newly developed in 2/26 patients (8%) treated with PFE and in 5/30 patients (17%) treated without PFE (p = 0.431). Peroneal nerve injury or discomfort due to proximal fibular overlength was not reported. The position of the proximal fibula should be critically assessed preoperatively under consideration of reference values before PTE. In consequence of this study, the authors do not routinely perform PFE concomitantly with PTE for correction of moderate LLD in children if the proximal fibula is localized within physiological radiographic margins determined by the established reference values.

Preclinical and Clinical Epigenetic-Based Reconsideration of Beckwith-Wiedemann Syndrome

Epigenetics has achieved a profound impact in the biomedical field, providing new experimental opportunities and innovative therapeutic strategies to face a plethora of diseases. In the rare diseases scenario, Beckwith-Wiedemann syndrome (BWS) is a pediatric pathological condition characterized by a complex molecular basis, showing alterations in the expression of different growth-regulating genes. The molecular origin of BWS is associated with impairments in the genomic imprinting of two domains at the 11p15.5 chromosomal region. The first domain contains three different regions: insulin growth like factor gene (IGF2), H19, and abnormally methylated DMR1 region. The second domain consists of cell proliferation and regulating-genes such as CDKN1C gene encoding for cyclin kinase inhibitor its role is to block cell proliferation. Although most cases are sporadic, about 5-10% of BWS patients have inheritance characteristics. In the 11p15.5 region, some of the patients have maternal chromosomal rearrangements while others have Uniparental Paternal Disomy UPD(11)pat. Defects in DNA methylation cause alteration of genes and the genomic structure equilibrium leading uncontrolled cell proliferation, which is a typical tumorigenesis event. Indeed, in BWS patients an increased childhood tumor predisposition is observed. Here, we summarize the latest knowledge on BWS and focus on the impact of epigenetic alterations to an increased cancer risk development and to metabolic disorders. Moreover, we highlight the correlation between assisted reproductive technologies and this rare disease. We also discuss intriguing aspects of BWS in twinning. Epigenetic therapies in clinical trials have already demonstrated effectiveness in oncological and non-oncological diseases. In this review, we propose a potential "epigenetic-based" approaches may unveil new therapeutic options for BWS patients. Although the complexity of the syndrome is high, patients can be able to lead a normal life but tumor predispositions might impair life expectancy. In this sense epigenetic therapies should have a supporting role in order to guarantee a good prognosis.

Juvenile Localized Scleroderma. Questions of Treatment

Juvenile localized scleroderma (JLS) is a group of childhood diseases with the main symptom — skin and subcutaneous structures lesions, without any organ involvement. There is active (inflammatory) and fibrotic phase in development of JLS. The JLS treatment during active phase (when skin lesions are reversible) is the most effective. The management is determined by the area and depth of skin lesions, appearance and spread of new lesions, presence of extracutaneous signs of the disease. Topical and systemic immunosuppressants are the basic therapy for JLS. The use of antibiotics is not suggested. Clinical scores (LoSCAT), ultrasound, thermography and magnetic resonance imaging are recommended to estimate the treatment efficacy.

Diagnosis and Management of Beckwith-Wiedemann Syndrome

Beckwith-Wiedemann syndrome (BWS) is a human genomic imprinting disorder that presents with a wide spectrum of clinical features including overgrowth, abdominal wall defects, macroglossia, neonatal hypoglycemia, and predisposition to embryonal tumors. It is associated with genetic and epigenetic changes on the chromosome 11p15 region, which includes two imprinting control regions. Here we review strategies for diagnosing and managing BWS and delineate commonly used genetic tests to establish a molecular diagnosis of BWS. Recommended first-line testing assesses DNA methylation and copy number variation of the BWS region. Tissue mosaicism can occur in patients with BWS, posing a challenge for genetic testing, and a negative test result does not exclude a diagnosis of BWS. Further testing should analyze additional tissue samples or employ techniques with higher diagnostic yield. Identifying the BWS molecular subtype is valuable for coordinating patient care because of the (epi)genotype-phenotype correlations, including different risks and types of embryonal tumors.

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.

Expert consensus document: Clinical and molecular diagnosis, screening and management of Beckwith-Wiedemann syndrome: an international consensus statement

Beckwith-Wiedemann syndrome (BWS), a human genomic imprinting disorder, is characterized by phenotypic variability that might include overgrowth, macroglossia, abdominal wall defects, neonatal hypoglycaemia, lateralized overgrowth and predisposition to embryonal tumours. Delineation of the molecular defects within the imprinted 11p15.5 region can predict familial recurrence risks and the risk (and type) of embryonal tumour. Despite recent advances in knowledge, there is marked heterogeneity in clinical diagnostic criteria and care. As detailed in this Consensus Statement, an international consensus group agreed upon 72 recommendations for the clinical and molecular diagnosis and management of BWS, including comprehensive protocols for the molecular investigation, care and treatment of patients from the prenatal period to adulthood. The consensus recommendations apply to patients with Beckwith-Wiedemann spectrum (BWSp), covering classical BWS without a molecular diagnosis and BWS-related phenotypes with an 11p15.5 molecular anomaly. Although the consensus group recommends a tumour surveillance programme targeted by molecular subgroups, surveillance might differ according to the local health-care system (for example, in the United States), and the results of targeted and universal surveillance should be evaluated prospectively. International collaboration, including a prospective audit of the results of implementing these consensus recommendations, is required to expand the evidence base for the design of optimum care pathways.

Management of growth arrest: Current practice and future directions

INTRODUCTION

Premature growth arrest can pose a challenge to the orthopedic surgeon. Various options for treating physeal arrest exist.

METHODS

Systematic searches were conducted on PubMed/Medline, ScienceDirect, OVID, and Cochrane Library. Secondary searching was performed, where certain articles from reference lists of the selected studies were reviewed that were not found in the primary search.

RESULTS

This review article discusses the different methods of management for premature growth arrest.

CONCLUSIONS

The use of mesenchymal stem cells provides a promising alternative treatment modality.

Orthopedic complications of linear morphea: Implications for early interdisciplinary care

Linear morphea of the limb primarily affects children, and extracutaneous manifestations are common. Orthopedic surgeons are often essential in the care of patients with linear morphea, yet there are few reports outlining specific orthopedic complications in this population. We sought to improve the understanding of orthopedic complications in linear morphea of the limb. Between 1999 and 2014, 51 children were evaluated for linear morphea of an extremity. Twenty-six (51%) had documented orthopedic manifestations. Outcome measures included limb length discrepancy, angular malalignment, limb atrophy, and orthopedic surgical intervention. Joint contractures were most common, affecting 88% of patients, followed by limb atrophy, angular deformity, and limb length discrepancy; 14% required surgical intervention. Despite the use of systemic immunosuppressive therapy in many patients, approximately half of patients with linear morphea of an extremity have orthopedic disease. Early orthopedist involvement is crucial to improve limb alignment and preserve function.

Percutaneous Epiphysiodesis Using Transphyseal Screws: a Case Series Demonstrating High Efficacy

BACKGROUND

Percutaneous epiphysiodesis using transphyseal screws (PETS) has been associated with implant failure, implant prominence, angular deformities, and delayed growth inhibition.

QUESTIONS/PURPOSES

The aim of this study was to assess the complication rate and efficacy (defined as actual growth inhibition divided by expected growth inhibition) of PETS and to identify factors associated with improved efficacy.

METHODS

Patients who underwent distal femoral and/or proximal tibial PETS between January 2007 and June 2014 were identified. Complications, efficacy, and final limb-length discrepancy (LLD) were calculated using multipliers and inhibition rates based on previous growth. Associations between efficacy and screw insertion angle (SIA), body mass index, and number of threads crossing the physis were calculated.

RESULTS

Eight-two patients (126 treated physes) were included. The mean pre-operative LLD was 27.7 mm (SD = 7.5). Following epiphysiodesis, 15 had temporary pain (18%), five had temporary effusion (6.1%), four had broken implants (4.9%), four developed mild angulation (4.9%), and three had failed epiphysiodesis requiring revision (3.7%). Thirty-one underwent screw removal (n = 31, 38%). Mean LLD at maturity was 17.3 mm (SD = 5.8 mm). Mean efficacy at the distal femur was 97% (SD = 46%), at the proximal tibia was 108% (SD = 66%) and was 103% (SD = 57%) overall. Increased screw threads across the lateral proximal tibial physis (Spearman's correlation coefficient = 0.67; 95% CI = 0.40-0.94) and higher BMI (Spearman's correlation coefficient = 0.55; 95% CI = 0.34-0.77) were positively associated with increased efficacy.

CONCLUSIONS

The efficacy of PETS may be more favorable than previously reported. Only 3.7% had serious complications requiring revision epiphysiodesis, lower than previous reports. Attention to sufficient screw threads across the physis may be important in optimizing PETS results.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Poor Efficiency of Eight-Plates in the Treatment of Lower Limb Discrepancy

BACKGROUND

Among the numerous existing epiphysiodesis procedures, the eight-plate-guided growth technique, initially described for angular deformities correction, has progressively gained popularity among pediatric orthopaedic surgeons to treat lower limb discrepancy (LLD). The goal of this study was to assess the efficacy of eight-plates in LLD.

METHODS

All children treated for LLD with eight-plates were prospectively included and followed until skeletal maturity. Efficacy of the epiphysiodesis was calculated 6 and 18 months postoperatively and at latest follow-up, according to a method previously validated for percutaneous epiphysiodesis using transphyseal screws (PETS). Radiologic measurements were performed using 3-dimensional low-dose stereoradiography. Intraoperative and postoperative complications were reported.

RESULTS

Thirty-two patients were included (average age at surgery, 12.5 y). For femoral epiphysiodesis, efficacy was only 23% at 6 months and 68% at latest follow-up. The procedure was even less efficient on the proximal tibia, with only 42% of the expected growth arrest at latest examination. Eight patients (20%) experienced plate-related pain during follow-up, and 5 physes (12.5%) required unplanned revision surgery.

CONCLUSIONS

Results of the current series show that the eight-plate technique procedure was associated with few perioperative complications, but the growth arrest observed at follow-up was unpredictable and lower than that achieved with PETS in previous reports. Eight-plate procedures cannot be considered as an efficient epiphysiodesis technique in comparison with standard technique.

LEVEL OF EVIDENCE

Level IV.

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.

Effectiveness of different minimally invasive epiphysiodesis techniques in the management of pediatric leg length discrepancies: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of this review is to synthesize the best available evidence on the use of percutaneous epiphysiodesis for the management of pediatric leg length discrepancies (LLDs). The effectiveness of four different percutaneous epiphysiodesis techniques will be compared, including transphyseal screws (percutaneous epiphysiodesis using transphyseal screws), physeal drilling and curettage, physeal stapling and guided growth with eight-Plates.Specific review questions to be addressed include.

Guided growth: mechanism and reversibility of modulation

In paediatric orthopaedics, deformities and discrepancies in length of bones are key problems that commonly need to be addressed in daily practice. An understanding of the physiology behind developing bones is crucial for planning treatment. Modulation of the growing bone can be performed in a number of ways. Here, we discuss the principles and mechanisms behind the techniques. Historically, the first procedures were destructive in their mechanism but reversible techniques were later developed with stapling of the growth plate being the gold standard treatment for decades. It has historically been used for both angular deformities and control of overall bone length. Today, tension band plating has partially overtaken stapling but this technique also carries a risk of complications. The diverging screws in these implants are probably mainly useful for hemiepiphysiodesis. We also discuss new minimally invasive techniques that may become important in future clinical practice.

Endoscopic-assisted epiphysiodesis: technique and 20-year experience

The aim of the study was to describe the endoscopic-assisted epiphysiodesis technique and review our 20-year experience with it. A retrospective review of 44 patients who underwent proximal tibia and/or distal femur endoscopic-assisted epiphysiodesis was carried out. Only patients who had preoperative and postoperative scanograms with clinical follow-up of at least 6 months were included. The mean length of follow-up was 36.8 months. All patients had radiographic evidence of physeal fusion within 6-12 months from the index procedure. No patient required revision surgery. Endoscopic-assisted epiphysiodesis is safe, effective, and achieves predictable physeal fusion. Advantages over current techniques include reduced radiation exposure and lack of requirement for hardware placement.

Prediction of Clinically Significant Leg-Length Discrepancy in Congenital Disorders

Leg-length discrepancy greater than 2 to 2.5 cm can potentially have an adverse effect on our walking and standing mechanisms and requires proper correction involving surgical treatment. However, for minor leg-length discrepancy in childhood, decision making for the indications for and timing of epiphysiodesis is difficult because of unpredictable final discrepancy. The purpose of this study was to analyze longitudinal changes of minor leg-length discrepancy in congenital disorders and to determine earlier predictive values for the clinically significant discrepancy. Twenty-one patients with congenital disorders who had minor leg-length discrepancy less than 2 cm at the first presentation were retrospectively evaluated. The patients were divided into 2 groups according to leg-length discrepancy at latest follow-up: the significant group (n=11) had 25 mm or more of leg-length discrepancy and the minor group (n=10) had less than 25 mm of leg-length discrepancy. The authors evaluated longitudinal changes of leg-length discrepancy within the first 10 years by mixed-effects regression model. All patients showed monotonically increasing leg-length discrepancy with age, except for 2 (neurofibromatosis type 1 and macrodactyly of the foot) who demonstrated fluctuating leg-length discrepancy. Mean annual rate of leg-length discrepancy change in the significant group was 2.1 mm across the first decade of life and was significantly larger than that in the minor group (difference in slope, 1.3 mm; P<.0001). In minor leg-length discrepancy associated with congenital disorders, the incidence of clinically significant leg-length discrepancy can be predictable by the annual rate of leg-length discrepancy change in the first decade of life.

[Special topics in pediatric orthopedics: options and limits of growth guidance]

BACKGROUND

A main task of pediatric orthopedics is the treatment of legs of different lengths or misshapen legs. Whereas for adult patients complicated and invasive operative interventions are necessary, the growth potential of the epiphysial plate can be utilized in childhood and adolescence to correct leg length differences and leg axis deformities.

THERAPY

Epiphysiodesis leads to a guidance of growth via a temporary or permanent and partial or complete blockade of the epiphysial plate depending on the indications. This method is principally a less invasive procedure with few complications.

CONCLUSION

Careful preoperative assessment of the indications and planning, precise operative technique and attentive postoperative control investigations are absolutely essential for successful treatment.

Air physiogram: technique for visualization of the resected physis in percutaneous epiphysiodesis

Obtaining an air physiogram improves visualization of the resected physis and allows the surgeon to assess whether a sufficient amount of growth plate has been removed during percutaneous drilling epiphysiodesis. From 2008 through 2011, the air physiogram technique was used in 37 percutaneous epiphysiodesis procedures about the knee (17 femora, 20 tibiae) in 31 children. Average follow-up was 41 months (range, 19-70 months). Thirty-six of 37 limb segments achieved radiographic fusion after the initial procedure. One tibia appeared to be partially fused and underwent revision epiphysiodesis. At final follow-up, all limb segments had successful epiphysiodesis and showed radiographic evidence of fusion.

Temporary hemiepiphysiodesis of the distal medial femur: MPFL in danger

INTRODUCTION

Temporary hemiepiphysiodesis (TH) with plate fixation is a well-accepted and common treatment for correcting leg malalignment in skeletally immature patients. The purpose of this study was to investigate any soft tissue damage caused during TH at the distal medial femur with a plate and two screws. We hypothesized that correct plate placement can affect the integrity of the medial stabilizing structures of the knee, especially the medial patellofemoral ligament (MPFL), the medial collateral ligament (MCL) or result in arthrotomy of the knee joint itself.

MATERIALS AND METHODS

In eight cadaveric knees of five adult humans a TH was performed with a plate and two cancellous screws at the distal medial femur using a standardized surgical technique. Subsequently the medial capsular and ligamentous structures were systematically exposed and assessed. Capsular and synovial tissue was also inspected for impingement by the plate or screws.

RESULTS

In all knees the MPFL was present. In two specimens the MPFL was intact and the plate was lying over the dorsal part of the MPFL close to the MCL. The MPFL was completely cut in two cases in the central part of the ligament. In four cases the MPFL was partially dissected or perforated by a screw and fixed to the femur by the plate. The MCL was intact and not impinged by the implant in any case. In total four of eight knees the capsule was transected or perforated by a screw or by a part of the plate, resulting in intraarticular implant placement.

CONCLUSIONS

Standard plate placement during TH on the distal medial femur frequently leads to damage to the MPFL, impingement of the MPFL, the capsular and synovial tissues or exposure of the knee joint.

The biomechanics of guided growth: does screw size, plate size, or screw configuration matter?

Guided growth with the eight-plate is a commonly used technique to correct angular limb deformities in children. However, the optimal combination of plate size, screw size, and screw configuration has not been determined. Using osteotomized femoral sawbones and a rail frame, we developed a growth model to examine the effect of these variables at 6-month, 12-month, and 18-month growth increments. The mean annual coronal plane change was 11.3°. Screw size and plate size were not associated with the rate of angular correction. Screw configuration was important, with parallel screws resulting in optimal correction at all time points compared with divergent screws (P<0.05).

Guiding femoral rotational growth in an animal model

BACKGROUND

Guided growth is most commonly utilized about the knee and ankle for the correction of coronal-plane deformities by the use of plates positioned perpendicular to the physis. Sagittal-plane deformity correction has been described as well. The purpose of our study was to examine the ability to affect axial-rotational growth. Our hypothesis was that placement of plates in an oblique orientation relative to the physis can induce rotational growth deformity.

METHODS

Our hypothesis was tested with use of a mathematical model and a bone model and subsequently in a rabbit model. Thirteen six-week-old rabbits underwent a rotational guided growth procedure involving the distal aspect of the right femur, with a sham procedure performed on the left side. Two plates were positioned in an oblique orientation relative to the physis, medially and laterally, to guide either internal or external rotational growth. After the rabbits were killed six weeks after the surgery, the femoral rotational profile was assessed by computed tomography scans of the dissected femora and the growth plates were examined histologically.

RESULTS

A significant effect on the rotational profile was found in the treated femora. When the plates were positioned to guide external rotation, the rotational profile was significantly greater in the treated femora (29.0° compared with 11.3° in the sham femora; p = 0.008). There was a positive linear correlation between the right-left difference in rotational profile and the change in inter-plate angle (R2 = 0.72, p = 0.001). Every 1° of inter-plate angle change induced 0.367° of rotational profile difference (p = 0.001). Histologically, a swirling effect of the physeal cell columns was seen in the treated femora.

CONCLUSIONS

Guided growth using plates was demonstrated to alter axial-rotational growth in a predictable fashion in a rabbit model.

CLINICAL RELEVANCE

Guided growth using plates may be effective for correction of rotational and multiplanar deformities.

The successful treatment of genu recurvatum as a complication following eight-Plate epiphysiodesis in a 10-year-old girl: a case report with a 3.5-year follow-up

We report a case of genu recurvatum following eight-Plate epiphysiodesis and the successful treatment of this complication. A 10-year-old patient underwent epiphysiodesis of the knee with eight-Plates. She was followed up and genu recurvatum developed as a complication. At the 12-month follow-up after epiphysiodesis, the treated knee showed a flexion of 135° and an extension of 35°. Lateral radiograph evaluation showed an extension change of the femur. During reoperation, the eight-Plates were repositioned more posterior, which resulted in successful treatment of the hyperextension. Eight-Plates can lead to (treatable) articular surface angle changes in the sagittal plane.