Results of screw epiphysiodesis for the treatment of limb length discrepancy and angular deformity

How to avoid genu recurvatum in leg-length discrepancy treated with tension-band plates. A volumetric magnetic resonance analysis

Aims and objectives

Genu recurvatum deformity after treatment of leg-length discrepancy (LLD) with tension-band plating is a recognized, but poorly described phenomenon in medical literature. The aim of this study was to evaluate clinical and radiological features of patients treated with tension-band plating for LLD assessing the development of a recurvatum deformity and its relationship to plate and screw disposition in a transversal plane, thus attempting to establish optimal plate positioning.

Materials and methods

Retrospective study of children with LLD treated with tension-band plating. Primary endpoints were clinical and radiological knee recurvatum and anterior and posterior physeal areas measured drawing a line spanning from the lateral to the medial tension-band plates in the transverse plane using volumetric magnetic resonance imaging (vMRI). These findings were compared between patients with and without knee recurvatum.

Results

Twelve children (mean age 11.7 years) were included. Average follow-up was 2.6 years (1.5-5.0). Tension-band plating led to a significant reduction in LLD (mean, 15 mm). Six patients (50 %) developed clinical genu recurvatum (mean, 22°). According to vMRI, patients with genu recurvatum had a larger posterior to anterior physeal area ratio in both distal femur (1.6 versus 0.9, p < 0.05) and proximal tibial physes (2.2 versus 1.0, p < 0.05).

Conclusion

The optimal position of the tension-band plates in distal femoral and proximal tibial physes should be in a point where a posterior to anterior physeal areas ratio is around 1.0, so as to achieve an even distribution of the physeal areas in the multidimensional physeal transverse plane. This point anatomically corresponds in the sagittal X-ray view to an imaginary line located just anterior to the posterior diaphyseal cortical bone on a true lateral radiograph for both femur and tibia.

A Novel Minimally Invasive Surgical Technique for Eight-Plate Hemiepiphysiodesis: Description and Evaluation

Background: Temporary hemiepiphysiodesis with tension band plates or eight-plates is a common surgical procedure to treat malalignment of the lower limb axis in skeletally immature patients. The objective of this study was to compare a new minimally invasive surgical procedure with the conventional procedure and evaluate its safety and effectiveness in order to reduce the risk of hypertrophic scarring, which may cause functional impairment as well as cosmetic issues. Methods: Sixty-five growth plates of either the femur or the tibia were evaluated in 33 patients treated for genu valgum or varum between 2010 and 2017. Each growth plate was considered an individual case. The modified procedure was used in 17 cases and the conventional procedure in 48 cases. The modified surgical procedure is characterized by an 8 mm incision and preparation of the epi-periosteal layer, in which the eight-plate is positioned via a guide-wire. Positioning and implantation are controlled via fluoroscopy. Skin incision length, duration of surgery, revision rate, achievement of a defined correction goal, and correction rate were analyzed. Results: Using the minimally invasive procedure, the mean skin incision length (23.94 ± 10.18 mm vs. 8.75 ± 2.14 mm, p < 0.001) could be significantly reduced. No significant difference was found in regard to the duration of surgery, revision rate, achievement of the correction goal or correction rate. Conclusions: The minimally invasive procedure results in a reduction in incision length without significant impact on the duration of surgery, revision rate, achievement of correction goal or correction rate. Consequently, the modified procedure can be regarded as equally as effective and safe as the conventional procedure.

Transphyseal Hemiepiphysiodesis: Is it Truly Reversible?

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

IV-Prospective case series.

Staples, tension-band plates, and percutaneous epiphysiodesis screws used for leg-length discrepancy treatment: a systematic review and proportional meta-analysis

BACKGROUND AND PURPOSE

The primary aim of this systematic review and meta-analysis was to evaluate the success rate of 3 different epiphysiodesis techniques with implant usage for the treatment of leg-length discrepancy (LLD) in the pediatric population. The secondary aim was to address effectiveness (final LLD) and the reported complications of staples, tension-band plates (TBP), and percutaneous epiphysiodesis screws (PETS).

METHODS

In this systematic review we searched MEDLINE (PubMed), Embase, Cochrane Library, Web of Science and Scopus for studies on skeletally immature patients with LLD treated with epiphysiodesis with an implant. The extracted outcome categories were effectiveness of epiphysiodesis (LLD measurements pre-/postoperatively, successful/unsuccessful) and complications that were graded on severity.

RESULTS

44 studies (2,184 patients) were included. 455 underwent epiphysiodesis with PETS, 578 patients with TBP, and 1,048 with staples. Successful epiphysiodesis was reported in 76% (95% confidence interval [CI] 61-89) with PETS (9 studies), 67% (CI 54-79) with TBP (10 studies), and 51% (CI 28-65) with Blount staples (8 studies). From pooled analysis, the severe complications rate was 7% for PETS, 17% for TBP, and 16% for Blount staples. Angular deformity was reported in 4% after PETS, 10% after TBP, and 17% after Blount staples.

CONCLUSION

Our results showed that epiphysiodesis with PETS implants was the most successful technique. PETS had a higher success rate, fewer severe complications, and a lower proportion with angular deformity.

Anterior Proximal Tibial Screw Hemiepiphysiodesis Decreases Posterior Tibial Slope in Knee Flexion Contracture: A Case Report

CASE

A 13-year-old adolescent boy with hemiplegic cerebral palsy suffering from fixed knee flexion deformity of 10° despite extensive conservative treatment. Owing to a posterior tibial slope (PTS) of 16°, anterior hemiepiphysiodesis was applied to the proximal tibia. The 2 screws were removed after 9 months. Final follow-up at 16 months showed complete knee extension and a PTS of 4°.

CONCLUSION

The presented technique is a good alternative in knee flexion deformity with an increased PTS and has surprisingly not been described in the literature. This might be worth considering for other pathologies such as pediatric anterior cruciate ligament injury with an increased PTS.

Does Combining Drilling and Curettage to Percutaneous Trans-epiphyseal Screws Improve Correction of Limb Length Discrepancy? A Comparative Study

Objectives

Physeal drilling and curettage (PDC) and percutaneous epiphysiodesis using transphyseal screws (PETS) are among the most widely used techniques to treat leg-length discrepancy (LLD). This study compared the efficacy and outcomes between PETS alone and PETS combined with PDC (PETS + PDC).

Methods

Retrospective study of children who underwent epiphysiodesis of the proximal tibia or distal femur with either PETS or PETS + PDC between 2008 and 2018 at a single institution. Radiographic parameters and complications were reviewed at completion of treatment and most recent follow-up.

Results

A total of 23 epiphysiodeses in 15 patients, average age 13.1 years, with either PETS (13 femur/tibias) or PETS + PDC (10 femur/tibias) were included. PETS patients were treated for a longer time (median: 24 months vs 11 months, p = 0.004), however, follow-up time was similar between groups (p = 0.577), on average 2.7 years. In the PETS group, LLD decreased from 2.55 to 0.84 cm at most recent follow-up (p = 0.010), and in the PETS + PDC group from 3.01 to 1.2 cm (p = 0.005), achieving a correction of 1.71 cm for PETS and 1.83 cm for PETS + PDC (p = 0.871). A correction of LLD to ≤ 2 cm was achieved in 8 PETS (89%) and 4 PETS + PDC cases (67%) (p = 0.525). Two PETS patients (22%) and 1 PETS + PDC (17%) patient returned to the OR for further correction due to persistent LLD (p = 1.000). No differences existed in total number of complications, angular deformity or return to physical activity between groups (p ≥ 0.05 for each comparison).

Conclusions

This study showed equal efficiency in resolving LLD between the PETS and PETS + PDC procedures with minimal operative complications.Level of Evidence III.

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

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

Physeal Sparing Approaches for MPFL Reconstruction

PURPOSE OF REVIEW

To update and concepts for pediatric physeal-sparing patellofemoral stabilization surgery.

RECENT FINDINGS

Recent studies have demonstrated positive results in patellofemoral stabilization in pediatric populations with physeal-sparing techniques that limit the potential for physeal damage. Comprehensive analysis remains limited by population and technique heterogeneity. Physeal-sparing patellofemoral stabilization, most significantly through physeal-sparing reconstruction of the medial patellofemoral ligament complex remains a viable option for pediatric patients with recurrent patellofemoral instability.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

BACKGROUND

Percutaneous epiphysiodesis using a transphyseal screw (PETS) or tension-band plating (TBP) has shown favourable correction results; however, the physeal behaviours in terms of rebound, stable correction, or overcorrection after guided growth have not been completely understood. In patients with idiopathic genu valgum, we therefore asked: (1) How is the correction maintained after implant removal of guided growth? (2) Is there any difference in the natural behaviours after PETS or TBP removal at the femur and tibia?

METHODS

We retrospectively reviewed 73 skeletally immature limbs with idiopathic genu valgum treated with PETS or TBP. PETS was performed in 23 distal femurs and 13 proximal tibias, and TBP was performed in 27 distal femurs and ten proximal tibias. Mechanical axis deviation (MAD), mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle were measured at pre-correction, implant removal, and final follow-up. Changes of ≤ 3° in mechanical angles after implant removal were considered stable. Comparisons between the implant, anatomical site, and existence of rebound were performed.

RESULTS

The mean MAD improved from - 18.8 mm to 11.3 mm at implant removal and decreased to -0.2 mm at the final follow-up. At the final follow-up, 39 limbs (53.4%) remained stable and only 12 (16.4%) were overcorrected. However, 22 limbs (30.1%) showed rebound. TBP was more common, and the correction period was longer in the rebound group (p < 0.001 and 0.013, respectively). In femurs treated with PETS, the mean mLDFA increased from 86.9° at implant removal to 88.4° at the final follow-up (p = 0.031), demonstrating overcorrection. However, a significant rebound from 89.7° to 87.1° was noted at the femur in the TBP group (p < 0.001). The correction of the proximal tibia did not change after implant removal.

CONCLUSION

The rebound was more common than overcorrection after guided growth; however, approximately half the cases demonstrated stable correction. The overcorrection occurred after PETS in the distal femur, while cases with TBP had a higher probability of rebound. The proximal tibia was stable after implant removal. The subsequent physeal behaviours after each implant removal should be considered in the guided growth.

An Anatomic Study of the Proximal Tibial Epiphysis With Relevance to Percutaneous Epiphysiodesis Using Transphyseal Screws (PETS)

BACKGROUND

Percutaneous epiphysiodesis using transphyseal screws (PETS) is a common procedure to correct lower extremity limb-length discrepancies in the pediatric population. A potential complication of this procedure is development of tibial valgus deformity, which may occur secondary to decreased screw purchase in the thinner medial proximal tibial epiphysis. The thickness of the proximal tibial epiphysis has not yet been well quantified, which was the aim of this study.

METHODS

Three-dimensional surface scans of 32 cadaveric proximal tibial epiphyses in specimens aged 3 to 17 years old were obtained and computer modeling software was utilized to measure the thickness of the proximal tibial epiphysis at 20 standardized potential screw insertion points according to a generated 5×4 map.

RESULTS

When normalized to the total width of the proximal tibial epiphysis, the lateral side is thicker compared with the medial side. The positions with the greatest thickness are located at the midline in the sagittal plane and 33% of the total physeal width away from the medial and lateral edges in the coronal plane (0.265 and 0.261 normalized thickness, respectively). The proximal tibial epiphysis is particularly thin 25% from the medial edge (normalized thickness range: 0.196 to 0.221). Multiple regression analysis revealed a significant relationship between increasing age and female sex with thinner normalized medial and lateral heights.

CONCLUSIONS

During PETS, areas for greater screw purchase are located centrally in the sagittal plane and 33% of the total width away from the medial and lateral edges of the proximal tibial epiphysis in the coronal plane. Caution should be taken when inserting screws in the medial 25% of the proximal tibial epiphysis as it is thinner relative to the lateral edge, particularly in females.

CLINICAL RELEVANCE

This study provides quantitative, anatomic data on the thickness of the proximal tibial epiphysis, which can direct screw placement during PETS for correcting limb-length discrepancies. These data may help lessen the risk of developing tibial valgus deformity although future clinical studies are necessary to fully evaluate this possibility.

Unsuccessful mid-term results for distal humeral hemiepiphysiodesis to treat cubitus varus deformity in young children

Cubitus varus is the most common complication following a pediatric humeral supracondylar fracture. No reports are available on the result of hemiepiphysiodesis to correct this deformity. We report the use of a transphyseal crossed cannulated screw (Metaizeau technique) in five very young children (mean 3 years and 7 months). No correction was observed after a mean of 3 years and 10 months of follow-up. The low growing capacity of the distal humeral physis makes corrective osteotomy the procedure of choice for cubitus varus deformity correction in children.

Distal Femur Growth Modification Surgery Is Associated With Higher Surgical Wound Complication Rate

BACKGROUND

Orthopaedic wound complications are often associated with extensive surgeries and patient medical conditions. However, we noticed wound complications in minor growth modification surgeries in children, including guided growth and epiphysiodesis. Herein, we report the complication rate and risk factors associated with pediatric growth modification surgeries.

METHODS

This retrospective study reviewed surgical wound complications in 622 pediatric orthopaedic patients who underwent growth modification surgeries (418 children) or osteotomies (204 children) in the lower extremities in a single center between 2007 and 2019. The grades II and III complications assessed using the modified Clavien-Dindo-Sink complication classification system were compared between growth modification and osteotomy. Risk factors for complications, including the type of surgery, age, body mass index, neuromuscular disease, operation time, surgical sites per patient, surgical location, and implant types, were analyzed using the logistic regression.

RESULTS

The complication rate was 6.9% per patient and 3.6% per surgical site (29 sites in 29 patients comprising 21 grade II and 8 grade III) in the growth modification group, which was >1.0% per patient and 0.6% per site in the osteotomy group (2 sites in 2 patients comprising 2 grade III infections; P =0.001). Among 418 patients with 797 surgical sites in the growth modification group, wound complications were associated with surgical location (5.2% at distal femur vs. 1.0% at proximal tibia, P =0.002) and implant type (0.5% using transphyseal screw vs. 4.3-10.5% using plates or staples, P =0.011).

CONCLUSION

Surgical wound complication was associated with growth modification surgeries using plates or staples at the distal femur. Our results alert orthopaedic surgeons to this minor but unneglectable problem. Transphyseal screws may be the implant of choice for guided growth and epiphysiodesis at the distal femur in older children, considering the lower risks of wound complication.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

[Epiphysiodesis and hemiepiphysiodesis : Physeal arrest and guided growth for the lower extremity]

The principals of growth arrest by epiphysiodesis and growth guidance by hemiepiphysiodesis are effective and powerful surgical techniques in pediatric orthopedics. These procedures can be used to correct leg length discrepancies as well as sagittal, coronal and oblique deformities. A differentiation is made between temporary and permanent techniques. The most significant advantage is that these techniques are minimally invasive and have low complication rates compared to acute osteotomy and gradual deformity correction. For optimal outcome an exact preoperative planning is needed to ensure accurate timing of the procedure, especially when permanent epiphysiodesis techniques are used. Although epiphysiodesis and hemiepiphysiodesis around the pediatric knee are most frequently used and can be considered the gold standard treatment of coronal plane deformities and leg length discrepancies, novel techniques for the hip and ankle are increasingly being performed. The successful clinical results with low complications support the broad use of hemiepiphysiodesis and epiphysiodesis for a variety of indications in the growing skeleton with deformities and leg length differences.

Percutaneous hemiepiphysiodesis using transphyseal screws for adolescent tibia vara

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

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.

Angular Deformities of the Knee in Children Treated with Guided Growth

Introduction:

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

Material and Methods:

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

Results:

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

Conclusion:

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III-prospective observational study.

Deformity Reconstruction Surgery for Blount's Disease

Blount's disease is an idiopathic developmental abnormality affecting the medial proximal tibia physis resulting in a multi-planar deformity with pronounced tibia varus. A single cause is unknown, and it is currently thought to result from a multifactorial combination of hereditary, mechanical, and developmental factors. Relationships with vitamin D deficiency, early walking, and obesity have been documented. Regardless of the etiology, the clinical and radiographic findings are consistent within the two main groups. Early-onset Blount's disease is often bilateral and affects children in the first few years of life. Late-onset Blount's disease is often unilateral and can be sub-categorized as juvenile tibia vara (ages 4-10), and adolescent tibia vara (ages 11 and older). Early-onset Blount's disease progresses to more severe deformities, including depression of the medial tibial plateau. Additional deformities in both groups include proximal tibial procurvatum, internal tibial torsion, and limb length discrepancy. Compensatory deformities in the distal femur and distal tibia may occur. When non-operative treatment fails the deformities progress through skeletal maturity and can result in pain, gait abnormalities, premature medial compartment knee arthritis, and limb length discrepancy. Surgical options depend on the patient's age, weight, extent of physeal involvement, severity, and number of deformities. They include growth modulation procedures such as guided growth for gradual correction with hemi-epiphysiodesis and physeal closure to prevent recurrence and equalize limb lengths, physeal bar resection, physeal distraction, osteotomies with acute correction and stabilization, gradual correction with multi-planar dynamic external fixation, and various combinations of all modalities. The goals of surgery are to restore normal joint and limb alignment, equalize limb lengths at skeletal maturity, and prevent recurrence. The purpose of this literature review is to delineate basic concepts and reconstructive surgical treatment strategies for patients with Blount's disease.

[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.

Is Proximal Fibula Epiphysiodesis Necessary When Performing a Proximal Tibial Epiphysiodesis?

BACKGROUND

Controversy exists regarding the need for proximal fibular epiphysiodesis in conjunction with proximal tibial epiphysiodesis to prevent relative overgrowth of the fibula. The purpose of this study was to determine the incidence of relative fibular overgrowth in patients who had undergone proximal tibial epiphysiodesis with or without proximal fibular epiphysiodesis to manage leg-length discrepancy.

METHODS

We identified patients who had undergone proximal tibial epiphysiodesis, with or without concomitant fibular epiphysiodesis, followed to skeletal maturity, and with adequate scanograms to measure tibial and fibular lengths. We assessed tibial and fibular lengths, ratios, and distances between the tibia and fibula proximally and distally preoperatively and at skeletal maturity, and obvious radiographic proximal migration of the fibular head.

RESULTS

A total of 234 patients met inclusion criteria, including 112 girls and 122 boys. In total, 179 patients had undergone concomitant fibular epiphysiodesis, and 55 had not. The fibular epiphysiodesis group was significantly younger preoperatively than the nonfibular epiphysiodesis group (average: 12.3 vs. 13.6 y), which accounted for most of the preoperative differences noted between the groups. Within the subset of younger patients (≥2 y of growth remaining at the time of epiphysiodesis), there were statistically significant differences between those with or without fibular epiphysiodesis at skeletal maturity in the proximal tibial-fibular distance (P<0.01) and the tibia:fibula ratio (0.96±0.02 vs. 0.98±0.02; P<0.02), but not in the distal tibial-fibular distance (P=0.46). Obvious fibular head proximal migration was noted in 10 patients, including 5/179 with concomitant proximal fibular epiphysiodesis, and 5/55 without (P<0.01). No patient was recorded as symptomatic with radiographic overgrowth, and no peroneal nerve injury occurred in any patient in this cohort.

CONCLUSIONS

On the basis of this study, concomitant proximal fibular epiphysiodesis does not appear to be necessary in patients with 2 years or less of growth remaining, nor does it unequivocally prevent fibular head overgrowth. While the tibia:fibula ratio was quite consistent in general, there were individuals with relative fibular head prominence for whom fibular epiphysiodesis may be appropriate, particularly in relatively immature patients.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Implant-Mediated Guided Growth for Coronal Plane Angular Deformity in the Pediatric Patient with Patellofemoral Instability

Pediatric patellofemoral instability is a complex problem, for which there are several anatomic risk factors. Coronal plane malalignment (i.e., genu valgum) is one cause of patellofemoral instability, and treatment of genu valgum has been associated with improved patellofemoral stability. Coronal plane angular deformity correction, typically achieved by distal femoral osteotomy in the adult population, can be achieved with less invasive surgical techniques in pediatric patients using implant-mediated guided growth. By temporarily tethering one side of an open physis to generate differential growth in the coronal plane, valgus malalignment can be corrected. We present our technique for medial distal femoral implant-mediated guided growth using tension band plating for treatment of pediatric patellofemoral instability associated with genu valgum. This technique is minimally invasive, has a low complication rate, and in conjunction with conventional treatment can reduce the risk of recurrent instability.

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

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

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

INTRODUCTION

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

HYPOTHESIS

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

MATERIAL AND METHODS

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

RESULTS

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

DISCUSSION

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

LEVEL OF THE STUDY

II, comparative prospective study.

Sagittal plane deformity after temporary epiphysiodesis of the distal femur for correcting limb length discrepancy

BACKGROUND

Outcome of the temporary epiphysiodesis procedure for limb length discrepancy (LLD) is commonly evaluated in the coronal plane. The purpose of this study was to investigate implant position and complications of the distal femur and patella in the sagittal plane after the temporary epiphysiodesis.

METHODS

We retrospectively reviewed 27 patients with LLD who underwent temporary epiphysiodesis of the distal femur using staples (11 patients) or eight-plates (16 patients) between 2007 and 2015. The mean age was 9.7 years (range, 6.3-13.8) at the time of epiphysiodesis. The implants were removed after a mean period of 2.6 years (range, 0.8-4.8) from the epiphysiodesis. Correction amount of LLD was measured on anteroposterior long leg standing radiographs. Implant position, extension deformity of the distal femur (>5° from epiphysiodesis to removal of implant) and patella baja (the epiphyseal line midpoint method < 1.0) were evaluated using lateral knee radiographs.

RESULTS

The average correction amount of LLD was 17.4 mm (range, 2-34). The average implant position was 43.1% (range, 35-55) from the anterior edge of the distal femoral epiphysis. At removal surgery, 16 patients (59%) had extension deformity of the distal femur and 14 patients (52%) showed patella baja. There were significant correlations between implant position and extension deformity (r = -0.51, p < 0.01) and as well as between correction amount of LLD and patella baja (r = -0.64, p < 0.01).

CONCLUSION

After temporary epiphysiodesis for the treatment of LLD, extension deformity of the distal femur and patella baja occurred frequently. Anterior placement of the implants is associated with extension deformity of the distal femur. The implant should be placed in the center of distal femoral physis, not the center of femoral shaft. Excessive correction of LLD should be avoided due to a risk of patella baja.

Hemiepiphyseodesis for Juvenile and Adolescent Tibia Vara Utilizing Percutaneous Transphyseal Screws

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level IV-therapeutic.

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

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

Management of Juvenile Hallux Valgus Deformity: the role of combined Hemiepiphysiodesis

Background

This study aimed to investigate the efficacy of percutaneous hemiepiphysiodesis for gradual correction of symptomatic juvenile hallux valgus (HV) deformity.

Methods

Between 2012 to 2014, 24 patients with symptomatic juvenile HV were treated by combined percutaneous medial drilling hemiepiphysiodesis of the first proximal phalanx and lateral transphyseal screw hemiepiphysiodesis of the first metatarsal at our institution. Twenty-one of 24 patients fulfilled inclusion criteria had a complete radiological and clinical follow-up of at least 2 years. Preoperative and postoperative radiographs of the feet were reviewed for measurements of hallux valgus angle (HVA), intermetatarsal angle (IMA), proximal metatarsal articular angle (PMAA), proximal phalangeal articular angle (PPAA), and metatarsal length ratio (MTLR). Clinical outcomes were assessed using the AOFAS hallux metatarsophalangeal-interphalangeal score.

Results

The study included 21 consecutive patients (37 ft) for analysis. The mean age at surgery was 12.0 years (SD = 1.3) and mean follow-up after surgery was 35.1 months (SD = 6.0). With the data available, the HV deformity improved in terms of the reduction of HVA by a mean of 4.7 degrees (P < .001) and the reduction of IMA by 2.2 degrees (P < .001). The PMAA and PPAA also improved significantly in the anteroposterior plane; however, the PMAA difference was insignificant in lateral plane as expected. The mean difference in the MTLR was 0.00 (P = .216) which was indicative of no length discrepancy between first and second metatarsals. The AOFAS score increased from 68.7 to 85.2 (P < .001). In correlation analysis, time to physeal closure was significantly correlated with the final HVA change (r = −.611, P = .003).

Conclusion

Although combined hemiepiphysiodesis does not create a large degree of correction as osteotomy, yet it did improve HV deformity with adequate growth remaining in our series. It is a procedure that can be of benefit to patients with symptomatic juvenile HV from this minimal operative approach before skeletal maturity.

Level of evidence

Level IV, retrospective case series.

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

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

How Accurate is the Multiplier Method in Predicting the Timing of Angular Correction After Hemiepiphysiodesis?

PURPOSE

The purpose of the study was to validate the accuracy of the Multiplier Method (MM) in predicting the timing of angular correction after hemiepiphysiodesis and to determine the role of using skeletal age when calculating those predictions.

METHODS

This retrospective study included 131 physes in 77 patients treated with hemiepiphysiodesis to gradually correct a coronal plane deformity before skeletal maturity. To compare the MM's predictions to the actual treatment duration, the "desired angular correction" was considered the actual achieved angular correction determined from the "endpoint x-ray" (last x-ray before implant removal). We measured the bone length and width of the growth plate from the preoperative x-ray and calculated the MM's prediction of the duration of treatment based on the MM formula. We compared the predicted duration to the observed duration of treatment for each case. The difference was calculated by subtracting the observed duration from the predicted duration. The result was the "absolute difference," which is the number of months over or under predicted by the MM.

RESULTS

The mean absolute difference between the MM's predicted duration and the observed duration was 2.31 months, which was highly significant (P≤0.001). The MM's prediction agreed with the observed duration of treatment (ie, zero absolute difference) in 15% of the predictions, 69% were under predicted, and 16% were over predicted. Sixty-eight percent of the absolute differences were within 3 months regardless of the direction of error. The mean difference was relatively less in genu varum cases and was statistically significant (P=0.047). Comparing the mean difference using chronological age and skeletal age in the formula showed no statistically significant difference.

CONCLUSIONS

The MM has a tendency to under predict. Therefore, doing a guided growth right before skeletal maturity should be started 2 to 4 months earlier than suggested by the MM. Moreover, our data did not show that the bone age gave more accurate predictions than chronological age.

LEVEL OF EVIDENCE

Level IV.

Tension band plating is less effective in achieving equalization of leg length

PURPOSE

Little data is available on the efficiency of different implants for epiphysiodesis. The purpose of this study is to compare the efficacy between plates and staples in decreasing leg-length discrepancy.

METHODS

A retrospective review of 19 children who underwent temporary epiphysiodesis of the legs was conducted, with a minimum of two years of follow-up. The bone length and length ratio to the short side were measured at six months, one year and two years postoperatively. The change in discrepancy was compared between staples and plates by an independent t-test, and the shortest time to a significant decrease in discrepancy was determined using a paired t-test.

RESULTS

Ten patients underwent 13 staple procedures in nine femurs and four tibias for a 2.8-cm discrepancy at age 11.8 years, and nine patients underwent 14 plate procedures in seven femurs and seven tibias for a 3.1-cm discrepancy at age 12.4 years. Patients were followed up to skeletal maturity, except two. The use of staples decreased the discrepancy in the bone ratio from +4.8% to +1.2% in two years, and the use of plates decreased this ratio from +5.1% to +3.3% in two years. The change in the length ratio was significantly greater after stapling. Six months were required after stapling before the first significant decrease in discrepancy; it took two years after plating.

CONCLUSIONS

This study showed a significantly lower efficacy for decreasing leg-length discrepancy by tension band plating. Orthopaedic surgeons should be aware of the limitations of using plates for suppressing bone growth.

LEVEL OF EVIDENCE

III.

The reliability of radiostereometric analysis in determining physeal motion in slipped capital femoral epiphysis in standard uniplanar and low-dose EOS biplanar radiography: a phantom model study

Physeal closure after slipped capital femoral epiphysis fixation can be difficult to assess on two-dimensional conventional radiographs. Radiostereometric analysis offers improved motion detection over conventional radiography, whereas the EOS biplanar imager provides a means for low radiation weight-bearing images. This phantom study assessed the reliability of measuring motion using radiostereometric analysis in the EOS using a slipped capital femoral epiphysis model. The accuracy and precision were better than 0.09±0.05 mm and 0.20°±0.36° when centered in the imaging space, were within the limits of clinical significance, and were not different from a standard uniplanar radiostereometric system.

A comparison of screw versus drill and curettage epiphysiodesis to correct leg-length discrepancy

PURPOSE

To compare two common surgical techniques of epiphysiodesis: drill/curettage epiphysiodesis (PDED) versus cross screw epiphysiodesis (PETS). The hypothesis is that the two techniques have similar efficacy but demonstrate differences in length of hospital stay (LOS), time to return to activity and complication rates.

METHODS

A retrospective review of growing children and adolescents less than 18 years old who required an epiphysiodesis with leg-length discrepancy (LLD) of 2 cm to 6 cm with minimum two years of follow-up was conducted. Characteristics including age at surgery, gender, epiphysiodesis location, side, operative time, LOS and hardware removal were compared across treatment groups. LLD, expected growth remaining (EGR) and bone age were determined preoperatively and at most-recent visit. The correction ratio (change in EGR) was calculated along with a 95% confidence interval (CI) to assess if correction in leg length was achieved.

RESULTS

A total of 115 patients underwent epiphysiodesis in the femur (53%), tibia (24%) or a combination (24%). The cohort was 47% male, with a mean age of 12.6 years (7.7 to 17.7) at surgery. Median follow-up was 3.7 years (2.0 to 12.7). In all, 23 patients underwent PETS and 92 patients had PDED. Both treatment groups achieved expected LLD correction. There was no significant difference in median operative time, complication rates or LOS. PETS patients returned to activity at a mean 1.4 months (interquartile range (IQR) 0.7 to 2.1) while PDED patients returned at a mean 2.4 months (IQR 1.7 to 3) (p < 0.001).

CONCLUSION

Effectiveness in achieving expected correction, LOS and operative time are similar between screw and drill/curettage epiphysiodesis. Patients undergoing PETS demonstrated a faster return to baseline activity than patients with PDED.

LEVEL OF EVIDENCE

III.

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.

Mechanical Testing of Epiphysiodesis Screws

Epiphysiodesis is performed to treat leg-length discrepancies and angular deformities in children. However, when placed across a physis to modulate growth, screws can bend or break postoperatively. This study evaluated the mechanical properties of 3 different screw designs commonly used when performing an epiphysiodesis. Six 4.0-mm cannulated, fully threaded; six 4.0-mm cannulated, partially threaded; and six 4.0-mm noncannulated, partially threaded cancellous screws underwent cantilever bending and tension testing in a simulated physis. All screws were tested in simulated cancellous bone foam blocks. All testing was performed using a servo-hydraulic testing machine to determine stiffness and ultimate load. For statistical analysis, one-way analysis of variance with Tukey's honestly significant difference test in post hoc analysis was used to assess significant differences among groups (P<.05). The noncannulated, partially threaded screws had a significantly lower stiffness than the 2 cannulated screw types in the tension test (P<.001) and bending test (P<.001). Additionally, the noncannulated, partially threaded screws had significantly higher ultimate load to failure than the 2 cannulated screw types in the tension test (P<.001) and the cannulated, partially threaded screws in the bending test (P=.045). The results indicate that noncannulated, partially threaded screws have a higher ultimate load capacity and are less stiff than both cannulated, partially threaded screws and cannulated, fully threaded screws. Surgeons should take into consideration that noncannulated, partially threaded screws are less likely to fail following epiphysiodesis. [Orthopedics. 2018; 41(2):e240-e244.].

Growth modulation by hemi epiphysiodesis using eight-plate in Genu valgum in Paediatric population

INTRODUCTION

Genu valgum is an angular deformity of the knee, often treated surgically by osteotomy or by growth modulation (using tension band, staples, transphyseal screws and eight-plate which require removal after correction). With this study, we attempt to evaluate the efficacy, rate of correction and complications with the use of 8-plate in the correction of genu valgum deformity in children.

MATERIAL AND METHOD

In a retrospective study of 24 patients with 11 bilateral and 13 unilateral (35 knees) genu valgum deformity which required surgical corrections were included. There were 11 males, and 13 females and all of them were treated with Steven's technique (Stevens, 2006) using eight-plate and monitored closely.

RESULT

Twenty-four patients with an average age of 10 years and 8 months (range: 5 yrs, 7 months-14 yrs, 2 months), with the mean preoperative & post-implant removal (Post-IR) tibiofemoral angle of 22.02° ± 5.15° (range 14°-31°) & 6.14° ± 1.92° (range 2°-10°) respectively, required an average time period of 1yr & 5m ± 5 m (range 10 months-28 months) for correction after which implants were removed. Of the 35 limbs, we achieved excellent results in 91.6%. One case (4.16%) had a partial correction of the deformity, and one case (4.16%) had reported with a superficial infection which was taken care. There were 2 cases (8.33%) of over-correction, which was gradually self-corrected during follow-up.

CONCLUSION

Our results reflect the efficacy of flexible titanium eight plate which corrects angular deformity by acting as a tension band on one side of the growth plate and offers the advantage of reversible Hemi epiphyseal growth modulation. Guided growth modulation is a best available alternative for the treatment of an angular deformity in the patients with open physis.

Treatment of genu valgum in children by means of temporary hemiepiphysiodesis using eight-plates: short-term findings

Background

Idiopathic genu valgum is a frequently diagnosed growth disorder in adolescence. Whenever the possibilities of conservative therapy have been exhausted, leg straightening by means of hemiepiphysiodesis has become the standard form of treatment. Because of their flexible screw-plate connection, eight-Plates have been reported in the literature to lead to lower complications regarding implant loosening and fracture compared to other implants.

The aim of this retrospective survey was to analyse our own patient population who were treated for genu valgum by means of temporary hemiepiphysiodesis near the knee using eight-Plates to modulate growth.

Methods

Between July 2007 and July 2015, 198 eight-Plates were implanted near the knee in 132 children suffering from genu valgum to modulate growth. Depending on the deformity analysis, an eight-Plate was implanted on the distal medial femur and/or the proximal medial tibia. By December 2015, they had been removed from 105 patients. The etiology of genu valgum was mainly idiopathic or associated withobesity. Evaluation was carried out clinically and radiologically (whole-leg X-ray in standing) including determination of the joint angles.

Results

The median follow-up period was about 46 months (12–102 months). The median age at implantation was 12.7 +/−6.76 years. Of the 105 patients, 45.7% (n = 48) were girls. The eight-Plates remained in place for a median period of 13 +/−1.76 months. Irrespective of the location of hemiepiphysiodesis, the intermalleolar distance was corrected to a median of 0 +/−2.1 cm while the anatomical femorotibial angle was corrected by on average 9 +/−2.7 °Mechanical lateral distal femoral angle changed an average 7 +/− 7.72 degrees. Medial proximal tibial angle changed an average 4 +/− 6.02 degrees. Complications necessitating surgery occurred in 2.8% of cases (1 wound infection, 3 corrective osteotomies following overcorrection).

Conclusion

Temporary hemiepiphysiodesis using eight-Plates is a gentle, simple and effective procedure used to treat genu valgum by modulating growth. Slight overcorrection is desirable due to the rebound phenomenon, especially in young patients with high growth potential and risk groups such as obese children. In adolescents with only low growth potential (older than 14 years), owing to the low correction potential, the indication should be strictly reviewed and the possible failure of therapy should be discussed with the patient. No differences were observed regarding the location of the implanted eight-Plates (femoral or tibial).

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.

Guided Growth: Novel Applications in the Hip, Knee, and Ankle

Hemiepiphyseodesis for angular deformities in the growing child is effective and avoids the complications of osteotomies and gradual correction with external fixation. This article reviews applications of screw hemiepiphyseodesis for coronal and sagittal plane deformities in the lower extremity. Indications, technical pearls, and pitfalls are discussed.

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

Background and purposes

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

Methods

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

Results

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

Conclusion

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

Epiphysiodesis Screw Bending

Percutaneous epiphysiodesis using transphyseal screws is a common method for treatment of limb length discrepancy and angular deformity. The authors report 3 cases of a previously unreported complication following treatment with percutaneous epiphysiodesis using transphyseal screws: bending of the transphyseal screw. In each case, this rare complication was associated with difficult removal of the screw. This retrospective case report accessed the medical records of 3 children, 2 boys and 1 girl, 9 to 14 years old. All of the children had 4.0-mm cannulated stainless steel screws ranging from 40 to 50 mm in length. Two of the patients had partially threaded and 1 had fully threaded screws with bending noted a minimum of 6 months following implantation. Additionally, each of the screws bent near the physis of the bone, which was not located at the center of the screw in every case or at the transition from threaded to nonthreaded portions in each partially threaded screw. To the authors' knowledge, these are the first reported cases of cannulated screw bending following transphyseal tibial or femoral placement for the correction of leg length or angular deformity in a pediatric population. Although the true incidence rate is unknown, screw bending following percutaneous epiphysiodesis presents complications in the hardware removal process. Further biomechanical tests should be conducted to determine the best screw design to minimize bending of transphyseal screws from physiologic growth. [Orthopedics. 2017; 40(4):e717-e720.].

The role of guided growth as it relates to limb lengthening

For decades, the classic indication for limb lengthening has been reserved for anisomelia that was expected to reach or exceed 5 cm at maturity. Epiphysiodesis was reserved for discrepancies in the 2-5 cm range. With the increasing sophistication of fixators, including rail, hexapod, and hybrid, complex deformities may be corrected simultaneously while moderate to extreme lengthening is achieved. More recently, iterations of telescoping intramedullary rods have further strengthened our armamentarium. Meanwhile, permanent epiphysiodesis techniques, both open and percutaneous, have yielded to more versatile and reversible tethering of one (angle) or both (length) sides of a physis. While the techniques of guided growth and callotasis seem to be diametrically opposed, they may be used in a tandem or complementary fashion, for the benefit of the patient. If treatment is undertaken during skeletal growth, one must be aware that issues remain regarding the accurate assessment of skeletal maturity and prediction of the ultimate outcome. Therefore, there is potential for over- or undercorrection. Reversible and serial guided growth now enable the surgeon to commence intervention at a comparatively young age, for the purpose of optimizing limb alignment and reducing the ultimate discrepancy. Frame application may be delayed or, in some cases, avoided altogether. With the limb properly aligned at the outset of lengthening, elective use of a telescoping intramedullary nail may now be favored over a frame accordingly.

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

Background

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

Methods

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

Results

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

Conclusions

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

Percutaneous epiphysiodesis using transphyseal screws for limb-length discrepancies: high variability among growth predictor models

PURPOSE

Percutaneous epiphysiodesis using transphyseal screws (PETS) was developed as a minimally invasive outpatient procedure to address limb-length discrepancy (LLD) that allowed immediate postoperative weight bearing and was potentially reversible by removing the screws. The aims of our study were to report our results using PETS for LLD and evaluate the accuracy of three growth predictor models.

METHODS

Sixteen patients with an average age of 14 years were treated for LLD using PETS. Thirteen patients had screws inserted in a parallel fashion and 3 had crossed screws. We compared the predicted LLD at skeletal maturity using the three growth predictor methods with the actual LLD at skeletal maturity and preoperative LLD with the final LLD at skeletal maturity.

RESULTS

The mean LLD at skeletal maturity between the predicted and final measurements was 0.2 cm using the Green-Anderson method, 1.4 cm using the Moseley method, and -0.1 cm using the Paley method. The mean preoperative LLD of 3.1 cm was corrected to 1.7 cm at skeletal maturity (p < 0.001). Six patients complained of pain over the screw heads; however, no patient developed an infection or angular deformity.

CONCLUSIONS

The three growth predictor methods predicted the final LLD within an average of 1.4 cm, but there was high variability. Although PETS improved the LLD by a mean of 1.4 cm, we believe the results would have been better if PETS was performed at an earlier skeletal age.

Rebound growth after hemiepiphysiodesis: An animal-based experimental study of incidence and chronology

Rebound growth after hemiepiphysiodesis may be a normal event, but little is known about its causes, incidence or factors related to its intensity. The aim of this study was to evaluate rebound growth under controlled experimental conditions. A total of 22 six-week-old rabbits underwent a medial proximal tibial hemiepiphysiodesis using a two-hole plate and screws. Temporal growth plate arrest was maintained for three weeks, and animals were killed at intervals ranging between three days and three weeks after removal of the device. The radiological angulation of the proximal tibia was studied at weekly intervals during and after hemiepiphysiodesis. A histological study of the retrieved proximal physis of the tibia was performed. The mean angulation achieved at three weeks was 34.7° (standard deviation (sd) 3.4), and this remained unchanged for the study period of up to two weeks. By three weeks after removal of the implant the mean angulation had dropped to 28.2° (sd 1.8) (p < 0.001). Histologically, widening of the medial side was noted during the first two weeks. By three weeks this widening had substantially disappeared and the normal columnar structure was virtually re-established. In our rabbit model, rebound was an event of variable incidence and intensity and, when present, did not appear immediately after restoration of growth, but took some time to appear.

[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.

Correction of coronal plane deformities around the knee using a tension band plate in children younger than 10 years

BACKGROUND

Guided growth through temporary hemiepiphysiodesis has gained acceptance as the preferred primary treatment in treating pediatric lower limb deformities as it is minimally invasive with a lesser morbidity than the traditional osteotomy. The tension band plate is the most recent development in implants used for temporary hemiepiphysiodesis. Our aim was to determine its safety and efficacy in correcting coronal plane deformities around the knee in children younger than 10 years.

MATERIALS AND METHODS

A total of 24 children under the age of 10 were operated for coronal plane deformities around the knee with a single extra periosteal tension band plate and two nonlocking screws. All the children had a pathological deformity for which a detailed preoperative work-up was carried out to ascertain the cause of the deformity and rule out physiological ones. The average age at hemiepiphysiodesis was 5 years 3 months (range: 2 years to 9 years 1 month).

RESULTS

The plates were inserted for an average of 15.625 months (range: 7 months to 29 months). All the patients showed improvement in the mechanical axis. Two patients showed partial correction. Two cases of screw loosening were observed. In the genu valgum group, the tibiofemoral angle improved from a preoperative mean of 19.89° valgus (range: 10° valgus to 40° valgus) to 5.72° valgus (range: 2° varus to 10° valgus). In patients with genu varum the tibiofemoral angle improved from a mean of 28.27° varus (range: 13° varus to 41° varus) to 1.59° valgus (range: 0-8° valgus).

CONCLUSION

Temporary hemiepiphysiodesis through the application of the tension band plate is an effective method to correct coronal plane deformities around the knee with minimal complications. Its ease and accuracy of insertion has extended the indication of temporary hemiepiphysiodesis to patients younger than 10 years and across a wide variety of diagnosis including pathological physis, which were traditionally out of the purview of guided growth.

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

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