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

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.

Updates in the Management of Leg Length Discrepancy: A Systematic Review

The aim of this study is to comprehensively investigate the recent literature on the management of leg length discrepancy (LLD). A thorough search of pertinent databases was done in order to find studies that satisfied the requirements for inclusion. A thorough search of PubMed, Web of Science, Scopus, and Science Direct was conducted to find pertinent literature. Rayyan Qatar Computing Research Institute (QRCI, Ar Rayyan, Qatar) was utilized during the whole operation. Eight studies, including a total of 345 patients, were included in our data, and 206 (59.7%) of them were males. Percutaneous epiphysiodesis was the surgical intervention of choice in four studies. LLD can be effectively corrected by temporary and permanent epiphysiodesis. One study reported the incidence of angular deformities following temporary epiphysiodesis. Circumferential periosteal and dual tension-band plating significantly reduced LLD, but reported the incidence of an "over-shoot" in some patients. Bilateral motion control shoes and orthotic insole both were found to improve the patient's gait and trunk symmetry, evidenced by longer and faster steps, reduced ground impact at heel strike, and lower peak plantar pressure in both limbs. Our findings confirm that no inferences about the superiority of a particular management approach for the treatment of LLD can be made. The poor quality of the studies shows that more randomized control trials and prospective studies on the subject are required.

The Influence of Temporary Epiphysiodesis of the Proximal End of the Tibia on the Shape of the Knee Joint in Children Treated for Leg Length Discrepancy

Background: Leg length discrepancy (LLD) is a common problem in the daily clinical practice of pediatric orthopedists. Surgical treatment using LLD temporary epiphysiodesis with eight-plate implants is a minimally invasive, safe, and well-tolerated procedure that provides good treatment effects with a relatively low percentage of complications. The main aim of this retrospective study was to determine the effect of epiphysiodesis on the shape of the proximal tibia. Methods: The retrospective study was based on medical records from 2010 to 2019. Radiographs taken before the epiphysiodesis and at 6-month intervals until the end of the treatment were investigated. A total of 60 patients treated for LLD were included in the study (24 girls, 36 boys). They were divided into three groups depending on the duration of the LLD treatment: group I (18 months), group II (30 months), and group III (42 months of treatment). Radiological parameters were assessed, including the roof angle (D), the slope angles (α and β), and the specific parameters of the tibial epiphysis, namely LTH (lateral tubercle height), MTH (medial tubercle height), and TW (tibial width). Results: The roof angle decreased in all the groups, which was accompanied by an increase in the β or α angle. LTH, MTH and TW also increased, and the differences before and after the treatment for the treated legs were statistically significant in all the studied groups. The greatest change in the shape of the articular surface of the proximal tibia occurred after 42 months of treatment. Conclusions: The study showed that epiphysiodesis affects the proximal tibial articular surface over prolonged treatment. Thus, there is a need for future long-term follow-up studies to elucidate the potential effects of LLD egalization.

[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.

Effects of tension band plating on coronal plane alignment of lower extremities in children treated for idiopathic limb length discrepancy

PURPOSE

One of the most common treatment methods for moderate limb length discrepancy in children is growth modulation using tension band plating. Coronal plane deformities after tension band plating for limb length discrepancy have been documented as an important complication in articles involving heterogeneous groups consisted of both idiopathic cases and patients with pathological physes. The aim of the study was to determine the rate of coronal plane deformities after treatment of a homogeneous group of idiopathic limb length discrepancy cases with tension band plating and to compare screw constructs of medial and lateral plates.

METHODS

Patient files were retrospectively reviewed for amount of limb length discrepancy, anatomical femorotibial angle, mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, and inter-screw angles of each plate on both sides of the tibiae and femora. Measurements at each follow-up period were compared to each other.

RESULTS

A total of 26 patient files (37 bones) were included to the study. The mean age was 10.5 years. The mean limb length discrepancy was 27.5 mm. Implants were removed after mean 34.5 months. The mean follow-up period was 58.5 months. There was no significant difference in inter-screw angle on each side of the bones at the time of implantation and in lower limb alignments during follow-up.

CONCLUSION

Treatment of mild-to-moderate idiopathic limb length discrepancy with tension band plating in children was found to be safe against any coronal plane deformity during follow-up until skeletal maturity.

LEVEL OF EVIDENCE

Level IV.

Hawthorne Effect in Gait Analysis of Children with In-Toeing Caused by Increased Femoral Anteversion

Background

In-toeing is one of the main reasons children are applying to the orthopedics clinic. In the clinical settings, during in-toeing gait assessment parents often define that their child does not walk same at the clinic as at home, linked possibly to Hawthorne effect.

Research Question

How does the in-toeing angle differ when children are aware, versus when they are not aware of their gait inspection?

Methods

This single center, clinical, cross-sectional, observational study looked into the variation in gait pattern of twelve children with in-toeing, with and without their awareness. Two videos for each child was recorded with a smart phone, once at the clinic while aware and once by the family without awareness, and uploaded into Kinovea software for gait analysis. The angle of foot in-toeing was measured and analyzed using SPSS comparison of means and correlations.

Results

The gait pattern evaluated with the angle of in-toeing showed a significant difference between the two videos of the same child. The angle difference returned a p value of 0.000 using paired sample t test and a Cohen's d value of 1.4, representing the large significance between clinic and family recorded videos. The initial foot in-toeing angle showed a moderate positive Pearson's correlation of 0.031 when compared with the angle difference in both settings.

Significance

These results highlight the importance of including family recorded videos in gait pattern analysis without the patient's awareness. The study not only shows the significant difference found which can be explained by Hawthorne Effect but also suggests a clearer path of understanding the child's condition with the family.

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.

Percutaneous epiphysiodesis using transphyseal screws (PETS) versus tension-band plating (TBP): comparative study of outcomes for correcting limb length discrepancy

OBJECTIVES

The best effective treatment strategy for limb length discrepancy (LLD) is still being debated. The goal of this study was to compare the efficacy and results of tension-band plating (TBP) and percutaneous epiphysiodesis using transphyseal screws (PETS) for LLD correction.

METHODS

From June 2008 to January 2019, children who had lower extremity epiphysiodesis with either TBP or PETS were reviewed retrospectively. At the conclusion of treatment, LLD, angular deformity, and complications were reviewed. The t-test or Wilcoxon rank sum test was used to compare continuous variables. Categorical variables were evaluated using Fisher's exact test or χ² test.

RESULTS

A total of 32 epiphysiodeses with TBP (14 patients, 24 femur/tibias) or PETS (13 patients, 23 femur/tibias) were compared. TBPs were conducted while the patients were younger (11.0 vs. 13.1 years, p = 0.005). The treatment durations were similar in both groups (TBP: 23.5 months vs. PETS: 24 months, p = 0.132). PETS had significantly shorter operative time (p = 0.047), length of hospital stay (p = 0.014), and time to return to full activity (p = 0.043). LLD in the TBP group reduced from 2.64 to 1.38 cm (p = 0.005), while in the PETS group it decreased from 2.76 to 1.08 cm (p = 0.001). During treatment, the rate of LLD correction was 0.49 ± 0.9 cm/year for limbs treated with TBP and 1.0 ± 1.1 cm/year for limbs treated with PETS (p = 0.185). At the end of treatment, 8 TBP cases (47%) and 9 PETS cases (60%) had achieved LLD ≤ 2 cm (p = 0.502), and at the most recent follow-up, this had grown to 11 (65%) in the TBP group and 12 (80%) in the PETS group. There were no significant differences in the total number of complications between groups (p > 0.05). Revision surgery was required in 11 TBP and 3 PETS limbs due to persistent LLD or angular deformity (AD) (p = 0.016). Logistic regression did not reveal any significant association between TBP and the rate of complication or revision surgery.

CONCLUSION

PETS and TBP are both effective methods for limb length equalization. PETS, on the other hand, was linked to a shorter operative time, a shorter hospital stay, a faster recovery to pre-operative function, and a lower complication rate. The rate of revision surgery due to persistent LLD or AD was higher in TBP. We advise surgeons against utilizing TBP to correct LLD.

LEVEL OF EVIDENCE

III.

Temporary Epiphysiodesis Using the Eight-Plate in the Management of Children with Leg Length Discrepancy: A Retrospective Case Series

BACKGROUND

Although eight-plates have been shown to be effective in correcting angular deformities of the knee, the literature is scarce regarding the efficiency of this method in treatment of children with LLD.

OBJECTIVES

The aim of this study was to determine the efficiency, rates of correction and complications of epiphysiodesis using eight-plate in the management of children with leg length discrepancy (LLD).

METHODS

Eleven consecutive patients with LLD (7 boys, median age = 9, age range 6-11 years) who were treated by temporary epiphysiodesis using eight-plates were retrospectively reviewed and included in the study. The main indication for temporary epiphysiodesis was an LLD between 2 and 5 cm in all patients. LLD and lower limb alignment were examined on lower extremity weight-bearing radiography preoperatively and at skeletal maturity. Longitudinal correction rate was calculated. The final LLD was categorized as ''good result'' (final LLD < 1.5 cm), ''fair result'' (1.5-2 cm), and ''poor result'' (> 2 cm).

RESULTS

The mean treatment period with the eight-plate was 44 (min to max = 32-72) months, and the mean follow-up from the index surgery to the final follow-up was 62 (min to max = 39-106) months. The mean LLD was significantly reduced from 39 (range 25-50) mm preoperatively to 22.40 (range 6-55) mm postoperatively (p = 0.006). The mean longitudinal correction rate was found to be 0.48 mm/mo. Radiographic evidence of lower limb deformity in frontal and sagittal planes was determined in neither preoperative nor postoperative deformity analysis. No major complications were recorded.

CONCLUSION

For the management of children with LLD of 2-5 cm, temporary hemiepiphysiodesis using the eight-plate seems to be an effective treatment with low complication rates.

The efficacy of two-hole tension band plates in the treatment of lower extremity limb length discrepancy

The main purpose of our study was to investigate the efficacy of dual two-hole tension band plates in the treatment of lower extremity limb length discrepancy (LLD). We retrospectively reviewed patients who underwent epiphysiodesis utilizing dual two-hole tension band plates due to lower extremity LLD between January 2012 and June 2018. The efficacy of epiphysiodesis was defined as the inhibited percentage of the expected growth of the physis between two time intervals and was calculated between 0-6 months and 6-18 months as the primary outcome. The relationship of efficacy of epiphysiodesis with time intervals, bone segments, physeal coverage percentage by the screws, age and interscrew angle and physeal health was also assessed. A total of 11 patients' 17 bone segments (9 femurs and 8 tibias) with a mean age of 8.7 ± 2.3 were included. The mean efficacy of the epiphysiodesis in the first 6 months for femurs was 23 ± 20 % (range, 0-53%) and for tibias was 21 ± 19 % (range, 0-53%); between 6 and 18 months it was 27 ± 19 % (range, 0-56%) for femurs and 15 ± 19 % (range, 0-50%) for tibias. In the first 6 months, physeal coverage percentage by the screws (r = 0.503, P = 0.04) and age (r = -0.534, P = 0.027) had a strong correlation with the epiphysiodesis efficacy. Dual two-hole tension band plating has variable efficacy in the treatment of LLD. Age and physeal coverage percentage by the screws could be related to epiphysiodesis efficacy.

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.

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.

Does eight-plate epiphysiodesis of the proximal tibia in treating angular deformity create intra-articular deformity?

Aims

Eight-plates are used to correct varus-valgus deformity (VVD) or limb-length discrepancy (LLD) in children and adolescents. It was reported that these implants might create a bony deformity within the knee joint by change of the roof angle (RA) after epiphysiodesis of the proximal tibia following a radiological assessment limited to anteroposterior (AP) radiographs. The aim of this study was to analyze the RA, complemented with lateral knee radiographs, with focus on the tibial slope (TS) and the degree of deformity correction.

Methods

A retrospective, single-centre study was conducted. The treatment group (n = 64 knees in 44 patients) was subclassified according to the implant location in two groups: 1) medial hemiepiphysiodesis; and 2) lateral hemiepiphysiodesis. A third control group consisted of 25 untreated knees. The limb axes and RA were measured on long standing AP leg radiographs. Lateral radiographs of 40 knees were available for TS analysis. The mean age of the patients was 10.6 years (4 to 15) in the treatment group and 8.4 years (4 to 14) in the control group. Implants were removed after a mean 1.2 years (0.5 to 3).

Results

No significant differences in RA (p = 0.174) and TS (p = 0.787) were observed. The limb axes were significantly corrected in patients with VVD (p < 0.001). The change in tibial slope (∆TS) did not correlate ( r = -0.026; p = 0.885) to the plate’s position on the physis when assessed by lateral radiographs.

Conclusion

We were not able to confirm the reported change in the bony morphology of the proximal tibia on AP radiographs in our patient population. In addition, no significant change in TS was detected on the lateral radiographs. A significant correction of the VVD in the lower limb axes was evident. Position of the implant did not correlate with TS change. Therefore, eight-plate epiphysiodesis is a safe and effective procedure for correcting VVD in children without disturbing the knee joint morphology. Cite this article: Bone Joint J 2020;102-B(10):1412–1418.

What's New in Pediatric Limb Lengthening and Deformity Correction?

Over the past 5 years, published literature regarding treatment of pediatric limb deformity and limb length discrepancy demonstrates much interest in better understanding, categorizing and treating these challenging problems. Many studies explore expanding and refining indications for traditional treatment methods like guided growth techniques. Other studies have evaluated the results of new techniques such as lengthening via mechanized intramedullary nails. Additionally, series comparing older and newer techniques such as lengthening with external devices versus mechanized nails are becoming increasingly available.

Temporary hemiepiphysiodesis for correcting idiopathic and pathologic deformities of the knee: A retrospective analysis of 355 cases

BACKGROUND

Hemiepiphysiodesis is a well-established treatment option in cases of pathologic deformities and leg discrepancies during evolution. The aim of this study was to evaluate the postoperative angular measurement, correction correlated with age at operation time, and postoperative complication rate.

MATERIAL AND METHODS

A total of 355 patients were treated with 887 8-plates between April 2007 and January 2013. Their mean age was 12.18 years (range four to 16 years), and the mean time to axis correction was 17.32 months (range two to 62 months). We analysed the entire population and also performed subgroup analyses for idiopathic, pathologic, varus, valgus and leg length discrepancy.

RESULTS

The mean durations (time from (hemi-) epiphysiodesis to implant removal) in the idiopathic and pathologic groups were 13.24 and 21.3 months, respectively. The time to implant removal was 18.39 months for idiopathic varus deformities and 11.07 months for idiopathic valgus deformities. For the pathologic deformity group it was 24.9 and 20 months in the varus and valgus subgroups, respectively.

CONCLUSIONS

Hemiepiphysiodesis is a well-established treatment option to correct angular deformities. The rate of correction was slower and less successful in pathologic deformities and for leg length discrepancies. This suggests that earlier intervention is appropriate for these patients. A higher body mass index (BMI) was observed for valgus deformity, but no correlation was present between BMI and durability.

Comparison of Temporary Epiphysiodesis With RigidTacks™ and Blount-Staples in a Porcine Animal Model Using Magnetic Resonance Imaging

RigidTack™ is a newly developed implant for total temporary epiphyseodesis. The implant combines the technical advantages of the traditionally used rigid Blount-staples and the newer flexible eight-plates™. Thus, the implant is rigid like the Blount-staples, which may be a biomechanical advantage in temporary epiphyseodesis, and has an easy and guided implantation technique like the eight-plate™. As in eight-plates™, supposedly only two RigidTacks™ are sufficient for temporary epiphyseodesis compared to six Blount-staples in traditional treatment. The goal of this study was to compare Blount-staples and RigidTacks™ in regard to the total potential of growth arrest, the occurrence of postoperative implant-associated complications, secondary angular deformities, and central joint deformations. Twelve pigs were allocated in two groups (n = 6) for treatment of the proximal tibia. Total temporary epiphysiodesis was performed with either four Blount-staples or two RigidTacks™. Magnetic resonance imaging (MRI)-scans were performed before and 14 weeks after surgery, and the amount and distribution of growth arrest were evaluated by measuring the interphyseal distance in nine defined zones. Total temporary epiphysiodesis with two RigidTacks™ resulted in a similar amount of growth arrest as that of four Blount-staples. No significant coronal or sagittal angular deformities or joint deformities were observed in either group; however, one secondary loosening of a Blount-staple occurred. The study concluded that Blount-staples and RigidTacks™ are adequate implants for total temporary epiphysiodesis. Whether or not the precise implant-placement through the guided implantation technique of RigidTacks™ and a reduced number of implants indeed lead to a reduction of secondary angular deformities has to be investigated in further clinical trials. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:946-953, 2020.

Update on guided growth concepts around the knee in children

Guided growth is part of the surgical armamentarium for limb-length discrepancy or axial deformity. It is an old concept, with several apparently conflicting techniques that are in fact usually complementary. Depending on whether the aim is to slow or arrest growth, to treat length discrepancy or axial deviation, techniques differ and the choice is partly determined by the indication. It is thus essential to know the technical details for each: temporary or definitive, complete or asymmetric, with or without implant. Considerations of fashion and personal habits may outweigh basic principles, and it is important to go back to the princeps descriptions: the Phemister, Bowen, Blount, Métaizeau and Stevens techniques and others all have their surgical specificities Apart from surgery itself, he indication and choice of technique depend on the patient's age and whether the abnormality to be treated is isolated or part of a wider syndrome, all of this being included in a precise strategy based on planning calculations that are indispensable ahead of any surgery. Guided growth can also be implemented elsewhere than in the limbs: wrist, ankle, or even hip; and it is beginning to be possible to correct sagittal and rotational deformities. All of this is furthermore achievable using emerging techniques that are less invasive, are reversible, and show equal efficacy.

Guided growth with tension band plate or definitive epiphysiodesis for treatment of limb length discrepancy?

Background

It is not exactly known whether guided growth or definitive epiphysiodesis techniques are superior in treating limb length discrepancy (LLD). The purpose of the present study was therefore to find out if definitive epiphysiodesis is associated with more powerful LLD correction than tension band plate epiphysiodesis.

Methods

Pediatric patients with LLD treated either with tension band plating as a guided growth technique (temporary epiphysiodesis) or a percutaneous drilling technique (definitive epiphysiodesis) around the knee and a minimum follow-up of 12 months were included in this retrospective study. Radiographic measurements were performed by two independent reviewers. The reduction in side difference between preoperative radiographs and last follow-up was calculated and compared between surgical techniques.

Results

Thirty-eight patients (mean age 13.6 years) were included, 17 treated with temporary and 21 with definitive epiphysiodesis. Average follow-up was at 578 days. The reduction of the LLD in 12 months was 5.7 mm in patients treated with temporary epiphysiodesis and 8.4 mm with definitive epiphysiodesis, respectively (p = 0.22). In both groups, LLD could be statistically significantly reduced after 12 and 24 months. Definitive epiphysiodesis had a lower revision rate (4.8% vs. 17.6%). Intra- and interobserver reliability of the measurements was excellent.

Conclusions

As in earlier studies supposed, temporary epiphysiodesis with tension band plating seems to correct LLD less powerful compared to definitive percutaneous epiphysiodesis. However, in the present study, the differences of LLD correction were not statistically significant. We do not recommend the use of tension band plates for LLD correction due to inferior correction with higher complication and revision rate.

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.

Biomechanical investigation of two long bone growth modulation techniques by finite element simulations

Implants used to correct pathological varus-valgus deformities (VVD) and leg length discrepancies (LLD) may not be optimized for the specific treatment, as suggested by their off-label use. Detailed analysis of this issue has been limited by the poorly understood mechanical behavior of the growing physis and ignorance of the loads acting on the implants. The aim of this study was to predict and compare the loading conditions of a growth modulation implant in VVD and LLD treatments. Idealized finite element (FE) models of the juvenile distal femur treated with the Eight-Plate implant were developed for VVD and LLD. Bone growth was simulated using thermal strains. The axial force in the plate was compared between the two treatments. Case-specific plate forces were predicted by virtually reproducing the screw deformation visible on radiographs of LLD (N = 4) and VVD (N = 4) clinical cases. The simple FE models reproduced the clinical implant deformations well. The resulting forces ranged from 129 to 580 N for the VVD patients. For LLD, this range was from 295 to 1002 N per plate, that is, 590-2004 N for the entire physis. The higher forces in LLD could be explained by restricted screw divergence in the double-sided implant application. For the first time, the loading conditions of a growth modulation implant were investigated and compared between two treatments by FE analyses, and the range of case-specific loads was predicted. These simulation tools may be utilized for guiding appropriate usage and for efficient development of implants. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1398-1405, 2018.

Regenerative Medicine Approaches for the Treatment of Pediatric Physeal Injuries

The physis, or growth plate, is a cartilaginous region at the end of children's long bones that serves as the primary center for longitudinal growth and characterizes the immature skeleton. Musculoskeletal injury, including fracture, infection, malignancy, or iatrogenic damage, has risk of physeal damage. Physeal injuries account for 30% of pediatric fractures and may result in impaired bone growth. Once damaged, cartilage tissue within the physis is often replaced by unwanted bony tissue, forming a "bony bar" that can lead to complications such as complete growth arrest, angular or rotational deformities, and altered joint mechanics. Children with a bony bar occupying <50% of the physis usually undergo bony bar resection and insertion of an interpositional material, such as a fat graft, to prevent recurrence and allow the surrounding uninjured physeal tissue to restore longitudinal bone growth. Clinical success for this procedure is <35% and often the bony bar and associated growth impairments return. Children who are not candidates for bony bar resection due to a physeal bar occupying >50% of their physis undergo corrective osteotomy or bone lengthening procedures. These approaches are complex and have variable success rates. As such, there is a critical need for regenerative approaches to not only prevent initial bony bar formation but also regenerate healthy physeal cartilage following injury. This review describes physeal anatomy, mechanisms of physeal injury, and current treatment options with associated limitations. Furthermore, we provide an overview of the current research using cell-based therapies, growth factors, and biomaterials in the different animal models of injury along with strategic directions for modulating intrinsic injury pathways to inhibit bony bar formation and/or promote physeal tissue formation. Pediatric physeal injuries constitute a unique niche within regenerative medicine for which there is a critical need for research to decrease child morbidity related to this injurious process.

Paediatric lower limb deformity correction with the Eight Plate: adverse events and correction outcomes of 126 patients from an international multicentre study

No large multicentre studies have yet been published on tension-band-like implants such as the Eight Plate to treat limb-length discrepancies and varus valgus deformities in children. Therefore, we carried out a retrospective international multicentre study including 126 patients to assess outcomes and to reliably quantify the incidence of implant-related and growth-plate related adverse events (AEs). Correction was achieved in 66% of varus valgus deformities and in 59% of limb-length discrepancies and maintained in 85%. Twenty (18%) patients experienced 43 AEs, which were primarily screw-related. The AE rate of the Eight Plate is low; however, many of them could be avoided through tighter monitoring.

Closing the growth plate: a review of indications and surgical options

PURPOSE OF REVIEW

The purpose is to review the indications for epiphysiodesis in the treatment of pediatric limb length discrepancies; provide an update on current diagnostic, planning, and surgical techniques; and to introduce possible future alternatives.

RECENT FINDINGS

Retrospective comparative studies have failed to demonstrate superiority of one epiphysiodesis technique over the others. EOS low-dose biplanar X-ray and smartphone growth prediction applications are improving our ability to diagnose and plan treatment for leg length discrepancy. Arthroscopically guided percutaneous epiphysiodesis and radiofrequency ablation are newer techniques that are still under investigation.

SUMMARY

Epiphysiodesis is the treatment of choice for children with predicted leg length discrepancies between 2-5 cm, provided that the physes are open with sufficient growth remaining. The most common epiphysiodesis techniques are performed percutaneously and either ablate the physis with drills/curettes or use metal implants to tether the physis and prevent further growth. Surgical treatment is typically ambulatory in nature, and allows for early return to weight bearing. In modern series, complication rates are less than 10%, with the majority being minor complications. Further high-quality prospective research is needed to determine the optimal epiphysiodesis surgical technique.