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

Epiphysiodesis for limb length discrepancy: a comparison of two methods

A retrospective review of 42 patients from 1999 to 2008 with at least 1-year follow-up was performed. The type and location of epiphysiodesis, average operative time and hospital stay, complications, timing and the final limb length discrepancy (LLD) were recorded. Computer tomography scanograms and mechanical axis view with grids were done to assess LLD. Twenty-six patients underwent Canale type epiphysiodesis compared with 14 receiving Metaizeau screw epiphysiodesis. The average operation time for Canale type was 42 and 45 min for screw epiphysiodesis. In the Canale group, there was a mean reduction in 2.5 cm in LLD from 3.7 to 1.2 cm over an average follow-up of 2.1 years. There were 4 minor and 2 major complications with a 92 % success rate defined as achieving the desired discrepancy correction. In the screw epiphysiodesis group, the mean change was 1.8 cm from 3.2 to 1.4 cm, over 2.2 years with 2 minor and 2 major complications and a success rate of 85 %. Percutaneous epiphysiodesis by any method is a reliable, minimally invasive method with minimal morbidity and an acceptable complication rate when compared to a corrective osteotomy or an open Phemister-type epiphysiodesis. This study has led to our preference for the Canale method, which in our hands has fewer complications and is more successful at reaching the desired discrepancy correction.

Growth guidance of angular lower limb deformities using a one-third two-hole tubular plate

PURPOSE

The eight-plate system for angular deformity correction is well known, reliable and effective at any age during growth. Due to high implant costs, we sought to evaluate the effectiveness and safety of a less expensive alternative.

METHODS

Between 2006 and 2011, 41 children with angular deformities were managed using a two-hole one-third tubular plate in cases where an eight plate would normally be indicated. Inclusion criteria in this retrospective study were: genu valgum and genu varum. X-ray documentation was performed before and after surgery and patients were followed clinically every 3 months after surgery. The cost per implant was 361.40 Sfr (Swiss Francs) compared to the eight plate at 737 Sfr.

RESULTS

Mean time for correction was 13 months. A mean LDFA/MPTA after correction of 89.9°/86.8° was recorded, as well as a mean correction angle of 6.8°/6.6°. The complication rate was 6.6 % (one superficial wound infection and one insufficient correction in an older child). These results compare favourably with published data on the eight plate.

CONCLUSION

The two hole one-third tubular plate seems to be a clinically and also cost effective alternative to the eight plate. Full deformity correction is gained for a fraction of the cost.

LEVEL OF EVIDENCE

Level III.

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

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

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

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

Guided growth by a stainless-steel tubular plate

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

Guided growth for the treatment of moderate leg-length discrepancy

The purpose of this study was to evaluate the effectiveness and complication rate of guided growth for the treatment of patients with a moderate leg-length discrepancy. The authors retrospectively reviewed all patients treated with guided growth for a moderate leg-length discrepancy at their institution between October 2004 and December 2010. Thirty-four patients met the inclusion criteria from an initial cohort of 105 patients. All patients were followed until screw removal or maturity occurred. Nine patients had a developmental leg-length discrepancy, and 25 had a congenital leg-length discrepancy. Average age was 12.6 years (range, 7-16 years). Average leg-length discrepancies, as measured on standing long-leg radiographs from the top of the pelvis, the top of the femoral heads, and the center of the ankle to the top of the femoral heads, were 22, 19, and 17 mm, respectively. Average discrepancies at screw removal or maturity were 13, 10, and 11 mm, respectively. Twenty of 33 patients had a leg-length discrepancy of less than 1 cm at maturity or screw removal. The leg-length discrepancy change in patients who underwent guided growth of the tibia was minimal. Leg-length discrepancies in patients who underwent guided growth of the femur or both the femur and the tibia changed by an average of 10 mm. One patient had a mechanical axis change greater than 1 zone, and 1 patient required treatment for angular deformity after being treated for a leg-length discrepancy. Guided growth is a safe and effective technique for treating moderate leg-length discrepancies.

Guided growth: the importance of a single tether. An experimental study

BACKGROUND

During the last few years, the use of the 8-plate as a technique for hemiepiphysiodesis has gained wide acceptance, as it has been shown that it works in a more physiological way than other methods such as staples or transphyseal screws. It has mechanically been compared with a tension band plate, and for this reason, only a single plate is needed. The following study was undertaken to test the 8-plate against the staples and assess factors that can influence the difference in results.

METHODS

A prospective experimental study was designed to compare the ability of 2 hemiepiphysiodesis methods, the 8-plate and the double staple, to produce angular deformity in the rabbit's tibia (group I). The variable studied was the variations in the articular line-diaphysis angle at 6 weeks. As the results showed that the 8-plate produced a bigger deformity, a second group was designed (group II) comparing single against double staple, under the hypothesis that the differences observed in the first group could be related to the number of anchors put across the physis and consequently depend on the volume of physis involved by the staples.

RESULTS

In group I, the 8-plate produced a bigger angulation at 6 weeks' time than the 2 staples (a difference of 6.5 degrees, P = 0.03). Similarly, in group II, the single staple produced a greater angulation than the 2 staples (difference 6 degrees, P = 0.08). When both groups were compared, no differences in the angulation produced by the 8-plate and the single staple with respect to the 2 staples were found.

CONCLUSIONS

These results suggest that one of the reasons why the 8-plate may act in a more "physiological way" (vs. the traditional 2-staple or 3-staple hemiepiphysiodesis) could be the fact that the growth plate is tethered only at a single point. Therefore, the physis retains a major potential for growth and deformity.

CLINICAL RELEVANCE

The 8-plate is superior in producing/correcting angular deformity when compared with the traditionally used staples (2 or more) but not when compared with a single staple.

Rate of correction after asymmetrical physeal suppression in valgus deformity: analysis using a linear mixed model application

BACKGROUND

This study was performed to estimate the rate of angular correction after asymmetrical physeal suppression and analyze the factors that influence the rate of correction by using a linear mixed model application.

METHODS

A total of 175 physes (72 distal femoral, 70 proximal tibial, and 33 distal tibial) from 78 consecutive patients with valgus angular deformity of the lower limb who underwent asymmetrical physeal suppression were included. The anatomic lateral distal femoral angle, the anatomic lateral proximal tibial angle, and the anatomic lateral distal tibial angle were measured from the teleroentgenograms of the patients' preoperative visit and periodic follow-ups. The rate of angular correction was adjusted by multiple factors by using a linear mixed model with age, sex, and surgical method as the fixed effects and each subject as the random effect. The final model included the age-specific and surgical method-specific rate and sex-specific and surgical method-specific intercept. Multivariate analysis was performed for this model.

RESULTS

In younger children (boys 14 y or younger and girls 12 y or younger), the rate of correction of valgus deformity at the distal femur, proximal tibia, and distal tibia was 0.71 degrees/month (8.5 degrees/y), 0.40 degrees/month (4.8 degrees/y), and 0.48 degrees/month (5.8 degrees/y), respectively. In older children, the rate of correction of valgus deformity at the distal femur, proximal tibia, and distal tibia was 0.39 degrees/month (4.7 degrees/y), 0.29 degrees/month (3.5 degrees/y), and 0.48 degrees/month (5.8 degrees/y), respectively. The rate of correction at the distal femur was significantly lower in older children (P = 0.025). The rate of angular correction at the proximal tibia was significantly faster in the screw group than in the staple group (P = 0.046).

CONCLUSIONS

Asymmetrical physeal suppression with staples, percutaneous transphyseal screws, and permanent method all are effective methods for treating valgus deformity in growing children. When we treat valgus deformity in growing children, we should take into consideration the fact that the rate of correction at the distal femur is lower in older children, and that at the proximal tibia is faster in the screw group.

LEVEL OF EVIDENCE

Therapeutic level III.

Guided growth with a noncannulated screw-plate system for angular deformity of the knee: a preliminary report

We assessed the result of guided growth for an angular knee deformity using a 3.5-mm noncannulated screw-plate system. Twenty-seven patients with angular deformities (10 distal femora, 13 proximal tibiae, and four both areas) underwent this procedure with the reconstruction plate and two noncannulated screws. Average age at the time of the procedure was 7.8 years and the average follow-up was 25.7 months. Except for one patient (two knees), 25 of 27 deformities showed a resolved outcome with a neutral alignment. The mechanical lateral distal femoral angle changed an average of 8.3° for 13 months and the medial proximal tibial angle changed an average of 7.7° for 11.8 months in the neutral state. The mean angle between the two screws was -2° in immediate postoperative radiographs and 23° in radiographs taken at the latest follow-up. Two patients showed a rebound outcome and one showed a failure of no correction. There was a superficial infection, but no mechanical failure of the screw and the plate was observed. The noncannulated screw-plate system may play a similar role of guided growth, to correct angular knee deformity, although a large series study with a long follow-up is required for a definitive conclusion.

Efficacy and late complications of percutaneous epiphysiodesis with transphyseal screws

Percutaneous epiphysiodesis using transphyseal screws (PETS) has been developed for the treatment of lower limb discrepancies with the aim of replacing traditional open procedures. The goal of this study was to evaluate its efficacy and safety at skeletal maturity. A total of 45 consecutive patients with a mean skeletal age of 12.7 years (8.5 to 15) were included and followed until maturity. The mean efficacy of the femoral epiphysiodesis was 35% (14% to 87%) at six months and 66% (21% to 100%) at maturity. The mean efficacy of the tibial epiphysiodesis was 46% (18% to 73%) at six months and 66% (25% to 100%) at maturity. In both groups of patients the under-correction was significantly reduced between six months post-operatively and skeletal maturity. The overall rate of revision was 18% (eight patients), and seven of these revisions (87.5%) involved the tibia. This series showed that use of the PETS technique in the femur was safe, but that its use in the tibia was associated with a significant rate of complications, including a valgus deformity in nine patients (20%), leading us to abandon it in the tibia. The arrest of growth was delayed and the final loss of growth at maturity was only 66% of that predicted pre-operatively. This should be taken into account in the pre-operative planning.

The 8-plate versus physeal stapling for temporary hemiepiphyseodesis correcting genu valgum and genu varum: a retrospective analysis of thirty five patients

PURPOSE

In skeletally immature patients, treatment of malalignment about the knee is possible by performing temporary hemi-epiphyseodesis. Following the well-established procedure of physeal stapling, the 8-plate was introduced as a new device. The purpose of this study was to compare physeal stapling with 8-plate hemi-epiphyseodesis. We focused on evaluating deformity correction, complication rate and duration of the procedures.

METHODS

We retrospectively analysed 35 patients (61 extremities, age 2.9-16.0 years) who were treated by temporary hemi-epiphyseodesis about the knee for correction of genu varum or genu valgum by using Blount staples (32 extremities) or the 8-plate (29 extremities). Plain radiographs were analysed at the time of operation and at hardware removal that included measurement of mechanical axis deviation, mechanical lateral distal femoral angle and mechanical medial proximal tibial angle. Time until hardware removal, operation time and complications were recorded.

RESULTS

A statistically significant improvement of all radiographic measurements could be achieved with comparable results in both groups. Complications were similar in both groups with no relevant differences in amount and severity. In the 8-plate group, however, the surgical time was significantly shorter by an average of ten minutes for implantation and 12 minutes for explantation.

CONCLUSIONS

Both Blount stapling and the 8-plate technique are methods for correction of genu varum and valgum deformity in skeletally immature patients; however, a shorter operating time for implantation and explantation was noted for the 8-plate technique.

Children ankle valgus deformity treatment using a transphyseal medial malleolar screw

INTRODUCTION

Ankle valgus deformity is rare in children. It generally leads to difficulties wearing shoes, walking instability and mechanical pain. No medical treatment is effective and the only option is surgical correction of the deformity. Two main options are available: supramalleolar osteotomy and medial malleolar epiphysiodesis. We report our experience with epiphysiodesis using a transphyseal medial malleolar screw.

PATIENTS AND METHODS

This is a retrospective study of all children followed for ankle valgus and treated by transphyseal medial malleolar screw epiphysiodesis in our department. The study included 10 cases of ankle valgus deformity in seven children (four with multiple extostoses, two type 1 neurofibromatosis, one Larsen's syndrome) who completed skeletal maturity. At surgery, median bone age was 12 years (10 to 13 years and 6 months) and the median tibiotalar angle was 17.5° (10° to 30°).

RESULTS

At skeletal maturity, preoperative valgus was corrected in six patients (9/10 ankles). The median tibiotalar angle was 5° (0° to 25°). Valgus was not corrected in one patient (30° to 25°). No postoperative complications occurred.

DISCUSSION

Epiphysiodesis by transphyseal medial malleolar screw is a simple, efficient and safe procedure to correct a significant or symptomatic ankle valgus deformity in children before skeletal maturity.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Temporary hemiepiphysiodesis with blount staples and eight-plates in pigs

Temporary hemiepiphysiodesis is a relatively minor surgical procedure in the growing child to allow guided growth to correct angular deformities. Blount staples (Stryker Howmedica, Kiel, Germany) have been used effectively for the past 50 years for physeal stapling; their limitations are poor mechanical purchase and easy extrusion from bone, implant breakage, and potential for physeal damage and permanent closure. Recently, an alternative device to Blount staples called the eight-Plate (Orthofix, McKinney, Texas) has been presented for hemiepiphysiodesis and guided growth. Their theoretical advantages over Blount staples include higher stability, faster correction of the deformity, and fewer complications.We performed a study in a pig model to compare the rate of angular deformity correction and implant extrusion after hemiepiphysiodesis with Blount staples and eight-Plates. In all animals, medial hemiepiphysiodesis was performed in the right proximal tibia with the eight-Plate and the left proximal tibia with the Blount staple. The medial slope angle, medial tibial plateau angle, proximal implant angle, distal implant angle, and distance of the body of the implant from the medial tibial cortex were measured on radiographs of the knee joints performed every 4 weeks. The angles of correction showed statistically significantly earlier effect on physeal guided growth of the eight-Plates compared to the Blount staples. Implant displacement/extrusion was statistically significantly lower for the eight-Plate. In this animal model, eight-Plates are significantly more effective than Blount staples for guided growth after temporary hemiepiphysiodesis.

Early experience with medial femoral tension band plating in idiopathic genu valgum

PURPOSE

For correction of angular deformity, tension band plating has been proposed as a safe and minimally invasive technique. The purpose of this study was to assess the experiences and report the rate of correction obtained with this procedure in patients with idiopathic genu valgum.

METHODS

This study was a retrospective review of 47 valgus deformities of the knee treated with medial hemiepiphysiodesis using a tension band plate. The tibiofemoral angle (TFA) and the anatomic lateral distal femoral angle (aLDFA) were assessed on anteroposterior (AP) radiographs of the lower extremity taken at multiple time intervals. The values were charted to determine the change in orientation of the joint surface over time. Pearson's correlation was used to analyze the correction over time. A subanalysis was performed evaluating the effect of age and the number of plates utilized.

RESULTS

A total of 47 deformities in 25 patients were reviewed. The average time of follow-up from index surgery was 12.7 months, with an average correction of 0.96° every 3 months or 3.8° per year. The aLDFA corrected at a faster rate in knees with two plates per hemiepiphysiodesis than those with one plate, 4.2° and 3.3° per year, respectively (P = 0.035). Girls <11 years of age and boys <13 years of age corrected at a rate of 4.5°, while older children corrected at a rate of 3.4° per year (P = 0.39). There were no complications or instrumentation breakages.

CONCLUSION

Hemiepiphysiodesis with tension band plating provides an effective and predictable correction of idiopathic genu valgum. Two plates appear to provide a greater rate of correction. There is also a trend toward faster correction in younger patients as well.

Surgical epiphysiodesis indications and techniques: update

PURPOSE OF REVIEW

To present a summary of epiphysiodesis indications and to report most recent advances in the field, along with their clinical relevance.

RECENT FINDINGS

Percutaneous epiphysiodesis using transphyseal screws (PETS) and guided growth using eight plates represent the most recent techniques used for hemiepiphysiodesis.

SUMMARY

PETS and guided growth have yielded very good results and low rates of complications and are the current standard for the management of angular deformities of the lower extremities in children. Permanent percutaneous epiphysiodesis remains the preferred method for the treatment of limb length discrepancies.

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

PURPOSE

The aim of this study was to compare the outcomes of angular deformity correction by hemiepiphyseal stapling versus percutaneous hemiepiphysiodesis using transphyseal screw in growing children.

METHODS

Forty-three physes in 19 patients underwent hemiepiphyseal stapling, and 37 physes in 23 patients underwent percutaneous transphyseal screw placement. All cases were followed up to skeletal maturity or for more than 1 year after hardware removal. Amounts and rates of angular deformity correction, physeal behaviors after hardware removal, and postoperative courses were compared between the 2 groups.

RESULTS

The goal of angular correction was achieved in all except 2 patients, who reached skeletal maturity precociously. The mean rates of angular correction were not significantly different between the 2 groups, in both distal femur and proximal tibia. Hardware was removed before skeletal maturity from 56 physes. Angular change remained within 3 degrees for 43 physes (76.8%) at more than 1 year postoperatively, and the rebound phenomenon was observed in 12 (21.4%). No significant difference was observed between the 2 groups in terms of physeal behavior after hardware removal. Patients in the screw group were administered less postoperative pain medication, had shorter hospital stays, and smaller operation scars. In the stapling group, 1 case was complicated due to an extruded staple, and another case experienced premature physeal arrest at 1.5 years postoperatively. One case in the screw group experienced correction failure, probably because of a technical error during screw placement.

CONCLUSIONS

Hemiepiphysiodesis using percutaneous transphyseal screw is as effective as hemiepiphyseal stapling in terms of angular deformity correction. Furthermore, hemiepiphysiodesis using transphyseal screw has the advantage of being a minimally invasive procedure, and in this series, did not cause permanent physeal arrest.

LEVEL OF EVIDENCE

Level III.

Guided growth for the correction of pediatric lower limb angular deformity

Guided growth is useful in correcting pediatric angular deformities. Although growth manipulation has been applied to various deformities, it is most commonly used to correct coronal plane deformity about the knee. Temporary hemiepiphysiodesis is performed using staples, percutaneous transphyseal screws, or a tension band plate. Permanent hemiepiphysiodesis can be done using either an open Phemister or a percutaneous approach. These techniques function by tethering one side of a growing physis, thereby allowing differential growth. Applied correctly, this can also result in angular deformity correction. Undercorrection and overcorrection are common problems with guided growth. However, careful preoperative planning and appropriate follow-up can minimize complications and allow for excellent deformity correction with minimal morbidity.

Temporary hemiepiphysiodesis with the eight-Plate for angular deformities: mid-term results

BACKGROUND

Angular deformities can be treated with corrective osteotomies and application of internal or external fixation. In children, this major intervention can be avoided with temporary hemiepiphysiodesis (i.e., guided growth). Recently, a new device called the eight-Plate Guided Growth System, consisting of a two-hole plate and two screws, was presented as an alternative to the widely used Blount staple to perform temporary hemiepiphysiodesis in children.

METHODS

Forty-three patients (54 physes, 51 limbs) underwent treatment between August 2004 and December 2005 with average follow-up after plate insertion of 2 years 2 months (range, 1 year 6 months to 2 years 6 months). Rate of correction and reversibility of this intervention were calculated.

RESULTS

Average age at eight-Plate implantation was 9 years 7 months (age range, 4 years 0 months to 14 years 3 months). eight-Plates were inserted for an average 14.2 months (range, 5.0-27.4 months). No growth disturbance was observed. Mechanical lateral distal femoral angle changed an average 10.00 degrees (range, 1-18 degrees) or 0.65 degrees/month (range, 0.05-1.22 degrees/month). Medial proximal tibial angle changed an average 7.78 degrees (range, 0-14 degrees) or 0.58 degrees/month (range, 0.13-1.67 degrees/month). In the two distal tibial cases, lateral distal tibial angle improved 6 degrees and 10 degrees (average change, 0.44 degrees/month). Mechanical axis deviation improved an average 25.4 mm (range, 0-74 mm) or 1.73 mm/month (range, 0-6.4 mm/month). Ten patients (13 limbs) had more than 10 months of radiographic follow-up after plate removal; ten limbs showed average rebound of 15.7 mm or 1.0 mm/month, indicating the reversibility of this procedure. Four cases failed to achieve correction.

CONCLUSIONS

The eight-Plate effectively treats angular deformities in growing children and is less likely to extrude spontaneously than the Blount staple. We have not observed growth disturbance or other complications related to this device.

Possible mistakes in prediction of bone maturation in fibular hemimelia by Moseley chart

The purpose of this study was to establish a nomogram in order to predict limb length discrepancies in children with unilateral fibular hemimelia more accurately. In 31 children with unilateral fibular hemimelia the femoral-tibial length and skeletal age were determined an average of seven times per case by sequential radiographs during growth. From the data, a skeletal age nomogram was developed which shows a steeply declining mean skeletal age pattern in unilateral fibular hemimelia (the slope in girls was -0.59 and in boys -0.64). This nomogram crosses the normal mean skeletal age line of the Moseley straight-line graph at 10.5 years in girls and at 12 years in boys, and continues to decline until maturity. The results demonstrate an abnormal skeletal maturation process in patients with unilateral fibular hemimelia. The consistently declining steep skeletal age nomogram in unilateral fibular hemimelia makes prediction of skeletal maturity and limb length discrepancy inaccurate by the standard predictive methods particularly when using early skeletal ages. The skeletal age nomogram from our data determines skeletal maturation in children with unilateral fibular hemimelia more accurately, and allows a correct prediction of limb length discrepancy.

Correcting genu varum and genu valgum in children by guided growth

A total of 25 children (37 legs and 51 segments) with coronal plane deformities around the knee were treated with the extraperiosteal application of a flexible two-hole plate and screws. The mean age was 11.6 years (5.5 to 14.9), the median angle of deformity treated was 8.3° and mean time for correction was 16.1 months (7 to 37.3). There was a mean rate of correction of 0.7° per month in the femur (0.3° to 1.5°), 0.5° per month in the tibia (0.1° to 0.9°) and 1.2° per month (0.1° to 2.2°) if femur and tibia were treated concurrently. Correction was faster if the child was under 10 years of age (p = 0.05). The patients were reviewed between six and 32 months after plate removal. One child had a rebound deformity but no permanent physeal tethers were encountered.

The guided growth technique, as performed using a flexible titanium plate, is simple and safe for treating periarticular deformities of the leg.

Advances in growth plate modulation for lower extremity malalignment (knock knees and bow legs)

PURPOSE OF REVIEW

Lower extremity angular deformities are among the most common nontraumatic conditions in children being referred to pediatric orthopedists. Understanding of this abnormality is essential for pediatricians and primary caregivers. There is a development in the surgical management of these problems that has improved the quality of care of affected children and adolescents.

RECENT FINDINGS

In recent years, we have improved our understanding of consequences of lower limb angular deformities on knees. New treatment options for angular deformity include the method of 'guided growth' using small, extraphyseal tension band plates.

SUMMARY

The development of this surgical technique for growth plate manipulation for the treatment of angular deformities of knees has expanded the indications for surgical management and has a potential to decrease the incidence and the severity of complications.

Percutaneous hemi-epiphysiodesis using transphyseal cannulated screws for genu valgum in adolescents

PURPOSE

The purpose of this study was to assess percutaneous femoral distal hemi-epiphysiodesis using transphyseal cannulated screws in order to correct valgus angular deformities of the knee in pediatric and adolescent patients.

METHODS

This is a prospective longitudinal study in which our experience with 52 patients is described.

RESULTS

We evaluated 100 knees surgically managed for pathologic genu valgum over a 68-month period. The average age at surgery for boys and girls was 14 years and 7 months (range 12.7-15.1 years) and 13 years and 6 months (range 12.9-14.8 years), respectively. The pre-surgical tibiofemoral (T-F) angle was measured at between 14.17° and 35.3°, and the postoperative T-F was measured at between 6.2° and 15.8° (7.2° ± 0.65°, mean ± standard deviation), for an average correction of 0.73° ± 0.45° per month). The mean follow-up after surgery was 3.2 years (range 2.3-5.3 years).

CONCLUSIONS

We demonstrate a simple, fast and reproducible surgical technique for percutaneous epiphysiodesis with low morbidity, rapid rehabilitation and a rapid return to school and sports activities. We experienced no complications, such as overcorrection, undercorrection, postoperative hematoma or infection. We conclude that percutaneous screw epiphysiodesis is an excellent option for the treatment of genu valgum in adolescents.

Mechanical axis following staple epiphysiodesis for limb-length inequality

BACKGROUND

Staple epiphysiodesis is an option for the treatment of limb-length discrepancies, but it is not without complications. The purpose of this study was to review the outcomes of staple epiphysiodesis, including changes in the mechanical axis.

METHODS

The study included patients who underwent, between 1990 and 2005, staple epiphysiodesis of the femur or tibia, or both, to address limb-length discrepancy. We reviewed preoperative, postoperative, and final long standing anteroposterior radiographs of fifty-four patients to assess limb-length discrepancy, shifts in the mechanical axis, changes in the mechanical axis zone, and changes in the anatomic lateral distal femoral angle and the medial proximal tibial angle. Postoperative radiographs were also reviewed to assess the adequacy of staple placement.

RESULTS

Three staple epiphysiodesis groups were identified: fifteen patients who underwent a distal femoral staple epiphysiodesis, eighteen who underwent a proximal tibial procedure, and twenty-one who underwent combined distal femoral and proximal tibial procedures. Fifty percent (twenty-seven) of the fifty-four patients showed a shift in the mechanical axis of > or =1 cm as compared with the preoperative measurement. Eighty-nine percent of these large shifts were varus in nature. The proximal tibial and combined epiphysiodeses resulted in significantly larger shifts in the mechanical axis (p = 0.002 and p = 0.006, respectively) and zone changes (p = 0.009 and p = 0.006, respectively) than did the distal femoral procedures. Six patients ultimately underwent a high tibial osteotomy to correct a post-stapling varus deformity. The proximal-lateral aspect of the tibia was by far the most common location for inadequate staple placement.

CONCLUSIONS

Mechanical axis deviation is common following staple epiphysiodesis for the treatment of limb-length discrepancy. Proximal tibial and combined distal femoral and proximal tibial staple epiphysiodeses, even if done well technically, lead to clinically relevant shifts in the mechanical axis of the lower extremity more than half of the time. Distal femoral staple epiphysiodesis may still be a safe option for the treatment of limb-length discrepancy, but we advise caution when utilizing proximal tibial staple epiphysiodesis to treat limb-length inequality.

Physeal stapling versus 8-plate hemiepiphysiodesis for guided correction of angular deformity about the knee

BACKGROUND

Angular deformity in the lower extremities results in cosmetic deformity, gait disturbance, pain, and early joint degeneration. Corrective osteotomy is the gold standard for angular deformity, but is a major surgical intervention with significant incidence of complication. For these reasons, hemiepiphysiodesis is an attractive alternative in the growing child to allow "guided growth" to correct the angular deformity. Physeal stapling has proven success, but hardware prominence or failure has been problematic. Recently, the tension band plate construct ("8-plate") has been promoted for hemiepiphysiodesis, citing ease of surgical technique and more rapid rate of correction. We sought to test the claim that the 8-plate effected a more rapid correction of angular deformity with a lower complication rate.

METHODS

Hemiepiphysiodesis for angular deformity in 63 lower extremities from 2000 to 2007 were retrospectively reviewed. Thirty-nine limbs received staple hemiepiphysiodesis and 24 received 8-plate hemiepiphysiodesis. Angular measurements were compared preoperatively, during the first year postoperatively, and at the time of hardware removal or skeletal maturity. Complications requiring additional surgery for the correction of angular deformity were noted in each group.

RESULTS

There was no difference between the 2 groups in the rate of correction (approximately 10 degrees/y, P=0.48). Complication rates were similar (12.8% vs. 12.5%, P=1.0). Patients with abnormal physes (eg, Blount disease, skeletal dysplasias) had a higher complication rate (27.8% vs. 6.7% for patients with normal physes, P=0.04) with no difference between the 8-plate and staple groups (P=1.0). The patients in the 8-plate group were significantly younger than those in the staple group (P=0.04).

CONCLUSIONS

The 8-plate is as effective as staple hemiepiphysiodesis for guided correction of angular deformity with respect to rate of correction and complications, even in somewhat younger patients. Higher complication rates are observed in patients with pathologic physes.

Epiphyseal stapling of the proximal tibia for idiopathic genu valgum

PURPOSE

The purpose of this study is to evaluate the clinical and radiological outcomes of hemiepiphysiodesis with a single medial staple of the proximal tibia in idiopathic genu valgum angular correction.

METHODS

A retrospective review was performed identifying nine adolescents (18 knees) treated for idiopathic adolescent genu valgum by means of a bilateral hemiepiphysiodesis with a single staple of the proximal tibia. The intermalleolar distance (IMD) and hip-knee-ankle angle were measured at skeletal maturity.

RESULTS

The IMD and hip-knee-ankle angle were reduced in all patients at skeletal maturity.

CONCLUSION

Hemiepiphysiodesis with a single medial staple of the proximal tibia seems to be a reliable and safe alternative method to achieve correction of an idiopathic genu valgum.

Temporary hemiepiphysiodesis for idiopathic genua valga in adolescents: percutaneous transphyseal screws (PETS) versus stapling

BACKGROUND

Genua valga are not merely a cosmetic problem but also predispose to gonarthrosis in adult life. In our retrospective study of 25 patients, we reviewed our present technique of medial hemiepiphysiodesis using percutaneous screws and compared it with our own results of stapling.

METHODS

Clinical evaluation was performed by estimation of the intermalleolar distance, radiological assessment by measuring the hip-knee-ankle angle until skeletal maturity. Average chronological age at the time of surgery was 14.5 years for boys and 12.7 years for girls. Average bone age (main indicator for timing of surgery) was 14.3 years for boys and 12.8 years for girls.

RESULTS

There is an average rebound phenomenon after removal of the screws of 2 degrees in one third of our patients. In another third of our patients' population, however, we observed a progression of correction of an average of 2 degrees. More than 90% of the patients were satisfied. None received revision surgery. There was only one person with an uncosmetic scar.

CONCLUSIONS

Percutaneous screws as treatment of idiopathic genua valga in children seem to be as safe and reliable as stapling but are a less invasive and a more cosmetic treatment.