The correction of genu valgum by epiphysial stapling

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Hemiepiphysiodesis for Idiopathic Genu Valgum Using Physeal Staples Versus Tension-Band Plating: A Systematic Review

This review assesses the outcomes of hemiepiphysiodesis in patients with idiopathic genu valgum (IGV) treated with physeal staples vs tension-band plating (TBP). A systematic review of the literature was conducted to identify articles examining the use of physeal staples vs TBP for the treatment of IGV in skeletally immature patients. No significant difference in overall mean deformity correction (P=.92) or correction per month (P=.61) was observed between groups. Repeat hemiepiphysiodesis was more common in patients who underwent TBP vs physeal staples (P=.05). Tension-band plating did not yield significantly improved results compared with physeal staples in skeletally immature patients with IGV. [Orthopedics. 2019; 42(6):e485-e491.].

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.

Temporary epiphyseodesis for limb-length discrepancy. 8- to 15-year follow-up of 34 children

BACKGROUND AND PURPOSE

For the treatment of leg-length discrepancies (LLDs) of between 2 and 5 cm in adolescent patients, several epiphyseodesis options exist and various complications have been reported. We reviewed the 8- to 15-year outcome after temporary epiphyseodesis in patients with LLD.

PATIENTS AND METHODS

34 children with LLD of up to 5 cm were included in the study. Mean age at epiphyseodesis was 12.8 (10-16) years. Temporary epiphyseodesis was performed with Blount staples or 8-plates. The LLD was reviewed preoperatively, at the time of implant removal, and at follow-up. Every child had reached skeletal maturity at follow-up. Long-standing anteroposterior radiographs were analyzed with respect to the mechanical axis and remaining LLD at the time of follow-up. Possible complications were noted.

RESULTS

The mean LLD changed from 2.3 (0.9-4.5) cm to 0.8 (-1.0 to 2.6) cm at follow-up (p<0.001). 21 patients had a final LLD of <1 cm, and 10 had LLD of <0.5 cm. At the time of follow-up, in 32 patients the mechanical axis crossed within Steven's zone 1. No deep infections or neurovascular lesions were seen. 4 implant failures occurred, which were managed by revision.

INTERPRETATION

Temporary epiphyseodesis is an effective and safe option for the treatment of LLD. The timing of the procedure has to be chosen according to the remaining growth, facilitating a full correction of the LLD. If inaccurate placement of staples is avoided, substantial differences between the mechanical axes of both legs at skeletal maturity are rare.

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.

Re-alignment-procedures for skeletal dysplasia in three patients with genetically diverse syndromes

OBJECTIVE

Disruption to endochondral ossification leads to delayed and irregular bone formation and can result in a heterogeneous group of genetic disorders known as osteochondrodysplasias. These genetic disorders arise through disturbances in the complex processes of skeletal growth causing development of unsightly skeletal deformities. METHODS : Each syndrome was diagnosed on the basis of detailed clinical and radiographic assessment. Lower limb deformities were the prime presenting feature.

RESULTS

Here are presented three patients with diverse genetic syndromes, namely Wolcott-Rallison syndrome (WRS), Kniest dysplasia (KD) and Desbuquois dysplasia (DS). Genetic testing was performed in the patients with WRS and DS. The diagnosis of KD was made purely on a clinical and radiographic basis. Variable orthopaedic interventions to realign these patients' lower limbs were implemented with the aim of improving their balance and gait.

CONCLUSIONS

The aim of this paper is twofold. The first part is to outline the importance of diagnosing the causes of various skeletal abnormalities in patients with osteochondrodysplasias by phenotypic and genotypic characterization. The second part is to demonstrate our techniques for surgical corrections in patients with joint laxity and malalignment and show how far techniques for growth modulation, re-alignment and ligament reconstruction have advanced.

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.

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.

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.

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.

Hemiepiphysiodesis for the correction of angular deformity about the knee

BACKGROUND

It is generally accepted that the presence of angular deformity about the knee that persists into the preadolescent years will not correct spontaneously. The goal of this study was to review our experience with hemiepiphysiodesis and physeal stapling for the correction of angular deformity to establish the efficacy of these procedures and to determine their indications and the rate of correction.

METHODS

A retrospective review of 48 patients undergoing hemiepiphysiodesis or physeal stapling about the knee was performed. Patients were included if they had at least 2 years of documented follow-up without an osteotomy.

RESULTS

The average follow-up was 30.4 months (range, 24-52 months). Genu varum was identified in 33 patients, genu valgum in 14 patients, and a windswept deformity in 1. Of the 52 limbs with genu varum, 35 were secondary to Blount disease. The group with genu varum unrelated to Blount disease presented a change in the mechanical axis from a mean of -32 degrees at surgery to a mean of - 13 degrees. The patients with Blount disease presented a change in the mechanical axis from a mean of -19 degrees at surgery to a mean of -16 degrees. The group with genu valgum presented a change in the mechanical axis from a mean of 20 degrees at surgery to a mean of 2 degrees.

CONCLUSIONS

Hemiepiphysiodesis is an effective means for correcting angular deformity about the knee in skeletally immature patients with both genu valgum and genu varum, so long as the genu varum is unrelated to Blount disease. Hemiepiphysiodesis is effective in preventing the progression of deformity in patients with Blount disease.

LEVEL OF EVIDENCE

Therapeutic-Level IV.

Correction of angular deformities of the knee by percutaneous hemiepiphysiodesis

Predicting patients' remaining angular growth and timing for hemiepiphysiodesis are crucial for correcting coronal plane knee deformities in children. We asked whether the Angular Deformity Versus Growth Remaining Chart predicted correction of coronal angular deformities of the knee in children. Serial orthoroentgenograms and the predictive chart were used to time percutaneous hemiepiphysiodesis, and the children were followed until skeletal maturity. Twenty-five consecutive children (35 extremities) with a mean skeletal age of 13 years (range, 9.6-16 years) had percutaneous hemiepiphysiodeses as described by Bowen and Johnson, and were followed up until skeletal maturity. At skeletal maturity, correction of varus and valgus coronal plane deformities were within 2 degrees (range, 0 degrees - 6 degrees) of the predicted value. The maximum limb-length discrepancy resulting from the procedure was 1.5 cm. The only complication was failure of a physeal bar formation hemiepiphysiodesis; this was treated successfully with a repeat percutaneous hemiepiphysiodesis. The percutaneous hemiepiphysiodesis is effective and has a low complication rate. Angular correction and timing for hemiepiphysiodesis can be predicted by using the Angular Deformity Versus Growth Remaining Chart in children with coronal plain knee deformities.

The effect of temporary hemiepiphyseal stapling on the growth plate: a radiologic and immunohistochemical study in rabbits

The purpose of this study was to investigate the effect of temporary hemiepiphyseal stapling on the bone geometry and proliferative activity of the physis in immature rabbits. Proximal medial epiphyseal stapling of the right tibia was performed in 46 6-week-old New Zealand white rabbits. The rabbits were assigned randomly into two groups. In group 1, the staples were inserted extraperiosteally and the rabbits were killed at the end of 3 weeks. In group 2, the staples were fixed subperiosteally (group IIA) or extraperiosteally (group IIB), the staples were removed at the end of 3 weeks, and the rabbits were killed at the end of 6 weeks. The articular line-diaphysis angle (ALDA) was significantly increased with 3 weeks of stapling. After the removal of staples, while ALDA continued to worsen in group IIA, it improved in group IIB. Bone was observed to bridge the physis in group IIA. However, the proliferative activity of the physis continued. Temporary hemiepiphyseal stapling is a safe and effective method for control of physeal growth of long bones before skeletal maturity. However, it is of paramount importance not to disturb the periosteum during stapling.