Percutaneous epiphyseodesis

Are percutaneous epiphysiodesis and Phemister technique effective in the treatment of leg-length discrepancy? A systematic review

Epiphysiodesis is considered the preferred treatment for children predicted to have leg length discrepancies (LLDs) 2-5 cm at maturity. The aim of this study was to systematically review the existing literature on the effectiveness of permanent epiphysiodesis for LLD treatment, and secondarily to address the reported complications of permanent epiphysiodesis techniques. This systematic review was performed according to PRISMA guidelines. We searched MEDLINE (PubMed), Embase, Cochrane Library, Web of Science and Scopus for studies on skeletally immature patients with LLD treated with permanent epiphysiodesis. The extracted outcome categories were effectiveness of epiphysiodesis (LLD measurements pre/post-operatively, successful/unsuccessful), physeal fusion/arrest, and complications that were graded on severity. Forty-nine studies (3051 patients) were included, 1550 underwent Phemister/modified Phemister epiphysiodesis and 1501 percutaneous epiphysiodesis (PE). Total successful permanent epiphysiodesis surgeries (16 studies) were 73.7% (516/700). Only 13 out of 23 studies had a mean final LLD of less than 1.5 cm. In total, 17.5% (513/2936) of complications were reported. 57 angular deformities were reported (1.9%). Phemister technique had higher percentage of complications (39%) than PE (19.1%) in total, but when failure to achieve adequate reduction in LLD was not included, complication rates for both were close to 14%. However, severe complications were 10.2% for Phemister group and 5.1% for PE. The high complication rates and the relative low success rate call for optimization of the timing and the applied techniques when treating LLD with permanent epiphysiodesis. Phemister technique was found to have higher percentage of severe complications than PE. Registration: PROSPERO (CRD42023435177).

[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.

Distal Femur Anterior Hemiepiphysiodesis for Fixed Knee Flexion Deformity in Neuromuscular Patients: A Systematic Review

BACKGROUND

In the past decade, distal femur anterior hemiepiphysiodesis for fixed knee flexion deformity has gained popularity. In this study, we aim to systematically review the literature on this technique as a treatment for fixed knee flexion deformity in patients with neuromuscular disorders.

METHODS

A systematic review was performed in the following databases: PubMed, Embase, and Medline. The inclusion criteria included anterior hemiepiphysiodesis of the distal femur for patients with neuromuscular disorders and fixed knee flexion deformities.

RESULTS

Our search yielded 419 titles. A total of 12 articles were qualified for final review based on the inclusion and exclusion criteria. The total number of patients was 279, with 483 knees corrected. The male to female ratio was 2.1:1, and the mean age of the patients was 11.3 ± 1.4 years (range 4-17 years). The mean preoperative flexion deformity was 23.1° ± 10.0° (range 10°-90°). The mean residual flexion deformity at the final follow-up was 8.6° ± 9.0° (range 0°-32.5°), which corresponds to a statistically significant decrease compared with the preoperative deformity (p < 0.05).

CONCLUSION

Anterior hemiepiphysiodesis for fixed knee flexion deformity provides favourable outcomes with low complication rates in patients with neuromuscular disorders. Future studies should focus on comparing the long-term outcomes of the different metal implants used for these operations.

LEVEL OF EVIDENCE

Level III. See Instructions for Authors for a complete description of levels of evidence.

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

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

A new standard radiographic reference for proximal fibular height in children

Background and purpose - To date there is a lack of studies defining the anatomical position of the proximal fibula. This is especially relevant when planning surgical interventions affecting the knee joint such as permanent or temporary epiphysiodesis to correct leg length discrepancies or angular deformities in growing patients. The goal of this study is to establish a standardized measurement technique and radiological reference values for the position of the proximal fibula in children.Patients and methods - 500 measurements were performed in calibrated long standing anteroposterior radiographs of 256 skeletally immature patients (8-16 years; 233 female, 267 male legs). As a radiographic reference in the frontal plane, the distance between the center of the proximal tibial growth plate and a line tangential to the tip of the fibular head and horizontal to the imaging plane was measured (dPTFH).Results - The average value of dPTFH in the studied population (median age 12 years) was -2.7 mm (SD 3, CI -3.0 to -2.5) and normally distributed (p = 0.1). There were no clinically significant sex or age-dependent differences. The inter-rater reliability analysis showed excellent ICC values (ICC = 0.88; CI 0.77-0.93).Interpretation - This study provides a new radiographic reference value to assess the position of the proximal fibula in relation to the proximal tibia in children and adolescents. This reference can aid preoperative decision-making as to whether additional fibular epiphysiodesis is necessary when performing tibial epiphysiodesis to correct moderate leg-length discrepancies.

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.

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

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

Lateral hemiepiphysiodesis of the first metatarsal for juvenile hallux valgus

BACKGROUND

Juvenile hallux valgus (JHV) frequently results in an impaired quality of life because of pain and deformity. We used a validated clinical score to investigate the efficacy of lateral hemiepiphysiodesis of the first metatarsal base as a treatment for JHV.

METHODS

We conducted a prospective, nonrandomized, single center cohort study of children who underwent lateral hemiepiphysiodesis for 31-IV, with a clinical and radiologic follow-up of at least 2 years. The efficiency of the procedure was assessed with the Hallux Metatarsophalangeal Interphalangeal Scale (HMIS), the metatarsophalangeal angle (MPA), and intermetatarsal angle (IMA).

RESULTS

Twelve patients (22 feet) with JHV were treated by lateral hemiepiphysiodesis between 2012 and 2015. Average age at surgery was 10 years, and average follow-up was 3.5 years. The average HMIS score increased from an average of 56 at baseline, to 92 at last follow-up ( p < 0.01). The average IMA decreased by 2°, from 13° preoperatively to 11° postoperatively. Average MPA decreased from 26° at baseline to 22° after surgery. No complications occurred in the immediate postoperative period, and no patient needed an additional procedure.

CONCLUSION

The HMIS score was significantly improved after lateral hemiepiphyslodesis, with a clear improvement in pain and functional impairment at last follow-up. We noted a stabilization of the IMA and MPA, but the radiologic benefit did not reach statistical significance. Our data support the use of lateral hemiepiphysiodesis as an effective and safe treatment of JHV.

Long-term results and comparison of the Green-Anderson and multiplier growth prediction methods after permanent epiphysiodesis using Canale's technique

PURPOSE

The aim of the study was to evaluate the accuracy and radiographic outcomes of Canale's method in patients with idiopathic leg-length discrepancy (LLD) following percutaneous epiphysiodesis. The accuracy of two common growth prediction methods was assessed.

METHODS

A total of 18 patients with 26 affected bones (eight distal femur, two proximal tibia, five combined) were clinically and radiologically analyzed after reaching skeletal maturity. We compared the final effect of epiphysiodesis at maturity with the expected effect of epiphysiodesis before surgery; these measures were calculated using the Green-Anderson and multiplier methods, respectively. We furthermore compared pre- and postoperative frontal and lateral plane radiographs.

RESULTS

The average LLD was 21.2 mm before surgery and 7.9 mm after epiphysiodesis. The final effect of both methods was not significantly different compared with the expected effect of epiphysiodesis before surgery. However, the prediction by the Green-Anderson method was closer to the definitive epiphysiodesis effect. The frontal plane radiographic deformity parameters did not change significantly after epiphysiodesis. The postoperative sagittal plane radiographic deformity parameters were in the normal range.

CONCLUSION

The Canale technique is a reliable method to reduce LLD in children. With regards to growth prediction, the Green-Anderson method using bone age seems to be more accurate than the multiplier method using chronological age. However, a relative over-estimation was observed with both methods in several cases, which might result in an insufficient correction.

LEVEL OF EVIDENCE

IV, Therapeutic study.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

III.

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

BACKGROUND

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

THERAPY

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

CONCLUSION

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

Dual 8-plate technique is not as effective as ablation for epiphysiodesis about the knee

BACKGROUND

Lower extremity length inequality can be problematic in children and is often addressed surgically. Several techniques have traditionally been utilized for epiphysiodesis, the goal being physeal ablation. Recently, 8-plates, initially developed for hemiepiphysiodesis, have been extended to epiphysiodesis by placing the plates on both medial and lateral sides of the physis. No prior studies have compared 8-plates with physeal ablation techniques.

METHODS

Between January 2003 and August 2009, 27 patients underwent epiphysiodesis surgery using either physeal ablation or 8-plate technique. Sixteen patients had physeal ablation and 11 had dual 8-plates. A retrospective chart review sought demographic data, outcomes, and complications. Radiographs were reviewed to measure pretreatment and posttreatment limb lengths.

RESULTS

The median improvement in limb length discrepancy was 15.5 mm in the physeal ablation group and 4 mm in the 8-plate group (P<0.001). This difference was maintained following linear regression factoring out the effect of time (10.78 mm for ablation vs. 5.62 mm for 8-plates; P=0.016). There was no statistically significant difference in complication rate between the groups (P=0.112).

CONCLUSIONS

Our study demonstrated physeal ablation to be a significantly superior treatment compared with dual 8-plates for epiphysiodesis. Despite theoretical advantages of 8-plates to perform epiphysiodesis about the knee, this study does not recommend the use of medial and lateral 8-plates to effect epiphysiodesis.

LEVEL OF EVIDENCE

Therapeutic III.

Percutaneous epiphysiodesis in the proximal tibia by a single-portal approach: evaluation by radiostereometric analysis

PURPOSE

We modified the method for tibial epiphysiodesis by solely using a lateral approach to the physis. From this small-incision approach, the lateral as well as the medial part of the tibial physis were ablated. The aim of our study was to see if this operative technique might be as effective as a bilateral approach, and reduce the operation time and usage time of the image intensifier. The epiphysiodeses were monitored by radiostereometric analysis (RSA), which is a well-established method for the analysis of micro movements and has been used to monitor percutaneous epiphysiodesis with the bilateral approach. There are no reports in the literature comparing single- with double-portal approaches for percutaneous epiphysiodesis evaluated by RSA.

METHODS

Twenty children were treated by percutaneous epiphysiodesis for leg length discrepancies ranging from 15 to 70 mm, comprising 14 boys and 6 girls with a mean age of 13 (11-15) years. The timing of epiphysiodesis was determined by using Moseley's straight-line graph and Paley's multiplier method. For the tibial epiphysiodesis, ten patients were operated with a single surgical approach from the lateral side (Group I) and ten patients were operated with a surgical approach from both the medial and the lateral sides (Group II). The percutaneous epiphysiodesis was monitored by RSA, a method which allows analysis of the three-dimensional dynamics of the epiphysis relative to the metaphysics. RSA examinations were performed postoperatively and after 6 weeks, 12 weeks, and 6 months.

RESULTS

From 0 to 6 weeks after epiphysiodesis, the mean longitudinal growth across the operated physis in the tibia in Group I was 0.26 (0.01-0.6) mm. In Group II, the mean growth for the first 6 weeks after surgery was 0.17 (0.01-0.5) mm. During the time period from 6 weeks to 12 weeks after surgery, there was a mean growth of 0.06 (0.00-0.18) mm in Group I and 0.03 (0.00-0.2) mm in Group II. The mean growth from 0 to 6 weeks after epiphysiodesis for all patients was 0.22 mm, which corresponds to 30 % of the normal growth rate. From 6 to 12 weeks, the mean growth for all patients was 0.046 mm, i.e., 6 % of the normal growth rate. From 12 weeks to 24 weeks, no significant growth across the operated physis was observed in neither Group I nor Group II. The mean surgical time was 26 (21-30) min in Group I and 43 (35-48) min in Group II. This difference was statistically significant (p = 0.006). The mean time for use of the image intensifier during surgery was 202 (191-236) s in Group I and 229 (185-289) s in Group II (p = 0.013).

CONCLUSIONS

In our study, a single-portal technique from the lateral side for percutaneous epiphysiodesis of the proximal tibia was as effective as the double-portal technique. Actual growth arrest appeared within 12 weeks after surgery. A single-portal technique for epiphysiodesis of the tibia is a safe technique, with less surgical time and less time for image intensification compared to the double-portal technique.

Chronologic change in the growth plate after radiofrequency-induced thermal injury: MRI-histologic correlation

OBJECTIVE

The purposes of this study were to assess chronologic changes in normal growth plate after radiofrequency-induced thermal injury and to evaluate the feasibility of MRI for revealing alteration of the growth plate.

MATERIALS AND METHODS

Radiofrequency ablation was performed on the right proximal tibia of 13 8-week-old New Zealand White rabbits. An 18-gauge cooled-tip electrode with a 5-mm active tip was placed distal to the physis under fluoroscopic guidance. MRI, including T1- and T2-weighted images, gradient-recalled echo images, and contrast-enhanced T1-weighted images, was performed 2, 4, and 12 weeks after ablation. Rabbits were sacrificed 2 (n = 4), 4 (n = 4), and 12 weeks (n = 5) after ablation. The sequential changes in the ablated zone, the injured physis, and the nonablated portion of the physis were correlated between MRI features and histologic results.

RESULTS

Diameter of the nonenhancing lesion on MR images strongly correlated with the size of the region of coagulation necrosis at gross examination. The intraclass correlation coefficients were 0.98 and 0.94 for the long and short axes (p < 0.001). On gradient-recalled echo images, physial conspicuity was less in the injured physis than in the nonablated portion and less in the ablated than the control tibia. Physial conspicuity was graded for comparison with physial thickness at microscopic examination. The thickness of the physis was less in the ablated than in the control tibia 4 and 12 weeks after treatment (p < 0.05, paired Student t test). The cartilage column of the injured physis was delaminated 2 weeks after treatment, and a bone bridge through the injured physis was detected at 4 weeks.

CONCLUSION

Radiofrequency-induced thermal injury causes early closure of the physis. MRI can depict the extent of radiofrequency-induced thermal injury and alterations in the physis that lead to early closure.

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.

Percutaneous radiofrequency epiphysiodesis in a rabbit model: a pilot study

BACKGROUND

Techniques for epiphysiodesis have evolved from open surgical techniques requiring direct observation of the physis to percutaneous techniques performed with fluoroscopy.

QUESTIONS/PURPOSES

Our purposes were to (1) describe a new minimally invasive surgical technique used to achieve epiphysiodesis using radiofrequency ablation, (2) document the effect of radiofrequency ablation on tibia length at 2, 6, and 12 weeks after ablation in a skeletally immature rabbit model, and (3) assess the effects of radiofrequency ablation on the histologic appearance of the proximal tibia physis and proximal tibia articular cartilage.

MATERIALS AND METHODS

We performed epiphysiodesis of the rabbit proximal tibia on 15 skeletally immature male New Zealand White rabbits using a 22-gauge radiofrequency probe. The probe was positioned percutaneously and heated to 90 degrees C for 4 minutes on the medial and lateral (1/2) of the physis. The opposite tibia was used as a control. Five animals were sacrificed at 2, 6, or 12 weeks postoperatively. Tibia length was compared using Faxitron(R) radiographs and electronic calipers. Histology of the growth plate was assessed with light microscopy.

RESULTS

We observed differences in tibia length between 4.16 mm and 11.59 mm (average 7.86 mm) at 12 weeks. The proximal tibia physis closed radiographically and histologically in all animals by 12 weeks. Histologic analysis showed no evidence of articular cartilage injury.

CONCLUSIONS

This technique was reproducible and resulted in bone fusion of the rabbit proximal tibial growth plate. The use of radiofrequency ablation as described in this report may be used as an alternative to other surgical epiphysiodesis techniques.

CLINICAL RELEVANCE

This technique may be useful for epiphysiodesis of small tubular bones of the hands and feet in humans.

[Arteriovenous malformations]

Arteriovenous malformations are serious high-flow vascular malformations. Four progressive stages have been described: dormancy, expansion, destruction and heart failure. Progression from one stage to another is not systematic but depends on events - physiological or traumatic, sometimes iatrogenic. Pulsed Doppler imaging of venous waveforms and magnetic resonance imaging (MRI) are the most informative examinations for both diagnosis and follow-up of arteriovenous malformations.Arteriography and angio-MRI help guide treatment decisions. Treatment of the malformation must not be envisioned until it reaches a symptomatic stage. It most often combines an endovascular procedures and wide surgical excision. A syndromic form must be considered in cases of systemic angioma.

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.

Efficacy and safety of percutaneous epiphysiodesis

BACKGROUND

The aims of this study were to evaluate outcomes of percutaneous epiphysiodesis, as described by Bowen, in 97 patients and to assess complications and determine whether the effect of the epiphysiodesis will accurately follow the Moseley chart predictions.

METHODS

A total of 97 patients were reviewed retrospectively. Fifty-six girls and 41 boys, with a mean skeletal age of 12.6 years (range, 10-16 years) at the time of operation, were followed up until skeletal maturity, a mean of 3.8 years (range, 1-10 years).

RESULTS

The mean residual leg length discrepancy (LLD) in 88 patients at maturity was 1.3 cm (range, 0-3.5 cm). In 9 patients, the epiphysiodesis was combined with a femoral lengthening or femoral shortening. The residual leg length discrepancy in these 9 patients was 3.3 cm at maturity (range, 0-6.5 cm). Minor complications including knee effusion (n = 2), superficial wound infection (n = 1), and exostosis (n = 3) occurred in 6 patients. Failure of the epiphysiodesis was the only major complication seen (n = 3).

CONCLUSIONS

This study shows that complications are infrequent when performing percutaneous epiphysiodesis and that the Moseley straight-line method accurately and efficaciously predicted the timing for percutaneous epiphysiodesis in all but one patient who had unpredictable growth from hemihypertrophy secondary to a hemangiomatosis.

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

The purpose of this study was to evaluate the technique of screw epiphysiodesis for effectiveness, predictability, and reversibility. We reviewed the cases of our first 60 patients (105 physes) treated with percutaneous screw epiphysiodesis or hemiepiphysiodesis. All cases were followed up to maturity or screw removal if growth remained after full correction. A total of 30 patients underwent the procedure for limb length inequality. Final inequality was compared with the predicted epiphysiodesis effect. A total of 30 patients (66 physes) underwent screw hemiepiphysiodesis for the correction of angular deformity. The degree of correction per month was calculated, the reversibility of the procedure was analyzed, and complications were evaluated. In the length group, at the end of treatment, the final limb length difference in the femur averaged 0.15 cm (SD, +/-0.37 cm) from the epiphysiodesis effect predicted by using the multiplier method. In the tibia, this difference was 0.05 cm (SD, +/-0.57 cm). In the angular group, the average correction in the distal femur was 6.91 degrees (SD, +/-3.75 degrees) or 0.75 degrees per month (SD, +/-0.45 degrees per month). In the proximal tibia, the average correction was 3.88 degrees (SD, +/-3.57 degrees) or 0.37 degrees per month (SD, +/-0.34 degrees per month). In all 13 cases where the screws were removed at the time of angular correction with significant growth remaining, growth resumed. Complications were minor and were related to incorrect placement of screws or minor hardware irritation. Percutaneous screw epiphysiodesis is a reliable, minimally invasive method with reliable results in both length and angular correction, with minimal morbidity, and with an acceptable complication rate.

Percutaneous epiphysiodesis of the lower extremity: a comparison of single- versus double-portal techniques

BACKGROUND

Percutaneous epiphysiodesis can be achieved using a single-portal or a double-portal technique. This study was performed to demonstrate any differences in outcomes, especially complications, between the 2 techniques.

METHODS

This was a retrospective review of cases at a single institution from 1983 to 2002 that yielded 336 children, in which 63 qualified for the study with at least 3 years of clinical follow-up. A comparison was performed through clinic chart review and radiographic measurement outcomes, searching for patient satisfaction, surgical time, and complications.

RESULTS

Minor complications included superficial infections, hematomas and effusions, whereas major complications included failure to arrest growth, partial arrest with angular deformity, fracture, and joint penetration. The single-portal group had an overall complication rate of 33.3%, with a major complication rate of 20% per patient. The double-portal group had a similar overall complication rate but only a 5.3% major complication rate per patient. There was no significant difference in patient demographics, operative times, or subjective complaints.

CONCLUSIONS

Many methods of percutaneous epiphysiodesis exist in the literature that report low complication rates that are comparable with the complication rate of the original open procedure. Our study demonstrated a significantly higher rate of complications (both minor and major) compared with results previously reported. Moreover, the use of a single-portal approach increased the possibility of major complication by nearly 4-fold as compared with the use of a double-portal approach that avoids crossing the midline of the physis.

Vascular malformations. Part II: associated syndromes

Cutaneous vascular malformations are rare disorders representing errors in vascular development. These lesions occur much less commonly but are often confused with the common infantile hemangioma. It is important to properly diagnose vascular malformations because of their distinct differences in morbidity, prognosis and treatment. Vascular malformations may be associated with underlying disease or systemic anomalies. Several of these syndromes are well defined and can often be distinguished on the basis of the flow characteristics of the associated vascular malformation.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be able to better recognize underlying diseases or systemic anomalies that may be associated with vascular malformations. Participants should also better understand the various syndromes and conditions discussed and become more familiar with their management.

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.

Magnetic Resonance Imaging of Remaining Physis in Partial Physeal Resection With Graft Interposition in a Rabbit Model

OBJECTIVE

The purpose of this study was to evaluate the effect of graft interposition into a physeal defect on the remaining physis.

MATERIALS AND METHODS

Bilateral partial physeal defects were made in the medial half of the proximal tibiae of 8-week-old New Zealand white rabbits (n=25). Biologic material (autogenous chondrocytes derived from perichondrial cells incorporated into beads) was implanted in the left-sided physeal defect, and right-sided untreated tibial defects were used as controls. Magnetic resonance (MR) imaging was obtained at 2, 4, 8, 12, and 16 weeks after operation using a 1.5-tesla MR unit. T1WI, T2WI, and gradient-recalled echo (GRE) images were obtained in the coronal plane. The MR features of physeal defects and of remaining physes were compared between grafted tibiae and controls, as were histologic results and the heights of the remaining physes.

RESULTS

Histologically, cartilage clusters were detected in the 17 cases of grafted tibiae (68%), whereas a bone bridge was observed in all controls. The cartilage clusters showed high signal intensity on both T2WI and GRE and low signal intensity on T1WI at 2 weeks postoperatively, and became low signal intensity on T2WI at 8 weeks. On GRE images, high signal intensities of the remaining physes disappeared earlier in the control tibiae than in the grafted tibiae. The remaining physes of control tibiae showed altered histologic configurations and a progressive decrease in physis height. Quantitative measurements of the height of the remaining growth plates showed a significant difference between grafted tibiae and controls (P <0.001).

CONCLUSION

Graft interposition into a partial physeal defect may prevent early closure of the remaining physis and bone bridge formation. MR imaging can depict alterations of remaining physes that lead to early closure of the physis.

Correction of non-Blount's angular knee deformity by permanent hemiepiphyseodesis

This retrospective study evaluated the results of permanent hemiepiphyseodesis for the correction of non-Blount's coronal plane angular knee deformity. The medical records and radiographs of 75 patients with 125 angular knee deformities were analyzed for overall rate of success and factors predicting successful correction of deformity. There were 38 patients with idiopathic genu valgum and 37 with various other skeletal disorders. Sixty-nine out of 75 patients had reached skeletal maturity at latest follow-up. One hundred six knees out of 125 were successfully treated by the procedure. Of the 19 remaining knees, 15 were operated on too close to skeletal maturity to expect correction and 4 were technically unsuccessful in achieving closure of the targeted physis. There were no complications other than overcorrection, which occurred in 15 knees (11 patients). This study indicates that permanent hemiepiphyseodesis is a very useful procedure if performed in a timely and technically successful manner.

Gait analysis of stapling for genu valgum

Many authors have advocated stapling or epiphysiodesis of the distal medial femur as a means of correcting genu valgum. However, in the literature, aside from clinical improvement (appearance, pain, function), objective evidence of kinetic and kinematic improvement is lacking. Therefore, the authors undertook a prospective gait analysis evaluation of a series of patients treated for genu valgum, comparing pre- and postsurgical measurements to document the benefits of normalizing the mechanical axis. These results indicate that after surgery knee and hip angles and knee moments were returned to within the normal range for a similarly aged control group.

Epiphyseal stapling and recombinant human growth hormone for correction of genu valgum in children with chronic renal insufficiency

Genu valgum (GV) and growth retardation are known complications of chronic renal insufficiency (CRI) in children. Physeal stapling is the preferred method for GV correction, provided epiphyseal growth continues after stapling. Growth retardation in these children thus renders this mode of therapy unreliable. The only alternative is corrective osteotomy with the associated risks, such as non-union of bone and recurrence. The authors sought to determine if recombinant human growth hormone (rhGH) administered after stapling can bring about continued physeal growth needed for correction. The medical records of five patients with CRI, GV, and growth retardation who had physeal stapling performed and received rhGH were reviewed. Resolution of GV and improvement in linear height was achieved in four patients within 2 years. The authors conclude that children with CRI, growth retardation, and moderate GV benefit from the simultaneous use of rhGH and knee stapling for correction of GV, thus avoiding osteotomies.

Epiphysiodesis of the lower extremity: results of the percutaneous technique

The results of 42 percutaneous epiphysiodeses of the lower extremity in 26 patients are reported. All patients achieved physeal arrest radiographically and clinically. No patient developed angular deformity from incomplete arrest. No neurovascular complications or fractures occurred. The average hospital stay for patients undergoing epiphysiodesis alone was 1 day. Percutaneous epiphysiodesis of the lower extremity provides a reliable and safe technique for growth plate arrest. The advantages of this technique include a cosmetic scar, short hospital stay, low incidence of complications, and reliable physeal arrest.