Anterior distal femoral stapling for correcting knee flexion contracture in children with arthrogryposis--preliminary results

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

Aims and objectives

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

Materials and methods

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

Results

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

Conclusion

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

Current rehabilitation practice for the evaluation and treatment of children with arthrogryposis: an international survey

PURPOSE

To describe the current practices in rehabilitation for the evaluation and treatment of children with arthrogryposis multiplex congenita (AMC).

MATERIALS AND METHODS

Rehabilitation practitioners worldwide with at least 2 years of experience with AMC were invited to complete an electronic survey on the evaluations and treatments used with children with AMC within five areas: muscle and joint function, self-care, mobility, pain, participation and psychosocial wellbeing.

RESULTS

Sixty five participants from nine countries completed the survey. Participants completed the sections applicable to their practice. Number of participants within each area varied between 24 and 53. Over 80% of participants used non-standardized evaluations across areas while <50% used patient-reported or standardized measures. Stretching of upper and lower limbs was reported by >80% across ages and clinical presentation severity. Strengthening reported by >70% was mainly used among children >3 years old with less severe contractures. Other interventions used across areas included orthotics (>70%), positioning (>80%), activity-based training (>80%), assistive devices for self-care (>50%) and mobility (>80%), and energy conservation (>70%). Over 70% of participants were involved in perioperative rehabilitation.

CONCLUSION

Knowledge of current pediatric rehabilitation practice in AMC, together with empirical evidence, may guide clinical decision-making and identify avenues for future research.

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.

Mechanics of guided growth of the distal femur for correction of fixed knee flexion deformities: an extra-articular technique

INTRODUCTION

Anterior distal femoral hemiepiphysiodesis using intra-articular plates for correction of pediatric fixed knee flexion deformities (FKFD) has two documented complications: postoperative knee pain and implant loosening. The aim of this study is to investigate the mechanical properties of a novel extra-articular technique for anterior distal femoral hemiepiphysiodesis in patients with FKFD and to compare them to the conventional technique.

MATERIALS AND METHODS

Sixteen femoral sawbones were osteotomized at the level of the distal femoral physis and fixed by rail frames to allow linear distraction simulating longitudinal growth. Each sawbone was tested twice: first using the conventional technique with eight plates placed anteriorly just medial and lateral to the femoral sulcus (group A) and then with plates inserted in the proposed novel location at the most anterior part of the medial and lateral surfaces of the femoral condyles with screws in the coronal plane (group B). Gradual linear distraction was performed, and the resulting angular correction was measured. Strain gauges were attached to the plates, and the amount of strain (and equivalent stress) over the plates in response to linear distraction was recorded. The two groups were compared using the Wilcoxon signed-rank test.

RESULTS

The amount of angular correction was statistically higher in group B (extra-articular plates) at 5, 10-, and 15-mm of distraction (p < 0.001). As regards stress over the plates, the maximum stress and the area under the curve (sum of all stresses measured throughout the distraction process) were significantly higher when the plates were inserted at the conventional position (group A) (p < 0.001).

CONCLUSIONS

During anterior distal femoral hemiepiphysiodesis, the fixation of the eight plates in the coronal plane at the anterior part of the femoral condyles may produce a greater amount of correction and a lower degree of stress over the implants as compared to the conventional technique.

Hemiepiphysiodesis for coronal angular knee deformities: tension-band plate versus percutaneous transphyseal screw

INTRODUCTION

Pediatric coronal plane knee deformities can be treated surgically using hemiepiphysiodesis. The two leading techniques used for hemiepiphysiodesis are: tension-band plates (TBP) and percutaneous transphyseal screws (PETS). We hypothesized that PETS would lead to faster guided correction of angular knee deformities than TBP.

MATERIALS AND METHODS

A retrospective cohort of 35 patients treated with either TBP or PETS in one medical institution was established. The cohort included both genu varum and genu valgum of both primary and secondary etiologies. We first compared the treatment groups for differences in demographic and malalignment characteristics. Then, we compared the treatment groups for differences in operation-related outcomes, radiological mechanical correction and complication rates.

RESULTS

We found that the use of PETS, compared to TBP, was associated with a faster implantation surgery and a shorter interval between implantation and removal, i.e., faster correction. Furthermore, PETS were associated with faster correction rates of the mechanical axis deviation, lateral distal femoral angle and medial proximal tibial angle. No significant differences in complication rates were found between the two treatments.

CONCLUSION

PETS provided a faster correction of angular knee deformities compared to TBP at similar complication rates. Hence, PETS could be considered a superior technique for hemiepiphysiodesis.

Novel Approach to Improving Knee Range of Motion in Arthrogryposis with a New Working Classification

Arthrogryposis multiplex congenita (AMC) is a rare condition defined as contrac-tures in multiple joints. Surgical interventions for severe knee flexion contractures have included posterior release, distraction and extension with external fixation and distal femoral extension osteotomies. These operations have been able to achieve knee extension, but not increase the range of motion. The purpose of this study was to review our experience with peroneal nerve decompression, posterior knee release and proximal femoral shortening. We retrospectively reviewed the medical charts and radiographs of all patients with a diagnosis of arthrogryposis who underwent aforementioned procedure. There were 39 patients with 73 knees included in the analysis with a mean follow-up of 21 months. The mean preoperative arc of motion was 45° and last followup arc of motion was 79° (p < 0.0001). The mean last followup flexion contracture was 8° (p < 0.0001). Additional subanalyses were performed on those with followup greater than 24 months and those with flexion contractures >60°; there were no differences found in these groups. This study demonstrates that it is possible to achieve a functional range of motion of the knees in patients with AMC while improving ambulatory function.

Orthopaedic care of the child with arthrogryposis: a 2020 overview

PURPOSE OF REVIEW

The orthopaedic treatment of children with arthrogryposis multiplex congenita has evolved steadily over the past two decades. Interrelated factors have spurred this on, including better appreciation of the functional potential of persons with arthrogryposis, development of newer procedures specific for the arthrogrypotic deformities, and outcomes studies that provide understanding of the overall capabilities of adults with arthrogryposis and follow-up to determine which treatments were beneficial and which were not. This article briefly sketches out of some of these advances and indicates areas that need further development.

RECENT FINDINGS

Outcome studies show that the majority of adults with arthrogryposis are ambulatory but less than half are fully independent. Adults frequently experience ongoing pain, particularly foot and back pain, limiting ambulation and standing. Advancements in the upper extremity treatment include improving elbow function, wrist repositioning, and improving thumb positioning. In the lower extremities, correction of hip and knee contractures leads to improved ambulatory potential, and treating clubfeet with serial casting decreases poor outcomes.

SUMMARY

Clinical evaluation, both physical examination and assessment of the patient's needs, are important in directing treatment in arthrogryposis. Further outcomes studies are needed to continue to refine procedures and define the appropriate candidates.

Update on guided growth concepts around the knee in children

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

Growth Modulation for Knee Coronal Plane Deformities in Children With Nutritional Rickets: A Prospective Series With Treatment Algorithm

To report prospectively the radioclinical outcome of guided growth surgery for coronal plane deformities around the knee in young children with nutritional rickets on the intermediate term, to assess the responsiveness of torsional deformities of the tibias to guided growth regarding function and objective clinical parameters, and to propose a treatment algorithm.

Tension band plate-guided growth of knee-flexion deformity in arthrogryposis multiplex congenita in which metaphyseal funnelization induced screw encroachment upon the neurovascular bundle

Knee-flexion deformity in arthrogryposis multiplex congenita is treated by serial casting into extension, distal femoral osteotomies, distal femoral-guided growth, hemiepiphysiodesis, external fixation, capsulotomy, and soft-tissue releases. We are aware of four cases treated by distal anterior femoral-guided growth with tension band plates in which an unreported complication occurred: the screws of the tension band plates penetrated the posterior cortex of the femur during remodeling with metaphyseal funnelization risking the neurovascular bundle. Inclusion criteria were cases with arthrogryposis multiplex congenita and knee-flexion deformity, treatment at our institution by distal anterior femoral-guided growth with tension band plates, and radiographic evidence of posterior cortex screw penetration during remodeling from growth. Six knees (four cases) met the inclusion criteria. The average age at the distal anterior femoral-guided growth with tension band plate operation was 5.8 years. Radiographs after 6.6 years of follow-up showed that the screws of the tension band plates, which at surgery were intrametaphyseal, had penetrated the posterior cortex of the femur. Four knees (two cases) had diffuse pain around the knee to lower leg area, and instrumentation removal alleviated the symptoms. During distal anterior femoral-guided growth with tension band plate operation for knee-flexion deformity in arthrogryposis multiplex congenita, we found that the screws of the tension band plates, which were initially located inside the metaphysis, may protrude through the posterior bone cortex during metaphyseal funnelization with growth, and may encroach upon the neurovascular tissues. Level of evidence: Level IV - case series.

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.

Muscle and joint function in children living with arthrogryposis multiplex congenita: A scoping review

Arthrogryposis multiplex congenita (AMC) is characterized by congenital joint contractures present in two or more body areas. Lack of fetal movement is the underlying cause of AMC, which can lead to abnormal connective tissue surrounding the joint resulting in stiffness and muscle atrophy. Treatment aims at improving function and mobility through surgical and/or conservative interventions. A scoping review was conducted to explore the existing knowledge of the evaluation and treatment of muscle and joint function in children with AMC. Three search engines were included and identified 1,271 articles. Eighty-seven studies met the selection criteria and were included in this review. All included studies focused on joints, 30 of which also assessed the muscle. Assessment most often included the position of the contractures (n = 72), as well as range of motion (n = 66). Interventions to improve muscle and joint function were reported in 82 of the 87 papers and included surgery (n = 70) and conservative interventions (n = 74) with bony surgery (i.e., osteotomy) the most common surgery and rehabilitation the most common conservative intervention. Recurrences of contractures were mentioned in 46 of the 68 studies providing a follow-up. Future studies should use validated measures to assess muscle and joint function, and conservative interventions should be described in greater detail and to include a longer follow-up.

Anterior Guided Growth of the Distal Femur for Knee Flexion Contracture: Clinical, Radiographic, and Motion Analysis Results

BACKGROUND

Fixed knee flexion deformity is common in children with neuromuscular disorders. Anterior guided growth (AGG) of the distal femur can achieve gradual correction in patients who are skeletally immature. Little outcome data are available on this procedure.

METHODS

This is a retrospective matched cohort study. Forty-two knees (26 patients) underwent AGG surgery at our institution between 2007 and 2017. All patients underwent instrumented 3-dimensional gait analysis (3DGA). A nonsurgical control group of 49 knees (43 patients) was selected that matched for age, severity of preoperative knee contracture, and 3DGA parameters. Clinical, radiographic, and 3DGA outcomes were assessed and compared.

RESULTS

Average preoperative knee flexion deformity in AGG group was 13±8 degrees. Following AGG, deformity improved by 8±7 degrees (P<0.001) as measured radiographically and by 7±7 degrees (P<0.001) as measured on physical examination. Average rate of correction was 0.7±0.6 degrees per month or 8±8 degrees per year. The 3DGA parameters such as minimum stance phase knee flexion and knee flexion at initial contact were also significantly improved following AGG. In contrast, flexion deformity as measured radiographically worsened by 3±3 degrees (P=0.002) in the control group. Twelve knees (29%) had failure of correction. Predictors of failure included older age, lower level of function, and greater severity of preoperative deformity. The age at time of surgery and the anteroposterior position of plate fixation relative to the distal femoral physis were associated with rate of correction.

CONCLUSIONS

In children with neuromuscular disorders, AGG of the distal femur is effective in improving degree of fixed knee flexion deformity as well as objective gait parameters. A significant portion of knees experience inadequate correction. Addressing factors associated with correction failure (ie, age and plate placement) may improve the procedure's success.

LEVEL OF EVIDENCE

Level III-case control study.

Anterior distal femoral hemiepiphysiodesis can reduce fixed flexion deformity of the knee: a retrospective study of 83 knees

Background and purpose - Fixed knee flexion deformity in children is a common problem in various diseases including myelomeningocele and cerebral palsy. Until now, only a few studies focusing on the surgical procedure of anterior distal femoral hemiepiphysiodesis have been published. We analyzed outcome and correction rate in the largest case series to date of patients treated by staples or 8-plates. Patients and methods - We reviewed the medical records of all patients with fixed knee flexion deformity who were treated with anterior distal femoral hemiepiphysiodesis using either staples or 8-plates between the years 2002 and 2017 (73 patients; 130 knees). 49 patients (83 knees) had completed treatment with implant removal at the time of full correction of the deformity or at skeletal maturity and were included. The average age at operation was 12 years (6-20). Patients were assigned to 3 different groups based on their diagnosis: cerebral palsy, myelomeningocele, and the "other" group.d Results - Mean fixed knee flexion deformity improved from 21° (10-60°) to 8° (0-50°) (p < 0.001) with an average correction rate of 0.44° per month (range -2.14° to 1.74°). The correction rate per month was lowest for patients with cerebral palsy (0.20°), followed by the myelomeningocele group (0.50°), and the "other" group (0.58°). Implant loosening occurred in 10% of the treated knees with consecutive re-implantation in 5% of the cases. Interpretation - Anterior distal femoral hemiepiphysiodesis is an effective and safe method for the treatment of fixed knee flexion deformity in children. The optimal timing depends on the remaining individual growth potential, the underlying disease, and the extent of the deformity.

Treatment of the Lower Extremity Contracture/Deformities

Lower extremity deformities of patients with arthrogryposis multiplex congenita present a wide spectrum of severity and deformity combinations. Treatment goals range from merely ensuring comfortable seating and shoe wear, to fully independent and active ambulation, but the overarching intention is to help realize the patient's greatest potential for independence and function. Treatment of hip and knee contractures and dislocations has become more interventional, whereas treatment of foot deformities has paradoxically become much less surgical. This article synopsizes the treatment strategies presented in September 2014 in Saint Petersburg, Russia at the second international symposium on arthrogryposis.

Failure of tension band plating: a case series

Growth modulation with tension band plates (TBP) has been shown to be a very useful method for the treatment of angular deformities in growing children. Recently, we have observed cases of failure where the epiphyseal screw was drawn through the physis into the metaphysis. This study describes a series of children who developed this complication. Patients who developed TBP failure after operative treatment of lower limb angular deformities were identified from the databases at four institutions over a 5-year period. The medical records were reviewed to record demographics, primary diagnoses, details of the operative procedure, development of physeal arrest, and recurrence of the original deformity. Six patients (five girls) with nine implant failures were identified. The mean age of the children at the time of implant insertion was 7.2 years (range, 4-10 years). The primary diagnoses included hypophosphatemic rickets (n=7), congenital pseudoarthrosis of the tibia associated with neurofibromatosis 1 (n=1), and post-traumatic malunion after distal tibial fracture (n=1). Of the nine TBP that presented with the complication, four were inserted into the medial distal femur (one bilateral case), two into the medial proximal tibia (one bilateral case), two into the lateral distal tibia, and one into the medial distal tibia. None of these patients developed physeal growth arrest at the last follow-up as assessed on the latest radiographs. The use of TBP for guided growth in patients younger than 10 years old with rickets, neurofibromatosis, or other conditions that produce osteopenia leads to an increased risk for implant failure. In these cases, it is important to confirm that the epiphyseal screw has good purchase. Patients with these features should be monitored closely for early detection of this complication.

Rotational deformities of the long bones can be corrected with rotationally guided growth during the growth phase

Background and purpose - Coronal and sagittal plane long bone deformities can be corrected with guided growth, whereas transverse plane rotational deformities require osteotomy and internal or external fixation. We investigated whether rotational changes can be introduced with the plating technique. Methods - 45 rabbits (6 weeks old) were divided into 3 groups. The unoperated right tibia was used as control. In groups 1 and 3, two plates were placed obliquely to the long axis and in different directions. In group 2, a sham operation was performed with screws. Animals in groups 1 and 2 were followed for 4 weeks. In group 3 the implants were removed 4 weeks after the operation to observe rebound effect, and the animals were followed for another 4 weeks. The tibial torsion was assessed on computed tomography (CT). External rotation was accepted as a negative value. Results - In group 1, mean torsion was -20° (SD 7.9) in the right tibia and -2.9° (SD 7.2) in the left tibia (p < 0.001). In group 2, mean torsion was -23° (SD 4.9) in the right tibia and -26° (SD 6.5) in the left tibia (p = 0.2). In group 3, mean torsion was -21° (SD 6.3) in the right tibia and -9.5° (SD 5.3) in the left tibia (p < 0.001). Intergroup evaluation for left torsion showed a significant difference between group 2 and the other groups (p < 0.001). When the rebound effect was evaluated, there was no statistically significant difference between groups 1 and 3 (p = 0.08). Interpretation - A rotational change was attained with this technique. Although a rebound effect was seen after implant removal, it did not reach statistical significance. The final rotational change remained constant.

Arthrogryposis: an update on clinical aspects, etiology, and treatment strategies

Arthrogryposes - multiple joint contractures - are a clinically and etiologically heterogeneous class of diseases, where accurate diagnosis, recognition of the underlying pathology and classification are of key importance for the prognosis as well as for selection of appropriate management. This treatment remains challenging and optimally in arthrogrypotic patients should be carried out by a team of specialists familiar with all aspects of arthrogryposis pathology and treatment modalities: rehabilitation, orthotics and surgery. In this comprehensive review article, based on literature and clinical experience, the authors present an update on current knowledge on etiology, classifications and treatment options for skeletal deformations possible in arthrogryposis.

Management of the knees in arthrogryposis

Arthrogryposis is defined as limited range of motion in three or more joints in two or more body parts. This article will describe treatment options for the arthrogrypotic knee. In all types of arthrogryposis, and in both extension and flexion deformities, very early treatment is favorable. Just after birth, traction and mobilization followed by serial casting could often greatly improve the range of motion. In the hyperextended knee, surgical lengthening of the extensor apparatus may be needed. Flexion deformities could be improved with temporary physeal arrest of the anterior distal femur by fixing two-hole plates over the physis on both sides of patella. The plates will result in a constrained growth of the anterior physis, and thus a very slow extension of the knee, which will give the nerves and vessels time to adjust. Pterygium, webbing of the knee joint, is a special subgroup that in selected mild cases could be treated with extensive surgical release of the webbing and orthotics. Arthrogrypotic knees can be treated with early reduction and maintenance with orthotics.

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.

Distal tibial physeal bridge: a complication from a tension band plate and screw construct. Report of a case

We report on a case of a tension band plate and screw construct (Eight Plate) used over the anterior distal tibia in an 9-year-old girl in an attempt to induce recurvatum of the ankle joint to correct a recalcitrant equinus deformity. With growth of the distal tibial physis, the epiphyseal screw was drawn through the physis into the distal tibial metaphysis, resulting in the creation of a transphyseal bony bar. Caution should be exercised when attempting temporary hemiepiphyseodesis using a plate and screw construct in small epiphyses or in an osteopenic bone.

Treatment of fixed knee flexion deformity by anterior distal femoral stapling

PURPOSE

The treatment of fixed knee flexion deformity through anterior distal femoral stapling has been investigated in only two studies so far, with promising results. The aim of the present study was to determine whether this technique might improve fixed knee flexion deformity in a series of growing children and adolescents with different conditions. Follow-up examinations were continued after staple removal in terms of a possible impairment of this deformity.

METHODS

We reviewed the medical records of all patients with fixed knee flexion deformity who had been treated by anterior distal femoral stapling at our institution. Twenty patients (37 knees) with a mean age of 12.7 years met the inclusion criteria (>12 months of follow-up; no additional procedures to correct fixed knee flexion deformity such as hamstring lengthening or posterior capsulotomy) and were evaluated in this study.

RESULTS

The mean fixed knee flexion deformity significantly improved from 21.4° (SD = 11.6) preoperatively to 7.0° (SD = 9.8) after a mean follow-up of 35.3 months. Young patients (<12 years) revealed superior improvement of this deformity, and especially children with distinct fixed knee flexion deformity of 30° or greater had benefit from early treatment. Impairment of flexion deformity was only seen in one patient (2 knees) after staple removal.

CONCLUSIONS

Our results demonstrate that anterior distal femoral stapling is an effective method for the treatment of fixed knee flexion deformity in growing children and adolescents. Rare complications, immediate mobilization, and a low recurrence rate after staple removal provide obvious advantages of this minimally invasive procedure.

LEVEL OF EVIDENCE

Retrospective therapeutic study, Level IV.

Management of knee deformities in children with arthrogryposis

Arthrogryposis includes heterogeneous disorders, characterized by congenital contractures of multiple joints. Knee involvement is very common (38-90 % of patients with amyoplasia) ranging from soft-tissue contractures (in flexion or hyperextension) to subluxation and dislocation. Flexion contractures are more common and disabling and show significant resistance to treatment and rate of recurrence. Surgical procedures vary with severity of contracture and patient age and include soft-tissue release, femoral shortening-extension osteotomy, gradual correction with Ilizarov, and femoral anterior epiphysiodesis. The presence of pterygium greatly complicates treatment, given the high rate of complications reported. Hyperextension deformities (recurvatum, anterior subluxation, and dislocation) have better prognosis for walking ability. Surgical options include percutaneous (or mini-open) quadriceps tenotomy, open quadricepsplasty, and femoral shortening osteotomy with limited arthrotomy. Knee dislocations usually require surgery and should be reduced early.

Anterior distal femoral hemiepiphysiodesis in the treatment of fixed knee flexion contracture in neuromuscular patients

AIM

Patients with neuromuscular diseases such as cerebral palsy (CP) and meningomyelocele (MMC) are prone to develop fixed knee flexion contracture. Distal femoral extension osteotomy allows acute correction of the deformity, but it is an extensive surgical procedure, and the complication rate is rather high. Immobilization can prolong the rehabilitation period, and may even result in deteriorated walking ability. The aim of this retrospective study was to evaluate the results of using anterior hemiepiphysiodesis of the distal femur to treat fixed flexion contracture of the knee.

MATERIALS AND METHODS

We studied 21 patients in our department from 2003 to 2009. Mean age was 10 years (5-15). Twelve suffered from MMC, five from CP, two from arthrogryposis, one had an enzyme defect, and one had Down's syndrome. Thirteen patients had a bilateral and eight a unilateral procedure. None of the patients underwent any other procedures. Two staples or 8-plates were inserted using two parapatellar incisions. Nine were operated on with staples and 12 with 8-plates. The plates or staples were removed when the desired effect of full knee extension was achieved or the patient reached skeletal maturity.

RESULTS

Mean fixed flexion contracture was 20° (10°-40°). Staples or 8-plates were removed after a mean of 24 (6-42) months. Mean fixed flexion contracture at removal was 10° (0°-30°). Two complications were seen: one infection and one supracondylar fracture.

CONCLUSION

Anterior distal femoral hemiepiphysiodesis using 8-plates or staples seems to be effective for correcting fixed knee flexion deformity in skeletally immature individuals. The complication rate is low (10 %). Our results are comparable to those of Kramer, Klatt, and Stevens. This procedure should be the primary treatment for fixed knee flexion contractures in neuromuscular patients with sufficient remaining growth.

Anterior femoral epiphysiodesis for the treatment of fixed knee flexion deformity in spina bifida patients

BACKGROUND

Fixed knee flexion deformity is a common problem in spina bifida patients. Owing to interference with ambulation, this deformity may lead to anterior knee pain and progressive crouch gait. If conservative treatment fails, surgical procedures including supracondylar femoral extension osteotomy, joint distraction, and posterior capsulotomy have to be considered. Potential complications of these procedures are fractures, neurovascular lesions, knee instability, and recurrent deformity with continued growth. As fixed knee flexion deformity in spina bifida patients frequently occurs bilaterally, this results in higher perioperative and postoperative risks and prolonged recovery, making these relatively invasive methods less appealing. In the skeletal immature patient, anterior femoral stapling is a feasible method to treat fixed knee flexion deformity as could be shown in an earlier study. In this study, anterior femoral stapling was performed in a series of patients with diverse etiologies, and the overall success rate was then calculated. The aim of this study was to determine whether anterior femoral epiphysiodesis may improve fixed knee flexion deformity in a group of spina bifida patients.

METHODS

Ten spina bifida patients with bilateral fixed knee flexion deformity (20 knees) were treated by anterior femoral epiphysiodesis through stapling. None of the patients received further knee procedures. The mean preoperative fixed knee flexion deformity was 20.3 ± 9.9 degrees (range: 10 to 40 degrees). Clinical and radiographic follow-up examinations were performed every 3 to 6 months after surgery.

RESULTS

All patients except 1 experienced significant improvement with a mean correction rate of 0.9 ± 0.5 degrees per month (range: 0.2 to 1.9 degrees). The residual flexion deformity averaged 5.3 ± 5.3 degrees (range: 0 to 15 degrees; P<0.001).

CONCLUSIONS

Anterior femoral epiphysiodesis through stapling is an effective and safe method for the treatment of fixed knee flexion deformity in growing children and adolescents with spina bifida.

LEVEL OF EVIDENCE

Therapeutic Study, Level IV.