Surgical rehabilitation of the planovalgus foot in cerebral palsy

Surgical management of pes planus in children with cerebral palsy: A systematic review

PURPOSE

Pes planus (or flatfoot) is the most common deformity in children with cerebral palsy. There are several surgical interventions used to treat it: single calcaneal osteotomies, extra-articular arthrodesis, double calcaneal osteotomy, calcaneo-cuboid-cuneiform osteotomy, intra-articular arthrodesis, and arthroereisis. There is currently no evidence on optimal treatment for flatfoot in children with cerebral palsy. Our purpose is to systematically review studies reporting complications, recurrence rates, and radiological outcomes of the surgical management of flatfoot in children with cerebral palsy.

METHODS

Five databases were searched to identify studies published from inception until July 2021, with keywords relating to flatfoot, cerebral palsy, and surgical interventions. We included prospective, retrospective, and comparative study designs in the English language. Data was extracted and tabulated in duplicate into Excel, and analysis was conducted using Python SciPy.

RESULTS

In total, 1220 studies were identified of which 44 met the inclusion criteria, comprising 2234 feet in 1364 patients with a mean age of 10.3 years and mean follow-up of 55.9 months. Radiographic outcomes showed improvement with all procedures; complications and recurrence rates were too poorly reported to compare. Only 6 (14%) studies were assessed as a low risk of bias. There was substantial heterogeneity of outcome measures.

CONCLUSION

There is a lack of high-quality, comparative studies assessing the radiological outcomes, complications, and recurrence rates of surgical alternatives to treat flatfoot in children with cerebral palsy. There is currently no clear evidence on optimal surgical treatment.

LEVEL OF EVIDENCE

IIa based on Oxford Centre for Evidence-based Medicine.

A Soft Pressure Sensor Skin to Predict Contact Pressure Limit Under Hand Orthosis

Customized static orthoses in rehabilitation clinics often cause side effects, such as discomfort and skin damage due to excessive local contact pressure. Currently, clinicians adjust orthoses to reduce high contact pressure based on subjective feedback from patients. However, the adjustment is inefficient and prone to variability due to the unknown contact pressure distribution as well as differences in discomfort due to pressure across patients. This paper proposed a new method to predict a threshold of contact pressure (pressure limit) associated with moderate discomfort at each critical spot under hand orthoses. A new pressure sensor skin with 13 sensing units was configured from FEA results of pressure distribution simulated with hand geometry data of six healthy participants. It was used to measure contact pressure under two types of customized orthoses for 40 patients with bone fractures. Their subjective perception of discomfort was also measured using a 6 scores discomfort scale. Based on these data, five critical spots were identified that correspond to high discomfort scores (>1) or high pressure magnitudes (>0.024 MPa). An artificial neural network was trained to predict contact pressure at each critical spot with orthosis type, gender, height, weight, discomfort scores and pressure measurements as input variables. The neural networks show satisfactory prediction accuracy with R² values over 0.81 of regression between network outputs and measurements. This new method predicts a set of pressure limits at critical locations under the orthosis that the clinicians can use to make orthosis adjustment decisions.

Botulinum Toxin Type A Injection for Spastic Equinovarus Foot in Children with Spastic Cerebral Palsy: Effects on Gait and Foot Pressure Distribution

PURPOSE

To investigate the effect of intramuscular Botulinum toxin type A (BoNT-A) injection on gait and dynamic foot pressure distribution in children with spastic cerebral palsy (CP) with dynamic equinovarus foot.

MATERIALS AND METHODS

Twenty-five legs of 25 children with CP were investigated in this study. BoNT-A was injected into the gastrocnemius (GCM) and tibialis posterior (TP) muscles under the guidance of ultrasonography. The effects of the toxin were clinically assessed using the modified Ashworth scale (MAS) and modified Tardieu scale (MTS), and a computerized gait analysis and dynamic foot pressure measurements using the F-scan system were also performed before injection and at 1 and 4 months after injection.

RESULTS

Spasticity of the ankle plantar-flexor in both the MAS and MTS was significantly reduced at both 1 and 4 months after injection. On dynamic foot pressure measurements, the center of pressure index and coronal index, which represent the asymmetrical weight-bearing of the medial and lateral columns of the foot, significantly improved at both 1 and 4 months after injection. The dynamic foot pressure index, total contact area, contact length and hind foot contact width all increased at 1 month after injection, suggesting better heel contact. Ankle kinematic data were significantly improved at both 1 and 4 months after injection, and ankle power generation was significantly increased at 4 months after injection compared to baseline data.

CONCLUSION

Using a computerized gait analysis and foot scan, this study revealed significant benefits of BoNT-A injection into the GCM and TP muscles for dynamic equinovarus foot in children with spastic CP.

Joint kinematics of surgeons during lumbar pedicle screw placement

BACKGROUND

A surgical robot for spine surgery has recently been developed. The objective is to assess the joint kinematics of the surgeon during spine surgery.

METHODS

We enrolled 18 spine surgeons, who each performed pedicle screw placement, and used an optoelectronic motion analysis system. Using three-dimensional (3D) motion images, distance changes in five joints and angle changes in six joints were calculated during surgery.

RESULTS

Distance fluctuations increased gradually from the proximal to the distal joint. Angle fluctuations were largest at the distal point but did not gradually increase, and the elbow showed the second largest fluctuation. Changes along the X axis were larger than those of the Y and Z axes.

CONCLUSION

The distances gradually increased from proximal portions of the body to the hand. In angle changes, the elbow was most dynamic during pedicle screw placement. The surgeons' whole joints carry out a harmonic role during lumbar pedicle screw placement. Copyright © 2015 John Wiley & Sons, Ltd.

Reported outcomes of lower limb orthopaedic surgery in children and adolescents with cerebral palsy: a mapping review

AIM

Lower limb surgery is often performed in ambulatory children with cerebral palsy (CP) to improve walking ability. This mapping review reports on outcome measures used in the published literature to assess surgical results, determine range and frequency of use, and map each measure to the International Classification of Functioning, Disability and Health.

METHOD

A mapped review of literature published between 1990 and 2011 was carried out to identify papers reporting the outcomes of lower limb orthopaedic surgery in ambulatory children with CP, aged 0 to 20 years.

RESULTS

A total of 229 published papers met the inclusion criteria. Thirty-two outcome measures with known psychometric properties were reported in the 229 papers. Twenty measures assess impairments in body structure and function and were used in 91% of studies. Ten measures assess restrictions in activity and participation and were used in 9% of papers. Two measures assessed quality of life. Since 1997, 29% of papers have used the Gross Motor Function Classification System to describe participants.

INTERPRETATION

The body of literature evaluating outcomes of lower limb orthopaedic surgery in CP is small but increasing. There is a need to develop a suite of outcome measures that better reflect outcomes across the International Classification of Functioning, Disability and Health, including activity and participation.

Outcome After Operative Fusion of the Tarsal Joints: A Systematic Review

Arthrodesis of 1 or more joints of the hindfoot is performed to treat severe functional impairment due to pain, deformity, and/or instability. Evaluation of the results of hindfoot arthrodesis from the published data has been difficult owing to the great variety of pathologic entities and surgical techniques reported in the studies. A comprehensive search for relevant reports, reference lists, and citation tracking of the included studies was conducted using the PubMed(®), Embase(®), and CINAHL(®) databases. The studies had to have been prospective, included patients with hindfoot problems, evaluated arthrodesis of 1 or more tarsal joints, and had at least 1 of the following primary clinical outcome parameters: pain, function, or complications. Two of us independently selected the relevant studies using predefined criteria and graded the quality of evidence using a 0 to 9 star scale according to the Newcastle-Ottawa Scale. A total of 16 prospective case series were included; 5 studies scored 6 stars, 8 scored 5 stars, 2 scored 4 stars, and 1 scored 3 stars. A best evidence synthesis was performed, and improvement in function and pain was found for 3 combinations: talonavicular arthrodesis for rheumatoid arthritis, triple arthrodesis for rheumatoid arthritis, and subtalar arthrodesis for post-traumatic arthritis showed good results for pain and function, the last especially when performed arthroscopically. The best evidence syntheses revealed good results for pain and function for these disease-operative technique combinations.

Characterization of postural stability in a simulated environment of an earthquake using in-shoe plantar pressure measurement

An abled individual is believed to be capable of withstanding and overcoming the severe tremors of an earthquake as has been ascertained in a previous study. However, the event-related physiological mechanisms of human postural stability during an earthquake are subject to further investigation. Accordingly, the objective of this study is to further characterize postural stability in a simulated environment of an earthquake using a pedar-x (novel gmbh, Munich, Germany) in-shoe dynamic plantar pressure measurement system. A foot mask, dividing each of the insoles into seven plantar loading regions, was employed in this study. This paper reports preliminary results obtained from a normal adult female test subject with right side dominance and a normal foot arch. The test trial was comprised of 12 stages, ranging from quiet standing to simulated earthquake magnitude of 6.7 degrees on the Richter's scale, which is considered to be violent. The study metrics included: mean plantar pressure, foot-to-ground contact duration, insole loading area, and the position, displacement, and instantaneous velocity of the center of pressure. The study showed bilateral quantifiable changes in these metrics by foot-mask-region as a result of increasing magnitudes of simulated tremors. The subject was able to defy the overwhelming perturbations and maintain her balance and postural stability throughout the test period. The significance of this study lies in its ability to determine the threshold of falling within different subject populations in the event of an earthquake.

Dynamic Foot Pressure Measurements for Assessing Foot Deformity in Persons With Spastic Cerebral Palsy

OBJECTIVES

To identify characteristics of foot pressure distribution in different foot deformities using a computerized insole sensor system, and to identify changes in these parameters after corrective surgery in children with spastic cerebral palsy (CP).

DESIGN

Before-after trial.

SETTING

University hospital.

PARTICIPANTS

Sixty-seven limbs of 44 children with spastic CP were assessed (35 equinus, 17 equinovarus, 15 equinovalgus).

INTERVENTION

Orthopedic surgery for foot deformities.

MAIN OUTCOME MEASURES

Parameters of foot contact pattern, pressure-time integral (PTI), and center of pressure (COP) trajectories were assessed before and at a minimum of 6 months postsurgery, using the F-scan system.

RESULTS

Prior to surgery, the medial midfoot relative impulse, which is PTI normalized by a percentage of the entire foot, differed significantly between foot deformity groups. Relative impulse was high on the lateral column of the foot in the equinovarus group and on the medial column of the foot in the equinovalgus group. Center of pressure index (COPI) and coronal index reflecting the asymmetry of the medial and lateral columns of the foot differed significantly between the equinovalgus and equinovarus groups. After surgery, significant changes occurred in foot contact patterns, including total contact area, contact length, contact width of hindfoot, and the relative impulse of specific areas of the foot. In addition, there were significant changes in the parameters of COP, such as anteroposterior displacement, slope, and velocity.

CONCLUSIONS

In dynamic foot pressure measurements using a computerized insole sensor system, the parameters reflecting medial or lateral changes in weight bearing, such as COPI and coronal index, appear to be useful for evaluating abnormalities and improvements after intervention in the frontal plane, such as varus and valgus. Additionally, assessment of parameters in foot contact patterns, PTIs, and COP path trajectories appears to be helpful in evaluating outcomes after corrective surgery.

Validation of a multisegment foot and ankle kinematic model for pediatric gait

This paper reports the development, accuracy, reliability, and validation protocol of a four-segment pediatric foot and ankle model. The four rigid body segments include: 1) tibia and fibula; 2) hindfoot--talus, navicular, and calcaneus; 3) forefoot--cuboid, cuneiforms, and metatarsals; and 4) hallux. A series of Euler rotations compute relative angles between segments. Validation protocol incorporates linear and angular testing for accuracy and reliability. Linear static system resolution is greatest in the Y orientation at 0.10 +/- 0.14 mm and 0.05 level of significance and 99.96% accuracy. Dynamic linear resolution and accuracy are 0.43 +/- 0.39 mm and 99.8%, respectively. Angular dynamic resolution computes to 0.52 +/- 3.36 degrees at 99.6% accuracy. These calculations are comparable to the Milwaukee adult foot and ankle model.

Surgical rehabilitation of the planovalgus foot in cerebral palsy

The objectives of this study were to quantitatively determine the effects of subtalar arthrodesis on the planovalgus foot using three-dimensional (3-D) gait analysis and plantar pressure measurements. Twelve children and adolescents with planovalgus foot deformity secondary to spastic cerebral palsy participated in this outcome study. The pediatric population were evaluated preoperatively and following subtalar fusion. Seventeen feet were operated for the correction of the planovalgus foot deformity. A Holter-type microprocessor-based portable in-shoe data acquisition system was used in this study to collect the multistep dynamic plantar pressure history, while a five-camera Vicon-based gait analysis system was used to track the lower extremity joint kinematics. The results obtained from the plantar pressure measurement showed significant increases in mean peak vertical plantar pressures postoperatively at the lateral midfoot and lateral metatarsal heads. Mean contact durations and mean pressure-time integrals were also significantly increased at these plantar locations following foot surgery. This redistribution in pressure metrics suggests the formation of new lateral plantar weight bearing areas. The 3-D gait analysis system, using standardized lower extremity measurements, was unable to reveal any significant changes in joint kinematics, particularly at the foot and ankle where the surgery was performed. This suggests the need for a more refined system to track the complex motion of the pediatric foot and ankle during gait.