Kinematic and kinetic evaluation of the ankle joint before and after tendo achilles lengthening in patients with spastic diplegia

Ankle Dorsiflexor Function after Gastrocsoleus Lengthening in Children with Cerebral Palsy: A Literature Review

Background and Objectives: Ambulant children with cerebral palsy can demonstrate persistent “foot drop” after successful gastrocsoleus lengthening (GSL) surgery for equinus deformity. This may be due to inadequate strength and/or selective motor control of the ankle dorsiflexor muscles. A procedure has been developed to reduce foot drop—Tibialis Anterior Tendon Shortening (TATS), to be performed in conjunction with GSL. However, it is currently unclear how ankle dorsiflexor function changes after surgery and which children could benefit from TATS. This review summarises changes in ankle dorsiflexor function after GSL for equinus, as reported in the literature. Methods: A search was performed of the Medline, Embase and PubMed databases from 1980 to 5 March 2021. Keywords included “cerebral palsy”, “equinus deformity”, “orthopedic procedures” and “gait analysis”. The search identified 1974 studies. Thirty-three cohort studies met the inclusion criteria for this review. Results: Twenty-two studies reported improvement in swing phase ankle dorsiflexion kinematics, after GSL. There was also evidence that clinical measures of ankle dorsiflexor strength improved after surgery. Four studies reported changes in selective motor control, with mixed results across the studies. Conclusions: There is good evidence that swing phase ankle dorsiflexion improves after GSL surgery. Although, there is limited evidence that this correlates with reduced foot drop or diminished need for an ankle-foot orthosis. Future research should be prospective, randomised, include a large sample size, and should focus on identifying the optimal candidates for TATS.

Surgical Management of Foot and Ankle Deformities in Cerebral Palsy

Children with cerebral palsy (CP) are at a high risk of developing foot and ankle deformities that can impact function, brace/shoe fit, and seating. The 3 commonly observed foot and ankle segmental malalignment patterns include equinus, planovalgus, and equinovarus. Assessment of foot deformities is multifaceted, requiring the collection and integration of data from a combination of sources that include the clinical history, standardized physical examination, observational and quantitative gait analysis, GMFCS classification, and radiographic findings. Surgical procedures are determined by identifying all segmental malalignments and assessing the contribution of dynamic or flexible soft-tissue imbalance, fixed soft-tissue imbalance, and skeletal deformities.

Equinus Correction During Multilevel Surgery in Adults With Cerebral Palsy

BACKGROUND

Equinus foot deformity constitutes a common gait disorder in ambulatory adults with bilateral spastic cerebral palsy (BSCP). The outcome after intramuscular aponeurotic lengthening in the context of single-event multilevel surgery (SEMLS) in adulthood has not been investigated.

METHODS

We followed a group of 31 ambulatory adults with BSCP and equinus who underwent SEMLS including gastrocnemius-soleus intramuscular aponeurotic recession or Achilles tendon lengthening. All patients were analyzed preoperatively and at least 1 year (mean follow-up period: 1.6 years) postoperatively by clinical examination and 3-dimensional instrumented gait analysis including the Gait Profile Score (GPS).

RESULTS

Clinical examination showed no significant improvement of ankle dorsiflexion ( P = .5) and an unchanged plantarflexion ( P = .7) with knee extended but a significant postoperative reduction of spasticity in the calf muscle ( P = .0001) as measured by clinical examination following the modified Ashworth scale. Significant improvement of mean ankle dorsiflexion in stance and swing ( P = .0001) was found. The GPS decreased and improved significantly (15.9 ± 4.6 to 11.4 ± 3.1; P = .0001). Persistence of equinus and calcaneal gait indicating under- and overcorrection at follow-up was found in 1 patient (3%), respectively.

CONCLUSION

Intramuscular gastrocnemius-soleus aponeurotic recession is part of multilevel surgery corrected equinus deformity in adults. The increase in muscle length led to significant improvement of kinetic and kinematic parameters during walking without a loss of muscle strength and push-off capacity. The risk of overcorrection after equinus correction in adults with BSCP was found to be relatively low.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The effect of plantar flexor lengthening on foot pressure in ambulatory children with cerebral palsy

This study aimed to assess the effects of plantar flexor lengthening (PFL) on dynamic foot pressures of children with cerebral palsy using pedobarographs. Of 97 enrolled, 13 children with 18 legs had PFL. Age at surgery was 4.7 (2.8-8.8) years. A significant increase in ankle dorsiflexion and heel impulse was achieved postoperatively and was maintained at 5 years. The coronal plane pressure index increased postoperatively, but reverted to preoperative levels at the 5-year follow-up. Children tend to have more valgus after PFL. In young children, there caution should be exercised to avoid over treating varus at the time of equinus correction to avoid overcorrection.

Recurrence of equinus foot deformity after tendo-achilles lengthening in patients with cerebral palsy

BACKGROUND

Recurrence of equinus deformity after surgery is common in patients with cerebral palsy. This retrospective study was undertaken to estimate the recurrence rate of the equinus deformity after tendo-Achilles lengthening (TAL) in patients with cerebral palsy and to investigate the risk factors associated with the recurrence.

METHODS

Two-hundred forty three ambulatory patients with cerebral palsy, who underwent TAL for equinus foot deformity since 1995, and had undergone a preoperative and postoperative 3-dimensional gait analysis, were included. Cox proportional hazards model was used to determine the significant contributing factor for the recurrence of equinus foot deformity.

RESULTS

The mean patient age at surgery was 7.8±2.7 years and the mean follow-up duration was 8.1±3.4 years. Equinus deformity recurred in 22 of the 243 patients (9.1%) and the Kaplan-Meier survival estimate was shown to be 89.4% at 10 years not needing repeat surgery. According to the multivariate analysis using the Cox proportional hazard model, preoperative ankle dorsiflexion at initial contact (P=0.016) was the only significant factor for recurrence of equinus deformity after surgery. Age at surgery and the type of limb involvement were not associated with the recurrence (P=0.433 and 0.269). The cutoff values of preoperative gait kinematics between the nonrecurrence and recurrence groups were -19 degrees of ankle dorsiflexion at initial contact (P=0.018).

CONCLUSIONS

This study showed that the severity of preoperative equinus deformity was a risk factor associated with recurrence after TAL in patients with cerebral palsy. Therefore, surgeons should consider the recurrence and later revision surgery for the patients with severe equinus foot deformity.

LEVEL OF EVIDENCE

Therapeutic level III.

Effects of simulated crouch gait on foot kinematics and kinetics in healthy children

Identification of secondary and tertiary impairments in neurologically induced gait deviations, such as crouch gait, is not always straightforward, but essential in order to decide upon the most efficient medical treatment in patients with cerebral palsy (CP). Until now, exact intersegmental dependency of the development of foot deformities has not been investigated. Therefore, the aim of this study was to explore if an artificially induced bilateral knee flexion contracture causes compensatory mechanisms in foot motion during gait in healthy children. Three-dimensional kinematic and kinetic data from 30 healthy children (mean age 10.6 years) were derived from the Oxford Foot model (OFM). Participants walked first in an artificially induced crouch gait (limitation of knee extension to 40°) and then normally. Walking speed was kept the same in both conditions. Analysis revealed small but significant (p<0.05) differences between the two conditions in hindfoot and forefoot kinematics in all three planes during the stance phase as well as for all peak internal moments within the foot. In general the foot tended to compensate for an artificial knee flexion contracture with an increase in maximal dorsiflexion, eversion and external rotation of the hindfoot, which also allowed increased foot motion in other foot segments. The results of this study showed that an isolated proximal joint contracture had an influence on foot position during stance in healthy children. Further interpretation of the data in relation to CP children will be possible as soon as comparable OFM data of pathological crouch gait is available.

Multilevel surgery for equinus gait in children with spastic diplegic cerebral palsy: medium-term follow-up with gait analysis

BACKGROUND

In children with spastic diplegia, surgery for ankle equinus contracture is associated with a high prevalence of both overcorrection, which may result in a calcaneal deformity and crouch gait, and recurrent equinus contracture, which may require revision surgery. We sought to determine if conservative surgery for equinus gait, in the context of multilevel surgery, could result in the avoidance of overcorrection and crouch gait as well as an acceptable rate of recurrent equinus contracture at the time of medium-term follow-up.

METHODS

This was a retrospective, consecutive cohort study of children with spastic diplegia who had had surgery for equinus gait between 1996 and 2006. All children had distal gastrocnemius recession or differential gastrocnemius-soleus complex lengthening, on one or both sides, as part of single-event multilevel surgery. The primary outcome measures were the Gait Variable Scores (GVS) and Gait Profile Score (GPS) at two time points after surgery.

RESULTS

Forty children with spastic diplegia, Gross Motor Function Classification System (GMFCS) level II or III, were included in this study. There were twenty-five boys and fifteen girls. The mean age was ten years at the time of surgery and seventeen years at the time of final follow-up. The mean postoperative follow-up period was 7.5 years. The mean ankle GVS improved from 18.5° before surgery to 8.7° at the time of short-term follow-up (p < 0.005) and 7.8° at the time of medium-term follow-up. The equinus gait was successfully corrected in the majority of children, with a low rate of overcorrection (2.5%) and a high rate of recurrent equinus (35%), as determined by sagittal ankle kinematics. Mild recurrent equinus was usually well tolerated and conferred some advantages, including contributing to strong coupling at the knee and independence from using an ankle-foot orthosis.

CONCLUSIONS

Surgical treatment for equinus gait in children with spastic diplegia was successful, at a mean of seven years, in the majority of cases when combined with multilevel surgery, orthoses, and rehabilitation. No patient developed crouch gait, and the rate of revision surgery for recurrent equinus was 12.5%.

Ankle dorsiflexor function after plantar flexor surgery in children with cerebral palsy

BACKGROUND

Surgical lengthening is used to address both overactivity and shortening of the spastic agonist muscle in children with cerebral palsy. It has been presumed that the function of the antagonist muscle will improve when the spastic agonist muscle has been surgically lengthened. The purposes of the current study were to use quantitative gait analysis to determine the prevalence of the ankle dorsiflexor muscles (antagonist) dysfunction during the swing phase of the gait cycle and to analyze how this function is affected following surgical lengthening of the ankle plantar flexor muscles (agonist).

METHODS

The study design was a retrospective, cohort series of fifty-three children with cerebral palsy who underwent gait analysis before and after surgical lengthening of the gastrocnemius-soleus muscle group. Data from the physical examination, gait study kinematics, and dynamic electromyography in swing phase were analyzed.

RESULTS

The mean age at the time of the initial gait analysis was eight years and eleven months. Significant improvements were noted in ankle dorsiflexion passive range of motion (p < 0.001), ankle dorsiflexor selective control (p = 0.002), ankle dorsiflexor strength (p = 0.001), and peak and mean ankle dorsiflexion in swing phase (p < 0.001 for each) following ankle plantar flexor lengthening surgery. Active ankle dorsiflexor function in swing phase was present in 79% of the extremities prior to ankle plantar flexor surgery. Swing phase dorsiflexor function was present in 96% of the extremities following surgery, with ten extremities improving from absent to present.

CONCLUSIONS

The kinematic data support the clinical impression that ankle dorsiflexion during swing phase is improved following ankle plantar flexor lengthening surgery in children with cerebral palsy. In the majority of patients, this was a consequence of the correction of a fixed equinus contracture of the ankle plantar flexors that was constraining preexisting ankle dorsiflexor function. Weakness of all of the muscles is common, and surgical lengthening should only be considered for the correction of recalcitrant muscle contractures. Improved function of the antagonist muscle should be anticipated and optimized by appropriately focused strength training and other modalities during rehabilitation.

Surgical correction of equinus deformity in children with cerebral palsy: a systematic review

PURPOSE

Equinus is the most common deformity in cerebral palsy. However, despite the large volume of published studies, there are poor levels of evidence to support surgical intervention. This study was undertaken to examine the current evidence base for the surgical management of equinus deformity in cerebral palsy.

METHODS

A systematic review of the literature using "equinus deformity", "cerebral palsy" and "orthopaedic surgery" generated 49 articles. After applying inclusion and exclusion criteria, 35 articles remained. The Oxford Centre for Evidence-Based Medicine (CEBM) levels of evidence and the Methodological Index for Non-Randomized Studies (MINORS) were used to grade the articles.

RESULTS

Studies ranged in sample size from 9 to 156 subjects, with an average of 38 subjects. The mean age of subjects at index surgery ranged from 5 to 19 years. Nineteen studies used instrumented gait analysis, with an average follow-up of 2.8 years. Seven studies reported that a younger age at index surgery was associated with an increased risk of recurrent equinus. The average rate of calcaneus in hemiplegic children was 1% and it was 15% in those with spastic diplegia. Most studies were level 4 quality of evidence, leading to, at best, only grade C recommendation.

CONCLUSIONS

Cerebral palsy subtype (hemiplegia versus diplegia) and age at index surgery were the two most important variables for determining the outcome of surgery for equinus deformity in cerebral palsy. Despite the great emphasis on differences in surgical procedures, there was less evidence to support the type of operation in relation to outcome.

Outcomes of gastrocnemius-soleus complex lengthening for isolated equinus contracture in children with cerebral palsy

BACKGROUND

The goal of the gastrocnemius-soleus complex (GSC) lengthenings in children with cerebral palsy (CP) is to achieve a plantigrade foot and normalize kinematics during gait. The study purpose was to evaluate the results of GSC lengthening for isolated equinus contracture in individuals with CP. It was hypothesized that GSC lengthenings would normalize passive ankle range of motion, kinematic, kinetic, and temporal spatial parameters.

METHODS

Gait data from 15 able-bodied participants from the laboratory normal database and passive range of motion, kinematic, kinetic, and temporal spatial gait parameters, and oxygen cost were collected and analyzed for 27 individuals with CP (36 limbs) with isolated equinus contracture who received GSC lengthenings. Data were compared between preoperative and postoperative assessments.

RESULTS

Mean age at baseline was 11.4 years (+/-3.2 y). Mean time between surgery and postoperative gait analysis was 1.3 years (+/-0.3 y). Passive range of motion measurements were obtained. Kinematic and kinetic data for the hip, knee and ankle, and temporal spatial parameters were obtained from a representative gait trial preoperatively and postoperatively. Paired t tests (P<0.05) determined whether preoperative data differed from postoperative data or from able-bodied data. The passive range of motion at the ankle was improved and normalized postoperatively. Ankle kinematics normalized without compensatory changes occurring at the knee or hip kinematics. Ankle moments and powers become more normal but did not completely normalize. Kinematics and kinetics of the hip and knee were not adversely affected. No changes in the temporal spatial data or oxygen cost occurred postoperatively.

CONCLUSIONS

These data support the finding that with appropriate patient selection isolated GSC lengthening does not result in overcorrection.

LEVEL OF EVIDENCE

Retrospective comparative study; level 3.

The relation of triceps surae surgical lengthening and crouch gait in patients with cerebral palsy

To investigate the effect of earlier triceps surae (TS) surgical lengthening at knee kinematics in the stance phase in patients with cerebral palsy (CP). One thousand and thirty-nine participants from an eligible total of 1750 children with CP were referred to gait analysis laboratory from January 2000 to April 2007. Inclusion criteria were the diagnosis of diparetic spastic CP levels I to III (GMFCS) and complete kinematics documentation. Patients with an asymmetrical knee pattern at kinematics and with different types of TS management among sides were excluded. The patients were divided into two groups according to the mean minimum knee flexion (MMKF) in stance phase: group A (n=253) MMKF > or =30 degrees and group B (n=786) MMKF less than 30 degrees . For each group, the occurrence of following procedures for TS in the past: (i) earlier surgery, (ii) gastrocnemius lengthening (zone I), (iii) gastrocnemius and soleus lengthening (zone II), and (iv) calcaneous tendon lengthening (zone III), was investigated. A chi test was applied to check if the number of procedures performed was different between groups. The level of significance was defined as P value of less than 0.05. The number of patients with no earlier surgeries at TS was higher in group B (51.8%) than in group A (39.1%), and this difference was significant (P<0.01). In addition, the number of procedures at the calcaneous tendon was more elevated in group A (36.8%) than in group B (27%), and this finding was statistically significant as well (P<0.02). The percentage of surgical lengthening at zones I and II was very similar between the groups A and B. This study has shown that patients without earlier surgical procedures at TS are more susceptible to reach better extension of the knees in the stance phase. Patients in a crouch gait had a higher number of calcaneous tendon lengthening performed in the past than patients with a more normal knee extension in the stance phase.

A prospective cohort study of the effects of lower extremity orthopaedic surgery on outcome measures in ambulatory children with cerebral palsy

BACKGROUND

Lower-extremity musculotendinous surgery is standard treatment for ambulatory children with deformities such as joint contractures and bony torsions resulting from cerebral palsy (CP). However, evidence of efficacy is limited to retrospective, uncontrolled studies with small sample sizes focusing on gait variables and clinical examination measures. The aim of this study was to prospectively examine whether lower-extremity musculotendinous surgery in ambulatory children with CP improves impairments and function measured by gait and clinical outcome tools beyond changes found in a concurrent matched control group.

METHODS

Seventy-five children with spastic CP (Gross Motor Function Classification System levels I to III, age 4 to 18 y) that underwent surgery to improve gait were individually matched on the basis of sex, Gross Motor Function Classification System level, and CP subtype to a nonsurgical cohort, minimizing differences in age and Gross Motor Function Measure Dimension E. At baseline and at least 12 months after baseline or surgery, participants completed gait analysis and Gross Motor Function Measure, and parents completed outcome questionnaires. Mean changes at follow-up were compared using analysis of covariance adjusted for baseline differences.

RESULTS

Surgery ranged from single-level soft tissue release to multilevel bony and/or soft tissue procedures. At follow-up, after correcting for baseline differences, Gillette Gait Index, Pediatric Outcomes Data Collection Instrument Expectations, and Pediatric Quality of Life Inventory (PedsQL) Physical Functioning improved significantly for the surgical group compared with the nonsurgical group, which showed minimal change.

CONCLUSIONS

On the basis of a matched concurrent data set, there was significant improvement in function after 1 year for a surgical group compared with a nonsurgical group as measured by the Gillette Gait Index, with few significant changes noted in outcome measures. Changes over 1 year are minimal in the nonsurgical group, supporting the possibility of ethically performing a randomized controlled trial using nonsurgical controls.

LEVEL OF EVIDENCE

Therapeutic level 2. Prospective comparative study.

Long-term evaluation of isolated gastrocnemius fascia lengthening in children with cerebral palsy using gait analysis

The aim of this study was the quantification of outcomes on gait pattern of isolated gastrocnemius fascia lengthening treatment in children with cerebral palsy over time using gait analysis. Twelve children with cerebral palsy were evaluated with gait analysis before and after gastrocnemius fascia lengthening, in different follow-up sessions (from 3 to more than 25 months after treatment). Twenty healthy children were included as controls. Data analysis showed significant improvements in ankle and knee kinematics and in ankle kinetics over time. The results showed that isolated gastrocnemius fascia lengthening improved lower extremity function without producing functional muscle weakness over time.

Kinematic and kinetic outcomes after identical multilevel soft tissue surgery in children with cerebral palsy

This study evaluates the outcomes of multilevel soft tissue surgery in 31 ambulatory children (n = 39 sides) with cerebral palsy. All children had undergone rectus femoris transfer, hamstring lengthening, and gastrosoleus lengthening for the purpose of correcting sagittal plane abnormalities. There were no simultaneous bony surgeries. Preoperative and postoperative evaluation consisted of clinical assessment and gait analysis, including 3-dimensional kinematics and kinetics. Results demonstrated improvements in knee and ankle function. At the knee, there was a decrease in mean flexion at initial contact (from 31 degrees [SD, +/-8 degrees] to 21 degrees [SD, +/-10 degrees]) and in stance (mean stance, 22 degrees [SD, +/-12 degrees] to 16 degrees [SD, +/-11 degrees]) associated with a decreased mean internal extensor moment in stance (from 0.09 Nm/kg [SD, +/-0.24 Nm/kg] to -0.03 [SD, +/-0.22 Nm/kg]). At the same time, knee flexion was preserved in swing and occurred earlier. At the ankle, mean dorsiflexion improved at the time of examination (from 8 degrees [SD, +/-9 degrees] to 14 degrees [SD, +/-11 degrees] with the knee in extension), in terminal stance (peak from 7 degrees [SD, +/-9 degrees] to 12 degrees [SD, +/-8 degrees]), and in swing. Peak ankle power generation in stance was preserved and shifted later in stance toward push-off, with no functional weakening of the ankle plantar flexors. A longer-term assessment of a subset of patients with a second postoperative gait analysis at a mean of 4 years after surgery showed that gains measured at 1 year were maintained during the longer term. A subgroup demonstrating a jump knee gait pattern (as defined by excessive knee flexion at initial contact followed by rapid knee extension to full knee extension in midstance) had a tendency to go into knee hyperextension in stance with resultant net knee flexor moment after surgery. This raises concern about the indications for hamstring lengthening in this patient group.

Assessment of mobility after multi-level surgery for cerebral palsy

In cerebral palsy, the site and severity of the brain lesion are directly linked to gross motor function and the development of musculoskeletal deformities. The relationship between walking ability and orthopaedic surgery in children with cerebral palsy is not fully understood. The development of new tools such as the Functional Assessment Questionnaire and the Functional Mobility Scale can be used to give new insights on the functional impact of multilevel surgery. These scales are most useful as part of systematic, long-term follow-up.

The effect of serial casting on gait in children with cerebral palsy: preliminary results from a crossover trial

Serial casting aims to improve an equinus gait pattern in children with spastic cerebral palsy (SCP). We evaluated the effect of short-term stretch casting on gait in children with SCP, compared to the natural history. A crossover trial, consisting of a control phase and a casting phase, was conducted with children randomised into two groups. Both groups were assessed clinically, and using 3D gait analysis, at 0, 5 and 12 weeks. Subjects in one group had the 3 month casting phase first and in the other had the 3 month control period first. Casts were changed weekly and set at maximum available ankle dorsiflexion. The mean changes at 5 weeks and 12 weeks from baseline measurements in the casting phase were compared with the change within the same time interval in the control phase. Significant improvements in passive ankle dorsiflexion (knee flexed) were found at 5 and 12 weeks. Passive ankle dorsiflexion (knee extended), ankle dorsiflexion in single support, ankle dorsiflexion in swing and minimum hip flexion in stance improved significantly at 5 weeks but not at 12 weeks from baseline. Other kinematic parameters, the score on the Gillette Functional Assessment Questionnaire, and maximum reported walking distance were not changed by casting. Casting to improve range appears to improve passive and dynamic ankle dorsiflexion, but the changes are small, short lived and do not appear to affect function.

Soft tissue surgery for equinus deformity in spastic hemiplegic cerebral palsy: effects on kinematic and kinetic parameters

The purpose of this study was to evaluate how soft tissue surgery for correcting equinus deformity affects the kinematic and kinetic parameters of the ankle and proximal joints. Sixteen children with spastic hemiplegic cerebral palsy and equinus deformities (age range 3-16 years) were included. Soft tissue surgeries were performed exclusively on the ankle joint area in all subjects. Using computerized gait analysis (Vicon 370 Motion Analysis System), the kinematic and kinetic parameters during barefoot ambulation were collected preoperatively and postoperatively. In all 16 children, the abnormally increased ankle plantar flexion and pelvis anterior tilting on the sagittal plane were significantly improved without a weakening of push-off (p < 0.05). In a group of 8 subjects with a recurvatum knee gait pattern before operation, the postoperative kinematic and kinetic parameters of the knee joint were significantly improved (p < 0.05). In a group of 8 subjects with ipsilateral pelvic external rotation before operation, the postoperative pelvic deviations on the transverse plane were significantly decreased (p < 0.05). These findings suggest that the soft tissue surgery for correcting equinus deformity improves not only the abnormal gait pattern of the ankle, but also that of the knee and pelvis.

Postoperative imaging of the ankle and foot

This article describes the relevant surgical detail and MR imaging appearance of common operations performed in the foot and ankle. To evaluate postsurgical patients critically, it is important to understand the primary clinical diagnosis, surgical treatment undergone, the interval since surgery, and patients' current clinical symptoms. Radiography is the most common imaging modality for evaluation of the postoperative ankle and foot. MR imaging may be useful for evaluating the soft tissues and osseous structures in the postsurgical foot and ankle.