Long-term effects after conversion of biarticular to monoarticular muscles compared with musculotendinous lengthening in children with spastic diplegia

Anterior Distal Femoral Hemiepiphysiodesis Does Not Change Pelvic Tilt in Children With Cerebral Palsy

BACKGROUND

Anterior distal femoral hemiepiphysiodesis (ADFH) is a surgical treatment choice to correct flexed knee gait and fixed knee flexion deformities in children with cerebral palsy who are skeletally immature. Increased anterior pelvic tilt has been reported after surgeries that correct knee flexion deformities, including hamstring lengthening (HSL) and distal femoral extension osteotomies, but anterior pelvic tilt has not been studied after ADFH. We hypothesized that anterior pelvic tilt would increase after ADFH, especially when combined with HSL, and it would correlate with the change in minimum knee flexion in stance and dynamic hamstring lengths.

METHODS

Thirty-four eligible participants (age: 13.0, SD: 2.0) were included. Change in mean pelvic tilt across the gait cycle was compared as a function of clinical and gait parameters using linear mixed models. The relationship of change in pelvic tilt to change in other variables was examined using Pearson correlation.

RESULTS

Overall, anterior pelvic tilt increased significantly after ADFH by 4.4 degrees ( P = 0.02). Further, the analysis revealed anterior pelvic tilt only increased significantly in the group that had concurrent HSL (11.1 degrees, P < 0.001). Overall, minimum knee flexion significantly decreased (increase in knee extension) in stance (-19.1 degrees, P < 0.001) and there was an increase in maximum normalized dynamic hamstring lengths (0.03, P < 0.001). The anterior pelvic tilt increased significantly in Gross Motor Function Classification System levels III to IV (5.9 degrees, P = 0.02) but did not change significantly in Gross Motor Function Classification System I to II (2.5 degrees, P = 0.37). Change in pelvic tilt was correlated with change in maximum dynamic hamstring lengths ( r = 0.87, P < 0.0001) and change in minimum knee flexion in stance ( r = -0.71, P < 0.0001).

CONCLUSIONS

Anterior distal hemiepiphysiodesis without concurrent HSL for flexion knee deformities does not result in increased anterior pelvic tilt. Surgeons should consider anterior distal hemiepiphysiodesis in patients with cerebral palsy and flexed knee gait, who preoperatively have long dynamically modeled hamstrings, are skeletally immature, and when maintenance of pelvic tilt is desired.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Mid-Term Results of Distal Femoral Extension and Shortening Osteotomy in Treating Flexed Knee Gait in Children with Cerebral Palsy

Background: Distal femoral extension and shortening osteotomy (DFESO) seems to be an effective method for the treatment of flexed knee gait in children with cerebral palsy. Nevertheless, studies investigating the mid- and long-term outcomes after such procedures are lacking in the literature. Therefore, the purpose of this study was to assess the mid-term outcomes regarding sagittal plane kinematics of the knee after DFESO with or without concomitant patella advancement. Furthermore, an evaluation of the postoperative course and possible recurrence of flexed knee gait was planned. Methods: In a prospective observational study, 19 patients (28 limbs; mean age 11.8 years (6.7–16.0 years)) were examined using 3-D gait analysis and clinical exam before (E₀) and at a mean of 38 months (E₂: 24–55 months) after surgery. Fifteen patients (22 limbs) had an additional first postoperative gait analysis (E₁) after a mean of 14 (10–20) months after surgery. In these patients, the postoperative changes between the short-term and mid-term gait analyses were evaluated. Results: DFESO led to a significant decrease in flexed knee gait with an improvement in sagittal plane kinematics during the stance phase. In addition, a slightly increased anterior pelvic tilt was observed at E₁, and we found a tendency towards stiff knee gait with a decrease in mean knee flexion in swing at E₂. Conclusions: DFESO led to a significant improvement in flexed knee gait in children with cerebral palsy. The therapeutic effect seems to be lasting on mid-term follow-up with a slight overall tendency to recurrence.

Long-term follow-up after multilevel surgery in cerebral palsy

INTRODUCTION

Single-event multilevel surgery (SEMLS) is frequently used to correct pathological gait patterns in children with bilateral spastic cerebral palsy (BSCP) in a single session surgery. However, in-depth long-term evaluation reports of gait outcomes are limited. Therefore, we investigated if SEMLS is able to correct lower extremity joint and pelvic angles during gait towards typically developing gait patterns (TDC) in children with BSCP, and if so, if this effect is durable over a 10-year period.

MATERIALS AND METHODS

In total 13 children with BSCP GMFCS level II at time of index-surgery between the ages of 7.7-18.2 years at the time of SEMLS were retrospectively recruited. Three-dimensional gait data were captured preoperatively, as well as at short-, mid-, and long-term post-operatively, and used to analyze: movement analysis profile (MAP), gait profile score (GPS), and lower extremity joint and pelvic angles over the course of a gait cycle using statistical parametric mapping.

RESULTS

In agreement with previous studies, MAP and GPS improved towards TDCs after surgery, as did knee extension during the stance phase (ɳ² = 0.67; p < 0.001), while knee flexion in the swing phase (ɳ² = 0.67; p < 0.001) and pelvic tilt over the complete gait cycle (ɳ² = 0.36; p < 0.001) deteriorated; no differences were observed between follow-ups. However, further surgical interventions were required in 8 out of 13 of the participants to maintain improvements 10 years post-surgery.

CONCLUSIONS

While the overall gait pattern improved, our results showed specific aspects of the gait cycle actually deteriorated post-SEMLS and that a majority of the participants needed additional surgery, supporting previous statements for the use of multilevel surgery rather than SEMLS. The results highlight that the field should not only focus on the overall gait scores when evaluating treatment outcomes but should offer additional long-term follow-up of lower extremity function.

Finding consensus for hamstring surgery in ambulatory children with cerebral palsy using the Delphi method

PURPOSE

There is marked variation in indications and techniques for hamstring surgery in children with cerebral palsy. There is particular uncertainty regarding the indications for hamstring transfer compared to traditional hamstring lengthening. The purpose of this study was for an international panel of experts to use the Delphi method to establish consensus indications for hamstring surgery in ambulatory children with cerebral palsy.

METHODS

The panel used a five-level Likert-type scale to record agreement or disagreement with statements regarding hamstring surgery, including surgical indications and techniques, post-operative care, and outcome measures. Consensus was defined as at least 80% of responses being in the highest or lowest two of the five Likert-type ratings. General agreement was defined as 60%-79% falling into the highest or lowest two ratings. There was no agreement if neither of these thresholds was reached.

RESULTS

The panel reached consensus or general agreement for 38 (84%) of 45 statements regarding hamstring surgery. The panel noted the importance of assessing pelvic tilt during gait when considering hamstring surgery, and also that lateral hamstring lengthening is rarely needed, particularly at the index surgery. They noted that repeat hamstring lengthening often has poor outcomes. The panel was divided regarding hamstring transfer surgery, with only half performing such surgery.

CONCLUSION

The results of this study can help pediatric orthopedic surgeons optimize decision-making in their choice and practice of hamstring surgery for ambulatory children with cerebral palsy. This has the potential to reduce practice variation and significantly improve outcomes for ambulatory children with cerebral palsy.

LEVEL OF EVIDENCE

level V.

Comparison between semitendinosus transfer to distal femur and medial hamstrings surgical lengthening for treatment of flexed knee gait in cerebral palsy

PURPOSE

Hamstrings surgical lengthening (HSL) has been frequently used for the treatment of flexed knee gait in cerebral palsy; however, recurrence of knee flexion deformity (KFD) and increase of anterior pelvic tilt (APT) were reported in a long-term follow-up.

RESEARCH QUESTION

The aim of this study was to compare semitendinosus transfer to distal femur (STTX) and semitendinosus surgical lengthening (STL) regarding the reduction of KFD and the increase of APT after flexed knee gait treatment.

METHODS

One hundred and eleven patients were evaluated and they were divided into two groups according to surgical procedures at knees: group A (65 patients/130 knees), including patients who received medial HSL as part of multilevel approach; group B (46 patients/92 knees), represented by patients who underwent orthopedic surgery including an STTX instead of STL.

RESULTS

Fixed knee flexion deformity (FKFD) decreased only in group B (from 6.79° to 2.96°, p < 0.001) after intervention. In kinematics, APT increased from 16.38° to 19.03° in group A (p = 0.003), while group B also increased from 15.26° to 20.59° (p < 0.001). The minimum knee flexion in stance phase (MKFS) reduced from 25.34° to 21.65° (p = 0.016) in group A and from 31° to 19.57° (p < 0.001) in group B. In the comparison between groups A and B, the increase of APT (p = 0.028) and reduction of FKFD (p < 0.001), popliteal angle (p = 0.001), bilateral popliteal angle (p = 0.003) and MKFS (p = 0.006) were higher after STTX than STL.

CONCLUSION

In the present study, patients who received STTX exhibited more improvement of knee extension at clinical examination and during gait than those who underwent to STL; however, STTX was not effective to prevent the increase of APT after flexed knee gait treatment.

Orthopaedic management of knee joint impairment in cerebral palsy: A systematic review and meta-analysis

BACKGROUND

The optimal management of impaired knee joint function in patients with cerebral palsy (CP) remains a significant and ongoing challenge in paediatric orthopaedic surgery.

RESEARCH QUESTION

What are the clinical and functional outcomes after operative and non-operative orthopaedic interventions for knee joint impairment in patients with CP?

METHODS

This systematic review and meta-analysis of orthopaedic interventions for the management of knee joint impairment in paediatric CP patients evaluated study-level data in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. We performed searches of the following electronic databases from their dates of inception to November 2019: Medline (Ovid), Embase (Ovid) and Pubmed. We extracted mean differences in pre-operative and post-operative measurements for the following outcomes: minimum knee flexion in stance; knee flexion at initial contact; maximum knee flexion in swing; range of motion; popliteal angle; fixed flexion deformity angle; and mean pelvic tilt.

RESULTS

Sixty-nine retrospective cohort studies, prospective cohort studies and RCTs comprising 2991 patients were included with 4578 knees analysed. Included studies were of sufficient quality as assessed by the MOOSE checklist. Operative interventions showed significant improvement in knee flexion at initial contact, knee flexion in stance, range of motion, popliteal angle and fixed flexion deformity which were comparable when subgrouped according to operative technique. In contrast, non-operative techniques and botulinum toxin injection did not confer significant improvements. Operative interventions for knee joint impairment led to increased mean pelvic tilt and reduced maximum knee flexion in swing.

SIGNIFICANCE

This review provides strong evidence that operative interventions for the management of knee joint impairment in cerebral palsy patients improve knee kinematics and clinical examination findings.

Follow-up of walking quality after end of growth in 28 children with bilateral cerebral palsy

PURPOSE

Assessment of surgical treatments on gait in patients with bilateral cerebral palsy (CP) is often performed in short-term studies. The purpose of this study was to analyze the influence of single-event multilevel surgery (SEMLS) on long-term evolution of gait using gait deviation index (GDI) and walking speed.

METHODS

In all, 28 patients with bilateral CP (Gross Motor Function Classification System I to III) with two clinical gait analyses (CGA) were included (mean age: 9.0 years (sd 2.9) at the first CGA, 19.6 years (sd 4.1) at the last, all of them at skeletal maturity). GDI, walking speed and their changes were calculated. Statistical analysis was performed to observe differences between baseline and follow-up CGA. Pearson's correlations were conducted to evaluate the associations between GDI and walking speed changes with: GDI at baseline and walking speed at baseline. GDI and walking speed evolution have been analyzed for two groups of patients: with and without SEMLS.

RESULTS

Regardless of the treatment, GDI was significantly higher at follow-up CGA (baseline: 73.1 (sd 13.1) versus follow-up: 80.1 (sd 13.2); p = 0.014). Significant negative correlations were found between GDI change and GDI at baseline (r = -0.52; p = 0.004) and between walking speed change and walking speed at the baseline (r = -0.70; p < 0.001). Regarding the group of patients with or without SEMLS, only significant improvement of GDI was found for patients with SEMLS (at baseline: 69.0 (sd 12.1) versus follow-up: 77.8 (sd 11.2); p < 0.05).

CONCLUSION

Analysis at skeletal maturity showed a gait quality maintained for patients without SEMLS and an improvement for patients with SEMLS.

LEVEL OF EVIDENCE

Level III.

Association of back pain and pelvic tilt during gait in individuals with cerebral palsy

BACKGROUND

Back pain prevalence may increase with lumbar lordosis during standing in individuals with cerebral palsy (CP). Multiple interventions undertaken in individuals with CP have been shown to increase anterior pelvic tilt.

RESEARCH QUESTION

Are pelvic tilt and trunk tilt (proxy measurements for lumbar lordosis) during gait associated with back pain prevalence in ambulatory individuals with CP?

METHODS

A retrospective investigation was performed among all patients with cerebral palsy visiting a single clinical motion analysis laboratory over a 3.5 year period (January 2015 - May 2018) who also had complete pain questionnaire data. Back pain prevalence and its association with sagittal plane kinematic parameters (pelvic tilt and trunk tilt) were analyzed.

RESULTS

Among the 700 patients that met the inclusion criteria, 594 were children and 106 were adults. Back pain prevalence was 11.1% in children and 36.8% in adults. As pelvic tilt and age increased, back pain increased (odds ratio 95% confidence interval: 1.002-1.061 and 1.052-1.109, respectively). Walking with an assistive device was not associated with back pain, nor was trunk tilt.

SIGNIFICANCE

Back pain was more common with increasing age in ambulatory individuals with CP. After controlling for assistive device use and age, there was a weak relationship between pelvic tilt and back pain. Future studies are needed to determine if this is this a causal relationship.

The increase of anterior pelvic tilt after semitendinosus transfer to distal femur in patients with spastic diplegic cerebral palsy

The aim of this study was to compare semitendinosus transfer to distal femur (STTX) to semitendinosus surgical lengthening (STL) regarding the increase of anterior pelvic tilt after flexed knee gait treatment. Thirty-nine patients were evaluated, and they were divided according surgical procedures at knees: STL group (22 patients/44 knees), which included patients who received medial hamstrings surgical lengthening as part of multilevel approach, and STTX group (17 patients/34 knees), which was represented by patients who underwent orthopedic surgery including a STTX instead of STL. In the present study, the mean anterior pelvic tilt increased in all groups after treatment and STTX was not effective to prevent it in a medium-term follow-up.

Multilevel Surgery for Children With Cerebral Palsy: A Meta-analysis

CONTEXT

Multilevel surgery (MLS) is standard care for reducing musculoskeletal disorders among children with spastic cerebral palsy (CP).

OBJECTIVE

To summarize the literature examining effects of MLS and satisfaction with MLS for children with CP.

DATA SOURCES

Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Central Register of Controlled Trials were searched.

STUDY SELECTION

Studies in which authors reported effects of or satisfaction with MLS in children with CP were selected.

DATA EXTRACTION

Two authors screened and extracted data on gross motor function, gait speed, gait (eg, Gait Profile Score), range of motion, strength, spasticity, participation, quality of life, satisfaction, and adverse events.

RESULTS

Seventy-four studies (3551 participants) were identified. One was a randomized controlled trial (RCT) (n = 19); the remainder were cohort studies. Pooled analysis of cohort studies revealed that MLS did not have a long-term effect on gross motor function (standardized mean difference [SMD]: 0.38; 95% confidence interval [CI]: -0.25 to 1.01) or gait speed (SMD: 0.12; 95% CI: -0.01 to 0.25) but did improve gait (SMD: -0.80; 95% CI: -0.95 to -0.65). The RCT also revealed no effect of MLS on gross motor function but improvements in the Gait Profile Score at 1 year. Participation and quality of life were reported in only 5 studies, and adverse events were adequately reported in 17 studies.

LIMITATIONS

Data were largely from cohort studies.

CONCLUSIONS

Findings reveal that gait, but not gross motor function, improves after MLS. RCTs and improved reporting of studies of MLS are required.

Evaluating the Effects of Ankle-Foot Orthosis Mechanical Property Assumptions on Gait Simulation Muscle Force Results

Musculoskeletal modeling and simulation techniques have been used to gain insights into movement disabilities for many populations, such as ambulatory children with cerebral palsy (CP). The individuals who can benefit from these techniques are often limited to those who can walk without assistive devices, due to challenges in accurately modeling these devices. Specifically, many children with CP require the use of ankle-foot orthoses (AFOs) to improve their walking ability, and modeling these devices is important to understand their role in walking mechanics. The purpose of this study was to quantify the effects of AFO mechanical property assumptions, including rotational stiffness, damping, and equilibrium angle of the ankle and subtalar joints, on the estimation of lower-limb muscle forces during stance for children with CP. We analyzed two walking gait cycles for two children with CP while they were wearing their own prescribed AFOs. We generated 1000-trial Monte Carlo simulations for each of the walking gait cycles, resulting in a total of 4000 walking simulations. We found that AFO mechanical property assumptions influenced the force estimates for all the muscles in the model, with the ankle muscles having the largest resulting variability. Muscle forces were most sensitive to assumptions of AFO ankle and subtalar stiffness, which should therefore be measured when possible. Muscle force estimates were less sensitive to estimates of damping and equilibrium angle. When stiffness measurements are not available, limitations on the accuracy of muscle force estimates for all the muscles in the model, especially the ankle muscles, should be acknowledged.

Effectiveness of surgical and non-surgical management of crouch gait in cerebral palsy: A systematic review

BACKGROUND

Cerebral palsy (CP) is a prevalent group of neuromotor disorders caused by early injury to brain regions or pathways that control movement. Patients with CP exhibit a range of functional motor disabilities and pathologic gait patterns. Crouch gait, characterized by increased knee flexion throughout stance, is a common gait pattern in CP that increases energy costs of walking and contributes to ambulatory decline. Our aim was to perform the first systematic literature review on the effectiveness of interventions utilized to ameliorate crouch gait in CP.

METHODS

Comprehensive searches of five medical databases yielded 38 papers with 30 focused on orthopaedic management.

RESULTS

Evidence supports the use of initial hamstring lengthenings and rectus femoris transfers, where indicated, for improving objective gait measures with limited data on improving gait speed or gross motor function. In contrast, evidence argues against hamstring transfers and revision hamstring lengthening, with recent interest in more technically demanding corrective procedures. Only eight studies evaluated alternatives to surgery, specifically strength training, botulinum toxin or orthoses, with inconsistent and/or short-lived results.

CONCLUSIONS

Although crouch in CP is recognized clinically as a complex multi-joint, multi-planar gait disorder, this review largely failed to identify interventions beyond those which directly address sagittal plane knee motion, indicating a major knowledge gap. Quality of existing data was notably weak, with few studies properly controlled or adequately sized. Outcomes from specific procedures are confounded by multilevel surgeries. Successful longer term strategies to prevent worsening of crouch and subsequent functional decline are needed.

LEVEL OF EVIDENCE

Systematic review.

A Systematic Review of the Effects of Single-Event Multilevel Surgery on Gait Parameters in Children with Spastic Cerebral Palsy

BACKGROUND

Three-dimensional gait analysis (3DGA) is commonly used to assess the effect of orthopedic single-event multilevel surgery (SEMLS) in children with spastic cerebral palsy (CP).

PURPOSE

The purpose of this systematic review is to provide an overview of different orthopedic SEMLS interventions and their effects on 3DGA parameters in children with spastic CP.

METHODS

A comprehensive literature search within six databases revealed 648 records, from which 89 articles were selected for the full-text review and 24 articles (50 studies) included for systematic review. The Oxford Centre for Evidence-Based Medicine Scale and the Methodological Index for Non-Randomized Studies (MINORS) were used to appraise and determine the quality of the studies.

RESULTS

Except for one level II study, all studies were graded as level III according to the Oxford Centre for Evidence-Based Medicine Scale. The MINORS score for comparative studies (n = 6) was on average 15.7/24, while non-comparative studies (n = 18) scored on average 9.8/16. Nineteen kinematic and temporal-distance gait parameters were selected, and a majority of studies reported improvements after SEMLS interventions. The largest improvements were seen in knee range of motion, knee flexion at initial contact and minimal knee flexion in stance phase, ankle dorsiflexion at initial contact, maximum dorsiflexion in stance and in swing phase, hip rotation and foot progression angles. However, changes in 3DGA parameters varied based on the focus of the SEMLS intervention.

DISCUSSION

The current article provides a novel overview of a variety of SEMLS interventions within different SEMLS focus areas and the post-operative changes in 3DGA parameters. This overview will assist clinicians and researchers as a potential theoretical framework to further improve SEMLS techniques within different SEMLS focus groups. In addition, it can also be used as a tool to enhance communication with parents, although the results of the studies can't be generalised and a holistic approach is needed when considering SEMLS in a child with spastic CP.

A Robotic Exoskeleton for Treatment of Crouch Gait in Children With Cerebral Palsy: Design and Initial Application

Crouch gait, a pathological pattern of walking characterized by excessive knee flexion, is one of the most common gait disorders observed in children with cerebral palsy (CP). Effective treatment of crouch during childhood is critical to maintain mobility into adulthood, yet current interventions do not adequately alleviate crouch in most individuals. Powered exoskeletons provide an untapped opportunity for intervention. The multiple contributors to crouch, including spasticity, contracture, muscle weakness, and poor motor control make design and control of such devices challenging in this population. To our knowledge, no evidence exists regarding the feasibility or efficacy of utilizing motorized assistance to alleviate knee flexion in crouch gait. Here, we present the design of and first results from a powered exoskeleton for extension assistance as a treatment for crouch gait in children with CP. Our exoskeleton, based on the architecture of a knee-ankle-foot orthosis, is lightweight (3.2 kg) and modular. On board sensors enable knee extension assistance to be provided during distinct phases of the gait cycle. We tested our device on one six-year-old male participant with spastic diplegia from CP. Our results show that the powered exoskeleton improved knee extension during stance by 18.1° while total knee range of motion improved 21.0°. Importantly, we observed no significant decrease in knee extensor muscle activity, indicating the user did not rely solely on the exoskeleton to extend the limb. These results establish the initial feasibility of robotic exoskeletons for treatment of crouch and provide impetus for continued investigation of these devices with the aim of deployment for long term gait training in this population.

Literature Review and Comparison of Two Statistical Methods to Evaluate the Effect of Botulinum Toxin Treatment on Gait in Children with Cerebral Palsy

AIM

This study aimed at comparing two statistical approaches to analyze the effect of Botulinum Toxin A (BTX-A) treatment on gait in children with a diagnosis of spastic cerebral palsy (CP), based on three-dimensional gait analysis (3DGA) data. Through a literature review, the available expert knowledge on gait changes after BTX-A treatment in children with CP is summarized.

METHODS

Part 1--Intervention studies on BTX-A treatment in children with CP between 4-18 years that used 3DGA data as an outcome measure and were written in English, were identified through a broad systematic literature search. Reported kinematic and kinetic gait features were extracted from the identified studies. Part 2--A retrospective sample of 53 children with CP (6.1 ± 2.3years, GMFCS I-III) received 3DGA before and after multilevel BTX-A injections. The effect of BTX-A on gait was interpreted by comparing the results of paired samples t-tests on the kinematic gait features that were identified from literature to the results of statistical parametric mapping analysis on the kinematic waveforms of the lower limb joints.

RESULTS

Part 1-53 kinematic and 33 kinetic features were described in literature. Overall, there is no consensus on which features should be evaluated after BTX-A treatment as 49 features were reported only once or twice. Part 2--Post-BTX-A, both statistical approaches found increased ankle dorsiflexion throughout the gait cycle. Statistical parametric mapping analyses additionally found increased knee extension during terminal stance. In turn, feature analyses found increased outtoeing during stance after BTX-A.

CONCLUSION

This study confirms that BTX-A injections are a valuable treatment option to improve gait function in children with CP. However, different statistical approaches may lead to different interpretations of treatment outcome. We suggest that a clear, definite hypothesis should be stated a priori and a commensurate statistical approach should accompany this hypothesis.