Botulinum Toxin Type A Injections Impact Hamstring Muscles and Gait Parameters in Children with Flexed Knee Gait

Using the gross motor function measure evolution ratio to compare different dosage of hyperbaric treatment with conventional therapies in children with cerebral palsy - could it end the controversy?

The Gross Motor Function Measure is used in most studies measuring gross motor function in children with cerebral palsy. In many studies, including those evaluating the effect of hyperbaric treatment, the Gross Motor Function Measure variations were potentially misinterpreted because of the lack of control groups. The Gross Motor Function Measure Evolution Ratio (GMFMER) uses historical data from the Gross Motor Function Classification System curves and allows to re-analyze previous published studies which used the Gross Motor Function Measure by considering the natural expected evolution of the Gross Motor Function Measure. As the GMFMER is defined by the ratio between the recorded Gross Motor Function Measure score increase and the expected increase attributed to natural evolution during the duration of the study (natural evolution yields a GMFMER of 1), it becomes easy to assess and compare the efficacy of different treatments.

Objective

The objective of this study is to revisit studies done with different dosage of hyperbaric treatment and to compare the GMFMER measured in these studies with those assessing the effects of various recommended treatments in children with cerebral palsy.

Methods

PubMed Searches were conducted to included studies that used the Gross Motor Function Measure to evaluate the effect of physical therapy, selective dorsal rhizotomy, botulinum toxin injection, hippotherapy, stem cell, or hyperbaric treatment. The GMFMER were computed for each group of the included studies.

Results

Forty-four studies were included, counting 4 studies evaluating the effects of various dosage of hyperbaric treatment in children with cerebral palsy. Since some studies had several arms, the GMFMER has been computed for 69 groups. The average GMFMER for the groups receiving less than 2 h/week of physical therapy was 2.5 ± 1.8 whereas in context of very intensive physical therapy it increased to 10.3 ± 6.1. The GMFMER of stem cell, selective dorsal rhizotomy, hippotherapy, and botulinum toxin treatment was, 6.0 ± 5.9, 6.5 ± 2.0, 13.3 ± 0.6, and 5.0 ± 2.9, respectively. The GMFMER of the groups of children receiving hyperbaric treatment were 28.1 ± 13.0 for hyperbaric oxygen therapy and 29.8 ± 6.8 for hyperbaric air.

Conclusion

The analysis of the included studies with the GMFMER showed that hyperbaric treatment can result in progress of gross motor function more than other recognized treatments in children with cerebral palsy.

Crouch Gait in Cerebral Palsy: Current Concepts Review

Background and Objective

Crouch gait is the most common pathological gait pattern in cerebral palsy and is commonly seen in patients with spastic diplegia. It is characterized by excessive knee flexion throughout the stance phase of gait cycle. The aim of this review is to discuss the current literature about CG for a more comprehensive understanding.

Methods

A literature review about various aspects of crouch gait in cerebral palsy was undertaken. This included its etiology and pathophysiology, biomechanics in crouch gait, natural history of untreated crouch gait, clinical and radiological evaluation and different modalities of available treatment.

Results

The etiology is multifactorial and the pathophysiology is poorly understood. This makes its management challenging, thereby leading to a variety of available treatment modalities. Inadvertent lengthening of muscle-tendon units is an important cause and can be avoided. A meticulous clinical and radiological evaluation of patients, supplemented by observational and instrumented gait analysis is mandatory in choosing correct treatment modality and improving the treatment outcome. Younger children can be managed satisfactorily by various non-operative methods and spasticity reduction measures. However, crouch gait in cerebral palsy has a progressive natural history and surgical interventions are needed frequently. The current literature supports combination of various soft tissue and bony procedures as a part of single event multilevel surgery. Growth modulation in the form of anterior distal femur hemiepiphysiodesis for correction of fixed flexion deformity of knee has shown encouraging results and can be an alternative in younger children with sufficient growth remaining.

Conclusions

In spite of extensive research in this field, the current understanding about crouch gait has many knowledge gaps. Further studies about the etiopathogenesis and biomechanics of crouch using instrumented gait analysis are suggested. Similarly, future research should focus on the long term outcomes of different treatment modalities through comparative trials.

Botulinum toxin type A for spasticity in cerebral palsy patients: Which impact on popliteal angle to hamstring length? A proof-of-concept study

BACKGROUND

Cerebral palsy (CP) is the most common physical disability in childhood. It is a heterogeneous condition in terms of etiology, motor type and severity of impairments. Clinical impairments, such as increased muscle tone (spasticity), muscle weakness and joint stiffness contribute to the abnormal development of functional activities, including gait.

OBJECTIVE

The objective of this study was to investigate the popliteal angle to hamstring length after ultrasound guided Incobotulinum toxin A injections for spasticity in CP patients.

METHODS

In this proof-of-concept study, we included outpatients with CP and crouch gait correlated to hamstrings spasticity referred to the Pediatric Rehabilitation outpatient clinic of Umberto I University Hospital, Sapienza University of Rome, in the period between February and October 2018.

METHODS

Modified Ashworth Scale (MAS) of hamstring muscles, Popliteal Angle and Modified Popliteal Angle, Passive Knee Extension and 10 Meter Walk Test (10MWT) were assessed at baseline (T0) and three weeks after ultrasound guided injection (T1) of Incobotulinum Toxin A (dose weight and site dependent).

RESULTS

Thirteen patients (5 male and 8 female), mean aged 9.91 ± 3.59, were included. The clinical evaluation at T0 showed hamstring muscles spasticity, with MAS of 2.4 ± 0.6, popliteal angle -51.7∘± 11.0∘, modified popliteal angle of -39.5∘± 11.0∘, passive knee extension of -14.0∘± 8.7∘ and 10MWT of 14.3 ± 4.6 seconds. At T1, hamstring muscles MAS mean value was 1.7 ± 0.6 (p< 0.01), popliteal angle 41.3∘± 7.0∘ (p< 0.001), modified popliteal angle -32.9∘± 10.4∘ (p< 0.001), passive knee extension -4.0∘± 4.2∘ (p< 0.05) and 10MWT 12.6 ± 4.8 seconds (p< 0.05). None of the treated patients reported any adverse event related to Incobotulinum Toxin A injection.

CONCLUSION

Incobotulinum toxin A treatment has been proven to be safe and effective for hamstring muscles spasticity management in CP patients. Further studies with larger samples and longer follow-up are warranted to assess the efficacy of this treatment on the popliteal angle.

Long-term outcome of hamstring lengthening versus transfer and the role of biceps femoris lengthening in patients with spastic diplegia and dynamic knee flexion in gait

BACKGROUND

Orthopedic treatment of flexed-knee gait consists of hamstring lengthening along with surgery at other levels. Transfer of the semitendinosus (hamstring transfer) was introduced to avoid increase of anterior pelvic tilt as well as reduce risk of recurrence.

METHODS

We retrospectively assessed children with spastic cerebral palsy and flexed-knee gait pre-operatively, 1 year post-operatively, and at a minimum of 7 years post-operatively.

RESULTS

The 39 patients were a mean 9.4 ± 3.4 years at the time of surgery, 20 subjects underwent hamstring transfer, and 19 subjects had hamstring lengthening with mean follow-up 9.1 years. Passive range of motion improved initially, but regressed at long term. Dynamic minimum knee flexion in stance decreased in both groups at the first post-operative study, and was maintained at final follow-up in 64-67% of patients. There was a small increase in anterior pelvic tilt at the 1-year follow-up which subsequently decreased to less than pre-operative in the hamstring lengthening group but remained mildly increased (5°) in the hamstring transfer group at final follow-up. Success in correcting stance knee flexion of the entire group was 69% of the Gross Motor Function Classification System grades I and II and 60% of the Gross Motor Function Classification System grade III subjects. Gait profile Score and sagittal knee Gait Variable Score both showed clinically important improvement after surgery and was mostly maintained long term for both groups. Lateral hamstring lengthening was beneficial in more severe patients, with minimal risk of adverse effects.

CONCLUSION

Hamstring surgery as part of single event multi-level surgery (SEMLS) is effective in correcting flexed-knee gait in 60%-70% of patients with minimal effect on anterior pelvic tilt. There was no added advantage to hamstring transfer. Biceps Femoris lengthening may be beneficial and without significant additional risk.

LEVEL OF EVIDENCE

level III.

Crouch gait or flexed-knee gait in cerebral palsy: Is there a difference? A systematic review

BACKGROUND

Crouch or flexed-knee gait is one of the most common pathological gait patterns in cerebral palsy (CP). Differences exist in definitions used; the degree of knee flexion, inclusion of hip or ankle position, and timing in the gait cycle. This ambiguity may be responsible for variations in prevalence rates and difficulty comparing data across studies.

RESEARCH QUESTION

What are the kinematic parameters used to define crouch or flexed-knee gait in CP gait? A secondary aim was to examine the quality of data reporting, focusing on the sample characteristics, inclusion/exclusion criteria and the choice of limb included for analysis.

METHODS

Articles included in this review reported on a specified cohort of adults or children with crouch or flexed-knee gait assessed with 3-dimensional gait analysis. A customised data extraction and quality assessment table was designed specific to the research question.

RESULTS

The majority (75 %) of included studies used the term crouch gait. Where the pattern was defined, 80 % of crouch papers and 94 % of flexed-knee gait papers based this solely on knee position. Kinematic parameters were clearly defined when they provided objective values of knee flexion, supported this with rationale and provided a reference point in the gait cycle. Only 22 % of crouch papers and 19 % of flexed-knee gait papers provided this information. The majority of studies (67 % crouch; 90 % flexed-knee) specified which limb(s) were included for analysis with the majority including both limbs. Objective values of knee flexion ranged from 8 o to 30 o.

SIGNIFICANCE

This review highlights that crouch and flexed knee are synonymous and ambiguity exists in the kinematic definition making it difficult to make compare data amongst study cohorts. Future research should provide detailed definitions including the threshold value of knee flexion, how it was derived, the timing in the gait cycle and the limb(s) included in analysis.