Mid-term development of hamstring tendon length and velocity after distal femoral extension osteotomy in children with bilateral cerebral palsy: a retrospective cohort study

Distal femoral osteotomy and patellar tendon advancement for the treatment of crouch gait in patients with bilateral spastic cerebral palsy

BACKGROUND

Crouch gait, or flexed knee gait, represents a common gait pattern in patients with spastic bilateral cerebral palsy (CP). Distal femoral extension and/or shortening osteotomy (DFEO/DFSO) and patellar tendon advancement (PTA) can be considered as viable options when knee flexion contractures are involved. Better outcomes have been reported after a combination of both, independently of the presence of knee extensor lag. In this study, we evaluated the clinical and kinematic outcomes of these procedures.

PATIENTS AND METHODS

We reviewed a cohort of 52 limbs (28 patients) who were treated for crouch gait by DFEO/DFSO alone (group 1, n = 15) or DFEO/DFSO + PTA (group 2, n = 37) as a part of single event multilevel surgery (SEMLS). The mean age at surgery was 14 years, and the mean follow-up time was 18 months. The physical examination data and three-dimensional standardized gait analysis were collected and analyzed before the surgery and postoperatively.

RESULTS

Overall knee range of motion improved in all limbs. The knee flexion decreased significantly in both groups at initial, mid, and terminal stance. Hip flexion significantly decreased in mid-stance for limbs in group 2. Both clinical and gait parameters were most improved in limbs who underwent DFEO/DFSO + PTA. Increased pelvic tilt was observed in both groups after surgery.

CONCLUSION

Although DFEO/DFSO alone was successful in correcting knee flexion contractures, PTA has helped to improve knee extensor lag and knee extension during gait.

LEVEL OF EVIDENCE

Therapeutic level IV.

Patellar tendon shortening surgery restores the knee extensor mechanism in flexed knee gait in children with cerebral palsy

BACKGROUND

This study evaluated a patellar tendon shortening (PTS) surgical procedure that uses an overlapping repair combined with an additional Tycron non-absorbable suture to support the shortening in children with Cerebral Palsy (CP). This study aimed to outline this surgical technique and to evaluate its effectiveness in restoring the knee extensor mechanism.

METHODS

The sagittal plane lower limb kinematics, peak knee extensor moment, gait deviation index (GDI), localised movement deviation profile (MDP), temporospatial parameters, passive knee extension ROM, quadriceps lag, and knee extensor strength were calculated pre- and postoperatively. To determine significant differences a robust linear regression model with high breakdown point and high efficiency was fitted to the data.

RESULTS

In this retrospective cohort study, a total of 41 patients with CP who were treated with unilateral or bilateral PTS in isolation or as part of single event multilevel surgery (SEMLS), with a mean age of 11.1 years were included. The knee extension angle improved at initial contact (p < 0.0001), and during stance phase (p < 0.0001). The peak internal knee extensor moment decreased during early (p = 0.0014) and late stance phase (p < 0.0001). The quadriceps lag decreased (p < 0.0001) and knee extensor strength increased (p < 0.0001). The GDI improved (p < 0.0001), as well as the localised MDP for sagittal angles (p < 0.0001) and moments (p = 0.0001). Walking speed (p = 1.0) remained unchanged, but the cadence decreased (p = 0.024) and step length increased (p = 0.0001).

CONCLUSIONS

The knee extension angle and moment during stance phase improved significantly. The children with CP in this study showed improvements in knee extensor strength and quadriceps lag. Thereby it can be concluded that the PTS procedure was able to restore the knee extensor mechanism effectively.

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.

Intraoperative neuromonitoring during distal femoral extension osteotomy in children with cerebral palsy

The most common treatment method for a fixed knee flexion contracture more than 10 degrees in cerebral palsy (CP) is distal femoral extension osteotomy (DFEO). However, a serious complication after a DFEO is neurological impairment. Its rates were reported as 5- 40%. Intraoperative neuromonitoring (IONM), widely used in spinal surgery and in other fields, is a valuable tool to define any neurological injury during operation. The aim of our study was to determine surgical steps with risk of neurological injury and to report if precautions would be effective in recovering signal loss. We performed IONM during DFEO of 23 knees of 12 children with CP. IONM was performed by recording somatosensory evoked potentials, transcranial motor evoked potentials and free-run electromyography during defined steps throughout the surgery. Preoperative and postoperative popliteal angles, flexion contractures and physeal posterior distal femoral angles were evaluated. We detected alert signals at osteotomy or manipulation steps of surgeries of all patients. We observed persistent alert signals in two cases (2 out of 23 knees; Group 2). In this group, the action potentials recovered only after 5 and 10 degrees of undercorrection at the osteotomy sites. Alert signals disappeared after a brief period of waiting in other cases. Throughout mean 37 months of follow-up, none of our patients experienced any neurological complication. The study concludes that the surgical steps in DFEO with a higher risk for a neurological complication were the osteotomy and manipulation steps. Alert signals were detected with the help of IONM, and preventive measures were effective in recovering neuromonitoring recordings.

Factors associated with increased terminal swing knee flexion in cerebral palsy

BACKGROUND

Increased terminal swing knee flexion (TSKF) impacts on step length, walking efficiency and may lead to knee flexion in stance in cerebral palsy (CP). Surgical lengthening of the hamstrings is often used to address this issue, but outcomes are inconsistent. There is an established association between TSKF and functional shortening or reduced lengthening velocity of the hamstrings. However, the aetiology of increased TSKF in CP is complex and additional associated factors are not well understood. An examination of clinical and kinematic factors associated with increased TSKF may demonstrate this complexity, highlight the multifactorial nature of this feature and provide a basis for enhanced treatment decision making.

RESEARCH QUESTION

What kinematic and clinical factors are associated with TSKF in individuals with CP?.

METHODS

A retrospective database review was conducted. Individuals with bilateral CP were identified and a subset was extracted which represented the full spectrum of degree of TSKF in the database. The total dataset for analysis was n = 88. Associations between absolute clinical and kinematic data and TSKF were explored using correlation analysis, linear and multivariate regression. Time series data were examined across quartiles using statistical parametric mapping analysis of variance (SPM ANOVA).

RESULTS

Increased TSKF was associated with overall gait impairment (GDI), degree of knee flexion throughout the stride, knee extension velocity, hamstring lengthening characteristics and functional status (GMFCS). There was no relationship to walking speed or clinical measures of hamstring extensibility on clinical assessment.

SIGNIFICANCE

TSKF is associated with multiple factors which clinicians need to consider when devising treatment strategies. Caution is advised when relying on degree of TSKF to independently guide surgical decision-making.

Muscle-tendon unit in children with cerebral palsy

Muscle-tendon unit surgery for correction of deformities and movement dysfunction in children with cerebral palsy (CP) is fairly complicated. An understanding of basic muscle-tendon unit properties and their adaptation to both CP and surgery are important to develop advances in this field. In this review, we provide information to therapists, surgeons, and scientists regarding the short- and long-term adaptations of the muscle-tendon unit. Surgical releases, lengthening, and transpositions are discussed, as are some of the tissue, cellular, and molecular adaptations. What this paper adds Muscle strength, tone, and control must be considered in surgical interventions for cerebral palsy (CP). Muscle-tendon unit lengthening causes significant and lasting weakness requiring prolonged rehabilitation. Sarcomere length increases in CP muscle may be one of the underlying causes of muscle weakness. Muscle satellite cells are decreased and epigenetically modified in a way that may limit muscle growth in CP.

Outcome domains and measures after lower limb orthopaedic surgery for ambulant children with cerebral palsy: an updated scoping review

AIM

To determine the reported outcome domains and measures used to assess lower limb orthopaedic surgery of ambulant children and young people with cerebral palsy (CP) and map these outcomes to the International Classification of Functioning, Disability and Health - Children and Youth (ICF-CY) framework.

METHOD

This updated scoping review included studies published between January 2016 and July 2019 in five databases: MEDLINE, PubMed, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials. Studies were included if participants were ambulant individuals with CP aged between 0 and 20 years who had undergone lower limb orthopaedic surgery. Health outcome domains and measures were identified and classified using the ICF-CY framework.

RESULTS

Forty-four eligible studies were identified with a total of 40 different outcome domains recorded. Among eligible studies, 44 (100%) measured body function and structural impairment and seven (16%) measured activity limitation and participation restriction. The most frequently reported outcome was gait pattern (n=37, 84%). Few studies reported adverse effects of surgery (n=13, 30%). Twenty-nine different outcome measures were identified. Patient-reported outcomes measures were used in 10 studies (23%).

INTERPRETATION

The review highlights a heterogeneity in the reported outcome domains and measures used in CP studies. The majority of the reported outcomes focus on the ICF-CY domain of body function and structure. The review also highlights a notable shift towards patient-reported outcomes in recent years. Development of a core outcome set for lower limb orthopaedic surgery would guide researchers to use more consistent and complete measurement sets.

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.

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.

Distal Femoral Shortening Osteotomy for Severe Knee Flexion Contracture and Crouch Gait in Cerebral Palsy

Although there have been advancements of surgical techniques to correct gait abnormalities seen in patients with cerebral palsy, the crouch gait remains one of the most difficult problems to treat. The purpose of this retrospective study was to examine our results of distal femoral shortening osteotomy (DFSO) and patellar tendon advancement (PTA), performed in patients with crouch gait associated with severe knee flexion contracture. A total of 33 patients with a mean fixed knee contracture of 38° were included in the study. The mean age at the time of surgery was 12.2 years and the mean follow-up was 26.9 months. The measurements of clinical, radiological, and gait parameters were performed before and after surgery. The mean degrees of knee flexion contracture, Koshino index of patella height, and Gait Deviation Index were found to be significantly improved at the time of final follow-up. The maximum knee extension during the stance phase improved by an average of 25°, and the range of knee motion during gait increased postoperatively. On the other hand, the mean anterior pelvic tilt increased by 9.9°. Also, the maximum knee flexion during the swing phase decreased and the timing of peak knee flexion was observed to be delayed. We conclude that combined procedure of DFSO and PTA is an effective and safe surgical method for treating severe knee flexion contracture and crouch gait. However, the surgeons should be aware of the development of increased anterior pelvic tilt and stiff knee gait after the index operation.