Contractures In Children Research Articles

Knee Flexion While Walking Exceeds Knee Flexion Contracture in Children with Spastic Cerebral Palsy.

Flexed knee gait is commonly related to contractures in children with cerebral palsy (CP). Therefore, knee position while walking was compared with passive knee extension and explored with respect to functional mobility. Gait was assessed with 3D motion analysis in 30 children with bilateral spastic CP, Gross Motor Function Classification System (GMFCS) levels I-III, and in 22 typically developing (TD) children. Knee angle at initial contact (KneeAngleIC) was greater than knee flexion in stance (MinKneeFlexSt) in all groups. MinKneeFlexSt exceeded knee contractures at GMFCS levels II and III. Both KneeAngleIC and MinKneeFlexSt were greater at GMFCS II and III than at GMFCS I and the TD group. The excessive knee flexion while walking at GMFCS II and III could not be explained by knee joint contractures. Functional mobility measured with the timed-up-and-go test took longer in children at GMFCS level III compared to the other groups, assumed to be explained by the energy-requiring flexed knee gait and spatial insecurity. Discriminating between passive knee extension at the physical assessment and maximum knee extension while weight bearing may contribute to further understanding of flexed knee gait and its causes in ambulating children with spastic bilateral CP.

Knee flexion while walking versus knee contractures in children with bilateral spastic cerebral palsy

Knee flexion while walking versus knee contractures in children with bilateral spastic cerebral palsy

Investigation of the “Surgical Cuts CO2 Laser Therapy Technique” to Treat Minor Burn Scar Contractures in Children

Fractional carbon dioxide (CO2) laser therapy has been shown to improve scar contractures following burns. However, the benefits of using other CO2 laser techniques to treat burn scar contractures are relatively unknown. This pilot study investigated a CO2 laser technique in which a series of perpendicular “surgical cuts” were created along the contracture. The aim of this study was to evaluate the effectiveness of using the “surgical cuts CO2 laser technique” in pediatric patients. This study included 12 participants with minor hand burn scar contractures that received one CO2 laser treatment using the surgical cuts technique. Trained assessors measured contractures pre- and post-laser therapy by assessing range of motion (ROM), digit length, and/or hand-span. All contractures were secondary to contact burns with the mean participant age equal to 5.5 years (SD 3.9). For all participants, at least one of the measured characteristics (ROM, hand-span, and digit length) improved after treatment. This pilot study demonstrated the benefit of using the surgical cuts CO2 laser technique to treat minor burn scar contractures. Future investigations are needed to further evaluate its effectiveness in comparison to the fractional CO2 laser therapy technique.

Frequency, facilitators, and barriers for range of motion to prevent shoulder contracture in brachial plexus birth injury: A pilot study.

This pilot study investigated the efficacy of passive range of motion (PROM) during the first year of life to prevent development of shoulder contractures in children with brachial plexus birth injury (BPBI) and identified facilitators and barriers to caregiver adherence with daily PROM. Five caregivers of children with upper trunk BPBI participated in retrospective interviews about the frequency with which they performed PROM during their child's first year of life including facilitators and barriers to daily adherence. Medical records were reviewed for documentation of caregiver-reported adherence and documented evidence of shoulder contracture by age one. Three of the five children had documented shoulder contractures; all three had delayed initiation or inconsistent PROM in the first year of life. Two without shoulder contractures received consistent PROM throughout the first year of life. Making PROM part of the daily routine was a facilitator to adherence while family contextual factors were barriers. Absence of shoulder contracture may be related to consistent PROM throughout the first year of life; decreased frequency of PROM after the first month of life did not increase the risk of shoulder contracture. Consideration of family routines and context may facilitate adherence with PROM.

Elbow flexion contractures in neonatal brachial plexus palsy: A one-year comparison of dynamic orthosis and serial casting

Objective Elbow flexion contractures are common complications of neonatal brachial plexus palsy, but evidence on how to treat these contractures is weak. This study compared the treatment of elbow flexion contractures using a dynamic orthosis or serial circular casting. Methods A randomized controlled trial was conducted with one-year follow-up. Children with an elbow flexion contracture of ≥30° were treated with either a night-worn dynamic orthosis for one year or serial casting for four weeks followed by night splinting. For pragmatic reasons, some participants were included in an open part of this study, this group was also analyzed separately. Degree of contracture and goal attainment scaling was evaluated at baseline and after 8, 20 and 54 weeks. Results 55 patients were analyzed in this trial, 32 of whom were randomized to treatment. At one-year follow-up of the randomized group, both dynamic splinting (median −8.5°, interquartile range [IQR] −13.5, −5) and serial casting (median −11.0°, IQR −16, −5) resulted in significant reduction of contracture (P < 0.001). The reduction was significantly greater with serial casting in the first 20 weeks, but not at one-year follow-up (P = 0.683). In the entire cohort, the individual functional goals had been reached in 24 out of 32 cases (80%) of dynamic splinting and 18 out of 23 cases (82%) of serial casting, respectively. Conclusion The dynamic night orthosis is comparable to serial casting for treating elbow flexion contractures in children with brachial plexus birth injury. We recommend selecting one of these treatment modalities in close consultation with parents and patients.

Can the Sup-ER Protocol Decrease the Prevalence and Severity of Elbow Flexion Deformity in Brachial Plexus Birth Injuries?

Brachial plexus birth injuries (BPBIs) can often result in functional and cosmetic deficits including, according to a recent scoping review, elbow flexion contractures in up to 48%. A treatment algorithm that includes a custom long-arm orthosis to optimize early glenohumeral joint positioning (Sup-ER protocol) has been shown to improve shoulder range of motion. Although the protocol was not intentionally designed to affect the elbow, this study investigates the prevalence and severity of elbow flexion contractures in children treated with that protocol. This prospective cross-sectional cohort study examined 16 children aged 4 and older with BPBI severe enough to be treated with the Sup-ER protocol. Passive and active elbow flexion and extension range of motion (ROM) were assessed in both arms. Elbow flexion contractures were defined as > 5o from neutral. Within the cohort of 16 patients (mean age: 7.0 years, range: 4.5-11.6 years), the mean maximal passive elbow extension was -6.2° in the affected arm and + 5.1° (hyperextension) in the unaffected arm. Zero patients had a severe elbow flexion contracture (>30o) and only 6/16 met the lowest threshold definition of elbow flexion contracture (>5o), with a mean onset at 22 months of age. This study suggests an unintended decreased prevalence and severity of elbow flexion contractures in children with more severe BPBI treated with the Sup-ER protocol, relative to published values.

Physical treatment of posttraumatic elbow contractures in children – our experience

The most common complications of elbow trauma are contractures and neurovascular injuries. The complications can be a result of the initial injury, but they can also be a result of a surgical treatment. In addition to orthopedic treatment of elbow fractures, physical therapy and rehabilitation play a significant role in treatment of posttraumatic contractures. To determine the effects of physical therapy and rehabilitation of posttraumatic elbow contractures in children. This was a retrospective cross-sectional study conducted in the University Clinic for Physical Medicine and Rehabilitation, Skopje in the period 01.01.2021 – 01.07.2022. A total of 52 children were included, at the age between 2 and 13 years who had a posttraumatic elbow contracture, limited range of motion, pain and/or limitations in accomplishing daily activities. Depending on the clinical finding, children underwent a relevant physical therapy (kinesitherapy, functional therapy, electrotherapy, thermotherapy, hydrotherapy and magnetotherapy) in duration of three weeks. For assessing the effects of the rehabilitation therapy, the range of motion of the elbow and forearm was examined along with the Flynn’s scale in all children, prior to and after completion of the physical treatment. Applied physical treatment resulted in a significant improvement in all analyzed movements such as: elbow flexion (p=0.00001), elbow extension (p=0.00001), forearm pronation (p=0.00001), forearm supination (p=0.0000) and Flynn’s scale (p=0.0000). After completion of the rehabilitation treatment, excellent results were registered in 41 (85%) children, moderate in 10 (19.23%) and favorable in 1 (1.92%). Timely and adequate application of physical therapy and rehabilitation can significantly improve the final outcome in treatment of posttraumatic elbow contractures in children. A combination of different physical procedures adequately applied and personalized can significantly improve the range of motion of the elbow.&#x0D;

Long-Term Outcomes of Biceps Rerouting for Flexible Supination Contractures in Children With Brachial Plexus Birth Injuries

Forearm supination contractures occur in 7% of children with brachial plexus birth injuries (BPBI). Biceps rerouting is proposed when pronation has deteriorated but is passively correctable to at least 0° (neutral). The purpose of this investigation was to evaluate long-term outcomes of biceps rerouting for this indication, including magnitude and maintenance of correction, complications, and subsequent osteotomy. We conducted a retrospective review of all children with BPBI and forearm supination contractures treated with biceps rerouting alone, for the above indications, from 1993 to 2017 with at least 2 years follow-up. Demographic information, BPBI characteristics, surgical details, and ranges of motion were obtained from medical records. Pre- and postoperative active pronation (AP) and supination (AS), elbow flexion contracture, and arc of forearm rotation (Arc) were analyzed using linear mixed-effect models. Twenty-five children (13 females; 13 left forearms; 15 global BPBI) underwent biceps rerouting at age 7 ± 3 years and were followed for 6 ± 3 years. Before surgery, the mean AP and AS were 6° ± 29° and 62° ± 27°, respectively. At the final follow-up, the mean AP, AS, and Arc were 39° ± 36°, 18° ± 34°, and 57° ± 42°, respectively. AP was significantly improved and AS was significantly decreased by 2years after surgery and at the final follow-up. Neither Arc nor elbow flexion contracture changed significantly. Two of 25 (8%) children underwent subsequent forearm osteotomy. Biceps rerouting in children with BPBI improves the forearm position when pronation is deteriorating by shifting the arc from supination to pronation without decreasing the arc of motion or worsening elbow flexion contractures. There is a low risk of complications and a limited need for subsequent forearm osteotomy. These results are maintained over time. When performed before passive pronation is reduced beyond neutral, this procedure may prevent severe supination contractures and reduce the need for forearm osteotomy. Therapeutic IV.

Новые подходы к лечению детей с посттравматическими контрактурами локтевого сустава

Abstract. Introduction Post-traumatic elbow contracture is a severe disabling condition of childhood that interferes with both physical and psychic aspects for the child. A high rate of poor results encourages surgeons seek for better surgical treatments. Current diagnostic modalities were practical to get the clinical picture of the contracture mechanogenesis and determine the treatment strategy. The goal of the study was to review long-term results of new surgical techniques developed for post-traumatic elbow contractures in children. Material and methods The inpatient records of 102 pediatric patients with post-traumatic elbow contractures operated on with the technique offered were reviewed. All patients underwent conventional radiological, ultrasound and MSCT examinations. Results Based on the pathobiomechanics of the injured elbow a mobilization technique was developed to ensure complete bone realignment, relieve pain and allow early exercises for the joint. Postoperative lavage of the joint cavity, intra-articular administration of corticosteroids and polyvalent enzymes in the early postoperative period facilitated improved long-term outcomes of elbow contractures. All patients reported good results. Discussion Tenotomies of the lateral ligaments can be added to arthrotomy and reconstruction of articular surfaces for temporary instability of the joint to restore movement in the elbow joint in severe cases. Post-traumatic elbow contractures are accompanied by impaired biomechanics. MSCT and 3D reconstruction of bone structures is the gold standard in the diagnosis of post-traumatic elbow contractures. Conclusion Bone impingements are to be addressed and an extended mobilization of the capsular ligamentous complex be provided for complete movement recovery through partial elbow instability to be temporarily ensured. Prolonged lavage of the elbow joint can be used to prevent adhesions and allow early elbow exercises and provide improved outcomes.

Outcome of Gastrocnemius Soleus Facial Lengthening in Ambulatory Patients With Cerebral Palsy

Background: Treatment of equinus contractures in children with cerebral palsy (CP) varies across centers. Existing literature utilizes mixed study populations with a variety of procedures. As such, there is limited knowledge regarding recurrence rates and efficacy of a single procedure performed on a homogenous cohort. Here we retrospectively evaluate outcomes from gastroc soleus fascial lengthenings (GSFL) performed at 2 centers with consistent approaches in both patient selection and operative technique. Methods: Subjects meeting inclusion criteria including CP diagnosis, ambulation status, and minimum follow-up criteria were identified. Revision rate was reported based on need for additional calf lengthening procedures. Functional outcomes were evaluated using physical exam measures and selected variables from computational gait analysis. Outcomes factors were identified by comparing revised subjects to unrevised. Longitudinal outcomes of index surgeries were assessed by comparing preoperative functional data to short-term, mid-term, and long-term data. Results: A total of 64 subjects with 87 limbs met inclusion criteria. In all, 25% of subjects and 21% of limbs went on to revision. Factors influencing revision were age at index surgery and gross motor function classification system (GMFCS) level. More than half of revised limbs had index surgery before age 7. Revision rates for subjects less than 7 were 44% compared with a 17% revision rate for ages 7 to 12, and a 4% revision rate on children older than 12. GMFCSIII subjects had significantly higher revision rates (43%) compared with GMFCSII (18%) and GMFCSI (11%) subjects. Ankle range of motion measures improved significantly with GSFL and most maintained improvements at all time periods. GSFL did not lead to significant calcaneal gait or crouch. Conclusions: This study evaluates long term efficacy of GSFL to address equinus in ambulatory children with CP. Overall revision rates are similar to previous reports for GSFL and other calf lengthening procedures. This information may be useful in setting expectations and counselling families. Younger subjects and those with more severe involvement are more likely to need revision surgery, with these factors compounding the likelihood in the younger GMFCSIII child. Level of Evidence: Level III—retrospective comparative study.

Обґрунтування ранньої нейрореабілітації в дітей неонатального віку

На підставі катамнестичного спостереження 25 новонароджених із вадами розвитку спинного мозку та постгеморагічною гідроцефалією, яким проводилось шунтування шлуночкової системи головного мозку, обґрунтована необхідність ранньої нейрореабілітації вже в перші дні життя, ще на етапі відділення реанімації та інтенсивної терапії. Вивчена ефективність розробленого комплексу заходів первинної реабілітації новонароджених на етапі виходжування після проведення інтенсивної терапії, з подальшою оцінкою її ефективності за шкалою Alberta Infant Motor Scale (AIMS) протягом першого року життя. Запропонована індивідуальна програма реабілітації з комплексом вправ залежно від потреб дитини та її можливостей дає значний позитивний результат щодо становлення моторних і сенсорних навичок дитини та профілактики їх згасання.

Functional and Clinical Outcomes of Combined Simultaneous Bilateral Anterior Distal Femoral Plate Hemiepiphysiodesis and Hamstrings Release in Management of Knee Flexion Contractures in Children With Neuromuscular Disorders.

We examined the clinical and functional outcomes of the simultaneous anterior distal femoral 8-plate hemiepiphysiodesis (ADF8PH) and hamstring release, for fixed knee flexion deformity in children with neuromuscular disease. To our knowledge, no published evidence is available that reports the outcomes of this combined techniques. Electronic medical records were retrospectively reviewed for 19 consecutive children who underwent bilateral ADF8PH and concomitant hamstrings release in our institution from 2012 to 2019. Relevant demographics, Gross Motor Functional Classification Score and preoperative and postoperative knee flexion contractures and popliteal angles were documented. The average age at the time of operation was 12±2.1 years. There were 15 males and 4 females. Diagnoses included cerebral palsy (n=16), Cornelia de Lange syndrome (n=1), hereditary spastic paraplegia type 56 (n=1) and fructose-1,6 bisphosphonate aldose B deficiency (n=1). Mean length of follow-up was 3.8 years (range: 1.5 to 7 y). Mean fixed knee flexion deformity improved from 28.9 to 13.4 degrees (P<0.001) at an average correction rate of 0.94 degrees per month. Mean popliteal angle improved from 81.8 to 44.4 degrees (P<0.001) in the early postoperative phase and to 51.8 degrees (P<0.001) in latest clinic review. Mean time to correction was 18.9 months. The agreed treatment goals of maintaining or promoting the use of standing frame and spinal/postural symmetry was attained in 18 patients (94.7%). Postoperative knee pain was reported in 2 cases (10.5%). We report 2 complications; 1 case of neurapraxia and 1 case of sepsis because of respiratory infection. Simultaneous bilateral ADF8PH with hamstrings release is a promising effective technique for correction of knee flexion contractures in skeletally immature individuals with neuromuscular disabilities. Our findings demonstrate improvement in clinical outcomes and maintaining functional outcomes, indicating the validity of this approach as a satisfactory, less invasive alternative in the management of this deformity. Level IV-therapeutic study.

Knee and foot contracture occur earliest in children with cerebral palsy: a longitudinal analysis of 2,693 children

Background and purpose — Joint contracture is a common problem among children with cerebral palsy (CP). To prevent severe contracture and its effects on adjacent joints, it is crucial to identify children with a reduced range of motion (ROM) early. We examined whether significant hip, knee, or foot contracture occurs earliest in children with CP. Patients and methods — This was a longitudinal study involving 27,230 measurements obtained for 2,693 children (59% boys, 41% girls) with CP born 1990 to 2018 and registered before 5 years of age in the Swedish surveillance program for CP. The analysis was based on 4,751 legs followed up for an average of 5.0 years. Separate Kaplan–Meier (KM) curves were drawn for each ROM to illustrate the proportions of contracture-free legs at a given time during the follow-up. Using a clustered bootstrap method and considering the child as the unit of clustering, 95% pointwise confidence intervals were generated for equally spaced time points every 2.5 years for each KM curve. Results — Contracture developed in 34% of all legs, and the median time to the first contracture was 10 years from the first examination. Contracture was most common in children with a higher Gross Motor Function Classification System (GMFCS) level. The first contracture was a flexion contracture preventing dorsiflexion in children with GMFCS level I or II and preventing knee extension in children with GMFCS level III to V. Interpretation — Early interventions to prevent knee and foot contractures in children with CP should be considered.

Anterior distal femoral hemiepiphysiodesis with and without patellar tendon shortening for fixed knee flexion contractures in children with cerebral palsy.

PurposeSurgery is often required for fixed knee flexion contractures in patients with neuromuscular conditions. Anterior distal femoral hemiepiphysiodesis (ADFH) is an alternative to distal femoral extension osteotomy (DFEO) in skeletally immature patients. ADFH is typically not accompanied by patellar tendon shortening surgery (PTS). Our purpose was to compare ADFH alone versus ADFH with PTS for treatment of fixed knee flexion contractures and crouched gait in children with cerebral palsy (CP).MethodsRetrospective review of pre- and postoperative gait analysis data for children with CP who underwent ADFH alone, or ADFH with PTS. Data were analysed using linear mixed models to control for covariates.ResultsIn total, 25 participants (42 limbs) were included, 17 male and eight female, mean age at surgery 12.9 (sd 1.9) years. Both groups experienced significant improvement in popliteal angle, knee extension range of motion (ROM) and knee extension in stance phase. Greater improvement was seen for all variables in the ADFH/PTS group, mainly due to greater popliteal angle and knee flexion during gait preoperatively in that group (p ≤ 0.02) rather than the procedure performed (p ≥ 0.19). There was no difference between groups postoperatively. Rate of contracture resolution was 0.5° to 1.0° per month, faster in larger contractures (p = 0.02).ConclusionsADFH with and without PTS is effective in improving knee extension in skeletally immature patients with CP, correcting contractures at a rate of 0.5° to 1.0° per month. Combined ADFH and PTS surgery may be preferable in patients with larger contractures of up to 30° to 35°.Level of evidenceIII

EFFECTIVENESS OF TENDON-MUSCLE PLASTY OF THE KNEE JOINT IN PATIENTS HAVING SPASTIC CEREBRAL PALSY WITH FLEXION CONTRACTURES OF KNEE JOINTS

Introduction. Cerebral palsy (CP) is the main cause of childhood neurological disability in the world. Due to the fact that the prevalence of knee contractures in children with cerebral palsy occupies the 3rd place in the structure of orthopedic pathology of the lower extremities, this topic is least covered in the scientific periodicals. Material and methods. Findings from 40 patients of the main group, aged 7-12 and having cerebral palsy (CP), were studied retrospectively. They had knee flexion contractures with patella alta. Findings of goniometry and of Gillette FAQ were analyzed before and after surgery. The Spearman coefficient was used for the correlation analysis of goniometry parameters and surgical intervention effectiveness before surgery. 35 patients having no bilateral CP damage and other diseases leading to lower limb deformities were included into the reference group. X-ray examination and goniometry assessment of a healthy limb were made in patient’s lying position on his back with passive extension; plus goniometry in a standing position with shin active extension. Results. The median of deformation angles before and after surgery was 20° and 5°, respectively (p

Role and implementation experience of splints in pediatric burn rehabilitation

The maintenance of posture and anti-contracture treatment are the critical elements of comprehensive burn rehabilitation in the overall treatment period of pediatric burns. Although domestic experts in burn discipline have formulated guidelines for burn rehabilitation, the maintenance of posture and design and manufacture of splints for anti-scar contractures in children with burns are different from that for adults with burns in many ways. Starting with paying the attention to the rehabilitation problems in pediatric burns, especially considering the anatomical, psychological, and social behavior characteristics of children in developmental period, the author's team effectively applies splints to maximize the prevention of contractures in children and maintain and improve the range of their joint movements. The splints designed to prevent contractures in pediatric burns shall fit the small limb and meet their expected goals of rehabilitation. In each aspect of the production and use of splints, it is necessary to fully evaluate and consider the scar characteristics, growth and development status, activity level, and compliance of children, and adaptability and fixation methods of the splints, so as to select the appropriate splint type and formulate the wearing plan.

852 A Novel Approach to Treating Minor Burn Scar Contractures in Children Using Laser Surgical Cuts

Abstract Introduction Minor burn scar contractures can be successfully treated with conservative approaches including Carbon Dioxide (CO2) laser therapy. While previous research has mainly focused on using the CO2 laser in a fractional mode to create a stamped pattern of holes (Figure A), less is known about how altering this pattern may affect the overall outcome of the contracture. Given this knowledge gap, our research group sought to investigate a new laser technique in which a series of lines, referred to as “laser surgical cuts,” are created across the length of the scar (Figure B). Thus, the aim of this pilot study was to evaluate the effectiveness of using this novel, laser surgical cuts technique to treat minor burn scar contractures in pediatric patients. Methods This prospective pilot study was carried out in the outpatient setting at our pediatric hospital. Only patients that had a minor burn scar contracture that crossed a joint on their palm and/or digits and who had consented to receive treatment with laser therapy were eligible to participate. Prior to treatment, a trained occupational and/or physiotherapist assessed each participant’s contracture by examining at least one of the following characteristics depending on the contracture’s location and extent of involvement: 1) range of motion (ROM), 2) digit length, 3) hand-span. Treatment consisted of one session of laser therapy during which surgical cuts were created across the length of the contracture followed by casting for approximately one week. Following cast removal, the initial contracture assessment was repeated and pre-post measures were compared. Results Seven patients participated in this study. All injuries were the result of contact burns and the mean age at assessment was 5.1 years. Overall, patients with flexion contractures (n = 4) experienced a mean improvement in ROM by 22.5° (SD 14.4). Patients with discrepancies in digit length (n = 4) experienced a mean improvement of 9.4% (pre = 5.3 cm, SD 1.6; post = 5.8 cm, SD 1.6) while those with discrepancies in hand-span (n = 3) experienced a mean improvement of 13.7% (pre = 14.6 cm, SD 3.4, post = 16.6 cm, SD 3.0). Conclusions We have shown that using the CO2 laser to create surgical cuts can improve minor contractures in burn-injured children. Further, we hypothesize that improvements in ROM, digit length, and hand-span are the result of a decrease in the mechanical tension across the contracture following treatment. Based on the positive findings obtained from this pilot study, a larger study with long-term follow-up is needed to determine if treatment with laser surgical cuts is more effective than using traditional, fractional CO2 laser settings. Applicability of Research to Practice Ultimately, if this novel laser technique is proven to be highly effective, the need for future contracture release surgeries may be reduced.

Does a Reduced Number of Muscle Stem Cells Impair the Addition of Sarcomeres and Recovery from a Skeletal Muscle Contracture? A Transgenic Mouse Model.

Children with cerebral palsy have impaired muscle growth and muscular contractures that limit their ROM. Contractures have a decreased number of serial sarcomeres and overstretched lengths, suggesting an association with a reduced ability to add the serial sarcomeres required for normal postnatal growth. Contractures also show a markedly reduced number of satellite cells-the muscle stem cells that are indispensable for postnatal muscle growth, repair, and regeneration. The potential role of the reduced number of muscle stem cells in impaired sarcomere addition leading to contractures must be evaluated. (1) Does a reduced satellite cell number impair the addition of serial sarcomeres during recovery from an immobilization-induced contracture? (2) Is the severity of contracture due to the decreased number of serial sarcomeres or increased collagen content? The hindlimbs of satellite cell-specific Cre-inducible mice (Pax7; Rosa26; n = 10) were maintained in plantarflexion with plaster casts for 2 weeks so that the soleus was chronically shortened and the number of its serial sarcomeres was reduced by approximately 20%. Subsequently, mice were treated with either tamoxifen to reduce the number of satellite cells or a vehicle (an injection and handling control). The transgenic mouse model with satellite cell ablation combined with a casting model to reduce serial sarcomere number recreates two features observed in muscular contractures in children with cerebral palsy. After 30 days, the casts were removed, the mice ankles were in plantarflexion, and the mice's ability to recover its ankle ROM by cage remobilization for 30 days were evaluated. We quantified the number of serial sarcomeres, myofiber area, and collagen content of the soleus muscle as well as maximal ankle dorsiflexion at the end of the recovery period. Mice with reduced satellite cell numbers did not regain normal ankle ROM in dorsiflexion; that is, the muscles remained in plantarflexion contracture (-16° ± 13° versus 31° ± 39° for the control group, -47 [95% confidence interval -89 to -5]; p = 0.03). Serial sarcomere number of the soleus was lower on the casted side than the contralateral side of the mice with a reduced number of satellite cells (2214 ± 333 versus 2543 ± 206, -329 [95% CI -650 to -9]; p = 0.04) but not different in the control group (2644 ± 194 versus 2729 ± 249, -85 [95% CI -406 to 236]; p = 0.97). The degree of contracture was strongly associated with the number of sarcomeres and myofiber area (r =0.80; P < 0.01) rather than collagen content. No differences were seen between groups in terms of collagen content and the fraction of muscle area. We found that a reduced number of muscle stem cells in a transgenic mouse model impaired the muscle's ability to add sarcomeres in series and thus to recover from an immobilization-induced contracture. The results of our study in transgenic mouse muscle suggests there may be a mechanistic relationship between a reduced number of satellite cells and a reduced number of serial sarcomeres. Contracture development, secondary to impaired sarcomere addition in muscles in children with cerebral palsy may be due to a reduced number of muscle stem cells.

Postanesthesia alternation of lower limb contractures in children with spastic cerebral palsy.

The aim of this study was to clarify the effects of general anesthesia (GA) on joint range of motion (ROM) in children with spastic cerebral palsy (SCP). Eighty-four SCP cases (mean age 8.4 years) admitted for first corrective surgery were retrospectively reviewed. Lower limb ROM were measured 1 day before operation and immediately after GA. Contracture of hip, knee, and ankle joints decreased significantly after GA, with + 11.1° (39.5%) for the hip abduction angle, -3.7° (18.0%) for the Thomas test, -15.0° (19.1%) for the popliteal angle, + 6.6° (39.8%) and 7.0° (109%) for ankle dorsiflexion with knee flexion and extension, respectively (all P < 0.001). These changes were correlated positively to pre-GA contracture and body weight, negatively to age, but independent of preoperative functional level, geographic classification of SCP, or modified Ashworth scale. On the basis of these findings, routine post-GA reassessments of joint ROM before corrective surgeries were recommended for pediatric SCP cases.

Contribution of extracellular matrix components to the stiffness of skeletal muscle contractures in patients with cerebral palsy

ABSTRACT Purpose: Joint contractures in children with cerebral palsy contain muscle tissue that is mechanically stiffer with higher collagen content than typically developing children. Interestingly, the correlation between collagen content and stiffness is weak. To date, no data are available on collagen types or other extracellular matrix proteins in these muscles, nor any information regarding their function. Thus, our purpose was to measure specific extracellular protein composition in cerebral palsy and typically developing human muscles along with structural aspects of extracellular matrix architecture to determine the extent to which these explain mechanical properties. Materials and Methods: Biopsies were collected from children with cerebral palsy undergoing muscle lengthening procedures and typically developing children undergoing anterior cruciate ligament reconstruction. Tissue was prepared for the determination of collagen types I, III, IV, and VI, proteoglycan, biglycan, decorin, hyaluronic acid/uronic acid and collagen crosslinking. Results: All collagen types increased in cerebral palsy along with pyridinoline crosslinks, total proteoglycan, and uronic acid. In all cases, type I or total collagen and total proteoglycan were positive predictors, while biglycan was a negative predictor of stiffness. Together these parameters accounted for a greater degree of variance within groups than across groups, demonstrating an altered relationship between extracellular matrix and stiffness with cerebral palsy. Further, stereological analysis revealed a significant increase in collagen fibrils organized in cables and an increased volume fraction of fibroblasts in CP muscle. Conclusions: These data demonstrate a novel adaptation of muscle extracellular matrix in children with cerebral palsy that includes alterations in extracellular matrix protein composition and structure related to mechanical function.