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.

Children who idiopathically toe-walk have greater plantarflexor effective mechanical advantage compared to typically developing children.

PURPOSE: The effective mechanical advantage (EMA) of the plantarflexor muscles is important for gait function and is likely different from typical in equinus gait. However, this has never been quantified for children who idiopathically toe-walk (ITW), despite being routinely altered through clinical intervention. METHODS: This study quantified the Achilles tendon and ground reaction force (GRF) moment arms, and the plantarflexor EMA of 5 children who ITW and 14 typically developing (TD) children, whilst walking on an instrumented treadmill. RESULTS: There was no difference in the Achilles tendon moment arm length throughout stance between groups (p > 0.05). Children who ITW had a significantly greater GRF moment arm length in early stance (20-24% p = 0.001), but a significantly shorter GRF moment arm length during propulsion (68-74% of stance; p = 0.013) than TD children. Therefore, children who ITW had a greater plantarflexor EMA than TD children when active plantarflexion moments were being generated (60-70% of stance; p = 0.007). Consequently, it was estimated that children who ITW required 30% less plantarflexor muscle force for propulsion. CONCLUSION: Clinical decision making should fully consider that interventions which aim to restore a typical heel-toe gait pattern risk compromising this advantageous leverage and thus, may increase the strength requirements for gait.

Muscle architecture and passive lengthening properties of the gastrocnemius medialis and Achilles tendon in children who idiopathically toe-walk.

Children who idiopathically toe-walk (ITW) habitually operate at greater plantarflexion angles and thus, at shorter muscle-tendon unit (MTU) lengths than typically developing (TD) children. Therefore, it is often assumed that habitual use of the gastrocnemius muscle in this way will cause remodelling of the muscle-tendon architecture compared to TD children. However, the gastrocnemius muscle architecture of children who ITW has never been measured. It is essential that we gain a better understanding of these muscle-tendon properties, to ensure that appropriate clinical interventions can be provided for these children. Five children who ITW (age 8 ± 2 years) and 14 TD children (age 10 ± 2 years) participated in this study. Ultrasound was combined with isokinetic dynamometry and surface electromyography, to measure muscle architecture at common positions and passive lengthening properties of the gastrocnemius muscle and tendon across full range of motion. Regardless of which common condition groups were compared under, both the absolute and normalised to MTU muscle belly and fascicle lengths were always longer, and the Achilles tendon length was always shorter in children who ITW than TD children (p < 0.05; large effect sizes). The passive lengthening properties of the muscle and tendon were not different between groups (p > 0.05); however, passive joint stiffness was greater in children who ITW at maximum dorsiflexion (p = 0.001) and at a joint moment common to all participants (p = 0.029). Consequently, the findings of this pilot study indicate a remodelling of the relative MTU that does not support the concept that children who ITW commonly experience muscle shortening. Therefore, greater consideration of the muscle and tendon properties are required when prescribing clinical interventions that aim to lengthen the MTU, and treatments may be better targeted at the Achilles tendon in children who ITW.

In vivo operating lengths of the gastrocnemius muscle during gait in children who idiopathically toe-walk.

NEW FINDINGS: What is the central question of this study? What are the in vivo operating lengths of the gastrocnemius muscle in children who idiopathically toe-walk? What is the main finding and its importance? Children who idiopathically toe-walk operate at more plantarflexed positions but at longer fascicle lengths than typically developing children during gait. However, these ranges utilised during gait correspond to where children who idiopathically toe-walk are optimally strong. This should be considered when prescribing clinical treatments to restore typical gait. ABSTRACT: Children who idiopathically toe-walk (ITW) habitually operate at greater plantarflexion angles than typically developing (TD) children, which might result in shorter, sub-optimal gastrocnemius fascicle lengths. However, currently no experimental evidence exists to substantiate this notion. Five children who ITW and 14 TD children completed a gait analysis, whilst gastrocnemius fascicle behaviour was simultaneously quantified using ultrasound. The moment-angle (hip, knee and ankle) and moment-length (gastrocnemius) relationships were determined from isometric maximum voluntary contractions (MVC) on an isokinetic dynamometer combined with ultrasound. During gait, children who ITW operated at more plantarflexed angles (Δ = 20°; P = 0.013) and longer muscle fascicle lengths (Δ = 12 mm; P = 0.008) than TD children. During MVC, no differences in the peak moment of any joint were found. However, peak plantarflexor moment occurred at significantly more plantarflexed angles (-16 vs. 1°; P = 0.010) and at longer muscle fascicle lengths (44 vs. 37 mm; P = 0.001) in children who ITW than TD children. Observed alterations in the moment-angle and moment-length relationships of children who ITW coincided with the ranges used during gait. Therefore, the gastrocnemius muscle in children who ITW operates close to the peak of the force-length relationship, similarly to TD children. Thus, this study indicates that idiopathic toe-walking is truly an ankle joint pathology, and children who ITW present with substantial alterations in the gastrocnemius muscle functional properties, which appear well adapted to the characteristic demands of equinus gait. These findings should be considered when prescribing clinical treatments to restore typical gait.

Pelvic Tilt Changes After Hamstring Lengthening in Children With Cerebral Palsy.

BACKGROUND: Flexion deformity of the knee is a common presentation in children with cerebral palsy with hamstring surgery as an option for addressing this. However, concerns with regard to increased pelvic tilt have been raised. The purpose of this study was to compare preoperative and postoperative pelvic tilt after isolated hamstring lengthening versus combined hamstring lengthening and the influence of Gross Motor Function Classification System (GMFCS) levels on pelvic tilt. METHODS: This retrospective study included 46 ambulatory children with cerebral palsy who had had open medial hamstring lengthening (mean age at surgery, 11 y 11 mo; SD, 2 y 11 mo; GMFCS I, 16; GMFCS II 20; GMFCS III 10). Twelve children underwent isolated surgery and 34 children underwent combined surgery. The isolated hamstring procedures could be combined with foot and/or ankle-level surgery, as only the hamstring procedure would affect the pelvic tilt. Combined surgery was defined as hamstring lengthening with other procedures performed at the knee or more proximally. The preoperative and postoperative 3-dimensional gait analysis data were evaluated in this study. RESULTS: Both the isolated and combined hamstring lengthening groups showed no significant change in pelvic tilt ([INCREMENT]1.28, P=0.203; [INCREMENT]1.47, P=0.113, respectively). A significant change in pelvic tilt was seen in children functioning at GMFCS III ([INCREMENT]4.66, P=0.009) but not GMFCS I and II ([INCREMENT]0.37, P=0.718; [INCREMENT]0.48, P=0.697). Significant postoperative decreases in the knee flexion angle at initial contact were seen for both isolated ([INCREMENT]5.72, P=0.010) and combined hamstring lengthening ([INCREMENT]10.95, P<0.001). CONCLUSIONS: Hamstring lengthening, for the majority of patients, did not lead to a clinically significant change in mean pelvic tilt and improved knee flexion angle at initial contact. Children who functioned at GMFCS level III had an increase in anterior pelvic tilt and caution should be exercised in this group. STUDY DESIGN: Level IV evidence-case series.

Distal tibial triplane fracture with ipsilateral tibial shaft fracture: A case series.

BACKGROUND & PURPOSE: Distal tibial Triplane fracture with ipsilateral tibial shaft fracture is a rare but important problem. This rarely reported combination of injuries if not recognised may lead to deleterious consequences. METHODS/PATIENTS: The local database of all emergency admissions was scrutinised to identify subjects before interrogation of the clinical notes and relevant radiographic imaging. FINDINGS: This paper reports a series of five children who were found to have triplane fracture of the distal tibia with concomitant ipsilateral fracture of the tibial shaft. CONCLUSIONS: We suggest that a high index of suspicion for concomitant fractures should be maintained in the presence of either triplane fracture of the distal tibia or tibial shaft fractures in the peri-adolescent child. Minimum appropriate imaging should include orthogonal full length plain radiographs of the tibia as well as formal ankle radiographs.

Intramedullary devices in the management of Judet III and IV paediatric radial neck fractures.

PURPOSE: The aim of this study is to discuss the results of different intramedullary devices used in the management of paediatric radial neck fractures and to suggest methods to avoid the pitfalls of the technique. METHODS: Thirty patients with isolated Judet III and IV fractures were included in this prospective study. Judet I and II fractures and radial neck fractures associated with other injuries were excluded. The final results were graded using the Metaizeau functional scoring system and Oxford Elbow Score. RESULTS: The functional result was good to excellent in 24 of 30 cases (80%). The mean Oxford Elbow Score was 44.32. The mean follow-up was 40.11 months. The complications seen were radiocapitellar joint penetration - 6 cases at mean 4.87 weeks, redisplacement - 6, radial epiphyseal sclerosis - 5, and heterotopic ossification - 1 case. CONCLUSION: Intramedullary K wires may result in radiocapitellar joint penetration. Titanium Elastic Nail System should not be used as purely fixation devices as they may not prevent redisplacement. Regular follow-up until at least 6 weeks is essential. Patients who have a Judet IV fracture and need open reduction should be given a guarded prognosis. The paper highlights the pitfalls of the technique and makes recommendations regarding the type of implant, follow-up and patient counselling in Judet IV fractures.

Is there a learning curve in foot and ankle surgery?

BACKGROUND: Previous studies of orthopaedic learning curves have largely described the introduction of new techniques to experienced consultants. End points have usually involved technical considerations. A paucity of evidence surrounds foot and ankle surgery. This study investigates the learning curve during a foot and ankle surgeon's first year, defined by functional outcome. METHODS: 150 patients underwent elective foot or ankle surgery during the whole period. Preoperative and 6 month postoperative functional scores were compared between the first and second 6 month groups. RESULTS: Functional improvement was greater, approaching significance, in the second group (p=0.0605). There was no difference for forefoot cases (p=0.345). Functional improvement was significantly greater in the second group with forefoot cases removed (p=0.0333). CONCLUSIONS: A learning curve exists in the first year of practice of foot and ankle surgery, demonstrated by functional outcome. This is confined to ankle, hindfoot and midfoot, but not forefoot surgery.

Effective Mechanical Advantage About the Ankle Joint and the Effect of Achilles Tendon Curvature During Toe-Walking.

Aim: To study the causes of locomotor dysfunction, estimate muscle forces, or understand the influence of altered sarcomere and muscle properties and behaviours on whole body function, it is necessary to examine the leverage with which contractile forces operate. At the ankle joint, current methods to quantify this leverage for the plantarflexors do not account for curvature of the Achilles tendon, and so may not be appropriate when studying equinus gait. Thus, novel methodologies need to be developed and implemented to quantify the Achilles tendon moment arm length during locomotion. Methods: Plantarflexor internal moment arm length and effective mechanical advantage of 11 typically developed young adults were calculated throughout stance, while heel-toe walking and voluntarily toe-walking on an instrumented treadmill. Achilles tendon moment arm was defined in two-ways: (1) assuming a straight tendon, defined between the gastrocnemius medialis myotendinous junction and Achilles tendon insertion point, and (2) accounting for tendon curvature, by tracking the initial path of the Achilles tendon from the calcaneal insertion. Results: When accounting for tendon curvature, Achilles tendon moment arm length and plantarflexor effective mechanical advantage did not differ between walking conditions (p > 0.05). In contrast, when assuming a straight tendon, Achilles tendon moment arm length (p = 0.043) and plantarflexor effective mechanical advantage (p = 0.007) were significantly greater when voluntary toe-walking than heel-toe walking in late stance. Discussion: Assuming a straight Achilles tendon led to a greater Achilles tendon moment arm length and plantarflexor effective mechanical advantage during late stance, compared to accounting for tendon curvature. Consequently, plantarflexor muscle force would appear smaller when assuming a straight tendon. This could lead to erroneous interpretations of muscular function and fascicle force-length-velocity behaviour in vivo, and potentially inappropriate and ineffective clinical interventions for equinus gait.

Resistance Training Combined With Stretching Increases Tendon Stiffness and Is More Effective Than Stretching Alone in Children With Cerebral Palsy: A Randomized Controlled Trial.

Aim: Stretching is often used to increase/maintain muscle length and improve joint range of motion (ROM) in children with cerebral palsy (CP). However, outcomes at the muscle (remodeling) and resulting function appear to be highly variable and often unsatisfactory. During passive joint rotation, the Achilles tendon lengthens more than the in-series medial gastrocnemius muscle in children with CP, which might explain the limited effectiveness of stretching interventions. We aimed to ascertain whether increasing tendon stiffness, by performing resistance training, improves the effectiveness of passive stretching, indicated by an increase in medial gastrocnemius fascicle length. Methods: Sixteen children with CP (Age median [IQR]: 9.6 [8.6, 10.5]) completed the study. Children were randomly assigned to a combined intervention of stretching and strengthening of the calf muscles (n = 9) or a control (stretching-only) group (n = 7). Medial gastrocnemius fascicle length at a resting ankle angle, lengthening during passive joint rotations, and tendon stiffness were assessed by combining dynamometry and ultrasound imaging. The study was registered on clinicaltrials.gov (NCT02766491). Results: Resting fascicle length and tendon stiffness increased more in the intervention group compared to the control group (median [95% CI] increase fascicle length: 2.2 [1.3, 4.3] mm; stiffness: 13.6 [9.9, 17.7] N/mm) Maximum dorsiflexion angle increased equally in both groups. Conclusion: This study provides proof of principle that a combined resistance and stretching intervention can increase tendon stiffness and muscle fascicle length in children with CP. This demonstrates that remodeling of muscle structure is possible with non-invasive interventions in spastic CP.

Short-term outcome of surgical arthrodiastasis of the ankle with Ilizarov frame in a cohort of children and young people with juvenile idiopathic arthritis.

OBJECTIVES: Despite medical advances, life-changing articular damage may still occur in patients with JIA. We report a cohort with destructive arthropathy of the ankle treated by surgical arthrodiastasis. METHODS: Eight patients (nine ankles) received arthrodiastasis by means of an Ilizarov frame between 2009 and 2013. Patient- and clinician-reported outcome measures were collated prospectively, with retrospective analysis of demographics, disease and pre-surgical treatment. RESULTS: Pre-surgery, all patients received IA CS (mean 0.8 injections/year) and MTX (mean diagnosis to treatment 3.8 years; two of eight started within 3 months). Seven of eight patients received biologic drugs. Pain scores improved by 56 and 29% (P < 0.005) at 6 and 12 months post-frame removal. American Academy Orthopaedic Foot and Ankle Society ankle-hindfoot scale, Oxford Ankle Foot Questionnaire-Child and Oxford Ankle Foot Questionnaire-Parent scores improved by 171, 62 and 80%, respectively (P < 0.005) at 12 months post-frame removal. Patients remained satisfied with surgical treatment for a mean of 13.3 months. There was transient pin site infection in three patients, and all patients had radiological improvement in joint space. CONCLUSION: Arthrodiastasis with an Ilizarov frame is a safe, well-tolerated technique that should be considered as a short-term joint-preserving procedure to improve pain and function when damage has occurred. Delays to systemic medical treatment in this cohort would be considered out-with standard modern practice but, although less prevalent, destructive ankle arthropathy continues to occur in JIA, and we believe this study to be relevant. The ankle is particularly susceptible to damage and, even if localized, should be treated early and aggressively with DMARDs and rapid progression to biologic therapies. LEVELOF EVIDENCE: Level IV.

Intra-articular dysplasia of the femoral head in developmental dysplasia of the hip.

Central to the current treatment of dysplasia of the hip (DDH) is the concept of congruent reduction of the hip. If the femoral head is aspherical in DDH, this concept needs reconsideration. MRI scans are used to examine the femoral head in children. Diameters of 14 DDH and 12 normal hips were measured in three planes by eight observers on two occasions. Femoral head sphericity was determined using the mathematical concept of eccentricity. In DDH, the femoral head was less spherical, most marked in the coronal plane, yielding a 'rugby ball'-shaped femoral head. Accordingly, concentric reduction of the femoral head in DDH is impossible.

Stability-based assessment of Monteggia-type injuries predicts failure of treatment.

Paediatric Monteggia-type injuries are complicated by treatment failure and posterior interosseous nerve palsy, without reliable predictive indicators. Outcome is considered to be good, with little patient-reported evidence. We propose novel radiographic parameters. A total of 33 Monteggia-type injuries were analysed. Posterior interosseous nerve palsy was strongly predicted by the Radial Head Displacement Index. The presence of two or more of three novel instability markers was associated strongly with treatment failure. Patient-reported outcome measures were almost uniformly excellent. We advocate the use of a new, inclusive, stability-based classification of Monteggia-type injuries to predict patients who require accurate internal fixation.

Buried versus unburied Kirschner wires in the management of paediatric lateral condyle elbow fractures: a comparative study from a tertiary centre.

There is little consensus on whether Kirschner wire (K-wire) burial is preferable in the management of paediatric lateral humeral condyle fractures. We identified 124 patients from May 2008 to August 2014. Sixty received buried K-wires and 64 received unburied wires. We found no significant difference in the infection rates between groups, but a high rate of skin erosion (23%) in the buried group, with a subsequent high rate of infection in this subgroup (40%). We found a strong association of wire erosion following early surgery. There is a considerable cost saving associated with using unburied wires. We therefore recommend the routine use of unburied wires.