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Mitigating clinician and community concerns about children's flatfeet, intoeing gait, knock knees or bow legs

2017; Wiley; Volume: 53; Issue: 11 Linguagem: Inglês

10.1111/jpc.13761

1440-1754

Angela Evans,

Musculoskeletal Disorders and Rehabilitation

Children's foot and lower limb postures are a common parental concern, and they present to a range of clinicians.1 Over 40% of children referred for flatfeet (pes planus), intoed gait, knock knees or bow legs are within physiologically normal limits.2 This represents a substantial, unnecessary cost to any health-care system and raises the need for effective triage. The dilemma for caring clinicians is that each of these common presentations can also be pathological. This may encourage clinicians to 'err on the side of caution' and refer to a specialist. A group of concerned clinicians and researchers has expressed concern about 'over-diagnosis', with the aim of 'winding back the harm caused by too much medicine' often sought by and administered to the 'worried well'.3 An observational study in primary care across 12 UK General Practices reported 55 033 musculoskeletal consultations for approximately 100 000 people over 12 months.1 One in seven of all consultations was for a musculoskeletal problem, most commonly the back. In children <15 years old, the foot was the most common (107/10 000), constituting 14% of all musculoskeletal consultations.1 In 2007, there were 1041 new referrals to the orthopaedic outpatient department at a Montreal children's hospital, with 872 cases originating from either primary care physicians (609 cases, 69.9%) or paediatricians (263 cases, 30.1%). Regardless of the referral source, 23.7% (207 cases) were found to be within normal physiological limits – 151 cases (24.9%) from primary care and 56 (21.3%) from paediatricians. This audit was repeated in 2009, with almost identical results.2 For the six main paediatric orthopaedic presentations, the findings were: scoliosis – 78% pathological, 22% physiological; intoeing – 21% pathological, 79% physiological; genu varum/valgum – 57% pathological, 43% physiological; flatfeet – 61% pathological, 39% physiological; hip dysplasia – 85% pathological, 15% physiological; and toe walking – 80% pathological, 20% physiological.2 Outpatient referrals for physiological conditions prolong waiting lists, are costly and delay consultants from assessing children with pathological conditions. 'Over-diagnosis', over-treatment and resource waste is a very relevant health-care issue.3 I can see that her legs are not straight. (Father of 1-year-old newly walking girl) His feet are a lot flatter than ours. (Parents of their first child) We Googled, and we think he is 'pigeon-toed'. (Parents of 3-year-old boy) Studies over 30 years agree that approximately 25–30% children <6 years old may exhibit intoeing gait as a part of normal development, and in-toeing per se is not an abnormality (Fig. 1).5 Normal gait angles vary. In one study, gait angles in children aged 4–16 years ranged from 8° adducted to 16° abducted (24° range).6 Another study in children aged 5–16 years reported gait angles of 26° adducted to 37° abducted (63° range).7 A clinical caveat is that normal and developmental intoeing gait is both symmetrical and painless.5 There is no good evidence that interventions for paediatric intoeing gait are beneficial. A small case series of the use of gait plates for tripping8 with no control group observed only short-term immediate effects. Children who present with an intoeing gait pattern and concomitant pain, asymmetry, recurrent trips/falls or who limp are not normal and require further investigation. Important differential diagnoses are given in Table 1. Infection Bone tumour or lesion Infection Bone tumour or lesion Juvenile idiopathic arthritis Juvenile idiopathic arthritis Muscular dystrophy or atrophy The development of coronal plane alignment of a child's knee is well documented.9-11 The expected parameters are: genu varum from birth to 2 years, straight legs at 2 years and more variably genu valgum aged 2–6 years. Again, normal and developmental knee alignment presentation is both symmetrical and painless, and largely age-specific.5 Normal knee angles in children have been observed repeatedly (Fig. 2).12 Study findings vary, but there is general consensus that genu varum after 2 years of age is abnormal (Fig. 2). The bony modelling process after age 2–3 years sees more load on the lateral knee and less medially. This results in genu valgum at age 3–4 years, which generally maximises after age 4–4.5 years and then reduces. Increased genu valgum is reported at puberty, especially for females.13 Children who also have knee pain, asymmetry of knee alignment, recurrent trips and falls or a limp are not normal and require further investigation (see Table 1 for differential diagnoses). Assess the child's limbs adjacent to the knee. Proximally, increased medial hip range of motion, medial torsion of the femur and tightness of joint capsular ligaments and/or tendons inserting medially to the knee joint (largely adductors, hamstrings) may influence knee position in either stance and/or gait. Distally, the foot posture, which reduces from flat or pronated as childhood progresses, can be associated with increased genu valgum. A quick method of checking the influence of foot posture on knee alignment is to examine the child's coronal plane knee position, both weight-bearing and non-weight bearing (Fig. 3). It may be relevant to repeat this examination with the child wearing their usual shoes because shoe support can stabilise the foot position (less flat), which may also reduce genu valgum in stance. Footwear affects children's foot position and gait15; showing that the effects that footwear alone can have on foot and lower limb position can help parents. Development of the foot, particularly the shape of the medial arch, is a common concern of parents and clinicians alike given the commonly known association between flatfeet and preclusion from military service.16 A flatfoot appearance is normal in the first decade of life, reducing by age 10. Flatfoot is more common in boys, overweight/obesity and younger children, and it varies with ethnicity.17-23 The indications for the treatment of this predominantly asymptomatic condition are controversial. It is important to ensure that the flatfeet are flexible rather than rigid, symmetrical and painless.24-26 The child with flatfeet that are rigid, painful or asymmetrical requires diagnosis and treatment as indicated. This is rare, especially in children <10 years of age (Table 1). Tripping, falling frequently and limp are unusual presentations needing investigation. Evidence from both randomised controlled trials27-29 and a systematic review30 (Table 2) supports customised foot orthoses for children with juvenile idiopathic arthritis (JIA) and foot pain, which improve both pain and function compared to athletic shoes or cushioned in-soles.31 In the absence of pain, there is no evidence for customised foot orthoses. Clinically, the use of structured footwear, stretching and strengthening exercises and lower-cost pre-fabricated foot orthoses may help improve gait.32 CFO: Children with foot pain and JIA FO seem to help painful flatfeet In-shoe wedges FO 'What else could it be?' – and lists most probabilities ('yellow flags'). 'What else could it be that's nasty?' – listing less common but very serious ('red flag') diagnoses. The 3qq has the potential to standardise assessments and help clinicians and parents. It is a general triage tool. For flat feet, it prompts clinicians to look more intently at gait as well as stance. It suggests an approach to the paediatric flatfoot that is painless, but the foot posture appearance and measures (e.g. FPI-6,34 Arch Index35) suggest a 'flatter than normal' foot for age. The older the child and the flatter the foot, the more important it is to re-visit the diagnosis, especially the 'yellow flags', and to observe gait efficiency. A positive history of symptomatic flatfeet in first-degree relatives, notable prominence of the talo-navicular joint medially36-38and an ineffective propulsive gait phase increase clinical suspicion and may indicate intervention or at least review. The designation of a 'red flag' needs to be retained for conditions for which the 3qq recommends immediate medical care (within 24 h).39 Infection, bone lesions or tumours; JIA; and muscular dystrophy or atrophy are important differential diagnoses. My diagnosis is developmental knock knees – it is symmetrical, and there is no pain in this 4 year old child. Hmmm, what else could it be? Her feet are really flat, she is very flexible (Beighton score 8/9; LLAS 20/24), and that's not a familial trait. Could it be a connective tissue extensibility condition, such as Ehlers Danlos? I don't want to miss anything that's nasty. The knees are symmetrically in valgum, there's no heat, swelling, or pain, and her mother says she's not been unwell at all, so, it's unlikely to be an infection, arthritis or a tumour. From here, the clinician can reasonably reassure the parents, and themselves, that this is not an urgent or 'red flag' presentation and communicate with the general practitioners or paediatrician regarding the aetiology of the marked hypermobility. Is this too much, or odd? (Table 1). The 3qq is applicable across all disciplines of both medical and allied health professionals who see children presenting with intoeing gait, knock knees (bowed legs) and flatfeet.