Nwdps protocol - A simple functional outcome assessment tool for clubfoot correction and a review of literature

Abstract

Introduction

Various clubfoot severity scoring systems are known to us. Dimeglio and Pirani Scoring systems are most widely used. Also, various treatment outcome measures have been proposed by researchers to assess patient satisfaction and results of treatment. None of the available methods are widely popular and amenable for routine use. A “nwdps protocol” was proposed for functional assessment of patients with clubfoot correction, where “n” was no pain during walking or running; “w” was ability to wear normal shoes; “d” was no significant difference in foot/shoe size of both sides; “p” was plantigrade foot and “s” was ability of the child to squat without heel lift-off. The aim of this study was to test this functional outcome assessment tool for easy day to day use post clubfoot correction.

Methods

The nwdps protocol was applied to all the children at followup on a yearly basis who underwent clubfoot deformity correction in Department of Orthopaedics of our Institute between March 2016 and January 2018.

Results

Eighty children were enrolled for the study, 45 had bilateral affection while 35 had unilateral affection. In all 125 feet were treated for clubfoot correction and evaluated using nwdps protocol. Each child was assessed by 2 researchers independently. There was no difference in functional assessment of 2 observers. Fifty-nine children were nwdp positive, one was nwps positive, while 2 were dwps positive at the end of 1 year. 79 children became nwdps positive at the end of 2nd year of followup.

Conclusion

Nwdps protocol is a very easy to remember and easy to use functional outcome assessment tool post clubfoot correction with high degree of objectivity and interobserver reliability.

Level of evidence

Level IV.

1. Introduction

There are various clubfoot severity grading systems available. Catterall made the first attempt at developing a grading system for clubfoot as a deformity.¹ However, the most popular grading systems are the Dimeglio and Pirani scoring systems.^2,3 They help in both assessing the clubfoot severity, progression of improvement in serial casting, targeting treatment end point, assessing relapses and comparing outcomes in an objective manner. They are standard quantitative tools being widely used for past several years.

However, a number of post correction outcome measures for functional assessment of clubfoot treatment have also been proposed by various researchers. These helps in assessment of different treatment outcomes, functional improvement and overall patient satisfaction to treatment.

There was a need to develop a functional outcome assessment tool applicable post clubfoot correction which can be used easily in outpatient department. It should allow objective assessment of patient satisfaction and function in order to have interobserver reliability. A “nwdps protocol” was proposed for functional assessment of patients with clubfoot correction, where “n” was no pain during walking or running; “w” was ability to wear normal shoes; “d” was no significant difference in foot/shoe size of both sides; “p” was plantigrade foot and “s” was ability of the child to squat without heel lift-off. The aim of this study was to test this functional outcome assessment tool for easy day to day use post clubfoot correction.

2. Methods

Each child undergoing clubfoot correction in Department of Orthopaedics of our Institute was subjected to this functional evaluation in outpatient department at the end of each year of followup. All 80 children attending clubfoot clinic of our institute between March 2016 and January 2018 were enrolled for the study of evaluating this outcome assessment tool. The results were evaluated and recorded as positive or negative. A nwdps positive meant that the child functional outcome was positive on all 5 parameters. Any or more than one negative parameter meant suboptimal functional outcome as per the protocol. Many times a child failed to co-operate for squatting during the clinician evaluation. This problem was resolved by asking the parents to take a multi-angle photo of the squatting child prior to OPD visit.

The nwdps assessment was done for each patient by 2 different orthopaedic surgeons independently on separate occasions not more than 7 days apart. Any interobserver discrepancy was noted.

3. Results

There were 80 clubfoot children in our study of which 52 were males and 28 were females. Forty-five children had bilateral affection, 11 had left sided affection and 24 had only right sided affection. Thus, in all 125 feet were subjected to correction. The minimum age at presentation was 1 day while maximum age at presentation was 12 years. Three children were treated surgically – 2 by JESS and 1 by ilizarov. Thirteen children were more than 85 percentile as per WHO weight for age chart, seven were late presenters, six were untreated (neglected) clubfoot children while two were syndromic children. These twenty-eight children (forty-seven feet) were treated by a modified Ponseti protocol, in which tendoachillis tenotomy and plantar fascia release was followed by serial casting. Rest of the forty-nine children (seventy-four feet) were treated by standard Ponseti method.

Table 1 presents the nwdps positivity of patients at the end of 1 year and at the end of 2 years. Eighteen children were nwdps positive at the end of first year of followup, ie. sixty-two had some or the other functional limitation at the end of first year of followup. Fifty-nine children were nwdp positive, one was nwps positive, and 2 were wdps positive at the end of first year of followup. Sixty-one children turned nwdps positive at the end of 2nd year of followup. Hence, in all seventy-nine children were nwdps positive by the end of 2 years of followup.

Table 1.

Year End Functional Assessment post Clubfoot Correction.

nwdps protocol assessment	End of 1st Year of Followup		End of 2nd Year of Followup
	Positive	Negative	Positive	Negative
nwdp	59	0	79	0
nwps	1	0	1	0
wdps	2	0	0	0
nwdps	18	0	79	0
s	21	59	80	0
d	79	1	79	1

No interobserver discrepancy was noted in any case.

4. Discussion

In 1979, Turco gave a subjective evaluation of overall condition of the foot after clubfoot surgical treatment as excellent, good, fair and failure based on cosmesis, function and radiography criteria.⁴ Turco also observed that lateral talocalcaneal angle is a more accurate indicator of clubfoot correction among all radiographic criteria. A year later, Laaveg and Ponseti presented a 100 point rating system of functional results of clubfoot treatment using parameters based of patient satisfaction (20 points), function (20 points), pain (30 points), position of the heel while standing (10 points), goniometer measured passive range of motion (10 points), and gait (10 points).⁵ The rating system was highly subjective. They also found a strong correlation between the lateral talocalcaneal angle, the functional rating and the patients’ satisfaction with the results of treatment.

The multipurpose Short Form-36 (SF-36) MOS (medical outcomes study) is a general 36 point questionnaire that subjectively evaluates functional health and psychometric well being after treatment of any condition including clubfoot.⁶ It is highly subjective but was used by many researchers for patient satisfaction survey after clubfoot correction. On the other hand, Roye's Disease Specific Instrument (DSI, Roye Tool) is a specific 10 point questionnaire for subjective evaluation of functional outcomes and patient satisfaction after clubfoot correction.⁷ It has a limitation of using guardian of the patient as health proxy and is amenable to subjectivity.

The American Orthopaedic Foot and Ankle Society Hindfoot and Midfoot Scales are clinical rating systems which evaluate outcomes based on pain, foot function and static alignment.⁸ Bensahel et al. developed the International Clubfoot Study Group (ICFSG) outcome evaluation system for clubfoot correction based on assessment of foot morphology (hindfoot, midfoot, global foot appearance, pes cavus or flat foot), function (passive motion, muscle function as assessed by Jones Classification, dynamic foot function, gait and shoe wear) and radiography (various radiographic angles).⁹ It allotted points to each criteria and thus was found to be objective with interobserver and intraobserver reliability.¹⁰

Foot motion analysis allows indepth examination of the functional outcomes after clubfoot correction.¹¹ But it requires elaborate analysis of segmental dynamic foot function. The Clubfoot Asssessment Protocol (CAP) involves a detailed assessment of movement quality and requires accurate passive mobility testing with a goniometer and muscle testing.¹² It contains 22 items in four sub-groups: mobility (8 items), muscle function (3 items), morphology (4 items), and motion quality I and II (7 items). Questions about pain, stiffness and daily activity/sport participation are subjective items and are not included in this reliability study. Pedobarography also helps in assessing the functional improvement after clubfoot correction.¹³ It also requires elaborate plotting of segmental foot pressures and centre of pressure during different phases of gait cycle. Foot Function Index is another 23 point subjective evaluation tool for functional assessment after clubfoot correction.¹⁴ Rasit et al. used Quantitative Clubfoot Assessment of Deformity (QCAD) for assessing outcomes of clubfoot treatment based on Pirani deformity severity score and anthropometric measurement includes leg length, mid-leg circumference, foot length and mid-foot circumference.¹⁵ The Bangla Tool, developed in Bangladesh, evaluated results of clubfoot management as a tool that was quick, relevant and reliable for use in children of walking age who present to clubfoot clinics.¹⁶ Three areas of examination are included: parent satisfaction, gait, clinical examination of the clubfoot. Points are given to each criterion and added to obtain a grading score. However, this too is time consuming and elaborate. Bohner Beke et al. used Clubfoot Disease-Specific Instrument (referred to as “Dongalab Specific Measurements”) of the 10 most commonly known best quality of life questionnaire as a patient-based assessment is used to determine the treatment of clubfoot and its effectiveness and to compare traditional and Ponseti's treatment methods.¹⁷ Dobbs used Laaveg and Ponseti 100 point rating system, Foot Function Index (visual analogue scale for measuring limitation of activity, pain and disability), SF-36 MOS, physical examination (gait, goniometer based range of motion, motor strength based of Jones Classification), radiographic angles and osteoarthritic changes in tarsal joints as graded by Kellgren system for statistically evaluating results of surgical correction of clubfoot.¹⁸

All these above described functional outcome measures are either objective (based on radiography or foot kinematic analysis) or subjective (patient based questionnaires) or a combination of both. One thing which is underlying these outcome measure tools is that they cannot be used easily on a day to day basis quickly in outpatient department. In contrast, nwdps protocol is very short and easy to remember, hence can be practically used in outpatient department on day to day basis.

Smythe et al. using the Delphi method, ranked the importance of 22 criteria to define an ácceptable or good clubfoot correction’ at the end of bracing with the Ponseti technique with the help of 18 experienced clubfoot practitioners and trainers from ten different countries in Africa. As per their consensus, definition of a successfully treated clubfoot included 4 criteria, namely, plantigrade foot, ability to wear a normal shoes, no pain, and satisfied parents.¹⁹ On the other hand, our proposed nwdps protocol involves criteria of no pain, shoe wearability, no difference in shoe size, plantigrade foot and ability to squat as discrete criteria for assessment of functional outcome of clubfoot treatment. Our all 5 criteria are patient/parent centric analysis of function and satisfaction with fair degree of objectivity. Nwdps protocol is reported as positive/negative with respect to 5 criteria, and not any range or scale. Hence, subjectivity in our 5 shortlisted criteria is low. Therefore, the interobserver reliability is also high, which is important in any assessment protocol, to allow comparison across various studies and time frames.

Squatting is a very important daily physical activity in developing world especially African and South Asian subcontinent and hence the incorporation of squatting as a functional assessment tool was important to assess patient functional outcome and satisfaction. Also, Asian squatting differs from Western squatting in the fact that Asian squatting requires more dorsiflexion of the foot than Western Squatting.

Our study is limited by the fact that it needs further evaluation of the assessment tool for long term followups and also multicentric multiobserver analysis for establishing its reliability. Another limitation is that it evaluates patient as a whole and children with bilateral clubfoot affection are considered lacking in a particular attribute even if it is lacking unilaterally. Also, minor variations in any variable or attribute is not accounted for. Since, this protocol is not score based, it is not meant for comparison of functional outcome between 2 groups of patients or studies.

5. Conclusion

Nwdps protocol is a very easy to remember and easy to apply functional assessment tool which can be used universally post clubfoot correction irrespective of the treatment methodology adopted.

Research involving human participants and/or animals

Our Study does not involve and human/animal drug or treatment trials.

Institutional review board/ethics committee approval

Taken.

Informed consent

Standard Parent's informed consent for procedures taken.

Compliance with ethical standards

Yes.

Level of Evidence

Level IV.

Funding

None.

Conflicts of interest

Author 1, Author 2 and Author 3 have no conflicts of interest.

Appendix A. Supplementary data

The following is the Supplementary data to this article: