Long term functional outcomes after early childhood pollicization

What's New in Congenital Hand Surgery

BACKGROUND

Congenital conditions of the hand and upper extremity are a frequent source of consultation among pediatric orthopaedists and hand surgeons. Advances in the fields of molecular biology and genetics have helped to better understand some of these conditions and redefine previous classification systems. New outcome measurement tools have been used to assess surgical results and have brought into focus a different aspect of the patients' experience.

METHODS

We searched PubMed database for papers related to the treatment of congenital hand anomalies published from January 1, 2015 to October 31, 2018. The search was limited to English articles yielding 207 papers. Three pediatric hand surgeons selected the articles based upon the criteria that the topic was germane, the article fell under the subheadings within the manuscript, and the conclusions were meaningful.

RESULTS

A total of 40 papers were selected for review, based upon their quality and new findings. Research articles with significant findings were included for syndactyly, symbrachydactyly, cleft hand, polydactyly, radial longitudinal deficiency, congenital radio-ulnar synostosis, and macrodactyly.

CONCLUSIONS

Our knowledge of the embryology and pathophysiology of congenital upper extremity conditions continues to evolve. Functional assessments combined with patient and parent-reported outcomes have our understanding of the results following surgical procedures. Further research and standardization of our scientific data will provide better answers and higher quality of evidence.

LEVEL OF EVIDENCE

Level V-literature review and expert opinion.

Congenital Deformities of the Hands

Evaluation of the pediatric musculoskeletal system may be difficult because of differences between children and adults. As children mature, their physical structure approaches that of an adult. However, in the meantime, varying stages of ossification and developmental timelines may confuse the average clinician. Congenital abnormalities of the upper extremity are extremely numerous, but here we present 10 that often are seen in clinical practice. The article discusses the diagnosis, evaluation, treatment, and outcomes of each condition.

Long-term outcomes after pollicization: a mean 11-year follow-up study

This study evaluates the long-term results of pollicization for a congenitally absent or severely hypoplastic thumb. Twenty-nine patients with 34 pollicizations were divided to two groups: those with simple thumb hypoplasia (22 pollicizations) and those with radial longitudinal dysplasia (12 pollicizations). The patients were followed from 1.3 to 32 years, with a mean follow-up time of 11 years. The patients were examined clinically and radiologically, and they completed a questionnaire concerning satisfaction with appearance, function, and social interaction. The Percival score was also calculated. In both groups, grip and pinch strengths of the operated hands were inferior to the normative age-related values. Radiologically, flattening of the original metacarpal head was found in 20 out of the 34 operated hands. We found better patient satisfaction in the simple hypoplasia group than in the radial longitudinal dysplasia group. The functional outcomes and patients' satisfaction did not correlate with the age of patients at operation. Level of evidence: IV.

The Second Toe-to-Hand Transfer for Full-length Thumb Reconstruction in Congenital Thumb's Grade IIIb to V Hypoplasia: MTPJ Arthrodesis Instead of Tendon Rebalansing

Congenital thumb hypoplasia is a rare deformity of the upper extremity. The classification of thumb hypoplasia was created by Blauth in 1967 (types I to V). The base of the first metacarpal bone is absent for hypoplasia types IIIb to V, therefore, toe-to-hand transplantation is not recommended. A stable first carpometacarpal joint has been considered a mandatory factor for a successful toe-to-hand transplantation. The aim of this study is to describe a new technique for thumb reconstruction with the second toe transfer and metatarsophalangeal joint (MTPJ) arthrodesis, which can provide a five-digit hand and restore thumb functionality for thumb hypoplasia IIIb to V. We performed second toe-to-hand transplantation with MTPJ arthrodesis for 3 pediatric patients (mean age, 69 mo) with congenital thumb hypoplasia IIIb (n=2), grade V (n=1). Long-term follow-up evaluated the functions and esthetics of the hands for grade IIIb patients (n=2). We believe the second toe transfer with MTPJ arthrodesis transplantation is a promising method for reconstructing a full-length congenital or traumatic thumb absence for the pediatric population.

Inter- and Intrarater Reliability of the Thumb Grasp and Pinch Assessment for Children Following Index Pollicization for Congenital Thumb Hypoplasia

PURPOSE

The Thumb Grasp and Pinch (T-GAP) assessment quantifies functional hand use in children with congenital thumb hypoplasia by categorizing grasp and thumb use patterns during assessment activities that encourage a variety of grasp and pinch styles. This study aims to demonstrate interrater and intrarater reliability results of the T-GAP.

METHODS

A retrospective review was performed of children who had undergone index finger pollicization for congenital thumb hypoplasia and subsequent evaluation with videotaping of the T-GAP assessment. Following a training period, 4 occupational therapists scored 11 T-GAP videos on 2 separate occasions, separated by at least 2 weeks. Intraclass correlation coefficients (ICCs), standard error of measurements, minimum detectable change (MDC), and Pearson correlation coefficients were calculated.

RESULTS

The T-GAP raw scores were 16 to 55, demonstrating a range of mild to severe hand grasp differences. The ICCs for the interrater reliability trials were 0.887 and 0.901. Intrarater ICCs were all above 0.88. The MDC for each trial was 8.1 and 6.7 points. Pearson correlation coefficients calculated for each rater and each pair of raters were above 0.8 in all cases.

CONCLUSIONS

Interrater and intrarater reliability testing results for the T-GAP were excellent in all cases; this strongly suggests that results from T-GAP assessments are reliable. The high ICCs suggest that raters can classify and score children's hand function consistently.

CLINICAL RELEVANCE

This study, in conjunction with previous work, suggests that the T-GAP may be an ideal approach to assessing the outcomes of pollicization and provide a means of ongoing assessment of children's grip and pinch function.

Feasibility of Ultrasound in Infant Wrist and Thumb Imaging

OBJECTIVES

To determine the feasibility of ultrasound (US) in infant lateral carpal and base-of-the-thumb imaging. We hypothesized that US would be a practical modality for visualizing the unossified structures.

METHODS

Institutional review board approval was obtained for this single-center pilot study. Healthy infants aged 12 months or younger were enrolled. Ultrasound examinations of the distal radial epiphysis through the first metacarpal were performed with a high-frequency transducer.

RESULTS

Ultrasound evaluations of the base of the thumb were performed in 18 healthy infants (mean age ± SD, 13.8 ± 9.1 weeks; 44% female). Assuming an elliptical shape, the mean areas of the scaphoid and first metacarpal epiphysis measured 0.85 ± 0.19 and 0.44 ± 0.087 cm² , respectively. The mean areas of the trapezium and ossified first metacarpal as approximate rectangular shapes measured 0.23 ± 0.069 and 0.49 ± 0.16 cm² . A perimeter tracing was also used as an alternative area calculation. The mean trapezium area-to-scaphoid area ratio (0.28 ± 0.10) showed less variability compared to the first metacarpal epiphysis area-to-scaphoid area ratio (0.55 ± 0.20) or first metacarpal area-to-scaphoid area ratio (0.64 ± 0.31).

CONCLUSIONS

Our data suggest that US is well suited for the evaluation of the lateral carpus and base of the thumb in young infants. These data serve as a reference to which wrist and thumb abnormalities can be compared.

A New, Direct Measure of Thumb Use in Children After Index Pollicization for Congenital Thumb Hypoplasia

PURPOSE

After index pollicization for congenital thumb hypoplasia, time-based hand dexterity tests do not indicate whether the new thumb is being used by a child. The Thumb Grasp and Pinch assessment (T-GAP) is a new outcome measure that classifies grasp and pinch styles to quantify use of the new thumb. The goal of this study was to establish concurrent validity and construct validity in the T-GAP.

METHODS

Data from children treated with index finger pollicization for congenital thumb hypoplasia were retrospectively reviewed. Measures of strength, range of motion, and scores on the Box and Blocks Test (BBT), 9-Hole Peg Test (NHPT), Functional Dexterity Test (FDT), and Task 7 (Heavy Objects) from the Jebsen-Taylor Test (JTT7) were recorded. Patients also completed the T-GAP consisting of 9 age-appropriate tasks, during which grasp patterns were classified. Spearman correlation coefficients were calculated comparing the T-GAP score with scores on the BBT, NHPT, FDT, and JTT7.

RESULTS

We evaluated 21 thumbs in 21 children an average of 71.7 months after pollicization surgery (range, 9-175 months). The T-GAP score was significantly correlated with BBT, NHPT, FDT, and JTT7 (R = 0.69, -0.60,-0.59, and -0.60, respectively). The T-GAP score was significantly correlated with tripod pinch, key pinch, and grip strength (R = 0.77, 0.75, and 0.71, respectively) and with opposition and grasp span (R = 0.50 and 0.52, respectively). The T-GAP was the only functional measure correlated with parent and patient satisfaction with thumb function.

CONCLUSIONS

Concurrent validity was supported by significant correlations between T-GAP score for all 4 dexterity measures. Construct validity was supported by significant correlations between strength and range of motion of the thumb and T-GAP score.

CLINICAL RELEVANCE

This evaluation may help surgeons and therapists better understand results after pollicization and determine whether the new thumb is being incorporated into daily activities.

Radial Longitudinal Deficiency: Recent Developments, Controversies, and an Evidence-Based Guide to Treatment

Radial longitudinal deficiency (RLD) is the most common congenital longitudinal deficiency at birth and represents a wide spectrum of upper extremity anomalies, from mild thumb hypoplasia to absent radius. Radial dysplasia may be isolated or associated with an array of systemic anomalies that should be familiar to pediatric hand surgeons. The management of RLD has evolved greatly since its inception in the late 19th century, largely due to decades of innovation that followed the thalidomide catastrophe of the 1960s. Yet controversy still exists regarding many aspects of RLD. Traditional treatments of radial dysplasia (ie, centralization) are unfortunately wrought with poor outcomes and high rates of recurrence, leading some authors to recommend alternative techniques for this condition. Reconstruction of the hypoplastic thumb, although less controversial, is just starting to see long-term outcomes. This article reviews the etiology, classification, and treatment options for RLD, highlighting recent developments and outcomes.

On-Top Index Pollicization After a Partial Amputation of a Syndactylized Hypoplastic Thumb in a Patient With Townes-Brocks Syndrome

Townes-Brocks syndrome is a rare autosomal dominant syndrome characterized by multiple malformations, including thumb anomalies. Thumb hypoplasia poses a specific problem, where a deficient thumb creates a significant handicap in hand function. The treatment goal is enabling pinch and grip activity, and the preferred procedure for a severely hypoplastic thumb is index finger pollicization. We present a case of on-top index pollicization in a 10-year-old, after a partial amputation of a previously syndactylized hypoplastic thumb, with a well-formed first carpometacarpal joint. The decision to proceed with pollicization was made after considering second toe-to-hand transfer and a standard pollicization with an amputation of the thumb remnants. Six months after the procedure, the outcome was evaluated as "good" (19 points) with Percival's assessment method. The patient uses the operated hand in all activities of daily life and is doing well in school. This patient's diagnosis of Townes-Brocks syndrome was confirmed with genetic testing, which gives grounds and incentive to further investigate other possible related conditions, and provide genetic counselling and risk assessment. In reconstruction of complex thumb malformations, especially after previous multiple operations, an individually tailored reconstruction plan, sometimes involving modifications of standard reconstructive procedures, is paramount in achieving good results.

Characterization of the disruption of neural control strategies for dynamic fingertip forces from attractor reconstruction

The Strength-Dexterity (SD) test measures the ability of the pulps of the thumb and index finger to compress a compliant and slender spring prone to buckling at low forces (<3N). We know that factors such as aging and neurodegenerative conditions bring deteriorating physiological changes (e.g., at the level of motor cortex, cerebellum, and basal ganglia), which lead to an overall loss of dexterous ability. However, little is known about how these changes reflect upon the dynamics of the underlying biological system. The spring-hand system exhibits nonlinear dynamical behavior and here we characterize the dynamical behavior of the phase portraits using attractor reconstruction. Thirty participants performed the SD test: 10 young adults, 10 older adults, and 10 older adults with Parkinson's disease (PD). We used delayed embedding of the applied force to reconstruct its attractor. We characterized the distribution of points of the phase portraits by their density (number of distant points and interquartile range) and geometric features (trajectory length and size). We find phase portraits from older adults exhibit more distant points (p = 0.028) than young adults and participants with PD have larger interquartile ranges (p = 0.001), trajectory lengths (p = 0.005), and size (p = 0.003) than their healthy counterparts. The increased size of the phase portraits with healthy aging suggests a change in the dynamical properties of the system, which may represent a weakening of the neural control strategy. In contrast, the distortion of the attractor in PD suggests a fundamental change in the underlying biological system, and disruption of the neural control strategy. This ability to detect differences in the biological mechanisms of dexterity in healthy and pathological aging provides a simple means to assess their disruption in neurodegenerative conditions and justifies further studies to understand the link with the physiological changes.

Congenital Anomalies of the Hand--Principles of Management

Physicians who specialize in pediatric orthopedics and hand surgery frequently encounter congenital hand abnormalities, despite their relative rarity. The treating physician should be aware of the associated syndromes and malformations that may, in some cases, be fatal if not recognized and treated appropriately. Although these congenital disorders have a wide variability, their treatment principles are similar in that the physician should promote functional use and cosmesis for the hand. This article discusses syndactyly, preaxial polydactyly and post-axial polydactyly, and the hypoplastic thumb.

Strength, Multijoint Coordination, and Sensorimotor Processing Are Independent Contributors to Overall Balance Ability

For young adults, balance is essential for participation in physical activities but is often disrupted following lower extremity injury. Clinical outcome measures such as single limb balance (SLB), Y-balance (YBT), and the single limb hop and balance (SLHB) tests are commonly used to quantify balance ability following injury. Given the varying demands across tasks, it is likely that such outcome measures provide useful, although task-specific, information. But the extent to which they are independent and contribute to understanding the multiple contributors to balance is not clear. Therefore, the purpose of this study was to investigate the associations among these measures as they relate to the different contributors to balance. Thirty-seven recreationally active young adults completed measures including Vertical Jump, YBT, SLB, SLHB, and the new Lower Extremity Dexterity test. Principal components analysis revealed that these outcome measures could be thought of as quantifying the strength, multijoint coordination, and sensorimotor processing contributors to balance. Our results challenge the practice of using a single outcome measure to quantify the naturally multidimensional mechanisms for everyday functions such as balance. This multidimensional approach to, and interpretation of, multiple contributors to balance may lead to more effective, specialized training and rehabilitation regimens.

Innovative evaluation of dexterity in pediatrics

STUDY DESIGN

Review paper.

INTRODUCTION

Hand dexterity is multifaceted and essential to the performance of daily tasks. Timed performance and precision demands are the most common features of quantitative dexterity testing. Measurement concepts such as rate of completion, in-hand manipulation and dynamic force control of instabilities are being integrated into assessment tools for the pediatric population.

PURPOSE

To review measurement concepts inherent in pediatric dexterity testing and introduce concepts that are infrequently measured or novel as exemplified with two assessment tools.

METHODS

Measurement concepts included in common assessment tools are introduced first. We then describe seldom measured and novel concepts embedded in two instruments; the Functional Dexterity Test (FDT) and the Strength-Dexterity (SD) Test.

DISCUSSION

The inclusion of novel yet informative tools and measurement concepts in our assessments could aid our understanding of atypical dexterity, and potentially contribute to the design of targeted therapy programs.