Characterizing the Timing of Surgical Repair of Congenital Hand Differences in the United States

Abstract

Background: Suggested timing of reconstruction of congenital hand differences varies widely. The goal of timely intervention is to achieve near-normal appearance and function. We evaluated national trends in surgical timing of congenital hand differences to determine whether interventions align with the literature. Methods: Recommended ages for surgical reconstruction were identified. The Pediatric National Surgical Quality Improvement Project database was queried from 2012 to 2020 for children who underwent surgery for simple syndactyly (SS), complex syndactyly (CS), polydactyly, or congenital trigger finger. Subgroup analysis was conducted to assess whether the surgeon’s subspecialty (plastic surgery vs orthopedic surgery, pediatric vs generalist) influenced the timing of repair. Results: Congenital trigger finger and CS reconstructions occurred largely within the recommended age range (73.8% and 52.2%, respectively). Polydactyly repairs primarily occurred earlier than the recommendations (54.0%). Timing of SS reconstruction was split, either occurring before (44.3%) or after (41.4%) the recommendations. For children with polydactyly, plastic surgeons were more likely to perform polydactyly reconstruction at a younger age compared with orthopedic surgeons (P = .0001). Conclusions: Established expert recommendations for the treatment of congenital hand differences are largely not followed in practice in the United States. This suggests that practice patterns may not be determined by the surgical literature.

Introduction

Congenital pediatric hand differences represent a significant cause of morbidity and disability in children. Polydactyly, the most common congenital malformation of the limbs, is characterized by an extra digit and occurs at an incidence of approximately 1 in 700 to 1000 live births. ¹ Syndactyly, with an incidence of 1 in 2000 to 3000 live births, is the fusion of adjacent digits. ¹ Trigger thumb, a condition affecting the tendons that flex the digit, presents with an incidence of 1 to 3 in 1000 while other trigger digits appear around 10 times less frequently.^{2 -4} Other congenital hand conditions, such as symbrachydactyly, amniotic band, radial club hand, and thumb hypoplasia, are rare and may have a more negative impact on gross and fine motor function, resulting in significant psychosocial burden to patients and caregivers.

Given the rapidly growing pediatric hand, each of the aforementioned conditions has a recommended optimal age for surgical treatment. Performing surgery too early can lead to higher rates of postoperative complications, such as scar contracture. Performing surgery too late can lead to increased risk for asymmetric growth, progressive malformation, and increasingly worse form and function. ⁵ The generally advised ages of surgery for simple syndactyly (SS), complex syndactyly (CS), polydactyly, and congenital trigger finger (CTF) are 18 to 24 months, 12 to 24 months, 12 to 24 months, and 1 to 4 years, respectively.^{2,5 -8} The recommended age may differ by patient depending on the number of digits involved, recommendations from anesthesiology or other specialties, and concurrent medical comorbidities.

Despite the importance of optimal timing for surgical treatment of congenital upper limb diseases, there are currently no studies analyzing whether surgeries occur at the advised ages, and whether surgeon-level factors such as surgeon-specialty or pediatric specialization influence the age at which surgery is performed.

Methods

Database and Patient Population

In 2012, the Pediatric National Surgical Quality Improvement Project (NSQIP-P) was created through the partnership between the American Pediatric Surgical Association and the American College of Surgeons (ACS). The goal of this project was to improve the tracking of national pediatric surgical outcomes. The NSQIP-P includes deidentified information including demographics, Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes, comorbidities, and 30-day postoperative outcomes from over 150 institutions. Each site uses ACS-trained clinical reviewers to ensure standardization and accuracy of data entry.

The NSQIP-P database was queried from 2012 to 2020 for patients under the age 18 who underwent 1 of 4 congenital hand operations with a concurrent ICD 9 or ICD 10 code for the specific hand difference. These procedures included SS (flaps and grafts only), CS (flaps, grafts, and bone osteotomies), polydactyly (including thumb duplication), and CTF. Patient and surgical characteristics were collected.

The institutional review board at our institution deemed this study exempt from review under the US Health and Human Services 2018 Requirements. The NSQIP-P database is deidentified and publicly available. This study was completed in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Study Design

Simple syndactyly and CS repairs were identified by first using the ICD 9/10 codes (755/Q70) and then the CPT codes to differentiate between the two procedures. Simple syndactyly repairs included the CPT codes 26560 and 26561 (repair, revision, and/or reconstruction procedures on the hand and fingers). Complex syndactyly repair only included the CPT code 26562. ⁹ Polydactyly repairs were identified by filtering for patients with ICD 9/10 codes 755.01, Q69.0, and Q69, ⁹ with a concurrent CPT code 26587 (reconstruction of supernumerary digit, soft tissue, and bone). ¹⁰ This category can include patients with larger and more complex postaxial polydactyly or with any of the range of preaxial polydactyly (thumb duplications). Congenital trigger finger release had a CPT code of 26055 (under incision procedures on the hand and fingers).

The NSQIP-P database was also queried for cases of symbrachydactyly, radial club hand, amniotic band, and thumb hypoplasia repairs. Due to low sample size, these procedures were not analyzed apart from simple time-to-event analysis. For completeness, the procedures and their inclusion criteria can be found in Supplemental Table 1.

Statistical Analysis

Each procedural data set was analyzed using SPSS 25 (IBM Corp, Armonk, New York) statistical software and GraphPad Prism 7 (GraphPad Software, San Diego, California). Statistical significance was defined as P less than .05 with 95% confidence intervals. Time-to-event analyses were performed for the ages at time of operation for all procedures. For each procedure, the percentages of patients who had their operation performed between the age periods of 0 to 0.5 year, greater than 0.5 to 1 years, greater than 1 to 1.5 years, greater than 1.5 to 2 years, greater than 2 to 2.5 years, greater than 2.5 to 3 years, greater than 3 to 3.5 years, greater than 3.5 to 4 years, and greater than 4 years were determined. In addition, the percentage of patients undergoing an operation within the advised period was recorded for each procedure.

Subgroup analyses were conducted to assess whether the year of operation or surgical subspecialty influenced age at operation. Each of the four included procedures was grouped based on the year the operation was performed and individually analyzed via a one-way analysis of variance. The procedures were also grouped based on the surgical subspecialty (pediatric vs nonpediatric, orthopedic surgery vs plastic surgery) and analyzed using independent two-tailed t tests.

Results

Population Demographics

A total of 7195 patients were included in this study. The largest subset of patients underwent CTF repair (N = 2816, 39.1%), followed by SS (N = 1962, 27.3%), polydactyly (N = 1881, 26.1%), and CS (N = 475, 6.6%). See Table 1 for relevant population demographics for each major condition. For most reconstructions, most patients were men, excluding CTF (N = 1445, 51.3% women). Sixty-one patients (0.85%) with rarer forms of congenital hand difference were also included.

Table 1.

Characteristics of Patients Undergoing Pediatric Hand Operations.

Patient characteristics	Surgical intervention
	SS (%)	CS (%)	PD (%)	CTF (%)
Sex
Male	1325 (67.5)	294 (61.9)	1141 (60.6)	1371 (48.7)
Female	637 (32.5)	181 (38.1)	740 (39.3)	1445 (51.3)
Race/ethnicity
White	1204 (61.4)	307 (64.6)	797 (42.4)	1878 (66.7)
Black	237 (12.1)	68 (14.3)	676 (35.9)	209 (7.4)
Asian	88 (4.5)	11 (2.3)	68 (3.6)	126 (4.4)
Native American	8 (0.4)	3 (0.6)	6 (0.3)	6 (0.2)
Native Hawaiian	9 (0.5)	1 (0.2)	10 (0.5)	9 (0.3)
Hispanic/Latinx	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)
Some other race	0 (0.0)	1 (0.2)	1 (0.05)	0 (0.0)
Unknown	416 (21.2)	84 (17.7)	323 (17.2)	588 (20.9)
Term status
Preterm	216 (11.0)	54 (11.4)	184 (9.8)	149 (5.3)
Term	1525 (77.7)	378 (79.6)	1546 (82.2)	2187 (77.7)
Unknown	221 (11.3)	43 (9.1)	151 (8.0)	480 (17.0)

Note. Summed percentages may not equal 100 due to rounding. SS = simple syndactyly; CS = complex syndactyly; PD = polydactyly; CTF = congenital trigger finger.

Age Distribution at Time of Operation

Congenital trigger finger was the operation with the highest percentage of operations occurring within the recommended timing (73.8%). The age distribution of patients is highlighted in Table 2. Relative to the other operations in this study, SS had the highest percentage of operations performed above the recommended timing, with 55.1% of operations occurring after the age of 18 months (Table 3). A distribution age at time of surgery is shown in Table 4 or Supplemental Figure S1. Overall, during the study period, the average age of patients at the time of SS repair significantly increased from 27.2 ± 30.4 in 2012 to 41.9 ± 45.9 in 2020 (P = .030, Table 5 or Supplemental Figure S2). Similarly, there was a trend of increasing age at the time of CTF repair between 2014 and 2017, from 35.7 ± 14 months to 38.9 ± 14 months (P = .007, Table 5 or Supplemental Figure S2). There was no change in the mean age of polydactyly or CS patients at time of repair during the study period. Of note, no cases of CTF repair were reported after 2017, possibly due to nationwide coding changes.

Table 2.

Age at Operation of Common Pediatric Hand Interventions.

Surgical intervention	N	Age	IQR	Advised timing
Simple syndactyly r.	1962	35.49 ± 38.69 mo	12.76-40.16 mo	18-24 mo 5
Complex syndactyly r.	475	24.76 ± 26.04 mo	11.53-26.66 mo	12-24 mo5,6
Polydactyly r.	1881	17.95 ± 25.70 mo	6.24-16.92 mo	12-24 mo 11
Congenital trigger finger r.	2816	3.12 ± 1.17 y	2.25-3.97 y	1-4 y2,5

Note. IQR = interquartile range (presented as quartile 1-quartile 3); r. = repair.

Data presented as mean ± SD.

Table 3.

Percentage of Cases Around the Advised Time Period.

Surgical intervention	N	Advised timing
		Recommended age	% before advised time period	% within advised time period	% after advised time period
Simple syndactyly r.	1962	18-24 mo 5	44.3	14.3	41.4
Complex syndactyly r.	475	12-24 mo5,6	27.2	52.2	20.6
Polydactyly r.	1881	12-24 mo 11	54.0	30.2	15.7
Congenital trigger r.	2816	1-4 y2,5	1.5	73.8	24.7

Note. r. = repair.

Table 4.

The Age Distributions of Common Pediatric Hand Interventions.

Surgical intervention	Frequency of age group at time of intervention, y
	0-0.5 (%)	0.5-1.0 (%)	1.0-1.5 (%)	1.5-2.0 (%)	2.0-2.5 (%)	2.5-3.0 (%)	3.0-3.5 (%)	3.5-4.0 (%)	4.0+ (%)
Simple syndactyly r.	3.4	17.2	24.3	14.3	8.1	4.5	4.2	3.0	21.1
Complex syndactyly r.	3.4	23.8	27.4	15.6	9.3	4.8	4.0	2.7	9.1
Polydactyly r.	21.3	33.1	22.5	7.3	3.0	2.4	1.8	1.1	7.5
Congenital trigger r.	0.5	0.9	5.3	10.3	17.2	15.6	14.8	10.6	24.7

Note. r. = repair.

Table 5.

The Age Distributions of Common Pediatric Hand Interventions by Year (2012-2020).

Surgical intervention	Average age at operation
	2012	2013	2014	2015	2016	2017	2018	2019	2020	P
Simple syndactyly r.
N	161	237	196	153	213	227	258	275	242
Mean age, mo	27.25 ± 30.44	36.66 ± 40.10	32.26 ± 33.93	36.70 ± 40.70	33.29 ± 33.67	37.68 ± 40.29	35.88 ± 39.27	35.35 ± 38.60	41.89 ± 45.94	.030*
Complex syndactyly r.
N	49	61	44	44	35	54	42	61	85
Mean age, mo	16.47 ± 11.65	25.70 ± 30.69	22.59 ± 18.33	25.99 ± 26.28	31.58 ± 42.61	27.11 ± 25.21	27.83 ± 30.99	24.45 ± 22.98	24.45 ± 22.98	.342
Polydactyly r.
N	197	289	276	216	145	164	177	222	195
Mean age, mo	17.84 ± 24.99	19.91 ± 28.90	18.01 ± 25.46	16.54 ± 20.98	16.95 ± 25.78	19.77 ± 32.63	16.73 ± 23.81	19.71 ± 25.52	14.93 ± 21.32	.483
Congenital trigger r.
N	367	479	524	395	471	580	0	0	0
Mean age, mo	36.89 ± 14.31	37.10 ± 13.87	35.67 ± 13.97	37.47 ± 13.97	38.11 ± 14.13	38.86 ± 14.04	NA	NA	NA	.007*

Note. r. = repair.

^*Indicates statistical significance at P less than .05.

Surgical Subspecialty Patterns

The vast majority of procedures were performed by plastic surgeons or orthopedic surgeons. However, the distribution varied based on the procedure (Table 6). Although the distribution was close to 50/50 for SS, CS, and polydactyly, most CTF repairs were performed by orthopedic surgery (N = 2203, 78.2%). The only condition in which there was a significant difference in mean age at operation between the plastic and orthopedic surgery was polydactyly, where the mean age at time of the repair was 15.48 ± 23.08 months for plastic surgery compared with 20.33 ± 27.68 months (P = .0001). Conversely, in comparing pediatric specialists to surgeons without that additional training, all repairs were more likely to be completed by pediatric specialists (Table 7). Similarly, there were no differences in the average age at operation between pediatric specialists and nonpediatric for all repairs.

Table 6.

The Age Distributions of Common Pediatric Hand Interventions: Plastics Versus Orthopedics.

Surgical intervention	Specialty
	Plastic surgery	Orthopedic surgery	P
Simple syndactyly
No. of patients	980	963
Mean age, mo	35.51 ± 40.09	35.51 ± 37.25	.997
Complex syndactyly
No. of patients	206	266
Mean age, mo	24.79 ± 29.55	24.69 ± 23.17	.967
Polydactyly
No. of patients	848	911
Mean age, mo	15.48 ± 23.08	20.33 ± 27.68	.0001*
Congenital trigger finger
No. of patients	588	2203
Mean age, mo	37.16 ± 14.04	38.23 ± 14.07	.100

^*Indicates statistical significance at P less than .05.

Table 7.

The Age Distributions of Common Pediatric Hand Interventions: Pediatric Versus Nonpediatric.

Surgical intervention	Specialty
	Pediatric	Nonpediatric	P
Simple syndactyly
No. of patients	1420	523
Mean age, mo	35.07 ± 37.88	36.72 ± 40.84	.421
Complex syndactyly
No. of patients	376	96
Mean age, mo	24.50 ± 26.31	25.64 ± 25.45	.697
Polydactyly
No. of patients	1340	419
Mean age, mo	18.13 ± 25.78	17.53 ± 25.36	.671
Congenital trigger finger
No. of patients	2256	535
Mean age, mo	37.51 ± 14.02	36.87 ± 14.21	.349

Other Congenital Hand Differences

The data for four less common congenital hand differences were also analyzed: symbrachydactyly, amniotic band, radial club hand, and thumb hypoplasia. There were fewer than 30 cases of each operation included in the NSQIP-P database, with the fewest in thumb hypoplasia repair (N = 11) and radial club hand repair (N = 1). Due to the limited sample sizes, these cases were not included in all analyses. Refer to Supplemental Table 2 for data related to the timing of these operations.

Discussion

Congenital hand differences are a group of anatomical differences with multiple causes, inheritance patterns, functional limitations, and repair options. This nationwide evaluation compares actual practice patterns regarding surgical timing to guidelines for timing in the surgical literature. Some studies, most of which are comprehensive reviews or retrospective, single-center studies, discuss suggested timelines based on lower quality evidence or surgeon’s preference.^{3,8 -10} As such, established recommendations regarding the optimal timing of these repairs are variable and often not based on high-quality evidence. Similarly, as congenital hand differences may be repaired by surgeons with different training, that is, plastic surgery versus orthopedic surgery or pediatric specialists versus generalists, recommendations often vary depending on the background and expertise of the operating surgeon.^12,13

Our findings provide insight into contemporary practices in the reconstruction of common congenital hand differences at a national level. For the most common congenital hand differences, most CTF releases occurred within the recommended age range (73.8%). Polydactyly and CS reconstruction primarily occurred before the recommended age range (54.0% and 52.2%, respectively). Simple syndactyly was nearly evenly split between occurring before and after the recommended age range (44.3% and 41.4%, respectively). There was also an overall increase in age at SS repair during the study period, from 27.25 ± 30.44 months in 2012 to 41.89 ± 45.94 months in 2020 (P = .030). This may reflect a larger push toward an intentional delay of SS to allow for more hand growth for increased tissue availability before repair, to prevent commissural creep, and to adjust for other complications related to syndactyly of unequal digits. The COVID-19 pandemic may have also delayed parents and caregivers from pursuing elective surgery, although the total number of SS procedures in 2020 was not significantly lower compared with previous years. Similarly, the age at CTF repair increased from 2014 to 2017. This may indicate a move toward nonsurgical management, as CTF often self-resolves.

Subspecialty-specific practice patterns for polydactyly were noted. Plastic surgeons tended to perform polydactyly repairs in younger patients compared with orthopedic surgeons (15.4 ± 23.1 months vs 20.3 ± 27.7 months, P = .0001). Differences in training may allow plastic and reconstructive surgery–trained surgeons to feel more comfortable performing reconstruction on patients at younger ages.

This study has several limitations. First, the NSQIP-P database, although extensive, may have inaccuracies and may not include all cases of a particular operation completed in the nation, as it relies on submitted cases. We used large groupings of each major class of congenital hand differences, which erases some clinically significant nuances such as differences in management decisions that may occur considering the severity of the anatomical variation, fingers affected (eg, in the case of syndactyly, short finger tethered to long finger vs fingers of similar length tethered), or the number of web spaces affected. Similarly, we have no data about other factors that could have affected the timing of surgery, such as a patient’s gestational age, other comorbidities (as hand differences may be corrected after more pressing anomalies in patients with certain syndromic causes of hand difference), socioeconomic status, or geographic location. In addition, the database and this study categorize patients based on self-identified race. The increased incidence of certain disease processes may be attributable to factors such as a patient’s genetic ancestry. Although race can be seen as a proxy for genetic ancestry, it is often not entirely comparable. ¹⁴ Moreover, the racial/ethnic breakdown in congenital hand repairs included in this database does have a higher-than-expected percentage of white patients compared with patients of other racial backgrounds. The US Census Bureau has reported that, as of 2015, most US children under 5 were not white. As such, this disparity may be evidence of a lack of access to care for racially diverse children. This study also includes no patients identified as Hispanic or Latinx. This is most likely inaccurate given the increasing population of Hispanic/Latinx children in the United States during the study period. It is likely that a percentage of the patients identified in the racial categories also have Hispanic ethnicity. This lack of clarity is a limitation of the data set and, consequently, our study results.

Conclusion

We describe the most common age ranges at the time of repair of several of the most common congenital hand differences using a large, nationwide database. We emphasize that these age ranges are not recommendations for the timing of surgical repair of congenital hand differences, solely evidence of current national practice patterns. Future studies are needed to support the creation of evidence-based recommendations for the reconstruction of congenital hand differences.