Congenital Upper Limb Anomalies

Disease/Disorder

Definition

Congenital upper limb anomalies (CULA), formerly known as Congenital upper limb deficiency, represents a spectrum of anomalies resulting from disruptions in formation or morphogenesis during embryonic limb development. These deficiencies can occur in isolation, affecting a singular limb, or involve multiple limbs, suggesting an underlying syndrome. Most CULA s primarily occur during the first trimester.¹

Historically, multiple classifications systems have been proposed to describe the diverse phenotypic presentations of CULA; however, the International Society for Prosthetics and Orthotics (IPSO) classification has been widely adopted for clinical application. The IPSO defines limb deficiency into two principal categories: transverse versus longitudinal deficiency. In a transverse presentation, there are no developed distal segments of the limb and naming is based on the segment that has no distal skeletal structure. On the other hand, a longitudinal deficiency will have distal limb growth and naming depends on impacted osseous structures.¹

The Oberg-Manske-Tonkin (OMT) classification was first introduced in 2010 (revised in 2014 and 2020) to evaluate limb deficiencies based on phenotypic presentation combined with knowledge of developmental biology to improve diagnostic precision. It is important to note that with complex or overlapping presentation, there can be combined diagnoses within the OMT systems.^2,3

Etiology

Congenital Upper Limb Deficiencies are complex and the etiology of most cases is unknown or multifactorial.⁴ It is also important to note that limb development begins early in the first trimester and direct causality is difficult to determine. Single limb involvement without syndromic features occurs sporadically.⁵

Known risk factors include Thalidomide use during pregnancy and maternal diabetes.¹ Other potential causes include genetic abnormalities, vascular involvement, drug exposure (antiepileptics and misoprostol), and chorionic villus sampling.

Studies have indicated that less than 40% of cases of limb anomalies have an identified molecular cause.^4,5 Recent studies have suggested associations with NAT1, NOS3, and SHSF-associated genes.⁴ Syndromes associated with limb deficiencies include Moebius syndrome, Poland Syndrome, VACTERL association, and Adams-Oliver Syndrome.

Vascular pathology has been implicated as most frequently associated with s. CULA Vascular causes include amniotic band syndrome, chorionic villus sampling, maternal thrombophilia, and disruption of branching vessels into the limbs.⁴

Epidemiology including risk factors and primary prevention

The incidence of congenital limb deficiencies varies with historical reports of 5.6 to 9.7 births for every 10,000 live births.⁵ More recent analysis suggests an overall worldwide average incidence of approximately 4.5 per 10,000 pregnancies, including outcomes of live birth, stillbirth, spontaneous abortion, and elective termination if anomaly was found.⁶ The data currently suggests that overall incidence of upper extremity involvement is estimated between 57-73% of cases, while the incidence of lower extremity involvement is estimated at 18-41% of cases.⁶  The most recent estimates in the United States per the Centers of Disease Control and prevention report 1 out of every 1,852 babies are impacted by limb difference at birth.⁷

A left terminal transradial deficiency is the most common CULA.¹ Similarly, radial longitudinal deficiency (RLD) is the most common longitudinal CULA at birth, occurring as often as 1 in 5,000 live births.⁸ Radial deficiencies can often occur with other congenital anomalies, with one-third of patients having an associated named syndrome (Holt-Oram Syndrome, Robert’s Syndrome) and two-thirds having associated medial or musculoskeletal abnormality (VACTERL association).⁸ Radial deficiencies are three to four times as common as ulnar deficiencies.⁹

Prenatal risk factors include maternal diabetes, exposure to chorionic villus sampling, prescription drug use (antiepileptics, thalidomide), and tobacco use.^1,4,5 Primary prevention includes counseling for families with known disorders, diligent obstetrical evaluation of medications, use of prenatal vitamins, counseling against ingestions/smoking, and treatment of diabetes.

Patho-anatomy/physiology

Much of critical limb development occurs between 26 days to 8 weeks gestation guided by a process that appears to be controlled by a small set of genes. Upper extremity CULA primarily occurs during this period due to a failure of mesodermal formation and/or limb differentiation. Normally, the upper limb develops proximally to distally with the upper arm developing before the forearm and hand. The hand itself develops in a distal to proximal fashion. With unilateral deficiency, ipsilateral abnormal organogenesis may occur. If bilateral, craniofacial anomalies are more likely.

Intrauterine fibrous amniotic bands may inhibit full limb development or may disrupt a previously intact limb. The exact pathophysiology of amniotic band syndrome remains controversial.

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

Generally, there are fewer complications with CULA compared with acquired limb deficiency. Children with upper CULA adapt activities of daily living skills to achieve functional milestones, with or without prosthetic intervention. In approximately 10% of cases, revision amputation may augment function.

Scoliosis occurs in 7% to 18% of patients with congenital limb anomalies and it is more common in patients with amelia.¹⁰ Scoliosis curves are typically monitored with a cautious approach to surgical intervention.

As children grow and develop, continued monitoring is imperative for evaluating functional change, muscle imbalances, overuse of the opposite limb, and limb growth patterns.

Specific secondary or associated conditions and complications

CULA is not associated with phantom pain; however, children can develop pain. Pain is more common in those with proximal deformity and bilateral involvement.¹¹ Terminal overgrowth may occur with amputation from amniotic band formation. Compromised skin integrity occurs with ill-fitting prostheses.

In upper extremity CULA, it is important to monitor for anomalies related to craniofacial, cardiac, and hematologic origins. ^1,5,8,9 There are several associated syndromes when assessing a child with upper extremity CULA, including Fanconi Syndrome, Thrombocytopenia with absence of radius syndrome, Holt-Oram Syndrome, and Baller-Gerold Syndrome. VACTERL association can also be seen in conjunction with limb deficiency.¹

As mentioned above, scoliosis is relatively common with CULA. The scoliosis curve should undergo routine monitoring to assess for functional impairment.

Essentials of Assessment

History

It is imperative to obtain full history regarding intrauterine course, material exposures, ingestions, and illnesses, and family history, including genetic abnormalities. If diagnosed post-natally, evaluation for syndromic features with expanded history regarding feeding difficulties, respiratory distress, bowel dysfunction, or cardiac abnormalities is warranted.

With improvements in ultrasonography, including the introduction of 3D evaluation opportunities, prenatal detection rate of upper limb abnormality is approximately 42%.⁵

Physical examination

It is important for providers to remember that many upper extremity CULA cases are associated with other anomalies. A complete physical examination is needed with every assessment, including assessment of the residual limb and deficiency, growth, development, and thorough systemic evaluation. Initial examination should include head to toe evaluation, including pectoral structures, cranial nerves, heart, skin, spine, anal structures and independent movement patterns.

As a child grows, close monitoring of range of motion, muscle bulk, and strength should be monitored. If a child wears a prosthetic, close evaluation of skin integrity is important to ensure no breakdown or verrucous hyperplasia. Functional integrity and integration of the involved extremity into tasks are paramount and can be observed through play and assessment of developmental milestones.

If a child is fitted with a prosthetic, it is imperative to evaluate the child with the prosthetic in place to ensure appropriate fit. Evaluations and modifications of the prosthesis are frequently needed in children and adolescence with CULA due to their rapid growth.

Functional assessment

A child’s function is directly observed and can be objectively measured. The Unilateral Below Elbow Test (UBET) was designed specifically for this population, for both prosthetic wearers and non-wearers. The Canadian Occupational Performance Measure is a family-centered tool that identifies priorities and guides therapy intervention. Observation of their mobility pattern is important to identify difficulties with weight bearing or balance. In addition to the standardized evaluations as above, play should be observed for fine motor skills and bimanual use.

The Patient Reported Outcomes Measurement Information System (PROMIS) and Pediatric Outcomes Data Collection Instrument (PODCI) are validated and sensitive tests for comparing patients with CULA. Compared to healthy individuals, patients with CULA may have lower functional scores. However, patients with CULA have lower scores with anxiety, depression and pain. They additionally had higher scores with peer relations.^12,13 When comparing between different age groups, young children demonstrated more upper extremity motor impairment.¹³

Laboratory studies

It is important to recall that up to one-third of radial deficiencies are associated with a syndrome.^1,5,8 Laboratory workup may identify genetic or other abnormalities in patients with dysmorphic or syndromic features but are not indicated in the absence of syndromic features, including most CULAs. When suspected, basic renal/metabolic function laboratories may identify other organ involvement, such as renal disease. In neonates with radial deficiency, baseline hematologic studies are indicated to identify treatable thrombocytopenia or anemia. A Diepoxybutane Test may be beneficial to screen for Fanconi anemia.⁵

Placental evaluation in the case of isolated transverse deficiency may be beneficial to assess for possible amniotic banding.⁵

Imaging

Initial imaging usually consists of prenatal ultrasound studies. Improvements in ultrasound technology and technique are leading to increased prenatal identification of limb deficiencies. It is estimated that approximately 42% of CULA cases are now identified on prenatal ultrasound, with estimates of 50% of those cases being identified using three-dimensional ultrasound.⁵ A significant number of cases are not discovered until birth.

Supplemental imaging, such as fetal magnetic resonance imaging(fMRI), may be indicated in cases where early detection of CULA is noted on ultrasonography or there is concern for a complex CULA presentation. The skeletal system, including development of the long bones, can be reasonably observed by fMRI at approximately 27 weeks gestation and can offer valuable insight to intrauterine development.¹⁴

Due to the association between upper CULA and syndromic involvement, children with upper limb deficiencies can have cardiac malformations and renal involvement. Imaging in the form of echocardiogram or renal ultrasound can be beneficial in the initial workup to identify any associated anomalies. If, on exam, there are any noted neurologic deficits, MRI of the brain to assess for abnormality may be warranted. Evaluation with skeletal survey can determine the extent of bony involvement, compare affected and unaffected sides, and assess for spinal abnormality.⁵

Early predictions of outcomes

Children with CULA adapt remarkably well to optimize function. A focus on task-specific devices should focus on the child’s values and goals. Prosthetic-driven function is generally enhanced with longer residual limbs; however, with a functionally retained wrist, prosthetic rejection is high. These patients function better without a prosthesis, especially with balanced muscle groups enabling full range of motion.

Although lower extremity prosthetic intervention is nearly universally accepted, meaningful use of upper extremity prosthetics is, and should be, guided by function. A child who functions better without a prosthesis will most likely reject one. While rejection rates of upper extremity prosthesis are higher than lower extremities, earlier fit and use of a prosthesis, under two years of age in congenital deficiency, is associated with higher long term use of the prosthetic.⁵ In cases of bilateral upper extremity involvement, some children will use their upper limbs together in a bimanual pattern to achieve adequate function.⁵

Overall, systemic involvement can range from very mild or very severe. Function in children with syndromic presentations may also be very varied in comparison to isolated or sporadic limb deficiency, depending on neurologic or multi-organ involvement. It should also be noted that if a child has a limb deficiency with an associated syndrome, life expectancy can be impacted. ¹⁵

Environmental

Evaluation of a child’s environment is crucial when prescribing a prosthesis. Obtaining history about the location of use of a prosthetic device could change a recommended prescription. Rural or farm environments favor body-powered devices, as would deserts, beaches, or places with inconsistent power sources. Myoelectric devices require geographic access to repair services.

It is also imperative to be mindful of the socioeconomic situation of the child and family involved. Prosthetics can be expensive and availability of therapy services limited depending on where the child lives versus ability to afford medical care.

Social role and social support system

As a child grows, develops, and matures, the perception surrounding their limb deficiency may evolve based on age, identity development, peer and family support, and body image.^5,15 Several studies have shown the importance of a strong support system on self-esteem, including support from family and peers.^5,15 Furthermore, several studies regarding quality-of-life show similar self-confidence and self-esteem scores in children with congenital upper limb deficiency in comparison to their peers.¹⁵ It is also important to note that children and adults with acquired limb deficiency have higher rates of depression and anxiety, so understanding cause of the limb deficiency and medical need of the child is imperative for care.^5,15

Overall, community involvement and support is imperative in promoting the wellbeing of children with CULA. This community support can come from family/caregivers, friends, educators/health care professionals, online support options, and peer mentors.^5,15

It is also important to note that children with perceived different abilities are at higher risk of experiencing bullying behaviors. It is important to ensure appropriate mental health and psychological support is available to children if needed.

Professional issues

The cultural context regarding treatment must incorporate values, morals, and expectations of the child, family, and society. Realistic goals and expectations are crucial. It is important to keep the child’s baseline functional status as well as goals for function in mind. Despite advanced technology, prostheses do not mimic normal functionality or cosmesis. Expected use, cost/benefit, and ease of operation must guide prosthetic decision-making. It is also imperative to approach this in a team setting, including the child, family members, pediatric rehabilitation physician, orthotist, and physical or occupational therapist.

Rehabilitation Management and Treatments

Available or current treatment guidelines

The goal for management of upper limb deficiencies focuses on the child’s ability to meet developmental milestones. Initial prosthetic intervention is introduced at approximately 6 months of age to facilitate sitting balance. The first prosthesis is typically fitted with a passive mitt for placing objects and bimanual tasks.¹ A more sophisticated prosthetic device can be introduced around 11-13 months of age to focus on simple grasping and releasing activities.¹ During these early developmental months and years, it is important that the child is supported through therapy services, both physical and occupational, in order to achieve the appropriate developmental milestones.

Patient acceptance of the prosthesis is dependent on multiple factors: level of limb loss, severity of comorbidities if present, comfort, and usefulness of the prosthesis. In general, the higher the limb absence, the less likely acceptance will be achieved. It should also be noted that children have higher rates of prosthetic abandonment with upper extremity prosthesis in comparison to adults.¹⁶

Prosthetic fittings are generally limb-level dependent and have a variety of options including oppositional, body-powered, and externally powered devices with hands, hooks of various shapes, mitts, etc. at the terminal end. The decision of which type of prosthesis to use is heavily dependent on the child and the family. Rural or farm environments may favor body-powered devices, as would deserts, beaches, or places with inconsistent power sources. Myoelectric devices require geographic access to repair services.

A wearing schedule helps with acceptance. Prosthetic use is positively impacted by parental support of the wearing, design, and expected function of the device. Additionally, upper limb prosthetics do not restore the sensory and proprioceptive input of the hand.

Surgical options are available based on level of deficiency and are utilized with caution. The Krukenberg Procedure can be utilized in children with absent hands by surgically separating the radius and ulna in the forearm, leading to a sensate surface with grasping ability. Cosmetic concerns are taken into account.¹ Upper extremity revision amputations are required in approximately 10% of upper limb deficiency cases with a goal of centralizing the hand and reconstructing the thumb for more functional use.¹ Similarly, a Vilkki procedure attaches a toe to the residual limb in order to promote a functional pincer grip for grasping.¹

Hand transplant surgery has changed amputation management in the adult population; however, in children with CULA, there is greater risk and uncertainty. In CULA, growth considerations are crucial, along with the possibility for different innervation, absent skeletal elements, and muscle integrity. Therefore, unless transplant can fully normalize function, the risk, including lifelong immunologic challenges, outweighs the currently understood benefits of hand transplantation.

At different disease stages

Congenital upper limb deficiencies include a varied spectrum of conditions, ranging from isolated unilateral limb involvement to syndromes involving multiple organ systems. Management heavily focuses on child-specific factors, including level of medical complexity, reasonable functional status and goals, and family involvement.

If appropriate, prosthetic intervention focuses on meeting developmental milestones to promote as much functional independence as possible. As a child grows, develops, and begins to explore his or her interests, prosthetic use and needs vary. As a child becomes more interested in hobbies or sports, prosthetics may be altered to fit the functional needs of the child.

Generally, body-powered devices are durable and cost-effective, and are prescribed early on. The simple cable mechanism translates movement directly to the terminal device. Myoelectric systems are costlier, heavier, and technologically fragile; however, these devices can be very helpful through using electrical signals through the residual muscles to coordinate movement.¹⁶ Devices should fit comfortably and prosthetic fit should be examined with each visit. It is also imperative to perform routine skin checks to ensure no breakdown or wounds from ill-fitting orthotics.

Coordination of care

For children with congenital upper limb deficiencies, it is imperative to have a strong interdisciplinary team working together to promote best outcomes for the affected child. The interdisciplinary team should include a pediatric physiatrist, occupational therapy, orthopedic surgery, prosthetists, and other specialist providers depending on medical complexity and comorbidities. Communication among the team is paramount to ensure the child’s needs are being met. A patient and family centered approach takes into account various aspects of the child’s life, including functional goals, ability to make appointments, financial or distance to care related concerns, and community/peer support.

Patient & family education

Child and family education is imperative in every visit, focusing on realistic goals and expectations as well as next steps in management. If a more complex presentation is involved, as with syndromes, comprehensive discussions regarding the diagnosis, organ involvement, and functional prognosis. Online support groups and information are available to families.

Emerging/unique interventions

The most important outcome measure is daily functional use and parental/patient report of function. Outcomes are influenced by independence, confidence, and self-determination. If a prosthesis is prescribed, guided patient/family interactions with care providers help to maximize the utility of the prosthetic device based on setting and functional tasks.

Objective measures, such as the ACMC, UBET, UNB, and the AHA are all functional tests used in the pediatric population to assess function.

Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

With any initial evaluation of a congenital upper limb deficiency, it is imperative to evaluate for multisystem involvement or syndromic presentation. More medically complex presentations require close follow up. The severity of the associated syndromes or comorbidities will influence prognosis and best next steps in management.

Early intervention with specialized occupational therapy and consideration of early prosthetic fitting is warranted in order to meet appropriate developmental milestones, particularly in the first few months to years of life.

While earlier prosthetic intervention before the age of 2 years is associated with higher device acceptance, children have higher rates of prosthetic abandonment in comparison with adults with similar amputation. A child’s view of their limb deficiency may change as they grow, develop, and become more self-aware.^5,15,16

There can be social, cultural, and religious implications to limb deficiencies. Continued reassurance and support, with consideration of psychology or behavioral health involvement, should always be provided.

Cutting Edge/Emerging and Unique Concepts and Practice

Myoelectric technology continues to improve and options are becoming available at a lower cost. However, scaling down the available and future options to child-sized components will take time. Prosthetics with multiple grip configurations are starting to develop, but still remain lacking when compared to traditional anatomic hand function.¹⁶ These devices often have articulations at the fingers for manual dexterity.

3D printing of prosthetics has been a significant focus in the prosthetic field. In 2012, the first 3D printed prosthetic device was created for children. The hope with further investigation of the use of 3D printed devices focuses on cost effectiveness, enhanced individualization to a child’s needs, and lighter weight. Furthermore, children require more frequent evaluations and alterations to prosthetic devices due to rapid growth during childhood and adolescence. Decreased cost and enhanced individualization may be more beneficial for ease of adjustments and obtaining a new prosthetic as a child grows and functional needs change.¹⁷ Similar to traditional prosthetics, 3D printed devices may be body powered or externally powered. Recent studies have noted decreased grasp performances of 3D printed limbs when compared to traditional prosthetic hand options.¹⁷ Further investigation is ongoing into improvements in 3D printed models.

Gaps in the Evidence-Based Knowledge

As technology advances, there continues to be disparity in prosthetic function, particularly grasp, versus a functional anatomic hand.¹⁷ Continued developments in lighter, sturdier, and more affordable myoelectric prosthetics are being explored. However, earlier integration into the pediatric population remains difficult. Furthermore, children require more frequent adjustments and replacement of prosthetic devices due to the rapid rate of growth and development. Exploration of options that have the capacity to grow and change with children would be a beneficial topic of further evaluation. 3D printed prosthetics are aimed at being a more cost effective, individualized solution for children who utilize prosthetic devices.

However, further development and studies need to evaluate the strength, durability, and grip capabilities of these devices.

References

1. Sara J Cuccurullo. (2020). Physical Medicine and Rehabilitation Board Review, Fourth Edition (Fourth edition). Demos Medical.
2. Goldfarb, Ezaki, Wall, Lam, Oberg(2020). The Oberg-Manske-Tonkin (OMT) Classification of congenital upper extremities: update for 2020. J Hand Surg Am, 45 (6) (2020), pp. 542-547
3. Wall, L., McCombe, D., Goldfarb, C., et al. (2024). The Oberg, Manske, and Tonkin Classification of Congenital Upper Limb Anomalies: A Consensus Decision-Making Study for Difficult or Unclassifiable Cases. The Journal of Hand Surgery. 49(4): 379
4. Shivers, E., Day, S., Dip, PG (2024). A Literature Review of the Causes of Congenital Limb Deficiencies Over the Last 20 Years. Journal of Prosthetics and Orthotics. 36(1):p e8-e17.
5. Scott-Wyard, P. (2023). Introduction to Limb Deficiency for the Pediatrician. The Pediatric Clinics of North America June 2023 70(3):531-543
6. Levesque, G; Reddi, R; Chhina, H, et al. (2024). Incidence of Congenital Limb Reduction Defects: A Systematic Review. Journal of Limb Lengthening & Reconstruction 10(2):p 31-54, Jul–Dec 2024.
7. Limb Reduction Defects [Internet]. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention; 2024 [cited 2025Oct15]. Available from: https://www.cdc.gov/birth-defects/about/limb-reduction-defects.html
8. Colen, D., Lin, I., Levin, S., Chang, B. Radial Longitudinal Deficiency: Recent Developments, Controversies, and an Evidence-Based Guide to Treatment. J Hand Surg Am. 2017;42(7):546e563.
9. Bednar MS, James MA, Light TR. Congenital longitudinal deficiency. J Hand Surg Am. 2009 Nov;34(9):1739-47.
10. Gettys, F. , Carpenter, A. & Stasikelis, P. (2020). The Role of MRI in Children With Congenital Limb Deficiencies With Associated Scoliosis. Journal of Pediatric Orthopaedics, 40 (5), e390-e393.
11. Schaeffer T, Canizares MF, Wall LB, et al. How Risky Are Risk Factors? An Analysis of Prenatal Risk Factors in Patients Participating in the Congenital Upper Limb Differences Registry. J Hand Surg Glob Online. 2022;4(3):147–152.
12. Bae, D. S., Canizares, M. F., Miller, P. E., Waters, P. M., & Goldfarb, C. A. (2018). Functional Impact of Congenital Hand Differences: Early Results From the Congenital Upper Limb Differences (CoULD) Registry. The Journal of Hand Surgery,43(4), 321-330. 2018.
13. Shoghi A., Bagley A., Wagner L.V., Abarca N. and James M.A.Patient-reported Outcomes for Children With Unilateral Congenital Below Elbow Deficiency.J Pediatr Orthop. 2022 Aug; Publish Ahead of Print.
14. Alrabai HM, Farr A, Bettelheim D, Weber M, Farr S. Prenatal diagnosis of congenital upper limb differences: a current concept review. J Matern Fetal Neonatal Med. 2017;30(21):2557–2563.
15. Lightdale-Miric N., Tuberty S. and Nelson D.Caring for Children With Congenital Upper Extremity Differences.J Hand Surg Am. 2021 Dec; 46 (12): 1105-1111.
16. Battraw, Marcus A; Fitzgerald, J; Joiner, W.; James, et al.. A review of upper limb pediatric prostheses and perspectives on future advancements. Prosthetics and Orthotics International. June 2022; 46(3):p 267-273.
17. Siegel JR, Harwood AC, Schofield JS. A Performance Evaluation of Commercially Available and 3D-Printable Prosthetic Hands: A Comparison Using the Anthropomorphic Hand Assessment Protocol. BMC Biomed Eng. 2024;6:8.

Original Version of the Topic

Ann C. Modrcin, MD, Matthew McLaughlin, MD. Congenital Upper Limb Deficiency. 12/02/2013.

Previous Revision(s) of the Topic

Matthew McLaughlin, MD, Suzan Lisenby, MD, Sumita Sharma, MD, Ann C. Modrcin, MD. Congenital Upper Limb Deficiency. 6/28/2018.

Matthew McLaughlin, MD, Amanda Lindenberg, DO, OT. Congenital Upper Limb Deficiency. 12/14/2022

Author Disclosure

Cristina Marie Sanders, DO, MS
Nothing to Disclose

Olivia Tincher, DO
Nothing to Disclose

Armin Seyedahmadi, DO
Nothing to Disclose