Unilateral Ulnar Hemimelia with Humeroradial Synostosis and Oligodactyly: A Rare Congenital Limb Anomaly

Abstract

Ulnar hemimelia (UH), a rare congenital skeletal condition, is frequently linked to other upper limb abnormalities and is characterized by the partial or total absence of the ulna. We describe a rare instance of a 12-year-old patient with unilateral UH, humeroradial synostosis, and oligodactyly. The patient presented with obvious left upper limb shortening and functional limitations. The absence of the ulna, fusion of the humerus and radius, and the underdeveloped digits were all verified by radiographic examination. This case emphasizes the phenotypic variability linked to UH and contributes to the small body of literature on such complex presentations. In order to improve function and quality of life, management prioritized physiotherapy, supportive care, and regular follow-up for possible surgical procedures. For the best outcomes, early detection and a multidisciplinary approach are crucial.

INTRODUCTION

Ulnar hemimelia (UH), also referred to as ulnar longitudinal defect, is a rare congenital skeletal anomaly associated with the absence of the ulna, either partially or completely.[1] UH was first recognized in 1683 and has a documented incidence of 1 in 150,000 live births.[2] With a male-to-female ratio of 3:2, UH predominantly affects men. In about 70% of cases, UH is unilateral, incomplete, and frequently affects the right ulna.[1,3] Clinically, individuals exhibit radial bowing, ulnar deviation of the wrist, and forearm shortening. These abnormalities may be accompanied by other skeletal findings, including radial head dislocation, humeroradial synostosis, or digital anomalies – syndactyly or oligodactyly.[4] In contrast to radial anomalies, UH is typically nonsyndromic, though a rare association with Cornelia de Lange or Poland syndromes is reported.[3]

Literature review suggests that cases of UH are seldom reported.[1,2,3,4,5,6,7] Here, we describe a unique case of unilateral incomplete UH associated with ipsilateral humeroradial synostosis and oligodactyly as well as contralateral oligodactyly.

CASE REPORT

A 12-year-old female child presented with upper limb disability resulting in pain, limited range of motion of elbows, and cosmetic disturbance of both forearms and hands. She is the second of two daughters born to nonconsanguineous healthy parents. There is no family history of any kind of congenital skeletal abnormalities in her sibling and extended family. Her mother reported no history of any drug, smoke, alcohol, or radiation exposure during pregnancy. She was born uneventfully at full term through normal vaginal delivery. There was no other significant health problem in her childhood, and she did not receive any surgical or nonsurgical treatment for the deformities involving the upper extremities.

On physical examination, the left upper limb appeared shortened, and the forearm was slightly curved. Both elbow joints had fixed-flexion. Moreover, pronation and supination of the radioulnar joint and elbow movements were restricted on both sides. Both hands oligodactyly and a mild ulnar-sided drift. There was no sensory deficit. With the right hand, she could perform basic tasks but with extreme difficulty. With her left hand, she was unable to perform any routine activities and was incapable of gripping.

X-ray examination revealed congenital left humeroradial synostosis with ulnar hypoplasia with postaxial polydactyl (vestigial digit) [Figure 1]. Moreover, there was right-sided oligodactyly involving the ulnar side of carpals, metacarpals, and phalanges, leading to fixed flexion deformity of the elbow joints [Figure 2]. Thus, the patient was diagnosed as a rare case of UH with complex upper limb abnormalities. Continuous passive physiotherapy was initiated, and the patient is currently being followed up.

Figure 1.

Anteroposterior radiograph of left forearm and hands illustrating unilateral, incomplete ulnar with oligodactyly (bidactyly), postaxial polydactyl (vestigial digit), involving the ulnar side of carpals, metacarpals, and phalanges. There was of fixed flexion deformity of the elbow joint with left radiohumeral synostosis

Figure 2.

Anteroposterior radiograph of right forearm and hands illustrating normal ulnar, with tridactyly involving the ulnar side of carpals, metacarpals, and phalanges. There was presence of fixed flexion deformity of the elbow joint, but radiohumeral synostosis was absent

DISCUSSION

Coined in 1863 by Isidore Geoffroy Saint-Hilaire,[8] hemimelia, a congenital skeletal abnormality, usually presents as the underdevelopment or absence of one side of the distal half of a limb.[3] Hemimelia may be caused by exposure to certain environmental factors during the embryonic stage, such as maternal history of smoking, as well as use of cocaine use or teratogenic drugs.[7] However, in our case, there was no history of maternal exposure to known environmental factors. In upper extremities, radial hemimelia is more frequent compared to others, with a documented incidence of 1:30,000 live births.[1] However, UH is a rare entity, mainly owing to the early development of the ulna during the 24–36 days embryonic period, which coincides with a period of high fetal mortality rate.[2] Although the clinical and radiological findings in our case are consistent with those in the literature, there are some distinctive aspects that call for additional discussion.

Our case was female, thus contradicting the high prevalence reported among males.[1] However, other authors have also documented UH in females.[2,7] In line with earlier reports, our case displayed classic UH characteristics such as radial bowing, ulnar-sided hand drift, and forearm shortening.[3] It is well known that humeroradial synostosis and the fixed flexion deformity of the elbow joints, observed in our case, are related, especially in Bayne’s Type 4 classification of UH.[9] The rare but serious complication known as humeroradial synostosis severely limits elbow mobility, as demonstrated by the patient’s limited pronation and supination.[7] The phenotypic variability of UH, which has been previously described in cases of UH,[1] is further highlighted in our case by the presence of oligodactyly on the right side and postaxial polydactyly (vestigial digit) on the left.

The four cases reported by Özdemir et al.[4] are similar to our case, where patients showed different levels of digital abnormalities, radial bowing, and ulnar deficiency. However, contrary to our case, only one of their patients had bilateral UH, while the others had unilateral UH.[4] In our case, the presence of humeroradial synostosis is consistent with the findings of Aggarwal et al.,[7] who described a case of UH with oligodactyly and humeroradial synostosis. Interestingly, their patient also exhibited fixed elbow flexion, supporting the link between abnormalities of the elbow joint and severe ulnar deficiency.

Our case differs from the one described by Afreh et al.,[2] where the patient had bilateral UH with complete ulnar absence and humeroradial synostosis. In contrast to their patient who had tridactyly, the current case demonstrated the range of digital abnormalities in UH by having oligodactyly on the right side and a vestigial digit on the left. Furthermore, the lack of syndromic characteristics in our case highlights the nonsyndromic nature of the majority of UH, in contrast to situations where UH is linked to or Cornelia de Lange or Poland syndromes.[2]

In our case, the functional disability, especially the inability to grip with the left hand, is typical of severe cases of UH, in which the degree of ulnar hypoplasia correlates with hand abnormalities.[5] As observed in similar cases, functional limitations are further exacerbated by humeroradial synostosis and the fixed flexion deformity of the elbows.[7] Since most patients can carry out activities of daily living without major limitations, unilateral UH frequently does not require surgical intervention.[5,6] However, patients with bilateral UH might require operations such as humeral derotational osteotomies, soft tissue releases, or elbow disarticulation with prosthetic placement.[6] As suggested by the literature, early physiotherapy may have prevented disuse atrophy and increased the range of motion.[4] As our case had unilateral UH, the parents were counseled about the progress of the condition, and passive physiotherapy was started. Currently, she is being followed up to track overall improvement and determine whether surgery is necessary to allow movement in the left elbow joint.

CONCLUSION

This uncommon instance of UH-related bilateral upper limb deformities with humeroradial synostosis and digital anomalies emphasizes the importance of early diagnosis and tailored treatment to enhance the functional outcomes and quality of life for impacted children.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal patient identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.