Bilateral congenital hallux varus with metatarsus adductus in a 6-year-old girl: A case report

Abstract

BACKGROUND

Congenital hallux varus (CHV) is a rare form of hallux varus deformity, characterized by medial deviation of the first toe at the metatarsophalangeal joint. It may be primary or secondary and presents clinically with pain and asymmetry with footwear.

CASE SUMMARY

We documented a case of a 6-year-old girl with bilateral CHV, accompanied by adduction of the toes in the left foot. Clinical diagnosis was made by physical examination and X-ray imaging based on Bleck’s classification. Conservative treatment did not show any noticeable improvement, so the child underwent corrective surgeries on both feet.

CONCLUSION

The patient’s family history is positive, which requires us to take into account the importance of checking for a family history with any complaint of CHV, and both feet must be evaluated to confirm whether the deformity is unilateral or bilateral.

Key Words: Congenital; Hallux varus; Bilateral; Congenital hallux varus; Case report

Core Tip: This paper highlights a rare case of bilateral congenital hallux varus in a child, accompanied by metatarsus adductus and a positive familial history. Two years of conservative treatment led to no improvement, therefore, surgical intervention, including osteotomy and soft tissue corrections, achieved satisfactory outcomes. Congenital hallux varus’s multifactorial etiology and classification challenges are discussed, emphasizing the importance of thorough evaluation and obtaining a detailed family history.

INTRODUCTION

Hallux varus (HV), by definition, is the medial deflection of the first digit of the foot at the metatarsophalangeal (MTP) joint[1-3], forming an angle between the longitudinal axis of both the metatarsal and proximal phalanx bones that can range from a few degrees to 90 degrees, and widening the cleft between the first two digits[3-5]. The deformity is rare compared to other deformities and is typically secondary to trauma, rheumatoid arthritis, or complications from hallux valgus correction surgery[1,3,4]. Congenital HV (CHV) is particularly rare[2]. It can be classified by etiology into two types: Primary, which is isolated and idiopathic, and secondary, which is associated with other deformities such as short metatarsals, longitudinal epiphyseal bracket (LEB) of the first metatarsal, or polydactyly. Studies suggest CHV may have a hereditary component as an autosomal dominant trait[2,3,5].

Patients with HV usually present with pain and difficulty adapting to footwear[1]. Diagnosis is typically based on clinical inspection, revealing a deviated digit with MTP joint extension, interphalangeal joint flexion, and proximal phalanx supination[1,4]. Examination of the joint’s mobility is critical, as the treatment approach varies between flexible and rigid MTP joints. Radiographic confirmation requires three standard X-ray images: Lateral, oblique, and a weight-bearing anteroposterior image. An axial sesamoid image may also be added if metatarsosesamoid arthritis is suspected[4].

Treatment strategies involve both conservative and surgical approaches. Non-operative measures, such as splinting or corrective footwear, are preferred for flexible MTP joints that respond to passive reduction[1,6]. Surgical interventions include McElvenny’s osseous approach and Farmer’s soft tissue approach[3-5]. Other techniques such as resection and tenotomy of the abductor hallucis muscle and tendon, metatarsal osteotomy, and arthrodesis were also suggested[5]. This paper will discuss the case of a 6-year-old with bilateral CHV resistant to conservative treatment. The purpose of this case report is to highlight a patient case of HV and the significance of an early diagnosis while providing a detailed explanation of its clinical diagnosis, treatment options, and associated literature.

CASE PRESENTATION

Chief complaints

A 6-year-old girl presented to the Pediatric Hospital in Damascus with CHV and digital adduction in the left foot, accompanied by partial cohesion between the second and third digits. The patient had a similar deformity in her right foot, which was surgically treated in another facility, the treated foot was fully functional and pain-free.

History of present illness

The patient’s deformity was bilateral and had been managed conservatively for two years using corrective orthopedic shoes, without significant improvement. Reparatory surgery was performed on the right foot at the age of five, and the patient was admitted for surgery on the left foot. The patient has no significant past medical history. However, she has a positive family history of the same deformity on the maternal side of the family, but no genetic study was conducted.

History of past illness

The patient has no significant past medical history.

Personal and family history

However, she has a positive family history of the same deformity on the maternal side of the family, but no genetic study was conducted.

Physical examination

The patient demonstrated normal mental and physical development. Inspection revealed medial deviation of the first toe, consistent with HV, and digital adduction in the left foot. A surgical scar was observed on the right foot from the previous procedure (Figure 1A). No other significant abnormalities were noted.

Figure 1 Patient’s feet. A: Patient’s feet before surgery: Left hallux varus/medial deviation in the great toe of the left foot and a surgical scar on the right foot from past corrective surgery; B: Pre-operative X-ray showing the medial deviation at the metatarsophalangeal joint and metatarsal adduction; C: Operative X-ray showing the fixed position of the metatarsophalangeal joint and metatarsals with the securing Kirschner wire.

Laboratory examinations

Routine laboratory tests showed normal results, except for a slight drop in hemoglobin (11.2 g/dL) and hematocrit levels (34%).

Imaging examinations

X-rays revealed metatarsal adduction (moderate metatarsus adductus, with the heel bisector passing through the 3^rd and 4^th webspace as per Bleck’s classification) and HV (Figure 1B).

FINAL DIAGNOSIS

Bilateral CHV with metatarsus adductus.

TREATMENT

Surgery was performed under general anesthesia. Three incisions were made near the first metatarsal: A distal medial incision for abductor hallucis myotomy, a distal lateral incision for capsular plication, and a proximal dorsal incision for closed wedge osteotomy and the insertion of Kirschner wire (K-wire) (Figure 1C), and a fourth incision between the bases of the third and the fourth metatarsals for closed wedge osteotomy.

OUTCOME AND FOLLOW-UP

Post-surgical X-ray and complete blood cell count were performed, the foot was put in a cast, and a neurovascular assessment was done. The patient was discharged the following day and her parents were advised to rest the limb above supination level, pay close attention to the limb’s vitality, and they were informed that the bandages around the wire’s entry point needed to be changed daily. The patient was scheduled for a review appointment two weeks later, then another one after 6 weeks to remove the cast and the wire. The patient came back for a follow-up visit after removing the wire at a local clinic and the examination was within normal limits. However, further follow-up information is unavailable due to the loss of contact with the patient’s guardians.

DISCUSSION

HV is a rare condition[2], in which the hallux is medially deviated at the MTP joint, forming an angle ranging from a few degrees to 90 degrees[1], and also causing the widening of the first web[3]. The most common cause of HV is iatrogenic after overcorrection of hallux valgus, it can also be secondary to arthropathic or neuropathic disorders. Among cases of HV, congenital CHV is a rare presentation. There are two types of CHV: The primary, idiopathic, type, and the second type, which is associated with skeletal malformation[2]. CHV can either be isolated or associated with other forefoot congenital deformities[3], such as poly-syndactyly or longitudinal epiphyseal bracket, a short first metatarsal bone[2], or a firm fibrous band parallel to the adducted hallux causing the toe deviation[3]. Other reasons that were also mentioned as main reasons in the cases described to CHV: Excessive tension of the medial articular capsule, excessive release of lateral articular structures, and overcorrection of the first intermetatarsal angle[6].

CHV not only causes a cosmetic problem, but also affects the growing child’s ability to walk and play, and it worsens with growth[2]. Categorizing HV is challenging due to its multifactorial physiopathology. A classification system solely based on rigid vs flexible deformities would oversimplify the complexity of the condition. Factors like interphalangeal joint contracture, rotational deformity, arthritis, and orthopedic malformations must also be considered. A thorough evaluation of these components is crucial for a systematic assessment of HV and for determining appropriate surgical interventions[7].

Pain-free anatomical correction (restoration of a neutral metatarsal phalanx) is the goal of hallux surgery using bone and soft tissue corrections to achieve such a satisfactory result of pain relief and the ability to wear shoes[8]. Treatment of HV begins with conservative treatment taping, bandages, or by fitting appropriate orthopedic shoes. Anti-inflammatory drugs are given to relieve pain if there are no contraindications for them. Corrective bandages and custom splints are used early in case of symptomatic deformity[6]. Non-surgical treatment has a success rate of approximately 22%[8]. Surgical treatment includes an osseous or soft tissue approach. Bajuri et al[1], suggest that the best treatment for CHV is a combination of both, however, Shim et al[5] highlighted that widening the first web space is a possible complication for the correction.

In this case, we report a case of bilateral CHV in a female child who had suffered from metatarsal adduction, specifically moderate metatarsus adductus with the heel bisector passing through the 3^rd and 4^th webspace as per Bleck’s classification, in addition to HV (Figure 1B); this was demonstrated in the clinical and radiographic examination of the left foot. The patient had a positive family history of this same condition. She underwent conservative treatment for two years without significant benefit. Given the young patient’s age, the decision was made to treat both limbs early, starting with the right foot, without any surgical complications, and with satisfactory treatment results. One year later, the left foot was surgically repaired; the surgical intervention was conducted under general anesthesia, involving three incisions near the first metatarsal. These included a distal medial incision for abductor hallucis myotomy, a distal lateral incision for capsular plication, and a proximal dorsal incision for a closed wedge osteotomy and insertion of K-wire (Figure 1C). A fourth incision was made between the bases of the third and fourth metatarsals for a closed wedge osteotomy. The primary limitation of this study is the lack of follow-up due to personal reasons on the patient’s end.

For this review of literature, we searched the PubMed and Google Scholar databases and included 7 cases from 2014 to 2022 that describe the deformity of HV. These cases were summarized in a table that includes the basic ideas that we discussed in the study (Table 1). One of them reported a case of a 16 year-old male. The surgical procedure was done by removal of the polyp and the accessory bone, tenotomy and lengthening of the abductor hallucis, flexor hallucis longus, and extensor hallucis longus, Osteotomy of the proximal phalanx, capsulotomy of the 1^st MTP joint, and lastly stabilizing the big and 2^nd toe with K-wires[1].

Table 1 A summary of other cases of congenital hallux varus.

Ref.	Patient (number)	Age, sex of patient	Chief complaint	History	Clinical examination findings	X-ray findings	Surgical procedures	Fixator removal timing	Hospitalization duration	Progression post-surgery	F/u
Bajuri et al[1], 2021	-	16 years, male	Limiting of physical activities Pain and difficulty with footwear fitting	No history of surgery or trauma	HV in the left foot	Shifting of proximal phalanx at MTP joint	Removal of the polyp and the accessory bone	Sutures removed after 2 weeks	Discharge day after 5 (day)	Non weight bearing for 8 weeks	Minimal callus formation after 6 weeks
					Polyp over the medial border of the left foot	An accessory bone over the medial cuneiform	Tenotomy and lengthening of abductor hallucis, flexor hallucis longus and extensor hallucis longus	K-wires removed after 8 weeks		Partial weight bearing for 1 month	Full union was formed after 3 months
					Widening 1st web space-1st MTP joint dorsiflexion and plantarflexion = 30°	Hallux angel = 20.4°	Osteotomy of proximal phalanx			Full weight-bearing after 3 months
						Intermetatarsal angle (normal) = 10.3°	Capsulotomyear of 1st MTP joint			Running after 4 months
							Stabilizing the big and 2nd toe with K-wires
Samelis et al[2], 2022	-	3 years, female	Difficulty with footwear fitting	No history of surgery or trauma	Bilateral HV at 1st MTP joint-Inversion of both feet	Short 1st metatarsal	Right foot: capsulotomyear of 1st MTP joint; tenotomy of extensor hallucis longus; correcting foot inversion	Splint removed after 6 weeks	NA	Gradual weight bearing was recommended	NA
			Affecting walking	No family history	Mild clawing in all toes	Normal IMA	Left foot was planned
Sulaiman et al[3], 2019	1	7 months, NA	NA	NA	HV and polysyndactyly of the right big toe	Split distal phalanx of the right hallux	Medial release and realignment of big toe, Farmer’s procedure	K-wire removed after 6 weeks	NA	NA	Good results after 8 years
							K-wire was reinserted back after 2 weeks
	2	2 years, NA	NA	NA	HV and polysyndactyly of the left big toe	Polysyndactyly and congenital HV of the left big toe	Medial release and realignment of big toe and resection of the phalanx with the usage of excess of plantar skin	Non used	NA	NA	Good/4 years
	3	3 years, NA	NA	NA	Short 1st metatarsal			1.6 mm K-wire used not mentioned when removed	NA	NA	Good/1 years
	4	2 years, NA	NA	NA	HV and polydactyly of the right big toe	HV and well separated polydactyly	Medial release and realignment of big toe + excision of phalanx + proximal based flap	External fixator removed 6 weeks after 1st surgery	NA	NA	Good/6 years
					Short 1st metatarsal + polydactyly			K-wire removed 4 weeks after 2nd surgery
Patil et al[9], 2014	-	23 years, male	Difficulty with footwear fitting and pants	No history of surgery or trauma	HV, polydactyly and syndactyly of the right big toe	Short 1st metatarsal with deformed head	Removal of lateral great toe since it was smaller and showed less vascularity	K-wire removed after 6 weeks (in both surgeries)	Discharged after 7 (day)	Non weight bearing for 6 weeks after 1st surgery	Satisfying results in a f/u X-ray after 3 years
					1st MTP joint dorsiflexion and plantarflexion = 20°	2 phalanges in the both big toes	Correction of medial big toe After 7 weeks	Splint removed 6 weeks after 1st surgery and continued for protection after the 2nd		Non weight bearing for 2 months after 2nd surgery
						Distal phalanx of lateral big toe was trapezoidal	MTP joint fusion a week after taking out the external fixator
						1 sesamoid at MTP joint
						IMA = 27°
Vlaić et al[10], 2018	1	19 years, male	Difficulty with footwear fitting	1 year of physical therapy for a metatarsus varus deformity in the left foot	HV and LEB in the 1st metatarsal of the left foot	Same results as clinical examination	At 26 months: Tenotomy of abductor hallucis; correction of 1st metatarsal bone and LEB	K-wire removed after 6 weeks	NA	Gradual weight bearing was recommended	Satisfying results clinicallyear although X-ray wasn’t as desired 24 months after 2nd surgery
							4.5 years after the 1st surgery: Correction of 1st MTP joint alignment by an osteotomy of 1st metatarsal with a fibular autologous graft and releasing soft tissues
	2	4 years, male	Difficulty with footwear fitting	Hypospadias surgery at 1.5 years conservative treatment for 1 years for flatfoot and HV deformities in the right foot	HV in the right foot	Wide and short 1st metatarsal pointing to LEB deformity in the right foot	At the age of 5.5 years: Resection of the LEB; correction of 1st metatarsal	K-wire removed after 5 weeks	NA	Gradual weight bearing was recommended	F/u for 32 months after surgery: Excellent results
	3	1 month, female	NA	NA	HV, polydactyly and LEB in the 1st metatarsal of the left foot	Same results as clinical examination	At 1 year: Removal of the accessory toe; capsulotomy of medial cuneiform metatarsal and 1st MTP joints; resection of bracket (no interposition graft); correction of 1st metatarsal with a K-wire	Fixator removed after 14 weeks	NA	NA	F/u for 31 months after surgery: Satisfactory results
Froehlich et al[11], 2014	-	15 years, female	Limiting of physical activities	No family history, syndromes or metabolic disorders	Bilateral HV	Radiographs showed shortening and bulging of the 1st metatarsal bilaterally along with a varus aligned joint surface of the 1st metatarsal. The epiphyses were closed, and the 1st metatarsal bone was approximately 24 mm shorter than the 2nd metatarsal (Figure 1B)	External fixator to reposition 1st metatarsal bone and hallux	Fixator removal timing	NA	1st surgery postoperative shoe and after the arthrodesis, the patient again used a postoperative shoe and was fully weightbearing for 6 weeks	Good results
			Psychological pressure		Bilateral brachymetatasia of 1st metatarsals		Arthrodesis of 1st MTP joint

NA: Not available; MTP: Metatarsophalangeal; IMA: Intermetatarsal angle; MRI: Magnetic resonance imaging; HV: Hallux varus; LEB: Longitudinal epiphyseal bracket; K-wires: Kirschner wires; F/u: Follow up.

Another case was a bilateral CHV in a 3-year-old girl. Surgical correction for her right foot consisted of capsulotomy of the 1^st MTP joint, tenotomy of the extensor hallucis longus, and correction of foot inversion. The same procedure was suggested for the left foot. This case was the only one reported to have a post-surgical complication, which was a moderate limitation of the 1st MTP joint movement[2]. There were 4 cases in one article in which the gender of the patients was not mentioned. They were managed as follows: (1) Patient 1: Medial release and realignment of big toe, Farmer’s procedure, K-wire was reinserted back after 2 weeks; (2) Patient 2 and patient 3: Medial release and realignment of the big toe and resection of the phalanx with the usage of excess plantar skin; and (3) Patient 4: Medial release and realignment of big toe, excision of phalanx, and proximal-based flap[3].

Patil et al[9] reported a unique surgical approach for their 23-year-old patient who suffered from polydactyly and syndactyly of the right great toe, which included removal of the lateral great toe due to its lack of perfusion, and correction of the medial big toe. The external fixator was taken out 7 weeks later, and a week later, MTP fusion was performed[9]. Vlaić et al[10] described the surgical plan made for 3 patients who had CHV associated with LEB: The first patient had his first surgery at the age of 26 months, which involved tenotomy of the abductor hallucis and correction of the 1^st metatarsal bone and LEB. Four and a half years after the first surgery, an osteotomy with a fibular graft was performed to correct the MTP joint alignment. The second patient underwent surgery to resect the LEB and correct the first metatarsal at the age of 5.5 years. The last patient, a 1-month-old female who had polydactyly, was managed by removal of the accessory toe, capsulotomy of the medial cuneiform metatarsal and MTP joints, correction of the first metatarsal with a K-wire, and resection of the bracket without grafting[10]. Froehlich et al[11] described a case of bilateral HV combined with bilateral brachymetatarsia. The treatment plan consisted of the usage of an external fixator to reposition the 1^st metatarsal bone and hallux, and arthrodesis of the 1^st MTP joint[11].

CONCLUSION

In conclusion, CHV is a hereditary condition that should be routinely assessed for by physical examination in children, especially in families with a positive history. Bilateral assessment is imperative due to the potential for deformity manifestation on both sides. Early detection through clinical examination helps with treatment flexibility before the condition becomes severe with age.