The butterfly vertebra is an uncommon congenital anomaly of the spine, arising from an asymmetrical fusion defect in the embryonic vertebral column [1]. First documented in 1844, this anomaly has different names such as cleft vertebra, sagittal cleft vertebra, anterior rachischisis, anterior somatoschisis, and anterior spina bifida [2,3].

During somatogenesis (weeks 3–6 of gestation), the butterfly vertebra forms in utero [2,4]. Normally, mesenchymal tissue forms somites initiating cartilaginous development at two chondrification centers, which merge to form a singular vertebral body. Adjacent somites between vertebral bodies create a denser mesenchymal region, forming the intervertebral disk [4]. The fusion of the vertebral body’s two chondrification centers allows the notochord to relocate into the intervertebral disk, aiding nucleus pulposus growth [4]. However, fusion hindered by persistent notochord remnants leads to the development of a butterfly vertebra deformity [2,5,6].

Identifying this benign spinal anomaly is crucial for medical professionals because it can be mistaken for a pathologic fracture, such as a compression fracture [7]. The butterfly vertebrae may be associated with additional congenital syndromes [8-12] and vertebral anomalies [13]. Although they typically do not induce neurological complications, butterfly vertebrae can persist without symptoms for a prolonged duration [14].

Two patients admitted for low back pain (LBP) resulting from traffic accidents and diagnosed with butterfly vertebra were effectively treated with integrative Korean traditional medicine therapies. This report seeks to (i) elucidate the butterfly vertebral deformity and (ii) delineate the characteristics of patients with LBP presenting with a butterfly vertebra, notwithstanding the absence of related symptoms.

1. Treatment methods

1) Acupuncture

Standardized needles (0.25 × 40 mm, disposable sterilized stainless steel; The Eastern Acupuncture Equipment Manufacturer) were used for electroacupuncture (2 Hz) sessions lasting 15 minutes. During hospitalization, acupuncture was performed twice daily and then reduced to once daily post-discharge. Targeted acupoints included bilateral BL23, BL24, BL25, BL26, BL40, and SP6.

2) Chuna therapy

Chuna therapy, lasting 10–15 minutes, was administered once daily, either before or after acupuncture treatment during hospitalization. Physicians performing the interventions received systematic regular training in Chuna manual therapy.

3) Pharmacopuncture

Shinbaro2 pharmacopuncture (Jaseng Wonoe Tangjunwon) was given daily, with 0.5 mL injected per acupoint (chosen from BL23, BL24, BL25, and BL26) using a disposable 29-G × 13 mm (1/2”) needle and a 1-mL insulin syringe (Sungsimmedical), to a depth of 1.3 cm. Pharmacopuncture components are detailed in Table 1.

Table 1 . Pharmacopuncture administered to the patients.

Pharmacopuncture prescription	Herbal medicine components (g/mL)	Daily dose
SJ3-SBO Shinbaro2	Paeonia lactiflora (0.0027)	4 vials (1 mL/vial)
	Ostericum koreanum (Max)
	Kitagaw (0.0013)
	Aralia continentalis (0.0013)
	Cortex eucommiae (0.0013)
	Achyranthis radix (0.0013)
	Rhizoma cibotii (0.0013)
	Radix ledebouriellae (0.0013)
	Acanthopanacis cortex (0.0013)
	Scolopendra subspinipes mutilans (0.0013)

4) Herbal medicine

Hwalhyuljitong-tang (case 1) and Ansinjitong-tang (case 2) were prescribed for LBP, which was the chief complaint of both patients. Patients’ medications were prepared at Jaseng Hospital of Korean Medicine and packed into pouches (75 mL per pouch). Inpatients were instructed to take the decoction in the morning and afternoon, 30 minutes after meals. The herbal components and daily dosing are outlined in Table 2.

Table 2 . Korean traditional medicine herbal prescriptions administered to the patients.

Hwalhyuljitong-tang (case 1)	Dose (g)	Ansinjitong-tang (case 2)	Dose (g)
Root of Codonopsis pilosula (Fr.) Nannf.	7.875	Rhizome of Zingiber officinale Rosc.	6
Semen of Prunus davidiana Fr.	6	Root of Rehmannia glutinosa (Gaertner) Libosch.	2.625
Root of Glycyrrhiza uralensis Fisch.	4.125	Root of Angelica gigas Nakai	2.625
Root of Angelica gigas Nakai	4.125	Sclerotium of Poria cocos (Schw.) Wolf	2.625
Root of Paeonia lactiflora Pall.	4.125	Root of Poria cocos (Schw.) Wolf	2.625
Tuber of Alisma canaliculatum A. Br. & Bouche	4.125	Rhizome of Notopterygium incisum Ting	1.875
Rhizome of Cyperus rotundus L.	4.125	Semen of Prunus davidiana Fr.	1.875
Root of Aucklandia lappa Decne.	3	Root of Angelica pubescens f. biserrata Shan et Yuan	1.875
Semen of Amomum villosum Loureiro	3	Semen of Thuja orientalis L.	1.875
Rhizome of Ligusticum chuanxiong Hort.	3	Semen of Zizyphus jujuba Mill.	1.875
Gum resin of Commiphora molmol Engler	1.125	Root of Polygala tenuifolia Willd.	1.875
Resin of Boswellia carterii Birdwood	1.125	Rhizome of Cnidium officinale Makino	1.875
		Root of Astragalus membranaceus Bunge	1.875
		Tuberous root of Pinellia ternata (Thunb.) Breit	1.5
		Root of Glycyrrhiza uralensis Fisch.	1.125
		Peel of Cinnamomum cassia Blume	1.125
		Fluit of Schizandra chinensis (Turcz.) Baill.	1.125
		Root of Panax ginseng C. A. Mey.	1.125
		Petal of Carthamus tinctorius L.	1.12

5) Cupping therapy

Dry cupping therapy was implemented twice daily during the hospitalization and reduced to once daily during outpatient treatment. Cupping therapy was administered in the lower back region using a manual vacuum pump for 5 minutes.

2. Evaluation

1) Numerical rating scale for low back pain

A scale from 0 to 10, where 0 signifies a state of no pain and 10 represents unbearable pain, allowed patients to select the current intensity of their pain, providing a standardized measure for assessing the LBP level experienced [15].

2) Range of motion for the lumbar region

Lumbar range of motion (ROM) assesses the maximum lumbar active ROM that allows patients to move without pain. Measurements in the lumbar flexion, extension, lateral bending, and external rotation were taken.

3) Oswestry Disability Index

The Oswestry Disability Index (ODI) was designed for assessing the functional disability of patients experiencing LBP in their everyday activities. The total score is determined by dividing the sum of individual scores by the number of answered items, yielding an average value. It includes 10 items, each scored from 0 to 5 [16]. This study used the authenticated Korean version of the ODI questionnaire [17].

4) Quality of life: EuroQoL 5-Dimension 5-Level

The EuroQoL 5-Dimension 5-Level (EQ-5D-5L) questionnaire encompasses five dimensions to assess the current health status (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression). Each dimension is evaluated on a 5-level scale (level 1, no problems; level 2, slight problems; level 3, moderate problems; level 4, severe problems; level 5, extreme problems) [18].

5) Patient global impression of change

Using a 7-level scale, patient global impression of change (PGIC) is a subjective, self-reported assessment utilized to gauge the patient’s degree of improvement. PGIC serves as a measure with a notable association with pain intensity and pain interference in the daily life of a patient [19].

Numerical rating scale (NRS) assessments were conducted upon admission, discharge, and daily throughout the inpatient stay. The scale was also employed during outpatient visits for treatment after discharge. ROM, ODI, and EQ-5D-5L assessments were conducted upon admission and at the time of discharge. PGIC assessments were conducted once at the time of discharge.

3. Case 1

1) Patient

A 40-year-old female patient.

2) Principal complaints

The chief complaint was LBP.

3) Onset and cause

The pain started after a traffic accident that occurred while the car was stationary on October 18, 2022.

4) Present illness

On October 18, 2022, a hospital-conducted X-ray imaging of the lumbar spine revealed butterfly vertebrae of T12 and S1 bodies. Consequently, the patient was admitted to the hospital on October 19, 2022.

5) Magnetic resonance imaging and radiography

An X-ray scan of the lumbar spine was conducted on October 18, 2022 (Fig. 1: [1] butterfly vertebra, T12 body; [2] 13th accessory ribs), and an magnetic resonance imaging (MRI) of the lumbar spine was performed on November 7, 2022 (Fig. 2: [1] lumbarization state of S1; [2] T12, S1 bodies butterfly vertebrae; [3] L5/S1 - both facet arthrosis).

Figure 1. Case 1: lumbar spine X-ray (October 18, 2022) revealed butterfly vertebrae in T12, S1 bodies.

Figure 2. Case 1: lumbar spine magnetic resonance imaging (November 7, 2022) in coronal view revealed butterfly vertebrae in the T12 body at (A) and S1 body at (B).

6) Progress

Upon admission, the patient had an NRS score for LBP of 7, ODI of 74, and EQ-5D-5L of 0.371. The patient reported experiencing constant dull pain from the upper to the lower back, which exacerbated during lower back extension. No evident neurological symptoms, such as muscle weakness or sensory deficits, were noted. By discharge on October 27, 2022, the NRS for LBP decreased to 3, ODI to 24, and EQ-5D-5L improved to 0.784, with PGIC of “very much improved.” ODI, EQ-5D-5L, and PGIC measurements are provided in Table 3. The patient was pain-free at rest, did not experience discomfort during flexion or extension of the lower back, and continued to exhibit no neurological symptoms. ROM measurements are provided in Table 4. On the last outpatient visit on November 15, 2022, the NRS for LBP was 1 (Fig. 3).

Figure 3. Case 1: changes in the in the numerical rating scale score for lower back pain. NRS, numerical rating scale.

Table 3 . Changes in ODI, EQ-5D-5L, and PGIC.

ROM of the lumbar spine	Case 1			Case 2
	Adm	D/C		Adm	D/C
ODI	74	24		45	80
EQ-5D-5L	0.371	0.784		10	20
PGIC	Much worse	Very much improved		Much worse	Much improved

ODI, Oswestry Disability Index; EQ-5D-5L, EuroQoL 5-Dimension 5-Level; PGIC, patient global impression of change; ROM, range of motion; Adm, admission; D/C, discharge..

Table 4 . Changes in the range of motion (ROM).

ROM of the lumbar spine (°)	Case 1			Case 2
	Adm	D/C		Adm	D/C
Flexion	50	85		45	80
Extension	5	15		10	20
Right lateral bending	15	30		20	30
Left lateral bending	10	25		20	30
Right rotation	30	35		25	40
Left rotation	25	35		20	40

Adm, admission; D/C, discharge..

4. Case 2

1) Patient

A 63-year-old female patient.

2) Principal complaints

The chief complaint was LBP.

3) Onset and cause

The pain started after a traffic accident that occurred while the car was stationary on May 11, 2022.

4) Present illness

On May 13, 2022, a hospital-conducted X-ray imaging of the lumbar spine revealed butterfly vertebrae of T9 and T10 bodies. Consequently, the patient was admitted to the hospital.

5) MRI and radiography

An X-ray scan of the lumbar spine was performed on May 13, 2022 (Fig. 4: [1] Butterfly vertebrae; T9, T10- different diagnosis compression fracture. [2] L4/5, L5/S1, disc space narrowing and atherosclerosis). An MRI of the lumbar spine was also performed on May 31, 2022 (Fig. 5: [1] T10 body; butterfly vertebra. [2] T8/9 bodies; small cartilaginous node upper bodies. [3] L4/5, mild bulging disc with disc degeneration; endplate change Modic type 2. Both facet arthrosis. [4] L5/S1, mild bulging disc with disc degeneration; endplate change Modic type 2).

Figure 4. Case 2: lumbar spine X-ray (May 13, 2022) revealed butterfly vertebrae in T9 and T10 bodies.

Figure 5. Case 2: lumbar spine magnetic resonance imaging (May 31, 2022) in coronal view revealed butterfly vertebrae in the T10 body.

6) Progress

Upon admission, the patient had an NRS score for LBP of 6, ODI of 76, and EQ-5D-5L of 0.515. The patient reported thoracolumbar aching pain while sitting, with nocturnal discomfort. No evident neurological symptoms were observed. By discharge on May 17, 2022, the NRS for LBP decreased to 3, ODI to 20, and EQ-5D-5L improved to 0.795, with PGIC of “much improved.” ODI, EQ-5D-5L, and PGIC measurements are provided in Table 3. Minimal pain was experienced, except during significant forward bending, and nocturnal pain disappeared, without neurological symptoms. ROM measurements are provided in Table 4. On the last outpatient visit on May 31, 2022, the NRS for LBP was 2 (Fig. 6).

Figure 6. Case 2: changes in the numerical rating scale score for low back pain. NRS, numerical rating scale.

In this report, both patients experienced lumbar sprain after traffic accidents and were diagnosed with butterfly vertebrae in the thoracic spine through X-ray imaging and MRI. Butterfly vertebrae appear on X-ray and magnetic resonance (coronal) images with the affected vertebrae showing widened lateral sides, forming a pattern where adjacent vertebral endplates face each other. MRI allows for the precise identification of the affected areas by observing the vertebral shapes and the soft tissues within the defects connected to the intervertebral discs above and below the affected vertebrae [20]. Neither of the patients exhibited features of any syndromes, and X-ray and MRI of the spine did not reveal vertebral anomalies such as supernumerary lumbar vertebrae, spina bifida, or diastematomyelia. The abnormal thoracic butterfly vertebrae were deemed a benign condition requiring no treatment. After a traffic accident, tenderness was noted in the lumbar region; however, no motor deficits, sensory abnormalities, or significant findings in the straight leg raising test were observed. Thus, the treatment approach for these patients centered on addressing their LBP resulting from traffic accidents, unrelated to the presence of butterfly vertebrae, akin to ordinary LBP cases.

In these cases, when a butterfly vertebra is incidentally discovered in a patient with LBP, providing similar treatment as typical LBP cases, after confirming the absence of any congenital syndromes and vertebral anomalies, resulted in symptom improvement. This finding suggests the importance of treating LBP in advance rather than considering the butterfly spine as asymptomatic and not treating it. However, this study has limitations, primarily regarding its scope, which only involved two patients with asymptomatic butterfly vertebrae. Consequently, generalizing the effectiveness of Korean traditional medicine treatments based solely on these cases is challenging. Despite these limitations, this study holds significance as the first report of two patients with butterfly vertebra treated in Korean medicine institutions, particularly considering the absence of reported cases within the Korean medicine field. Additional clinical studies and higher-level evidence-based research in this domain are deemed necessary for further insights.

Conceptualization: DHL, OBK. Formal analysis: DHL. Investigation: DHL, OBK. Methodology: DHL. Writing – original draft: DHL, OBK. Writing – review & editing: All authors.

The authors have no conflicts of interest to declare.

None.

The patient’s medical records and personal information were obtained from the Jaseng Hospital of Korean Medicine Institutional Review Board (IRB no. JASENG 2023-11-009).