Costal cartilage injuries: Massages that went wrong!

INTRODUCTION

Blunt chest injury is a major cause of morbidity and mortality and is usually secondary to high-energy trauma such as road traffic accidents and contact sports. While both rib and costal cartilage fractures occur, the latter are underdetected, especially on radiographs.^[1] With the advent of ultrasound (USG), computed tomography (CT), and magnetic resonance imaging (MRI), these injuries are increasingly being picked up.^[2] Body massage as a cause of costal cartilage injuries is not reported in the literature, and such injuries, when not diagnosed early, can result in chronic pain and instability. This article documents massage-related costal cartilage injuries diagnosed on CT and MRI in three patients.

CASE SERIES

Case 1

A 42-year-old male presented to the emergency with left upper chest pain. Clinical examination revealed focal swelling and tenderness around the left sternoclavicular joint. The patient admitted that the pain started following a body massage after his recent overseas travel to a South Asian country. He had taken analgesics for pain relief before consulting the physician. The chest radiograph was normal [Figure 1a]. A plain CT of the chest was performed, which showed a left sternochondral junction fracture, subsequently confirmed by MRI. Minimal fluid was also noted within the left sternoclavicular joint space with overlying soft tissue edema [Figure 1b-e]. The patient was reassured and managed conservatively.

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Figure 1:

(a) Chest radiograph in PA view shows no abnormality. (b and c) Plain bone window computed tomography sections in axial and coronal planes show a linear hypodense fracture line across the left sternochondral junction (white arrow) Dashed circle shows normal sternochondral junction on the right side. (d and e) T2 weighted fat saturated axial and coronal images show linear hyperintense fracture line across the hypointense cartilage (white arrows). The dashed arrow in (c) is overlying edema. S: Manubrium sterni, PA: Posteroanterior.

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Case 2

A 51-year-old male presented to a general physician with complaints of right upper chest pain, swelling, and low-grade fever. Clinical examination showed focal swelling, tenderness, and erythema in the right upper medial chest. Mild lymphocytosis was present. Ultrasound revealed focal fluid collection in the right upper anterior chest within the pectoralis muscles [Figure 2a]. Septic arthritis of the right sternoclavicular joint was suspected, and contrast-enhanced MRI and complimentary CT were performed. Patchy marrow edema and enhancement of the right sternoclavicular joint with joint effusion and surrounding soft-tissue edema were seen. Fracture of the right sternochondral cartilage was additionally picked up, which raised a possible prior injury [Figure 2b-f]. Retrospectively, the patient was admitted to a history of undergoing body massage 3 weeks prior. A diagnosis of missed costochondral injury complicated by infection was made. US-guided sampling of the collection was attempted, and the patient was treated with antibiotics until full clinical recovery.

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Figure 2:

(a and b) Ultrasound and Doppler of the right anterior chest wall show a small collection (arrow) and focal muscle edema with vascularity. The dashed arrow points to suspicious cartilage discontinuity. (c and d) Plain computed tomography axial sections in soft tissue and bone windows show a linear fracture line across the right sternochondral junction (white arrows) with erosions and overlying soft tissue (dashed arrow in c). (e) T2-weighted coronal section shows a hyperintense fracture line (white arrow) across the right sternochondral junction. The circle indicates associated distraction of the sternoclavicular joint. (f) Post-contrast T1 weighted image in the coronal plane shows enhancement of surrounding soft tissue (dashed arrows). Solid white arrow points to the fracture line.

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Case 3

A 47-year-old male consulted a physician for episodic left lower chest pain. The pain was exaggerated on deep breathing. On examination, there was focal tenderness in the left lower costal margin with occasional clicking feel on palpation. Imaging investigations included plain CT followed by MRI, which confirmed a fracture of the left 10^th costal cartilage in the lateral aspect with surrounding edema [Figure 3]. On questioning, the patient recalled undergoing a body massage a couple of weeks back, following which the pain started. He denied any other traumatic incident. The costal fracture was attributed to the body massage. The patient was conservatively managed.

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Figure 3:

(a and b) Plain computed tomography of the lower chest in axial and sagittal planes show fracture of the left 10th costal cartilage with adjacent soft-tissue edema (solid arrow). (c and d) magnetic resonance imaging T2-weighted axial and coronal sections shows disruption of the left 10th costal cartilage with adjacent edema (arrow).

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DISCUSSION

Costal cartilages connect the ribs to the sternum directly or indirectly and are responsible for the flexibility of the thoracic cage and respiratory motion. The first rib connects to the manubrium through the sternochondral joint. The second to seventh ribs connect to the body of the sternum.^[3] The rest of the ribs connect to the lower cartilage, which is indirectly articulating with the sternum.^[4] Thus every rib anteriorly has two junctions – the costochondral and the sternochondral junction composed of hyaline cartilage; the 2–7 joints are synovial, and the first is synarthrodial [Figure 4].

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Figure 4:

(a and b) Normal appearance of costal cartilages on magnetic resonance. Circle in b demonstrates normal sternochondral junction. (c and d) Normal appearance of costal cartilages on computed tomography (CT). Arrows in d show normal costochondral and sternochondral attachments. (e) Volume-rendered CT of the anterior chest wall nicely depicts the costal cartilage attachments.

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Calcification of the cartilage starts in middle age. The pattern of calcification differs between males and females, the former showing peripheral calcification and the latter showing central/core calcification.

Unossified costal cartilage is not visualized on radiographs, and hence, costal injuries that can accompany rib injuries are easily missed.^[5] Ultrasound is a radiation-free, easily available modality that can detect occult rib and cartilage fractures. Cartilage is slightly less echogenic than cortical bone, and fracture can be seen as hypoechoic linear discontinuity, which can be confirmed on the dynamic scan.^[6] It can additionally identify associated hematoma or muscle injury. USG is of limited utility in ossified cartilages and in cases where trauma history is uncertain.^[5]

CT and MRI are the other modalities used for the evaluation of costal cartilage in a wide variety of pathologies including trauma, infection, or involvement by tumor.

On CT, the unossified cartilage is mildly heterogenously hyperdense with a smooth contour. Ossification can be seen as a continuous or interrupted line or central in location.^[5] On MRI, it is hypointense on both T1 and T2 with or without central heterogeneities.^[2] The relation with the bone can be sharply demarcated on non-fat saturated sequences.

Trauma to the costal cartilage is commonly due to a direct hit to the chest wall, as in road traffic accidents, work related, violent coughing, contact sports injuries, or cardiac resuscitation.^[4,7,8] Unlike bone fractures, which heal by neoformative process, chondrocyte healing is suboptimal, and delayed with vertical calcifications; hence, delayed diagnosis can result in chronic pain and instability.^[1,9] Biopsy of such lesions can mimic chondroid neoplasms, adding to unnecessary apprehension.^[5]

Massage-related chest injuries are rarely reported in literature, especially the imaging aspect.^[10] Very little information is available to conclude on the prevalence and pattern of such injuries, but the authors assume that the mechanism of injury is a direct thumping or compressive force on the chest wall resulting in a fracture of the cartilage. Most patients do not recall or relate to a massage event. Pain is the most common symptom but can be intermittent and hence ignored by the individual. Pain on deep inspiration due to irritation of the underlying pleura can be present.

Any discontinuity or fracture can be seen as a hypodense line on CT reaching both margins or as a linear vertically oriented T2 hyperintensity across the hypointense cartilage on MRI. First, sternochondral fractures are more obliquely oriented with a triangular piece of attached cartilage at the sternal end.^[2] Surrounding edema or hematoma can be seen both superficial and deep to the chest wall.

One pitfall in the interpretation of CT is that the peripheral ossification can be normally interrupted and should not be mistaken for a fracture. For a confident diagnosis, the fracture line should be through the complete thickness of the cartilage.

Large hematomas, involvement of multiple cartilages, sternoclavicular joint involvement, and lung, pleural, or vascular involvement can complicate the healing and can have delayed clinical presentations.^[4,9] Secondary infection can occur as in our case, but the authors did not find enough literature supporting the same.

Costal cartilage fractures are managed conservatively with rest, chest belts, and anti-inflammatory drugs.^[6] Surgical intervention is rarely indicated.

CONCLUSION

Costal cartilage injuries are underestimated as they are not seen on radiographs that are commonly obtained to detect rib fractures. Hence, they are neglected, and patients may continue to have chronic pain or present with complications such as infection. Massage-related chondral injuries are rarely addressed in the literature but could be more prevalent, and presentations like this should raise suspicion. CT and MRI are equally good in identifying the fracture.