MON-791 - Association between Pectus Excavatum and Low Bone Mineral Density: A Case Series

Introduction: Pectus excavatum (PE) is a common chest wall deformity resulting from abnormal costal hyaline cartilage development (1), and it can be associated with connective tissue disorders (CTDs) such as Ehlers-Danlos and Marfan syndromes (2). Severity of PE is quantified with the Haller Index (HI), the ratio of the largest internal width of the ribcage to the shortest distance from sternum to vertebra on CT; HI > 3.25 is typically an indication for surgical correction (3). Though low bone mineral density (BMD) and fractures are often seen in CTDs, the relationship between PE and low BMD has not been well studied. Presented here is a case series of four patients with PE and low BMD.

Clinical Presentation:
Four patients presenting to the Yale Bone Center for evaluation of low BMD and/or fracture assessment were noted to have PE in their clinical history.

Case 1: A 71-year-old woman was referred for evaluation of low BMD on Dual-Energy X-ray Absorptiometry (DXA): Femoral Neck T-score -2.5, Total Hip T-score -2.7. Noted to have a history of pectus excavatum; CT chest reveals HI 9.5.

Case 2: A 55-year-old woman with documented diagnosis of CTD was referred due to rib fracture after hyperextending an arm. She has a history of PE with HI 3.0.

Case 3: A 54-year-old woman with osteopenia on DXA was referred for evaluation. She has a history of PE with HI 2.7.

Case 4: A 57-year-old man with PE (HI 4.8) and associated atelectasis of left lingula was referred after compression fractures of T12, L2, and L3.

Discussion:
These patients, aged 54 to 71, included one man. Three were diagnosed with osteoporosis, two due to fragility fractures and one due to low BMD on DXA. The fourth was diagnosed with osteopenia via DXA. PE varied in severity among the patients, and only one has a documented CTD diagnosis.

Conclusion:
Patients with PE are at increased risk for CTDs and may also be at increased risk for low bone mass. While CTDs have been associated with both PE and low BMD (2, 4) there are no established links between this common chest wall deformity and low BMD or increased fracture risk. As such, there is minimal guidance regarding screening this population for osteoporosis. Further study is crucial to best identify and treat patients.

1. David VL. Current Concepts in the Etiology and Pathogenesis of Pectus Excavatum in Humans-A Systematic Review. J Clin Med. 2022;11(5):1241. doi:10.3390/jcm11051241
2. Creswick HA, Stacey MW, Kelly RE, et al. Family study of the inheritance of pectus excavatum. J Pediatr Surg. 2006;41(10):1699-1703. doi:10.1016/j.jpedsurg.2006.05.071
3. Haller JA, Kramer SS, Lietman SA. Use of CT scans in selection of patients for pectusexcavatum surgery: A preliminary report. J Pediatr Surg. 1987;22(10):904-906. doi:10.1016/S0022-3468(87)80585-7
4. Bultink IEM. Bone Disease in Connective Tissue Disease/Systemic Lupus Erythematosus. Calcif Tissue Int. 2018;102(5):575-591. doi:10.1007/s00223-017-0322-z

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