Association of Unilateral Latissimus Dorsi Muscle Harvest for Breast Reconstruction with Postoperative Spinal Posture

Background: The latissimus dorsi muscle originates from the lower thoracic spine with broad attachment and plays a subsidiary role in spinal postural stability. The authors investigated whether harvesting unilateral latissimus dorsi muscle for breast reconstruction could influence spinal posture in the long term. Methods: Patients who underwent immediate unilateral breast reconstruction between 2002 and 2010 were reviewed. They were grouped according to reconstruction methods: latissimus dorsi muscle flap and tissue expander/implant. The Cobb angle was assessed twice at each of five different time points (preoperatively and 2, 4, 6, and 8 years postoperatively) by an independent physician blinded to the reconstruction modality. Postoperative scoliosis was defined as a mean Cobb angle greater than 10 degrees at 8 years postoperatively. The trends of changes in Cobb angle over time and the rates of postoperative scoliosis were compared between reconstruction methods. Results: In total, 153 women were analyzed, including 102 using latissimus dorsi muscle flap and 51 using tissue expander/implant, with a median follow-up of 103 months. The latissimus dorsi flap group showed enhanced trends of increasing postoperative Cobb angles as compared with the tissue expander/implant group, and the difference remained significant after adjusting for other variables (p = 0.001). The rate of postoperative scoliosis was significantly higher in the latissimus dorsi flap group than in the control group (p = 0.029). Multivariable analyses revealed that use of the latissimus dorsi flap was associated with a significantly increased rate of postoperative scoliosis. Conclusion: Unilateral latissimus dorsi muscle flap harvest for breast reconstruction might be associated with changes in spinal posture in the long term.