Chest wall implosion injuries secondary to side impact are unusual but devastating injuries. The purpose of this series is to describe the clinical entity, present a surgical technique to reduce and repair the thoracic cage deformity without thoracotomy, and report outcomes in nine patients. Institutional review board approved retrospective case series, surgical technique. Level I Trauma Center. Twenty-two patients were admitted during 7-year period with thoracic cage implosion injuries and multiple segmental rib fractures from a side impact mechanism. All patients' required mechanical ventilation and had an implosion deformity along the posterolateral thoracic cage, pulmonary contusion, and clavicular fractures. Nine patients underwent repair of rib fractures through a paramidline posterior approach without thoracotomy using standard 2.4-mm titanium plates. Seven patients with similar fracture pattern treated nonoperatively were used as a historical control. Total intubation time, intensive care unit (ICU) length of stay (LOS), and final shoulder function using the Constant Murley scoring system were compared between the two groups. Average age, male to female ratio, and injury severe score were comparable for both cohorts (p > 0.6). Average follow-up was 16 months versus 12 months for the operative and nonoperative groups, respectively, (p = 0.11). In the operative group, 8 of 9 (89%) patients were extubated within 24 hours of surgery; 3 of 9 (33%) were extubated in the operating room. In the operative group, seven patients underwent internal fixation of the clavicle and progressed to union with a mean Constant score of 93. Nine patients had nonoperative treatment of the clavicle with a mean Constant score of 75 (p = 0.04). Total intubation time (1.9 days) was significantly shorter in the operative group than the nonoperative controls at 13.3 days (p < 0.01) and length of ICU stay was also shortened at 5.7 (4-8) days versus 16.7 (10-26) days, respectively, (p < 0.01). Chest wall implosion injuries with fixed deformities of the thoracic cage, multiple segmental rib fractures, and clavicular injury are a distinct clinical entity, which can be effectively managed with a posterior paramidline approach without thoracotomy. Reduction of the deformity and repair of the rib fractures led to a dramatic reduction in time to extubation, ICU LOS, and in-hospital complications including pneumonia and sepsis. Repair of the clavicular fracture appeared to be beneficial.