The management of sternoclavicular injuries in skeletally immature patients has not been well described. The purpose of this study was to describe the authors' experience treating this rare and potentially life-threatening injury. All skeletally immature patients who underwent treatment for a medial clavicular physeal fracture or sternoclavicular dislocation between 2003 and 2011 were identified using ICD-9 diagnostic codes. Sternoclavicular injuries with posterior displacement were isolated from this cohort for a thorough chart review. Patients were contacted to complete brief phone surveys and shoulder-specific outcome instruments. A total of 12 boys (mean age, 14.8±2.74 years), followed for an average of 10.3 months (range, 0-54 months), were identified. The incidence of significant associated symptoms was 8.3% (1 of 12). Eight patients were initially treated with closed reduction, 2 (25%) successfully and 6 (75%) requiring subsequent open reduction. Four of the 12 patients underwent an immediate open reduction. Braided composite sutures were used to treat all injuries that underwent open reduction (10 of 12). Complete data were obtained from 6 patients, all of whose injuries had been treated with open reduction. All 6 had returned to their full activity level, and all self-reported perfect Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and Simple Shoulder Test scores (0 and 12, respectively). Among skeletally immature patients, medial clavicular physeal fractures and sternoclavicular dislocations can be effectively managed with closed or open reduction. When closed reduction is unsuccessful or is contraindicated, open reduction with braided composite sutures is associated with excellent results.

Higher rates of poor outcomes in displaced midshaft clavicle fractures treated nonoperatively have recently been reported. Along with expanding indications for operative fixation and increasing application of locked plate constructs, it is unknown whether complications related to bicortical penetration of the clavicle can be avoided using unicortical fixation. The purpose of this study is to compare the biomechanical properties of unicortical and bicortical fixation in precontoured vs manually contoured locking clavicle plates. Forty-eight Sawbone composite human clavicle specimens (item #3408; Pacific Research Laboratories, Vashon, Washington) with a midshaft clavicle osteotomy were reduced and plated in 8 specimens each using a bicortical and unicortical fixation for each of 3 locked plate constructs (3.5-mm LCP Reconstruction Plate; 3.5-mm LCP Superior Clavicle Plate; 3.5-mm LCP Superior Anterior Clavicle Plate; Synthes, Inc, West Chester, Pennsylvania). Specimens were tested for stiffness in axial torsion and cantilever bending and then loaded to failure in 3-point bending. Data were analyzed using 2-way analysis of variance and Tukey's test (P<.05). No significant differences were found between unicortical and bicortical fixation in failure load, cantilever bending, and cross body stiffness. Bicortical fixation was significantly stiffer than unicortical fixation in torsion only for the same plates. Significant differences also existed between plates in torsion. Unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation to avoid complications associated with posteroinferior hardware penetration following clavicle fracture fixation based on the biomechanical performance of these constructs. However, it remains unclear whether these differences will be clinically significant.

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Our current understanding of knee mechanics and anterior cruciate ligament (ACL) function is predominately based on data recorded during simulations of clinical examinations or the application of nonphysiologic loads and motions. These methodologies provide little information on knee and ACL mechanics during activities of daily living (ADLs). Additionally, researchers have not directly measured knee kinetics, knee contact pressures, and ACL forces, and it is unknown how these parameters change with different activities. This study quantified the effects of activity level on vertical ground reaction forces, knee kinematics, and joint and ligament forces during in vivo motions. Five female Suffolk sheep were walked twice weekly on a treadmill during level (0°), inclined (+6°), and declined (−6°) gait for 12 weeks. Electromagnetic (EM) trackers were surgically implanted onto the left distal femur and the left proximal tibia, and in vivo motions were recorded for all activities. Following sacrifice, the in vivo motions were applied to their respective knees using a serial robot with a multi‐axis load cell. In vitro simulations were repeated to measure (a) total knee forces, (b) contact pressure maps, and (c) ACL‐only forces. Declining the gait surface led to increased posterior translation during the swing phase and decreased flexion at hoof‐strike, decreased medial contact pressure at push‐off, decreased ACL force at hoof‐strike and increased ACL force at push‐off. This study established a system that can be used to examine knee mechanics and ACL forces during ADLs for different knee states to define design requirements for ACL reconstruction techniques.