How well do contoured superior midshaft clavicle plates fit the clavicle? A cadaveric study

Background: Given the degree of variation in clavicular morphology, 4 clavicle plating systems were examined for their congruity as superior, midshaft, anatomic clavicle (SMAC) plates in a cadaveric study. Methods: SMAC plates from 4 manufacturers were applied to 79 dry right human clavicles. Two systems offered multiple (4) variations of plates (MP), 1 offered two variations (TP), and 1 had a single plate (SP). Two examiners applied and clamped the best-fitting plate from each system onto each of the 79 clavicles and then graded them: 1, poor fit; 2, good fit; and 3, anatomic fit. Each examiner repeated the process to assess intraobserver and interobserver reliability. The scores were averaged to produce a final score for each system for each clavicle. Results: The MP systems scored the highest (32%-37% anatomic, 54%-63% good, 5%-8% poor), followed by the TP system (30% anatomic, 53% good, 17% poor), and finally the SP system (9% anatomic, 59% good, 32% poor). Of note, clavicular length significantly correlated with a higher degree of conformity in all plating systems (Spearman rank correlation P < .05 for each system). In clavicles longer than 150 mm, the MP and TP systems performed identically, with the SP system close behind. Contouring of the plate is needed in 73% of cases overall. Conclusion: Plating systems with multiple plate shape variations are more advantageous when dealing with smaller-sized clavicles, typically in females. However, when dealing with larger clavicles, there was no real difference.