"Hidden" laryngeal injuries in homicidal strangulation: how to detect and interpret these findings

These studies were designed to demonstrate that the usual method of laryngeal dissection carries a significant risk of overlooking important laryngeal injuries. Formalin-fixed hyoid-larynx complexes were prepared in a prospective forensic study involving 191 cases of homicidal strangulation, 1984 to 1997. The basic steps of the applied method included: complete resection of the thyroid cartilage, a horizontal incision through the cricoid cartilage before opening the larynx dorsally, inspection of the laryngeal joints, and incisions of the laryngeal muscles. Using this procedure allowed us to detect the following injuries, which otherwise would have been destroyed or overlooked: (a) 17 incomplete fractures restricted to the dorsal surfaces of the thyroid laminae and 10 incomplete or non-dislocated fractures of the cricoid cartilage. In 7 cases, such a "hidden" fracture was the only laryngeal injury resulting from neck compression. (b) Extensive laryngeal muscle hemorrhages, especially of the vocal folds, were found in almost half of all cases, more rarely in strangulation by ligature and more frequently in manual strangulation. Gross hemorrhages were the decisive local laryngeal finding in 19 cases. (c) Laryngeal joint injuries (bleedings) were found in 18% to 52% of the different strangulation types. (d) Hemorrhages of the laryngeal mucosa were common findings that occur in about 60% of all cases; only in rare cases do such bleedings have a special diagnostic value. The quantity and significance of findings obtainable from complete preparation clearly document Camps's demand made in 1976 to dispense with the usual laryngeal dissection technique (dorsal scissor incision through the cricoid cartilage), at least in (questionable) strangulation cases.