A high rate of falls and traumatic fractures occurs after extensor mechanism reconstruction: a cohort study including both allograft and synthetic mesh grafts

BACKGROUND: Extensor mechanism disruption following total knee arthroplasty (TKA) significantly impairs knee function and quality of life. Extensor mechanism reconstruction (EMR) is effective but carries risks, including post-operative falls due to persistent quadriceps weakness and extensor lag. We sought out to answer the following four questions: What is the incidence of traumatic events following EMR after TKA using different grafting and reconstruction techniques? Are there significant differences in the rate of traumatic events based on the type of graft used (allograft vs. mesh graft) in EMR? What is the association between post-operative extensor lag and the occurrence of traumatic events in patients who have undergone EMR? Does the use of assistive devices influence the occurrence of traumatic events post-EMR? METHODS: This retrospective cohort study at an academic center included 41 patients (mean age: 67.8 ± 10.1 years; 61% female) who underwent EMR post-TKA at a single academic center. Reconstructions included allograft (n = 25) and synthetic mesh grafts (n = 16). Patient demographics, ASA Score, type of EMR, and post-operative extensor lag were documented. The primary outcome was the occurrence of traumatic events post-EMR. Statistical analysis involved Fisher's exact test, with p < 0.05 considered significant. RESULTS: Of the 41 patients, 16 (39%) experienced post-operative falls leading to traumatic injuries. No significant differences were found in traumatic event rates between the allograft (36%) and mesh graft (43.75%) groups. The mean extensor lag was 7° ± 14°, with no statistically significant association observed between the degree of extensor lag and traumatic events. The use of assistive devices did not significantly influence the occurrence of traumatic events. CONCLUSION: More than one-third of patients experienced traumatic events following EMR after TKA, highlighting the need for comprehensive post-operative management and patient counseling. The study found no statistically significant association between graft type, extensor lag, or use of assisted devices and the occurrence of these events. Further research is required to understand the risk factors and improve patient outcomes in this clinically challenging domain.