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Objectives and questions: Extensor mechanism disruption (EMD) following total knee arthroplasty (TKA) significantly impairs knee function and quality of life, often resulting in instability, extensor lag, and compromised gait mechanics. Extensor mechanism reconstruction (EMR) is performed to restore function but may contribute to postoperative falls due to persistent quadriceps weakness and impaired neuromuscular control. This study aims to evaluate: (1) The incidence of traumatic events after EMR post-TKA, (2) Differences in traumatic event rates between allograft and synthetic mesh grafts, (3) The association between postoperative extensor lag and fall risk, (4) The influence of assistive device use on postoperative fall rates.

Material and methods: A retrospective cohort study was conducted at a tertiary academic center, including 41 patients who underwent EMR after TKA. Patient demographics, ASA scores, graft type (allograft vs. mesh graft), and postoperative extensor lagwere recorded. The primary outcome was the occurrence of traumatic events, including falls leading to fractures or soft tissue injuries. Statistical analysis utilized Fisher’s exact test, with significance set at P < 0.05.

Results: A total of 16 patients (39%) experienced postoperative falls resulting in traumatic injuries, highlighting a substantial risk following EMR. The incidence of falls was comparable between allograft (36%) and mesh graft (43.75%) groups (p=0.6197), indicating that graft type did not influence fall risk. The mean postoperative extensor lag was 7° ± 14°, but no significant association was found between extensor lag severity and traumatic event occurrence (p=0.114). Additionally, the use of assistive devices (e.g., walkers, canes) did not significantly affect the risk of falls (p=0.1242).

Discussion and conclusion: Nearly 40% of patients who underwent EMR after TKA experienced postoperative falls or traumatic injuries, reinforcing the need for enhanced postoperative rehabilitation and fall prevention strategies. Neither graft type, extensor lag, nor assistive device use significantly influenced traumatic event rates, suggesting that other factors, such as proprioceptive deficits, balance impairments, and persistent quadriceps dysfunction, may play a more critical role. These findings emphasize the importance of multidisciplinary postoperative management, including targeted rehabilitation protocols, strength training, and fall risk assessments. Further research is warranted to identify modifiable risk factors and optimize rehabilitation strategies to reduce fall risk and improve functional outcomes in this high-risk population.