Abstract
Introduction
Instability after total knee arthroplasty (TKA) represents, in excess of, 7% of reasons for implant failure. This mode of failure is correlated with soft-tissue imbalance, and has continued to be problematic despite advances in implant technology. Thus, understanding the options available to execute safe and effective soft-tissue release is critical to mitigating future complications due to instability. This study aimed to use intraoperative sensors to evaluate a multiple needle puncturing technique (MNPT), in comparison with traditional transection-based release, to determine its biomechanical and clinical efficacy.
Methods
Seventy-five consecutive, cruciate-retaining TKAs were performed, as part of an 8-site multicenter study. All procedures were performed with the use of an intraoperative sensor to ensure quantitative balance, as per previously reported literature. Of the 75-patient cohort, 50 patients were balanced with the MNPT; 20 patients were balanced with traditional transection. All patients were followed out to 1-year, and administered KSS, WOMAC, and satisfaction. Alignment and ROM was captured for all patients, pre-operatively and at the 1-year follow-up interval.
Results
All patient joints could be released to a balanced joint state, regardless of technique used. There was no significant difference between the two groups (MNPT vs. transection), pre-operatively, with respect to range of motion or alignment (114° MNPT; 114° transection). At 1-year, post-operatively, there was no significant difference in WOMAC score, KSS scores, satisfaction, or ROM (Respectively: 13.1 MNPT vs. 14.6 transection; 174.9 MNPT vs.176.5 transection; 31.7 “Very Satisfied” MNPT vs. 32.2 “Very Satisfied” transection; 124° MNPT vs. 125° transection). No adverse outcomes related to balancing technique have been reported.
Discussion
Instability contributes to the current 2.7 billion dollar TKA revision burden in the United States. Understanding the efficacy of different techniques in soft-tissue balancing may help to mitigate unfavorable complications. In this study, it was found that the MNPT is just as safe and effective at achieving soft-tissue balance as transectional release techniques, and showed no deviation from the achievement of optimal post-operative outcomes at 1-year. This technique, when used with intraoperative sensors to quantify joint balance, may thereby offer a more controlled way to release soft-tissue, incrementally, to achieve precise balance.
