Abstract：
OBJECTIVE: The purpose of this study is to evaluate the in vivo medial and lateral joint laxities across various total knee arthroplasty (TKA) alignment categories correlated to (1) hip-knee-ankle angle, (2) proximal tibial angle and (3) distal femoral angle in a consecutive group of patients undergoing robotic-assisted TKA.
METHODS: Using ligament tensions acquired during 805 robotic-assisted TKA with a dynamic ligament tensor under a load of 70-90 N, the relationship between medial and lateral collateral ligament laxity and overall limb alignment was established. Only knees with neutral or mechanical varus alignment were included and divided into five groups: neutral (0°-3°), varus 3°-5°, varus 6°-9°, varus 10°-13° and varus ≥14°. Groups were further subdivided by the intraoperative medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA). The distraction of the medial and lateral sides was compared across the various alignments using an analysis of variance.
RESULTS: The ability to distract the medial collateral ligament in extension and flexion was proportional to the degree of varus deformity, increasing from 4.0 ± 2.3 mm in the neutral group to 8.7 ± 3.2 mm in the varus ≥14° group (p < 0.0001). On the lateral side, the distraction of the lateral collateral ligament decreased in both extension (2.2 ± 2.4 vs. 1.2 ± 2.7, p < 0.0001) and flexion (2.8 ± 2.8 to 1.7 ± 3.0, p < 0.0001) with increasing native varus deformity. MPTA and LDFA had similar effects, where increasing MPTA varus and LDFA valgus increased medial distractibility in extension and flexion. There was significant variability of the stretch of the ligaments within and across all alignment categories, in which the standard deviation of the groups ranged from 2.0 to 3.0 mm.
CONCLUSIONS: This study demonstrates increased medial ligament distractibility with increasing varus deformity. However, there was significant variability in ligamentous laxity within various limb alignment categories suggesting the anatomy and soft tissue identity of the knee is complex and highly variable. TKAs seeking to be more anatomic will not only need to restore alignment but also native soft tissue tensions.
METHODS: Level III, prognostic.
METHODS: Using ligament tensions acquired during 805 robotic-assisted TKA with a dynamic ligament tensor under a load of 70-90 N, the relationship between medial and lateral collateral ligament laxity and overall limb alignment was established. Only knees with neutral or mechanical varus alignment were included and divided into five groups: neutral (0°-3°), varus 3°-5°, varus 6°-9°, varus 10°-13° and varus ≥14°. Groups were further subdivided by the intraoperative medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA). The distraction of the medial and lateral sides was compared across the various alignments using an analysis of variance.
RESULTS: The ability to distract the medial collateral ligament in extension and flexion was proportional to the degree of varus deformity, increasing from 4.0 ± 2.3 mm in the neutral group to 8.7 ± 3.2 mm in the varus ≥14° group (p < 0.0001). On the lateral side, the distraction of the lateral collateral ligament decreased in both extension (2.2 ± 2.4 vs. 1.2 ± 2.7, p < 0.0001) and flexion (2.8 ± 2.8 to 1.7 ± 3.0, p < 0.0001) with increasing native varus deformity. MPTA and LDFA had similar effects, where increasing MPTA varus and LDFA valgus increased medial distractibility in extension and flexion. There was significant variability of the stretch of the ligaments within and across all alignment categories, in which the standard deviation of the groups ranged from 2.0 to 3.0 mm.
CONCLUSIONS: This study demonstrates increased medial ligament distractibility with increasing varus deformity. However, there was significant variability in ligamentous laxity within various limb alignment categories suggesting the anatomy and soft tissue identity of the knee is complex and highly variable. TKAs seeking to be more anatomic will not only need to restore alignment but also native soft tissue tensions.
METHODS: Level III, prognostic.
摘要：
目的：本研究的目的是评估与（1）髋-膝-踝角度相关的各种全膝关节置换术（TKA）排列类别的体内内侧和外侧关节松弛度，（2）胫骨近端角和（3）股骨远端角连续组患者接受机器人辅助TKA。
方法：使用805机器人辅助TKA期间在70-90N的载荷下使用动态韧带张量获得的韧带张力，建立了内侧和外侧副韧带松弛与整体肢体排列之间的关系。仅包括中性或机械内翻的膝盖，并分为五组：中性（0°-3°），内翻3°-5°,内翻6°-9°,内翻10°-13°,内翻≥14°。根据术中内侧胫骨近端角（MPTA）和外侧股骨远端角（LDFA）进一步细分。使用方差分析在各种排列中比较了内侧和外侧的牵张。
结果：牵开内侧副韧带伸展和屈曲的能力与内翻畸形程度成正比，从中性组的4.0±2.3mm增加到内翻≥14°组的8.7±3.2mm（p<0.0001）。在侧面，外侧副韧带的牵张在两个伸展中都减少了（2.2±2.4vs.1.2±2.7，p<0.0001）和屈曲（2.8±2.8至1.7±3.0，p<0.0001），伴随着天然内翻畸形的增加。MPTA和LDFA有类似的效果，MPTA内翻和LDFA外翻的增加增加了伸展和屈曲的内侧可分散能力。所有排列类别内和之间的韧带伸展均存在显着差异，其中各组的标准偏差范围为2.0至3.0mm。
结论：这项研究表明，随着内翻畸形的增加，内侧韧带的分散性增加。然而,在不同的肢体排列类别中,韧带松弛存在显著差异,提示膝关节的解剖结构和软组织特性是复杂且高度可变的.寻求更多解剖的TKA不仅需要恢复对齐，而且还需要恢复天然软组织张力。
方法：三级，预后。
方法：使用805机器人辅助TKA期间在70-90N的载荷下使用动态韧带张量获得的韧带张力，建立了内侧和外侧副韧带松弛与整体肢体排列之间的关系。仅包括中性或机械内翻的膝盖，并分为五组：中性（0°-3°），内翻3°-5°,内翻6°-9°,内翻10°-13°,内翻≥14°。根据术中内侧胫骨近端角（MPTA）和外侧股骨远端角（LDFA）进一步细分。使用方差分析在各种排列中比较了内侧和外侧的牵张。
结果：牵开内侧副韧带伸展和屈曲的能力与内翻畸形程度成正比，从中性组的4.0±2.3mm增加到内翻≥14°组的8.7±3.2mm（p<0.0001）。在侧面，外侧副韧带的牵张在两个伸展中都减少了（2.2±2.4vs.1.2±2.7，p<0.0001）和屈曲（2.8±2.8至1.7±3.0，p<0.0001），伴随着天然内翻畸形的增加。MPTA和LDFA有类似的效果，MPTA内翻和LDFA外翻的增加增加了伸展和屈曲的内侧可分散能力。所有排列类别内和之间的韧带伸展均存在显着差异，其中各组的标准偏差范围为2.0至3.0mm。
结论：这项研究表明，随着内翻畸形的增加，内侧韧带的分散性增加。然而,在不同的肢体排列类别中,韧带松弛存在显著差异,提示膝关节的解剖结构和软组织特性是复杂且高度可变的.寻求更多解剖的TKA不仅需要恢复对齐，而且还需要恢复天然软组织张力。
方法：三级，预后。
