Shatrov Jobe, Coulin Benoit, Batailler Cécile, Servien Elvire, Brivio Angela, Barrett David, Walter Bill, Lustig Sebastien
Landmark Orthopaedics, St. Leonards, Sydney, Australia; The University of Sydney, Australia; Orthopaedics Surgery and Sports Medicine Department, FIFA Medical Center of Excellence, Croix-Rousse Hospital, Lyon University Hospital, Lyon, France.
Orthopaedics Surgery and Sports Medicine Department, FIFA Medical Center of Excellence, Croix-Rousse Hospital, Lyon University Hospital, Lyon, France.
J ISAKOS. 2025 Feb;10:100364. doi: 10.1016/j.jisako.2024.100364. Epub 2024 Nov 20.
Balancing the patellofemoral joint (PFJ) in total knee arthroplasty (TKA) involves avoiding over-stuffing. The purpose of this study was to assess how often a strategy of recreating the anterior space of the trochlea (full extension) led to the trochlea depth being recreated in both mid-flexion (30-40°) and deep flexion (80-90°).
One hundred and twenty two consecutive patients undergoing robotic-assisted TKA had femoral components placed according to functional alignment principals and were assessed. The femoral component was sized and positioned in order to ensure that the anterior flange was within 2 mm of the native anatomy, corresponding to a patella position of full extension (0° flexion). Trochlea depth restoration in 3 positions along the floor of the trochlea groove was compared and measured. The trochlea was defined as balanced if the prosthesis was within 2 mm of the native anatomy. Patients were divided into over-stuffed (prosthesis >2 mm above the native anatomy) or under-stuffed (prosthesis >2 mm beneath the native anatomy).
All patients 122/122 (100%) had a balanced trochlea in full extension. In total 54 TKA were over or under-stuffed at either mid-flexion or deep flexion. In mid-flexion, 3/122 (2.5%) trochlea were over-stuffed and 39/122 (32%) trochlea were under-stuffed. In deep flexion, 25/122 (20.5%) of trochlea's were overstuffed and 30/122 (24.6%) were under-stuffed. In mid-flexion, balanced trochlea components were more externally rotated relative to the posterior condylar axis compared to unbalanced components (2.35° external rotation vs 1.21°, p=0.004). There were no other significant differences observed between the balanced and unbalanced trochlea groups in mid or deep flexion.
Over 40% of TKA over or under-stuff the trochlea in deeper flexion despite the anterior flange being positioned within 2 mm of the native anatomy in full extension. The rate of over or under-stuffing in mid and deep flexion was similar (>40%); however, in mid-flexion, under-stuffing of the native trochlea was more common. The concept of PFJ over or under-stuffing in TKA needs to be redefined to consider the full arc of flexion of the trochlea groove, and the biomechanical and clinical consequences of under-stuffing the trochlea investigated further.
Level IV.
全膝关节置换术（TKA）中平衡髌股关节（PFJ）需要避免填充过度。本研究的目的是评估重建滑车前部间隙（完全伸直位）的策略在多大程度上能使滑车深度在中度屈曲（30 - 40°）和深度屈曲（80 - 90°）时均得以重建。
122例连续接受机器人辅助TKA的患者，其股骨假体按照功能对线原则放置并进行评估。确定股骨假体的尺寸和位置，以确保前凸缘与原解剖结构相差在2毫米以内，对应髌骨完全伸直（0°屈曲）的位置。比较并测量滑车沟底部3个位置的滑车深度恢复情况。如果假体与原解剖结构相差在2毫米以内，则定义滑车为平衡。患者分为填充过度（假体高于原解剖结构2毫米以上）或填充不足（假体低于原解剖结构2毫米以上）。
所有122例患者（100%）在完全伸直时滑车是平衡的。共有54例TKA在中度屈曲或深度屈曲时存在填充过度或不足的情况。在中度屈曲时，122例中有3例（2.5%）滑车填充过度，39例（32%）滑车填充不足。在深度屈曲时，122例中有25例（20.5%）滑车填充过度，30例（24.6%）填充不足。在中度屈曲时，与不平衡的滑车组件相比（外旋1.21°），平衡的滑车组件相对于后髁轴更向外旋转（外旋2.35°，p = 0.004）。在中度或深度屈曲时，平衡和不平衡的滑车组之间未观察到其他显著差异。
尽管在完全伸直时前凸缘与原解剖结构相差在2毫米以内，但超过40%的TKA在深度屈曲时滑车存在填充过度或不足的情况。中度和深度屈曲时填充过度或不足的发生率相似（>40%）；然而，在中度屈曲时，原滑车填充不足更为常见。TKA中PFJ填充过度或不足的概念需要重新定义，以考虑滑车沟的整个屈曲弧度，并进一步研究滑车填充不足的生物力学和临床后果。
四级
