OrthoSport Victoria, Melbourne, Victoria, Australia.
Sports Surgery Clinic, Dublin, Ireland.
Am J Sports Med. 2023 Aug;51(10):2596-2602. doi: 10.1177/03635465231180859. Epub 2023 Jul 12.
The natural history of Kaplan fiber (KF) injuries after acute primary anterior cruciate ligament (ACL) reconstruction (ACLR) remains unknown.
PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the temporal change in the magnetic resonance imaging (MRI) appearance of the KF complex after acute primary ACLR. It was hypothesized that KF injuries would resolve with time.
Case series; Level of evidence, 4.
A retrospective MRI analysis was conducted on 89 patients with ACL-injured knees to assess the change in the radiological appearance of KFs after primary ACLR. Patients who had undergone index MRI and ACLR within 90 days of the injury and further MRI at 9 months after surgery were included. Diagnostic criteria to identify radiological evidence of a KF injury and its subsequent resolution were applied, including the presence of high signal intensity on fluid-sensitive sequences, which is indicative of a pathological process radiologically. The proximity of KFs to the femoral cortical suspensory device (CSD) was noted on MRI scans and quantified in millimeters.
A KF injury was identified in 30.3% (27/89) of patients, with isolated high signal intensity observed in an additional 18.0% (16/89). At 9 months, MRI evidence of the reconstitution of the KF complex was found in 51.9% (14/27) of patients, with persistent discontinuity in the remaining patients (13/27). All patients (16/16) with isolated high signal intensity had complete resolution on repeat MRI scans. KF thickening was observed in 26.1% (12/46) of patients with previously healthy KFs and in 25.0% (4/16) with isolated high signal intensity. The CSD was positioned in close proximity (≤6 mm) to the center of the KF attachment in 61.8% (55/89) of patients, and this was associated with increased rates of KF thickening.
The KF injury resolved radiologically in over half of the patients at 9 months after acute primary ACLR. High signal intensity in the region of the KFs on index MRI scans resolved in all cases, with evidence of residual KF thickening in only one-quarter of cases on repeat MRI scans, equivalent to the rate in those with healthy KFs. As such, it is not advisable to use high signal intensity on preoperative MRI scans as the sole criterion for the diagnosis of a KF injury. The position of the CSD after ACLR was intimately related to the KF attachment in the majority of patients, which was associated with KF thickening on postoperative MRI scans.
急性初次前交叉韧带（ACL）重建（ACLR）后 Kaplan 纤维（KF）损伤的自然史尚不清楚。
目的/假设：本研究旨在评估急性初次 ACLR 后 KF 复合体的 MRI 表现的时间变化。假设 KF 损伤会随时间而消退。
病例系列；证据水平，4 级。
对 89 例 ACL 损伤膝关节进行回顾性 MRI 分析，以评估初次 ACLR 后 KF 放射学表现的变化。纳入的患者均在损伤后 90 天内行初次 MRI 和 ACLR 检查，并于术后 9 个月进一步行 MRI 检查。应用诊断标准来确定 KF 损伤及其随后的消退的放射学证据，包括在液体敏感序列上出现高信号强度，这在影像学上提示存在病理过程。在 MRI 扫描上注意 KF 与股骨皮质悬吊装置（CSD）的接近程度，并以毫米为单位进行量化。
30.3%（27/89）的患者存在 KF 损伤，另外 18.0%（16/89）的患者存在孤立的高信号强度。在 9 个月时，在 51.9%（27/51）的患者中发现 KF 复合体的再构成有 MRI 证据，其余患者（13/27）仍存在连续性中断。所有孤立高信号强度的患者（16/16）在重复 MRI 扫描中均完全消退。在先前健康的 KF 中有 26.1%（12/46）的患者和在孤立高信号强度中有 25.0%（4/16）的患者存在 KF 增厚。在 89 例患者中，有 61.8%（55/89）的患者的 CSD 与 KF 附着中心的距离≤6mm，这与 KF 增厚的发生率增加有关。
在初次 ACLR 后 9 个月时，超过一半的患者的 KF 损伤在影像学上消退。在初次 MRI 扫描中 KF 区域的高信号强度在所有病例中均消退，在重复 MRI 扫描中仅四分之一的病例中存在残留的 KF 增厚，与健康 KF 的发生率相当。因此，不建议仅将术前 MRI 扫描上的高信号强度作为 KF 损伤的诊断标准。ACL 后 CSD 的位置与大多数患者的 KF 附着密切相关，这与术后 MRI 扫描上的 KF 增厚有关。
