Purpose To determine whether the addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament reconstruction (ACLR) reduces rotational laxity of the knee, and to compare the clinical results of this treatment with those of ACLR alone. Methods PubMed, Embase, and Cochrane Library were searched by two researchers for clinical studies comparing ACLR with and without LET. Studies with only evidence levels I and II and studies in which anterior lateral ligament reconstruction was performed with grafts were excluded. The risk of bias of the studies was assessed using the Cochrane risk-of-bias and modified Downs & Black tools. The outcomes included (1) functional outcomes; (2) knee laxity measures; (3) knee injury osteoarthritis and outcome score; and (4) complications. The outcomes of the two groups were extracted, summarized and compared. Results A total of 234 studies were retrieved and 223 were excluded. Eleven clinical studies with 1745 patients were included in our meta-analysis. Compared to the patients who underwent ACLR alone, the patients who underwent ACLR with LET had reduced pivot-shift (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.31 to 0.74, p = 0.0009), and lower graft failure rate (OR 0.34, 95% CI 0.20 to 0.55, p < 0.0001). Conclusion Compared with ACLR only, ACLR combined with LET can effectively reduce rotation laxity of the knee joint, and reduce the graft failure rate in high-risk patients. However, the effects on the function and activity level of patients cannot be confirmed.

Purpose This study aimed to assess the distribution of diferent anterior cruciate ligament (ACL) tear locations in diferent magnetic resonance imaging (MRI) planes, and to explore the relationships of ACL tear types with both meniscus injuries and bone bruising. Methods A retrospective study was performed in patients under 60 years old who underwent MRI scans in the sagittal and coronal oblique planes of the knee for ACL tears between 2014 and 2020. Patients with reports of chronic tears, partial tears, or prior surgeries were excluded. Tear locations were classiied into ive types, and the meniscus tear measurement variables included the presence of ramp, root, bucket-handle, and other types of tears. All injuries were conirmed by arthroscopy. Meanwhile, the presence and location of bone bruising were analysed and scored with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) bone bruising subscale. Results A total of 291 patients were included. The prevalence rates of type I and type III injuries were 23/291 (7.9%) and 145/291 (49.8%) in the sagittal plane and 22/291 (7.6%) and 179/291 (61.5%) in the oblique coronal plane, respectively. The prevalence of medial meniscus tears with ACL tears was 126/291 (43.3%), while that of lateral meniscus tears with ACL tears was 77/291 (26.5%). The highest prevalence of medial meniscus injury with ACL tears was 15/22 (68.2%) for type I injuries. Bone bruises were located on the lateral femoral center in 125 patients (46%) and on the lateral tibia posterior in 132 patients (48%); the common areas of bone bruising were slightly correlated with type III ACL tears but not correlated with type I ACL tears. ConclusionThe plane in which an MRI scan is performed afects the classiication of ACL tears. The tear type is associated with the prevalence of medial meniscus injuries, and medial meniscus tears are most prevalent in type I ACL tears. Level of evidence IV.

PurposeThis study aimed to determine the correlation between the intraoperative diameter of double‐stranded peroneus longus tendon (2PLT) and length of the PLT autograft and preoperative ultrasound (US) measurements, as well as radiographic and anthropometric measurements. The hypothesis was that US can accurately predict the diameter of 2PLT autografts during operation. MethodsTwenty‐six patients underwent ligament reconstruction with 2PLT autografts were included. Preoperative US was used to calculate the in situ PLT cross‐sectional area (CSA) at seven levels (0, 1, 2, 3, 4, 5, 10 cm proximal to the harvest start point). Femoral width, notch width, notch height, maximum patellar length, and patellar tendon length were determined on preoperative radiographs. Intraoperative measurements of PLT were made, including all fiber lengths of PLT and diameters of 2PLT using sizing tubes calibrated to 0.5 mm. ResultsCSA at 1 cm proximal to the harvest site had the highest correlation with the diameter of 2PLT (r = 0.84, P < 0.001). Calf length had the highest correlation with PLT length (r = 0.65, P < 0.001). The diameter of the 2PLT autografts could be predicted by the following formula: 4.6 + 0.2 × [sonographic CSA of PLT at 1 cm level]; the length of PLT could be predicted by the following formula: 5.6 + 0.5 × Calf length. ConclusionThe diameter of 2PLT and length of PLT autografts can be accurately predicted by preoperative US and calf length measurements, respectively. Accurate preoperative prediction of the diameter and length of autologous grafts can provide the most suitable and individualized graft for patients. Level of evidenceIV.

Background Infrapatellar fat pad (IPFP) is regarded as an essential knee tissue involved in osteoarthritis (OA) for its potential structural-related or metabolism-related function. This cross-sectional study aims to identify which part is more related to OA. Methods Patients with knee OA ( n = 53) and healthy controls ( n = 54) were prospectively recruited. Based on high-resolution magnetic resonance imaging with a slice thickness of only 0.35 mm, IPFP structural-related parameters (volume and maximal area), metabolism-related parameter (signal), degeneration indicators, and patellar maltracking indicators (patellar translation, patellofemoral angle, and Insall-Salvati ratio) were measured. IPFP volume (maximal area, and signal) was compared between healthy controls and OA patients. The level of significance for all comparisons was set as .05. Results OA patients had higher IPFP signal (672.9 ± 136.9 vs 567.3 ± 63.6, p = .009), but no significant difference in IPFP volume or maximal area compared with healthy controls. In healthy controls, IPFP signal was positively associated with age ( β = 1.481; 95% CI: 0.286–2.676; p = .018); IPFP maximal area was positively related to Insall-Salvati ratio ( β = 0.001; 95% CI: 0.0003–0.0017; p = .039), but not associated with patellar translation and patellofemoral angle. In OA patients, IPFP signal was positively associated with cartilage loss ( β = 0.005; 95% CI: 0.003–0.007; p = .013); no correlation between knee pain and IPFP volume or maximal area was observed. Conclusions The metabolism-related function of IPFP, which can be reflected by the IPFP signal, might play a more critical role in OA progression than its structural function.

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