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Purpose: To quantify the effects of lateral extra-articular tenodesis (LET) on tibiofemoral compartment contact area and pressures, knee kinematics, and forces., Methods: Nine cadaveric knees were tested using a robotic testing system. Two loading conditions, (1) anterior tibial translational load coupled with axial compression and (2) internal tibial torque coupled with axial compression, were applied for each knee state at full extension and 30°, 60°, and 90° of knee flexion. Kinematic data was recorded for 3 knee states: anterolateral capsule (ALC) competent, ALC deficient, and post-LET using a 6-mm semitendinosus graft. In situ force in the anterior cruciate ligament (ACL) was quantified using the principle of superposition by comparing the change in force measured before and after the removal of the ALC. Contact area and pressures in each tibiofemoral compartment were measured by replaying kinematics after soft tissues were removed and pressure sensors were inserted., Results: In response to an anterior tibial translational load, mean contact area in the medial compartment decreased by 33.1% from the ALC-competent to post-LET knee states at 90° of knee flexion (P = .042). No significant differences in lateral compartment contact pressure were found between knee states. In situ force in the ACL in response to an anterior tibial translational load decreased by 43.4% and 50% from the ALC-deficient to post-LET knee states at 60° (P = .02) and 90° (P = .006). No significant difference in kinematics was observed between the ALC-competent and post-LET knee states in each of the loading conditions at all knee flexion angles (P > .05)., Conclusions: In this in vitro model, LET with a semitendinosus graft did not significantly overconstrain the knee or increase pressure in the lateral compartment. Additionally, LET reduced the in situ force in the ACL in the setting of ALC injury., Clinical Relevance: The lack of knee overconstraint without significant increases in lateral compartment pressures indicates that if an LET with semitendinosus graft is not overtensioned, accelerated degenerative changes in the lateral compartment may not be expected after this procedure., (Copyright © 2020 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the effect of knee flexion angle during graft fixation on outcomes and complications following medial patellofemoral ligament (MPFL) reconstruction., Methods: Three databases (PubMed, EMBASE, and MEDLINE) were searched from database inception to January 2018. After screening based on inclusion and exclusion criteria, patient demographics, fixation technique, graft selection, outcomes, and complications were extracted from the included studies. The studies were grouped based on flexion angle used during graft fixation: low (0°-30°) and high (45°-90°) flexion angle group. Methodological Index for Non-Randomized Studies criteria were used to assess the quality of each included study. Descriptive statistics are presented., Results: Seventeen studies (of 3,399) were included and were either cohort (n = 1) or case series (n = 17) study designs. A total of 556 patients with a mean age of 23.6 years (range, 10-60 years) underwent MPFL reconstructions, with 458 patients in the 0° to 30° fixation group and 98 in the 45° to 90° fixation group. The mean Kujala score improved from 45 to 72.9 (365 patients) preoperatively to 83 to 94.5 (460 patients) postoperatively for the 0° to 30° fixation group and from 53.3 to 72 preoperatively to 92.2 to 95.2 postoperatively for the 45° to 90° fixation group (98 patients)., Conclusions: The knee flexion angle during MPFL graft fixation ranges from 20° to 90°. Graft fixation at low and high knee flexion angles during MPFL reconstruction showed excellent patient-reported outcomes and low patellar redislocation rates overall, with no clear differences between the 2 groups based on the currently available data., Level of Evidence: Level IV, systematic review of Level III-IV studies., (Copyright © 2019. Published by Elsevier Inc.)

Background: The role of the anterolateral capsule in knee stability has recently been advocated by studies reporting that a distinct ligament exists in this area. Defining the structural properties of the anterolateral capsule can provide insight into its contribution to joint stability. The structural properties of the iliotibial band also need to be determined, as it is a common graft used for extra-articular tenodesis., Purpose/hypothesis: The purpose of this study was to determine the structural properties of the anterolateral capsule and iliotibial band. The hypothesis was that the iliotibial band will have comparable structural properties to the anterolateral capsule because it is generally an accepted graft for extra-articular reconstruction surgeries., Study Design: Controlled laboratory study., Methods: Nine human cadaveric knees (average age, 57 ± 10 years) were dissected to assess the presence of a discrete capsular thickness originating from the lateral femoral epicondyle to the lateral tibial plateau between the Gerdy tubercle and the fibular head. For each knee, 2 constructs were prepared: (1) a bone-anterolateral capsule-bone specimen and (2) a strip of iliotibial band attached to the Gerdy tubercle. Structural properties, including ultimate load, ultimate elongation, and stiffness, were determined for the anterolateral capsule and the iliotibial band. After tensile testing, plain radiographs were obtained for evaluation of the Segond fracture. A paired t test was used to compare the structural properties of the anterolateral capsule with the iliotibial band. Significance was set at P < .05., Results: Two of the 9 specimens were found to have a discrete thickening of the anterolateral capsule. The iliotibial band had almost 50% higher ultimate load and nearly 3 times higher stiffness (487.9 ± 156.9 N and 73.2 ± 24.1 N/mm, respectively) compared with the anterolateral capsule (319.7 ± 212.6 N and 26.0 ± 11.5 N/mm, respectively) (P < .05 for both). The anterolateral capsule had about double the ultimate elongation compared with the iliotibial band (15.5 ± 7.3 and 8.6 ± 1.4 mm, respectively; P < .05)., Conclusion: The anterolateral capsule demonstrated significantly reduced structural properties compared with the iliotibial band. The anterolateral capsule did not have a higher ultimate load compared with the posteromedial capsule as reported in the literature., Clinical Relevance: The decision to perform an extra-articular reconstruction using an iliotibial band graft should be considered carefully. Unnecessary reconstructions using soft tissue grafts with structural properties that far exceed that of the anterolateral capsule may result in overconstraint of the ACL-reconstructed knee., (© 2016 The Author(s).)

Background: Neuromata formation in the infrapatellar branch of the saphenous nerve (IPBSN) has been well described as a potential complication of arthroscopic knee surgery and knee trauma. Resection has been proven to provide improvement of pain and increased range of motion. Currently, physical examination and surgical exploration based on anatomic landmarks are the standard for intraoperative localization of IPBSN neuromas., Objective: To demonstrate the anatomy of the IPSBN and the use of preoperative ultrasound and needle placement for localization of the nerve before sectioning., Methods: Using both anatomic dissections and the combination of preoperative ultrasound and curved-needle placement, we demonstrate the technical nuances to localize the IPBSN before operative section., Results: Cadaveric dissection is used to illustrate the main trunk of the IPSBN and its branches. In 2 cases, ultrasound guidance was effectively used to localize the saphenous nerve and its branches and facilitate the operative treatment of patients with symptomatic IPBSN neuromas., Conclusion: Ultrasound is a widely accepted and commonly utilized imaging modality; however, in this report, ultrasound-guided needle localization was used to aid in the resection of neuromas of small, painful sensory nerves.

Fat pad impingement syndrome refers to anterior knee pain caused by hemorrhage, inflammation, fibrosis and/or degeneration of the anterior knee fat pads. Symptomatic impingement of the prefemoral fat pad can be clinically significant but easily overlooked on magnetic resonance imaging, unless looked for. It should be evaluated in patients with persistent anterior knee pain, particulary if accompanied with mechanical symptoms and lack of intra-articular pathology.

The aim of this study was to determine whether there is a difference in the presence of the lateral intercondylar ridge and the lateral bifurcate ridge between patients with sub-acute and chronic ACL injuries. We hypothesized that the ridges would be present less often with chronic ACL deficiency. Twenty-five patients with a chronic ACL injury were matched for age and gender to 25 patients with a sub-acute ACL injury. The lateral intercondylar ridge and lateral bifurcate ridge were scored as either present, absent, or indeterminate due to insufficient visualization by three blinded observers. The kappa for the three observers was .61 for the lateral intercondylar ridge and .58 for the lateral bifurcate ridge. The lateral intercondylar ridge was present in 88% of the sub-acute patients and 88% of the chronic patients. The lateral bifurcate ridge was present in 48% of the sub-acute and 48% of the chronic patients. This matched-pairs case-control study was unable to show a difference in the presence of the femoral bony ridges between patients with acute and chronic ACL injuries. The authors would suggest looking for the ridges as a landmark of the native ACL insertion site during ACL reconstruction in both acute and chronic ACL injuries.