Inflammatory biomarkers and state of the tibiofemoral joint in the osteoarthritic knee: a narrative review.

Background: The healing process is initiated by injurious stimuli in response to cellular damage. Upon recruiting proinflammatory biomarkers to the tissue site of injury, the release of additional biomarkers occurs, including the likes of cytokines, matrix molecules, macrophages, neutrophils, and others. This influx of immune system mediators can occur for chronic periods, and though its intention is for healing the original injurious stimuli, it is also suspected of causing long term cartilage impairment following internal structure damage. The objective of this narrative review is to identify which inflammatory factors have the leading roles in the progression of osteoarthritis (OA) following knee injuries and how they fluctuate throughout the healing process, both acutely and chronically. Methods: This narrative review was performed following a computerized search of the electronic database on PubMed in May 2023. Abstracts related to the inflammatory biomarkers of the post-traumatic knee were included for review. Key Content and Findings: The chronic low-level inflammation that leads to OA leads to the destruction of the cartilage extracellular matrix, which new and developing orthopedic research is still attempting to find resolve for. Some of this damage is attributed to the biomechanical alterations that occurs following injury, though with most procedures capable of joint biomechanical restoration, focus has rather been shifted toward the environment of inflammatory biomarkers. Conclusions: Future studies will be aiming to improve the diagnostics of OA, focusing on a consistent correlation of inflammatory biomarkers with imaging. Additionally, biochemical treatments will need to focus on validating reproducible modulation of signaling molecules, in attempts to lessen the chronic elevations of destructive biomarkers.

Anatomic Anterolateral Ligament Reconstruction with Iliotibial Band Graft and Concomitant Anterior Cruciate Ligament Reconstruction.

Anterior cruciate ligament (ACL) reconstruction (ACLR) attempts to restore native ACL function. Persistent anterolateral instability is a common symptom after ACLR that can lead to worse patient outcomes. Additional surgeries, like anterolateral ligament reconstruction (ALLR), can augment the ACL graft and help increase anterolateral rotational stability. Certain indications for ACLR with ALLR include high-grade pivot shift, increased posterior tibial slope (>12°), revision ACLR, and concomitant ligamentous or meniscal injuries. We describe an anatomic ALLR technique using an 8 cm long × 1 cm wide strip of the inferior aspect of the iliotibial band fixed at the native attachment sites of the ALL.

Morphologic Variants of Posterolateral Tibial Plateau Impaction Fractures in the Setting of Primary Anterior Cruciate Ligament Tear.

BACKGROUND: Impaction fractures of the posterolateral tibial plateau commonly occur in the setting of anterior cruciate ligament (ACL) tears, with considerable variability found in fracture size and morphologic features. PURPOSE: The primary objective was to characterize different morphologic variants of posterolateral tibial plateau impaction fractures. The secondary objective was to investigate the association between these impaction fracture variants and concomitant meniscal and ligamentous injuries. STUDY DESIGN: Cross-sectional study; Level of evidence 3. METHODS: Patients treated for primary ACL tears and having magnetic resonance imaging available were included in this study, and magnetic resonance images were reviewed with denotation of displaced posterolateral tibial impaction fractures. A classification system was created based on morphologic variants of impaction fractures; associations were evaluated through use of independent chi-square testing. RESULTS: There were 825 knees meeting the inclusion criteria, with displaced posterolateral tibial plateau impaction fractures present in 407 knees (49.3%). We observed 3 distinct morphologic variants of lateral tibial plateau impaction fractures: (I) posterior cortical buckle not involving the articular surface; (II) posterior impaction fracture involving the articular surface, with subtypes based on (A) tibial plateau depth bone loss <10% and (B) bone loss >10%; and (III) displaced osteochondral fragment, with subtypes for (A) shear or (B) depressed fragment. Type IIIA impaction fractures were associated with an increased incidence of lateral meniscus posterior root tears (33.3% vs 12.4%; P = .009) and an increased incidence of lateral meniscal tears (83.3% vs 56.7%; P = .024) compared with all knees without type IIIA impaction fracture. An increased incidence of medial collateral ligament (MCL) tears was noted in patients with type IIIA impaction fractures compared with those who had no fracture or had another fracture type (61.1% vs 20.1%; P < .001). Type IIIB impaction fractures were associated with an increased incidence of lateral meniscal tears (80.0% vs 56.2%; P = .005). CONCLUSION: A high prevalence of displaced posterolateral tibial plateau impaction fractures occur in the setting of ACL tears, and they can be classified into distinct morphologic subtypes. Posterolateral tibial plateau impaction fractures with displaced depressed or shear fragments were both associated with an increased incidence of lateral meniscal tears, whereas impaction fractures with a shear fragment were associated with an increased incidence of lateral meniscus posterior root tears and MCL tears.

Posterior Medial Meniscus Root Tears Potentiate the Effect of Increased Tibial Slope on Anterior Cruciate Ligament Graft Forces.

BACKGROUND: Increased posterior tibial slope and posterior medial meniscus root tears increase the force experienced by the anterior cruciate ligament (ACL) and predispose patients to higher rates of primary ACL injury or ACL graft failure after an ACL reconstruction (ACLR). However, the interplay among sagittal plane tibial slope, medial meniscus root tears, and ACLR graft force remains inadequately defined. PURPOSE/HYPOTHESIS: The purpose was to quantify the effect of sagittal plane tibial slope on ACLR graft force at varying knee flexion angles with an intact medial meniscus, a posterior medial meniscus root tear, and a medial meniscus root repair. Our null hypothesis was that changes in slope and meniscal state would have no effect on the forces experienced by the ACLR graft. STUDY DESIGN: Controlled laboratory study. METHODS: Ten male fresh-frozen cadaveric human knees underwent a posteriorly based high tibial osteotomy. A spanning external fixator and wedges of varying sizes were used to stabilize the osteotomy and allow for accurate slope adjustment. After ACLR, specimens were compressed with a 1000-N axial load at flexion angles of 0° and 30° for each of the 3 meniscal states and at tibial slopes of 0° to 15° at 3° increments. Graft loads were recorded through a force transducer clamped to the graft. RESULTS: Increasing tibial slope led to a linear increase in ACLR graft force at 0° and 30° of knee flexion. Posterior medial meniscus root tear led to significant increases in ACLR graft forces over the intact state, while root repair restored the function of the medial meniscus as a secondary stabilizer. At 30° of knee flexion, the tibial slope effect on ACLR graft force was potentiated in the root tear state as compared with the intact and root repair states-test of interaction effect: t(139) = 2.67 (P = .009). CONCLUSION: Increases in tibial slope lead to a linear increase in ACLR graft forces, and this effect is magnified in the setting of a posterior medial meniscus root tear. At slopes >12°, a slope-changing osteotomy could be considered in the setting of a revision ACLR with a concomitant medial meniscus root tear. CLINICAL RELEVANCE: Defining the relationship between tibial slope and varying states of meniscal insufficiency can help determine when it may be necessary to perform a slope-decreasing proximal tibial osteotomy before ACLR and meniscal repair.

An Acute Osteochondral Defect Secondary to Fabella Impaction: A Case Report.

CASE: A healthy 37-year-old man sustained a knee injury after performing a deep flexion maneuver while skiing and noted immediate knee pain and swelling. Because of persistent inability to fully extend his knee and persistent posterolateral knee pain, he was evaluated and noted to have an acute osteochondral defect of the posterolateral femoral condyle directly adjacent to his fabella. After a trial of nonoperative interventions, he elected to undergo an arthroscopic-assisted open excision of the fabella and a chondroplasty of the posterolateral femoral condyle defect. CONCLUSION: A traumatic osteochondral defect secondary to a lateral fabella impaction is a rare pathology but must be evaluated in patients performing deep flexion maneuvers who have persistent knee pain and mechanical symptoms. When there is a focal defect with increased edema of both the fabella and posterolateral femoral condyle, an arthroscopic chondroplasty and fabella excision is a valid treatment to return the patient back to desired activities.