Quantitative MRI Analysis of Patellofemoral Joint Cartilage Health 2 Years After Anterior Cruciate Ligament Reconstruction and Lateral Extra-Articular Tenodesis.

BACKGROUND: The addition of an iliotibial band-based lateral extra-articular tenodesis (LET) to anterior cruciate ligament (ACL) reconstruction (ACLR) has been shown to reduce failure rates. However, there are concerns as to the potential overconstraint of tibiofemoral kinematics that may increase the risk of cartilage degradation. To date, no clinical study has investigated the effect of LET on patellofemoral joint articular cartilage health. HYPOTHESIS: It was hypothesized that at 2 years postoperatively, (1) the addition of LET at the time of ACLR would have no effect on cartilage health on magnetic resonance imaging (MRI), and (2) higher cartilage relaxation values would be associated with worse patient-reported and functional outcomes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A subset of patients from the STABILITY 1 randomized controlled trial were included. All patients underwent primary ACLR with a hamstring autograft. Patients were randomized to either LET augmentation or not. Cartilage status in the patellofemoral joint between the ACLR group and ACLR+LET group was compared using 2-year postoperative quantitative MRI and the ACL osteoarthritis scores of both the surgical and the contralateral nonsurgical knees. Objective functional outcomes and patient-reported outcome measures (PROMs) were attained. RESULTS: A total of 92 patients (43 patients in the ACLR group; mean age, 18.9 ± 3.2 years; 60.5% female; and 49 patients in the ACLR+LET group; mean age, 18.7 ± 3.2 years, 63.3% female) were included. No significant differences were seen in the mean values (ms) for adjusted T1ρ/T2 relaxation times in the medial patella (47.8/42.2 vs 47.3/43.2), central patella (45.5/42.5 vs 44.1/42.7), lateral patella (48.2/43.5 vs 47.3/43.0), medial trochlea (54.7/50.9 vs 56.4/50.9), central trochlea (53.3/51.1 vs 53.1/52.0), and lateral trochlea (54.9/52.1 vs 53.9/52.6) between the ACLR and ACLR+LET groups. No difference in overall ACL osteoarthritis scores was observed (P = .99). An increase in medial patellar T2 relaxation times was associated with a decreasing International Knee Documentation Committee score (P = .046), Knee injury and Osteoarthritis Outcome Score (KOOS) Symptoms subscale score (P = .01), and total KOOS (P = .01). CONCLUSION: There was no statistical difference in patellofemoral cartilage health between knees 2 years after primary ACLR with hamstring tendon autograft with or without LET. Statistically significant correlations were found between quantitative MRI relaxation times, functional outcome scores, and PROMs; however, the correlations were weak and the clinical significance is unknown. REGISTRATION: NCT02018354 (ClinicalTrials.gov identifier).

Quantitative Magnetic Resonance Imaging of Lateral Compartment Articular Cartilage After Lateral Extra-articular Tenodesis.

BACKGROUND: Concerns have arisen that anterior cruciate ligament reconstruction (ACLR) with lateral extra-articular tenodesis (LET) may accelerate the development of posttraumatic osteoarthritis in the lateral compartment of the knee. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate whether the augmentation of ACLR with LET affects the quality of lateral compartment articular cartilage on magnetic resonance imaging (MRI) at 2 years postoperatively. We hypothesized that there would be no difference in T1rho and T2 relaxation times when comparing ACLR alone with ACLR + LET. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A consecutive subgroup of patients at the Fowler Kennedy Sport Medicine Clinic participating in the STABILITY 1 Study underwent bilateral 3-T MRI at 2 years after surgery. The primary outcome was T1rho and T2 relaxation times. Articular cartilage in the lateral compartment was manually segmented into 3 regions of the tibia (lateral tibia [LT]-1 to LT-3) and 5 regions of the femur (lateral femoral condyle [LFC]-1 to LFC-5). Analysis of covariance was used to compare relaxation times between groups, adjusted for lateral meniscal tears and treatment, cartilage and bone marrow lesions, contralateral relaxation times, and time since surgery. Semiquantitative MRI scores according to the Anterior Cruciate Ligament OsteoArthritis Score were compared between groups. Correlations were used to determine the association between secondary outcomes (including results of the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Lower Extremity Functional Scale, 4-Item Pain Intensity Measure, hop tests, and isokinetic quadriceps and hamstring strength tests) and cartilage relaxation. RESULTS: A total of 95 participants (44 ACLR alone, 51 ACLR + LET) with a mean age of 18.8 years (61.1% female [58/95]) underwent 2-year MRI (range, 20-36 months). T1rho relaxation times were significantly elevated for the ACLR + LET group in LT-1 (37.3 ± 0.7 ms vs 34.1 ± 0.8 ms, respectively; P = .005) and LFC-2 (43.9 ± 0.9 ms vs 40.2 ± 1.0 ms, respectively; P = .008) compared with the ACLR alone group. T2 relaxation times were significantly elevated for the ACLR + LET group in LFC-1 (51.2 ± 0.7 ms vs 49.1 ± 0.7 ms, respectively; P = .03) and LFC-4 (45.9 ± 0.5 ms vs 44.2 ± 0.6 ms, respectively; P = .04) compared with the ACLR alone group. All effect sizes were small to medium. There was no difference in Anterior Cruciate Ligament OsteoArthritis Scores between groups (P = .99). Weak negative associations (rs = -0.27 to -0.22; P < .05) were found between relaxation times and quadriceps and hamstring strength in the anterolateral knee, while all other correlations were nonsignificant (P > .05). CONCLUSION: Increased relaxation times demonstrating small to medium effect sizes suggested early biochemical changes in articular cartilage of the anterolateral compartment in the ACLR + LET group compared with the ACLR alone group. Further evidence and long-term follow-up are needed to better understand the association between these results and the potential risk of the development of osteoarthritis in our patient cohort.

High tibial osteotomy to neutral alignment improves medial knee articular cartilage composition.

PURPOSE: The purpose of this study was to: (1) test the hypothesis that HTO improves articular cartilage composition in the medial compartment without adversely affecting the lateral compartment and patella, and; (2) explore associations between knee alignment and cartilage composition after surgery. METHODS: 3T MRI and standing radiographs were obtained from 34 patients before and 1-year after HTO. Articular cartilage was segmented from T2 maps. Mechanical axis angle (MAA), posterior tibial slope, and patellar height were measured from radiographs. Changes in T2 and radiographic measures were assessed using paired t tests, and associations were assessed using Pearson correlation coefficients. RESULTS: The mean (SD) MAA before and after HTO was - 6.5° (2.4) and 0.6° (3.0), respectively. There was statistically significant shortening [mean (95%CI)] of T2 in the medial femur [- 2.8 ms (- 4.2; - 1.3), p < 0.001] and medial tibia [- 2.2 ms (- 3.3; - 1.0), p < 0.001], without changes in the lateral femur [- 0.5 ms (- 1.6; 0.6), p = 0.3], lateral tibia [0.2 ms (- 0.8; 1.1), p = NS], or patella [0.5 ms (- 1.0; 2.1), p = NS). Associations between radiographic measures and T2 were low. 23% of the increase in lateral femur T2 was explained by postoperative posterior tibial slope (r = 0.48). CONCLUSION: Performing medial opening wedge HTO without overcorrection improves articular cartilage composition in the medial compartment of the knee without compromising the lateral compartment or the patella. Although further research is required, these results suggest HTO is a disease structure-modifying treatment for knee OA.

High Tibial Osteotomy: An Update for Radiologists.

High tibial osteotomy (HTO) is a surgical procedure to treat symptomatic unicompartmental osteoarthritis (OA) associated with knee malalignment. There has been a recent resurgence of interest in HTO in patients who prefer joint-preserving surgery because HTO shifts the knee's mechanical axis from the arthritic compartment to a neutral position, thereby reducing knee pain, slowing progression of OA, and delaying the need for a total knee arthroplasty. The ideal candidates for HTO are patients who are young, active, and nonobese who have isolated varus deformity of the knee resulting from medial compartment OA. Radiography is critical in the preoperative evaluation for HTO and can help expand surgical indications to include a wider variety of patients. Radiography is also routinely obtained in postoperative assessment and is typically the first test to indicate complications. This review describes the radiologic aspects of HTO, including preoperative imaging assessment and normal and abnormal postoperative imaging appearances. Surgical techniques and osteotomy fixation devices are described, with a focus on the medial opening wedge approach. Given the growing interest in HTO, radiologists should become familiar with the basics of the procedure and the role of imaging in preoperative and postoperative evaluation.

The Imaging Spectrum of Synovial Sarcomas: A Pictorial Review From a Single-Centre Tertiary Referral Institution.

Synovial sarcomas are malignant soft-tissue tumors that typically affect young patients. They can arise from nearly anywhere in the body, most commonly the extremities, head and neck, and thorax. The imaging features are highly variable and depend on the anatomic origin. Most lesions present as large aggressive heterogeneous masses containing hemorrhagic and cystic foci, often with calcification. However, up to one-third of lesions have commonly benign features and can appear homogeneously solid or cystic. Especially in these cases, their innocuous imaging and clinical presentation can lead to delayed diagnosis. Therefore, knowledge of the imaging spectrum is crucial to ensuring adequate follow-up or timely pathologic sampling. We reviewed 30 pathologically proven cases in various anatomic sites from our institution to illustrate these characteristics.