Medial Condyle Research Articles

Tibial-Sling Triangular Medial Collateral Ligament Reconstruction With Posterior Oblique Ligament Limb

Background: While most medial-sided knee injuries can be managed conservatively, high-grade injuries of the posteromedial corner have been reported to have less than optimal outcomes with conservative approaches, resulting in residual valgus and rotational instability. Consensus among experts postulates that treatment should be based on reconstructing both the superficial medial collateral ligament (sMCL) and the posterior oblique ligament (POL). We present a modified technique of a tibial-sling anatomic MCL reconstruction with a POL limb. Indications: High-grade injuries of the posteromedial corner, specifically injuries with medial joint gapping in extension or grade 3 medial-sided tears. Technique Description: The MCL is reconstructed with a semitendinosus autograft in a tibial sling, created by converging perpendicular bone tunnels at its anatomic tibial insertion, and fixed to a femoral tunnel in the isometric point just posterior and proximal to the medial epicondyle with the knee at 30° of flexion. That same single femoral tunnel will be shared by the two strands of the semitendinosus graft and a limb of gracilis autograft to reproduce the POL, passed through a tibial tunnel in the posteromedial margin of medial tibial condyle, and fixed in extension. Discussion/Conclusion: As recent evidence suggests that medial reconstruction should be preferred over repair, due to favorable complication and failure rates, we describe a technique that is both anatomic-based, reproducing the 2 main medial knee structures (sMCL, POL), and also cost-saving, with decreased need of fixation devices. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Distal femoral torsion is correlated with higher-grade trochlear dysplasia and shorter anterior condyles in patients with patellar dislocation and increased femoral torsion.

To describe the characteristics of femoral torsion in patients with different segmental torsion types and to evaluate the correlations between segmental torsion and the morphology of the femoral condyles and trochlea in patients with patellar dislocation and increased femoral torsion. Between January 2021 and March 2023, 69 patients were included and classified into two groups according to the femoral segment contributing the most to total torsion: 32 patients in Group A (femoral neck and shaft torsion) and 37 patients in Group B (distal torsion). Trochlear dysplasia was evaluated using Dejour's classification and sulcus angle. The morphology of the femoral condyles was evaluated using the lengths and ratios of the medial and lateral condyles. Correlations between femoral torsion and morphology were evaluated. Total torsion was significantly correlated with femoral neck and shaft torsion (r = 0.882, P < 0.001) and distal torsion (r = 0.262, P = 0.030). Femoral neck and shaft torsion was significantly increased with increasing total torsion. The trochlear sulcus was flatter and more dysplastic, and the anterior condyles were shorter in Group B. Distal torsion was significantly correlated with the lengths of the medial and lateral anterior condyles (r = - 0.567, P < 0.001; r = -0.701, P < 0.001), sulcus angle (r = 0.611, P < 0.001) and Dejour trochlea type (r = 0.512, P = 0.001), while femoral neck and shaft torsion showed no correlations. Femoral torsion is a complex of femoral neck and shaft torsion and distal torsion, especially femoral neck and shaft torsion. Distal torsion was significantly correlated with a flatter trochlear sulcus, higher-grade trochlear dysplasia, and shorter anterior condyles. The new findings highlighted the importance of the segmental evaluation of femoral torsion, which would facilitate understanding of the anatomical characteristics of femoral torsion in patients with patellar dislocation and increased femoral torsion and may lead to improvement in the surgical options regarding femoral torsion. Level III.

MRI overestimates articular cartilage thickness and volume compared to synchrotron radiation phase-contrast imaging.

Accurate evaluation of morphological changes in articular cartilage are necessary for early detection of osteoarthritis (OA). 3T magnetic resonance imaging (MRI) has highly sensitive contrast resolution and is widely used clinically to detect OA. However, synchrotron radiation phase-contrast imaging computed tomography (SR-PCI) can also provide contrast to tissue interfaces that do not have sufficient absorption differences, with the added benefit of very high spatial resolution. Here, MRI was compared with SR-PCI for quantitative evaluation of human articular cartilage. Medial tibial condyles were harvested from non-OA donors and from OA patients receiving knee replacement surgery. Both imaging methods revealed that average cartilage thickness and cartilage volume were significantly reduced in the OA group, compared to the non-OA group. When comparing modalities, the superior resolution of SR-PCI enabled more precise mapping of the cartilage surface relative to MRI. As a result, MRI showed significantly higher average cartilage thickness and cartilage volume, compared to SR-PCI. These data highlight the potential for high-resolution imaging of articular cartilage using SR-PCI as a solution for early OA diagnosis. Recognizing current limitations of using a synchrotron for clinical imaging, we discuss its nascent utility for preclinical models, particularly longitudinal studies of live animal models of OA.

Three-dimensional Assessment of Temporomandibular Joint Volume, and Condylar and Glenoid-fossa Morphology: A Cone-beam Computed Tomography Study.

The condylar and glenoid fossa morphology can alter in patients with temporomandibular disorders (TMD), which can lead to changes in the temporomandibular joint (TMJ) space volume. Volumetric evaluation of TMJ can represent the entire three-dimensional (3D)-joint space between the condyle and glenoid fossa. To perform 3D assessment of TMJ volume, condylar, and glenoid-fossa morphology using cone-beam computed tomography and evaluate the correlation between these parameters. Thirty-four patients (age: 13.50 years) who had no previous history of TMD were included. The volume of TMJ space was measured and divided into anterior, posterior, medial, and lateral TMJ volume. The antero-posterior (AP) and medio-lateral (ML) condylar width, AP and ML glenoid-fossa width, and glenoid-fossa depth were evaluated. Statistical analyses were performed with R software at a 0.05 significance level. Each parameter was compared between the left and right sides using a paired-t test. The correlations between the parameters were obtained by the Pearson correlation coefficient. There was no significant difference between lateral and medial TMJ volume; however, posterior TMJ volume was significantly greater than anterior TMJ volume. A significant correlation was observed between AP glenoid-fossa width and TMJ volume, glenoid-fossa depth and TMJ volume, AP position of the condyle and anterior TMJ volume, ML position of the condyle and medial TMJ volume, glenoid-fossa width and condyle width in AP and ML dimension, glenoid-fossa depth and AP glenoid-fossa width. In addition to the evaluation of condylar and glenoid-fossa morphology, assessment of TMJ space volume is important for comprehensive evaluation of the joint.

Setting the distal and posterior condyle of the femoral component to restore the medial pre-arthritic femoral articular surface results in better outcomes after total knee arthroplasty

PurposeThe present study of total knee arthroplasty (TKA) describes an intra-operative method that determines the direction and quantifies the magnitude of deviation of the distal and the posterior medial and lateral (DM, PM, DL, and PL) condyle of the femoral component relative to the pre-arthritic femoral articular surface. For each femoral condyle, the deviations were categorized, and an analysis determined which had better or worse Forgotten Joint Score (FJS), Oxford Knee Score (OKS), and WOMAC scores at 1-year follow-up.MethodsFour academic arthroplasty surgeons supervised a cemented primary CR TKA (Triathlon, Stryker) on 120 consecutive patients. 103 that completed patient-reported outcome measures (PROMs) were analyzed. The surgeon determined the direction and the magnitude of deviation of the condyle of the femoral component by intraoperatively measuring the thickness of the femoral resection, adding compensations of 1 mm for the saw kerf and 2 mm for worn cartilage, and then subtracting the thickness of the femoral component’s condyle. For each femoral condyle, a Kruskal–Wallis test determined the categories of deviation with clinically important and significantly different 1-year PROMs.ResultsA 1 to 2.5 mm and 3 mm or more proximal deviation of the DM condyle of the femoral component worsened the median FJS by 35 and 40 points, OKS by 9 and 14 points, and WOMAC score by 9 and 17 points, respectively, relative to those with a –0.5 to 0.5 mm deviation (p < 0.01). A 1 to 2.5 mm and 3 mm or more anterior deviation of the PM condyle of the femoral component worsened the FJS by 34 and 48 points, OKS by 7 and 13 points, and WOMAC scores by 8 and 16 points, respectively (p < 0.01). Deviations of the DL and PL condyle of the femoral component did not affect PROMs (p ≥ 0.13).ConclusionsAlthough many factors can affect PROM, such as patient expectations, the surgeon should understand that setting the DM and the PM condyles of the femoral component within 1 mm of the patient’s pre-arthritic femoral articular surface can potentially result in better FJS, OKS, and WOMAC scores at 1 year.Level of evidenceII, Prospective cohort study

Positron emission tomography assessment of metacarpal/metatarsal condylar fractures post surgical repair: Prospective study in 14 racehorses.

To assess 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) findings associated with metacarpal/metatarsal condylar fractures at the time of fracture repair and through healing. Prospective descriptive study. Fourteen Thoroughbred racehorses. 18F-NaF PET was performed within 4 days of surgical metacarpal/metatarsal condylar fracture repair, on both the injured and contralateral limb. Follow-up PET scans were offered at 3- and 5-months post fracture repair. Areas of abnormal uptake were assessed using a previously validated grading system. Eight fractures were located in the parasagittal groove (PSG) (six lateral and two medial) and six fractures were located abaxial to the PSG (non-PSG) through the palmar/plantar condyle (all lateral). All horses in the latter group had uptake in the lateral palmar condyle of the contralateral limb suggestive of stress remodeling. Three horses with PSG fractures had uptake in a similar location in the contralateral limb. Horses with lateral condylar fracture only presented minimal or mild uptake in the medial condyle, which is considered atypical in the front limbs for horses in full training. Four horses developed periarticular uptake in the postoperative period suggestive of degenerative joint disease, three of these horses had persistent uptake at the fracture site. These four horses did not return to racing successfully. The findings of this study provide evidence of pre-existing lesions and specific uptake patterns in racehorses suffering from metacarpal/metatarsal condylar fractures. PET has a possible role in the prevention, diagnosis, and postoperative monitoring of metacarpal/metatarsal condylar fractures in racehorses.

Reimagined MPFL Reconstruction: Retinacular Fixation of the Doubled Hamstring Graft at the Patella and Suture Anchor-Based Femoral Fixation.

Lateral patellar dislocation is frequently observed among teenagers and young adults. There is no consensus on the best type of graft or fixation strategy for the femur and patella, and complications such as iatrogenic patella fracture, tunnel malposition, and grafting failure are common. The objective of our research is to find out the functional outcome of a new method of medial patellofemoral ligament (MPFL) reconstruction, which involves two key components: (1) patellar fixation is accomplished by suturing the two limbs of the looped doubled hamstring graft in a divergent fashion to the retinaculum at the medial border of the upper half of patella and (2) the placement of a suture anchor tied to the graft at the isometric point on the medial femur condyle. This study is a retrospective assessment of patients who underwent MPFL reconstruction at our hospital between September 2018 and August 2020. Patients were monitored for at least 2 years after the initial procedure until August 2022. A total of 29 patients were recruited for the study, with 22 being females and the average age being 30.38 years. During the postoperative period, none of the participants experienced instability, redislocation, patellar/femoral fractures, or abnormal distal femur growth. The Tegner-Lysholm knee score was good to excellent for 17 (58.6%) participants, fair for 10 (34.5%) participants, and poor for 2 (6.9%) participants. The Kujala anterior knee pain score was more than 80 for 19 (65.5%) participants. This research presents a significant achievement rate of the surgical procedure, accompanied by the mean Tegner-Lysholm knee score of 82.68 and the mean Kujala anterior knee pain score of 82.71. Notably, there were no complications observed in the postoperative period.

Biphasic parameter determination of sheep articular cartilage from stress relaxation data using an optimized 3D FE-based method

Abstract Mechanical characteristics of hard and soft tissues are central features for the quantitative description of tissue properties. In this study, we present a biphasic 3D-FE-based method to determine the biomechanical properties of sheep stifle joint articular cartilage (load-bearing area of the medial and lateral femur condyle, n = 28) from stress relaxation indentation tests (s = 0.1 mm, t = 180 s). The FE-model computation was optimized by exploiting the axial symmetry and mesh resolution. Parameters were determined using the Levenberg-Marquardt-algorithm. Results showed significant differences between the biomechanical parameters of the lateral (n = 11) and medial (n = 17) femur condyle of the sheep stifle joint articular cartilage. R² of the fit results varied between 0.91 and 0.99. Overall values for the Young’s modulus were 1.316 ± 0.778 MPa, for the Poisson’s ratio 0.106 ± 0.088 and for the permeability 0.008 ± 0.004 mm4/Ns. Future work will focus on studying the influence of experimental settings on the results obtained with the biphasic 3D-FE-model.

QCT-based computational bone strength assessment updated with MRI-derived ‘hidden’ microporosity

Microdamage accumulated through sustained periods of cyclic loading or single overloading events contributes to bone fragility through a reduction in stiffness and strength. Monitoring microdamage in vivo remains unattainable by clinical imaging modalities. As such, there are no established computational methods for clinical fracture risk assessment that account for microdamage that exists in vivo at any specific timepoint. We propose a method that combines multiple clinical imaging modalities to identify an indicative surrogate, which we term ‘hidden porosity’, that incorporates pre-existing bone microdamage in vivo. To do so, we use the third metacarpal bone of the equine athlete as an exemplary model for fatigue induced microdamage, which coalesces in the subchondral bone. N = 10 metacarpals were scanned by clinical quantitative computed tomography (QCT) and magnetic resonance imaging (MRI). We used a patch-based similarity method to quantify the signal intensity of a fluid sensitive MRI sequence in bone regions where microdamage coalesces. The method generated MRI-derived pseudoCT images which were then used to determine a pre-existing damage (Dpex) variable to quantify the proposed surrogate and which we incorporate into a nonlinear constitutive model for bone tissue. The minimum, median, and maximum detected Dpex of 0.059, 0.209, and 0.353 reduced material stiffness by 5.9%, 20.9%, and 35.3% as well as yield stress by 5.9%, 20.3%, and 35.3%. Limb-specific voxel-based finite element meshes were equipped with the updated material model. Lateral and medial condyles of each metacarpal were loaded to simulate physiological joint loading during gallop. The degree of detected Dpex correlated with a relative reduction in both condylar stiffness (p = 0.001, R2 > 0.74) and strength (p < 0.001, R2 > 0.80). Our results illustrate the complementary value of looking beyond clinical CT, which neglects the inclusion of microdamage due to partial volume effects. As we use clinically available imaging techniques, our results may aid research beyond the equine model on fracture risk assessment in human diseases such as osteoarthritis, bone cancer, or osteoporosis.

Patients with trochlear dysplasia have dysplastic medial femoral epiphyseal plates.

To investigate the growth of the epiphyseal plate in patients with trochlea dysplasia using a 3D computed tomography (CT)-based reconstruction of the bony structure of the distal femur. The epiphysis plate was divided into a medial part and a lateral part to compare their differences in patients with trochlear dysplasia. This retrospective study included 50 patients with trochlea dysplasia in the study group and 50 age- and sex-matched patients in the control group. Based on the CT images, MIMICS was used to reconstruct the bony structure of the distal femur. Measurements included the surface area and volume of the growth plate (both medial and lateral), the surface area and capacity of the proximal trochlea, trochlea-physis distance (TPD) (both medial and lateral), and height of the medial and lateral condyle. The surface area of the medial epiphyseal plate (1339.8 ± 202.4mm2 vs. 1596.6 ± 171.8mm2), medial TPD (4.9 ± 2.8mm vs. 10.6 ± 3.0mm), height of the medial condyle (1.1 ± 2.5mm vs. 4.9 ± 1.3mm), and capacity of the proximal trochlear groove (821.7 ± 230.9mm3 vs. 1520.0 ± 498.0mm3) was significantly smaller in the study group than in the control group. A significant positive correlation was found among the area of the medial epiphyseal plate, the medial TPD, the height of the medial condyle and the capacity of the proximal trochlear groove (r = 0.502-0.638). The medial epiphyseal plate was dysplastic in patients with trochlea dysplasia. There is a significant positive correlation between the surface area of the medial epiphyseal plate, medial TPD, height of the medial condyle and capacity of the proximal trochlear groove, which can be used to evaluate the developmental stage of the trochlea in clinical practice and to guide targeted treatment of trochlear dysplasia. III.

Bone mineral density around the knee after open wedge high tibial osteotomy measured up to 24months in 51 patients.

To evaluate bone mineral density (BMD) and radiographic and clinical outcomes of patients with varus knee osteoarthritis treated with open wedge high tibial osteotomy (OWHTO). We hypothesised that medial condyle BMD would decrease and lateral condyle BMD would increase after OWHTO. Overall, 51 patients (mean age: 65.3years; female: 40, male: 11) treated with OWHTO were prospectively enrolled. Several angles using whole single-leg radiographs were measured preoperatively and up to 24months postoperatively. Five square tibial regions of interest (ROI) located below the proximal tibia as T1-T5 from medial to lateral regions and two square femoral ROI as F1 and F2 from medial and lateral regions, respectively, were defined. M/L BMD ratio was used to define the medial-to-lateral condyle BMD ratio. Femoral condyle BMD (F1 and F2) around the knee, as well as lumbar spine, and ipsilateral and contralateral femoral neck BMD, were measured before OWHTO and 3, 6, 12 and 24months after OWHTO using dual-energy X-ray absorptiometry. Furthermore, tibial condyle BMD (T1-T5) around the knee was measured before and 24months after OWHTO. Clinical outcomes were evaluated using the Knee Society knee and function scores, the Knee Injury and Osteoarthritis Outcome Score, and the Lysholm score preoperatively and 24months postoperatively. A power analysis was performed. F1 BMD decreased by 19.2% from before to 3months postoperatively. F2 BMD did not change up to 24months after OWHTO. Femoral M/L BMD ratio decreased by 22.2% 3months after OWHTO. T1 BMD and tibial M/L BMD ratio decreased, whilst T3, T4 and T5 BMD increased 24months after OWHTO. Mean hip-knee-ankle angle (HKA) and weight-bearing line ratio were corrected from - 6.8° to 4.5° and 14.7 to 60.7%, respectively, postoperatively. Lumbar spine BMD did not change up to 12months postoperatively. Ipsilateral femoral neck BMD decreased up to 6months after OWHTO. Medial femoral condyle BMD decreased rapidly within 3months and continued to decrease up to 12months, but lateral femoral condyle BMD did not change after OWHTO. BMD measurements around the knee condyle enabled the evaluation of the changes in stress distribution before and after OWHTO with accelerated rehabilitation. II.

Can ultrasound-guided radiofrequency ablation of genicular nerves of the knee, be performed without locating corresponding arterial pulsations—a cadaveric study

IntroductionGiven the rising prevalence of knee osteoarthritis, radiofrequency ablation of genicular nerves (RFA) has emerged as a promising treatment option for knee pain. The knee has an extremely complex and variable innervation with nearly 13 genicular nerves described. The frequently ablated genicular nerves are the superomedial (SMGN), the superolateral (SLGN), and the inferomedial (IMGN) genicular nerves. Conventionally, under ultrasound guidance, these nerves are ablated near the corresponding arterial pulsations, but due to the rich vascular anastomosis around the knee joint, identifying the arteries corresponding to these constant genicular nerves can be tedious unless guided by some bony landmarks. In this study, we have evaluated whether it is possible to accurately target these three genicular nerves by just locating bony landmarks under ultrasound in human cadaveric knee specimens.MethodsFifteen formalin-fixed cadaveric knee specimens were studied. SMGN was targeted 1 cm anterior to the adductor tubercle in the axial view. For SLGN, in the coronal view, the junction of the lateral femoral condyle and shaft was identified, and at the same level in the axial view, the crest between the lateral and posterior femoral cortex was targeted. For IMGN in the coronal view, the midpoint between the most prominent part of the medial tibial condyle and the insertion of the deep fibers of the medial collateral ligament was marked. The medial end of the medial tibial cortex was then targeted at the same level in the axial view. The needle was inserted from anterior to posterior, with an in-plane approach for all nerves. Eosin, 2% W/V, in 0.1 ml was injected. Microdissection was done while keeping the needle in situ. Staining of the nerve was considered a positive outcome, and the percentage was calculated. The nerve-to-needle distance was measured, and the mean with an interquartile range was calculated.ResultThe accuracies of ultrasound-guided bony landmarks of SMGN, SLGN, and IMGN were 100% in terms of staining, with average nerve-to-needle distances of 1.67, 3.2, and 1.8 mm respectively.ConclusionIt is with 100% accuracy, that we can perform RFA of SMGN, SLGN, and IMGN under ultrasound guidance, by locating the aforementioned bony landmarks.

FUNCTIONAL OUTCOME OF ISOLATED MEDIAL FEMORAL CONDYLE FRACTURES MANAGED WITH PLATE OSTEOSYNTHESIS - A CASE SERIES

Purpose: Isolated medial condyle fractures of femur with metaphyseal extension are a rare type of injury around knee joint. Most common mode of injury is high-energy trauma (road traffic accident, fall from height, sports injury) and is commonly seen in younger age group. Is open reduction and internal fixation with locking plates is the treatment of choice for sagittal plane medial femur condyle fractures with metaphseal extension? Methods: We conducted a prospective study from 1st January 2018 to 31st December 2021 including 12 patients (seven males and five females) with isolated medial femur condyle fractures (AO 33B2.1). In our study, open reduction and internal fixation was performed with medial femur plates or T-buttress plates in all 12 cases. At final follow-up, functional outcome was evaluated using ‘functional criteria’, ‘IKS knee and function score’ and radiological assessment. Results: At final follow-up, out of 12 patients, 11 had excellent to good outcome according to ‘Kolmert Functional score’ and ‘IKS knee and function score’ were 83.33 and 78.33. At final follow-up, one out of twelve patients had extensor lag of 10 and flexion around 90. Conclusion: Isolated fractures of medial condyle with metaphyseal extension have good outcome in terms of function if proper anatomical reduction is achieved and supplemented with locking plates.

Investigating Risk Factors and Magnetic Resonance Imaging (MRI)-Based Grading of Subchondral Incomplete Fracture (SIF) of Medial Femoral Condyle.

Subchondral insufficiency fractures (SIF) of the knee joint are prevalent in osteoporosis patients over the age of 55. Early diagnosis of SIF fracture of the medial femoral condyle is crucial for delaying disease progression, early therapy, and potential disease reversal. Magnetic resonance imaging (MRI) is useful in detecting SIF, which is often undetectable on initial radiographs. This study aimed at developing a grading system for subchondral insufficiency fractures (SIF) based on MRI to predict outcomes and evaluate risk factors. In this study, MRI was used to examine SIF risk variables in the medial condyle of the femur to help clinicians diagnose, treat, and delay the condition. A total of 386 patients with SIF from 2019 to 2021 were retrospectively analyzed and divided into 106 patients in the disease group and 280 patients in the control group according to whether they had SIF. The lesion site, meniscus, ligament, and other parameters were evaluated and compared. At the same time, a grading system was introduced to stratify and statistically analyze the size of the lesion area, the degree of bone marrow edema (BME), meniscus tears, and other parameters in the patients. Most SIF were low-grade (LG) fractures, and the predictors of LG and high-grade (HG) fractures included heel tear (P =0.031), degree of medial malleolus degeneration (P < 0.001), advanced age (P < 0.001), and lesion size (P < 0.001). The prognostic factors that showed significant differences between the two groups included age (P =0.027), gender (P =0.005), side (P =0.005), medial tibial plateau injury (P < 0.0001), femoral medullary bone marrow edema (P < 0.0001), medial tibial plateau bone marrow edema (P < 0.0001), meniscus body partial injury (P =0.016), heel tear (P =0.001), anterior cruciate ligament injury (P =0.002), and medial collateral ligament injury (P < 0.0001). This current study proposed an MRI-based grading system for inferior condylar fractures of the femur, in which HG inferior condylar fractures are associated with severe medial malleolus degeneration, advanced age, lesion size (correlation), and meniscus heel tears.

A plain radiography may underestimate the steep posterior tibial slope of the medial condyle in elderly Japanese with varus knee osteoarthritis undergoing arthroplasties

PurposeUnderstanding the native posterior tibial slope (PTS) is important especially in cruciate ligament retaining total knee arthroplasty (TKA) and uni-compartmental knee arthroplasty (UKA). This study investigated the efficacy of PTS with lateral knee radiograph (radiographic PTS) by comparing it with PTS of medial and lateral tibial condyles (MPTS and LPTS) by computed tomography (CT). MethodsIn patients who underwent TKA and UKA on varus knee osteoarthritis, radiographic PTS, MPTS, and LPTS were measured. Spearman's correlation was used to compare the radiographic PTS and PTS on CT. More than 3° delta PTS (CT PTS - radiographic PTS) were defined as positive outliers. ResultsThree-hundred and twenty-six osteoarthritic knees (278 TKAs and 48 UKAs) were evaluated. The mean radiographic PTS, MPTS, LPTS was 8.0 ​± ​2.9°, 10.2 ​± ​4.2°, and 8.3 ​± ​3.3°, respectively. Plain radiograph tended to underestimate steep MPTS, and its correlations to LPTS (ρ ​= ​0.65, p ​< ​0.001) and MPTS (ρ ​= ​0.54, p ​< ​0.001) were moderate. The positive outliers were observed in 136/326 (42%) and 36/326 (12%) knees in medial and lateral condyles, respectively. Even in UKA, the positive outliers were observed in 13/48 (28%) knees in medial condyle. ConclusionsRadiographic PTS better reproduced LPTS, but did not accurately reproduce MPTS in varus knee osteoarthritis. Radiographic PTS may not detect steep medial PTS. Surgeons should be cautious because the actual PTS of the medial tibial condyle may be different from that preoperatively measured on plain radiographs.

Shear wave elastography and T2* mapping in the detection of early-stage trochlear cartilage damage.

The presence of degenerative changes in joint cartilage is one of the major features in osteoarthritis. To investigate the contribution of shear wave elastography and T2* mapping to the early diagnosis of femoral trochlear cartilage damage. A total of 30 individuals whose trochlear cartilage structure was evaluated as normal in conventional magnetic resonance imaging (MRI) sequences (control group) were prospectively compared with 30 patients who had early-stage cartilage damage findings on conventional MRI (study group), by performing B-mode ultrasonography, shear wave elastography, and T2* mapping. Cartilage thickness, shear wave, and T2* mapping measurements were recorded. After evaluating B-mode ultrasound and conventional MRI sequences, cartilage thickness was found to be significantly higher in the study group on both B-mode ultrasound and MRI. Shear wave velocity values of the study group (medial condyle [MC] 4.65 ± 1.11 m/sn, intercondylar [IC] 4.74 ± 1.20 m/sn, and lateral condyle [LC] 5.42 ± 1.48 m/sn) were observed to be significantly lower than the control group (MC 5.60 ± 0.77 m/sn, IC 5.85 ± 0.96 m/sn, and LC 5.63 ± 1.05 m/sn) (P < 0.05). T2* mapping values were significantly higher in the study group (MC 32.38 ± 4.04 ms, IC 35.78 ± 4.85 ms, and LC 34.04 ± 3.40 ms) than that of the control group (MC 28.07 ± 3.29 ms, IC 30.63 ± 3.45 ms, and LC 29.02 ± 3.24 ms). Shear wave elastography and T2* mapping are reliable methods for evaluating early-stage trochlear cartilage damage.

Dual-tissue transplantation versus osteochondral autograft transplantation in the treatment of osteochondral defects: a porcine model study

BackgroundOsteochondral injury is a common sports injury, and hyaline cartilage does not regenerate spontaneously when injured. However, there is currently no gold standard for treating osteochondral defects. Osteochondral autograft transplantation (OAT) is widely used in clinical practice and is best used to treat small osteochondral lesions in the knee that are < 2 cm2 in size. Autologous dual-tissue transplantation (ADTT) is a promising method with wider indications for osteochondral injuries; however, ADTT has not been evaluated in many studies. This study aimed to compare the radiographic and histological results of ADTT and OAT for treating osteochondral defects in a porcine model.MethodsOsteochondral defects were made in the bilateral medial condyles of the knees of 12 Dian-nan small-ear pigs. The 24 knees were divided into the ADTT group (n = 8), OAT group (n = 8), and empty control group (n = 8). At 2 and 4 months postoperatively, the knees underwent gross evaluation based on the International Cartilage Repair Society (ICRS) score, radiographic assessment based on CT findings and the magnetic resonance observation of cartilage repair tissue (MOCART) score, and histological evaluation based on the O'Driscoll histological score of the repair tissue.ResultsAt 2 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score were significantly better in the OAT group than the ADTT group (all P < 0.05). At 4 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score tended to be better in the OAT group than the ADTT group, but these differences did not reach statistical significance (all P > 0.05).ConclusionsIn a porcine model, ADTT and OAT are both effective treatments for osteochondral defects in weight bearing areas. ADTT may be useful as an alternative procedure to OAT for treating osteochondral defects.

Poster 254: Osteochondral Allograft Transplantation Using Dowell Technique for the Treatment of Steroid-Associated Osteonecrosis of the Femoral Condyles: Arthroplasty-Free Survival at 5 and 10 Years

Objectives: Steroid-associated osteonecrosis of the femoral condyles is a known complication of long- term or high dose steroid exposure. This is a not infrequent situation for patients with inflammatory conditions such as Lupus or Ulcerative Colitis and in patients with malignancies leukemia requiring bone marrow transplant. Historically, osteonecrosis was a contraindication for osteochondral allograft transplantation (OATS), however, recent evidence has indicated OATS maybe a durable treatment option. While results using the shell OATS technique has been reported in the steroid-associated osteonecrosis population, there is a dearth of information on the long-term survival for the newer dowel OATS technique. The aim of this study was to retrospectively analyze survival of OATS using the dowel technique for the treatment of steroid-associated osteonecrosis of the femoral condyles. Methods: Institutional database was queried to identify eligible patients. Inclusion criteria included diagnosis of aseptic or secondary osteonecrosis of the distal femur, osteochondral allograft transplantation surgical treatment, dowel OATS technique, and history of steroid use for a medical condition. Exclusion criteria included previous cartilage restoration or arthroplasty surgery and incomplete records. No age criteria were used to exclude patients. Patient charts were reviewed for demographic details, information about underlying pathologic condition and steroid exposure, surgical details, and revision OATS or conversation to arthroplasty. Primary outcomes were arthroplasty-free survival and revision-free survival. Results: 27 knees in 25 patients with an average age of 27.6 years (range 16-59 years) were identified with an average follow up of 6.2 years (range 0.7-22 years). Medical conditions included 10 malignancies (5 post-bone marrow transplant) and 13 autoimmune diseases. Distribution of osteonecrosis of the femoral condyles included 1 isolated medial condyle, 5 isolated lateral condyles, 21 medial and lateral condyles. All patients underwent dowel OATS technique. Patients received on average of 2.2 grafts (range 1-5 grafts) with an average combined graft area of 6.67 cm2 (range 1.5 to 20.4 cm2). 10 patients had concomitant procedures and 10 patients had supplemental graft fixation. All patients were treated between 2006 and 2020. Arthroplasty-free survival was 88%, 85%, 60% at 5, 8, 10 years. Revision OATS or arthroplasty free survival was 81%, 77%, 55% at 5, 8, 10 years. Graft failures included 1 revision OATS at 7.7 years secondary to cartilage delamination and 4 conversions to total knee arthroplasty at 1.6, 1.9, 8.7, 9.5 years. Conclusions: Osteochondral Allograft Transplantation is an acceptable and durable treatment option in patients with steroid-associated osteonecrosis with 88% arthroplasty-free survival at 5 years and 60% arthroplasty-free survival at 10 years. Future studies should capture patient reported outcomes and investigate factors leading to arthroplasty conversion such as age at time of OATS, etiology of osteonecrosis, extent of osteonecrosis. [Table: see text]

Osteochondral Allograft and Concurrent Meniscal Allograft Transplantation

Background: Symptomatic, full-thickness chondral defects often are associated with meniscal deficiencies. These are difficult problems to manage in the young, high-demand patient population. A number of differing techniques have been published with no consensus. While more recent techniques have favored minimally invasive approaches, an open approach with tubercle osteotomy to maximize visualization of all knee compartments can still provide favorable outcomes when using a careful technique and postoperative protocol. Indications: Young, high-demand patients with long-standing meniscal deficiency and resultant chondral defects are indicated for cartilage restoration and preservation procedures. A meniscal allograft transplantation is indicated in symptomatic patients with prior total or subtotal meniscectomy. It is important to address other concomitant pathology such as instability, alignment, and chondral defects. Concomitant procedures are often performed with meniscal transplants, including osteochondral allograft transplantation for larger defects. Technique Description: This surgical technique video demonstrates a tibial tubercle osteotomy approach to gain access to both the medial and lateral tibiofemoral compartments. An arthroscopic-assisted bone slot technique was performed for meniscal allograft transplantation. Appropriately sized osteochondral allograft bone plugs were then transplanted onto the medial and femoral condyles with a press fit technique. Results: At 1-year follow-up, the presented patient has regained full motion and are back to full activities. Discussion/Conclusion: Full-thickness chondral defects associated with meniscal deficiency in a young, high-demand patient is a difficult problem to manage. Recent results using minimally invasive approaches have demonstrated favorable mid- and long-term outcomes. In patients with pathology that may preclude a minimally invasive approach, an open technique with osteotomy can still have a promising outcome. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Poster 321: MENISCAL RAMP LESIONS IN ADOLESCENT PATIENTS UNDERGOING PRIMARY ACL RECONSTRUCTION

Objectives: Meniscal ramp lesions describe a specific injury to the meniscocapsular junction at the posterior horn of the medial meniscus. The lesions are strongly associated with anterior cruciate ligament (ACL) injuries and may affect the biomechanical stability of the knee if left untreated. Despite the increasing rates of ACL reconstructions performed in adolescents each year, the prevalence and risk factors for ramp lesions in this patient population is poorly understood. The purpose of this study was to determine the prevalence and risk factors for ramp lesions in children and adolescent patients undergoing primary ACL reconstruction. Methods: All patients ≤19 who underwent primary ACL reconstruction at a single institutional between 2019 and 2021 were included. All surgeries were performed by three fellowship trained orthopedic surgeons. Patients were considered to have a ramp lesion if one was identified arthroscopically at the time of ACL reconstruction. Basic demographic data, preoperative imaging, and other arthroscopic findings at the time of ACL reconstruction were reviewed. Results: 247 consecutive patients who underwent ACL reconstruction were reviewed. Patients were excluded if they had had prior ACL injury, prior knee surgery, fibular hemimelia, or incomplete documentation. A total of 230 patients met inclusion criteria. Average age at time of injury was 15.7 years (range 4.0-18.2 years). A ramp lesion was identified in 12% of patients. Posteromedial tibial bone bruise on preoperative MRI and medial femoral chondromalacia at time of ACL reconstruction were associated with the presence of a ramp lesion, Figure 1A (OR = 2.6, 95% CI [1.15, 5.93]). A striation pattern of medial femoral chondromalacia was highly specific for the presence of a ramp lesion, Figure 1B (OR = 424.3, 95% CI [50.99, 3531.3]). Sensitivity and specificity for detecting a ramp lesion was 68% and 76% with preoperative MRI and 68% and 99.5% with medial condyle striations, respectively. Conclusions: The prevalence of a ramp lesion in our cohort was 12%, mirroring historical reports in adult patients. Posteromedial bone bruising and medial femoral chondromalacia, especially in a striation pattern, should increase suspicion for the presence of a ramp lesion in patients undergoing ACL reconstruction.