Medial Femoral Condyle Research Articles

Patient-Specific Distal Femoral Guides Optimize Cartilage Topography Matching in Osteochondral Allograft Transplantations

Background: Osteochondral allograft (OCA) transplantation is an important surgical technique for full-thickness chondral defects in the knee. For patients undergoing this procedure, topography matching between the donor and recipient sites is essential to limit premature wear of the OCA. Currently, there is no standardized process of donor and recipient graft matching. Purpose: To evaluate a novel topography matching technique for distal femoral condyle OCA transplantation using 3-dimensional (3D) laser scanning to create 3D-printed patient-specific instrumentation in a human cadaveric model. Study Design: Descriptive laboratory study. Methods: Human cadaveric distal femoral condyles (n = 12) underwent 3D laser scanning. An 18-mm circular osteochondral recipient defect was virtually created on the medial femoral condyle (MFC), and the position and orientation of the best topography-matched osteochondral graft from a paired donor lateral femoral condyle (LFC) were determined using an in silico analysis algorithm minimizing articular step-off distances between the edges of the graft and recipient defect. Distances between the entire surface of the OCA graft and the underneath surface of the MFC were evaluated as surface mismatch. Donor (LFC) and recipient (MFC) 3D-printed patient-specific guides were created based on 3D reconstructions of the scanned condyles. Through use of the guides, OCAs were harvested from the LFC and transplanted to the reamed recipient defect site (MFC). The post-OCA recipient condyles were laser scanned. The 360° articular step-off and cartilage topography mismatch were measured. Results: The mean cartilage step-off and graft surface mismatch for the in silico OCA transplant were 0.073 ± 0.029 mm (range, 0.005-0.113 mm) and 0.166 ± 0.039 mm (range, 0.120-0.243 mm), respectively. Comparatively, the cadaveric specimens postimplant had significantly larger step-off differences (0.173 ± 0.085 mm; range, 0.082-0.399 mm; P = .001) but equivalent graft surface topography matching (0.181 ± 0.080 mm; range, 0.087-0.396 mm; P = .678). All 12 OCA transplants had mean circumferential step-off differences less than a clinically significant cutoff of 0.5 mm. Conclusion: These findings suggest that the use of 3D-printed patient-specific guides for OCA transplantation has the ability to reliably optimize cartilage topography matching for LFC to MFC transplantation. This study demonstrated substantially lower step-off values compared with previous orthopaedic literature when also evaluating LFC to MFC transplantation. Using this novel technique in a model performing MFC to MFC transplantation has the potential to yield further enhanced results due to improved radii of curvature matching. Clinical Relevance: Topography-matched graft implantation for focal chondral defects of the knee in patients improves surface matching and has the potential to improve long-term outcomes. Efficient selection of the allograft also allows improved availability of the limited allograft sources.

A larger radius of the medial femoral posterior condyle is a risk factor for medial meniscus posterior root tears

BackgroundStudies have shown an association between medial meniscus posterior root tears (MMPRT) and morphologic characteristics of the bone. However, the association between distal femoral bone morphology and MMPRT, particularly the medial femoral posterior condyle, is poorly understood. Our study aimed to determine the association between the morphologic characteristics of the medial posterior femoral condyle and MMPRT.MethodsA retrospective case-control study was performed from January 2021 to January 2022. After screening based on the inclusion and exclusion criteria, two matched groups were analyzed: the MMPRT group and the isolated lateral meniscus tears group. The hip-knee-ankle angle (HKA) and Kellgren-Lawrence grade (KLG) were measured on radiographs; the medial tibial slope angle (MTSA), medial tibial plateau depth (MTPD), and radius of the medial femoral posterior condyle (RMFPC) were measured on magnetic resonance imaging (MRI) in both groups. The area under the curve (AUC) and the best cutoff value for predicting MMPRT were calculated by using receiver operating characteristic (ROC) curve analysis.ResultsThe final analysis included a total of 174 patients (87 MMPRT patients and 87 controls). Significant differences were shown in the RMFPC (17.6 ± 1.0 vs. 16.2 ± 1.0, p < 0.01) and MTSA (6.4 ± 2.0 vs. 4.0 ± 1.3, p < 0.01), which were larger than those of the control group. The MTPD (1.8 ± 0.6 vs. 2.9 ± 0.7, p < 0.01) and HKA (175.4 ± 2.2 vs. 179.0 ± 2.7, p < 0.01) of the injury group were significantly different from the control group, and both were lower than the control group. However, between the MMPRT and control groups on the KLG (2.3 ± 0.6 vs. 2.2 ± 0.6, p = 0.209), there was no statistically significant difference. Among them, the RMFPC cutoff value was calculated to be 16.8 mm by ROC curve analysis, and the sensitivity and specificity were both 81.61%.ConclusionsThis study demonstrated that larger RMFPC, MTSA, smaller MTPD, and HKA were all associated with MMPRT, and RMFPC ≥ 16.8 mm was considered as a significant risk factor for MMPRT.

The Immature Pediatric Appendicular Skeleton.

Growth and maturation occur in a predictable pattern throughout the body and within each individual bone. In the appendicular skeleton, endochondral ossification predominates in long bones and growth plates. The ends of these long bones are sites of relative weakness in the immature skeleton and prone to injury from acute insult and overuse. We present the normal histoanatomy and physiology of the growth plate complex, highlighting the unique contribution of each component and shared similarities between primary and secondary complexes. Components of the growth plate complex include the physis proper, subjacent vascularity within the growth cartilage, and the ossification front. The second section describes imaging considerations and features of normal and abnormal growth. Finally, we review the Salter-Harris classification for acute fractures and offer examples of characteristic overuse injury patterns involving the epiphyseal (proximal humerus and distal radius), apophyseal (medial epicondyle and tibial tubercle), and secondary growth plate complexes (medial femoral condyle and capitellar osteochondritis dissecans). This article provides a foundation and basic framework to better understand and anticipate potential complications and growth disturbances and to ensure optimal follow-up and early intervention when treatment can be less invasive.

Investigating the Bone Bruise Patterns in Pediatric Patients With Contact and Noncontact Acute Anterior Cruciate Ligament Tears: A Multicenter Study

Background: In adults with anterior cruciate ligament (ACL) tears, bone bruises on magnetic resonance imaging (MRI) scans provide insight into the underlying mechanism of injury. There is a paucity of literature that has investigated these relationships in children with ACL tears. Purpose: To examine and compare the number and location of bone bruises between contact and noncontact ACL tears in pediatric patients. Study Design: Cohort study; Level of evidence, 3. Methods: Boys ≤14 years and girls ≤12 years of age who underwent primary ACL reconstruction surgery between 2018 and 2022 were identified at 3 separate institutions. Eligibility criteria required detailed documentation of the mechanism of injury and MRI performed within 30 days of the initial ACL tear. Patients with congenital lower extremity abnormalities, concomitant fractures, injuries to the posterolateral corner and/or posterior cruciate ligament, previous ipsilateral knee injuries or surgeries, or closed physes evident on MRI scans were excluded. Patients were stratified into 2 groups based on a contact or noncontact mechanism of injury. Preoperative MRI scans were retrospectively reviewed for the presence of bone bruises in the coronal and sagittal planes using fat-suppressed T2-weighted images and a grid-based mapping technique of the tibiofemoral joint. Results: A total of 109 patients were included, with 76 (69.7%) patients sustaining noncontact injuries and 33 (30.3%) patients sustaining contact injuries. There were no significant differences between the contact and noncontact groups in terms of age (11.8 ± 2.0 vs 12.4 ± 1.3 years; P = .12), male sex (90.9% vs 88.2%; P > .99), time from initial injury to MRI (10.3 ± 8.1 vs 10.4 ± 8.9 days; P = .84), the presence of a concomitant medial meniscus tear (18.2% vs 14.5%; P = .62) or lateral meniscus tear (69.7% vs 52.6%; P = .097), and sport-related injuries (82.9% vs 81.8%; P = .89). No significant differences were observed in the frequency of combined lateral tibiofemoral (lateral femoral condyle + lateral tibial plateau) bone bruises (87.9% contact vs 78.9% noncontact; P = .41) or combined medial tibiofemoral (medial femoral condyle [MFC] + medial tibial plateau) bone bruises (54.5% contact vs 35.5% noncontact; P = .064). Patients with contact ACL tears were significantly more likely to have centrally located MFC bruising (odds ratio, 4.3; 95% CI, 1.6-11; P = .0038) and less likely to have bruising on the anterior aspect of the lateral tibial plateau (odds ratio, 0.27; 95% CI, 0.097-0.76; P = .013). Conclusion: Children with contact ACL tears were 4 times more likely to present with centrally located MFC bone bruises on preoperative MRI scans compared with children who sustained noncontact ACL tears. Future studies should investigate the relationship between these bone bruise patterns and the potential risk of articular cartilage damage in pediatric patients with contact ACL tears.

Vascularized Bone Graft in Mangled Hand Reconstruction

Extensive bone defects especially in conjunction with associated coverage involvement in mangled hands, pose significant challenges to hand and upper extremity surgeons. Vascularized bone grafts often play a vital role for effective treatment now-a-days. It not only bypasses the drawbacks of conventional grafts but also allows for simultaneous one stage reconstruction of its coverage as well as repairs other injured structures.Preoperative evaluation of mangled hand is crucial, the injury extent, including circulation, patient expectations and clinical reality should be all taken into consideration before finalizing the reconstruction plan. The fibula bone and other vascularized bone flaps such as iliac crest bone and medial femoral condyle and some others as well as corresponding spare part can provide effective solutions. Especially important considerations about surgeons’ experience and expertise , donor site morbidity , postoperative care and rehabilitation are essential for optimal outcomes. In this article , we would like to share our current practicing vascularized bone flaps in mangled hand reconstructions.

Free medial femoral condyle osteocutaneous flap for repairing stage IIIB osteonecrosis of the lunate: a case report

BackgroundThere are several surgical options for osteonecrosis of the lunate, and confirming the effectiveness of various surgical methods remains challenging. Here, we present a case of stage IIIB osteonecrosis of the lunate repaired with a free medial femoral condyle osteocutaneous flap.Case presentationA 43-year-old male construction worker was admitted to our hospital due to right wrist pain, impaired mobility, and pain aggravated by activity for 10 months. The patient was diagnosed with stage IIIB osteonecrosis of the lunate based on the orthopantomogram and magnetic resonance imaging of the right wrist. Considering the patient’s medical history, physical examination, auxiliary examination, and wishes, reconstruction was performed using a free medial femoral condyle osteocutaneous flap. After the flap survived completely, the K-wires were removed one month after the operation, the external brace was removed two months after the operation, and functional wrist rehabilitation was initiated. After six months of follow-up, the wrist swelling and pain resolved, and the reconstructed lunate bone was viable. Additionally, the last follow-up was conducted in the sixth month after surgery; the affected hand grip strength improved from about 70% (28 kg) to 80% (32 kg) compared with the healthy side (40 kg); the visual analog scale score decreased from 6.5 points before the operation to 1 point; and the MAYO score increased from 60 points before the operation to 85 points.ConclusionsThe success of this case reinforces the potential of the free medial femoral condyle osteocutaneous flap as a new treatment option for stage IIIB osteonecrosis of the lunate and further expands the existing treatment options. Using a free medial femoral condyle osteocutaneous flap to reconstruct the lunate and restore the carpal anatomy may.

A Single Incision Technique for Medial Patellofemoral Ligament Repair with Augmentation Using a Reinforced Bio-Inductive Implant

Patella dislocations and resultant recurrent instability commonly occur. Surgery for patella dislocation is indicated after subsequent dislocation or after an initial dislocation with articular cartilage injury of the patella or femur. The strength of an isolated medial patellofemoral ligament (MPFL) repair has been shown to be insufficient to prevent recurrent dislocation. Multiple different techniques to augment the MPFL repair using various autologous and allografts, as well as high tensile strength sutures or synthetic ligaments have been developed. Most of the techniques use two incisions: one near the patella and the other by the medial femoral condyle. The purpose of this study is to demonstrate a single incision technique for MPFL repair with augmentation using a reinforced bio-inductive (RBI) implant. The single-incision technique does have advantages over the two-incision techniques. Furthermore, the RBI implant is easily reproducible docked into the patella sockets without difficulty and has an initial inherent strength comparable to the semitendinosus. The RBI heals to bone and allows for infiltration of the patient’s own cells which strengthens the augmentation over time.

Large Human Fabella Bone

Fabella bone is identified as an accessory and evolutionary sesamoid bone in humans. It was noticed as an irregular shape located within the lateral head of gastrocnemius in the posterolateral capsule of the left knee of a 55-year-old male. Another smaller fabella was noted and both were kept in a safe place Measurements were taken after a week and their length was 2.7 cm and 1.8 cm respectively. The size of fabella usually ranges from 5mm-20mm in diameter, but in this study, the length of the larger one was 2.7 cm. Fabella originated as a small cartilaginous nodule and underwent endochondral ossification. It helps to reduce resistance within tendons and redirect muscle forces. In humans, gastrocnemius acts to flex the knee and plantar flex the foot. Fabella function was thought to stabilize the femoral complex and medial femoral condyle. Patients with fabella pain syndrome usually complain of increased posterolateral pain during the full extension of the knee joint. Fabella pain syndrome could be treated with physical therapy, local anaesthetics injection, radial extracorporeal shock wave therapy or fabellectomy. It has been observed that there has been an increase in the prevalence of fabella in recent years. Larger moments acting on the knee and increasing muscle or tendon strain could produce stimuli essential to encourage fabella formation.

Subchondral insufficiency fractures: overview of MRI findings from hip to ankle joint.

Subchondral insufficiency fracture (SIF) represents a potentially severe condition that can advance to osteoarthritis, with collapse of the articular surface. SIF manifests as a fracture in bone weakened by non-tumorous disease, precipitated by repetitive physiological stress, without a clear history of major trauma. It is observed along the central weight-bearing region of the femoral condyle, with a higher incidence in the medial femoral condyle, but also in other large weight-bearing synovial joints, such as the femoral head, tibial plateau, or talus.A review of the literature from the past six years was performed by searching PubMed and ScienceDirect databases, using the keywords "subchondral insufficiency fracture" and "spontaneous osteonecrosis of the knee". The inclusion criteria were scientific papers presented in the English language that reported on the magnetic resonance imaging (MRI) aspects of SIF of the lower limb.Detecting SIF at the level of the hip, knee, and ankle may present challenges both clinically and radiologically. The MRI appearance is dominated by a bone marrow edema-like signal and subchondral bone changes that can sometimes be subtle. Subchondral abnormalities are more specific than the pattern of bone marrow edema-like signal and are best shown on T2-weighted and proton-density-weighted MR images. MRI plays an important role in accurately depicting even subtle subchondral fractures at the onset of the disease and proves valuable in follow-up, prognosis, and the differentiation of SIF from other conditions. · Subchondral insufficiency fractures may affect the hip, knee, and ankle.. · Subchondral insufficiency fractures may heal spontaneously or progress to collapse.. · MRI is important for the detection, follow-up, and prognosis of subchondral insufficiency fractures.. · Differential diagnosis may include transient osteoporosis and osteonecrosis of systemic origin.. · Buturoiu MM, Ghiea S, Weber M. Subchondral insufficiency fractures: overview of MRI findings from hip to ankle joint. Fortschr Röntgenstr 2024; DOI 10.1055/a-2344-5337.

Analysis of Variation in Sagittal Curvature of the Femoral Condyles.

In designing femoral components, which restore native (i.e., healthy) knee kinematics, the flexion-extension (F-E) axis of the tibiofemoral joint should match that of the native knee. Because the F-E axis is governed by the curvature of the femoral condyles in the sagittal plane, the primary objective was to determine the variation in radii of curvature. Eleven high accuracy three-dimensional (3D) femur models were generated from ultrahigh resolution CT scans. The sagittal profile of each condyle was created. The radii of curvature at 15 deg increments of arc length were determined based on segment circles best-fit to ±15 deg of arc at each increment. Results were standardized to the radius of the best-fit overall circle to 15 deg-105 deg for the femoral condyle having a radius closest to the mean radius. Medial and lateral femoral condyles exhibited multiradius of curvature sagittal profiles where the radius decreased at 30 deg flexion by 10 mm and at 15 deg flexion by 8 mm, respectively. On either side of the decrease, radii of segment circles were relatively constant. Beyond the transition angles where the radii decreased, the anterior-posterior (A-P) positions of the centers of curvature varied 4.8 mm and 2.3 mm for the medial and lateral condyles, respectively. A two-radius of curvature profile approximates the radii of curvature of both native femoral condyles, but the transition angles differ with the transition angle of the medial femoral condyle occurring about 15 deg later in flexion. Owing to variation in A-P positions of centers of curvature, the F-E axis is not strictly fixed in the femur.

Advantages of cone beam computed tomography for evaluation of subchondral insufficiency fractures of the knee compared to MRI

To determine the diagnostic yield of cone beam computed tomography (CBCT) compared with 3 T magnetic resonance imaging (MRI) for the evaluation of subchondral insufficiency fractures of the knee. Consecutive patients with subchondral insufficiency fractures of the knee examined by 3 T MRI and CBCT of the femoral condyles were reviewed. Two experienced raters graded the lesion severity on 3 T MRI and CBCT images: grade 1: no signs of a subchondral bone lesion; grade 2: subchondral trabecular fracture or cystic changes, but without infraction of the subchondral bone plate; grade 3: collapse of the subchondral bone plate. Ratings were repeated after six weeks to determine reliability. In addition, the bone lesion size was measured as elliptical area (mm2) and compared between CBCT and T1-weighted MRI sequences. Among 30 patients included (43.3% women; mean age: 60.9 ± 12.8 years; body mass index (BMI) 29.0 ± 12.8 kg/m2), the medial femoral condyle was affected in 21/30 patients (70%). The grading of subchondral lesions between MRI and CBCT did not match in 12 cases (40%). Based on MRI images, an underestimation (i.e., undergrading) compared with CBCT was observed in nine cases (30%), whereas overgrading occurred in three cases (10%). Compared to CBCT, routine T1-weighted 3 T sequences significantly overestimated osseus defect zones in sagittal (84.7 ± 68.9 mm2 vs. 35.9 ± 38.2 mm2, p < 0.01, Cohen’s d = 1.14) and coronal orientation (53.1 ± 24.0 mm2 vs. 22.0 ± 15.2 mm2, p < 0.01, Cohen’s d = 1.23). The reproducibility of the grading determined by intra- and inter-rater agreement was very high in MRI (intra-class correlation coefficient (ICC) 0.78 and 0.90, respectively) and CBCT (ICC 0.96 and 0.96, respectively). In patients with subchondral insufficiency fractures of the knee, the use of CBCT revealed discrepancies in lesion grading compared with MRI. These findings are clinically relevant, as precise determination of subchondral bone plate integrity may influence the decision about conservative or surgical treatment. CBCT represents our imaging modality of choice for grading the lesion and assessing subchondral bone plate integrity. MRI remains the gold standard modality to detect especially early stages.

Poster 256: Is There a Difference Between Medial and Lateral Femoral Condyle Allografts? An Outcome and Survivorship Analysis

Objectives: Focal chondral and osteochondral defects in the knee are problematic and are often difficult to treat. One solution is the use of osteochondral allograft (OCA) transplantation. A majority of the literature deliberates lesions located to the medial femoral condyle (MFC), but little is discussed regarding the lateral femoral condyle (LFC). Given the limited data, the purpose of this study was to compare graft survivorship and patient-reported outcomes (PROs) among patients who underwent OCA transplantation of the MFC or LFC. Methods: A total of 208 patients who underwent primary OCA transplantation of the MFC and 111 patients who underwent primary OCA transplantation of the LFC between 1997 and 2021 were identified from a prospectively collected single-surgeon cartilage registry. Overall, 66% were male and the mean age was 30.5 years. Most patients presented for OCA for osteochondritis dissecans (57%). Mean allograft size was 6.7 cm2. All patients had a minimum 2-year follow-up. Reoperations following the OCA transplantation were captured. Failure of the allograft was defined as removal of the graft (OCA revision or conversion to arthroplasty). PROs were measured both pre and postoperatively using the Knee Injury and Osteoarthritis Outcomes Scores (KOOS), International Knee Documentation Committee (IKDC), and Merle d’Aubigné-Postel scales. Patient satisfaction was also assessed. Results: Patients with MFC grafts were older than patients with LFC grafts (33 years and 26 years respectively; p&lt;0.001) and had a slightly higher BMI (25.6 and 24.4 respectively; p=0.039). There were no differences between groups in regard to diagnosis, sex, number of allografts transplanted, or size of the allograft. Reoperations occurred in 27.9% of patients with MFC grafts and 26.1% of patients with LFC grafts (p=0.737). OCA failure occurred in 12% of MFC grafts and 9% of LFC grafts (p=0.413). The 10-year survivorship was 88% for MFC grafts and 92.9% for LFC grafts (p=0.543) (Figure 1). Among patients who had the allograft in situ at latest follow-up, the mean follow-up duration was 9.4 years for MFC grafts and 8.6 years for LFC grafts (p=0.313). At latest follow-up, KOOS, IKDC, and Merle d’Aubigné-Postel scores were similar between patients with MFC and LFC grafts. Patients with MFC grafts reported a slightly higher rate of satisfaction compared to patients with LFC grafts (93.7% and 86.3% respectively, p=0.041). Conclusions: Little data is available comparing treatment of medial and lateral femoral condyle lesions with osteochondral allografts. Clinical perception is that LFC lesions have inferior outcome to MFC lesions, but we did not find this to be true. We found little difference in reoperation rates and survivorship, as well as patient-reported clinical outcomes as measured on the KOOS, IKDC, and Merle d’Aubigné-Postel scales. There was a small difference in patient satisfaction. We conclude that there is similar outcome when using allografts for either medial or lateral femoral condyle lesions.

Paper 52: Association of Mechanical Axis with Osteochondritis Dissecans of the Femoral Condyle

Objectives: Osteochondritis dissecans (OCD) is a condition characterized by abnormal subchondral bone with disturbance of overlying articular cartilage. Pathophysiology for the etiology and underlying mechanism of OCD lesion development is not fully understood. The purpose of this study was to determine the association of lower extremity weightbearing axis with femoral condyle OCD lesion location, and if this association was affected by certain patient and OCD lesion characteristics such as lesion stability, skeletal maturity, and the presence of the OCD lesion on the medial versus lateral femoral condyle. Methods: This was a retrospective case series at a single, large academic institution. The primary outcome was the association of femoral condyle OCD lesion location with lower extremity weightbearing axis as categorized by Cahill and Berg zones of the knee. Secondary outcomes included sub-group analyses (treatment, skeletal maturity, and lesion stability) and contribution of femoral and tibial mechanical axis to lower extremity weightbearing axis deviations (mechanical lateral distal femoral angle [mLDFA] and medial proximal tibial angle [MPTA]). For unilateral OCD lesions, mechanical axis was compared between affected and unaffected lower extremities. Results: Eighty-six patients and 95 knees with an OCD lesion of the femoral condyle were identified, with 9 patients (11%) having bilateral OCD lesions. There were 74% male patients with average age of 21 years old. 65% of knees had closed distal femoral physes, 82% of OCD lesions were unstable on MRI imaging, and 85% underwent a surgical procedure. Seventy-five percent of OCD lesions were located in Cahill and Berg zone 2 at the lateral aspect of the medial femoral condyle. Lower extremity mechanical axis was located in the same zone as the OCD lesion in 48% of cases and within the same knee compartment in 56% of cases. Over 90% of OCD lesions were within ±1 zone of the weightbearing axis. There were no significant differences in the association of mechanical axis and OCD lesion location in subgroup analysis of medial versus lateral femoral condyle OCD lesions, skeletal maturity, stability of the lesion, or treatment group. For patients with varus alignment and medial femoral condyle OCD lesions, the mean mLDFA was 89.9° and MPTA was 85.4°, whereas for valgus alignment and lateral femoral condyle lesions, the mLDFA was 84.8° and MPTA was 88.8°. Both the mLDFA and MPTA were significantly different when comparing medial to lateral femoral condyle OCD lesions (p &lt;0.001 and &lt;0.001, respectively). Patients with unilateral medial femoral condyle OCD lesions were more likely to have varus alignment of the affected extremity compared to the contralateral extremity (59% vs. 36%, p = 0.01). Conclusions: This study demonstrated a relationship between lower extremity mechanical weightbearing axis and femoral condyle OCD location. Patients with unilateral medial femoral condyle OCD lesions are more likely to have varus alignment in the affected extremity. Varus alignment associated with medial femoral condyle lesions had similar varus contributions from both femoral and tibial alignment whereas valgus alignment in the setting of lateral femoral condyle lesions appear to have predominantly femoral contributions. There were no significant differences in association with mechanical axis among medial versus lateral femoral condyle lesions, OCD lesion stability, or distal femoral physeal status. More work is required to better understand the relationship between mechanical axis and femoral condyle OCD lesion pathophysiology with the long-term goal of identifying patients at risk for progression of lesion instability and developing potential interventions to preserve articular cartilage.

A Morphological Study of Distal Femoral Varus Deformity.

Background In the management of medial compartment knee osteoarthritis via around-knee osteotomy (AKO) and total knee arthroplasty (TKA), evaluating the lateral distal femoral angle (LDFA) is crucial. This angle reflects the presence of distal femoral varus deformity. This study aims to explore the relationship between LDFA and lower extremity bone morphology and identify factors contributing to a high LDFA. Methods A retrospective analysis was conducted on 59 patients who underwent AKO or TKA at our hospital. Alignment of the lower extremity was assessed using X-rays, and bone morphology was investigated through computed tomography (CT) employing the ZedKnee® system(LEXI, Tokyo, Japan). Each measured parameter was analyzed. Results Our findings indicate a significant correlation between LDFA and several parameters, including age, femoral tibial angle (FTA), hip knee ankle angle (HKA), percentage of mechanical axis (% MA), femoral bowing angle, femoral tibial joint torsion, and the height of lateral and medial femoral condyles. A multiple-regression analysis determined that the most significant influences on LDFA were the heights of the femoral condyle, age, and HKA. Conclusion LDFA is significantly affected by the heights of the medial and lateral femoral condyles and tends to increase with age, possibly as a result of attrition of the medial femoral condyle. Given its significance, LDFA should be carefully considered as a preoperative indicator in AKO and TKA to guide surgical caution when LDFA is elevated.

The association of the medial meniscus covering ratio with knee cartilage thickness at 15 medial compartment subregions as found by three-dimensional analysis using MRI.

The correlation of cartilage thickness measured by three-dimensional (3D) magnetic resonance imaging (MRI) and the medial meniscal coverage ratio (MMCR), which presented pathology of the medial meniscus extrusion (MME) in 3D MRI, has not yet been elucidated. The study's purpose was to retrospectively verify whether the average cartilage thickness calculated by the automatic MRI 3D analysis system for each subregion was correlated with MMCR. A total of 60 patients underwent medial meniscus repair or high tibial osteotomy to treat their medial knee osteoarthritis. Cartilage thickness and MMCR were automatically calculated using 3D MRI software. The MMCR was defined as the ratio of the area covered by the meniscus within the medial tibial cartilage area to the total medial tibial cartilage area. The association between MMCR and the average cartilage thickness at 15 subregions in the medial femoral condyle (MFC) and medial tibial plateau (MTP) was evaluated using Spearman's rank correlation coefficient. Kellgren-Lawrence grade exhibited a negative correlation with MMCR and a positive correlation with MME width. Cartilage thickness in the MTP had a moderately positive correlation with MMCR at four subregions and a weakly positive correlation at another subregion. Cartilage thickness in the MFC showed a moderately positive correlation with MMCR at five subregions and a weakly positive correlation at one subregion. Cartilage thickness calculated by automatic MRI 3D analysis system had a positive correlation with MMCR for all subregions of the anterior and middle subregions in the MFC and for five regions of nine subregions of the anterior and middle subregions in the MTP. Level II, cross-sectional study (diagnosis).

Joint line convergence angle is the most associated alignment factor with the severity of medial knee osteoarthritis.

The purpose of this study was to evaluate the relationship between the joint line convergence angle (JLCA) and the severity of medial knee osteoarthritis (OA). We hypothesise that JLCA is the most associated factor with the severity of medial knee OA. This retrospective study included a total of 202 knees that underwent either high tibial osteotomy or medial meniscus repair/partial resection. Kellgren-Lawrence grade and hip-knee-ankle angle (HKAA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA) and JLCA were assessed from preoperative radiographs. Medial meniscus extrusion (MME) was measured using preoperative magnetic resonance imaging. The International Cartilage Research Society (ICRS) grade on the medial femoral condyle and medial tibial plateau were also assessed. The relationships between JLCA and Kellgren-Lawrence grades and MME and ICRS grades were analysed using Spearman's correlation test and regression analysis. The JLCA was correlated with the Kellgren-Lawrence grade (R = 0.765, p < 0.001), MME (R = 0.638, p < 0.001), ICRS grade on the MFC (R = 0.586, p < 0.001) and the MTP (R = 0.586, p < 0.001). Regression analysis showed that age (p = 0.002) and JLCA (p < 0.001) were associated with Kellgren-Lawrence grade. Furthermore, JLCA was related to ICRS grade on the MFC (p < 0.001) and MTP (p < 0.001). The JLCA, reflecting radiological severity, meniscus status, and cartilage lesion, was the most associated alignment parameter in the severity of medial knee OA. The JLCA may be beneficial for quantitative assessment of medial knee OA. Level III, retrospective cohort study.

Poster 369: Medial and Lateral Posterior Tibial Slope in the Skeletally Immature: A Cadaveric Study

Objectives: Increased knee posterior tibial slope (PTS) angle is risk factor for primary and secondary ACL injury. Adult biomechanical research indicates that decreasing the PTS may reduce ACL injuries, and osteotomy techniques have been developed to alter tibia slope to reduce risk of re-injury. Pediatric and adolescent athletes have the highest rates of primary and secondary ACL injury, and many in this age group may have abnormal PTS angle. The purpose of this study was to evaluate PTS in medial and lateral tibial plateaus in large database of CT scans, and to develop normative PTS data in this age group. Methods: IRB approval was waived, as the specimens were donated for research, no genetic information was collected, and there were no plans for family contact. 83 pediatric knee CT scans, ranging from ages 1 to 12, were analyzed using OsiriX imaging software. The PTS was evaluated at two distinct points on sagittal CT sections: (1) At the medial tibia plateau and 2) lateral tibial plateau, both aligned with the central part of on a coronal view of the medial femoral and lateral femoral condyles respectively condyle. Results: The average medial PTS angle was 6.56° ± 3.84° and 6.81° ± 3.62° for the lateral PTS. There was not a significant statistical difference between the medial and lateral PTS (P = 0.6632, determined using an independent-samples t-test and analysis of variance). When plotting the age versus PTS, we observed a positive correlation with the medial PTS (R2 = 0.0385) and a negative correlation with the lateral PTS (R2 = 0.0393). Conclusions: The data demonstrate variability in medial and lateral pediatric PTS and provides normative values for pediatric PTS values. For pediatric patients undergoing ACL surgeries, consideration of increased PTS values that are associated with higher rates of recurrent ACL injury may influence surgical treatment techniques. Correction of increased PTS to lower ACL injury risk is performed in adults with major corrective osteotomy surgery, but such procedures have not been performed in children due to osteotomy-induced damage to growth plates. Due to open growth plates, pediatric patients may be treated with minimally invasive guide growth procedures to lower PTS, with minimal complication risk. Guided growth procedures have a long history of successful alignment correction in the coronal plane. Future animal and clinic studies may also demonstrate the safety and effectiveness of guided growth sagittal plane correction as applied to increased PTS. PTS developmental anatomy and its relationship to ACL injury is crucial for surgical advancements, including the use of low risk guided growth interventions to reduce PTS and ACL injury in pediatric patients with high risk of recurrent injury.

A Preliminary Study of Quantitative MRI Cartilage Loss Fraction and Its Association With Future Arthroplasty Using the Osteoarthritis Initiative Database.

Background and objective Osteoarthritis (OA) is the most common arthritis in the world. Despite the high disease burden, there is no therapy to prevent, halt, or reverse OA, and many clinical trials relied on radiographic biomarkers for therapy response. It is important to identify patients with early OA who will eventually need arthroplasty, the end-stage treatment for osteoarthritis. This pilot study evaluates a novel MRI biomarker, cartilage loss fraction, for association with future arthroplasty and evaluates its feasibility of use and effect size estimates. Materials and methods Publicly available knee MRIs from the Osteoarthritis Initiative were used. A total of 38 participants with Kellgren-Lawrence (K-L) grade >1 and 38 participants with K-L grade ≤ 1 at enrollment were matched in age, sex, race, and BMI, and assessed for the degree of full-thickness cartilage loss, or cartilage loss fraction. Univariate conditional logistic regression analysis was performed for differences in cartilage loss fractions between groups. Receiver operating characteristic (ROC) curve analysis was performed to assess the association of MRI biomarkers and knee arthroplasty during the eight-year follow-up. Results The medial femoral condyle, medial tibial plateau, total, and two-year progression cartilage loss fractions were significantly higher in participants with K-L grade >1 (p < 0.01 for all) and showed high area under the curve (AUC) values on ROC analysis (812, 0.827, 0.917, and 0.933, respectively).These results were comparable or more strongly associated with other OA grading schemes. Conclusion MRI biomarker cartilage loss fractions are significantly higher in subjects with K-L grade >1 and show a strong association with arthroplasty.After further validation, cartilage loss fracture may be used to predict future arthroplasty.

Three-dimensional bone morphology is a risk factor for medial postmeniscectomy syndrome: A retrospective cohort study.

The study aims to identify differences in tibiofemoral joint morphology between responders (R group, no pain) to arthroscopic partial medial meniscectomy (APMM) versus medial postmeniscectomy syndrome patients (MPMS group, recurrent pain at 2 years postmeniscectomy) in a clinically neutrally aligned patient population. The second aim was to build a morphology-based predictive algorithm for response to treatment (RTT) in APMM. Two patient groups were identified from a large multicentre database of meniscectomy patients at 2 years of follow-up: the R group included 120 patients with a KOOS pain score > 75, and the MPMS group included 120 patients with a KOOS pain score ≤ 75. Statistical shape models (SSMs) of distal femur, proximal tibia and tibiofemoral joint were used to compare knee morphology. Finally, a predictive model was developed to predict RTT, with the SSM-derived morphologic variables as predictors. No differences were found between the R and MPMS groups for patient age, sex, height, weight or cartilage status. Knees in the MPMS group were significantly smaller, had a wider femoral notch and a smaller medial femoral condyle. A morphology-based predictive model was able to predict MPMS at 2 years follow-up with a sensitivity of 74.9% (95% confidence interval [CI]: 74.4%-75.4%) and a specificity of 81.0% (95% CI: 80.6%-81.5%). A smaller tibiofemoral joint, a wider intercondylar notch and smaller medial femoral condyle were observed shape variations related to medial postmeniscectomy syndrome. These promising results are a first step towards a knee morphology-based clinical decision support tool for meniscus treatment. Case-control study. Level IIIb.

Thumb Metacarpal Reconstruction with a Medial Femoral Condyle Flap.

Thumb Metacarpal Reconstruction with a Medial Femoral Condyle Flap.