Femorotibial Joint Research Articles

Fluctuation of Bone Marrow Lesions and Inflammatory MRI Markers over 2 Years and Concurrent Associations with Quantitative Cartilage Loss.

To assess whether change of semiquantitatively magnetic resonance imaging (MRI)-defined bone marrow lesions (BMLs) and inflammatory markers is associated with change in quantitatively-assessed cartilage loss in the femorotibial joint (FTJ) in knees with radiographic osteoarthritis (OA) over 24 months. Participants were included from the IMI-APPROACH and the Osteoarthritis Initiative FNIH studies. Semiquantitative MRI assessment was performed for BMLs, Hoffa- and effusion-synovitis. Quantitative cartilage thickness measurements were performed manually. Definitions of change included number of subregions with BMLs, change in sum and change in maximum increase in size. Change in Hoffa-synovitis and effusion-synovitis was categorized in addition. Between-group comparisons regarding cartilage loss in the FTJ, medial and lateral compartments were performed using analysis of variance (ANOVA). A total of 629 participants were included. Knees without any BMLs at baseline (BL) and follow-up (FU) had significantly less cartilage loss compared to the other subgroups. Change in both directions in the sum score of BMLs was associated with increased rates of cartilage loss. Maximum increase in size of BMLs was associated with increased rates of cartilage loss (FTJ increase by 2 grades -0.183 mm, 95% CI [-0.335, -0.031], by 3 grades -0.306 mm, [-0.511, -0.101]). Worsening of Hoffa-synovitis was associated with increased rates of cartilage loss. Knees without BMLs at BL and FU showed lowest rates of cartilage loss. Knees with an increase in BML size showed increased rates of concurrent cartilage loss. Approaches with the aim to inhibit BML development, avoidance of increase in size and avoidance of Hoffa-synovitis worsening may have beneficial effects on cartilage loss.

Stress Distribution Patterns of the Femorotibial Joint After Medial Closing-Wedge Distal Femoral Varus Osteotomy: An Evaluation Using Computed Tomography Osteoabsorptiometry.

Distal femoral varus osteotomy (DFVO) is an established surgical procedure for addressing valgus malalignment across various knee conditions. However, the effect of DFVO on stress distribution within the femorotibial joint has not been explored through in vivo studies. To (1) explore the distribution pattern of subchondral bone density across the proximal tibia in nonarthritic knees without arthritis and in those of patients with valgus knees, (2) assess changes in the pattern of bone density distribution in patients with valgus knees before and after medial closing-wedge (MCW) DFVO, and (3) determine the correlation between leg alignment and changes in bone density distribution. Cohort study; Level of evidence, 3. The authors retrospectively analyzed clinical and radiographic data from 14 patients (14 knees; mean age, 44 years; 3 men, 11 women) treated with MCW-DFVO for lateral compartment osteoarthritis (OA) due to valgus malalignment, alongside a control group of 18 patients (18 knees; mean age, 21 years; 4 men, 14 women) without OA. The distribution patterns of subchondral bone density distribution on the femorotibial articular surface of the tibia were examined both preoperatively and >1 year postoperatively using computed tomography osteoabsorptiometry. Quantitative analyses were conducted on the locations and percentages of the high-density areas (HDAs) on the articular surface. The mean time between surgery and the postoperative radiograph and computed tomography absorptiometry imaging was 13.6 months (range, 11-19 months). The mean length of clinical follow-up was 28.7 months (range, 14-62 months) after surgery. The mean proportion of HDA in the lateral compartment relative to the total HDA (lateral ratio) was significantly greater in the preoperative OA group (58.8%) compared with the control group (41.1%) (P < .001). After MCW-DFVO, the mean lateral ratio in the OA group notably declined to 45.3% (P < .001). The lateral ratio exhibited a significant correlation with the hip-knee-ankle angle in both the control (r = 0.630; P = .011) and OA (r = 0.537; P = .047) groups. Moreover, the alteration in the lateral ratio after MCW-DFVO showed a significant relationship with changes in the hip-knee-ankle angle (r = 0.742; P = .002) and the mechanical lateral distal femoral angle (r = -0.752; P = .002). Within the lateral compartment, HDAs in the 3 lateral regions of the 4 lateral subregions diminished after MCW-DFVO, whereas in the medial compartment, HDAs in the 3 lateral subregions saw an increase. The mean lateral ratio was significantly greater in the preoperative OA group compared with the control group. MCW-DFVO resulted in a redistribution of HDA from the lateral to the medial compartment of the proximal tibial articular surface. The extent of alignment correction after MCW-DFVO was closely linked to the shifts in HDA distribution, reflecting changes in stress distribution.

Are there laterality differences in passive flexion and extension of the proximal limb joints in working Siberian Husky dogs?

Differences between left and right-side joint range of motion may affect canine locomotive ability and movement. Passive range of motion (PROM) joint measurement provides the limits that a particular joint can move in its physiological planes of motion without influence of muscle activity. To compare left and right-side flexion and extension of the glenohumeral, humeroulnar/humeroradial, coxofemoral and femorotibial joints and for laterality PROM differences. Siberian Husky dogs were selected (n = 18) of mixed gender, aged (1.4–11.8) years living and working together from a single kennel. Joint PROM was measured using goniometry, a validated, non-invasive method, by the same investigator previously tested for acceptable measurement repeatability. Dogs were conscious and placed in standing position. Triplicate measures of joint flexion and extension were taken on both sides of each dog for afore-mentioned joints. Median values of triplicate measures were computed. Paired t-tests compared laterality of joint PROM, gender, age (&lt; 6 vs. &gt; 6 years) effects. Inferential symmetry indices [SI] were calculated. There was no significant difference (p &gt; 0.05) between left and right-side flexion and extension measures for all joints. Gender had no significant effect (p &gt; 0.05) on joint flexion or extension measures for all joints. Age (&lt; 6 vs. &gt; 6 years) had a significant effect on right hip flexion (p &lt; 0.001) and for both left and right-side shoulder flexion (p &lt; 0.001); elbow flexion (p = 0.001 and p &lt; 0.001); hip extension (p = 0.02 and p &lt; 0.001) respectively. The shoulder joint showed greatest PROM asymmetry (SI = 3.63%). Bilateral PROM measures are important to consider in joint movement and assessment. These results warrant further investigation with larger cohorts of defined age groups.

Comparison of MRI Osteoarthritis Knee Score with Clinico-Radiological Grading

Abstract Background Knee joint osteoarthritis (OA) is among the most prevalent degenerative diseases of the joints in the body. Various scoring system exists for grading OA, such as (1) magnetic resonance imaging (MRI) Osteoarthritis Knee Score (MOAKS), (2) clinical grading by Western Ontario and McMaster Universities Arthritis Index (WOMAC), and (3) X-ray grading of the Kellgren–Lawrence grading system (K-L). Objectives To study MRI findings and MOAKS scoring of knee OA and correlation with WOMAC and K-L scoring. Setting and Design Cross-sectional study in hospital population. Methods and Material A total 40 knee OA cases underwent an MRI of the knee. MOAKS scoring was done and compared with K-L grading and WOMAC scores. Statistical Analysis Collected data were compiled systematically and interpreted using IBM SPSS statistics software 25.0. A p-value of less than 0.05 was considered significant. Results The mean total WOMAC score was 9. K-L grade 2 was the most prevalent X-ray grade. Bone marrow lesion (BML) and cartilage loss in MOAKS score were greater in the medial femorotibial region. A moderate positive correlation was noted between the WOMAC score and K-L grade; full-thickness articular cartilage loss score at the medial femorotibial joint (MFTJ) and WOMAC score; partial-thickness articular cartilage loss score at lateral femorotibial joint (LFTJ) and WOMAC total pain score. No correlation was found between BML and pain severity score. Conclusion Higher WOMAC scores were associated with higher grades of K-L scoring and score of cartilage loss (partial and full thickness) of the MOAKS scoring system. The rest of the features of the MOAKS score (BML score, osteophyte, and synovitis) had no significant association with pain severity and K-L grading.

Tribological properties of the beetle leg joints

Tribological properties of femoro-tibial leg joints in two beetles, darkling beetle Zophobas morio and Congo rose chafer Pachnoda marginata were studied. Very low friction of 0.004 was revealed by the direct measurements in the joint. It is assumed that semi-solid lubricant functioning as in technical bearings is one of the leading factors of the friction minimization. Dependence of the surface texture and physical chemical properties (hydrophobicity) on the cuticle friction was analysed. Contribution of the surface texture to the tribological properties of contacting surfaces was examined by the measurement in the tribosystem “contacting surface/glass”. It is supposed that coefficient of friction (COF) decreases with decrease of surface roughness. At the same time, no statistically significant correlation was found between the hydrophobicity of the surface and the value of the friction coefficient.

Biocompatible Solutions: Evaluating the Safety of Repeated Intra-Articular Injections of pMPCylated Liposomes for Knee Osteoarthritis Therapy in Rat Models.

Knee osteoarthritis (OA) poses a significant health care burden globally, necessitating innovative therapeutic approaches. CCoat, a novel poly(2-[methacryloyloxy]ethyl phosphorylcholine) (pMPC)ylated liposome device, protects the cartilage surface of the joint from mechanical wear through an entropy-favored process. Two preclinical studies were performed to explore the safety of CCoat following repeated intra-articular (IA) injections into the knee joint (i.e., femorotibial joint) in Sprague-Dawley rats. The studies involved 2 or 3 IA injections, at an interval of 2 or 3 weeks, and an observation period of 1 or 13 weeks after the last injection. Assessments included clinical, histopathological, and immunofluorescent evaluations. In study 1, no mortality or abnormal clinical signs occurred. At 1 week post last injection, histopathology revealed minimal vacuolated macrophages beneath the synovial membrane, predominantly M2-like, indicating a nonadverse response. Immunofluorescent staining supported M2-like macrophage predominance. Study 2 confirmed these findings with no systemic effects over 13 weeks. Statistical analyses indicated no significant differences in body weight, clinical pathology, or organ weights compared with controls. Results affirming the safety of pMPCylated liposomes following repeated IA injections in rat. This novel lubricant coating approach shows promise in OA therapy, with this safety assessment supporting its potential clinical application.

Is detection of disease-modifying osteoarthritis drug treatment more effective when performing cartilage morphometry without blinding to MR image acquisition order?

ObjectiveWe here explore whether observed treatment effects of a putative disease modifying osteoarthritis drug (DMOAD) are greater when cartilage morphometry is performed with rather than without knowledge of MRI acquisition order (unblinded/blinded to time point). MethodsIn the FORWARD randomized controlled trial, 549 knee osteoarthritis patients were randomized 1:1:1:1:1 to three once-weekly intra-articular injections of placebo, 30µg sprifermin every 6 or 12 months(M), or 100µg every 6/12M. After year 2, cartilage segmentation of baseline through 24M MRIs was performed, with blinding to acquisition order. After year 5, 24 and 60M MRIs were analyzed together, with unknown relative order, but with segmented BL images as reference (24M unblinded vs. BL), by the same operators. Total femorotibial joint cartilage thickness (TFTJ_ThC) change was obtained for 352 participants analyzed under both conditions. Results24M data read unblinded to order revealed a -35±44 µm lower TFTJ_ThC than blinded analysis (all groups: lower/upper bounds -120/+51µm; correlation r2=97%). With unblinded analysis, the placebo group lost -46±57µm TFTJ_ThC over 24M, whereas 100µg/every 6M lost -2.2±73µm (difference=44µm [95%CI: 22,66]). With blinded analysis, placebo lost -11±53µm, whereas 100µg/every 6M gained 30±62µm (difference=40µm [95%CI: 21,60]). 100µg sprifermin injected every 6M showed statistically significant (p<0.001) treatment effects in TFTJ_ThC, with Cohen D=-0.66 for unblinded and D=-0.69 for blinded analysis. ConclusionsThese results do not reveal that detection of proposed DMOAD treatment is enhanced with MRIs read unblinded to order; rather, the sensitivity is similar to blinded analysis. Choices on blinded vs. unblinded analysis may thus be based on other criteria.

A Clinical Study of Knee Joint Ligament Injury with Ayurvedic Treatment

Knee is one of the largest and most complex joint of body. The complexity is because where there will be fusion of Lateral femorotibial, Medial femorotibial and Femoropatellar joints. Here a case report of 24 years female while playing had a sudden trauma to right knee with severe pain and swelling. Patient was unable to flex the knee joint. On MRI she was diagnosed with thinning and altered signal intensity of anterior cruciate ligament with partial tear and thickening of the medial meniscus with horizontal tear in posterior horn. By this patient was unable to do day to day activities. Here 2 months of Ayurvedic treatment was followed by patient who provided relief from pain and brought a significant improvement in the movement of knee joint.

Surgical Repair of Psittacine Femorotibial Luxation: A Case Series.

Luxation of the psittacine femorotibial joint most commonly occurs following trauma or as a development abnormality. Historically, this injury is considered to have a poor prognosis in birds; however, surgical management may result in acceptable and functional outcomes. This case series describes the surgical techniques, complications, and outcomes of 7 cases of femorotibial luxation in psittacine birds. Of the 7 cases, 6 were chronic injuries. Surgical repair methods included conjoined intramedullary pinning, transarticular pinning with an external skeletal fixator (ESF), a combination of extracapsular stabilization and ESF, ESF alone, and a combination of conjoined intramedullary pins with an ESF. An acceptable outcome was achieved in 75% (6/8) of luxated femorotibial joints managed with surgical methods. All cases were female birds of various species, suggesting a possible sex predisposition for stifle luxation.

Associated patellofemoral osteoarthritis is not a contraindication for unicompartmental knee replacement. Report of one hundred ten prostheses with an average 6-year follow-up

IntroductionAssociated patellofemoral joint osteoarthritis (APFJ-OA) has typically been considered a contraindication for unicompartmental knee arthroplasty (UKA) in the treatment of femorotibial joint osteoarthritis. However, this contraindication is being challenged. The aim of this study was to assess clinical and functional outcomes, complications, and implant survival in medial or lateral UKA, regardless of clinical symptoms or radiographic signs of APFJ-OA. MethodsThis retrospective, comparative study included patients treated with medial or lateral UKA regardless of preoperative symptoms or signs of APFJ-OA, with a minimum 2-year follow-up. Intraoperatively, knees were subdivided based on APFJ-OA grade, according to the Outerbridge classification. Clinical and functional outcomes were analyzed using the 2011 Knee Society Score (KSS) at the last follow-up control. APFJ-OA was treated systematically, in a tailored, stepwise fashion according to its severity. Complications and implant survival rates were evaluated. Two-sided paired T-test, ANOVA, and Kruskal–Wallis tests were used with a significance level of 5%. ResultsFinally, 110 UKAs were assessed 81 (73.6%) medial and 29 (26.4%) laterals. The average follow-up was 6 years (2–19.5). According to Outerbridge, 22 knees (20%) were in grade 2, 59 (53.6%) were in grade 3, and 29 (26.4%) were in grade 4. All three groups showed a statistically significant increase in KSS scores and range of motion. There were no significant differences in clinical KSS improvement and flexion contracture between Outerbridge groups (average 35.7 and −4.9, respectively). Group 3 showed statistically significant improvement in functional KSS when compared to group 2 (68.8 vs 61.2). In maximum flexion, groups 3 and 4 did significantly better than group 2 (20° vs 15°). Three prostheses (2.7%) needed revision after 7, 8.6, and 12 years due to aseptic tibial loosening. Implant survival was 100% at 5 (64 of 64), 97% at 7 (30 of 31), 93% at 9 (14 of 15), and 89% at 12 years, respectively (8 of 9). ConclusionClinical and functional results, complications, and survival of medial or lateral UKA were not negatively affected by APFJ-OA assessed intraoperatively using the Outerbridge classification after an average follow-up of 6 years. We consider that APFJ-OA is not a contraindication for UKA when treated systematically according to its severity. Level of evidenceIV.

No correlation found between palpation and ultrasound for evaluation of effusion in the medial femorotibial and femoropatellar joint compartments of horses.

To compare palpation and ultrasound scores of effusion of the medial femorotibial and femoropatellar joints of horses. 40 horses (80 stifles) were evaluated over a 12-week period. Horses > 1 year of age without history of stifle disease were enrolled from September to December 2022. Palpation of right and left medial femorotibial and femoropatellar joint compartments was performed. Amount of effusion was scored by a board-certified large animal surgeon, a third-year large animal surgery resident, and an equine sports medicine intern. Effusion of right and left medial femorotibial and femoropatellar joints was quantified with ultrasound by a board-certified equine sports medicine and rehabilitation clinician. Amount of effusion on palpation and ultrasound was graded as none-mild (1), moderate (2), or severe (3). A 2-way intraclass correlation coefficient evaluated interrater reliability of palpation scores. The Spearman rank correlation determined association between palpation and ultrasound scores. Interrater reliability for palpation of effusion was poor between all observers for all joint compartments. No significant correlation was identified between palpation and ultrasound scores for any joint compartment for any observer. Clinicians often rely on palpation of joint effusion as an indication of stifle pathology. We found interrater reliability to be poor for palpation scores, indicating low agreement for palpation of joint effusion between clinicians within our group. No correlation was found between palpation and ultrasound scores for joint effusion, indicating that clinicians should not rely on palpation alone to quantify joint effusion of the medial femorotibial and femoropatellar joints.

Surgical Repair of Psittacine Femorotibial Luxation: A Case Series.

Luxation of the psittacine femorotibial joint most commonly occurs following trauma or as a development abnormality. Historically, this injury is considered to have a poor prognosis in birds; however, surgical management may result in acceptable and functional outcomes. This case series describes the surgical techniques, complications, and outcomes of 7 cases of femorotibial luxation in psittacine birds. Of the 7 cases, 6 were chronic injuries. Surgical repair methods included conjoined intramedullary pinning, transarticular pinning with an external skeletal fixator (ESF), a combination of extracapsular stabilization and ESF, ESF alone, and a combination of conjoined intramedullary pins with an ESF. An acceptable outcome was achieved in 75% (6/8) of luxated femorotibial joints managed with surgical methods. All cases were female birds of various species, suggesting a possible sex predisposition for stifle luxation.

New morphological and biological contributions to adults and immature forms of Pissonotusparaguayensis (Fulgoromorpha, Delphacidae) in wetlands of Argentina.

In the search for insects as biological control agents for the water primrose, the delphacid Pissonotusparaguayensis (Delphacidae) was found on Ludwigiagrandiflorasubsp.hexapetala (Onagraceae) in a wetland of Central East Argentina. The morphology of the unknown females (brachypterous and macropterous) and immature stages are described and illustrated. Adults and nymphs were collected in wetlands of Del Plata River Basin, from Buenos Aires to the northeastern part of Argentina. A rearing methodology was developed to perform biological studies. Both winged forms and structural features of the female genitalia are described for the first time at the genus level. Eggs and immature stages are described and keyed; fifth nymphal instars may be easily recognised by the yellowish colouration, blackish on dorsal of head, thorax and abdomen with conspicuous yellowish pits, ventrally only darkened on base of frons extended to lower level of eyes and dorsal surface of antennomeres I and II, and legs with distinctive black marks at femoro-tibial joint and apex. The geographical distribution is updated, expanding its range into Argentina, making Buenos Aires the southernmost limit of the genus in America. Biological information of the species is also reported here: life cycle, fecundity, oviposition behaviour, and host plant. Field observations showed that P.paraguayensis breeds, feeds, and causes damage to L.g.subsp.hexapetala. This delphacid presents a certain degree of specificity to the Ludwigia species in the Jussiaea section in host specificity tests. More studies are required to test this species as a potential biological control agent.

Mechanosensory encoding of forces in walking uphill and downhill: force feedback can stabilize leg movements in stick insects.

Force feedback could be valuable in adapting walking to diverse terrains, but the effects of changes in substrate inclination on discharges of sensory receptors that encode forces have rarely been examined. In insects, force feedback is provided by campaniform sensilla, mechanoreceptors that monitor forces as cuticular strains. We neurographically recorded responses of stick insect tibial campaniform sensilla to "naturalistic" forces (joint torques) that occur at the hind leg femur-tibia (FT) joint in uphill, downhill, and level walking. The FT joint torques, obtained in a previous study that used inverse dynamics to analyze data from freely moving stick insects, are quite variable during level walking (including changes in sign) but are larger in magnitude and more consistent when traversing sloped surfaces. Similar to vertebrates, insects used predominantly extension torque in propulsion on uphill slopes and flexion torques to brake forward motion when going downhill. Sensory discharges to joint torques reflected the torque direction but, unexpectedly, often occurred as multiple bursts that encoded the rate of change of positive forces (dF/dt) even when force levels were high. All discharges also showed hysteresis (history dependence), as firing substantially decreased or ceased during transient force decrements. These findings have been tested in simulation in a mathematical model of the sensilla (Szczecinski NS, Dallmann CJ, Quinn RD, Zill SN. Bioinspir Biomim 16: 065001, 2021) that accurately reproduced the biological data. Our results suggest the hypothesis that sensory feedback from the femoro-tibial joint indicating force dynamics (dF/dt) can be used to counter the instability in traversing sloped surfaces in animals and, potentially, in walking machines.NEW & NOTEWORTHY Discharges of sensory receptors (campaniform sensilla) in the hind legs of stick insects can differentially signal forces that occur in walking uphill versus walking downhill. Unexpectedly, sensory firing most closely reflects the rate of change of force (dF/dt) even when the force levels are high. These signals have been replicated in a mathematical model of the receptors and could be used to stabilize leg movements both in the animal and in a walking robot.

Meniscal disruption associated with septic arthritis in three neonatal foals

SummaryThe objective of this study was to report clinical characteristics, surgical management and medium‐term (6–12 months) outcomes of three Arabian neonatal foals with meniscal disruption associated with septic arthritis of the lateral femorotibial joint. The three neonatal Arabian foals with septic arthritis of the lateral femorotibial joint (LFTJ), were diagnosed with disruption of the lateral meniscal (LM). Suspicion of meniscal pathology was based on ultrasonography, computed tomography (in 2 foals) and confirmed during arthroscopy. Treatment included arthroscopic debridement and lavage of the joint with debridement of the meniscal disruption. Postoperative care included systemic and intra‐articular antimicrobials, based on culture and sensitivity results. Two of the foals received intra‐articular injections of autologous mesenchymal stem cells. Marked LM disruption was observed in the LFTJ of the affected joints of all foals, involving the meniscal body (n = 3) and caudal horn (n = 1). Purulent material within the torn tissue was debrided with a synovial resector. Foal 1 was lame‐free as a yearling. Foal 2 was lame at walk at 7.5 months and euthanised due to poor prognosis. Foal 3 showed mild lameness at trot in a straight line at 6 months. Disruption of the LM continued to be visible on US in both foals at these timepoints. It was concluded that meniscal disruption and infection should be considered as a differential in neonatal foals with persistent femorotibial septic arthritis. In such cases, the LM could be the primary nidus of infection.

Which method for femoral component sizing when performing kinematic alignment TKA? An in silico study

IntroductionThe kinematically alignment (KA) technique for TKA aims to reproduce the pre-arthritic knee anatomy, including both the femoro-tibial and femoro-patellar joints. An in silico study was conducted to compare 3 different femoral component sizing techniques to identify the anatomical landmark which allows closest restoration of the native trochlear anatomy. Our study's question was: what was the best method for sizing the femoral component when performing KA-TKA? It was hypothesized that sizing the femoral component by aiming to restore the groove height would be the best method to restore the native trochlear anatomy. MethodsGMK sphere® (Medacta) femoral component 3D models were virtually kinematically aligned on 30 tri-dimensional (3D) bony osteoarthritis knee models. The femoral component was mediolaterally positioned to match distal native and prosthetic grooves. Three methods were used to size the femoral component: a conventional method with the anterior femoral cut flush to the femoral cortex (C-KATKA) and two alternative personalized methods aiming to recreate either the medial facet's height (ATM-KATKA) or the groove's height (ATG-KATKA). In-house analysis software was used to compare native and prosthetic trochlear articular surfaces and mediolateral implant overhangs. ResultsCompared with the C-KATKA, ATG-KATKA and ATM-KATKA techniques increased the component size by a mean of 0.90 (SD 0.31, min 0.5 to max 1.5) (p<0.001) and 1.02 (SD 0.31, min 0.5 to max 1.5) (p<0.001), respectively. C-KATKA technique substantially proximally understuffed the trochleae with maximum values of 7.11mm (SD 1.39, min 3.93mm to max 10.57mm) in the medial facet, 4.72mm (SD 1.27, min 1.46mm to max 6.86mm) in the lateral facet and 4.51mm (SD 1.40, min 1.92mm to max 7.30mm) in the groove, respectively. Alternative techniques understuffed medial facet with maximum values of 5.07mm (SD 1.29, min 2.83mm to max 8.34mm) and 4.70mm (SD 1.52, min 0.83mm to max 8.04mm) for ATG-KATKA and ATM-KATKA techniques, respectively. There was no significant understuffing of the groove or lateral facet for alternative techniques (ATM and ATG). The ATM-KATKA and ATG-KATKA techniques generated mediolateral implant overhang, mainly postero-lateral, with a rate of 90.0% and 86.7%, respectively. In this study, no mediolateral implant overhang was found for C-KATKA. Discussion/conclusionThe C-KATKA technique substantially understuffs the native trochlear articular surfaces in medial, lateral and groove parts. Alternative techniques (ATM-KATKA and ATG-KATKA) for sizing the femoral component better restore the native trochlear anatomy but also generate a high rate of postero-lateral implant overhangs. Would this postero-lateral implant overhang be clinically deleterious remains unknown? The aspect ratio of contemporary femoral TKA implants can probably be optimized to allow a better anatomical restoration of the anterior femoral compartment. Level of evidenceII, in silico study.

Association between infrapatellar fat pad ultrasound elasticity and anterior knee pain in patients with knee osteoarthritis

This study investigates whether infrapatellar fat pad (IPFP) elasticity is associated with anterior knee pain in patients with knee osteoarthritis (KOA). The IPFP elasticity of 97 patients with KOA (Kellgren and Lawrence [KL] grades of the femorotibial and patellofemoral joints ≥ 2 and ≤ 2, respectively), aged 46–86 years, was evaluated via shear wave speed using ultrasound elastography. The patients were divided into two groups according to the presence or absence of anterior knee pain. Univariate analyses were used to compare patient age, sex, femorotibial KL grade, magnetic resonance imaging findings (Hoffa, effusion synovitis, bone marrow lesion scores, and IPFP size), and IPFP elasticity between the groups. Multivariate logistic regression analyses were subsequently performed using selected explanatory variables. IPFP elasticity was found to be associated with anterior knee pain in the univariate (p = 0.007) and multivariate (odds ratio: 61.12, 95% CI 1.95–1920.66; p = 0.019) analyses. Anterior knee pain is strongly associated with stiffer IPFPs regardless of the femorotibial KL grade, suggesting that ultrasound elastography is useful for the diagnosis of painful IPFP in patients with KOA.

Association of AI-determined Kellgren–Lawrence grade with medial meniscus extrusion and cartilage thickness by AI-based 3D MRI analysis in early knee osteoarthritis

The associations among Kellgren–Lawrence (KL) grade, medial meniscus extrusion (MME), and cartilage thickness in knee osteoarthritis (OA) remain insufficiently understood. Our aim was to determine these associations in early to moderate medial tibiofemoral knee OA. We included 469 subjects with no lateral OA from the Kanagawa Knee Study. KL grade was assessed using artificial intelligence (AI) software. The MME was measured by MRI, and the cartilage thickness was evaluated in 18 subregions of the medial femorotibial joint by another AI system. The median MME width was 1.4 mm in KL0, 1.5 mm in KL1, 2.4 mm in KL2, and 6.0 mm in KL3. Cartilage thinning in the medial femur occurred in the anterior central subregion in KL1, expanded inwardly in KL2, and further expanded in KL3. Cartilage thinning in the medial tibia occurred in the anterior and middle external subregions in KL1, expanded into the anterior and middle central subregions in KL2, and further expanded in KL3. The absolute correlation coefficient between MME width and cartilage thickness increased as the KL grade increased in some subregions. This study provides novel insights into the early stages of knee OA and potentially has implications for the development of early intervention strategies.

A novel solution for the patient with knee ankylosing spondylitis: a case report

Link of Video Abstract: https://youtu.be/wskQdvBx0c0 Background: Knee ankylosis is a joint condition that causes functional limitation that becomes more severe when accompanied by pain. Arthroplasty is a complex and intricate reconstruction procedure that is more challenging when there is a structural limitation that requires a technique modification. In this report, we presented a rare case of a young patient with knee ankylosis and flexion contracture treated with arthroplasty. Case Presentation: A 20-year-old young woman came to the hospital with stiffness in her left knee, inability to sit well and crouch, and difficulty getting up from sitting. Based on the physical examination and X-ray of the left knee, the patient showed bone ankylosis on the femorotibial joint with a 100 flexion, which confirmed knee ankylosis. Arthroplasty was performed with a parapatellar medial approach. After eight months of supervision, the patient was able to perform an active flexion within 1050 and a full extension on the left knee. In our patient, arthroplasty brought a satisfying functional outcome and pain reduction, which was also supported by previous studies with the same procedure on ankylosis patients. Conclusion: Arthroplasty can be considered the main therapy option for joint deformities due to its more satisfying outcomes.

Clinical and radiological efficacy of single-dose intra-articular high-molecular-weight hyaluronic acid in knee osteoarthritis.

While visco-supplementation is being used for the treatment of knee osteoarthritis (OA), the published reports vary widely in benefits afforded by this treatment. It was therefore proposed to assess the objective parameters along with subjective outcomes. Our study assessed the radiological and clinical efficacy of single-dose high-molecular-weight intra-articular hyaluronic acid (HMW-IAHA) injection in knee OA. This interventional cohort study was conducted in a calculated sample size of 44 patients with knee OA. Visual analog scale (VAS) and knee OA and outcome score (KOOS) were used for clinical assessment, and whole organ magnetic resonance imaging score (WORMS) for radiological assessment. The subjects were given a single dose of HMW-IAHA injection, 90 mg/3 ml, and were assessed on day 0 and day 90. Statistical Package for Social Sciences (SPSS) software was used. At the day 90 follow-up, there was an improvement in mean ± standard deviation values of VAS score (day 0: 8.53 ± 0.81, day 90: 5.97 ± 0.87), KOOS score (day 0: 27.33 ± 15.18, day 90: 57.26 ± 14.26), and the cartilage signal and morphology in the medial femorotibial joint (day 0: 11.02 ± 6.26 and day 90: 10.91 ± 6.22) and patellofemoral joint (day 0: 10.35 ± 4.36 and day 90: 10.28 ± 4.39) compartments. There was a decrease in synovitis score from 2.3 ± 1.61 to 1.3 ± 1.3 in the medial femorotibial joint compartment and total WORMS score (day 0: 66.57 ± 36.06, day 90: 65.14 ± 35.62). A single dose of intra-articular injection with high-molecular-weight hyaluronic acid produces improvement in the clinical symptoms and quality of life as well as is effective in maintaining the articular cartilage integrity and reducing synovial inflammation.