Tibial Surface Research Articles

Influence of tibial bearing curvatures of a customised total knee implant on squatting motion and loads

A range of preliminary designs of customised total knee implants (CTKIs) was created by resurfacing the distal femur and applying different tibial bearing surface curvatures. These were then compared with a scaled off-the-shelf symmetric total knee implant (STKI). To evaluate the biomechanical performance, a dynamic knee simulation model was created with patient-specific muscle and ankle joint loads calculated from an OpenSim musculoskeletal model. Simulation results showed the transverse curvatures of the tibial bearing surface influenced femoral mediolateral translation, while its longitudinal curvatures affected femoral adduction. Compared to the STKI, the CTKIs could restore patient knee function.

Infection Rate of Reamed versus Unreamed Intramedullary Nailing in Open Tibia Fractures

Background: Intramedullary nailing (IM nailing) is the standard of care for the treatment of most diaphyseal lower extremity fractures. A few studies have assessed and compared the infection rate following reamed and unreamed IM nailing in open long bone fractures. In the present study, we attempted to compare the infection rate between two procedures in open fractures of tibia. Methods: In this prospective study, we included consecutive patients suffering from open fractures of tibia (Gustilo subtypes II or IIIA) who required IM nailing. Patients younger than 16 years old, other Gustilo types (I, IIIB, and IIIC), fractures reaching to the tibial plateau articular surface, and simultaneous fractures of other bones in the extremity were excluded. All patients were followed up for one year to assess the postoperative infection rate. Results: Of 59 patients, 37 underwent reamed IM nailing and 22 underwent unreamed IM nailing. In reamed group, 4 cases (10.8%) experienced an infection requiring reoperation and antibiotic therapy, while in the unreamed group, it was 5 cases (22.7%). The difference between the groups was not statistically significant. Conclusion: Reamed and unreamed IM nailing procedures for fractures of tibia have similar outcome regarding long-term postoperative infections that require reoperation and antibiotic therapy.

Finite Element Analysis of the Effect of Talar Osteochondral Defects of Different Depths on Ankle Joint Stability.

BackgroundTalus cartilage injury leads to changes in biomechanics of the ankle joint and ultimately affects ankle joint function, but which talus cartilage defects require surgery is still uncertain. This research used a finite element method to simulate the effect of different depth of talus cartilage defects on the stress and stability of the ankle joint in a certain area.Material/MethodsA three-dimensional finite element model with different depths of osteochondral defects was created to simulate and calculate joint stress and displacement of the articular surface of the distal tibia and the proximal talus while the ankle joint was in the push-off, midstance, and heel-strike phases.ResultsThe equivalent stress of the proximal talus did not change significantly at a defect depth of 1 mm, whereas the equivalent stress of the upper talus increased significantly at a defect depth of ≥3 mm or more, reaching a maximum value at a defect depth of 10 mm. The equivalent stress of the tibial cartilage and the equivalent stress and displacement in the corresponding forces in the midstance phase and heel-strike phase were significantly different from those in the normal group, but the difference in stress in each defect group was not obvious.ConclusionsThe effect of cartilage defects of the talus on biomechanics of the ankle is clear, especially in the midstance and push-off phases. When the defect reaches the subchondral bone (at a depth of 3 mm), the most obvious change in ankle joint stability occurs, and it does not increase linearly with the increase in depth of the defect.

Imaging Approaches for Accurate Determination of the Quadriceps Angle.

ObjectivesA retrospective study was conducted using magnetic resonance image (MRI) and a full‐length standing scanogram (FLSS) to measure the quadriceps angle (Q‐angle) while avoiding soft tissue interference.MethodsTwo steps were retrospectively carried out in two case series. The first step involved using MRI to define the standardized patellar center (PC) and the tibial tubercle (TT) on the frontal plane of the MRI in one group of 60 consecutive patients (from July 2016 to December 2016, 29 men and 31 women, average of 46 years). The next step was transferring the location of the standardized PC and the TT from the MRI to the FLSS in another group of 100 consecutive patients (from April 2009 to March 2014, 50 men and 50 women, average of 36 years). The pelvis and intact femur, knee, and tibia were used to determine the Q‐angle on the FLSS.ResultsThe standardized PC was positioned 42% from the lateral end of femur trans‐epicondylar line. The TT was 2 cm distal to the tibial articular surface and 37% from the lateral end of tibial width. The average Q‐angle was 9.5° in 100 patients (8.8° in 50 men and 10.1° in 50 women, P = 0.02). The average femoral length was 42.9 cm in 100 patients (44.7 cm in 50 men and 41.1 cm in 50 women, P < 0.001). Women and men had similar pelvic width (27.9 vs 27.8 cm, P = 0.89).ConclusionUsing the FLSS may help to accurately determine the Q‐angle. Men and women have similar pelvic width. A larger Q‐angle in women may be mainly due to the shorter femur.

Clinical analysis of full-repair strategy under small incision for closed Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture

To investigate the safety, feasibility, and efficacy of full repair strategy under small incision in the treatment of closed Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture. The clinical data of 57 patients with closed Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture treated by full repair strategy (fracture, ligament, and cartilage repair) under small incision between January 2012 and January 2017 were retrospectively analyzed. There were 31 males and 26 females, with an average age of 41.1 years (range, 21-65 years). The causes of injury included traffic accident injury in 33 cases and falling injury in 24 cases. All of them were closed fractures, including 20 cases of medial malleolus fracture, 37 cases of complete medial malleolus but deep and shallow rupture of deltoid ligament. The average time from injury to admission was 9.6 hours (range, 3-34 hours). The quality of reduction of distal tibial articular surface (based on Ketz-Sanders standard), the reduction of tibiofibular syndesmosis (the anterior and posterior distances of distal tibiofibular syndesmosis and the lateral ankle twist angle measured by CT scan at 10 mm above the ankle joint line), and the fracture healing were evaluated. The medial clear space (MCS), tibiofibular clear space (TFCS), and distal fibular tip to lateral process of talus (DFTL) were measured on the X-ray films of ankle points. Before and after operation, the pain and functional improvement of ankle joint were evaluated by visual analogue scale (VAS) score and American Orthopedic Foot and Ankle Association (AOFAS) score, and the activities of ankle dorsiflexion and plantar flexion were measured. Three cases with osteochondral lesions of the talus were found during operation and all were treated with microfracture techniques. Tournament paralysis occurred in 2 cases after anesthesia. The surgical incisions healed by first intention in all patients. All the 57 patients were followed up 24-84 months, with an average of 38.6 months. All patients achieved bone healing without bone nonunion and malunion at 12 months after operation. The reduction quality of distal tibial articular surface was excellent in 56 cases and good in 1 case at 3 months after operation, the excellent and good rate was 100%. There was no significant difference in the MCS, TFCS, DFTL, anterior distance of distal tibiofibular syndesmosis, posterior distance of distal tibiofibular syndesmosis, and lateral ankle twist angle between the affected and healthy sides at 12 months after operation ( P>0.05). At last follow-up, the VAS score, AOFAS score, ankle dorsiflexion and plantar flexion activities of the affected side were significantly improved when compared with preoperative ones ( P<0.05). Compared with the healthy side, there was no significant difference in ankle dorsiflexion and plantar flexion activities ( P>0.05). Full-repair strategy under small incisions for the treatment of Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture is effective and safe. It can not only reduce wound complications, but also improve the quality of joint reduction of the ankle joint and distal tibiofibular syndesmosis. Full repair of ligaments and cartilage can improve the internal fixation strength and joint stability of the ankle joint.

Reliability of two different measuring techniques with computer tomography for penetration and distribution of cement in the proximal tibia after total knee arthroplasty

BackgroundTo evaluate the reliability of two different techniques for measuring penetration and distribution of the cement mantle in the proximal tibia after total knee arthroplasty (TKA) with Computer Tomography (CT) in vivo.MethodsStandardized CT scans of the proximal tibia were taken 1 to 2 years after total knee arthroplasties implanted with a surface cementing technique. These prospectively acquired transversal CT images of the surface of the proximal tibia were divided into four quadrants and were assessed once manually and once with a numerical computing program (MATLAB® Update 2, The MathWorks, Inc.) based on Hounsfield Units by one of the researchers. The assessments were repeated by the same and a second researcher. The ratio cement/trabecular bone was calculated 1, 3 and 5 mm distal of the tibia tray per quadrant. Kruskall-Wallis tests with multiple pairwise comparisons (Dunn’s test) were used to determine differences between the quadrants. Intra- and inter-rater reliability as well as the inter method reliability were assessed with the Intraclass Correlation Coefficient (ICC) per level of depth and with Bland-Altman plots.ResultsA total of 92 CT scans were included. The intra- and inter-rater reliability of the manual method ranged from 0.22 and 0.52. The intra- and inter-rater reliability of the matlab method varied between 0.98 to 0.99.The median percentage cement measured with the matlab method 1 mm underneath the tibial tray varied between 82 and 88%; at 3 mm depth between 38 and 54% and at 5 mm between 15 and 25%. There was significantly (p < 0.05) less cement in the antero-medial quadrant compared to the antero-lateral and postero-lateral quadrant at 3 mm and 5 mm depth.ConclusionsDistribution and penetration of cement in the proximal tibia in a total knee arthroplasty can be measured reliably with CT in combination with the matlab method presented in this manuscript. This method can be used for clinical purposes as well as for scientific research.Trial registrationMETC-nr: 06–104 Dossier NL14807.098.06/versie 06.

The tibial lateral axis is a novel extraarticular landmark for detection of the tibial anteroposterior axis.

Although the tibial rotation axis is significant in knee arthroplasty, no reliable extraarticular landmark has been proposed. We hypothesized that the tibial lateral axis (TLA), a tangential line of the lateral tibial surface, is perpendicular to the surgical epicondylar axis (SEA) and compared it to other existing landmarks by 3D-CT. Fifty legs in 25 consecutive patients were studied. Using their preoperative CT, the TLAs were identified on slices at 10-50% of the total length of the tibia and the measured differences of angles against the line perpendicular to the SEA (the tibial AP axis) were calculated. The differences between the SEA and the femoral and tibial posterior condylar axis, Akagi's line and the line between the medial intercondylar spine and the medial border of the patellar tendon (sAP line)(intraarticular), the ankle axis, and the transmalleolar axis (extraarticular) were also calculated and compared. The mean values of TLA at 10%, 20%, 30% were virtually parallel to the SEA (0.97° ± 4.84°, 0.02° ± 4.61°, 1.10° ± 4.97°, respectively). They were equivalent to existing intraarticular landmarks and superior to existing extraarticular landmarks, and these levels corresponded to the tip to the lower end of the tibial tubercle (at 10.8% and 17.0% of total tibial length). The proximal TLAs can be an extraarticular bony landmark that indicates the line perpendicular to the SEA. A prospective study is needed to prove the validity and accuracy of the axes clinically.

Viscosupplementation may preserve tibial cartilage and collagen in osteoarthritis: findings from a preclinical model of osteoarthritis

PurposeIntraarticular (IA) hyaluronic acid (HA) injection is used to reduce pain and improve mobility in knee osteoarthritis (OA). Little is known about histopathological changes underlying HA efficacy. This study investigated dose-related effects of 1% sodium hyaluronate (BioHA) on knee joint histopathology and pain responses in a medial meniscal tear (MMT) rat model of OA.MethodsFollowing MMT surgery, rats were randomized into treatment groups: single IA injection of vehicle, BioHA, or an avian-derived hyaluronic acid (hylan G-F 20) on Day 7; or 3 weekly injections of vehicle or BioHA on Days 7, 14, and 21. On Day 35, joints were evaluated by microscopic histopathology for cartilage degeneration, collagen degeneration, synovitis, and cytokine expression (tumor necrosis factor α, transforming growth factor β).ResultsJoint pathology for control animals was consistent with that expected for the MMT model. Rats treated with 3 injections of IA-BioHA had significantly reduced collagen degeneration (21%) relative to control animals. No significant change in collagen degeneration was observed for rats given a single injection of hylan G-F 20 or IA-BioHA compared to control animals. HA treatment did not affect cytokine expression.ConclusionsIA-BioHA viscosupplementation in a rat MMT model of OA showed preservation of joint cartilage and collagen. This effect was most pronounced on tibial surfaces having less severe injury, suggesting that treatment should be initiated early in the disease process. A comparison of responses to IA-BioHA or hylan G-F 20 in the MMT rat OA model suggest IA-BioHA may be more effective in preserving joint connective tissue.

Varying development of femoral and tibial subchondral bone tissue and their interaction with articular cartilage during progressing osteoarthritis.

Differences between tibial and femoral joint surfaces and knee compartments concerning coupled bone and cartilage turnover or bone-cartilage cross talk have not been previously examined, although the mechanical and biological interaction of the mineralized subchondral tissues with articular cartilage is of great importance for advancing osteoarthritis. Therefore, with the help of immunohistochemistry and real-time polymerase chain reaction (RT-PCR), human knee joint cartilage tissue was investigated for expression of key molecules of the extracellular matrix and cartilage composition (collagen type I and II, aggrecan) plus proteoglycan content (colorimetric analysis). Furthermore, we correlated the results with 3D microcomputed tomography of the underlying subchondral bone (high-resolution micro-CT system). Measurements were performed in dependence of the anatomical site (femoral vs. tibial, medial and lateral each) to identify regional differences during the osteoarthritic process. From an enduring series of 108 patients undergoing implantation of TKA, 34 osteochondral samples with lesions macroscopically classified as ICRS grade 1b (group A) and 34 samples with ICRS grade 3a/3b lesions (group B) were compared with 21 healthy controls. Concerning 3D analysis, the medial femoral condyle and tibia showed the most significant increase in bone volume fraction and a decrease in the trabecular number in group B frequently accompanied by subchondral bone resorption pits and enchondral ossification. Under physiological conditions, tibia plateaus show lower bone volume fraction than the corresponding femoral site and this difference enlarges with advancing OA. Partially even contradictory behavior was observed such as trabecular separation at the lateral tibial and medial plateau in osteochondral OA samples of the same patients. Collagen type II expression levels show faster and varying changes than type I during the OA process, leading to a lower positive or negative correlation with bone microstructural analysis, especially on the tibia plateau. Structural bone and cartilage parameter changes showed varying developments and correlations among each other in the different compartments of the knee. As a clinical conclusion, therapies to postpone or prevent cartilage degeneration by influencing the loss of mineralized bone could be site dependent.

Placement of an anatomic tibial tunnel significantly improves the medial meniscus posterior extrusion at 90° of knee flexion following medial meniscus posterior root pullout repair.

The purpose of this study was to evaluate the influence of tibial tunnel position in pullout repair for a medial meniscus (MM) posterior root tear (MMPRT) on postoperative MM extrusion. Thirty patients (median age 63years, range 35-72years) who underwent transtibial pullout repairs for MMPRTs were included. Three-dimensional computed tomography images of the tibial surface were evaluated using a rectangular measurement grid for assessment of tibial tunnel position and MM posterior root attachment. Preoperative and postoperative MM medial extrusion (MMME) and posterior extrusion (MMPE) at 10° and 90° knee flexion were measured using open magnetic resonance imaging. Tibial tunnel centers were located more anteriorly and more medially than the anatomic center (median distance 5.8mm, range 0-9.3mm). The postoperative MMPE at 90° knee flexion was significantly reduced after pullout repair, although there was no significant reduction in MMME or MMPE at 10° knee flexion after surgery. In the correlation analysis of the displacement between the anatomic center to the tibial tunnel center and improvements in MMME, and MMPE at 10° and 90° knee flexion, there was a significant positive correlation between percentage distance and improvement of MMPE at 90° knee flexion. This study demonstrated that the nearer the tibial tunnel position to the anatomic attachment of the MM posterior root, the more effective the reduction in MMPE at 90° knee flexion. Our results emphasize that an anatomic tibial tunnel should be created in the MM posterior root to improve the postoperative MMPE and protect the articular cartilage in a knee flexion position. Placement of an anatomic tibial tunnel significantly improves the MMPE at 90° of knee flexion after MM posterior root pullout repair. IV.

Moment arm function dictates patella sagittal height anatomy: Rabbit epiphysiodesis model alters limb length ratios and subsequent patellofemoral anatomical development.

Patellofemoral anatomical dysplasia is associated with patellofemoral instability and pain. The closure of the knee physis occurs at the same age as the peak incidence of patellofemoral dislocation. This study determined the effect on the patellofemoral anatomical development in a rabbit epiphysiodesis model. Twenty-four skeletally immature New Zealand White rabbits were divided into three groups (a) distal femur epiphysiodesis (FE) (b) proximal tibia epiphysiodesis (TE) (c) control; no epiphysiodesis (C) performed at 6 weeks of age. The primary endpoint was shape analysis using three-dimensional reconstructions of micro-computed tomographys (CTs) performed at 30 weeks of age. The limb length ratios (femur:tibia) were significantly different for both FE (mean 0.72, SD 0.0381, P < .001) and TE (mean 0.91, SD 0.0383, P < .001) treatment groups compared to control (mean 0.81, SD 0.0073). Patella height, as measured from the most distal point of the patella to the tibial joint surface (modified Caton-Deschamps measurement), was lower (baja) in the FE and higher (alta) for the TE, compared with the control group. Our findings suggest femoral and tibial shortening can influence the development of the patellofemoral joint, which may be dictated by moment arm function and is potentially responsible for the etiology of patella alta. Future studies are warranted to explore this association further with the view for the development of treatment options for patella alta in human patients.

Improved Visualization by Central Subluxation of the Lateral Meniscus in Comminuted Lateral Tibial Plateau Fractures.

The goal of surgical reconstruction of comminuted tibial plateau fractures is an anatomical reconstruction and stable fixation of the articular surface. This can be difficult due to poor visualization of the posterolateral and central segments of the articular surface of the proximal tibia. To improve visualization, the lateral approach can be extended with an osteotomy of the femoral epicondyle. In most cases, use of the extended lateral approach allows the whole lateral plateau to be visualized. Nevertheless, in some cases, an osteotomy alone is not enough to expose the entire fracture, especially the central segments of the tibial plateau. For these specific cases, we developed an additional technical trick that significantly improves articular visualization; the lateral meniscocapsular fibers are dissected allowing for central subluxation of the lateral meniscus, while leaving the anterior and posterior roots intact. With central subluxation of the lateral meniscus in comminuted tibial plateau fractures, the joint surface can be completely visualized, allowing an anatomical reduction even in highly complex fractures.

Sex determination from dimensions of distal tibiae in adult Kenyans: A discriminant function analysis

PurposeTo assess the utility of the dimensions of the distal tibial articular surface in determining the sex of an individual in a sample Kenyan population. Basic proceduresA total of 156 tibiae were obtained for the present study from the Department of Human Anatomy, University of Nairobi and the osteology collection of the National Museums of Kenya, Nairobi. Measurements were taken directly from the bone using a digital pair of vernier calipers (Sealey Professional Tools™). Morphometric data were analyzed and measurements were expressed in means ± standard deviation. The independent Student's t-test was used to determine statistically significant differences in the means of the measured morphometric variables between male and female subjects. A step-wise multivariate discriminant analysis was carried out to produce a linear function to compare the measurements of the tibia. Main findingsMale subjects had statistically significant (p <0.05) larger dimensions of the fibular incisura, tibial plafond and medial malleolus. The width of the tibial plafond had the highest discriminating power amongst the measured dimensions of the tibia correctly classifying 73.0% of tibiae. Principal conclusionThe width of the tibial plafond has high discriminative power in sex determination using the dimensions of the distal tibia. The linear equation derived from incorporating the length of the tibial plafond and the depth of the fibular incisura could correctly classify 75.7% of the tibiae. The dimensions of the distal tibial articular surfaces can therefore be used in determination of the sex of an individual with reasonable accuracy.

The posterior tibial slope is mainly created by the posterior rotation of the tibial condyles

Constitutional varus in the coronal plane is formed based on the Hueter-Volkmann's law. The varus deformity occurs at the proximal metaphysis of the tibia and the tibial condyle rotates medially. In the sagittal plane, we hypothesized that the posterior slope angle of the tibial articular surface may also occur at the proximal metaphysis and the tibial condyle rotates posteriorly. The purpose of this study was to verify the hypothesis. A total of 208 patients who underwent TKA had lateral view proximal tibia digital radiograph on which seven parameters were analyzed. The posterior slope angle of the tibial articular surface relative to the anterior wall of the tibial condyle and that relative to the anterior cortex of the tibial shaft were assessed. Correlation between the position of the tibial condyle and the posterior slope angle of the articular surface were assessed. The proximal tibial condyle itself did not have a posterior slope in the 86.5% of the participants. Posterior rotation of the tibial condyle created posterior slope of the tibial articular surface relative to the anterior cortex of the tibial shaft. The more tibial condyle was posteriorly rotated, the more the tibial articular surface shifted posteriorly. Study findings showed that the posterior tibial slope occurs at the proximal metaphysis of the tibia, and the tibial condyle rotates posteriorly. The posterior tibial slope involves the posterior shift of the tibial articular surface. The posterior tibial slope is mainly created by the posterior rotation of the tibial condyle.

Morphometric analysis of medial and lateral tibia plateau and adaptability with Oxford partial knee replacement in a Japanese population.

In unicompartmental knee arthroplasty (UKA), tibial components must be correctly sized and positioned so that tibial cut surfaces are well covered without marked under- or overhang with impingement of the surrounding soft tissue. We used morphometric data of both medial and lateral tibial plateaus separately to plan UKA and evaluated the compatibility of the measurement data to the dimensions of six currently available tibial prostheses in a Japanese population. Using computed tomography, we preoperatively examined 60 patients (30 medial and 30 lateral osteoarthritis (OA)) scheduled for primary UKA at our hospital between 2013 and 2017. Each tibial cutting surface was measured in the transverse plane at 2 mm below the respective joint line. We used anteroposterior and mediolateral length to calculate the mediolateral length/anteroposterior ratio of both medial and lateral compartments. We then compared measurements across six current UKA systems: Oxford fixed tibia and fixed lateral tibia, Triathlon, TRIBRID, JOURNEY UNI, and HLS Uni Evolution. We found no significant differences in morphometric data between the medial and the lateral OA. The cutting surface of lateral plateau, however, had smaller anteroposterior dimensions, greater mediolateral length, and higher mediolateral length/anteroposterior ratio than those of medial plateau. Therefore, in this Japanese population-based study, Oxford lateral tibia had good compatibility with the measurement data of lateral compartments. Lateral compartments had lower anteroposterior length, greater mediolateral length, and higher mediolateral length/anteroposterior ratio than those of medial compartments. We, therefore, strongly recommend using Oxford fixed lateral tibia for lateral OA over other current tibial prostheses because of superior coverage.

The fibular notch: an anatomical study.

Reduction of the distal fibula into the fibular notch (FN) poses a problem that has not been fully resolved, yet. A number of methods have been developed for the assessment of the position of the fibula in the FN, but none of them is ideal. A majority of authors assess the FN 1cm above the tibiotalar joint space, without specifying the reason for the choice of this distance. None of the previous studies has addressed at what level the FN is the deepest. Our findings show that it is 4-5mm above the ankle joint space and verification of this hypothesis has been the aim of this study. Dry adult tibial bone specimens from the Pachner's collection of the Institute of Anatomy of 1st Faculty of Medicine, Charles University, Prague were used in the study. Height of the FN at its widest point, 3mm and 10mm above the articular surface of the distal tibia were measured in each specimen, as well as the depth of the FN at the deepest point, 3mm and 10mm above the articular surface of the distal tibia and the distance between the highest point of this surface and the deepest point of the notch. The mean length of the tibia was 350mm; the mean height of the FN was 42.5mm; the mean width of the FN at its widest point was 23.6mm, at 3mm above the tibiotalar joint space 22mm, 10mm above this articular surface of distal tibia (tibial plafond) 18.9mm. The mean depth of the notch at 3mm above the tibial plafond was 3.8mm, at 10mm above this surface 4.1mm. The maximum mean depth of the notch was 4.5mm, the distance from this point to the highest point of the tibial plafond was 5.3mm. The deepest point of the FN lies 5mm above the articular surface of the tibial plafond, with the mean value of the depth being 4.5mm. This region is, therefore, ideal for assessment of the position of the distal fibula in the FN.

Is Indian osteoarthritis different? Emerging scenarios of disease pattern and implications for diagnosis and treatment of osteoarthritis in India

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; There are many studies to show comparative cartilage wear of medial and lateral compartment of knee. However, there are no studies in Indians that compare relative cartilage loss between femur and tibia.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; 44 patients with osteoarthritic knee at our center were posted for operative intervention in the form of partial or total knee arthroplasty and included in this study. Each patient had an magnetic resonance imaging (MRI) (cartogram) and weight bearing X-rays of the same knee. Intraoperative qualitative cartilage loss both femoral and tibial surfaces was observed and confirmed with preop findings of cartilage loss on X-ray or MRI.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The wear/loss of cartilage in 44 patients in femur is approximately twice that of tibia.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Femoral cartilage loss is significantly more than tibia in Indians. These findings carry significance of not waiting for bone on bone arthritis to consider active treatment for Indian osteoarthritis patients. Bone on bone arthritis has so far been considered the litmus test for any intervention for osteoarthritis, even in India. Specific attention should rather be given to the femoral condyle clinically and radiologically. The authors have already described “The Dervan RIM sign” for the same purpose. The wear pattern is different from Caucasians and focus cannot be on joint space narrowing which is only with equally prevalent tibial and femoral cartilage wear.&lt;/p&gt;&lt;p class="abstract"&gt; &lt;/p&gt;

Functional outcome of tibial plateau fracture managed conservatively

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Tibial plateau fractures involve the articular surface of the proximal tibia. They account for approximately 1% of adult fractures. A number of articles have been published regarding tibial plateau fracture management. Interestingly excellent results have been published concluding not all fractures of the tibial plateau require surgery and not all displaced intra-articular fractures need to be reduced surgically. In this method we used conservative method to restore normal joint anatomy, joint stability, and functional motion and avoid complications.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This study design is prospective study including forty randomly selected cases of diagnosed tibial plateau fracture presented in Orthopaedic department of tertiary referral centre over 18 months period and treated with conservative method. The patients then were followed up and evaluation of outcome was analyzed as per modified Rasmussen clinical criteria and radiological criteria at six months.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; In this study, tibial plateau fracture was seen more in patients of age group 31-40 (35%). Mean age being 41.25 years. There were 28 (70%) male and 12 (30%) female. Road traffic accident comprises the majority of cases (75%). Regarding radiological outcome, 41.5% had excellent result, 34.3% had good result, 8.5% had fair result and 15.7% had poor result. 84% had acceptable outcome. The Rasmussen’s functional outcome at final follow up was 46% patients had excellent result, 30% had good result, 12% had fair result and 12% had poor result. 88% had acceptable clinical outcome.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Conservative management of tibial plateau is still a reliable, inexpensive and alternative treatment option with favourable functional outcome.&lt;/p&gt;

Validation and sensitivity of model-predicted proximal tibial displacement and tray micromotion in cementless total knee arthroplasty under physiological loading conditions

The initial fixation of cementless tibial trays after total knee arthroplasty is crucial to bony ingrowth onto the porous surface of the implants, as micromotion magnitudes exceeding 150 μm may inhibit bone formations and limit fixation. Experimental measurement of the interface micromotions is still very challenging. Thus, previous studies investigated micromotions at the bone-tray interface via finite element methods, but few performed direct validation via in vitro cadaveric testing under physiological loading conditions. Additionally, previous models were validated by solely considering relative displacements of the marker couples placed around the tray-bone interface. In this paper, we present an experimental-computational validation framework for investigating micromotions at the tray-bone interface under physiological conditions. Three cadaveric specimens were implanted with cementless rotating-platform implants and tested under gait, deep knee bending, and stair descent loads. Corresponding subject-specific finite element models were developed and used to predict the marker (tray-bone) relative displacements and tibial surface displacements. Experimental measurements were used to validate model estimations. Subsequent sensitivity analyses were performed on implantation and friction parameters to represent model uncertainties.The models appropriately differentiated between locations, activities, and specimens. The average root-mean-square (RMS) differences and correlations between measured marker relative displacements and predictions from the ‘best-matching’ models were 13.1 μm and 0.86. RMS differences and correlations between measured surface displacements and predictions were 78.9 μm and 0.84. Full-field interface micromotions were investigated and compared with predicted marker relative displacements. The marker relative displacements underestimated the actual interface micromotions. Initial tray-bone alignment in anterior-posterior, flexion-extension, and varus-valgus degrees of freedom have a considerable impact on the interface micromotions. The validated cadaveric models can be further used for pre-clinical assessments of new TKR tray design. The outcomes of the sensitivity analyses provide further insights into reducing interface micromotions via clinical techniques.

Predicting Knee Joint Instability Using a Tibio-Femoral Statistical Shape Model.

Statistical shape models (SSMs) are a well established computational technique to represent the morphological variability spread in a set of matching surfaces by means of compact descriptive quantities, traditionally called “modes of variation” (MoVs). SSMs of bony surfaces have been proposed in biomechanics and orthopedic clinics to investigate the relation between bone shape and joint biomechanics. In this work, an SSM of the tibio-femoral joint has been developed to elucidate the relation between MoVs and bone angular deformities causing knee instability. The SSM was built using 99 bony shapes (distal femur and proximal tibia surfaces obtained from segmented CT scans) of osteoarthritic patients. Hip-knee-ankle (HKA) angle, femoral varus-valgus (FVV) angle, internal-external femoral rotation (IER), tibial varus-valgus (TVV) angles, and tibial slope (TS) were available across the patient set. Discriminant analysis (DA) and logistic regression (LR) classifiers were adopted to underline specific MoVs accounting for knee instability. First, it was found that thirty-four MoVs were enough to describe 95% of the shape variability in the dataset. The most relevant MoVs were the one encoding the height of the femoral and tibial shafts (MoV #2) and the one representing variations of the axial section of the femoral shaft and its bending in the frontal plane (MoV #5). Second, using quadratic DA, the sensitivity results of the classification were very accurate, being all >0.85 (HKA: 0.96, FVV: 0.99, IER: 0.88, TVV: 1, TS: 0.87). The results of the LR classifier were mostly in agreement with DA, confirming statistical significance for MoV #2 (p = 0.02) in correspondence to IER and MoV #5 in correspondence to HKA (p = 0.0001), FVV (p = 0.001), and TS (p = 0.02). We can argue that the SSM successfully identified specific MoVs encoding ranges of alignment variability between distal femur and proximal tibia. This discloses the opportunity to use the SSM to predict potential misalignment in the knee for a new patient by processing the bone shapes, removing the need for measuring clinical landmarks as the rotation centers and mechanical axes.