Mechanical Femorotibial Angle Research Articles

Assessment of preoperative planning and intraoperative accuracy of the AIKNEE system for total knee arthroplasty

BackgroundThe aim of this retrospective study was to evaluate the effectiveness and accuracy of the AIKNEE system in preoperative planning and intraoperative alignment for total knee arthroplasty (TKA).MethodsA total of 64 patients were planned preoperatively by the AIKNEE system, including the measurement of mechanical femorotibial angle (mFTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) using three-dimensional reconstructed images. Intraoperatively, the actual prosthesis size and alignment were compared to the planned parameters. Postoperative outcomes, including pain levels, range of motion (ROM), and Knee Scoring System (KSS) scores, were assessed after surgery. Statistical analyses were performed to evaluate the correlation between alignment deviations and postoperative function.ResultsThe AIKNEE system accurately predicted the prosthesis size in thirty-one of femoral cases (48%) and forty-seven of tibial cases (73%). Deviations of mFTA, LDFA, and MPTA from the target value were within 3° in 88%, 92%, and 95% of cases, respectively. A significant improvement was observed in postoperative pain, ROM, and KSS scores (p < 0.001). Correlation analysis revealed that greater deviations in mFTA and LDFA were associated with increased pain (p = 0.004, 0.047) and lower KSS scores (p = 0.027).ConclusionThe AIKNEE system demonstrated promising results in predicting prosthesis size and achieved alignment within the desired range in a majority of cases. Postoperative outcomes, including pain levels and functional improvement, were favorable.

Relevance of instrumented gait analysis in the prediction of the rebound phenomenon after guided growth intervention

Predictors of rebound after correction of coronal plane deformities using temporary hemiepiphysiodesis (TH) are not well defined. The following research questions were tested: (1) Is the dynamic knee joint load useful to improve rebound prediction accuracy? (2) Does a large initial deformity play a critical role in rebound development? (3) Are BMI and a young age risk factors for rebound? Fifty children and adolescents with idiopathic knee valgus malalignment were included. A deviation of the mechanical femorotibial angle (MFA) of ≥ 3° into valgus between explantation and the one-year follow-up period was chosen to classify a rebound. A rebound was detected in 22 of the 50 patients (44%). Two predictors of rebound were identified: 1. reduced peak lateral knee joint contact force in the first half of the stance phase at the time of explantation (72.7% prediction); 2. minor initial deformity according to the MFA (70.5% prediction). The best prediction (75%) was obtained by including both parameters in the binary logistic regression method. A TH should not be advised in patients with a minor initial deformity of the leg axis. Dynamic knee joint loading using gait analysis and musculoskeletal modeling can be used to determine the optimum time to remove the plates.

Superior accuracy in knee double level osteotomy using a novel hybrid fixation technique compared to conventional double plating.

This study aimed to compare two different double-level knee osteotomy (DLO) fixation techniques. The primary outcome reported the radiological coronal plane correction and its accuracy. The secondary outcomes reported the correction outliers, the clinical outcomes, the 5-year postoperative satisfaction and the complications. A retrospective review of a single surgeon osteotomy database identified 52 cases of DLO between 2011 and 2019, of which 24 cases met the inclusion criteria. Patients were categorised into two groups: the nail-plate (NP) group fixed with a magnetic extendable intramedullary tibial nail and femoral conventional plate, and the double-plate (DP) group fixed with conventional plates (tibia and femur). Radiographic parameters were recorded, including the mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), joint line convergence angle (JLCA) and weight-bearing line ratio (Mikulicz %). Surgical accuracy was calculated as the difference between the achieved and the planned correction. Outliers were defined as those with a greater than 10% difference from the planned correction. Simple knee value scores and visual analogue scale for pain were recorded preoperatively and postoperatively at 2 and 5 years. Five-year patient satisfaction was recorded. A total of 24 patients were included: the NP group (n = 12) and the DP group (n = 12). Significant coronal plane corrections were achieved in the NP group for the mean mFTA (preoperative 167.9° ± 3.4° to postoperative 182.1° ± 1.4°), the mean MPTA (preoperative 83.5° ± 2.9° to postoperative 91.3° ± 2.8°) and the mean mLDFA (preoperative 89.8° ± 3.4° to postoperative 85.9° ± 4.4°). Similarly, significant coronal plane corrections were achieved in the DP group for the mean mFTA (preoperative 168.6° ± 4.4° to postoperative 182.2° ± 2°), the mean MPTA (preoperative 84.2° ± 2° to postoperative 88.3° ± 4.1°) and the mean mLDFA (preoperative 90.7° ± 2.9° to postoperative 83.9° ± 1.7°) (all p < 0.05). The mean correction accuracy was higher for the NP versus DP group at 3.4 ± 3.4% versus 7.1 ± 3.9% (intergroup p < 0.05). There were no outliers in the NP group versus two outliers (overcorrected) (16.7%) in the DP group. Significant clinical improvement was reported in both groups at 2 and 5 years postoperatively (all p < 0.05). Superior correction accuracy and no outliers were achieved in hybrid fixation double-level knee osteotomy compared to the conventional double-plating technique. The magnetic extendable nail offers the advantage of fine-tuning the correction postoperatively and could be a potential research template for future designs of postoperative correction implants. Level III, retrospective cohort study.

Mid-term results of an anatomic total knee replacement design.

A significant proportion of patients remain dissatisfied following total knee arthroplasty (TKA) surgery. Reasons for this are unclear. Contemporary implants seek to mirror innate anatomy. Such innovations are necessarily subject to scrutiny to validate their use. The Zimmer-Biomet Persona® Personalized Knee system is such an anatomic TKA. This work seeks to establish medium term survival data and patient reported outcomes for this implant. This was a cohort study of prospectively collected data on all patients undergoing Persona TKA at our institution. Patients were managed using a standardised protocol for intra- and post-operative care. Survivorship data were collected using our National Joint Registry and corroborated with local data. Range of motion, Oxford Knee Score (OKS) and patient satisfaction were recorded at six weeks and one year post-operatively. Hip-knee-ankle radiographs were used to record pre- and post-operative alignment. Data were collected for 749 knees in 679 patients. Overall survivorship was 99.0% at a mean 5.35years, with seven patients undergoing revision surgery during the study period. Significant improvements in the OKS (mean 20.7 points) and range of motion were observed (mean 104.6° at one year). 94.9% of patients were satisfied at one year. Mean correction was to a mechanical femoro-tibial angle of 0.8° varus. We demonstrate excellent medium term survival of the Persona TKA in this large cohort, coupled with improvements in patient reported outcomes, range of motion and patient satisfaction at one year which compare favourably to other implants.

Medial opening-wedge high tibial osteotomy with microfracture in treatment of varus medial compartmental knee osteoarthritis: clinical outcomes and second-look arthroscopic results.

Objective: This study aimed to investigate the clinical outcomes of medial opening high tibial osteotomy (MOWHTO) combined with arthroscopic microfracture in the treatment of varus medial compartmental knee osteoarthritis and to assess cartilage regeneration using second-look arthroscopy. Methods: This study involved 86 patients (86 knees) who underwent MOWHTO and microfracture from August 2016 to August 2020, including 15 men and 71 women with an average age of 55.3 ± 7.6years (range, 42-71years). The patients underwent a second-look arthroscopy to evaluate the status of cartilage regeneration at the time of plate removal, an average of 2years after the initial osteotomy. Clinical and radiological examinations were performed preoperatively and at the final follow-up visit. The radiologic evaluation included the weight-bearing line ratio (WBL ratio), mechanical femorotibial angle (FTA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTS) and Kellgren-Lawrence (KL) grade. Clinical outcomes were assessed using the Knee Society score (KSS) and International Knee Documentation Committee (IKDC) scores. Arthroscopic findings were assessed by macroscopic evaluation of cartilage repair according to the International Cartilage Repair Society (ICRS) grading system. Results: The mean KSS and IKDC scores significantly improved at the final follow-up compared to the scores obtained preoperatively (p < 0.05). At the time of plate removal, a second-look arthroscopic examination showed that the ICRS grade of the medial femoral condyle was as follows: grade I -11 cases, grade II -56, grade III-12, and grade IV-7, and cartilage regeneration was seen in 85% of knees (73/86). The ICRS grade of medial tibial plateau was grade I-12 cases, grade II-44, grade III-22, and grade IV-8, and cartilage regeneration was seen in 63% of knees (54/86). Significant differences were observed between cartilage regeneration and clinical outcomes (p < 0.05). Clinical results were better in the good cartilage regeneration group (grades I and II) than were in the poor cartilage regeneration group (grades III and IV). Conclusion: MOWHTO combined with arthroscopic microfracture can effectively improve clinical outcomes in the treatment of varus medial compartmental knee osteoarthritis. Cartilage regeneration can be promoted by correcting varus deformities, which affect clinical outcomes.

Intra- and interobserver reliability analysis of pediatric lower limb parameters on digital long leg radiographs

BackgroundMalalignments of the lower extremity are common reasons for orthopedic consultation because it may lead to osteoarthritis in adulthood. An accurate and reliable radiological assessment of lower limb alignment in children and adolescents is essential for clinical decision-making on treatment of limb deformities and for regular control after a surgical intervention.ObjectiveFirst, does the analysis of full-length standing anteroposterior radiographs show a good intra- and interobserver reliability? Second, which parameter is most susceptible to observer-dependent errors? Third, what is the Standard Error of Measurement (SEM95%) of the absolute femoral and tibial length?MethodsTwo observers evaluated digital radiographs of 144 legs from 36 children and adolescents with pathological valgus alignment before a temporary hemiepiphysiodesis and before implant removal. Parameters included Mechanical Femorotibial Angle (MFA), Mechanical Axis Deviation (MAD), mechanical Lateral Distal Femoral Angle (mLDFA), mechanical Medial Proximal Tibial Angle (mMPTA), mechanical Lateral Proximal Femoral Angle (mLPFA), mechanical Lateral Distal Tibial Angle (mLDTA), Joint Line Convergence Angle (JLCA), femur length, tibial length. Intra- and interobserver reliability (ICC2,1), SEM95% and proportional errors were calculated.ResultsThe intra- and interobserver reliability for almost all measurements was found to be good to excellent (Intra-ICC2,1: 0.849–0.999; Inter-ICC2,1: 0.864–0.996). The SEM95% of both observers was found to be ± 1.39° (MFA), ± 3.31 mm (MAD), ± 1.06° (mLDFA) and ± 1.29° (mMPTA). The proportional error of MAD and MFA is comparable (47.29% vs. 46.33%). The relevant knee joint surface angles show a lower proportional error for mLDFA (42.40%) than for mMPTA (51.60%). JLCA has a proportional error of 138%. Furthermore, the SEM95% for the absolute values of the femoral and tibial length was 4.53 mm for the femur and 3.12 mm for the tibia.ConclusionsIn conclusion, a precise malalignment measurement and the knowledge about SEM95% of the respective parameters are crucial for correct surgical or nonsurgical treatment. The susceptibility to error must be considered when interpreting malalignment analysis and must be considered when planning a surgical intervention. The results of the present study elucidate that MAD and MFA are equally susceptible to observer-dependent errors. This study shows good to excellent intra- and interobserver ICCs for all leg alignment parameters and joint surface angles, except for JLCA.Trial registration: This study was registered with DRKS (German Clinical Trials Register) under the number DRKS00015053.Level of evidenceI, Diagnostic Study.

The Validity of Motion Capture Analysis System against the Gold Standard Long-Standing Radiography in the Measurement of Lower Extremity Alignment.

Motion capture analysis (MCA) has the advantage of providing a static and dynamic leg axis analysis without radiation. Nevertheless, there is a lack of evidence regarding the accuracy of this technique. To test whether mechanical femorotibial axis angle (MAA) measurement recorded with a non-invasive MCA system is equal to the gold standard static long-standing full-leg radiographs (LSX) and if the degree of malalignment or other parameters (BMI, body mass, height, age) influence the accuracy, a total of 102 consecutive patients were examined using LSX and MCA. Static as well as all gait motion phases at 3 km/h were analyzed regarding the difference between the two angles. There was no statistical difference for MAA between LSX (MAArad) and MCA (MAAstat) (p = 0.091). There was a strong correlation (rs = 0.858, p < 0.001) between the two methods. The highest accuracy was detected for values of standing MCA. Also, the gait MCA values showed strong correlation with LSX but weaker correlation compared to standing MCA (initial swing rs = 0.549; terminal stance rs = 0.815; p < 0.001). BMI, body mass, and height did not influence the accuracy of MCA. MCA enables frontal alignment analysis with high accuracy and without the side effect of radiation.

Application of SolidWorks software in preoperative planning of high tibial osteotomy.

Open-wedge high tibial osteotomy (HTO) is a common surgical treatment for medial osteoarthritis in young and active patients. The accuracy of osteotomy is closely associated with postoperative efficacy. The accuracy of digital preoperative planning is higher than that of the preoperative manual measurement and several computer software with varying accuracy and convenience are used for digital preoperative planning. This study aimed to use the SolidWorks software for HTO preoperative planning and to determine its accuracy and reliability in HTO preoperative planning. We reviewed the data of 28 patients with 54 with medial compartment knee arthritis who underwent open-wedge HTO preoperative planning using SolidWorks between June 2019 and March 2021. The standard anteroposterior standing whole-leg radiographs were assessed before and 6 weeks after the surgery. The correction angle, weight-bearing line (WBL) ratio, mechanical femorotibial angle (mFTA), and medial proximal tibial angle (MPTA) before and after the surgery were compared. The clinical results were evaluated using the Knee Society score. At 6 weeks after the surgery, the WBL ratio was corrected from 16.8% to 50.5%, mFTA was corrected from 6.4° varus to 1.2° valgus, and MPTA was corrected from 83.4° to 89.3°. No significant difference was observed between the predicted correction angle before the surgery and the correction angle measured 6 weeks after the surgery (t = -1.745, p = 0.087). The knee score and function score of Knee Society increased from 76.4 and 80.7 before surgery to 95.0 and 95.7, respectively. The SolidWorks software showed high accuracy and reliability in preoperative planning of open-wedge HTO in patients with medial compartment knee arthritis.

Distal Femoral Valgus Resection Angle in Conventional Total Knee Arthroplasty - a CT Scanogram Study.

In conventional total knee arthroplasty (TKA), the distal femur valgus resection angle (DFVA) is decided either by measuring the specific resection angle for each patient on preoperative anteroposterior hip-knee-ankle (HKA) weight-bearing radiograph or using a fixed resection angle of five to seven degrees, when such facilities are not available. This study aims to measure the DVFA in TKA patients using preoperative HKA non-weight-bearing computerized tomography (CT) scanogram scout films and determine its relation with preoperative coronal plane lower-limb deformities. In this retrospective radiological study, various measurements were performed on bilateral, preoperative hip-knee-ankle CT scanograms of 73 knee osteoarthritis patients who had presented for total knee replacement surgery using a standard protocol. The angle between the femoral anatomical axis and femoral mechanical axis was measured as the femoral mechanical anatomical angle (FMAA), which corresponds to the surgical DFVA. The angle between the femoral and tibial mechanical axes was measured as mechanical femorotibial angle (MFTA). The correlation between FMAA and MFTA was studied. The mean FMAA for the study group was 6.45° (range 3° to 11°, SD 1.17°). The MFTA for the study group ranged from 24° varus to 14° valgus. The alignment was valgus in 14.4% (n=21), varus in 84.2% (n=123), and "0 degrees" in 1.3% (n=2). With valgus coronal alignment taken as positive and varus as negative, the Pearson's correlation coefficient for MFTA with FMAA was r = -0.5183 (p<0.001), indicating that valgus knees tended to have a smaller FMA angle and varus knees tended to have a larger FMA angle. In the non-availability of individualized measurements, in primary TKA, we recommend setting DFVA as five degrees for valgus deformities, six degrees for mild/moderate varus deformities (MFTA <15°) and seven degrees for severe varus deformities (MFTA > 15°).

Spacer Block Technique Was Superior to Intramedullary Guide Technique in Coronal Alignment of Femoral Component after Fixed-Bearing Medial Unicompartmental Knee Arthroplasty: A Case-Control Study.

Backgrounds and Objectives: The spacer block technique in unicompartmental knee arthroplasty (UKA) has still a concern related to the precise position of the component in the coronal and sagittal planes compared to intramedullary guide technique. The purposes of this study were to explore whether the spacer block technique would improve the radiological alignment of implants and clinical outcomes compared with the outcomes of the intramedullary guide technique in fixed-bearing medial UKA. Materials and Methods: In total, 115 patients who underwent unilateral, fixed-bearing medial UKA were retrospectively reviewed and divided into group IM (intramedullary guides; n = 39) and group SB (spacer blocks; n = 76). Clinical assessment included range-of-motion and patient-reported outcomes. Radiological assessment included the mechanical femorotibial angle, coronal and sagittal alignments of the femoral and tibial components, and coronal femorotibial congruence angle. Results: All clinical outcomes showed no significant differences between groups. The coronal femoral component angle was valgus 2.4° ± 4.9° in IM group and varus 1.1° ± 3.2° (p < 0.001). In group IM, the number of outlier in coronal femoral component angle (<−10° or 10°<) was 3 cases, while in group SB, there was no outlier (p = 0.014). The coronal femorotibial congruence angle was significantly less in group SB (mean 1.9°, range, −3.2°~8.2°) than in group IM (mean 3.4°, range, −9.6°~16.5°) (p = 0.028). Conclusions: In the group SB, the coronal alignment of femoral component was closer to neutral, and outlier was less frequent than in the group IM. The spacer block technique was more beneficial in achieving proper coronal alignment of the femoral component and congruence of femorotibial components compared to the intramedullary guide technique in fixed-bearing medial UKAs.

Correlation of Tibial Torsion With Lower Limb Alignment and Femoral Anteversion in Patients With Patellar Instability.

Alignment and rotation of the lower extremities have been suggested to be predisposing pathologic factors for patellar instability. To elucidate the relationship between the lower limb alignment and lower extremity rotation in patients with patellar instability. Cross-sectional study; Level of evidence, 3. Included were 83 patients with patellar instability. Computed tomography scans and standing full-leg radiographs were used to measure the tibial tuberosity-trochlear groove (TT-TG) distance, mechanical femorotibial angle (mFTA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), femoral torsion, and tibial torsion of the different segments. The relationships between femoral torsion, tibial torsion of the different segments, and the mFTA, mLDFA, and mMPTA were evaluated. The levels of tibial torsion and femoral torsion in patients with varus, normal, or valgus alignment were compared with 1-way analysis of variance and chi-square test. The total tibial torsion was significantly associated with total femoral anteversion (r = 0.329; P = .002) and mFTA (r = -0.304; P = .005). There were no significant correlations between mFTA and TT-TG distance or femoral anteversion. Compared with patients with valgus malalignment, patients with varus malalignment tended to have higher tibial torsion. Tibial torsion was associated with leg axis alignment and femoral anteversion in patients with patellar instability. Patients with patellar instability, especially those with concurrent leg axis deformities, should undergo further radiological imaging so that tibial torsion can be assessed and a diagnosis of torsion deformity made early in the treatment pathway and the proper surgical plan formulated.

Medial Closing-Wedge Distal Femoral Varus Osteotomy via Lateral Approach: The Modified Technique for Treating Valgus Osteoarthritic Knee as Case Series

Objective: The medial closing-wedge distal femoral varus osteotomy (MCW-DFVO) was an excellent operation for painful valgus lateral unicompartmental osteoarthritic (OA) knee, especially in the young patient. Originally, it requires a medial approach that has more precarious. On top of that, releasing of the iliotibial band that is the deforming force needs added incision. Therefore, this study aims to describe the modified surgical technique of MCW-DFVO that uses a lateral approach and lateral plating to treat the valgus OA knee. Additionally, we also reveal the outcomes of our technique as the case series.&#x0D; Materials and Methods: Ten patients (12 knees) who underwent MCW-DFVO via a lateral approach were retrospectively reviewed. The inclusion criteria were age 18-60 years, isolated lateral compartmental OA knee (Kellgren-Lawrence grade 3-4), no significant patellofemoral pain, and range of motion (ROM) &gt; 90 degrees. We excluded the inflammatory joint disease, unstable knee (femorotibial joint subluxation &gt; 1 cm), and prior surgical procedure. Demographic data, pre- and postoperative ROM, radiographic outcomes, complications, and survivorship were recorded.&#x0D; Results: The mean age, body mass index, and preoperative ROM were 55.3 ± 4.0 years, 25.4 ± 3.7 kg/m2 and 113.3 ± 11.5 degrees, respectively. The preoperative mechanical femorotibial angle was 162.3 ± 4.8 degrees, and the final post-operative alignment was 182.3 ± 2.6 degrees. Overall mean operative time of this technique was 92.5 ± 26.7 minutes. During the mean follow-up period of 8.3 ± 3.1 years, all osteotomy were united and the final postoperative ROM was decreased to 108.8 ± 11.7 degrees. One knee required plate removal due to hardware irritation, and another knee required subsequent total knee arthroplasty at 1 and 8.5 years after MCW-DFVO, respectively. The survivorship of this technique was 91.7% at the mean survival time of 13.8 years (95% confidence interval, 11.9 – 15.7 years).&#x0D; Conclusion: This study proposed the modified surgical technique of MCW-DFVO via a lateral approach. This technique provided the excellent correction angle, union rate and survivorship.

Comparison of postoperative alignment using fixed angle versus variable angle distal femoral resection in uncomplicated total knee replacement.

This study aimed to compare the postoperative alignment of the lower limbs using fixed angle versus variable valgus angle distal femur resection in uncomplicated total knee replacement (TKR) and to determine the mean valgus correction angle (VCA) in the study population. This was a prospective comparative study conducted between July 2018 and December 2019 in patients with osteoarthritic knees who underwent primary TKR. Forty-nine patients with 54 knees completed the study. They were randomized into fixed valgus angle (group A) and variable valgus angle (group B) groups. Twenty-four patients with 26 knees were in group A who had distal femur resection with 5-degree valgus correction, while 25 patients with 28 knees were in group B who had distal femur resection with individualized valgus correction angle calculated from hip-knee-ankle scanogram. The demographic data were comparable in the two groups. There was no statistically significant difference between the groups in the mean preoperative mechanical femorotibial angle (MFTA). The fixed angle group had a mean postoperative MFTA of 2.0 ± 2.8°, while variable angle group had a mean of 1.6 ± 2.4°. However, the difference between the groups did not reach statistical significance (p = 0.60). The mean VCA in the study population was 5.8 ± 1.2° (Range 4-9°). Our study has shown that the use of variable valgus angle for distal femur resection in uncomplicated TKR did not significantly improve the accuracy of restoring the postoperative coronal alignment within 0 ± 3°.

The coronal alignment technique impacts deviation from native knee anatomy after total knee arthroplasty.

The aim of this study was to analyze and quantify the changes in native coronal alignment of a population of TKA patients according to different alignment goals. Five hundred and twenty TKAs were analyzed. The following angles were measured using an image-free navigation system prior to prosthetic implantation: medial femorotibial mechanical angle without stress and with maximum manual stress to reduce the deformity, medial distal femoral mechanical angle, medial proximal tibial mechanical angle. The native angles were derived from the osteoarthritic knee angles using a validated correction technique, and the overall, femoral and tibial coronal phenotypes were defined. Five different coronal alignment techniques were simulated: mechanical (MA), restricted mechanical (RMA), anatomical (AA), kinematic (KA) and restricted kinematic (RKA). The overall, femoral and tibial coronal phenotypes were compared before and after TKA. The primary endpoint was the binary criterion of whether or not TKA restored the natural overall phenotype. Secondary endpoints were the binary criteria of whether or not the natural femoral and tibial phenotypes were restored by TKA. The rates of restored and non restored phenotypes were compared with a Chi-square test at a 0.05 level of significance, with post hoc tests between all pairs of techniques at a 0.01 level of significance. The overall phenotype was restored significantly differently by the five alignment techniques: 15% for MA, 23% for RMA, 2% for AA, 100% for KA and 79% for RKA (p < 0.001). There was a significant difference between each of the technique pairs (p < 0.01 to p < 0.001), except for the mechanical alignment-restricted mechanical alignment pair. The femoral phenotype was restored significantly differently by the five alignment techniques: 37% for MA, 58% for RMA, 19% for AA, 100% for KA and 85% for RKA (p < 0.001). The tibial phenotype was restored significantly differently by the five alignment techniques: 36% for MA, 36% for RMA, 17% for AA, 100% for KA and 88% for RKA (p < 0.001). There was a significant difference between each pair of techniques for both femoral and tibial phenotypes (p < 0.01 to p < 0.001). Except for the kinematic alignment technique, the various alignment techniques induce significant changes in the pre-arthritic anatomy of the TKA patient. The surgeon must be aware of these modifications. The clinical relevance of this alteration still needs to be defined. III.

Is there any benefit in the combined ligament reconstruction with osteotomy compared to ligament reconstruction or osteotomy alone?: Comparative outcome analysis according to the degree of medial compartment osteoarthritis with anterior or posterior cruciate ligament insufficiency.

The purpose of this study was to compare the outcomes of middle-aged patients with anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) insufficiency by assessing different groups: high tibial osteotomy (HTO), HTO with combined ligament reconstruction, and isolated ligament reconstruction according to the alignment change and medial compartment osteoarthritis (OA). From 2014 to 2019, middle-aged (40-65years) patients with knee instability were enrolled in this retrospective study. They were categorized into three groups: group I, HTO; group II, HTO with combined ACL or PCL reconstruction; and group III, isolated ligament reconstruction. Radiological outcomes, including Kellgren-Lawrence grade, mechanical femorotibial angle (mFTA), weight-bearing line (WBL) ratio, and posterior tibial slope were compared. Knee stability and clinical outcomes were also compared. Seventy-nine patients completed the final assessment. Group I was older than other two groups (p = 0.006). Groups I and II had a higher body mass index (p = 0.043) and more preoperative varus alignment than group III (p < 0.001). OA severity was ranked in the order of group I, II, and III (p < 0.001). Group I showed more valgus alignment than group II after HTO (p = 0.024 for mFTA and 0.044 for WBL ratio, respectively). Compared to their preoperative status, all three groups showed significant improvement in knee stability (p < 0.001); however, group I showed inferior knee stability regardless of ACL or PCL reconstruction (p < 0.001 and 0.043, respectively). All clinical scores significantly improved in the three groups (p < 0.001), and they showed comparable clinical outcomes in the final assessment. Our strategy in managing middle-aged patients with knee instability according to the varus alignment and medial degeneration showed favorable stability and clinical outcomes. Middle-aged patients with knee instability should be managed with different strategies depending on their status. Case-control study; Level-III.

Difference between medial and lateral tibia plateau in the coronal plane: importance of preoperative evaluation for medial unicompartmental knee arthroplasty

BackgroundSetting bone cutting levels for different joint line orientations of the medial and lateral tibia plateaus in individual patients is not clear. We aimed to evaluate the difference between joint line orientation of the medial and lateral tibia plateaus relative to the horizontal line of mechanical axis of tibia as tibial plateau difference (TPD) for an optimal tibial bone cut in medial unicompartmental knee arthroplasty (UKA) and determine which factors could influence TPD. We aimed to investigate the effect of preoperative TPD on polyethylene liner size in medial UKA.MethodsTPD in the coronal plane were measured in 181 female patients (181 knees). To determine the morphology of proximal tibia according to the severity of osteoarthritis, the patients were classified into three groups based on diagnosis and treatment: 80 who underwent robot-assisted medial UKA, 45 who underwent total knee arthroplasty (TKA), and 56 with early-stage osteoarthritis (OA) who had conservative management. Also, we divided the medial UKA group into two groups according to TPD (greater than or less than 5 mm) and compared polyethylene liner sizes.ResultsNo significant difference was observed in TPD (p = 0.662), difference between the medial and lateral femoral condyle levels (p = 0.54), medial proximal tibial angle (p = 0.169), or posterior tibial slope (p = 0.466) among the three groups. Increased TPD was significantly associated with increased mechanical femorotibial angle(mFTA) (p < 0.01). The medial UKA group was divided into two groups according to TPD greater or less than 5 mm. Thicker polyethylene liners were used for groups with TPD greater than 5 mm (8.5 ± 0.7 mm versus 8.2 ± 0.3 mm, p = 0.01). Additionally, the proportion of patients using the thinnest polyethylene (8 mm) in each TPD group (greater or less than 5 mm) was higher in patients with TPD less than 5 mm (82.4% versus 58.7%, p = 0.038).ConclusionsPreoperative measurement of TPD is important to help surgeons predict the most appropriate bone cutting level in the coronal plane in primary medial UKA. Tibial bone resection would be likely to be thicker than needed in patients with increased TPD in medial UKA.

Индивидуальный подход к лечению пациентов с повреждением медиального мениска в сочетании с варусной деформацией голени

Introduction Meniscus tear is one of the most common injuries of the knee joint. Medial meniscus tear accounts for 23–31 % of knee joint injuries. The main method of treatment is partial resection. As reported, 13.5 % of patients undergo arthroplasty within 15 years after meniscus resection, what is regarded as an unsatisfactory result. Purpose To evaluate and compare the long-term clinical, functional and radiological results of surgical treatment in patients with medial meniscus tear combined with varus deformity of the tibia and without it. Materials and methods From 2013 to 2020, medial meniscus tear was treated in 245 patients. The patients were divided into 4 groups. Group 1 included patients with a mechanical femorotibial angle (MFTА) from 0º to 3º who had arthroscopic meniscus resection (AMR). In the 2nd group, all patients also underwent AMR, but their MFTА was more than 3º. In group 3, patients with MFTА from 3º to 5º underwent simultaneous AMR and proximal fibular osteotomy (PFO) with the formation of a defect. Group 4 included patients with MFTА more than 5º, who underwent high tibial osteotomy (HTO) and AMR. Changes in the main lines and angles were assessed with telemetry radiography of the lower extremities. Functional results were evaluated before and after surgery using the Lysholm Knee Scoring Scale, 2000 IKDC, KOOS. Results Isolated meniscus resection in patients with MFTА more than 3º without axial correction leads to a gradual increase in the deformity by 1,070 ± 0.50º during the first year after surgery, and by 2.20 ± 0.70º to the fifth year. In groups 1, 3 and 4, there was no statistically significant increase in MFTА during the entire observation period. The clinical treatment results of patients of the four groups in the first three years after surgery did not differ statistically. However, within the period from 3 to 5 years, patients with MFTА greater than 3º who underwent only AMR had poorer clinical results than in the other groups (p &lt; 0.001). Conclusions A personalized approach to the method of surgical treatment for medial meniscus tear based on the MFTА enables to correct the mechanical axis of the lower extremities and MFTА, and thus improve the long-term clinical, functional and radiological results of surgical treatment.

Our experience of the management of severe bone defects in primary total knee arthroplasty with cement and screws with undersizing of tibia

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;There are several options for dealing with tibial bone defects during total knee arthroplasty in severe primary osteoarthritis. The aim of this study was to report the midterm results of TKA with screw and cement augmentation of moderate-sized tibial bone defects.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Patients with osteoarthritis who had posterior stabilised TKA with screw and cement augmentation of the tibia were reviewed retrospectively. Patients were assessed preoperatively and at follow-up using the International knee society knee score and function score, and radiographic analysis of alignment and signs of loosening.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results&lt;/strong&gt;&lt;strong&gt;:&lt;/strong&gt; 60 knee in 60 patients were included in the study. The mean age was 71 years; mean follow-up was 58 months. KS improved from 46 to 76 and FS from 51 to 92. The femorotibial mechanical angle changed from 174 to 178. There were no signs of osteolysis or loosening, and no revisions. Radiolucent lines at the cement bone interface were common but non- progressive.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Midterm clinical and radiographic results of TKA with screw and cement augmentation for moderate tibial defects were satisfactory.&lt;/p&gt;

Similar outcomes including maximum knee flexion between mobile bearing condylar-stabilised and fixed bearing posterior-stabilised prosthesis: a case control study

PurposeProsthesis design influences stability in total knee arthroplasty and may affect maximum knee flexion. Posterior-stabilised (PS) and condylar-stabilised (CS) designed prosthesis do not require a posterior-cruciate ligament to provide stability. The aim of the current study was to compare the range of motion (ROM) and clinical outcomes of patients undergoing cemented total knee arthroplasty (TKA) using either a PS or CS design prosthesis.MethodsA total of 167 consecutive primary TKAs with a CS bearing (mobile deep-dish polyethylene) were retrospectively identified and compared to 332 primary TKA with a PS constraint, with similar design components from the same manufacturer. Passive ROM was assessed at last follow-up with use of a handheld goniometer. Clinical scores were assessed using Patient-Reported Outcome Measures (PROMs); International Knee Society (IKS) knee and function scores and satisfaction score. Radiographic assessment was performed pre and post operatively consisting of mechanical femorotibial angle (mFTA), femoral and tibial mechanical angles measured medially (FMA and TMA, respectively) on long leg radiographs, tibial slope and patella height as measured by the Blackburne-Peel index (BPI).ResultsBoth groups had a mean follow-up of 3 years (range 2–3.7 years). Mean post-operative maximum knee flexion was 117° ± 4.9° in the PS group and 119° ± 5.2° in the CS group (p = 0.29). Postoperative IKS scores were significantly improved in both groups compared to preoperative scores (p < 0.01). The mean IKS score in the PS group was 170.9 ± 24.1 compared to 170.3 ± 22.5 in the CS group (p = 0.3). Both groups had similar radiographic outcomes as determined by coronal and sagittal alignment, tibial slope and posterior condylar offset ratio measurements. When considering the size of tibial slope change and posterior-condylar offset ratio, there was no differences between groups (p = 0.4 and 0.59 respectively). The PS group had more interventions for post-operative stiffness (arthrolysis or manipulation under anaesthesia) 8 (2.7%) compared to 1 (0.6%) in the CS group (p = 0.17).ConclusionCondylar-stabilised TKA have similar patient outcomes and ROM at a mean follow-up of 3 years compared to PS TKA. Highly congruent inserts could be used without compromising results in TKA at short term.Level of evidenceLevel IV, retrospective case control study.

Effectiveness of intraoperative tibia fibular angle and femoral fibular angle in predicting coronal lower limb alignment after medial open-wedge high tibial osteotomy

To explore the prediction of postoperative coronal lower limb alignment by the tibia fibular angle (TFA) and femoral fibular angle (FFA) after osteotomy in medial open-wedge high tibial osteotomy (MOWHTO). A clinical data of 20 patients with medial compartment osteoarthritis, who were treated with MOWHTO between September 2019 and September 2020, was retrospectively analyzed. Among them, there were 9 males and 11 females; the age ranged from 46 to 69 years, with an average of 56.0 years. The body mass index (BMI) was 21.3- 35.7 kg/m 2, with an average of 26.7 kg/m 2. Osteoarthritis involved 11 cases of left knee and 9 cases of right knee; the disease duration was 2-6 years, with an average of 3.8 years. According to the Kellgren-Lawrence classification, there were 7 cases of grade Ⅰ, 9 cases of grade Ⅱ, and 4 cases of grade Ⅲ. The angle and height for open-wedge was planned preoperatively by osteotomy master software, and the TFA and FFA were measured by software after simulated osteotomy. The intraoperative angle for open-wedge was adjusted according to TFA and FFA after simulated osteotomy.The lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), mechanical femorotibial angle (mFTA), weight-bearing line (WBL) ratio, TFA, and FFA were measured before operation and at 2 days after operation. The difference (X) between the intraoperative measurement value and the preoperative plan value of TFA/FFA, and the difference (Y) between the postoperative WBL ratio and the target alignment (62.5%) were calculated, and the correlation between the two indicators was analyzed by Pearson's test. According to the median BMI of patients (25.81 kg/m 2), the patients were allocated into high BMI group (>25.81 kg/m 2, n=10) and low BMI group (≤25.81 kg/m 2, n=10), and the influencing factors of WBL ratio was analyzed by linear regression. There was no significant difference between pre- and post-operation in LDFA and JLCA ( P>0.05); while there were significant differences between pre- and post-operation in MPTA, mFTA, and WBL ratio ( P<0.05). The TFA was (89.5±4.0)° during operation and (87.7±4.7)° after operation, showing significant difference ( t=2.991, P=0.008). There was a positive correlation between the difference (X) between the intraoperative measurement value and the preoperative plan value of TFA and the difference (Y) between the postoperative WBL ratio and the target alignment ( r=0.595, P=0.006). The FFA was (86.9±4.3)° during operation and (85.7±4.4)° after operation, showing significant difference ( t=1.760， P=0.094). There was a positive correlation between the difference (X) between the intraoperative measurement value and the preoperative plan value of FFA and the difference (Y) between the postoperative WBL ratio and the target alignment ( r=0.536, P=0.015). After BMI stratification, X was an influential factor of Y in the low BMI group ( P<0.05), but X was not an influential factor of Y in the high BMI group ( P>0.05). Intraoperative FFA and TFA can predict coronal limb alignment after MOWHTO. FFA and TFA can predict more preciselyfor patients with BMI≤25.81 kg/m 2.