Lower Limb Alignment Research Articles

Learning curve and short-term clinical outcomes of a new seven-axis robot-assisted total knee arthroplasty system: a propensity score-matched retrospective cohort study

ObjectiveThe purpose of the present study was to determine the learning curve for a novel seven-axis robot-assisted (RA) total knee arthroplasty (TKA) system and to explore whether it could provide superior short-term clinical and radiological outcomes compared with conventional surgery.MethodsIn the present retrospective study, 90 patients who underwent RA-TKA were included in robot-assisted system (RAS) group and 90 patients who underwent conventional TKA were included in the conventional group. The duration of surgery and robot-related complications were recorded to evaluate the learning curve through cumulative sum and risk-adjusted cumulative sum methods. The demographic data, preoperative clinical data, preoperative imaging data, duration of surgery, alignment of the prosthesis, lower limb force line alignment, Knee Society score, 10-cm visual analog scale pain score and range of motion were compared between the RAS and conventional groups. In addition, the proficiency group was compared with the conventional group using propensity score matching.ResultsRA-TKA was associated with a learning curve of 20 cases for the duration of surgery. There was no significant difference in indicators representing the accuracy of the prosthetic installation between the learning and proficiency phases in RA-TKA group patients. A total of 49 patients in the proficiency group were matched with 49 patients from the conventional group. The number of postoperative hip–knee–ankle (HKA) angle, component femoral coronal angle (CFCA), component tibial coronal angle (CTCA), and sagittal tibial component angle (STCA) outliers in the proficiency phase was lower than that in the conventional group, while deviations of the HKA angle, CFCA, CTCA, and STCA in the proficiency phase were significantly lower than those in the conventional group (P < 0.05).ConclusionIn summary, from the learning curve data, 20 cases are required for a surgeon using a novel seven-axis RA-TKA system to enter the proficiency phase. In the proficiency group, compared with the conventional group using propensity score matching, the RAS was found to be superior to the conventional group in prosthesis and lower limb alignment.

High tibial osteotomy for acute correction and subsequent gradual tensioning of the posterolateral knee ligament complex in treating genu varum combined with a lateral thrust using the Ilizarov technique in adults: surgical technique and early results

ObjectiveTo report the early results of using the Ilizarov technique in performing medial wedge opening high tibial osteotomy (MWOHTO) combined with gradual tensioning of the posterolateral corner in adult patients presenting with genu varum (GV) and lateral thrust.MethodsA prospective case series study included 12 adult patients with a mean age of 25.2 ± 8.1 years who presented with GV deformity associated with lateral thrust. They were evaluated clinically using the “hospital for special surgery” (HSS) knee scoring system. Radiological evaluation was performed using long film from hip to knee to ankle (HKA) radiographs; the overall mechanical alignment was measured as the HKA angle, the upper tibial deformity was measured as the medial proximal tibial angle (MPTA), and the joint line convergence angle (JLCA) was measured. Surgical technique included using Ilizarov for MWOHTO below the level of the tibial tubercle, acute correction of the GV deformity, fibular osteotomy, and gradual distalization of the proximal fibula.ResultsAfter a mean follow-up of 26.3 ± 6.4 months, all osteotomies were united. All patients achieved fibular osteotomy site bony union except two with a fibrous union. The HSS score showed improvement from a mean preoperative score of 88.7 ± 7.6 to a postoperative 97.3 ± 3.9 (P < 0.05). The overall mechanical lower limb alignment improved significantly from a mean preoperative HKA of 164.5 ± 3.2 to a postoperative 178.9 ± 1.6 (P < 0.05). The MPTA improved significantly from 74.6 ± 4.1 to 88.9 ± 2.3, as well as the JLCA from 12.17 ± 1.9 to 2.3 ± 1.7 (P < 0.05). Grade 1 pin tract infection was developed in four patients and was treated conservatively. In two patients, mild pain over the fibular osteotomy site was relieved over time. The lateral thrust reoccurred at the last follow-up evaluation in the two poliomyelitis patients.ConclusionMWOHTO, concomitant with tensioning the knee lateral soft tissue structure at the same setting through applying an Ilizarov apparatus, showed promising functional and radiological outcomes.

Comparison of accuracy for hip-knee-ankle (HKA) angle by X-ray and knee motion analysis system and the relationships between HKA and gait posture

BackgroundThe lower limb mechanical axis was used to assess the severity of knee osteoarthritis (KOA) with varus/valgus deformity and the accuracy of targeted lower limb alignment correction after operation by conventional X-rays. There are lots of parameters to assess the gait in elder patients such as velocity, stride length, step width and swing/stance ratio by knee joint movement analysis system. However, the correlation between the lower limb mechanical axis and gait parameters is not clear. This study is aimed at obtaining the accuracy of the lower limb mechanical axis by the knee joint movement analysis system and the correlation between the lower limb mechanical axis and gait parameters.MethodsWe analysed 3D knee kinematics during ground gait of 99 patients with KOA and 80 patients 6 months after the operations with the vivo infrared navigation 3D portable knee joint movement analysis system (Opti-Knee®, Innomotion Inc, Shanghai, China). The HKA (Hip-Knee-Ankle) value was calculated and compared to X-ray findings.ResultsHKA absolute variation after the operation was 0.83 ± 3.76°, which is lower than that before the operation (5.41 ± 6.20°, p = 0.001) and also lower than the entire cohort (3.36 ± 5.72). Throughout the cohort, a significant correlation with low coefficients (r = -0.19, p = 0.01) between HKA value and anterior-posterior displacement was found. In comparing the HKA values measured on the full-length alignment radiographs and 3D knee joint movement analysis system (Opti-Knee), there was a significant correlation with moderate to high coefficients (r = 0.784 to 0.976). The linear correlation analysis showed that there was a significant correlation between the values of HKA measured by X-ray and movement analysis system (R2 = 0.90, p < 0.01).ConclusionsData with equivalent results as HKA, the 6DOF of the knee and ground gait data could be provided by infrared navigation based 3D portable knee joint movement analysis system comparing with the conventional X-rays. There is no significant effect of HKA on the kinematics of the partial knee joint.

Lower Limb Alignment Evaluation. Are We Getting This Wrong? We Walk On Our Heel Not Our Ankle

Lower Limb Alignment Evaluation. Are We Getting This Wrong? We Walk On Our Heel Not Our Ankle

Aseptic loosening of tumor prostheses in distal femur after revision surgery: a retrospective study

BackgroundTumor prostheses of the distal femur after revision surgery is associated with high rates of aseptic loosening, which has introduced great challenges to the survival of patients, but only a few studies have evaluated their X-ray imaging. The purpose of this study was to analyze the risk factors for recurrence of aseptic loosening and make recommendations to reduce the incidence of aseptic loosening after revision surgery of tumor prostheses in the distal femur.MethodA retrospective analysis was performed on 23 patients who had revision surgery for distal femur prostheses due to aseptic loosening between June 2002 and June 2021. They were divided into two groups based on the condition of the prostheses after revision surgery: loosening group (9 patients) and control group (14 patients). Following the initial replacement, the length and diameter of the prosthetic intramedullary stem were measured through the standard full-length anteroposterior X-ray imaging of both lower limbs. The osteotomy length, femoral length and diameter, femoral intramedullary stem diameter, hip-knee-ankle angle (HKAA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and so on were measured as well. Following that, statistical analysis was performed.ResultsPatients in the loosening group had statistically significant differences in the ratio of prostheses length to femur length (71.89 ± 6.62) and the ratio of intramedullary stem diameter to femoral diameter (25.50 ± 6.90) (P < 0.05), when compared to the control group. The HKAA (175.58 ± 2.78), mLDFA (94.42 ± 2.57), and the deviation angle between the lower limb alignment and the tibial prostheses force line (2.23 ± 1.09) in the loosening group were significantly different from those in the control group (P < 0.05) on postoperative radiographs of the entire length of the lower limbs. The lowest score in intramedullary manubrium I indicated less osteolysis, while the highest score in intramedullary manubrium III indicated the most serious osteolysis, and the difference was statistically significant (P < 0.05).ConclusionsOur study suggests that the use of longer and thicker intramedullary stems can effectively decrease the occurrence of aseptic loosening. Additionally, it is important to avoid using the original prostheses and reconstruct the standard line of lower limb force to further reduce the incidence of aseptic loosening. It is crucial to closely monitor the distal segment of the intramedullary stem for osteolysis after surgery.

Correlation between Femoral Neck Version, Sagittal Femoral Bowing Angle and Sagittal Offset of the Femoral Head from the Distal Femur Axis in an Osteological Collection.

Radiographic analysis of lower limb alignment is crucial for the planning and evaluation of deformity correction. Assessment in the sagittal plane is often overlooked compared with the coronal plane for a variety of reasons. We aimed to investigate the relationship between the femoral head in the sagittal plane and femoral neck version in the axial plane, and how sagittal femoral bowing angle (sFBA) may contribute. Twenty-five each of high (1-2 standard deviations above mean), normal (2.5° below to 2.5° above the mean), and low (1-2 standard deviations below the mean) version femurs were randomly selected from an osteological collection database, photographed and measured for sFBA and sagittal offset of femoral head from the distal femur axis. Lines were drawn within the proximal and distal quartiles of the shaft to create sFBA. The offset of the distal quartile line and the femoral head was also measured. High intra- and inter-observer correlations were established. The relationship between parameters was assessed using the Pearson coefficient (r). Sagittal offset of the femoral head from the distal femur axis was found to be highly correlated with sFBA (r = 0.78), and only mildly with femoral neck version (r = 0.52). Sagittal femoral bowing angle and femoral neck version share no relationship (r = 0.05). Neither the sFBA nor sagittal femoral head offset is strongly associated with femoral neck version. Our data reinforce the need for long leg lateral films to include the femoral head in sagittal deformity analysis, as imaging limited to the knee will not account for the effect of bowing on femoral head position. Ho D, Liu RW, Mcclure PK. Correlation between Femoral Neck Version, Sagittal Femoral Bowing Angle and Sagittal Offset of the Femoral Head from the Distal Femur Axis in an Osteological Collection. Strategies Trauma Limb Reconstr 2023;18(1):12-15.

A Torn Discoid Lateral Meniscus Impacts Lower-Limb Alignment Regardless of Age: Surgical Treatment May Not Be Appropriate for an Asymptomatic Discoid Lateral Meniscus.

A discoid lateral meniscus (DLM) is more prone to tear, and treatment of this condition is challenging. The purpose of the present study was to investigate (1) whether a torn DLM is associated with more varus alignment than a torn semilunar lateral meniscus (SLM) and (2) whether the lower-limb alignment associated with a torn DLM changes with age. Consecutive patients who underwent arthroscopic knee surgery for a torn lateral meniscus were included. Patients with a torn DLM (confirmed on arthroscopy) were allocated to the DLM group; those with a torn SLM were allocated to the SLM group. After strict screening according to the inclusion and exclusion criteria, 436 and 423 patients were included in the DLM and SLM groups, respectively. The mechanical axis deviation (MAD), hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle, and medial proximal tibial angle were compared between the 2 groups after propensity score matching. Additionally, the correlation of the HKA and MAD with age was evaluated within the DLM group. After propensity score matching, all baseline characteristics were well balanced between the 2 groups. The DLM group had significantly more varus alignment than the SLM group (MAD: 3.6 mm ± 9.6 mm versus 1.1 mm ± 10.3 mm, respectively, p = 0.001; HKA: 179.1° ± 2.9° versus 179.9° ± 3.0°, respectively, p = 0.001). Within the DLM group, the MAD (R = 0.10, p = 0.032) and HKA (R = -0.13, p = 0.007) had a weak correlation with age. Patients with a torn DLM had more varus knee alignment than those with a torn SLM, and this trend did not increase with age after minimizing the effects of osteoarthritis. Therefore, surgical treatment may not be appropriate for asymptomatic DLM. Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Comparison of CT and EOS in assessing coronal lower limb alignment when planning total knee arthroplasty

BackgroundAs surgical technologies and alignment strategies develop, accuracy of lower limb alignment assessment gains increasing importance. The current gold standard remains long leg (4ft) radiographs. Other measures include computed tomography (CT) and EOS scans. This study aimed to compare CT and EOS long leg views to determine the reliability of assessment of hip-knee-angle (HKA) in arthritic knees. Materials and MethodsA retrospective study of 96 knees in patients undergoing total knee arthroplasty (TKA) was performed comparing HKA alignment data from EOS and CT. Coronal HKA and sagittal flexion angle were assessed by two independent observers. Inter-observer correlation was calculated. ResultsThe coronal alignment on EOS was strongly positively correlated to coronal alignment on CT (r = 0.927, p = 0.001). 12 knees (13 %) exceeded CT vs EOS difference of 3°. Inter-rater reliability was excellent (intra-class coefficients >0.9). The mean difference between CT and EOS was significantly greater for patients with fixed flexion >10° (0.68) vs <10° (−0.2) p = 0.004. Mean difference in HKA did not differ between those 0–10° varus and >10° varus (p = 0.273). Valgus HKA had a higher mean difference (1.9°) compared to varus knees (−0.4°) (p = 0.001). ConclusionCT and EOS showed excellent inter-rater reliability and correlated well. Increased sagittal plane deformity does effect coronal HKA assessment. Extreme varus did not affect the mean difference significantly, while valgus did. For the majority of patients either CT or EOS will give a reliable assessment of HKA but beware those with significant valgus or sagittal deformity where both modalities may be necessary to plan TKA.

Restoration or relative overcorrection of pre-arthritic coronal alignment leads to improved results following medial unicompartmental knee arthroplasty.

A pre-arthritic alignment strategy for medial unicompartmental knee arthroplasty (UKA) aims to restore a patient's native lower limb alignment which may translate into improved outcomes. This study aimed to assess whether patients with pre-arthritically aligned knees versus patients with non-pre-arthritically aligned knees demonstrated improved mid-term outcomes and survivorship following medial UKA. The hypothesis was that pre-arthritic alignment in medial UKA would lead to better postoperative outcomes. A retrospective study of 537 robotic-assisted fixed-bearing medial UKA was conducted. During this procedure, the surgical goal was to restore pre-arthritic alignment guided by re-tensioning of the medial collateral ligament (MCL). For study purposes, coronal alignment was retrospectively evaluated using the mechanical hip-knee-ankle angle (mHKA). Pre-arthritic alignment was estimated through the arithmetic hip-knee-ankle (aHKA) algorithm. Knees were grouped according to the difference between postoperative mHKA and estimated pre-arthritic alignment (i.e., mHKA-aHKA) as Group 1 (pre-arthritically aligned: mHKA restored within 2.0° of the aHKA), Group 2 (mHKA > 2.0° overcorrected relative to the aHKA), or Group 3 (mHKA > 2.0° undercorrected relative to the aHKA). Outcomes included the Knee Injury and Osteoarthritic Outcome Score for Joint Replacement (KOOS, JR), Kujala, proportions of knees achieving the patient acceptable symptom state (PASS) for these scores, and survivorship. PASS thresholds for KOOS, JR and Kujala were determined using a receiver operating characteristic curve method. A total of 369 knees were categorized as Group 1, 107 as Group 2, and 61 as Group 3. At 4.4 ± 1.6years follow-up, mean KOOS, JR was comparable among groups, while Kujala was significantly worse in Group 3. The proportion of knees achieving the PASS for Kujala (76.5 points) was lower in Group 3 (n = 32; 59%) compared to Group 1 (n = 260; 74%) (p = 0.02). 5-year survivorship was higher in Group 1 and Group 2 (99% and 100%, respectively) compared to Group 3 (91%) (p = 0.04). Pre-arthritically aligned knees and knees with relative overcorrection from their pre-arthritic alignment following medial UKA demonstrated improved mid-term outcomes and survivorship compared to knees with relative under correction from their pre-arthritic alignment. These results encourage restoring or relatively overcorrecting pre-arthritic alignment to optimize outcomes following medial UKA, and caution against under correction from the pre-arthritic alignment. IV, case series.

Associations between long-term exercise participation and lower limb joint and whole-bone geometry in young and older adults.

Introduction: Features of lower limb bone geometry are associated with movement kinematics and clinical outcomes including fractures and osteoarthritis. Therefore, it is important to identify their determinants. Lower limb geometry changes dramatically during development, partly due to adaptation to the forces experienced during physical activity. However, the effects of adulthood physical activity on lower limb geometry, and subsequent associations with muscle function are relatively unexplored. Methods: 43 adult males were recruited; 10 young (20-35years) trained i.e., regional to world-class athletes, 12 young sedentary, 10 older (60-75years) trained and 11 older sedentary. Skeletal hip and lower limb geometry including acetabular coverage and version angle, total and regional femoral torsion, femoral and tibial lateral and frontal bowing, and frontal plane lower limb alignment were assessed using magnetic resonance imaging. Muscle function was assessed recording peak power and force of jumping and hopping using mechanography. Associations between age, training status and geometry were assessed using multiple linear regression, whilst associations between geometry and muscle function were assessed by linear mixed effects models with adjustment for age and training. Results: Trained individuals had 2° (95% CI:0.6°-3.8°; p = 0.009) higher femoral frontal bowing and older individuals had 2.2° (95% CI:0.8°-3.7°; p = 0.005) greater lateral bowing. An age-by-training interaction indicated 4° (95% CI:1.4°-7.1°; p = 0.005) greater acetabular version angle in younger trained individuals only. Lower limb geometry was not associated with muscle function (p > 0.05). Discussion: The ability to alter skeletal geometry via exercise in adulthood appears limited, especially in epiphyseal regions. Furthermore, lower limb geometry does not appear to be associated with muscle function.

Hip abduction angle after open-wedge high tibial osteotomy is associated with the timed up & go test and recurrence of varus alignment

The aim of this study is to investigate the association between the hip abduction angle (HAA) and lower limb alignment as well as the clinical assessments in open-wedge high tibial osteotomy (OWHTO) patients. A total of 90 patients who underwent OWHTO were included. The demographic characteristics and clinical assessments (the Visual Analogue Scale for activities of daily living, the Japanese knee osteoarthritis measure, the Knee injury and Osteoarthritis Outcome Score, the Knee Society score, the Timed Up & Go (TUG) test, the single standing (SLS) test and muscle strength) were recorded. The patients were divided into two groups according to the HAA at 1 month after operation: the HAA (−) group (HAA < 0°) and the HAA (+) group (HAA ≥ 0°). Clinical scores except for the SLS test and radiographic parameters except for the posterior tibia slope (PTS), lateral distal femoral angle (LDFA) and lateral distal tibial angle (LDTA) were significantly improved at 2 years postoperatively. Regarding the two groups, scores on the TUG test in the HAA (−) group were significantly lower than those in the HAA (+) group (p = 0.011). The hip-knee-ankle angle (HKA), weight bearing line (WBLR) and knee joint line obliquity (KJLO) in the HAA (−) group were significantly higher than those in the HAA (+) group (p < 0.001, 0.001 and p = 0.025). In contrast, the LDFA in the HAA (−) group were significantly lower than those in the HAA (+) group (p < 0.001). The TUG test and the LDFA were weakly positively correlated with the HAA (r = 0.34, 0.42, p < 0.001 and 0.001). In contrast, the HKA, WBLR and KJLO had a weak negative correlation with the HAA (r = − 0.43, − 0.38 and − 0.37, p < 0.001, 0.001 and 0.001). This study showed the postoperative HAA was significantly associated with the TUG test and the HKA, WBLR, LDFA, and KJLO. A higher postoperative HAA might induce varus recurrence and poor outcomes of the gait parameter.

Learning curve of robot-assisted total knee arthroplasty and its effects on implant position in asian patients: a prospective study

BackgroundRobot-assisted total knee arthroplasty (r-TKA) can reportedly achieve more accurate implant positioning than conventional total knee arthroplasty (c-TKA), although its learning curve is controversial. Moreover, few studies have investigated r-TKA in Asians, who have different anatomical characteristics. This study aimed to determine the learning curve for r-TKA and compare implant positions between r-TKA and c-TKA according to the learning curve in Asian patients.MethodsThis prospective study included 50 consecutive c-TKAs (group C), followed by 50 consecutive r-TKAs conducted using the MAKO robotic system (Stryker, USA). Cumulative summation analyses were performed to assess the learning curve for operative time in r-TKA. Accordingly, the r-TKA cases were divided into the initial (group I) and proficiency cases (group P). The femoral and tibial component positions in the coronal, sagittal, and axial planes and lower limb alignment were compared among the three groups.Resultsr-TKA was associated with a learning curve for operative time in 18 cases. The operative time was significantly shorter in groups C and P than that in group I, with no significant difference between groups C and P. Groups I and P demonstrated fewer outliers with respect to lower limb alignment, femoral component coronal position, axial position, and tibial component sagittal position than those in group C, with no significant difference between groups I and P.ConclusionThe operative time did not differ significantly between r-TKA and c-TKA after the learning curve. Surgeons could expect more accurate and reproducible lower limb alignment and implant positioning with r-TKA in Asian patients, irrespective of the learning curve.

Value of personalized osteotomy in primary total knee arthroplasty for severe varus knee osteoarthritis

To explore application value and efficacy of personalized osteotomy in primary total knee arthroplasty (TKA) for severe varus knee osteoarthritis. From June 2018 to January 2020, 36 patients (49 knees) with severe varus knee osteoarthritis were treated, including 15 males (21 knees) and 21 females (28 knees), aged from 59 to 82 years old with an average of (67.6 ± 6.5) years old;the course of disease ranged from 9.5 to 20.5 years with an average of (15.0 ± 5.0) years;11 patients (15 knees) with Kellgren-Lawrence grade Ⅲ and 25 patients (34 knees) with grade Ⅳ according to Kellgren-Lawrence grading. According to AORI clsssification of tibial bone defects, 8 patients (15 knees) were typeⅠTa and 16 patients (18 knees) were typeⅡ T2a. All patients' femor-tibial angle (FTA) was above 15°, and received primary TKA with personalized osteotomy. Thirty-three patients (45 knees) were treated with posterior-stabilized (PS) prostheses, 13 patients (15 knees) with PS prostheses combined with a metal pad and extension rod on the tibial side, and 3 patients (4 knees) with legacy constrained condylar knee (LCCK) prostheses. FTA, posterior condylar angle (PCA), medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA) before and after operation at 1 month were measured and compared by using picture archiving and communication systems (PACS). Recovery of lower limbs before and after operation at 12 months was evaluated by American Knee Society Score(KSS), and complications were observed and recorded. All 36 patients (49 knees) were followed up from 15 to 40 months with an average of (23.46±7.65) months. FTA, MPTA were corrected from preoperative (18.65±4.28)° and (83.75±3.65)° to postoperative (2.35±1.46)° and (88.85±2.25)° at 1 month, respectively (P<0.001). PCA was decreased from (2.42±2.16)° before operation to (1.65±1.35)° at 1 month after operation, LDFA improved from (89.56 ± 3.55)° before operation to (91.63±3.38)° at 1 month after operation (P<0.05). KSS increased from (67.58±24.16) before opertion to(171.31±15.24) at 12 months after operation, 14 patients (19 knees) got excellent result, 19 (26 knees) good, and 3 (4 knees) fair. Personalized osteotomy is helpful for recovery of axial alignment of lower limbs and correct placement of prosthesis, could effectively relieve pain of knee joint, recover knee joint function.

OSTEOTOMIES AROUND THE KNEE INTERFERE WITH ALIGNMENT OF THE HINDFOOT: KNEE SURGEONS SHOULD NOT FORGET THE ANKLE JOINT. A SYSTEMATIC REVIEW OF BIOMECHANICAL AND CLINICAL STUDIES

Several emerging reports suggest an important involvement of the hindfoot alignment in the outcome of knee osteotomy. At present, studies lack a comprehensive overview. Therefore, we aimed to systematically review all biomechanical and clinical studies investigating the role of the hindfoot alignment in the setting of osteotomies around the knee.A systematic literature search was conducted on multiple databases combining “knee osteotomy” and “hindfoot/ankle alignment” search terms. Articles were screened and included according to the PRISMA guidelines. A quality assessment was conducted using the Quality Appraisal for Cadaveric Studies (QUACS) - and modified methodologic index for non-randomized studies (MINORS) scales.Three cadaveric, fourteen retrospective cohort and two case-control studies were eligible for review. Biomechanical hindfoot characteristics were positively affected (n=4), except in rigid subtalar joint (n=1) or talar tilt (n=1) deformity. Patient symptoms and/or radiographic alignment at the level of the hindfoot did also improve after knee osteotomy (n=13), except in case of a small pre-operative lateral distal tibia- and hip knee ankle (HKA) angulation or in case of a large HKA correction (&gt;14.5°). Additionally, a pre-existent hindfoot deformity (&gt;15.9°) was associated with undercorrection of lower limb alignment following knee osteotomy. The mean QUACS score was 61.3% (range: 46–69%) and mean MINORS score was 9.2 out of 16 (range 6–12) for non-comparative and 16.5 out of 24 (range 15–18) for comparative studies.Osteotomies performed to correct knee deformity have also an impact on biomechanical and clinical outcomes of the hindfoot. In general, these are reported to be beneficial, but several parameters were identified that are associated with newly onset – or deterioration of hindfoot symptoms following knee osteotomy. Further prospective studies are warranted to assess how diagnostic and therapeutic algorithms based on the identified criteria could be implemented to optimize the overall outcome of knee osteotomy.Remark: Aline Van Oevelen and Arne Burssens contributed equally to this work

Impact of the diaphyseal femoral deformity on the lower limb alignment in osteoarthritic varus knees

The impact of a diaphyseal femoral deformity on knee alignment varies according to its severity and localization. The aims of this study were to determine a method of assessing the impact of diaphyseal femoral deformities on knee alignment for the varus knee, and to evaluate the reliability and the reproducibility of this method in a large cohort of osteoarthritic patients. All patients who underwent a knee arthroplasty from 2019 to 2021 were included. Exclusion criteria were genu valgus, flexion contracture (> 5°), previous femoral osteotomy or fracture, total hip arthroplasty, and femoral rotational disorder. A total of 205 patients met the inclusion criteria. The mean age was 62.2 years (SD 8.4). The mean BMI was 33.1 kg/m2 (SD 5.5). The radiological measurements were performed twice by two independent reviewers, and included hip knee ankle (HKA) angle, mechanical medial distal femoral angle (mMDFA), anatomical medial distal femoral angle (aMDFA), femoral neck shaft angle (NSA), femoral bowing angle (FBow), the distance between the knee centre and the top of the FBow (DK), and the angle representing the FBow impact on the knee (C'KS angle). The FBow impact on the mMDFA can be measured by the C'KS angle. The C'KS angle took the localization (length DK) and the importance (FBow angle) of the FBow into consideration. The mean FBow angle was 4.4° (SD 2.4; 0 to 12.5). The mean C'KS angle was 1.8° (SD 1.1; 0 to 5.8). Overall, 84 knees (41%) had a severe FBow (> 5°). The radiological measurements showed very good to excellent intraobserver and interobserver agreements. The C'KS increased significantly when the length DK decreased and the FBow angle increased (p < 0.001). The impact of the diaphyseal femoral deformity on the mechanical femoral axis is measured by the C'KS angle, a reliable and reproducible measurement.

The Effect of Core Stability Exercises on Lower Limb Alignment, Upper and Lower Limb Function in Kyokushin Girls

Purpose: This study was conducted to investigate the effect of 6 weeks of core stability exercises in the trunk area on lower limb alignment and lower and upper limb function in Kyokushin athletes. Methods: The statistical sample of the research included 30 female Kyokushin players aged 14-18 years, who were randomly divided into two experimental and control groups. The control group performed common Kyokushin exercises and the experimental group performed core stability exercises for 6 weeks. Analysis of covariance (ANCOVA) and paired t-tests were used to compare between groups and within groups. Results: The results of the paired t-test showed a significant effect of training programs on changes in upper and lower limb function in both experimental and control groups (P≤0.05); however, a significant difference was observed between the pre-test and post-test in both control and experimental group. The test was not observed in the Q angle (P&gt;0.05). The results of ANCOVA test showed that after controlling the effect of the pre-test, a significant difference was observed in lateral jump (P≤0.05) between the experimental and control groups. However, no difference was observed between the two groups in the changes of closed kinetic chain upper extremity stability test (CKCUEST), square jump, and Q angle (P&gt;0.05). Conclusion: Considering the nature of Kyokushin and the research results, it is suggested that people working in Kyokushin do not feel the need for core stability exercises separately.

Comparison of the radiographic outcomes and total blood loss between pinless navigation and conventional method in minimally invasive total knee arthroplasty

BackgroundComputer-assisted surgical navigation has been used in total knee arthroplasty (TKA) procedures for years trying to the accuracy of prosthesis placement. We conducted this prospective randomized clinical trial to compare the accuracy of the radiographic parameters of the prosthesis, total blood loss (TBL), and related complications, between a new pinless navigation system (Stryker OrthoMap Express Knee Navigation) and conventional method in patients undergoing minimally invasive (MIS) TKA procedures.Patient and methodsA consecutive series of 100 patients underwent unilateral primary TKA were randomly assigned into two groups: navigation group and convention group. The radiographic parameters of the knee implant and the alignment of lower limb were measured at 3 months after surgery. TBL was calculated according to Nadler’s method. The duplex ultrasonography of both lower limbs was performed in all patients to detect the presence of deep-vein thrombosis (DVT).ResultsTotally, 94 patients have completed the radiographic measures. Only the coronal femoral component angle in the navigation group (89.12° ± 1.83°) had significant differences from that in the convention group (90.09° ± 2.18°) (p = 0.022). There were no differences in the rate of outliers. The mean TBL in the navigation group was 841 ± 267 mL, which was similar to that in the convention group at 860 ± 266 mL (p = 0.721). Postoperative DVT risk did not differ between the two groups (2% vs. 0%, p = 0.315).ConclusionThis pinless navigation TKA showed a comparable acceptable alignment compared with conventional MIS-TKA. There were no differences regarding postoperative TBL between the two groups.

Automatic Assessment of Lower-Limb Alignment from Computed Tomography.

Preoperative planning of lower-limb realignment surgical procedures necessitates the quantification of alignment parameters by using landmarks placed on medical scans. Conventionally, alignment measurements are performed on 2-dimensional (2D) standing radiographs. To enable fast and accurate 3-dimensional (3D) planning of orthopaedic surgery, automatic calculation of the lower-limb alignment from 3D bone models is required. The goal of this study was to develop, validate, and apply a method that automatically quantifies the parameters defining lower-limb alignment from computed tomographic (CT) scans. CT scans of the lower extremities of 50 subjects were both manually and automatically segmented. Thirty-two manual landmarks were positioned twice on the bone segmentations to assess intraobserver reliability in a subset of 20 subjects. The landmarks were also positioned automatically using a shape-fitting algorithm. The landmarks were then used to calculate 25 angles describing the lower-limb alignment for all 50 subjects. The mean absolute difference (and standard deviation) between repeat measurements using the manual method was 2.01 ± 1.64 mm for the landmark positions and 1.05° ± 1.48° for the landmark angles, whereas the mean absolute difference between the manual and fully automatic methods was 2.17 ± 1.37 mm for the landmark positions and 1.10° ± 1.16° for the landmark angles. The manual method required approximately 60 minutes of manual interaction, compared with 12 minutes of computation time for the fully automatic method. The intraclass correlation coefficient showed good to excellent reliability between the manual and automatic assessments for 23 of 25 angles, and the same was true for the intraobserver reliability in the manual method. The mean for the 50 subjects was within the expected range for 18 of the 25 automatically calculated angles. We developed a method that automatically calculated a comprehensive range of 25 measurements that defined lower-limb alignment in considerably less time, and with differences relative to the manual method that were comparable to the differences between repeated manual assessments. This method could thus be used as an efficient alternative to manual assessment of alignment. Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Assessing Leg Length Discrepancy Is Necessary Before Arthroplasty in Patients With Unilateral Crowe Type IV Hip Dislocation.

THA for high-riding developmental dysplasia of the hip (DDH) is challenging in terms of length equalization. Although previous studies suggested preoperative templating on AP pelvic radiographs is insufficient in patients with unilateral high-riding DDH because of hypoplasia of the hemipelvis on the affected side and unequal femoral and tibial length on scanograms, the results were controversial. The EOS™ (EOS™ Imaging) is a biplane X-ray imaging system using slot-scanning technology. Length and alignment measurements have been shown to be accurate. We used the EOS to compare the lower limb length and alignment in patients with unilateral high-riding DDH. (1) Is there an overall leg length difference in patients with unilateral Crowe Type IV hip dysplasia? (2) In patients with unilateral Crowe Type IV hip dysplasia with an overall leg length difference, is there a consistent pattern of abnormalities in the femur or tibia that account for observed differences? (3) What is the impact of unilateral high-riding Crowe Type IV dysplasia on femoral neck offset and knee coronal alignment? Between March 2018 and April 2021, we treated 61 patients with THA for Crowe Type IV DDH (high-riding dislocation). EOS imaging was performed preoperatively in all patients. Eighteen percent (11 of 61) of the patients were excluded because of involvement of the opposite hip, 3% (two of 61) were excluded for neuromuscular involvement, and 13% (eight of 61) had previous surgery or fracture, leaving 40 patients for analysis in this prospective, cross-sectional study. Each patient's demographic, clinical, and radiographic information was collected with a checklist using charts, Picture Archiving and Communication System, and an EOS database. EOS-related measurements that were related to the proximal femur, limb length, and knee-related angles were recorded for both sides by two examiners. The findings of the two sides were statistically compared. The overall limb length was not different between the dislocated and nondislocated sides (mean 725 ± 40 mm versus 722 ± 45 mm, mean difference 3 mm [95% CI -3 to 9 mm); p = 0.08). Apparent leg length was shorter on the dislocated side (mean 742 ± 44 mm versus 767 ± 52 mm, mean difference -25 mm [95% CI -32 to 3 mm]; p < 0.001). We observed that a longer tibia on the dislocated side was the only consistent pattern (mean 338 ± 19 mm versus 335 ± 20 mm, mean difference 4 [95% CI 2 to 6 mm]; p = 0.002), but there was no difference between the femur length (mean 346 ± 21 mm versus 343 ± 19 mm, mean difference 3 mm [95% CI -1 to 7]; p = 0.10). The femur of the dislocated side was longer by greater than 5 mm in 40% (16 of 40) of patients and shorter in 20% (eight of 40). The mean femoral neck offset of the involved side was shorter than that of the normal side (mean 28 ± 8 mm versus 39 ± 8 mm, mean difference -11 mm [95% CI -14 to -8 mm]; p < 0.001). There was a higher valgus alignment of the knee on the dislocated side with a decreased lateral distal femoral angle (mean 84° ± 3° versus 89° ± 3°, mean difference - 5° [95% CI -6° to -4°]; p < 0.001) and increased medial proximal tibia angle (mean 89° ± 3° versus 87° ± 3°, mean difference 1° [95% CI 0° to 2°]; p = 0.04). A consistent pattern of anatomic alteration on the contralateral side does not exist in Crowe Type IV hips except for the length of the tibia. All parameters of the limb length could be shorter, equal to, or longer on the dislocated side. Given this unpredictability, AP pelvis radiographs are not sufficient for preoperative planning, and individualized preoperative planning using full-length images of the lower limbs should be performed before arthroplasty in Crowe Type IV hips. Level I, prognostic study.

Knee Alignment Correction by High Tibial Osteotomy Reduces Symptoms and Synovial Inflammation in Knee Osteoarthritis Accompanied by Macrophage Phenotypic Change From M1 to M2.

This study aimed to determine whether alignment correction by high tibial osteotomy (HTO) can change the biologic intraarticular microenvironment of osteoarthritic (OA) knees. Synovial tissue (ST) and fluid (SF) were collected from the affected knees of 31 OA patients during initial HTO and plate removal surgeries. Changes in gene expression in ST were investigated by microarray and real-time polymerase chain reaction (PCR). ST specimens were also evaluated histologically using synovitis scores and immunofluorescence staining to determine macrophage polarity. Cytokines and chemokines in SF were analyzed by enzyme-linked immunosorbent assays. The mechanism of macrophage polarization was investigated in human peripheral blood mononuclear cell-derived macrophages and fibroblast-like synoviocytes (FLS) stimulated with cartilage fragments. We also evaluated Spearman correlations between Knee Injury and Osteoarthritis Outcome scores (KOOS) and macrophage-related gene expression. The microarray results indicated down-regulated inflammatory genes and pathways. Real-time PCR determined that genes expressing proinflammatory IL1B and IL6 were down-regulated and M2 macrophage-related IL1RA, IL10, CCL18, and CD206 were up-regulated. Histologic findings revealed attenuated synovitis scores and a shift from M1 to M2 macrophages. Interleukin-1β (IL-1β) concentrations in SF decreased after HTO. Cartilage fragments were responsible for M1 macrophage polarization and proinflammatory gene and protein expression in macrophages, whereas cartilage fragments up-regulated only IL-6 protein in FLS. Postoperative KOOS positively correlated with the expression of the M2-related genes CCL18 and CD206. Correction of lower limb alignment with HTO attenuated synovial inflammation and changed macrophage polarization from M1 to M2, suggesting an improved intraarticular environment in knee OA.