Tibia Vara Research Articles

No clinical outcome difference between varus phenotypes after medial opening-wedge high tibial osteotomy at 2 years follow-up.

Clinical studies regarding medial open-wedge high tibial osteotomy (MOWHTO) often analyse a large group of mechanical varus knees rather than differentiating for its primary varus-inducing component. This study aims to compare the radiological and clinical outcomes of the most prevalent varus malalignment phenotypes using the coronal plane alignment of the knee (CPAK) classification. MOWHTO cases with minimal 2-year clinical follow-up were retrospectively selected from a knee osteotomy database (2016-2020). Based on the medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA), subjects were allocated to the correct CPAK phenotype pre- and postoperatively. Clinical outcomes were the numeric rating scale (NRS), the knee injury and osteoarthritis outcome score (KOOS) and the therapeutic response rate (TRR) at 2-year follow-up. Inter-observer correlation coefficient (ICC) and unpaired student t test were performed for cross-phenotype comparison. One hundred thirty-five (135) subjects were found eligible (53.0 years old ±9.6 [19-77], 72% male, 53% left-sided). The most prevalent preoperative phenotype was CPAK 1 (n = 70 (52%)) and the postoperative phenotype was CPAK 6 (n = 66 (49%)). All CPAK phenotypes improved significantly relative to baseline but cross-phenotype comparison yielded no significant differences in clinical outcome. The TRR at 2 years was 67% for CPAK 1, 69% for CPAK 2and 87% for CPAK 4. The TRR for CPAK 6 was 64% compared with 80% for CPAK 9, which was not significantly different. At 2-yearfollow-up, no clinically significant differences are observed between different CPAK phenotypes. Accurate MOWHTO corrections provide significant clinical improvement even in the femoral-driven varus knee and the constitutional varus knee dominated by intra-articular wear. The clinical indication for MOWHTO performance should not be reduced to the medial arthritic varus knee with underlying tibial varus alone. Level IV, retrospective comparative study.

FREQUENCY OF TIBIA VARA AMONG OBESE ADOLESCENTS: DESCRIPTIVE CROSS-SECTIONAL STUDY

Background of the study: Tibia Vara is defined as a growth abnormality which leads to Varus malalignment of the lower limb. It is caused by excessive loading on the medial part of proximal tibia. Progressive Tibia Vara can result in a bowleg deformity which is most noticeable in posteromedial part of upper tibial physis. Other than that, it gives rise to in toeing of feet and lateral knee thrust, altering the normal biomechanics of an individual. This study aim to determine the frequency of Tibia Vara among obese adolescents (13-18years). Methodology: A descriptive cross-sectional study was done using non probability convenient sampling. Total 214 obese adolescents of age range 13 to 18 years were recruited from different parks and schools of Lahore. Adolescents with BMI less than 30 and with history of fracture or dislocation in the lower limb were excluded from the study. Manual goniometer was used to assess tibia vara in obese adolescent which had an intra-rater reliability of 0.75. Results: Out of 214 obese adolescents, 128 were male and 86 were female. The percentage of Tibia Vara in this population was found to be 38% (n= 82). Whereas; on the basis of gender, male participants presenting with Tibia vara was found to be 26% (n= 56) and the percentage of females reported with Tibia vara was only 12% (n= 26). Conclusion: Tibia vara had been reported in 38% of the obese adolescents in Lahore, Pakistan. Whereas, on the basis of gender most frequently tibia vara was reported among male participants. Keywords: Adolescents, juvenile, biomechanics, blount disease, obesity, sedentary lifestyle, slipped capital femoral epiphysis.

Tibia vara caused by focal fibrocartilaginous dysplasia: A rare case report

Tibia vara caused by focal fibrocartilaginous dysplasia: A rare case report

Economic evaluation of high tibial osteotomy: Closing wedge is more cost-effective than open wedge technique when analysing the KOOS-12 improvement.

The purpose of this study was to compare the cost-effectiveness of two techniques for performing a knee valgus osteotomy: opening wedge high tibial osteotomy (OW-HTO) vs closing wedge high tibial osteotomy (CW-HTO). In this economic evaluation study, a cost-effectiveness analysis from the perspective of the Spanish public healthcare system was performed, comparing OW-HTO with CW-HTO. All patients with medial knee osteoarthritis who underwent one of these procedures between 2018 and 2020 in our institution were included. The cost analysis included operating room, implant, graft and hospital admission costs. Functional outcomes (KOOS-12, Tegner activity scale, pain and satisfaction) and radiological outcomes (hip-knee-ankle angle, medial proximal tibial angle, tibial slope and patellar height) were analysed. The cost-effectiveness ratio was obtained by calculating the cost of improving the minimal clinically important difference (MCID) of KOOS-12 for each procedure. All costs are expressed in 2020 euros. Fifty-one patients met the inclusion criteria (27 OW-HTO and 24 CW-HTO). Good to excellent functional outcomes, significant pain reduction (>6 points) and high patient satisfaction (>9/10) were observed in both groups. Both techniques yielded excellent radiological outcomes. N.s. differences in functional or radiological outcomes improvements between both procedures were found. However, the OW-HTO group presented a higher total cost than the CW-HTO group (4612.1 ± 765.6€ vs. 1827.1 ± 701.9€; p < 0.001). The cost-effectiveness ratio was 818.1 ± 46.8 €/MCID for the CW-HTO procedure and 2414.3 ± 115.2 €/MCID for the OW-HTO procedure (p = 0.025). The CW-HTO procedure presented a cost-effectiveness ratio almost three times lower than the OW-HTO procedure. Both techniques allowed to achieve of good to excellent functional outcomes, significant pain reduction and high patient satisfaction while correcting the varus limb malalignment and the metaphyseal tibial varus in patients with medial compartment osteoarthritis. Level III; economic study.

Comparison of clinical, imaging and second-look arthroscopic outcomes between varus knee patients with and without preoperative tibial varus deformity after medial opening-wedge high tibial osteotomy

PurposeThis study aimed to compare the regeneration status of articular cartilage, clinical, and radiologic outcomes between varus knee patients with and without preoperative tibial varus deformity (PTVD) after medial opening-wedge high tibial osteotomy (OWHTO) MethodsVarus knee patients who had undergone OWHTO were divided into two groups according to preoperative medial proximal tibial angle (MPTA): a great varus (GV) group (MPTA <85°) and a mild varus (MV) group (85°≤preoperative MPTA <87°). The hip–knee–ankle (HKA) angle, weight-bearing line ratio (WBL%), MPTA, joint line convergence angle and joint line obliquity were measured. Second-look arthroscopy was undertaken 24 months after HTO. The Knee Society (KS) function score and knee score, and Lysholm score were used to evaluate the functional outcomes. All parameters were evaluated preoperatively and 24 months after HTO. ResultsThe GV group had greater varus than the MV group in HKA and WBL% before surgery, but greater valgus after surgery. The arthroscopic probe before HTO revealed the advanced chondral damage in the GV group and lighter chondral damage in the MV group. The regeneration of medial femoral condyle was considerably more frequent in the GV group (72.5%, 45/62) than in the MV group (50.0%, 27/54) (P = 0.030). No significant differences were observed in all functional outcomes preoperatively and 24 months after HTO. ConclusionThe extent of cartilage regeneration in patients without PTVD was inferior to that in those with PTVD, but the functional outcomes were comparable. OWHTO may be a treatment option in a selected subset of varus knee patients without PTVD.

Knee

The December 2023 Knee Roundup360 looks at: Obesity is associated with greater improvement in patient-reported outcomes following primary total knee arthroplasty; Does mild flexion of the femoral prosthesis in total knee arthroplasty result in better early postoperative outcomes?; Robotic or manual total knee arthroplasty: a randomized controlled trial; Patient-relevant outcomes following first revision total knee arthroplasty, by diagnosis: an analysis of implant survivorship, mortality, serious medical complications, and patient-reported outcome measures using the National Joint Registry data set; Sagittal alignment in total knee arthroplasty: are there any discrepancies between robotic-assisted and manual axis orientation?; Tourniquet use does not impact recovery trajectory in total knee arthroplasty; Impact of proximal tibial varus anatomy on survivorship after medial unicondylar knee arthroplasty; Bone cement directly to the implant in primary total knee arthroplasty?; Maintaining joint line obliquity optimizes outcomes in patients with constitutionally varus knees.

Outcomes of late-stages infantile Blount's disease managed by acute single stage: medial hemi-plateau elevation and metaphyseal osteotomy. Eight case series.

This study aimed to evaluate the clinical and radiological outcomes of surgical intervention involving acute medial hemi-plateau elevation and metaphyseal osteotomy with internal fixation and growth modulation for late-stages Blount's disease. A retrospective analysis was conducted on consecutive patients with late-stages infantile tibia vara between 2014 and 2020. Inclusion criteria consisted of children aged 8 years and older with Blount's disease with Langenskiold stage IV, V or VI, tibia vara more than 30*, medial plateau depression angle (MPDA) exceeding 25* and knee instability with a minimum follow-up period of 3 years. Patients with Limb length discrepancy greater than 5 cm were excluded. Data collection included assessments of age, weight, disease stage, clinical tibiofemoral angle (TFA), mechanical medial proximal tibial angle (mMPTA), MPDA, tibial torsion and knee instability. Functional outcomes were evaluated using modified Pediatric Outcome Data Collection Instruments (PODCI) scores. The study included 5 children with 8 affected limbs. Among them, three children with five limbs had recurrent deformities after previous surgeries. All cases showed significant improvements in TFAs, mMPTA, tibial torsion, knee instability and modified PODCI scores. Complications included 4 cases of superficial infections, 1 intra-articular fracture, 2 minor screw breakage and 2 on-table under correction. Surgical intervention involving acute Single-stage medial hemi-plateau elevation and metaphyseal osteotomy leads to satisfactory outcomes in late-stages Blount's disease among older children. It is crucial to achieve proper correction of all deformity components during surgery, with epiphysiodesis on the lateral side to prevent further recurrence. Continuous follow-up until skeletal maturity is essential for optimal results.

How Do the Morphological Abnormalities of Femoral Head and Neck, Femoral Shaft and Femoral Condyle Affect the Occurrence and Development of Medial Knee Osteoarthritis.

At present, the main viewpoint is that tibial varus is the main reason of medial knee osteoarthritis (OA), and high tibial osteotomy (HTO) is also the main alignment correction method to correct medial knee OA. In contrast, the impact of the anatomical alignment of the femur on medial knee OA is often overlooked. We evaluated the increased risk for medial knee OA because a varus alignment could be attributed to the anatomical reasons that include hip anatomy, femoral shaft bowing (FSB) and femoral condylar dysplasia. The present research adopted a cross-sectional study method. We selected 62 patients with HTO in the Third Hospital of Hebei Medical University from June 2021 to March 2022 as the HTO group and 55 healthy volunteers as the control group. Femoral neck-shaft angle (NSA), lateral FSB, mechanical lateral distal femoral angle (mLDFA) and hip-knee-ankle (HKA) was radiographically examined within the two groups. The femoral neck length and offset were also measured, and the ratio is represented by the ratio of the femoral neck length to off-set (N/O). The 2-tailed Student t-test was used to compare the differences between groups when the data were in accordance with a normal distribution. Otherwise, the Mann-Whitney U tests was used to compare the differences between groups. Compared to the control group, the HTO group had a higher offset (p < 0.05), greater femoral neck length (p < 0.05), and decreased (more varus) NSA (p < 0.05). The HKA in the HTO group was 172.20 ° (3.50°), which was significantly lower than that of the control group 177.00° (3.05°), (p < 0.001), while the medial OA was associated with more varus HKA. The mean mLDFA was 89.10 ° (2.35°) and 87.50° (2.85°) in the HTO and control groups (p < 0.005), respectively. The mean lateral FSB values of the full-length radiographs were larger (p < 0.001) in the HTO group (4.24° ± 3.25°) than that in control group (1.16° ± 2.32°). The reduction of NSA (coxa vara) and the increase of the mLDFA can lead to medial knee OA, while the lateral FSB also affects medial OA. We believe that femoral deformity is also one of the cause of the medial knee OA. Therefore, it is necessary to evaluate the joint deformity of the femur and tibia before surgery in order to determine whether to use HTO alone to correct the lower limb alignment.

Recurrence and Complication Rates of Surgical Treatment for Blount's Disease in Children: A Systematic Review and Meta-Analysis.

Blount's disease is a growth disorder of the proximal tibia that causes progressive genu varum in children. Surgical treatment is recommended if the deformity worsens, but which intervention is best remains controversial. This study aims to identify factors influencing outcomes and determine the most effective surgical approach. A systematic review was conducted of studies published before January 2022. In total, 63 retrospective studies with CEBM IIIb/IV levels were included (1672 knees in 1234 patients). The most commonly reported treatment was acute correction via osteotomy (47%), followed by hemiepiphysiodesis (22%) and gradual correction (18%). Combined procedures were reported in 13% of cases. The overall recurrence rate was 18%, with a significant difference when comparing the recurrence rates after gradual correction with those after hemiepiphysiodesis (7% and 29%, respectively). Major complications beyond recurrence were observed in 5% of cases. A meta-analysis of the available raw data showed a significantly increased recurrence rate (39%) among treated children who were between 4.5 and 11.25 years of age and were followed for a minimum follow-up of 2.5 years. Overall, poor evidence with which to establish an optimal treatment for Blount's disease was found. This study remarked on the need for early diagnosis, classification, and treatment of infantile tibia vara, since a significant rate of recurrence was found in neglected cases.

Comparison of Static Lower Extremity Alignment in Female Ballet Dancers and Non-ballet Dancer

PURPOSE This study aimed to: 1) compare the differences in static lower-extremity alignment (SLEA) between female ballet dancers (BD) and non-ballet dancers (NBD); 2) investigate the differences among gesture leg (GL) and supporting leg (SL) in BD and dominant leg (DL) in NBD; and 3) compare limb asymmetry between groups.METHODS Twenty-nine female BD and 20 NBD were recruited for this study. The quadriceps, tibiofemoral, rearfoot, and genu-recurvatum angles, tibial torsion and varum, and navicular drop height were measured. An independent &lt;i&gt;t&lt;/i&gt;-test was conducted to compare SLEA and limb asymmetry between groups. One-way analysis of variance with Bonferroni post-hoc tests were performed to determine the differences among the GL, SL and DL.RESULTS BD showed lower quadriceps and rearfoot angles, less tibial varum and navicular drop, and greater tibiofemoral angle (&lt;i&gt;p&lt;/i&gt;&lt;.005) than NBD. BD showed less quadriceps angle asymmetry but greater tibial torsion asymmetry (&lt;i&gt;p&lt;/i&gt;&lt;.01) than NBD. GL and SL in BD showed differences in quadriceps, tibiofemoral, rearfoot angle, tibial torsion and navicular drop compared to NBD.CONCLUSIONS Repetitive dance movements can transfer varying forces to the GL and SL, potentially contributing to SLEA asymmetry. An intervention strategy that can reduce SLEA asymmetry in BD is needed, as is the identification of elements of ballet training that contribute to maintaining a normal SLEA.

Fixed-Bearing Unicompartmental Knee Arthroplasty in Tibia Vara Knees Results in Joint Surface Malalignment and Varus Joint Line Obliquity, but Does Not Affect Functional Outcomes at Greater Than 5 Years Follow-Up

BackgroundThis study aimed to investigate the clinical outcomes of fixed-bearing medial unicompartmental knee arthroplasty (UKA) for tibia vara knees and the associated changes in joint space malalignment (JSM) and joint line obliquity (JLO). MethodsWe retrospectively analyzed a consecutive group of 100 patients who underwent fixed-bearing medial UKA with a preoperative medial proximal tibia angle (MPTA) ≥86° (n = 50) and MPTA <86° (n = 50) and who had a minimum 5-year follow-up. Radiological parameters, including the hip-knee-ankle angle, MPTA, and the postoperative JSM and JLO, were measured. Functional evaluation was performed using the range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index score. ResultsThe MPTA <86° group showed significantly higher postoperative JLO (91.8 versus 90.4°, respectively; P = .002) and JSM (6.1 versus 4.2°, respectively; P = .026) compared to the MPTA ≥86° group. Functional outcomes, including range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index scores, were not significantly different between the 2 groups. ConclusionsFixed-bearing medial UKA is a safe and effective surgical option for patients who have tibia vara knees, as an increase in JLO and JSM postoperatively does not have a clinically relevant impact, even after a minimum 5-year follow-up.

Supplementary Fibular-guided Growth in Treatment of Late-onset Blount Disease

Purpose: Blount disease is due to an idiopathic defect in the posteromedial proximal tibial physis resulting in increasing bowing of the leg in addition to lateral knee thrust with lateral collateral ligament laxity. Our rationale is that Blount disease has a bony and ligamentous laxity element of the lateral collateral ligament that can be corrected simultaneously through hemiepiphysiodesis of the tibia and epiphysiodesis of proximal fibula physis by cannulated screws. Patients and Methods: This is a retrospective study conducted on 23 limbs with tibia vara treated between 2010 and 2017 followed up for 2 to 6 years. Ages ranged from 9 to 13 years with a late-onset type of Blount disease. We used a percutaneous transphyseal fully threaded screws traversing the proximal tibial lateral hemiepiphysis, and another screw inserted traversing the proximal fibular epiphysis. Results: There was a statistically significant improvement of the radiographic parameters, especially in the form of joint line congruence angle in both supine and standing positions. All patients were clinically and radiographically completely corrected without complications, except 1 patient with a surgical site superficial infection, treated medically. Conclusion: Fibular-guided growth surgery with lateral proximal tibia epiphysiodesis is a minimally invasive technique that improves the corrective power of hemiepyphysiodesis of the posterolateral compartment of the knee. Level of Evidence: Level IV, retrospective case series.

Long leg radiographs underestimate the degree of constitutional varus limb alignment and joint line obliquity in comparison with computed tomography: a radiographic study.

The purpose of this study was to understand if differences exist between computed tomography (CT) and long leg radiographs (LLR) when defining coronal plane alignment of the lower limb in total knee arthroplasty (TKA). It aimed to identify any such differences between the two imaging modalities by quantifying constitutional limb alignment (arithmetic hip-knee-ankle angle (aHKA), joint line obliquity (JLO) and Coronal Plane Alignment of the Knee (CPAK) type within the same population. A retrospective radiographic study compared pre-operative LLR and CT measurements in patients undergoing robotic-assisted TKA. The aHKA, JLO and CPAK types were calculated after measuring the medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA). The primary outcomes were the mean differences in aHKA (MPTA-LDFA), JLO (MPTA + LDFA) and proportions of CPAK types between LLR and CT groups. The secondary outcomes were the differences in CT-derived MPTA values based on four different tibial sagittal landmarks. After exclusions, 465 imaging sets were analysed in 394 patients. There was a statistically significant mean difference between LLR and CT, respectively, for both MPTA (87.5° vs. 86.2°; p < 0.01) and LDFA (88.7° vs. 87.3°; p < 0.01). There were also statistically significant differences for aHKA (-0.2° vs. -1.1°) and JLO (175.1° vs. 173.4°) for LLR and CT, respectively (both p < 0.01). CT increased the proportion of patients with CPAK Type I (constitutional varus aHKA, apex distal JLO) and CPAK Type II (neutral aHKA, apex distal JLO), and decreased numbers of CPAK Types III-VI. There were significant mean differences in the MPTA using varying sagittal landmarks. Alignment determined by LLRs underestimates the magnitude of both constitutional varus alignment and joint line obliquity compared to CT, differences that notably increase the proportions of patients included in CPAK Types I and II. These distinctions are primarily due to underestimation of proximal tibial varus when measured on LLRs compared to CT, which more specifically defines articular weight-bearing points. III.

Open Wegde Tibial Osteotomy: New Approach and Advantages of the Technique

The tibial valgus osteotomy is a so-called conservative" surgical technique used in the treatment of knee osteoarthritis in the early stages of evolution, as opposed to non-conservative techniques such as knee prostheses. Internal knee osteoarthritis is promoted by an anomaly of the axis of the lower limb (genu varum). When there is an axis defect, the stresses are poorly distributed and the weight of the body is applied more on the internal side, accelerating the wear of the cartilage. When this is not too significant, we can propose to slow down its evolution by modifying the axis of the knee by an osteotomy. This is the tibial valgus osteotomy. This osteotomy can be performed in 2 different ways either by “opening” the internal part of the tibia (it is the tibial varus osteotomy by internal addition) or by “closing” its external part (external subtraction osteotomy). The choice of one or the other of these 2 operating techniques is up to each surgeon.

Three-dimensional computed tomographic angular measurements of the canine tibia using a bone-centered coordinate system.

Canine tibial alignment is determined by two-dimensional angular measurements, and tibial torsion is challenging. Aim of the study was the development and evaluation of a CT technique to measure canine tibial varus and torsion angles independent from positioning and truly three-dimensional. A bone-centered 3D cartesian coordinate system was introduced into the CT-scans of canine tibiae and aligned with the anatomical planes of the bone based on osseous reference points. Tibial torsion, and varus (or valgus) angles were calculated based on geometric definition of projection planes with VoXim® medical imaging software using 3D coordinates of the reference points. To test accuracy of the tibial torsion angle measurements, CT scans of a tibial torsion model were performed in 12 different hinge rotation setups ranging from the normal anatomical situation up to +/ 90° and compared to goniometer measurements. Independency of tibial positioning on the CT scanner table was evaluated in 20 normal canine tibiae that were scanned in a position parallel to the z-axis and two additional off-angle double oblique positions having 15° and 45° deviation in direction of the x- and y-axes. Angular measurements in oblique positions were compared with the normal parallel position by subtraction. Precision was tested using clinical CT scans of 34 canine patients with a clinical diagnosis of patellar luxation. Accuracy testing in the tibial torsional deformity model revealed a difference of 0.2° demonstrated by Passing-Bablok analysis and Bland-Altman-Plots. Testing for independency from tibial positioning resulted in mean differences less than 1.3°. Precision testing in clinical patients resulted in coefficients of variation for repeated measurements of 2.35% (intraobserver agreement) and 0.60% (interobserver agreement) for the tibial torsion angle, and 2.70% (intraobserver agreement) and 0.97% (interobserver agreement) for the tibial varus (or valgus) angle. The technique is lacking determination of bone deformities in the sagittal plane, and demonstration of accuracy in severe complex bone deformities in multiple planes.In conclusion, we developed a method to measure canine tibial torsional and varus or valgus deformities, that calculates in 3D space, and we demonstrated its accuracy in a torsional deformity model, and its precision in CT data of clinical patients.

Gradual on top-of-acute correction of neglected adolescent tibia vara by percutaneous tibial osteotomy and two-ring Ilizarov frame.

This study aims to assess the effect of gradual correction after acute translation of the tibia in tibia vara using a two-ring Ilizarov frame on the correction of mechanical axis deviation (MAD), union time, and the rate of complications. Between September 2018 and January 2021, a total of 30 patients (25 males, 5 females; mean age: 20±5 years; range, 15 to 25 years) with adolescent tibia vara were included. The patients had a transverse fibular ostectomy and percutaneous tibial osteotomy below the level of the tibial tuberosity. Acute correction of the rotation deformity combined with acute translation was done. A two-ring Ilizarov frame with a medial distractor and two lateral hinges were used to fix the osteotomy and the coronal plane deformity was gradually corrected. The mean follow-up was 24±4 months. All patients had improvement in the mechanical medial proximal tibial angle (mMPTA) and MAD postoperatively. There was an improvement in the Hospital for Special Surgery knee score at one year postoperatively. No neurovascular complications or union complications were observed. Acute translation followed by gradual angulation of the proximal tibia in cases with adolescent tibia vara yields better correction of the mechanical axis with good functional and radiological outcomes.

Maintaining Joint Line Obliquity Optimizes Outcomes of Functional Alignment in Total Knee Arthroplasty in Patients With Constitutionally Varus Knees

BackgroundFunctional alignment (FA) strives to balance the knee soft-tissue envelope during total knee arthroplasty (TKA) using implant alignment adjustments rather than soft-tissue releases. There is a debate on how best to achieve FA. We compared minimum two-year outcomes between FA with a mechanical alignment plan [FA(m)] and FA with a kinematic alignment plan [FA(k)]. The null hypothesis was that there would be no difference in outcomes between FA(m) and FA(k). MethodsProspective data was collected from 300 consecutive robotic-assisted FA TKAs [135 FA(m) and 165 FA(k)]. Patient reported outcomes were obtained preoperatively and 2 years postoperatively. The coronal plane alignment of the knee classification was used to classify knee alignment phenotypes. ResultsOverall limb alignment was equivalent between groups. Final implant alignment was different between FA(m) and FA(k) groups, with FA(k) TKAs having higher tibial varus (P < .01), higher femoral valgus (P < .01), and higher joint line obliquity (P < .01). Patients reported higher Forgotten Joint Score-12 scores with FA(k) TKAs (79.4 versus 71.6, P = .018) and greater range of motion (125 versus 121°; P = .003). Patients who had constitutional varus reported the greatest improvement with FA(k) technique (Forgotten Joint Score at minimum 2 years of 89 versus 65; P < .001). ConclusionUtilizing an individualized alignment plan [FA(k)] led to a final implant position with greater joint line obliquity, yet the same overall limb alignment. This was associated with improved outcomes at 2 years post-TKA in patients who had constitutional varus. Three-dimensional component position and joint line obliquity affect the outcomes following TKA independently of coronal limb alignment.

Predicting Success of Deformity Correction With Tension Band Plating in Early-Onset Tibia Vara.

Angular deformity correction with tension band plating has not been as successful in early-onset tibia vara (EOTV) as it has been in other conditions. Our hypothesis is that perioperative factors can predict the success of lateral tibial tension band plating (LTTBP) in patients with EOTV. A retrospective review was performed at 7 centers evaluating radiographic outcomes of LTTBP in patients with EOTV (onset <7y of age). Single-event tibial LTTBP outcome was assessed through medial proximal tibial angle (MPTA). The final limb alignment following comprehensive limb growth modulation (CLGM), which could include multiple procedures, was assessed by mechanical axis zone (MAZone), mechanical tibio-femoral angle (mTFA), and mechanical axis deviation (MAD). Preoperative age, weight, deformity severity, medial physeal slope, and Langenskiöld classification +/- modification were investigated as predictors of outcome. Success was defined as the correction or overcorrection to normal age-adjusted alignment. The minimum follow-up was 2 years except when deformity correction, skeletal maturity, or additional surgery occurred. Fifty-two patients with 80 limbs underwent 115 tibial LTTBP procedures at a mean age of 5.3y, including 78 primary, 21 implant revisions, and 15 reimplantations for recurrence. Tibial LTTBP resulted in a mean change of +8.6 o in MPTA and corrected 53% of tibias. CLGM resulted in MAD correction for 54% of limbs.Univariate analysis showed that success was best predicted by preoperative age, weight, MPTA, and MAD. Multivariate analysis identified that preoperative-MPTA/MAD and preoperative-weight<70kg were predictive of MPTA and MAD correction, respectively. The probability of success tables are presented for reference. Successful correction of MPTA to age-adjusted norms following a single-event LTTBP occurred in 53% of tibias and was best predicted by preoperative-MPTA and preoperative body weight <70kg. Comprehensive growth modulation corrected limbs in 54%. The probability of correction to age-adjusted MAD is best estimated by preoperative-MAZone 1 or 2 (MAD ≤40mm). Limbs with preoperative-MAD>80mm improved, but ultimately all failed to correct completely with CLGM. Osteotomy may need to be considered with these severe deformities. While modified Langenskiöld classification and medial physeal slope have been shown to predict the outcome of osteotomy, they were not predictive for LTTBP. Change in MPTA was common after physeal untethering. Level-III.

Predicting Deformity Correction of Growth Modulation in Late-onset Tibia Vara.

Growth modulation in late-onset tibia vara (LOTV) has been reported to yield variable results. We hypothesized that parameters of deformity severity, skeletal maturity, and body weight could predict the odds of a successful outcome. A retrospective review of tension band growth modulation for LOTV (onset ≥8 y) was performed at 7 centers. Tibial/overall limb deformity and hip/knee physeal maturity were assessed on preoperative anteroposterior standing lower-extremity digital radiographs. Tibial deformity change with first-time lateral tibial tension band plating (first LTTBP) was assessed by medial proximal tibia angle (MPTA). Effects of a growth modulation series (GMS) on overall limb alignment were assessed by mechanical tibiofemoral angle (mTFA) and included changes from implant removal, revision, reimplantation, subsequent growth, and femoral procedures during the study period. The successful outcome was defined as radiographic resolution of varus deformity or valgus overcorrection. Patient demographics, characteristics, maturity, deformity, and implant selections were assessed as outcome predictors using multiple logistic regression. Fifty-four patients (76 limbs) had 84 LTTBP procedures and 29 femoral tension band procedures. For each 1-degree decrease in preoperative MPTA or 1-degree increase in preoperative mTFA the odds of their successful correction decreased by 26% in the first LTTBP and 6% by GMS, respectively, controlling for maturity. The change in odds of success for GMS assessed by mTFA was similar when controlling for weight. Closure of a proximal femoral physis decreased the odds of success for postoperative-MPTA by 91% with first LTTBP and for final-mTFA by 90% with GMS, controlling for preoperative deformity. Preoperative weight ≥100 kg decreased the odds of success for final-mTFA with GMS by 82%, controlling for preoperative mTFA. Age, sex, race/ethnicity, type of implant, and knee center peak value adjusted age (a method for bone age) were not predictive of outcome. Resolution of varus alignment in LOTV using first LTTBP and GMS, as quantified by MPTA and mTFA, respectively, is negatively impacted by deformity magnitude, hip physeal closure, and/or body weight ≥100 kg. The presented table, utilizing these variables, is helpful in the prediction of the outcome of the first LTTBP and GMS. Even if complete correction is not predicted, growth modulation may still be appropriate to reduce deformity in high-risk patients. Level III.

The effect of orthotics on plantar pressure in children with infantile tibia vara (Blount's disease)

Albeit some studies have revealed the effectiveness of the orthosis use in infantile tibia vara (ITV), hitherto no study has shown the effects of these orthosis on plantar pressures. This study aims to reveals the effects of orthosis on plantar pressure in infantile tibia vara. Fourteen children (mean age: 27.14 ± 5.00 months) with infantile tibia vara made up the study group and 14 healthy children (mean age: 26.42 ± 5.33 months) constituted the control group. The plantar pressure distribution was evaluated with WALKINSENSE. ITV group was evaluated before and after orthosis. The control group did not use orthosis and was evaluated once. After orthosis, it was determined that lateral foot pressure decreased, and medial foot pressure increased in the hindfoot. After orthosis, medial pressure decreased in the forefoot (p < 0.05). The pressure in the forefoot of the control group was significantly higher than that in the ITV group (before and after orthosis) (p < 0.05). After orthosis, the pressure was similar in the posterior and mid-foot sensors between the ITV group and the control group (p˃0.05). The orthosis can be effective in achieving the normalization of the soles pressure distribution in children with ITV.