Relationships between reference lines altered during leg shape correction as requested by the patient

Introduction Patients who want their leg shape changed often identify the O- or X-shaped legs with varus or valgus deformity striving for ideally shaped legs as classified by A. A. Artemiev. The purpose of the study was to compare changes in the relationship between reference lines as mechanical axis deviation (MAD), mechanical medial proximal tibial angle (mMPTA), mechanical lateral distal tibial angle (mLDTA) and the associated duration of the correction (CP), fixation (FP) and frame-on periods (FoP) in patients who underwent correction to have the legs shape as requested and those who underwent tibial deformity correction. Material and methods There were 43 patients (84 segments operated on) in the cosmesis group and 15 participants (28 segments operated on) in orthopedic group. Preperative MAD, mMPTA, mLDTA measured 17.48 ± 1.14 mm medially, 84.90 ± 0.35° and 90.61 ± 0.39° in the cosmesis patients; 19.18 ± 2.86 mm medially, 84.04 ± 0.35°, 89.09 ± 0.37° in orthopaedic patients with no statistically significant differences observed between the groups. Results CP, FP and FoP lasted for 41.93 ± 3.96, 97.67 ± 7.78 and 139.60 ± 5.15 days in the cosmesis group, and 18.22 ± 3.05, 134.89 ± 9.42 and 153.00 ± 8.49 in controls. FP/CP, CP/FoP, FP/FoP measured 0.57 ≈ 1/2, 0.31 ≈ 1/3, 0.69 ≈ 2/3 in the cosmesis group and 0.15 ≈ 1/7; 0.12 ≈ 1/8; 0.88 ≈ 7/8 in controls. MAD, mMPTA, mLDTA measured 6.08 ± 0.87 mm laterally, 90.80 ± 0.31°, 88.62 ± 0.35° in the cosmesis participants, and 0.61 ± 0.82 mm laterally, 89.46 ± 0.54°, 87.68 ± 0. 63° in controls. Discussion There were no statistically significant differences in FoP with different duration of CP (≈ 1/3 FoP for the cosmesis group and ≈ 1/8 FoP for controls). The means of MAD, mMPTA of measured up to tibial valgus in cosmesis patients and were well within acceptable limits of normal in controls.Tibial valgus was caused by too much overcorrection (by ¼ on average).

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Genu valgum deformity – correction by a wedgeless implantless femoral “V” osteotomy

Acta Orthopaedica Belgica ◽

10.52628/87.2.07 ◽

2021 ◽

Vol 87 (2) ◽

pp. 247-254

Author(s):

Amrit Goyal ◽

Vikas Gupta ◽

Meenakshi Goyal ◽

Rajesh Chandra ◽

Vinod K Sharma

Keyword(s):

Internal Fixation ◽

Mechanical Axis ◽

Deformity Correction ◽

Image Intensifier ◽

Valgus Knee ◽

Axis Deviation ◽

Mechanical Axis Deviation ◽

Tibiofemoral Angle ◽

Average Value ◽

Intermalleolar Distance

Coronal malalignment of the knee joint is very common in developing countries especially because of nutritional rickets. Significant valgus deformity needs to be treated surgically to improve appearance, gait and function of the patient. The purpose of this prospective study was to evaluate the results of supracondylar “V” osteotomy as a surgical technique for correction of the valgus knee deformity. This study was conducted in a tertiary level teaching hospital and 30 cases were included in the study. For all the patients deformity was assessed using ana- tomical tibiofemoral angle, mechanical axis deviation and intermalleolar distance preoperatively and post- operatively. The average age of our patients was 13.7 years and the average follow up was3.29 years (1.39-14.22 yrs). Clinically the average value of intermalleolar distance preoperatively was 16cm and 3.2 cm postperatively. Average pre-operative tibiofemoral angle was 23° and the average postoperative angle was 6 0 which was found to be statistically significant using the Paired t test (p<0.005). The average value of preoperative mechanical axis deviation was 3.1 cm which decreased to an average value of 1.1 cm postoperatively. The results with this technique have been encouraging. The advantages of this technique are low morbidity, good stability allowing early ambulation, ability to adjust alignment postoperatively by casting and no need for internal fixation. Few studies have been conducted on osteotomies that do not require internal fixation and are inherently stable. This technique has the advantage of practically no occurrence of any infection or a second surgery to remove hardware in children and adolescents. Since no specialized instrumentation, image intensifier and implants are required, it is cost effective and can be used in any primary care or district level surgical setup in a developing country like ours.

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Potential Influence of Factors For Genu Valgus With Hereditary Multiple Exostoses

10.21203/rs.3.rs-491364/v1 ◽

2021 ◽

Author(s):

Ya Liu ◽

Jianfeng Fang ◽

Yao Liu ◽

Zheng Zhang ◽

Xiaodong Wang ◽

...

Keyword(s):

Mechanical Axis ◽

Valgus Deformity ◽

Osteoarthritis Of The Knee ◽

Potential Influence ◽

Mechanical Axis Deviation ◽

Hereditary Multiple Exostoses ◽

Medial Proximal Tibial Angle ◽

Multiple Exostoses ◽

Bivariate Logistic Regression ◽

Limb Deformities

Abstract Background: Genu valgus is one of the most common limb deformities in hereditary multiple exostoses (HME). However, it is easily concealed and may account for subsequent osteoarthritis of the knee. The potential influence of factors for genu valgus is still not well known. Methods: The knees of 56 patients (33 male, 23 female) with HME were investigated bilaterally. The mean age at evaluation was 8.9 years (range, 1.5–15.8 years). Knee valgus was described by the mechanical axis deviation (MAD), mechanical lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA). We investigated gender, age, body mass index (BMI), total number of palpable osteochondromas, number of radiographic osteochondromas around the knee, forearm deformities, morphology and distribution of lesions, and correlations between these factors and genu valgus. The measurement of LDFA and MPTA was to identify the sources of genu valgus deformity.Results: Based on the measurement of the mechanical axis, limbs were classified as genu valgus (n = 22) or normal mechanical axis groups (n = 90). The different severities of the genu valgus patients were classified by MAD. By bivariate logistic regression, genu valgus was significantly associated with more sessile and flared metaphyseal lesions. However only the number of flared metaphyseal lesions had a significant influence on the severity of genu valgus. By analyzing the LDFA and medial proximal tibial angle MPTA, it was found that abnormalities of both proximal tibia and distal femur play important roles in genu valgus. There were no differences between the genu valgus and normal mechanical axis groups in forearm deformities caused by HME, nor did this differ by severity of genu valgus. Conclusions: Early detection of sessile and flared metaphyseal knee lesions in patients with HME can contribute to early intervention of genu valgus.Level of Relevance: Level 2.

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Trigonometric Analysis of the Mechanical Axis Deviation Induced by Telescopic Intramedullary Femoral Lengthening Nails

Journal of Applied Biomechanics ◽

10.1123/jab.27.4.385 ◽

2011 ◽

Vol 27 (4) ◽

pp. 385-391 ◽

Cited By ~ 5

Author(s):

Rolf D. Burghardt ◽

John E. Herzenberg ◽

Manfred H. Burghardt

Keyword(s):

Knee Joint ◽

Mechanical Axis ◽

Axis Deviation ◽

Intramedullary Nails ◽

Mechanical Axis Deviation ◽

Femoral Lengthening ◽

Relationship Of ◽

The Relationship ◽

Lengthening Nail

Femoral lengthening with intramedullary nails can create alterations in the mechanical axis of the limb. This is based on the relationship of the anatomic femur axis to the mechanical femur axis, which is typically 5–9 degrees valgus. We developed trigonometric formulas to calculate the predicted change, using the lengths of the tibia, femur, and whole limb; the amount of lengthening; and the angle between the anatomic and the mechanical axis of the femur. We recognized three patterns depending on whether the overall limb mechanical axis is lateral (valgus), medial (varus), or straight through the center of the knee. The varus and valgus patterns lead to similar formulas. When the mechanical axis goes directly through the center of the knee joint, the formula simplifies. These formulas could be incorporated into digital radiographic programs to predict the change in mechanical axis deviation that will develop from lengthening along the anatomic femur axis with an intramedullary lengthening nail.

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Effect of foot deformity on conventional mechanical axis deviation and ground mechanical axis deviation during single leg stance and two leg stance in genu varum

The Knee ◽

10.1016/j.knee.2007.07.009 ◽

2007 ◽

Vol 14 (6) ◽

pp. 452-457 ◽

Cited By ~ 24

Author(s):

Sameer Shrikrishna Desai ◽

Gautam M. Shetty ◽

Hae-Ryong Song ◽

Seok Hyun Lee ◽

Tae Young Kim ◽

...

Keyword(s):

Mechanical Axis ◽

Genu Varum ◽

Axis Deviation ◽

Foot Deformity ◽

Mechanical Axis Deviation ◽

Single Leg Stance

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Interobserver and Intraobserver Reliability in the Evaluation of Mechanical Axis Deviation

Journal of Pediatric Orthopaedics ◽

10.1097/bpo.0b013e31819b9188 ◽

2009 ◽

Vol 29 (3) ◽

pp. 281-284 ◽

Cited By ~ 20

Author(s):

J. Eric Gordon ◽

Ryan C. Chen ◽

Matthew B. Dobbs ◽

Scott J. Luhmann ◽

Margaret M. Rich ◽

...

Keyword(s):

Mechanical Axis ◽

Intraobserver Reliability ◽

Axis Deviation ◽

Mechanical Axis Deviation

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An Innovative Method of Assessing the Mechanical Axis Deviation in the Lower Limb in Standing Position

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2016/17324.8042 ◽

2016 ◽

Author(s):

Jagannath Kamath

Keyword(s):

Lower Limb ◽

Mechanical Axis ◽

Standing Position ◽

Axis Deviation ◽

Mechanical Axis Deviation ◽

Innovative Method

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A computer assessment of the effect of hindfoot alignment on mechanical axis deviation

Computer Methods and Programs in Biomedicine ◽

10.1016/j.cmpb.2013.09.010 ◽

2014 ◽

Vol 113 (1) ◽

pp. 126-132 ◽

Cited By ~ 6

Author(s):

Naven Duggal ◽

Gabrielle M. Paci ◽

Abhinav Narain ◽

Leandro Grimaldi Bournissaint ◽

Ara Nazarian

Keyword(s):

Mechanical Axis ◽

Axis Deviation ◽

Computer Assessment ◽

Hindfoot Alignment ◽

Mechanical Axis Deviation

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A Computer Model Assessment of the Effect of Hindfoot Alignment on Mechanical Axis Deviation and Ankle Fractures

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00214 ◽

2018 ◽

Vol 3 (3) ◽

pp. 2473011418S0021

Author(s):

Naven Duggal ◽

Patrick Williamson ◽

Ara Nazarian

Keyword(s):

Compressive Stress ◽

Lower Limb ◽

Muscle Force ◽

Mechanical Axis ◽

Stress Fractures ◽

Biomechanical Study ◽

Lateral Malleolus ◽

Axis Deviation ◽

Pes Planus ◽

Mechanical Axis Deviation

Category: Basic Sciences/Biologics Introduction/Purpose: Conventional mechanical axis is calculated from the center of the femoral head to the center of the ankle. Mechanical axis deviation of the lower limb can be associated with a pes planus hindfoot. Malalignment of the lower limb has been shown to increase progression of osteoarthritis of the knee and ankle and decrease joint arthroplasty longevity. Clinically, a pes planus hindfoot has also been seen with patients who present with a stress fracture of the lateral malleolus. This biomechanical study aims to utilize computer modeling to evaluate the hypothesis that altered force transmission on the lateral malleolus with resultant stress fractures in a pes planus model is attributable to mechanical axis deviation. Methods: A free-body diagram of the fibula in single leg stance was generated by modeling the fibula as a uniform cylinder. It includes the axially applied load and a single evertor muscle force as an eccentric load applied to the mid-diaphysis . Previously derived relationships between body weight (BW = 667 N, 150lbs) and a) normal axial fibula load (BW*0.17) and b) muscle force (BW*0.25) were used. Fibula length (286.5 mm) and diameter (8 mm) were derived from anthropological data. Mechanical axis deviation in pes planus was simulated in two manners: 1) increased (2 and 3 times normal) axial fibula load and 2) increased evertor muscle force. The compressive stress along the length of the bone was determined through static analysis and the total applied load was compared to theoretical Euler buckling load. Results: Increasing the load on the fibula, either by increasing the axial load (Figure 1A) or the muscle load (Figure 1B), increases the maximum compressive stress below the lateral muscle origins, namely the section between the distal tibiofibular ligaments and the evertor muscles. The compressive stress for both cases was less than the compressive yield stress of cortical bone (200 MPa) and cancellous bone (100 MPa) even as the force was increased to the critical buckling value. This model serves as a first attempt to relate the spatial distribution of stress in the fibula with muscle force, axial load, and compressive stress in light of distal fibular fractures associated with pes planus. Conclusion: The importance of lower extremity mechanical axis deviation is well established in the progression of arthritis in the knee and ankle. The role of the mechanical axis in the predisposition of stress fractures around the ankle has not been evaluated in the literature. This biomechanical study represents the first attempt to understand how deviation of the mechanical axis can result in stress fractures of the lateral malleolus. Future studies including a finite element analysis will provide further information and the results of these studies may alter how clinicians treat patients with stress fractures of the fibula.

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