Mean Hip-knee-ankle Angle Research Articles

Highly variable coronal tibial and femoral alignment in osteoarthritic knees: a systematic review.

There is a lack of knowledge about coronal alignment variability in osteoarthritic knees. Therefore, the purpose of this article was to systematically review the literature and collect data about the lower limb alignment including hip-knee-ankle angle (HKA), femoral mechanical angle (FMA), tibial mechanical angle (TMA) and the joint line convergence angle (JLCA) in osteoarthritic knees. A systematic review was performed using the electronic databases MEDLINE (PubMed), EMBASE and Google Scholar. The following keywords were used: (morphology OR geometr* OR anatomy OR alignment OR phenotypes), (coronal OR neutral OR varus OR valgus), (knee OR lower limb OR femur OR tibia) and (osteoarthritis OR arthritis). Out of 110 full-text articles retrieved, 15 studies were included. Demographic information included author's names, year of publication, imaging modality, sample size and patient demographics (i.e. sex, age, etc.). Descriptive statistics, such as means, ranges, and measures of variance [e.g. standard deviations, 95% confidence intervals (CI)] for all angles (HKA, FMA, TMA, JLCA) are presented. Thirteen studies reported mean overall HKA angles ranging from 163.5° ± 2.3° to 179.9° ± 4.8°. The mean HKA angles in females were between 164.1° ± 7.2° and 178.8° ± 4.8°, and in malesbetween 163.4° ± 5.5° and 177.4° ± 3.9°. The lowest and highest reported HKA angles were - 27.7° and + 22.0°, respectively. Seven studies reported mean FMA angles. Mean values ranged from 92.7° ± 2.7° valgus to 88.6° ± 2° varus. The reported mean FMAs for male were 87.9° ± 0.5° to 90.7° ± 3° and for female 89.91° ± 2.8° to 92.9° ± 3.1°. Six studies reported mean TMA values. TMA ranged from 81.7° ± 3.9° varus to 87.7° ± 4.1° varus. Only three studies reported mean JLCA angles, which ranged from - 4.3° to - 6.4° ± 3.8°. Osteoarthritic knees showed a huge variation in overall coronal limb alignment as well as in femoral and tibial coronal alignment. Current total knee arthroplasty (TKA) alignment philosophies and preoperative planning do not sufficiently consider these variation, which might be one reason for unhappy knees after TKA. IV, systematic review.

Phenotyping of hip-knee-ankle angle in young non-osteoarthritic knees provides better understanding of native alignment variability.

There is a lack of knowledge about the native coronal knee alignment in 3D. The currently used classification system (neutral, valgus and varus) oversimplifies the coronal knee alignment. The purpose of this study was therefore (1) to investigate the coronal knee alignment in non-osteoarthritic knees using 3D-reconstructed CT images and (2) to introduce a classification system for the overall knee alignment based on phenotypes. The hospital registry was searched for patients younger than 45years and older than 16, who received a CT according to the Imperial Knee Protocol. Patients with prosthesis, osteoarthritis, fractures or injury of the collateral ligaments were excluded. Finally, 308 non-osteoarthritic knees of 160 patients remained (102 males and 58 females, mean age ± standard deviation (SD) 30 ± 7years). The overall lower limb alignment was defined as the hip-knee-ankle angle (HKA), which is formed by lines connecting the centers of the femoral head, the knee and the talus. The angle was measured using a commercially planning software (KneePLAN 3D, Symbios, Yverdon les Bains, Switzerland). Descriptive statistics, such as means, ranges, and measures of variance (e.g., standard deviations) are presented. Based on these results, the currently used classification system was evaluated and a new system, based on phenotypes, was introduced. These phenotypes consist of a phenotype-specific mean value (a HKA value) and cover a range of ± 1.5° from this mean (e.g., 183° ± 1.5°). The mean values represent 3° increments of the angle starting from the overall mean value (mean HKA = 180°; 3° increments = 183° and 177°, 186° and 174°). The distribution of these limb phenotypes was assessed. The overall mean HKA was 179.7° ± 2.9° varus and values ranged from 172.6° varus to 187.1° valgus. The mean HKA values for male and female were 179.2° ± 2.8° and 180.5° ± 2.8°, respectively, which implied a significant gender difference (r2 = 0.23). The most common limb phenotype in males was NEUHKA0° (36.4%), followed by VARHKA3° (29.2%) and VALHKA3° (23.1%). The most common limb phenotype in females was NEUHKA0° (36.4%), followed by VALHKA3° (22.1%) and VARHKA3° (15.0%). The measurements using 3D-reconstructed CT images confirmed the great variability of the overall lower limb alignment in non-osteoarthritic knees. However, the currently used classification system (neutral, varus, valgus) oversimplifies the coronal alignment and therefore the introduced classification system, based on limb phenotypes, should be used. This will help to better understand individual coronal knee alignment. Level III, retrospective cohort study.

Native non-osteoarthritic knees have a highly variable coronal alignment: a systematic review.

Coronal alignment of the knee is defined by the hip-knee-ankle angle (HKA), the femoral mechanical angle (FMA), the tibial mechanical angle (TMA), and the joint line convergence angle (JLCA). To date, there is still a lack of knowledge about the variability of native coronal knee alignment. The purpose of this paper is to present a systematic review ofthe current literature about the variability of coronal knee alignment (HKA, FMA, TMA, and JLCA) in non-osteoarthritic knees. The electronic databases MEDLINE, EMBASE, and Google Scholar were searched from database inception to search date (November 1, 2018) and screened for relevant studies. The PRISMA guidelines were followed. Inclusion criteria were studies that reported the coronal alignment of the native, non-osteoarthritic knee. A total of 15 studies met the inclusion criteria. Thirteen studies performed the measurements on weight-bearing long-leg standing radiographs (LLR), one study used MRI, and one study used the EOS imaging system. The mean HKA ranged from 176.7°±2.8° (male) to 180.7° (female). The mean FMA ranged from 92.08°±1.78° (female) to 97.2°±2.7° (female). The mean TMA ranged from 84.6°±2.5° (female) to 89.6° (female). The mean JLCA ranged from - 0.47°±0.98° (male) to - 1.9°±1.4° (female). This systematic review provides a detailed overview about the variability of the coronal knee alignment in non-osteoarthritic knees. The broad variability of all coronal alignment parameters highlights the necessity for a more anatomic and individualized approach in knee arthroplasty. It also offers the fundament to understand the changes in osteoarthritic knees. Systematic review, Level IV.

Knee thrust prevalence and normative hip-knee-ankle angle deviation values among healthy individuals across the lifespan

To report the prevalence of varus thrust and normative values for hip-knee-ankle (HKA) angle deviation across the lifespan, and to explore associations between HKA angle deviation and selected clinical factors. This was a cross-sectional observational study of 572 participants from the 1000 Norms Project, aged 3-101 years and who self-reported as being healthy. Video recordings (2D) of frontal plane gait were reviewed by physiotherapists for presence of knee thrust and quantification of HKA angle deviation (the difference between HKA angle at initial contact and mid-stance). Age and sex-stratified normative HKA angle deviation values were presented as means and 95% confidence intervals (CIs). Correlations were calculated between HKA angle and clinical measures (age, sex, body mass index (BMI), alignment, knee and hip strength, Knee Injury and Osteoarthritis Outcomes Scores (KOOS), foot posture index, temporo-spatial gait, and hypermobility). Overall, 31% of the cohort had varus thrust, most prevalent among adults older than 60 years (42%) and children aged 3-9 (41%). Varus thrust was common in adolescents (25%) and adults aged 20-59 (23%). Mean HKA angle deviation for the entire cohort was 1.2° (95%CI: 1.07, 1.36) towards varus, and 2.1° (95%CI: 1.84, 2.36) among people with clinical varus thrust. Weak associations were identified between HKA angle deviation and BMI, stride width, and KOOS-Sports among adolescents, and in adults weakly associated with height. Prevalence of varus thrust is common across the lifespan. Normative values established here can be readily used by clinicians and researchers in monitoring this gait deviation.

Normative values of knee thrust among healthy individuals across the lifespan

Varus thrust is a gait deviation and a known risk factor for knee osteoarthritis. Prevalence of varus thrust and normative values of stance-phase knee deviation across the lifespan are unknown. The aim of the study was to report prevalence of varus thrust and normative values for hip-knee-ankle (HKA) angle deviation across the lifespan, and to explore associations between HKA angle deviation and selected clinical factors. This is a cross-sectional study of 572 participants from the 1000 Norms Project. People aged 3–101 years who self-reported as being healthy were eligible to participate. Video recordings (2D) of frontal plane gait were analysed for presence of varus or valgus thrust and quantification of HKA angle deviation (difference between HKA angles at initial contact and mid-stance). Correlation and multiple regression analyses explored the relationship between HKA angle and age, sex, body mass index (BMI), alignment, knee and hip strength, Knee Injury and Osteoarthritis Outcomes Scores (KOOS), foot posture index, gait parameters, and hypermobility. Thirty-one percent (31%) of the cohort had varus thrust. This was most prevalent among adults > 60 years (42%) and children < 10 years (41%), and was also common in adolescents (25%) and adults aged 20–59 (23%). Mean HKA angle deviation for the entire cohort was 1.2° (95% CI: 1.07–1.36), and 2.1° (95% CI: 1.84–2.36) among people with clinical varus thrust. BMI, stride width, KOOS-Sports for adolescents, and height for adults were independently associated with HKA angle deviation. Varus thrust is prevalent across the lifespan. Normative values established here can be readily used by clinicians and researchers in monitoring this deviation.

Surgical treatment for knee osteoarthritis subsequent to previous femur fractures

Objective To investigate the indications and clinical outcomes of total knee arthroplasty or osteotomy for knee osteoarthritis subsequent to previous femur fractures. Methods Six patients (three male and three female) with knee osteoarthritis subsequent to previous femur fractures were analyzed retrospectively between February 2006 and February 2017. The average age of patients was 58.2±10.3 years old, ranged from 51 to 79 years. Four patients underwent total joint replacement and two underwent osteotomy. The average age of patients in joint replacement group was 60.5±12.3 years old. The age of the two patients in the osteotomy group was 51 and 55 years old, respectively. The extra-articular deformity angle of the coronal plane of the femur, lateral distal femur angle of mechanical axis, hip-knee-ankle angle (HKA) of preoperative and postoperative were determined on long-standing radiography. The mean angle of the extra-articular deformity in the joint replacement group was 17.0±7.7 degrees. The angle of the extra-articular deformity in the osteotomy group was 34 and 20 degrees. Lateral distal femur angle of mechanical axis in the joint replacement group was within the range of 87±7 degrees. Lateral distal femur angle of mechanical axis in the osteotomy group was out of the range of 87±7 degrees. The mean preoperative HKA of the joint replacement group was 161.8±8.0 degrees. The preoperative HKA of the osteotomy group was 155 and 160 degrees, respectively. Knee function was estimated according to knee range of motion and Knee Society Score (KSS). The results of postoperative hip-knee-ankle angle, knee range of motion (ROM) and knee society score were compared between the two groups. Results The mean HKA of the joint replacement group reached 176.0±2.8 degrees at one year postoperatively. The HKA of the osteotomy group improved to 177 and to 175 degrees at one year postoperatively. The average preoperative knee ROM improved significantly from 71±16 degrees preoperatively to 113±5 degrees postoperatively. The mean knee ROM of the joint replacement group was 113.0±6.8 degrees. The knee ROM of two patients in the osteotomy group was 110 and 115 degrees, respectively. The average preoperative KSS score improved significantly from 46±3 preoperatively to 88±3 postoperatively. The mean KSS of the joint replacement group was 88.8±3.0, while the KSS of the osteotomy group was 85 and 82. No bone nonunion was observed in the two patients in osteotomy group. Conclusion For patients with knee osteoarthritis subsequent to previous femur fractures, satisfactory short-term clinical outcomes could be obtained by total knee arthroplasty or osteotomy with the strict selection of proper operative indications. Key words: Femoral fractures; Osteoarthritis; Arthroplasty, replacement, knee

Failure of high tibial varus osteotomy for lateral tibio-femoral osteoarthritis with < 10° of valgus: Outcomes in 19 patients

BackgroundOsteotomy is a rational approach to slowing knee osteoarthritis progression by modifying loads, thereby avoiding joint replacement in younger individuals. Varus femoral osteotomy is recommended only in patients with more than 10° of valgus. The objective here was to assess outcomes of tibial varus osteotomy in patients with lateral compartment tibio-femoral osteoarthritis and less than 10° of valgus. The hypothesis was that high tibial varus osteotomy produces satisfactory and long-lasting improvements. Material and methodsA single-centre retrospective study was conducted in 19 consecutive patients managed by high tibial varus osteotomy between January 2005 and May 2012. Mean age was 54.5years. The clinical IKS knee and function scores and radiological parameters were determined pre-operatively then after 6 and 12months and at last follow-up. The primary outcome measure was the global IKS score. Failure was defined as a global IKS score <140 or total knee arthroplasty (TKA). Secondary outcome measures were a post-operative hip-knee-ankle (HKA) angle between 180° and 183° and less than 10° of joint line obliquity. The hypothesis was that high tibial varus osteotomy produced satisfactory and long-lasting improvements in lateral compartment tibio-femoral osteoarthritis. ResultsAfter the mean follow-up of 4.3years (range, 2–9years), 10/19 patients had a global IKS score <140. Among them, 7 underwent TKA after a mean of 5.0±2.7years. Varus tibial osteotomy was followed by significant improvements in the IKS knee and function scores from baseline to last follow-up (P<0.05). A global IKS<140 predicted TKA. Mean HKA angle values were 186.3±2.9° pre-operatively and 181.3°± 3.9°at last follow-up (P<0.05); the HKA angle was within the 180°–183° range in 8 (42.1%) patients. Mean post-operative joint line obliquity was 7.8±3.0°. An HKA angle outside the 180–183° range and joint line obliquity >10° were associated with poor outcomes. DiscussionHigh tibial varus osteotomy produces unsatisfactory medium-term outcomes, with an overall failure rate of 52%. At present, high tibial varus osteotomy has no role in the management of lateral compartment tibio-femoral osteoarthritis with <10° of valgus. Level of evidenceIV, retrospective cohort study.

Comparison of Double and Single Leg Weight-Bearing Radiography in Determining Knee Alignment.

Knee malalignment is an important modifiable cause of osteoarthritis (OA). Surgical therapeutic procedures depend on proper knee alignment assessment. The purpose of this study was to compare knee alignment parameters between double and single leg weight-bearing radiographs and to evaluate the reproducibility of inter- and intra-observer measurements. One hundred eight patients (59 male and 49 female) with knee deformity visited at Kerman Knee Clinic were selected. Full limb anteroposterior (AP) Radiographs were taken for each participant in double and single leg weight-bearing positions. Hip-Knee-Ankle Angle (HKAA), Medial-Proximal-Tibial Angle (MPTA), Lateral-Distal-Femoral Angle (LDFA) and Joint-Line-Convergence Angle (JLCA) measured. Images stored on PC were examined by three observers to assess inter and intra observer reproducibility. Data analysis was done by SPSS software. The mean age of patients was 48.4 (±6.84) years, mean BMI was 26.55 (±1.94) Kg/m2. The mean HKAA and JLCA were significantly different between double and single leg weight-bearing radiographs. Intraclass correlation coefficient (ICC) test showed high (0.99) inter-reproducibility between three observers in all cases, except one (ICC=0.92). Intra-observer reproducibility indicated a strong correlation between the observer's measurements at different times (ICC > 0.99). HKAA and JLCA were affected by the patient's position. Observer and time interval had no effect on either of HKAA, MPTA, LDFA, and JLCA. Also the measurement of knee alignment parameters was not dependent on observer's experience. In conclusion single leg weight-bearing radiography is more representative of knee alignment and is inter and intra-observer reproducible.

Clinical evaluation and quantitative analysis of knee varus thrust: A reliability and validity study

Purpose: Identified by clinical observation, a varus thrust is defined as a dynamic bowing-out of the knee in the lateral direction during the weight bearing phase of gait and accompanied by return to a less varus alignment during the swing phase of gait. A varus thrust may further increase medial knee load of the knee joint and therefore be of detriment to people with medial knee osteoarthritis (OA). Varus thrust has been identified in 17-31% of individuals with knee OA and has been associated with a 4-fold increased likelihood of radiographic disease progression. As varus thrust has recently gained attention, little is known about inter-rater reliability of this clinically-observed test and the ability to quantify this risk factor using clinically available video technology. The aim of this study was to assess the intra-rater and inter-rater reliability of the clinical test to identify the presence of knee varus or valgus thrust. We also aimed to evaluate if varus or valgus thrust can be quantified using two-dimensional video analysis in older healthy adults. Methods: Fifty participants with no clinical signs of knee OA, aged 60-79, were recruited from the community. Participants walked barefoot at their comfortable walking speed along a 10 meter walkway, at the end of which a video camera was positioned. The limb was exposed for video recording and the dominant limb was the index knee with markers placed anteriorly on the anterior superior iliac spine, patella and midway between medial and lateral malleoli. Each participant completed five gait trails with the three middle trails used for quantifying knee motion. To describe the knee function of the sample, participants completed the Knee Injury and Osteoarthritis Outcome Score (KOOS). Clinically observed varus or valgus thrust was scored by two examiners who reviewed videos of over two sessions and the results were analysed for intra-rater and inter-rater reliability using the Kappa coefficient. Consensus on thrust presence classifications for all participants was reached to validate the quantitative measure of thrust using two-dimensional video analysis (P&O Clinical Movement Data, Siliconcoach Ltd, Dunedin, NZ). Video analysis was conducted by manually locating the markers and were used to define the hip-knee-ankle (HKA) angle. The change in HKA angle between initial contact and mid-stance was used to evaluate validity of this measure. We conducted a receiver operator curve (ROC) to determine the accuracy of the quantitative measure in distinguishing thrust presence. Results: Intra-rater reliability in the clinical evaluation of thrust demonstrated substantial agreement (p<0.001, k=0.74-0.84). Inter-rater reliability revealed moderate agreement between observers (k=0.77, p<0.001). After reaching consensus on classification of thrust, 70% of the participants demonstrated no thrust, 26% had a varus thrust and 4% had a valgus thrust. Quantitative analysis demonstrates that participants with no thrust had a mean HKA angle of 1.13° (SD = 1.1), those with varus thrust had 3.21° (SD = 0.8) and two participants with valgus thrust had -0.8° (SD = 1.7). We identified a statically significant difference (p<0.001) in the HKA angle change between participants who had no thrust and those with varus thrust. There were no statistically significant differences in participant characteristics between thrust classifications. The change in HKA angle was found to be 90.2% accurate in distinguishing participants with varus thrust and those with no thrust (p<0.001). Conclusions: Clinical evaluation of varus thrust demonstrates moderate to substantial reliability. Both clinical evaluation and quantitative analysis using simple readily available tools can be used to classify and quantify a varus thrust. Both methods of assessment have the potential to be easily transferred into the clinical setting and be used as a predictive tool or to objectively monitor severity of varus thrust.

The implications of mechanical alignment on soft tissue balancing in total knee arthroplasty.

We hypothesized that the individual bone geometry is the most important variable to achieve acceptable soft tissue balancing during total knee arthroplasty. Long-standing 3-foot films and computer navigation data from 90 patients with varus (n = 45) or valgus deformity (n = 45) were utilized who underwent navigated total knee arthroplasty. Mean age was 65 ± 8 years with 50 women and 40 men. Hip-knee-ankle angle (HKA) was measured and ranged from 23° varus to 21.5° of valgus. Three additional measurements were made: lateral distal femoral angle (DFA), the intraarticular angle (IAA), and the medial proximal tibial angle (PTA). Intra-operative computer navigation data were obtained. Knees were then stressed with both a maximum varus/valgus moment in 10° flexion. Values were compared with the angle measurements of 3-foot films. Maximum varus/valgus measurements were correlated with HKA for both varus and valgus knees. Varus knees: Mean HKA measured 9° ± 5°, and the maximum varus stress measured intraoperatively was 12° ± 4°. The mean DFA, PTA, and IAA were 88° ± 2.5°, 84° ± 3.4°, and 4.5° ± 2.5°, respectively. If the HKA was <10°, the deformity was correctable in (16/26) 61 % of cases. Positive correlation exists between the HKA, and maximal varus stress obtained intraoperatively (r = 0.75, p < 0.0001). IAA correlated with increasing HKA (r = 0.80, p < 0.0001). Mean IAA was significantly greater in the varus than valgus group (4.5 ± 2.6 vs 3.2 ± 2.4, respectively, p = 0.01). Valgus knees: Mean HKA measured was 9.4° ± 4°. The mean DFA, PTA, and IAA were 83° ± 2°, 89.5° ± 2°, and 3.2° ± 2.4°, respectively. If the HKA was more than 10°, maximal varus stress of the knee was able to correct the valgus deformity (15/22) 68 % of the time. If the HKA was <10°, the deformity was correctable in (21/23) 91 % of cases. Positive correlation exists between the HKA and maximal valgus stress examination (r = 0.74, p < 0.0001). There was a positive correlation of IAA with increasing HKA (r = 0.61, p < 0.0001). Mean flexion contracture for varus knees was 6.3° ± 6.9° compared with 0.8° ± 7.6° in the valgus group (p = 0.0004). These data suggest that soft tissues play more of a role in the varus knee deformity than they do in the valgus knee and that the bony contribution may be the main contributing factor to the overall deformity of the valgus knee. IV.

Factors contributing to inherent varus alignment of lower limb in normal Asian adults: Role of tibial plateau inclination

PurposeThis prospective study aimed to evaluate radiographically, mechanical or hip–knee–ankle (HKA) axis in healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40years of age to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it. MethodsThree hundred and eighty-eight lower limbs were evaluated using full length, standing hip-to-ankle radiographs in 198 healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40years of age to assess the hip–knee–ankle (HKA) angle, medial proximal tibial angle (MPTA), femoral bowing and femoral neck–shaft angle to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it. ResultsOverall, the mean HKA angle was 177.6°±2.6° with 34.5% of limbs in inherent varus (mean HKA angle 174.9°±1.8°). The incidence of inherent varus was significantly higher (p=0.01) in males (40%) compared to females (28%) but similar among Indian (34%) and Korean subjects (35%). The hip–knee–ankle (HKA) angle showed significant positive correlation (r=0.82, p<0.001) with only the medial proximal tibial angle (MPTA). ConclusionsInherent varus alignment of the lower limb is fairly common among asymptomatic, Asian adults. These results raise several pertinent questions regarding the role of inherent varus in the aetiopathogenesis of knee osteoarthritis and in lower limb realignment procedures.

Fixator-assisted medial tibial plateau elevation to treat severe Blount's disease: Outcomes at maturity

Severe forms of Blount's disease may be associated with medial tibial plateau (MTP) depression. Management should then take account of joint congruence, laxity, limb axis, torsional abnomality, leg length discrepancy (LLD) and eventual recurrence history. Eight knees (six patients) were managed in a single step comprising MTP elevation osteotomy, lateral epiphysiodesis and proximal tibia osteotomy to correct varus and rotational deformity. Fixation was achieved using an Ilizarov external fixator. Mean age was 10.5 years. Mean hip-knee-ankle (HKA) angle was 151°; distal femoral varus, 94°; metaphyseal-diaphyseal angle (MDA), 27°; and angle of depression of the medial tibial plateau (ADMTP), 42°. Predicted residual proximal tibial growth was 2.6 cm. At a mean 48 months' follow-up, results were good in six cases, medium in one and poor (due to incomplete lateral epiphysiodesis) in one. Mean lateral tibial torsion was 9° and final LLD 11 mm. Weight-bearing was resumed at 2 months, and the fixator was removed at 5.5 months postoperatively. At end of follow-up, mean HKA angle was 179.6°, MDA 7.3° and ADMTP 5.4°. This technically demanding procedure gave satisfactory results in terms of axes and congruence; longer term assessment remains needed. Level IV. Retrospective study.