Anatomic Lateral Distal Femoral Angle Research Articles

Pelvic limb alignment measured by computed tomography in purebred English Bulldogs with medial patellar luxation.

The aim of the study was to describe the differences in pelvic limb alignment between healthy purebred English Bulldogs and those with medial patellar luxation through the measurement of femoral and tibial angles on computed tomography images in multiplanar reconstruction modality (MPR-CT). Twenty-one purebred English Bulldogs were included and divided into two groups: one including healthy dogs (15 limbs) and the other including those with medial patellar luxation (24 limbs). Three different observers used MPR-CT to measure the following angles: anatomical lateral proximal femoral angle (aLPFA), anatomical lateral distal femoral angle (aLDFA), mechanical lateral proximal femoral angle (mLPFA), mechanical lateral distal femoral angle (mLDFA), angle of inclination of the femoral neck (AI), angle of anteversion (AA), mechanical medial proximal tibial angle (mMPTA), mechanical medial distal tibial angle (mMDTA), mechanical caudal distal tibial angle (mCdDTA), mechanical caudal proximal tibial angle (mCdPTA), and the tibial torsion angle (TTA). A Mann-Whitney U test was used to compare each variable in both groups. The values for aLDFA and mLDFA in the medial patellar luxation population were significantly increased compared to healthy subjects (p <0.05). No significant differences were observed for the other variables. In our population, an increased distal femoral varus was associated with medial patellar luxation. Our results could be useful to determine whether or not angular deformity of the femur is present and help determine the degree of correction necessary to restore alignment.

Selective hemiepiphyseodesis for patellar instability with associated genu valgum

Background/AimsPatellar instability limits activity and promotes arthritis. Correcting genu valgum with selective hemiepiphyseodesis can treat patellar instability. MethodsWe retrospectively reviewed 26 knees with patellar instability and associated genu valgum that underwent hemiepiphyseodesis. ResultsAverage anatomic lateral distal femoral angle (aLDFA) significantly corrected. Symptoms improved in all patients. All competitive athletes returned to sports. One complication occurred. ConclusionsIn genu valgum, the patella seeks an abnormal mechanical axis, resulting in patellar instability. By correcting the mechanical axis with hemiepiphyseodesis, patellar instability symptoms improve and patients return to sports. Complications are rare. Selective hemiepiphyseodesis is recommended when treating patellar instability with associated genu valgum.

The normal radiological anteroposterior alignment of the lower limb in children.

The development of reconstructive surgery of the lower limbs aimed at multilevel correction demands a precise knowledge of the physiological variations in general radiological parameters of the lower limbs in children of various age groups. It is crucial in systemic skeletal diseases, when deformities affect limbs and the surgeon does not have an intact limb as a reference. The aim of this retrospective study was to establish the normal radiological values of lower limb parameters used in the surgical correction of deformities in children of various age groups. Teleradiographs of the lower limbs taken in children with unilateral congenital or posttraumatic deformity were retrospectively reviewed. Weight-bearing full-length anteroposterior radiographs of the entire lower extremities were taken in a standing position. The study involved 215 extremities of 208 children (93 girls and 115 boys); the ages ranged from 2 years 1 month to 15 years 11 months old. Key variables included the anatomic medial proximal femoral angle (aMPFA), anatomic lateral distal femoral angle (aLDFA), anatomic medial proximal tibial angle (aMPTA), anatomic lateral distal tibial angle (aLDTA), mechanical axis deviation (MAD), the angle formed by the femoral anatomical axis and the mechanical axis of the lower limb. The means and dynamics of variations, standard deviations (SD) and 95% confidence intervals of each parameter were calculated for each age and gender group. Simple regression analysis was performed to determine the relationship between the patient's age and the magnitude of aMPFA, aLDFA, aMPTA and aLDTA. Simple regression analysis showed a significant inverse correlation between patient age and the magnitude of aMPFA: the correlation coefficient was -0.77. A statistically significant inverse correlation between the MAD and the angle between the anatomic femoral axis and mechanical limb axis was found: the correlation coefficient was -0.53. In general, the received values were concordant to results of other studies. It concerned the MAD, aLDFA, aMPTA and angle between the mechanical limb axis and anatomic femoral axis. This is the first chronological evaluation of aMPFA and aLDTA from a relavively large series of patients. These normative data should be taken into consideration when evaluating lower limb alignment in children or applied in practice for planning and evaluation of the quality of surgical correction of complex deformities.

Integrating various common indexes of bony alignment in femoral supracondyle

Indexes, which can optimally represent the bony alignment around the knee, are still controversial. Three common indexes, mechanical axis (MA), anatomic axis (AA), and anatomic lateral distal femoral angle (aLDFA), were integrated to simplify patient follow-up in the femoral supracondylar region. Eighty consecutive adult patients (40 men, 40 women; age range 19-40 years) were studied using a full-length standing scanogram. Thirteen indexes, including MA, AA, and aLDFA, were measured and integrated. The relationships among these indexes were analyzed. The MA of the lower extremity passed with an average of 6.6 mm (9.2% of the tibial articular surface width) medial to the knee center. The supracondylar axis (SA) was an average of 2.0° more valgus than the AA in the femoral supracondyle. An average 1.1° deviation was noted in the AA, as measured by the femoral shaft axis or a line connecting the piriformis fossa to the knee center. The femoral MA may be more favorable than the MA of the lower extremity in order to represent an ideal weight-bearing line. The AA and aLDFA may be measurable via the SA in the anteroposterior view of the plain knee radiograph. Thus, patient follow-up becomes much more convenient.

Distal Femoral Valgus Deformity Following Plate Fixation of Pediatric Femoral Shaft Fractures

This study investigated the frequency and potential risk factors associated with the development of distal femoral valgus deformity following plate fixation of diaphyseal femoral fractures in children. Records of eighty-five skeletally immature patients who underwent plate fixation of a diaphyseal femoral fracture at a tertiary-care pediatric center from January 2003 to December 2010 were reviewed. Demographic data and clinical information were analyzed. Radiographic measurement of the distance from the distal plate edge to the distal femoral physis and of the anatomic lateral distal femoral angle was performed. Development of distal femoral valgus deformity was defined as a change in the anatomic lateral distal femoral angle of ≥5° in the valgus direction. Logistic regression analysis and contingency tables were used to relate the development of distal femoral valgus deformity with retention of hardware, patient age, fracture site, plate-to-physis distance, and the location of a bend in the plate at fixation. Midshaft fractures (45%) were more common than proximal or distal diaphyseal fractures. Intraoperatively, the plate was bent proximally or distally, or both, in 80% of the patients. Distal femoral valgus deformity of ≥5° was seen in ten patients, eight of whom had distal diaphyseal fractures. Three of the ten patients developed symptoms as a result of the distal femoral valgus deformity that required at least one unplanned additional surgical procedure. On the basis of the statistical analysis, patients with a plate-to-physis distance of ≤20 mm (relative risk= 12.77, p = 0.005) and a distal fracture (relative risk = 11.0, p < 0.001) were at a significantly higher risk of developing distal femoral valgus deformity. Although not clearly an independent factor, a distal bend was also found to be associated with distal femoral valgus deformity (p = 0.004) but was not predictive of the pathology. Distal femoral valgus deformity occurred in 30% of patients with distal diaphyseal fractures and in 12% overall. We advocate long-term monitoring of patients with femoral plate fixation, particularly those in whom the plate is placed ≤20 mm from the distal femoral physis.

A histomorphometric study of cellular layers after hemiepiphyseal stapling on the physeal plate in rabbits

BackgroundEpiphyseal stapling has been widely used to correct angular deformity. The mechanism, however, has not been well determined. To determine the effect of temporary hemiepiphyseal stapling on the cellular layers of the physis, a histomorphometric study was performed using immature rabbits. MethodsDistal lateral epiphyseal stapling of the right femur was performed on 6-week-old New Zealand white rabbits. Thirty rabbits were randomly assigned to five groups, and six rabbits in each group were analyzed weekly for up to 5weeks. ResultsThe distal femur was deformed into the valgus, and the anatomical lateral distal femoral angle decreased with the passage of time. In the sequential histomorphometry of the operated physeal plate, the area ratio of each layer, compared to the control side, decreased every week. The total area of the physeal plate had decreased up to 60% at the 5th week compared to the area of the 1st week, and the area of the proliferative layer decreased by the greatest amount among the three layers. ConclusionsOur findings suggest that the proliferation of chondrocytes seemed to be more suppressed by the compression of the stapling, thereby slowing the growth rate, although hypertrophy of the chondrocytes was also suppressed.

Rate of Correction After Asymmetrical Physeal Suppression in Valgus Deformity

This study was performed to estimate the rate of angular correction after asymmetrical physeal suppression and analyze the factors that influence the rate of correction by using a linear mixed model application. A total of 175 physes (72 distal femoral, 70 proximal tibial, and 33 distal tibial) from 78 consecutive patients with valgus angular deformity of the lower limb who underwent asymmetrical physeal suppression were included. The anatomic lateral distal femoral angle, the anatomic lateral proximal tibial angle, and the anatomic lateral distal tibial angle were measured from the teleroentgenograms of the patients' preoperative visit and periodic follow-ups. The rate of angular correction was adjusted by multiple factors by using a linear mixed model with age, sex, and surgical method as the fixed effects and each subject as the random effect. The final model included the age-specific and surgical method-specific rate and sex-specific and surgical method-specific intercept. Multivariate analysis was performed for this model. In younger children (boys 14 y or younger and girls 12 y or younger), the rate of correction of valgus deformity at the distal femur, proximal tibia, and distal tibia was 0.71 degrees/month (8.5 degrees/y), 0.40 degrees/month (4.8 degrees/y), and 0.48 degrees/month (5.8 degrees/y), respectively. In older children, the rate of correction of valgus deformity at the distal femur, proximal tibia, and distal tibia was 0.39 degrees/month (4.7 degrees/y), 0.29 degrees/month (3.5 degrees/y), and 0.48 degrees/month (5.8 degrees/y), respectively. The rate of correction at the distal femur was significantly lower in older children (P = 0.025). The rate of angular correction at the proximal tibia was significantly faster in the screw group than in the staple group (P = 0.046). Asymmetrical physeal suppression with staples, percutaneous transphyseal screws, and permanent method all are effective methods for treating valgus deformity in growing children. When we treat valgus deformity in growing children, we should take into consideration the fact that the rate of correction at the distal femur is lower in older children, and that at the proximal tibia is faster in the screw group. Therapeutic level III.

Evaluation of the Effect of Distal Femoral Elevation on Radiographic Measurement of the Anatomic Lateral Distal Femoral Angle

To determine the effect of elevation of the distal femur on radiographic determination of the anatomic lateral distal femoral angle (aLDFA) in an in vitro canine model. In vitro study. Cadaveric canine femora (n = 7 pairs). Dissected femora were positioned in a custom-mounting frame. The distal end of the frame was elevated in 5° increments from 0° to 45°, with craniocaudal (CrCd) radiographs obtained at each position. The aLDFA was measured from the radiograph of each femur at each elevation. Statistical comparison of measured values was performed and radiographs were evaluated for radiographic indicators of positioning. There was significant increase in measured aLDFA at all elevations >5° when compared to 0° elevation. The mean value for aLDFA increased from 92.3° at 0° elevation to 95.0° at 45° elevation. The femoral trochlear ridges and walls of the intercondylar fossa were identified as the most useful radiographic landmarks. The fabellae, though extrafemoral and inconsistently retained in the current study, may also be beneficial. The lesser trochanter and nutrient foramen were less useful landmarks because of anatomic variability. Elevation of the distal femur had a significant effect on measured aLDFA at all elevations greater than 5°.

Reliability of Lower-limb Alignment Measurements in Patients With Multiple Epiphyseal Dysplasia

Although radiographic measurements are used in multiple epiphyseal dysplasia (MED) during correction of lower-limb alignment, the reliabilities of the measurements are unclear. We determined interobserver and intraobserver reliabilities of the measurement methods used in evaluation of lower-limb alignment in MED. After consensus building, we included 10 radiographic measurement methods widely used to evaluate lower-limb alignment: mechanical tibiofemoral angle, anatomic tibiofemoral angle, mechanical axis deviation, joint line convergence angle, mechanical lateral distal femoral angle, anatomic lateral distal femoral angle, mechanical medial proximal tibial angle, anatomic medial proximal tibial angle, epimetaphyseal angle, and tibial metadiaphyseal angle. A study group consisting of 30 patients with MED was compared with a control group consisting of 30 sex- and age-matched patients with genu varum and genu valgum. Mean age in both groups was 11 years (study group: SD, 2 years; range, 6-16 years; control group: SD, 2 years; range, 6-15 years). Interobserver and intraobserver reliabilities of all radiographic measurement methods were obtained and expressed by intraclass correlation coefficients (ICCs). Mechanical tibiofemoral angle, anatomic tibiofemoral angle, and mechanical axis deviation were associated with high interobserver reliability (ICCs, 0.987, 0.985 and 0.982, respectively). Epimetaphyseal angle had the lowest reliability (ICC, 0.280). Intraobserver reliability exhibited similar trends, with mechanical axis deviation and mechanical tibiofemoral angle having the highest ICCs and epimetaphyseal angle the lowest. Mechanical tibiofemoral angle, anatomic tibiofemoral angle, and mechanical axis deviation are reasonably reliable measures of alignment in MED. The lateral distal femoral angle and medial proximal tibial angle (mechanical and anatomic) can be used as complementary measurement methods. Level II, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

Radiographic measurement for femoral varus in Pomeranian dogs with and without medial patellar luxation

To measure radiographically the inclination angle (ICA), femoral varus angle (FVA), anatomical lateral distal femoral angle (aLDFA), and mechanical lateral distal femoral angle (mLDFA) in Pomeranian dogs with and without medial patellar luxation (MPL). Stifles of 34 Pomeranian dogs were graded and allocated into three groups: normal, grades I-II MPL, and grade III MPL. Angle values were measured from craniocaudal radiographs of the hindlimbs by each of the three examiners on three separate occasions. Each of the three groups consisted of 15 stifles. Means ± SD for the ICA, FVA, aLDFA and mLDFA in the normal stifles were 136.46 ± 7.12°, 5.85 ± 3.18°, 95.21 ± 3.48° and 99.46 ± 4°, respectively. No significant differences (p>0.05) in the measured values for the ICA between groups were observed. The FVA, aLDFA and mLDFA values in grade III MPL group were significantly (p<0.05) greater than those in the other two groups. Significant differences in the three angles between the normal and grades I-II MPL groups were not observed. Significant change of distal femoral varus exists in Pomeranian dogs with grade III MPL.

Comparison of Femoral Angulation Measurement Between Radiographs and Anatomic Specimens Across a Broad Range of Varus Conformations

To determine if measurement of anatomic lateral distal femoral angle (aLDFA) from radiographs is valid across a broad range of femoral varus conformations. Radiographic and anatomic study. Large breed canine cadavers (n = 5) and femora (n = 10). Cadavers were held in dorsal recumbency and 8 craniocaudal radiographic projections made of each femur: 1 image pre- and postosteotomy and at each of 6 progressive levels of induced distal varus deformity. Femurs were collected. Three blinded examiners independently measured varus on each radiograph (R-aLDFA) and femoral specimen (S-aLDFA) on 3 separate occasions. Intra- and interobserver variance in R-aLDFA and S-aLDFA measurements were determined. The strength of relationship between R-aLDFA and S-aLDFA and positive and negative predictive values for R-aLDFA were calculated. Intra- and interobserver variance in R-aLDFA (mean, 0.54% and 0.40%, respectively) and S-aLDFA (mean, 0.43% and 0.41%, respectively) were acceptable. The strength of relationship between R-aLDFA and S-aLDFA (adjusted R2 = 78.2%) was marginally below the acceptance criterion of 80%. Using aLDFA ≥ 102° as an indication for corrective femoral osteotomy, radiography was successful in correctly identifying corrective femoral osteotomy candidates (positive predictive value) and noncandidates (negative predictive value) 72% and 96% of the time, respectively.

Early experience with medial femoral tension band plating in idiopathic genu valgum

PurposeFor correction of angular deformity, tension band plating has been proposed as a safe and minimally invasive technique. The purpose of this study was to assess the experiences and report the rate of correction obtained with this procedure in patients with idiopathic genu valgum.MethodsThis study was a retrospective review of 47 valgus deformities of the knee treated with medial hemiepiphysiodesis using a tension band plate. The tibiofemoral angle (TFA) and the anatomic lateral distal femoral angle (aLDFA) were assessed on anteroposterior (AP) radiographs of the lower extremity taken at multiple time intervals. The values were charted to determine the change in orientation of the joint surface over time. Pearson’s correlation was used to analyze the correction over time. A subanalysis was performed evaluating the effect of age and the number of plates utilized.ResultsA total of 47 deformities in 25 patients were reviewed. The average time of follow-up from index surgery was 12.7 months, with an average correction of 0.96° every 3 months or 3.8° per year. The aLDFA corrected at a faster rate in knees with two plates per hemiepiphysiodesis than those with one plate, 4.2° and 3.3° per year, respectively (P = 0.035). Girls <11 years of age and boys <13 years of age corrected at a rate of 4.5°, while older children corrected at a rate of 3.4° per year (P = 0.39). There were no complications or instrumentation breakages.ConclusionHemiepiphysiodesis with tension band plating provides an effective and predictable correction of idiopathic genu valgum. Two plates appear to provide a greater rate of correction. There is also a trend toward faster correction in younger patients as well.

Mechanical Axis Following Staple Epiphysiodesis for Limb-Length Inequality

Staple epiphysiodesis is an option for the treatment of limb-length discrepancies, but it is not without complications. The purpose of this study was to review the outcomes of staple epiphysiodesis, including changes in the mechanical axis. The study included patients who underwent, between 1990 and 2005, staple epiphysiodesis of the femur or tibia, or both, to address limb-length discrepancy. We reviewed preoperative, postoperative, and final long standing anteroposterior radiographs of fifty-four patients to assess limb-length discrepancy, shifts in the mechanical axis, changes in the mechanical axis zone, and changes in the anatomic lateral distal femoral angle and the medial proximal tibial angle. Postoperative radiographs were also reviewed to assess the adequacy of staple placement. Three staple epiphysiodesis groups were identified: fifteen patients who underwent a distal femoral staple epiphysiodesis, eighteen who underwent a proximal tibial procedure, and twenty-one who underwent combined distal femoral and proximal tibial procedures. Fifty percent (twenty-seven) of the fifty-four patients showed a shift in the mechanical axis of > or =1 cm as compared with the preoperative measurement. Eighty-nine percent of these large shifts were varus in nature. The proximal tibial and combined epiphysiodeses resulted in significantly larger shifts in the mechanical axis (p = 0.002 and p = 0.006, respectively) and zone changes (p = 0.009 and p = 0.006, respectively) than did the distal femoral procedures. Six patients ultimately underwent a high tibial osteotomy to correct a post-stapling varus deformity. The proximal-lateral aspect of the tibia was by far the most common location for inadequate staple placement. Mechanical axis deviation is common following staple epiphysiodesis for the treatment of limb-length discrepancy. Proximal tibial and combined distal femoral and proximal tibial staple epiphysiodeses, even if done well technically, lead to clinically relevant shifts in the mechanical axis of the lower extremity more than half of the time. Distal femoral staple epiphysiodesis may still be a safe option for the treatment of limb-length discrepancy, but we advise caution when utilizing proximal tibial staple epiphysiodesis to treat limb-length inequality.

Hemiepiphyseal Stapling for Angular Deformity Correction Around the Knee Joint in Children With Multiple Epiphyseal Dysplasia

Angular deformity around the knee joint in patients with multiple epiphyseal dysplasia (MED) causes alteration in knee biomechanics as well as cosmetic problem. We report angular correction by hemiepiphyseal stapling (HES) and physeal behavior after stapling removal in MED patients. In 17 knees of 9 MED patients, 16 distal femoral and 8 proximal tibial physes were stapled. Age at operation ranged from 8.2 to 13.9 years. Thirteen knees were in valgus alignment and 3 in varus and were followed up for an average of 3.9 years. Angular deformity change was evaluated by the anatomical lateral distal femoral angle or anatomical medial proximal tibial angle. Mechanical axis deviation was defined as the percentage ratio of distance from the knee joint center to mechanical axis divided by half the width of the tibial plateau. Amount of angular correction by HES at the distal femur was 15.3 +/- 6.4 degrees for an average of 17.4 months, and at the proximal tibia, 8.6 +/- 2.0 degrees for an average of 13.4 months. Twelve distal femoral physes remained stationary (angular change <3 degrees) and 4 rebounded (loss of correction >3 degrees) after staple removal, whereas 5 proximal tibial physes remained stationary, 2 rebounded, and 1 was progressive. Neither hardware problems nor clinical complications other than overcorrection or undercorrection were encountered. At the latest follow-up, mechanical axis deviation remained within +/-50% in 14 of 17 knees. The remaining 3 knees failed because of premature closure of the distal femoral physis, causing undercorrection of the deformity, insufficient rebound of an overcorrected knee, or progressive angular change after staple removal. Hemiepiphyseal stapling is effective for angular correction in MED with minimal surgical insult. However, as physeal behavior after staple removal is rather unpredictable, overcorrection over zone 1 should be avoided, and close monitoring is mandatory until skeletal maturity.

Pediatric Deformity Correction Using a Multiaxial Correction Fixator

Circular fixators have been used successfully to correct multiplanar deformities but are often cumbersome and may be difficult to apply. We determined whether a monolateral fixator, which allows for correction of angular deformity and displacement in three planes, can correct lower extremity deformities to within normal radiographic means (anatomic lateral distal femoral angle, anatomic medial proximal tibial angle, and tibial femoral angle). We retrospectively reviewed the clinical records and radiographs of 22 consecutive patients (25 limbs) who underwent deformity correction using a new multiaxial monolateral external fixator. The patients were 4 to 16 years of age. We had a minimum 1.2-year followup (mean, 2.14 years; range, 1.2-3.1 years). Those with primary femoral and tibial deformities had improvements in the mean deviation from normal of the anatomic lateral distal femoral angle, anatomic medial proximal tibial angle and tibial femoral angle. Patients with Blount's disease had improvements in the mean anatomic medial proximal tibial angle from 59.9 masculine to 87.8 masculine. Five patients had complications (two pin site infections, one premature consolidation, one knee flexion contracture, one recurrence of varus). Six patients developed secondary deformities, all of which were corrected using the primary or secondary hinge. We conclude this fixator can produce satisfactory results with relatively few complications. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Measurement of Femoral Angles in Four Dog Breeds

To develop a standard method of measurement for femoral angles and report values for normal Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers. Retrospective evaluation of canine pelvis and femoral radiographs. Radiographs of Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers (n=100 for each breed). Anatomic lateral distal and proximal femoral angle, mechanical lateral distal and proximal femoral angle, and femoral angle of inclination were measured from radiographs. For the 4 breeds (Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers, respectively) anatomic lateral distal femoral angles were 97 degrees , 97 degrees , 94 degrees , and 98 degrees ; mechanical lateral distal femoral angles were 100 degrees , 100 degrees , 97 degrees , and 100 degrees ; anatomic lateral proximal femoral angles were 103 degrees , 98 degrees , 101 degrees , and 96 degrees ; mechanical lateral proximal femoral angles were 100 degrees , 95 degrees , 97 degrees , and 93 degrees ; and inclination angles were 134 degrees , 134 degrees , 132 degrees , and 137 degrees . Labrador Retrievers, Golden Retrievers, and Rottweilers had significantly higher values for both anatomic and mechanical lateral distal femoral angle than German Shepherds. Anatomic and mechanical lateral proximal angles were greatest for Labrador Retrievers and lowest for Rottweilers. Anatomic and mechanical femoral joint angles vary between breeds of dogs. Values for femoral joint angles may be clinically useful for angular limb deformity diagnosis, treatment, and assessment.

Incidence of Distal Femoral and Distal Tibial Deformities in Infantile and Adolescent Blount Disease

The purpose of this study was to assess distal femoral and tibial deformity in patients with infantile and adolescent Blount disease. This was a retrospective review of patients at the authors' institution diagnosed with Blount disease. Thirty-eight patients (21 in the infantile group and 17 in the adolescent group) met the study criteria. Measurements of the anatomic lateral distal femoral angle (aLDFA), anatomic lateral distal tibial angle (aLDTA), and tibiofemoral angle (TFA) were made from long-leg radiographs. The results of the infantile and adolescent measurements were compared with each other and to a normal database. Intraobserver and interobserver error was determined. The adolescent aLDFA measurements were significantly greater (more varus) than for the infantile group and normal database. The aLDTA (ankle) measurements were not statistically different between the two groups, or from the normal database. Analysis of both intraobserver and interobserver error for the aLDFA and aLDTA showed good reliability.