Lateral Proximal Femoral Angle Research Articles

Comparison of short-term radiographic outcomes of medial parapatellar, mini-midvastus, and subvastus surgical approaches in fast-track total knee arthroplasty

Purpose: Due to the difficulties in accessing the knee joint, correct prosthesis placement is of great importance during the implementation of total knee arthroplasty (TKA). This study aimed to compare short-term radiographic X-ray outcomes in patients who underwent fast-track TKA with medial parapatellar (MPP), mini-midvastus (mMV), or subvastus (SV) surgical approaches.
 Materials and methods: Between 2018 and 2020, 93 patients operated with MPP, mMV, and SV surgical approaches and who had complete data of radiographic outcomes before and sixth-week postoperative were retrospectively analyzed and patients divided into three groups: MPP (n=31), mMV (n=31), and SV (n=31). The alignments of preoperative and sixth-week postoperative X-ray images of the surgical approaches were measured. The operative time of fast-track TKA implementation with MPP, mMV, and SV surgical approaches was recorded.
 Results: The MPP group had higher preoperative lateral distal femoral angle than the mMV group and a higher preoperative lateral proximal femoral angle than SV group (p=0.018 and p=0.027, respectively). The mMV group had higher postoperative proximal medial tibial angle than SV group (p=0.011). In the postoperative sixth week, the MPP and mMV groups had a lower posterior tibial slope angle than SV group (p=0.001). The MPP approach had significantly shorter operative time than mMV and SV approaches (p=0.001).
 Conclusion: The outcomes indicate that MPP, mMV, and SV surgical approaches are preferable and feasible in obtaining a satisfactory prosthesis alignment during fast-track TKA. The MPP approach may be preferable because of its shorter operative time and potential advantage in minimizing surgical complication risks.

Enhancing Precision and Efficiency in Knee Arthroplasty: A Comparative Analysis of Computer-Assisted Measurements with a Novel Software Tool versus Manual Measurements for Lower Leg Geometry.

(1) Background: The aim of this prospective study was to evaluate measurement software in comparison with manual measurements using inter-observer and intra-observer variability on radiographs in the preoperative planning of total knee arthroplasty. (2) Methods: Two independent observers retrospectively measured the mechanical lateral proximal femoral angle (mLPFA), the mechanical lateral distal femoral angle (mLDFA), the joint line convergence angle (JLCA), the mechanical medial proximal tibial angle (mMPTA), the mechanical lateral distal tibial angle (mLDTA), the hip-knee angle or mechanical tibial-femoral axis angle (HKA), and the anatomical-mechanical angle (AMA) on 55 long-leg anteroposterior radiographs manually twice, followed by measurements using dedicated software. Variability between manual and computer-aided planning was assessed, and all measurements were performed a second time after 14 days in order to assess intra-observer variability. (3) Results: Concerning intra-observer variability, no statistically significant difference was observed regarding the software-based measurements. However, significant differences were noted concerning intra-observer variability when measuring the mLDFA and AMA manually. Testing for statistical significance regarding variability between manual and software-based measurements showed that the values varied strongly between manual and computer-aided measurements. Statistically significant differences were detected for mLPFA, mLDFA, mMPTA, and mLPTA on day 1, and mLPFA, mMPTA, and mLPTA on day 15, respectively. (4) Conclusions: Preoperative planning of leg axis angles and alignment using planning software showed less inter- and intra-observer variability in contrast to manual measurements, and results differed with respect to manual planning. We believe that the planning software is more reliable and faster, and we would recommend its use in clinical settings.

Femoral lengthening using limb reconstruction system augmented with only one antegrade flexible nail in children: early results.

Several techniques have been described for decreasing the duration of external fixator use, augmenting stability, and minimizing complications. The purpose of the present study was to evaluate the clinical results and complications of femoral lengthening procedures using the Limb Reconstruction System (LRS) in combination with a single antegrade flexible intramedullary nail (FIN). Femoral lengthening with LRS and FIN was applied to 14 patients (aged 6-16 years) between 2017 and 2021. The etiology was a congenital femoral deficiency in 12 patients and post-traumatic growth arrest in two. A single nail was inserted antegradely through the trochanteric apophysis in each patient. Radiographs and medical records of the patients were assessed retrospectively. The mean lengthening achieved was 4.8 ± 1.0 cm. The mean duration of external fixation was 181 days (range 139-248 days) and the mean healing index was 39.6 ± 12.1 days/cm. The mean values of mechanical medial proximal tibial angle, mechanical lateral distal tibial angle, mechanical lateral proximal femoral angle, and mechanical lateral distal femoral angle were within the normal range at the last follow-up. Seven of the 14 cases had a regenerate deformity that caused a displacement of more than 2 mm in the mechanical axis deviation, none of them was greater than 10 mm and considered clinically insignificant. Fracture was seen in two limbs with regenerate deformity. This study suggests that LRS in combination with only one FIN may be an effective alternative for femoral lengthening, with acceptable complication rates.

Intra- and interobserver reliability analysis of pediatric lower limb parameters on digital long leg radiographs

BackgroundMalalignments of the lower extremity are common reasons for orthopedic consultation because it may lead to osteoarthritis in adulthood. An accurate and reliable radiological assessment of lower limb alignment in children and adolescents is essential for clinical decision-making on treatment of limb deformities and for regular control after a surgical intervention.ObjectiveFirst, does the analysis of full-length standing anteroposterior radiographs show a good intra- and interobserver reliability? Second, which parameter is most susceptible to observer-dependent errors? Third, what is the Standard Error of Measurement (SEM95%) of the absolute femoral and tibial length?MethodsTwo observers evaluated digital radiographs of 144 legs from 36 children and adolescents with pathological valgus alignment before a temporary hemiepiphysiodesis and before implant removal. Parameters included Mechanical Femorotibial Angle (MFA), Mechanical Axis Deviation (MAD), mechanical Lateral Distal Femoral Angle (mLDFA), mechanical Medial Proximal Tibial Angle (mMPTA), mechanical Lateral Proximal Femoral Angle (mLPFA), mechanical Lateral Distal Tibial Angle (mLDTA), Joint Line Convergence Angle (JLCA), femur length, tibial length. Intra- and interobserver reliability (ICC2,1), SEM95% and proportional errors were calculated.ResultsThe intra- and interobserver reliability for almost all measurements was found to be good to excellent (Intra-ICC2,1: 0.849–0.999; Inter-ICC2,1: 0.864–0.996). The SEM95% of both observers was found to be ± 1.39° (MFA), ± 3.31 mm (MAD), ± 1.06° (mLDFA) and ± 1.29° (mMPTA). The proportional error of MAD and MFA is comparable (47.29% vs. 46.33%). The relevant knee joint surface angles show a lower proportional error for mLDFA (42.40%) than for mMPTA (51.60%). JLCA has a proportional error of 138%. Furthermore, the SEM95% for the absolute values of the femoral and tibial length was 4.53 mm for the femur and 3.12 mm for the tibia.ConclusionsIn conclusion, a precise malalignment measurement and the knowledge about SEM95% of the respective parameters are crucial for correct surgical or nonsurgical treatment. The susceptibility to error must be considered when interpreting malalignment analysis and must be considered when planning a surgical intervention. The results of the present study elucidate that MAD and MFA are equally susceptible to observer-dependent errors. This study shows good to excellent intra- and interobserver ICCs for all leg alignment parameters and joint surface angles, except for JLCA.Trial registration: This study was registered with DRKS (German Clinical Trials Register) under the number DRKS00015053.Level of evidenceI, Diagnostic Study.

Evaluation of pelvic limb angles in dogs with medial patellar luxation: Comparison of radiography and computed tomography

The aim of the present study was to compare the results from measurements of anatomical and mechanical angles of the femur and tibia by means of two diagnostic imaging methods – conventional radiography and computed tomography in normal dogs and dogs with medial patellar luxation (MPL). The study was done with 16 dogs (23 joints) from four small breeds (Mini-Pinscher, Chi-hua-hua, Yorkshire Terrier and Pomeranian). The results showed statistically significant differences between both imaging techniques in the values of mechanical lateral proximal femoral angle (mLPFA) and anteversion angle (AA) in joints with grade II MPL and in the anatomical lateral and medial distal femoral angles (aLDFA, aMDFA) and AA in grade III MPL. In healthy dogs, both methods differed considerably with regard to values of mechanical medial proximal and mechanical lateral distal femoral angles (mMPFA, mLDFA), the mechanical cranial proximal tibial angle (mCrPTA) and the quadriceps angle (Q-angle).

Varus morphology and its surgical implication in osteoarthritic knee and total knee arthroplasty

BackgroundKnee varus alignment represents a notorious cause of knee osteoarthritis. It can be caused by tibial deformity, combined tibial–femoral deformity and/or ligament imbalance. Understanding malalignment is crucial in total knee arthroplasty to restore frontal plane neutral mechanical axis. The aim of this study was to determine which factor contributes the most to varus osteoarthritic knee and its related surgical implications in performing a total knee arthroplasty.MethodsWe retrospectively evaluated 140 patients operated for total knee arthroplasty due to a varus knee. Full-leg hip to ankle preoperative X-rays were taken. Radiological parameters recorded were: mechanical axis deviation, hip–knee–ankle, anatomical–mechanical angle, medial neck shaft angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), lateral proximal femoral angle, lateral distal tibial angle (LDTA), femoral bowing, and length of tibia and femur. We also determined ideals tibial and femoral cuts in mm according to mechanical alignment technique. A R2 was calculated based on the linear regression between the predicted values and the observed data.ResultsThe greatest contributor to arthritic varus (R = 0.444) was MPTA. Minor contributors were mLDFA (R = 0.076), JLCA (R = 0.1554), LDTA (R = 0.065), and femoral bowing (R = 0.049). We recorded an average of 7.6 mm in lateral tibial cut thickness to restore neutral alignment.ConclusionsThe radiological major contributor to osteoarthritic varus knee alignment is related to proximal tibia deformity. As a surgical consequence, during performing total knee arthroplasty, the majority of the correction should therefore be made on tibial cut.

Morfometrijski parametri proksimalnog okrajka butne kosti i njihov uticaj na zglob kuka

Introduction: The femur is a long bone (ossa longa) that forms the hip and knee joints, supporting the weight of almost the entire body. This study is based on analyzing certain angles on the proximal femur that represent anthropometrically and surgically significant parameters, with clinical significance in diseases such as metabolic and degenerative bone disorders, arthritis, various hip trauma and disease. Aim: Determining the significance of certain morphometric parameters of the proximal femur and exploration of their impact on the hip joint. Material and methods: This cross-sectional study encompasses measuring four parameters: shaft length, the collodiaphyseal angle (CDA), the medial proximal femoral angle (MPFA) and the lateral proximal femoral angle (LPFA), on adult femora belonging to the archive of the Institute of anatomy "Niko Miljanić" of the Univerisity of Belgrade, Faculty of Medicine. A digital goniometer precise to two decimal places was used for all measurements. Results: Forty-seven femora were examined, 25 of which were left and 22 right femora of unknown gender and age, since none of the examined parameters could be used in procuring such information. The average femoral shaft length was 39.9 ± 2.7 cm, the shortest 34.8 cm and the longest 45.7 cm. The Collodiaphyseal angle (CDA) was 127.64 ± 4.25° on average, with the minimum being 119.1° and the maximum 137.7°. Average LPFA was 87.21 ± 3.07°, the lowest 81.6 and the highest 93.0°. Finally, MPFA was 86.9 ± 3.73° on average, with the smallest being 78.7° and the largest 94.5°. The Medial proximal femoral angle of right femora was significantly lower than the MPFA of left femora (p = 0,016). Conclusion: Eleven samples had a CDA below normal (< 124°), with three being defined as coxa vara (CDA < 120°). One had a CDA above normal (> 135°), being defined as coxa valga. Outside of reference values, LPFA was determined on 11 samples, being below normal (<85°) in all of them, whilst MPFA had 13 with only one of them being below normal (< 80°).

Radiographic analysis of lower limb alignment in professional football players.

To radiographically analyze lower limb alignment in adult asymptomatic professional football players and to correlate these values to clinical measurements. Twenty-four asymptomatic players [24.2 (3.6) years] were enrolled. Standard bilateral lower limb anteroposterior weight-bearing radiographs were acquired and clinical measurement of intercondylar/intermalleolar (ICD/IMD) distance was performed. Coronal plane mechanical alignment was assessed by five angles: leg mechanical axis (LMA), lateral proximal femoral angle (LPFA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and lateral distal tibial angle (LDTA). Their values were compared to the reference values for adult population. An inter-individual comparison between right/left and dominant/non-dominant leg was added. The sum of bilateral LMA was correlated against ICD/IMD and against ICD/IMD adjusted for body height. Football players presented with ICD/IMD of 46.5 (19.8) mm. Two, out of five, lower leg coronal angles showed significant differences (p < 0.001) compared to reference data from literature: LMA 5.8 (3.0)º vs.1.2 (2.2)º and MPTA 83.5 (2.6)º vs. 87.2 (1.5)º. No significant differences between left/right leg and dominant/non-dominant leg were established. Summed up bilateral LMA showed a high correlation to IMD/ICD (r = 0.8395; R2 = 0.7048), and even higher to ICD/IMD adjusted for body height (r = 0.8543; R2 = 0.7298). This study was radiographically confirming increased varus of elite football players toward general population. Apex of the varus deformity was located in the proximal tibia. Clinical measurement of ICD/IMD adjusted for body height highly correlated with the radiographic values of coronal alignment; therefore, it may be used in population studies.

Lower Limb Malrotation Is Regularly Present in Long-Leg Radiographs Resulting in Significant Measurement Errors.

Weight-bearing long-leg radiographs are commonly used in orthopaedic surgery. Measured parameters, however, change when radiographs are conducted in different rotational positions of the leg. It was hypothesized that rotational errors are regularly present in long-leg radiographs resulting in wrong measurements. In 100 consecutive long-leg radiographs conducted according to the method of Paley, rotation was assessed by fibular overlap. Angular parameters in radiographs (mechanical lateral proximal femoral angle (mLPFA), mechanical lateral distal femoral angle (mLDFA), angle between the anatomical and mechanical femoral axis (AMA), mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal tibial angle (mLDTA), and the mechanical femoral and tibial axis (mFA-mTA) were measured and deviations related to malrotation calculated. An average internal rotation of 8 degrees was found in lower limbs showing a range between 29 degrees of internal and 22 degrees of external rotation. As a result, mean differences before and after rotational correction for measured parameters (mLPFA, mLDFA, AMA, mMPTA, mLDTA, mFA-mTA) ranged between 0.4 and 1.7 degrees (-2.1; 5.6 95% confidence interval [CI]). In conclusion, malrotation of lower limbs is regularly present in long-leg radiographs. As all measured parameters are influenced by malrotation, correct lower limb rotation needs to be verified.

The effects of residual hip deformity on coronal alignment of the lower extremity in patients with unilateral slipped capital femoral epiphysis.

PurposeThe aim of our explorative study was to compare the differences in the coronal alignments of the hip, knee and ankle on the slip side and non-slip sides in patients with slipped capital femoral epiphysis (SCFE).MethodsThe study group consisted of 28 patients. On the full-length standing radiographs, measurements of articulo-trochanteric distance (ATD), neck-shaft angle (NSA), femoral offset, hip-knee-ankle axis, femur-tibial angle, mechanical axis deviation ratio (MAD-r), anatomical medial proximal femoral angle (aMPFA), mechanical lateral proximal femoral angle (mLPFA), anatomical lateral distal femoral angle (aLDFA), mechanical lateral distal femoral angle (mLDFA), knee joint line congruency angle, mechanical medial proximal tibial angle (mMPTA), mechanical lateral distal tibial angle (mLDTA), ankle joint line orientation angle (AJOA), and leg length discrepancy (LLD) were performed. The data from the slip side were compared with those from the non-slip side.ResultsAt skeletal maturity, there were significant differences between the slip side and non-slip side in ATD (p <0.001), NSA (p <0.001), MAD-r (p <0.001), aMPFA (p <0.001), aLDFA (p = 0.03), mLDFA (p = 0.04), mLDTA (p = 0.02), AJOA (p <0.001) and LLD (p<0.001).ConclusionResidual deformity in the proximal femur after epiphyseal slip and premature epiphysiodesis could cause changes in the coronal alignment of the lower extremity. We can add lower extremity alignment examination to follow-up protocol to rule out secondary problems in patients with SCFE.Level of EvidenceLevel III, retrospective comparative study

Radiographic determination of pelvic limb orthopaedic measurements in maned wolf (Chrysocyon brachyurus).

The aim of this study was to determine some radiographic reference values for hip joint, femur and patella in maned wolves. Ten maned wolves (Chrysocyon brachyurus), five live (G1) and five cadavers (G2), were used. There were no statistically significant differences in the radiological measurements between right and left pelvic limbs of the G1 and G2, except for mechanical lateral proximal femoral angle (mLPFA) in both Groups. The comparison of the measurements between Groups showed difference only for mechanical lateral distal femoral angle (mLDFA). Norberg angle values were 113.1° and 112.9° for G1 and G2. The values of femoral angle of inclination by Hauptman A and Hauptman B methods were 139.7° and 128.6° for G1, and 139.3° and 128.7° for G2. Femoral varus angle values were 5.5° for G1 and 3.9° for G2. The values of anatomic lateral distal femoral angle and anatomic lateral proximal femoral angle were 96.8° and 95.2° for G1, and 95.0° and 95.6° for G2. The values of mLDFA for G1 and G2 were 96.5° and 95.7°. The values of mLPFA were 95.8 (right) and 93.5 (left) for G1, and 95.7 (right) and 93.8 (left) for G2. The values of patellar ligament length, patellar length and L:P ratio were 4.6, 2.4cm and 1.9 for G1, and 4.4, 2.3cm and 1.8 for G2. In conclusion, the radiographic reference values described for the hip joint, the femur and the patella, may be useful in the diagnosis of diseases and deformities in maned wolves.

Radiographic measurements of the hindlimbs in crab‐eating foxes (Cerdocyon thous, Linnaeus, 1766)

Life expectancy of crab-eating foxes in captivity is approximately 11years, which favours the development of diseases including orthopaedic disorders. However, to understand disorders that may affect these animals, it is worth determining a normal range of measurements. Therefore, this study aimed to evaluate radiographic measurements of joint angles of the hindlimbs and the ratio of patellar ligament length to patellar length in healthy crab-eating foxes. Fifteen captive crab-eating foxes (Cerdocyon thous), eight males and seven females, aged more than 1year old, weighing 5.5-7.9kg were used. Anatomic and mechanical femoral joint angles were assessed in ventrodorsal radiographic views, and mediolateral views were taken to measure patellar ligament length and patellar length, and the tibial plateau angle. The right and left hindlimbs were evaluated. All measurements were conducted in triplicate by the same investigator. No statistically significant differences were observed between sides in the radiographic measurements. The anatomic lateral proximal femoral angle and the anatomic lateral distal femoral angle recorded mean values of 95.43° and 92.75°, respectively. The mechanical lateral proximal femoral angle and the mechanical lateral distal femoral angle recorded mean values of 93.39° and 96.75°, respectively. Inclination angles measured according to the Tomlinson, Hauptman A and Hauptman B methods were 133.80°, 147.32° and 128.63°, respectively. The tibial plateau recorded 18.77°, and the ratio of the patellar ligament length to the patellar length was 1.99. In conclusion, the collected data are important to characterize the normal values of crab-eating fox limbs.

Measurements of femoral angles, femur length, and hip width in cat radiographs

ABSTRACT Femoral angle, femur length, and hip width were measured in radiographs of 92 intact domestic cats, males and females of mixed breed from the Center for Zoonosis Control of the Federal District. The animals showed no trauma, orthopedic diseases or angular deformities and had closed physeal lines. Accordingly, we measured aLPFA (anatomical lateral proximal femoral angle, aLDFA (anatomical lateral distal femoral angle), mLPFA (mechanical lateral proximal femoral angle), mLDFA (mechanical lateral distal femoral angle), IA (femoral inclination angle), FL (femur length) and HW (hip width) using ventrodorsal radiographs, with both hindlimbs in a single exposure to an X-ray beam centered on the hip. The mean values of the variables were: mLPFA: 82.5±3.62°; aLPFA: 80.1±4.29°; mLDFA: 96.1±3.51° (males) and 97.3±2.05° (females); aLDFA: 94,3±3.43°; IA: 136.6±3.86°; FL: 12.9±0.55cm (males) and 13.4±0.66cm (females); and HW: 3.1cm±0.23 (males) and 3.5±0.26cm (females). These values will serve as a reference for the diagnosis of angular deformities and as support for planning corrective osteotomies in domestic cats.

Changes in Hip, Knee, and Ankle Coronal Alignments After Total Hip Arthroplasty With Transverse Femoral Shortening Osteotomy for Unilateral Crowe Type IV Developmental Dysplasia of the Hip

BackgroundTo investigate changes in lower extremity coronal alignment in patients with unilateral Crowe type IV developmental dysplasia of the hip who underwent total hip arthroplasty with transverse femoral shortening osteotomy. MethodsWe reviewed the preoperative and 1-year postoperative full-length lower extremity radiographs of 25 patients. Femoral offset (FO), mechanical hip-knee-ankle angle, anatomical axis, mechanical axis deviation (MAD), mechanical lateral proximal femoral angle, anatomical medial proximal femoral angle, mechanical lateral distal femoral angle, anatomical lateral distal femoral angle, knee joint line congruency angle, mechanical medial proximal tibial angle, mechanical lateral distal tibial angle, ankle joint line orientation angle, tibial plafond talus angle, extremity length, and pelvic obliquity were measured on both the operative and nonoperative sides. ResultsPostoperatively, there were significant changes in FO (P = .001), hip-knee-ankle angle (P = .004), MAD (P = .016), mechanical lateral proximal femoral angle (P = .001), anatomical medial proximal femoral angle (P = .012), mechanical lateral distal femoral angle (P = .043), and ankle joint line orientation angle (P = .012) on the operative side. Only MAD (P = .035) changed significantly on the nonoperative side. ConclusionModification of FO and reconstruction of hip joint anatomy led to neutralization of knee and ankle valgus alignment. Effects on the nonoperative side were minimal.

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.

Intraobserver and intermethod reliability for using two different computer programs in preoperative lower limb alignment analysis

Background and objectiveProfessional graphics editing programs can be used in the preoperative planning of lower limb deformity correction surgery. This study was conducted to test the reliability of using such programs versus FDA approved medical planning software. Materials and methodsThirty long standing lower limb radiographs had been selected. Two different computer programs (Adobe Photoshop) versus planning software (MediCAD) were used in the analysis of lower limb alignment. The following angles were measured twice:Lateral Proximal Femoral Angle (LPFA), mechanical Lateral Distal Femoral Angle (mLDFA), Joint Line Convergence Angle (JLCA), Medial Proximal Tibial Angle (MPTA), Lateral Distal Tibial Angle (LDTA) and Mechanical Axis Deviation (MAD). Intraclass correlation coefficient (ICC) was used to assess the intraobserver and intermethod reliability and the mean differences between measurements were calculated. ResultsIntraobserver and intermethod reliability scores were very good (>0.95) for all measurements. The highest reliability was for MAD (0.999). LPFA and LDTA had the highest variability and a range of intraobserver absolute difference up to 4.8° and 3.7° respectively. ConclusionComputer assisted lower limb alignment analysis is reliable whether using graphics editing program or specialized planning software. However slight higher variability for angles away from the knee joint can be expected.

Evaluation of bone deformities of the femur, tibia, and patella in Toy Poodles with medial patellar luxation using computed tomography.

To evaluate morphological parameters of the femur, tibia, and patella in Toy Poodles with medial patellar luxation (MPL) using three-dimensional (3D) computed tomography (CT) and to compare these parameters between radiography and CT. Thirty-five hindlimbs of Toy Poodles were divided into normal and grade 2 and 4 MPL groups. The anatomical and mechanical lateral proximal femoral angle, anatomical and mechanical lateral distal femoral angle (aLDFA, mLDFA), femoral varus angle (FVA), inclination of the femoral head angle, procurvation angle, anteversion angle (AA), frontal angle of the femoral neck, mechanical medial proximal or distal tibial angle, mechanical cranial proximal or distal tibial angle, tibial plateau angle, tibial torsion angle (TTA), Z angle, relative tibial tuberosity width, ratio of the medial distance of tibial tuberosity to the proximal tibial width (MDTT/PTW), patella size, and the patellar ligament length: patellar length (L:P) ratio were evaluated on radiography and 3D CT. The aLDFA, mLDFA, FVA, and TTA were significantly larger and the AA, MDTT/PTW, and patella were significantly smaller in the grade 4 MPL group. There were significant differences in many parameters between imaging tools, and CT was considered less susceptible to potential artefacts and rotational deformities. Toy Poodles with grade 4 MPL had significant femoral varus deformity, medial displacement of the tibial tuberosity, internal torsion of the proximal tibia, and hypoplasia of the patella.

Radiographic Assessment of Lower Limb Lengthening in Achondroplastic Patients, Using the Ilizarov Frame: A 5-19 Year Follow up Study

Background: The effectiveness of the Ilizarov ring fixator in correcting achondroplasia’s lower limb deformities is known. However, whether the long term postoperative result is comparable to normal population standards, has not been analyzed. Materials and Methods: Nineteen (19) achondroplastic patients, 12 males and 7 females, aged 19-38 years, who at the age of 9-19 years, had undergone both tibia and femur lengthening, using the Ilizarov method, were included in the study. Patients were evaluated 5-19 years after their last surgery, using standardized long lower limb anteroposterior and lateral standing radiographs. Tibial and femoral lengthening gain was measured. A comparison between the achondroplastic patients at follow up and comparative radiographic parameters of the normal population was made, concerning– at the frontal plane- LPFA (lateral proximal femoral angle), LDFA (lateral distal femoral angle), MPTA (medial proximal tibial angle), LDTA (lateral distal tibial angle) and MAD (mechanical axis deviation) and – at the sagittal plane- PDFA (posterior distal femoral angle), PPTA (posterior proximal tibial angle) and ADTA (anterior distal tibial angle). Results: Mean angle values at follow up were: LPFA 118, LDFA 95.5, MPTA 87.8, LDTA 93, PDFA 85.1, PPTA 84, ADTA 88.3 while MAD mean value was 28. LPFA, LDFA, LDTA, PPTA, ADTA and MAD values were statistically significantly different (p<0.001) between achondroplastic patients and normal population. Conclusions: The use of the Ilizarov method for lower limb deformity correction, in achondroplastic patients, provides a functional length gain. It substantially corrects the three-dimensional deformities of the disease but, it does not restore the radiological image within normal standards. Level of Evidence Level II, Retrospective Prognostic study.

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.