Lateral Distal Tibial Angle Research Articles

An automatic measurement method for ankle key angles based on point cloud segmentation network

AbstractIn clinical practice, anterior distal tibialangle (ADTA) and lateral distal tibialangle (LDTA) are important evaluation indexes, which can reflect the degree of deformity and determine the type of deformity to a certain extent. The measurement process of these parameters involves the localization of multiple key regions. To simplify the process of measuring ADTA and LDTA, an automatic measurement method is proposed. First, this study constructs an ankle 3D point cloud dataset by 3D reconstruction of ankle electron computed tomography (CT) data, and then, an ankle point cloud segmentation network with a Self‐Attention mechanism and kernel point convolution combined with each other is constructed, and the ankle point cloud data with labels are input to this network to predict the ankle bone feature points. Finally, the segmented feature points are fitted, and the tibial backbone axis and distal tibial articular surface can be drawn, and based on the fitting results, ADTA and LDTA are obtained. Compared with manual measurements by physicians, the proposed method in this study achieved an average error of 0.46° with a passing rate of 97.7% for ADTA measurement. For LDTA measurement, the average error was 0.69° with a passing rate of 98%. The ankle joint key angle measurement system developed in this study meets the accuracy requirements of orthopedics and significantly reduces the workload for doctors.

Preoperative foot and ankle radiographic evaluation for total knee arthroplasty

PurposeTo radiographically evaluate the ankle and foot complications in preoperative patients for total knee arthroplasty (TKA) in Japan. MethodsThis study included 500 legs of 500 patients who planned to undergo primary TKA in affiliated hospitals of our university from August 2020 to November 2021. Hip to calcaneus view, anterior view of the ankle joint, and anterior and lateral views of the foot were taken within 1 month preoperatively. We measured hip-knee-ankle angle (HKA), mechanical ankle joint axis point (MAJAP), lateral distal tibial angle (LDTA), tibio-plafound inclination (TPI), talar inclination (TI), ankle joint line convergence angle (A-JLCA), talo-first metatarsal angle (TMA), calcaneal pitch angle (CPA), hallux valgus angle (HVA), first-second intermetatarsal angle (M1M2A), first fifth intermetatarsal angle (M1M5A), talonavicular coverage angle (TNCA), and percentage of Takakura Tanaka classification. ResultsMean measured values were as follows: HKA: 11.0°; MAJAP, 39.6%; LDTA: 92.2°; TPI: 6.9°; TI: 7.2°; A-JLCA: 0.3°; TMA:−4.3° (<−4° in 247 feet, 49.4%); CPA: 15.9°(<20° in 366 feet, 73.2%); HVA: 16.8° (mild in 70 feet, 14.0%; moderate in 42 feet, 8.4%; severe in 23 feet, 4.6%); M1M2A: 11.1°(>9° in 373 feet, 74.6%); M1M5A: 31.1°(≥30° in 321 feet, 64.2%); TNCA: 10.6° (≥7° in 375 feet, 75.0%); Takakura Tanaka classification Stage ​≥ ​IIIa in 108 feet, 21.6%. ConclusionsMild-to-severe hallux valgus was noted in 26.5% of patients and Stage IIIa or higher ankle osteoarthritis in 21.6%, and abnormal alignment—including flat feet—was indicated in some patients. Patient's knee, foot, and ankle symptoms should be considered before TKA.

The Management of Tibial Bone Defects: A Multicenter Experience of Hexapod and Ilizarov Frames.

Bone defects may be managed with bone transport or acute shortening and lengthening using circular external fixation devices. We performed a multicenter retrospective cohort study to compare the outcomes between the Ilizarov frames and hexapod frames for the management of bone defects. Patients treated for bone defects using either Ilizarov or hexapod frames were included for analysis in two specialist institutions. Primary outcomes were time to consolidation, bone healing index (BHI), and external fixator index (EFI). Radiographic parameters included the medial proximal tibial angle, lateral distal tibial angle, posterior proximal tibial angle, and anterior distal tibial angle. There were 137 hexapods and 90 Ilizarov frames in total. The mean time to follow-up was 3.7 years in the hexapod group and 4.0 years in the Ilizarov group. Hexapods had a significantly lower time to consolidation (253 days versus 449 days) (P < 0.0001) and BHI (59.1 days/cm versus 87.5 days/cm) (P < 0.0001). Hexapods had a significantly better EFI (72.3 days/cm versus 96.1 days/cm) (P = 0.0009). Hexapods may confer a significant advantage over Ilizarov frames in the management of bone defects. Time to consolidation, radiographic parameters, BHI, and EFI are all superior in hexapods.

Correction of tibial multiplanar deformities using single Taylor external fixator combined with biplanar osteotomy

To investigate the effectiveness of single Taylor external fixator combined with biplanar osteotomy on correction of tibial multiplanar deformities. Between October 2016 and December 2021, 11 patients with tibial multiplanar deformities (20 sides) were treated with single Taylor external fixator and biplanar osteotomy. Of them, 4 were male and 7 were female; the average age ranged from 13 to 33 years (mean, 21.9 years). Diagnosis included rickets severe genu varum deformity (7 cases, 14 sides), rickets severe genu valgum deformity (2 cases, 4 sides), multiple osteochondromatosis calf deformity (1 case, 1 side), neurofibromatosis medial lower leg anterior arch deformity with short of leg (1 case, 1 side). After fibular osteotomy and tibial multiplanar osteotomy, a Taylor external fixator was installed. After operation, the deformities were corrected successively and fixed completely. The osteotomy healed, then the external fixator was removed. Before operation and at 12 months after operation, the full-length X-ray films were taken. The leg-length discrepancy, medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), posterior proximal tibial angle (PPTA), anterior distal tibial angle (ADTA), and tibial rotation angle were measured. The degree of lower limb deformity was scored with reference to a customized tibial mechanical axis scoring table. Osteotomy was successfully completed without neurovascular injury and other complications. The external fixator was adjusted for 28-46 days, with an average of 37 days, and the external fixator was worn for 136-292 days, with an average of 169 days. Mild needle infection during the fixation period occurred in 3 sides, refracture at the distal tibial osteotomy in 1 side after removing the external fixator, and nonunion of the distal fibular osteotomy in 1 side. All patients were followed up 369-397 days (mean, 375 days). At 12 months after operation, the lower limb discrepancy decreased, but there was no significant difference ( P>0.05). MPTA, LDTA, PPTA, ADTA, and tibial rotation angle improved, and the differences in LDTA, ADTA, and tibial rotation angle were significant ( P<0.05). The score of lower limb deformity was significantly higher than that before operation ( P<0.05), and the results were excellent in 9 sides, good in 8 sides, fair in 3 sides, with the excellent and good rate of 85%. Single Taylor external fixator combined with biplanar osteotomy is effective in the correction of tibial multiplanar deformities.

MAKO robot-assisted total knee arthroplasty cannot reduce the aggravation of ankle varus incongruence after genu varus correction ≥ 10°: a radiographic assessment

IntroductionThe objective of this study was to investigate the ankle alignment alterations after the correction of knee varus deformity in MAKO robot-assisted total knee arthroplasty (MA-TKA).MethodsA retrospective analysis was conducted for 108 patients with TKA from February 2021 to February 2022. Patients were divided into two groups based on MAKO robot involvement during the procedure: the MA-TKA group (n = 36) and the conventional manual total knee arthroplasty (CM-TKA) group (n = 72). The patients were divided into four subgroups according to the degree of surgical correction of the knee varus deformity. Seven radiological measurements were evaluated pre and post-surgery: mechanical tibiofemoral angle (mTFA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), tibial plafond inclination angle (TPIA), talar inclination angle (TIA), and tibiotalar tilt angle (TTTA). TTTA is a quantitative representation of the extent of ankle incongruence.ResultsThe number of mTFA, mLDFA, and MPTA outliers in the MA-TKA group was significantly lower compared to the CM-TKA group (P<0.05). Knee varus deformity was properly corrected and the mechanical axis was restored in all patients, regardless of the treatment group. Only for varus corrections ≥ 10° did TTTA change significantly (p < 0.01) and ankle varus incongruence aggravate post-operation. The ΔTTTA correlated negatively with ΔTFA (r=-0.310,P = 0.001) and correlated positively with ΔTPIA (r = 0.490,P = 0.000). When the varus correction was ≥ 7.55°, the probability of ankle varus incongruence exacerbation increased 4.86-fold.ConclusionCompared with CM-TKA, MA-TKA osteotomy showed more precision but was unable to reduce post-operation ankle varus incongruence. When the varus correction ≥ 10°, ankle varus incongruence aggravated, while when the varus correction ≥ 7.55°, the probability of ankle varus incongruence increased 4.86-fold. This may occasion the pathogenesis of ankle pain following TKA.

Valgus alignment of the femoral component is associated with higher revision rates 10years after TKA.

Appropriate positioning and alignment of tibial and femoral component in primary total knee arthroplasty (TKA) are factors of major importance directly related to patient satisfaction and implant survival. Most literature works elaborate on overall post-operative alignment and its correlation to implant survival. However, less is known about the impact of individual component alignment. The purpose of this study was to investigate the effect of undercorrection of overall alignment as well as the effect of individual tibial and femoral component alignment on the post-operative failure rate after total knee arthroplasty. Clinical and radiographic data of primary TKA cases from 2002 to 2004, with a minimum of 10-year follow-up, were retrospectively reviewed. The pre- and post-operative hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA) were measured on weight-bearing, full-length antero-posterior lower limb radiographs. Statistical analysis was performed to establish the correlation between both overall and implant alignment and revision rate. In total, 379 primary TKA cases were evaluated. The mean time of follow-up was 12.9years (range 10.3-15.9years, SD = 1.8). Nine out of 379 cases were revised due to aseptic loosening; the mean time to revision was 5.5years (range 1.0-15.5years, SD = 4.6). Varus undercorrection of overall alignment was not associated with a higher rate of revision (p = 0.316). Post-operative valgus femoral alignment (mLDFA < 87°) contributed to a significant decreased prosthesis survival in contrast to neutral femoral alignment (revision rate valgus group: 10.7% and neutral group: 1.7%; p = 0.003). Post-operative tibial mechanical alignment was not identified as a significant predictor for implant survival (revision rate varus group: 2.9% and neutral group: 2.4%; p = 0.855). Primary TKA showed significantly higher revision rates when the femoral component was placed in > 3° of valgus (mLDFA < 87°). In contrast, postoperative overall residual varus alignment (HKA) and varus alignment of the tibial component were not related to higher revision rates at a minimum 10-year follow-up after TKA. These findings should be considered when choosing component position in individualised TKA. III.

Hip abduction angle after open-wedge high tibial osteotomy is associated with the timed up & go test and recurrence of varus alignment

The aim of this study is to investigate the association between the hip abduction angle (HAA) and lower limb alignment as well as the clinical assessments in open-wedge high tibial osteotomy (OWHTO) patients. A total of 90 patients who underwent OWHTO were included. The demographic characteristics and clinical assessments (the Visual Analogue Scale for activities of daily living, the Japanese knee osteoarthritis measure, the Knee injury and Osteoarthritis Outcome Score, the Knee Society score, the Timed Up & Go (TUG) test, the single standing (SLS) test and muscle strength) were recorded. The patients were divided into two groups according to the HAA at 1 month after operation: the HAA (−) group (HAA < 0°) and the HAA (+) group (HAA ≥ 0°). Clinical scores except for the SLS test and radiographic parameters except for the posterior tibia slope (PTS), lateral distal femoral angle (LDFA) and lateral distal tibial angle (LDTA) were significantly improved at 2 years postoperatively. Regarding the two groups, scores on the TUG test in the HAA (−) group were significantly lower than those in the HAA (+) group (p = 0.011). The hip-knee-ankle angle (HKA), weight bearing line (WBLR) and knee joint line obliquity (KJLO) in the HAA (−) group were significantly higher than those in the HAA (+) group (p < 0.001, 0.001 and p = 0.025). In contrast, the LDFA in the HAA (−) group were significantly lower than those in the HAA (+) group (p < 0.001). The TUG test and the LDFA were weakly positively correlated with the HAA (r = 0.34, 0.42, p < 0.001 and 0.001). In contrast, the HKA, WBLR and KJLO had a weak negative correlation with the HAA (r = − 0.43, − 0.38 and − 0.37, p < 0.001, 0.001 and 0.001). This study showed the postoperative HAA was significantly associated with the TUG test and the HKA, WBLR, LDFA, and KJLO. A higher postoperative HAA might induce varus recurrence and poor outcomes of the gait parameter.

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.

Hodnocení frontálního postavení distální části dolní končetiny podle sklonu horizontální linie kloubní štěrbiny hlezna

PURPOSE OF THE STUDY Osteotomies around the knee are an established technique for treating knee osteoarthritis and other knee conditions by redistributing the body's weight and force within and around the knee joint. The aim of this study was to determine if the Tibia Plafond Horizontal Orientation Angle (TPHA) is a reliable measure for describing ankle alignment of the distal tibia in the coronal plane. MATERIALS AND METHODS This retrospective study included patients who underwent supracondylar rotational osteotomies for correction of femoral torsion. All patients had standing radiographs taken preoperatively and postoperatively with both knees pointed forward. Five variables, including Mechanical Lateral Distal Tibia Angle (mLDTA), Mechanical Malleolar Angle (mMA), Malleolar Horizontal Orientation Angle (MHA), Tibia Plafond Horizontal Orientation Angle (TPHA), and Tibio Talar Tilt Angle (TTTA), were collected. The preoperative and postoperative measurements were compared to each other using the Wilcoxon signed rank test. RESULTS A total of 146 patients were included in the study, with a mean age of 51.47 ± 11.87 years. There were 92 (63.0%) males and 54 (37.0%) females. MHA decreased from 14.0° ± 5.32° preoperatively to 10.59° ± 3.93° (p < 0.001) postoperatively, and TPHA decreased from 4.88° ± 4.07° preoperatively to 3.82 ± 3.10° (p = 0.013) postoperatively. The change in TPHA was significantly correlated with the change in MHA (r = 0.185, CI 0.023 - 0.337; p = 0.025). No differences were found between the measurements of mLDTA, mMA, and mMA pre- and postoperatively. DISCUSSION The orientation of the ankle should be taken into consideration during preoperative planning of osteotomies and should be measured in cases of postoperative ankle pain. CONCLUSIONS The TPHA is a reliable measure for describing ankle alignment of the distal tibia in the frontal plane. Key words: osteotomy, ankle, realignment, coronal alignment, preoperative planning.

The application of intramedullary nails and transmedullary support screws in surgical treatment of distal tibia fracture

Introduction. Fractures of the distal tibia are a difficult treatment problem due to the specific anatomy of this area and the soft tissue injuries resulting from trauma. A distal fracture is short, has a wide marrow cavity, and the asymmetric muscle forces acting on it can cause secondary displacements despite the originally correct positioning. Against the background of the problems presented above, the fixation with an intramedullary nail (IMN) with the use of TMS (trans medullary support) screws directional screws seems to be the best alternative for treatment. Aim. The aim of this study was to evaluate the bone fracture repositioning after surgical treatment of tibia fracture, the time of bone healing and the function of the upper ankle joint. Materials and methods. Forty patients treated surgically due to a fracture of the distal tibia with the use of an intramedullary nail and TMS screws were included in this study. The mean follow-up time was 25.3 months. The function of the ankle joint of the injured limb was evaluated using the AOFAS, VAS and SF-36 questionnaires. Radiological documentation was assessed in terms of correct bone fragment repositioning, placement of directional screws and correct union of the fibula. Post-operative X-rays as well as X-rays taken at the end of treatment in AP and lateral projection were also assessed, evaluating LDTA (lateral distal tibial angle) and ADTA (anterior distal tibial angle). Results. The function of the ankle joint after surgical treatment of a distal tibia fracture using the IMN + TMS method is as follows: AOFAS score 91.5, VAS 2.2 / 10 points. The range of motion of the ankle joint: the angles of ankle movement were significantly greater in the case of the uninjured limb compared to the injured one. Bone union was obtained in all patients. In 80% of patients, it was achieved in less than 6 months. Assessment of repositioning after surgery – mean LDTA angle after surgery was 89 and mean ADTA angle after surgery was 86 (standard LDTA 90, ADTA 85). Conclusions. The function of the ankle joint after treatment of a distal tibial fracture with an intramedullary nail and TMS screws according to the AOFAS and VAS scale was very good and allowed for the anatomical bone fragment fixation. The bone healing after fixation of the distal tibial fracture with an intramedullary nail and TMS screws was shorter than 6 month in most cases.

EFFECT OF HIGH TIBIAL OSTEOTOMY ON ANKLE AND SUBTALAR JOINT ALIGNMENT

This study aimed to examine the effect of high tibial osteotomy (HTO) on the ankle and subtalar joints via analysis of static radiographic alignment. We hypothesised that surgical alteration of the alignment of the proximal tibia would result in compensatory distal changes.35 patients recruited as part of the wider Biomechanics and Bioengineering Centre Versus Arthritis HTO study between 2011 and 2018 had pre- and postoperative full-length weightbearing radiographs taken of their lower limbs. In addition to standard alignment measures of the limb and knee (mechanical tibiofemoral angle, Mikulicz point, medial proximal tibial angle), additional measures were taken of the ankle/subtalar joints (lateral distal tibial angle, ground-talus angle, joint line convergence angle of the ankle) as well as a novel measure of stance width. Results were compared using a paired T-test and Pearson's correlation coefficient.Following HTO, there was a significant (5.4°) change in subtalar alignment. Ground-talus angle appeared related both to the level of malalignment preoperatively and the magnitude of the alignment change caused by the HTO surgery; suggesting subtalar positioning as a key adaptive mechanism. In addition to compensatory changes within the subtalar joints, the patients on average had a 31% wider stance following HTO. These two mechanisms do not appear to be correlated but the morphology of the tibial plafond may influence which compensatory mechanisms are employed by different subgroups of HTO patients.These findings are of vital importance in clinical practice both to anticipate potential changes to the ankle and subtalar joints following HTO but it could also open up wider indications for HTO in the treatment of ankle malalignment and osteoarthritis.

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.

Emerged donor limb growth morbidity and malalignment after combined ipsilateral tibial and fibular cortical harvest graft in children. Early follow-up report.

The quantity of bone grafts required in certain pediatric conditions is sometimes substantial. This retrospective study details the radiological changes occurring in the donor leg and ankle following the simultaneous harvest of large diaphyseal cortical grafts from the tibia and fibula in 14 children (16 legs). The following preoperative and follow-up radiological parameters were measured and compared for donor legs: the longitudinal continuous regeneration of fibula, distal fibular station, medial proximal tibial angle, lateral distal tibial angle, posterior proximal tibial angle (PPTA), anterior distal tibial angle and interphyseal angle (tibia diaphyseal angulation) in both coronal and sagittal planes. Additionally, the impact of fibular regeneration in combined harvests was separately analyzed. Children were operated at the mean age of 52 months. Mean follow-up of 25.2 months was available. At follow-up, the donor tibia healed completely in all legs whereas fibular regeneration was complete only in 10 legs (62.5%). At follow-up, ankle valgus was present in 6 out of 16 legs (37%) and tibia valga increased in all legs except one (94%). Procurvatum was present in 7 legs. The fibular nonregeneration group was prone to ankle valgus deformity ( P = 0.014), valgus angulation of tibial diaphysis ( P = 0.0076) and lower mean PPTA ( P = 0.026) when compared to the regenerate group. There was a complication of stress fracture in one donor tibia. Combined tibial and fibular harvest is a major surgical undertaking in children. The donor limbs have their share of complications postharvest, more so when the fibula remains nonregenerated. Serial monitoring of donor sites is emphasized.

Effect of Q-angle, lateral distal tibial angle and hip muscle torques on ankle injury.

The ankle sprain is the most common ankle injury. Although the factors that increase the risk of ankle injury are included in the literature, the definitive evidence is controversial. The aim of our study was to examine whether Q-angle, lateral distal tibial angle (LDTA), and hip muscle torque are associated with ankle sprain. Thirty-six individuals who underwent an axial X-ray examination of the lower extremity following ankle sprain were included. The Q-angle and LDTA were measured on the axial knee X-rays on both sides. The isometric muscle strength was measured with a digital handheld dynamometer for the quadriceps femoris muscle, the gluteus medius muscle and the gluteus maximus muscle. Muscle torques were calculated by multiplying isometric muscle strength values with the distance to the joint center. Discrimination analysis shows that the gluteus maximus (0.90), gluteus medius (0.49), quadriceps femoris muscle torques (0.34), and lateral distal tibial angle (0.43) were the factors that most contributed to ankle sprain. No significant relationship was found between the Q-angle and ankle sprain (p = 0.603). A strong relationship was found between LDTA, quadriceps femoris, gluteus medius and gluteus maximus muscle torques and ankle sprain (p = 0.014, p < 0.001, p = 0.011, p = 0.002, respectively). In conclusion, the torques of the proximal muscle may be more related than the Q-angle to lateral ankle sprain injury. Individuals with high LDTA should also be carefully examined for the risk of ankle sprain.

A novel approach for joint line restoration in revision total ankle arthroplasty based on the three-dimensional registration of the contralateral tibia and fibula

PurposeThe use of total ankle arthroplasty (TAA) is increasing over time, as so will the need for revision TAAs in the future. Restoration of the ankle joint line (JL) in revision TAA is often difficult due to severe bone loss. This study analyzed the accuracy of a three-dimensional (3D) registration of the contralateral tibia and fibula to restore the ankle joint line (JL) and reported side-to-side differences of anatomical landmarks.Methods3D triangular surface models of 96 paired lower legs underwent a surface registration algorithm for superimposition of the mirrored contralateral lower leg onto the original lower leg to approximate the original ankle JL using a proximal, middle and distal segment. Distances of the distal fibular tip, anterior and posterior medial colliculus to the JL were measured and absolute side-to-side differences reported. Anterior lateral distal tibial angle (ADTA) and lateral distal tibial angle (LDTA) were measured.ResultsMean JL approximation was most accurate for the distal segment (0.1 ± 1.4 mm (range: -3.4 to 2.8 mm)) and middle segment (0.1 ± 1.2 mm (range: -2.8 to 2.5 mm)) compared to the proximal segment (-0.2 ± 1.6 mm (range: -3.0 to 4.9 mm)) (p = 0.007). Distance of the distal fibular tip, the anterior, and posterior medial colliculus to the JL, ADTA and LDTA yielded no significant side-to-side differences (n.s.).Conclusion3D registration of the contralateral tibia and fibula reliably approximated the original ankle JL. The contralateral distal fibular tip, anterior and posterior medial colliculi, ADTA and LDTA can be used reliably for the planning of revision TAA with small side-to-side differences reported.Level of EvidenceIV.

Use of a Lightweight Portable Fluoroscopy Device for Obtaining Weightbearing Ankle Images

Category: Ankle; Other Introduction/Purpose: Portable fluoroscopy devices provide point-of-care imaging in emergency and out-patient clinics. In patients suffering from ankle syndesmosis injuries, imaging under physiologic load can lead to more accurate diagnosis, particularly in subtle cases. In this study, we compared weightbearing images obtained using a novel lightweight portable battery-powered fluoroscopy device with a conventional radiography device regarding syndesmosis examination measurements. Methods: In this prospective study, eleven healthy participants underwent bilateral three-view weightbearing imaging of both ankles using a radiography (X-ray group) device and a portable fluoroscopy system (Smart-C group). Radiographic measurements were done by two observers on anteroposterior, mortise, and lateral views were compared between the two techniques. These measurements included talar tilt, tibiofibular clear space, tibiofibular overlap, plafond malleolar angle, medial distal tibial angle, medial clear space, lateral distal tibial angle, anterior and posterior tibiofibular distance were measured using the appropriate view. Data were compared between the two techniques; the interobserver agreement was calculated within each group. P&lt;0.05 was considered statistically significant. Results: Comparing the two imaging modalities, there was no significant difference between the measurements in Smart-C and X- ray groups except plafond malleolar angle. The overall interobserver agreement was excellent between the two observers. There was no significant difference between the measures by the two observers and between the bilateral ankles. Conclusion: Our results support the use of weightbearing images using portable fluoroscopy device as an alternative for the conventional radiography systems, particularly in limited-resource settings.

Fully automated measurement on coronal alignment of lower limbs using deep convolutional neural networks on radiographic images

BackgroundA deep convolutional neural network (DCNN) system is proposed to measure the lower limb parameters of the mechanical lateral distal femur angle (mLDFA), medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), joint line convergence angle (JLCA), and mechanical axis of the lower limbs.MethodsStanding X-rays of 1000 patients’ lower limbs were examined for the DCNN and assigned to training, validation, and test sets. A coarse-to-fine network was employed to locate 20 key landmarks on both limbs that first recognised the regions of hip, knee, and ankle, and subsequently outputted the key points in each sub-region from a full-length X-ray. Finally, information from these key landmark locations was used to calculate the above five parameters.ResultsThe DCNN system showed high consistency (intraclass correlation coefficient > 0.91) for all five lower limb parameters. Additionally, the mean absolute error (MAE) and root mean squared error (RMSE) of all angle predictions were lower than 3° for both the left and right limbs. The MAE of the mechanical axis of the lower limbs was 1.124 mm and 1.416 mm and the RMSE was 1.032 mm and 1.321 mm, for the right and left limbs, respectively. The measurement time of the DCNN system was 1.8 ± 1.3 s, which was significantly shorter than that of experienced radiologists (616.8 ± 48.2 s, t = -180.4, P < 0.001).ConclusionsThe proposed DCNN system can automatically measure mLDFA, MPTA, LDTA, JLCA, and the mechanical axis of the lower limbs, thus helping physicians manage lower limb alignment accurately and efficiently.

Comparison of mid-term clinical results between lag screw fixation and Kirschner wire fixation after close reduction in adolescent triplane distal tibia epiphyseal fracture

ObjectiveTo compare the mid-term clinical results of lag screw and Kirschner wire fixation(KWF) for close reduction in triplane distal tibia epiphyseal fracture. MethodsA retrospective analysis of 25 cases of triplane fractures of the distal tibia treated in our department from Jan 2017 to Dec 2019 was performed, Lag screw fixation(LSF) was used in 14 cases and Kirschner wire fixation in 11 cases, the clinical results were evaluated by premature epiphyseal closure(PPC) rate, the American Orthopaedic Foot and Ankle Score (AOFAS) Ankle-hindfoot foot scoring system, the lateral distal tibial angle (LDTA) from X-ray. ResultsAll the 25 children were followed up for a mean of 34(ranging 26–52) months. AOFAS scores improved from a mean of 33(ranging 29–43) pre-op, to 82(ranging 77–88) at three month follow up, to 92 (ranging 88–98) at last follow-up in all 25 cases. Till last follow up there was no cases premature physeal closure in LSF group but 4 cases in KWF group, LDTA in both groups at last follow up shows no ankle varus or valgus deformity, and the ankle joint function was not limited in all cases. ConclusionLag screw and Kirschner wire fixation methods can both achieve good clinical effects for triplane distal tibia epiphyseal fracture. Lag screw fixation provide lower PPC rate but Kirschner wire fixation save one anesthesia and surgery.

Controlling the angle between the distal locking screw and tibiotalar joint tangent helps to reduce the occurrence of misalignment of distal tibial fractures treated with intramedullary nail fixation

BackgroundStudies have shown that on the coronal plane, whether the direction of the distal locking screw is parallel to the tangent line of the tibiotalar joint can be used to determine whether there is varus or valgus deformity after the treatment of distal tibial fractures with intramedullary nail (IMN) fixation. However, there has been no statistical analysis of the included angle on the coronal plane, and there have been no reports on whether there is a relationship between the direction of the distal locking screw on the sagittal plane or the included angle of the tangent line of the tibiotalar joint and the postoperative alignment of distal tibial fractures treated with IMN fixation.ObjectiveOur aim was to evaluate the relationship between the angles formed by the distal locking screw and the tibiotalar joint tangent (ADTTs) on the sagittal and coronal planes and postoperative alignment in the treatment of distal tibial fractures with IMN fixation.MethodsWe performed a retrospective analysis of 100 patients with distal tibial fractures treated with IMN fixation using the suprapatellar approach. On the coronal and sagittal planes, the ADTTs were arranged from small to large and divided into 4 groups, namely, groups A, B, C and D. One-way ANOVA was used to compare the lateral distal tibial angle (LDTA) and anterior distal tibial angle (ADTA) among all groups, and the chi-square test was used to compare the incidence of postoperative tibial misalignment among all groups. Univariate analysis was performed using chi-square tests to identify factors that might be associated with dislocation, including fibular open reduction and internal fixation (ORIF), limited open reduction, ADTT, IMN diameter, injury mechanism, open vs. closed fracture, comminution, and fibular fracture level. Then, the statistically significant variables in the univariate analysis were included in a multivariate logistic regression equation to evaluate the independent factors related to misalignment.ResultsOn the coronal plane, the ADTTs of groups A, B, C and D were < 0°, 0°-1.3°, 1.3°-2.7° and > 2.7°, respectively. The mean LDTAs of groups B and C (0°-1.3° and 1.3°-2.7°), group A (< 0°) and group D (> 2.7°) were 89.5 ± 1.6°, 92.0 ± 3.2° and 85.8 ± 3.5°, respectively (P < 0.01). Deformity greater than 5° were more likely in groups A and D than groups B and C [14 of 50 (28%) vs. 1 of 50 (2%), P < 0.001]. On the sagittal plane, the ADTTs of groups A, B, C and D were < 8.9°, 8.9°-10.4°, 10.4°-11.7° and > 11.8°, respectively. The average ADTAs of groups B and C (8.9°-10.4° and 10.4°-11.7°), group A (< 8.9°) and group D (> 11.8°) were 80.4 ± 1.3°, 83.1 ± 3.7° and 77.9 ± 2.5°, respectively (P < 0.01). Deformity greater than 5° was more likely in groups A and D than groups B and C [13 of 50 (26%) vs. 0 of 50 (0%), P < 0.001]. An ADTT of 0°-2.7° on the coronal plane and 8.9°-11.7° on the sagittal plane (OR: 0.08, P = 0.02) and limited open reduction (OR: 0.21, P < 0.01) were independent factors that reduced the likelihood of misalignment.ConclusionThe alignment of distal tibial fractures after surgery is sensitive to the ADTT and use of limited open reduction. Controlling the ADTT between 0° and 2.7° on the coronal plane and between 8.9° and 11.7° on the sagittal plane is helpful to reduce the occurrence of misalignment after the treatment of distal tibial fractures by IMN fixation.

Using short knee radiographs to predict the coronal alignment after TKA: Is it an accurate proxy for HKA on full-length images?

BackgroundThe postoperative clinical outcomes has been extensively demonstrated to correlate with the coronal alignment after total knee arthroplasty (TKA). However, in different studies, either the hip-knee-ankle angle (HKA) on a full-length radiograph or the femorotibial angle (FTA) on a short knee film was used to categorize the postoperative coronal alignment. Meanwhile, several different FTA ranges were regarded as neutral alignment in different studies. As a result, it is still unknown that how FTA on short knee films and HKA related to each other. The FTA may be able to become an accurate proxy of HKA to predict the coronal alignment. The purpose of this study was to explore the correlation between the FTA and the HKA after TKA and to find the most accurate FTA range.MethodsAbout 223 patients were included in this study and standard weight-bearing short knee films as well as full-length radiographs were acquired. The pre- and postoperative FTA, as well as the postoperative anatomical lateral distal femoral angle (aLDFA) and anatomical medial proximal tibial angle (aMPTA) were measured on short knee films by two orthopedic surgeons independently. On full-length films, the pre- and postoperative FTA, the pre- and postoperative HKA, as well as the postoperative mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA) were also recorded by two other surgeons independently. Pearson correlation analysis was performed to compare FTA and HKA, aMTPA and mMTPA, aLDFA and mLDFA, respectively.ResultsThe postoperative FTA and HKA had a good correlation (r = 0.86). The agreements were reached 82.7%, 71.0%, and 68.2% of all patients using three previously reported FTA ranges. When analyzing the independent alignment of the tibial tray and the femoral component, 84.1% and 57.9% of all patients was reached an agreement on the classification.ConclusionsOn most occasions, the consistence between the FTA and HKA in assessing the coronal limb alignment of the lower extremity and the tibial component is satisfactory. However, the postoperative full-length film is still needed to evaluate accurately the coronal alignment of the femoral component.