Incidence of Rotational Malalignment after Intertrochanteric Fracture Intramedullary Nailing: A CT-Based Prospective Study.

Background and Objectives: Rotational malformation after intramedullary nailing of intertrochanteric fractures is a relatively common, possibly severe, and difficult-to-detect complication, since intraoperative radiographic imaging allows for the assessment of the quality of reduction in the frontal and sagittal planes, but not in the transverse plane. The purpose of this study is to evaluate the rotational malalignment after intramedullary nailing of intertrochanteric fractures and to investigate a possible connection with specific patients' or fractures' characteristics. Materials and Methods: 74 patients treated with intramedullary nailing due to an intertrochanteric fracture underwent a postoperative CT of the pelvis-hips and knees. The value of the anteversion was measured both in the operated-on (angle 1) and in the healthy hip (angle 2) based on the technique described by Jeanmart et al. and the difference in anteversion (D angle = angle 1 minus angle 2) was calculated. A positive D angle indicated the presence of excessive internal overcorrection of the distal fragment during fracture reduction, while a negative D angle indicated the presence of excessive external overcorrection. The absolute value of the D angle represents the postoperative difference in anteversion between the two hips. The patients were divided into three groups according to this value: group A, with D < 5° (physiological difference); group B, with 5° < D < 15° (acceptable rotational alignment); and group C, with D ≥ 15° (rotational deformity). Results: Group A constitutes 56.8%, group B 12.2%, and group C 31.1% of the study population. Overall, 79.7% of the patients presented a positive angle D, while, for group C, the percentage was even higher at 91.3%. According to the AO/OTA classification system, 37.8% of the cases were stable fractures, 47.3% were unstable fractures, and 14.9% were reverse oblique fractures. Based on our analysis, the type of fracture has a serious impact on the rotational alignment, since the statistical significance of the mean angle D for the three types of fracture is reliable (p = 0.029). Stable fractures present the lowest anteversion difference values, while reverse oblique fractures present the highest difference. Conclusions: Our study reveals that the percentage of rotational malalignment after the intramedullary nailing of intertrochanteric fractures remains high (31.1%), despite the proper use of radiographic imaging during the intraoperative fracture reduction. In most cases (91.3%), this malalignment appears to be a matter of internal overcorrection. A clear correlation between hip's rotational deformity and patients' functional outcome has yet to be proven, and constitutes our objective in the near future.

Risk factors for malalignment after intramedullary nail treatment of distal tibia fractures with associated fibula fractures.

PURPOSE: Malalignment of distal tibia fractures can lead to malunion/nonunion or alter the limb mechanical axis which may cause arthritis. Proposed methods to decrease malalignment include fibular fixation or multiplanar interlocking screws, however these remain controversial. This study aimed to identify factors associated with malalignment in distal tibial fractures with associated fibular shaft fractures. METHODS: A retrospective review was performed of distal tibia fractures with associated fibular shaft fractures treated with intramedullary nailing at two level one trauma centers between 2015 and 2019. Cases involving malalignment (> 5° of deviation from anatomic axis on either coronal/sagittal axis) on final follow-up (minimum three months postoperatively) were compared to those without malalignment with regard to demographics, fracture characteristics, intraoperative characteristics, and complications. RESULTS: The rate of malalignment was 13%. On multivariate analysis, multiplanar distal interlocking screw fixation (odds ratio [OR], 0.18; 95% confidence interval [CI] 0.03-0.92) was associated with a decreased rate of final malalignment, while nail diameter > 10 mm was associated with a higher rate (OR, 4.05; 95% CI 1.25-13.11). Fibular fixation was not associated with malalignment. CONCLUSION: Multiplanar distal interlocking screws may protect against malalignment. Fibula fixation does not appear associated with a decreased rate of malalignment in distal tibia fractures treated with intramedullary nails. LEVEL OF EVIDENCE: III.

Intramedullary nailing of femoral shaft fractures: an analysis of rotational malunions using 3D EOS.

PURPOSE: Rotational malalignment and leg length discrepancy after intramedullary nailing of femoral shaft are frequent. This study has three objectives: evaluate the rate of femoral rotational malalignment and leg length discrepancy using EOS imaging after antegrade intramedullary nailing of femoral shaft fracture, find a relevant clinical examination to detect malrotation and identified risk factors. METHODS: We performed a retrospective single-centre study between January 2014 and January 2022. Fifty-eight patients were clinically and radiographically assessed at a minimum of three months. RESULTS: The femoral rotation of the operated side was significantly greater by a mean of 15.4° in internal rotation compared to the healthy side. There was no statically significant difference for the femoral length (p = 0.08). CONCLUSION: When using EOS stereography following antegrade intramedullary nailing of post-traumatic diaphyseal femur fractures, a statistically significant difference of more than 15.4° in internal rotation was found for femoral rotation on the operated side compared to the healthy side.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [B. Poirot] Last name [Seynaeve]. Also, kindly confirm the details in the metadata are correct.The last name of the first author was corrected : Given name = B. and last name = Poirot Seynaeve The details in matadata are correct LEVEL OF EVIDENCE: III.

Kinematically aligned TKA restores physiological patellofemoral biomechanics in the sagittal plane during a deep knee bend.

PURPOSE: Although patellofemoral complications after kinematically aligned (KA) TKA are infrequent, the patellar flexion angle and proximal-distal patellar contact location through flexion, and incidence of patellar loss of contact at full extension are unknown. The present study determined whether the patellar flexion angle and proximal-distal patellar contact location of a KA TKA performed with anatomic, fixed-bearing, posterior cruciate-retaining (PCR) components differed from those of the native contralateral knee during a deep knee bend, and determined the incidence of patellar loss of contact at full extension for KA TKA only. METHODS: During a deep knee bend from full extension to maximum flexion, both knees were imaged in a lateral view using single-plane fluoroscopy for 25 patients with a calipered KA TKA and a healthy native knee in the contralateral limb. The patellar flexion angle and proximal-distal patellar contact location were measured on images from full extension to maximum flexion in 30° increments. Paired t tests at each flexion angle determined the significance of the difference between the KA TKA knees and the native contralateral knees. In the KA TKA knees, the incidence of patellar loss of contact at full extension was determined. Patient-reported outcome scores also were recorded including the Oxford Knee Score. RESULTS: Mean patellar flexion angles were not different between the KA TKA knees and the native contralateral knees throughout the motion arc. The largest statistically significant difference in the mean proximal-distal patellar contact locations was 4 mm. The incidence of patellar loss of contact in the KA TKA knees at full extension was 8% (2 of 25 patients). The median Oxford Knee Score was 46 out of 48. CONCLUSIONS: Calipered KA TKA performed with anatomic, fixed-bearing, PCR components restored patellar flexion angles to native and largely restored the proximal-distal patellar contact locations, which at most differed from the native contralateral knee by approximately 10% of the mean proximal-distal patellar length. In the KA TKA knees, the incidence of patellar loss of contact was infrequent. These objective biomechanical results are consistent with the relatively high subjective patient-reported outcome scores herein and support the low incidence of patellofemoral complications following KA TKA previously reported. LEVEL OF EVIDENCE: Therapeutic, level III.

Unilateral anterior knee pain is associated with increased patellar lateral position after stressed lateral translation.

PURPOSE: To objectively compare side-to-side patellar position and mobility in patients with idiopathic unilateral anterior knee pain (AKP) using a stress-testing device concomitantly with magnetic resonance imaging. It is hypothesized that the painful knees present greater patellar mobility than the contralateral non-painful knees. METHODS: From a total sample of 359 patients, 23 patients with idiopathic unilateral AKP (30.9 years, 23.4 kg/m2, 43% males) were included within the present study. Both knees of all the patients were examined by conventional imaging, including the measurement of trochlear sulcus angle, Caton-Deschamps index, tibial tuberosity to trochlear groove distance, patellar tilt angle and patellar subluxation (both at rest and upon quadriceps contraction). Additionally, the same patients underwent stress testing (Porto Patella Testing Device); these measurements were taken with the patella at rest, after lateral patellar translation and after lateral patellar tilt. Clinical and functional outcomes were obtained using physical examination and the Kujala and Lysholm scores. RESULTS: Painful knees showed statistically significant higher patellar lateral position after stressed lateral translation than non-painful knees (p = 0.028), 9.8 ± 3.6 mm and 7.1 ± 6.3 mm, respectively. The adjusted multivariate logistic model identified the patellar position after lateral displacement to be significantly associated with AKP (OR = 1.165) and the model (AUC = 0.807, p < 0.001) showed reasonable sensitivity (67%) and specificity (73%). CONCLUSION: Patients with idiopathic unilateral AKP with morphologically equivalent knees showed statistically significant increased patellar lateral position after stressed lateral displacement in their painful knee. The greater lateral patellar mobility quantified by the PPTD testing brings more objectivity to the diagnosis. LEVEL OF EVIDENCE: II.

Correction of Genu Valgum in Patients With Congenital Fibular Deficiency.

BACKGROUND: Patients with congenital fibular deficiency often develop genu valgum secondary to lateral femoral condylar hypoplasia. Guided growth strategies are often performed to correct limb alignment when adequate skeletal growth remains. METHODS: A retrospective review of patients with postaxial hypoplasia of the lower extremity managed with an amputation strategy and who had a guided growth procedure for coronal plane limb malalignment during their course of treatment was performed. Clinical and radiographic data, including measures of coronal plane deformity and alignment, type of amputation, subsequent operative procedures, and complications were recorded. RESULTS: Seventeen patients (20 extremities) met study inclusion criteria (mean follow-up 8.8 y). Foot ablation and hemiepiphysiodesis for valgus deformity of the knee was performed in all extremities. The average age at the time of initial hemiepiphysiodesis was 11.2 years at an average of 8.8 years from the initial amputation procedure. The mean preoperative mechanical axis deviation was 26.5 mm, which was corrected to a mean mechanical axis deviation of 7.0 mm. Fifteen (75%) of the extremities had correction of the deformity to neutral alignment after the initial procedure. Lack of correction occurred in 3 extremities, and overcorrection occurred in 2 extremities. Additional procedures were required in 5 extremities for rebound valgus deformity after hardware removal. CONCLUSIONS: In patients with postaxial hypoplasia, regular monitoring of the residual limb for growth-related changes must occur to ensure optimal function and prosthetic fit. Timing of the guided growth procedure is critical, as younger patients may be more likely to experience rebound deformity. Families and patients should be made aware that growth might be unpredictable in this population with risks of both overcorrection and undercorrection. LEVEL OF EVIDENCE: Level IV-case series.

Congenital Pseudarthrosis of the Fibula: Controlling Ankle Valgus in a Heterogenous Condition.

BACKGROUND: Congenital pseudarthrosis of the fibula (CPF) is a rare disorder characterized by a deficiency in the continuity of the fibula and can lead to progressive ankle valgus malalignment. An existing classification system for CPF is imperfect and may contribute to heterogeneity in reporting and discrepancy of outcomes in the literature. METHODS: Fifteen patients with CPF treated at our institution between 1995 and 2017 were retrospectively identified. Only patients with dysplasia leading to spontaneous fracture or pseudarthrosis were included in this series. The median age at presentation was 2.5 years (range: 3 mo to 13.4 y). The median duration of follow-up from the initial presentation was 11.8 years (range: 2.0 to 24 y). Chart review and serial radiographs were analyzed to assess natural history and outcomes following surgery. RESULTS: The coexistence of tibial dysplasia in CPF is very common. Patients were classified into 3 groups based on the degree of tibial involvement-group 1: no evidence of tibial dysplasia, group 2: mild tibial dysplasia, and group 3: significant tibial dysplasia. Age at presentation and age at which fibular fracture occurred were progressively younger with a greater degree of tibial involvement (P<0.05). In the absence of surgical intervention, group 1 patients did not undergo progressive ankle valgus (defined as the valgus change in tibiotalar angle by ≥4 degrees), whereas all patients in groups 2 and 3 did (P<0.001). Fibular osteosynthesis was performed in 6 patients, with union seen only in group 1 patients. Ten patients underwent distal tibiofibular fusion, with no cases of nonunion seen. Distal tibiofibular fusion with or without medial distal tibial hemiepiphysiodesis halted the progression of ankle valgus in 8 of the 10 patients. Further progression of ankle valgus occurred only in patients who did not undergo concurrent medial distal tibial hemiepiphysiodesis and with considerable wedging of the distal tibial epiphysis at the time of fusion. CONCLUSIONS: Tibial dysplasia and CPF are intimately related. Grouping patients on this basis may help guide natural history and treatment and may explain discrepancies in findings in the literature. Fibular osteosynthesis, distal tibiofibular fusion, and medial distal tibial hemiepiphysiodesis may all have an important role in the treatment of CPF. LEVEL OF EVIDENCE: Level IV-case series.

Initial displacement as a risk factor for avascular necrosis of the femoral head in pediatric femoral neck fractures: a review of one hundred eight cases.

PURPOSE: To evaluate the correlation between avascular necrosis (AVN) and the amount (severity) and direction (translation and angulation) of initial displacement of pediatric femoral neck fractures. METHODS: We retrospectively reviewed 108 pediatric patients (mean age 10.3 ± 4.1 years) with femoral neck fractures. The amount of initial translation (T) and angulation (A) was measured on anteroposterior (AP; TAP% and AAP) and lateral (TL% and AL) radiographs. The direction of translation was determined on AP (medial or lateral) and lateral radiographs (anterior or posterior). Furthermore, the presence of a comminuted medial cortex on the AP pelvis radiograph was also recorded. Logistic regression analysis, receiver operating characteristic (ROC) curve analysis, student's t tests, and chi-square tests were used to evaluate the correlation between AVN and the severity and direction of displacement. RESULTS: Twenty-eight out of 108 hips (25.9%) developed AVN of the femoral head. Logistical regression analysis indicated that TAP%, TL%, AAP, and AL were risk factors for AVN (P < 0.05). The analysis of ROC curves found that TAP% over 37.4% and TL% over 29% were the cut-off values for an increased incidence of AVN; similarly, AAP over 8° and AL over 18.6° were the cut-off values for an increased incidence of AVN. The amount of initial translation is a better predictor of AVN than angulation is; fractures with posterior translation (P = 0.002) and/or medial comminution had a significantly higher incidence of AVN (P = 0.005). The mean diagnostic accuracy of translation (74-75%) was significantly higher than that of angulation (65-66%). CONCLUSIONS: Displacement severity and direction are important radiological parameters to be assessed in children with femoral neck fractures. Initial translation better predicts AVN than angulation does. Posterior translation and medial comminution are associated with an increased risk of AVN.

Gender difference in bowing of the sagittal femoral morphology measurement using magnetic resonance imaging.

The importance of femoral sagittal bowing on total knee arthroplasty (TKA) has not been actively discussed. Femoral sagittal bowing can lead to cortex damage, fractures, or femoral malalignment. Therefore, the purpose of this study was to evaluate femoral sagittal bowing at different segments of the femur in the Korean population, and to discuss the implications on total knee arthroplasty. Differences in the morphology of femoral sagittal bowing for 978 patients-829 women and 148 men-were evaluated using magnetic resonance imaging. The angle between the femoral mechanical axis and the anterior cortex line was measured for all the patients. In addition, the gender difference in femoral sagittal bowing was investigated. The angle of femoral sagittal bowing with the mechanical axis was 2.8˚ ± 2.2˚. The angles for femoral sagittal bowing were 2.9˚ ± 2.2˚ and 2.3˚ ± 2.6˚ for females and males, respectively. Thus, a gender difference was found in the femoral sagittal bowing (p < 0.05). Excessive sagittal bowing of the femur can affect the final sagittal position of the femoral component, and this has implications for implant design selection. We recommend that surgeons accurately perform pre-operative evaluation of femoral bowing to prevent potential malalignment, rotation, and abnormal stresses between the femur and implant.

[Torsional deformities of the femur in patients with femoroacetabular impingement : Dynamic 3D impingement simulation can be helpful for the planning of surgical hip dislocation and hip arthroscopy]. / Femorale Torsionsfehler bei Patienten mit femoroazetabulärem Impingement : Die dynamische 3D Impingementsimulation kann bei der Planung der chirurgischen Hüftluxation und der Hüftarthroskopie behilflich sein.

BACKGROUND: Torsional deformities of the femur include femoral retrotorsion and increased femoral torsion, which are possible causes for hip pain and osteoarthritis. For patients with femoroacetabular impingement (FAI), torsional deformities of the femur represent an additional cause of FAI in addition to cam and pincer-type FAI. OBJECTIVES: The aim of this article is to provide an overview of measurement techniques and normal values of femoral torsion. The clinical presentation, possible combinations and surgical therapy of patients with torsional deformities of the femur will be discussed. METHODS: For measurement of femoral torsion, CT or MRI represent the method of choice. The various definitions should be taken into account, because they can lead to differing values and misdiagnosis. This is the case especially for patients with high femoral torsion. Dynamic 3D impingement simulation using 3D-CT can help to differentiate between intra und extra-articular FAI. RESULTS AND DISCUSSION: Femoral retrotorsion (< 5°) can lead to anterior intra- and extraarticular (subspine) FAI, between the anterior iliac inferior spine (AIIS) and the proximal femur. Increased femoral torsion (> 35°) can lead to posterior intra- and extra-articular ischiofemoral FAI, between the lesser/greater trochanter and the ischial tuberosity. During clinical examination, a patient with femoral retrotorsion exhibits loss of internal rotation and a positive anterior impingement test. Hips with increased femoral torsion show high internal rotation if examined in prone position and have a positive FABER and posterior impingement test. During surgical therapy for patients with torsional deformities, intra and extra-articular causes for FAI in addition to cam and pincer-deformities should be considered. In addition to hip arthroscopy and surgical hip dislocation, also femoral rotational or derotational osteotomies should be evaluated during surgical planning of these patients.

[The past, present and future of the control of axial alignment of the lower extremity in high tibial osteotomy].

High tibial osteotomy(HTO) is an effective method for the treatment of knee osteoarthritis by transferring the weight bearing line to the lateral tibial plateau, which can significantly reduce the pressure and cartilage lesion of medial knee compartment.However, under- and over-correction of weight bearing line can lead to early postoperative failure.It is necessary to define the standard of axis correction, make correct preoperative plan, ensure the accuracy of operation and consider the risk factors of under- and over-correction of axis.With the advent of the era of intelligent medicine, the application of patient-specific instrumentation technology based on three dimention printing and navigation technology will help to achieve the precise control of axial alignment in high tibial osteotomy.

[Early clinical effects of total knee arthroplasty with kinematic alignment assisted by patient-specific instrumentation].

Objective: To examine the clinical effects of the treatment of knee osteoarthritis patients with kinematic alignment technique of total knee replacement (KA-TKA) assisted by patient-specific instrumentation (PSI). Methods: The clinical data of 14 patients with knee osteoarthritis treated with unilateral KA-TKA assisted by PSI at Department of Orthopaedic Surgery, Beijing Chaoyang Hospital Affiliated to Capital Medical University from May 2018 to August 2019 were analyzed retrospectively. There were 6 males and 8 females, aged 66.6 years (range: 56 to 79 years), 9 left knees and 5 right knees. The operation time, soft tissue release and extra varus or valgus osteotomy were recorded. The data of osteotomy blocks were measured and compared with the corresponding position of the prostheses. The hip knee ankle angle (HKA), the mechanical distal femoral lateral angle (mLDFA) and the proximal tibial medial angle (MPTA) were measured before and 3 months after the operation. The knee joint functional score (KS-F) , knee joint clinical score (KS-C) and the Western Ontario McMaster (WOMAC) Osteoarthritis Index were recorded and compared by paired t test or Wilcoxon non-parametric test. Results: The operation time was (81.8±16.9) minutes (range: 60 to 115 minutes), 2 cases were manually increased varus osteotomy by 2 mm and 1 patient received lateral retinaculum release. There was no extra medial or lateral soft tissue release. Intraoperative measurement of the resection showed that the femoral side mismatch was within 2 mm. The medial and lateral condyle, the medial and lateral posterior condyles were relatively overcut by 0.50 mm, 0.21 mm, 0.93 mm, and 0.71 mm, respectively. The tibial side mismatch was within 1.5 mm, the medial and lateral plateau were relatively undercut by 0.43 mm and 0.32 mm. HKA was corrected from (8.8±5.6) ° to (1.6±4.3) ° (t=20.723, P=0.000) .KS-C improved from 28.21±13.47 preoperative to 78.07±8.01 postoperative (t=-16.570, P=0.000); KS-F improved from 41.00±15.25 preoperative to 84.93±10.85 postoperative (t=-14.675, P=0.000).WOMAC Osteoarthritis Index decreased from 53.5 (25.75) (M(Q(R))) preoperative to 5.5 (5.25) postoperative (Z=-3.297, P=0.001) .No statistically significant difference was found in mLDFA and MPTA before and after surgery. No significant patellofemoral complication was recorded during follow-up time. Conclusions: PSI assisted TKA resection has high accuracy. KA-TKA aims to restore the native anatomy of the knee joint, only corrects the malalignment of lower extremities caused by articular cartilage wear, with less interference to soft tissues, easy to obtain satisfactory knee joint laxity and has a promising early clinical effect.

Preliminary experience with an image-free handheld robot for total knee arthroplasty: 77 cases compared with a matched control group.

BACKGROUND: Achieving an optimal limb alignment is an important factor affecting the long-term survival of total knee arthroplasty (TKA). This is the first study to look at the limb alignment and orientation of components in TKA using a novel image-free handheld robotic sculpting system. METHODS: This case-controlled study retrospectively compared limb and component alignment of 77 TKAs performed with a robot (Robot-group) with a matched control group of patients who received conventional alignment with intramedular rods (Control group). Alignment and component positioning was measured on full-leg weight-bearing and standard lateral X-rays by two independent observers. The image-free handheld robotic sculpting system calculated the planned and achieved mechanical axis (MA). Outliers were defined as > 3° deviation from planned alignment. RESULTS: Mean MA was 180.1° (SD = 1.9) in the Robot-group, compared to the Control group with a mean MA of 179.1° (SD = 3.1, p = 0.028). We observed 5 outliers (6%) in the Robot-group and 14 outliers (18%, p = 0.051) in the Control group. Fraction of outliers of the frontal tibial component was 0% in the Robot-group versus 8% in the Control group (p = 0.038). There were no other statistical differences regarding the implant positioning between both groups. CONCLUSION: The Robot-group showed significantly less outliers compared to the conventional technique. Whether these differences are clinically relevant is questionable and should be investigated on the long term. Randomized controlled trials with larger patient series will be needed in the future to confirm our preliminary results.

The effects of pelvic belt use on pelvic alignment during and after pregnancy: a prospective longitudinal cohort study.

BACKGROUND: Pelvic alignment changes during pregnancy and post-childbirth. Pelvic belts exert external forces that compress and stabilize the joints, and therefore, could influence pelvic alignment. However, limited information is available regarding this potential effect. Therefore, the purpose of this study is to investigate the influence of pelvic belt use on pelvic alignment during and after pregnancy. METHODS: Data of 201 pregnant women in late pregnancy and 1 month after childbirth were used. Pelvic alignment measurements, including anterior and posterior pelvic width, pelvic asymmetry, and pelvic belt use during and after pregnancy were investigated. Participants were divided into four groups according to pelvic belt use: before and after childbirth (BAC), before childbirth only (BC), after childbirth only (AC), and non-use (NU). Then, an initial one-way ANOVA was conducted to compare the amount of change in pelvic alignment from late pregnancy to post-childbirth between the groups. After the initial analysis, a multivariate regression analysis was performed to determine the statistically significant differences between the groups to consider other factors that influenced pelvic alignment such as age, BMI, number of previous childbirths, vaginal delivery and pelvic asymmetry in late pregnancy. Next, a cutoff point for subgroup stratification based on the weekly duration of pelvic belt use and inter-group changes in pelvic alignment were compared. RESULTS: As the result of the initial one-way ANOVA, the decrease in pelvic asymmetry from during pregnancy to postpartum for BAC was greater than that for AC. Moreover, multiple regression analysis showed that the effect of pelvic belt that was revealed in the initial analysis was statistical significance even after adjustment for other factors. Moreover, pelvic asymmetry in the BAC group decreased, compared to being increased or unchanged in the NU and AC groups when the group cutoff time was 7 h per week. CONCLUSIONS: Continuous and extended use of pelvic belts during and after pregnancy might be related to modifications of pelvic asymmetry in the perinatal period. Therefore, the instruction of correct and comfortable usage and the recommendation of continuous use of pelvic belt especially during pregnancy are required for prevention of some discomforts related to pelvic malalignment.

Development and validation of a prediction model for knee joint line orientation after high tibial osteotomy.

BACKGROUND: Maintenance of optimal knee joint line orientation (KJLO) is important after high tibial osteotomy (HTO). No tools, however, are currently available that could predict the value of postoperative KJLO before surgery. First, this study sought to determine the effects of various preoperative anatomical alignment parameters to postoperative KJLO. Based upon these analyses, we aimed to devise an equation that predicts the value of postoperative KJLO. METHODS: A total of 14 radiographic parameters were measured in preoperative and postoperative full-limb standing anteroposterior radiographs on 50 patients who underwent open-wedge HTO. The parameters were analysed using multivariable linear regression to predict KJLO after HTO. External validation of the equation was done with 20 patients who underwent HTO at another institution. RESULTS: After HTO, KJLO increased from - 0.8° to 2.9° (P < 0.001). Based on the multivariable linear regression analysis, an equation was derived that can estimate postoperative KJLO after HTO; postoperative KJLO(°) = 1.029 + 0.560 × preoperative KJLO(°) + 0.310 × preoperative tibia plateau inclination(°) + 0.463 × aimed correction angle(°). The adjusted coefficients of determination value for this equation was 0.721. The equation also showed good calibration and predictability in external validation with predicted squared correlation coefficient of 0.867. CONCLUSIONS: This study analysed the effects of preoperative anatomical alignment parameters on the postoperative KJLO. An equation which predicts postoperative KJLO with preoperative anatomical alignment factors was devised and validated. This equation would help in selecting optimal patients for HTO and in selecting the optimal target correction angle in HTO.

Are changes in radiological leg alignment and femoral parameters after total hip replacement responsible for joint loading during gait?

BACKGROUND: Gait kinematics after total hip replacement only partly explain the differences in the joint moments in the frontal plane between hip osteoarthritis patients after hip replacement and healthy controls. The goal of this study was to determine if total hip replacement surgery affects radiological leg alignment (Hip-Knee-Shaft-Angle, femoral offset, Neck-Shaft-Angle and varus/valgus alignment) and which of these parameters can explain the joint moments, additionally to the gait kinematics. METHODS: 22 unilateral hip osteoarthritis patients who were scheduled for total hip replacement were included in the study. Preoperatively and 1 year postoperatively all patients had biplanar radiographic examinations and 3D gait analysis. RESULTS: The operated leg showed significantly (P < 0.05) more varus (1.1°) as well as a larger femoral offset (+ 8 mm) and a larger Hip-Knee-Shaft-Angle (+ 1.3°) after total hip replacement; however no significant differences in the joint moments in the frontal plane compared to healthy controls were found. The hip moment (first half of stance) and the knee moments (first and second half of stance) were mostly determined by the varus/valgus alignment (29% and respectively 36% and 35%). The combination with a kinematic parameter (knee range of motion, foot progression angle) increased the predictive value for the knee moments. CONCLUSION: In our patient group the joint moments after total hip replacement did not differ from healthy controls, whereas radiological leg alignment parameters changed significantly after the total hip replacement. A combination of these radiological leg parameters, especially the varus alignment, and the deviating kinematics explain the joint moments in the frontal plane during gait after total hip replacement surgery. For surgeons it is important not to create too much of a structural varus alignment by implanting the new hip joint as varus alignment can increase the knee adduction moment and the risk for osteoarthritis of the medial knee compartment. TRIAL REGISTRATION: This study was retrospectively registered with DRKS (German Clinical Trials Register) under the number DRKS00015053. Registered 1st of August 2018.

Comparison of radiological features of high tibial osteotomy and tibial condylar valgus osteotomy.

BACKGROUND: The purpose of this study was to compare radiological features between high tibial osteotomy (HTO) and tibial condylar valgus osteotomy (TCVO), in order to define the radiological indication criteria for TCVO. METHODS: Thirty-two cases involving 35 knees that had undergone HTO and the same number that had undergone TCVO for knee osteoarthritis were retrospectively evaluated. Characteristics of both groups did not differ significantly. Lower limb alignment, bone morphology, joint congruity, and joint instability were measured in standing full-length leg and knee radiographs obtained before and after surgery. RESULTS: Radiological features in the TCVO group included greater frequencies of advanced knee OA grade, varus lower limb malalignment, depression of the medial tibial plateau, and varus-valgus joint instability compared to the HTO group before surgery. However, tibial morphology, alignment of the lower limb, and joint instability improved to comparable levels after surgery in both groups. CONCLUSIONS: TCVO appears preferable in cases with advanced knee OA, destroyed or inclined medial tibial plateau, widened and subluxated lateral joint, and high varus-valgus joint instability.

The Impact of Transphyseal Anterior Cruciate Ligament Reconstruction on Lower Extremity Growth and Alignment.

PURPOSE: To evaluate the effect of transphyseal anterior cruciate ligament (ACL) reconstruction on lower extremity radiographic growth and alignment. METHODS: We retrospectively reviewed patients who underwent transphyseal ACL reconstruction and were followed to skeletal maturity or at least 2 years, with the nonoperative limb used as an internal control. Changes in coronal plane alignments and tibial slope of the operative limb were compared with a Wilcoxon test. Associations among sex, tunnel, and graft characteristics and failure; changes in coronal plane measures and tunnel size; and tunnel angles and the development of deformity were examined by χ-square and correlation coefficients. RESULTS: Fifty-nine patients (41 boys and 18 girls) underwent surgery at a mean age of 12.5 years (range, 6.8-16.0 years). There were differences in changes in the mechanical lateral distal femoral angle comparing operative and nonoperative limbs (decreased 1.1° in girls and 1.9° in boys ≤13 years of age, P = .0008 and .025, respectively) and in changes in tibial slope of the operative limb (decreased 2.1° in male patients >13 years, P = .012). No patient developed a new limb length difference >1 cm. Two boys were treated for deformities. Eight additional patients developed >5° difference in alignment for a rate of radiologic deformity of 10 of 59 or 17%. Neither graft failure nor the presence of deformity was associated with sex, tunnel size, mode of femoral tunnel positioning, inclination of tunnels, or the use of allograft. CONCLUSIONS: Radiographically evident limb deformities following transphyseal ACL reconstruction occurred at a rate of 17%, although these deformities were clinically evident in only 5% of patients. Tunnels intersecting physes near cortical margins may increase the risk of developing deformity. Regular follow-up should include alignment radiographs to detect deformities despite the clinical appearance of neutral limb alignment. LEVEL OF EVIDENCE: Level III, case-control study.

Influence of limb alignment and prosthetic orientation on patient-reported clinical outcomes in total knee arthroplasty.

BACKGROUND: The relationship between postoperative limb alignment and clinical outcomes in primary total knee arthroplasty (TKA) is well reported, but the instruments used to evaluate clinical outcomes of TKA are mainly scoring systems from the physician's viewpoint, not patient-reported outcomes. The purpose of this study was to investigate retrospectively the relationship between postoperative limb alignment and patient-reported clinical outcomes using the 2011 Knee Society Knee Scoring System (2011 KSS). METHODS: The present study included 155 knees of patients (median age, 74 years) who underwent primary TKA for varus osteoarthritis, with a mean follow-up period of 46 months. The subjects were divided into three groups based on postoperative limb alignment and femoral and tibial component positioning angle (varus, neutral, and valgus). The 2011 KSS scores were compared among the groups. RESULTS: For limb alignment, the postoperative objective knee indicator score was significantly lower in the valgus group than in the varus and neutral groups, whereas no significant differences were observed in any subjective categories of the 2011 KSS. However, for the femoral component angle, functional activity scores were significantly lower in the valgus group than in the varus and neutral groups. CONCLUSIONS: The subjective patient-reported score was not affected by the postoperative limb alignment. However, the valgus femoral component angle resulted in lower subjective functional scores. For clinical relevance, postoperative valgus positioning of femoral component should be avoided from patient-reported functional aspects during TKA.

An Algorithm for Detection and Correction of Pelvic Tilt in Total Hip Replacement.

Successful joint replacement surgery requires precise preoperative planning and intraoperative placement of implants such that the function of the joint is optimized biomechanically and biologically. The five-step "pelvic tilt algorithm" will enhance the outcome of hip replacement surgery as a result of improved acetabular component alignment. It will solve the problem of pelvic tilt as an unknown variable during hip replacement surgery, and will allow for more consistent and accurate acetabular component placement.