Varus Group Research Articles

Varus stem positioning does not affect long-term functional outcome in cementless anatomical total hip arthroplasty.

Varus positioning is the most common femoral malposition in total hip arthroplasty (THA). We compared the long-term outcomes of an anatomical cementless femoral stem positioned in varus versus neutral alignment. Data were retrospectively reviewed for all patients receiving a cementless anatomical femoral stem in THA for osteoarthritis between 1998 and 2008.Exclusion criteria were complex cases, incomplete data or follow-up < 1year. Primary outcome was survival rate with complications and secondary outcomes were clinical scores, thigh pain, radiological score, cortical hypertrophy and filling rate. Of the 283 included patients, 127 stems were classified as varus and 156 neutral. Mean follow-up was 10years. Femoral stem size was smaller in the varus group (4.1 vs. 4.4, p = 0.047). A stem-filling rate < 80% was more frequent in the varus group (p < 0.001). The long-term survival rate without any revision procedure was 94.8% ± 2.3% (95%CI 88.4-98.7) in the varus group and 94.1% ± 2.0% (95%CI 91.3-99.1) in the neutral group (p = 0.55). There was no difference in clinical scores, thigh pain or complication occurrence between groups. The Engh-Massin score was lower in the varus group (p < 0.01) and cortical hypertrophy was higher (p < 0.001). A varus alignment of a cementless anatomic femoral stem does not affect survivorship, clinical outcomes or complication rate on an average follow-up of 10years, despite increasing stress-shielding rates.

Comparison of the Outcome of the 3-Component Salto Total Ankle Arthroplasty for Ankle with Preoperative Varus, Valgus and Neutral Alignment in End-Stage Osteoarthritis

Category:Ankle; Ankle ArthritisIntroduction/Purpose:As the popularity of total ankle arthroplasty (TAA) increases, indication of TAA also expands. Recently, the ankles more than 20° of varus or valgus deformity in the coronal plane are treated with TAA. However, severe varus or valgus deformity should be corrected in the coronal plane to avoid residual mal-alignment that leads to instability, insert wear, and clinical failure. In this study, we compare the clinical and radiologic outcome of the Salto mobile bearing 3-component total ankle prosthesis for ankles with preoperative varus, neutral, and valgus alignment.Methods:TAA was performed in 101 consecutive ankles (99 patients) by a single surgeon using 3-component Salto total ankle implant from June 2014 to October 2019. A prospectively collected database was used to identify all patients who underwent primary TAA with a minimum 1-year follow-up. We classified the enrolled ankles as neutral, varus, or valgus groups. More than 10° of tibial anterior surface angle, talta tilt angle, tibial axis-talar dome angle, talar dome-ground surface angle (TD-GSA), or tibio- calcaneal angle was defined as varus or valgus groups. All patients were followed up at postoperative three months, six months, at one year and yearly thereafter. Clinical outcome scoring was done pre-operatively and post-operatively. American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot functional score, pain VAS, satisfaction score and clinical range of motion (ROM) were collected along with weight-bearing radiographs of the ankle. Post-operative coronal alignment of the component were evaluated with radiographs.Results:The average follow-up was 21.6 months (range, 12-71). Preoperatively, there were 63 ankles (62%) with varus deformity, 27 ankles (27%) with neutral alignment, and 11 ankles with valgus deformity. In preoperative varus group, 13 ankles (21%) were performed with concomitant lateral sliding calcaneal osteotomy, and 23 ankles (37%) with deltoid release. No additional procedures for the correction of ankle and hindfoot deformity were performed in preoperative neutral and valgus groups. VAS pain score and AOFAS score were significantly improved in all groups (p < 0.05). Overall satisfaction rate was 88%. After TAA, there were no significant radiologic alignment among the groups (3.9° (range, 0.7°~9.7°) in varus group, 4.1° (range, 0.4°~6.8°) in neutral group, and 2.2° (range, -0.4°~4.4°) in valgus group; p > 0.05).Conclusion:There was no significant difference in outcome among the varus, neutral, and valgus groups postoperatively in the TAA series using single Salto 3-componenet implant. Postoperative neutral alignment was achieved in all ankles. For favorable long-term outcomes, coronal alignment should be corrected with proper additional procedures in TAA.

Effects of femoral offset and mechanical axis of the lower extremity on hip after osteotomy for adult developmental dysplasia of the hip

To investigate the effects of femoral offset and mechanical axis of the lower extremity on hip after osteotomy for adult developmental dysplasia of the hip (DDH). A clinical data of 62 adult patients with DDH (62 hips), who underwent periacetabular osteotomy combined with femoral osteotomy between January 2016 and May 2019 and met selective criteria, was retrospectively analyzed. There were 6 males and 56 females. The age ranged from 18 to 38 years, with an average of 24.4 years. Body mass index ranged from 15.8 to 31.8 kg/m 2, with an average of 21.8 kg/m 2. There were 44 cases of Hartofilakidis typeⅠ and 18 cases of typeⅡ. According to the modified Tönnis osteoarthritis staging, 46 cases were stage 0 and 16 cases were stageⅠ. There were 13 cases with pelvic anteversion, 40 cases with normal pelvis, and 9 cases with pelvic retroversion. Intraoperative blood loss, length of hospital stay, and complications were recorded. Postoperative hip function was evaluated by Harris score and International Hip Outcome Tool (iHOT) score. The femoral offset, collo-diaphyseal angle, hip-knee-ankle angle (HKA), knee valus angle, CE (Wiberg central-edge angle), anterior CE angle, and acetabular index angle were measured and the osteotomy healing was observed on X-ray films. Patients were grouped according to postoperative femoral offset (≥48 mm or <48 mm) and HKA [varus group (HKA<177°), normal group (HKA 177°-183°), and valgus group (HKA>183°)]. Harris score and iHOT score were compared between groups. Intraoperative blood loss ranged from 200 to 1 550 mL, with an average of 476 mL. The length of hospital stay ranged from 8 to 21 days, with an average of 13.3 days. All incisions healed by first intention. All patients were followed up 2.0-4.5 years, with an average of 2.8 years. At 1 year after operation, the Harris score and iHOT score of the hip joint significantly increased when compared with those before operation ( P<0.05); there were significant differences in the femoral offset, collo-diaphyseal angle, HKA, knee valus angle, CE angle, anterior CE angle, and acetabular index angle between pre- and post-operation ( P>0.05). According to the modified Tönnis osteoarthritis staging, 38 cases were stage 0 and 24 cases were stageⅠ; and there was no significant difference between pre- and post-operation ( χ 2=2.362, P=0.124). There were 11 cases with pelvic anteversion, 38 cases with normal pelvis, and 13 cases with pelvic retroversion, showing no significant difference when compared with that before operation ( χ 2=0.954, P=0.623). The pubic branch osteotomy did not heal in 9 cases, proximal femur osteotomy did not heal in 2 cases, and inferior pubic ramus stress fracture occurred in 5 cases. There were significant differences ( P<0.05) in the Harris score and iHOT score between femoral offset≥48 mm group ( n=10) and femoral offset<48 mm group ( n=52). There was no significant difference ( P>0.05) in Harris score and iHOT score between varus group ( n=13), normal group ( n=40), and valgus group ( n=9). Periacetabular osteotomy combined with femoral osteotomy can improve the femoral offset and mechanical axis of the lower extremity of patients with DDH, and improve the functional score of the hip. However, excessive increase of femoral offset during femoral osteotomy is not desirable, resulting in low postoperative functional score.

Frontal knee alignment influences the vertical orientation of the femoral neck in standing position.

AimsThe aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck.MethodsLong-leg standing radiographs of patients undergoing realignment surgery around the knee were used. The hip-knee-ankle angle (HKA) and the vertical orientation of the femoral neck in relation to the floor were measured, prior to surgery and after osteotomy-site-union. Linear regression was performed to determine the influence of knee alignment on the vertical orientation of the femoral neck.ResultsThe cohort included 147 patients who underwent knee realignment-surgery. The mean age was 51.5 years (SD 11). Overall, 106 patients underwent a valgisation-osteotomy, while 41 underwent varisation osteotomy. There was a significant association between the orientation of the knee and the coronal neck-orientation. In the varus group, the median orientation of the femoral neck was 46.5° (interquartile range (IQR) 49.7° to 50.0°), while in the valgus group, the orientation was 52.0° (IQR 46.5° to 56.7°; p < 0.001). Linear regression analysis revealed that HKA demonstrated a direct influence on the coronal neck-orientation (β = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002). Linear regression also showed that realignment surgery was associated with a significant influence on the change in the coronal femoral neck orientation (β = 5.6 (95% CI 1.5 to 9.8); p = 0.008).ConclusionVarus or valgus knee alignment is associated with either a more horizontal or a more vertical femoral neck orientation in standing position, respectively. Subsequently, osteotomies around the knee alter the vertical orientation of the femoral neck. These aspects are of importance when planning osteotomies around the knee in order to appreciate the effects on the adjacent hip joint. The concept may be of even more relevance in dysplastic hips.Cite this article: Bone Jt Open 2021;2(12):1057–1061.

Poor Correction Capacity of Preexisting Ankle Valgus Deformity after Total Knee Arthroplasty.

This study investigated the differences in ankle alignment changes after TKA in patients with varying preexisting ankle deformities. We retrospectively examined 90 knees with osteoarthritis and varus deformity in 78 patients who underwent TKA. Preoperative and postoperative radiographic parameters were analyzed. According to their preexisting ankle deformity, patients were assigned to the valgus or varus group. Overall, 14 (15.6%) cases were of preoperative valgus ankle deformity; the remainder were of preoperative varus ankle deformity. Hip–knee–ankle angle (HKA), tibial plafond–ground angle (PGA), and talus–ground angle (TGA) all exhibited significant correction in both groups; however, tibial plafond–talus angle (PTA) and superior space of ankle joint (SS) only changed in the varus group. The median PTA and SS significantly decreased from 1.2° to 0.3° (p < 0.001) and increased from 2.5 to 2.6 mm (p = 0.013), respectively. Notably, ∆PTA positively correlated with ∆HKA in the varus group (r = 0.247, p = 0.032) but not in the valgus group. Between-group differences in postoperative PTA (p < 0.001) and ∆PTA (p < 0.001) were significant. The degree of ankle alignment correction after TKA differed between patients with preexisting varus and valgus ankle deformities. TKA could not effectively correct the preexisting ankle valgus malalignment.

True Kinematic Alignment Is Applicable in 44% of Patients Applying Restrictive Indication Criteria-A Retrospective Analysis of 111 TKA Using Robotic Assistance.

Introduction: Image-based robotic assistance appears to be a promising tool for individualizing alignment in total knee arthroplasty (TKA). The patient-specific model of the knee enables a preoperative 3D planning of component position. Adjustments to the individual soft-tissue situation can be done intraoperatively. Based on this, we have established a standardized workflow to implement the idea of kinematic alignment (KA) for robotic-assisted TKA. In addition, we have defined limits for its use. If these limits are reached, we switch to a restricted KA (rKA). The aim of the study was to evaluate (1) in what percentage of patients a true KA or an rKA is applicable, (2) whether there were differences regarding knee phenotypes, and (3) what the differences of philosophies in terms of component position, joint stability, and early patient outcome were. Methods: The study included a retrospective analysis of 111 robotic-assisted primary TKAs. Based on preoperative long leg standing radiographs, the patients were categorized into a varus, valgus, or neutral subgroup. Initially, all patients were planned for KA TKA. When the defined safe zone had been exceeded, adjustments to an rKA were made. Intraoperatively, the alignment of the components and joint gaps were recorded by robotic software. Results and conclusion: With our indication for TKA and the defined boundaries, “only” 44% of the patients were suitable for a true KA with no adjustments or soft tissue releases. In the varus group, it was about 70%, whereas it was 0% in the valgus group and 25% in the neutral alignment group. Thus, significant differences with regard to knee morphotypes were evident. In the KA group, a more physiological knee balance reconstructing the trapezoidal flexion gap (+2 mm on average laterally) was seen as well as a closer reconstruction of the surface anatomy and joint line in all dimensions compared to rKA. This resulted in a higher improvement in the collected outcome scores in favor of KA in the very early postoperative phase.

Varus alignment of the tibial component up to seven degrees is not associated with poor long-term outcomes in a neutrally aligned total knee arthroplasty.

The purpose of this retrospective study was to evaluate the effect of varus alignment of the tibial component on the outcomes with a minimum follow-up of 10years. The hypothesis was that varus alignment of the tibial component might not affect the outcomes and survival of a neutrally aligned primary TKA. A matched case-control study was designed between 66 patients with varus alignment of the tibial component and 66 with neutral alignment with a minimum follow-up of 10years. Functional outcome was assessed with the knee surgery scores (KSS) and reduced Western Ontario and MacMaster Universities questionnaire (WOMAC). Patient satisfaction was evaluated by a 0-10 visual analog scale. Radiological evaluation was performed at early postoperative and at final follow-up. The mean follow-up was 11.9 (SD 2.6) years for both groups. The mean postoperative proximal tibial angle in the varus group was 85.0° (SD 0.9) and 88.8° (SD 0.9) in control group. At the final follow-up, there were no significant differences in KSS, WOMAC, range of motion or patient satisfaction. There were no differences in the coronal anatomical alignment of the TKA between groups. Revision of TKA was performed in four knees in the varus group, and one in control group, due to aseptic loosening of the tibial component in all cases. TKA survival at 10years was not significantly different between groups. The alignment of the tibial component up to 7° varus did not negatively affect implant survival, patient satisfaction, and function of a well-aligned TKA, with a minimum postoperative follow-up of 10years. III.

Factors Influencing the Varus Deformity of Humeral Head in Proximal Humerus Fractures and Its Relation to Functional Outcome.

Fractures of the proximal humerus represent approximately 4% of all fractures and 26% of humerus fractures. Proper reduction, stable internal fixation and early initiation of physiotherapy help to achieve a good functional outcome. Aim of this study was to evaluate varus fixation/malunion of proximal humerus fractures and its relation to functional outcome. We retrospectively evaluated 32 patients with proximal humerus fractures who were surgically treated between 2015 and 2017 at tertiary care hospital. We divided the patients into three groups on the basis of the neck-shaft angle as valgus group, normal group and varus group to observe the influence of neck-shaft angle on efficacy. Patients were evaluated for functional outcome using the Constant-Murley score. Two-part fractures had better functional outcome (Constant score = 75.15) compared to three parts with the moderate functional outcome (Constant score = 68.81) and the four-part fracture had poor functional outcome (Constant score = 52.66). After 6months of follow-up, 13 patients had a neck-shaft angle of less than 126°. The functional outcome is significantly better among patients with normal neck-shaft angle and had a mean Constant score of 76.63 as compared to patients with varus deformity had a mean Constant score 60 (p = 0.001). 10 patients did not have medial support, in which 08 patients had neck-shaft angle less than 126° and 2 had a normal neck-shaft angle. High fracture comminution, improper restoration of medial continuity causes varus deformity of the humeral head and it leads to poor functional outcome. The small sample size is the limitation of our study.

Association between Proximal Tibiofibular Joint Morphology and Knee Alignment in Osteoarthritis Patients

This study aimed to determine whether proximal tibiofibular joint (PTFJ) morphology was related to knee alignment in osteoarthritis (OA) patients. Methods: 67 OA patients were enrolled in this study. The morphology of the PTFJ including articular shape type, articular surface area, joint inclination, relative articular height, and joint declination were measured from 3D models. The knee alignment of each subject was characterized as varus, normal, or valgus according to the femorotibial angle (FTA). The FTA was measured on weight-bearing X-rays. Multinomial logistic regression analysis was used to evaluate the association between PTFJ morphology and knee alignment. Results: there were significant differences between varus, valgus, and normal FTA groups in terms of shape type (p = 0.021), inclination of the PTFJ (p = 0.025), relative articular height (p = 0.019), and PTFJ declination angle (p = 0.011). A higher relative articular height (OR: 0.608, 95% CI: 0.205–0.998, and p = 0.017) and lower declination angle (OR: 0.632, 95% CI: 0.601–0.887, and p =0.019) were found to be associated with an increased likelihood of having a valgus FTA rather than a varus FTA. Conclusion: our results indicate that PTFJ morphology is associated with knee alignment.

Energy Absorption Strategies in the Lower Extremities during Double-Leg Landings in Knee Valgus Alignment

Landing with the knee in a valgus position may alter energy absorption strategies in the lower extremities and increase mechanical stress on the knee joint. We compared the energy absorption strategies in the lower extremities during valgus and varus landings. Seventeen females were divided into valgus and varus groups. Lower extremity kinetic data were obtained during drop jumps, using a three-dimensional motion analysis system. Negative mechanical work in the lower extremities were calculated during landing. The valgus group exhibited significantly more negative mechanical work at the knee, and less negative mechanical work at the hip, compared with the varus group. However, there was no difference in the negative mechanical work at the ankle between the two groups. Findings suggest that an increased valgus landing reduces the contribution of the hip to energy absorption and is associated with a reciprocal increased contribution by the knee. Hence a knee valgus landing position may be a key biomechanical factor that increases energy absorption in the knee, thereby increasing the risk of injury. Results further indicate that this can be prevented by adopting a knee varus position on landing, which facilitates absorption of the mechanical load at the hip, rather than at the knee.

Effect of the presence of the articular cartilage on the femoral component rotation in total knee arthroplasty in female and varus osteoarthritis knees

PurposeSurgical techniques for total knee arthroplasty (TKA) require femoral rotational corrections that alter the position of the surface of the posterior femoral joint especially in kinematic alignment. However, preoperative planning of TKA based on computed tomography (CT), without knowing the femoral cartilage thickness, may cause post-surgery failures in femoral rotation. Therefore, this study aimed to evaluate the effects of posterior condyle cartilage thickness on rotational alignment in the femoral component.MethodsThree-dimensional magnetic resonance imaging (MRI) scans were obtained for 139 male and 531 female osteoarthritis patients. The angles defined by the femoral posterior condylar axis (PCA) and the surgical transepicondylar axis (TEA) were evaluated with respect to the presence of cartilage. Additionally, these effects were evaluated with respect to patient gender and varus/valgus condition.ResultsIn all patients, the angle between the TEA and PCA was significantly greater in the presence of cartilage than in the absence of cartilage. This result was also seen in female patients. However, there was no difference in the TEA/PCA angle in male patients based on the presence of cartilage. The TEA/PCA angle was significantly greater in the presence of cartilage than in the absence of cartilage in the female varus group. However, there were no differences in the TEA/PCA angle based on the presence of cartilage in the male varus/valgus and female valgus groups. Cartilage thickness in the posterior femoral condyle was significantly greater on the lateral side than on the medial side in all and male patients. However, there was no difference between the genders regarding cartilage thickness.ConclusionSurgical planning for TKA based on CT does not consider articular cartilage and could lead to external malrotation of the femoral implant. Therefore, the effect of the remaining posterior condylar cartilage should be considered by surgeons to prevent over-rotation of the femoral component, especially in female varus knees.

Residual varus alignment can reduce joint awareness, restore joint parallelism, and preserve the soft tissue envelope during total knee arthroplasty for varus osteoarthritis.

The objectives were to compare the coronal joint configuration of the knee joints, coronal gap imbalances requiring substantial medial release, and patient-reported outcomes, including the forgotten joint score, between knees in which residual varus alignment was intentionally allowed according to an individualised lower limb analysis and those with mechanical alignment in total knee arthroplasty for varus osteoarthritis. Consecutive primary navigated total knee arthroplasty procedures for varus osteoarthritis were retrospectively reviewed. The study cohort was stratified based on whether residual varus alignment was intentionally allowed. Propensity-score matching was performed based on the baseline characteristics, including demographic characteristics, preoperative radiological measurements, and the Western Ontario and McMaster University Osteoarthritis Index (mechanical alignment group vs residual varus group). The patient-reported outcomes and coronal joint line orientation of the knee (relative to the ground) and ankle were evaluated. Coronal gap differences and coronal gap imbalances were analysed using intraoperative gap measurements. Relative to the ground and ankle, the postoperative knee joint line orientation slanted down laterally in the mechanical alignment group (-3.05˚ ± 1.62, relative to the ground; -2.65˚ ± 1.56, relative to the ankle joint), but was parallel in the residual varus group (-0.75˚ ± 1.59, relative to the ground; -0.95˚ ± 1.71, relative to the ankle joint). Coronal gap differences at extension and the proportion of coronal gap imbalances requiring substantial medial release were 1.27 ± 1.53 and 6% in the residual varus group and 2.32 ± 1.24 and 15% in the mechanical alignment group. Postoperatively, the residual varus group showed higher Western Ontario and McMaster University Osteoarthritis Index scores and total forgotten joint scores than the mechanical alignment group (6.97 ± 4.75 vs. 10.31 ± 5.74 and 56.42 ± 12.85 vs. 45.69 ± 14.49, respectively). Intentionally allowed residual varus alignment with individualised analysis of lower limb alignment restored the parallel joint line of the knees, preserved the soft tissue envelope, and reduced joint awareness after total knee arthroplasty for varus osteoarthritis. Therapeutic, Level III retrospective case-control study.

Relationship between lower limb alignment distribution and short-term clinical results after primary total knee arthroplasty in patients with varying degrees of knee varus

To analyze the relationship between the distribution of lower limb alignment and short term clinical efficacy in patients with varus-type osteoarthritis after primary total knee arthroplasty (TKA). From December 2016 to March 2018, 87 patients (101 knees) with knee osteoarthritis were treated with the first total knee arthroplasty by the same medical group, including 21 males(25 knees) and 66 females(76 knees), ranging in age from 51 to 85 years old, with a mean of (67.6±7.0) years old. According to the difference of hip knee ankle angle (HKA) after total knee arthroplasty, the patients were divided into 4 groups:neutral position group (group A), -3°≤HKA≤3°, 50 knees;slight varus group (group B), 3°< HKA<6°, 20 knees;severe varus group (group C), HKA≥6°, 20 knees;valgus group (group D), HKA<- 3°, 11 knees. The preoperative sex, age, body mass index, operative side, preoperative and postoperative knee joint activity, HSS score, KSS clinical and functional score were compared among the 4 groups, and the relationship between the force line distribution of femoral and tibial prosthesis and the recent clinical effect was compared. All the patients were followed up with a mean duration of(18.4±4.0) months. The range of motion of knee joint, HSS and KSS scores at the latest follow-up after operation in the 4 groups were higher than those before operation, and the difference was statistically significant (P<0.001). There were significant differences in HSS and KSS scores among the 4 groups at the latest follow up (P<0.05);and the results in group A were better than those in group C and group D (P<0.05);the results in group B were better than those in group C and group D (P< 0.05);there was no significant difference between group A and group B or group C and group D(P>0.05). There was no significant difference in knee joint activity among the 4 groups. The score of femoral prosthesis force line within ±3°was better than that of the other group (P<0.05), and the score of tibia prosthesis force line had no significant difference between within ±3° group and other group (P>0.05). The short term clinical efficacy of patients with knee varus osteoarthritis after primary total knee arthroplasty is related to the distribution of lower limbs alignment. The short-term clinical efficacy of slight inversion position can be similar to that of neutral position. The force line distribution of femoral prosthesis is related to the short term clinical efficacy after primary knee arthroplasty.

Importance of Three-Dimensional Evaluation of Surgical Transepicondylar Axis in Total Knee Arthroplasty.

In total knee arthroplasty, the surgical transepicondylar axis (SEA) is one of the most reliable rotation axes for stabilizing of the patellofemoral joint. The SEA is identified with reference to the lateral epicondyle and the medial sulcus of the medial epicondyle. However, these two structures rarely appear on the same plane on computed tomography (CT), and it is necessary to take two points in separate images. Many surgeons measure the SEA on the same image (pseudo SEA) instead. We aimed to determine the difference between true SEAs and pseudo SEAs. A total of 31 normal knees and 24 varus knees were included in this study. Three-dimensional (3D) models of the femur were reconstructed from CT images, and a reconstructed plane was made using the International Society of Biomechanics coordinate system. Pseudo SEAs drawn in the plane passing through the lateral epicondyle and medial sulcus were defined as l-SEA and m-SEA, respectively. L-SEA, m-SEA, true SEA, and posterior condylar axis (PCA) were projected onto the International Society of Biomechanics coordinate plane and, "p l-SEA," "p m-SEA," "p true SEA," and "p PCA" were obtained. The true SEA angle was defined as the angle between p true SEA and p PCA. The l-SEA angle or m-SEA angle was defined as the angle between the p l-SEA or p m-SEA and p PCA, respectively. There were no statistically significant differences between true SEA angle (2.64 ± 2.01 degrees) and pseudo SEA angle (l-SEA angle: 2.74 ± 2.07 degrees, m-SEA: 2.54 ± 2.19 degrees). Conversely, 12 knees in the normal group and 2 knees in the varus group had differences of more than 1 degree (p = 0.01). Among them, 6 knees in the normal group and 0 knees in the varus group had a difference of 2 degrees or more (p = 0.03). In most cases, pseudo SEA can be substituted for true SEA.

The Effect of Total Knee Arthroplasty on Hindfoot Alignment in Patients with Severe Genu Varum and Genu Valgum.

The maintenance of deformity in the ankle and hindfoot after correction of knee deformity following knee arthroplasty may cause abnormal tension in the knee and patient dissatisfaction. The aim of this study was to determine the effect of knee arthroplasty on the hindfoot alignment in patients with severe genu varum and valgum. A total of 84 patients with primary osteoarthritis, were enrolled in the study. The knee deformity was measured using a long leg film before surgery. The long axial radiographic view of hindfoot was taken in the standing position for all patients, before and six months after surgery. Comparisons were made on changes in the hindfoot angles measured before and after surgery. A total of 84 patients with mean age of 62.28 ± 7.77 years, 77 (92%) and seven patients (eight percent) had knee varus and valgus deformity, respectively. In the knee varus group, the mean preoperative hindfoot angle was + 5.32 ± 6.12 ° (valgus) which was changed to - 0.25 ± 4.91 ° (varus) in the postoperative phase. In the knee valgus group, the mean pre and postoperative hindfoot angles were - 7.71 ± 7.06° (varus) and - 2.14 ± 5.92 ° (varus), respectively. The mean preoperative hindfoot angle in severe and very severe varus knee groups were + 5.45 ± 3.30 and + 5.28 ± 6.86 °, respectively. These angles were changed to + 0.21± 5.17 and -1.60 ± 3.89° six months after surgery, respectively. The mean preoperative hindfoot angle in severe and very severe valgus knee deformity groups were - 7.00 ± 4.69 and -8.66 ± 10.69 °, respectively. These angles were changed to - 2.00 ± 5.71 and - 2.33 ± 7.50 °after surgery, respectively. There was no significant difference between patients with severe and very severe deformity in terms of pre and post-operative hindfoot angle. The hindfoot alignment is significantly corrected after knee arthroplasty. The severity of knee deformity does not correlate with the severity of the hindfoot deformity before and after surgery.

Mid-level constraint may correct coronal plane imbalance without compromising patient function in patients with severe osteoarthritis

IntroductionMid-level constraint (MLC) in Total Knee Arthroplasty (TKA) offer surgeons the opportunity to obtain a well-balanced varus-valgus balance in the setting of slight ligament imbalance. As such, we sought to evaluate patient reported outcome measures (PROMs), alignment correction, and rate of revision between the MLC group and a cohort of posterior stabilized (PS) knees in a cohort of patients with preoperative degenerative arthritis. Materials/methodsWe performed a retrospective review of 57 MLC knees and 96 PS knees from a single manufacturer that were implanted by a single surgeon. We found the average age (68.91 vs. 68.40, p = 0.72), average BMI (30.88 vs. 29.14, p = 0.10), and gender breakdown (25:32 vs. 28:69, p = 0.08) to be comparable between the two cohorts. The latest follow-up was 4.0 years in the MLC group and 3.8 years in the PS group, p = 0.26. ResultsThe two cohorts inherently resulted in significantly different preoperative deformities (MCL knees: average varus deformity 13.75°, average valgus deformity 12.37°; PS knees average varus deformity 15.14°, average valgus deformity 10.8°). There were more valgus knees in the MLC group (36 vs. 22 (p < 0.001), respectively), but the postoperative alignment was the same. MLC cohort: preoperative varus group had 4.74° of valgus postoperatively, preoperative valgus group had 5.43° of valgus postoperatively. PS cohort: preoperative varus group had 5.40° of valgus postoperatively, preoperative valgus group had 4.80° of valgus postoperatively. We found a significant difference in Knee Injury and Osteoarthritis Outcome Score (KSCRS-Total) between the two groups (MLC 163.9 vs. PS 132.8, p = 0.003). There was no significant difference in terms of Range of Motion (ROM) (MLC 121° vs. PS 122°, p = 0.58), anterior knee pain (MLC 1.75 vs. PS 1.81, p = 0.39), or Pain VAS (MLC 25.1 vs. PS 28.6, p = 0.46). There was similar rate of revision between the cohorts (3.5% MLC vs. 2.10% PS, p = 0.13). There was no significant difference in manipulation rate (8.78% MLC vs. 9.40% PS, p = 0.38). Conclusion/discussionThis study demonstrated that the use of MLC in TKA allows surgeons to correct preoperative deformities with equal or improved functional outcomes compared to PS knees. In general, we recommend that surgeons try to balance the knee and use the least amount of constraint possible but should consider MLC when needed and use such implants if they are unable to balance the varus-valgus gap.

Predicting clinical outcomes after total knee arthroplasty from preoperative radiographic factors of the knee osteoarthritis

BackgroundTotal knee arthroplasty (TKA) is the major surgical treatment for end-stage osteoarthritis (OA). Despite its effectiveness, there are about 20% of patients who are dissatisfied with the outcome. Predicting the surgical outcome preoperatively could be beneficial in order to guide clinical decisions.MethodsOne-hundred and ten knees of 110 consecutive patients who underwent TKAs for varus knees resulting from OA were included in this study. Preoperative varus deformities were evaluated by femorotibial angle (FTA), medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA), and classified as a severe varus (SV) or a mild varus (MV) group. The osteophyte score (OS), which we developed originally, was also calculated based on the size of the osteophytes and classified as groups with more or less osteophytes. We compared preoperative and 1-year postoperative range of motion, the Knee Society Score, and Japanese Knee injury Osteoarthritis Outcome Score (KOOS) between SV and MV groups (varus defined by FTA, MPTA, or LDFA), in each group with more or less osteophytes.ResultsWhen varus deformities were defined by FTA, regardless of OS, postoperative KOOS subscales and/or the improvement rates were significantly higher in the SV group than in the MV group. When varus defined by MPTA, regardless of OS, there were no significant differences in postoperative KOOS subscales between groups. However, when varus defined by LDFA, scores for pain, activities of daily living (ADL), and quality of life (QOL) on postoperative KOOS and/or the improvement rates were significantly higher in the SV group than in the MV group only in patients with less osteophytes. No significant differences were found between groups in patients with more osteophytes.ConclusionsWe classified OA types by radiographic measurements of femur and tibia in combination with OS. Postoperative patient-reported outcomes were better in patients with SV knees but were poor in patients with knees with MV deformity and less osteophytes.

The Relationship between Knee Adduction Moment and Knee Osteoarthritis Symptoms according to Static Alignment and Pelvic Drop.

Objectives To investigate the relationship between external knee adduction moment (KAM) and knee osteoarthritis (OA) symptoms according to static alignment and pelvic drop. Methods Ninety-five participants with symptomatic knee OA were included. Radiographic severity was graded by Kellgren and Lawrence (KL) scale. The hip-knee-ankle (HKA) angle was used to assess limb alignment from a full-length lower-limb radiograph. KAM-related variables (peak KAM and KAM impulse) and pelvic drop angle were determined from 3D gait analysis. Symptoms were assessed via visual analog scale (VAS) for pain and hospital for special surgery (HSS) score for physical function. The relationship between KAM and symptoms was evaluated according to radiographic severity and pelvic drop using linear models. Results According to the more affected knee in the varus group, both the two KAM-related measures (peak KAM and KAM impulse) were positively associated with greater VAS pain and were negatively associated with HSS score. Only peak KAM was correlated with VAS and HSS in the valgus group. VAS pain score of the more affected knee was positively correlated with pelvic drop angle. Stratified by pelvic drop angle, KAM-related variables were more positively associated with VAS pain and negatively associated with HSS score for patients with pelvic drop angle ≤3 degrees. The relationships between KAM and symptoms according to radiographic disease severity remained confusing. Conclusions Static alignment and pelvic drop angle significantly affected relationships between KAM-related variables and knee OA symptoms, which may explain the confusing results as shown by previous studies.

Influence of Preoperative Tibiotalar Alignment in the Coronal Plane on the Survival of Total Ankle Replacement: A Systematic Review.

It remains controversial whether significant preoperative tibiotalar varus and valgus deformity should be contraindications for total ankle replacement (TAR). The primary aim of this systematic review was to analyze the influence of preoperative tibiotalar varus and valgus alignment on the survival of TAR. The databases MEDLINE and Embase were searched from onset through September 2018. Two authors performed study selection and data extraction using a predefined data extraction tool. Implant survival in the alignment groups was reported as "revisions per 100 component years." Additional procedures, complications, and revisions were also reported. Assessment of the methodological quality was performed using the Newcastle-Ottawa Scale (NOS). In total, 17 studies were considered eligible, in which a total of 1692 TARs were included from 1627 patients. The weighted mean follow-up was 52.4 (range, 1-147) months. The neutral alignment group included 711 TARs, the varus group included 545 TARs, and the valgus group included 332 TARs. Total revisions were 52, 37, and 36 in the preoperative tibiotalar neutral, varus, and valgus alignment groups, respectively. Revisions per 100 observed component years were 1.6, 1.7, and 2.5 in the preoperative tibiotalar neutral, varus, and valgus alignment groups, respectively. A total of 129 complications and 447 additional procedures were reported in 601 TARs. There was a strong indication that preoperative varus alignment in the coronal plane had a comparable implant survival to neutral alignment. Preoperative valgus alignment demonstrated a more negative influence on implant survival. Level III, systematic review.

MRI Analysis for Clarification of Mechanism of Ankle Osteoarthritis: When the Talar Tilt Exceeds 15 Degrees, the BME Pattern of the Ankle Are Changes

Category:Ankle ArthritisIntroduction/Purpose:In recent years, total ankle arthroplasty (TAA) has been widely performed for severe ankle osteoarthritis (OA). However, TAA is not always successful in cases of advanced varus; in fact, some researchers have stated caution regarding its indication. Previously, to elucidate the pathological condition of ankle OA using MRI, we investigated that confirmed the existence of an association among the Takakura–Tanaka classification, foot and ankle alignment, and bone marrow edema (BME). In this study, we focused on the talar tilt angle and compared the cases of terminal ankle OA as per Takakura– Tanaka classification (stage 3b and 4) wherein this angle exceeded 15° with those wherein it did not exceed in terms of the mode of BME onset.Methods:Of 616 cases of ankle OA diagnosed in our hospital between May 2009 and January 2018, we examined the MRI images of 52 feet of 50 patients diagnosed with severe ankle OA. The talar tilt angle with the ankle under load was measured using frontal X-ray, following which the presence/absence of BME was determined by dividing the talus, subtalar, and Chopart’s joints into 22 regions (areas 1–11 and 1’–11’). In statistical analysis, we first obtained the total number of BME incidences for each case. Then, after dividing this disease group into severe varus (SV; talar tilt angle = 15° or more) and mild varus (MV; talar tilt angle < 15°) groups, we compared t-test scores for the respective BME incidence rates. Furthermore, we used Fisher’s exact test to examine differences in terms of BME incidence rates between the two groups for each subdivided region.Results:No significant differences were found between the two groups in terms of BME incidence rates for each case. However, the rates in each area were significantly lower in the SV group than in the MV group for area 2 (SV group, 14%; MV group, 57%) and area 4 (SV group, 7%; MV group, 39%), i.e. the SV groups corresponding to the outer surface of the trochlea talar.Conversely, in the subtalar joint, the rates were significantly higher in the SV group than in the MV group for area 10 (SV group, 36%; MV group, 11%) and area 10’ (SV group, 29%; MV group, 5%), i.e. the medial surface of the calcaneus.Conclusion:In cases of severe ankle OA wherein the talar tilt angle exceeds 15°, the load exerted on the outer side of the talus decreases in the talar joint, whereas a greater load is exerted on the medial subtalar joint located at the innermost side in the subtalar joint. Differences in terms of the mode of BME incidence in the subtalar joint, which is not replaced with normal TAA, may be a poor prognostic factor for postoperative TAA.