Varus Alignment Research Articles

Hybrid closing-wedge DTO using PSI was selected for a patient wit severe deformity post-fracture malunion, which enable good alignment correction and patient satisfaction

BackgroundHigh tibial osteotomy (HTO) is an effective treatment option for deformity correction after fracture. However, performing precise corrective osteotomy for cases with a severe varus deformity and a significant posterior slope poses a significant challenge. Three-dimensional (3D) bone model construction and patient-specific instrumentation (PSI) created from preoperative Computed tomography (CT) may be useful tools in achieving successful outcome for such cases. The present technique describes a hybrid closing-wedge distal tuberosity tibial osteotomy (Hybrid CWDTO) using two PSIs.MethodsPreoperative planning was performed in 3D with reference to the contralateral normal lower extremity CT taken preoperatively, which was then mirrored for analysis. A full-scale bone model and two PSIs were constructed based on this plan to allow for complex correction. During surgery, osteotomy was performed using these sterilized PSIs as guides.ResultsRadiographic imaging showed that medial proximal tibial angle (MPTA) improved from 68 to 84 degrees and posterior tibial slope (PTS) improved from 19 to 6 degrees. The standing leg radiograph showed a mechanical varus alignment improvement from 12 to 3 degrees. The 2011 Knee Society Scoring system (2011 KSS) improved from 31 to 95 in objective knee indicators, from 10 to 24 in symptoms, from 14 to 40 in patient satisfaction and from 51 to 95 in activities.ConclusionHybrid CWDTO using PSIs is a useful surgical technique for alignment correction post-malunion while also achieving high patient satisfaction. This can assist surgeons in treating complex deformities that are otherwise difficult to treat.

Impact of Aging and Knee Osteoarthritis on Lower Limb Alignment and CPAK Classification: Gender Differences in a Japanese Cohort.

Objective: This study investigates the impact of age and knee osteoarthritis (OA) on the coronal plane alignment of the lower extremity in Japanese males and females, utilizing the Coronal Plane Alignment of the Knee (CPAK) classification system. Methods: A cross-sectional analysis was conducted with 150 male and 150 female patients. Participants were divided into three groups according to age and OA progression. The mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA) were measured using standard digital long-leg radiographs. Arithmetic hip-knee-ankle angle (aHKA) and joint line obliquity (JLO) were calculated, and the CPAK classification was performed to verify the distribution among the three groups. Results: The results showed increased varus alignment of the mean mLDFA correlated with OA in both genders and with aging in males. The mean mMPTA did not change in males but shifted toward varus in females with both aging and OA. Both genders demonstrated a constitutional varus alignment with the progression of osteoarthritis (males: 1.3 ± 2.4° to -3.5 ± 3.7°, p < 0.001; females: -1.2 ± 3.2° to -3.6 ± 2.9°, p < 0.001). However, this trend with aging was observed only in females (0.0 ± 2.5° to -1.2 ± 3.2°, p = 0.018). JLO maintained its apex distal position with aging and OA progression in all subjects. The study further revealed a notable transition from CPAK Type II to Type I with OA progression in both genders, additionally influenced by aging in females. Conclusions: Aging affects coronal alignment and CPAK classification differently across genders. With OA progression, there was a shift toward smaller aHKA, while JLO remained unchanged. Compared to other races, young Japanese people exhibit similar CPAK distributions, but distinct differences appear in OA-affected individuals, highlighting potential racial variations in CPAK classifications.

Changes and associations between synovial fluid and magnetic resonance imaging markers of osteoarthritis after high tibial osteotomy

BackgroundMechanobiological mechanisms of osteoarthritis (OA) are unclear. Our objectives were to explore: 1) changes in knee joint physiology using a large panel of synovial fluid biomarkers from before to one year after high tibial osteotomy (HTO) surgery, and 2) the association of changes in the synovial fluid biomarkers with the changes in MRI measures of knee effusion-synovitis and articular cartilage composition.MethodsTwenty-six patients with symptomatic knee OA and varus alignment underwent synovial fluid aspirations and 3 T MRI before and one year after medial opening wedge HTO. Cytokine and growth factor levels in synovial fluid were measured with multiplex assays. Ontology and pathway enrichment was assessed using data protein sets with gene set enrichment analysis (GSEA), and analyzed using linear mixed effects models. MRIs were analyzed for effusion-synovitis and T2 cartilage relaxation time using manual segmentations. Changes in biomarker concentrations were correlated to changes in MRI effusion-synovitis volume and articular cartilage T2 relaxation times.ResultsDecreased enrichment in Toll-like receptor and TNF-α signalling was detected one year after HTO. The leading contributors to this reduction included IL-6, TNF-α and IL-1β, whereas the highest contributors to positive enrichment were EGF, PDGF-BB and FGF-2. Effusion-synovitis volume decreased (mean [95%CI]) one year after HTO (-2811.58 [-5094.40, -528.76mm3]). Effusion-synovitis volume was moderately correlated (r [95% CI]) with decreased MMP-1 (0.44 [0.05; 0.71]), IL-7 (0.41 [0.00; 0.69]) and IL-1β (0.59 [0.25; 0.80]) and increased MIP-1β (0.47 [0.10; 0.73]). Medial tibiofemoral articular cartilage T2 relaxation time decreased (mean [95% CI]) one year after HTO (-0.33 [-2.69; 2.05]ms). Decreased T2 relaxation time was moderately correlated to decreased Flt-3L (0.61 [0.28; 0.81]), IL-10 (0.47 [0.09; 0.73]), IP-10 (0.42; 0.03–0.70) and increased MMP-9 (-0.41 [-0.7; -0.03]) and IL-18 (-0.48 [-0.73; -0.10]).ConclusionsDecreased aberrant knee mechanical loading in patients with OA is associated with decreased biological and imaging measures of inflammation (measured in synovial fluid and on MRI) and increased anabolic processes. These exploratory findings suggest that improvement in knee loading can produce long-term (one year) improvement in joint physiology.

Gender, BMI, and Age-Related Variations in Lower Limb Alignment Parameters and CPAK Phenotypes in Chinese Patients with Knee Osteoarthritis.

Research on the distribution of and the variation in coronal plane alignment of the knee (CPAK) in the Chinese osteoarthritis population is limited. We aimed to establish the CPAK classification based on the characteristics of lower limb alignment in the Chinese osteoarthritis population. We also investigated variations in lower limb alignment parameters and CPAK phenotypes based on gender, body mass index (BMI), and age. A retrospective study was conducted on a total of 944 knees diagnosed with osteoarthritis in 479 patients from January 2017 to December 2023. A scatterplot was used to describe the distribution of the CPAK classification, and the differences in lower limb alignment parameters and the CPAK classification were compared across genders (male, female), ages (middle-aged/<65 years, elderly/≥65 years), and BMI categories (normal/<25 kg/m2, overweight and obese/≥25 kg/m2) using the chi-squared test or Fisher's exact test. The average arithmetic hip-knee-ankle angle and joint line obliquity (JLO) were -3.03° ± 5.69° and 174.45° ± 4.29°, respectively. There was a higher prevalence of constitutional varus alignment in males and the overweight or obese group, while constitutional valgus alignment was more common in females and the normal BMI group (p < 0.05). Additionally, females had a greater apex distal JLO than males (p < 0.05). There were no statistically significant differences in lower limb alignment parameters among different age groups (p > 0.05). Although there were variations in alignment parameters across different genders and BMI categories in the knee osteoarthritis population, the predominant CPAK classifications were type I (38.03%), followed by type II (20.02%) and type IV (17.06%). The most common CPAK types were I, II, and IV, and they were not influenced by gender, BMI, or age, indicating that the CPAK classification can reliably reflect constitutional alignment. A better understanding of native alignment variability can aid in providing patient-specific recommendations when considering orthopedic alignment strategies.

Humeral stem alignment of curved short stem in reverse shoulder arthroplasty: Varus/Valgus alignment is not a determinant for clinical outcomes

BackgroundThis study aimed to investigate the influence of curved short stem alignment within the proximal humerus on the clinical outcomes of reverse shoulder arthroplasty. We hypothesized that the varus/valgus alignment would yield clinical outcomes comparable to those of a neutral alignment. MethodsWe retrospectively reviewed 167 patients who underwent reverse shoulder arthroplasty using the Aequalis Ascend Flex implant between January 2017 and December 2021. The study categorized the patients into three groups based on the angle difference between the humeral axis and the stem axis: neutral group (GN, defined as within ±5 degrees), valgus group (GL), and varus group (GR). Functional outcomes were assessed using the visual analog scale pain score, subjective shoulder value, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and active range of motion. Routine radiographic evaluations were also conducted to assess the filling ratio and bone resorption. ResultsAmong 138 patients, 89 were in the GN group, 37 (27%) in the GL group, and 12 (9%) in the GR group. The average degree of varus alignment was 6 (range from 5 to 7 degrees), while the average degree of valgus alignment was -7 (range from -8 to -5 degrees). According to our findings, the clinical outcomes did not exhibit significant differences between the three groups. Furthermore, the radiological outcomes showed no significant differences among the three groups. ConclusionsCompared to neutral alignment, varus or valgus alignment of the humeral stem in reverse shoulder arthroplasty using a curved short stem does not significantly affect clinical outcomes.

Outcomes After Osteochondral Allograft Transplantation of the Medial Femoral Condyle in Patients With Varus and Nonvarus Alignment

Background: Fresh osteochondral allograft (OCA) transplantation is an effective technique for the treatment of focal chondral and osteochondral defects in the knee. Coronal-plane malalignment leads to increased contact forces within a compartment and subsequently the cartilage repair site and may lead to higher failure rates. However, the magnitude of the effect of coronal-plane malalignment on graft survivorship and clinical outcomes has not been well characterized. Purpose: To evaluate how varus malalignment affects graft survival and patient-reported outcomes after isolated OCA transplantation of the medial femoral condyle (MFC). Study Design: Cohort study; Level of evidence, 3. Methods: A total of 70 patients (74 knees) who underwent primary OCA transplantation of the MFC between 2005 and 2019 were identified from a prospectively collected single-surgeon cartilage registry with a minimum 2-year follow-up. Coronal-plane alignment was evaluated utilizing standing hip-to-ankle radiographs. OCA failure, defined as removal of the graft or conversion to arthroplasty, and reoperations were recorded. Patient-reported outcomes were obtained preoperatively and postoperatively using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, modified Merle d’Aubigné–Postel score, and overall patient satisfaction score. Results: The mean mechanical tibiofemoral angle for patients with varus alignment was 3.9° of varus (range, 1.1° to 8.9°) and for patients with nonvarus alignment it was 0.02° of valgus (range, 3.6° varus to 4.6° valgus). Graft survivorship was 95.3% in the varus group and 95.8% in the nonvarus group (P = .918) at 5 years postoperatively. Reoperations after OCA transplantation occurred in 14.0% of the varus group and 22.6% of the nonvarus group (P = .336). The mean International Knee Documentation Committee total score improved from 45.2 preoperatively to 74.8 at latest follow-up in the varus group and from 40.5 preoperatively to 72.3 at latest follow-up in the nonvarus group. Patient satisfaction was >85%. Conclusion: Patients undergoing isolated OCA transplantation of the MFC had high rates (>90%) of graft survivorship and significant improvements in pain and function. Patients with mild preexisting varus malalignment were found to have no difference in the failure rate or clinical outcomes compared with patients with nonvarus alignment.

Femoral and tibial phenotypes of varus alignment in a Southeast Asian arthritic population: a descriptive study.

Knowledge of femoral and tibial morphology is important for patient-specific surgery in both joint reconstruction and preservation procedures. Studies evaluating morphological variance in femoral and tibial alignments in Asian populations are scarce. This is the first descriptive study evaluating the femoral and tibial phenotypes of varus alignment in a Southeast Asian population. Long-leg coronal standing radiographs of 2021 limbs were obtained, and the hip-knee-ankle angle, mechanical lateral distal femoral angle, medial proximal tibial angle and joint line convergence angle were measured. Joint line obliquity was calculated, and the knees were classified according to the Coronal Plane Alignment of Knee (CPAK) classification. Descriptive analyses on alignment parameters and demographic data (age, gender, ethnicity and body mass index [BMI]) were performed and entered into a linear regression model. The highest frequency of limb alignment in the population was found to be CPAK type I (52.71%, n = 1003). Tibial varus was the largest contributor of varus malignment. Of the varus knees (n = 1247), varus deformity was found solely in the tibia (68.60%), solely in the femur (2.07%) and was contributed by both the femur and the tibia (4.97%). In the linear regression model, BMI was found to be a strong determinant for femoral varus (P = 0.004) and joint line incongruence (P < 0.001). The findings of this study will be important to surgeons during planning for joint preservation procedures (such as corrective osteotomies) and joint arthroplasties to restore alignment.

Arthroscopic Centralization of the Medial Meniscus Reduces Load on a Posterior Root Repair Under Dynamic Varus Loading: A Biomechanical Investigation

Background: In addition to the integrity of the meniscal hoop function, both the anterior and posterior meniscus roots as well as the meniscotibial and meniscofemoral ligaments are crucial in restraining meniscal extrusion. However, the interaction and load sharing between the roots and these peripheral attachments (PAs) are not known. Purposes: To investigate the influence of an insufficiency of the PAs on the forces acting on a posterior medial meniscus root repair (PMMRR) in both neutral and varus alignment and to explore whether meniscal centralization reduces these forces. Study Design: Controlled laboratory study. Methods: In 8 fresh-frozen human cadaveric knees, an arthroscopic transosseous root repair (step 1) was performed after sectioning the posterior root of the medial meniscus. The pull-out suture was connected to a load cell to allow measurement of the forces acting on the root repair. A medial closing-wedge distal femoral osteotomy was performed to change the mechanical axis from neutral to 5° of varus alignment. The meniscus was completely released from its PAs (step 2), followed by transosseous arthroscopic centralization (step 3). Each step was tested in both neutral and varus alignment. The specimens were subjected to nondestructive dynamic varus loading under axial compression of 300 N in 0°, 15°, 30°, 45°, and 60° flexion. The changes in force acting on the PMMRR were statistically analyzed using a mixed linear model. Results: Axial loading in neutral alignment led to an increase of the force of root repair of 3.1 ± 3.1 N (in 0° flexion) to 6.3 ± 4.4 N (in 60° flexion). In varus alignment, forces increased significantly from 30° (3.5 N; 95% CI, 1.1-5.8 N; P = .01) to 60° (7.1 N; 95% CI, 2.7-11.5 N; P = .007) flexion, in comparison with neutral alignment. Cutting of the PAs in neutral alignment led to a significant increase of root repair forces in all flexion angles, from 7.0 N (95% CI, 1.0-13.0 N; P = .02) to 9.1 N (95% CI, 4.1-14.1 N; P = .003), in comparison with the intact state. Varus alignment significantly increased the forces in the cut states from 4.8 N (95% CI, 1.0-8.5 N; P = .02) to 11.1 N (95% CI, 4.2-18.0 N; P = .006) from 30° to 60° flexion, in comparison with the neutral alignment. Arthroscopic centralization led to restoration of the native forces in both neutral and varus alignment, with no significant differences between the centralized and intact states. Conclusion: An insufficiency of the PAs of the medial meniscus, as well as varus alignment, led to increased forces acting on a PMMRR. These forces were reduced via an arthroscopic meniscal centralization. Clinical Relevance: Performing arthroscopic meniscal centralization concomitantly with PMMRR may reduce failure of the repair by reducing the load of the root.

Total Ankle Arthroplasty as a Correction Tool for Foot Deformities: Analyzing the Impact on Medial Column Alignment Adaptation Through Weightbearing Computed Tomography.

While weightbearing computed tomography (WBCT) has been instrumental in analyzing total ankle arthroplasty (TAA) positioning, there is a notable gap in the literature regarding adaptive changes in the foot's medial column after TAA. This study aims to bridge this gap by comparing preoperative and postoperative alignments of the foot's medial column and analyzing if a correlation exists between TAA coronal alignment correction and medial column alignment adaptation. Sixty patients who underwent a lateral approach TAA for end-stage osteoarthritis (OA) between January 2021 and April 2023 were included in this retrospective study. Patients were divided into varus (n = 30) and valgus (n = 30) groups. Preoperative and postoperative WBCT scans were analyzed to measure medial column alignment. Statistical analysis evaluated alignment corrections and correlations. Both groups showed significant plantarflexion of the second tarsometatarsal (TMT) angle, with a median adaptation of -1 degree (IQR -3, 0; P < .01) in the valgus group and -1 degree (IQR -3, 0; P = .03) in the varus group. The varus group exhibited increased plantarflexion of the first TMT angle (median -1 degree, IQR -1, -2; P = .03). Both groups demonstrated increased adduction of the medial column. The talonavicular coverage angle adaptation averaged 7.2 ± 14 degrees (P < .01) in the valgus and 9 ± 12 degrees (P < .01) in the varus group. The talo-first metatarsal axial angle adaptation was 5 ± 13 degrees (P = .03) in the valgus group and 9.5 ± 15 degrees (P = .08) in the varus group. WBCT analysis revealed significant medial column adaptation post-TAA in varus and valgus alignments. However, no correlation was found between hindfoot correction and forefoot adaptation, making it challenging to predict the need for additional realignment surgeries. Future studies should explore the relationship between tibiotalar correction and medial column alignment to improve outcomes and the influence of total ankle design on medial column adaptation. Level III, retrospective case control study.

Valgus-Related Elbow Pathology is not Associated with Decreased Baumann’s Angle: A Case-Control Study

BackgroundPrevious studies have demonstrated that varus alignment of the elbow has been associated with lateral condylar fractures. However, for other pediatric and adolescent elbow pathologies, the influence of upper extremity alignment has not been investigated. This study aimed to compare elbow alignment (quantified using Baumann’s angle) among patients with medial epicondyle humeral fractures and capitellum osteochondritis dissecans (OCD) and age- and sex-matched control patients. MethodsPediatric and adolescent patients (ages 5-18, inclusive) treated at a tertiary care hospital for medial epicondyle fractures (MEFx) and capitellum OCD lesions from January 2016 and October 2023 were retrospectively reviewed. Patients aged 5-18 with anteroposterior (AP) elbow radiographs demonstrating no elbow pathology were included as controls. Patients were matched 1:1:1 based on sex and chronologic age within 2 years and placed into cohorts by injury. Baumann’s angle was compared across groups using one-way ANOVA after data normality was established via Shapiro Wilk tests. Linear regression was used to assess whether fracture displacement in millimeters (in the medial epicondyle fracture group) or OCD lesion size (in the capitellum OCD group) correlated with Baumann’s angle. Two-tailed significance threshold was set as p≤0.05. Results72 matched patients were included (24 MEFx, 24 OCD, 24 controls). Mean age of the overall sample was 13.8±1.9 years, with 79% male. Mean Baumann’s angle was 75.7±5.9 degrees in MEFx, 71.7±7.9 degrees in OCD, and 74.1±5.2 degrees in controls (p=0.181). There was no association between fracture displacement and Baumann’s angle in the MEFx group (p=0.75), and there was no association between OCD lesion size and Baumann’s angle in the OCD group (p=0.31). ConclusionsThere was no difference in Baumann’s angle among pediatric and adolescent patients with MEFx, capitellum OCD lesions, and age and sex-matched controls. These findings suggest that static distal humerus alignment does not increase the risk for these injuries. Future studies should seek to evaluate dynamic alignment and its influence on these pathologies. Level of EvidenceIII

Does Mal-alignment of the CLS Spotorno Femoral Stem Correlate with Functional Outcome of Patients Undergoing Total Hip Arthroplasty? An Evaluation at Mid-term Follow Up.

The straight and thin design of the CLS Spotorno stem makes it prone for coronal plane mal-alignment, with potential for cortical impingement; reactive osteogenesis and thigh pain have been documented in this situation with some stems. The literature is scarce about the effect of distal mal-alignment with this particular stem, and its relationship with thigh pain, functional outcomes and stem survival. We assessed functional outcomes with incidence of varus/valgus CLS stem alignment, and correlated stem subsidence of these thin stems with hip scores. Hip arthroplasty cases with CLS Spotorno stems, operated between 2015 and 2022, with a minimum follow up of 18months were evaluated. Radiology included 100% pelvis x-rays with bilateral hips (anteroposterior with 15° internal rotation plus lateral views); parameters documented were coronal mal-alignment, stem subsidence, any pedestal formation and heterotrophic ossification (HO); special note was made of any thigh pain, and functional outcomeswere recorded using mHHS and SF-36 scores. We evaluated 65 patients with 79 operated hips at an average follow up of 5.26years. 31.6% (25/79) stems were neutrally aligned, 64.6% (51/79) were in varus alignment and 3.8% (3/79) were in valgus alignment. The mean subsidence was 3.15mm + 2.26 and 3 cases had Pedestal formation at the stem tip. There was no correlation between varus/valgus stem positions with the mHHS (p = 0.271) and SF-36 score (p = 0.553), which also did not correlate with the stem subsidence. HO formation was seen in 16 hips (20.3%), but no cases in our series needed revision during follow up. Significant distal malalignment with some subsidence were noted in the hips studied; despite these radiological issues, there were excellent mid-term outcomes and good stems survival, implying that distal malposition may have no bearing on functional outcomes.

High Prevalence of Varus Knee Malalignment in Adolescent Football Players-Clinical Lower Leg Axis Measurements of Male Junior Football Players Aged 7 to 18 Years.

Football, as the most popular sport worldwide, has long been under suspicion of causing varus knee alignment as early as adolescence. However, no causal relationship has yet been found. The first step to do so would be to determine the prevalence of lower leg malalignment among male junior football players depending on age, performance level and the number of active seasons played. Leg axis alignment in frontal plane was determined in male junior football players of different age levels between 7 and 18 years by measuring the intercondylar/intermalleolar distance (ICD/IMD) in an upright position. In addition to anthropometric data, multiple sport-specific data such as the start of their football career or training time per week were collected by means of questionnaires (clinical trial registration number: DRKS00020446). 207 male junior football players were included in this survey. The mean age was 12.8 years. Within the group of 15 to 18 year olds, the prevalence of varus knee malalignment was highest at just under a third (32.1%). In the subpopulation that played actively for more than ten seasons, 28.9% showed varus leg axis. Regarding performance level, the highest IMD/ICD values and highest prevalence of varus alignment were found among football players who play on a semi-professional level (16.7%), compared to amateur (11.4%) and high-performance levels (2.8%). Further research is necessary to investigate if this high prevalence of varus knee in children of a higher age and higher playing levels is due to the selection bias of football players with varus knee or a real development of varus knee in individuals.

Investigation of Novel Radiological Parameters to Predict Treatment Failure and Ideal Surgical Interventions in Young Femoral Neck Fractures Treated with Triple Cannulated Screw: A Retrospective Analysis.

Treatment failure remains a challenge in young femoral neck fractures treated with triple cannulated screws (TCS). This study aims to identify novel radiological parameters that can predict treatment failure and propose surgical techniques to enhance the success of TCS or aid in selecting alternative methods. We conducted a retrospective analysis of 87 patients who underwent surgery for femoral neck fractures between February 2014 and June 2022, meeting the inclusion criteria. Patients achieving union were categorized as Non-Fail (Group 1), while those experiencing nonunion were categorized as Fail (Group 2). Various demographic and clinical factors were assessed, including age, gender, fracture side, and fracture classification (Garden and Pauwels). Radiological parameters such as fragmentation in the medial cortex, postoperative fracture displacement in the calcar region, collo-diaphyseal angle (CDA) difference (varus/valgus alignment), and several newly defined parameters (modified tip apex distance (m-TAD), tip cortex distance (TCD), upper-lower screw-cortex distance/neck diameter, the calcar screw-cortex distance/neck diameter (Buyukdogan index), and sub-capital area/basocervical area (Dogan index) were evaluated. Patients developing nonunion were studied to establish potential cut-off values based on radiological parameters. Of the patients, 61 were classified as Non-Fail (Group 1) and 26 as Fail (Group 2). Both groups exhibited similar distributions in terms of gender, fracture side, Pauwels classification, and follow-up times (p > 0.05). However, Group 2 had a higher mean age than Group 1 (p = 0.006). There was a significant difference between the two groups in terms of Garden classification (p = 0.0003). Furthermore, postoperative calcar displacement, varus alignment, m-TAD, TCD, upper-lower screw-cortex distance/neck diameter ratio, Buyukdogan index, and Dogan index showed significant differences between the groups (p < 0.05). Conversely, medial calcar fragmentation did not differ significantly between the groups (p > 0.05). The Dogan index (≤ 0.5) can serve as an independent preoperative predictor of treatment failure, aiding in the selection of more effective surgical interventions than TCS. Varus alignment (> 10 degrees), the upper-lower screw-cortex distance to the neck diameter (> 0.45) and Buyukdogan index (> 0.2) are influenced by the surgical technique of TCS application and should be considered to decrease the success of TCS.

The INVISION Talar Component in Revision Total Ankle Arthroplasty: Analysis of Early Outcomes.

Launched in 2018 for revision total ankle arthroplasty (rTAA), the INVISION talar component addresses subsidence when poor talar bone stock is present. Due to the recency of the market-availability of the INVISION, studies evaluating its efficacy are lacking. This study presents the first analysis of early-term outcomes of patients undergoing rTAA with the INVISION talar component. This was a single-center, retrospective review of 28 patients undergoing rTAA with the INVISION talar component and INBONE II tibial component performed between 2018 and 2022. Data on preoperative characteristics, postoperative complications, secondary procedures, and survivorship were collected. The primary outcome measures were rates of major complications, re-operation, and implant failure. Secondary outcomes included post-operative changes in varus and valgus alignment of the tibia and talus. The most common secondary procedures performed with rTAA were medial malleolus fixation (n = 22, 78.6%) and gastrocnemius recession (n = 14, 50%). Overall, 10.7% (n = 3) of patients underwent reoperation and 14.3% (n = 4) suffered major complications. Incidence of implant failure was 10.7% (n = 3). All reoperations were caused by infection. Mean varus alignment of the tibia and talus improved from 4.07 degrees and 4.83 degrees to 1.67 degrees and 1.23 degrees, respectively. Mean valgus alignment of the tibia and talus improved from 3.67 degrees and 4.22 degrees to 2.00 degrees and 2.32 degrees, respectively. In a series of 28 patients undergoing rTAA with the INVISION talar component, we discovered comparatively low rates of reoperation, major complication, and implant failure (10.7%, 14.3%, and 10.7%). The INVISION system appears to have a reasonable safety profile, but further studies evaluating long-term outcomes are required to assess the efficacy of the INVISION system.

Radiological Assessment of Coronal Plane Alignment of the Knee Phenotypes in the Romanian Population.

Background: The Coronal Plane Alignment of the Knee (CPAK) classification system has been developed as a comprehensive framework delineating nine coronal plane phenotypes, based on arithmetic hip-knee angle (aHKA) and joint line obliquity (JLO). Our study aimed to assess the prevalence of knee phenotypes in the Romanian population using the CPAK classification, encompassing both osteoarthritic and healthy cohorts. Methods: We conducted an observational cross-sectional study, analyzing data from 500 knees with osteoarthritis and 500 healthy knees that met the inclusion criteria. Demographic data were collected, and radiological parameters including lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), aHKA, and JLO were measured. Knee phenotypes were categorized using the CPAK classification. Results: In the osteoarthritic cohort, the most prevalent CPAK phenotype was type I (42.4%), characterized by varus alignment and an apex distal joint. Conversely, in the healthy population, CPAK type II, indicating neutral alignment and an apex distal joint, was the most prevalent phenotype (39.0%). CPAK types VII, VIII, and IX were rare. Conclusions: Our findings demonstrate similarities in knee phenotypes compared to other populations, with some minor differences and particularities. The CPAK classification proves to be a valuable tool in assessing knee tyalignment.

Paper 52: Association of Mechanical Axis with Osteochondritis Dissecans of the Femoral Condyle

Objectives: Osteochondritis dissecans (OCD) is a condition characterized by abnormal subchondral bone with disturbance of overlying articular cartilage. Pathophysiology for the etiology and underlying mechanism of OCD lesion development is not fully understood. The purpose of this study was to determine the association of lower extremity weightbearing axis with femoral condyle OCD lesion location, and if this association was affected by certain patient and OCD lesion characteristics such as lesion stability, skeletal maturity, and the presence of the OCD lesion on the medial versus lateral femoral condyle. Methods: This was a retrospective case series at a single, large academic institution. The primary outcome was the association of femoral condyle OCD lesion location with lower extremity weightbearing axis as categorized by Cahill and Berg zones of the knee. Secondary outcomes included sub-group analyses (treatment, skeletal maturity, and lesion stability) and contribution of femoral and tibial mechanical axis to lower extremity weightbearing axis deviations (mechanical lateral distal femoral angle [mLDFA] and medial proximal tibial angle [MPTA]). For unilateral OCD lesions, mechanical axis was compared between affected and unaffected lower extremities. Results: Eighty-six patients and 95 knees with an OCD lesion of the femoral condyle were identified, with 9 patients (11%) having bilateral OCD lesions. There were 74% male patients with average age of 21 years old. 65% of knees had closed distal femoral physes, 82% of OCD lesions were unstable on MRI imaging, and 85% underwent a surgical procedure. Seventy-five percent of OCD lesions were located in Cahill and Berg zone 2 at the lateral aspect of the medial femoral condyle. Lower extremity mechanical axis was located in the same zone as the OCD lesion in 48% of cases and within the same knee compartment in 56% of cases. Over 90% of OCD lesions were within ±1 zone of the weightbearing axis. There were no significant differences in the association of mechanical axis and OCD lesion location in subgroup analysis of medial versus lateral femoral condyle OCD lesions, skeletal maturity, stability of the lesion, or treatment group. For patients with varus alignment and medial femoral condyle OCD lesions, the mean mLDFA was 89.9° and MPTA was 85.4°, whereas for valgus alignment and lateral femoral condyle lesions, the mLDFA was 84.8° and MPTA was 88.8°. Both the mLDFA and MPTA were significantly different when comparing medial to lateral femoral condyle OCD lesions (p &lt;0.001 and &lt;0.001, respectively). Patients with unilateral medial femoral condyle OCD lesions were more likely to have varus alignment of the affected extremity compared to the contralateral extremity (59% vs. 36%, p = 0.01). Conclusions: This study demonstrated a relationship between lower extremity mechanical weightbearing axis and femoral condyle OCD location. Patients with unilateral medial femoral condyle OCD lesions are more likely to have varus alignment in the affected extremity. Varus alignment associated with medial femoral condyle lesions had similar varus contributions from both femoral and tibial alignment whereas valgus alignment in the setting of lateral femoral condyle lesions appear to have predominantly femoral contributions. There were no significant differences in association with mechanical axis among medial versus lateral femoral condyle lesions, OCD lesion stability, or distal femoral physeal status. More work is required to better understand the relationship between mechanical axis and femoral condyle OCD lesion pathophysiology with the long-term goal of identifying patients at risk for progression of lesion instability and developing potential interventions to preserve articular cartilage.

Association of Mechanical Axis With Osteochondritis Dissecans of the Femoral Condyle.

Osteochondritis dissecans (OCD) is a condition characterized by abnormal subchondral bone with disturbance of overlying articular cartilage. The role of weightbearing alignment in the pathophysiology of OCD lesion development is not fully understood. Lower extremity mechanical axis would be concordant with femoral condylar OCD lesion location. Cross-sectional study; Level of evidence, 3. Cases were identified from a single, large academic institutional database using International Classification of Diseases, Ninth Revision and Tenth Revision and Current Procedural Terminology codes associated with OCD. Patients were included if they had a magnetic resonance imaging scan demonstrating the OCD lesion and lower extremity alignment radiographs. OCD lesion location was identified using Cahill and Berg zones. The primary outcome was the association of OCD lesion location with weightbearing mechanical axis. Secondary outcomes included the association of mechanical axis with skeletal maturity, OCD lesion stability, and treatment. For unilateral OCD lesions, mechanical axis was compared between affected and unaffected lower extremities. A total of 86 patients (95 knees) with an OCD lesion of the femoral condyle were identified. The population was 74% male, and the mean age was 21 years. In total, 65% of knees had closed physes, 82% of lesions were unstable, and 85% underwent a surgical procedure. Mechanical axis was located in the same zone as the OCD lesion in 48% of cases and within the same compartment in 56% of cases. Spearman correlation coefficient demonstrated a moderate positive correlation (rs = 0.59). No significant differences were found in the association of mechanical axis and OCD lesion location in subgroup analysis of medial versus lateral femoral condylar OCD lesions, skeletal maturity, stability of the lesion, or treatment group. For patients with varus alignment and medial femoral condylar OCD lesions, the mean lateral distal femoral angle was 89.9°, and medial proximal tibial angle was 85.4°; for valgus alignment and lateral femoral condylar lesions, the lateral distal femoral angle was 84.8°, and medial proximal tibial angle was 88.8°. Patients with unilateral medial femoral condylar OCD lesions were more likely to have varus alignment of the affected extremity compared with the contralateral extremity (59% vs 36%; P = .01). This study demonstrated a relationship between lower extremity mechanical weightbearing axis and femoral condylar OCD location. Patients with unilateral medial femoral condylar OCD lesions frequently had asymmetric varus alignment in the affected extremity.

Large angular correction of arithmetic coronal alignment is associated with residual lateral laxity after total knee arthroplasty in varus knees for Japanese patients.

One of the most common types of coronal plane alignment of the knee (CPAK) is type I, which is characterised by varus alignment and apex distal joint line obliquity. The purpose of this study was to evaluate the association of changes in arithmetic hip-knee-ankle angle (aHKA) with both postoperative joint laxity and patient-reported outcome measures (PROMs) in patients with CPAK type I following mechanical alignment (MA) total knee arthroplasty (TKA). Of 111 consecutive knees in 92 patients with osteoarthritis who underwent primary TKA, 80 knees (72.0%) with CPAK type I phenotype preoperatively were evaluated. All TKAs were performed to achieve neutral MA by a medial stabilising gap balancing technique. Pre- to postoperative change in aHKA was defined as ΔaHKA. The 80 CPAK type I knees were divided into a larger ΔaHKA group (>7°) and a smaller ΔaHKA group (≤7°). PROMs, including the Knee Society Score and Forgotten Joint Score-12, were assessed before and 2 years after surgery. Pre- and postoperative joint laxity was assessed using a Telos arthrometer. Twenty-two knees showed a larger ΔaHKA, and postoperative lateral joint laxity in varus stress was significantly greater in these patients than in those with a smaller ΔaHKA (6.8° vs. 4.5°, p = 0.006). There were no significant differences between the groups in PROMs (p = n.s.). Postoperative lateral laxity was associated with larger aHKA changes than smaller aHKA changes in CPAK type I knees after TKA. However, no statistically significant differences in PROMs were found according to the amount of change in aHKA. Level III.

Comparison between Total Hip Arthroplasty for Avascular Osteonecrosis of Femoral Head and That for Fixation Failure of Femoral Neck Fracture

Objective: To compare the clinical and radiologic results between primary total hip replacement arthroplasty (THRA) in patients with avascular necrosis of femoral head (AVN) and secondary THRA in patients with fixation failure of femoral neck fracture.Methods: From March 2014 to February 2021, we retrospectively evaluated a total of 53 patients who underwent either THRA for AVN (33 cases) or THRA for fixation failure of femoral neck fracture (20 cases). Clinical performances and Hemodynamic scales were evaluated. Radiologic analyses were conducted to assess stem alignment, stem stability, the appearance of heterotrophic ossification, stress shielding, and any signs of osteolysis or loosening.Results: THRA for AVN showed a mean blood loss of 881 mL and a 2.1 g/dL preoperative–postoperative (preop–postop) hemoglobin (Hb) difference. Meanwhile, THRA for fixation failure of femoral neck fracture showed a mean blood loss of 1,072 mL and a 3.2 g/dL preop–postop Hb difference (P= 0.017 and P= 0.034, respectively). The mean operation time was 70 minutes in THRA for AVN and 91 minutes in THRA for fixation failure of femoral neck fracture (P= 0.035). Stem alignment was varus 1.50° in AVN and varus 3.50° in fixation failure of femoral neck fracture. There was one case of a varus femoral stem in AVN and six such cases in the fixation failure of femoral neck fractures. This was a statistically significant difference (P= 0.010 and P= 0.020, respectively).Conclusion: Secondary THRA in patients with fixation failure of femoral neck fracture showed longer operation time, larger bleeding, and more varus stem alignment than primary THRA in patients with AVN.

Clinical and Radiological Outcomes of Medial Meniscal Allograft Transplantation Combined With Realignment Surgery.

The outcomes of medial meniscal allograft transplantation (MMAT) combined with high tibial osteotomy (HTO) compared with isolated MMAT remain unclear. To compare the clinical and radiological results of MMAT combined with HTO and isolated MMAT. Cohort study; Level of evidence, 3. This retrospective study included 42 consecutive patients, who were divided into group M (isolated MMAT; n = 22) and group H (MMAT combined with HTO with a varus angle >3°; n = 20). Group differences in subjective knee scores, isokinetic muscle strength test, and radiological outcomes (Kellgren-Lawrence grade, mechanical axis, graft extrusion, graft status, and articular cartilage loss) were compared. The mean follow-up period was 29.2 ± 4.9 months and 27.4 ± 5.3 months for groups M and H, respectively. The Lysholm score improved from 55.4 ± 9.5 to 81.3 ± 9.7 and from 52.6 ± 8.9 to 84.2 ± 10.2 in groups M and H, respectively (both P < .001). The International Knee Documentation Committee subjective score improved from 51.4 ± 10.3 to 79.6 ± 9.4 and from 49.3 ± 11.4 to 81.4 ± 8.3 in groups M and H, respectively (both P < .001). Both groups showed no significant differences in subjective knee scores and isokinetic extensor strength at the final follow-up. The rate of preoperative and postoperative high International Cartilage Regeneration & Joint Preservation Society grade (≥3) did not differ between the 2 groups. Group M showed greater coronal graft extrusion than did group H (3.3 ± 0.7 mm vs 2.7 ± 0.8 mm; P = .014); the rate of pathologic graft extrusion (≥3 mm) was not higher in group M (40.9%) than in group H (20%) with the number of patients available (P = .143). Both groups showed no significant difference in the graft status. Graft tears were observed in 2 patients (9%) in group M and 1 patient (5%) in group H (P = .607). Clinical scores significantly improved after isolated MMAT and MMAT combined with HTO compared with preoperative values, and their short-term outcomes were similar. Postoperative graft extrusion was greater in patients who underwent isolated MMAT, implying that active correction of varus alignment during MMAT may help in intra-articular biomechanics.