Morphologic difference and size mismatch in the medial and lateral tibial condyles exist with respect to gender for unicompartmental knee arthroplasty in the Korean population.

PURPOSE: The purpose of this study was to characterize the geometry of the proximal tibia in both genders in the Korean population. Anthropometric data on the medial and lateral tibial condyles of the osteoarthritic knees of 149 males and 814 females were obtained using three-dimensional magnetic resonance imaging. METHODS: In the medial and lateral proximal tibial condyles, the anteroposterior (AP) dimension, widest dimension (WD) at defined points, and condylar aspect ratio were evaluated. These measurements were compared with similar dimensions of the tibial components from five commonly used unicompartmental knee arthroplasty (UKA) designs in Korea. RESULTS: Both the AP dimension and WD in the medial and lateral tibial condyles of the male patients were significantly greater than those of the female patients (P < 0.05). In addition, the AP dimension and WD were greater in the medial than in the lateral tibial condyle (P < 0.05). There was WD overhang in three and two prostheses in the medial and lateral tibial condyles, respectively. A decrease in the condylar aspect ratio with an increasing AP dimension was found in the medial and lateral tibial condyles for both the male and female patients. CONCLUSIONS: Smaller medial and lateral tibial condylar dimensions are more frequent in Korean women than in Korean men. This study highlights the finding that conventional UKA designs lead to size mismatch in the Korean population and may indicate an important guideline on proper gender-specific UKA tibial prostheses with different WD/AP dimension aspect ratios. In addition, this study suggests that the shape of the medial tibial plateau is different to that of the lateral plateau, which can lead to a mediolateral overhang for medial UKA in an attempt to optimize the AP coverage. LEVEL OF EVIDENCE: III.

Femoral trochlear morphology is associated with anterior cruciate ligament injury in skeletally immature patients.

PURPOSE: Knee joint morphology is a known contributor to anterior cruciate ligament (ACL) injury, and the shape of the distal femur condyle is one of the associated factors. However, the relationship between femoral trochlear morphology and ACL injury is unclear, especially in pediatric patients. Therefore, the present study aimed to evaluate the effect of femoral trochlear morphology on ACL injury in pediatric patients and investigate the possibility of gender differences. METHODS: In total, 116 skeletally immature children aged 3-18 years with primary ACL injuries were matched with a control group of 116 skeletally immature children. Lateral trochlear inclination, trochlear facet asymmetry, trochlear depth, and sulcus angle were evaluated using magnetic resonance imaging (MRI). Differences between patient groups and gender were investigated. Receiver-operating characteristic (ROC) curves were constructed to obtain the sensitivity and specificity of all parameters. RESULTS: A significant difference was observed in the sulcus angle and trochlear inclination between the ACL injury and control groups (p < 0.05). No significant difference was observed between the ACL injury and control groups with respect to the anatomic patellar instability risk factors. All parameters showed an area under the curve of 0.6 in the ROC analysis, indicative of failure of the diagnostic test. CONCLUSIONS: There was a significant association between femoral trochlear morphology and increased risk of ACL injury in pediatric patients. No gender difference was found except in the trochlear depth. It was showed that the difference in trochlear morphology should be considered between normal children and pediatric patients with ACL injury to increase the awareness regarding ACL injuries. LEVEL OF EVIDENCE: III.

Gender differences exist in rotational anatomy of the distal femur in osteoarthritic knees using MRI.

PURPOSE: Optimal rotational alignment of the femoral component is essential for total knee arthroplasty (TKA). The femoral transepicondylar axis (TEA), Whiteside's line (WSL), and posterior condylar axis (PCA) are various intra-operative references that can be used to determine femoral rotation, and each has advantages and disadvantages. This study aimed to define the rotational anatomy of the distal femur and investigate its relationship with gender in osteoarthritic knees. METHODS: Magnetic resonance imaging (MRI) was obtained from 1522 patients (1298 females and 224 males) with end-stage knee osteoarthritis prior to TKA. MRI was constructed into three-dimensional models. The angles between the TEA and WSL, WSL and PCA, and TEA and PCA were calculated for each patient. In addition, gender differences in femoral rotation were evaluated. RESULTS: The PCA was 2.2° ± 1.0° internally rotated relative to the TEA. WSL was 1.2° ± 2.8° externally rotated relative to the TEA. The WSL to TEA relationship exhibited greater variability than the PCA to TEA relationship. PCA was more internally rotated and WSL was more externally rotated relative to TEA in female group than male group. Based on the standard reference rules of 3° external rotation from the PCA that has been conventionally used, 15.7% of patients showed external rotation lower 1° or greater than 5° external rotation from the PCA. In the mean external rotation of the TEA from the PCA (2.2°) from this population; however, the percentage of patients showing ± 2° from their TEA dropped to 5.1% of patients. CONCLUSION: Gender difference and variability exist in distal femoral rotational anatomy. These data can be useful in consideration of femoral anatomy variability and gender difference. The same cutting angle may lead to malrotation of the femoral component. LEVEL OF EVIDENCE: Consecutive patients, level III.

Gender difference exists in sagittal curvature of the distal femoral condyle morphology for osteoarthritic population.

PURPOSE: The aim of this study was to investigate gender-related differences in the sagittal curvature of the distal femoral condyle in the Korean osteoarthritic population METHODS: The sagittal curvatures of the distal femoral condyle of 1979 Korean patients (1680 female and 299 male) were evaluated using magnetic resonance imaging (MRI). MRI scans were obtained before total knee arthroplasty (TKA) in consecutive patients with end-stage osteoarthritis. The sagittal curvature of the distal medial and lateral femoral condyles was characterized with respect to the anterior, distal, and posterior circles. The diameter of each circle was measured. This study included 1873 varus and 106 valgus knees. RESULTS: The anterior, distal, and posterior diameters were significantly greater in the male patients than in the female patients (P < 0.05). In the male patients, the lateral diameter was significantly greater than the medial diameter in the anterior and posterior circles (P < 0.05). However, in the female patients, the lateral diameter was significantly greater only in the anterior circle. In both genders, the medial diameter was significantly greater than the lateral diameter of the distal circle (P < 0.05). For both the varus and valgus knees, the lateral diameter was greater than the medial diameter in the anterior circle. CONCLUSIONS: It has been concluded that the sagittal curvature of the femoral condyles in females is significantly different to their male counterparts. This study provides a reliable evaluation of the sagittal curvature of the femoral condyle in the Korean population. These gender-related differences in the sagittal curvature of the femoral condyle may require further investigation to determine surgical implications such as in TKA, and the existence of gender-related dimorphism in specific knee injuries and pathologies, such as ligament injuries and tibiofemoral problems. LEVEL OF EVIDENCE: III.

Difference in coronal curvature of the medial and lateral femoral condyle morphology by gender in implant design for total knee arthroplasty.

PURPOSE: The purpose of this study was to investigate the morphometric data obtained from the three-dimensional magnetic resonance images of ethnic Korean knee osteoarthritis, and to evaluate the morphological differences between the coronal curvature of the female and male femoral condyles. METHODS: The differences in coronal curvature of the femoral condyle morphology of 1990 patients (1689 females and 301 males) were evaluated in three dimensions. A close-fit diameter was, respectively, generated on the medial and lateral femoral condyle articular surfaces, and these diameters reflect the coronal diameter of the femoral condyle curvature. These measurements were compared with those of the femoral design of five different commonly used total knee arthroplasty (TKA) implant designs. RESULTS: The average diameter of the curvature of the medial condyles was significantly larger than that of the lateral condyles (P < 0.05). This trend was found in the male and female groups. In addition, the average diameter of the curvature of the femoral condyles was found to significantly differ between males and females (P < 0.05). For four TKA implant designs, the average diameter of the coronal curvature of femoral condyle was smaller than that obtained via our measurements, whereas one TKA implant design yielded a smaller average diameter. Furthermore, the medial and lateral coronal curvatures of the femoral condyle were symmetric in all TKA implant designs. CONCLUSION: The study provided a reliable and consistent evaluation of the coronal curvature of femoral condyles in the Korean population. These results showed that a gender-specific or asymmetric femoral component design is required to regenerate the coronal curvature of the femoral condyles for ethnically Korean males and females.

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.

Morphometric study of gender difference in osteoarthritis posterior tibial slope using three-dimensional magnetic resonance imaging.

Posterior tibial slope (PTS) is an important parameter of sagittal alignment associated with postoperative stability and kinematics after total knee arthroplasty (TKA). However, data are limited regarding the innate gender differences in PTS in Koreans. The current study separately measured the PTS of the medial and lateral tibial plateau on magnetic resonance images of 511 patients with knee joint osteoarthritis who had Kellgren and Lawrence grade 3 and 4 (430 women, 81 men) and compared the measurements between and within the genders. The tibia was then rotated to the tibial plateau with the tibial centroid axis and the PTS was evaluated from best-fit planes on the surface of the proximal tibia and individually for the medial, lateral, and overall plateaus. The average overall PTS was 10.0° ± 3.5°. The average overall PTS of the female and male patients was 10.2° ± 3.4° and 8.8° ± 4.0°, respectively. The average medial PTS was 10.4° ± 4.0°, significantly greater than the mean lateral PTS of 8.7° ± 3.9° (P < 0.05). The average medial and lateral tibial slopes for female patients were 10.7° ± 3.8° and 8.8° ± 3.8°, respectively, while the average medial and lateral tibial slopes for male patients were 8.9° ± 4.8° and 7.9° ± 4.7°, respectively. The medial and overall PTS were significantly greater in female patients than in male patients (P < 0.05). The results showed a gender difference in PTS and that medial PTS was greater than lateral PTS. These findings have clinical relevance in knee reconstructive surgery for determining ideal placement of the posterior slope tibial component. Surgeons should be aware of variability and gender differences in the tibial slope of patients undergoing TKA.

Gender-related morphological differences in sulcus angle and condylar height for the femoral trochlea using magnetic resonance imaging.

PURPOSE: This study aimed to elucidate the primary differences in trochlear morphology between men and women utilizing three-dimensional magnetic resonance image reconstruction of the femoral trochlea. METHODS: Differences in anthropometric femoral trochlea data of 975 patients (825 women, 150 men) were evaluated. The following morphological parameters were measured at three flexion angles (15°, 30°, and 45°) of the femoral trochlea: the sulcus angle, condylar height, and the trochlear groove orientation and mediolateral groove position. RESULTS: The sulcus angle was significantly greater in women than in men at 15° and 45° flexions (P < 0.05). However, there was no gender difference found in the sulcus angle at 30° flexion. Medial and lateral condylar height values were greater in men than in women for the three flexion angles (P < 0.01). The trochlear groove orientation and mediolateral groove position showed no gender-related differences. CONCLUSIONS: Magnetic resonance image reconstruction demonstrated that measurement of trochlear morphology varied significantly between men and women. This study provides guidelines for the design of a suitable femoral component for total knee arthroplasty, considering gender-specific differences in the Korean population. Biomechanical guidelines for total knee arthroplasty in Korean individuals can be optimized using our finding, so as the risk of patellar dislocation to be decreased. Surgeons should be aware of gender differences in femoral trochlear to optimize choice of implant. LEVEL OF EVIDENCE: III.

Gender differences in morphology exist in posterior condylar offsets of the knee in Korean population.

PURPOSE: This study aimed to analyze the morphometric data from magnetic resonance images of arthritic knees in Korean adults, and to identify the existence of morphological differences of femoral posterior condylar offset (PCO) between genders. METHODS: The differences in anthropometric PCO data in 975 patients (825 female and 150 male) were evaluated. The distances from the anterior and posterior femoral shaft cortex line to the most posterior femoral condyle tangent line were defined as the anterior-posterior dimension (AP) and the PCO. The PCO ratio (PCOR) was calculated as PCO/AP. RESULTS: The medial PCO was greater than the lateral PCO (26.3 ± 2.2 vs. 24.3 ± 2.3 mm, p < 0.01). This difference was observed in both female patients (medial: 26.2 ± 2.2 mm vs. lateral: 24.2 ± 2.2 mm, p < 0.01) and male patients (medial: 26.8 ± 2.3 mm vs. lateral: 24.8 ± 2.4 mm, p < 0.01). The medial and lateral PCO values were also greater in male patients than in female ones (p < 0.01). In contrast, PCOR was greater in female patients than in male ones, both in the medial and lateral femoral condyles (p < 0.01). CONCLUSIONS: It was shown that medial and lateral PCO and PCOR were asymmetric, and that there was gender difference in Korean population in our study. In addition, our data showed that the PCOR of contemporary TKAs may be small for Asian patients that may not be sufficient to meet the needs of the Korean patient population. These results confirm that a gender-specific femoral component design is necessary to recreate the PCO for male and female Asian populations. LEVEL OF EVIDENCE: Non-consecutive patients, Level III.

Outcomes After Limited or Extensive Bursectomy During Rotator Cuff Repair: Randomized Controlled Trial.

PURPOSE: To evaluate the effects of extensive bursectomy (EB) and limited bursectomy (LB) during arthroscopic rotator cuff repair. METHODS: In the EB group (n = 39), subacromial bursae were thoroughly removed from anterior to posterior and lateral to medial. In the LB group (n = 39), bursectomy was minimized to allow torn cuff visualization and tendon repair. Visual analog scale pain scores, passive forward flexion, external rotation at the side (ER), and internal rotation at the back were measured at 5 weeks and 3, 6, and 12 months after surgery. At each time point, bursal thickness was measured and repair integrity was assessed by sonography or magnetic resonance imaging. RESULTS: The analysis included 36 patients in the LB group and 35 in the EB group. Group visual analog scale pain scores were not significantly different at any time (P > .05 for all). Forward flexion and internal rotation at the back showed no intergroup difference during follow-up. However, ER was significantly better in the LB group at 6 months and 1 year postoperatively (31° ± 15° vs 22° ± 16° [P = .020] and 40° ± 19° vs 27° ± 20° [P = .009], respectively). Integrity failures were not significantly different at 5 weeks and at 3, 6, and 12 months (P > .05 for all). Marked bursal thickening (>2 mm) was more frequently observed in the EB group (18 of 32 in the LB group and 27 of 32 in the EB group) at 6 months (P = .014). CONCLUSIONS: EB during arthroscopic rotator cuff repair appears to have no benefit in terms of reducing pain. More adhesions in the subacromial space after EB may result in slower motion recovery, especially in terms of ER. The extent of bursectomy did not affect tendon integrity. However, marked bursal thickening was more frequently observed in the EB group. LEVEL OF EVIDENCE: Level I, randomized controlled study.

Reliability and modality analysis of patellar height measurement in pediatric knee.

Introduction: Various measurement methods and imaging technique are in use to measure patellar height in pediatric patients. However, there is no gold standard as to which measurement method and modality are the most reliable for pediatric patients. Therefore, the aim of this study was to determine the inter-observer reliability, intra-observer reliability, and applicability of various patellar height measurement methods in pediatric knee. Additionaly, we analyzed the reliability across different imaging modalities. Methods: Total 450 pediatric patients (age: 5-18 years) were evaluated using lateral knee radiographs and magnetic resonance imaging (MRI). The patellar height ratios were measured using five methods. Five methods were Insall-Salvati (IS), Koshino-Sugimoto (KS), Blackburne-Peel (BP), modified Insall-Salvati (MIS), and Caton-Deschamps (CD). The patients were categorized into two age groups: P (ages 5-13) and Q (ages 14-18). Each measurement was conducted twice by two raters. The intra-observer reliability, inter-observer reliability and inter-modality reliability were calculated. In addition, applicability was defined as the possibility to apply each measurement method to each age group. Results: The KS method showed the highest inter-observer reliability and intra-observer reliability when using MRI for both age groups. The inter-observer reliability and intra-observer reliability of the IS for lateral knee radiographs was highest among all observers for group Q. The CD method showed the highest inter-observer reliability in group P, while the KS showed the highest intra-observer reliability in group P using lateral radiographs. The KS method showed the highest inter-modality reliability in group P, while the IS showed the highest inter-modality reliability in group Q. The KS method was applicable to all patients when using lateral knee radiography, and the IS method was applicable to all patients when using MRI. Conclusions: Our results show that the reliability of various measurement method and imaging technique differed based on pediatric knee age group when measuring patellar height. Therefore, in the case of pediatric patients, reliability measurement methods and imaging techniques according to the patient's age should be applied.

Spontaneous Deltoid Tear in Cuff Tear Arthropathy and Its Effect on the Outcome of Reverse Total Shoulder Arthroplasty: A Comparison Using Propensity Score Matching.

Background: Deltoid function critically influences the results of reverse total shoulder arthroplasty (RTSA), and spontaneous deltoid attrition tears are frequently detected in cuff tear arthropathy (CTA) patients; however, the clinical impacts of these tears on RTSA outcomes are undetermined. Our aim was to determine the effect of spontaneous deltoid attrition tears on postoperative outcomes after RTSA without an additional deltoid procedure. Methods: Seventy-two patients who underwent RTSA for CTA with preoperative magnetic resonance imaging (MRI) and a minimum clinical follow-up of 1 year (mean, 32 months) were retrospectively reviewed in the study. Patients with a history of previous shoulder surgery or injury were excluded. The presence and location of deltoid attrition tears were determined in preoperative MRI. Propensity score matching (1:1) was performed to construct tear and no-tear groups. Finally, 21 patients, matched with respect to age, sex, hand dominance, symptom duration, medical comorbidity (obesity, diabetes mellitus, and coronary artery disease), Hamada grade, and implant type, were assigned to each group. Clinical outcomes (functional scores, isometric power, and range of motion) in the two groups were compared. Results: Deltoid attrition tears were detected in 21 of the 72 enrolled cases (29.1%). Anterolateral deltoid was the most frequent location and no tear was detected in the posterior deltoid. The tear rate increased with disease severity (Hamada G2, 4.8%; G3, 23.8%; > G4, 71.4%). No pre- or postoperative clinical variables differed significantly between the tear and no tear groups. Conclusions: Deltoid attrition tears were detected in 29% of CTA patients who underwent RTSA. The most common site was the anterolateral region and tear prevalence tended to increase with CTA progression. However, RTSA was found to provide satisfactory outcomes regardless of the presence of a deltoid attrition tear.

Evaluation of age group and sex differences in the measurement of patellar height of pediatric knee in a Korean population.

Introduction: Various methods based on bony landmarks are used to determine patellar height. This study analyzed five methods for patellar height measurement on lateral knee radiographs, namely, the Insall-Salvati, Koshino-Sugimoto, Blackburne-Peel, modified Insall-Salvati, and Caton-Deschamps methods. Methods: Overall, 425 pediatric participants (221 males, 204 females; age range 5-18 years) were included and were divided equally into three age groups (A, 5-10 years; B, 11-13 years; and C, 13-18 years). For the comparison of the applicability of each method, the applicable probabilities for each age group and sex-based differences were analyzed using logistic regression techniques. Intra-rater reliability and inter-rater variability were analyzed by two trained raters. Results: The Koshino-Sugimoto method was applicable to all patients. The 80% applicable age of female patients was lower than that of male patients for the Blackburne-Peel (male = 11.9, female = 11) and Caton-Deschamps (male = 11.9, female = 11.1) methods. However, in the Insall-Salvati (male = 12, female = 12.1) and modified Insall-Salvati (male = 12.6, female = 13.1) methods, the 80% applicable age in male patients was lower than that in female patients. The Koshino-Sugimoto method showed the highest variability in group B, while the Insall-Salvati showed the highest variability in group C. In terms of intra-observer reliability, the Caton-Deschamps method showed the same reliability as the Insall-Salvati method, in group C. Conclusions: Our results demonstrated differences in the reliability, variability, and applicability of patellar height measurement methods according to age group. The applicability of patellar height measurement methods also differed according to sex. Therefore, based on age group and sex, different methods should be used for patellar height measurement in pediatric patients.

Existence of Gender-Based Difference in Morphology of Convex Lateral Tibial Plateau in Korean Population Primary Knee Joint Osteoarthritis.

PURPOSE: Morphological differences in the knee joints of females and males have been reported in a previous study. These differences have realized the need of developing a gender-specific prosthesis. However, anatomical studies on gender-based differences in the proximal tibial plateau's sagittal curvature have rarely been conducted. Therefore, this study is aimed at evaluating the geometry of the sagittal curvature of the proximal tibial plateau in the Korean population. METHODS: Three-dimensional data for the sagittal curvature of the tibial plateau morphology from 1976 patients (i.e., 299 male and 1677 female) were assessed using magnetic resonance imaging. The sagittal profiles of the tibial plateaus were also evaluated. The independent t-test and paired t-test were used for statistical analysis. RESULTS: The proximal tibia had concave and convex surfaces in the medial and lateral plateaus, respectively, for both genders. In addition, the medial diameter of the tibial plateau was significantly greater than the lateral diameter for both genders. Gender-based difference was not found in the medial diameter of the tibial plateau but was observed in the lateral diameter. CONCLUSION: These results may provide guidelines for a suitable knee implant design for the Korean patients. The incorporation of this shape information in the medial and lateral sides in the prosthetics for a total knee arthroplasty and a lateral unicompartmental knee arthroplasty can improve knee range motion.

Correlation of Femoral Trochlear Dysplasia With Anterior Cruciate Ligament Injury in Skeletally Immature Patients.

BACKGROUND: Reports of anterior cruciate ligament (ACL) injury in patients with skeletal immaturity have been increasing. Variations in knee joint anatomy have been linked to ACL injury risk factors. PURPOSE: To identify associations between ACL injury, patella alta, and femoral trochlear dysplasia in patients with skeletal immaturity by using magnetic resonance imaging (MRI). STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: This retrospective study included 231 patients with skeletal immaturity-116 with acute complete noncontact ACL injury and 115 without ACL injury (controls)-who underwent knee MRI. Cases of femoral trochlear dysplasia were divided into 4 types according to the Dejour classification scheme. Patellar height and patellar tendon length were measured via sagittal MRI, and the Insall-Salvati ratio (ISR) was calculated. RESULTS: In the ACL injury group, 56 (48.3%) knees exhibited trochlear dysplasia, including 51 (91.1%) that were Dejour type A; and in the control group, 12 (10.4%) knees exhibited trochlear dysplasia, 12 (100%) Dejour type A. The prevalence of femoral trochlear dysplasia was significantly higher in the ACL injury group than in the control group (P < .001). The ISR was not significantly different between the ACL injury and control groups (0.9 ± 0.2 vs 1 ± 0.2 mm; P = .16). The correlation between ISR >1.2 and presence of ACL injury was not significant. CONCLUSION: Femoral trochlear dysplasia was associated with ACL injury in patients with skeletal immaturity. In particular, Dejour type A femoral trochlear dysplasia was correlated with ACL injury patients with skeletal immaturity. Also, the possibility of ACL damage exists in patients with skeletal immaturity and femoral trochlear dysplasia.

Anatomic Differences in the Sagittal Knee Joint Are Associated With ACL Injury: Results From a Skeletally Immature Korean Population.

BACKGROUND: Differences in tibiofemoral articular morphology are associated with risks of anterior cruciate ligament (ACL) injury. PURPOSE: To determine whether bony and cartilaginous morphological characteristics are related to ACL injury in pediatric patients and to investigate any differences according to sex. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 200 skeletally immature Korean patients from a single institution were included in this study; 100 patients had an ACL injury, and 100 had an intact ACL. Condylar morphology and tibial slopes were evaluated and compared between the groups, and differences between sexes were evaluated in the ACL-injured group. RESULTS: The lateral femoral curvature was significantly greater and the lateral and medial tibial curvatures were significantly smaller in the ACL-injured group than in the intact group (P < .01 for all). In addition, the lateral and medial femoral curvatures as well as the lateral tibial curvature were significantly smaller in female than in male patients (P < .01 for all). Both the medial and lateral tibial slopes were greater in the ACL-injured versus intact group (medial slope, 5.5° vs 5.0°; lateral slope, 3.0° vs 1.3°, respectively); this difference was statistically significant for lateral tibial slope (P = .026). No sex-based differences were found for medial or lateral tibial slope. CONCLUSION: Femoral and tibial curvatures as well as lateral tibial slope were significantly different between the ACL-injured and ACL-intact patients, and the lateral tibial curvature was significantly smaller in female than in male patients. Medial and lateral tibial slopes were not associated with a significant difference in ACL injury between male and female patients.

Medio-Lateral and Flexion-Extension Gap Imbalances in Mechanically Aligned Total Knee Arthroplasty Using Measured Resection Technique in Korean Patients: 3D Simulation.

BACKGROUND: It is well known that the measured resection (MR) technique in mechanically aligned (MA) total knee arthroplasty (TKA) generates significant gap imbalances, but little is known about whether this applies to the knees of Asian patients. The aim of this study was to evaluate the medio-lateral and flexion-extension gap imbalances and to find the most optimal posterior femoral condyle resection method for operating on the knees of Asian patients. METHODS: In total, 738 magnetic resonance imaging (MRI) scans of consecutive patients who underwent TKA were obtained. Four posterior femoral condylar resection methods were used: alignment by the surgical transepicondylar axis (TEA), Whiteside's line (WSL), 3° external rotation to the posterior condylar axis (PCA), and flexion-extension axis (FEA). RESULTS: For the medial compartments, there were significant differences between the flexion and extension gaps in the varus knee group in all four methods, but there were no differences between the flexion and extension gaps in the valgus knee group. For the lateral compartment, all the methods showed significant differences except for WSL of the valgus knee group and FEA of the varus knee group. CONCLUSIONS: In Asian patients, the use of the MA MR technique inevitably leads to medio-lateral or flexion-extension imbalances. Therefore, surgeons should consider which methods can minimize imbalances and choose the best method within the technically possible range.

Gender-Based Quantitative Analysis of the Grand Piano Sign in Mechanically Aligned Total Knee Arthroplasty in Asians.

In mechanically aligned (MA) total knee arthroplasty (TKA), the grand piano sign helps surgeons to further ensure the proper external rotation of the femoral component. The goal of this study was to determine the sex-related differences in the shape of the anterior resection surface using 3D magnetic resonance imaging (MRI) models. MRI scans were performed on 267 consecutive patients (202 women and 65 men) with osteoarthritis who underwent TKA in order to reconstruct a 3D model. Virtual anterior condylar resection was performed based on the surgical transepicondylar axis (sTEA), Whiteside's line (WSL), and flexion-extension axis (FEA). On the anterior resection surface, both lateral length (LatL) and medial length (MedL) were measured, and the ratio between the two (MedL/LatL) was calculated. The mediolateral width of the distal femur (ML) and anterior resection surface (M'L') were measured, and the ratio between the M'L' and ML (M'L'/ML) was calculated. Both the lateral deviation (LD) and the ratio between LD and ML (LD/ML) were also determined. Morphological classification of the anterior resection surface was conducted based on the presence of a definite medial peak. When based on the sTEA or WSL, the MedL/LatL of female subjects was significantly greater than that of male subjects (p < 0.001 and p < 0.05, respectively). The MedL/LatL of the FEA was consistently larger than that obtained using the sTEA or WSL. Among female subjects, the MedL/LatL of the sTEA was significantly greater than that of the WSL, although this was not the case in either the total study population or the male subjects alone. When based on the sTEA, the M'L'/ML was statistically greater in the female subjects (p < 0.01). The LD was greater in the male subjects (p < 0.01), but there was no difference between the male and female subjects when comparing the LD/ML (p = 0.93). The proportion of double- and single-peak types was not significantly different between the sexes (p = 0.196). Surgeons should be aware that the shape of the anterior resection surface may differ depending on the sex of the patient. The results of this study provide more consistent surgical outcomes as well as fundamental anatomical data for designing suitable prostheses applicable to the Korean population.

Effects of a Thermosensitive Antiadhesive Agent on Single-Row Arthroscopic Rotator Cuff Repair.

BACKGROUND: Postoperative stiffness after rotator cuff repair is a common complication that can lead to poor outcomes and patient discomfort. The application of an antiadhesive agent at the time of repair recently became an option for clinicians, but little information is available on its effects. PURPOSE: To evaluate and compare retear rates, the incidence of postoperative stiffness, and the clinical outcomes of patients who underwent cuff repair with or without the application of an antiadhesive agent. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Among 296 patients who underwent arthroscopic rotator cuff repair surgery, we compared the outcomes of those injected with a thermosensitive gel antiadhesive agent into the subacromial space (112 cases) versus noninjected controls (184 cases). Retear rates in the 2 groups were determined by magnetic resonance imaging at 1 year after surgery. Shoulder joint range of motion and functional scores were evaluated serially. RESULTS: The rate of retear was significantly lower in the injection group (20/112 cases; 17.9%) than the control group (53/184 cases; 28.8%) (P = .034). Postoperative stiffness was not significantly different between the 2 groups (P = .710). Among the data regarding range of motion, only forward flexion at 6 months after surgery showed superior results in the injection group. Functional scores showed conflicting results: The control group had better visual analog scale scores for pain (injection vs control: 2.17 vs 1.68 at 6 months; 1.82 vs 1.28 at 12 months), American Shoulder and Elbow Surgeons scores (79.89 vs 89.64 at 12 months), and simple shoulder test scores (8.70 vs 10.06 at 12 months), whereas the injection group had better Constant-Murley scores (injection vs control: 59.49 vs 55.60 at 3 months; 77.35 vs 71.98 at 6 months; 87.28 vs 81.56 at 12 months). CONCLUSION: The tendon healing rate was significantly higher in the group receiving an antiadhesive agent than in the control group. No intergroup difference was seen in the occurrence of postoperative stiffness. However, the pain-related functional score showed inferior results in the injection group at 12 months. The biological action of antiadhesive agents in rotator cuff repair should be further evaluated.

Long Head of the Biceps Tendon Tenotomy versus Subpectoral Tenodesis in Rotator Cuff Repair.

BACKGROUD: Lesions of the long head of the biceps tendon (LHBT) are one of the most common pathologies in patients with a rotator cuff tear. Although various procedures have been shown to be effective for treating LHBT lesions during rotator cuff repair, no consensus has been reached regarding the most effective treatment. The purpose of this study was to compare the outcomes of tenotomy vs subpectoral tenodesis of the LHBT in arthroscopic rotator cuff repair. METHODS: The records of 135 patients who underwent arthroscopic rotator cuff repair with biceps tenotomy or subpectoral tenodesis for a partial LHBT tear of > 50% were initially reviewed. Finally, 77 patients (38 patients with tenotomy and 39 patients with subpectoral tenodesis) with an intact rotator cuff, who underwent a functional evaluation at 1 year postoperatively, were enrolled in this retrospective study. RESULTS: The average follow-up was 13.3 ± 4.36 months (13.2 ± 1.4 months in the tenotomy group and 13.6 ± 2.7 months in the subpectoral tenodesis group; p = 0.416). Demographic and surgical data were not significantly different between the 2 groups. Preoperatively, biceps groove tenderness, Speed's test, and Yergason test results were positive in 27.3%, 27.3%, and 10.4% of the study subjects, respectively. Compared with preoperative values, all functional scores including shoulder muscle power were significantly improved postoperatively, and no significant intergroup difference was observed (all p > 0.05). A visible Popeye deformity was not encountered in either group at the final follow-up. Eight patients in the tenotomy group and 7 patients in the subpectoral tenodesis group complained of mild anterior shoulder pain (p = 0.731), and 4 patients in each group complained of groove tenderness (p = 0.969). No surgical or postoperative complication occurred in either group. CONCLUSIONS: Both biceps tenotomy and subpectoral tenodesis performed during rotator cuff repair improved pain and function and resulted in comparable clinical outcomes. Residual symptoms associated with the remnant LHBT in the groove may not be a problem after adhesion of LHBT.