Application of a machine learning and optimization method to predict patellofemoral instability risk factors in children and adolescents.

PURPOSE: Conservative treatment remains the standard approach for first-time patellar dislocations. While risk factors for patellofemoral instability, a common paediatric injury, are well-established in adults, data concerning the progression of paediatric recurrent patellar dislocation remain scarce. A reproducible method was developed to quantitatively assess the patellofemoral morphology and anatomic risk factors in paediatric patients using magnetic resonance imaging (MRI) and machine learning analysis. METHODS: Data were analyzed from a retrospective review (2005-2022) of paediatric patients diagnosed with acute lateral patellar dislocation (54 patients) who underwent MRI and were compared with an age-based control group (54 patients). Patellofemoral, tibial, tibiofemoral and patellar height parameters were measured. Differences between groups were analyzed with respect to MRI parameters. The potential diagnostic utility of the parameters was assessed via machine learning and genetic algorithm analyses. RESULTS: Significant differences were observed between the two groups in six patellofemoral morphological parameters. Regarding patellar height morphological parameters, all methods exhibited significant between-group differences. Among the tibia and tibiofemoral morphological parameters, only the tibial tubercle-trochlear groove distance exhibited significant differences between the two groups. No sex-related differences were present. Significant variations were observed in patellar height parameters, particularly in the Koshino-Sugimoto (KS) index, which had the highest area under the curve (AUC: 0.87). Using genetic algorithms and logistic regression, our model excelled with seven key independent variables. CONCLUSION: KS index and Wiberg index had the strongest association with lateral patellar dislocation. An optimized logistic regression model achieved an AUC of 0.934. Such performance is considered clinically relevant, indicating the model's effectiveness for the intended application. LEVEL OF EVIDENCE: Level Ⅲ.

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.

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.

The posterior cortical axis as an alternative reference for femoral component placement in total knee arthroplasty.

BACKGROUND: Although several reference axes have been established for determining femoral rotational alignment during total knee arthroplasty (TKA), the most accurate axis is undetermined. This study determines the relationship between the posterior cortical axis (PCA) and the trochlear anterior line (TAL) of the femur in relation to the epicondylar axis. METHODS: A total of 341 patients who underwent TKA for osteoarthritis were enrolled. Patients who had undergone previous bony surgery or replacement that might have changed the femoral geometry were excluded. Finally, 336 patients (200 females and 136 males) were included in the study. The angles between the transepicondylar axis (TEA) and TAL and TEA and the femoral PCA (FPCA) were evaluated. We also assessed whether there was any significant differences in variance and gender in these two angles. Student's t tests were used to determine the significance of coronal alignment and any gender-based differences. The variances between the TAL/TEA and FPCA/TEA angles were compared using F tests. RESULTS: The FPCA was externally rotated by 2.6° ± 3.6°, and the trochlear anterior line was internally rotated by 5.2° ± 5.5°, relative to the TEA. Gender-based differences were observed in the comparisons between anatomical references and TEA. CONCLUSIONS: The FPCA is a more conservative landmark than the TAL for intraoperative or postoperative approximation of the TEA. When conventional reference axes, such as the posterior condylar axis and the anteroposterior axis, are inaccurate, surgeons can refer to this alternative reference. These findings demonstrate that the FPCA may be useful for determining the rotational alignment of the femoral component before and during TKA.

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

PURPOSE: Surgical 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. METHODS: Three-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. RESULTS: In 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. CONCLUSION: Surgical 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.

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.

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.

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.

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 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.

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.

Kinematic Alignment in Cruciate Retaining Implants Improves the Biomechanical Function in Total Knee Arthroplasty during Gait and Deep Knee Bend.

Kinematic alignment (KA), which co-aligns the rotational axes of the components with three kinematic axes of the knee by aligning the components to the prearthritic joint lines, has been a recently introduced surgical technique. However, whether KA and cruciate retaining (CR) implants provide better biomechanical function during activities than mechanical alignment (MA) in posterior stabilized (PS) implants is unclear. We evaluated the biomechanical functions during the stance phase gait and deep knee bend, with a computer simulation and measured forces in the medial and lateral collateral ligaments and medial and lateral contact stresses in the polyethylene insert and patellar button. The forces on the medial collateral ligament in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions, whereas those on the lateral collateral ligament did not show any difference between the two surgical alignment techniques in the stance phase gait condition. The maximum contact stresses on the medial PE inserts in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions. However, the maximum contact stresses on the lateral PE inserts and the patellar button did not differ between MA and KA. The biomechanical function was superior in KA TKA than in MA TKA, and KA was more effective in CR TKA. This comparison could be used as a reference by surgeons to reduce the failure rates by using KA TKA instead of MA TKA.

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-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.

Does preoperative mechanical prophylaxis have additional effectiveness in preventing postoperative venous thromboembolism in elderly patients with hip fracture?-Retrospective case-control study.

BACKGROUND: Elderly patients undergoing hip fracture surgery (HFS) are at increased risk of postoperative venous thromboembolism (VTE). To reduce this risk, combined postoperative mechanical and chemical thromboprophylaxis has been routinely performed after HFS in these patients. This retrospective case-control study was conducted to evaluate the additional effectiveness of preoperative mechanical thromboprophylaxis for the prevention of VTE following HFS in elderly patients. METHODS: Of 539 consecutive patients aged 70 years or older undergoing HFS, 404 (control group) did not receive preoperative mechanical thromboprophylaxis, while 135 (study group) received mechanical thromboprophylaxis using an intermittent pneumatic compression device and graduated compression stockings from the time of admission until surgery. All patients received combined postoperative mechanical and chemical thromboprophylaxis following HFS in accordance with the same protocol. The incidence of symptomatic VTE confirmed based on clinical symptoms and 3-dimensional CT angiography within one month of surgery was investigated in both groups. RESULTS: The American Society of Anesthesiologists grade was higher (p = 0.016) in the study group and more patients in this group had concomitant cardiovascular and neurologic diseases (p = 0.005 and p = 0.009, respectively). In addition, more patients in the study group had received anticoagulant medication preinjury owing to comorbidities (39% vs 28%, p = 0.025). The overall incidences of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) were 7.4% and 3.7%, and 2.2% and 1.5% in the control and study groups, respectively. According to multiple logistic regression, symptomatic DVT significantly reduced in the study group (OR 0.28, p = 0.042), while there was no significant difference in the incidence of symptomatic PE between the two groups (p = 0.223). CONCLUSIONS: Preoperative mechanical thromboprophylaxis may confer an additional benefit by preventing postoperative VTE without adding more risk of perioperative bleeding in elderly patients with hip fracture.

Cervical foraminal and discal height after dynamic rotational plating in the cervical discectomy and fusion.

STUDY DESIGN: This is a retrospective study. PURPOSE: To evaluate the effect of the dynamic rotational plate to the intervertebral foraminal and discal height after anterior cervical discectomy and fusion. OVERVIEW OF LITERATURE: There is no report regarding the changes of foraminal and discal height following cervical dynamic rotational plating. METHODS: We reviewed the outcomes of 30 patients (36 levels), who were followed-up for an average of 15 months (range, 12-57 months) after undergoing fusions with anterior cervical dynamic rotational plating for cervical radiculopathy, from March 2005 to February 2009. The changes of foraminal and intervertebral discal height of the operated levels were observed on oblique and lateral radiographs obtained at the preoperative, postoperative and follow-up examinations. RESULTS: The foraminal and discal height increased sufficiently, immediately following the operation. However, follow-up results showed gradual decrease in the foraminal and discal height. After 6 months of the surgery, they showed little difference compared with the preoperative heights. However, clinically, patients showed improvements in radiating pain during the follow-up period. CONCLUSIONS: Anterior cervical dynamic rotational plating was an effective treatment modality for cervical radiculopathy without the deterioration of the foraminal and intervertebral discal height.