Kwan Kyu Park

Correlation between metabolic syndrome and knee osteoarthritis: data from the Korean National Health and Nutrition Examination Survey (KNHANES)

BackgroundThis study was designed to investigate the correlations of knee osteoarthritis (OA) with metabolic syndrome (MetS) and MetS parameters in Korean subjects.MethodsThis study included data from 270 subjects with knee OA and 1964 control subjects with a mean age of 54.56 (SD 11.53) years taken from the Korean National Health and Nutritional Examination Survey (KNHANES) 2008. Multivariate logistic regression analysis was conducted to examine possible associations for knee OA with MetS and MetS parameters.ResultsMetS was shown to be associated with an increased risk of knee OA in female subjects in unadjusted analysis (OR 1.798, 95% CI 1.392, 2.322), but this significance disappeared when adjusted for confounding factors (OR 1.117, 95% CI 0.805, 1.550). No significant association between MetS and knee OA was found in male subjects. Among parameters of MetS, only high waist circumference (WC) in female subjects was significantly associated with an increased prevalence of knee OA, even after adjusting for confounding factors, while no other significant associations were found in both male and female subjects.ConclusionWe found that WC was associated with knee OA in female subjects, but neither MetS nor any parameters thereof were shown to be associated with knee OA in the Korean subjects of this study. Although we found no relationship between a pre-inflammatory state of MetS and knee OA, we believe further investigation of this relationship in various aspects is warranted, as MetS may also be a risk factor for complications in knee OA related procedures.

Detection of Prefracture Hip Lesions in Atypical Subtrochanteric Fracture with Dual-Energy X-ray Absorptiometry Images

PURPOSE To retrospectively assess how often and how early hip dual-energy x-ray absorptiometry (DXA) images show prefracture lesions in patients with atypical subtrochanteric fracture (ASF) and determine whether DXA images with assessment of prodromal symptoms could be used for early ASF prediction. MATERIALS AND METHODS The retrospective research protocol complied with HIPAA and was institutional review board approved, with waiver of informed consent. Among 62 women with ASF, nine without hip DXA images and seven without clear documentation of prodromal symptoms were excluded. Serial DXA images of 52 hips in 46 patients were included. Among them, 33 hips were assessed with ipsilateral DXA. For this ipsilateral group, each hip was assessed for prodromal symptoms and focal cortical changes in the lateral subtrochanteric femur cortex at DXA. Overall and cumulative detection rates for prodromal symptoms, DXA, and DXA with prodromal symptoms were measured and compared with a general linear model for overall detection rate and Cox proportional hazard models for cumulative detection rate. Thirty-three representative ipsilateral images and 199 images from subjects without fractures were reviewed in random order for prefracture lesions by three musculoskeletal radiologists independently, and the performance of DXA in ASF prediction was assessed. RESULTS Overall detection rates for DXA, prodromal symptoms, and DXA with prodromal symptoms were 61% (20 of 33), 42% (14 of 33), and 73% (24 of 33), respectively, in the ipsilateral group. Overall detection rate comparisons showed that DXA with prodromal symptoms was superior to prodromal symptoms alone (P = .0377). The cumulative detection rate curve for DXA with prodromal symptoms was also superior to that of prodromal symptoms alone (P = .0018). Sensitivity and specificity of DXA in ASF prediction ranged from 52% (17 of 33) to 58% (19 of 33) and 99% (197 of 199) to 100% (199 of 199), respectively. CONCLUSION Assessment of hip DXA images combined with conventional assessment of prodromal symptoms enables detection of more ASFs earlier than assessment based on prodromal symptoms alone.

Evaluation of postoperative range of motion and functional outcomes after cruciate-retaining and posterior-stabilized high-flexion total knee arthroplasty.

Purpose The purpose of this study was to compare postoperative range of motion and functional outcomes among patients who received high-flexion total knee arthroplasty using cruciate-retaining (CR-Flex) and posterior-stabilized (PS-Flex) type prostheses. Materials and Methods Among 127 patients (186 knees) who underwent high-flexion total knee arthroplasty between 2005 and 2007, 92 knees were placed in the CR-Flex group, and 94 knees were placed in the PS-Flex group. After two years of postoperative follow-up, clinical and radiographic data were reviewed. Postoperative non-weight-bearing range of knee motion, angle of flexion contracture and functional outcomes based on the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) functional sub-scale were assessed and compared between the two groups. Results After the 2-year postoperative period, the mean range of motion was 131° in the CR-Flex group and 133° in the PS-Flex group. There were no significant differences in postoperative range of motion between the two groups. Only age at operation and preoperative range of motion were significantly associated with postoperative range of motion after high-flexion total knee arthroplasty. Postoperative functional outcomes based on the WOMAC functional sub-scale were slightly better in the CR-Flex group (9.2±9.1 points) than in the PS-Flex group (11.9±9.6 points); however, this difference was not statistically significant (p=non-significant). Conclusion The retention or substitution of the posterior cruciate ligament does not affect postoperative range of motion (ROM) or functional outcomes, according to 2 years of postoperative follow-up of high-flexion total knee arthroplasty.

The Results of Long-term Follow-up of Total Hip Arthroplasty Using Hydroxyapatite-coated Cups

Purpose The aim of this study was to report the long-term outcome and the failure mechanism of cementless total hip arthroplasty (THA) using hydroxyapatite (HA)-coated acetabular cup. Materials and Methods From January 1992 to May 1994, a total of 123 consecutive cementless primary THAs were performed using a HA-coated acetabular cup with metal-on-polyethylene articulation. We retrospectively evaluated 66 hips available for follow-up at a mean 18.3 years (range, 10.4-23.6 years). The survival analysis was performed by the Kaplan-Meier method. We defined end point as any failure that required a reoperation of acetabular component. Results Thirty-nine of 66 hips (59.1%) were defined as a failure for progressive acetabular osteolysis or aseptic loosening of the cup. Acetabular osteolysis was observed in 47 hips (71.2%) and 33 hips (50.0%) were revised because of cup loosening. The Kaplan-Meier method showed the survival rate of the acetabular cup to be 46.3% at 15 years and 34.8% at 20 years for any failure that required a reoperation of acetabular component. Conclusion The long-term survival rate of THA using HA-coated acetabular cup was unsatisfactory, and it was attributed to vulnerable property of HA coating and progressive osteolysis.

Predicting proximal femur rotation by morphological analyses using translucent 3-dimensional computed tomography

BackgroundPredicting rotation of proximal femur in femur fracture surgeries is important to prevent malrotation.ObjectiveWe aimed to prevent malrotation by developing a simple guideline that enables the prediction of proximal femur rotation using translucent 3-dimensional computed tomography (3D CT).DesignRetrospective.SettingOne tertiary general hospital in the Republic of Korea.PatientsThirty-six subjects who underwent CT angiographies for vascular evaluation.InterventionTranslucent 3D CT images were created from the CT data.Main outcome measureMorphologic ratios of the great trochanter (GT) and lesser trochanter (LT) with the hip center as a basic point were measured at neutral position and at 5°, 10°, 15°, 20°, 25°, and 30° of internal rotation (IR) and external rotation (ER). The rotation angles at which the GT ratio becomes 0.5 and 0.33 and the rotation angles at which the LT ratio becomes 0.0 and 1.0 were determined to serve as guide angles.ResultsBoth the proportion of GT and LT compared with proximal femur with hip center as a reference (GT and LT ratio) gradually increased in the shift from IR to ER. At a neutral position, the GT and LT ratios were approximately 0.4 and 0.5, respectively. At 10°–15° of ER, the approximate GT and LT ratios were 0.5 and 1.0, respectively. At 30° of ER, the GT ratio exceeded 0.6, and the LT ratio exceeded 1.0. Between 10° and 15° of IR, the GT ratio decreased to approximately 0.33 and the LT ratio decreased to 0.0, which indicated that the LT was invisible.ConclusionsWe suggested practical values which might be useful as a reference in the operating room practically and hope that our findings would be helpful to prevent malrotation while performing proximal femur or femur shaft surgeries.

Management of Blood Loss in Hip Arthroplasty: Korean Hip Society Current Consensus

The volume of hip arthroplasty is stiffly increasing because of excellent clinical outcomes, however it has not been shown to decrease the incidence of transfusions due to bleeding related to this surgery. This is an important consideration since there are concerns about the side effects and social costs of transfusions. First, anemia should be assessed at least 30 days before elective hip arthroplasty, and if the subject is diagnosed as having anemia, an additional examination of the cause of the anemia should be carried and steps taken to address the anemia. Available iron treatments for anemia take 7 to 10 days to facilitate erythropoiesis, and preoperative iron supplementation, either oral or intravenous, is recommended. When using oral supplements for iron storage, administer elemental iron 100 mg daily for 2 to 6 weeks before surgery, and calculate the dose using intravenous supplement. Tranexamic acid (TXA) is a synthetic derivative of the lysine component, which reduces blood loss by inhibiting fibrinolysis and clot degradation. TXA is known to be an effective agent for reducing postoperative bleeding and reducing the need for transfusions in primary and revision total hip arthroplasties. Patient blood management has improved the clinical outcome after hip arthroplasty through the introduction and research of various agents, thereby reducing the need for allogeneic blood transfusions and reducing the risk of transfusion-related infections and the duration of hospitalizations.

The impact of generalized joint laxity on clinical outcomes of total knee arthroplasty

PurposeThe aim of this study was to investigate whether the severity of generalized joint laxity influences preoperative and postoperative clinical outcomes and if patients with severe generalized joint laxity would require a thicker polyethylene (PE) liner during total knee arthroplasty (TKA).MethodsA total of 338 female patients undergoing TKA were divided into two groups according to generalized joint laxity. Preoperative and postoperative (at 3 years) patellofemoral scale, AKS, WOMAC, ROM, and satisfaction VAS were compared between the two groups. Additionally, PE liner thickness was compared.ResultsPreoperatively, flexion contracture and WOMAC stiffness scores in the severe laxity group were significantly lower than those in the no to moderate laxity group (p < 0.001 for both). There was no significant difference in postoperative clinical outcomes of patellofemoral scale, AKS, WOMAC, or ROM or in satisfaction VAS between the two groups. There was a significant difference in PE liner thickness between the two groups (10.3 ± 1.3 versus 11.4 ± 1.2, p = 0.043).ConclusionsThere was no significant difference of clinical outcomes between the patients with and without severe generalized joint laxity after 3 years of follow-up after TKA, even though preoperative clinical outcomes indicated that the patients with severe generalized joint laxity showed significantly smaller flexion contraction and better WOMAC stiffness score. Since patients with generalized joint laxity require a thicker PE liner, care should be taken to avoid cutting too much bone from patients with severe generalized joint laxity.Level of evidenceRetrospective comparative study, Level III.

Flexed femoral component improves kinematics and biomechanical effect in posterior stabilized total knee arthroplasty

PurposeThe kinematics and biomechanics of the knee joint are important in ensuring patient satisfaction and functional ability after total knee arthroplasty (TKA). There has been no study on knee joint mechanics with regard to the sagittal alignment of the femoral component. The objective of this study is to determine the extent of the impact of the femoral component’s sagittal alignment on kinematics and biomechanics.MethodsA validated computational TKA model was used. The femoral component was simulated at − 3°, 0°, 5°, and 7° of flexion in the sagittal plane. This study evaluated the tibiofemoral (TF) joint kinematics, contact point, quadriceps force, and contact stress on the patellofemoral (PF) joint under a deep-knee-bend condition.ResultsThe kinematics of the TF joint in the posterior direction increased with the flexion of the femoral component position. For all tasks, the overall posterior locations of the TF contact points were observed in the medial and lateral compartments as the femoral component flexion angle increased. The quadriceps force and contact stress on the PF joint decreased with the femoral component flexion.ConclusionThis study found that the femoral component sagittal position is an important factor in knee joint mechanics. In this study, the flexion of femoral component showed a stable reconstruction of the knee extensors’ mechanism. Surgeons may consider neutral-to-mild flexed femoral component position, without concerns of anterior notching of the femoral cortex.

Reliability of Intraoperative Knee Range of Motion Measurements by Goniometer Compared with Robot-Assisted Arthroplasty

&NA; Accurate measurement of knee range of motion (ROM) is critical to predict the outcomes of knee surgery and prognosis. We investigated the reliability of knee ROM measurements by goniometer compared with robotic system. Fifty‐three patients with medial osteoarthritis who were planning to undergo unicompartmental knee arthroplasty (UKA) with robotic UKA were prospectively enrolled. During the operation, knee ROM measurement was performed in both flexion and extension before and after insertion of the implant using both a goniometer and robotic system. The intraclass correlation coefficient (ICC) of extension measured by the goniometer and robotic system showed good agreement; however, the ICC of flexion did not show good agreement. During passive flexion, the mean values measured before insertion of the implant were significantly lower by goniometer (134.6 ± 6.43) than by robot (145.4 ± 6.80; p = 0.017); likewise, the mean values after insertion of the implant were significantly lower by goniometer (138.6 ± 6.07) than by robotic system (147.0 ± 6.60; p = 0.045). A goniometer can underestimate knee ROM measurements compared with robotic system, especially in flexion. Orthopaedic surgeons should be cautious when measuring the flexion angle with a goniometer.

Do zip-type skin-closing devices show better wound status compared to conventional staple devices in total knee arthroplasty?

This study compared the pain score, cosmetic outcome and wound complication rate between zip‐type skin‐closing device and conventional staple device. Forty‐five subjects with zip‐type skin‐closing device (the zip group) and 45 subjects with the conventional staple device (the staple group) after total knee arthroplasty were compared. Visual analogue scale score was significantly higher on postoperative (PO) 1, 3, 14 day (D) in the staple group compared to the zip group (P < 0·05). The Vancouver scar score was significantly better in the zip group compared to that of the staple group (4·6 ± 0·7 versus 6·9 ± 1·3, P = 0·043) on PO 90D. There was no significant wound complication rate between the two groups. The zip‐type skin‐closing device showed less pain PO 14D, especially during dressing and removal of the device, and better cosmetic outcome 3 months after surgeries. Surgeons may consider using the zip‐type skin‐closing device for patients who want less pain and better cosmetic outcome.