Accuracy of 2D CT-Based Measurements of Rotational Alignment of the Femoral Component for Total Knee Arthroplasty

Purpose@#We aimed to investigate the accuracy of two-dimensional computed tomography (2D-CT)-based methods for measuring rotational alignment of the femoral component during total knee arthroplasty in comparison to reference values for three-dimensional (3D) reconstruction. @*Materials and Methods@#We selected the “most protruding transepicondylar axis section,” “most protruding posterior condylar line section,” and “distal femoral cut section” on 2D-CT images for 100 knees. We investigated posterior condylar angle (PCA) and condylar twist angle (CTA) values using three different methods on 2D-CT and compared to these values to those obtained using a 3D model. @*Results@#The mean PCA and CTA values were 2.8° and 7.0° on the 3D model and 2.0° to 2.1° and 5.9° to 6.0° on 2D-CT, respectively. Errors in PCA and CTA measurement included internal rotation of 0.8° and 1.1° with the 1-plane and 2-plane methods and 0.9° and 1.0° with the assumed resection method, respectively. @*Conclusion@#Mean errors in PCA and CTA values measured using three different methods on 2D-CT were not significantly different. However, PCA and CTA values measured on 2D-CT were approximately 1° smaller than their 3D values. Thus, we suggest that adding 1° to the mean PCA and CTA values obtained from a single plane of 2D-CT would provide values similar to those obtained from 3D reconstruction.

Accuracy of 2D CT-Based Measurements of Rotational Alignment of the Femoral Component for Total Knee Arthroplasty

Purpose@#We aimed to investigate the accuracy of two-dimensional computed tomography (2D-CT)-based methods for measuring rotational alignment of the femoral component during total knee arthroplasty in comparison to reference values for three-dimensional (3D) reconstruction. @*Materials and Methods@#We selected the “most protruding transepicondylar axis section,” “most protruding posterior condylar line section,” and “distal femoral cut section” on 2D-CT images for 100 knees. We investigated posterior condylar angle (PCA) and condylar twist angle (CTA) values using three different methods on 2D-CT and compared to these values to those obtained using a 3D model. @*Results@#The mean PCA and CTA values were 2.8° and 7.0° on the 3D model and 2.0° to 2.1° and 5.9° to 6.0° on 2D-CT, respectively. Errors in PCA and CTA measurement included internal rotation of 0.8° and 1.1° with the 1-plane and 2-plane methods and 0.9° and 1.0° with the assumed resection method, respectively. @*Conclusion@#Mean errors in PCA and CTA values measured using three different methods on 2D-CT were not significantly different. However, PCA and CTA values measured on 2D-CT were approximately 1° smaller than their 3D values. Thus, we suggest that adding 1° to the mean PCA and CTA values obtained from a single plane of 2D-CT would provide values similar to those obtained from 3D reconstruction.

Principles for Management of Periprosthetic Acetabular Fractures after Hip Arthroplasty

Periprosthetic acetabular fracture (PAF) is an uncommon complication following hip arthroplasty. However, as the number of people needing hip prostheses continues to rise, the absolute number of PAF is expected to increase as well. These fractures may occur either intraoperatively or postoperatively. Postoperative fractures can be caused by traumatic events or by pathologic conditions related to periacetabular osteolysis. The management of PAF usually depends on the degree of displacement and the stability of the acetabular component. While most of non-displaced fractures can be managed nonoperatively by protected weight bearing, displaced fractures with unstable implants require surgical intervention, which is often technically challenging. This review summarized the latest findings on the epidemiology, the diagnosis, the classification, and the treatment of PAF.

Utility of False Profile View for Screening of Ischiofemoral Impingement / 대한고관절학회지

PURPOSE: Ischiofemoral impingement (IFI)-primarily diagnosed by magnetic resonance imaging (MRI)-is an easily overlooked disease due to its low incidence. The purpose of this study was to evaluate the usefulness of false profile view as a screening test for IFI. MATERIALS AND METHODS: Fifty-eight patients diagnosed with IFI between June 2013 and July 2017 were enrolled in this retrospective study. A control group (n=58) with matching propensity scores (age, gender, and body mass index) were also included. Ischiofemoral space (IFS) was measured as the shortest distance between the lateral cortex of the ischium and the medial cortex of lesser trochanter in weight bearing hip anteroposterior (AP) view and false profile view. MRI was used to measure IFS and quadratus femoris space (QFS). The receiver operating characteristics (ROC), area under the ROC curve (AUC) and cutoff point of the IFS were measured by false profile images, and the correlation between the IFS and QFS was analyzed using the MRI scans. RESULTS: In the false profile view and hip AP view, patients with IFI had significantly decreased IFS (P < 0.01). In the false profile view, ROC AUC (0.967) was higher than in the hip AP view (0.841). Cutoff value for differential diagnosis of IFI in the false profile view was 10.3 mm (sensitivity, 88.2%; specificity, 88.4%). IFS correlated with IFS (r=0.744) QFS (0.740) in MRI and IFS (0.621) in hip AP view (P < 0.01). CONCLUSION: IFS on false profile view can be used as a screening tool for potential IFI.

Robotic Surgery in the Orthopedic Field / 대한정형외과학회잡지

Of the many factors that affect the clinical outcomes of orthopedic surgery, the surgical procedure is the most important. Robotics have been developed to perform the surgical procedures more accurately and consistently. Robotic surgical procedures in the orthopedic field were developed 20 years ago. Some designs of surgical robots have disappeared due to practical problems and complications, and an another design of surgical robots is emerging. To date, the use of robot surgery in arthroplasty is still controversial in terms of the clinical outcomes, practicality, and cost-effectiveness, even though it has been reported to be effective in the alignment and positioning of components in the field of artificial joints. Early robotic surgery was based mainly on active robot surgery according to the scheduled operation without the intervention of the operator. Recently the semi-active system of robotic surgery has been introduced. In a semi-active system, the robot constrains the surgeon to a haptic boundary defined by the computer based on the 3-dimensional imaging preoperative plan, and the operator can change the preoperative plan through real-time feedback during operation.

Paralabral Cyst of the Hip Compressing Common Femoral Vein Treated with Sono-guided Cyst Aspiration Followed by Arthroscopic Labral Debridement: A Case Report / 대한고관절학회지

Paralabral cyst around hip is reported to be a cause of compression of the major neurovascular structures. Although, arthroscopic cyst and labral debridement is generally accepted as the effective treatment, there is limited literature available regarding treatment options for paralabral cysts in the hip. We present a case of paralabral cyst compressing left common femoral vein in the hip that was treated with sono-guided cyst aspiration followed by arthroscopic labral debridement.

Paralabral Cyst of the Hip Compressing Common Femoral Vein Treated with Sono-guided Cyst Aspiration Followed by Arthroscopic Labral Debridement: A Case Report / 대한고관절학회지

Paralabral cyst around hip is reported to be a cause of compression of the major neurovascular structures. Although, arthroscopic cyst and labral debridement is generally accepted as the effective treatment, there is limited literature available regarding treatment options for paralabral cysts in the hip. We present a case of paralabral cyst compressing left common femoral vein in the hip that was treated with sono-guided cyst aspiration followed by arthroscopic labral debridement.

Decreased Lumbar Lordosis and Deficient Acetabular Coverage Are Risk Factors for Subchondral Insufficiency Fracture

Subchondral insufficiency fracture (SIF) of the femoral head occurs in the elderly and recipients of organ transplantation. Osteoporosis and deficient lateral coverage of the acetabulum are known risk factors for SIF. There has been no study about relation between spinopelvic alignment and anterior acetabular coverage with SIF. We therefore asked whether a decrease of lumbar lordosis and a deficiency in the anterior acetabular coverage are risk factors. We investigated 37 patients with SIF. There were 33 women and 4 men, and their mean age was 71.5 years (59-85 years). These 37 patients were matched with 37 controls for gender, age, height, weight, body mass index and bone mineral density. We compared the lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, acetabular index, acetabular roof angle, acetabular head index, anterior center-edge angle and lateral center-edge angle. Lumbar lordosis, pelvic tilt, sacral slope, lateral center edge angle, anterior center edge angle, acetabular index and acetabular head index were significantly different between SIF group and control group. Lumbar lordosis (OR = 1.11), lateral center edge angle (OR = 1.30) and anterior center edge angle (OR = 1.27) had significant associations in multivariate analysis. Decreased lumbar lordosis and deficient anterior coverage of the acetabulum are risk factors for SIF as well as decreased lateral coverage of the acetabulum.

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

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.

Effect of Zoledronate on the Expression of Vascular Endothelial Growth Factor-A by Articular Chondrocytes and Synovial Cells: An in Vitro Study

BACKGROUND: The aim of this in vitro study was to determine the effect of zoledronate, which is frequently used to treat osteoporosis, on osteoarthritis by analyzing zoledronate-induced expression of vascular endothelial growth factor-A (VEGF-A) in chondrocytes and synovial cells. METHODS: After chondrocytes and synovial cells were separated and cultured, zoledronate was added, and VEGF-A and pigment epithelium-derived factor (PEDF) expression were quantified by real-time polymerase chain reaction and Western blotting. RESULTS: There was no significant difference in the expression of VEGF-A mRNA in chondrocytes between the zoledronate group and the control group on the 8th day of culture. The expression of both VEGF-A and PEDF mRNA in synovial cells was significantly decreased in the zoledronate group (P<0.05). CONCLUSIONS: Zoledronate decreases the expression of VEGF-A in synovial cells and may affect the development and progression of osteoarthritis.

Comparison of the Radiologic Outcomes following the Kinds of Implants in Treating Unstable Osteoporotic Intertrochanteric Fracture / 대한골다공증학회지

OBJECTIVES: To determine whether kinds of implants would influence on the radiologic outcomes in the treatment of unstable osteoporotic intertrochanteric fractures. MATERIALS AND METHODS: In this retrospective study, radiologic outcomes of 151 patients with unstable osteoporotic intertrochanteric fractures undergoing surgical treatments were compared based on the types of fixation implants as follows : PFNA (53 cases, group I), gamma nail 3(31 cases, group II), CHS with TSP (43 cases, group III), and helical blade type LCP-DHS with TSP (24 cases, group IV). On the follow-up radiographs after operations, we assessed differences of bone union durations, neck-shaft ankle changes, lag screw or helical blade slippages, and varus alpha angle changes among the study groups. RESULTS: All the radiologic outcomes evaluated in this study were not significantly different among the study groups. The average bone union durations of the group I, II, III and IV were 17.7, 18.0, 18.2, and 17.8 weeks, respectively (P=0.429). The average variation of neck-shaft angle of the group I, II, III and IV were 3.6degrees, 3.1degrees, 3.7degrees and 2.9degrees, respectively (P=0.273). The average lag screw or blade slippage of the group I, II, III and IV were 5.1 mm, 3.3 mm, 3.6 mm and 2.7 mm, respectively (P=0.154). The average variation of varus alpha of the group I, II, III and IV were 5.3degrees, 4.7degrees, 4.1degrees and 4.6masculine, respectively (P=0.894). CONCLUSIONS: This study indicates that four typical types of fixation implants for treating unstable osteoporotic intertrochanteric fractures would not lead to differences in postoperative radiological outcomes.

Bilateral Insufficiency Fracture of Medial Subtrochanteric Area of the Femur: A Case Report / 대한고관절학회지

A non-traumatic, incomplete insufficiency fracture commonly involves the lateral side of the femoral cortex; whereas a non-traumatic, incomplete stress fracture commonly involves the medial side of the femoral cortex. Here, we describe a case of a 66-year-old woman with a two-month history of bilateral thigh pain without trauma or medication usage who was diagnosed with bilateral subtrochanteric insufficiency fractures involving the medial side of the femoral cortex.

Result of Total Knee Arthroplasty in Pre-operative Adreanal Insufficiency Patients / 대한정형외과연구학회지

PURPOSE: The purpose of this study is to investigate to effect of adrenal insufficiency on the results of TKA. MATERIALS AND METHODS: A total of 89 patients (89 knees) treated with TKA from March, 2008 to October, 2008 were enrolled in this study. Levels of serum cortisol and adrenocorticotropic hormone (ACTH) were checked preoperatively. Hydrocortisone 50~75 mg was injected to adrenal insufficient group at 7:00 AM and 4:00 PM on operative day and the following day. We evaluated the range of motion, the knee society knee score and function score at preoperatively and 2 years follow up, and compared the results between non-adrenal insufficiency group (NAI) and adrenal insufficiency group (AI). RESULTS: Cortisol and ACTH levels were reduced in 36 of 89 patients. All of 36 patients of low cortisol level do not stimulated in ACTH stimulation test. In the adrenal insufficiency group the knee society score (KSS) improved from 49.8 to 86.8 and the knee society functional score (KSFS) from 42.6 to 89.5 at 2 years follow-up. In the control group KSS rose from 51.9 to 84.3 and KSFS from 49.4 to 88.6 during the same period. In adrenal insufficient patients, there were no postoperative complication to include mortality, infection, periprosthetic fracture except skin lesions during operation or postoperatively. There was a case of rupture of quadriceps tendon on the 10th postoperative day which was treated with primary repair. CONCLUSION: Based on our study, there was no increased operative and postoperative complications except skin lesions and 1 case quadricepse tendon rupture in patients with adrenal insufficiency group.

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 131degrees in the CR-Flex group and 133degrees 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.

Distal Femoral Rotational Alignment Based on Mechanical Axis of the Femur: A 3-Dimensional Computed Tomographic Scan in Vivo Assessment / 대한정형외과학회잡지

PURPOSE: To measure and to analyze the relationships among the rotational axes of the distal femoral region by means of 3-dimensional (3D) computed tomographic (CT) images taken perpendicularly to the mechanical axis and a 3D rendering program. MATERIALS AND METHODS: Fifty cases involving the lower extremity were included in this study, which used 3D computed tomographic angiograms. CT images of the perpendicular cross-sections to the mechanical axis of the femur were obtained by processing 3D recombinant images using Aquaris NET(R). The following anatomical angles were obtained from axial imaging using the 3D reconstructed bone model: transepicondylar axis, surgical transepicondylar axis, anteroposterior axis, and real posterior condylar axis. RESULTS: In the tomographic images, the angles to the real posterior condylar axis formed by the anatomical femoral transepicondylar axis, the anatomical femoral transepicondylar axis, and the anteroposterior axis were 6.34+/-1.23degrees, 2.43+/-1.56degrees, and 96.52+/-1.77degrees, respectively. The angles to the anatomical femoral transepicondylar axis formed by the anteroposterior axis and the surgical femoral transepicondylar axis were 90.19+/-1.61degrees and 3.91+/-0.90degrees, respectively. In the recombinant 3D femur model, the angles to the real posterior condylar axis formed by the anatomical femoral transepicondylar axis and the anteroposterior axis were 6.29+/-1.86degrees, and 93.33+/-3.76degrees, respectively. And, the angle for anteroposterior axis from anatomical transepicondylar axis was 87.04+/-4.11degrees. CONCLUSION: The method of measuring the rotational axes of the distal femur using the CT image taken perpendicularly to the mechanical axis is considered reproducible. In particular, the measurement method using the anatomical transepicondylar axis is more accurate than that using the anteroposterior axis.

Navigation-Assisted Total Knee Arthroplasty for the Knee Retaining Femoral Intramedullary Nail, and Distal Femoral Plate and Screws

Proper ligament balancing, restoration of the mechanical axis and component alignment are essential for the success and longevity of a prosthesis. In conventional total knee arthroplasty (TKA), an intramedullary guide is used to improve the alignment. An extramedullary guide can be used in cases of severe femoral bowing or intramedullary nailing but its use is more subjective and relies on the surgeon's experience. This paper reports two successful cases of navigation-assisted TKA for severe right knee osteoarthritis retaining a femoral intrameullary nail, and left knee osteoarthritis retaining a distal femoral plate.

Femoral Neck Anteversion Measured Using a 3D CT Scan Perpendicular to the Mechanical Axis of the Femur

PURPOSE: We wanted to measure the femoral neck anteversion (FNA) angles using a 3D CT scan that perpendicularly cut the mechanical axis of the femur and to assess the accuracy and reproducibility of different measuring methods. MATERIALS AND METHODS: We obtained 95 cases of 3D CT images of the cross-section perpendicular to the mechanical axis of the femur. The methods used to measure the FNA angles included a method using the CT image of the area where the femoral neck is confluent to the greater trochanter (method 1), a method using the CT image taken from the neck base immediately prior to the beginning of the area of the lesser trochanter (method 2) and a method by which measurements are made after putting 3D bone models on a horizontal plane in virtual space (method 3). The reference axes of the distal femur we used were the anatomical transepicondylar axis, the surgical transepicondylar axis and the real posterior condylar axis. RESULTS: The FNA angles measured by method 1 were 4.79+/-6.41degrees to the anatomical transepicondylar axis (ATEA), 6.09+/-6.58degrees to the surgical transepicondylar axis (STEA) and 7.96+/-6.81degrees to the real posterior condylar axis (rPCA). The FNA angles measured by method 2 were 16.01+/-8.31degrees to the ATEA, 19.52+/-8.38degrees to the STEA and 21.79+/-8.52degrees to the rPCA. The FNA angles measured by method 3 were 20.15+/-12.89degrees to the rPCA. CONCLUSION: The measurement of the FNA angle using a 3D CT scan perpendicular to the mechanical axis is reproducible. The measurement method on the neck base level is more reliable than the one on the proximal neck confluence, and more similar to the measurement method by classic definition.

Comparison of Kyphoplasty and Lordoplasty in the Treatment of Osteoporotic Vertebral Compression Fracture

STUDY DESIGN: A retrospective study. PURPOSE: To compare the level of restoration of the vertebral height, improvement in the wedge and kyphotic angles, and the incidence of complications in osteoporotic compression fracture in patients treated with either kyphoplasty or lordoplasty. OVERVIEW OF LITERATURE: Kyphoplasty involves recompression of the vertebral bodies. Recently, a more effective method known as lordoplasty was introduced. METHODS: Between 2004 and 2009, patients with osteoporotic thoracolumbar vertebral compression fractures were treated by either kyphoplasty (n = 24) or lordoplasty (n = 12) using polymethylmethacrylate (PMMA) cement, and the results of the two interventions were compared. A visual analogue scale was used to measure the pain status. Preoperative and postoperative radiographs were analyzed to quantify the anterior vertebral height restoration and the wedge and kyphotic alignment correction. RESULTS: All patients in both groups reported a significant decrease in pain. The anterior heights increased 24.2% and 17.5% after the lordoplasty and kyphoplasty procedures, respectively (p < 0.05). Three months after the procedures, there was a larger decrease in the loss of anterior vertebral height in the kyphoplasty group (12.8%) than in the lordoplasty group (6.3%, p < 0.05). The wedge angles decreased after both procedures. The wedge angle in the lordoplasty group maintained its value after 3 months (p < 0.05). The kyphotic angular correction was 11.4 and 7.0degrees in the lordoplasty and kyphoplasty groups, respectively (p < 0.05). Both kyphotic deformities worsened to a similar degree of 5degrees after 3 months. CONCLUSIONS: Lordoplasty is more useful than kyphoplasty in terms of the improved anatomic restoration and postoperative maintenance.

Proximal Femoral Nail Antirotation versus Compression Hip Screw with Trochanter Stabilizing Plate for Unstable Intertrochanteric Hip Fractures

PURPOSE: To analyze and compare the clinical and radiologic results of treatments in unstable intertrochanteric fractures of the femur with proximal femoral nail antirotation (PFNA) and compression hip screw with trochanter stabilizing plate (CHS with TSP). MATERIALS AND METHODS: We retrospectively reviewed the results of 66 cases of unstable intertrochanteric fractures of the femur treated with PFNA (Group I) and CHS with TSP (Group II) which could be followed up for minimum a year. We evaluated several comparative factors such as operation time, blood loss, time to bone union, changes in neck-shaft angle, sliding of screw (or blade), complications, postoperative pain, social-function score of Jensen, and mobility score of Parker and Palmer. RESULTS: Group I showed shorter operation time and less blood loss with significance than group II (p0.05). Two cases of cutting out of the blade through the femoral head were found in group I. One case of cutting out of the screw, one case of the breakage of the plate, and loosening of the plate were found in group II as complications. CONCLUSION: We think that there were no significant differences between PFNA and CHS with TSP in view point of radiologic and clinical outcomes in unstable intertrochanteric fractures of the femur, but PFNA is less invasive device than CHS with TSP, therefore it may be useful device in elderly patients.

Cementless Total Hip Arthroplasty Using a Ceramic on Ceramic Bearing Surfaces in Patients 60 or More Years Old

PURPOSE: To investigate clinical and radiographic results for cementless total hip arthroplasty (THA) using ceramic-on-ceramic articulation in patients over 60 years old. MATERIALS AND METHODS: Between May 2000 and February 2007, we analyzed 44 THAs that used ceramic-on-ceramic articulation in 34 patients aged 60 or older. The mean follow-up duration was 3.2 years; the mean age was 66.8 years. Clinical and radiographic evaluations were carried out. Risk factors for dislocation were evaluated. RESULTS: Final Harris hip scores increased to an average of 90 points from an average of 51 points preoperatively. Radiographic findings demonstrated that fixations around the stems and the acetabular cups were stable. There was no aseptic loosening and osteolysis around the implants. There were 10 cases of posterior dislocation within 3 months postoperatively. Two revisions were done, one due to a recurrent dislocation and one to a ceramic head fracture. Risk factors for dislocation were ASA score, cup anteversion angle and total anteversion angle. CONCLUSION: Cementless THAs using ceramic-on-ceramic articulation for patients aged sixty or more elicits good clinical and radiographic results. Because of the high rate of early dislocation and damage to the ceramic, we call attention to the position of the implants and postoperative management in elderly, debilitated patients.