No Difference in Clinical Outcomes and Survivorship for Robotic, Navigational, and Conventional Primary Total Knee Arthroplasty with a Minimum Follow-up of 10 Years

Background@#Computer-assisted surgery, including robotic and navigational total knee arthroplasty (TKA), has been proposed as a technique used to improve alignment of implants. The purpose of this study was to compare the clinical and radiological outcomes during a minimum follow-up period of 10 years among robotic, navigational, and conventional TKA. @*Methods@#A total of 855 knees (robotic group, 194; conventional group, 270; and navigational group, 391) were available for physical and radiological examinations over a mean follow-up period of 10 years. The survival rate was analyzed using the KaplanMeier method based on the survival endpoint. The Hospital for Special Surgery score, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society Score, and range of motion were used for clinical evaluation. The hip-knee-ankle (HKA) axis angle, the coronal inclination of femoral and tibial components, and the presence of radiolucent lines were also assessed at the final follow-up. @*Results@#All clinical assessments at the final follow-up revealed improvements in the three groups without any significant difference among the groups (p> 0.05). The cumulative 10-year survival rate was 97.4% in the robotic group, 96.6% in the conventional group, and 98.2% in the navigational group, with no significant difference (p = 0.447). The rates of complication-associated surgery were not significantly different among the groups (p = 0.907). Only the proportion of outliers in the HKA axis angle showed a significant difference (p = 0.001), but other radiological outcomes were not significantly different among the three groups. @*Conclusions@#Our study demonstrated satisfactory survival rates for robotic, navigational, and conventional TKAs and similar clinical outcomes during the long-term follow-up. Larger studies with continuous serial data are needed to confirm these findings.

Trend Shift in the Cause of Revision Total Knee Arthroplasty over 17 Years

Background@#The number of revision total knee arthroplasty (TKA) has been increasing. Although many studies have analyzed the causes of revision TKA in Western countries, a limited number of studies have analyzed changes in causes of or trends in revision TKA in Asia. This study analyzed and determined the frequency and causes of failures after TKA in our hospital. We also analyzed the differences and trends over the past 17 years. @*Methods@#A total of 296 revision TKAs performed in a single institution from 2003 to 2019 were analyzed. During the 17-year study period, patients who had undergone primary TKA between 2003 and 2011 were classified into a past group, while those who had undergone primary TKA from 2012 to 2019 were classified into a recent group. A revision performed within 2 years after primary TKA was defined as early revision. Further, differences in causes of revision TKA according to the interval from primary TKA to revision TKA were determined. The causes of revision TKA were analyzed through a comprehensive analysis of patients’ medical records. @*Results@#Overall, infection was the most common cause of failure (151/296 cases, 51.0%). Compared to the past group, the recent group had a relatively higher proportion of patients undergoing revision TKA for mechanical loosening (past group, 19.1% vs.recent group, 31.9%) and instability (11.2% vs. 13.5%) and a relatively lower proportion of patients undergoing revision TKA for infection (56.2% vs. 48.8%), polyethylene (PE) wear (9.0% vs. 2.9%), osteolysis (2.2% vs. 1.9%), and malalignment (2.2% vs. 1.0%).On comparison according to the interval from primary TKA to revision TKA, the rate of infection relatively decreased, whereas the rate of mechanical loosening and instability relatively increased in the late revision TKA compared to the early revision TKA. @*Conclusions@#Infection and aseptic loosening were the most common reasons of revision TKA in both past and recent groups.Compared to the past, revision TKA due to PE wear has decreased significantly and revision TKA due to mechanical loosening has relatively increased recently. Orthopedic surgeons need to be aware of recent trends in mechanisms of failure and should try to recognize and address the probable causes in TKA

Mesenchymal Stem Cells Decrease Tunnel Widening of Anterior Cruciate Ligament Reconstruction in Rabbit Model

BACKGROUND AND OBJECTIVES: The study investigated the effect of mesenchymal stem cells (MSCs) or fibrin glue on tunnel widening after anterior cruciate ligament (ACL) reconstruction compared with biologic free control without any biologic agents in the rabbit model. METHODS AND RESULTS: ACL reconstructions were performed in 18 New Zealand white rabbits. All animals were divided into 3 groups according to the following reconstruction conditions and euthanized 12 weeks postoperatively for radiologic and histologic analyses. Thirty-two knees (control group=10; fibrin group=11; MSCs group=11) were finally evaluated. On micro-CT scan, mean femoral tunnel widening on oblique-sagittal image was 0.7±0.4 mm in the control group, 0.22±0.1 mm in the fibrin group and 0.25±0.1 mm in the MSCs group (p=0.001). Fibrin group and MSCs group showed significant differences compared with control group (p=0.002, 0.002). Mean tibial tunnel widening on oblique-sagittal image was 0.76±0.5 mm, 0.27±0.1 mm and 0.29±0.2 mm in the control, fibrin and MSCs group. Fibrin and MSCs group showed significant differences compared with control group (p=0.017, 0.014). Hounsfield Units (HU) were not significantly different between 3 groups (p>0.05). Histological analysis revealed that the architecture of graft in the MSCs group featured hypercellularity and compact collagen deposit. CONCLUSION: ACL reconstruction using MSCs seemed decrease tunnel widening in rabbit model. Further study with large animals is required to confirm efficacy on decreasing tunnel widening.

Factors Affecting Tibial Tuberosity-Trochlear Groove Distance in Recurrent Patellar Dislocation

BACKGROUND: The tibial tuberosity-trochlear groove (TT-TG) distance is used to determine the necessity of tibial tubercle osteotomy. We conducted this study to determine the extent to which each of the tibial tuberosity lateralization, trochlear groove medialization, and knee rotation angle affects the TT-TG distance in both normal and patella dislocated patients and thereby scrutinize the rationale for tuberosity transfer based on the TT-TG distance. METHODS: Retrospective analysis of rotational profile computed tomography was done for patella dislocated and control group patients. Femoral anteversion, tibial torsion, knee rotation angle, tuberosity lateralization, and trochlear groove medialization were assessed in all patients. Relationship of these parameters with the TT-TG distance was investigated to evaluate their effects on the TT-TG distance. RESULTS: We observed that the patellar dislocation group, compared to the control group, had increased TT-TG distance (mean, 19.05 mm vs. 9.02 mm) and greater tuberosity lateralization (mean, 64.1% vs. 60.7%) and tibial external rotation in relation to the femur (mean, 7.9° vs. −0.81°). CONCLUSIONS: Tuberosity lateralization and knee rotation were factors affecting patellar dislocation. These factors should be considered in addition to the TT-TG distance to determine the need for tibial tubercle osteotomy in patients with patellar dislocation.

Is Immediate Postoperative Mechanical Axis Associated with the Revision Rate of Primary Total Knee Arthroplasty? A 10-Year Follow-up Study

BACKGROUND: Achieving neutral limb alignment during total knee arthroplasty (TKA) has been considered an important determinant in the long-term prosthesis survival. The purpose of this study was to evaluate the association between the immediate postoperative mechanical alignment of the lower limb and the rate of revision TKA by comparing an acceptable mechanical axis group (within ± 3° from neutral alignment) and an outlier group (> 3° deviation from neutral alignment). METHODS: Between 2000 and 2006, clinical and radiographic data of 334 primary TKAs were retrospectively reviewed to determine the 10-year Kaplan-Meier survival rate. Patients were divided into acceptable and outlier groups according to the mechanical axis checked postoperatively within a month. Clinical outcomes were assessed using Hospital for Special Surgery, Knee Society Score, and Western Ontario and McMaster Universities Osteoarthritis Index score preoperatively and at the final follow-up. Postoperative complications and revision rates were also evaluated. RESULTS: The mean change in mechanical axis between the immediate postoperative examination and the last follow-up was greater in the outlier group (1.6 ± 2.7) than in the acceptable group (0.8 ± 2.4). The revision rates were significantly different between the two groups (p = 0.04). At the last follow-up, clinical scores were all improved in both groups compared to each preoperative condition. There were no significant differences in clinical scores between the two groups at the last follow-up. The 10-year Kaplan-Meier survival analysis showed a tendency towards better survival with restoration of neutral mechanical axis. However, the difference was not statistically significant (p = 0.25). CONCLUSIONS: Restoration of neutral limb alignment is a factor that can result in a lower revision rate and higher longevity in TKA. However, there were no significant differences in clinical outcomes between the two groups.

Causes of Aseptic Persistent Pain after Total Knee Arthroplasty

BACKGROUND: Persistent pain after total knee arthroplasty (TKA) is dissatisfying to the patient and frustrating to the surgeon. The purpose of this study is to evaluate the aseptic causes and clinical course of intractable pain following TKA. METHODS: Of the total 2,534 cases of primary TKA reviewed, 178 cases were classified as having aseptic persistent pain that was not resolved within 1 year after surgery. Except for the cases with periprosthetic fracture (56 knees), 122 cases of aseptic painful TKA were divided into two groups: intra-articular group (83 knees) and extra-articular group (39 knees). RESULTS: In the intra-articular group, the main reasons for pain were aseptic loosening (n = 40), polyethylene wear (n = 16), instability (n = 10), recurrent hemarthrosis (n = 5), patellar maltracking (n = 4), tendon ruptures (n = 4), and stiffness (n = 2). In the extraarticular group, 10 knees (25.6%) were found to have nerve entrapment in the spine, 6 knees (15.4%) were found to have hip osteoarthritis or femoral head avascular necrosis. The reasons for persistent knee pain in the remaining 23 knees (59.0%) still remain elusive. CONCLUSIONS: Persistent pain after TKA originated from pathology of extra-articular origin in a considerable number of cases in this study. Therefore, it is important to perform thorough preoperative evaluations to reduce pain resulting from extra-articular causes. Furthermore, meticulous surgical procedures and optimal alignment are required to reduce pain of intra-articular origin related to implant wear, instability, and patellar maltracking.

Robotic Total Knee Arthroplasty with a Cruciate-Retaining Implant: A 10-Year Follow-up Study

BACKGROUND: This study compared clinical and radiological results between robotic total knee arthroplasty (TKA) and conventional TKA with a cruciate-retaining implant at 10-year follow-up. The hypothesis was that robotic TKA would allow for more accurate leg alignment and component placement, and thus enhance clinical and radiological results and long-term survival rates. METHODS: A total of 113 primary TKAs performed using a cruciate-retaining implant in 102 patients from 2004 to 2007 were reviewed retrospectively. Of the 113 TKAs, 71 were robotic TKAs and 42 were conventional TKAs. Clinical outcomes (visual analogue scale pain score, Hospital for Special Surgery score, Western Ontario and McMaster University score, range of motion, and complications), radiological outcomes, and long-term survival rates were evaluated at a mean follow-up of 10 years. RESULTS: Clinical outcomes and long-term survival rates were similar between the two groups. Regarding the radiological outcomes, the robotic TKA group had significantly fewer postoperative leg alignment outliers (femoral coronal inclination, tibial coronal inclination, femoral sagittal inclination, tibial sagittal inclination, and mechanical axis) and fewer radiolucent lines than the conventional TKA group. CONCLUSIONS: Both robotic and conventional TKAs resulted in good clinical outcomes and postoperative leg alignments. Robotic TKA appeared to reduce the incidence of leg alignment outliers and radiolucent lines compared to conventional TKA.

Causes and Clinical Outcomes of Revision Total Knee Arthroplasty

PURPOSE: The purpose of this study was to evaluate causes and clinical outcomes of revision total knee arthroplasty (TKA) with a minimum 2-year follow-up. MATERIALS AND METHODS: We performed a retrospective review on the records of 225 revision TKAs performed from 2003 to 2012 at a single institution. Finally, 206 cases were conducted. To evaluate clinical outcomes, we checked the range of motion (ROM), Knee Society (KS) score, Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score preoperatively, 6 months postoperatively and yearly thereafter and complications after revision TKA. RESULTS: The causes of revision TKA were septic complications in 120 and aseptic complications in 86. The main aseptic complication was periprosthetic fracture in 36, followed by 25 loosening, 13 polyethylene wear and 9 instability. At the final follow-up, patients showed improvements in ROM and KS, HSS and WOMAC scores. Of the total, 7 patients underwent re-revision due to reinfection in 6 and periprosthetic fracture in 1. CONCLUSIONS: Due to development of implants and surgical techniques, mechanical complications such as aseptic loosening and instability that need a revision decreased whereas septic complications relatively increased. Therefore, we should be cautious for the occurrence of infection. Overall, revision TKA provided clinical improvement in knee function and patient satisfaction.

Radiologic Measurement of Tibial Tuberosity-Trochlear Groove (TT-TG) Distance by Lower Extremity Rotational Profile Computed Tomography in Koreans

BACKGROUND: Tibial tuberosity-trochlear groove (TT-TG) distance is important in the assessment and treatment of patellofemoral disorders. However, normal and pathological TT-TG values have not been established in Koreans. The purpose of this study was to evaluate the TT-TG distance in the Korean population using lower leg rotational profile computed tomography (CT) scans. METHODS: One hundred rotational profile CT scans were retrospectively collected from patients without knee joint problems aged between 25 to 82 years. TT-TG distances were measured, and statistical analysis was performed. Each CT scan was measured twice in a blinded, randomized manner by three reviewers. Patients with pre-existing knee joint problems were excluded from the study; hence 15 of the 100 patients were excluded because of deformity or unreadable CT scans. Thus, 85 of the 100 patients were included in the study. RESULTS: Interobserver and intraobserver reliability of TT-TG distance measurements was good. The median TT-TG distance for this Korean population was 11.24 mm (mean, 10.24 +/- 0.8 mm). TT-TG distance measured nearly 2 mm less on rotational profile CT scans. CONCLUSIONS: Some of the TT-TG distances on rotational profile CT scans were significantly correlated, indicating that they could be accepted. Furthermore, the values on CT scans showed good reliability. In this study, the TT-TG distance in normal Korean people was approximately 10.24 mm without significant differences in TT-TG values between genders.

Comparison of Radiological Parameters between Normal and Patellar Dislocation Groups in Korean Population: A Rotational Profile CT-Based Study

PURPOSE: Patellofemoral instability is a common cause of anterior knee pain in adolescents and young adults. Most normal and pathological values for diagnosing patellofemoral instability are based on Western literature. We conducted this radiological study to determine normal values for different patellofemoral parameters in a Korean population and to evaluate their usefulness in diagnosis. MATERIALS AND METHODS: We retrospectively reviewed the rotational profile computerized tomography (CT) scans of the patellar dislocation and control groups. Trochlear, patellar, rotational profile, and trochleo-patellar alignment parameters were compared between the groups. Receiver operating characteristic curves were drawn for significant parameters, and sensitivity and specificity were calculated for the cut-off values. RESULTS: There were 48 patients in the patellar dislocation group and 87 patients in the control group. In the control group and patellar dislocation group, the mean sulcus angle was 132.5° and 143.3°, respectively, trochlear depth was 6.04 mm and 3.6 mm, bisect offset was 56.4% and 99.9%, lateral patellar tilting was 9.8° and 19.2°, patellar facet asymmetry was 63.5% and 45.16%, and the tibial tuberosity-trochlear groove (TT-TG) distance was 10.91 mm and 27.16 mm, respectively. CONCLUSIONS: The trochlear depth, bisect offset, patella tilting, and TT-TG distance were parameters that significantly contributed to patellar instability. Rotational profile CT can be considered a good diagnostic tool to assess all these parameters that help to identify anatomical aberration resulting in patellofemoral instability, thereby helping in formulating the most effective treatment plan.

Effect of Tranexamic Acid on Blood Loss and Blood Transfusion Reduction after Total Knee Arthroplasty

PURPOSE: Total knee arthroplasty (TKA) accompanies the risk of bleeding and need for transfusion. There are several methods to reduce postoperative blood loss and blood transfusion. One such method is using tranexamic acid during TKA. The purpose of this study was to confirm whether tranexamic acid reduces postoperative blood loss and blood transfusion after TKA. MATERIALS AND METHODS: A total of 100 TKA patients were included in the study. The tranexamic acid group consisted of 50 patients who received an intravenous injection of tranexamic acid. The control included 50 patients who received a placebo injection. The amounts of drainage, postoperative hemoglobin, and transfusion were compared between the groups. RESULTS: The mean amount of drainage was lower in the tranexamic acid group (580.6±355.0 mL) than the control group (886.0±375.5 mL). There was a reduction in the transfusion rate in the tranexamic acid group (48%) compared with the control group (64%). The hemoglobin level was higher in the tranexamic acid group than in the control group at 24 hours postoperatively. The mean units of transfusion were smaller in the tranexamic acid group (0.76 units) than in the control group (1.28 units). CONCLUSIONS: Our data suggest that intravenous injection of tranexamic acid decreases the total blood loss and transfusion after TKA.

Surgical Treatment of Neglected Traumatic Quadriceps Tendon Rupture with Knee Ankylosis

Quadriceps tendon rupture is an uncommon injury. This disabling condition is the result of direct or indirect trauma. It requires surgical repair to avoid poor outcomes in cases of neglected or chronic rupture. In most acute cases, simple tendon suture or reinsertion is suitable for an extensor mechanism reconstruction of the knee joint. However, chronic lesions often require a tendon graft or flap reconstruction. We report a case of a 15-year-old male who was diagnosed with a chronic quadriceps rupture with a patellar superior pole fracture. We performed quadriceps reconstruction using tibialis anterior allograft tendon and additional screw fixation to reconstruct the extensor mechanism and recover knee joint range of motion to prevent a high-level functional restriction. The treatment was difficult and limited due to neglect for 9-months that led to ankylosis accompanied with nonunion of tibial fracture. Our surgical treatment using allograft tendon resulted in a very good outcome after 30 months of follow-up.

Biomechanical Study of the Fixation Plates For Opening Wedge High Tibial Osteotomy

PURPOSE: The purpose of this study was to compare the mechanical stability of three types of plate systems for opening wedge high tibial osteotomy. MATERIALS AND METHODS: Forty-eight fresh frozen porcine tibia specimens were assigned to three different fixation device groups: Aescular group (16 specimens) was fixed with Aescular plates; Puddu group (16 specimens) with a Puddu plate, and TomoFix group (16 specimens) with a TomoFix plate. We compared axial displacements under compression loads from 200 to 2,000 N and maximal loads at failure among 8 specimens per group. We also compared displacements under cyclic load after 100 cycles at a compressive load of 2,000 N among 8 specimens per group. RESULTS: In all three groups, displacement under compression load increased with the increase in the axial compressive load; however, no significant intergroup differences were observed in the mean values under tested loading conditions. The mean maximal loads at failure were not significantly different (6,055, 6,798, and 6,973 N in the Aescular, Puddu, and TomoFix groups, respectively; p=0.41). While the TomoFix group showed less extension and strain during the cyclic load test, the mean values showed no significant differences among groups. CONCLUSIONS: All three plate systems were found to provide fixation stability suitable for bearing axial compression and cyclic loads while walking.

Survival and Risk Factor Analysis of Open Wedge Tibial Osteotomy for Medial Unicompartmental Osteoarthritis / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the mid to long-term clinicoradiological results of open wedge high tibial osteotomy performed as the primary treatment for medial unicompartmental osteoarthritis of the knee and to analyze the factors that affect the survival rate. MATERIALS AND METHODS: The study cohort consisted of 124 patients who underwent open wedge high tibial osteotomy for medial unicompartmental osteoarthritis of the knee and had a minimum follow-up period of five years. Hospital for special surgery (HSS) and the Western Ontario and MacMaster (WOMAC) scores, tibiofemoral angle, mechanical axis of lower limb, medial proximal tibia angle, and tibia posterior slope angle were used to evaluate the clinical and radiographic outcomes over the mean follow-up period of 85 months. The risk factors that affected the survival rate were calculated by multivariate regression analysis. RESULTS: Mean HSS scores and WOMAC scores showed significant improvements at the final follow-up. The tibiofemoral angle was improved to 8.4 degrees of valgus after surgery. A total of 12 patients (9.7%) failed to survive until the final follow-up resulting in 8 year survivorship of 90.3%. Risk factors significantly affecting the survival rate afteropen wedge high tibial osteotomy included a high body mass index (BMI), severe varus deformity, severe osteoarthritis (Kellgren-Lawrence Grade III or IV) preoperatively and overcorrection angles in operation. CONCLUSION: Open wedge high tibial osteotomy showed good clinical and radiological outcomes in the current study. Analysis of the risk factors influencing survivorship after open wedge high tibial osteotomy suggests that the surgical procedure be avoided or modified with patients who have a high BMI, severe varus deformity, or severe osteoarthritis symptoms preoperatively.

Retraction: Comparison of Accuracy of Navigation between Infrared Optical and Electromagnetic Systems / 대한정형외과학회잡지

This article has been retracted.

Retraction: Stress Fracture of the Tibial Plateau After Navigation Assisted Unicondylar Knee Arthroplasty: A Report of 2 Cases / 대한정형외과학회잡지

This article has been retracted.

Navigation Guided Open Wedge High Tibial Osteotomy / 대한정형외과학회잡지

Navigation systems are currently being widely used in orthopedic surgery. The mechanical axis alignment can be judged accurately via a navigation system. High tibial osteotomy (HTO) is a procedure that aims to change the mechanical axis of the lower limb, transferring the body weight across healthy articular cartilage. Several studies have shown that accurate correction is the leading predictor for success. And, by using a navigation system, accurate multiplane measurements of the lower limb alignment can be performed intraoperatively in real time, and alignment adjustments can be made as the surgeon desires. Compared with the conventional cable-method, computer navigation significantly improves the accuracy of postoperative leg axis, reduces correction variability with fewer outliers, and reduces radiation time. This paper reviews the advantages, clinical results, complications, pitfalls, and posterior tibial slope control in navigation guided open wedge HTO.

Comparison of Results of Total Knee Arthroplasty Performed Using the Navigation System and the Conventional Technique: Minimal Follow-Up of 5 Years / 대한정형외과학회잡지

PURPOSE: Authors compared the laxity, radiologic and clinical outcomes of total knee arthroplasty (TKA) performed using the navigation system and using the conventional technique at least 5-year follow-up. MATERIALS AND METHODS: Total of 92 TKAs were included for this study. Forty seven TKAs were performed by the navigation group and 45 TKAs were performed by the conventional surgery. At the final follow up, to evaluate knee joint laxity, varus-valgus laxities were measured on the stress radiographs taken with varus or valgus loads at 90degrees of flexion. The radiologic measurements and the clinical evaluations were compared between two groups. RESULTS: At the final follow-up, the mean of valgus laxities were 3.9degrees in the navigation group and 4.0degrees in the conventional group, and the corresponding mean of varus laxities were 4.0degrees and 4.3degrees (p=0.19, p=0.22) at 90degrees flexion state. Although there was no significant difference in the total laxities (7.8degrees in the navigation group and 8.1degrees in the conventional group, p=0.35). However, more than 10degrees of total laxity was significantly reduced in the navigation group (1 knee in the navigation group and 6 knees in the conventional group, p=0.04). The outlier numbers at mechanical axis, the mean of coronal inclination of the femoral and tibial component and the mean of sagittal inclination of the femoral and tibial component in the two groups were significantly different. Stiffness of WOMAC score was significantly better in the navigation than in the conventional group (p<0.001). CONCLUSION: Varus-valgus laxity was significantly different in the two groups as were the outlier numbers. The navigation system could provide good, improved alignment accuracy of the lower extremity and better result in stiffness of knee compared with conventional technique.

Minimum Two-year Results of Revision Total Knee Arthroplasty Following Infectious or Non-infectious Causes

PURPOSE: To compare clinical outcome of revision total knee arthroplasty (TKA) between the infected and non-infected groups. MATERIALS AND METHODS: This study compared the clinical and radiographic results of 21 infected and 15 non-infected revision TKAs at a minimum 2-years follow-up. Clinical evaluations were assessed using the range of motion (ROM), Hospital for Special Surgery (HSS) score, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and Western Ontario and McMaster Universities (WOMAC) score. Radiologic evaluations were assessed using the radiographic results of the American Knee Society and joint line change. RESULTS: Patients operated for non-infectious causes had significantly better postoperative ROM than the infected group (infected group, 101.7degrees; non-infected group, 117.8degrees). The infected group achieved significantly poor HSS (79.2 vs. 85.5), KSKS (75.5 vs. 86.6), KSFS (76.9 vs. 85.5), WOMAC (30.3 vs. 21.2) scores than the non-infected group. Postoperative joint line elevation was lower in the infected versus non-infected group (0.5 mm vs. 2.1 mm), but there was no significant difference. CONCLUSIONS: Revision TKA is an effective treatment that can provide successful results in the infected as well as non-infected patients. The overall results of non-infected revision were more satisfactory than infected revision.

Simultaneous Bilateral Quadriceps Tendon Rupture in a Patient with Chronic Renal Failure

Bilateral quadriceps tendon rupture is an unusual injury, but may be encountered in patients with various chronic diseases after minor trauma. This article presents a case of bilateral quadriceps tendon rupture of a 38-year-old woman with chronic renal failure. Surgical repair was performed using a bone tunnel technique with a nonabsorbable suture and a suture anchor. Postoperative magnetic resonance imaging confirmed complete healing of the repair site, and clinically active extension with 120 degrees of range of motion was achieved.