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

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.

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.
Animals ; Anterior Cruciate Ligament Reconstruction ; Anterior Cruciate Ligament ; Biological Factors ; Collagen ; Fibrin ; Fibrin Tissue Adhesive ; Knee ; Mesenchymal Stromal Cells ; Rabbits ; Transplants

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.
Arthroplasty, Replacement, Knee* ; Extremities ; Follow-Up Studies* ; Humans ; Knee ; Longevity ; Lower Extremity ; Ontario ; Osteoarthritis ; Postoperative Complications ; Prosthesis Failure ; Retrospective Studies ; Survival Rate

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.
Femur ; Humans ; Knee ; Osteotomy ; Patella ; Patellar Dislocation* ; Retrospective Studies

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.
Arthroplasty ; Arthroplasty, Replacement, Knee* ; Follow-Up Studies* ; Humans ; Incidence ; Knee ; Leg ; Ontario ; Range of Motion, Articular ; Retrospective Studies ; Robotics ; Survival Rate

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.
Arthroplasty, Replacement, Knee* ; Chronic Pain ; Head ; Hemarthrosis ; Humans ; Knee ; Necrosis ; Nerve Compression Syndromes ; Osteoarthritis, Hip ; Pain, Intractable ; Pathology ; Periprosthetic Fractures ; Polyethylene ; Rupture ; Spine ; Tendons

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.
Arthroplasty ; Arthroplasty, Replacement, Knee ; Follow-Up Studies ; Humans ; Knee ; Ontario ; Osteoarthritis ; Patient Satisfaction ; Periprosthetic Fractures ; Polyethylene ; Range of Motion, Articular ; Retrospective Studies

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.
Adult ; Aged ; Aged, 80 and over ; Female ; Femur/*anatomy & histology/*diagnostic imaging ; Humans ; Leg/anatomy & histology/diagnostic imaging ; Male ; Middle Aged ; Reference Values ; Republic of Korea ; Tibia/*anatomy & histology/*diagnostic imaging ; Tomography, X-Ray Computed

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.
Adolescent ; Allografts ; Ankylosis ; Follow-Up Studies ; Humans ; Knee Joint ; Knee ; Male ; Quadriceps Muscle ; Range of Motion, Articular ; Rupture ; Sutures ; Tendons ; Tibial Fractures ; Transplants