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Chondrosarcomas, malignant cartilaginous neoplasms, are capable of transitioning to highly aggressive, metastatic, and treatment-refractory states, resulting in significant patient mortality. Here, we aim to uncover the transcriptional program directing such tumor progression in chondrosarcomas. We conduct weighted correlation network analysis to extract a characteristic gene module underlying chondrosarcoma malignancy. Hypoxia-inducible factor-2α (HIF-2α, encoded by EPAS1) is identified as an upstream regulator that governs the malignancy gene module. HIF-2α is upregulated in high-grade chondrosarcoma biopsies and EPAS1 gene amplification is associated with poor prognosis in chondrosarcoma patients. Using tumor xenograft mouse models, we demonstrate that HIF-2α confers chondrosarcomas the capacities required for tumor growth, local invasion, and metastasis. Meanwhile, pharmacological inhibition of HIF-2α, in conjunction with the chemotherapy agents, synergistically enhances chondrosarcoma cell apoptosis and abolishes malignant signatures of chondrosarcoma in mice. We expect that our insights into the pathogenesis of chondrosarcoma will provide guidelines for the development of molecular targeted therapeutics for chondrosarcoma., Chondrosarcomas are frequently aggressive, understanding the transcriptional changes associated with progression may help in developing new treatments. Here, the authors show that HIF-2α is increased in expression on progression and pharmacological inhibition of the protein together with chemotherapy is a useful strategy for controlling tumour growth in mice.

Introduction: The aims of this study were to (1) assess the bone mineral density (BMD) around the knee joint, (2) determine the correlation between central and knee BMDs, and (3) investigate the factors associated with BMD around the knee joint in patients with knee osteoarthritis (OA). Methodology: This cross-sectional study included 122 patients who underwent total knee arthroplasty. Central and knee dual-energy X-ray absorptiometry was performed preoperatively. BMD at 6 regions of interest (ROIs) around the knee joint were measured, and their correlations with central BMD were determined using Spearman's correlation analysis. Lower limb alignment, severity of OA, body mass index (BMI), preoperative functional and pain scores were assessed to elucidate the factors associated with knee BMD using linear regression analysis. Results: Around the knee joint, BMD was the lowest at the distal femoral metaphysis and lateral tibial condyle. Knee BMD was significantly correlated with central BMD. However, the correlation coefficients varied by the ROI. Additionally, multivariate analysis revealed different associations with respect to the regions around the knee joint. Varus alignment of the lower limb was associated with increased BMD of the medial condyles and decreased BMD of lateral condyles. High grade OA was a protective factor; it was associated with increased BMD at the lateral condyles of the femur and tibia. Higher BMI was an independent protective factor in all ROIs around the knee joint except the lateral femoral condyles. Lower functional level was not associated with decreased BMD, whereas a higher pain score was significantly associated with lower BMD at the proximal tibial metaphysis. Conclusions: Knee BMD was significantly correlated with central BMD. However, the correlations varied with the regions around the knee joint probably due to their independent association with the alignment of the lower limb, severity of OA, BMI, and preoperative pain level.

The purpose of this study was to analyze the epidemiology of T-score discordance between the spine and femur in the South Korean population and compare the prevalence of T-score discordance between the Korean osteoporosis population and atypical femoral fracture (AFF) patients.A total of 12,422 subjects from the Korea National Health and Nutrition Examination Survey were reviewed retrospectively. T-score discordance was defined as a difference of ≥ 1 standard deviation between the lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD). The prevalence of T-score discordance (low LS [LS BMDFN BMD], low FN [LS BMDFN BMD], and total [low LS + low FN]) was investigated in the osteoporosis and non-osteoporosis groups and stratified by sex and age. T-score discordance of 63 patients with AFFs diagnosed at a single institution was compared with that of the Korean osteoporosis population using propensity score matching.T-score discordance was prevalent in the Korean osteoporosis population (44.8%), and low LS discordance (37.5%) was more frequently seen than low FN discordance (7.2%) (T-score discordance was highly prevalent in the Korean osteoporosis population, and low LS discordance was more common than low FN discordance. Nevertheless, the prevalence of low LS discordance was significantly higher in AFF patients than in the Korean osteoporosis population.

BACKGROUND Tranexamic acid (TXA) is typically discontinued on the day of total knee arthroplasty (TKA). However, bleeding may persist for several days. We sought to determine whether sequential administration of intravenous (IV) and oral TXA could reduce hemoglobin (Hb) drop more than IV TXA alone. We also wanted to determine whether the use of additional oral TXA increased the rate of complications of deep vein thrombosis (DVT) or symptomatic pulmonary embolism (PE). METHODS This prospective, randomized controlled trial included 141 patients. We compared the Hb drop, estimated blood loss (EBL), and transfusion rate of patients receiving IV TXA alone (group IV, n = 48) to those of patients who received IV TXA followed by oral TXA for 2 days (group 2D, n = 46) or 5 days (group 5D, n = 47). IV TXA was administered 10 minutes prior to the tourniquet release and 3 hours after the first IV TXA administration. Computed tomography (CT) was performed on postoperative day 6 to identify radiographic evidence of DVT. We also assessed the prevalence of symptomatic DVT and PE. RESULTS There were no differences in maximal Hb drop, Hb drops measured at each time point, EBL, or transfusion rate among the 3 groups. The mean maximal Hb drop was 3.5 g/dL in group IV, 3.2 g/dL in group 2D, and 3.4 g/dL in group 5D. The mean EBL was 999.9 mL in group IV, 886.4 mL in group 2D, and 972.5 mL in group 5D. One patient in each group required a transfusion. There were no differences in the prevalence of radiographic evidence of DVT or symptomatic DVT. Symptomatic DVT occurred in 3 patients in group IV and 2 patients in group 5D. One patient in group IV developed a symptomatic PE. CONCLUSIONS Although there was no increase in the complication rate, the sequential administration of oral TXA for up to 5 days after IV TXA did not decrease Hb drop. Therefore, our findings suggest that sequential use of oral and IV TXA is not recommended. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

This study aimed to (1) evaluate the preoperative Hb cut-off value for transfusion after unilateral and bilateral staged (1 week apart) TKAs, respectively, and (2) determine whether cause of preoperative anemia can affect transfusion rate after TKA. A total of 951 patients who underwent TKA (unilateral: 605, bilateral staged: 346) from 2016 to 2019 were reviewed retrospectively. Patient demographics, comorbidities, preoperative Hb level, surgery types, and cause of anemia were evaluated as possible risk factors. The cut-off values for preoperative Hb level to reduce transfusion after TKA were evaluated in each surgery type. Preoperative Hb level, surgery type, and cardiac disease were identified as the risk factors for transfusion after TKA, and preoperative Hb levels of 11.8 (AUC 0.88) and 12.8 (AUC 0.76) were the cut-off values for transfusion after unilateral and staged bilateral TKAs, respectively. Although transfusion rate was higher in anemia with iron deficiency (ID) group than anemia without ID group, preoperative Hb level was also lower in anemia with ID group than anemia without ID group. Single use of preoperative Hb level with different cut-offs depending on the surgery types can be useful indicator for preoperative optimization regardless of cause of anemia.

The role of unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) remains controversial, even though SONK involves only one compartment of the knee joint. We aimed to compare the survival rate and clinical outcomes of UKA in SONK and medial compartment osteoarthritis (MOA) via a meta-analysis of previous studies. MEDLINE, Embase, and Cochrane Library were searched up to January 2018 with keywords related to SONK and knee arthroplasty. Studies were selected with predetermined inclusion criteria: (1) medial UKA as the primary procedure, (2) reporting implant survival or clinical outcomes of osteonecrosis and osteoarthritis, and (3) follow-up period > 1 year. Quality assessment was performed using the risk of bias assessment tool for non-randomized studies. A random-effects model was used to estimate the pooled relative risk (RR) and standardized mean difference. The incidence of UKA revision for any reason was significantly higher in SONK than in MOA group (pooled RR = 1.83, p = 0.009). However, the risk of revision due to aseptic loosening was not significantly different between the groups. Moreover, when stratified by the study quality, high-quality studies showed similar risk of overall revision in SONK and MOA (p = 0.71). Subgroup analysis revealed no significant difference in failure between SONK and MOA after cemented mobile and fixed bearing UKA. Results of uncemented UKA were reported only in one study, which showed higher failure of SONK compared to MOA. Clinical outcomes after UKA were similar between SONK and MOA (p = 0.66). Cemented UKA has similar survival and clinical outcomes in SONK and MOA. Prospective studies designed specifically to compare the UKA outcomes in SONK and MOA are necessary.

Studies regarding the best strategy to determine appropriate femoral component rotation during bilateral total knee arthroplasty (TKA) in wind swept deformities (WSD) are very limited. The purpose of this study was (1) to evaluate whether femoral rotational profiles differ between varus and valgus osteoarthritic knees in WSD and (2) to analyze the correlation between femoral rotational profiles and coronal radiologic parameters.A total of 40 patients who were diagnosed with bilateral knee osteoarthritis with WSD between January 2010 and December 2020 at a single institution were retrospectively reviewed. On axial computed tomography scans, femoral rotational profile parameters such as the clinical transepicondylar axis (cTEA) and anterior-posterior (AP) axis were compared between valgus and varus osteoarthritic knees. In standing full-limb AP radiographs, coronal radiographic parameters including hip-knee-ankle angle (HKA), valgus correction angle (VCA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA) were measured in both knees. The correlation between the varus-valgus cTEA difference, and differences in coronal radiologic parameters was analyzed.In valgus osteoarthritic knees, cTEA was significantly increased compared to varus osteoarthritic knees by 1.5° (valgus: 7.65° ± 1.82°, varus: 6.15° ± 1.58°, p 0.001). All coronal radiologic parameters, including HKA, LDFA, MPTA, JLCA, and VCA, were significantly different between valgus and varus knees. In correlation analysis, the varus-valgus cTEA difference was significantly correlated with LDFA (r = 0.365, p = 0.021), MPTA (r = 0.442, p = 0.004), and HKA differences (r = 0.693, p 0.001), with the HKA difference showing the strongest correlation with the cTEA difference.In bilateral knee osteoarthritis with WSD, valgus knees showed significantly increased cTEA compared to varus knees, and the cTEA difference positively correlated with the HKA difference between valgus and varus knees. To determine the optimal femoral component rotation during TKA in WSD, assessment of cTEA with pre-operative CT scans or careful intra-operative measurement is recommended, especially in patients with large HKA difference.III, Retrospective cohort study.

The degree of cartilage degeneration assessed intraoperatively may not be sufficient as a criterion for patellar resurfacing in total knee arthroplasty (TKA). However, single-photon emission tomography/computed tomography (SPECT/CT) is useful for detecting osteoarthritic involvement deeper in the subchondral bone. The purpose of the study was to determine whether SPECT/CT reflected the cartilage lesion underneath the patella in patients with end-stage osteoarthritis (OA) and whether clinical outcomes after TKA without patellar resurfacing differed according to the severity of patellofemoral (PF) OA determined by visual assessment and SPECT/CT findings. This study included 206 knees which underwent TKA. The degree of cartilage degeneration was graded intraoperatively according to the International Cartilage Repair Society grading system. Subjects were classified into low and high uptake groups according to the degree of bone tracer uptake (BTU) on SPECT/CT in the PF joint. The Feller's patella score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed preoperatively and postoperative 1 and 2 years. The increased BTU in the PF joint was associated with more severe degenerative cartilage changes underneath the patella (p

Introduction Implant material is a more important factor for periprosthetic tibial bone resorption than implant design after total knee arthroplasty (TKA). The virtual perturbation study was planned to perform using single case of proximal tibia model. We determined whether the implant materials’ stiffness affects the degree of periprosthetic tibial bone resorption, and whether the effect of material change with the same implant design differed according to the proximal tibial plateau areas. Materials and methods This three-dimensional finite element analysis included two cobalt-chromium (CoCr) and two titanium (Ti) tibial implants with different designs. They were implanted into the proximal tibial model reconstructed using extracted images from computed tomography. The degree of bone resorption or formation was measured using the strain energy density after applying axial load. The same analysis was performed after exchanging the materials while maintaining the design of each implant. Results The degree of periprosthetic tibial bone resorption was not determined by the type of implant materials alone. When the implant materials were changed from Ti to CoCr, the bone resorption in the medial compartment increased and vice versa. The effect of material composition’s change on anterior and posterior areas varied accordingly. Conclusions Although the degree of bone resorption was associated with implant materials, it differed depending on the design of each implant. The effect on the degree of bone resorption according to the materials after TKA should be evaluated while concomitantly considering design.

Summary Cellular senescence is a complex stress response implicated in aging. Autophagy can suppress senescence but is counterintuitively necessary for full senescence. Although its anti-senescence role is well described, to what extent autophagy contributes to senescence establishment and the underlying mechanisms is poorly understood. Here, we show that selective autophagy of multiple regulatory components coordinates the homeostatic state of senescence. We combined a proteomic analysis of autophagy components with protein stability profiling, identifying autophagy substrate proteins involved in several senescence-related processes. Selective autophagy of KEAP1 promoted redox homeostasis during senescence. Furthermore, selective autophagy limited translational machinery components to ameliorate senescence-associated proteotoxic stress. Lastly, selective autophagy of TNIP1 enhanced senescence-associated inflammation. These selective autophagy networks appear to operate in vivo senescence during human osteoarthritis. Our data highlight a caretaker role of autophagy in the stress support network of senescence through regulated protein stability and unravel the intertwined relationship between two important age-related processes.

Background We determined whether postoperative intravenous (IV) iron supplementation could reduce transfusion rate in patients undergoing staged bilateral total knee arthroplasty (TKA). Furthermore, we examined whether hemoglobin (Hb) levels and iron profile differed between patients with and without postoperative IV iron supplementation. Methods This retrospective, comparative cohort study included 126 patients who underwent primary staged bilateral TKA during a single hospitalization. The second TKA was performed at a week’s interval. Group iron (n = 65) received IV iron immediately after each surgery, while patients in group no-iron (n = 61) received no iron after surgery. Transfusion rate, change in Hb levels, and iron profile including serum iron, ferritin, total iron binding capacity, and transferrin saturation were evaluated preoperatively; on postoperative days 1, 2, and 4 after the first TKA; and postoperative days 1, 2, 4, and 7, 6 weeks, and 3 months after the second TKA. Results There were no significant differences in Hb levels and transfusion rate following staged bilateral TKA between patients with and without postoperative IV iron supplementation although serum iron profiles were improved in patients with IV iron supplementation. Conclusion Postoperative IV iron supplementation immediately after acute blood loss caused by TKA was not effective in improving the transfusion rate. Therefore, surgeons should use protocols other than postoperative IV iron supplementation for reducing the transfusion rate in patients undergoing staged bilateral TKA in a single hospitalization. Level of Evidence III.

IntroductionAt present, information about clinical efficacy and adverse events of controlled release (CR) form of pelubiprofen, a prodrug of 2-arylopropionic acid with relatively selective effects on cyclooxygenase-2 activity, remains scarce. In this study, we sought to determine non-inferiority of pelubiprofen CR 90 mg/day compared to aceclofenac 200 mg/day regarding clinical efficacy and adverse events after a 4-week course of medication in the patients with symptomatic knee osteoarthritis.Materials and methodsA total of 191 patients were randomly assigned to take either pelubiprofen CR 90 mg (n = 95) or aceclofenac 200 mg (n = 96). The primary outcome variable was non-inferiority of pain reduction between baseline and week 4 when assessed using a 100 mm pain visual analogue scale (VAS). Pelubiprofen was considered non-inferior to aceclofenac if the upper limit of the one-sided 97.5% confidence interval for the difference in terms of pain VAS was above 15 mm (the average change of pain VAS in the pelubiprofen group-pain VAS reduction in the aceclofenac group). Secondary outcome variables were the changes in 100 mm pain VAS at week 2 versus baseline, K-Western Ontario, and McMaster University Arthritis Index (K-WOMAC) changes at weeks 2 and 4 as compared to baseline, patient global assessment at weeks 2 and 4. The frequency and amount of rescue medicine usage at weeks 2 and 4 were also evaluated as the secondary outcome variable. For safety analysis, adverse events, clinical laboratory tests, vital signs, and physical examinations were assessed and conducted at each follow-up visit.ResultsAt week 4, the pain VAS values were significantly reduced in both groups receiving either pelubiprofen CR 90 mg or aceclofenac 200 mg as compared to the baseline. However, the pelubiprofen group and the aceclofenac group respectively showed the pain VAS changes of -22 and -21.9 in the pre-protocol set and -20.8 and -21.7 in the full analysis set, confirming non-inferiority. The pelubiprofen CR 90 mg showed a reduced incidence of adverse events compared to the aceclofenac 200 mg (p = 0.005).ConclusionsPelubiprofen CR 90 mg is as effective as aceclofenac 200 mg with reduced adverse events for the treatment of symptomatic knee osteoarthritis.

We aimed at determining whether the coronal alignment of lower extremity was related to rotational geometry of distal femur, femoral anteversion, and tibial torsion in patients with knee osteoarthritis.A total of 422 lower extremities were divided into 3 groups according to the coronal alignment: valgus (n = 31), neutral (n = 78), and varus group (n = 313). Condylar twisting angle was measured to determine rotational geometry of distal femur as the angle between the clinical transepicondylar axis and the posterior condylar line. Femoral anteversion was assessed using the angle between a line intersecting the femoral neck and the posterior condylar line (pFeAV) and the angle between the same line and transepicondylar axis that is not affected by posterior condylar variations (tFeAV). Tibial torsion was evaluated by measuring the angle between the posterior condyles of the proximal tibia and the transmalleolar axis.As the coronal alignment changed from varus to valgus, the condylar twisting angle increased (r = 0.253, P.001; 6.6° in varus, 7.4° in neutral, and 10.2° in valgus group). Although the pFeAV also increased (r = 0.145, P = .003), the tFeAV did not change significantly (P = .218). Mean tFeAV was 4.3° in varus, 4.7° in neutral, and 6.5° in valgus group. In contrast, as the coronal alignment changed from varus to valgus, the external tibial torsion increased (r = 0.374, P.001; 22.6° in varus, 26.3° in neutral, and 32.6° in valgus group).The change patterns of the rotational profiles of the lower extremity according to the coronal alignment should be considered in order to obtain satisfactory rotational alignment after TKA.

Background This study aimed to determine the prevalence of excessive lateral pressure syndrome (ELPS) in potential candidates for high tibial osteotomy (HTO) using single-photon emission computed tomography–computed tomography (SPECT–CT). We also sought to identify risk factors related to the presence of ELPS. Methods This retrospective study included 150 patients (216 knees) who were candidates for HTO from an initial screening of 3579 patients (7158 knees). There were 183 female and 33 male knees with a mean age of 58 years. The presence of ELPS was defined as a grade 3 uptake on the SPECT–CT at the lateral PF joint. To determine the risk factors related to the ELPS, multivariate regression analysis was performed with independent demographic and radiographic variables. Results Increased uptake on the lateral side of the PF joints was detected in 120 knees (56% of total subjects). Of these, 34 (16%) knees presented with a grade 3 uptake, which indicated the presence of ELPS. No single risk factor had significant associations with the presence of ELPS. Conclusions A considerable number of the knees that were candidates for HTO had ELPS. Nonetheless, we did not find any risk factor related to the presence of ELPS. These results suggest that surgeons should be cautious when diagnosing concomitant ELPS despite acceptable radiographic findings from patellofemoral joints when performing HTO.

The purpose of this study is to compare the progression rate of bone union and clinical outcomes of opening wedge high tibial osteotomy (OWHTO) using allogenous bone chip or tri-calcium phosphate (TCP) granule as bone graft materials. The hypothesis was that the bone union progression in OWHTOs using TCP granule grafts would be comparable to that of OWHTOs using allogenous bone chip grafts. Between 2011 and 2013, 54 patients who had undergone OWHTO for genu varum and osteoarthritis were randomized to one of the two groups at five centres. TCP granule was used to fill the defect in 27 patients and lyophilized allogenous bone chip was used in the other 27 patients. The degree of bone union was classified on a five-point scale and evaluated using plain radiographs of the knee at 6 weeks, 3 months, 6 months, and 12 months postoperatively. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, pain Visual Analogue Scale (VAS) score and complications were also evaluated. The highest degree of bone union observed at 6 and 12 months postoperatively was grade 4, and the number of cases of union progression at each time-point was not significantly different between the two groups (p > 0.05). WOMAC and pain VAS scores also showed no differences between the two groups. No complications were observed during the 12-month period following OWHTO in either group. OWHTO using TCP granule bone substitute showed similar bone union rates and clinical outcomes compared to allogenous bone chip grafts. TCP granule can be used as bone substitutes instead of allogenous bone chip grafts in OWHTO. Level 1.

BACKGROUND Some patients with recurrent symptomatic instability after primary anterior cruciate ligament (ACL) reconstruction have an extension deficiency (ED). This study (a) compared preoperative clinical conditions between the ED and non-ED groups undergoing revision ACL reconstruction, (b) documented clinical and arthroscopic findings in ACL-reconstructed patients with reinstability and ED, and (c) determined whether the ED could be resolved and whether the clinical results of revision surgery differed between the ED and non-ED groups. METHODS This study included 58 patients who underwent revision ACL reconstruction. Patients were divided into the ED and non-ED groups. Preoperatively, the demographics and clinical conditions of the two groups were compared. Intraoperatively, the pathological structures that related to ED were documented. After surgery, the degree of postoperative ED and functional outcomes were compared between the two groups at 2-year follow-up. RESULTS The International Knee Documentation Committee subjective score and SF-36 physical component summary scores were worse in the ED group than the non-ED group preoperatively (54 vs 48 [P = 0.014]; 42 vs 39 [P = 0.031], respectively). Intraoperatively, the ED group showed significantly more frequent graft malposition (50% vs 5%), anvil osteophytes (44% vs 0%), and scarring around posterior intercondylar notch (100% vs 0%). However, there was no difference in the degree of postoperative ED and functional outcome between the two groups at follow-up. CONCLUSIONS ED in patients with recurrent instability after primary ACL reconstruction could be treated with good clinical result by addressing the pathological conditions causing ED in addition to ACL re-reconstruction.

Background We sought to document the incidences of deep vein thrombosis (DVT) before and after total knee arthroplasty (TKA). In addition, we aimed to explor whether routine preoperative DVT evaluation was useful to establish DVT treatment strategies after TKA. Finally, we wanted to evaluate whether the incidences of DVT differed between patients undergoing unilateral and staged bilateral TKA within the same hospitalization period. Methods The retrospective study included 153 consecutive patients (253 knees) with osteoarthritis who underwent primary TKA. After surgery, mechanical compression devices (only) were used for DVT prophylaxis. DVT status before and after TKA was determined via 128-row, multidetector, computed tomography/indirect venography. Results Overall, the preoperative DVT incidence was 2.6% per patient and 1.6% per knee. All preoperative DVTs were distal in nature and asymptomatic. After TKA, newly developed thrombi were evident in various calf veins, without propagation of any pre-existing thrombi. Postoperatively, the overall incidences of DVT were 69.9% per patient and 58.5% per knee. The DVT incidences were 66% per patient and 69.8% per knee in the unilateral TKA group. In contrast, the incidences were 72% per patient and 55.5% per knee in the staged bilateral TKA group. There was one case of symptomatic distal (unilateral TKA; 0.65% per patient and 0.4% per knee) and proximal DVT (bilateral TKA; 0.65% per patient and 0.4% per knee), respectively. Conclusions The incidence of symptomatic DVT was low in Asian patients treated with mechanical compression devices alone, although substantial portion of patients had DVT after surgery. Routine preoperative DVT evaluation is probably not necessary; preoperative DVT was rare and of limited clinical relevance. Furthermore, staged bilateral TKA during a single period of hospitalization does not increase the incidence of DVT.

Background We sought to determine the 10-year survivorship of single-radius, posterior-stabilized total knee arthroplasty (TKA) in Asian patients. We also aimed to determine whether the long-term clinical and radiographic results differed between patients with and without patellar resurfacing. Methods This retrospective study included 148 (115 patients) consecutive single-radius, posterior-stabilized TKAs. Ten-year survivorship analysis was performed using the Kaplan–Meier method with additional surgery for any reason as the end-point. Furthermore, long-term clinical and radiographic results of 109 knees (74%; 84 patients) with more than 10-year follow-up were analyzed. Ten-year survivorship and long-term outcomes after surgery were determined, and outcomes were compared between patients with and without patellar resurfacing. Results The cumulative survival rate of the single-radius posterior-stabilized TKA of 148 knees was 97.7% (95% confidence interval, 93.1%–99.3%) at 10 years after surgery. Three knees required additional surgery during the 10-year follow-up because of one case of instability and two cases of periprosthetic infections. Mean postoperative Knee Society knee score and function score were 97 points and 75 points, respectively. There were no cases of aseptic loosening of the prosthesis, even though a non-progressive radiolucent line was found in 10 (9%) knees. There were no differences in postoperative scores and degree of patellar tilt and displacement between patients with and without patellar resurfacing. Conclusions Single-radius, posterior-stabilized TKA showed satisfactory long-term clinical and radiographic outcomes in Asian patients regardless of patellar resurfacing, with comparable survivorship to that reported in westerners.

Background To date, there has been no established protocol regarding the timing of the scheduled administration of antiemetics in total knee arthroplasty (TKA). Previous prospective studies analyzing the scheduled use of antiemetics differed in the timing at which the drugs were administered. However, antiemetic drugs are not administered post-operatively until noxious stimuli caused by drugs used during anesthesia and operative procedures. The purpose of this study was 1) to determine whether preoperative scheduled administration of an antiemetic drug can reduce iatrogenic postoperative nausea and vomiting (PONV) in TKA compared to postoperative administration, and 2) to determine whether there was a difference in postoperative pain, patient satisfaction, and complications after TKA between pre- and postoperative administrations.Methods This retrospective study included patients who were assigned to either intravenous administration of the antiemetic drug (ramosetron) 1 hour before surgery (pre-injection group: 50 patients) or at the end of surgery (post-injection group: 51 patients). The incidence of PONV and the frequency of rescue medicine use were recorded until 48 hours postoperation. Postoperative pain level and satisfaction were also assessed using the visual analogue scale (VAS). Possible complications associated with serotonin receptor antagonists; for example, headaches, dizziness, and drowsiness were also assessed.Results The incidence of nausea events was lower in the pre-injection group than in the post-injection group. However, there was no difference between the two groups in terms of frequency of vomiting events and the use of rescue medicine for PONV. Also, postoperative pain, satisfaction scores, and incidence of complications were not different between the two groups.Conclusions The patients with preoperative scheduled administration of antiemetics showed lower incidence of nausea events than those with postoperative administration. However, it is difficult to conclude that the extent of the effect was clinically significant. Further research is needed to determine the optimal timing and method for more effective antiemetic treatment.

Osteoarthritis (OA) is a prevalent degenerative disease, which involves progressive and irreversible destruction of cartilage matrix. Despite efforts to reconstruct cartilage matrix in osteoarthritic joints, it has been a difficult task as adult cartilage exhibits marginal repair capacity. Here we report the identification of tankyrase as a regulator of the cartilage anabolism axis based on systems-level factor analysis of mouse reference populations. Tankyrase inhibition drives the expression of a cartilage-signature matrisome and elicits a transcriptomic pattern that is inversely correlated with OA progression. Furthermore, tankyrase inhibitors ameliorate surgically induced OA in mice, and stem cell transplantation coupled with tankyrase knockdown results in superior regeneration of cartilage lesions. Mechanistically, the pro-regenerative features of tankyrase inhibition are mainly triggered by uncoupling SOX9 from a poly(ADP-ribosyl)ation (PARylation)-dependent protein degradation pathway. Our findings provide insights into the development of future OA therapies aimed at reconstruction of articular cartilage., Osteoarthritis results from the progressive destruction of cartilage matrix. Here, Kim et al. identify tankyrase as a regulator of cartilage matrix anabolism, and find that tankyrase inhibition, by preventing SOX9 PARylation, protects from cartilage destruction in a mouse model of osteoarthritis.

There is little information about the management and clinical outcomes of the periprosthetic fracture after total knee arthroplasty (TKA) with a stem extension. The purposes of this study were to demonstrate management of the periprosthetic fractures after TKA with a stem extension, to report treatment outcomes, and to determine whether dual-plate fixation is superior to single-plate fixation regarding the radiographic bone union time and incidence of metal failure. This retrospective study included 15 knees with periprosthetic fractures after TKA using a stem extension. We demonstrated the fracture characteristics and management according to the fracture location and implant stability. The radiographic union time was determined. Complications, range of motion, and functional outcomes, including Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score were assessed. Periprosthetic fractures after TKA with stem extension were 1 metaphyseal fracture without implant loosening, 7 diaphyseal fractures adjacent to the stem without implant loosening, 3 diaphyseal fractures away from the stem without implant loosening, and 4 fractures with implant loosening. Treatment included immobilization using a long leg cast, open reduction and internal fixation (ORIF), and re-revision TKA. There was no difference in functional outcomes and range of motion pre- and posttreatment. The complications included 2 cases of subsequent implant loosening. Patients in the dual-plating required a shorter bony union time than those in the single-plating (2.4 ± 1.1 vs 7.4 ± 2.2 months; P = .003). Periprosthetic fractures after TKA with stem extension could be managed individually according to the fracture location and implant stability. Complications were not uncommon even if patients were able to return to their preinjury functional level posttreatment. To avoid complications after ORIF, the dual plate was superior to the single plate, and subtle implant loosening should not be overlooked.

Although the importance of quadriceps femoris function was reported previously, little is known about volume-related factors and their effects on clinical outcomes after total knee arthroplasty (TKA). We sought to determine whether there was a bilateral difference in vastus medialis muscle volume measured on single-photon emission computed tomography–computed tomography (SPECT-CT) in patients who underwent unilateral TKA. We also aimed to determine whether vastus medialis volume was related to osteoarthritis (OA) severity or scintigraphic uptake degree around the knee joint on SPECT-CT. And finally, we attempted to investigate the factors, such as vastus medialis volume and scintigraphic uptake degree, associated with the functional outcomes of TKA. This retrospective study included 50 patients (41 female, 9 male) undergone unilateral TKA due to primary OA. The maximal cross-sectional area of the vastus medialis was measured on axial SPECT-CT images. Scintigraphic uptake degrees and Kellgren-Lawrence (K-L) grade at the tibiofemoral joints were assessed. We compared maximal cross-sectional area of the vastus medialis on SPECT-CT for difference of bilateral lower limbs. We also analyzed the relationship between volume of vastus medialis and scintigraphic uptake measured on SPECT-CT and the severity of OA on conventional radiographs. The clinical outcomes were evaluated using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index at baseline and at 1 and 2 years after surgery. The relationship between preoperative muscle volume and scintigraphic uptake on SPECT-CT and WOMAC index was analyzed. The amount of muscle volume measured on SPECT-CT was smaller in operated limb in patients who underwent unilateral TKA. Preoperative vastus medialis muscle volume was not related to preoperative OA severity measured on conventional radiographs and scintigraphic uptake on SPECT-CT. However, a decreased vastus medialis muscle volume was related to worse clinical outcomes after TKA (P = .045), whereas the degree of scintigraphic uptake on SPECT-CT was not associated with postoperative clinical outcomes. Muscle volume of vastus medialis was decreased in the operated knee than in the nonoperated knee, and that was correlated with worse postoperative results. Even if the preoperative volume of vastus medialis were not related to OA severity on conventional radiographs and scintigraphic uptake on SPECT-CT, preservation and improvement of the muscle mass of the knee undergoing TKA is important.

The aim of this study was to determine whether the infection control rate of a modified debridement, antibiotics, and implant retention (DAIR) protocol (DAIR with antibiotic-impregnated cement beads) is comparable to that of 2-stage revision for acute periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). We also aimed to determine whether this modified DAIR technique produced better clinical results than those obtained using 2-stage revision in terms of functional outcome, range of motion (ROM), and patient satisfaction at 2 years after surgery. This retrospective comparative study included patients who underwent modified DAIR (7 patients, 9 knees) or 2-stage revision (8 patients, 9 knees) for acute PJI of the knee joint. Infection control rate, functional outcome measured using Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, ROM and patient satisfaction were compared between the two groups. There was no difference in infection control rates between the modified DAIR and 2-stage revision groups (78% vs 78%, respectively). In contrast, surgical outcome in the modified DAIR group was tended to be better than 2-stage revision group, but it did not reach statistical significance. Median maximal range of flexion was 103° in the modified DAIR group and it was 90° in the 2-stage group (P = .191). In addition, the median WOMAC function score was 24 in the modified DAIR group and it was 30 in the 2-stage group (P = .076). Median patient satisfaction measured using visual analogue scale was 8 in the modified DAIR group and 5 in the 2-stage group (P = .069). The infection control rates of the modified DAIR protocol and 2-stage revision protocol were similar for the treatment of acute PJI of the knee joint. However, the modified DAIR protocol could not provide substantially increased functional outcomes and patient satisfaction compared to 2-stage revision. Therefore, the modified DAIR technique should be considered to be of limited use in patients with high surgical morbidity.

A two-stage approach to total knee arthroplasty (TKA) using an antibiotic-impregnated articulating cement spacer is an option for an infected arthritic knee. Vancomycin combined with broad-spectrum antibiotics can be used to make an antibiotic-impregnated articulating cement spacer. Causative organisms are sometimes not confirmed before surgery. Joint infections of multidrug-resistant organisms are increasing. Therefore, routine combinations of antibiotics may not be effective. We present a case of a patient who developed vancomycin-resistant Pseudomonas aeruginosa infection in an arthritic knee. A 71-year-old man was initially diagnosed with pyogenic arthritis caused by Staphylococcus aureus. He underwent arthroscopic debridement elsewhere. However, the infection persisted. He was referred to our hospital, and we performed a two-stage TKA using a vancomycin-based antibiotic-impregnated articulating cement spacer. Vancomycin-resistant P. aeruginosa was identified after surgery. Intravenous colistin was added. However, this failed, either because vancomycin was not effective against P. aeruginosa, or because insufficient systemic colistin due to colistin-induced acute kidney injury. Therefore, debridement was repeated, and colistin-loaded cement spacer was inserted. The spacer delivered high concentrations of colistin to the infected joint with decreased systemic effects. Thus, less systemic colistin was used. The infection was controlled without recurrent acute kidney injury. One year after surgery, conversion to TKA was successfully performed. A two-stage approach to TKA using a colistin-loaded articulating cement spacer can be used for an arthritic knee infected by vancomycin-resistant P. aeruginosa. Furthermore, local administration of colistin using a cement spacer can reduce the systemic side effects of colistin.

Background Occasionally, patients experience new or increased ankle pain following total knee arthroplasty (TKA). The aims of this study were to determine (1) how the correction of varus malalignment of the lower limb following TKA affected changes in alignment of the ankle and hindfoot, (2) the difference in changes in alignment of the ankle and hindfoot between patients with and without ankle osteoarthritis (OA), and (3) whether the rate of ankle pain and the clinical outcome following TKA differed between the 2 groups. Methods We retrospectively reviewed prospectively collected data of 56 patients (99 knees) treated with TKA. Among these cases, concomitant ankle OA was found in 24 ankles. Radiographic parameters of lower-limb, ankle, and hindfoot alignment were measured preoperatively and 2 years postoperatively. In addition, ankle pain and clinical outcome 2 years after TKA were compared between patients with and without ankle OA. Results The orientation of the ankle joint line relative to the ground improved from 9.4° of varus to 3.4° of varus, and the valgus compensation of the hindfoot for the varus tilt of the ankle joint showed a 2.2° decrease following TKA. Patients in the group with ankle OA showed decreased flexibility of the hindfoot resulting in less preoperative valgus compensation (p = 0.022) compared with the group without ankle OA. The postoperative hindfoot alignment was similar between the 2 groups because of the smaller amount of change in patients with ankle OA. The group with ankle OA had a higher rate of increased ankle pain (38% compared with 16%) as well as a worse Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (mean of 22.2 compared with 14.2) following TKA. Conclusions A considerable proportion of patients who underwent TKA had concomitant ankle OA with reduced flexibility of the hindfoot. These patients experienced increased ankle pain following TKA and a worse clinical outcome. Level of evidence Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The purpose of this study was to assess the overall clinical results and range of motion (ROM) after total knee arthroplasty (TKA) in patients with preoperative stiffness. We also aimed to determine whether the severity or cause of the stiffness can affect the clinical outcome after surgery. This retrospective study included 122 knees (117 patients) with follow-up of more than 2 years (mean age, 64.3 years). TKA was performed using posterior-stabilized, varus-valgus constrained (VVC), and hinged prostheses. To determine the effect of the severity of stiffness on the clinical outcome, the subjects were divided into two groups: the severe group (preoperative ROM ≤ 50°; 18 knees) and the moderate group (preoperative ROM, 50°-90°; 104 knees). Then, clinical results and ROM were compared according to the severity or cause of preoperative stiffness. After surgery, preoperative ROM (mean, 78°; range, 25°- 90°) was improved (mean, 107°; range, 70°- 130°). The severe group more frequently used the VVC or hinged prostheses (72% vs. 18%). Furthermore, the severe group had worse knee and function scores as well as more complications (33% vs. 13%), even though the severe group had a greater ROM increment (47° vs. 27°) after surgery. Patients with osteoarthritis and rheumatoid arthritis showed better ROM and clinical results compared to patients with infectious or traumatic arthritis. Although TKA in stiff knees can be successful, the results are inferior in knees with severe stiffness and knees with infectious or traumatic arthritis.

Purpose The aim of this study was to determine the outcomes of bursoscopic ossicle excision in young and active patients with unresolved Osgood-Schlatter disease. Methods This retrospective study included 18 male military recruits. A direct bursoscopic ossicle excision was performed using low anterolateral and low anteromedial portals. Outcomes were evaluated using the Lysholm knee score, pain score on a visual analog scale (VAS) (from 0 to 10), and Tegner activity scale score. In addition, patients were asked whether they could kneel or squat and whether they were able to return to their duty after surgery. Patient satisfaction was evaluated using the VAS and by asking whether patients thought that the prominence of the tibial tuberosity was reduced and whether they would recommend the same surgical treatment to others. Complications after surgery were also evaluated. Results The mean Lysholm knee score was 71 preoperatively and improved to 99 after surgery. The mean VAS pain score was 6.5 in the preoperative period and decreased to 0.9 after surgery. In addition, the mean Tegner activity scale score improved from 2.7 preoperatively to 6.2 at final follow-up. However, 4 patients were not able to return to their duty, and 4 patients still had difficulties with kneeling after surgery. A superficial infection occurred in 1 patient, and a recurrent ossicle formation was found in 1 patient. Of 18 patients, 17 were satisfied with their surgical outcomes, and the mean VAS score for patient satisfaction was 8.8. Furthermore, all but 1 patient would recommend the same surgical treatment to others. However, 6 patients did not believe that the prominence of the tibial tuberosity was reduced. Conclusions Bursoscopic ossicle excision showed satisfactory outcomes in selective young and active patients with persistent symptoms. However, bursoscopic surgery showed limitation in reducing the prominence of the tibial tuberosity. Level of Evidence Level IV, therapeutic case series.

A progressive loss of cartilage matrix leads to the development of osteoarthritis (OA). Matrix homeostasis is disturbed in OA cartilage as the result of reduced production of cartilage-specific matrix and increased secretion of catabolic mediators by chondrocytes. Chondrocyte senescence is a crucial cellular event contributing to such imbalance in matrix metabolism during OA development. Here, we identify miR-204 as a markedly up-regulated microRNA in OA cartilage. miR-204 is induced by transcription factors GATA4 and NF-κB in response to senescence signals. Up-regulated miR-204 simultaneously targets multiple components of the sulfated proteoglycan (PG) biosynthesis pathway, effectively shutting down PG anabolism. Ectopic expression of miR-204 in joints triggers spontaneous cartilage loss and OA development, whereas miR-204 inhibition ameliorates experimental OA, with concomitant recovery of PG synthesis and suppression of inflammatory senescence-associated secretory phenotype (SASP) factors in cartilage. Collectively, we unravel a stress-activated senescence pathway that underlies disrupted matrix homeostasis in OA cartilage.

We hypothesized that the circumstances of the two consecutive operations of a simultaneous bilateral total knee arthroplasty (TKA) are different, and could lead to different outcomes of overlapping bilateral TKAs. Both knees of 420 subjects were evaluated in the current study. In the second TKA, there were more incidence rates of outlier in mechanical femoro-tibial angle (16.2% vs. 9.0%), more blood loss (735 vs. 656 mL), and longer operation time (61, 58 minutes respectively), as compared to the first TKA, while no significant differences in clinical outcomes. In conclusion, there were no significant differences in the clinical outcomes even though few distinct outcomes due to different circumstances of the surgery. Awareness of these findings can help the continued success of bilateral TKA in an increasing patient population.

We sought to determine the relationship between the mechanical axis-derived and the anatomic landmark-derived femoral rotational axes using three dimensional computed tomographic images of 20 lower extremities. The mechanical axis-derived femoral rotational axis was created on the distal articular surface of the femur using coronal mechanical limb axis and the reconstructed images of the femur. Then, we measured the angular difference between mechanical axis-derived and anatomic landmark-derived femoral rotational axes. The mechanical axis-derived femoral rotational axis was externally rotated with a mean of 2.2° (range, 0 to 4.7°; SD, 1.0) compared with the surgical epicondylar axis. Our findings should be considered to obtain a proper femoral rotational axis in total knee arthroplasty.

Staged bilateral total knee arthroplasty (TKA) may provide an ideal clinical model for the study of central sensitization. In staged TKA, hyperalgesia may be induced as a result of repeated surgical injury possibly via central sensitization, which can decrease functional outcomes. Therefore, we hypothesized that in staged bilateral TKA, patients would have greater pain in the second operated knee than in the first. Thirty patients undergoing staged bilateral TKA at a 1-week interval were enrolled. Postoperative pain, which was reported on the basis of a visual analog scale (VAS; primary outcome) at rest and at maximum knee flexion, and the amount of patient-controlled analgesic (i.v. fentanyl) and rescue analgesic (i.v. ketoprofen; secondary outcomes) administered during the 48 h after the operation, were compared between the first and second TKA. VAS scores at rest and at maximum knee flexion were greater on the second operated knee (P.001 and P.01, respectively). The cumulative amounts of patient-controlled analgesic and the rescue analgesic were greater in the second than in the first TKA (P.001 and P.05, respectively). Patients undergoing staged bilateral TKA experience greater postoperative pain in the second operated knee than the first. This suggests extension of hyperalgesia beyond the initially injured site to remote regions after surgical injury, in which central sensitization may be involved. Therapeutic approaches to reduce such hyperalgesia induced in the course of staged operations are required.

In studies of TKA, treating each knee as an independent case in patients with bilateral TKAs can lead to errors, because patients with bilateral and unilateral TKAs may achieve different levels of function and because the assumption of statistical independence is violated.We determined whether (1) patients undergoing bilateral TKAs have different demographics and preoperative and postoperative function from those undergoing unilateral TKAs, and (2) means, SEs, and p values change substantially based on how the two cases of bilateral TKAs are treated in statistical analyses.We retrospectively compared 513 patients undergoing unilateral TKAs and 602 patients undergoing bilateral TKAs regarding demographics (age, gender, BMI), preoperative and 1-year postoperative function (motion arc, American Knee Society score, patellofemoral score, WOMAC(TM), SF-36). Each case of a bilateral TKA was treated as independent in the reference analyses. Then changes of mean, SEs, and p values were compared with those of the reference method when three other methods of analysis were used: using mean values of both knees, randomly selecting one side, and using a generalized estimating equation.Patients undergoing bilateral TKAs had higher female predominance (95% versus 90%) and BMI (27.4 versus 26.1 kg/m(2)) than those undergoing unilateral TKAs. Although patients undergoing bilateral TKAs had worse preoperative function, they achieved comparable function at 1 year. The mean values did not differ considerably depending on the four methods. The SEs and p values of the reference method were generally the smallest, but the differences appeared negligible.Our analyses suggest bilaterality can be ignored in the analysis of TKA, since postoperative function is comparable between unilateral and bilateral TKAs and the theoretical errors in statistical analysis had little effect on the results.

The purposes of this study were to analyze the results of revision ACL reconstruction, and to determine the effects of pre-revision combined injuries, degenerative changes, and post-revision magnetic resonance imaging (MRI) findings on clinical results. Forty patients (41 operations) were enrolled in this study. Clinical results and stabilities were evaluated. Radiological results were evaluated using Fairbank scale. For the subgroup analysis, Fairbank scale and preoperative combined injuries were used. Follow-up MRIs were also available for 31(75.6%) patients and we searched for relations between MRI findings and clinical results. Significant improvements in subjective, objective scores (p0.0001), and stability (p0.0001) were observed between pre-revision surgery and final follow-up results. In the subgroup analysis according to the degenerative change, the mild group achieved better clinical results than the severe group (p=0.015 and 0.035, respectively). In the subgroup analysis according to the combined injuries, no significant difference was observed between 2 groups in terms of final follow-up Lysholm and IKDC subjective scores (p=0.083 and 0.085, respectively). No relation was found between clinical or stability results and MRI findings (p=0.26~0.99). Our results show that the severities of combined injuries were not correlated with clinical results, but the severities of degenerative changes were correlated with clinical results and that results were better in the no or mildly degenerated group. We also found that MRI is helpful for evaluating revision ACL, but that no relation was found between clinical or stability results and MRI findings of the graft after revision surgery.

The purpose of this study was to examine a developed surgical technique by performing a mid-term evaluation of clinical and stability results and complications.Thirty patients who underwent transtibial posterior cruciate ligament (PCL) reconstruction using a bioabsorbable cross-pin tibial back side fixation method were enrolled in this prospective study. Lysholm and International Knee Documentation Committee (IKDC) knee scales were used to evaluate clinical outcomes. Stability was evaluated using a Telos device with a 150 N force at 90 degrees of knee flexion. Follow-up magnetic resonance imaging (MRI) was also performed in 20 (66.7%) patients, and complications were evaluated. Those with complication by MRI were assigned to an abnormal MRI group.The follow-up period was 47 (range, 25-62) months. On comparing preoperative and final follow-up clinical results, Lysholm and IKDC knee scale scores were found to have improved significantly (P 0.001). The mean side-to-side difference in posterior translation measured using a Telos device was 13.4 ± 3.1 mm (range 10-20 mm) preoperatively and 3.2 ± 1.5 mm (range 1-7 mm) at last follow-up, which represented a significant improvement in stability (P 0.001). Five patients showed cyst formation in the tibial tunnel and two patients showed a significant signal increase at the anterior portion of the tibial tunnel, which was believed to indicate a pro-cystic status. The normal and abnormal MRI groups had similar Lysholm and IKDC knee scale scores and stress radiographs (P 0.05).Single-bundle transtibial PCL reconstruction using a bioabsorbable cross-pin tibial back side fixation was found to produce satisfactory clinical and stability results. However, despite these satisfactory results, a potential complication of tibial cyst formation was observed.Case series, Level IV.

The purpose of this study was to evaluate the accuracy of the characteristic magnetic resonance imaging (MRI) findings of medial meniscal root tear in the coronal, sagittal and axial planes. Thirty arthroscopically diagnosed patients who had undergone preoperative knee MRI were included in this study. They were compared to 30 age-matched patients with medial meniscus tears without root tears. The findings used for imaging analysis were as follows: the radial tear on the meniscal root of the medial meniscus in the axial plane, the presence of the truncation sign in the coronal plane and the ghost meniscus sign in the sagittal plane. Meniscal extrusion in the coronal plane was also evaluated. All the MRI findings of both groups were statistically analyzed. All the findings were more frequently found in the root tear group than those in the control group (P

Background: The correlation between graft appearance and clinical outcome after double-bundle anterior cruciate ligament (ACL) reconstruction is a major concern. In this study, the graft appearance was assessed with use of second-look arthroscopy and was correlated with the clinical outcome. Overall clinical outcomes after double-bundle ACL reconstruction with use of a single tibial tunnel were analyzed. Methods: Thirty-seven knees that underwent second-look arthroscopy after double-bundle ACL reconstruction and sixty-two knees that underwent double-bundle ACL reconstruction without subsequent second-look arthroscopy were included in this retrospective study. The ninety-nine patients enrolled were followed for thirty-five months (range, twenty-four to fifty-eight months), and the mean duration from ACL reconstruction to second-look arthroscopy was twenty-five months (range, twelve to thirty-six months). Graft thickness, apparent graft tension, and synovial coverage were graded during second-look arthroscopy. Correlations were sought between graft appearance and Lysholm knee scores, International Knee Documentation Committee (IKDC) grades, anterior laxity, and pivot-shift test results. Results: Postoperatively, ninety-four (94.9%) of the ninety-nine knees had an IKDC rating of B or higher, mean anterior laxity was 1.29 mm (range, 0 to 6 mm), and ninety-two knees (92.9%) had a negative pivot-shift result. With regard to graft thickness and tension, anteromedial bundles were graded as A in twenty-eight (75.7%) of the thirty-seven second-look knees and as B in nine knees (24.3%). Posterolateral bundles were graded as A in twenty-five knees (67.6%), B in six knees (16.2%), and C in six knees (16.2%). With regard to synovial coverage, anteromedial bundles were graded as C in only two knees (5.4%) and posterolateral bundles were graded as C in six knees (16.2%). No correlation was found between graft appearance and clinical outcome. Conclusions: In the present study, we observed that clinical outcomes were as satisfactory with a single tibial tunnel as with two tibial tunnels. However, more tears and poorer synovial coverage were observed for posterolateral than for anteromedial bundles during second-look arthroscopy. No significant correlation was found between graft appearance and clinical outcome. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

[Introduction][1] We describe a surgical release for patients who have a lack of elbow flexion limiting the ability to perform activities of daily living after trauma. ![Figure][2] ![Figure][2] [Step 1: Mobilize the Ulnar Nerve][3] Mobilize the ulnar nerve through the cubital tunnel with the accompanying superior ulnar collateral vessels. ![Figure][2] [Step 2: Dissect the Triceps and Resect the Posterior Aspect of the Capsule][4] Dissect the triceps from the distal part of the humerus and resect the posterior aspect of the capsule to expose the olecranon tip and fossa. ![Figure][2] [Step 3: Resect the Posterior Band of the Medial Collateral Ligament][5] Release the posterior band of the medial collateral ligament while continually checking the flexion arc until >130° of flexion can be achieved. ![Figure][2] [Step 4: Resect the Anterior Aspect of the Capsule][6] Perform an anterior approach if there is persistent flexion contracture or any impingement restricting full flexion. [Step 5: Lengthen the Triceps If Indicated][7] Consider triceps lengthening if you cannot achieve >130° of passive flexion with two fingers. ![Figure][2] [Step 6: Transpose the Ulnar Nerve Anteriorly][8] Locate the released ulnar nerve over the medial humeral epicondyle on the fascia overlying the common flexor-pronator muscles. [Step 7: Postoperative Management][9] Physical therapy consists of active-assisted and gentle passive flexion and extension exercises of the elbow, usually for two to six months. [Results][10] Forty-two patients with 130° of flexion can be achieved. ![Figure][2] [Step 4: Resect the Anterior Aspect of the Capsule][6] Perform an anterior approach if there is persistent flexion contracture or any impingement restricting full flexion. [Step 5: Lengthen the Triceps If Indicated][7] Consider triceps lengthening if you cannot achieve >130° of passive flexion with two fingers. ![Figure][2] [Step 6: Transpose the Ulnar Nerve Anteriorly][8] Locate the released ulnar nerve over the medial humeral epicondyle on the fascia overlying the common flexor-pronator muscles. [Step 7: Postoperative Management][9] Physical therapy consists of active-assisted and gentle passive flexion and extension exercises of the elbow, usually for two to six months. [Results][10] Forty-two patients with

Tenosynovial giant cell tumor, previously called pigmented villonodular synovitis (PVNS), is a rare benign neoplastic process that may involve the synovium of the joint. The disorder is usually monoarticular and only a few cases have been reported on polyarticular involvement. Herein, we present a case of localized intra-articular tenosynovial giant cell tumor in a 29-year-old man involving both knee joints with a description of the MR imaging and histological findings.

This study examined whether or not conservative treatment of an acutely injured anterior cruciate ligament (ACL) could be successful in a select group of patients. Routine ACL reconstruction surgery in all acute ACL-injured patients should be avoided. We hypothesize that acutely injured ACL with mild instability at the initial physical examination could be improved even if there is disruption of ACL fibers on magnetic resonance images (MRI).Among 232 acute ACL-injured patients who visited our institution from March 1997 to April 2006, 48 were treated non-operatively. Patients diagnosed with an acute ACL injury by MRI with Lachman testor =grade 1 were treated non-operatively. In this study, 30 male and 18 female patients with a mean age of 31.8 years were enrolled. The initial and follow-up Lachman test and pivot shift test were performed 3 weeks after the injury. The Lysholm knee scoring scale, International Knee Documentation Committee (IKDC) score and KT-2000 were obtained at the last follow-up.There were 12 complete (25%) and 36 incomplete ACL ruptures (75%). The patients were followed up clinically and with MRI for 21.5 and 11.3 months, respectively. The follow-up Lachman test improved to grade 0 in 41 patients (87%). Thirty-six patients (76%) showed no laxity in the follow-up pivot shift test. The last follow-up IKDC score was a mean value of 91.1 points. KT 2000 was performed in 40 patients with a mean side-to-side difference of 2.85 mm. Of 48 patients, 46 showed restored ACL continuity and 39 (84%) showed restored low signal intensity on MRI.A selective group of ACL tears with mild instability (Lachmanor =grade 1), though these seem to be complete tears on MRI, can show restoration of their continuity and signals on the MRI. Joint laxity on physical examination was improved at follow-up. These results suggest that a select group of patients with an acute ACL injury can successfully undergo non-operative treatment. In addition, unnecessary early ACL reconstruction surgery should be avoided.

The purpose of this study was to assess the correlations between dynamic postural stability and muscle strength, anterior instability, and knee scores in anterior cruciate ligament (ACL) deficient knees.We examined 40 male patients with ACL injury prior to surgery. Maximal torques of flexors and extensors of the injured knee at 60 and 180 degrees /s were evaluated using an isokinetic testing device. Anterior translations of the tibia were measured using a KT-2000 arthrometer, and dynamic postural stabilities were measured during single-leg stance using the Biodex Stability System (BSS). Knee statuses were evaluated using Lysholm and International Knee Documentation Committee (IKDC) knee scores. Correlations between dynamic postural stability and muscle strength, anterior instability, and knee scores were determined.Significant correlations were found between maximal torques of the extensor of injured knees at 60 and 180 degrees /s (r = -0.52, p = 0.048 and r = -0.46, p = 0.019, respectively) and dynamic postural stability, and maximal torques of flexors of injured knees showed similar relations (r = -0.51, p = 0.0048 and r = -0.47, p = 0.016, respectively). Lysholm and IKDC knee scores were also found to be correlated with dynamic postural stability (r = -0.49, p = 0.001 and r = -0.52, p = 0.005, respectively). However, no correlation was found between grade of anterior translation measured using the KT-2000 arthrometer and dynamic postural stability (p = 1.0).Dynamic postural stability determined using the BSS appears to be influenced by muscle strength, as determined by isokinetic testing, but not with grade of anterior translation measured using a KT-2000 arthrometer. Subjective knee scores appear to improve in parallel with dynamic postural stability.

BackgroundTears of the medial meniscus posterior horn (MMPH) are frequently found in knees with deficient anterior cruciate ligaments (ACLs). There are few studies that have evaluated healing of the menisci and the factors associated with healing.HypothesisThe repaired menisci would show good healing in the knees with reconstructed ACLs, and the healing capacity of the menisci would differ according to the size, type, and location of the tear as well as the age and gender.Study DesignCase series; Level of evidence, 4.MethodsFrom August 1997 to February 2007, 311 knees underwent MMPH repair using either a modified all-inside or inside-out technique with concomitant ACL reconstruction. Among these patients, a second-look arthroscopy was performed at a mean of 37.7 months postoperatively (range, 12-128 months) in 140 patients. Clinical parameters and outcomes were evaluated. The repaired menisci were divided into complete, incomplete, and failure-to-heal groups. The factors associated with meniscal healing were statistically assessed.ResultsAmong 140 patients, 118 (84.3%) showed complete healing, 17 (12.1%) had incomplete healing, and 5 (3.6%) failed to heal. The clinical success rate was 96.4% (135/140) because patients in the incomplete group showed no clinical symptoms associated with meniscal tears. Healing was associated with the tear location (P < .001) and type of tear (P = .0237) on the univariate analysis and the location (P = .0401) only on the multivariate analysis.ConclusionRepaired MMPH tears in knees with reconstructed ACLs healed without complications and had satisfactory clinical results. The tear location and type were factors associated with healing on the univariate analysis and location only on the multivariate analysis.

Purpose To evaluate the effectiveness of all-inside repair of posterior lateral meniscus root full-thickness tears with preoperative and postoperative magnetic resonance imaging (MRI) and to propose a system of classifying posterior lateral meniscus root tears. Methods From June 2003 to March 2007, 27 (6.95%) of a consecutive series of 388 anterior cruciate ligament reconstructions had a concomitant posterior lateral meniscus root tear. Of the patients, 25 (92.6%) were followed up for a more than 1 year. There were 22 male and 3 female patients, with a mean age of 28.8 years. The mean timing of surgery after injury was 40.8 months. The preoperative and postoperative MRI scans were analyzed and compared. We classified posterior lateral meniscus root tears according to arthroscopic findings. Results There was no postoperative effusion, joint-line tenderness, or positive McMurray provocation testing observed at the last follow-up. No statistically significant improvement was observed in the coronal plane in the 18 follow-up MRI scans ( P = .096); however, sagittal extrusion improved significantly ( P = .007). Posterior lateral meniscus root tears were classified based on arthroscopic findings: type I, oblique flap; type II, T shape; type III, longitudinal cleavage; or type IV, chronic inner loss. A type I tear was found in 7 patients, type II in 4, type III in 4, and type IV in 10. Conclusions After repair of posterior lateral meniscus root tears, MRI showed that the displaced lateral meniscus was reduced, mainly in the sagittal plane. Posterior lateral meniscus root tears were classified based on arthroscopic findings: type I, oblique flap; type II, T shape; type III, longitudinal cleavage; or type IV, chronic inner loss. Level of Evidence Level IV, therapeutic case series.

Background Anatomic limb alignment often differs from mechanical limb alignment after total knee arthroplasty (TKA). We sought to assess the accuracy, specificity, and sensitivity for each of three commonly used ranges for anatomic limb alignment (3-9°, 5-10° and 2-10°) in predicting an acceptable range (neutral ± 3°) for mechanical limb alignment after TKA. We also assessed whether the accuracy of anatomic limb alignment was affected by anatomic variation. Methods This retrospective study included 314 primary TKAs. The alignment of the limb was measured with both anatomic and mechanical methods of measurement. We also measured anatomic variation, including the femoral bowing angle, tibial bowing angle, and neck-shaft angle of the femur. All angles were measured on the same full-length standing anteroposterior radiographs. The accuracy, specificity, and sensitivity for each range of anatomic limb alignment were calculated and compared using mechanical limb alignment as the reference standard. The associations between the accuracy of anatomic limb alignment and anatomic variation were also determined. Results The range of 2-10° for anatomic limb alignment showed the highest accuracy, but it was only 73 % (3-9°, 65 %; 5-10°, 67 %). The specificity of the 2-10° range was 81 %, which was higher than that of the other ranges (3-9°, 69 %; 5-10°, 67 %). However, the sensitivity of the 2-10° range to predict varus malalignment was only 16 % (3-9°, 35 %; 5-10°, 68 %). In addition, the sensitivity of the 2-10° range to predict valgus malalignment was only 43 % (3-9°, 71 %; 5-10°, 43 %). The accuracy of anatomical limb alignment was lower for knees with greater femoral (odds ratio = 1.2) and tibial (odds ratio = 1.2) bowing. Conclusions Anatomic limb alignment did not accurately predict mechanical limb alignment after TKA, and its accuracy was affected by anatomic variation. Thus, alignment after TKA should be assessed by measuring mechanical alignment rather than anatomic alignment.

We sought to determine the usefulness and the disadvantages of the navigation in medial opening wedge high tibial osteotomy (MOWHTO) compared to the conventional technique, in terms of target coronal alignment achievement, tibial slope maintenance, radiation exposure and operative time. We retrospectively compared 40 knees treated with navigated MOWHTO by one surgeon with 20 knees treated with conventional MOWHTO by another surgeon. Screw length of the plate was predetermined using validated simple algorithms only in the navigation group to facilitate the operation. The acceptable range of the postoperative coronal alignment was defined as 2°–6° of the mechanical tibiofemoral angle (mTFA) and 55 %–70 % of the weight loading line coordinate (WLL). The proportion of the coronal alignment outlier, posterior tibial slope change, fluoroscopy time and operative time were compared. The coronal alignment outliers were fewer in the navigation group, but the differences were not significant (mTFA outlier 18 % vs. 30 %, p = 0.326; WLL outlier 20 % vs. 30 %, p = 0.519). Tibial slope was maintained in the navigation group (+0.3°, p = 0.732), whereas increased in the conventional group (+3°, p

Background Magnetic resonance imaging (MRI) may be useful to diagnose a posterolateral plica syndrome of the elbow joint because this syndrome has less clear clinical features. The purposes of this study were to document mediolateral and sagittal dimensions of a posterolateral synovial fold and to determine the proportion of subjects with the posterolateral plica in asymptomatic elbows. We also aimed to determine whether the dimensions of the posterolateral synovial fold and the prevalence of the plica differ between symptomatic and asymptomatic subjects. Materials and methods This retrospective review of prospectively collected data included 50 asymptomatic elbows (asymptomatic group) and 14 elbows with arthroscopically confirmed posterolateral plicae (plica group). The mediolateral and sagittal dimensions of the posterolateral synovial fold were measured. In addition, the criteria for the prevalence of posterolateral plica was determined with conventional MRI as synovial fold dimension ≥ 3 mm and coverage of radial head by synovial fold ≥ 30%. Results The plica group showed larger posterolateral synovial fold dimensions compared to the asymptomatic group. The median mediolateral and sagittal dimensions of the synovial fold in the asymptomatic group were 3.8 mm and 4.7 mm, respectively. Dimensions in the plica group were 7.0 mm and 7.4 mm, respectively. When the presence of posterolateral plica was determined using the dimension criteria, there was no difference in the prevalence of the plica between the asymptomatic and the plica group. However, using the coverage criteria, the prevalence of posterolateral elbow plica was significantly greater in the plica group than the asymptomatic group (64% vs. 18%; p < 0.001). Conclusions The patients who underwent arthroscopic surgery for posterolateral plica syndrome had larger dimensions of the posterolateral synovial fold and higher prevalence of the posterolateral plica on conventional MRI compared to the asymptomatic subjects.

The aim of this study was to determine whether pain intensity and wound complication rates differ between patients with and without preservation of the infrapatellar fat pad (IPFP) after minimally invasive total knee arthroplasty (TKA). The authors also sought to determine whether IPFP preservation affects operation time.This retrospective study included 448 knees with primary TKA. The IPFP was totally resected in 201 knees (IPFP-R group), and was preserved in 247 knees (IPFP-P group). Pain score was determined using the visual analog scale during the first 72 h after surgery. Wound complication rates and operation times were also evaluated. A wound complication was defined as persistent wound drainage for three or more days after surgery.There was no difference in pain levels between the two groups. However, there were fewer wound complications in the IPFP-P group (3 %) than in the IPFP-R group (13 %). The operation time was longer in the IPFP-P group than in the IPFP-R group (70 vs. 64 min, respectively).Although IPFP preservation delayed operation time, it decreased wound complications after MIS TKA. These findings are important to consider when deciding whether or not to resect the IPFP. Whenever possible, IPFP preservation is probably the preferred technique to reduce wound complications.

Background The prosthesis of contemporary total knee arthroplasty (TKA) has been modified to provide a more familiar environment for higher flexion angle of the replaced knee. The design modifications continue based on evidence reported in the literature. However, whether these modifications of the prosthesis design lead to improvements in clinical results needs further investigation. We determined whether the prosthesis modifications based on recent evidence improve clinical and radiographic results following high flexion TKA. Methods 524 patients who underwent primary TKA using two different high flexion prostheses were divided to Group 1 (HF-1) using a high flexion prosthesis, group 2 (HF-2) using the more recently devised high flexion prosthesis, which claims to be adopted from evidence proposed in the literature. Clinical outcomes included ranges of motion (ROM), the Knee Society knee and function score (KSKS and KSFS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, radiologic evaluation, and complication related to surgery. Results No differences in terms of clinical and radiographic results were observed between the groups at the 2 year follow-up. The mean ROM was 123°and 124° in the HF-1 and HF-2 groups, respectively. KSKS were 90 and 89.1, KSFS were 76.6 and 81.8, and total WOMAC scores were 23.1 and 24.9 in the HF-1 and HF- 2 groups. No differences of the incidences of radiolucency on radiographs (1.4% in HF-1, 2.1% in HF-2) and dislocation (1 case in HF-1 only) was observed. Conclusions Even if recent modifications in the design of high flexion TKA prosthesis were based on evidence in the literature, they did not provide meaningful improvements in short-term clinical and radiographic outcomes after TKA. Surgeons should consider our findings when choosing a prosthesis for their patients. Electronic supplementary material The online version of this article (doi:10.1186/1471-2474-15-433) contains supplementary material, which is available to authorized users.

Background The objectives of this study were to describe changes in physical activity profiles of Korean patients after TKA and to determine whether the postoperative physical activity level is influenced by patient socio-demographic factors and postoperative functional outcomes. We also sought to determine whether regular postoperative physical activity is associated with greater patient satisfaction after TKA. Methods This observational study included 369 patients. Physical activity profiles before and after TKA were evaluated using a questionnaire that contained the UCLA activity scale and types of sports activities. The associations of socio-demographic features and postoperative functional outcomes with the physical activity levels were assessed using subgroup comparisons and partial correlation analyses. In addition, the effects of regular physical activity on patient satisfaction with replaced knees were evaluated using subgroup comparisons. Results Walking, swimming and bicycling were the three most common sports activities both before and after TKA. After TKA, the mean activity level remained similar (UCLA score = 4.5 before TKA vs. 4.8 after TKA); however, the frequency of moderate activity levels (UCLA scale, 4-6) and moderate types of physical activities increased. Patients with higher postoperative function scores reported higher postoperative activity levels, but socio-demographic factors were not associated with activity level. Regular physical activity was associated with greater patient satisfaction. Conclusions This study provides valuable information about realistic expectations for physical activity after TKA. Regular participation in physical activity should be encouraged to improve patient satisfaction.

In total knee arthroplasty (TKA), the gap expansion effect by soft tissue laxity and bone resection amount influence directly on the proper gap size and ideal polyethylene insert thickness. In this study, we hypothesized if bone resection level could be controlled lesser as gap expansion effect resulted in the effects on gap expansion of the collateral release and lax lateral structure, appropriate gap size would be attained without extensive medial soft tissue release even in severe varus deformed knee. The purpose of this study was to show the usefulness of preoperative calculation of soft tissue laxity for determining the appropriate gap size for the targeted PE thickness in TKA. The preoperative varus stress view was used to estimate the effect of soft tissue release on extension gap expansion after primary bone resection. The amount of bone resection was determined with a parallel bone resection device used in our institution. Lateral laxity amount was applied into the device. This study was a retrospective review of 850 TKAs [451 with

Pseudo-patella baja (PPB) is a surgical complication that can arise from total knee arthroplasty and occurs when the patella tendon is not shortened but the level of the femorotibial joint line is elevated. The goal of this study was to assess the performance of a technique specifically designed to prevent the occurrence of PPB and its radiological results.Ninety-nine patients undergoing total knee arthroplasty were included. Patients were divided into a non-correction group and a correction group. The correction group were applied an additional metal block in order to reduce the excess resection of the distal femur. To evaluate PPB, the change in the pre- and postoperative joint line was measured using the modified Blackburne-Peel Index (BPI).In the non-correction group, 68 of 74 cases showed an occurrence of PPB (92 %), in the correction group, 6 of 57 cases showed an occurrence of PPB (11 %). The preoperative-modified BPI of the non-correction group was not significantly different from that of the correction group (0.6 ± 0.1 vs. 0.6 ± 0.2). The modified BPI decreased significantly in the non-correction group after TKA (0.6 ± 0.1 vs. 0.2 ± 0.1, p0.05). However, the modified BPI did not change significantly in the correction group after TKA (0.6 ± 0.2 vs. 0.6 ± 0.2).The comparison of preoperative and postoperative radiological results showed that our intervention maintained the joint line without elevation. We proposed an effective method to prevent various complications due to the joint line elevation that occur in PPB.III.