Kinematical alignment better restores native patellar tracking pattern than mechanical alignment.

PURPOSE: The purpose of this study was to assess whether kinematic alignment (KA) outperforms mechanical alignment (MA) in restoring patellar tracking to native patterns by using a clustering algorithm. METHODS: Twenty cadavers (40 knees) were evaluated. For each cadaver, one knee was randomly assigned to KA and the other to MA. KA total knee arthroplasty (TKA) procedures were performed using a caliper-verified technique, while MA TKA procedures utilized a measured resection technique. Subsequently, all specimens were mounted on a customized knee-testing system, and patellar tracking was measured using a motion analysis system. All patellar tracking data were clustered using the density-based spatial clustering of applications with noise algorithm. Differences in patellar tracking patterns and the restoration of native patellar tracking were compared between the two alignment strategies. RESULTS: Patellar tracking patterns following KA were considerably different from MA. Pre- and post-TKA patellar tracking patterns following MA were grouped into separate clusters, whereas a substantial proportion of patellar tracking patterns following KA were grouped into the pre-TKA dominant cluster. Compared to MA, a greater proportion of patellar tracking patterns following KA showed similar patterns to native knees (p < 0.05) and more patellar tracking patterns following KA paired with preoperative patterns (p < 0.01). CONCLUSION: KA restored native patellar tracking patterns more closely compared to MA. LEVEL OF EVIDENCE: Level I, therapeutic study.

Postoperative Hemodynamics of Total Knee Arthroplasty Unaffected by Cementless Approach under Contemporary Patient Blood Management Protocol: A Propensity Score-Matched Study.

(1) Background: A cementless total knee arthroplasty (TKA) is a recent and an increasingly popular innovation that enhances porous fixation surfaces. However, the lack of cemented sealing of an exposed resected bone has raised concerns about the potential for greater blood loss. The goals of this study were to determine if a cementless approach impacts post-TKA hemodynamics and to identify risk factors for blood loss in instances of cementless (vs. cemented) TKAs under a contemporary patient blood management (PBM) protocol. (2) Methods: We recruited 153 consecutive patients undergoing unilateral TKAs between 2019 and 2023. All enrollees received cementless or cemented prostheses of the same design (cementless, 87; cemented, 66). After propensity score matching for demographics, there were 46 patients in each group. We then compared blood loss metrics (total [TBL] and estimated [EBL]), drainage volumes, hemoglobin (Hb) levels, and transfusion rates by group. (3) Results: Post-TKA hemodynamics (i.e., TBL, EBL, drainage, Hb level, and transfusion rate) of cementless (n = 46) and cemented (n = 46) TKA groups did not differ significantly. In addition, the proportions of patients with Hb drops > 3.0 g/dL were similar for the two groups. A logistic regression analysis revealed that only preoperative Hb and EBL during the early postoperative period were predictive of a substantial fall in Hb levels. The fixation method was not associated with Hb decline > 3.0 g/dL by postoperative Day 3. (4) Conclusion: The cementless TKA has no impact on customary post-TKA hemodynamics and is not associated with greater TKA-related blood loss when implementing a contemporary PBM protocol.

No Blood Loss Increase in Cementless vs. Cemented Fixation Following Bilateral Total Knee Arthroplasty: A Propensity Score Matching Study.

Background and Objectives: Recent advancements in three-dimensional printing technology have enhanced the biologic fixation of cementless total knee arthroplasty (TKA), therefore increasing the utilization of newer-generation cementless implants. However, the lack of sealing and tamponade effect of cement on the resected bone surface after cementless TKA raises concerns regarding the potential for greater blood loss compared to cemented TKA. The aim of this study was to (1) compare blood loss and transfusion rates between cementless and cemented TKAs and (2) identify the risk factor for higher blood loss in patients who underwent 1-week-interval staggered bilateral (SB) TKA. Materials and Methods: This retrospective, propensity-matched study included 54 cementless and 53 cemented SB TKAs performed by a single surgeon from 2019 to 2023 with a single implant that has similar design features in both cementless and cemented implants. All patients underwent 1-week-interval SB TKA and received the same patient blood management (PBM) and rehabilitation protocol. The estimated total blood loss (TBL), transfusion rate, and total hemoglobin drop were assessed. Patients were categorized according to TBL into average TBL and higher TBL groups. Univariate and multiple logistic regression analyses were performed to identify risk factors for higher blood loss. Results: There was no difference in TBL between cementless and cemented TKA groups (1233 ± 299 and 1282 ± 309 mL, respectively; p > 0.05). In addition, no between-group differences in the transfusion rate and mean total hemoglobin drop were observed. The logistic regression analyses revealed that whether TKA was cementless or cemented was not associated with higher blood loss; rather, the only identified risk factor was the pre-TKA patient blood volume (odd ratio 1.001, 95% confidence interval 1.000-1002, p = 0.026). Conclusions: Contemporary cementless fixation does not increase blood loss or transfusion rates compared to cemented fixation in patients undergoing 1-week-interval staggered bilateral TKA.

Mobile-Bearing has no Benefit Over Fixed-Bearing Total Knee Arthroplasty in Joint Awareness and Crepitus: A Randomized Controlled Trial.

BACKGROUND: Given higher component conformity, rotational availability of polyethylene insert, and more physiologic patellofemoral tracking, mobile-bearing (MB) total knee arthroplasty (TKA) is supposed to offer advantages in joint perception and crepitus. The purpose of this study was to investigate whether MB TKA offers superior outcomes over fixed-bearing (FB) TKA in terms of joint awareness and crepitus. METHODS: This prospective, randomized, controlled trial included 49 FB and 49 MB TKAs that shared the same posterior-stabilized femoral component. Primary outcomes included joint awareness assessed with the Forgotten Joint Score and crepitus graded according to severity and sound at 3 years postoperatively. Secondary outcomes were the range of motion, the Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, component position, and joint line level on radiographs. RESULTS: The Forgotten Joint Score showed no significant difference between the FB (67 points; range, 0-100) and MB groups (63 points; range, 13-100) (P = .440). For crepitus, no significant differences were found in the overall incidence rate (FB group, 18%; MB group, 12%; P = .386) and grade (grade 1, 6 versus 5; grade 2, 2 versus 1; grade 3, 1 versus 0, respectively). There were no significant differences in range of motion, Knee Society Score, and Western Ontario and McMaster Universities Osteoarthritis Index, as well as radiographic outcomes between the two groups (all, P > .05). CONCLUSION: MB TKA offers no benefits in terms of joint awareness and crepitus compared with FB TKA at mean 3 years postoperatively. The theoretical advantages of MB TKA have yet to be demonstrated in practice, leaving the selection of bearing type to the surgeon's judgment. LEVEL OF EVIDENCE: Level II.

Guided-Motion Bicruciate-Stabilized Total Knee Arthroplasty Reproduces Native Medial Collateral Ligament Strain.

Background and Objectives: Guided-motion bicruciate-stabilized (BCS) total knee arthroplasty (TKA) includes a dual cam-post mechanism with an asymmetric bearing geometry that promotes normal knee kinematics and enhances anterior-posterior stability. However, it is unclear whether the improved biomechanics after guided-motion BCS TKA reproduce soft tissue strain similar to the strain generated by native knees. The purpose of this cadaveric study was to compare medial collateral ligament (MCL) strain between native and guided-motion BCS TKA knees using a video extensometer. Materials and Methods: Eight cadaver knees were mounted onto a customized knee squatting simulator to measure MCL strain during flexion in both native and guided-motion BCS TKA knees (Journey II-BCS; Smith & Nephew, Memphis, TN, USA). MCL strain was measured using a video extensometer (Mercury® RT RealTime tracking system, Sobriety s.r.o, Kurim, Czech Republic). MCL strain level and strain distribution during knee flexion were compared between the native and guided-motion BCS TKA conditions. Results: The mean and peak MCL strain were similar between native and guided-motion BCS TKA knees at all flexion angles (p > 0.1). MCL strain distribution was similar between native and BCS TKA knees at 8 of 9 regions of interest (ROIs), while higher MCL strain was observed after BCS TKA than in the native knee at 1 ROI in the mid portion of the MCL at early flexion angles (p < 0.05 at ≤30° of flexion). Conclusions: Guided-motion BCS TKA restored the amount and distribution of MCL strain to the values observed on native knees.

Central Sensitization Is Associated with Inferior Patient-Reported Outcomes and Increased Osteotomy Site Pain in Patients Undergoing Medial Opening-Wedge High Tibial Osteotomy.

Background and Objectives: Studies have shown that centrally sensitized patients have worse clinical outcomes following total knee arthroplasty (TKA) than non-centrally sensitized patients. It is unclear whether central sensitization (CS) affects patient-reported outcomes (PROs) and/or level of osteotomy site pain in patients undergoing medial opening-wedge high tibial osteotomy (MOWHTO). The purpose of this study was to determine whether CS is associated with PROs and osteotomy site pain following MOWHTO. Materials and Methods: A retrospective evaluation was conducted on 140 patients with varus knee osteoarthritis (OA) who were treated with MOWHTO and monitored for two years. Before surgery, the Central Sensitization Inventory (CSI) was used to assess CS status, and a CSI of 40 or higher was considered indicative of CS. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and pain visual analogue scale (VAS) were used to assess PROs. The minimal clinically important difference (MCID) for the WOMAC was set as 4.2 for the pain subscore, 1.9 for the stiffness subscore, 10.1 for the function subscore, and 16.1 for the total based on the results of a previous study. The WOMAC score, pain VAS score of the osteotomy site, and the achievement rates of WOMAC MCID were compared between the CS and non-CS groups. Results: Thirty-seven patients were assigned to the CS group, whereas 84 were assigned to the non-CS group. Before surgery, the CS group showed a higher WOMAC score than the non-CS group (58.7 vs. 49.4, p < 0.05). While there was a statistically significant improvement in WOMAC subscores (pain, stiffness, function, and total) for both groups at two years after surgery (all p < 0.05), the CS group had a higher WOMAC score than the non-CS group (37.1 vs. 21.8, p < 0.05). The CS group showed significantly inferior results in pre- and postoperative changes of WOMAC subscores (pain, function, and total) relative to the non-CS group (all p < 0.05). In addition, pain at the osteotomy site was more severe in the CS group than in the non-CS group at two years after surgery (4.8 vs. 2.2, p < 0.05). Patients with CS had worse MCID achievement rates across the board for WOMAC pain, function, and total scores (all p < 0.05) compared to the non-CS group. Conclusions: Centrally sensitized patients following MOWHTO had worse PROs and more severe osteotomy site pain compared to non-centrally sensitized patients. Furthermore, the WOMAC MCID achievement rate of patients with CS was lower than that of patients without CS. Therefore, appropriate preoperative counseling and perioperative pain management are necessary for patients with CS undergoing MOWHTO. Level of Evidence: Level III, case-control study.

Restoration of the Joint Line Configuration Reproduces Native Mid-Flexion Biomechanics after Total Knee Arthroplasty: A Matched-Pair Cadaveric Study.

Background: Recent evidence supports that restoration of the pre-arthritic condition via total knee arthroplasty (TKA) is associated with improved post-TKA performance and patient satisfaction. However, whether the restored pre-arthritic joint line simulates the native mid-flexion biomechanics remains unclear. Objective: We performed a matched-pair cadaveric study to explore whether restoration of the joint line via kinematically aligned (KA) TKA reproduced native knee biomechanics more accurately than the altered joint line associated with mechanically aligned (MA) TKA. Methods: Sixteen fresh-frozen cadaveric knees (eight pairs) were affixed onto a customized knee-squatting simulator for measurement of femoral rollback and medial collateral ligament (MCL) strain during mid-flexion. One knee from each cadaver was randomly designated to the KA TKA group (with the joint line restored to the pre-arthritic condition) and the other to the MA TKA group (with the joint line perpendicular to the mechanical axis). Optical markers were attached to all knees and rollback was analyzed using motion capture cameras. A video extensometer measured real-time variations in MCL strain. The kinematics and MCL strain prior to and following TKA were measured for all specimens. Results: KA TKA was better for restoring the knee kinematics to the native condition than MA TKA. The mid-flexion femoral rollback and axial rotation after KA TKA were consistently comparable to those of the native knee. Meanwhile, those of MA TKA were similar only at ≤40° of flexion. Furthermore, KA TKA better restored the mid-flexion MCL strain to that of the native knee than MA TKA. Over the entire mid-flexion range, the MCL strain of KA TKA and native knees were similar, while the strains of MA TKA knees were more than twice those of native knees at >20° of flexion. Conclusions: The restored joint line after KA TKA effectively reproduced the native mid-flexion rollback and MCL strain, whereas the altered joint line after MA TKA did not. Our findings may explain why patients who undergo KA TKA experience superior outcomes and more natural knee sensations during daily activities than those treated via MA TKA.

Dual-Energy CT-Based Bone Mineral Density Has Practical Value for Osteoporosis Screening around the Knee.

Introduction: Adequate bone quality is essential for long term biologic fixation of cementless total knee arthroplasty (TKA). Recently, vertebral bone quality evaluation using dual-energy computed tomography (DECT) has been introduced. However, the DECT bone mineral density (BMD) in peripheral skeleton has not been correlated with Hounsfield units (HU) or central dual-energy X-ray absorptiometry (DXA), and the accuracy remains unclear. Materials and methods: Medical records of 117 patients who underwent TKA were reviewed. DXA was completed within three months before surgery. DECT was performed with third-generation dual source CT in dual-energy mode. Correlations between DXA, DECT BMD and HU for central and periarticular regions were analyzed. Receiver operating characteristic (ROC) curves were plotted and area under the curve (AUC), optimal threshold, and sensitivity and specificity of each region of interest (ROI) were calculated. Results: Central DXA BMD was correlated with DECT BMD and HU in ROIs both centrally and around the knee (all p < 0.01). The diagnostic accuracy of DECT BMD was higher than that of DECT HU and was also higher when the T-score for second lumbar vertebra (L2), rather than for the femur neck, was used as the reference standard (all AUC values: L2 > femur neck; DECT BMD > DECT HU, respectively). Using the DXA T-score at L2 as the reference standard, the optimal DECT BMD cut-off values for osteoporosis were 89.2 mg/cm3 in the distal femur and 78.3 mg/cm3 in the proximal tibia. Conclusion: Opportunistic volumetric BMD assessment using DECT is accurate and relatively simple, and does not require extra equipment. DECT BMD and HU are useful for osteoporosis screening before cementless TKA.

Intravenous Ferric Carboxymaltose Improves Response to Postoperative Anemia Following Total Knee Arthroplasty: A Prospective Randomized Controlled Trial in Asian Cohort.

Background: Ferric carboxymaltose (FCM) is an intravenous (IV) high-dose iron that is effective in the treatment of iron deficiency anemia. This study was performed to determine whether postoperative FCM infusion is effective at improving hemoglobin (Hb) responders, Hb and iron profiles, and the patient's quality of life (QOL). Methods: A total of 110 patients with postoperative anemia, defined by a Hb < 10 g/dL within 3 days of unilateral primary TKA, between June 2018 and February 2020 were randomized into either the FCM or Control group. On postoperative day 3, the FCM group (55 patients) received IV FCM while the Control group (55 patients) did not. The Hb responders (Hb increase ≥ 2 g/dL compared to baseline), Hb level, iron profiles (ferritin, total iron-binding capacity (TIBC), transferrin saturation (TSAT)), and EQ-5D scores were compared at weeks 2, 4, and 8. Results: The FCM group demonstrated a significantly greater number of Hb responders (p < 0.001) and a higher Hb level (p = 0.008) at 2 weeks postoperative than did the Control group. The FCM group recovered its preoperative Hb level between 4 and 8 weeks. In contrast, the Control group did not recover its preoperative level until 8 weeks. The FCM infusion group also had higher serum ferritin, iron and TSAT, and lower TIBC levels than those of the Control group between 2 and 8 weeks (all p < 0.001). However, there was no significant difference in the postoperative transfusion rate (p = 0.741) or EQ-5D score between the two groups (all p > 0.05). Discussion: In postoperative anemia following TKA, IV FCM increases the Hb response and improves Hb and iron metabolism variables, however, it does not affect the transfusion rate or QOL.

Synergistic effect of the anterolateral ligament and capsule injuries on the knee laxity in anterior cruciate ligament injured knees: A cadaveric study.

INTRODUCTION: There is much controversy about the practical role of the anterolateral ligament (ALL) and its relation to other anterolateral knee structures including the anterolateral capsule (ALC) and iliotibial band (ITB). The purpose of this cadaveric study was to investigate the effect of the ALL and ALC injuries on knee laxity with the iliotibial band (ITB) preserved in the anterior cruciate ligament (ACL)-injured knee. HYPOTHESIS: The ALL and ALC would contribute to knee joint stability during anterior translation and internal rotation of the tibia in an ACL-injured knee. MATERIAL AND METHODS: For 10 fresh-frozen cadaveric knees, we measured knee laxity with the following state of knee injuries with ITB preserved: (1) intact knee, (2) ACL-sectioned knee (ACL-), (3) additional sectioning of the ALL (ACL-/ALL-), and (4) additional sectioning of the ALC (ACL-/ALL-/ALC-). We did biomechanical measurements in internal-external rotation, anterior-posterior translation, and varus-valgus angulation for each condition at knee flexion angles of 0°, 30°, 60°, and 90°. RESULTS: After we sectioned the ALL (ACL-/ALL-), the mean IR at 0°, 30°, 60°, and 90° of knee flexion were significantly increased, compared to the intact knee (p=<0.001, <0.001, <0.001, and 0.002) and ACL- (p=<0.001, <0.001, <0.001, and 0.002). The additional transection of the ALC (ACL-/ALL-/ALC-) significantly increased IR laxity from the ACL-/ALL- at 30°, 60°, and 90° (p=0.005, 0.003, and 0.047). For anterior laxity, ACL-/ALL- resulted in significantly increased anterior laxity from the ACL- at 30° and 60° (p=0.003 and 0.019), and ACL-/ALL-/ALC- significantly increased anterior laxity even from the ACL-/ALL- at 30° and 60° (p=0.007 and 0.011). For varus laxity, ACL-/ALL- resulted in significantly increased varus laxity from both the intact knee and ACL- at 60° (p=0.004 and 0.007) and 90° (p=<0.001 and<0.001). ACL-/ALL-/ALC- resulted in significantly increased varus from ACL-/ALL- at 60° and 90° (p=<0.001 and 0.003). CONCLUSION: The anterolateral ligament and anterolateral capsule injuries in ACL-injured knees even with ITB preserved had a synergistic effect on knee laxity in the aspects of internal rotation, anterior translation, and varus angulation. LEVEL OF EVIDENCE: II, Controlled laboratory study.

Is the patient aware of the difference between resurfaced and nonresurfaced patella after bilateral total knee arthroplasty? A systematic review of simultaneous bilateral randomized trials.

PURPOSE: The optimal practice of patellar management in total knee arthroplasty (TKA) remains controversial. This systematic review was conducted to compare patella-related (1) patient-reported outcome measures (PROMs), (2) clinical outcomes, and (3) reoperation rates after TKA with patellar resurfacing (PR) and nonresurfacing (NPR) in single patients undergoing bilateral patellar procedures during simultaneous bilateral TKA. METHODS: This review included prospective bilateral randomized trials investigating patella-related PROMs, clinical outcomes, and reoperation (secondary resurfacing and patellar component revision) and other patella-related complications in single patients undergoing randomly assigned PR and NPR during bilateral TKA. RESULTS: Six studies were included. There was no difference in PROMs between PR and NPR in five studies, whereas PR was found to be superior to NPR in one study. Five studies reported similar functional outcomes and complication rates between PR and NPR, while one study found better clinical outcomes and a lower complication rate in PR. Between-group secondary resurfacing and patellar revision rates were similar in all studies. CONCLUSIONS: The majority of patients who underwent bilateral patellar procedures could not tell the difference between PR and NPR following bilateral TKA. There were no differences in clinical outcomes or reoperation and complication rates between PR and NPR. No evidence was found to support routine PR. LEVEL OF EVIDENCE: Therapeutic Level 1.

Centrally sensitized patients undergoing total knee arthroplasty have higher expectations than do non-centrally sensitized patients.

PURPOSE: The goal of this retrospective observational study is to determine whether patients with and without central sensitization (CS) undergoing total knee arthroplasty (TKA) have similar preoperative expectations. It was hypothesized that the degree of preoperative expectations is higher in patients with CS than in those without. METHODS: The data of 324 patients who underwent primary unilateral TKA for knee osteoarthritis were reviewed and CS was measured using the Central Sensitization Inventory (CSI), which is a validated self-reported questionnaire consisting of a total of 25 questions. CS was defined as a CSI score of 40 or more. Patient expectations were investigated using the Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES) comprising five categories including pain relief, baseline activity, high flexion activity, social activity, and psychological well-being. The expectations of patients, the Western Ontario and McMaster Universities arthritis index (WOMAC) and American Society of Anesthesiologists (ASA) classification scores were compared between the CS and non-CS groups. RESULTS: The top three patient expectations in both groups were pain relief, psychological well-being, and walking ability. The total score for the expectations was 55.0 ± 8.3 in the CS group and 52.3 ± 10.4 in the non-CS group, indicating that the expectations of the CS group were higher than the non-CS group before TKA (p < 0.05). When the items on the HSS-KRES scale and the five categories were compared, the CS group had significantly higher expectations for pain relief and psychological well-being than did the non-CS group (all p < 0.05). CONCLUSION: The expectations of patients with CS before TKA were higher than those without CS. Given the limited improvement in patient-reported outcome measures of patients with CS undergoing TKA, they should be counseled to be realistic especially with their preoperative expectations of pain relief and psychological well-being. LEVEL OF EVIDENCE: III.

Risk factors and preventive strategy for excessive coronal inclination of tibial plateau following medial opening-wedge high tibial osteotomy.

PURPOSE: To investigate risk factors and suggest preventive strategy for excessive coronal inclination of tibial plateau following medial opening-wedge high tibial osteotomy (MOWHTO). METHODS: A total of 133 consecutive patients who underwent MOWHTO were retrospectively enrolled. Patients were divided into two groups based on postoperative medial proximal tibial angle (post-MPTA) of 95°: control group (n = 111, 83.5%) with post-MPTA less than 95° and excessive MPTA group (n = 22, 16.5%) with post-MPTA 95° or more. Demographics, radiographic parameters [mechanical lateral distal femoral angle (mLDFA), MPTA, posterior tibial slope, joint line obliquity (JLO), hip-knee-ankle angle, joint line convergence angle (JLCA), weight bearing line ratio, and correction angle], and clinical outcomes of patients were compared. Multiple logistic regression analysis was performed to determine risk factors for post-MPTA 95° or more. RESULTS: Multiple logistic regression analysis showed that preoperative JLO ≥ 3° [odds ratio (OR) 6.940, 95% confidence interval (CI) 2.373-20.296, p < 0.001] and preoperative JLCA ≥ 5° (OR 5.723, 95% CI 1.833-17.865, p = 0.008) were statistically significant risk factors for post-MPTA ≥ 95°. Incidences of excessive MPTA following MOWHTO in patients with none, one, and two risk factors preoperatively were 3.7%, 26.7%, and 77.8%, respectively. CONCLUSION: Preoperative JLO ≥ 3° and JLCA ≥ 5° were two significant risk factors for excessive MPTA following MOWHTO. Thus, surgeon should consider other types of osteotomy if these two risk factors are present together preoperatively in MOWHTO candidates. LEVEL OF EVIDENCE: Level III.

Influence of increased pain sensitivity on patient-reported outcomes following total knee arthroplasty.

PURPOSE: The purpose of this study was to discover whether increased pain sensitivity was associated with postoperative pain and patient-reported outcome measures (PROMs) after total knee arthroplasty (TKA). METHODS: Pain sensitivity was evaluated preoperatively using a pain sensitivity questionnaire (PSQ). Resting, walking, nighttime, and average pain visual analog scale (VAS) were measured before surgery and 6 weeks, 3 months, 6 months, and 1 year after surgery. PROMs were also evaluated based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and patient satisfaction. The association between pain VAS average score, WOMAC total score, and PSQ score (minor, moderate, and total score) was assessed at each stage. RESULTS: There were 59 patients with a high PSQ score (≥ 5.2) and 53 with a low PSQ score (< 5.2). Up to 1 year postoperatively, the group with high PSQ scores had higher resting, walking, nighttime, and average pain VAS scores than the group with low scores (all p < 0.05). Worse preoperative WOMAC pain, function, and total scores continued until 1 year after surgery in the high-scoring PSQ group (all p < 0.05). The group with low PSQ scores was more satisfied with surgery than the group with high scores (p = 0.027). There was a positive correlation between preoperative PSQ score and pain VAS average score at all time points (all p < 0.05). A relationship between PSQ score and WOMAC total score was also observed (all p < 0.05). CONCLUSION: Increased pain sensitivity is a factor related to higher postoperative pain levels and inferior PROMs in patients undergoing primary TKA. LEVEL OF EVIDENCE: Case-controlled study, III.

Changes in joint space width over time and risk factors for deterioration of joint space width after medial opening-wedge high tibial osteotomy.

PURPOSE: The purpose of this study was to evaluate the changes in joint space width (JSW) over time after medial opening-wedge high tibial osteotomy (MOWHTO) and identify risk factors for deterioration of JSW using anteroposterior (AP) and Rosenberg views. METHODS: We retrospectively analyzed changes in JSW of 104 MOWHTO patients whose preoperative osteoarthritis (OA) grade was K-L grade 3 or less on AP and Rosenberg views. Serial changes in JSW were assessed from preoperatively to at least 3 years postoperatively. Patients were divided into two groups according to JSW change patterns on each of AP and Rosenberg views: non-deterioration group had either unchanged or increased JSW, and deterioration group had decreased JSW. Clinical outcomes were compared using Western Ontario and McMaster Universities OA Index (WOMAC) score between groups. Multivariate logistic regression analysis was performed to identify risk factors for deterioration of JSW. RESULTS: JSW on average for all patients increased 0.5 mm and 0.8 mm on AP and Rosenberg views, respectively (p < 0.05). Non-deterioration group showed significant improvement based on patient-reported outcomes (WOMAC) than deterioration group (all p < 0.05). Undercorrection was an independent risk factor for failure to achieve maintained or increased JSW on both AP (OR 6.885, 95% CI 1.976-23.986, p = 0.002) and Rosenberg (OR 12.756, 95% CI 2.952-55.129, p = 0.001) views. CONCLUSION: JSW increased gradually and continuously on standing AP and Rosenberg views until postoperative 3 years after MOWHTO. Deterioration of JSW following MOWHTO was closely related to the undercorrection and affected clinical outcomes. LEVEL OF EVIDENCE: Level III, case control study.

Kinematically aligned total knee arthroplasty restores more native medial collateral ligament strain than mechanically aligned total knee arthroplasty.

PURPOSE: Kinematically aligned total knee arthroplasty (KA TKA) targets restoration of patient-specific alignment and soft tissue laxity. However, whether KA TKA reproduces native soft tissue strain remains unclear. This cadaveric study tested the hypothesis that KA TKA would better restore the quantitative strain and strain distribution of medial collateral ligament (MCL) to the native healthy knee compared to mechanically aligned (MA) TKA. METHODS: Twenty-four fresh-frozen cadaver knees (12 pairs) were mounted on a customized knee squatting simulator to measure MCL strain during flexion. For each pair, one knee was assigned to KA TKA and the other to MA TKA. During KA TKA, the amount of femur and tibia resected was equivalent to implant thickness without MCL release using the calipered measuring technique. MA TKA was performed using conventional measured resection techniques. MCL strain was measured using a video extensometer (Mercury® RT RealTime tracking system, Sobriety s.r.o, Czech Republic). MCL strain and strain distribution during knee flexion were measured, and the measurements compared between native and post-TKA conditions. RESULTS: Mean and peak MCL strain were similar between KA TKA and native knees at all flexion angles (p > 0.1 at all flexion angles) while mean strain at all flexion angles and peak strain at ≥ 60º of MA TKA were approximately twice those of the native knees (p < 0.05 at ≥ 60º of flexion). In addition, greater MCL strain was observed in 4 of 12 regions of interest (ROI) after MA TKA (M1, M2, P1 and P2) compared to the native knee, whereas after KA TKA, MCL strain measurements were similar at all but 1 ROI (P2). CONCLUSIONS: KA TKA restored a more native amount and distribution of MCL strain compared to MA TKA. These findings provide clues for understanding why patients may experience better performance and more normal knee sensations after KA TKA compared to MA TKA. LEVEL OF EVIDENCE: Therapeutic study, Level I.

Porcine-Derived Collagen-Augmented Chondrogenesis Technique for Treating Knee Cartilage Defects.

Articular cartilage is virtually incapable of self-healing in the event of a defect. Microfracture is the most frequently used bone marrow stimulation technique1, but there is the limitation of unpredictable quality of the cartilage repair following bone marrow stimulation2. To resolve the shortcomings of the microfracture technique, various reinforcing technologies have been developed, including the porcine-derived collagen-augmented chondrogenesis technique (C-ACT)3. The collagen gel utilized in that procedure is a product called CartiFill (Sewon Cellontech), made from highly purified pig-derived type-I collagen. It has been modified into an atelocollagen, by removing telopeptides, to virtually eliminate the risk of rejection. The collagen matrix provides not only a 3-dimensional structure for cartilage differentiation, but also mechanical support3,4. DESCRIPTION: Porcine-derived C-ACT is initiated by creating a mixture of atelocollagen, thrombin, and fibrinogen. First, thrombin is mixed with atelocollagen and placed in one arm of an assembled Y-shaped syringe, and fibrinogen is placed in the other arm. The articular cartilage defect site is confirmed in a routine arthroscopic procedure. The articular margin is debrided, and the calcified lesion is cleanly removed. Then, microfractures are created. After creating a more extended incision at the anteromedial portal, the microfracture site is prepared by removing moisture. The prepared atelocollagen mixture is applied to the defect site as a single layer, although a second layer can be formed 1 to 2 minutes later. After 5 minutes, the stability is verified by range of motion of the knee.Indications for this procedure include (1) cartilage defects in the knee, including knee osteoarthritis and knee traumatic arthritis; (2) knee osteoarthritis with a Kellgren-Lawrence grade of 3 or less; (3) hip-knee-ankle malalignment of <5° or a deformity that is able to be surgically corrected; and (4) knee stability, or instability that is able to be surgically corrected.Contraindications for this procedure include (1) patient or family history of autoimmune disease, (2) history of anaphylactic reaction, (3) history of hypersensitivity to an implant, (4) history of allergy to porcine or bovine protein, and (5) inflammatory arthritis such as rheumatoid and gouty arthritis.C-ACT is a procedure for cartilage repair, and the effects of this procedure can be limited in cases with a deep subchondral bone defect; however, there is no limit to the size of the cartilage defect in terms of patient selection for C-ACT. ALTERNATIVES: There are several alternatives to C-ACT, ranging from the simple microfracture technique to autologous chondrocyte implantation5, matrix-induced autologous chondrocyte implantation6, autologous matrix-induced chondrogenesis7, osteochondral autograft transplantation8, and stem cell therapy. There are various ways to recover from an articular cartilage defect, but C-ACT does not require a 2-stage technique, as is necessary with both autologous chondrocyte implantation procedures. Therefore, C-ACT has the advantages of ease of operation and being a single-stage procedure3,9. RATIONALE: C-ACT can be classified as an upgraded version of microfracture, which is the most common treatment method for articular cartilage defects. With the microfracture technique, repaired cartilage is limited to fibrous cartilage and does not include hyaline cartilage3,4. However, a recent study reported that C-ACT exhibited a superior quality of repaired cartilage compared with microfracture3,4. EXPECTED OUTCOMES: Previous studies have reported favorable results with the use of C-ACT3,4. Kim et al.4 compared atelocollagen augmentation with microfracture alone in patients undergoing medial opening wedge high tibial osteotomy for the treatment of medial compartment osteoarthritis. Although there was no clinical difference between the 2 groups, the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score and the International Cartilage Repair Society II score were superior in the atelocollagen augmentation group. In addition, the microfracture group formed fibrous-like cartilage compared with the hyaline-like cartilage created in the atelocollagen augmentation group. A recent multicenter randomized study compared the use of C-ACT and microfracture and found that C-ACT exhibited significantly better results in several MOCART subscores and quantitative T2 mapping, indicating a histologically superior form of repaired cartilage compared with microfracture3. According to recent research, microfracture is superior to autologous chondrocyte implantation in terms of cost-effectiveness10. Similar results appear to be applicable to C-ACT. C-ACT requires an additional $1,300 for material costs; however, C-ACT showed better cartilage regeneration on magnetic resonance imagining and histology3,4, and higher rate of patients meeting the 20%-improvement rate in visual analogue scale pain scores at 24 months postoperatively compared with microfracture3. Long-term studies will be needed to assess whether histological superiority of C-ACT is reflected in meaningful improvements to clinical outcomes. IMPORTANT TIPS: Debride all of the damaged cartilage to subchondral bone and remove the calcified layer without interfering with tissue repairTake special care when creating the atelocollagen mixture to ensure that it is accurately manufacturedDry the defect site with use of suction or gauze to aid in atelocollagen adhesion when applying atelocollagen.

Intravenous Tranexamic Acid Has Benefit for Reducing Blood Loss after Open-Wedge High Tibial Osteotomy: A Randomized Controlled Trial.

(1) Background: the purpose of this study was to investigate the efficacy and safety of intravenous (IV) administration of tranexamic acid (TXA) in patients undergoing medial opening wedge high tibial osteotomy (MOWHTO). (2) Methods: a total of 73 patients were randomly allocated into two groups (TXA group and control group). The primary outcome was total perioperative calculated blood loss after MOWHTO. Secondary outcomes included self-reported pain severity using a 10-point visual analog scale (VAS) and the EuroQol-5 Dimension (EQ-5D) questionnaire. The postoperative allogeneic transfusion rate and wound complications were compared. Deep vein thrombosis (DVT) incidence was compared by conducting DVT computed tomography imaging. (3) Results: the total blood loss after surgery was 470.9 mL in the TXA group and 739.3 mL in the control group, showing a significant difference (p < 0.001). There were no differences in pain VAS scores between the two groups (all p > 0.05). No difference in preoperative EQ-5D scores for any items existed between the two groups. No transfusion was performed in either group. There was no difference in DVT incidence or the rate of wound complications between the two groups. (4) Conclusion: in patients undergoing MOWHTO, IV TXA reduces total blood loss and drainage amount. However, no additional benefits in clinical outcomes, transfusion rate, or wound complications were apparent, with similar DVT incidence rates.

Efficacy and safety of celecoxib combined with JOINS in the treatment of degenerative knee osteoarthritis: study protocol of a randomized controlled trial.

BACKGROUND: The aim of this study will be to investigate the therapeutic effect and safety of non-steroidal anti-inflammatory drugs (NSAIDs) along with symptomatic slow-acting drugs for the treatment of osteoarthritis (SYSADOA), JOINS tablets, for degenerative knee osteoarthritis (OA) treatment and to determine the analgesic and anti-inflammatory effects of the combination therapy. In addition, we will investigate whether JOINS treatment alone after NSAID and JOINS combination treatment is effective in relieving and maintaining knee OA symptoms. METHODS: This study will be a prospective, randomized, double-blind endpoint study design. All patients will be randomly assigned to either intervention (celecoxib+JOINS) or control (celecoxib+placebo) groups. In Part 1, the intervention group will be administered celecoxib once a day and JOINS three times a day for a total of 12 weeks. In the control group, celecoxib will be administered once a day and JOINS placebo three times a day for a total of 12 weeks. In Part 2, JOINS alone and JOINS placebo alone will be administered for an additional 24 weeks in both groups, respectively. The primary endpoint will be the amount of change during the 12 weeks as assessed using the Western Ontario and McMaster Universities Osteoarthritis Index total score compared with baseline. The secondary endpoint will be the amount of change at 1, 4, 12, 24, and 36 weeks from the baseline for pain visual analog scale, Brief Pain Inventory, Short Form Health Survey-36 and biomarkers. RESULTS: The trial was registered with Clinical-Trials.gov (NCT04718649). The clinical trial was also registered on Clinical Research Information Service (CRIS) with the trial registration number KCT0005742. CONCLUSIONS: The combination treatment of the most commonly used SYSADOA drug, JOINS, and selective COX-2 inhibitor celecoxib as the representative NSAID for knee OA treatment, can be compared with celecoxib alone treatment to determine the safety or therapeutic effect.

Efficacy of duloxetine compared with opioid for postoperative pain control following total knee arthroplasty.

BACKGROUND: The purpose of this study was to assess the efficacy of duloxetine as an alternative to opioid treatment for postoperative pain management following total knee arthroplasty (TKA). METHODS: Among 944 patients, 290 (30.7%) of patients received opioid or duloxetine for pain control for 6 weeks when the pain Visual Analogue Scale (VAS) score was greater than 4 out of 10 at the time of discharge. 121 patients in the Opioid group and 118 in the Duloxetine group were followed up for more than one year. Preoperative and postoperative patient reported outcome measures (pain VAS score, Western Ontario and McMaster Universities OA Index (WOMAC) score were compared. The rate of further drug prescription (opioid or duloxetine) after 6 weeks of first prescription, 30-day readmission rate, and side effects were also investigated. RESULTS: There was no significant difference in pain VAS score, WOMAC Pain and Function score, at each time point between before and after surgery (all p>0.05). Fifteen (9.8%) patients in the opioid group and six (4.4%) patients in the duloxetine group were prescribed additional medication after first 6 weeks, showing no significant (p>0.05) difference in proportion. The 30-day readmission rate and the incidence of side effects were also similar (all p>0.05). There was no difference in the incidence of side effects between the two groups (p>0.05). CONCLUSION: Duloxetine and opioid did not show any difference in pain control, function, and side effects for up to one year after TKA. Although large-scale randomized controlled trials are still required to further confirm the side effects of duloxetine, it can be considered as an alternative to opioid for postoperative pain control following TKA.