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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Total knee arthroplasty in femoral bowing: does patient specific instrumentation have something to add? A randomized controlled trial.

BACKGROUND: Patient-specific instrumentation (PSI) proponents have suggested the benefits of improved component alignment and reduced outliers. In this randomized controlled trial, we attempted to assess the advantage of using PSI over conventional intermedullary (IM) guides for primary total knee arthroplasty (TKA) with bilateral severe femoral bowing (> 5°). A parallel trial design was used with 1:1 allocation. We hypothesize that PSI would support more accurate alignment of components and the lower-limb axis during TKA with severe femoral bowing in comparison with conventional IM guides. METHODS: Among 336 patients undergoing bilateral TKAs due to knee osteoarthritis, 29 patients with bilateral lateral femoral bowing of more than 5° were included in this study. Every patient was assigned randomly to PSI on one side and to conventional instrumentation lateralization of the entry point of the femoral IM guide was applied on the other with a goal of neutral mechanical alignment. The assessment of coronal alignment was completed by measuring the hip-knee-ankle (HKA) angle on preoperative and postoperative long film standing radiographs. Coronal and sagittal orientations of femoral and tibial components were assessed on weight-bearing radiographs. The rotational alignment of the femoral component was evaluated using computed tomography. RESULTS: The postoperative mean ± standard deviation (SD) HKA angle was varus 4.0° (± 2.7°) for conventional technique and varus 4.1° (± 3.1°) for PSI, with no differences between the two groups (p = 0.459). The component orientation showed no significant differences except with respect to the sagittal alignment of the femoral component (p = 0.001), with a PSI mean ± SD flexion of 5.8° (± 3.7°) and a conventional method mean ± SD flexion of 3.2° (± 2.5°), due to the intentional 3° flexion incorporated in the sagittal plane to prevent femoral notching in PSI planning. Computed tomography assessment for rotational alignment of the femoral components showed no difference between the two groups concerning the transepicondylar axis (p = 0.485) with a PSI mean ± SD external rotation of 1.5° (± 1.3°) and conventional mean ± SD external rotation of 1.5° (± 1.6°). CONCLUSION: PSI showed no advantage over lateralization of the femoral entry for IM guidance. LEVEL OF EVIDENCE: 1 TRIAL REGISTRATION: Registered on US national library of medicine ClinicalTrials.gov ( NCT02993016 ) on December 12th 2016.

Alignment adjustment using the Valgus stress technique can increase the surgical accuracy of novice surgeons during medial opening-wedge high Tibial osteotomy.

BACKGROUND: The purpose of this study was to compare the degree of accuracy of coronal alignment correction with use of the "alignment adjustment under valgus stress technique" between expert and novice surgeons during medial opening-wedge high tibial osteotomy (MOWHTO). METHODS: Forty-eight patients who underwent MOWHTO performed by an expert surgeon (expert group) and 29 by a novice surgeon (novice group) were enrolled in analysis. During surgery, lower-extremity alignment was corrected using the "alignment adjustment under valgus stress technique". Normocorrection was defined as a weight-bearing line ratio between 55 and 70% and the correction accuracy was compared between expert and novice groups using the ratio of normocorrection to outliers. The clinical outcomes were also compared using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at 1 year after surgery. RESULTS: The undercorrection rate was 14.6% in the expert group and 13.8% in the novice group, while the overcorrection rate was 2.1% in the expert group and 3.4% in the novice group. In the ratio of normocorrection to outliers, no difference was found between the two groups at the one-year follow-up visit (83.3% in the expert group vs. 82.8% in the novice group; p > 0.05). Also, no significant differences were seen in WOMAC subscores immediately preoperatively and at 1 year after surgery (all p > 0.05). CONCLUSION: Adhering to the "alignment adjustment under valgus stress technique" protocol enabled novice surgeons to achieve similar surgical accuracy as that of an expert surgeon in coronal alignment during MOWHTO. LEVEL OF EVIDENCE: Level III.

Double-Bundle Anterior Cruciate Ligament Reconstruction With Lateral Extra-Articular Tenodesis Is Effective in Restoring Knee Stability in a Chronic, Complex Anterior Cruciate Ligament-Injured Knee Model: A Cadaveric Biomechanical Study.

PURPOSE: To compare knee stability after intra-articular isolated double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) and single-bundle (SB) and DB ACLR combined with lateral extra-articular tenodesis (LET) in a chronic, complex anterior cruciate ligament (ACL)-injured knee model. METHODS: In 10 fresh-frozen cadaveric knees, we measured knee laxity in the following order: (1) intact knee; (2) ACL-sectioned knee; (3) complex ACL-injured knee model with additional sectioning of the anterolateral complex and the posterior horns of the medial and lateral menisci; (4) SB ACLR plus LET; (5) DB ACLR; and (6) DB ACLR plus LET. RESULTS: In comparison with the intact knee, significantly increased internal rotation (IR) laxity persisted at 60° and 90° after DB ACLR (P = .002 and P = .003, respectively). SB ACLR plus LET and DB ACLR plus LET resulted in significant reductions in IR laxity at 90° (P = .003 and P = .037, respectively), representing overconstraint in IR. SB ACLR plus LET resulted in persistently increased external rotation (ER) laxity at 30°, 60°, and 90° (P = .001, P < .001, and P < .001, respectively). The DB ACLR condition persistently showed significant increases in anterior tibial translation laxity at 60° and 90° (P = .037 and P = .024, respectively). A greater increase in ER laxity was seen after SB ACLR plus LET versus DB ACLR plus LET at 30°, 60°, and 90° (P < .001, P < .001, and P < .001, respectively). CONCLUSIONS: DB ACLR plus LET restored intact knee stability in IR, ER, and anterior tibial translation laxity at 0°, 30°, 60°, and 90° of knee flexion except for overconstraint in IR at 90° in a chronic, complex ACL-injured knee model. CLINICAL RELEVANCE: This cadaveric study provides some biomechanical evidence to support performing DB ACLR combined with LET to restore knee stability after a complex, chronic knee injury involving an ACL tear combined with anterolateral complex injury and irreparable tears of the posterior horns of the medial and lateral menisci.

2-Octyl Cyanoacrylate Topical Adhesive as an Alternative to Subcuticular Suture for Skin Closure After Total Knee Arthroplasty: A Randomized Controlled Trial in the Same Patient.

BACKGROUND: The 2-octyl cyanoacrylate topical adhesive with flexible self-adhesive polyester mesh (Dermabond Prineo) is becoming widely used in many surgical fields. However, no prior studies have tested the efficacy and safety of this topical adhesive compared with subcuticular suture in the same patient. The purpose of this study was to compare the efficacy and safety between Dermabond Prineo and subcuticular suture for skin closure in patients undergoing same-day bilateral total knee arthroplasties (TKAs). MATERIALS AND METHODS: A prospective, double-blind randomized controlled trial was performed in 51 patients scheduled to undergo same-day bilateral TKAs. One knee was randomly assigned to the Dermabond Prineo and the other knee was allocated to the subcuticular suture. As primary outcomes, Vancouver scar scale was evaluated at 6 months and Patient and Observer Scar Assessment Scale was evaluated at 2 weeks, 6 weeks, 3 months, and 6 months. Secondary outcomes included cosmesis efficacy (Hollander wound evaluation scale [HWES] and cosmesis visual analog scale [VAS]), time and pain efficiency (skin suture time, stitch out time, and stitch out pain VAS), and safety (wound complications during the 6-month follow-up period). The primary and secondary outcome measures were compared between groups. RESULTS: There were no significant differences in Vancouver scar scale and Patient and Observer Scar Assessment Scale at 6 months. Although there were no significant differences in HWES at 2 weeks, the Dermabond Prineo group showed better step-off border item of HWES. There was also no difference in cosmesis VAS at 6 months. The Dermabond Prineo group showed superior results in terms of time (suture time: Dermabond Prineo = 191 second (sec) ± 60.1 sec, subcuticular suture = 356.8 sec ± 92.3 sec; stitch out time: Dermabond Prineo = 4 sec ± 1.3 sec, subcuticular suture = 26.6 sec ± 4.2 sec, all P < .001) without significant differences in pain scale (P = .823) or wound complications (all P > .05). CONCLUSION: Comparing cosmetic efficacy, time efficiency, and safety, Dermabond Prineo provided quicker wound closure, shorter stitch out time, and better wound margin coaptation in the early postoperative period but similar cosmetic efficacy compared with subcuticular suture. Based on our study, Dermabond Prineo is a useful alternative to subcuticular suture in patients undergoing TKA. LEVEL OF EVIDENCE: Therapeutic level 1.

Posterior stabilized total knee arthroplasty reproduces natural joint laxity compared to normal in kinematically aligned total knee arthroplasty: a matched pair cadaveric study.

PURPOSE: As the goal of kinematic aligned (KA) total knee arthroplasty (TKA) is to preserve soft tissue tension to the native knee, many KA surgeons recommend cruciate-retaining (CR) prosthesis. However, how a posterior-stabilizing (PS) prosthesis affects the biomechanics of a KA TKA remains unclear. This cadaveric study tested the hypothesis that a PS prosthesis in KA TKA would produce biomechanics similar to CR prosthesis and KA TKA with a PS prosthesis would produce more native knee biomechanics than mechanical aligned (MA) TKA with PA prosthesis. METHODS: Fourteen cadaver knees (7 pairs) were mounted on a knee-testing system to measure knee motion during flexion. For each pair, 1 knee was assigned to KA TKA and the other to MA TKA. In the KA TKA group, the native knee, CR TKA, and PS TKA were tested sequentially. MA TKA was performed using conventional measured resection techniques with a PS prosthesis. All kinematics were measured and compared with the native knee before and after surgery. RESULTS: A PS prosthesis restored femoral rollback similar to a CR prosthesis. CR TKA showed less lateral rollback at knee flexion ≤ 60° than the native knee. There were no differences in soft tissue tensions among the native knee, CR, and PS prosthesis, except in varus tension at 30° of flexion. Varus tension of CR TKA was larger than those of PS TKA and the native knee after KA TKA with < 1 degree difference. Meanwhile, KA TKA achieved knee motion that was closer to the native knee than did MA TKA at ≥ 60° of flexion when using a PS prosthesis. There were no differences in soft tissue tension between KA-PS and MA-PS TKA. CONCLUSIONS: After KA TKA, a PS prosthesis affords similar femoral rollback and soft tissue tension when compared with a CR prosthesis. A PS TKA may be a feasible strategy for patients requiring a PS prosthesis when performing KA TKA. LEVEL OF EVIDENCE: Therapeutic Laboratory study, I.

How Does Preoperative Central Sensitization Affect Quality of Life Following Total Knee Arthroplasty?

BACKGROUND: Central sensitization (CS) has been recently identified as a significant risk factor for persistent pain and patient dissatisfaction following total knee arthroplasty (TKA). However, it remains unclear as to whether the preoperative CS persists after the elimination of a nociceptive pain source by TKA, or how CS affects the quality of life after TKA. METHODS: A total of 222 consecutive patients undergoing primary TKA were enrolled in the study. All patients were preoperatively screened for CS using the Central Sensitization Inventory (CSI) and categorized into either a CS (n = 55; CSI ≥ 40) or non-CS group (n = 167; CSI < 40). CSI, pain visual analog scale (VAS), Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index score, and satisfaction were recorded at postoperative 2 years. RESULTS: Two years after TKA, preoperative CS remained unchanged; there was no difference between preoperative and postoperative CSI scores, and both preoperative and postoperative CSI severity levels were similar (P > .1). The CS group showed worse pain VAS, KSS, and Western Ontario and McMaster Universities Osteoarthritis Index scores than did the non-CS group (P < .01) and more patients in the CS group were dissatisfied with all activities (P < .01). However, a similar percentage of the CS group achieved the previously documented minimal clinically important difference in pain VAS and KSS, compared with the non-CS group. Multivariate regression analysis revealed that preoperative CSI scores were associated with dissatisfaction at postoperative 2 years. CONCLUSION: Preoperative CS was persistent at 2 years after TKA. Although CS patients achieved comparable clinical improvement following TKA, CS patients had worse quality of life, functional disability, and dissatisfaction than non-CS patients.

What Factors Predict Patient Dissatisfaction After Contemporary Medial Opening-Wedge High Tibial Osteotomy?

BACKGROUND: Although current advances in surgical techniques have improved outcomes of the medial opening-wedge high tibial osteotomy (MOWHTO), the factors associated with patient dissatisfaction remain unclear. Thus, the purpose of this study is to identify risk factors for patient dissatisfaction following contemporary MOWHTO. METHODS: We retrospectively reviewed prospectively collected data on 140 consecutive MOWHTO patients using an anatomical locking plate with a minimum follow-up of 2 years. Patient demographics, pain Visual Analogue Scale, Western Ontario and McMaster Universities Osteoarthritis Index, Kellgren-Lawrence (K-L) grade, activity level, articular cartilage and meniscal status, hip-knee-ankle angle, change in alignment, and postoperative weight-bearing line ratio were recorded. Patients were categorized using the New Knee Society Score into satisfied (satisfaction score ≥20) or dissatisfied (satisfaction score <20) groups. Patient and surgical factors were compared between the groups by the identified predictors. Multiple logistic regression analysis was used to analyze risk factors, including K-L grade IV medial osteoarthritis (OA), preoperative pain Visual Analogue Scale, total Western Ontario and McMaster Universities Osteoarthritis Index score, postoperative hip-knee-ankle angle, change in alignment, and partial meniscectomy. RESULTS: Of the 140 patients, 24 (17.1%) were dissatisfied with their results. Multiple logistic regression analysis showed that only K-L grade IV medial OA was statistically associated with patient dissatisfaction following MOWHTO (odds ratio 4.911, 95% confidence interval 1.820-13.256, P < .01). CONCLUSION: Severe medial OA was an independent risk factor for dissatisfaction following contemporary MOWHTO using a rigid locking plate. Surgeons should take this into consideration when counseling and choosing surgical options in MOWHTO candidates with severe medial OA. LEVEL OF EVIDENCE: Level III.

Patient Expectations and Satisfaction After Medial Opening Wedge High Tibial Osteotomy.

BACKGROUND: The objective of this study is to assess preoperative patient expectations of medial opening wedge high tibial osteotomy (MOWHTO) and related postoperative fulfillment, to increase understanding of associated factors of postoperative satisfaction. METHODS: One hundred fifteen patients who underwent MOWHTO were enrolled. Patients' expectations were measured using the Hospital for Special Surgery-Knee Replacement Expectations Survey. Fulfillment of expectations and satisfaction was evaluated using the Hospital for Special Surgery Knee Replacement Fulfillment of Expectations Survey and a 5-point Likert scale at 2 years, postoperatively. The discrepancies between preoperative expectation and postoperative fulfillment score were also assessed. Preoperative and postoperative patient-reported outcomes were evaluated using Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. Univariate and multivariate analyses were performed to model predictions for satisfaction. RESULTS: The most expected items were "pain relief," "walking ability," and "perform daily activities." The top 3 items with the biggest discrepancies between expectation and fulfillment scores were "kneeling," "squatting," and "pain relief." Ninety patients (78.3%) were satisfied and 25 (21.7%) were dissatisfied at 2 years postoperative. Multivariate logistic regressions showed that patient expectations did not affect satisfaction. Small discrepancies between expectation and fulfillment scores (odds ratio [OR] 105.304, 95% confidence interval 20.974-528.714, P < .001), high postoperative fulfillment scores (OR 1.198, 95% CI 1.110-1.293, P < .001), and low postoperative Western Ontario and McMaster Universities Arthritis Index total scores (OR 0.932, 95% CI 0.894-0.971, P < .001) were significantly associated with patient satisfaction. CONCLUSION: The small discrepancy between preoperative expectations and postoperative fulfillment of expectations was a major contributor to patients' satisfaction following MOWHTO.

Comparison of implant position and joint awareness between fixed- and mobile-bearing unicompartmental knee arthroplasty: a minimum of five year follow-up study.

PURPOSE: To compare the implant position and patient-reported outcomes (PROs) regarding joint awareness using the Forgotten Joint Score (FJS) following between fixed-bearing (FB) and mobile-bearing (MB) unicompartmental knee arthroplasty (UKA) with a minimum of five years' follow-up. METHODS: One hundred fifteen consecutive UKAs (58 FB UKAs and 57 MB UKAs) performed were retrospectively evaluated. We compared the radiographic parameters including component positions and relationships as well as lower extremity alignment. Post-operative clinical outcomes were assessed using Knee Society Score (KSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Tegner activity score, and FJS. RESULTS: The MB UKA group showed more convergent componentry relationship between femoral and tibial components (p < 0.001). The joint line of the MB UKA group was restored significantly better (p < 0.05). In addition, the positioning of femoral and tibial components of the MB UKA group showed less deviation from the weight-bearing line (WBL) (p < 0.05). Although there were no differences in KSS, WOMAC, and Tegner activity scores between the groups, the MB UKA group showed significantly better FJS than did the FB UKA group at five years post-operatively (p < 0.05). CONCLUSION: The MB UKA group had a more convergent componentry relationship, less deviation from WBL, better joint-line restoration, and reduced joint awareness than did the FB UKA group at five years follow-up.