The remnant-tensioning (RT) anterior cruciate ligament reconstruction (ACLR) has been reported to have excellent postoperative outcomes. However, the influence of graft selection on postoperative outcomes of autografts and allografts after RT-ACLR has been poorly investigated. The purpose of our study was to compare the clinical, radiological, and second-look arthroscopic outcomes of autografts and allografts following RT-ACLR. Between January 2013 and May 2020, 94 and 64 patients were enrolled in auto (hamstring tendon) and allo (tibialis tendon) groups, respectively. For subgroup analysis, patients were divided into two age categories: ≤34 and > 34 years of age. Stability tests, including the Lachman and Pivot shift tests, side-to-side differences on Telos stress radiographs and KT-2000 arthrometer, patient-reported outcome measurements (PROMs), and graft status on postoperative magnetic resonance imaging (MRI) and second-look arthroscopy, were evaluated and compared between the two groups. The two groups showed no statistically significant differences in stability outcomes or PROMs for patients aged ≤ 34 and > 34 years. Furthermore, both groups demonstrated comparable postoperative graft status on postoperative MRI and second-look arthroscopy analyses in patients aged ≤ 34 and > 34 years. RT-ACLR using allografts yielded similar postoperative clinical outcomes, MRI findings, and second-look results compared to autografts, irrespective of patients’ age. Therefore, allografts may serve as a viable option for patients scheduled for RT-ACLR.

PURPOSE:This study aimed to determine the ideal remaining discoid meniscal width after reshaping surgery and to investigate the preoperative risk factors for changes in the meniscal width. METHODS:Twenty-nine pediatric patients (39 knees) who underwent arthroscopic reshaping for symptomatic discoid lateral meniscus (DLM) were retrospectively analyzed. MRI was performed postoperatively and at 6 months or 1-2 years. Changes in meniscal width were measured, and logistic regression and receiver operating characteristic (ROC) curve analyses identified risk factors and cut-off values. RESULTS:The meniscal width gradually decreased, particularly in the midbody (25.7 % at 6 months and 38.1 % at 1-2 years, postoperatively). Risk factors for width reduction included a complete-type DLM (β = 26.0, P = 0.036) and a smaller preoperative meniscal height (β = -4.51, P = 0.048). The ROC curve analysis indicated that a preoperative meniscal height of ≤ 3.3 mm and preserving a meniscal width of ≤ 8.5 mm after surgery may result in a residual meniscal width of less than 5 mm. CONCLUSION:The ideal remaining meniscal width after reshaping surgery should be > 8.5 mm to minimize the risk of postoperative degeneration. Surgeons should consider preserving additional meniscal tissue, especially in patients with risk factors such as complete DLM or a meniscal height of less than 3.3 mm, to improve long-term joint preservation.

Background:Remnant tensioning (RT) anterior cruciate ligament (ACL) reconstruction has been reported to have excellent postoperative outcomes for femoral-side tears. However, the influence of remnant continuity (RC) on the postoperative results after RT ACL reconstruction remains unclear. Purpose:To investigate the effects of RC on the postoperative clinical, radiological, and second-look arthroscopic outcomes after RT ACL reconstruction for femoral-side ACL tears. Study Design:Cohort study; Level of evidence, 3. Methods:This study included 94 patients who underwent RT ACL reconstruction using the hamstring tendon for femoral-side ACL tears between 2015 and 2020. The patients were divided into 2 groups according to the continuity of the remnant tissue: RC (n = 50) and remnant discontinuity (RD) (n = 44). Stability tests, including the Lachman and pivot-shift tests, side-to-side difference on Telos stress radiographs and KT-2000 arthrometer, patient-reported outcome measurements (PROMs), and graft status on postoperative magnetic resonance imaging (MRI) and second-look arthroscopy were evaluated. Results:Results of all stability tests and PROMs significantly improved postoperatively. The mean follow-up periods were 35.3 and 36.8 months in the RC and RD group, respectively. The 2 groups showed no statistically significant differences in stability outcomes or PROMs. Furthermore, the RC and RD groups showed comparable postoperative graft status on postoperative MRI and second-look arthroscopy. Conclusion:RT ACL reconstruction for RD between the femoral insertion site and ACL tissue showed comparable postoperative outcomes, including stability test, PROMs, postoperative MRI, and second-look arthroscopic data, to surgery for RC in femoral-side tears.

BACKGROUND:This study aimed to investigate the biomechanical effect of subacromial spacer (physically depressing the humeral head) and magnets (concavity compression restoration) in massive rotator cuff tear (MRCT). We assessed the influence on superior stability by employing the subacromial spacer (the spacer effect) and magnets (concavity compression effect) separately or in combination in MRCT. METHODS:A customized shoulder testing system tested 7 fresh-frozen cadaveric shoulders. The prosthesis implantation was performed prior to all experimental conditions. Each specimen underwent the following conditions: (1) intact rotator cuff without magnets, (2) MRCT without magnets, (3) MRCT with magnets, (4) MRCT with a spacer, and (5) MRCT with magnets and a spacer. For each condition, superior migration and subacromial contact pressure were measured at 0°, 30°, and 60° abduction angles. RESULTS:Condition 2 resulted in a significant increase in both superior migration and subacromial contact pressure compared to condition 1. Condition 3 exhibited no significant differences in both parameters compared to condition 2 (P > .05). In condition 4, both parameters significantly decreased (P < .05), and in condition 5, levels were restored to those of the intact condition with no significant difference. Neither parameter between conditions 4 and 5 differed significantly (P > .05). CONCLUSION:The combination of the static (spacer) and dynamic (concavity compression) effect demonstrated restoration of superior migration and subacromial contact pressure after MRCT to levels comparable to the intact condition. However, the subacromial spacer alone also showed positive results, and the influence of concavity compression was minimal. To achieve superior stability in MRCT, the static role (spacer) as superior restraint is more critical for rotator cuff function than the dynamic role (concavity compression).

Mesenchymal stem cells (MSCs) spontaneously assemble into three-dimensional (3D) spheroids under matrix-deficient conditions such as the synovial cavity, although their functional significance has yet to be fully elucidated. In this study, we used concave microwell cultures to promote the spontaneous aggregation of adipose-derived MSCs (ASCs) from OA patients, thereby mimicking the intra-articular microenvironment. We analyzed the paracrine factors of ASC aggregates and compared it with that of conventional 2D monolayer cultures. Notably, 3D aggregation significantly increased the secretion of HGF and VEGF, whereas FGF2 levels remained relatively unchanged. These results indicate that the structural characteristics of ASC aggregates enhance the secretion of key paracrine factors involved in angiogenesis and tissue repair. To functionally evaluate the biological relevance of the secreted factors, conditioned media (CM) from ASC aggregates were applied to human articular chondrocytes. The CM significantly promoted chondrocyte proliferation, an effect that was abolished by the addition of HGF-neutralizing antibodies, thereby highlighting HGF as a central mediator of the regenerative response. Additionally, we further explored whether extracellular factors could modulate growth factor expression such as HGF. In this context, we investigated the impact of low-concentration hyaluronic acid (HA), a key synovial component widely used in OA treatment. Co-treatment with HA not only amplified the expression and secretion of HGF, VEGF, and FGF2, but also promoted ASC proliferation. ASCs forming functional aggregates may exert regenerative effects as active paracrine modulators, and the addition of low-dose hyaluronic acid is expected to further enhance this function, offering a promising strategy for MSC-based osteoarthritis therapy.

Osteoarthritis (OA) is a degenerative joint disease which lacks reliable biomarkers for monitoring disease progression. Current assessment methods rely primarily on radiographic Kellgren-Lawrence (K-L) grading and symptom-based scores, which often show poor concordance with underlying molecular changes. Here, we present a label-free diagnostic strategy for classifying OA severity based on type II collagen in synovial exosomes, using surface-enhanced Raman spectroscopy (SERS). Exosomal surface type II collagen (ExoCOL2A1), quantified from synovial fluid of OA patients, exhibited a significant inverse correlation with radiographic severity and demonstrated superior diagnostic capability compared to other protein markers. To enable non-destructive detection, a plasmonic gold nanoparticle substrate was used to acquire the SERS spectra of whole synovial exosomes, which were subsequently analyzed using a deep neural network (DNN). The DNN model accurately classified OA severity based on spectral characteristics, achieving a prediction accuracy of 95.3 %, and outperforming traditional machine learning models such as LDA, SVM, and kNN. Principal component analysis further identified ExoCOL2A1-associated spectral peaks as key contributing factors for the exosomal SERS spectrum. These findings establish the clinical potential of exosomal type II collagen as OA severity-associated markers and highlight the utility of AI-integrated SERS as a non-invasive diagnostic platform.

Abstract Background This study aimed to evaluate the femoral tunnel position and fiber length of the anterolateral ligament (ALL) reconstruction compared with the natural anatomy of the ALL. We also evaluated whether the femoral tunnel position would affect residual pivot shift. Methods This study was a retrospective review of 55 knees that underwent ALL reconstruction considering the anatomical and functional aspects, during primary anterior cruciate ligament (ACL) reconstruction in the presence of a high-grade pivot shift or revisional ACL reconstruction. We determined the position of the femoral tunnel and the length of graft using a three-dimensional (3D)-computed tomography (CT) model after ALL reconstruction. We also measured graft excursion during surgery and examined pivot shift 2 years after surgery. We conducted a subgroup analysis of femoral tunnel position, fiber length, isometricity, and residual pivot shift depending on whether the tunnel was anterior or posterior to the lateral epicondyle (LE). We also performed a subgroup analysis depending on whether the ACL reconstruction was primary or revisional. Results The mean femoral tunnel position was 2.04 mm posterior and 14.5 mm proximal from the center of the LE. The mean lengths of the anterior and posterior fibers were 66.6 and 63.4 mm, respectively. The femoral tunnel was positioned more proximally than the anatomical position, and both anterior and posterior ALL fibers were longer than the natural anatomy. The anteroposterior femoral tunnel position was significantly correlated with anterior (p = 0.045) and posterior (p = 0.037) fiber excursion. In the subgroup analysis, there was no significant difference in the residual pivot shift between the posterior and anterior tunnel positions. However, there were significant differences for proximal position (p < 0.001) and fiber length (p = 0.006). There was no significant difference between primary and revisional ACL regarding femoral tunnel position and fiber lengths. Conclusion It is challenging to reproduce both anatomical and functional aspects of ALL reconstruction in both primary and revision ACL reconstruction. Especially for functional reconstruction, the femoral tunnel tended to be positioned more proximally than the anatomical position. However, the femoral tunnel position did not affect functional clinical outcomes at the 2-year follow-up. Level of evidence Level IV Case series.

Interleukin-6 (IL-6) expression in mesenchymal stem cells (MSCs) has been shown to play a pivotal role in modulating cartilage regeneration and immune responses, particularly in the context of diseases that involve both degenerative processes and inflammation, such as osteoarthritis (OA). However, the precise mechanism through which IL-6 and other immune-regulatory factors influence the therapeutic efficacy of autologous adipose-derived stem cells (ASCs) transplantation in OA treatment remains to be fully elucidated. This study aims to investigate the relationship between IL-6 expression in autologous ASCs isolated from OA patients and their impact on immune modulation, particularly focusing on the regulation of Receptor Activator of Nuclear factor Kappa-Β Ligand (RANKL), a key mediator of immune-driven cartilage degradation in OA. Autologous ASCs were isolated from the stromal vascular fraction (SVF) of adipose tissue obtained from 22 OA patients. The isolated ASCs were cultured and characterized using reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and flow cytometry to the phenotype and immune regulatory factors of MSCs. Based on IL-6 expression levels, ASCs were divided into high and low IL-6 expression groups. These groups were then co-cultured with activated peripheral blood mononuclear cells (PBMCs) to evaluate their immune-modulatory capacity, including the induction of regulatory T cells, inhibition of immune cell proliferation, and regulation of key cytokines, such as interferon-gamma (IFN-γ). Additionally, RANKL expression, a critical factor in osteoclastogenesis and cartilage degradation, was assessed in both ASC groups. High IL-6-expressing ASCs demonstrated a significantly greater capacity to inhibit immune cell proliferation and IFN-γ production compared to their low IL-6-expressing counterparts under co-culture conditions. Moreover, the group of ASCs with high IL-6 expression showed a marked reduction in RANKL expression, suggesting enhanced potential to control osteoclast activity and subsequent cartilage defect in OA. Conclusion: Autologous ASCs with elevated IL-6 expression exhibit enhanced immunomodulatory properties, particularly in regulating over-activated immune response and reducing osteoclastogenesis through RANKL suppression. These findings indicate that selecting ASCs based on IL-6 expression could enhance the therapeutic efficacy of ASC-based treatments for OA by mitigating immune-driven joint inflammation and cartilage degradation, potentially slowing disease progression.

For many years, sustained-release drug delivery systems (SRDDS) have emerged as a featured topic in the pharmaceutical field. Particularly for chronic diseases, such as osteoarthritis, there is a lot of demand for SRDDS because of the long treatment period and repetitive medication administration. Thus, we developed an injectable PLGA-F127 microsphere (MS) that is capable of the in situ conversion to an implant. The microprecipitation method for PLGA-F127 MS was established, and the physicochemical stability of the products was confirmed. The microspheres were assembled into a single mass in 37 °C aqueous conditions and showed a remarkably delayed drug release profile. First, the release started with no significant initial burst and lagged for 60 days. After that, in the next 40 days, the remaining 75% of the drugs were constantly released until day 105. We expect that our PLGA-F127 MS could be employed to extend the release period of 2 months of medication to 4 months. This could be a valuable solution for developing novel SRDDS for local injections.

Purpose (the aim of the study): Osteoarthritis is a growing challenge globally, particularly with the aging population. The market demand for osteoarthritis solutions is increasing, yet conventional treatments fall short due to the lack of effective drugs and devices. While emerging technologies are attempting to fill gaps, there remains considerable potential for improvement in usability and patient compliance. Without a fundamental treatment, the immediate goal is safe pain management. To tackle this, we're developing an innovative intra-articular injection device for osteoarthritis, offering at least 3 months of simultaneous pain relief and inflammation treatment.

Purpose: This study aimed to investigate the correlation between serum creatinine levels and the presence and severity of radio-graphic knee osteoarthritis (OA) in individuals aged >= 50 years while adjusting for potential confounders. Materials and Methods: Cross-sectional data from the 2009-2011 Korea National Health and Nutrition Examination Survey com-prising 3428 individuals aged >= 50 years were utilized. The Kellgren-Lawrence (K-L) grading scale was used to assess the radio-graphic presence and severity of knee OA. Logistic regression and receiver operating characteristic analyses were used to investi-gate the association between serum creatinine levels and the presence of knee OA, whereas ordinal regression was used to assess the impact of creatinine levels on knee OA severity. Results: The presence of radiographic knee OA conferred by low serum creatinine levels was found to be significant in both sexes [odds ratio (OR), 0.118; 95% confidence interval (CI), 0.045-0.314, p<0.001 for men; OR, 0.148; 95% CI, 0.040-0.549, p=0.004 for women]. Low serum creatinine was significantly associated with knee OA-graded K-L severity in each sex-based group [beta, -1.923; standard error, 0.478; p<0.001 for men and beta, -1.532; SE, 0.575; p=0.008 for women]. Conclusion: Low serum creatinine level was associated with a higher presence of knee OA in both men and women, and was also linked to the severity of the disease. These findings suggest that the serum creatinine level may be a potential biomarker for assessing the presence and severity of knee OA.

Background: Various arthroscopic rotator cuff repair techniques are being used for the treatment of rotator cuff tears with the development of surgical instruments. However, retears after repair are not completely avoidable, and efforts to reduce retears remain a challenge. Purpose/Hypothesis: To introduce a new repair technique, the double-row modified Mason-Allen technique with a single knot, and to compare clinical outcomes and retear rates with the single-row modified Mason-Allen technique. It was hypothesized that this new technique would have a better clinical outcome and significantly lower retear rate than the single-row modified Mason-Allen technique. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 110 patients with small- to medium-sized (<1.5 cm) full-thickness supraspinatus tears were enrolled into 2 groups, with 65 patients receiving the single-row modified Mason-Allen technique (group A) and 45 patients receiving the double-row modified Mason-Allen technique with a single knot (group B). The clinical and functional outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) score; Disabilities of the Arm, Shoulder and Hand (DASH) score; and visual analog scale (VAS) for pain and satisfaction scores. All patients enrolled in this study were monitored for a minimum of 24 months. Magnetic resonance imaging was performed to analyze the integrity of tendons and retear at 6 months after surgery. Results: No statistically significant differences between the 2 groups were found regarding the VAS for pain, ASES, and DASH scores. However, retear was found in 9 patients (13.8%) in group A and 1 patient (2.2%) in group B. The difference in the retear rate was statistically significant between the 2 groups ( P = .037). Conclusion: A significantly lower retear rate and comparable clinical outcomes were seen after the double-row modified Mason-Allen repair technique with a single knot when compared with the single-row modified Mason-Allen technique. Based on these findings, the double-row modified Mason-Allen repair technique with a single knot can be considered a surgical treatment option that can provide sufficient stability in small- to medium-sized supraspinatus tears.

Background Disruption of the rotator cuff muscles compromises concavity compression force, which leads to superior migration of the humeral head and loss of stability. A novel idea of using the magnetic force to achieve shoulder stabilization in massive rotator cuff tears (MRCTs) was considered because the magnets can stabilize two separate entities with an attraction force. This study aimed to investigate the biomechanical effect of the magnetic force on shoulder stabilization in MRCTs. Methods Seven fresh frozen cadaveric specimens were used with a customized shoulder testing system. Three testing conditions were set up: condition 1, intact rotator cuff without magnets; condition 2, an MRCT without magnets; condition 3, an MRCT with magnets. For each condition, anterior-posterior translation, superior translation, superior migration, and subacromial contact pressure were measured at 0°, 30°, and 60° of abduction. The abduction capability of condition 2 was compared with that of condition 3. Results The anterior-posterior and superior translations increased in condition 2; however, they decreased compared to condition 2 when the magnets were applied (condition 3) in multiple test positions and loadings (p < 0.05). Abduction capability improved significantly in condition 3 compared with that in condition 2, even for less deltoid loading (p < 0.05). Conclusions The magnet biomechanically played a positive role in stabilizing the shoulder joint and enabled abduction with less deltoid force in MRCTs. However, to ensure that the magnet is clinically applicable as a stabilizer for the shoulder joint, it is necessary to thoroughly verify its safety in the human body and to conduct further research on technical challenges.

PURPOSE:To compare the clinical, radiographic, and second-look arthroscopic outcomes between double-bundle (DB) anterior cruciate ligament (ACL) reconstruction (DB group) and combined single-bundle (SB) ACL and anterolateral ligament (ALL) reconstruction (SB + ALL group) by a prospective randomized controlled trial. METHODS:From May 2019 to June 2020, 84 patients were enrolled in this study. Among them, 10 were lost to follow-up. Thirty-six and 38 patients were successfully allocated to the DB (mean follow up 27.3 ± 4.2 months) and SB + ALL groups (27.2 ± 4.5 months), respectively. The preoperative and postoperative Lachman test, pivot shift test, anterior translation on stress radiographs, KT-2000 arthrometer, Lysholm score, International Knee Documentation Committee score, and Tegner activity score were evaluated and compared. Graft continuity was evaluated using postoperative magnetic resonance imaging (MRI) (32 and 36 patients underwent MRI in the DB and SB + ALL groups at 7.4 ± 3.2 and 7.5 ± 2.9 months after surgery, respectively), and second-look examinations (second-look examination and tibial screw removal were performed concomitantly when patients (1) had tibial screw-related irritation or (2) needed the screws removed, 28 and 23 patients underwent examinations in the DB and SB + ALL groups at 24.0 ± 6.8 and 24.9 ± 8.1 months after surgery, respectively). All measurements were compared between the groups. RESULTS:Postoperative clinical outcomes significantly improved in both groups. (All variables showed P < .001) No statistically different outcomes were found between the 2 groups. Additionally, postoperative graft continuity on MRI and second-look examinations were not different between the 2 groups. CONCLUSIONS:The DB and SB + ALL groups showed similar postoperative clinical, radiographic, and second-look arthroscopic outcomes. Both groups showed excellent postoperative stability and clinical outcomes compared with the preoperative measurements. LEVEL OF EVIDENCE:Level II, randomized controlled trial.

During medial opening wedge high tibial osteotomy (MOWHTO), sometimes the plate tends to be positioned anteromedially. The plate position can affect the length of the proximal screw, which significantly affects stability after osteotomy. Therefore, research on the correlation among plate position, screw length, and clinical outcomes is needed. This retrospective review examines 196 knees in 175 patients who underwent MOWHTO from May 2012 to December 2018, for symptomatic medial compartment osteoarthritis with a varus alignment of > 5°. We evaluated the anteroposterior plate position, length of proximal screw, and postoperative computed tomography (CT). We reviewed patients’ clinical outcome scores, presence of lateral hinge fracture, neurovascular complications, and infection. The correlation among proximal plate position, proximal screw length, and clinical outcomes was evaluated using Pearson’s correlation analysis. A subgroup analysis by screw angle (> 48 ° or < 48 °) was also performed using chi-square test and Student t-test. The mean proximal plate position was 16.28% (range, 5.17–44.74) of the proximal tibia’s anterior-to-posterior distance ratio, and the proximal screw length averaged 63.8 mm (range, 44–80 mm). Proximal posteromedial plate position and proximal screw length were significantly correlated (r2 = 0.667, P < .001), as were screw angle and length (r2 = 0.746, P < .001). Medial plating (< 48°) can use a longer proximal screw; nevertheless, no significant difference occurred in clinical outcomes between the two groups. Also, no differences occurred in complication rate, including hinge fracture. With more medially positioned plating during MOWHTO, we can use longer proximal screws. However, there was no significant difference in clinical outcomes and the incidence of lateral hinge fractures regardless of plate position and screw length.

Background: Time-dependent changes in lower extremity alignment after an opening-wedge high tibial osteotomy (OWHTO) have been poorly investigated. Moreover, few studies have investigated risk factors of postoperative alignment change. Purposes: To investigate time-dependent alignment changes and identify predictive factors for postoperative alignment change after OWHTO. Study Design: Case-control study; Level of evidence, 3. Methods: This study included patients who underwent OWHTO between March 2010 and September 2018. A total of 142 knees with a mean follow-up of 42 months were included and classified as the change group when the amount of hip-knee-ankle (HKA) angle change was >1°; if otherwise, then as the no-change group. HKA angle was obtained at 6 time points: preoperatively and at 3 months, 6 months, 1 year, 2 years, and final follow-up postoperatively. Multiple regression analysis was performed to identify the factors that were correlated with the changes in the HKA angle from 3 months to the final follow-up. Results: Among the 142 knees, 59 (42%) were included in the change group. The overall postoperative HKA angles progressed serially toward varus after OWHTO. The mean angles of the 6 time points were 8.5°, –3.7°, –3.6°, –3.3°, –3.1°, and –2.7°, respectively. The mean HKA angles of the change and no-change groups were 9.1°, –4.3°, –3.4°, –2.8°, –2.0°, and –1.4° and 8.1°, –3.3°, –3.8°, –3.6°, –3.8°, and –3.7°, respectively. Greater change in the HKA angle was predicted by preoperatively greater valgus stress joint line convergence angles and less medial joint space width. Conclusion: Of the cases of OWHTO, 42% showed correction loss of >1° at a mean follow-up of 42 months. The overall postoperative HKA angles progressed serially to varus angles after OWHTO. Preoperative greater valgus stress joint line convergence angles and less medial joint space width were predictive factors for greater change in alignment toward varus after OWHTO.

Objective To compare the clinical outcomes among three analgesic techniques, continuous femoral nerve block (CFNB), epidural patient-controlled analgesia (EPCA) and periarticular injection (PAI), in patients undergoing total knee arthroplasty (TKA). Methods This retrospective case–control study enrolled patients that underwent TKA. Visual analogue scale (VAS) pain scores, sleep disturbance, additional opioid consumption and incidence of opioid-related side-effects were assessed. Results A total of 120 patients were categorized into three groups: EPCA (group A, n = 40), PAI (group B, n = 40) and CFNB (group C, n = 40). Group C had significantly lower VAS pain scores than groups A and B at 8, 12 and 24 h after TKA. There were no significant differences in VAS pain scores among the three groups from 48 h after TKA. Sleep quality on the first day after surgery was significantly better in group C than in groups A and B. Additional opioid consumption was significantly lower in the group C than in the groups A and B. Group C showed a lower rate of opioid-related side-effects than groups A and B. Conclusion CFNB was a more effective additional analgesic technique than EPCA or PAI for acute postoperative pain control within 24 h of TKA.