Cementless and Cemented Total Knee Arthroplasties Have Similar Outcomes but Cementless Patellar Component Migration was Observed in a Paired Randomized Control Trial.

BACKGROUND: Cementless total knee arthroplasty (TKA) has become increasingly popular. Some surgeons are concerned about pain, implant stability, and metal-backed patellar component survivorship. This study investigated the outcomes of cementless compared with cemented TKA in bilateral cases. METHODS: We randomized 80 knees in 40 osteoarthritic knee patients who underwent bilateral TKA with patellar resurfacing under one anesthesia. All participants received cementless prostheses in one knee and cemented prostheses in the other. The outcomes were knee function measured by the forgotten joint scores, modified Western Ontario and McMaster Universities Osteoarthritis Index, knee ranges of motion, pain levels, operative times, radiographic outcomes, and complications. All knees were followed for a minimum of 2 years (2 to 3 years). RESULTS: Cementless and cemented TKA had similar functional outcomes in forgotten joint score (97 ± 5 versus 98 ± 3 points, P = .52), modified Western Ontario and McMaster Universities Osteoarthritis Index score (3 ± 4 versus 3 ± 2 points, P = .96), and ranges of motion (134 ± 7° versus 134 ± 7°, P = .16). The postoperative pain was also similar (P > .05). There were 4 cementless patellar components had superior migration for an average of 3.5 mm (range, 1.77 to 4.16) without loosening. The mean time of migration was 4 (range, 2 to 6) weeks. CONCLUSIONS: Cementless TKA had similar functional outcomes and recovery patterns compared with cemented TKA. However, there was concern of cementless component migration at patellae.

Do we need to restore patellar thickness after total knee arthroplasty with patellar resurfacing?

PURPOSE: The aim of this study was to investigate whether increased patellar thickness after resurfacing decreased knee flexion angle and had any effect on functional outcomes comparing with patellar thickness restoration (patelloplasty) in patients undergoing primary total knee arthroplasty (TKA) or not. METHODS: We retrospectively reviewed 220 patients undergoing primary TKA: 110 patients undergoing patelloplasty and 110 patients received overstuffed patellar resurfacing using subchondral bone cut at lateral facet technique were recruited. The mean increase in patellar thickness after resurfacing equal to 2 ± 1.2 mm. The outcomes were postoperative knee flexion angle and modified Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score at minimum 2 year after surgery. RESULTS: The mean postoperative knee flexion angles were similar between overstuffed resurfacing group and patelloplasty group (132 ± 7° vs. 134 ± 8°, 95% confidence interval [CI] - 6.9-1.8°, p = 0.1). The mean increase in postoperative knee flexion was 13° in both groups (p = 0.94). The mean change of overall modified WOMAC score was also similar between the two groups (42 ± 12 vs. 39 ± 9 points, 95% CI - 1.7-9.4 points, p = 0.17). CONCLUSION: This study demonstrated that increased patellar thickness has no effect on postoperative knee flexion angle and functional outcomes in TKA. The finding clarified the misunderstanding principle of native patellar thickness restoration after resurfacing which had made many surgeons to refrain from resurfacing especially in patient who had thin patella.

Synovium removal from the articular side of the quadriceps tendon around the superior pole of patella reduces the crepitus after total knee arthroplasty.

PURPOSE: The purpose of this study was to investigate whether synovium removal from the articular side of the quadriceps tendon around the superior pole of the patella after total knee arthroplasty (TKA) reduced the incidence of patellar crepitus (PC) or not. METHODS: We retrospectively reviewed 134 consecutive patients who underwent primary posterior stabilized (PS)-TKA by one surgeon from 2010 to 2013. Sixty-seven patients performed without touching synovium at superior pole of patella and 67 patients performed with removing all synovium from superior pole of patella were compared; none had patellar resurfacing. Patients were followed up two and six weeks, three, six and 12 months and annually thereafter. The primary outcome was the incidence of PC, detected during follow-up, and was graded as absent (0), fine (1), or coarse (2). RESULTS: At one year of follow-up, the synovial removal (SR) group had a significant lower rate of PC compared to the synovial preserved (SP) group: 15/67 (22%) vs 34/67 (51%), adjusted odds ratio = 0.29, 95% confidence interval (CI) = 0.14 to 0.64, P = 0.002. All PC in SR group were grade 1 while four knees in SP group were grade 2. Mean PC onset was eight months after surgery (range 1.5 to 12, P = 0.78) in both groups. CONCLUSION: Removal of the synovium from the articular side of the quadriceps tendon around the superior pole of patellar reduced the incidence of PC after primary PS-TKA without patellar resurfacing. This is a promising technique and might enlighten surgeons to reduce the noise and improve patient satisfaction after total knee replacement.

Intravenous Dexamethasone Injection Reduces Pain From 12 to 21 Hours After Total Knee Arthroplasty: A Double-Blind, Randomized, Placebo-Controlled Trial.

BACKGROUND: Pain after total knee arthroplasty (TKA) affects postoperative recovery and patient satisfaction. The analgesic benefits of corticosteroids have not been well studied. We, therefore, investigated the analgesic effects of intravenous (IV) dexamethasone (DEX) in patients undergoing a TKA. METHODS: This was a randomized, double-blind, placebo-controlled trial of 0.15 mg/kg of IV DEX vs saline placebo in unilateral TKA. Fifty patients/arm were recruited. Primary outcomes were pain level, determined by a visual analog scale, and the amount of morphine consumption (mg) ≤48 hours post-TKA. Secondary outcomes were rates of nausea and vomiting, C-reactive protein concentrations, and functional outcomes. RESULTS: The DEX group had a significantly lower mean visual analog scale score both at rest and during motion at 12, 15, 18, and 21 hours (P < .05). At 21 hours, the mean difference (Δ) in pain at rest was -11 points (95% confidence interval [CI], -21 to -2 points; P = .02) while the mean difference in pain during motion was -15 points (95% CI, -25 to -5 points; P = .004). The DEX group also had lower rates of nausea and vomiting: 29/50 (58%) vs 42/50 (84%) (P = .008) and lower mean C-reactive protein level: 89 vs 167, Δ = -78 mg/L (95% CI, -100 to -58 mg/L, P < .0001). There were no significant differences in mean morphine consumption by 48 hours, modified Western Ontario and McMaster University Osteoarthritis Index scores, and range of motion of the knee at 3-month follow-up (P > .05). CONCLUSION: IV DEX relieves postoperative pain between 12 to 21 hours after TKA and may be a useful adjunct for controlling pain in patients undergoing TKA.

High-dose (3 g) topical tranexamic acid has higher potency in reducing blood loss after total knee arthroplasty compared with low dose (500 mg): a double-blind randomized controlled trial.

BACKGROUND: Topical intra-articular tranexamic acid (IA-TXA) has been proven to be safe and effective in reducing postoperative blood loss after primary total knee arthroplasty (TKA). The objective of this study was to investigate the efficacy of high dose (3 g) compared with low dose (500 mg) of IA-TXA in postoperative blood loss after primary TKA. METHODS: A double-blind randomized controlled trial was conducted in 80 patients who had undergone primary TKA. The patients were divided into two groups according to intra-articular TXA doses: high-dose group (3 g IA-TXA) and low-dose group (500 mg IA-TXA). The drug was injected into the joint capsule after fascial closure without suction drainage. The primary outcomes were maximum hemoglobin drop (g/dL) and calculated total blood loss (mL). Postoperative blood transfusions, thromboembolic events and functional outcomes were also recorded. RESULTS: The mean maximum hemoglobin drop was 1.3 g/dL lower in 3 g IA-TXA group compared to the 500 mg IA-TXA group [1.7 vs 3.0 g/dL, 95% confidence interval (CI) 0.9-1.7 g/dL, P < 0.001]. The 3 g IA-TXA group had 370 mL less calculated total blood loss compared to the 500 mg IA-TXA group (551 vs 921 mL, 95% CI 252-489 mL, P < 0.001). One patient in the 500 mg IA-TXA group required transfusion, while no patient in the 3 g IA-TXA group received transfusion (P = 0.31). Any thromboembolic event was not found, and functional outcome was similar between the two groups. CONCLUSIONS: Application of high-dose, 3 g topical IA-TXA was 43% more effective in reducing postoperative blood loss compared with low dose of 500 mg in primary TKA. Optimal doses in between the above two doses may be a worthwhile further investigation.

Rotational component alignment in patient-specific total knee arthroplasty compared with conventional cutting instrument.

BACKGROUND: Although many studies investigated the accuracy of customized cutting block (CCB), the data on rotational alignment are still lacking. The study aimed to assess whether CCB improved the component rotational position compared with conventional cutting instrument (CCI) using computed tomography scanning. METHODS: Eighty-six of 102 total knee arthroplasties from the previous randomized study were analyzed. The outcomes were rotational position of the femoral and tibial components, frequency of outliers and intra-class correlation coefficient. RESULTS: The mean femoral component rotation was not different between CCB versus CCI: 0.9° ± 0.8° versus 1.1° ± 1.1° (P = 0.29). Both groups had similar outlier frequencies: 2% (CCB) versus 2% (CCI) (P = 0.74). CCB had nearly 1° less mean tibial component deviation compared with CCI (P < 0.001): (1) dorsal tangent reference (DTR): 0.7° ± 0.8° versus 1.5° ± 1.0°, and (2) tibial trans-epicondylar reference (TTR): 0.5° ± 0.9° versus 1.4° ± 1.1°. Outlier frequencies were similar: (1) DTR: 0% CCB versus 5% CCI (P = 0.24), and (2) TTR: 5% in CCB versus 12% CCI (P = 0.20). Measurements based on tibial tubercle showed that CCB had ~ 1.4° less mean tibial component deviation compared with CCI: 0.3° ± 1.4° versus 1.7° ± 1.6° (P < 0.001) with a corresponding, less frequency of outliers: 0% versus 19% (P = 0.002). However, there was poor intra-observer reproducibility (0.61). CONCLUSIONS: CCB did not improve femoral component rotational alignment compared with CCI nor affect outlier frequency, but it marginally improved the accuracy of tibial rotational alignment. The tibial tubercle reference point had poor intra-observer reproducibility.

Comparison of Customized Cutting Block and Conventional Cutting Instrument in Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Customized cutting block (CCB) was designed to ensure the accurate alignment of knee prostheses during total knee arthroplasty. Given the paucity of CCB efficacy data, we compare CCB with conventional cutting guide using a randomized controlled trial. METHODS: One hundred eight osteoarthritic knee patients underwent total knee arthroplasty by one experienced surgeon were randomized to receive CCB (n = 54) or conventional cutting instrument (CCI) surgery (n = 54). The primary outcomes were limb alignment, prostheses position, and operative time. The secondary outcomes were hemodynamic alteration after surgery, functional outcomes (modified Western Ontario and McMaster University Osteoarthritis Index) and range of motion at 2 years after surgery. RESULTS: Mean hip-knee-ankle angle in the CCB group was 179.4° ± 1.8° vs 179.1° ± 2.4° in the CCI group, Δ = 0 (95% confidence interval [CI] -0.6 to 1.1, P = .55). Mean operative time was faster in the CCB arm: 93 ± 12 vs 104 ± 12 minutes, Δ = 11 (95% CI -16.7 to -7.2, P < .0001). There were no differences in hemodynamic parameters, mean blood loss (446 [CCB] vs 514 mL [CCI], Δ = -68 [95% CI -138 to 31 mL, P = .21]), postoperative hemoglobin changes, incidence of hypotension (systolic <90 mm Hg), oliguria, and rates of blood transfusion. Functional outcomes and range of motion were also similar. CONCLUSION: There was no improvement in alignment, hemodynamic changes, blood loss, and knee functional outcomes. CCB reduced surgical time by 11 minutes in our population. CCB cost-effectiveness should be further investigated.

Is Regular Knee Radiograph Reliable Enough to Assess the Knee Prosthesis Position?

BACKGROUND: Proper knee alignment and prosthesis position may theoretically provide better surgical results and increase longevity of total knee arthroplasty. The 3-feet standing long radiograph (LR) is the gold standard for assessment of these parameters. However, the conventional standing regular knee radiograph (RR) is still being used because of convenience and lower cost. We conducted a study to investigate the accuracy of RR compared to LR in assessing the coronal plane prosthesis position. METHODS: We conducted a retrospective cross-sectional study in 100 knee radiographs in 88 patients with knee prostheses. The picture archiving and communications system was used to produce digitized radiographs and perform the angle measurements. LR images were cropped to the same size as the RRs to eradicate rotation error. The femoral component angle (FCA), tibial component angle (TCA), and tibiofemoral angle (TFA) were measured and analyzed by Student t-test. Pearson's correlation coefficient was used to assess interobserver and intraobserver reliability. RESULTS: The RR measurements resulted in a mean increment of 1.3° (95% confidence interval [CI], 0.9°-1.6°; P < .001) for FCA and 1.4° (95% CI, 1.0°-1.9°; P < .001) for TFA compared to LR. The TCAs were similar between 2 techniques (0.2° mean difference; 95% CI, 0°-0.4°; P = .11). RR provided very strong intraobserver reproducibility but only strong interobserver reliability for FCA and TCA while LR provided very strong correlation for all angles. CONCLUSION: RR overestimation of FCA and TFAs in a valgus alignment was minimal, suggesting RR could be an acceptable alternative to LR.

Electric cautery does not reduce blood loss in primary total knee arthroplasty compared with scalpel only surgery a double-blinded randomized controlled trial.

PURPOSE: The purpose of this study was to systematically compare blood loss between the electric cautery and scalpel used in primary total knee arthroplasty (TKA). METHODS: We performed a double-blind trial randomizing osteoarthritic knee patients undergoing unilateral TKA done by either using scalpel (group S) or cautery (group C). Primary outcomes were total blood loss calculated from maximum haemoglobin drop and blood loss collected in drain. Secondary outcomes were systemic inflammatory response (serum C-reactive protein), wound complications, and functional outcomes assessed over three months. RESULTS: A total of 80 patients were recruited. Group S had similar calculated total blood loss compared to group C (1070 (S) vs 1128 (C) mL, 95% CI - 219 to 103, p = 0.47). There was no difference in the mean drain-collected blood loss between the two groups (443 (S) vs 486 (C) mL, 95% CI - 128 to 47, p = 0.36). Group C had higher serum C-reactive protein level at 48 hours after TKA compare to group S (105 vs 140 mg/dL, 95% CI - 66 to - 4, p = 0.03). Wound complications and functional outcomes at three months were also similar between the two groups. CONCLUSIONS: Using electric cautery does not reduce total blood loss as we thought it would be in primary TKA compare to scalpel only surgery and it is also associated with a greater systemic inflammatory response. Cautery used in TKA which operated under tourniquet may not be worthwhile for the risk of hazardous smoke and the increasing cost.

Periarticular multimodal drug injection is better than single anesthetic drug in controlling pain after total knee arthroplasty.

BACKGROUND: Postoperative pain is one of the issues that concern most patients after total knee arthroplasty (TKA). Periarticular multimodal drug injection and single anesthetic agent injection have been shown to effectively reduce postoperative pain. The purpose of this study was to compare the efficacy between multimodal drug injection and single anesthetic drug injection in controlling pain after TKA using a double-blinded randomized controlled trial. METHODS: Sixty-four osteoarthritic patients who underwent primary TKA were randomized into two groups. The multimodal drug injection group (group M) received levobupivacaine 150 mg, ketorolac 30 mg and morphine 5 mg, while the single anesthetic drug injection group (group S) received only levobupivacaine 150 mg. The primary outcomes were pain level (VAS), quantity of opioid consumption (mg) and time to request the first dose of analgesic drug (min). RESULTS: Multimodal drug injection provided lower pain level in the first 4 h after surgery (VAS rest: 30 vs 46, p = 0.02; VAS motion: 45 vs 66, p = 0.03). They consumed less morphine mostly in the first 8 h after surgery (5 vs 12 mg, p < 0.0001) and had approximately 2 h longer time to request the first dose of analgesic drug (254 vs 148 min, p = 0.02). CONCLUSIONS: Multimodal drug injection decreases pain level, reduces morphine consumption in the early postoperative period and prolongs the analgesic effect compared to single anesthetic drug. One may consider using single anesthetic agent only in patients who have high risk of opioid or NSAIDs side effect.

Improved participants' understanding of research information in real settings using the SIDCER informed consent form: a randomized-controlled informed consent study nested with eight clinical trials.

PURPOSE: This study aimed to test the applicability and effectiveness of the principles and informed consent form (ICF) template proposed by the Strategic Initiative for Developing Capacity in Ethical Review (SIDCER) across multiple clinical trials involving Thai research participants with various conditions. METHODS: A single-center, randomized-controlled study nested with eight clinical trials was conducted at Thammasat University Hospital, Thailand. A total of 258 participants from any of the eight clinical trials were enrolled and randomly assigned to read either the SIDCER ICF (n = 130) or the conventional ICF (n = 128) of the respective trial. Their understanding of necessary information was assessed using the post-test questionnaire; they were allowed to consult a given ICF while completing the questionnaire. The primary endpoint was the proportion of the participants who had the post-test score of ≥80%, and the secondary endpoint was the total score of the post-test. RESULTS: The proportion of the participants in the SIDCER ICF group who achieved the primary endpoint was significantly higher than that of the conventional ICF group (60.8 vs. 41.4%, p = 0.002). The total score of the post-test was also significantly higher among the participants who read the SIDCER ICF than those who read the conventional ICF (83.3 vs. 76.0%, p < 0.001). CONCLUSIONS: The present study demonstrated that the SIDCER ICF was applicable and effective to improve Thai research participants' understanding of research information in diverse clinical trials. Using the SIDCER ICF methodology, clinical researchers can improve the quality of ICFs for their trials.

Intraosseous concentration and inhibitory effect of different intravenous cefazolin doses used in preoperative prophylaxis of total knee arthroplasty.

BACKGROUND: The aim of this study was to compare the intraosseous concentrations and the inhibitory effects on the growth of Staphylococcus aureus of 1 g versus 2 g of intravenous (IV) prophylactic cefazolin in total knee arthroplasty (TKA). MATERIALS AND METHODS: Eighteen patients (21 knees) with primary knee osteoarthritis were divided into two groups receiving 1 g (12 patients: 14 knees) versus 2 g (six patients: seven knees) IV prophylactic cefazolin prior to the incision in TKA. Subchondral bone samples (proximal tibia, distal femur) were taken during the operation. These samples were analyzed for intraosseous concentration of cefazolin and their inhibitory effects on the growth of S. aureus, using high-performance liquid chromatography (HPLC) and agar disc diffusion bioassays. RESULTS: The mean intraosseous concentration in the 2 g dose group was significantly higher than in the 1 g dose group in the proximal tibia (p = 0.007) and distal femur (p = 0.016). There were no significant differences between the two groups in terms of mean inhibitory effects in the proximal tibia or distal femur (p > 0.05). No significant correlations were found between the intraosseous concentrations and inhibitory effects in the proximal tibia (r = 0.18, p = 0.52) and distal femur (r = -0.29, p = 0.30). CONCLUSION: IV cefazolin at a dose of 2 g produced greater intraosseous concentrations overall than a dose of 1 g. However, the higher intraosseous concentrations did not correlate with higher inhibitory effects.

Moving a skin incision to lateral side of tibial tubercle reduces the risk of persistent skin numbness compared with a regular midline one: A randomized paired study in bilateral total knee arthroplasty.

BACKGROUND: The midline incision during total knee arthroplasty (TKA) is known to damage the infrapatellar branch of the saphenous nerve (IPBSN), leading to lateral flap numbness. The aim was to evaluate the rate of persistent skin numbness (RSN) and area of skin numbness (AON) after a lateral-based skin incision compared with the standard midline incision in bilateral TKA patients. METHODS: Thirty-six patients undergoing bilateral TKA were included and randomly assigned to receive the lateral skin incision (lateral side of the tibial tubercle) on one knee and the standard midline incision on the contralateral. All other surgical steps were identical. Primary outcomes were the RSN at 1 year and the AON at 6 weeks, 3, 6, and 12 months postoperatively. Kneeling ability test (KAT), operative time, and length of incision were also recorded. RESULTS: The lateral incision had half the RSN at 12 months compared to the midline incision (25% vs 53%; p = 0.01). The median AON at 1-year after surgery was 0 [0-0.5] cm2 in lateral incision vs 4 [0-7.5] cm2 in midline group (p < 0.001). KAT was minimally better in the lateral group at 110° of kneeling between 6-month to 1-year. Operative time and length of incision were similar between both groups. CONCLUSION: The lateral skin incision reduced RSN by approximately 50% compared with the midline incision. The AON in lateral incision was 4 cm2 smaller than midline at 1-year after surgery. Moving a skin incision more lateral may be considered to minimize the numbness after TKA.

Is pain after TKA better with periarticular injection or intrathecal morphine?

BACKGROUND: Postoperative pain after TKA is a major concern to patients. The best technique to control pain is still controversial. Intrathecal morphine or periarticular multimodal drug injection are both commonly used and both appear to provide better pain control than placebo, but it is unclear whether one or the other provides better pain control. QUESTIONS/PURPOSES: We asked whether intrathecal morphine or periarticular multimodal drug injection provides better pain control with fewer adverse events. METHODS: In a prospective, double-blind, randomized controlled trial we randomized 57 patients with osteoarthritic knees who underwent TKAs into two groups. Group M (n = 28) received 0.2 mg intrathecal morphine while Group I (n = 29) received periarticular multimodal drug injection. Postoperative pain was managed with patient-controlled analgesia using ketorolac. The outcomes were pain levels, the amount of analgesic drug used, and drug-related side effects. Patients and evaluators were blinded. All patients were followed up to 3 months. RESULTS: We found no difference in postoperative pain level, analgesia drug consumption, blood loss in drain, and knee function. More patients in Group M required antiemetic (19 [69%] versus 10 [34%]) and antipruritic drugs (10 [36%] versus three [10%]) than patients in Group I. CONCLUSIONS: The two techniques provide no different pain control capacity. The periarticular multimodal drug injection was associated with lower rates of vomiting and pruritus.

Histological features of knee osteoarthritis treated with triamcinolone acetonide and hyaluronic acid.

Osteoarthritis (OA) is one of the most common degenerative joint diseases leading to disability in the end stage. Although intra-articular triamcinolone acetonide (TA) is one of the OA treatments that have been widely used, the side effects of such corticosteroids are still controversial. Intra-articular hyaluronic acid (HA) injection is another therapeutic option for patients with OA who do not want to use corticosteroids because of their side effects. However, the difference between the histological features associated with TA and HA in the treatment of OA remains unclear. Thus, the present study aimed to compare the histological effects of TA and HA on the cartilage of patients with knee OA. In the current study, 31 patients diagnosed with grade 3-4 knee OA on the Kellgren-Lawrence radiographic grading scale were separated into three groups: TA (n=12); HA (n=7) and untreated group (n=12). Histological examination of the whole articular cartilages of the patients was performed with hematoxylin and eosin and Alcian staining, as well as using a TUNEL assay. Clinical data such as cartilage thickness, structural and component deterioration, proteoglycan levels, apoptosis and empty lacunae were compared between the three groups. The results showed a high level of deterioration in both TA and HA groups but not in the untreated group, although the thickness of cartilage in the HA group was lower compared with that in the TA and untreated groups. The proteoglycan levels in the TA group were lower compared with those in the HA group. Moreover, the number of empty lacunae in the HA group was higher compared with that in the TA group, while no difference in apoptosis was found between TA and HA groups. A significant difference was not found in the histological staining between TA and HA groups. On the other hand, a significant difference was found in cartilage deterioration between the medial and lateral sides in these groups. TA and HA groups showed comparable histological results. TA injection is cheaper and easier but has more adverse effects for patients with knee OA than HA injection. Therefore, orthopaedists should select TA or HA based on the economic and specific needs of patients.

Rapid decalcification of articular cartilage and subchondral bone using an ultrasonic cleaner with EDTA.

Articular cartilage and subchondral bones were used to be the samples for studying effects of drugs in the joint degenerative diseases such as osteoarthritis. Because of the deposition of mineral salts, articular cartilage and subchondral bones require decalcification process to soften the tissues. EDTA is a chelating agent that is commonly used to remove mineral salts, but this step is time-consuming and can take as long as 45 days. Commercial ultrasonic cleaner and microwave oven were reported to reduce the decalcification timing. The aim of this study is to determine and compare the decalcification of human articular cartilage and subchondral bone using EDTA together with ultrasonic cleaner or microwave oven. Hundred pieces of articular cartilage and subchondral bones obtained from osteoarthritis patients undergone total-knee-replacement were divided into 10 groups according to decalcification method (ultrasonic cleaner or microwave) and timing (2, 4, 6, 8, and 10 h). In each group, all cartilage and subchondral bone pieces were decalcified and sectioned, and subsequently stained with haematoxylin and eosin, Von Kossa, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, or caspase-3 immunohistochemistry. The optimal timing of decalcification of articular cartilage and subchondral bones using EDTA together with ultrasonic cleaner was at 8 and 10 h, while the timing using EDTA together with microwave oven was more than 10 h. Clear TUNEL and caspase-3 signals were obtained from samples decalcified using EDTA together with ultrasonic cleaner for 8 h. In summary, to our knowledge, this is the first study that compared EDTA decalcification between ultrasonic cleaner and microwave oven. Here, we report a new methodology for decalcification for articular cartilage and subchondral bones that reduces decalcification time from weeks to hours and is suitable for further pathological analyses.

Factors Affecting the Risk of Aseptic Patellar Complications in Primary TKA Performed with Cemented All-Polyethylene Patellar Resurfacing.

BACKGROUND: Patellar complications are a consequential cause of failure of primary total knee arthroplasty (TKA). The purpose of this study was to evaluate the association of demographic and patient factors with the long-term risk of patellar complications as a function of time in a very large cohort of primary TKAs performed with patellar resurfacing. METHODS: We identified 27,192 primary TKAs utilizing cemented all-polyethylene patellar components that were performed at a single institution from 1977 through 2015. We evaluated the risk of any aseptic patellar complication and any aseptic patellar reoperation or revision, subanalyzed risks of reoperation or revision for loosening, maltracking/instability, and wear, and evaluated the risk of clinical diagnosis of patellar fracture and clunk/crepitus. The mean age at TKA was 68 years (range, 18 to 99 years); 57% of the patients were female. The mean body mass index (BMI) was 32 kg/m2. The primary diagnosis was osteoarthritis in 83%, and 70% of the TKAs were posterior-stabilized. Median follow-up was 7 years (range, 2 to 40 years). Risk factors for each outcome were evaluated with Cox regression models. RESULTS: Nine hundred and seventy-seven knees with all-polyethylene patellae developed patellar complications. Survivorship free from any aseptic patellar complication was 93.3% at 20 years. Twenty-year survivorship free from any aseptic patellar reoperation was 97.3% and free from any aseptic patellar revision was 97.4%. Fifteen-year survivorship for the same end points for procedures performed from 2000 to 2015 was 95.7%, 99.2% and 99.3% respectively, representing substantial improvements compared with implants placed before 2000. Univariate analysis demonstrated that male sex (hazard ratio [HR], 1.4), an age of <65 years (HR, 1.3), and a BMI of ≥30 kg/m2 (HR, 1.2) were associated with increased risk of patellar complications (all p ≤0.01). Posterior-stabilized designs were associated with fewer patellar reoperations and revisions overall (HR, 0.4 and 0.4; p < 0.001) but higher risk of patellar clunk/crepitus (HR, 14.1; p < 0.001). CONCLUSIONS: The 20-year survivorship free from any aseptic patellar complication in this series of cemented all-polyethylene patellae was 93%. Important risk factors for any aseptic patellar complication were male sex, an age of <65 years, a BMI of ≥30 kg/m2, and a patella implanted before 2000. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Lumbar Epidural Corticosteroid Injection Reduces Subacute Pain and Improves Knee Function in the First Six Weeks After Total Knee Arthroplasty: A Double-Blinded Randomized Trial.

BACKGROUND: Pain control immediately following total knee arthroplasty (TKA) has been a focus for orthopaedists. However, control of subacute pain, which may persist up to 3 months, is usually not optimized. The efficacy of epidural corticosteroids in reducing pain after surgery is documented, but data on their efficacy in controlling subacute pain after TKA are lacking. Our aim was to investigate the efficacy of an epidural corticosteroid in controlling pain in the first 3 months following TKA using a double-blinded randomized clinical trial. METHODS: One hundred and eight patients with osteoarthritis of the knee who underwent TKA and received analgesic drugs through an epidural catheter for 48 hours were randomized to receive either 40 mg (1 mL) of triamcinolone acetonide plus 5 mL of 1% lidocaine, or 6 mL of 1% lidocaine alone before catheter removal. The outcomes of interest were pain level during motion and at rest, knee function, and range of motion, which were recorded up to 3 months after surgery. Multilevel regression models were used to estimate the differences between groups. RESULTS: The corticosteroid + lidocaine group had a lower average level of pain during motion compared with the lidocaine-only group, as measured by a visual analog scale (VAS), from day 3 to 7 weeks postoperatively (p < 0.05). At 7 weeks, the mean difference was -7 points (95% confidence interval [CI], -12.8 to -1.0 points; p = 0.033). The corticosteroid + lidocaine group also had a better mean overall modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 6 weeks postoperatively (28 compared with 33 points; 95% CI, -8.6 to -0.6 points; p = 0.03). There was no difference between the groups in the level of pain at rest and knee range of motion during the 3-month period (p > 0.05). CONCLUSIONS: Lumbar epidural corticosteroid injection reduced pain during motion for 7 weeks and provided better knee function at 6 weeks postoperatively compared with lidocaine alone. There was no difference detected with respect to pain at rest and knee range of motion during the 3-month follow-up. Epidural corticosteroids could improve patient satisfaction during the early weeks of recovery after TKA. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.