Annual incidence and assessment of risk factors for early-onset deep surgical site infection following primary total knee arthroplasty in osteoarthritis.

Aims: This study aims to determine difference in annual rate of early-onset (≤ 90 days) deep surgical site infection (SSI) following primary total knee arthroplasty (TKA) for osteoarthritis, and to identify risk factors that may be associated with infection. Methods: This is a retrospective population-based cohort study using prospectively collected patient-level data between 1 January 2013 and 1 March 2020. The diagnosis of deep SSI was defined as per the Centers for Disease Control/National Healthcare Safety Network criteria. The Mann-Kendall Trend test was used to detect monotonic trends in annual rates of early-onset deep SSI over time. Multiple logistic regression was used to analyze the effect of different patient, surgical, and healthcare setting factors on the risk of developing a deep SSI within 90 days from surgery for patients with complete data. We also report 90-day mortality. Results: A total of 39,038 patients underwent primary TKA for osteoarthritis during the study period. Of these, 275 patients developed a deep SSI within 90 days of surgery, representing a cumulative incidence of 0.7%. The annual infection rate did not significantly decrease over the seven-year study period (p = 0.162). Overall, 13,885 (35.5%) cases were excluded from the risk analysis due to missing data. Risk factors associated with early-onset deep SSI included male sex, American Society of Anesthesiologists grade ≥ 3, blood transfusion, acute length of stay, and surgeon volume < 30 TKAs/year. Early-onset deep SSI was not associated with increased 90-day mortality. Conclusion: This study establishes a reliable baseline infection rate for early-onset deep SSI after TKA for osteoarthritis using robust Infection Prevention and Control surveillance data, and identifies several potentially modifiable risk factors.

Perioperative outcomes associated with general and spinal anesthesia after total joint arthroplasty for osteoarthritis: a large, Canadian, retrospective cohort study.

BACKGROUND: Compared with general anesthesia, spinal anesthesia has many benefits for patients undergoing total hip (THA) or total knee (TKA) arthroplasty, but few studies have explored rates of morbidity and mortality. We aimed to compare perioperative outcomes by anesthetic type for patients undergoing THA or TKA for osteoarthritis. METHODS: We identified patients who underwent primary THA or TKA from the affiliated institute's database. We calculated inpatient, 30-day, 60-day and 90-day mortality rates, as well as 90-day perioperative complications, readmissions and length of stay (LOS). We compared outcomes between groups using logistic regression and propensity-adjusted multivariate analysis. RESULTS: We included 6100 (52.2%) patients undergoing THA and 5580 (47.8%) undergoing TKA. We found no differences by anesthetic type in mortality rates up to 90 days after surgery. Patients under spinal anesthesia were less likely to need a blood transfusion (THA odds ratio [OR] 0.75, 95% confidence interval [CI] 0.60 to 0.92; TKA OR 0.52, 95% CI 0.40 to 0.67) and were more likely to be discharged home among those who underwent TKA (OR 1.61, 95% CI 1.30 to 2.00). Patients who received spinal anesthesia for THA had a longer LOS (0.28 d, 95% CI 0.17 to 0.39), and patients who received spinal anesthesia for TKA had a shorter LOS than those who received general anesthesia (-0.34 d, 95% CI -0.51 to -0.18). Anesthetic type was not associated with any difference in adverse events. CONCLUSION: These findings may inform decisions on anesthetic type for total joint arthroplasty, especially for rapid discharge protocols. Further research is needed to understand postoperative pain and functional outcomes between anesthetic types.

Do psychiatric disorders affect patient reported outcomes and clinical outcomes post total hip and knee arthroplasty?

INTRODUCTION: The purpose of this study is to evaluate the role of major psychiatric illness on patient outcomes after total joint arthroplasty. METHODS: Patients with a diagnosis of a major psychiatric disorder undergoing total joint arthroplasty were retrospectively matched one-to-one with a cohort without such a diagnosis. Major psychiatric disorder in the registry was identified by diagnosis of anxiety, mood, or a psychotic disorder. Primary outcome of interest included perioperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcomes included EuroQol-5D, adverse events, length of stay, 30-day readmission, and discharge destination. RESULTS: Total number of patients were 1828. The total hip arthroplasty (37.80 ± 17.91, p = 0.023) and the total knee arthroplasty psychiatric group (43.38 ± 18.41, p = 0.050) had significantly lower pre-operative WOMAC scores. At 3 months, the total hip arthroplasty (76.74 ± 16.94, p = 0.036) and total knee arthroplasty psychiatric group (71.09 ± 18.64, p < 0.01) again had significantly lower 3-month post-operative WOMAC score compared to the control groups. However, outcomes at 1 year were difficult to interpret, as patients with major psychiatric conditions had an extremely high loss to follow-up. Compared to the control groups, the total hip arthroplasty and total knee arthroplasty psychiatric group had an increased length of stay by 1.43 days (p < 0.01) and 0.77 days, respectively (p = 0.05). Similarly, the psychiatric groups were discharged directly home less often (total hip arthroplasty 86.9%, p = 0.024 and total knee arthroplasty 87.6%, p = 0.022) than the control groups. CONCLUSION: Patients with the diagnosis of a major psychiatric illness have an increased length of stay and are more likely to require a rehabilitation facility, compared to the control groups. Arguably, of utmost importance, there is a very high rate of loss to follow-up within the psychiatric groups. As such, we recommend these patients should be treated for their diagnosis prior to total joint arthroplasty. Furthermore, importance of clinical follow-up should be emphasized carefully.

One-stage versus 2-stage bilateral total joint arthroplasty: a matched cohort study.

Background: Patients with bilateral end-stage hip or knee arthritis want to know if it is safe to have bilateral surgery under a single anesthetic, to restore their quality of life as quickly as possible. The purpose of this study was to assess if there is an increase in the rate of postoperative medical adverse events, length of stay (LOS), blood transfusion rate and 30-day readmission rate among patients who undergo 1-stage bilateral total hip arthroplasty (BTHA) and 1-stage bilateral total knee arthroplasty (BTKA) compared with patients who undergo 2-stage BTHA and BTKA. Methods: Our study cohorts included patients who underwent BTHA and BTKA between Apr. 1, 2009, and Jan. 31, 2016, in Alberta, Canada. To minimize selection bias associated with our retrospective study design, we matched patients who underwent 1-stage BTHA and BTKA with patients with patients who underwent 2-stage BTHA and BTKA, respectively, for age, sex and number of presurgical risk factors using propensity score in a matching ratio of 1:1. Results: Our study included 1645 patients who underwent BTHA and 4125 patients who underwent BTKA. We matched 195 patients who underwent 1-stage BTHA and 302 patients who underwent 1-stage BTKA with patients who underwent 2-stage BTHA and BTKA, respectively. There was no significant difference in postoperative medical adverse events between the 1-stage and 2-stage matched cohort groups for both BTHA (adjusted odds ratio [OR] 1.3, 95% confidence interval [CI] 0.3-4.9) and BTKA (adjusted OR 0.9, 95% CI 0.3-2.6). There was no difference in inpatient, 30- or 90-day mortality between the 2 groups for BTHA or BTKA. Patients who underwent 1-stage BTHA and BTKA had a shorter acute length of stay but increased total length of stay (acute care and rehabilitation unit) and were less likely to be discharged home postoperatively. One-stage BTHA and BTKA were associated with higher odds of blood transfusion than 2-stage BTHA and BTKA. The 30-day readmission rate was significantly lower for 1-stage BTHA than for the 2-stage BTHA matched cohort (adjusted OR 0.3, 95% CI 0.1-0.8), whereas there was no difference in the 30-day readmission rate (adjusted OR 0.6, 95% CI 0.2-1.7) between the 1-stage and 2-stage BTKA matched cohorts. Finally, operating room time was significantly lower for 1-stage BTHA (49.6 min less) and 1-stage BTKA (66.7 min less) than for the 2-stage arthroplasty procedures. Conclusion: Healthy patients who undergo 1-stage BTHA and BTKA have postoperative medical complication rates comparable to those of patients who undergo 2-stage procedures with the additional benefits of a shorter acute length of stay, but they do have a higher risk of blood transfusion and are less likely to be discharged directly home from the acute care hospital. A multicentre randomized controlled trial on this topic is currently being condcuted by the Canadian Arthroplasty Society.

Contexte: Les patients atteints d'arthrite bilatérale de la hanche ou du genou au stade terminal veulent savoir s'il est sécuritaire de subir une chirurgie bilatérale avec une seule anesthésie pour retrouver leur qualité de vie le plus rapidement possible. Le but de cette étude était de comparer le taux de complications postopératoires de nature médicale, la durée du séjour hospitalier, le taux de transfusions sanguines et le taux de réadmissions à 30 jours chez les patients selon que les arthroplasties totales de la hanche bilatérales (ATHB) et les arthroplasties totales du genou bilatérales (ATGB) se font en 1 étape ou en 2 étapes. Méthodes: Les cohortes de notre étude incluaient des patients qui ont subi des ATHB et des ATGB entre le 1er avril 2009 et le 31 janvier 2016 en Alberta, au Canada. Pour réduire le biais de sélection associé à notre protocole d'étude rétrospective, nous avons assorti les patients soumis aux ATHB et aux ATGB en 1 étape à ceux qui les ont subies en 2 étapes, respectivement, selon l'âge, le sexe et le nombre de facteurs de risque préopératoires, avec score de propension et rapport 1:1. Résultats: Notre étude a regroupé 1645 patients soumis à des ATHB et 4125 patients soumis à des ATGB. Nous avons assortis 195 patients soumis aux ATHB en 1 étape et 302 patients soumis aux ATGB en 1 étape avec des patients soumis à des ATHB et des ATGB en 2 étapes, respectivement. On n'a noté aucune différence significative quant aux complications postopératoires de nature médicale entre les groupes des cohortes assorties pour les interventions en 1 et en 2 étapes, tant avec les ATHB (rapport des cotes [RC] ajusté 1,3, intervalle de confiance [IC] de 95% 0,3­4,9), qu'avec les ATGB (RC ajusté 0,9, IC de 95% 0,3­2,6). Il n'y a pas eu de différences au plan de la mortalité à 30 jours ou à 90 jours chez les patients hospitalisés des 2 groupes avec les ATHB ou les ATGB. Les patients soumis aux ATHB et aux ATGB en 1 étape ont séjourné moins longtemps en soins actifs, mais la durée totale de leur séjour a été plus longue (soins actifs et réadaptation) et ils étaient moins susceptibles de retourner à la maison au moment de leur congé hospitalier après l'intervention. Les ATHB et les ATGB en 1 étape ont été associées à un risque plus grand de transfusions sanguines que les ATHB et les ATGB en 2 étapes. Le taux de réadmission à 30 jours a été significativement plus faible avec les ATHB en 1 étape que dans la cohorte assortie soumise aux ATHB en 2 étapes (RC ajusté 0,3, IC de 95% 0,1­0,8), tandis qu'il n'y a eu aucune différence au plan des taux de réadmission à 30 jours (RC ajusté 0,6, IC de 95% 0,2­1,7) entre les cohortes assorties soumises aux ATGB en 1 et 2 étapes. En terminant, le temps opératoire a été significativement plus bref avec les ATHB et les ATGB en 1 étape (respectivement 49,6 minutes et 66,7 minutes de moins) comparativement aux arthroplasties en 2 étapes. Conclusion: Les patients en bonne santé qui subissent des ATHB et des ATGB en 1 étape ont des taux de complications postopératoires de nature médicale comparables à ceux qui les subissent en 2 étapes, avec l'avantage additionnel d'un séjour hospitalier plus bref en soins actifs; mais ils sont exposés à un risque plus grand de transfusions sanguines et sont moins susceptibles de retourner directement à la maison en quittant l'hôpital de soins actifs. La Société canadienne d'arthroplastie procède actuellement à un essai randomisé et contrôlé multicentrique à ce sujet.

Does Age Influence Patient-Reported Outcomes in Unilateral Primary Total Hip and Knee Arthroplasty?

BACKGROUND: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are used to treat patients with end-stage arthritis. Previous studies have not demonstrated a consistent relationship between age and patient-reported outcomes. The purpose of this study is to assess the impact of age on patient-reported outcomes after unilateral primary THA or TKA. METHODS: A retrospective review of available data in Alberta Bone and Joint Health Institute (ABJHI) Data Repository was performed. We identified 53,498 unilateral primary THA and TKA between April 2011 and 2017. Patients were divided by age into 3 categories: <55, 55-70, and >70. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and EuroQoL 5-dimension (EQ-5D) Canada scores were obtained at presurgery, 3 and 12 months postoperatively. RESULTS: For TKA, younger patients had larger improvements in WOMAC scores at 3 and 12 months (P = <.001-.033), and in EQ-5D scores at 3 months (P < .001). When adjusted, patients <55 had lower WOMAC and EQ-5D scores at 3 months postoperatively compared to those 55-70 or >70 (all P < .01). Outcomes at 12 months did not differ between age-groups. For THA, younger patients had larger improvements in WOMAC at 3 months (P = .03). When adjusted, patients <55 had higher WOMAC scores at 12 months postoperatively compared to those 55-70 or >70, and higher EQ-5D scores compared to those 55-70 (all P < .05). CONCLUSION: While a multitude of factors go in to quantifying successful THA or TKA, this study suggests that patient age should not be a deterrent when considering the impact of age on patient-reported outcomes.

Does body mass index affect the rate of adverse outcomes in total hip and knee arthroplasty? A retrospective review of a total joint replacement database

Background: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are reliable surgical options to treat pain and disability resulting from degenerative conditions around the hip and knee. Obesity is a modifiable risk factor that contributes to significant morbidity. The purpose of this study was to retrospectively compare outcomes in primary hip and knee arthroplasty for patients with increased body mass index (BMI) and those with normal BMI, using data from the registry of the Alberta Bone and Joint Health Institute (ABJHI). Methods: We retrospectively reviewed the data compiled in the ABJHI registry between March 2010 and July 2016. We reviewed outcomes with respect to length of stay, discharge destination, 30-day readmission, postoperative infection, postoperative transfusion requirements, postoperative adverse events and in-hospital postoperative mechanical complications. Results: A total of 10 902 patients (6076 women, 4826 men) who underwent THA and 16 485 patients (10 057 women, 6428 men) who underwent TKA were included in the study. For both THA and TKA, patients with increased BMI had an increased number of in-hospital medical events, had an increased rate of deep infection, were less likely to be discharged home (p < 0.001) and had decreased transfusion requirements (p < 0.001) than patients whose weight was in the normal range. Increased BMI increased the rate of 30-day readmission and length of stay in the THA cohort but not in the TKA cohort. Increased BMI had no effect on acute postoperative dislocation or periprosthetic fractures. Patients with a BMI of 30 kg/m2 or greater required a THA 1.7 years earlier than patients of normal weight, patients whose BMI was 35 kg/m2 or greater required a THA 3.4 years earlier, and patients whose BMI was 40 kg/m2 or greater required a THA 5.8 years earlier. In the TKA cohort, patients with a BMI of 30 kg/m2 or greater required a TKA 2.7 years earlier than patients whose weight was in the normal range, patients with a BMI of 35 kg/m2 or greater required a TKA 4.6 years earlier, and patients whose BMI was 40 kg/m2 or greater required a TKA 7.6 years earlier. Conclusion: Our study quantifies the effects of obesity in primary hip and knee arthroplasty. It provides a greater understanding of the risks in the obese population when contemplating joint arthroplasty.

Contexte: La prothèse totale de la hanche (PTH) et la prothèse totale du genou (PTG) sont des options chirurgicales fiables pour traiter la douleur et l'invalidité résultant de maladies dégénératives de la hanche et du genou. L'obésité est un facteur de risque modifiable qui contribue significativement à la morbidité. Le but de cette étude était de comparer de manière rétrospective le résultat des interventions primaires pour prothèses de la hanche et du genou selon que les patients avaient un indice de masse corporelle (IMC) normal ou élevé à partir des données du registre de l'Alberta Bone and Joint Health Institute (ABJHI). Méthodes: Nous avons analysé de manière rétrospective les données compilées par le registre de l'ABJHI entre mars 2010 et juillet 2016. Nous avons passé en revue les paramètres suivants : durée du séjour hospitalier, destination post-congé, réadmissions dans les 30 jours, infections postopératoires, besoins transfusionnels postopératoires, complications postopératoires et complications mécaniques postopératoires perhospitalières. Résultats: En tout, 10 902 patients (6076 femmes, 4826 hommes) ayant subi une PTH et 16 485 patients (10 057 femmes, 6428 hommes) ayant subi une PTG ont été inclus dans l'étude. Tant pour la PTH que pour la PTG, les patients ayant un IMC élevé ont présenté un plus grand nombre de complications médicales en cours d'hospitalisation; ils ont aussi présenté un nombre plus élevé d'infections profondes, étaient moins susceptibles de pouvoir retourner chez eux au moment de leur congé (p < 0,001) et ont eu moins besoin de transfusions (p < 0,001) comparativement aux patients dont le poids se situait dans l'éventail des valeurs normales. L'IMC élevé a été en corrélation avec une augmentation du taux de réadmission à 30 jours et de la durée du séjour dans la cohorte soumise à une PTH, mais non dans la cohorte soumise à une PTG. L'IMC élevé n'a exercé aucun effet sur la dislocation postopératoire aiguë ou les fractures périprothétiques. Les patients ayant un IMC de 30 kg/m2 ou plus ont eu besoin d'une PTH 1,7 an plus tôt que les patients de poids normal, les patients ayant un IMC de 35 kg/m2 ou plus ont eu besoin d'une PTH 3,4 ans plus tôt, et les patients ayant un IMC de 40 kg/m2 ou plus ont eu besoin d'une PTH 5,8 ans plus tôt. Dans la cohorte soumise à la PTG, les patients ayant un IMC de 30 kg/m2 ou plus ont eu besoin d'une PTG 2,7 ans plus tôt que les patients de poids normal, les patients ayant un IMC de 35 kg/m2 ou plus ont eu besoin d'une PTG 4,6 ans plus tôt, et les patients ayant un IMC de 40 kg/m2 ou plus ont eu besoin d'une PTG 7,6 ans plus tôt. Conclusion: Notre étude quantifie les effets de l'obésité sur le recours aux interventions primaires pour prothèse de la hanche et du genou. Elle permet de mieux comprendre les risques auxquels est exposée la population obèse lorsqu'une intervention pour prothèse articulaire est envisagée.

Surgical Approaches in Total Hip Arthroplasty Cost Per Case Analysis: A Retrospective, Matched, Micro-costing Analysis in a Socialised Healthcare System.

BACKGROUND: Total hip arthroplasty (THA) offers an effective method of pain relief and restoration of function for patients with end-stage arthritis. The anterior approach (AA) claims to benefit patients with decreased pain, increased mobilisation and decreasing length of hospital stay (LOS). In a socialised healthcare platform we questioned whether the AA, compared to posterior (PA) and lateral (LA) approaches, can decrease the cost burden. METHODS: Using a retrospective matched cohort study, we matched 69 AA patients to 69 LA and 69 PA patients for age (p = 0.99), gender (p = 0.99) and number of pre-surgical risk factors (p = 0.99). First, we used the Resource Intensity Weights (RIW) using the Health Services agreed on method of calculating cost. Secondly, micro-costing analysis was performed using the financial services data for each patient's hospital stay. RESULTS: Using the RIW based cost analysis and 2-day reduction (95% CI 1.8-2.4) in LOS, the AA offers an estimated savings per case of $4099 (p < 0.001) compared to the LA and PA. Using micro-costing analysis, we found a total saving of $1858.00 per case (95% CI 1391-2324) when comparing the AA to the PA and LA. There was a statistically significant cost savings using every category: Net Direct Salary ($901.00, p < 0.001), Net Drug ($8.00, p = 0.003), Patient Supply ($454.00, p = 0.001), Patient Drug ($15.00, p = 0.008), Indirect Cost ($385.00, p < 0.001), Patient Care Administration ($106.00, p < 0.001). Furthermore, the AA saved 142 minutes of in-hospital rehabilitation time. CONCLUSION: The AA THA provides statistically significant reductions in cost compared to PA and LA while releasing rehabilitation resources.

Association between Allogeneic Blood Transfusion and Wound Infection after Total Hip or Knee Arthroplasty: A Retrospective Case-Control Study.

Background: To assess using a retrospective case control study, whether patients undergoing primary, elective total hip or knee arthroplasty who receive blood transfusion have a higher rate of post-operative infection compared to those who do not. Materials and Methods: Data on elective primary total hip or knee arthroplasty patients, including patient characteristics, co-morbidities, type and duration of surgery, blood transfusion, deep and superficial infection was extracted from the Alberta Bone and Joint Health Institute (ABJHI). Logistic regression analysis was used to compare deep infection and superficial infection in blood-transfused and non-transfused cohorts. Results: Of the 27892 patients identified, 3098 (11.1%) received blood transfusion (TKA 9.7%; THA 13.1%). Overall, the rate of superficial infection (SI) was 0.5% and deep infection (DI) was 1.1%. The infection rates in the transfused cohort were SI 1.0% and DI 1.6%, and in the non-transfused cohort were SI 0.5% and DI 1.0%. The transfused cohort had an increased risk of superficial infection (adjusted odds ratio (OR) 1.9 [95% CI 1.2-2.9, p-value 0.005]) as well as deep infection (adjusted OR 1.6 [95% CI 1.1-2.2, p-value 0.008]). Conclusion: The odds of superficial and deep wound infection are significantly increased in primary, elective total hip and knee arthroplasty patients who receive blood transfusion compared to those who did not. This study can potentially help in reducing periprosthetic hip or knee infections.

Does Rehabilitation before Total Knee Arthroplasty Benefit Postoperative Recovery? A Systematic Review.

BACKGROUND: Arthritis is the most common form of joint disease. Total knee arthroplasty (TKA) is the most effective surgical intervention for end-stage knee osteoarthritis. The purpose of this study is to access whether patients who participated in preoperative rehabilitation before primary TKA received any postoperative benefit compared to patients who did not participate in preoperative rehabilitation. MATERIALS AND METHODS: A comprehensive search of Medline, PubMed, Embase, CENTRAL, CINAHL, Ageline, and hand searching references and abstracts was performed. Inclusion criteria included patients undergoing primary and unilateral TKA. Exclusion criteria included patients who have bilateral, unicompartmental, or revision TKA. All studies compared preoperative exercise program versus no preoperative exercise. Outcomes included patients' function, acute care length of stay (LOS), pain, and stiffness. The Western Ontario and McMaster Universities Osteoarthritis Index and 36-Item Short-Form Health Survey functional scales were used to assess these outcomes. Assessment was performed within 3 months of TKA. RESULTS: Of 1347 articles, 1308 studies were excluded during title and abstract screening. Thirty nine articles underwent full-text screening and were narrowed to five studies matching all criteria. Two studies were combined showing a significant decrease in LOS favoring preoperative exercise (-0.93, 95% confidence interval: -1.29, -0.57). There was a lack of evidence to show any difference regarding self-reported function, stiffness, pain, and physical role. CONCLUSION: Preoperative exercise program may be beneficial and is associated with a significant decrease in length of hospital stay. No conclusive evidence can be delineated from the literature with respect to clinical outcome measures. Well-designed randomized trials would strengthen this position.

Quality of assessment of randomized controlled trials in blood conservation after joint arthroplasty.

Blood transfusion after joint arthroplasty occurs in up to two thirds of patients. We conducted a systematic review of the literature to determine the methodological quality of published randomized controlled trials (RCTs). We searched MEDLINE, EMBASE, and Cochrane to identify RCTs in arthroplasty with blood conservation as the primary outcome from 2001 to 2007. Methodological quality was evaluated using the Detsky index. We identified 62 RCTs. The mean Detsky score was 73% ± 14%. Epidemiology affiliation (P = .003), funding support (<.001), and year of publication (<.001) were the predictors of reporting quality, predicting 46% of the variability (R(2) = 0.46). This suggests poor reporting quality of trials in blood conservation. The inclusion of an epidemiologist or a biostatistician for the design of a trial is strongly recommended.

A novel method to measure cryoprotectant permeation into intact articular cartilage.

Successful cryopreservation of articular cartilage (AC) could improve clinical results of osteochondral allografting and provide a useful treatment alternative for large cartilage defects. However, successful cartilage cryopreservation is limited by the time required for cryoprotective agent (CPA) permeation into the matrix and high CPA toxicity. This study describes a novel, practical method to examine the time-dependent permeation of CPAs [dimethyl sulfoxide (DMSO) and propylene glycol (PG)] into intact porcine AC. Dowels of porcine AC (10 mm diameter) were immersed in solutions containing high concentrations of each CPA for different times (0, 15, 30, 60 min, 3, 6, and 24 h) at three temperatures (4, 22, and 37 degrees C), with and without cartilage attachment to bone. The cartilage was isolated and the amount of cryoprotective agent within the matrix was determined. The results demonstrated a sharp rise in the CPA concentration within 15-30 min exposure to DMSO and PG. The concentration plateaued between 3 and 6 h of exposure at a concentration approximately 88-99% of the external concentration (6.8 M). This observation was temperature-dependent with slower permeation at lower temperatures. This study demonstrated the effectiveness of a novel technique to measure CPA permeation into intact AC, and describes permeation kinetics of two common CPAs into intact porcine AC.