Effects of anaesthesia method, tourniquet use and adiposity status on outcomes after total knee arthroplasty

Total knee arthroplasty (TKA) is a common and effective treatment for knee osteoarthritis. We investigated whether TKA performed under spinal or general anaesthesia and with or without a surgical tourniquet is associated with different postoperative outcomes. Additionally, we investigated the predictive performance of adiposity status on TKA-related outcomes and the applicability of a predictive risk index for persistent postsurgical pain (PPP) to TKA patients. We randomized 404 TKA patients into spinal versus general anaesthesia groups and no-tourniquet versus tourniquet groups between October 2016 and December 2018. We measured patients’ preoperative body fat percentage and body mass index and inquired for the presence of the risk factors that are included in the risk index for PPP. Patients underwent TKA according to randomization and were followed for up to 12 months after surgery. We compared the randomization groups in terms of pain management, pain, nausea, change in haemoglobin levels and adverse events during hospital stay, length of hospital stay and PPP at 3 and 12 months after TKA. In analyses concerning the role of adiposity status, we examined associations between preoperative body fat percentage (and body mass index) and multiple in-hospital and follow-up outcomes for up to 12 months after TKA. In the study concerning the applicability of the risk index to TKA patients, the low- to moderate-risk and high-risk groups for PPP were compared in terms of pain scores at 3 and 12 months after surgery. The cumulative doses of intravenous oxycodone by patient-controlled analgesia device during the first 24 postoperative hours were not significantly different between the spinal and general anaesthesia groups nor between the no-tourniquet and tourniquet groups. Similarly, the use of other pain-relieving methods during hospital stay did not differ between the study groups. The spinal anaesthesia group reported more vomiting and postoperative nausea 24 hours after surgery than the general anaesthesia group. Haemoglobin levels decreased 0.5 g/dL more in the no-tourniquet than tourniquet group; however, the incidence rates for blood transfusions did not differ between the groups. Differences in the incidence of adverse events and length of hospital stay were not significant. The spinal anaesthesia group reported better improvements than the general anaesthesia group in three of six investigated pain variables at 12 months after TKA. The tourniquet group reported better improvements than the no-tourniquet group in five pain severity variables at 12 months. However, differences in the improvements were not considered clinically important in either the anaesthesia or tourniquet comparisons. Increase in preoperative body fat percentage was significantly associated with decreased knee range of motion at 12 months after TKA. Similarly, increase in preoperative body mass index was associated with reduced range of motion at 12 months. Increase in body mass index was also associated with slightly increased surgery time. However, these findings were not regarded clinically relevant. Additionally, body fat percentage and body mass index were not significantly associated with in-hospital pain management, pain, length of hospital stay nor patient-reported pain, function, quality of life and satisfaction to TKA at 12 months after surgery. In study concerning the applicability of the predictive risk index for PPP, the low- to moderate-risk group reported less pain 3 and 12 months after TKA than the high-risk group. However, the threshold for minimal clinical importance between groups was reached in merely one of seven investigated pain variables at 12 months. Our results suggest that whether TKA is performed under spinal or general anaesthesia and with or without a tourniquet seems to have no clinical impact on pain management, acute pain, in-hospital adverse events, length of hospital stay or PPP. Spinal anaesthesia may be associated with a higher risk for postoperative nausea and vomiting than general anaesthesia in TKA. For patients who are not morbidly obese, body fat percentage and body mass index appear poorly predictive of TKA-related in-hospital results and patient-reported 1-year outcomes. The previously presented risk index does not appear applicable in predicting PPP at 12 months after TKA.Polven kokotekonivelleikkaus on yleinen ja tehokas pitkälle edenneen polven nivelrikon hoitomenetelmä. Anestesiamenetelmänä tässä leikkauksessa voi käyttää spinaalipuudutusta tai yleisanestesiaa ja leikkauksen aikaista verenvuotoa voi vähentää verityhjiömansettia käyttämällä. Selvitimme, johtavatko eri anestesia- ja verityhjiömenetelmät erilaisiin tuloksiin polven kokotekonivelleikkauksen jälkeen. Tutkimme myös, ovatko kehon rasvaprosentti ja painoindeksi ennustekijöitä polven kokotekonivelleikkauksen tuloksille ja soveltuuko aikaisemmin esitetty leikkauksen jälkeisen pitkittyneen kivun ennustemalli polven kokotekonivelleikkauspotilaille. Tutkimus toteutettiin Peijaksen sairaalassa 2016–2019. Satunnaistimme 404 polven kokotekonivelleikkauspotilasta sekä anestesiamenetelmän (spinaalipuudutus tai yleisanestesia) että verityhjiömansetin käytön (kyllä tai ei) suhteen. Mittasimme potilaiden leikkausta edeltävän rasvaprosentin ja painoindeksin sekä tiedustelimme heiltä pitkittyneen kivun ennustemalliin sisältyvien riskitekijöiden olemassaoloa. Potilaat hoidettiin leikkauksessa satunnaistamisryhmän mukaisesti, heitä seurattiin sairaalassaoloaikana ja he tulivat kontrollikäynneille 3 ja 12 kuukautta leikkauksen jälkeen. Spinaalipuudutuksessa ja yleisanestesiassa sekä verityhjiömansetin kanssa ja ilman sitä leikatut ryhmät eivät eronneet toisistaan merkittävästi sairaalajakson aikaisen kivunhoidon tai raportoidun kivun suhteen. Spinaalipuudutusryhmässä oli enemmän oksentelua ja pahoinvointia 24 tuntia leikkauksen jälkeen kuin yleisanestesiaryhmässä, mutta pahoinvointilääkitysten käytössä ei ollut merkittäviä eroja. Veren hemoglobiinipitoisuus oli leikkauksenjälkeisenä päivänä laskenut 5 g/l enemmän ilman verityhjiötä kuin verityhjiön kanssa leikatussa ryhmässä, mutta verituotteiden siirtomäärissä ei ollut eroja. Anestesia- tai verityhjiöryhmät eivät eronneet toisistaan merkittävästi sairaalassaoloaikana todettujen haittatapahtumien tai sairaalahoidon keston suhteen. Muutokset raportoidussa kivussa 3 ja 12 kuukautta leikkauksen jälkeen eivät myöskään eronneet merkittävästi vertailtavien ryhmien välillä. Kehon rasvaprosentin ja painoindeksin lisääntyminen olivat yhteydessä polven liikelaajuuden pienenemiseen 12 kuukautta leikkauksen jälkeen. Painoindeksin jokaista 1 kg/m2 lisäystä kohti leikkausaika piteni 0,6 minuutilla. Rasvaprosentti ja painoindeksi eivät ennustaneet sairaalahoidon aikaista kipua, kipulääkitysten käyttöä tai haittatapahtumia, kuten ei myöskään sairaalahoidon kestoa tai potilaiden 12 kuukautta leikkauksen jälkeen raportoimaa kipua, toimintakykyä, elämänlaatua tai tyytyväisyyttä polven tekonivelleikkaukseen. Pitkittyneen kivun ennustemallin mukaan määriteltyjen pienen tai kohtalaisen riskin ja suuren riskin ryhmien välillä havaittiin kliinisesti merkittävä ero vain yhdessä seitsemästä vertaillusta kipumuuttujasta vuosi leikkauksen jälkeen. Tulostemme perusteella spinaalipuudutuksessa tai yleisanestesiassa ja verityhjiön kanssa tai ilman verityhjiötä tehdyn polven kokotekonivelleikkauksen jälkeisessä kivunhoidossa, akuutissa tai pitkittyneessä kivussa, sairaalajakson aikaisissa haittatapahtumissa tai sairaalahoidon kestossa ei vaikuta olevan kliinisesti merkittäviä eroja. Spinaalipuudutukseen voi kuitenkin liittyä yleisanestesiaa suurempi riski polven kokotekonivelleikkauksen jälkeiselle oksentelulle ja pahoinvoinnille. Kehon rasvaprosentti ja painoindeksi vaikuttavat huonoilta polven kokotekonivelleikkauksen tulosten ennustekijöiltä. Tutkimamme pitkittyneen kivun ennustemalli ei vaikuta soveltuvan ennustamaan kipua, jota potilaat kokevat vuosi polven kokotekonivelleikkauksen jälkeen

Postoperative pain as a risk factor for stiff knee following total knee arthroplasty and excellent patient-reported outcomes after manipulation under anesthesia

Background and purpose - Manipulation under anesthesia (MUA) is the first-choice treatment for stiffness following total knee arthroplasty (TKA) unresponsive to pain management and physiotherapy. Some of the predisposing factors and patient-reported outcome measures (PROMs) following MUA remain poorly studied. We retrospectively investigated the etiological risk factors and the outcomes of MUA. Patients and methods - 391 TKA patients from a randomized trial comparing the use of a tourniquet and anesthesia (spinal or general) were analyzed, and patients needing MUA were identified (MUA group). We evaluated in-hospital opioid consumption, Oxford Knee Score (OKS), range of motion (ROM), and pain assessed by the Brief Pain Inventory-short form with a 1-year follow-up. Results - 39 (10%) MUA patients were identified. The MUA patients were younger (60 years vs. 64 years, difference -4, 95% CI -6 to -1) and had higher postoperative oxycodone consumption (66 mg vs. 51 mg, median difference 11, CI 1-22) than the no-MUA patients. The proportion of MUA patients who contacted the emergency department within 3 months because of pain was larger than that of non-MUA patients (41% vs. 12%, OR 5, CI 3-10). At the 1-year follow-up, the ROM was improved by 39 degrees following MUA, but the total ROM was worse in the MUA group (115 degrees vs. 124 degrees, p < 0.001). No difference was found in the OKS between the MUA and no-MUA patients. Interpretation - Higher postoperative pain seems to predict MUA risk. MUA performed 3 months postoperatively offers substantial ROM improvement and comparable PROMs to no-MUA patients 1 year after TKA.Peer reviewe

Effects or anaesthesia method and tourniquet use on recovery following total knee arthroplasty : a randomised controlled study

Background: We investigated the effects of spinal and general anaesthesia and surgical tourniquet on acute pain and early recovery after total knee arthroplasty (TKA). Methods: Patients (n=413) were randomised to four parallel groups: spinal anaesthesia with or without tourniquet, and general anaesthesia with or without tourniquet. The primary outcome was patient-controlled i.v. oxycodone consumption over 24 postoperative hours. Results: Results from 395 subjects were analysed. Median i.v. oxycodone consumption did not differ between the four groups (spinal anaesthesia without [36.6 mg] and with tourniquet [38.0 mg], general anaesthesia without [42.3 mg] and with tourniquet [42.5 mg], P=0.42), between spinal (37.7 mg) and general anaesthesia (42.5 mg) groups (median difference -3.1, 95% confidence interval [CI] -7.4 to 1.2, P=0.15) and between tourniquet and no-tourniquet groups (40.0 vs 40.0 mg, median difference -0.8, CI -5.1 to 3.5, P=0.72). Vomiting incidence was higher with spinal than with general anaesthesia (21% [42/200] vs 13% [25/194], CI 1.05 to 3.1, P=0.034). The mean haemoglobin decrease was greater without than with tourniquet (-3.0 vs -2.5 g dl(-1), mean difference -0.48, CI -0.65 to -0.32, P Conclusions: For TKA, spinal and general anaesthesia with or without tourniquet did not differ in 24-h postoperative opioid consumption, pain management, blood transfusions, in-hospital complications, and length of hospital stay. Vomiting incidence was higher in the spinal than in the general anaesthesia group. Tourniquet use caused smaller decreases in haemoglobin levels.Peer reviewe

Verityhjiön käytön vaikutus polven tekonivelleikkauksen tuloksiin: satunnaistettu tutkimus

English abstrac

Intravenous patient-controlled analgesia vs nurse administered oral oxycodone after total knee arthroplasty : a retrospective cohort study

Objectives: Severe post-operative pain is common after total knee arthroplasty. Patient-controlled analgesia is an alternative method of pain management, whereby a patient administers his or her own pain medication. Patients seem to prefer this method over nurse-administered analgesia. However, it remains unclear whether patients using patient-controlled analgesia devices use higher or lower doses of opioids compared to patients treated with oral opioids. Methods: This retrospective study examined 164 patients undergoing total knee arthroplasty. Post-operatively, 82 patients received oxycodone via intravenous patient-controlled analgesia devices, while the pain medication for 82 patients in the control group was administered by nurses. The main outcome measure was the consumption of intravenous opioid equivalents within 24 h after surgery. Secondary outcome measures were the use of anti-emetic drugs and the length of stay. Furthermore, we evaluated opioid-related adverse event reports. Results: The consumption of opioids during the first 24 h after surgery and the use of anti-emetic drugs were similar in both groups. The median opioid dose of intravenous morphine equivalents was 41.1 mg (interquartile range (IQR): 29.5-69.1 mg) in the patient-controlled analgesia group and 40.5 mg (IQR: 32.4-48.6 mg) in the control group, respectively. The median length of stay was 2 days (IQR: 2-3 days) in the patient-controlled analgesia group and 3 days (IQR: 2-3 days) in the control group (p=0.02). The use of anti-emetic drugs was similar in both groups. Conclusions: The administration of oxycodone via intravenous patient-controlled analgesia devices does not lead to increased opioid or anti-emetic consumptions compared to nurse-administered pain medication after total knee arthroplasty. Patient-controlled analgesia might lead to shortened length of stay.Peer reviewe

Testing of a predictive risk index for persistent postsurgical pain on patients undergoing total knee arthroplasty : A prospective cohort study

BackgroundWe investigated whether a universal predictive risk index for persistent postsurgical pain (PPP) is applicable to patients who undergo total knee arthroplasty (TKA). MethodsIn this cohort study, 392 participants of a randomized study investigating the effects of anaesthesia methods and tourniquet use on TKA were divided into low-, moderate-, and high-risk groups for PPP, as suggested in the previous risk index study. Patients reported pain using the Oxford Knee Score pain subscale and Brief Pain Inventory-short form preoperatively and 3 and 12 months postoperatively. We compared the pain scores of the low- to moderate- and high-risk groups at respective time points and investigated changes in pain scores and the prevalence of PPP at 3 and 12 months after surgery. ResultsThe high-risk group reported more pain 3 and 12 months after TKA than the low- to moderate-risk group. However, of seven variables, only a single difference reached the threshold for minimal clinical importance between the groups at 12 months. Additionally, at 12 months, the low- to moderate-risk group reported slightly worse improvements in three of seven pain variables than the high-risk group. Depending on the definition, the prevalence of PPP ranged from 2% to 29% in the low- to moderate-risk group and 4% to 41% in the high-risk group 12 months postoperatively. ConclusionsAlthough the investigated risk index might predict clinically important differences in PPP between the risk groups at 3 months after TKA, it seems poorly applicable for predicting PPP at 12 months after TKA. SignificanceAlthough many risk factors for persistent postsurgical pain after total knee arthroplasty have been identified, predicting the risk of this pain has remained a challenge. Results of the current study suggest that accumulation of previously presented modifiable risk factors might be associated with increased postsurgical pain at 3 months, but not at 12 months after total knee arthroplasty.Peer reviewe

Fat tissue is a poor predictor of 1 year outcomes after total knee arthroplasty : A secondary analysis of a randomized clinical trial

Background and objective: Obesity may increase the risk of adverse events after total knee arthroplasty (TKA). Although body mass index (BMI) is commonly used in categorizing obesity, its accuracy is limited. Body fat percentage (BFP) might indicate adiposity status and predict arthroplasty-related outcomes better than BMI. We investigated whether BFP is predictive of TKA-related outcomes. Methods: In this secondary analysis, BFP was measured preoperatively from 294 participants of a randomized trial that investigated the effects of tourniquet and anesthesia methods on TKA. Data concerning in-hospital assessments and events were collected. Knee range of motion (ROM) was measured, the Brief Pain Inventory-short form and Oxford Knee Score questionnaires were used to collect data on patient-reported pain and function, and the 15-dimensional health-related questionnaire was used to assess quality of life preoperatively and 3 and 12 months postoperatively. The patients reported satisfaction to TKA 3 and 12 months postoperatively. Data concerning infectious and thromboembolic events within 90 postoperative days and revision surgery, manipulation under anesthesia, and mortality within 1 year were collected. A separate post hoc analysis was performed for 399 participants to assess the effects of BMI on the respective outcomes. Results: A 1-unit increase in BFP affected the ROM by -0.37 degrees (95% confidence interval (CI) = -0.60 to -0.13) 12 months after surgery. BFP was not significantly associated with the operation time or adverse events. However, the number of most adverse events remained too low for adjusted analysis. A 1-unit increase in BMI increased the operation time by 0.57 min (95% CI = 0.10 to 1.04) and affected the ROM by -0.47 degrees (95% CI = -0.74 to -0.20) 12 months postoperatively. Neither BFP nor BMI was significantly associated with acute pain, pain management, length of stay, or with pain, function, quality of life, or satisfaction to TKA at 12 months after surgery. Conclusions: BFP seems to be a poor predictor of in-hospital results and of patient-reported outcomes 1 year after TKA. Twitter handle In this secondary analysis of a randomized trial, body fat percentage was poorly predictive of clinical outcomes during hospital stay and of patient-reported outcomes 1 year after TKA.Peer reviewe