Effect of arthroscopic partial meniscectomy on structural degeneration of the knee - A 5-year MRI-based follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trial.

OBJECTIVE: To assess the 5-year effects of arthroscopic partial meniscectomy (APM) vs. placebo surgery on the development of the structural changes of the knee by magnetic resonance imaging (MRI). DESIGN: This multicentre, randomized, participant- and outcome-assessor-blinded, placebo-surgery-controlled trial was carried out in Finland. We randomized 146 adults, mean age 52 years (range 35 to 65) to undergo either APM or placebo surgery. The subjects had symptoms of degenerative medial meniscus tear, a tear verified in MRI and arthroscopy, and no advanced osteoarthritis at baseline. We compared the baseline and 5-year follow-up MRIs using MRI Osteoarthritis Knee Score scoring to derive subregional data on cartilage damage, osteophytes and bone marrow lesions (BMLs). Progression of structural cartilage changes analyzed per subregion was the main outcome, that of osteophytes and BMLs secondary outcomes. We analyzed the progression with multilevel logistic regression model on subregion-level data, adjusted for randomization stratification factors, and using robust standard errors. RESULTS: Sixty-three (90%) subjects in the APM and 73 (96%) in the placebo-surgery group had MRI at both time points. The adjusted odds ratio (APM vs. placebo-surgery) was 1.31 (95% confidence interval 0.81, 1.94) for progression of cartilage damage, 2.86 (1.16, 6.21) for osteophytes, and 1.43 (0.84, 2.43) for BMLs. CONCLUSIONS: We found a slightly greater risk for progression of osteophytes in the APM group compared to the placebo-surgery group at 5 years after surgery. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01052233 and NCT00549172).

Comparison of the effect of dexmedetomidine intrathecal injection and intravenous infusion on subarachnoid blockade during knee arthroscopy procedures: a randomized controlled trial.

BACKGROUND: Comparison of whether intrathecal dexmedetomidine prolongs spinal anesthesia-associated sensorimotor blockade more than intravenous infusion during knee arthroscopy procedures performed under subarachnoid blockade. METHODS: Ninety patients aged 18-75 years, ASA class I-II, who underwent knee arthroscopy between October 2022 and April 2023 were randomized into intrathecal、intravenous and control groups.Subjects received three modes of administration: an intrathecal group (2 ml of 1% ropivacaine + 1 ml of 5 µg dexmedetomidine, along with intravenous saline infusion), an intravenous group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, with dexmedetomidine pumped intravenously at a dose of 0.5 µg/kg/h), and a control group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, along with intravenous saline infusion). Total analgesic duration, duration of sensory and motor blockade, Ramsay sedation score, Visual Analogue Score (VAS) at different postoperative time points, and occurrence of adverse effects were recorded. RESULTS: The total analgesia duration was significantly longer in the intrathecal group than in the intravenous and control groups (352.13 ± 51.70 min VS 273.47 ± 62.57 min VS 241.41 ± 59.22 min, P < 0.001).The onset of sensory block was shorter in the intrathecal group than in the intravenous and control groups (4 [3-4]min VS 5 [4-5]min VS 5 [4-5]min; P < 0.001);the onset of motor block was shorter in the intrathecal group than in the intravenous group and the control group (5 [4-5]min VS 5 [5-6]min VS 6[5.5-7]min; P < 0.001).Sedation scores were higher in the intravenous group than in the intrathecal and control groups (P < 0.001). At 5 h postoperatively, the VAS score in the intrathecal group was lower than that in the intravenous and control groups (P < 0.001). At 24 h postoperatively, the VAS score in the intrathecal group was lower than that in the control group (P < 0.001). In addition, the incidence of bradycardia was significantly higher in the intravenous group than in the intrathecal and control groups (30%, 6.5%, and 3.4%, respectively; P = 0.018, P = 0.007). CONCLUSIONS: Intrathecal administration of dexmedetomidine did prolong the total analgesia duration, as well as accelerate the onset of sensory-motor blockade compared with intravenous infusion, and did not result in any hemodynamic instability or other adverse events at the doses studied. TRIAL REGISTRATION: This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 26/09/2023 with the registration number ChiCTR2300076170.

Esketamine use is associated with shortened postoperative hospital stay in patients after knee arthroscopic surgery: a propensity score-matched cohort study.

BACKGROUND: Previous studies have examined anesthetics to improve postoperative prognosis after knee arthroscopic surgery. However, it is currently unknown whether perioperative anesthetics can influence postoperative hospital stay. We investigated the impact of esketamine after knee arthroscopic surgery on post-operative length of stay, fever and surgical site infection. METHODS: This study included 455 patients who underwent knee surgery between January2020 and August 2021at a tertiary hospital in China. Patient characteristics, preoperative laboratory values, intra-operative anesthetic data, and postoperative outcomes were collected. Univariate and multivariate logistic regression analyses with or without propensity score matching were performed to identify factors related to post-operative discharge within 3 days(PD3). RESULTS: A total of 297 cases met our inclusion criteria. The mean age of patients was 42 ± 14 years, mean body mass index, 24.1 ± 3.5 kg/m2, 157(53%) patients were male. Meniscus-related procedures accounted for the most part of all the procedures with a percentage of 40.4%, followed by combined procedures of 35.4%. After we adjusted for demographic and intraoperative characteristics with propensity score matching, esketamine use was significantly associated with PD3 with the highest odds ratio of 2.28 (95% confidence interval (CI): 1.18-4.41, p = 0.014). CONCLUSION: Esketamine use was associated with PD3 in patients underwent knee arthroscopic surgery. The findings of this study will be useful to anesthesiologists in making informed decisions regarding the choice of anesthetics for knee joint diseases. TRIAL REGISTRATION: This study was approved by the Ethics Committee (Approval No.:2023-041-01) of the Eighth Affiliated Hospital, Sun Yat-sen University and retrospectively registered.

Self-defined former smokers consume the highest opioid quantities following knee and shoulder arthroscopy.

PURPOSE: To identify risk factors associated with increased postoperative opioid consumption and inferior pain outcomes following knee and shoulder arthroscopy. METHODS: Using the data set from the NonOpioid Prescriptions after Arthroscopic Surgery in Canada (NO PAin) trial, eight prognostic factors were chosen a priori to evaluate their effect on opioid consumption and patient-reported pain following arthroscopic knee and shoulder surgery. The primary outcome was the number of oral morphine equivalents (OMEs) consumed at 2 and 6 weeks postoperatively. The secondary outcome was patient-reported postoperative pain using the Visual Analogue Scale (VAS) at 2 and 6 weeks postoperatively. A multivariable linear regression was used to analyse these outcomes with eight prognostic factors as independent variables. RESULTS: Tobacco usage was significantly associated with higher opioid usage at 2 (p < 0.001) and 6 weeks (p = 0.02) postoperatively. Former tobacco users had a higher 2-week (p = 0.002) and cumulative OME (p = 0.002) consumption compared to current and nonsmokers. Patients with a higher number of comorbidities (p = 0.006) and those who were employed (p = 0.006) reported higher pain scores at 6 weeks. Patients in the 'not employed/other' category had significantly lower pain scores at 6 weeks postoperatively (p = 0.046). CONCLUSION: Former smoking status was significantly associated with increased post-operative opioid consumption following knee and shoulder arthroscopy at 2 and 6 weeks postoperatively. Increased pain was found to be significantly associated with employment status and an increasing number of comorbidities at 6 weeks postoperatively. These findings can aid clinicians in identifying and mitigating increased opioid utilization as well as worse pain outcomes in high-risk patient populations. LEVEL OF EVIDENCE: Level III, cohort study.

Knee Arthroscopy Following Total Knee Arthroplasty is Not Associated With an Elevated Risk of Infection.

BACKGROUND: Recent literature has suggested that knee arthroscopy (KA) following ipsilateral primary total knee arthroplasty (TKA) may be associated with an increased risk of periprosthetic joint infection (PJI). However, prior studies on this subject have relied on insurance databases or have lacked control groups for comparison. This study aimed to evaluate the risk of PJI in patients undergoing ipsilateral KA after primary TKA at a single institution. METHODS: Our total joint registry was queried to identify 167 patients (178 knees) who underwent ipsilateral KA for any indication other than infection following primary TKA (KA + TKA group). The average time from TKA to KA was 2.1 ± 2.3 years. The average follow-up from primary TKA and from KA was 8.4 ± 5.4 years and 6.3 ± 5.4 years, respectively. The mean patient age was 63 ± 11 years, the mean body mass index was 31 ± 5, and 64% were women. The most common indications for KA were patellar clunk or patellofemoral synovial hyperplasia (66%) and arthrofibrosis (16%). Patients in the KA + TKA group were matched to 523 patients who underwent TKA without subsequent KA (TKA group) based on age, sex, date of surgery, and body mass index. The primary outcome measure was survivorship free from PJI. RESULTS: There was no statistical difference in the overall rate of PJI between the KA + TKA group (n = 2, 1.1%) compared to the TKA group (n = 3, 0.6%) (hazard ratio 2.0, 95% confidence interval 0.3 to 12.0, P = .4). At 5 and 10 years after TKA, there was no difference in survivorship free of PJI between the 2 groups (P = .8 and P = .3, respectively). CONCLUSIONS: A PJI is a rare complication of KA after TKA. The rate of PJI in patients undergoing KA following TKA is not significantly increased. LEVEL OF EVIDENCE: III.

The potential of posterior cruciate ligament buckling phenomenon as a sign for partial anterior cruciate ligament tears.

INTRODUCTION: Diagnosis of a partial tear of the anterior cruciate ligament (ACL) can be challenging with physical examination and imaging techniques. Although magnetic resonance imaging (MRI) has high sensitivity and specificity for diagnosing complete ACL tears, its effectiveness may be limited when it is used to diagnose for partial tears. The hypothesis of the present study is that the posterior cruciate ligament (PCL) buckling phenomenon, which is a secondary sign of complete ACL tears on MRI, may be a useful method for diagnosing partial ACL tears. MATERIALS AND METHODS: The data of 239 patients who underwent knee arthroscopy in a single institution between 2016 and 2022 were analyzed retrospectively. Patients were divided into three groups based on the condition of their ligaments: partial tears, complete tears and intact ligaments. To evaluate the buckling phenomenon on sagittal T2-weighted MRI, measurements of the posterior cruciate ligament angle (PCLA) and the posterior cruciate ligament-posterior cortex angle (PCL-PCA) were conducted in each group. Subsequently, the ability of these two measurement methods to distinguish partial tears from the other groups was assessed. RESULTS: Both methods provided significantly different results in all three groups. Partial tears could be distinguished from intact ligaments with 86.8% sensitivity, 89.9% specificity when PCLA < 123.13° and 94.5% sensitivity, 93.2% specificity when PCL-PCA < 23.77°. Partial tears could be distinguished from complete tears with 79.5% sensitivity, 78.4% specificity when PCLA > 113.88° and with 86.1% sensitivity, 85.3% specificity when PCL-PCA > 16.39°. CONCLUSION: The main finding of the present study is that the PCLA and PCL-PCA methods are useful on MRI for diagnosing partial ACL tears. PCLA value between 113°-123° and PCL-PCA value between 16°-24° could indicate a partial ACL tear. With these methods, it is possible to distinguish partial tears from healthy knees and reduce missed diagnoses. In addition, the differentiation of partial and complete tears by these methods may prevent unnecessary surgical interventions. LEVEL OF EVIDENCE: Level III.

Pay attention to the evidence: in the longer term, intraarticular corticosteroid injections offer only harm for knee osteoarthritis.

With respect to the long-term effects of intra-articular corticosteroid injections (IACIs) in knee osteoarthritis (OA), we are at the stage where it seems like the jury has returned a verdict but the judge hasn't yet accepted it. Supporters of IACIs for knee OA, when reading about potential and actual harms and complete lack of any benefit in the medium- or long- term, are now clutching at straws that we shouldn't even expect to observe any benefit in the longer term. Sadly, the same arguments that orthopaedic surgeons use to justify continuing with knee arthroscopy when there are only documented long-term harms and no documented long-term benefits, are being used by rheumatologists to justify continuing with IACIs for knee OA. The only actual reason to keep recommending both IACIs and knee arthroscopy (which sadly society guidelines still do) is the "status quo", with the self-affirming argument that the quality of the RCTs published to date is not (yet) high enough to justify a change in expert opinion. There is a very strong argument against preserving the status quo for knee OA: outcomes everywhere keep getting worse. Knee replacements seem to be on a steady growth curve upwards in all countries and knee OA prevalence itself is also increasing. Something is badly wrong with the status quo for knee OA: if we were getting good results with medical treatment then fewer people would be needing knee replacements, not more. A very easy place to start questioning the status quo is to read a systematic review showing worse results than all comparators for IACIs followed by an editorial saying "let's not give up on IACIs for knee OA just yet". But as mentioned you could just as easily start with an orthopaedic journal editorial saying "let's not give up on knee arthroscopy just yet" after a systematic review showing no benefit for this procedure either.

Femoral nerve block using lower concentration ropivacaine preserves quadriceps strength while providing similar analgesic effects after knee arthroscopy.

PURPOSE: Femoral nerve block (FNB) is widely used in patients undergoing knee arthroscopy. However, the most commonly used concentration of ropivacaine (0.2% or above) may cause an unexpected decrease in the muscle strength of the quadriceps. Therefore, a lower concentration of ropivacaine (0.1%) for FNB was administered to investigate the effect on quadriceps strength and postoperative pain after knee arthroscopy. METHODS: This was a double-blind, randomized, controlled trial (ChiCTR2000041404). A total of 83 patients scheduled for elective knee arthroscopy were randomized to receive 0.1% or 0.2% ropivacaine for FNB under ultrasound guidance. The primary outcomes were quadriceps strength and numerical rating scale (NRS) pain score. Quadriceps strength was measured before surgery and 6 h and 24 h after surgery, while NRS score was recorded before surgery, at the postanaesthesia care unit (PACU), and 6 h and 24 h after surgery. Multiple linear regression tests were used to compare the differences in quadriceps strength and NRS score between the two groups. Two-factor analysis of variance, using the factors group and time of measurement, was used for repeated NRS scores. Secondary outcomes included knee mobility, side effects, patient satisfaction, and length of hospital stay. RESULTS: The mean (SD) quadriceps strength at 6 h after surgery was 7.5 (5.7) kg for the 0.1% ropivacaine group and 3.0 (4.4) kg for the 0.2% ropivacaine group. The mean difference adjusted for baseline characteristics was - 5.2 (95% CI - 7.2 to - 3.1) kg (P < 0.001). There was no significant difference between the two groups in quadriceps strength at 24 h after surgery. The mean differences in the average NRS score and maximum NRS score in the PACU were - 0.6 (P = 0.008) and - 1.0 (P < 0.001), respectively. There was no significant difference in NRS score at 6 h or 24 h after surgery. Two-factor analysis of variance showed no significant difference in the interaction factors of time and group for average NRS score and maximum NRS score. CONCLUSIONS: Compared with 0.2% ropivacaine, 0.1% ropivacaine for FNB preserved quadriceps strength at 6 h after knee arthroscopy while providing similar analgesic effects. LEVEL OF EVIDENCE: I.

Prediction of complications and surgery duration in primary TKA with high accuracy using machine learning with arthroplasty-specific data.

PURPOSE: The number of primary total knee arthroplasties (TKA) is expected to rise constantly. For patients and healthcare providers, the early identification of risk factors therefore becomes increasingly fundamental in the context of precision medicine. Others have already investigated the detection of risk factors by conducting literature reviews and applying conventional statistical methods. Since the prediction of events has been moderately accurate, a more comprehensive approach is needed. Machine learning (ML) algorithms have had ample success in many disciplines. However, these methods have not yet had a significant impact in orthopaedic research. The selection of a data source as well as the inclusion of relevant parameters is of utmost importance in this context. In this study, a standardized approach for ML in TKA to predict complications during surgery and an irregular surgery duration using data from two German arthroplasty-specific registries was evaluated. METHODS: The dataset is based on two initiatives of the German Society for Orthopaedics and Orthopaedic Surgery. A problem statement and initial parameters were defined. After screening, cleaning and preparation of these datasets, 864 cases of primary TKA (2016-2019) were gathered. The XGBoost algorithm was chosen and applied with a hyperparameter search, a cross validation and a loss weighting to cope with class imbalance. For final evaluation, several metrics (accuracy, sensitivity, specificity, AUC) were calculated. RESULTS: An accuracy of 92.0%, sensitivity of 34.8%, specificity of 95.8%, and AUC of 78.0% were achieved for predicting complications in primary TKA and 93.4%, 74.0%, 96.3%, and 91.6% for predicting irregular surgery duration, respectively. While traditional statistics (correlation coefficient) could not find any relevant correlation between any two parameters, the feature importance revealed several non-linear outcomes. CONCLUSION: In this study, a feasible ML model to predict outcomes of primary TKA with very promising results was built. Complex correlations between parameters were detected, which could not be recognized by conventional statistical analysis. Arthroplasty-specific data were identified as relevant by the ML model and should be included in future clinical applications. Furthermore, an interdisciplinary interpretation as well as evaluation of the results by a data scientist and an orthopaedic surgeon are of paramount importance. LEVEL OF EVIDENCE: Level IV.

Effect of knee arthroscopic debridement combined with peripatellar denervation on restoration of knee function in patients with knee osteoarthritis.

BACKGROUND: This research examines knee osteoarthritis (OA), a prevalent orthopedic disease marked by cartilage degeneration and chronic synovitis, leading to pain, restricted mobility, and eventual loss of knee function. Notably, patellofemoral osteoarthritis constitutes a significant proportion of knee OA cases. Our study aims to assess the impact of knee arthroscopic debridement coupled with peripatellar denervation on restoring knee function in OA patients and analyze the risk factors affecting treatment outcomes. By doing so, we hope to contribute to the informed selection of clinical treatment plans, addressing a disease that, if untreated, significantly impairs patients' quality of life. METHODS: A total of 211 patients with knee osteoarthritis treated in our hospital from June 2020 to June 2022 were analyzed retrospectively. Among them, 116 patients received arthroscopic knee debridement treatment alone as the control group, and 95 in the observation group were combined with denervation treatment based on the control group. The clinical efficacy of the two groups of patients after treatment was evaluated, and patients' pain was counted using the pain visual analogue score (VAS) method. The knee range of motion (ROM) was used to count the mobility of the patients and to compare the operative time, intraoperative perfusion volume, and length of stay between the two groups. According to the effectiveness after treatment, patients were divided into the improvement group (effective + markedly effective) and the non-improvement group, and the risk factors affecting the clinical efficacy of patients after treatment were analyzed by logistic regression. RESULTS: The total treatment efficiency of patients in the control group was lower than that of those in the observation group (P < 0.05). There was no difference in intraoperative perfusion volume and length of stay between patients in both groups (P > 0.05). However, the operative time was shorter in the control group compared with that in the observation group (P < 0.001). The post-treatment VAS scores of patients in the observation group were lower than those in the control group, while the ROM scores were higher than those of the control group (P < 0.001). Age, BMI, and preoperative VAS score were found to be independent risk factors for patient outcome by logistic regression analysis (P < 0.05). CONCLUSION: knee arthroscopic debridement combined with peripatellar denervation has a significant improvement in the restoration of knee function in patients with knee osteoarthritis and reduces their level of pain.

Comparison between micro-anchor skin dressing and liquid bonding agent for elective knee arthroscopy portal closure.

OBJECTIVE: The objective of the current study was to evaluate outcomes of elective knee arthroscopy portal closure comparing two skin closure techniques. METHOD: This was a randomised controlled trial including healthy volunteers aged ≥18 years undergoing elective knee arthroscopy that used two portals. At the time of surgery, each patient's two arthroscopy portal closures were randomised to one of two closure techniques; the first technique used approximation of the skin with a micro-anchor skin dressing (BandGrip Inc., US), while the second closure technique used an absorbable suture (Biosyn Monofilament, Medtronic) and a liquid bonding agent skin closure (Dermabond, Ethicon Inc., US). Postoperative complications and patient-reported outcomes were evaluated at the first visit after knee arthroscopy and at six weeks postoperatively. RESULTS: A total of 38 patients (76 portals) were enrolled in this study. No patients reported wound complications of either portal; thus, there was no significant difference (p>0.05) in wound complication rates between the skin closure techniques. Survey questions regarding any difference in appearance and cosmesis between the closure techniques' portal sites were responded to by 15 patients, all of whom indicated no difference in appearance between the portal sites. There was also no statistically significant difference between the two closure techniques with regards to appearance. CONCLUSION: There was no significant difference in presence of wound complications or appearance between skin closure with the micro-anchor skin dressing and the absorbable suture/liquid bonding agent skin closure.

[Shaving of popliteal artery secondary to a knee arthroscopy]. / Cas clinique. Lésion iatrogène de l'artère poplitée lors d'une arthroscopie du genou.

Popliteal artery lesions are rare complications of knee surgery and may have significant sequelae depending on the length of time it takes to diagnose this type of vascular injury. We present two case reports of popliteal artery following meniscus resection by shaving.

Les cas de lésions iatrogènes de l'artère poplitée liées à la chirurgie orthopédique du genou sont des complications rares, qui peuvent entraîner des séquelles importantes en cas de retard dans le diagnostic de ce type d'atteintes vasculaires. Nous vous présentons deux cas particuliers de plaie de l'artère poplitée à la suite d'une résection des ménisques lors d'une arthroscopie.

Outcomes of arthroscopic-assisted lateral tibial plateau fixation: a systematic review.

PURPOSE: The purpose of this study is to evaluate and summarize the current literature on outcomes of arthroscopic-assisted tibial plateau fixation (AATPF) when applied for only lateral tibial plateau fractures. METHODS: A comprehensive search of nine databases was conducted: ClinicalTrials.gov, Cochrane Library via Wiley, Embase and MEDLINE via Ovid, Global Index Medicus, PubMed, Scopus, SPORTDiscus via EBSCO, and Web of Science Core Collection. The study was performed in concordance with PRISMA guidelines. Studies eligible for inclusions included Schatzker I-III lateral tibial plateau fractures with a minimum of 6-month follow-up. Data extraction was performed by two authors independently using a predesigned form. RESULTS: A total of 17 studies, 7 prospective and 10 retrospective, including 565 patients (age 15-82 years old) treated with AATPF were included in this review with follow-up ranging from 6 to 138 months. All 10 studies that used categorical functional outcomes demonstrated excellent/very good or good outcomes in > 90% of patients. When compared to patients managed with the traditional open reduction internal fixation (ORIF), patients treated with AATPF had statistically significantly better range of motion mean difference [5.21° (95% CI - 2.50 to 12.92, p < 0.0001)], lower blood loss [66.19 mL (95% confidence interval (CI) 32.54-99.84 mL, p < 0.0001)], shorter hospital stay [- 1.41 days (95% CI - 3.39 to 0.58 days, p < 0.0001)], better Hospital Special Surgery score [11.31 (95% CI 6.49-16.12, p < 0.0001)], and higher Rasmussen radiographic score [1.26 (95% CI - 0.72 to 3.23, p < 0.0001)]. CONCLUSION: AATPF is a promising treatment of lateral tibial plateau fractures with some advantages over the traditional ORIF. LEVEL OF EVIDENCE: Therapeutic Level III.

Intra-articular steroid injection at the time of knee arthroscopy increases risk of post-operative infection.

PURPOSE: To evaluate the risk of post-operative infection after intra-articular steroid injection at the time of knee arthroscopy at a single institution high-volume sports medicine practice. METHODS: The electronic medical record at a single institution was queried for all patients who underwent knee arthroscopy from 2011 to 2019. Patients were included if they underwent more simple arthroscopic procedures: diagnostic arthroscopy, meniscectomy, loose body removal, synovectomy, or microfracture. Patients were excluded if they underwent more complex procedures, such as ligament reconstruction, meniscus repair, or any open procedures. These patients' medical records were then queried for current procedural terminology and international classification of disease codes indicating post-operative infection. Individual chart review was performed on this group of patients to determine if a true postoperative infection occurred within 6 months of the index arthroscopy. Patients were then categorized into "intra-operative steroid injection" versus "no steroid" based on each surgeon's preferred intra-operative analgesic injection cocktail. RESULTS: A total of 6889 patients were identified, including 2416 (35.1%) who were given intra-articular steroid at the time of knee arthroscopy. Post-operative infection occurred in 10 patients (0.15%) at a median of 18 days (range 9-42 days), 7 who received intra-operative steroid injection (0.29%) and 3 who did not (0.067%), p = 0.040. The relative risk of infection for those who received intra-operative steroid injection was 4.32 times higher than those who did not, with a number needed to harm of 448. There were no significant differences in age, body mass index, smoking status, or the prevalence of diabetes between those who got infected and those who did not. CONCLUSIONS: Knee infection following arthroscopic surgery is rare. Intra-operative steroid injection during arthroscopic knee surgery is associated with a 4.3-fold increased risk of subsequent knee infection. While the overall risk remains low, the use of intra-operative steroids is expected to result in one additional knee infection for every 448 arthroscopic procedures performed. LEVEL OF EVIDENCE: IV.

Meniscectomy is still a frequent orthopedic procedure: a pending need for education on the meniscus treatment possibilities.

PURPOSE: The purpose of this study was to evaluate the current status of education of polish surgeons in the subject of meniscus repair possibilities. The analysis of the possible correlations between the number of knee arthroscopy procedures performed by polish surgeons and their decision whether to remove or to repair the damaged meniscus has been performed. METHODS: Two-hundred and five registered orthopedic surgeons took part in surveys. The questionnaire contained the description of 20 patients with different types of meniscus damage and three questions concerning the experience in knee arthroscopy (two questions) and a choice of the treatment method (one question). Comparisons were made between knee arthroscopy experts (> 100 arthroscopies performed per year) and non-experts (≤ 100 cases). RESULTS: The questionnaire was completed by 194 knee surgeons from Poland with different levels in knee arthroscopy experience. For most cases, experts and non-experts agreed on the meniscus treatment method. Statistically significant differences in the recommended treatment between experts and non-experts were observed in 4 cases, where experts decided to repair the damage rather than to perform the meniscectomy. CONCLUSIONS: Meniscectomy remains a frequent orthopedic procedure, despite meniscal sparing having been advocated for several decades now and despite the existence of meniscus repair technique which gives good clinical outcomes-augmentation of the damaged meniscus with a collagen membrane. Polish surgeons still need education on the meniscus treatment possibilities. LEVEL OF EVIDENCE: V.

Preoperative muscle thickness influences muscle activation after arthroscopic knee surgery.

PURPOSE: The aim of this study was to compare the correlation between preoperative quadriceps femoris muscle thickness and postoperative neuromuscular activation and quadriceps femoris strength in patients with and without patellofemoral pain after arthroscopic partial meniscectomy. METHODS: A series of 120 patients were prospectively analysed in a longitudinal cohort study of patients scheduled for arthroscopic partial meniscectomy. The patellofemoral pain group included patients who developed anterior knee pain after surgery while the control group included those who had not done so. Patients with preoperative patellofemoral pain, previous knee surgeries as well as those on whom additional surgical procedures had been performed were excluded. Of the 120 initially included in the study, 90 patients were analysed after the exclusions. RESULTS: There is a direct correlation between preoperative quadriceps femoris muscle thickness and the neuromuscular activity values and the strength of the muscle at 6 weeks after surgery. These results were seen exclusively in the group of patients who do not develop patellofemoral pain (0.543, p = 0.008). The group of patients who developed anterior knee pain in the postoperative period did not show this correlation (n.s.). CONCLUSION: In patients without patellofemoral pain after meniscectomy, the greater the preoperative thickness of the quadriceps femoris, the more postoperative neuromuscular activation and strength they had. This correlation did not occur in those patients who develop patellofemoral pain after meniscal surgery. LEVEL OF EVIDENCE: II.

Machine learning in knee arthroplasty: specific data are key-a systematic review.

PURPOSE: Artificial intelligence (AI) in healthcare is rapidly growing and offers novel options of data analysis. Machine learning (ML) represents a distinct application of AI, which is capable of generating predictions and has already been tested in different medical specialties with various approaches such as diagnostic applications, cost predictions or identification of risk factors. In orthopaedics, this technology has only recently been introduced and the literature on ML in knee arthroplasty is scarce. In this review, we aim to investigate which predictions are already feasible using ML models in knee arthroplasty to identify prerequisites for the effective use of this novel approach. For this reason, we conducted a systematic review of ML algorithms for outcome prediction in knee arthroplasty. METHODS: A comprehensive search of PubMed, Medline database and the Cochrane Library was conducted to find ML applications for knee arthroplasty. All relevant articles were systematically retrieved and evaluated by an orthopaedic surgeon and a data scientist on the basis of the PRISMA statement. The search strategy yielded 225 articles of which 19 were finally assessed as eligible. A modified Coleman Methodology Score (mCMS) was applied to account for a methodological evaluation. RESULTS: The studies presented in this review demonstrated fair to good results (AUC median 0.76/range 0.57-0.98), while heterogeneous prediction models were analysed: complications (6), costs (4), functional outcome (3), revision (2), postoperative satisfaction (2), surgical technique (1) and biomechanical properties (1) were investigated. The median mCMS was 65 (range 40-80) points. CONCLUSION: The prediction of distinct outcomes with ML models applying specific data is already feasible; however, the prediction of more complex outcomes is still inaccurate. Registry data on knee arthroplasty have not been fully analysed yet so that specific parameters have not been sufficiently evaluated. The inclusion of specific input data as well as the collaboration of orthopaedic surgeons and data scientists are essential prerequisites to fully utilize the capacity of ML in knee arthroplasty. Future studies should investigate prospective data with specific and longitudinally recorded parameters. LEVEL OF EVIDENCE: III.

Performing a knee arthroscopy among patients with degenerative knee disease: one-third is potentially low value care.

PURPOSE: The purpose of this study was to assess in which proportion of patients with degenerative knee disease aged 50+ in whom a knee arthroscopy is performed, no valid surgical indication is reported in medical records, and to explore possible explanatory factors. METHODS: A retrospective study was conducted using administrative data from January to December 2016 in 13 orthopedic centers in the Netherlands. Medical records were selected from a random sample of 538 patients aged 50+ with degenerative knee disease in whom arthroscopy was performed, and reviewed on reported indications for the performed knee arthroscopy. Valid surgical indications were predefined based on clinical national guidelines and expert opinion (e.g., truly locked knee). A knee arthroscopy without a reported valid indication was considered potentially low value care. Multivariate logistic regression analysis was performed to assess whether age, diagnosis ("Arthrosis" versus "Meniscal lesion"), and type of care trajectory (initial or follow-up) were associated with performing a potentially low value knee arthroscopy. RESULTS: Of 26,991 patients with degenerative knee disease, 2556 (9.5%) underwent an arthroscopy in one of the participating orthopedic centers. Of 538 patients in whom an arthroscopy was performed, 65.1% had a valid indication reported in the medical record and 34.9% without a reported valid indication. From the patients without a valid indication, a joint patient-provider decision or patient request was reported as the main reason. Neither age [OR 1.013 (95% CI 0.984-1.043)], diagnosis [OR 0.998 (95% CI 0.886-1.124)] or type of care trajectory [OR 0.989 (95% CI 0.948-1.032)] were significantly associated with performing a potentially low value knee arthroscopy. CONCLUSIONS: In a random sample of knee arthroscopies performed in 13 orthopedic centers in 2016, 65% had valid indications reported in the medical records but 35% were performed without a reported valid indication and, therefore, potentially low value care. Patient and/or surgeons preference may play a large role in the decision to perform an arthroscopy without a valid indication. Therefore, interventions should be developed to increase adherence to clinical guidelines by surgeons that target invalid indications for a knee arthroscopy to improve care. LEVEL OF EVIDENCE: IV.

Machine-learning model successfully predicts patients at risk for prolonged postoperative opioid use following elective knee arthroscopy.

PURPOSE: Recovery following elective knee arthroscopy can be compromised by prolonged postoperative opioid utilization, yet an effective and validated risk calculator for this outcome remains elusive. The purpose of this study is to develop and validate a machine-learning algorithm that can reliably and effectively predict prolonged opioid consumption in patients following elective knee arthroscopy. METHODS: A retrospective review of an institutional outcome database was performed at a tertiary academic medical centre to identify adult patients who underwent knee arthroscopy between 2016 and 2018. Extended postoperative opioid consumption was defined as opioid consumption at least 150 days following surgery. Five machine-learning algorithms were assessed for the ability to predict this outcome. Performances of the algorithms were assessed through discrimination, calibration, and decision curve analysis. RESULTS: Overall, of the 381 patients included, 60 (20.3%) demonstrated sustained postoperative opioid consumption. The factors determined for prediction of prolonged postoperative opioid prescriptions were reduced preoperative scores on the following patient-reported outcomes: the IKDC, KOOS ADL, VR12 MCS, KOOS pain, and KOOS Sport and Activities. The ensemble model achieved the best performance based on discrimination (AUC = 0.74), calibration, and decision curve analysis. This model was integrated into a web-based open-access application able to provide both predictions and explanations. CONCLUSION: Following appropriate external validation, the algorithm developed presently could augment timely identification of patients who are at risk of extended opioid use. Reduced scores on preoperative patient-reported outcomes, symptom duration and perioperative oral morphine equivalents were identified as novel predictors of prolonged postoperative opioid use. The predictive model can be easily deployed in the clinical setting to identify at risk patients thus allowing providers to optimize modifiable risk factors and appropriately counsel patients preoperatively. LEVEL OF EVIDENCE: III.

Prophylaxis for preventing venous thromboembolism in knee arthroscopy and soft tissue reconstruction: consensus statements from an international panel of experts.

PURPOSE: There is a lack of consensus regarding need for Venous Thrombo Embolism (VTE) prophylaxis following arthroscopic knee surgery and open soft tissue knee reconstruction. Clear cut guidelines like ones for trauma surgery and arthroplasty do not exist and the published literature is limited to case reports with a few society guidelines. Given this lack of consensus, we conducted a modified Delphi questionnaire of international experts to provide recommendations on this topic. METHODS: The consensus statements were generated using an anonymised 3 round modified Delphi questionnaire, sent to an international panel of 38 knee surgeons, with an 80% agreement being set as the limit for consensus. The responses were analysed using descriptive statistics with measures like mode, median and box plots. Feedback was provided to all panelists based on responses from the previous rounds to help generate the consensus. RESULTS: Six consensus statements were generated after the three rounds of Delphi. Patient factors, prolonged surgery duration and family history of thrombogenic events emerged as the main points to be taken into consideration for prophylaxis. CONCLUSION: It was established through this study, that there exists a select group of patients undergoing arthroscopic surgery that justify the usage of VTE prophylaxis. The expert responses to most of the questions in different scenarios favoured usage of VTE prophylaxis based on patient factors like advanced age, past history of VTE, smoking, oral contraceptive use etc. LEVEL OF EVIDENCE: Level V.