Rotating-Hinge Revision Total Knee Arthroplasty Provides Greater Arc of Motion Gains for Patients Who Have Severe Arthrofibrosis.

INTRODUCTION: Arthrofibrosis is a common postoperative total knee arthroplasty (TKA) complication that results in limited range of motion (ROM). There is limited literature on outcomes after revision TKA (rTKA) for arthrofibrosis based on preoperative ROM restriction. The aims of this study were to: (1) examine ROM trajectory after rTKA for arthrofibrosis patients who have severe versus non-severe limitations; (2) compare ROM gains and final arc of motion (AOM) between severe and non-severe cohorts; (2a) compare ROM gain in a severe cohort treated with a rotating hinge (RH) versus a non-rotating hinge (non-RH) construct; and (3) assess the impact of arthrofibrosis severity on patient-reported outcome measures (PROMs). METHODS: Patients were divided into 2 groups: Group A had preoperative ROM < 70o (severe), and Group B had preoperative ROM > 70o (non-severe). Patients were assessed clinically using AOM gain, absolute ROM, Knee injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS, JR), Lower Extremity Activity Scale (LEAS), and pain scores. Postoperative gains in AOM were compared between both groups. RESULTS: A total of 56 rTKAs (Group A (severe): n = 36, Group B (non-severe): n = 20) were performed for patients who have postoperative fibrosis. Group B had better ROM at the one-year timepoint (Group B: 95.9 ± 22.5 versus Group A: 83.2 ± 25.7). Group A had significantly better improvement in absolute AOM than Group B (31.1 ± 20.9 versus 11.4 ± 25.0, P < 0.01). The RH group demonstrated significantly better absolute AOM gain than the non-RH group (41.3 ± 19.4 versus 18.3 ± 15.2, P < 0.001). However, there were no significant differences in PROMs between Groups A and B or between RH and NRH groups at the final follow-up. DISCUSSION: Final ROM achieved between severe and non-severe arthrofibrosis groups were similar, and patients who have severe arthrofibrosis can expect greater absolute ROM gains and similar functional outcomes than non-severe arthrofibrosis patients. The RH rTKAs provided greater AOM gains for patients who have severe arthrofibrosis, with equivalent functional outcomes to non-RH implants. For severe arthrofibrosis patients, RH designs provided twice the overall ROM gain, however, longer follow-up is necessary to determine whether RH designs have inferior overall implant survivorship.

Exploring the molecular mechanisms and shared potential drugs between rheumatoid arthritis and arthrofibrosis based on large language model and synovial microenvironment analysis.

Rheumatoid arthritis (RA) and arthrofibrosis (AF) are both chronic synovial hyperplasia diseases that result in joint stiffness and contractures. They shared similar symptoms and many common features in pathogenesis. Our study aims to perform a comprehensive analysis between RA and AF and identify novel drugs for clinical use. Based on the text mining approaches, we performed a correlation analysis of 12 common joint diseases including arthrofibrosis, gouty arthritis, infectious arthritis, juvenile idiopathic arthritis, osteoarthritis, post infectious arthropathies, post traumatic osteoarthritis, psoriatic arthritis, reactive arthritis, rheumatoid arthritis, septic arthritis, and transient arthritis. 5 bulk sequencing datasets and 4 single-cell sequencing datasets of RA and AF were integrated and analyzed. A novel drug repositioning method was found for drug screening, and text mining approaches were used to verify the identified drugs. RA and AF performed the highest gene similarity (0.77) and functional ontology similarity (0.84) among all 12 joint diseases. We figured out that they share the same key pathogenic cell including CD34 + sublining fibroblasts (CD34-SLF) and DKK3 + sublining fibroblasts (DKK3-SLF). Potential therapeutic target database (PTTD) was established with the differential expressed genes (DEGs) of these key pathogenic cells. Based on the PTTD, 15 potential drugs for AF and 16 potential drugs for RA were identified. This work provides a new perspective on AF and RA study which enhances our understanding of their pathogenesis. It also shed light on their underlying mechanism and open new avenues for drug repositioning studies.

Increased Rate of Surgery for Loss of Motion Following Anterior Cruciate Ligament Reconstruction During COVID-19.

OBJECTIVES: To investigate the incidence and risk factors associated with loss of motion after anterior cruciate ligament reconstruction (ACLR) during the coronavirus disease 2019 pandemic (COVID-19). METHODS: A retrospective review of patients undergoing primary ACLR between March 2017-November 2022 by a senior high-volume orthopaedic surgeon was performed. Exclusion criteria included revision ACLR, multiligamentous knee surgery, and age <14 years. The COVID-19 group was categorized according to the United States Centers for Disease Control Public Health Emergency declaration dates (January 31, 2020-May 11, 2023). To minimize confounding variables associated with the early stages of COVID-19, patients who underwent ACLR between December 1, 2019 and February 29, 2020 were excluded. Loss of motion was defined using the International Knee Documentation Committee (IKDC) criteria for loss of motion of the knee (i.e. an extension deficit >5° or flexion deficit >15° compared to the contralateral knee) 3-12 months after ACLR, or surgery to restore motion within 12 months of ACLR. RESULTS: A total of 336 individuals that underwent 352 primary ACLRs (164 pre-COVID-19, 188 during COVID-19) were included (mean age 25.2 ± 10.6 years, 44% female). The overall rate of postoperative loss of motion was 15% (n=53) and 9% (n=31) required surgery to restore motion within 12 months of ACLR. More patients underwent surgery for loss of motion during COVID-19 compared to pre-COVID-19, which was statistically significant (12% (n=23) vs 5% (n=8) respectively, P=0.02). However, a statistically significant difference in the rate of loss of motion was not detected (18% (n=33) vs 12% (n=20) respectively, P=0.16). A statistically significant increased median time from injury to ACLR was observed during COVID-19 compared to pre-COVID-19 (55 vs 37 days, P<0.01). More patients were unable to achieve terminal extension (0°) at minimum 9 months postoperatively during COVID-19 compared to pre-COVID-19 (10% vs 3%, P=0.04) and motion was worse at this interval (0°-136° vs -2°-138°, P<0.01). CONCLUSION: Surgery for loss of motion following ACLR was more common during COVID-19. Decreased access to elective medical care, changed activity level, psychological effects, or COVID-19 itself, may explain the increased rate of surgery for loss of motion during COVID-19. LEVEL OF EVIDENCE: Case series; level IV.

Neighborhood socioeconomic disadvantage does not predict need for manipulation under anesthesia or range of motion following total knee arthroplasty.

Background: Studies have linked socioeconomic factors including lower income and minority race with worse functional outcomes following total knee arthroplasty (TKA). Arthrofibrosis is a common complication following TKA, and manipulation under anesthesia (MUA) is an effective treatment option for arthrofibrosis. This study aimed to determine if neighborhood-level socioeconomic disadvantage predicts need for MUA and postoperative range of motion (ROM) among patients undergoing primary elective TKA. Methods: We performed a retrospective cohort study of primary TKAs performed at a single institution over a three-year duration. Area Deprivation Index (ADI) was used to determine each patient's level of socioeconomic disadvantage based on their home address. Patients were allocated into three groups based on ADI: least socioeconomic disadvantage (ADI 1-3), middle socioeconomic disadvantage (ADI 4-6), and most socioeconomic disadvantage (ADI 7-10). Demographic factors and comorbid conditions were recorded. Bivariate analysis was used to evaluate the relationship between degree of socioeconomic disadvantage and need for MUA and postoperative ROM. Results: In total, 600 patients were included and 26.7 % were categorized as most disadvantaged. In comparison to the middle and least disadvantaged groups, these patients were more likely to be Women (71.2 vs. 67.9 and 58.6 %; p = 0.027), younger (60.7 vs. 62.9 and 66.3 years; p < 0.001) and have higher BMI (34.9 vs. 33 and 31.7; p < 0.001) (most disadvantaged vs. middle and least). Analysis revealed no difference in rate of MUA (6.3 vs. 2.5 vs. 4 %; p = 0.179) or postoperative ROM (98 vs. 98 vs. 100°; p = 0.753) between the three groups (most, middle, and least disadvantaged, respectively). Conclusion: Neighborhood socioeconomic disadvantage does not predict rate of MUA or postoperative ROM following TKA. Patients residing in neighborhoods with higher ADI who underwent TKA were more likely to be younger, Women, and have higher BMI, consistent with previous literature. Our results support efforts to improve access to orthopaedic care, including TKA, to patients of all socioeconomic levels.

Arthroscopic fibroarthrolysis and mobilization under anesthesia is a simple, reproducible, and satisfactory method for the treatment of patients with severe post-traumatic arthrofibrosis of the knee.

OBJECTIVE: To evaluate the range of motion (ROM) of the knee in patients with severe post-traumatic knee arthrofibrosis after being treated with arthroscopic fibroarthrolysis (AFA) and manipulation under anesthesia (MUA). METHODS: Case series of patients with severe post-traumatic knee arthrofibrosis who underwent AFL+MUA in a national referral center. The primary outcome to be assessed was ROM before and after surgery and then at 3-month intervals until a minimum follow-up of one year was completed. RESULTS: 51 patients were included. The main injuries preceding the stiffness were tibial plateau fracture (37.3%), distal femur fracture (27.5%), and femoral shaft fracture (15.7%). Forty-five patients had severe flexion deficits with a median preoperative flexion of 70°. Intraoperative flexion significantly improved to 110°. Significant loss of flexion was observed at 3 and 6 months, however, patients regained ROM in the 9 and 12-month follow-ups. At discharge, 80% of the patients achieved flexion of 90° or more. There were 4 intraoperative complications and 3 reinterventions were performed. CONCLUSION: AFA+MUA can help patients with severe post-traumatic knee arthrofibrosis to recover ROM in most cases. However, this procedure is not without risks and complications, therefore, careful consideration should be given to its indication and execution.

Clinical Outcomes of Arthroscopic Adhesiolysis: A Case Series of 40 Patients With Postoperative Knee Stiffness.

Introduction Restricted range of motion over the knee joint is a known complication following the surgical procedure. Aggressive rehabilitation protocols can initially manage knee stiffness due to arthrofibrosis. If conservative management fails, surgical (open or arthroscopic) release is the preferred modality of management. We present a series of 40 patients with postoperative knee stiffness who were treated with arthroscopic adhesiolysis. Material and methods This is a retrospective study conducted at Phoenix Orthopedic Superspeciality Hospital, Nagpur, India, from 2017 to 2021. Our study included 40 patients with postoperative knee joint stiffness, of whom 27 were males and 13 were females. The study considered the duration of stiffness, which ranged from six months to five years. All patients underwent arthroscopic knee release. A rigorously supervised physical therapy program followed this procedure. Patients were examined at three months, six months, and one year to assess improvement in knee range of movement. Results Out of 40 patients, six were classified as Shelbourne type 4, and the remaining were Shelbourne type 3. Twenty-three of 40 patients developed arthrofibrosis following intra-articular or peri-articular fracture fixation surgery; 11 patients were operated on arthroscopically for anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) reconstruction. Three patients developed stiffness following total knee replacement, one following patellectomy, and three following infection after fracture fixation. The mean pre-op knee range of motion (ROM) was 48.875 degrees. Following arthroscopic release, the mean improvement in ROM was 60 degrees intra-operatively. The average postoperative range was 108.25 degrees. Conclusion Arthroscopic adhesiolysis and quadriceps release are reliable methods for dealing with postoperative knee stiffness. It prevents wound complications and increases the chances of surgical site infection due to smaller incisions. Postoperatively, we achieved an average increase of 60 degrees in ROM over the knee joint.

Magnetic Resonance Imaging of Cyclops Lesion in Patients With Non-reconstructed Anterior Cruciate Ligament.

Introduction The term cyclops lesion refers to localized anterior fibrosis, which is the abnormal proliferation of fibrous tissue in a joint that develops in the anterior aspect of the intercondylar notch. It is a known cause of extension loss of the knee after anterior cruciate ligament (ACL) reconstruction; however, it can be found in patients who have not undergone any surgical repair of the ACL. The term "cyclops lesion" was given based on the arthroscopic appearance of the fibrous nodule and vessels that resemble an eye. The purpose of this study is to highlight the existence of cyclops lesions in non-operated knees. Methods We conducted a study on 10 patients who were subjected to an MRI knee in a Siemens Magnetom Vida 3 Tesla (Erlangen, Germany) machine. We retrospectively analyzed all 10 cases in our institution from July 2021 to March 2022. These subjects had a previous history of trauma, and they presented with complaints of pain and difficulty in knee extension but no history of previous ligament repair. All patients underwent an MRI examination. When a cyclops lesion was revealed on MR imaging, the signal-intensity characteristics, location, and size were documented. Results There were a total of 10 patients included in the study, of whom eight were males and two were females. The most common clinical presentation in all our cases was difficulty in the extension of the knee, while there was associated instability and difficulty in walking in some patients. There was a demonstrable cyclops lesion near the tibial attachment of ACL in eight (80%) patients, whereas it was found to be located just lateral to the anterior intercondylar notch in the rest of the two (20%) patients. Conclusion MRI is an effective tool to evaluate unexplained pain, functional limitations, and limited range of motion in patients with suspected arthrofibrosis. MRI also helps determine the extent of fibrosis involvement and excludes other complications that may have a similar clinical picture.

Risk factors for failure of manipulation under anesthesia after total knee arthroplasty.

BACKGROUND: Manipulation under anesthesia (MUA) is a well-established treatment for stiffness after total knee arthroplasty (TKA). Risk factors for failure of MUA remain largely unknown. The primary aim of this study was to identify risk factors for failure of MUA after TKA. METHODS: We performed a retrospective cohort study including 470 patients who underwent MUA after primary TKA with minimum 2 year follow-up. Patients were grouped into success (n = 412) or failure (n = 58) cohorts; failure was defined as flexion < 90° at most recent follow-up or revision for stiffness. The increase in flexion post-MUA for the cohort was calculated. Several clinical, patient, and surgical factors were analyzed using univariate, followed by multivariable logistic regression models to identify independent risk factors associated with failure. RESULTS: The mean increase in flexion was 42° (range 0-115). BMI 30-35 (p = 0.01, odds ratio (OR) 2.42; 95% CI 1.25-4.68) and poorer pre-MUA flexion (p < 0.01, OR 1.43; 95% CI 1.23-1.67) were risk factors for failure. When considering revision for stiffness only, BMI 30-35 (p = 0.01, OR 3.27; 95% CI 1.41-7.61), lower pre-MUA flexion (p < 0.01, OR 1.43; 95% CI 1.18-1.75), and history of prior knee surgery (p = 0.04, OR 2.31; 95% CI 1.06-5.04) were predictors of failure. Time to MUA (p = 0.48), thromboprophylaxis (p = 0.44), pre-operative opioid use (p = 0.34), depression/anxiety (p = 1.0), and several other factors analyzed were not associated with failure. CONCLUSION: In this large cohort, elevated BMI and lower pre-MUA flexion were risk factors for failure of MUA. History of prior knee surgery was an additional predictor of requiring revision for stiffness.

Biomechanical outcomes of pharmacological therapies for post-traumatic arthrofibrosis in preclinical animal models: a systematic review and meta-analysis.

PURPOSE/AIM OF THE STUDY: There is still no evidence of which drug has the greatest therapeutic potential for post-traumatic arthrofibrosis. The aim of this study is to systematically review the literature for quality evidence and perform a meta-analysis about the pharmacological therapies of post-traumatic arthrofibrosis in preclinical models. MATERIALS AND METHODS: A comprehensive and systematic search strategy was performed in three databases (MEDLINE, EMBASE and Web of Science) retrieving studies on the effectiveness of pharmacological therapies in the management of post-traumatic arthrofibrosis using preclinical models in terms of biomechanical outcomes. Risk of bias assessment was performed using the SYRCLE's risk of bias tool. A meta-analysis using a random-effects model was conducted if a minimum of three studies reported homogeneous outcomes for drugs with the same action mechanism. RESULTS: Forty-six studies were included in the systematic review and evaluated for risk of bias. Drugs from 6 different action mechanisms of 21 studies were included in the meta-analysis. Overall, the methodological quality of the studies was poor. Statistically significant overall effect in favor of reducing contracture was present for anti-histamines (Chi2 p = 0.75, I2 = 0%; SMD (Standardized Mean Difference) = -1.30, 95%CI: -1.64 to -0.95, p < 0.00001) and NSAIDs (Chi2 p = 0.01, I2 = 63%; SMD= -0.93, 95%CI: -1.58 to -0.28, p = 0.005). CONCLUSIONS: Anti-histamines, particularly ketotifen, have the strongest evidence of efficacy for prevention of post-traumatic arthrofibrosis. Some studies suggest a potential role for NSAIDs, particularly celecoxib, although heterogeneity among the included studies is significant.

The association between losartan potassium prescription and postoperative outcomes following total knee arthroplasty: A TriNetX analysis.

BACKGROUND: Total knee arthroplasty (TKA) is a common surgical procedure performed to alleviate pain and improve functional outcomes in patients with knee osteoarthritis and rheumatoid arthritis who have failed conservative treatments. Arthrofibrosis has been extensively studied due to its negative impact on TKA outcomes. Losartan, an angiotensin receptor blocker (ARB), has the potential to improve TKA outcomes by inhibiting TGF-ß and decreasing fibrosis. This study aims to analyze a large-scale, real-world healthcare database to investigate the association between losartan potassium prescription and postoperative outcomes such as readmissions, ED visits, and the need for MUA or revision TKA. HYPOTHESIS: Based on previous literature and the nature of ARBs, it is expected that the addition of losartan will aid in better outcomes for patients following a primary TKA. PATIENTS AND METHODS: In this retrospective observational study, the TriNetX Research Network (TriNetX) database was queried as of June 21, 2023. All patients who underwent a primary total knee arthroplasty (TKA) prior to June 21, 2022 were included. Patients were then divided into two cohorts by whether they had an active losartan potassium prescription within the year prior to their surgery to within 90days postoperatively. Patients were then propensity-matched to eliminate differences in demographics and comorbidities. RESULTS: Losartan TKA patients were 1.18 [OR: 0.85 (95% CI: 0.79-0.90), p<0.001] times less likely to be readmitted within 90days and were 1.15 (OR: 0.87 (95% CI: 0.79-0.96); p=0.009) times less likely to undergo a manipulation under anesthesia (MUA) within the 1-year postoperative period. There were no statistically significant differences in rates of emergency department (ED) visits at 90days postoperatively or revision TKAs at 1year postoperatively. DISCUSSION: In conclusion, patients with an active losartan prescription prior to TKA had a significantly lower likelihood of readmission within 90days and a lower likelihood of undergoing MUA within the 1-year postoperative period compared to patients not taking losartan. This presents an opportunity for further clinical investigation to explore the value of losartan in TKA. LEVEL OF EVIDENCE: III; an observational cohort study.

The efficacy of vitamin E in preventing arthrofibrosis after joint replacement.

BACKGROUND: Arthrofibrosis is a joint disorder characterized by excessive scar formation in the joint tissues. Vitamin E is an antioxidant with potential anti-fibroblastic effect. The aim of this study was to establish an arthrofibrosis rat model after joint replacement and assess the effects of vitamin E supplementation on joint fibrosis. METHODS: We simulated knee replacement in 16 male Sprague-Dawley rats. We immobilized the surgical leg with a suture in full flexion. The control groups were killed at 2 and 12 weeks (n = 5 per group), and the test group was supplemented daily with vitamin E (0.2 mg/mL) in their drinking water for 12 weeks (n = 6). We performed histological staining to investigate the presence and severity of arthrofibrosis. Immunofluorescent staining and α2-macroglobulin (α2M) enzyme-linked immunosorbent assay (ELISA) were used to assess local and systemic inflammation. Static weight bearing (total internal reflection) and range of motion (ROM) were collected for functional assessment. RESULTS: The ROM and weight-bearing symmetry decreased after the procedure and recovered slowly with still significant deficit at the end of the study for both groups. Histological analysis confirmed fibrosis in both lateral and posterior periarticular tissue. Vitamin E supplementation showed a moderate anti-inflammatory effect on the local and systemic levels. The vitamin E group exhibited significant improvement in ROM and weight-bearing symmetry at day 84 compared to the control group. CONCLUSIONS: This model is viable for simulating arthrofibrosis after joint replacement. Vitamin E may benefit postsurgical arthrofibrosis, and further studies are needed for dosing requirements.

The Chitranjan S. Ranawat Award: Manipulation Under Anesthesia to Treat Postoperative Stiffness After Total Knee Arthroplasty: A Multicenter Randomized Clinical Trial.

BACKGROUND: Manipulation under anesthesia (MUA) occurs in 4% of patients after total knee arthroplasty (TKA). Anti-inflammatory medications may target arthrofibrosis pathogenesis, but the data are limited. This multicenter randomized clinical trial investigated the effect of adjuvant anti-inflammatory medications with MUA and physical therapy on range of motion (ROM) and outcomes. METHODS: There were 124 patients (124 TKAs) who developed stiffness after primary TKA for osteoarthritis enrolled across 15 institutions. All received MUA when ROM was < 90° at 4 to 12 weeks postoperatively. Randomization proceeded via a permuted block design. Controls received MUA and physical therapy, while the treatment group also received one dose of pre-MUA intravenous dexamethasone (8 mg) and 14 days of oral celecoxib (200 mg). The ROM and clinical outcomes were assessed at 6 weeks and 1 year. This trial was registered with ClinicalTrials.gov. RESULTS: The ROM significantly improved a mean of 46° from a pre-MUA ROM of 72 to 118° immediately after MUA (P < .001). The ROM was similar between the treatment and control groups at 6 weeks following MUA (101 versus 99°, respectively; P = .35) and at one year following MUA (108 versus 108°, respectively; P = .98). Clinical outcomes were similar at both end points. CONCLUSIONS: In this multicenter randomized clinical trial, the addition of intravenous dexamethasone and a short course of oral celecoxib after MUA did not improve ROM or outcomes. However, MUA provided a mean ROM improvement of 46° immediately, 28° at 6 weeks, and 37° at 1 year. Further investigation in regards to dosing, duration, and route of administration of anti-inflammatory medications remains warranted. LEVEL OF EVIDENCE: Level 1, RCT.

Arthroscopic Arthrolysis of Knee: Timing, Technique and Results.

Aim: To evaluate the functional outcomes of patients undergoing arthroscopic arthrolysis of the knee and find the ideal timing for arthrolysis to achieve maximum range of motion (ROM) of the knee. Methods: All patients who underwent arthroscopic arthrolysis for post-operative joint stiffness following surgery for injuries around knee joint at a tertiary care centre from 2009 to 2023 were included in this study. The patients' details such as primary injury, time interval between the index surgery and arthrolysis, improvement in knee range of ROM and Lysholm score from prior to arthrolysis to last follow-up post arthrolysis were retrieved from hospital database and analysed. Results: Total of 42 patients who underwent arthroscopic arthrolysis of knee from 2009 to 2023 were included in this study. Follow-up range was 6 months to 6 years. ROM after arthrolysis significantly improved in the early and delayed arthrolysis groups as compared to late arthrolysis groups (mean 126.25 and 115.62 vs 106.3, p < 0.05). Patients treated with early arthroscopic arthrolysis (within 3 months) showed significant increase in post operative Lysholm score compared to other groups (p < 0.05). ROM of 120° and beyond was achieved in 75% of cases in early arthrolysis group compared to 62.8% and 39% in delayed and late arthrolysis group (p < 0.05). Conclusions: Arthroscopic arthrolysis done within 6 months (with maximum effect when done within 3 months) after the primary surgery leads to significant improvement in ROM and functional scores as compared to those with late arthrolysis group.

Risk factors for reoperation for arthrofibrosis following primary anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study is to identify the rate and risk factors for a reoperation for arthrofibrosis following primary anterior cruciate ligament (ACL) reconstruction. METHODS: Prospective data recorded in the New Zealand ACL Registry were cross-referenced with data from the Accident Compensation Corporation (ACC). Primary ACL reconstructions performed between April 2014 and May 2021 were analysed. The ACC database was used to identify patients who underwent a reoperation for a diagnosis of arthrofibrosis. Multivariable survival analysis was performed to compute adjusted hazard ratios (aHR) and 95% confidence intervals. RESULTS: A total of 12,296 primary ACL reconstructions were analysed, of which 230 underwent a reoperation for arthrofibrosis (1.9%) at a mean follow-up of 3.6 years. A higher risk of arthrofibrosis was observed in females (aHR = 1.76, p = 0.001), patients with a history of previous knee surgery (aHR = 1.82, p = 0.04) and when a transtibial drilling technique was used (aHR = 1.53, p = 0.03). ACL reconstruction >6 months after injury had the lowest rate of arthrofibrosis (1.3%, aHR = 0.45, p = 0.01). There was no difference in risk between early surgery within 6 weeks versus delayed surgery between 6 weeks and 6 months after injury (2.9% versus 2.1%, aHR = 0.78, not significant). CONCLUSION: Female sex, previous knee surgery and a transtibial drilling technique increased the risk of reoperation for arthrofibrosis. Early surgery within 6 weeks of injury was not associated with an increased risk when compared with surgery between 6 weeks and 6 months after injury. LEVEL OF EVIDENCE: Level III.

Acute Anterior Cruciate Ligament Reconstruction Performed Within 10 Days of Injury Does Not Increase Risk of Postoperative Arthrofibrosis: A Systematic Review and Meta-analysis.

BACKGROUND: The optimal timing of anterior cruciate ligament (ACL) reconstruction (ACLR) remains a controversial topic. Previous reviews have demonstrated that there are no differences between early and delayed ACLR; however, these studies have been limited by heterogeneous definitions of acute ACL injury. PURPOSE: To evaluate postoperative patient functional outcomes and risk for arthrofibrosis after acute arthroscopic ACLR performed ≤10 days after injury. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using multiple medical databases. Inclusion criteria were studies that evaluated postoperative range of motion outcomes for patients undergoing ACLR ≤10 days after initial ACL injury. For included comparative studies comparing patient groups undergoing ACLR ≤10 days and patients undergoing "delayed" ACLR after ≥3 weeks of initial injury, quantitative analysis was performed to assess for differences in postoperative arthrofibrosis, reoperation rates, and patient-reported outcomes between groups. DerSimonian-Laird binary random-effects models were constructed to quantitatively describe the association between the ACLR time period and patient outcomes by generating effect estimates in the form of odds ratios with 95% CIs. Qualitative analysis was performed to describe variably reported patient outcomes and the risk of arthrofibrosis after ACLR for noncomparative studies. RESULTS: Screening yielded 6 full-text articles with 448 patients who underwent ACLR (296 ACLR <10 days, 152 ACLR >3 weeks), with a pooled mean age of 28.1 years. For studies amenable to quantitative analysis, there were no significant differences between ACLR performed ≤10 days and ACLR performed at the 3-week point or after in terms of postoperative stiffness (3 studies; odds ratio, 1.27; P = .508), Tegner scores (2 studies; mean difference, -0.056; P = .155), or reoperation for stiffness (3 studies; odds ratio, 0.869; P = .462). The overall incidence of postoperative arthrofibrosis after 12 months of follow-up was 11 of 296 (3.7%) for ACLRs performed ≤10 days versus 6 of 152 (3.9%) for those performed at the 3-week point or after. CONCLUSION: ACLR performed ≤10 days after the inciting injury does not increase the risk of postoperative arthrofibrosis and demonstrates similar patient-reported outcomes compared with ACLR performed at the 3-week point or after.

Unexpected positive cultures in patients with arthrofibrosis following total hip and total knee arthroplasty.

PURPOSE: It has been suggested that low-grade infections could be the cause of arthrofibrosis. However, this hypothesis has not been conclusively proven. The aim of this study is to assess the incidence of unexpected positive cultures (UPC) in patients undergoing revision total joint arthroplasty for a diagnosis of arthrofibrosis. METHODS: A retrospective single-centre review was performed. All patients who underwent an aseptic revision due to histologically confirmed arthrofibrosis (based on the synovial-like interface membrane (SLIM) criteria) were included. The incidence of UPC was then calculated. RESULTS: A total of 147 patients were included. Of these, 100 underwent a total knee arthroplasty (TKA) procedure and 46 a total hip arthroplasty (THA) surgery. One patient had a periprosthetic joint infection and was therefore excluded. Of the 146 included patients, 6 had confirmed UPC (4.08%). The following bacteria were identified: Anaerococcus octavius, Staphylococcus epidermidis, Enterobacter cloacae, Staphylococcus hominis, Streptococcus pluranimalium, Staphylococcus pettenkoferi. CONCLUSIONS: Our results suggest that the incidence of UPC in patients with arthrofibrosis is low. It is lower than that of UPC in patients that undergo a revision for other causes. There is no proven relationship between histologically confirmed arthrofibrosis following total joint arthroplasty and prosthetic joint infection.

Shoulder Adhesive Capsulitis Prior to Total Knee Arthroplasty is Associated With Increased Rates of Postoperative Stiffness Requiring Manipulation Under Anesthesia and Arthroscopic Lysis of Adhesions.

BACKGROUND: Arthrofibrosis following total knee arthroplasty (TKA) and adhesive capsulitis (AC) of the shoulder develop via a similar pathologic process. The purpose of this study was to examine the relationship between these two conditions. METHODS: This was a retrospective cohort study using a large nationwide claims database. Patients who had a history of shoulder AC prior to TKA were compared to TKA patients who did not have AC history comparing rates of postoperative stiffness, manipulation under anesthesia (MUA), arthroscopic lysis of adhesions (LOAs), and revision arthroplasty at postoperative timepoints (3 months, 6 months, 1 year, and 2 years). RESULTS: Within 3 months, 6 months, 1 year, and 2 years of their TKAs, patients who had a history of AC prior to TKA were significantly more likely to experience stiffness (OR [odds ratio] = 1.29, 1.28, 1.32, and 1.36, respectively) and LOAs (OR = 6.78, 3.65, 2.99, and 2.81, respectively). They also showed increased risk of MUA within 6 months, 1 year, and 2 years (OR = 1.15, 1.15, and 1.16, respectively) of their TKAs. Patients having a preoperative diagnosis of AC did not have an increased risk of undergoing revision surgery 1 year or 2 years after their TKAs (P > .05). CONCLUSIONS: Patients diagnosed with AC prior to TKA experience higher rates of postoperative stiffness, resulting in additional interventions such as MUA and LOAs. These findings identify a particularly high-risk patient population that may benefit from additional interventions prior to and following TKA. LEVEL OF EVIDENCE: This is a level III prognostic study.

Postoperative Angiotensin Receptor Blocker Use is Associated With Decreased Rates of Manipulation Under Anesthesia, Arthroscopic Lysis of Adhesions, and Prosthesis-Related Complications in Patients Undergoing Total Knee Arthroplasty.

BACKGROUND: The cellular mechanisms underlying excess scar tissue formation in arthrofibrosis following total knee arthroplasty (TKA) are well-described. Angiotensin receptor blockers (ARB), particularly losartan, is a commonly prescribed antihypertensive with demonstrated antifibrotic properties. This retrospective study aimed to assess the rates of 1- and 2-year postoperative complications in patients who filled prescriptions for ARBs during the 90 days after TKA. METHODS: Patients undergoing primary TKA were selected from a large national insurance database, and the impact of ARB use after TKA on complications was assessed. Of the 1,299,106 patients who underwent TKA, 82,065 had filled at least a 90-day prescription of losartan, valsartan, or olmesartan immediately following their TKA. The rates of manipulation under anesthesia (MUA), arthroscopic lysis of adhesions (LOA), aseptic loosening, periprosthetic fracture, and revision at 1 and 2 years following TKA were analyzed using multivariable logistic regressions to control for various comorbidities. RESULTS: ARB use was associated with decreased rates of MUA (odds ratio [OR] = 0.94, 95% confidence interval (CI), 0.90 to 0.99), arthroscopy/LOA (OR = 0.86, 95% CI, 0.77 to 0.95), aseptic loosening (OR = 0.71, 95% CI, 0.61 to 0.83), periprosthetic fracture (OR = 0.58, 95% CI, 0.46 to 0.71), and revision (OR = 0.79, 95% CI, 0.74 to 0.85) 2 years after TKA. CONCLUSIONS: ARB use throughout the 90 days after TKA is associated with a decreased risk of MUA, arthroscopy/LOA, aseptic loosening, periprosthetic fracture, and revision, demonstrating the potential protective abilities of ARBs. Prospective studies evaluating the use of ARBs in patients at risk for postoperative stiffness would be beneficial to further elucidate this association.

Patient-reported allergies are associated with increased rate of postoperative stiffness after arthroscopic rotator cuff repair.

BACKGROUND: Several risk factors have been identified for the development of postoperative shoulder stiffness, and there has been increasing interest in orthopedic literature regarding patient-reported allergy (PRA) as an identifiable risk factor for adverse outcomes. The purpose of this study is to determine whether PRAs are associated with subsequent rates of diagnosis of adhesive capsulitis (AC) or return to the operating room for postoperative shoulder stiffness within 2 years after arthroscopic rotator cuff repair (ARCR). METHODS: Current Procedural Terminology surgical billing codes were used to retrospectively identify patients who underwent ARCR at a single urban academic institution from January 2012 to December 2020 with minimum 2-year follow-up. Lysis of adhesions (LOA), manipulation under anesthesia (MUA), and AC of the shoulder were further queried within 2 years postoperatively for the ipsilateral shoulder. Patients were excluded if they had undergone ipsilateral MUA/LOA or received a diagnosis of AC before the index procedure. Demographic characteristics and medical comorbidities (hypertension, diabetes, hyperlipidemia, and hypothyroidism) were extracted from electronic medical records. Baseline characteristics were compared between patients with and without PRAs. Multivariate logistic regression analyses were performed to determine the association of the presence of PRAs overall, as well as the presence of 1, 2, or 3 or more PRAs, with subsequent MUA/LOA or diagnosis of AC within 2 years postoperatively. RESULTS: Of 7057 patients identified in the study period, 6583 were eligible for the final analysis. The mean age was 56.6 ± 11.7 years, and the mean body mass index was 29.1 ± 5.6. Overall, 19.3% of patients (n = 1271) reported at least 1 allergy, and 7.1% (n = 469) had >1 PRA. A total of 44 patients (0.7%) underwent subsequent ipsilateral MUA/LOA within 2 years postoperatively, whereas 93 patients (1.4%) received a diagnosis of ipsilateral AC in the same time frame. PRAs were significantly associated with subsequent diagnosis of AC (odds ratio [OR]: 2.39; 95% confidence interval [CI]: 1.45-3.92; P < .001), but not MUA/LOA (OR: 1.97, 95% CI: 1.26-3.61; P = .133). Patients with 2 PRAs had greater odds of being diagnosed with AC than patients with 1 PRA (OR: 2.74; 95% CI: 1.14-5.99; P = .012). Although this association was nonsignificant for MUA/LOA, patients with 2 PRAs (OR: 2.67; 95% CI: 0.96-8.80; P = .059) demonstrated a similar statistical trend. CONCLUSION: PRAs are associated with increased odds of receiving a diagnosis of AC within 2 years after ARCR but were not found to be associated with return to the operating room for postoperative stiffness.

Low-Dose Irradiation and Rotating-Hinge Revision for the Treatment of Severe Idiopathic Arthrofibrosis Following Total Knee Arthroplasty: A Review of 60 Patients With a Mean 6-Year Follow-Up.

BACKGROUND: Severe idiopathic arthrofibrosis after total knee arthroplasty (TKA) is a challenging problem to treat. Low-dose irradiation may decrease fibro-osseous proliferation, while rotating-hinge (RH) revision allows for distal femur shortening and collateral ligament sacrifice. This study reports the clinical outcomes and implant survivorship in patients treated with low-dose irradiation and RH revision for severe idiopathic arthrofibrosis following TKA. METHODS: A retrospective review was performed on 60 consecutive patients. Patients who had greater than 80° arc of knee motion or less than 15° flexion contracture were excluded. Mean follow-up was 6 years (range, 2 to 14). Kaplan-Meier survivorship analyses were performed, and logistic regressions were used to determine associations between preoperative patient characteristics and clinical outcomes. RESULTS: Median flexion contracture and median terminal flexion at presentation were 20 and 70°, respectively; at final follow-up, 59 of 60 patients (98%) had ≤10° flexion contracture and 49 of 60 patients (82%) had ≥90° of flexion. The 10-year survivorship free from reoperation for any reason, revision for any reason, and revision for aseptic loosening were 63, 87, and 97%, respectively. There were 27% percent of patients who underwent a manipulation under anesthesia postoperatively, which was the most common reason for return to the operating room. A greater number of prior surgeries was significantly associated with worse range of motion at the final follow-up (P = .004). There were no known radiation-associated complications. CONCLUSIONS: Patients with severe idiopathic arthrofibrosis following TKA treated with low-dose irradiation and RH revision maintained a gain in knee range of motion of 60° with reliable flexion contracture correction at a mean 6-year follow-up. A manipulation under anesthesia was common in the postoperative period. Survivorship free from revision for aseptic loosening was excellent at 10 years.