Aims. The practice of alternating operating theatres has long been used to reduce surgeon idle time between cases. However, concerns have been raised as to the safety of this practice. We assessed the payments and outcomes of total knee arthroplasty (TKA) performed during overlapping and nonoverlapping days, also comparing the total number of the surgeon’s cases and the total time spent in the operating theatre per day. Materials and Methods. A retrospective analysis was performed on the Centers for Medicare & Medicaid Services (CMS) Limited Data Set (LDS) on all primary elective TKAs performed at the New England Baptist Hospital between January 2013 and June 2016. Using theatre records, episodes were categorized into days where a surgeon performed overlapping and nonoverlapping lists. Clinical outcomes, economic outcomes, and demographic factors were calculated. A regression model controlling for the patient-specific factors was used to compare groups. Total orthopaedic cases and aggregate time spent operating (time between skin incision and closure) were also compared. Results. A total of 3633 TKAs were performed (1782 on nonoverlapping days; 1851 on overlapping days). There were no differences between the two groups for length of inpatient stay, payments, mortality, emergency room visits, or readmission during the 90-day postoperative period. The overlapping group had 0.74 fewer skilled nursing days (95% confidence interval (CI) -0.26 to -1.22; p < 0.01), and 0.66 more home health visits (95% CI 0.14 to 1.18; p = 0.01) than the nonoverlapping group. On overlapping days, surgeons performed more cases per day (5.01 vs 3.76; p < 0.001) and spent more time operating (484.55 minutes vs 357.17 minutes; p < 0.001) than on nonoverlapping days. Conclusion. The study shows that the practice of alternating operating theatres for TKA has no adverse effect on the clinical outcome or economic utilization variables measured. Furthermore, there is opportunity to increase productivity with alternating theatres as surgeons with overlapping cases perform more cases and spend more time operating per day. Cite this article: Bone Joint J 2019;101-B:1081–1086

Aims. The aims of this study were to compare the efficacy and safety of intra-articular and intravenous (IV) tranexamic acid (TXA) in controlling perioperative blood loss in total knee arthroplasty (TKA) using a randomized, double-blinded equivalence trial. Patients and Methods. A total of 182 patients aged between 45 and 75 years undergoing unilateral TKA at a tertiary centre were randomized to receive TXA, either 1.5 g intra-articularly after closure of the wound (n = 91) or two doses of 10 mg/kg IV (n = 91). The primary outcome measure was the reduction in the level of haemoglobin (Hb) in the blood on the fifth postoperative day. Secondary outcome measures were the total, visible, and hidden blood losses (TBL, VBL, HBL). We assumed equivalence of the primary outcome in both routes with a margin of ± 0.35gm/dl. Block randomization using computer-generated random numbers was used. The patients and the assessor of outcome were blinded. Results. All patients completed the study. The mean difference in the reduction of the level of Hb between the two groups was -0.0055 gm/dl, with two-sided 95% confidence interval (CI) being -0.29 to 0.27, well within the predefined equivalence margin of ± 0.35gm/dl. The groups were comparable with regard to TBL, VBL, HBL, and complications. No patient needed a blood transfusion. Conclusion. A single intra-articular dose and two IV doses of TXA give equivalent efficacy and safety in the management of blood loss at TKA. Cite this article: Bone Joint J 2018;100-B:152–60

Introduction. At a time when many surgeons are reluctant to perform a unilateral TKA in the obese patient, little is written on the safety and efficacy of bilateral simultaneous TKA in this same patient population. While these potential benefits are attractive to patients, surgeons may be hesitant to perform bilateral TKA due to the greater physical demand placed on the patient, and a potential increase in postoperative complication. The primary aim of this study was to analyze the impact of obesity on clinical outcomes and complication rates of patients undergoing bilateral TKA under one anesthetic. Materials and Methods. The clinical outcomes of 133 patients (266 knees) who underwent bilateral TKA between 2013 and 2016 were reviewed. The procedures were performed by three separate surgeons across three major academic institutions. ASA scores, tourniquet time, operative time, blood loss, length of stay, readmission, and postoperative complications were compared between different BMI categories of less than 30 kg/ m2, 30–34.99 kg/ m2, 35–39.99 kg/ m2and above 40 kg/ m2. Results. There were 83 females and 50 males who underwent bilateral TKA identified, with an average age of 60.17 years. The average LOS was 5 days and there was no significant impact of BMI on the length of stay or blood loss. 31 out of 133 patients experienced either a minor or major complication postoperatively (Table 1). Obese patients experienced more complications than non-obese patients. Specifically, patients identified as morbidly obese experienced a complication rate of 44.4%. This was significantly higher than the complication rate in the non-obese (less than 30 kg/ m2) patient cohort, 20.8% (p=.034). Of the 31 complications, 10 patients required a return to the operating room for a manipulation under anesthesia. There was no significant difference in the manipulation rate for the obese and non-obese patient. As BMI increased; postoperative ROM displayed a trend in the negative direction (Table 2). On average, obese patients had significantly higher ASA scores, with only 13.8% of patients with a BMI below 30 assigned an ASA score of 3 in comparison to 50% of patients with a BMI of 40 and above (p= .013) (Table 3). Higher BMI was significantly correlated with longer operative times (p=.002). Conclusion. Similar to numerous unilateral TKA studies in the obese patient, greater complication rates in the obese patient population were noted. The majority of complications that occurred within the time of this study were minor and did not affect the outcome of the procedure. Surgeons should carefully analyze the comorbidities of patients with a BMI above 40 kg/m2 such as cardiac history, diabetes mellitus, and smoking status when considering operating on morbidly obese patients and take steps to address these comorbidities and maximize the patient prior to surgery. For any figures or tables, please contact authors directly

Introduction

Bilateral TKA is proven to be safe in a select group of patients. Patients with symptomatic bilateral knee arthritis who are not candidates for simultaneous bilateral TKA are subjected to staged surgery. The main objective of this study is to determine the safe window when second TKA can be performed in patients requiring bilateral TKA

Intra-operative, peri-articular injection of local anaesthesia is an increasingly popular way of controlling pain following total knee replacement. At the same time, the problems associated with allogenic blood transfusion have led to interest in alternative methods for managing blood loss after total knee replacement, including the use of auto-transfusion of fluid from the patient’s surgical drain. It is safe to combine peri-articular infiltration with auto-transfusion from the drain. We performed a randomised clinical trial to compare the concentration of local anaesthetic in the blood and in the fluid collected in the knee drain in patients having either a peri-articular injection or a femoral nerve block. Clinically relevant concentrations of local anaesthetic were found in the fluid from the drains of patients having peri-articular injections (4.92 μg/ml (sd 3.151)). However, none of the patients having femoral nerve blockade had detectable levels. None of the patients in either group had clinically relevant concentrations of local anaesthetic in their blood after re-transfusion.

The evidence from this study suggests that it is safe to use peri-articular injection in combination with auto-transfusion of blood from peri-articular drains during knee replacement surgery.

Objectives

The objective of this study was to compare the early migration characteristics and functional outcome of the Triathlon cemented knee prosthesis with its predecessor, the Duracon cemented knee prosthesis (both Stryker).

Introduction

We examined the effect on blood loss of two standardised intravenous bolus doses of 500 mg of Tranexamic Acid, a fibrinolytic inhibitor that reduces blood loss following Knee Arthroplasty (KA).

Aims. Implantation of ultra-purified alginate (UPAL) gel is safe and effective in animal osteochondral defect models. This study aimed to examine the applicability of UPAL gel implantation to acellular therapy in humans with cartilage injury. Methods. A total of 12 patients (12 knees) with symptomatic, post-traumatic, full-thickness cartilage lesions (1.0 to 4.0 cm. 2. ) were included in this study. UPAL gel was implanted into chondral defects after performing bone marrow stimulation technique, and assessed for up to three years postoperatively. The primary outcomes were the feasibility and safety of the procedure. The secondary outcomes were self-assessed clinical scores, arthroscopic scores, tissue biopsies, and MRI-based estimations. Results. No obvious adverse events related to UPAL gel implantation were observed. Self-assessed clinical scores, including pain, symptoms, activities of daily living, sports activity, and quality of life, were improved significantly at three years after surgery. Defect filling was confirmed using second-look arthroscopy at 72 weeks. Significantly improved MRI scores were observed from 12 to 144 weeks postoperatively. Histological examination of biopsy specimens obtained at 72 weeks after implantation revealed an extracellular matrix rich in glycosaminoglycan and type II collagen in the reparative tissue. Histological assessment yielded a mean overall International Cartilage Regeneration & Joint Preservation Society II score of 69.1 points (SD 10.4; 50 to 80). Conclusion. This study provides evidence supporting the safety of acellular UPAL gel implantation in facilitating cartilage repair. Despite being a single-arm study, it demonstrated the efficacy of UPAL gel implantation, suggesting it is an easy-to-use, one-step method of cartilage tissue repair circumventing the need to harvest donor cells. Cite this article: Bone Joint J 2023;105-B(8):880–887

Aims. Total knee arthroplasty (TKA) with a highly congruent condylar-stabilized (CS) articulation may be advantageous due to increased stability versus cruciate-retaining (CR) designs, while mitigating the limitations of a posterior-stabilized construct. The aim was to assess ten-year implant survival and functional outcomes of a cemented single-radius TKA with a CS insert, performed without posterior cruciate ligament sacrifice. Methods. This retrospective cohort study included consecutive patients undergoing TKA at a specialist centre in the UK between November 2010 and December 2012. Data were collected using a bespoke electronic database and cross-referenced with national arthroplasty audit data, with variables including: preoperative characteristics, intraoperative factors, complications, and mortality status. Patient-reported outcome measures (PROMs) were collected by a specialist research team at ten years post-surgery. There were 536 TKAs, of which 308/536 (57.5%) were in female patients. The mean age was 69.0 years (95% CI 45.0 to 88.0), the mean BMI was 32.2 kg/m. 2. (95% CI 18.9 to 50.2), and 387/536 (72.2%) survived to ten years. There were four revisions (0.7%): two deep infections (requiring debridement and implant retention), one aseptic loosening, and one haemosiderosis. Results. Kaplan-Meier analysis demonstrated no difference in implant survival according to sex, age, or obesity status. Ten-year PROMs were available for 196/387 (50.6%) surviving patients and were excellent: mean Oxford Knee Score 34.4 (95% CI 32.7 to 36.1); mean Forgotten Joint Score (FJS) 51.2 (95% CI 16.1 to 86.3); mean EuroQol five-dimension five-level questionnaire score 69.9 (95% CI 46.8 to 93.0); 141/196 (71.9%) achieved the 22-point FJS patient-acceptable symptom state (PASS); and 156/196 (79.6%) were “very satisfied or satisfied”. Conclusion. This is the only large study reporting ten-year implant survival and functional outcomes of TKA using a cemented single-radius design and with a CS tibial bearing construct. The findings of excellent implant survival, safety, and functional outcomes indicate that this combination is a safe and effective option in routine TKA. Further investigation of this single-radius design TKA with CS tibial bearings with well-matched patient study groups will allow further insight into the performance of these implants. Cite this article: Bone Joint J 2024;106-B(8):808–816

Aims. This study aims to determine difference in annual rate of early-onset (≤ 90 days) deep surgical site infection (SSI) following primary total knee arthroplasty (TKA) for osteoarthritis, and to identify risk factors that may be associated with infection. Methods. This is a retrospective population-based cohort study using prospectively collected patient-level data between 1 January 2013 and 1 March 2020. The diagnosis of deep SSI was defined as per the Centers for Disease Control/National Healthcare Safety Network criteria. The Mann-Kendall Trend test was used to detect monotonic trends in annual rates of early-onset deep SSI over time. Multiple logistic regression was used to analyze the effect of different patient, surgical, and healthcare setting factors on the risk of developing a deep SSI within 90 days from surgery for patients with complete data. We also report 90-day mortality. Results. A total of 39,038 patients underwent primary TKA for osteoarthritis during the study period. Of these, 275 patients developed a deep SSI within 90 days of surgery, representing a cumulative incidence of 0.7%. The annual infection rate did not significantly decrease over the seven-year study period (p = 0.162). Overall, 13,885 (35.5%) cases were excluded from the risk analysis due to missing data. Risk factors associated with early-onset deep SSI included male sex, American Society of Anesthesiologists grade ≥ 3, blood transfusion, acute length of stay, and surgeon volume < 30 TKAs/year. Early-onset deep SSI was not associated with increased 90-day mortality. Conclusion. This study establishes a reliable baseline infection rate for early-onset deep SSI after TKA for osteoarthritis using robust Infection Prevention and Control surveillance data, and identifies several potentially modifiable risk factors. Cite this article: Bone Joint J 2023;105-B(9):971–976

Aims. Adenosine, lidocaine, and Mg. 2+. (ALM) therapy exerts differential immuno-inflammatory responses in males and females early after anterior cruciate ligament (ACL) reconstruction (ACLR). Our aim was to investigate sex-specific effects of ALM therapy on joint tissue repair and recovery 28 days after surgery. Methods. Male (n = 21) and female (n = 21) adult Sprague-Dawley rats were randomly divided into ALM or Saline control treatment groups. Three days after ACL rupture, animals underwent ACLR. An ALM or saline intravenous infusion was commenced prior to skin incision, and continued for one hour. An intra-articular bolus of ALM or saline was also administered prior to skin closure. Animals were monitored to 28 days, and joint function, pain, inflammatory markers, histopathology, and tissue repair markers were assessed. Results. Despite comparable knee function, ALM-treated males had reduced systemic inflammation, synovial fluid angiogenic and pro-inflammatory mediators, synovitis, and fat pad fibrotic changes, compared to controls. Within the ACL graft, ALM-treated males had increased expression of tissue repair markers, decreased inflammation, increased collagen organization, and improved graft-bone healing. In contrast to males, females had no evidence of persistent systemic inflammation. Compared to controls, ALM-treated females had improved knee extension, gait biomechanics, and elevated synovial macrophage inflammatory protein-1 alpha (MIP-1α). Within the ACL graft, ALM-treated females had decreased inflammation, increased collagen organization, and improved graft-bone healing. In articular cartilage of ALM-treated animals, matrix metalloproteinase (MMP)-13 expression was blunted in males, while in females repair markers were increased. Conclusion. At 28 days, ALM therapy reduces inflammation, augments tissue repair patterns, and improves joint function in a sex-specific manner. The study supports transition to human safety trials. Cite this article: Bone Joint Res 2024;13(6):279–293

Abstract. Introduction. The aim of this study was to determine if elite athletes could return to professional sport after MCL or PLC reconstruction using LARS ligaments and to demonstrate the safety and efficacy of LARS by reporting sport longevity, subsequent surgeries and complications. Methods. A retrospective review of all extra-articular knee ligament reconstructions in elite athletes utilising LARS ligaments by 3 knee surgeons between January 2013 and October 2020 was undertaken. Return to play (RTP) was defined as competing at professional level or national/ international level in amateur sport. Results. Sixty-four (84.2%) MCL and 12 (15.8%) PLC reconstructions utilising LARS in elite athletes were included. 52 (68.4%) underwent concomitant cruciate(s) reconstruction. The mean age was 25.1 years (SD +/− 4.50. Most were football (35, 46.1%) or rugby players (35, 46.1%). Sixty-seven athletes (88.2%) RTP with 65 (97.0%) of these playing at the same or higher Tegner level. 56 (83.6%) and 20 (57.1%) were still playing at 2 and 5 years post-surgery. Six (7.9%) players (5 of whom RTP) required further surgery relating to the LARS / metalwork and there was one case of adverse local inflammatory reaction to the synthetic material. There was one MCL re-rupture, sustained 4 years after RTP. Conclusion. Utilising LARS in extra-articular knee ligament reconstructions allows 88.2% of athletes, with a variety of knee ligament injuries, to return to elite sport. The low morbidity rates coupled with 57% of athletes still playing 5 years post-surgery suggests the LARS is safe and effective in these cases

Abstract. Introduction. Uni-compartmental knee replacement (UKR) has become popularised due to quicker recovery times, reduced postoperative pain, and blood loss. The desire to increase bed capacity and reduce costs, while preserving safety and patient satisfaction, has led to increased interest in day-case arthroplasty. This study observes the feasibility of UKR as a day-case procedure and whether this affects short and long-term postoperative outcomes. Methodology. Between 2018 and 2021, at a single institution and operated by a single orthopaedic surgeon, seventy-seven patients received a UKR on an elective basis. The patients were divided into two groups: ‘day-case’ for those discharged on the same day, and ‘non day-case’ group. Results. 31 patients were identified as day case procedures with the remaining 46 requiring between one to three days before discharge. Mean age, sex, modal ASA score, BMI, Charlson co-morbidity index, and pre-op oxford knee score showed no statistically significant difference between the two groups (p>0.05). No significant difference between the post-op oxford knee score at 1 year was found for patients treated and discharged as a day case procedure (37.8 +/− 6.88) and those who remained as an inpatient postoperatively (37.8 +/− 10.7); t(df) = −0.0007, p=0.994. No patients in either group suffered any complications beyond the peri-operative period. 30-day and 90-day readmission rates were equal. Conclusions. With no significant differences in post-op knee scores, complication, and readmission rates, we feel UKR can be performed as a viable day case procedure in a planned elective setting. This will result in significant cost savings

Abstract. Introduction. We present a case series of patients that underwent knee ligament reconstruction with graft reinforcement using FibreTape (Arthrex), a 2mm wide non-biodegradable polyethylene tape. Outcomes and safety of this novel technique are reported. Methods. Data were collected from a prospectively maintained database from 03/2011 to 11/2019. All skeletally mature patients that underwent reinforced knee ligament reconstruction surgery at Basingstoke and North Hampshire Hospital were included. The cohort was interrogated for outcomes including failure, complications, and subjective patient reported outcomes at 6,12 and 24 months postoperatively. Results. 438 patients were eligible. The mean age was 33.4 years and 68% of them were males. This included 171 ACL reconstructions, 96 ACL with anterolatreal ligament reconstructions, 59 bicruciate reconstructions, 30 ACL with posterolateral corner, 49 posterior cruciate ligament with one other ligament and 33 other ligament reconstruction. Allograft was used for 125 patients. 338 cases related to primary reconstruction. The overall complication rate was 5.3%, with a 2.1% re-rupture rate. There were 9 patients with a re-rupture and 5 of them had undergone multiligament reconstruction. We found a statistically significant improvement in all subjective scoring indices post-operatively up to 2 years. There were no complications directly related to the use of ligament reinforcement. Conclusion. Graft reinforcement is a safe option in the management of knee ligament injuries. Encouraging results were observed in patient reported outcomes. Reinforcement is technically reproducible and may represent an answer for graft failure rates, especially in multiligament reconstructions. Further application and evaluation is necessary to confirm its benefit

Aims. The aim of this study is to compare the effectiveness and safety of thromboprophylactic treatments in patients undergoing primary total knee arthroplasty (TKA). Methods. Using nationwide medical registries, we identified patients with a primary TKA performed in Denmark between 1 January 2013 and 31 December 2018 who received thromboprophylactic treatment. We examined the 90-day risk of venous thromboembolism (VTE), major bleeding, and all-cause mortality following surgery. We used a Cox regression model to compute hazard ratios (HRs) with 95% confidence intervals (CIs) for each outcome, pairwise comparing treatment with dalteparin or dabigatran with rivaroxaban as the reference. The HRs were both computed using a multivariable and a propensity score matched analysis. Results. We identified 27,736 primary TKA patients who received thromboprophylactic treatment (rivaroxaban (n = 18,846); dalteparin (n = 5,767); dabigatran (n = 1,443); tinzaparin (n = 1,372); and enoxaparin (n = 308)). In the adjusted multivariable analysis and compared with rivaroxaban, treatment with dalteparin (HR 0.68 (95% CI 0.49 to 0.92)) or dabigatran (HR 0.31 (95% CI 0.13 to 0.70)) was associated with a decreased risk of VTE. No statistically significant differences were observed for major bleeding or all-cause mortality. The propensity score matched analysis yielded similar results. Conclusion. Treatment with dalteparin or dabigatran was associated with a decreased 90-day risk of VTE following primary TKA surgery compared with treatment with rivaroxaban. Cite this article: Bone Joint J 2021;103-B(10):1571–1577

Abstract. Introduction. Controversy exists regarding the optimal tibial coronal alignment in total knee arthroplasty. Many believe navigation or robotics are required to set kinematic alignments or to ensure they remain within ‘safe’ limits e.g. maximum 5° varus on the tibia. Given most navigation or robotic systems require the surgeon to identify the ankle malleoli, this study aimed to radiographically analyse standardly used intra-operative landmarks around the ankle, assessing their value in achieving kinematic alignment / setting safety boundaries. Materials and Methods. Long leg alignment radiographs were analysed independently by two orthopaedic surgeons at two time points, eight weeks apart. Angles were measured between the long axis of the tibia (TB) and: 1. lateral malleolus (TB-LM), 2. lateral border of the talus (TB-LT) and 3. medial aspect of the medial malleolus (TB-MM). Intra- and inter-rater reliabilities were assessed. Results. One hundred and sixty-seven radiographs in 119 patients were analysed; mean age 71.6 years. Mean angles (95% CI) were: TB-LM 4.8° (4.7°- 4.8°), TB-LT 2.6° (2.5° - 2.6°) and TB-MM 4.2° (4.1° - 4.2°). Interrater reliability was good for TB-LM (ICC = 0.72) and TB-MM (ICC=0.67), and fair for TB-LT (ICC= 0.50). Intra-rater reliability was excellent for all measures (ICC >0.85). Conclusion. There are consistent angles between tibial alignment and ankle landmarks. Using these landmarks, with standard instrumentation and alignment checks, allows surgeons to define safe limits, e.g. maximum 4.8° tibial varus if aligned to the tip of the lateral malleolus or set a 2.5° varus cut, without the need for added technology

Aims. The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective. Methods. The OBC and the patellotrochlear index were used as part of the Oswestry Patellotrochlear Algorithm (OPTA) to guide the surgical treatment of patients with patellar instability. Patients were assigned to one of four treatment groups: medial patellofemoral ligament reconstruction (MPFLr); MPFLr + tibial tubercle distalization (TTD); trochleoplasty; or trochleoplasty + TTD. A prospective analysis of a longitudinal patellofemoral database was performed. Between 2012 and 2018, 202 patients (233 knees) with a mean age of 24.2 years (SD 8.1), with recurrent patellar instability were treated by two fellowship-trained consultant sports/knee surgeons at The Robert Jones and Agnes Hunt Orthopaedic Hospital. Clinical efficacy of each treatment group was assessed by Kujala, International Knee Documentation Committee (IKDC), and EuroQol five-dimension questionnaire (EQ-5D) scores at baseline, and up to 60 months postoperatively. Their safety was assessed by complication rate and requirement for further surgery. The pattern of clinical outcome over time was analyzed using mixed regression modelling. Results. In all, 135 knees (mean age 24.9 years (SD 9.4)) were treated using a MPFLr. Ten knees (7.4%) required additional surgery. A total of 50 knees (mean age 24.4 years (SD 6.3)) were treated using MPFLr + TTD. Ten (20%) required additional surgery. A total of 20 knees (mean age 19.5 years (SD 3.0)) were treated using trochleoplasty + TTD. Three patients (15%) required additional surgery. In each treatment group, there was a significant improvement in Kujala, IKDC, and EQ-5D at one year postoperatively (p < 0.001) with a recognized level of overall complication rate. Conclusion. The OBC is a valid assessment tool to grade patients with trochlear dysplasia and, when used as part of the OPTA, helps to determine treatments that are safe and effective. This fulfils the requirements for its application in mainstream clinical practice. Cite this article: Bone Joint J 2021;103-B(10):1586–1594

Introduction. Active robotics for total knee Arthroplasty (TKA) uses a CAD-CAM approach to plan the correct size and placement of implants and to surgically achieve planned limb alignment. The TSolution One Total Knee Application (THINK Surgical Inc., Fremont, CA) is an open-implant platform, CT-based active robotic surgical system. A multi-center, prospective, non-randomized clinical trial was performed to evaluate the safety and effectiveness of robotic-assisted TKA using the TSolution One Total Knee Application. This report details the findings from the IDE. Methods. Inclusion criteria for patients receiving robotic TKA were: primary unilateral TKA; Kellgren-Lawrence OA grade 3 or 4; BMI < 40 kg/m2; coronal plane deformity < 20° varus; sagittal flexion contracture < 15°. In addition to monitoring all adverse events (AE), a pre-defined list of relevant major AEs were specifically identified to evaluate safety (Healy et al, 2013): medial collateral ligament injury; extensor mechanism disruption; neural deficit; periprosthetic fracture; patellofemoral dislocation; tibiofemoral dislocation; and vascular injury. Bleeding complications were also assessed. Malalignment rate, defined as the percentage of patients with more than a ± 3° difference in varus-valgus alignment from the preoperative plan, was used to determine accuracy of the active robotic system. Knee Society Scores (KSS) and Short Form 12 (SF-12) Health Surveys were assessed as clinical outcome measures. For each outcome, results were compared to published values associated with manual TKA. Results. A total of 115 patients were enrolled at 6 US centers and followed for a maximum of 12 months after surgery. Mean surgical time (incision to close) improved consistently as the technique evolved (first 10 cases = 131.5 min, first 20 cases = 122.4 min), with mean robot time = 45.8 min. The incidence of pre-defined AEs identified was 0%, serving as a measure of safety of the procedure. Outside of the pre-defined list, only one AE was definitely associated with the use of the device; a metal pin was left inside the knee joint but no reoperation was performed. No patients required a blood transfusion. Alignment outside of the ± 3° goal was 11.2% with a difference of 0.5° ± 1.9° (mean ± STD), which represents a 45% statistically significant (posterior probability > 0.95) reduction in malalignment compared to the literature (Mason et al, 2007). Mean KSS Functional scores improved from 40.5 at baseline to 65.3 at 3 months, mean KSS Objective scores improved from 36.8 to 81.0, mean KSS Patient Satisfaction scores improved from 14.4 to 30.6, and mean SF-12 Physical Component scores improved from 32.9 to 43.5. Discussion. The TSolution One Total Knee Application is descended from an active robotic system used in >8000 cases outside the United States since 2002. This trial represents the first US based study of this technology for primary TKA. The clinical study demonstrated positive safety outcomes as none of the seven pre-defined AEs were observed and there were no cases requiring transfusion. A positive effectiveness outcome was also demonstrated as the malalignment rate found in this study showed a substantial reduction from the 32% malalignment rate published in the literature for conventional instruments. KSS and SF-12 scores were comparable to other published TKA series. For figures, tables, or references, please contact authors directly

Introduction. Arthrofibrosis remains a persistent complication following total knee arthroplasty (TKA). Although manipulation under anesthesia (MUA) is an effective early treatment, the risks and value of this procedure beyond 3 months after TKA remain controversial. The purpose of this study was to examine the safety and efficacy of late MUAs for arthrofibrosis. Methods. From our institutional total joint registry, 82 TKAs (77 patients) who underwent MUA >3 months after primary (83%) or revision (17%) TKA were identified. Mean time to MUA was 7 months: 66% performed between 4–6 months, 18% between 7–12 months, 16% beyond 12 months. MUAs were coupled with arthroscopic assistance in 26% (12% limited lysis of adhesions, 13% formal arthroscopic debridement). Mean age was 61 years, 59% females, and mean BMI was 33kg/m. 2. Mean follow-up was 5 years. Results. No fractures, extensor mechanism disruptions, or other complications related to late MUA occurred. The mean ROM gained after MUA was 18° (76° to 94°, p<0.001). Substantial ROM gains (≥20°) occurred in 50%, while 21% made no gains or lost ROM after MUA. ROM gains ≥20° occurred in 54% of primary TKAs and 28% of revision TKAs. While ROM gains were higher when performed between 3–6 months (21°) compared to 6–12 months (13°) and >12 months (11°), these differences did not reach statistical significance (p=0.26). No differences in mean ROM gains were observed in MUAs performed with or without arthroscopic assistance (19° versus 15°, p=0.54). Kaplan Meier survivorship free of repeat MUA and revision TKA were 85% and 80% at 20 years, respectively. Conclusion. Late MUA, coupled with arthroscopic assistance in selected patients, was safe in a broad range of stiff primary and revision TKAs with no fractures or extensor disruptions occurring. While mean ROM improvements were modest, a substantial subset of patients achieved clinically important ROM gains ≥20°. Summary. Late MUA substantially improved ROM in a subset of patients with stiff TKAs and was done safely. In selected patients, arthroscopic lysis of adhesions or formal debridement aided the perceived safety and efficacy

Introduction. The purpose of bundled payment programs is to reduce cost via risk sharing, while still maintaining quality. If savings are achieved under a historic target price, the orthopedic surgeon will receive a monetary bonus. If costs are higher, a portion is deducted from payment to the orthopedic surgeon. The purpose of this study was to evaluate our experience with the Bundled Payments for Care Improvement Program (BPCI) when run by an orthopedic surgeon group to determine patient safety and who benefited the most financially. Methods. This program ran from January 2015 through September 2018. 3,186 Medicare total hip and knee replacements, elective (DRG 470) and for fracture (DRG 469), performed by our group were included. 90 day hospital and all postoperative expenditures were reconciled against our historic cost. All patients were medically optimized with discharge plans established preoperatively. We developed preferred skilled nursing facilities and home health care agencies with synergistic medical providers so that discharges were recommended as soon as appropriate. We hired two full-time case managers to have direct contact with patients pre-and post-operatively. Waiver assistance such as house and pet sitters were used if necessary at our expense. 35% of savings went to the convener, who acted as a liaison between our group and CMS. Expenditures for the 90-day period for all patients were calculated to determine where savings occurred and which entity benefitted financially. Results. There was an average 9.2% reduction in hospital readmissions. An estimated total savings of $5,100,000 occurred. There was a 17% reduction in hospital costs, a 12.1% reduction in admissions to skilled nursing facilities with a 34% reduction in length of stay, and a 5% reduction in admissions to inpatient rehabilitation facilities. There was a 35% reduction in home health visits, but no change in outpatient physical therapy visits. After group expenses, final bonus to the orthopedic provider was on average $262 per patient. Conclusion. The physician managed program was very successful from Medicare's standpoint, achieving significant monetary savings without reducing quality of care. However, the bonus to the providing and managing physicians was nominal. It also does not take into consideration the 50 plus hours spent in meetings to develop this program. Participation could be considered a defensive posture so as not to lose more reimbursement. However, experience was gained which will be valuable for future gain sharing programs. Physicians and physician organizations need to sit at the head of the table to manage future payment bundles and perhaps also act as the convener. We deserve this, as a result of demonstrating high safety and cost savings. For figures, tables, or references, please contact authors directly