Aims. Single-shot adductor canal block (ACB) after total knee arthroplasty (TKA) for postoperative analgesia is a common modality. Patients can experience breakthrough pain when the effect of ACB wears off. Local anaesthetic infusion through an intra-articular catheter (IAC) can help manage breakthrough pain after TKA. We hypothesized that combined ACB with ropivacaine infusion through IAC is associated with better pain relief compared to ACB used alone. Methods. This study was a prospective double-blinded placebo-controlled randomized controlled trial to compare the efficacy of combined ACB+ IAC-ropivacaine infusion (study group, n = 68) versus single-shot ACB+ intra-articular normal saline placebo (control group, n = 66) after primary TKA. The primary outcome was assessment of pain, using the visual analogue scale (VAS) recorded at 6, 12, 24, and 48 hours after surgery. Secondary outcomes included active knee ROM 48 hours after surgery and additional requirement of analgesia for breakthrough pain. Results. The study group (mean visual analogue scale (VAS) pain score of 5.5 (SD 0.889)) experienced significant reduction in pain 12 hours after surgery compared to the control group (mean VAS 6.62 (SD 1.356); mean difference = 1.12, 95% confidence interval (CI) -1.46 to 0.67; p < 0.001), and pain scores on postoperative day (POD) 1 and POD-2 were lower in the study group compared to the control group (mean difference in VAS pain = 1.04 (-1.39 to -0.68, 95% CI, p < 0.001). Fewer patients in the study group (0 vs 3 in the control group) required additional analgesia for breakthrough pain, but this was not statistically significant. The study group had significantly increased active knee flexion (mean flexion 86.4° (SD 7.22°)), compared to the control group (mean 73.86° (SD 7.88°), mean difference = 12.54, 95% CI 9.97 to 15.1; p < 0.014). Conclusion. Combined ACB+ ropivacaine infusion via IAC is a safe, reproducible analgesic modality after primary TKA, with superior analgesia compared to ACB alone. Further large volume trials are warranted to generate evidence on clinical significance on analgesia after TKA. Cite this article: Bone Jt Open 2021;2(12):1082–1088

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

Aims. The aim of this study was to identify the most effective regimen of multiple doses of oral tranexamic acid (TXA) in achieving maximum reduction of blood loss in total knee arthroplasty (TKA). Patients and Methods. In this randomized controlled trial, 200 patients were randomized to receive a single dose of 2.0 g of TXA orally two hours preoperatively (group A), a single dose of TXA followed by 1.0 g orally three hours postoperatively (group B), a single dose of TXA followed by 1.0 g three and nine hours postoperatively (group C), or a single dose of TXA followed by 1.0 g orally three, nine, and 15 hours postoperatively (group D). All patients followed a routine enhanced-recovery protocol. The primary outcome measure was the total blood loss. Secondary outcome measures were hidden blood loss (HBL), reduction in the level of haemoglobin, the rate of transfusion and adverse events. Results. Groups C (661.1 ml, . sd. 262.4) and D (597.7 ml, . sd. 219.6) had significantly lower mean total blood loss compared with groups A and B. The mean HBL was significantly lower in groups B (699.2 ml), C (533.1 ml) and D (469.9 ml) than in group A (p = 0.006, p < 0.001, and p < 0.001, respectively). Groups C (2.22 ml, . sd. 0.91) and D (2.04 ml, . sd. 0.95) had a lower reduction in the level of haemoglobin than groups A and B. However, there were no differences between groups C and D in relation to the three parameters. Conclusion. The addition of two or three postoperative doses of TXA to one preoperative dose produced a significant reduction in blood loss. The two-dose postoperative regimen is the least necessary regimen for clinical efficacy in primary unilateral TKA. The three-dose regimen produced maximum reduction of blood loss. Cite this article: Bone Joint J 2018;100-B:1025–32

INTRODUCTION

Mobile bearing unicompartmental knee replacement (UKR) is an accepted treatment for patients with isolated medial unicompartmental knee osteoarthritis (OA) with a full thickness cartilage loss. The aim of this study was to determine if this recommendation was correct and if the procedure could be used for partial-thickness cartilage loss.

Aims

The aim of this study was to compare the effectiveness of a femoral nerve block and a periarticular infiltration in the management of early post-operative pain after total knee arthroplasty (TKA).

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).

Pain, swelling and inflammation are expected during the recovery from total knee arthroplasty (TKA) surgery. The severity of these factors and how a patient copes with them may determine the ultimate outcome of a TKA. Cryotherapy and compression are frequently used modalities to mitigate these commonly experienced sequelae. However, their effect on range of motion, functional testing, and narcotic consumption has not been well-studied.

A prospective, multi-center, randomised trial was conducted to evaluate the effect of a cryopneumatic device on post-operative TKA recovery. Patients were randomised to treatment with a cryopneumatic device or ice with static compression. A total of 280 patients were enrolled at 11 international sites. Both treatments were initiated within three hours post-operation and used at least four times per day for two weeks. The cryopneumatic device was titrated for cooling and pressure by the patient to their comfort level.

Patients were evaluated by physical therapists blinded to the treatment arm. Range of motion (ROM), knee girth, six minute walk test (6MWT) and timed up and go test (TUG) were measured pre-operatively, two- and six-weeks post-operatively. A visual analog pain score and narcotic consumption was also measured post-operatively.

At two weeks post-operatively, both the treatment and control groups had diminished ROM and function compared to pre-operatively. Both groups had increased knee girth compared to pre- operatively. There was no significant difference in ROM, 6MWT, TUG, or knee girth between the 2 groups. We did find a significantly lower amount of narcotic consumption (509 mg morphine equivalents) in the treatment group compared with the control group (680 mg morphine equivalents) at up to two weeks postop, when the cryopneumatic device was being used (p < 0.05). Between two and six weeks, there was no difference in the total amount of narcotics consumed between the two groups. At six weeks, there was a trend toward a greater distance walked in the 6MWT in the treatment group (29.4 meters versus 7.9 meters, p = 0.13). There was a significant difference in the satisfaction scores of patients with their cooling regimen, with greater satisfaction in the treatment group (p < 0.0001). There was no difference in ROM, TUG, VAS, or knee girth at six weeks. There was no difference in adverse events or compliance between the two groups.

A cryopneumatic device used after TKA appeared to decrease the need for narcotic medication from hospital discharge to 2 weeks post-operatively. There was also a trend toward a greater distance walked in the 6MWT. Patient satisfaction with the cryopneumatic cooling regimen was significantly higher than with the control treatment.

Aims. To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration. Methods. The OCD lesion was created on the trochlear groove of left articular cartilage of femur per rat (40 rats in total). The experimental groups were Sham, OCD, and ESWT (0.25 mJ/mm. 2. , 800 impulses, 4 Hz). The animals were euthanized at 2, 4, 8, and 12 weeks post-treatment, and histopathological analysis, micro-CT scanning, and immunohistochemical staining were performed for the specimens. Results. In the histopathological analysis, the macro-morphological grading scale showed a significant increase, while the histological score and cartilage repair scale of ESWT exhibited a significant decrease compared to OCD at the 8- and 12-week timepoints. At the 12-week follow-up, ESWT exhibited a significant improvement in the volume of damaged bone compared to OCD. Furthermore, immunohistochemistry analysis revealed a significant decrease in type I collagen and a significant increase in type II collagen within the newly formed hyaline cartilage following ESWT, compared to OCD. Finally, SRY-box transcription factor 9 (SOX9), aggrecan, and TGF-β, BMP-2, -3, -4, -5, and -7 were significantly higher in ESWT than in OCD at 12 weeks. Conclusion. ESWT promoted the effect of TGF-β/BMPs, thereby modulating the production of extracellular matrix proteins and transcription factor involved in the regeneration of articular cartilage and subchondral bone in an OCD rat model. Cite this article: Bone Joint Res 2024;13(7):342–352

Aims. Platelet-rich plasma (PRP) intra-articular injections may provide a simple and minimally invasive treatment for early-stage knee osteoarthritis (OA). This has led to an increase in its adoption as a treatment for knee OA, although there is uncertainty about its efficacy and benefit. We hypothesized that patients with early-stage symptomatic knee OA who receive multiple PRP injections will have better clinical outcomes than those receiving single PRP or placebo injections. Methods. A double-blinded, randomized placebo-controlled trial was performed with three groups receiving either placebo injections (Normal Saline), one PRP injection followed by two placebo injections, or three PRP injections. Each injection was given one week apart. Outcomes were prospectively collected prior to intervention and then at six weeks, three months, six months, and 12 months post-intervention. Primary outcome measures were Knee Injury and Osteoarthritis Outcome Score (KOOS) and EuroQol five-dimension five-level index (EQ-5D-5L). Secondary outcomes included visual analogue scale for pain and patient subjective assessment of the injections. Results. A total of 102 patients were recruited. The follow-up period was 12 months, at intervals of six weeks, 12 weeks, six months, and 12 months. KOOS-Total significantly improved in all groups at these time intervals compared to pre-injection. There was an improvement in EQ-5D-5L index scores in saline and single injection groups, but not in the multiple injection group. Comparison of treatment groups showed no additional beneficial effect of single or multiple PRP injections above that displayed in the saline injection group. Subjective patient satisfaction and recommendation of treatment received demonstrated a similar pattern in all the groups. There was no indication of superiority of either single or multiple PRP injections compared to saline injections. Conclusion. There is no evidence that single or multiple PRP had any additional beneficial effect compared to saline injection up to 12 months, follow-up after treatment of early stage symptomatic OA of the knee. Cite this article: Bone Joint J 2022;104-B(6):663–671

Abstract. Introduction. Multiple strategies, used either in isolation or combination, are available to reduce the need for post-operative blood transfusion in joint replacements. Amongst them, the use of tranexamic acid (TXA) has been rising and this study was conducted to compare the efficacy of topical and intravenous TXA in bilateral total knee replacement patients. Materials and methods. Randomised prospective study with 120 patients (male: female: 25:95) undergoing bilateral TKA. Patients were divided into two groups A and B after computer randomization, who received intravenous or topical (intra-articular) TXA respectively. Results. The average haemoglobin loss in intravenous group was 90.2379 g/L as compared to 39.137 g/L in topical group (p < 0.005). Moreover, there was reduction in blood loss in topical (330.1602 ml) as compared to intravenous group (764.9622 ml). The blood transfusion rate was more for the intravenous group (average 1.73 units) than for the topical group (average 0.75, unit). WOMAC score at 6 weeks in the intravenous group was 12.50, and in the topical group was 7.23 (p value < 0.001). Conclusion. Topical TXA is better than intravenous TXA for reduction of blood loss, which also reduces the need for blood transfusion in bilateral TKA patients

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

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

Abstract. Introduction. To compare the efficacy of adductor canal blocks (ACB) and periarticular anesthetic injections (PAI) with bupivacaine in total knee arthroplasty. Methods. 90 patients undergoing primary total knee arthroplasty under spinal anesthesia were randomized to 1 of 3 groups: ACB alone (15 mL of 0.5% bupivacaine), PAI alone (50 mL of 0.25% bupivacaine with epinephrine) and ACB + PAI. Primary outcome in this study was the visual analog scale (VAS) pain score in the immediate postoperative period. Secondary outcomes included postoperative opioid use, activity level during physiotheraphy, length of hospital stay and ROM. Results. Mean VAS pain score was significantly higher with ACB alone, compared with the score after use of ACB+PAI, on POD1 and POD3. Total opioid consumption through POD3 was significantly higher when ACB alone had been used compared with PAI alone and ACB+PAI. Opioid consumption in the ACB-alone group was significantly higher than that in the ACB + PAI group on POD2 and POD3 and significantly higher than that in the PAI alone group on POD2. There was no significant difference in opioid consumption between the patients treated with PAI alone and those who received ACB + PAI. The activity level during physiotherapy on POD0 was significantly lower after use of ACB alone than after use of PAI alone or ACB + PAI. Conclusion. Higher pain scores after total knee arthroplasty done with an ACB and without PAI, suggesting that ACB alone is inferior for perioperative pain control. There were no significant differences between ACB alone, PAI alone and ACB + PAI inparameters measured

Abstract. INTRODUCTION. A paucity of literature exists regarding efficacy of lateral unloader bracing in treatment for pathologies effecting the lateral compartment of the knee. We evaluate patient outcomes following customised lateral unloader bracing (cLUB) in treatment of lateral compartment osteoarthritis (LCOA), lateral tibial plateau fractures (LTPF) and spontaneous osteonecrosis of knee (SONK). METHODS. Institutional study approval was obtained. All patients undergoing cLUB between January 2013 and January 2021 were included, and prospectively followed-up. Visual Analogue Scales (VAS), Oxford Knee Scores (OKS) and Knee Injury and Osteoarthritis Outcome Scores (KOOS) were assessed at brace fitting and final follow-up. Brace compliance, complications and surgical interventions were also collected. Statistical analysis utilised paired t-test. RESULTS. 71 patients (LCOA n=47, LTPF n=21, SONK n=3) were analysed. VAS, OKS and KOOS scores show significant improvements after bracing (p<0.05). Brace compliance was 90.5%. One patient developed a deep-vein thrombosis, 12.7% suffered skin irritation (n=5 LTPF/n=4 LCOA) managed with bio-skin calf sleeves, and brace intolerance occurred in 8.5% (n=6). Brace survivorship was 64.8% (n=46). Twenty-five patients underwent post-bracing surgery; LTPF n=2, LCOA n=22, SONK n=1. The mean time interval between brace fitting and arthroplasty for LKOA patients was 2.1 (range 0.5-4) years. CONCLUSION. Our cohort demonstrates good compliance and significant improvements with cLUB across acute and chronic pathologies. Surgery and associated risks were avoided in certain cases. Further research is required alongside a cost-analysis. However, with increasing disease burden and surgical waiting times cLUB could be a crucial component of management in selected knee pathology cases

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

Aims. The management of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is challenging. The correct antibiotic management remains elusive due to differences in epidemiology and resistance between countries, and reports in the literature. Before the efficacy of surgical treatment is investigated, it is crucial to analyze the bacterial strains causing PJI, especially for patients in whom no organisms are grown. Methods. A review of all revision TKAs which were undertaken between 2006 and 2018 in a tertiary referral centre was performed, including all those meeting the consensus criteria for PJI, in which organisms were identified. Using a cluster analysis, three chronological time periods were created. We then evaluated the antibiotic resistance of the identified bacteria between these three clusters and the effectiveness of our antibiotic regime. Results. We identified 129 PJIs with 161 culture identified bacteria in 97 patients. Coagulase-negative staphylococci (CNS) were identified in 46.6% cultures, followed by Staphylococcus aureus in 19.8%. The overall resistance to antibiotics did not increase significantly during the study period (p = 0.454). However, CNS resistance to teicoplanin (p < 0.001), fosfomycin (p = 0.016), and tetracycline (p = 0.014) increased significantly. Vancomycin had an 84.4% overall sensitivity and 100% CNS sensitivity and was the most effective agent. Conclusion. Although we were unable to show an overall increase in antibiotic resistance in organisms that cause PJI after TKA during the study period, this was not true for CNS. It is concerning that resistance of CNS to new antibiotics, but not vancomycin, has increased in a little more than a decade. Our findings suggest that referral centres should continuously monitor their bacteriological analyses, as these have significant implications for prophylactic treatment in both primary arthroplasty and revision arthroplasty for PJI. Cite this article: Bone Joint J 2021;103-B(6 Supple A):171–176

Introduction. Topical diclofenac has proven efficacy and safety in the management of osteoarthritic pain. Its therapeutic efficacy is dependent on its ability to deliver pharmacodynamically active concentrations to the underlying tissues in the affected joint. However, the disposition of topical diclofenac is not fully characterized, and no studies have been performed using diclofenac diethylamine 2.32% gel. Methods. This study investigated the penetration of topical diclofenac into knee synovial tissue and fluid and evaluated relative exposure in the knee versus plasma. In this phase 1, double-blind, placebo-controlled steady-state multicenter pharmacokinetic study, patients scheduled for arthroplasty to treat knee OA were randomly assigned 2:1 to 4 g diclofenac/placebo gel, applied to the affected knee every 12 hours for 7 days pre-surgery. Diclofenac concentrations were measured in synovial tissue, fluid, and plasma ≥12 hours after last application. Adverse events (AEs) were evaluated. Diclofenac concentrations were assayed by validated high-performance liquid chromatography and tandem mass spectrometry. Results. Samples were obtained from 45 (diclofenac n=29; placebo n=16) of 47 patients enrolled. Mean (SD) age was 71.2 (7.9) years with 52.2% women and mean (SD) BMI 30.7 (4.8) kg/m. 2. All diclofenac-treated participants had measurable diclofenac concentrations in synovial tissue (mean [95% CI]) 1.57 [1.12, 2.20] ng/g) and fluid 2.27 [1.87, 2.76] ng/mL ≥12 hours after the last dose. The mean (95% CI) ratio of diclofenac in synovial tissue:plasma was 0.32 (0.23, 0.45) and in synovial fluid:plasma was 0.46 (0.34, 0.54). AEs were similar for diclofenac (55.2%) and placebo (58.8%); none were treatment related. No correlation (r=−0.003) between BMI and synovial fluid concentration, and weak positive correlation (r=0.315) between BMI and synovial tissue concentration were observed. Conclusions. Topical diclofenac diethylamine 2.32% gel penetrated the knee and remained detectable at the end of the final 12-hour dosing cycle. BMI had no impact on diclofenac's penetration into the knee

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

Aims. We propose a state-of-the-art temporary spacer, consisting of a cobalt-chrome (CoCr) femoral component and a gentamicin-eluting ultra-high molecular weight polyethylene (UHMWPE) tibial insert, which can provide therapeutic delivery of gentamicin, while retaining excellent mechanical properties. The proposed implant is designed to replace conventional spacers made from bone cement. Methods. Gentamicin-loaded UHMWPE was prepared using phase-separated compression moulding, and its drug elution kinetics, antibacterial, mechanical, and wear properties were compared with those of conventional gentamicin-loaded bone cement. Results. Gentamicin-loaded UHMWPE tibial components not only eradicated planktonic Staphylococcus aureus, but also prevented colonization of both femoral and tibial components. The proposed spacer possesses far superior mechanical and wear properties when compared with conventional bone cement spacers. Conclusion. The proposed gentamicin-eluting UHMWPE spacer can provide antibacterial efficacy comparable with currently used bone cement spacers, while overcoming their drawbacks. The novel spacer proposed here has the potential to drastically reduce complications associated with currently used bone cement spacers and substantially improve patients’ quality of life during the treatment. Cite this article: Bone Joint J 2020;102-B(6 Supple A):151–157

Aims

Unicompartmental knee arthroplasty (UKA) is the preferred treatment for anterior medial knee osteoarthritis (OA) owing to the rapid postoperative recovery. However, the risk factors for UKA failure remain controversial.