Introduction. High flexion knee arthroplasties have been designed to allow up to 155 degrees flexion and enable high flexion activities such as kneeling and squatting. To date randomised controlled trials have shown no difference in range of movement (ROM) between high flexion and standard designs. Objectives. The aim of this study was to determine if there is a difference in functional outcome and ROM between the standard and high flexion design of the PFC Sigma TKA system. Methods. 84 patients with the diagnosis of osteoarthritis undergoing primary total knee arthroplasty were randomised to receive either a PFC Sigma or PFC Sigma RP-F total knee arthroplasty. ROM, Oxford Knee Score, Knee Society Score, Patella score and SF-12v2 were assessed independently before and at one year after surgery. Patients were blinded to the implant they received. Results. 42 patients in each group were included in this study and underwent surgery. 77 patients (92%) completed their one-year follow-up. There was no statistically significant difference in preoperative scores between groups. At one year there was a statistically significant difference in ROM between the groups with a mean of 105 degrees in the PFC Sigma and 114 degrees in the PFC Sigma RP-F group (p=0.01). There was also a statistically significant difference in flexion with 106 degrees and 115 degrees respectively (p=0.007). The difference in improvement in ROM and flexion was also statistically significant between the groups (p=0.009 and p=0.008). There was no statistically significant difference in any of the functional outcome scores. Conclusions. This is the first randomised controlled trial to show a statistically significant difference in ROM and flexion between a standard and a high flexion design TKA. Further follow-up will be carried out to determine if these differences persist over time and to evaluate the long-term survival of the different designs

There is ongoing debate on the benefits of fixed versus mobile bearing Unicompartmental Knee Replacement (UKR). We report the results from a randomised controlled trial comparing fixed and mobile bearing of the same UKR prosthesis. Forty patients were randomized to receive identical femoral components and either a fixed or mobile bearing tibial component. At 6.5 years follow-up 37% of the mobile bearing design had been revised and 14% for the fixed bearing design. The main reasons for revision were pain and loosening. These results were compared with data from The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) that show a cumulative percent revision of 24.2% for the mobile bearing Preservation UKR at 6.5 years. All locally explanted mobile bearings were examined microscopically, and 83% demonstrated significant backside wear. Constraint on the undersurface of the bearing coupled with a congruent upper surface may have contributed to the excessive revision rate. This is the first randomised controlled trial examining mobile and fixed variations of the same UKR prosthesis and shows this design of UKR with the mobile bearing has an unacceptably high revision rate and patients with this knee design should be closely monitored

Introduction. Many prosthetic design changes have been introduced in attempt to improve outcomes following TKA; however there is no consensus as to whether these changes confer benefits to patients. This study aimed to assess whether patients treated with a modern implant design had an enhanced patient outcome compared to a traditional model in a double blind randomised controlled trial. Methods. 212 consecutive patients were prospectively randomised to receive either a modern (Triathlon) or a traditional (Kinemax) TKA (both Stryker Orthopaedics). 6 surgeons at a single unit performed all procedures in a standardised manner. A single researcher, blinded to implant allocation, performed all assessments. Patients were assessed pre-operatively, and at 6, 26, 52 weeks post-surgery with the Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, goniometry, timed functional assessment, lower limb power (Leg Extensor Power Rig) and pain numerical rating scales (NRS). Change in scores and between group differences were assessed with Two-Way Repeated Measures ANOVAs. Results. Both groups benefited from TKA demonstrating significant improvement in all parameters (p = < 0.001 in all cases). Significant interaction of the implant was observed in 1 year change score of OKS (F = 4.28, p = 0.04), knee flexion (F = 8.42, p = 0.004), lower limb power output (F = 11.33, p = 0.001) and maximal pain report (F = 7.44, p = 0.001), the modern implant superior in each case. Larger change scores were observed in WOMAC and timed functional assessments, but were not statistically significant. Conclusions. In a large prospective double blind randomised controlled trial, patients receiving a modern implant design demonstrated a significantly enhanced patient outcome in terms of knee range of motion, lower limb power output, reduced maximal pain report, and a clinically meaningful reduction in the OKS compared to a traditional design

We reviewed all 717 manuscripts published in the 1997 issues of the British and American volumes of the Journal of Bone and Joint Surgery and in Clinical Orthopaedics and Related Research, from which 33 randomised, controlled trials were identified. The results and sample sizes were used to calculate the statistical power of the study to distinguish small (0.2 of standard deviation), medium (0.5 of standard deviation), and large (0.8 of standard deviation) effect sizes. Of the 33 manuscripts analysed, only three studies (9%) described calculations of sample size. To perform post-hoc power assessments and estimations of deficiencies of sample size, the standard effect sizes of Cohen (small, medium and large) were calculated. Of the 25 studies which reported negative results, none had adequate power (β < 0.2) to detect a small effect size and 12 (48%) lacked the power necessary to detect a large effect size. Of the 25 studies which did not have an adequate size of sample to detect small differences, the average used was only 10% of the required number. Our findings suggest that randomised, controlled trials in clinical orthopaedic research utilise sample sizes which are too small to ensure statistical significance for what may be clinically important results

Unicompartmental Knee Replacement (UKR) is associated with fewer complications, faster recovery and better function than Total Knee Replacement (TKR). However, joint registries demonstrate a higher revision rate in UKR, limiting its use. Currently most UKRs are cemented and performed using a minimally invasive technique. In joint registries, common reasons for revision include aseptic loosening and pain. These problems could potentially be addressed by using cementless implants, which may provide more reliable fixation. The objectives of this study were to compare the quality of fixation (determined by the incidence and appearance of radiolucencies), and clinical outcomes of cemented and cementless UKR at five years. A randomised controlled trial was established with 63 knees (62 patients) randomised to either cemented (32 patients) or cementless UKR (30 patients). Fixation was assessed with fluoroscopic radiographs aligned to the bone-implant interface at one and five years. Outcome scores were collected pre-operatively and at one, two and five years, including Oxford Knee Score (OKS), American Knee Society Score, objective and functional (AKSS-O/F) and Tegner Activity Scale (TAS), expressed as absolute scores and 0–5 year change (δ) scores. Four patients died during the study period. There were no revisions. Mean operative time was 11 minutes shorter in the cementless group (p=0.029). At five years, there was no significant difference in any outcome measure except AKSS-F and δAKSS-F which were significantly better in the cementless group (both p=0.003). There were no femoral radiolucencies in either group. There were significantly more tibial radiolucencies in the cemented group (20/30 vs 2/27, p< 0.001). There were nine complete radiolucencies in the cemented group and none in the cementless group (p< 0.001). Cementless fixation provides improved fixation at five years compared to cemented fixation in UKR, maintaining equivalent or superior clinical outcomes with a shorter operative time and no increase in complications

Introduction. The aims of this study were to undertake a prospective randomised trial to compare functional outcome, strength and range of motion after treatment of medial collateral ligament injuries by either early unprotected mobilisation or mobilisation with a hinged brace. Methods. Patients were randomised into either unprotected mobilisation or mobilisation with a hinged brace. Assessments occurred at 2 weeks, 6 weeks, 3 months and 6 months. Outcome measures included validated questionnaires (International Knee Documentation Committee and Knee Injury and Osteoarthritis Outcome Score scores), range of motion measurements and strength testing. Results. Eighty six patients (mean age 30.4) were recruited. There were 53 men and 33 women. The mode of injury was sport in 56 patients (65%) with football, rugby and skiing being the most common types of sport involved. The mean time to return to full weight bearing was 3 weeks in both groups. The mean time to return to work was 4.6 weeks in the braced group and 4.1 weeks in the non-braced group (p=0.79). Return to running was at a mean of 14.3 weeks in the braced group and 12.8 weeks in the non-braced group (p=0.64). Return to full sport was 22 weeks in the braced group and 22.1 weeks in the non-braced group (p=0.99). There was no significant difference in range of movement or pain scores between the two groups at 2,6,12 and 24 weeks. Conclusions. The use of a hinged knee brace does not influence recovery after a medial collateral injury

Financial impact and patient satisfaction with four different anticoagulants for hip and knee arthroplasty in patients with a previous history of VTE- A prospective randomised trial. Introduction. New generation oral anticoagulants (dabigatran/rivaroxaban) have recently become available for the prevention of venous thromboembolism (VTE) following hip and knee arthroplasty. Traditional therapies (warfarin/low molecular weight heparins) are less costly, but have several limitations. The aim of this study was to evaluate the financial impact of substituting enoxaparin and warfarin with newer therapies dabigatran and rivaroxaban. A secondary objective was to investigate patient satisfaction with these treatments. Methods. A randomised prospective study was conducted over a 12 month period. Patients with a history of VTE undergoing hip or knee replacement were randomised to receive one of four anticoagulants for five weeks post surgery. Information was gathered during the hospital stay and then post discharge, by telephone, for five weeks(35 days)to determine costs. The costs included cost of drug, nursing time, blood monitoring and transport costs. The patients were also asked to complete the Duke Anticoagulation Satisfaction Scale (DASS). The DASS is a 26 item questionnaire which has 7 responses for each question. Results. Although dabigatran and rivaroxaban had higher drug acquisition costs, warfarin and enoxaparin were financially more costly overall. These additional costs were mainly due to increased blood monitoring and time for training and administration which is not required for newer therapies. DASS scores were significantly better with dabigatran (38.5±5.1) and rivaroxaban (38.6±8.3) compared to warfarin (71.8±16.2) and enoxaparin (68.5±14.2) (p< 0.001). This indicates more satisfaction for patients prescribed dabigatran or rivaroxaban compared to traditional therapies. Conclusion. The use of new generation oral anticoagulants has the potential to significantly reduce the financial burden of thromboprophylaxis on the NHS with an additional benefit of better patient satisfaction when compared to traditional therapies

Introduction. Viscosupplementation is used widely to provide symptomatic relief to patients with knee OA. This study aimed to compare the efficacy and safety of the standard (3×2ml) and single (1×6ml) dosing regimens of hylan G-F 20. Methods. Prospective, randomized, blinded (reviewers), comparative independent study. Inclusion criteria was OA knee pain e 60mm on a 100mm VAS; no prior intra articular (IA) injection. Patients were randomised to recieve 1 × 6mL or 3 × 2mL hylan G-F 20. Follow-up at 1, 6, 12, 26 and 52 weeks. Analgesics prohibited for 24 hours prior to follow-up assessments and NSAID's for 26 wks. All adverse events (AE) were recorded. Primary outcome measure: Target knee pain (VAS) at 26 weeks. Secondary outcome measures included WOMAC, Oxford knee score, SF12. Results. 412 patients were randomized (1 × 6mL N=194, 3 × 2 mL N=218). There were no significant differences in age, gender or grade of OA. Injection and/or treatment-related AE (all mild/moderate) were reported in 10.5% (3 × 2 mL) and 9.1% (1 × 6 mL) of patients Significant pain reduction was observed in both groups at 26 weeks (3 × 2 mL: 50% (mean) decrease, 1 × 6mL: 45%). There were no significant differences between groups for any of the primary or secondary outcome measures at 26 weeks. Discussion and Conclusion. Single dose of 6 mL hylan G-F 20 offer comparable safety and efficacy to 3 × 2 mL at 26 weeks. It provides both the patients and physicians a choice with the potential additional benefits of reduced operational costs

We report our five-year functional results comparing navigated and conventional total knee replacement. To our knowlege this represents the first Level 1 study comparing function in navigated and conventional total knee replacement at five years. An origianl cohort of 71 patients undergoing Duracon (Stryker Orthopaedics, St. Leonards, Australia) total knee replacement without patellar resurfacing were prospectively randomised to undergo operation using computer navigation (Stryker Image Free Computer Navigation System (version 1.0; Stryker Orthopaedics))(n=35) or a jig-based method (n=36). The two groups were matched for age, gender, height, weight, BMI, ASA grade abd pre-operative deformity. All operations were performed by a single surgeon. Reviews were undertaken by senior physiotherpist blinded to participant status using validated outcome scoring tools (Knee Society Score, WOMAC Score and Short Form SF-36 Score). All patients underwent CT scanning of the implanted prosthesis as per Perth CT Knee Protocol to assess component alignment. After 5 years 24 patients in the navigated group and 22 patients in the conventional group were available for review. At 5 years no statistically significant difference was seen in any of the aforementioned outcome scores when comparing navigated and conventional groups. No statistically significant differencewas seen between 2- and 5-year results for either group. Due to the relatively low numbers in each group these data were compared with retrospective cohorts of navigated (n=100) and conventional (n=70) Duracon total knee replacements performed outwith this study over the same 5-year period. WITHIN the retrospective cohorts no statistically significant differences were found when comparing any of the aforementioned outcome scores. In addition, when comparing parallel scores between prospective and retrospective groups again no statistically significant differences were identified. At 5-years post-operatively the functional outcome between computer navigated and conventional total knee replacement appears to be no different despite the better alignment achieved using navigation

Introduction. Debate continues regarding the relative advantages of ceramic-on-ceramic (CoC) and metal-on-polyethylene (MoP) articulations in total hip arthroplasty (THA). Perceived benefits of CoC include longevity, and low wear - in turn limiting the effects of particulate wear debris. However, CoC bearings cost significantly more, and concern remains over the risk of ceramic fracture; a complication not seen with MoP bearings, which are also cheaper. Method. We electronically randomised 268 consecutive patients undergoing THA to receive either a CoC or MoP articulation. Patients aged over 72 were excluded. In all patients the prosthesis used was an uncemented ABG II (Stryker, USA), implanted by one of the two senior authors (HDA, ABM). Patients were scored preoperatively, and at annual follow-up clinics, using SF36, Visual Analogue (VAS), Merle d'Aubigné (MD) and Oxford Hip (OHS) Scores. Satisfaction levels were also documented. Results. Follow-up ranged from 4–10 years (mean 73.9 months). 56 patients died or were lost to follow-up, leaving 212 (79.1%); 102 CoC and 110 MoP respectively. There was no statistical difference in age, follow-up, pre-operative scoring, surgeon numbers of each prosthesis or sex distribution between groups. 5 CoC patients underwent revision surgery, compared with 4 MoP. Mean follow-up scores in the CoC group were: SF36 67.9, VAS 1.5, MD 16.5 and OHS 28.2, for the MoP cohort, results were: SF36 61.1, VAS 2.4, MD 16.3 and OHS 21.8. None of these were statistically significant differences, and satisfaction levels were the same between groups. Discussion. Our data suggest that, up to 10 years, both articulations give equal satisfaction, survivorship and functional outcomes. Anecdotally, many surgeons appear increasingly to favour ceramic bearings in THA; although longer follow-up may be needed to demonstrate any advantages of ceramic over MoP, results such as ours should perhaps be considered when making this decision

Increasing knee flexion following total knee arthroplasty (TKA) has become an important outcome measure. Surgical technique is one factor that can influence knee motion. In this study, it was hypothesised that stripping of the posterior knee capsule could improve flexion and range of motion (ROM) following TKA. Patients who were undergoing TKA were prospectively randomised into two groups - one group (62 patients) were allocated stripping of the posterior knee capsule (PCS), the other group (66 patients) no stripping (no-PCS). The primary outcome was change in flexion and ROM compared to pre-operative measurements at three time points; after wound closure, 3months and 1year post-operatively. Secondary outcomes were absolute measurements of flexion, extension, ROM and complications. All operations were performed by a single surgeon using the same implant and technique. All patients received identical post-operative rehabilitation. There was a significant gain in flexion after wound closure in the PCS group (p=0.022), however there was no significant difference at 3months or 1year post-operatively. Absolute values of extension (p=0.008) and flexion (p=0.001) 3months post-operatively were significantly reduced for the PCS group. The absolute value of ROM was significantly higher for the no-PCS group at 3months (p=0.0002) and 1year (p=0.005). There were no significant difference in the rate of complications. Posterior capsular stripping causes a transient increase in flexion that does not persist post-operatively. We do not recommend routine stripping of the posterior knee capsule in patients undergoing TKA

Introduction

Total hip arthroplasty (THA) is undertaken to relieve pain and to restore mobility. The orthopaedic community remains divided on the influence of surgical approach in achieving functional recovery most quickly and effectively. We report a study comparing THA performed through a posterior (Posterior) against anterior approach (Heuter).

Metal on Metal hip resurfacing (MoM HR) can be an effective operation for the young arthritic hip population. However, errors in cup orientation have been associated with increased wear, circulating blood metal ions, and soft tissue abnormalities that can lead to premature failure of the bearing surface and subsequent revision surgery. While image free computer guidance has been shown to increase surgical accuracy in total hip arthroplasty, the role of image based technology in MoM HR is unclear. In this study, we compared the accuracy of cup orientation in MoM HR performed by either freehand technique or CT based navigation.

Seventy five patients (81 hips) underwent either freehand (n=42) or navigation (n=39) surgery, both requiring a three dimensional (3D) CT surgical plan. Surgery was conducted by hip specialists blind to the method of cup implantation until the operation. Deviation in inclination and version from the planned orientation, as well as, number of cups within a 10° safe zone and 5° optimal zone of the target position was calculated using post operative 3D CT analysis.

Error in inclination was significantly reduced with navigation compared to freehand technique (4° vs 6°, p=0.02). We could not detect a difference between the two groups for version error (5° vs 7°, p=0.06). There was a significantly greater number of hips within a 10° (87% vs 67%, p=0.04) and 5° (50% vs 20%, p=0.06) safe zone when navigated.

Image based navigation can substantially improve accuracy in cup orientation. The results of our freehand group appear better than historic controls, suggesting the use of a 3D plan may help to reduce technical error and improve the learning curve in this technically demanding procedure. We advocate the use of image based navigation in MoM hip resurfacing arthroplasty.

Introduction

Arthrodesis of the 1st metatarso-phalangeal joint (MTPJ) is a common procedure in forefoot surgery for hallux rigidus and severe hallux valgus. Debate persists on two issues - the best preparation method for the articular surfaces, and the optimal technique for operative stabilisation of the joint.

Objectives. Minimally invasive surgery (MIS) has gained popularity for hallux valgus, compared to the traditional scarf osteotomy (OS). Though evidence suggests similar clinical outcomes, there is paucity of randomised controlled studies. This study aimed to assess the feasibility of conducting a randomised controlled trial comparing the patient recorded and clinical outcomes for the surgical management of Hallux Valgus between OS and MIS Chevron Akin (MICA). Methods. Patients suitable for surgical correction were invited to participate. Post-op rehabilitation was standardised for both groups. Patients completed a validated questionnaire (Manchester Oxford Foot questionnaire and EQ-5D-5L) pre-operatively and post-operatively at 6 months and 1 year. Radiological parameters and range of motion were measured pre-and post-operatively. Results. 31 patients were recruited between Dec 2017 and June 2022. 17 patients were randomised to MICA (15 female, mean age 51) and 15 to OS (14 female, mean age 51). Both groups had a significant improvement in all MOXFQ parameters at 6m and 12m, as well as radiological parameters. VAS improved for OS (p=0.048) and for MICA (p=0.059) at 6m. There was no significant improvement in EQ-5D in either group at 12 months and no significant difference in operative time (p=0.53). There was a higher number of complications in the MICA group with 5 removal of metalwork (29.4%) and 2 superficial infections (11.8%) versus none in the OS group. The dorsiflexion significantly improved in the OS group at 6months (p=0.04). Recruitment rate dipped during COVID. No patients were lost at follow up. Conclusion. Both surgical options show similar clinical results, but higher complication rates were seen with MICA. This study illustrates the feasibility to conduct a randomised control trial for the comparison between the two techniques. Challenges to recruitment included surgeon equipoise, patient preference, training requirement and the pandemic which could be mitigated in a larger study

Surgical site infections following orthopaedic surgery are a serious complication associated with increased morbidity and mortality. Intra-wound antibiotic powder may be able to provide infection prophylaxis locally with less systemic adverse effects, and promising results have been reported in systematic reviews of its use in spine surgery. This study aims to analyse the efficacy and adverse effect profile of intra-wound antibiotics in reducing surgical site infections in orthopaedic surgery for traumatic pelvic and lower limb fractures. A systematic review was conducted for studies reporting on the incidence of surgical site infections following administration of intra-wound antibiotic powder in pelvic and lower limb trauma surgery. Randomised controlled trials, cohort and case-control studies were included. A meta-analysis was conducted for deep surgical site infections. Seven studies were included in the systematic review including six retrospective case-control studies and one randomised controlled trial. Results of the meta-analysis suggest a potential 23% reduction in the odds of developing a deep surgical site infection in patients treated with intra-operative antibiotic powder compared with those managed with intravenous antibiotics alone (OR 0.77, 95% CI 0.52 – 1.13), although the results did not reach statistical significance. Notable selective bias against intra-wound antibiotics and suboptimal study design were found in the retrospective studies, however the randomised controlled trial reported a significant reduction in deep surgical site infections with intra-wound vancomycin powder. There were no reports of systemic adverse outcomes and minimal risk of wound complications with the use of intra-wound antibiotics. This review suggests the use of intra-wound antibiotic powder in pelvic and lower limb trauma surgery may reduce the incidence of deep surgical site infections. Further powered studies including randomised controlled trials are required to confirm the results highlighted in this study

Interstitial supraspinatus tears can cause persistent subacromial impingement symptoms despite non operative treatment. Autologous tendon cell injection (ATI) is a non-surgical treatment for tendinopathies and tear. We report a randomised controlled study of ATI compared to corticosteroid injection (CS) as treatment for interstitial supraspinatus tears and tendinopathy. Inclusion criteria were patients with symptom duration > 6 months, MRI confirmed intrasubstance supraspinatus tear, and prior treatment with physiotherapy and ≥ one CS or PRP injection. Participants were randomised to receive ATI to the interstitial tear or corticosteroid injection to the subacromial bursa in a 2:1 ratio, under ultrasound guidance. Assessments of pain (VAS) and function (ASES) were performed at baseline, and 1, 3, 6 and 12 months post treatment. 30 participants (19 randomised to ATI) with a mean age of 50.5 years (10 females) and a mean duration of symptoms of 23.5 months. Baseline VAS pain and ASES scores were comparable between groups. While mean VAS pain scores improved in both groups at 3 months after treatment, pain scores were superior with ATI at 6 months (p=0.01). Mean ASES scores in the ATI group were superior to the CS group at 3 months (p=0.026) and 6 months (p=0.012). Seven participants in the CS group withdrew prior to 12 months due to lack of improvement. At 12 months, mean VAS pain in the ATI group was 1.6 ± 1.3. The improvements in mean ASES scores in the ATI group at 6 and 12 months were greater than the MCID (12.0 points). At 12 months, 95% of ATI participants had an ASES score > the PASS (patient acceptable symptom state). This is the first level one study using ATI to treat interstitial supraspinatus tear. ATI results in a significant reduction in pain and improvement in shoulder function

Patients awaiting resolution of swelling and oedema prior to ankle surgery can represent a significant burden on hospital beds. Our study assessed whether external pneumatic intermittent compression (EPIC) can reduce delays to surgery. Our prospective randomised controlled trial (n= 20) compared outcomes of patients treated with EPIC vs control group managed with ice and elevation. Included were patients aged <18 years with isolated closed ankle fractures admitted for management of swelling prior to surgery. Excluded were open fractures, injuries to contralateral leg, diabetes, absent pulses, peripheral vascular disease, inability to consent, no requirement for admission. Eligible patients were randomised to active or control arms. All patients were managed initially with reduction and back slab application. Patients in active arm fitted with EPIC (Hydroven 3000) device over the back slab. Assessment by treating team determined the time at which patient is assessed ready for surgery. Patients in the treatment arm were assessed as ready for surgery sooner, (123 hrs vs 168hrs, T score = 1.925, P 0.035) and had a shorter time to surgery (167 hrs vs 216 hrs, T score = 1.748, P 0.047) Length of stay was reduced bud did not reach statistical significance. (259 hrs vs 269 hrs, T score 0.229, P 0.41). Our results showed a statistically and clinically significant reduction in time that patients were assessed ready for surgery and time to surgery in the treatment cohort. We conclude that although further data is needed to achieve an adequately powered study and assess the safety profile of the EPIC, incorporation of EPIC into routine clinical practice has the potential for significant cost savings

Glenoid baseplate positioning for reverse total shoulder replacements (rTSR) is key for stability and longevity. 3D planning and image-derived instrumentation (IDI) are techniques for improving implant placement accuracy. This is a single-blinded randomised controlled trial comparing 3D planning with IDI jigs versus 3D planning with conventional instrumentation. Eligible patients were enrolled and had 3D pre-operative planning. They were randomised to either IDI or conventional instrumentation; then underwent their rTSR. 6 weeks post operatively, a CT scan was performed and blinded assessors measured the accuracy of glenoid baseplate position relative to the pre-operative plan. 47 patients were included: 24 with IDI and 23 with conventional instrumentation. The IDI group were more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane when compared to the conventional group (p=0.01). The IDI group had a smaller degree of error when the native glenoid retroversion was >10° (p=0.047) when compared to the conventional group. All other parameters (inclination, anterior/posterior plane, glenoids with retroversion <10°) showed no significant difference between the two groups. Both IDI and conventional methods for rTSA placement are very accurate. However, IDI is more accurate for complex glenoid morphology and placement in the superior-inferior plane. Clinically, these two parameters are important and may prevent long term complications of scapular notching or glenoid baseplate loosening. Image-derived instrumentation (IDI) is significantly more accurate in glenoid component placement in the superior/inferior plane compared to conventional instrumentation when using 3D pre-operative planning. Additionally, in complex glenoid morphologies where the native retroversion is >10°, IDI has improved accuracy in glenoid placement compared to conventional instrumentation. IDI is an accurate method for glenoid guidewire and component placement in rTSA

Joint registries suggest a downward trend in the use of uncemented Total Knee Replacements (TKR) since 2003, largely related to reports of early failures of uncemented tibial and patella components. Advancements in uncemented design such as trabecular metal may improve outcomes, but there is a scarcity of high-quality data from randomised trials. 319 patients <75 years of age were randomised to either cemented or uncemented TKR implanted using computer navigation. Patellae were resurfaced in all patients. Patient outcome scores, re-operations and radiographic analysis of radiolucent lines were compared. Two year follow up was available for 287 patients (144 cemented vs 143 uncemented). There was no difference in operative time between groups, 73.7 v 71.1 mins (p= 0.08). There were no statistical differences in outcome scores at 2 years, Oxford knee score 42.5 vs 41.8 (p=0.35), International Knee Society 84.6 vs 84.0 (p=0.76), Forgotten Joint Score 66.7 vs 66.4 (p=0.91). There were two revisions, both for infection one in each group (0.33%). 13 cemented and 8 uncemented knees underwent re-operation, the majority of these being manipulation under anaesthetic (85.7%), with no difference (8.3% vs 5.3%, 95% CI -2.81% to 8.89%, p = 0.31). No difference was found in radiographic analysis at 2 years, 1 lucent line was seen in the cemented group and 3 in the uncemented group (0.67% v 2.09%, 95%CI -4.1% to 1.24%, p = 0.29). We found no difference in clinical or radiographic outcomes between cemented and uncemented TKR including routine patella resurfacing at two years. Early results suggest there is no difference between cemented and uncemented TKR at 2 years with reference to survivorship, patient outcomes and radiological parameters