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Aim To compare the outcomes of cemented and cementless Unicompartmental Knee Replacements (UKR) at 5 years after surgery. Methods 262 cemented and 262 cementless medial mobile-bearing UKR, implanted by four high-volume surgeons using identical indications and surgical techniques, were reviewed by independent physiotherapists at 5 years. Survival, Oxford Knee Score (OKS), American Knee Society Score (AKSS), and EQ-5D-5L were assessed. The cementless cohort was mainly implanted after the cemented. Each cohort was divided into early and late sub-groups and compared, to assess if any differences were due to progressive improvement in surgical practice over time. Results There were no significant differences between the cohorts for demographics, pre-operative scores, and 5-year revision (0.8%), re-operation (1.5%), and complication rates (5%). The cementless cohort had significantly better 5-year OKS (43v41, p = 0.008), AKSS-Objective (94v90, p = 0.049) and EQ-5D-5L (0.81v0.87, p = 0.0001). Pain sub-scores within OKS, AKSS, and EQ-5D-5L were also significantly better in the cementless cohort, and the differences were proportionally much greater and more significant than differences in their respective overall scores. There was no significant improvement in scores between the early and late subgroups of the cohorts, whereas the ‘early-cementless’ cohort had significantly better scores than the contemporaneously implanted ‘late-cemented’ cohort. This suggests that differences found were due to implant type, instead of improved surgical practice over time. Conclusion Cementless UKR is associated with better clinical outcomes than cemented UKR, which is primarily due to improved pain relief. Both cemented and cementless UKR are safe with low reoperation and complication rates, and a 5-year survival of 99%.

Aims To report mid- to long-term results of Oxford mobile bearing domed lateral unicompartmental knee arthroplasty (UKA), and determine the effect of potential contraindications on outcome. Methods A total of 325 consecutive domed lateral UKAs undertaken for the recommended indications were included, and their functional and survival outcomes were assessed. The effects of age, weight, activity, and the presence of full-thickness erosions of cartilage in the patellofemoral joint on outcome were evaluated. Results Median follow-up was seven years (3 to 14), and mean age at surgery was 65 years (39 to 90). Median Oxford Knee Score (OKS) was 43 (interquartile range (IQR) 37 to 47), with 260 (80%) achieving a good or excellent score (OKS > 34). Revisions occurred in 34 (10%); 14 (4%) were for dislocation, of which 12 had no recurrence following insertion of a new bearing, and 12 (4%) were revised for medial osteoarthritis (OA). Ten-year survival was 85% (95% confidence interval (CI) 79 to 90, at risk 72). Age, weight, activity, and patellofemoral erosions did not have a significant effect on the clinical outcome or survival. Conclusion Domed lateral UKA provides a good alternative to total knee arthroplasty (TKA) in the management of lateral compartment OA. Although dislocation is relatively easy to treat successfully, the dislocation rate of 4% is high. It is recommended that the stability of the bearing is assessed intraoperatively. If the bearing can easily be displaced, the fixed rather than the mobile bearing version of the Oxford lateral tibial component should be inserted instead. Younger age, heavier weight, high activity, and patellofemoral erosions did not detrimentally affect outcome, so should not be considered contraindications.

Post-traumatic stress disorder (PTSD) impacts many veterans and active duty soldiers, but diagnosis can be problematic due to biases in self-disclosure of symptoms, stigma within military populations, and limitations identifying those at risk. Prior studies suggest that PTSD may be a systemic illness, affecting not just the brain, but the entire body. Therefore, disease signals likely span multiple biological domains, including genes, proteins, cells, tissues, and organism-level physiological changes. Identification of these signals could aid in diagnostics, treatment decision-making, and risk evaluation. In the search for PTSD diagnostic biomarkers, we ascertained over one million molecular, cellular, physiological, and clinical features from three cohorts of male veterans. In a discovery cohort of 83 warzone-related PTSD cases and 82 warzone-exposed controls, we identified a set of 343 candidate biomarkers. These candidate biomarkers were selected from an integrated approach using (1) data-driven methods, including Support Vector Machine with Recursive Feature Elimination and other standard or published methodologies, and (2) hypothesis-driven approaches, using previous genetic studies for polygenic risk, or other PTSD-related literature. After reassessment of ~30% of these participants, we refined this set of markers from 343 to 28, based on their performance and ability to track changes in phenotype over time. The final diagnostic panel of 28 features was validated in an independent cohort (26 cases, 26 controls) with good performance (AUC = 0.80, 81% accuracy, 85% sensitivity, and 77% specificity). The identification and validation of this diverse diagnostic panel represents a powerful and novel approach to improve accuracy and reduce bias in diagnosing combat-related PTSD.

We studied subchondral intraosseous pressure (IOP) in an animal model during loading and with vascular occlusion. We explored bone compartmentalisation by saline injection. Needles were placed in the femoral condyle and upper tibia of 5 anaesthetised rabbits and connected to pressure recorders. The limb was loaded with and without proximal vascular occlusion. An additional subject had simultaneous triple recordings at the femoral head, femoral condyle and proximal tibia. In a further subject saline injections at three sites were carried out alternately. Loading alone caused a rise in subchondral IOP from 11.7mmHg (SD 7.1mmHg) to 17.9mmHg (SD 8.1mmHg) p This is the first study to report changes in IOP in vivo during loading and with combinations of vascular occlusion and loading. IOP is not a constant but is reduced during proximal arterial occlusion and increased with proximal venous occlusion. Whatever the perfusion state, in vivo load is transferred partly by hydraulic pressure. We suggest that joints act as hydraulic pressure barriers. An understanding of subchondral physiology may be important in understanding osteoarthritis and other bone diseases.

Purpose Whilst medial UKR is indicated for full-thickness cartilage loss (FTCL) on occasion it has been used to treat partial-thickness cartilage loss (PTCL). This matched case-control study investigates the five-year outcomes in a consecutive series of UKR implanted for PTCL. Methods Between 2002 and 2014, 94consecutive UKR (90patients) were implanted by two surgeons for PTCL and followed up independently for a mean 6years (range 1-13). These cases were matched 1:2 based on age, gender and preoperative OKS with knees with FTCL anteromedial osteoarthritis managed with UKR. Functional outcomes, implant survival and incidence of reoperations was assessed at one, two and five years. A sub-study of 36knees (36patients) with PTCL who had had pre-operative MRI was performed to identify whether there were any MRI factors that predicted outcomes. Results Knees with PTCL had significantly worse functional outcomes (OKS and AKSS-O) at one, two and five years postoperatively. A quarter of knees with PTCL reported fair or poor results and a fifth failed to achieve a clinically significant improvement from baseline of four points or more on the OKS, double that seen in knees with FTCL. Whilst no difference in implant survival was detected between groups, knees with PTCL had a triple the reoperation rate with the majority, three-quarters, being arthroscopies for persistent pain. Patients with PTCL who achieved fair or poor outcomes were younger with worse preoperative functional scores, compared to those who achieve good or excellent outcomes however no other differences in baseline demographics were seen. MRI findings (FTCL, subchondral oedema, synovitis or effusion) did not provide additional prognostic information. Conclusion Medial UKR should be reserved for patients with FTCL, whilst some patients with PTCL do achieve good results, at present, we cannot identify which these will be and in this situation MRI is not only unhelpful but also misleading.

Background The indications for unicompartmental knee replacement (UKR) remain controversial. Previously recommended contra-indications include: age under 60years, weight 180lb (82kg) or over, patients undertaking heavy labour, chondrocalcinosis, and exposed bone in the patellofemoral joint. This study explores whether these contra-indications are valid in mobile-bearing UKR. Methods Using a prospective series of 1000 consecutive medial UKR in which the reported contra-indications were not applied, the functional outcome and survival in patients with or without contra-indications were compared. Results Of the 1000 consecutive UKR (818 patients) 68% (678 knees) would be considered contra-indicated based on published contra-indications. At a mean follow-up of ten-years (5 to 17) there was no difference in American Knee Society Objective Scores (AKSS-O) (p=0.05) or Oxford Knee Score (OKS) (p=0.08) between groups. However, knees with contra-indications had significantly (p=0.02) fewer poor outcomes and significantly better AKS Functional Scores (AKSS-F) (p The 3% of UKR performed in young males (age Conclusion This large case series provides evidence that patients with the previously reported contra-indications do as well as, or even better than, those without contra-indications. Therefore these contra-indications should not apply to mobile-bearing UKR.

Aims: Periprosthetic fracture (PF) after primary total hip arthroplasty (THA) is an uncommon but potentially devastating complication. This study aims to investigate the influence of cemented stem designs on the risk of needing a revision for a PF. Patients and Methods: We analysed data on 257 202 primary THAs with cemented stems and 390 linked first revisions for PF recorded in the National Joint Registry (NJR) of England, Wales and Northern Ireland to determine if a cemented femoral stem brand was associated with the risk of having revision for a PF after primary THA. All cemented femoral stem brands with more than 10 000 primary operations recorded in the NJR were identified. The four most commonly used cemented femoral stems were the Exeter V40 (n = 146 409), CPT (n = 24 300), C-Stem (n = 15 113) and Charnley (n = 20 182). We compared the revision risk ratios due to PF amongst the stems using a Poisson regression model adjusting for patient factors. Compared with the Exeter V40, the age, gender and ASA grade adjusted revision rate ratio was 3.89 for the cemented CPT stem (95% confidence interval (CI) 3.07 to 4.93), 0.89 for the C-Stem (95% CI 0.57 to 1.41) and 0.41 for the Charnley stem (95% CI 0.24 to 0.70). Conclusions: The limitations of the study include incomplete data capture, analysis of only PF requiring revision and that observation does not imply causality. Nevertheless, this study demonstrates that the choice of a cemented stem may influence the risk of revision for PF.