Aims. The purpose of our study was to determine whether mesenchymal stem cells (MSCs) are an effective and safe therapeutic agent for the treatment of knee osteoarthritis (OA), owing to their cartilage regeneration potential. Methods. We searched PubMed, Embase, and the Cochrane Library, with keywords including “knee osteoarthritis” and “mesenchymal stem cells”, up to June 2019. We selected randomized controlled trials (RCTs) that explored the use of MSCs to treat knee OA. The visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), adverse events, and the whole-organ MRI score (WORMS) were used as the primary evaluation tools in the studies. Our meta-analysis included a subgroup analysis of cell dose and cell source. Results. Seven trials evaluating 256 patients were included in the meta-analysis. MSC treatment significantly improved the VAS (mean difference (MD), –13.24; 95% confidence intervals (CIs) –23.28 to –3.20, p = 0.010) and WOMAC (MD, –7.22; 95% CI –12.97 to –1.47, p = 0.010). The low-dose group with less than 30 million cells showed lower p-values for both the VAS and WOMAC. Adipose and umbilical cord–derived stem cells also had lower p-values for pain scores than those derived from bone marrow. Conclusion. Overall, MSC-based cell therapy is a relatively safe treatment that holds great potential for OA, evidenced by a positive effect on pain and knee function. Using low-dose (25 million) and adipose-derived stem cells is likely to achieve better results, but further research is needed. Cite this article: Bone Joint Res 2020;9(10):719–728

Aims. Kashin-Beck disease (KBD) is a kind of chronic osteochondropathy, thought to be caused by environmental risk factors such as T-2 toxin. However, the exact aetiology of KBD remains unclear. In this study, we explored the functional relevance and biological mechanism of cartilage oligosaccharide matrix protein (COMP) in the articular cartilage damage of KBD. Methods. The articular cartilage specimens were collected from five KBD patients and five control subjects for cell culture. The messenger RNA (mRNA) and protein expression levels were detected by quantitative reverse transcription PCR (qRT-PCR) and western blot. The survival rate of C28/I2 chondrocyte cell line was detected by MTT assay after T-2 toxin intervention. The cell viability and mRNA expression levels of apoptosis related genes between COMP-overexpression groups and control groups were examined after cell transfection. Results. The mRNA and protein expression levels of COMP were significantly lower in KBD chondrocytes than control chondrocytes. After the T-2 toxin intervention, the COMP mRNA expression of C28/I2 chondrocyte reduced and the protein level of COMP in three intervention groups was significantly lower than in the control group. MTT assay showed that the survival rate of COMP overexpression KBD chondrocytes were notably higher than in the blank control group. The mRNA expression levels of Survivin, SOX9, Caspase-3, and type II collagen were also significantly different among COMP overexpression, negative control, and blank control groups. Conclusion. Our study results confirmed the functional relevance of COMP with KBD. COMP may play an important role in the excessive chondrocytes apoptosis of KBD patients. Cite this article: Bone Joint Res 2020;9(9):578–586

Objectives. The purpose of this study was to create a novel ex vivo organ culture model for evaluating the effects of static and dynamic load on cartilage. Methods. The metatarsophalangeal joints of 12 fresh cadaveric bovine feet were skinned and dissected aseptically, and cultured for up to four weeks. Dynamic movement was applied using a custom-made machine on six joints, with the others cultured under static conditions. Chondrocyte viability and matrix glycosaminoglycan (GAG) content were evaluated by the cell viability probes, 5-chloromethylfluorescein diacetate (CMFDA) and propidium iodide (PI), and dimethylmethylene blue (DMMB) assay, respectively. Results. Chondrocyte viability in the static model decreased significantly from 89.9% (. sd. 2.5%) (Day 0) to 66.5% (. sd. 13.1%) (Day 28), 94.7% (. sd. 1.1%) to 80. 9% (. sd. 5.8%) and 80.1% (. sd. 3.0%) to 46.9% (. sd. 8.5%) in the superficial quarter, central half and deep quarter of cartilage, respectively (p < 0.001 in each zone; one-way analysis of variance). The GAG content decreased significantly from 6.01 μg/mg (. sd. 0.06) (Day 0) to 4.71 μg/mg (. sd. 0.06) (Day 28) (p < 0.001; one-way analysis of variance). However, with dynamic movement, chondrocyte viability and GAG content were maintained at the Day 0 level over the four-week period without a significant change (chondrocyte viability: 92.0% (. sd. 4.0%) (Day 0) to 89.9% (. sd. 0.2%) (Day 28), 93.1% (. sd. 1.5%) to 93.8% (. sd. 0.9%) and 85.6% (. sd. 0.8%) to 84.0% (. sd. 2.9%) in the three corresponding zones; GAG content: 6.18 μg/mg (. sd. 0.15) (Day 0) to 6.06 μg/mg (. sd. 0.09) (Day 28)). Conclusion. Dynamic joint movement maintained chondrocyte viability and cartilage GAG content. This long-term whole joint culture model could be of value in providing a more natural and controlled platform for investigating the influence of joint movement on articular cartilage, and for evaluating novel therapies for cartilage repair. Cite this article: Y-C. Lin, A. C. Hall, A. H. R. W. Simpson. A novel organ culture model of a joint for the evaluation of static and dynamic load on articular cartilage. Bone Joint Res 2018;7:205–212. DOI: 10.1302/2046-3758.73.BJR-2017-0320

Objectives. The major problem with repair of an articular cartilage injury is the extensive difference in the structure and function of regenerated, compared with normal cartilage. Our work investigates the feasibility of repairing articular osteochondral defects in the canine knee joint using a composite lamellar scaffold of nano-ß-tricalcium phosphate (ß-TCP)/collagen (col) I and II with bone marrow stromal stem cells (BMSCs) and assesses its biological compatibility. Methods. The bone–cartilage scaffold was prepared as a laminated composite, using hydroxyapatite nanoparticles (nano-HAP)/collagen I/copolymer of polylactic acid–hydroxyacetic acid as the bony scaffold, and sodium hyaluronate/poly(lactic-co-glycolic acid) as the cartilaginous scaffold. Ten-to 12-month-old hybrid canines were randomly divided into an experimental group and a control group. BMSCs were obtained from the iliac crest of each animal, and only those of the third generation were used in experiments. An articular osteochondral defect was created in the right knee of dogs in both groups. Those in the experimental group were treated by implanting the composites consisting of the lamellar scaffold of ß-TCP/col I/col II/BMSCs. Those in the control group were left untreated. Results. After 12 weeks of implantation, defects in the experimental group were filled with white semi-translucent tissue, protruding slightly over the peripheral cartilage surface. After 24 weeks, the defect space in the experimental group was filled with new cartilage tissues, finely integrated into surrounding normal cartilage. The lamellar scaffold of ß-TCP/col I/col II was gradually degraded and absorbed, while new cartilage tissue formed. In the control group, the defects were not repaired. Conclusion. This method can be used as a suitable scaffold material for the tissue-engineered repair of articular cartilage defects. Cite this article: Bone Joint Res 2015;4:56–64

Objectives. We sought to determine if a durable bilayer implant composed of trabecular metal with autologous periosteum on top would be suitable to reconstitute large osteochondral defects. This design would allow for secure implant fixation, subsequent integration and remodeling. Materials and Methods. Adult sheep were randomly assigned to one of three groups (n = 8/group): 1. trabecular metal/periosteal graft (TMPG), 2. trabecular metal (TM), 3. empty defect (ED). Cartilage and bone healing were assessed macroscopically, biochemically (type II collagen, sulfated glycosaminoglycan (sGAG) and double-stranded DNA (dsDNA) content) and histologically. Results. At 16 weeks post-operatively, histological scores amongst treatment groups were not statistically different (TMPG: overall 12.7, cartilage 8.6, bone 4.1; TM: overall 14.2, cartilage 9.5, bone 4.9; ED: overall 13.6, cartilage 9.1, bone 4.5). Metal scaffolds were incorporated into the surrounding bone, both in TM and TMPG. The sGAG yield was lower in the neo-cartilage regions compared with the articular cartilage (AC) controls (TMPG 20.8/AC 39.5, TM 25.6/AC 33.3, ED 32.2/AC 40.2 µg sGAG/1 mg respectively), with statistical significance being achieved for the TMPG group (p < 0.05). Hypercellularity of the neo-cartilage was found in TM and ED, as the dsDNA content was significantly higher (p < 0.05) compared with contralateral AC controls (TM 126.7/AC 71.1, ED 99.3/AC 62.8 ng dsDNA/1 mg). The highest type II collagen content was found in neo-cartilage after TM compared with TMPG and ED (TM 60%/TMPG 40%/ED 39%). Inter-treatment differences were not significant. Conclusions. TM is a highly suitable material for the reconstitution of osseous defects. TM enables excellent bony ingrowth and fast integration. However, combined with autologous periosteum, such a biocomposite failed to promote satisfactory neo-cartilage formation. Cite this article: E. H. Mrosek, H-W. Chung, J. S. Fitzsimmons, S. W. O’Driscoll, G. G. Reinholz, J. C. Schagemann. Porous tantalum biocomposites for osteochondral defect repair: A follow-up study in a sheep model. Bone Joint J 2016;5:403–411. DOI: 10.1302/2046-3758.59.BJR-2016-0070.R1

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. Cite this article: Bone Joint J 2020;102-B(8):1033–1040

Aims. The aim of this study was to evaluate antegrade autologous bone grafting with the preservation of articular cartilage in the treatment of symptomatic osteochondral lesions of the talus with subchondral cysts. Patients and Methods. The study involved seven men and five women; their mean age was 35.9 years (14 to 70). All lesions included full-thickness articular cartilage extending through subchondral bone and were associated with subchondral cysts. Medial lesions were exposed through an oblique medial malleolar osteotomy, and one lateral lesion was exposed by expanding an anterolateral arthroscopic portal. After refreshing the subchondral cyst, it was grafted with autologous cancellous bone from the distal tibial metaphysis. The fragments of cartilage were fixed with 5-0 nylon sutures to the surrounding cartilage. Function was assessed at a mean follow-up of 25.3 months (15 to 50), using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot outcome score. The radiological outcome was assessed using MRI and CT scans. Results. The mean AOFAS score improved from 65.7 (47 to 81) preoperatively to 92 (90 to 100) at final follow-up, with 100% patient satisfaction. The radiolucent area of the cysts almost disappeared on plain radiographs in all patients immediately after surgery, and there were no recurrences at the most recent follow-up. The medial malleolar screws were removed in seven patients, although none had symptoms. At this time, further arthroscopy was undertaken, when it was found that the mean International Cartilage Repair Society (ICRS) arthroscopic score represented near-normal cartilage. Conclusion. Autologous bone grafting with fixation of chondral fragments preserves the original cartilage in the short term, and could be considered in the treatment for adult patients with symptomatic osteochondral defect and subchondral cysts. Cite this article: Bone Joint J 2018;100-B:590–5

Objectives. Sustained intra-articular delivery of pharmacological agents is an attractive modality but requires use of a safe carrier that would not induce cartilage damage or fibrosis. Collagen scaffolds are widely available and could be used intra-articularly, but no investigation has looked at the safety of collagen scaffolds within synovial joints. The aim of this study was to determine the safety of collagen scaffold implantation in a validated in vivo animal model of knee arthrofibrosis. Materials and Methods. A total of 96 rabbits were randomly and equally assigned to four different groups: arthrotomy alone; arthrotomy and collagen scaffold placement; contracture surgery; and contracture surgery and collagen scaffold placement. Animals were killed in equal numbers at 72 hours, two weeks, eight weeks, and 24 weeks. Joint contracture was measured, and cartilage and synovial samples underwent histological analysis. Results. Animals that underwent arthrotomy had equivalent joint contractures regardless of scaffold implantation (-13.9° versus -10.9°, equivalence limit 15°). Animals that underwent surgery to induce contracture did not demonstrate equivalent joint contractures with (41.8°) or without (53.9°) collagen scaffold implantation. Chondral damage occurred in similar rates with (11 of 48) and without (nine of 48) scaffold implantation. No significant difference in synovitis was noted between groups. Absorption of the collagen scaffold occurred within eight weeks in all animals. Conclusion. Our data suggest that intra-articular implantation of a collagen sponge does not induce synovitis or cartilage damage. Implantation in a native joint does not seem to induce contracture. Implantation of the collagen sponge in a rabbit knee model of contracture may decrease the severity of the contracture. Cite this article: J. A. Walker, T. J. Ewald, E. Lewallen, A. Van Wijnen, A. D. Hanssen, B. F. Morrey, M. E. Morrey, M. P. Abdel, J. Sanchez-Sotelo. Intra-articular implantation of collagen scaffold carriers is safe in both native and arthrofibrotic rabbit knee joints. Bone Joint Res 2016;6:162–171. DOI: 10.1302/2046-3758.63.BJR-2016-0193

Aims. Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP. Methods. We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement. Results. A total of 108 patients were enrolled. The mean preoperative MP was 58.3% (SD 31.7%), which improved to 9.1% (SD 15.6%) at the last follow-up. NSA and MHR improved from 156.5° (SD 11.5°) and 82.3% (SD 8.6%) to 126.0° (SD 18.5°) and 89.1% (SD 9.0%), respectively. Factors affecting the postoperative MHR were preoperative MP (p = 0.005), immediate postoperative MP (p = 0.032), and history of Dega osteotomy (p = 0.046). Conclusion. We found that hip sphericity improves with HRS. Preoperative MP, reduction quality, and acetabular coverage influence femoral head remodelling. We recommend that surgeons should consider intervention early before hip displacement progresses and that during HRS, definite reduction and coverage of the femoral head should be obtained. Cite this article: Bone Joint J 2021;103-B(1):198–203

Aims. Recent studies have suggested that corticosteroid injections into the knee may harm the joint resulting in cartilage loss and possibly accelerating the progression of osteoarthritis (OA). The aim of this study was to assess whether patients with, or at risk of developing, symptomatic osteoarthritis of the knee who receive intra-articular corticosteroid injections have an increased risk of requiring arthroplasty. Methods. We used data from the Osteoarthritis Initiative (OAI), a multicentre observational cohort study that followed 4,796 patients with, or at risk of developing, osteoarthritis of the knee on an annual basis with follow-up available up to nine years. Increased risk for symptomatic OA was defined as frequent knee symptoms (pain, aching, or stiffness) without radiological evidence of OA and two or more risk factors, while OA was defined by the presence of both femoral osteophytes and frequent symptoms in one or both knees. Missing data were imputed with multiple imputations using chained equations. Time-dependent propensity score matching was performed to match patients at the time of receving their first injection with controls. The effect of corticosteroid injections on the rate of subsequent (total and partial) knee arthroplasty was estimated using Cox proportional-hazards survival analyses. Results. After removing patients lost to follow-up, 3,822 patients remained in the study. A total of 249 (31.3%) of the 796 patients who received corticosteroid injections, and 152 (5.0%) of the 3,026 who did not, had knee arthroplasty. In the matched cohort, Cox proportional-hazards regression resulted in a hazard ratio of 1.57 (95% confidence interval (CI) 1.37 to 1.81; p < 0.001) and each injection increased the absolute risk of arthroplasty by 9.4% at nine years’ follow-up compared with those who did not receive injections. Conclusion. Corticosteroid injections seem to be associated with an increased risk of knee arthroplasty in patients with, or at risk of developing, symptomatic OA of the knee. These findings suggest that a conservative approach regarding the treatment of these patients with corticosteroid injections should be recommended. Cite this article: Bone Joint J 2020;102-B(5):586–592

Advanced MRI cartilage imaging such as T. 1. -rho (T1ρ) for the diagnosis of early cartilage degradation prior to morpholgic radiological changes may provide prognostic information in the management of joint disease. This study aimed first to determine the normal T1ρ profile of cartilage within the hip, and secondly to identify any differences in T1ρ profile between the normal and symptomatic femoroacetabular impingement (FAI) hip. Ten patients with cam-type FAI (seven male and three female, mean age 35.9 years (28 to 48)) and ten control patients (four male and six female, mean age 30.6 years (22 to 35)) underwent 1.5T T1ρ MRI of a single hip. Mean T1ρ relaxation times for full thickness and each of the three equal cartilage thickness layers were calculated and compared between the groups. The mean T1ρ relaxation times for full cartilage thickness of control and FAI hips were similar (37.17 ms (. sd.  9.95) and 36.71 ms (. sd. 6.72), respectively). The control group demonstrated a T1ρ value trend, increasing from deep to superficial cartilage layers, with the middle third having significantly greater T1ρ relaxation values than the deepest third (p = 0.008). The FAI group demonstrated loss of this trend. The deepest third in the FAI group demonstrated greater T1ρ relaxation values than controls (p = 0.028). These results suggest that 1.5T T1ρ MRI can detect acetabular hyaline cartilage changes in patients with FAI

Aims. To assess the effect of physical exercise (PE) on the histological and transcriptional characteristics of proteoglycan-induced arthritis (PGIA) in BALB/c mice. Methods. Following PGIA, mice were subjected to treadmill PE for ten weeks. The tarsal joints were used for histological and genetic analysis through microarray technology. The genes differentially expressed by PE in the arthritic mice were obtained from the microarray experiments. Bioinformatic analysis in the DAVID, STRING, and Cytoscape bioinformatic resources allowed the association of these genes in biological processes and signalling pathways. Results. Arthritic mice improved their physical fitness by 42.5% after PE intervention; it induced the differential expression of 2,554 genes. The bioinformatic analysis showed that the downregulated genes (n = 1,371) were significantly associated with cellular processes that mediate the inflammation, including Janus kinase-signal transducer and activator of transcription proteins (JAK-STAT), Notch, and cytokine receptor interaction signalling pathways. Moreover, the protein interaction network showed that the downregulated inflammatory mediators interleukin (IL) 4, IL5, IL2 receptor alpha (IL2rα), IL2 receptor beta (IL2rβ), chemokine ligand (CXCL) 9, and CXCL12 were interacting in several pathways associated with the pathogenesis of arthritis. The upregulated genes (n = 1,183) were associated with processes involved in the remodelling of the extracellular matrix and bone mineralization, as well as with the processes of aerobic metabolism. At the histological level, PE attenuated joint inflammatory infiltrate and cartilage erosion. Conclusion. Physical exercise influences parameters intimately linked to inflammatory arthropathies. Research on the effect of PE on the pathogenesis process of arthritis is still necessary for animal and human models. Cite this article:Bone Joint Res. 2020;9(1):36–48

Cartilage defects of the hip cause significant pain and may lead to arthritic changes that necessitate hip replacement. We propose the use of fresh osteochondral allografts as an option for the treatment of such defects in young patients. Here we present the results of fresh osteochondral allografts for cartilage defects in 17 patients in a prospective study. The underlying diagnoses for the cartilage defects were osteochondritis dissecans in eight and avascular necrosis in six. Two had Legg-Calve-Perthes and one a femoral head fracture. Pre-operatively, an MRI was used to determine the size of the cartilage defect and the femoral head diameter. All patients underwent surgical hip dislocation with a trochanteric slide osteotomy for placement of the allograft. The mean age at surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months (3 to 74). The mean Harris hip score was significantly better after surgery (p < 0.01) and 13 patients had fair to good outcomes. One patient required a repeat allograft, one patient underwent hip replacement and two patients are awaiting hip replacement. Fresh osteochondral allograft is a reasonable treatment option for hip cartilage defects in young patients. Cite this article: Bone Joint J 2014;96-B(11 Supple A):11–16

Aims. Rheumatoid arthritis (RA) is a systematic autoimmune disorder, characterized by synovial inflammation, bone and cartilage destruction, and disease involvement in multiple organs. Although numerous drugs are employed in RA treatment, some respond little and suffer from severe side effects. This study aimed to screen the candidate therapeutic targets and promising drugs in a novel method. Methods. We developed a module-based and cumulatively scoring approach that is a deeper-layer application of weighted gene co-expression network (WGCNA) and connectivity map (CMap) based on the high-throughput datasets. Results. Four noteworthy RA-related modules were identified, revealing the immune- and infection-related biological processes and pathways involved in RA. HLA-DMA, HLA-DMB, HLA-DPA1, HLA-DPB1, HLA-DQB1, HLA-DRA, HLA-DRB1, BLNK, BTK, CD3D, CD4, IL2RG, INPP5D, LCK, PTPRC, RAC2, SYK, and VAV1 were recognized as the key hub genes with high connectivity in gene regulation networks and gene pathway networks. Moreover, the long noncoding RNAs (lncRNAs) in the RA-related modules, such as FAM30A and NEAT1, were identified as the indispensable interactors with the hub genes. Finally, candidate drugs were screened by developing a cumulatively scoring approach based on the selected modules. Niclosamide and the other compounds of T-type calcium channel blocker, IKK inhibitor, and PKC activator, HIF activator, and proteasome inhibitor, which harbour the similar gene signature with niclosamide, were promising drugs with high specificity and broad coverage for the RA-related modules. Conclusion. This study provides not only the promising targets and drugs for RA but also a novel methodological insight into the target and drug screening. Cite this article: Bone Joint Res 2020;9(8):501–514

Aims. Medial unicompartmental knee arthroplasty (UKA) is associated with successful outcomes in carefully selected patient cohorts. We hypothesised that severity and location of patellofemoral cartilage lesions significantly influences functional outcome after Oxford medial compartmental knee arthroplasty. Patients and Methods. We reviewed 100 consecutive UKAs at minimum eight-year follow-up (96 to 132). A single surgeon performed all procedures. Patients were selected based on clinical and plain radiographic assessment. All patients had end-stage medial compartment osteoarthritis (OA) with sparing of the lateral compartment and intact anterior cruciate ligaments. None of the patients had end-stage patellofemoral OA, but patients with anterior knee pain or partial thickness chondral loss were not excluded. There were 57 male and 43 female patients. The mean age at surgery was 69 years (41 to 82). At surgery the joint was carefully inspected for patellofemoral chondral loss and this was documented based on severity of cartilage loss (0 to 4 Outerbridge grading) and topographic location (medial, lateral, central, and superior or inferior). Functional scores collected included Oxford Knee Score (OKS), patient satisfaction scale and University College Hospital (UCH) knee score. Intraclass correlation was used to compare chondral damage to outcomes. Results. All patients documented significant improvement in pain and improved functional scores at mid-term follow-up. There were four revisions (mean 2.9 years, 2 to 4; standard deviation (. sd). 0.9) in this cohort, three for tibial loosening and one for femoral loosening. There was one infection that was treated with debridement and insert exchange. The mean OKS improved from 23.2 (. sd. 7.1) to 39.1 (. sd. 6.9); p < 0.001. The cohort with central and lateral grade 3 patellofemoral OA documented lower mean satisfaction with pain (90, . sd.  11.8) and function (87.5, . sd. 10.3) on the patient satisfaction scale. On the UCH scale, patients reported significantly decreased mean overall scores (7.3, . sd. 1.2 vs 9, . sd. 2.3) as well as stair climb task (3.5, . sd. 0.3 vs 5, . sd. 0.1) when cartilage lesions were located centrally or laterally on the PFJ. Patients with medial chondral PFJ lesions behave similar to patients with no chondral lesions. Conclusion. Topographical location and severity of cartilage damage of the patella can significantly influence function after successful Oxford medial UKA. Surgeons should factor this in when making their operative decision, and undertake to counsel patients appropriately. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):11–15

With medial unicompartmental osteoarthritis (OA) there is occasionally a full-thickness ulcer of the cartilage on the medial side of the lateral femoral condyle. It is not clear whether this should be considered a contraindication to unicompartmental knee replacement (UKR). The aim of this study was to determine why these ulcers occur, and whether they compromise the outcome of UKR. Case studies of knees with medial OA suggest that cartilage lesions on the medial side of the lateral condyle are caused by impingement on the lateral tibial spine as a result of the varus deformity and tibial subluxation. Following UKR the varus and the subluxation are corrected, so that impingement is prevented and the damaged part of the lateral femoral condyle is not transmitting load. An illustrative case report is presented. Out of 769 knees with OA of the medial compartment treated with the Oxford UKR, 59 (7.7%) had partial-thickness cartilage loss and 20 (2.6%) had a full-thickness cartilage deficit on the medial side of the lateral condyle. The mean Oxford Knee Score (OKS) at the last follow-up at a mean of four years was 41.9 (13 to 48) in those with partial-thickness cartilage loss and 41.0 (20 to 48) in those with full-thickness loss. In those with normal or superficially damaged cartilage the mean was 39.5 (5 to 48) and 39.7 (8 to 48), respectively. There were no statistically significant differences between the pre-operative OKS, the final review OKS or of change in the score in the various groups. We conclude that in medial compartment OA, damage to the medial side of the lateral femoral condyle is caused by impingement on the tibial spine and should not be considered a contraindication to an Oxford UKR, even if there is extensive full-thickness ulceration of the cartilage

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To explore the novel molecular mechanisms of histone deacetylase 4 (HDAC4) in chondrocytes via RNA sequencing (RNA-seq) analysis.

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Adenosine, lidocaine, and Mg²⁺ (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.

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To assess the incidence of radiological lateral osteoarthritis (OA) at 15 years after medial unicompartmental knee arthroplasty (UKA) and assess the relationship of lateral OA with symptoms and patient characteristics.

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Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters.