Validation of a new meniscal root repair technique that will be biomechanically superior to current gold standard procedures and, at the same time, will allow controlled adjustable fixation. Medial and lateral meniscus from 10 porcine knees were collected. An iatrogenic posterior root tear was created and a single transosseous tibial tunnel technique that closely replicates the repair procedure with a 2-mm-wide-knottable braided tape was performed. Randomly, in one group (A) two simple cinch stitch were applied to suture the posterior root of the meniscus and, in the other group (B), a simple stich that holds the meniscus in two points in a crosse match configuration was used. For final fixation, alternating surgeon's knots (A group) and a doubled suture knot that allows an adjustable fixation were used (B group). All repairs were standardized for location and the repair stiches were placed in the body of the meniscus. The new suture configuration (B group) showed a better biomechanical performance in terms of load for both the medial [151,0-560,3] 306,9±173,8N and the lateral posterior root fixation [268,2-463,1] 347,4±74,3N in comparison to the cinch stitch (A group) [219,0-365,2] 268,9±58,7N and [219,0-413,6] 318,0±72N. The maximum stiffness was also higher for the new tested suture configuration (B group) for both the medial meniscus [10,6-34,5] 18,9±9,2N/mm vs [7,1-12,7] 10,9±2,2N/mm and the lateral meniscus [16,0-27,9] 21,6±5,5N/mm vs [7,6-15,6] 12,6±3,5N/mm. The presented new meniscal root repair is biomechanically superior to current gold standard techniques, as the cinch stich made with tape, keeping the simplicity and reproducibility of the procedure and, at the same time, is economically advantageous since a single tape in needed and allows adjustable fixation of the repair over a button

To ensure clinical relevance, the in vitro engineering of tissues for implantation requires artificial replacements to possess properties similar to native anatomy. Our overarching study is focussed on developing a bespoke bone-tendon in vitro model replicating the anatomy at the flexor digitorum profundus (FDP) tendon insertion site at the distal phalanx. Anatomical morphometric analysis has guided FDP tendon model design consisting of hard and soft tissue types. Here, we investigate potential materials for creation of the model's bone portion by comparison of two bone cements; brushite and genex (Biocomposites Ltd). 3D printed molds were prepared based on anatomical morphometric analysis of the FDP tendon insertion site and used to cast identical bone blocks from brushite and genex cements. Studies assessing the suitability of each cement type were conducted e.g. setting times, pH on submersion in culture medium and interaction with fibrin gels. Data was collected using qualitative imaging and qualitative measurements (N=3,n=6) for experimental conditions. Both brushite (BC) and genex (GC) cements could be cast into bespoke molds, producing individual blocks and were mixed/handled with appropriate setting times. On initial submersion in culture medium, BC caused a reduction in pH values (7.49 [control]) to 6.85) while GC remained stable (7.59). Reduction in pH value also affected fibrin gel interaction where gel was seen to be detaching/not forming around BC and medium discolouration was noted. This was not observed in GC. While GC outperformed BC in initial tests, repeated washing of BC led to pH stabilisation (7.5,3xwashes), consistent with their further use in this model. This study has compared BC and GC as materials for bone block production. Both materials show promise, and current work assessing material properties and cell proliferation are needed to inform our choice for use in our FDP-tendon-bone interface model. This research was supported by an ORUK Studentship award (ref:533). Genex was kindly provided by Biocomposites, Ltd

Abstract. Introduction. Ultrasonic cutting in surgery has great potential. However, a key limitation is heat created by friction between the bone and the blade. Bone has poor thermal conductivity which hinders the dissipation of heat, causing cell death near the cut site In addition, ultrasonic vibration may create microcracks. It was hypothesised that these effects on bone would vary with the frequency and displacement of the ultrasonically powered blade. Therefore varying frequencies and displacements of the tip of the blade were studied to find the combination with fewest microcracks and lowest temperature rise at the bone-tool interface. Aim. To explore the effect of different frequencies and tip displacements of ultrasonic cutting devices on the amount of thermal and mechanical damage. Methods. In vitro tests were conducted on fresh rat femoral shafts using two different frequencies; 20kHz and 35kHz.Two displacement amplitudes of two different frequencies were used: 23.9 μm (p-p) and 7.5 μm (p-p) both at 20kHz and 18.7 μm (p-p) and 27 μm (p-p) both at 35kHz and. Cooling was used to emulate clinical conditions. Histological examination (H & E and TUNEL) was performed to identify live and dead cells. Further rat femoral shafts (n=6) were exposed to the same number of cuts by each tool to identify any micro-damage induced by different electrical currents using Micro-CT and confocal Laser scanning microscope. All experimental data were expressed as mean ± standard deviation. Statistical analysis was performed using one-way ANOVA, followed by Post Hoc multiple comparisons test. Differences between groups were considered statistically significant at p < 0.05. Results. The cut site at 7.5 μm (p-p) in 20kHz displayed only indentation instead of a cut, and was excluded. Histological examination revealed a high incidence of cell death at the cutting edge, in both frequencies. At 35kHz and 27 μm (p-p) some charring was evident, while at 20kHz and 23.9 μm (p-p) more irregularities were seen on the surface of the cut indicating instability during cutting when this setting was used. In contrast, the 35kHz at 18.7 μm (p-p) resulted in a smoother cutting surface. The highest cell death percentage ranged from 25% (at 35kHz, 18.7 μm (p-p)) to 44 % (at 35kHz, 27 μm (p-p)). Most of the tool's effect was located within 25 µm of the cut surface. There was a significant decrease to < 5 % at 200 µm. No cell death was found over 200 µm from the cut surface in both frequencies (35 kHz and 20 kHz). No significant difference in total percentage cell death was found between cutting at 35kHz and 18.7 μm (p-p) and at 20kHz and 23.9 μm (p-p). No microcracks were detected along the depth of the cut site at either frequency. Conclusion. Of the 2 ultrasonic cutting frequencies tested, the combination of the higher vibration frequency (35kHz) and the lower displacement amplitude (18.7 μm (p-p) demonstrated least damage to the bone tissue. No microcracks were displayed when using either of the ultrasonic cutting frequencies. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction and Objective. Despite pure alumina have shown excellent long-term results in patients undergoing total hip arthroplasty (THA), alumina matrix composites (AMCs) composed of alumina and zirconium oxide are more commonly used. There are no comparative studies between these two different ceramics. We performed a retrospective case-control study to compare results and associated complications between AMC from two manufacturers and those with pure alumina from another manufacturer. Materials and Methods. 480 uncemented THAs with ceramic on ceramic (CoC) bearing surfaces (288 men and 192 women; mean age of 54.1 ± 12.4 years), were implanted from 2010 to 2015. Group 1: 281 THAs with pure alumina; Group 2A: 142 with AMC bearing in a trabecular titanium cup. Group 2B: 57 hips with AMC bearing with a porous-coated cup. Results. The mean follow-up was 7.3 years. There was one late infection in group 1, eight dislocations, three in group 1 (1.1%), three in group 2A (2.1%), all with a 36 mm femoral head, and two in group 2C (3.5%). Liner malseating was found in one hip in group 1, and in five hips in group 2C, of these, there were four liner fractures (7.0%). Four cups were revised for iliopsoas impingement (three in group 1 and one in group 2B). Two cups were revised for aseptic loosening, one in group 1 and one in group 2A, and four revised femoral stems in group 2A, three for subsidence and another for postoperative periprosthetic B. 2. fracture. The mean preoperative Harris Hip Score was 48.6 ± 3.3 in the whole series and 93.9 ± 7.2 at the end of follow-up. The survival rate of revision for any cause was 98.2% (95% Confidence Interval: 96.6–99.8) at ten years for group 1, 95.8% (95% CI: 92.1–99.5) for group 2A, and 91.1% (95% CI: 83.7–98.5) for group 2B (log-rank 0.030). Conclusions. Outcome of uncemented CoC THA in young patients was satisfactory at mid-term in all three groups. However, liner fractures were frequent in group 2B. All dislocated hips in group 2A had a 36 mm femoral head diameter, and revision due to any cause was less frequent in group 1. Pure alumina CoC THA can be used as a benchmark for comparison with newer CoC THAs

Meniscal tears are the most common injury in the knee, affecting 66/100,000 people/year. Surgical treatment includes arthroscopic meniscectomy or meniscal repair. Little is known regarding medium-term outcomes following these procedures in isolated meniscal tears. This study aims to quantitatively evaluate patients with meniscal tears, and those who have undergone meniscectomy and meniscal repair using validated patient reported outcome measures (PROMs), further exploring factors which affect surgical outcomes.

This observational study screened 334 patients who underwent arthroscopic surgery at South Tyneside Hospital since August 2013. 134 patients with isolated meniscal tears were invited to complete postal PROMs. A combination of patient notes and radiological imaging was used to collect information of interest including age, gender, knee-laterality, injured meniscus, tear pattern, procedure performed, complications, and associated injuries.

A total of 115 patients (pre-operative patients with current meniscal tear (n=36), meniscectomy (n=63), meniscal repair (n=16)) were included in the analysis with 96% successful PROM completion. Both meniscectomy and meniscal repairs (mean 55-months follow-up) showed better outcomes than pre-operative patients with meniscal tears. Meniscal repairs demonstrated superior outcomes across all PROMs when compared to meniscectomy, with a greater mean overall KOOS score of 17.2 (p=0.009). Factors including higher pre-operative Kellgren-Lawrence Grade, pre-operative articular cartilage lesions and bilateral meniscectomies were shown to negatively influence outcomes.

Both meniscectomy and meniscal repair maintain clinical benefit at mean 55-months follow-up, affirming their use for treatment of meniscal tears. When feasible, meniscal repair should be performed preferentially over meniscectomy in isolated meniscal tears. Identified predictive factors allow adequate treatment stratification in specific patient groups.

Introduction

Anterior shoulder instability results in labral and osseous glenoid injuries. With a large osseous defect, there is a risk of recurrent dislocation of the joint, and therefore the patient must undergo surgical correction. An MRI evaluation of the patient helps to assess the soft tissue injury. Currently, the volumetric three-dimensional (3D) reconstructed CT image is the standard for measuring glenoid bone loss and the glenoid index. However, it has the disadvantage of exposing the patient to radiation and additional expenses. This study aims to compare the values of the glenoid index using MRI and CT.

The pelvic girdle and spine vertebral column work as a long chain influenced by pelvic tilt. Spinal deformities or other musculoskeletal conditions may cause patients to compensate with excessive pelvic tilt, producing alterations in the degree of lumbar lordosis and subsequently causing pain. The objective of this study is to assess the effect of open and closed chain anterior or posterior pelvic tilt on lumbar spine kinematics using an in vitro cadaveric spine model.

Three human cadaveric spines with intact pelvis were suspended with the skull fixed in a metal frame. Optotrak 3D motion system tracked real-time coordinates of pin markers on the lumbar spine. A force-torque digital gage applied consistent force to standardize the acetabular or sacral axis’ anterior and posterior pelvic tilt during simulated open and closed chain movements, respectively.

In closed chain PPT, significant differences in relative intervertebral compression existed between L1/L2 [-2.54 mm] and L5/S1 [-11.84 mm], and between L3/L4 [-2.78 mm] and L5/S1 [-11.84 mm] [p <.05]. In closed chain APT, significant differences in relative intervertebral decompression existed between spinal levels L1/L2 [2.87mm] and L5/S1[24.48 mm] and between L3/L4 [2.94 mm] and L5/S1 [24.48 mm] [p <.05]. In open chain APT, significant differences in relative intervertebral decompression existed between spinal levels L4/L5 [1.53mm] and L5/S1 [25.14 mm] and between L2/L3 [1.68 mm] and L5/S1 [25.14 mm] [p<.05 for both]. Displacement during closed chain PPT was significantly greater than during open chain PPT, whereas APT showed no significant differences.

In PPT, open chain pelvic tilts did not produce as much lumbar intervertebral displacement compared to closed chain. In contrast, APT saw no significant differences between open and closed chain. Additionally, results illustrate the increase in lumbar lordosis during APT and the loss of lordosis during PPT.

Screw fixation is an established method for anterior cruciate ligament (ACL) reconstruction, although with a high rate of implant-related complications. An allograft system for implant fixation in ACL reconstruction, the Shark Screw ACL (surgebright GmbH) could overcome some of the shortcomings of bioabsorbable screws, such as foreign body reaction, need for implant removal and imaging artefacts. However, it needs to provide sufficient mechanical stability. Therefore, the aim of this study was to investigate the biomechanical stability, especially graft slippage, of the novel allograft system versus a conventional bioabsorbable interference screw (BioComposite Interference Screw; Arthrex Inc.) for tibial implant fixation in ACL reconstruction.

Twenty-four paired human proximal tibiae (3 female, 9 male, 72.7 ± 5.6 years) underwent ACL reconstruction. The quadrupled semitendinosus and gracilis tendon graft were fixed in one specimen of each pair using the allograft fixation system Shak Screw ACL and the contralateral one using an interference screw. All specimens were cyclically loaded at 1 Hz with peak load levels monotonically increased from 50 N at a rate of 0.1 N/cycle until catastrophic failure. Relative movements of the graft versus the tibia were captured with a stereographic optical motion tracking system (Aramis SRX; GOM GmbH).

The two fixation methods did not demonstrate any statistical difference in ultimate load at graft slippage (p = 0.24) or estimated survival at slippage (p = 0.06). Both, the ultimate load and estimated survival until failure were higher in the interference screw (p = 0.04, and p = 0.018, respectively). Graft displacement at ultimate load reached values of up to 7.2 mm (interference screw) and 11.3 mm (Shark Screw ACL).

The allograft screw for implant fixation in ACL reconstruction showed similar behavior in terms of graft slippage compared to the conventional metal interference screw but underperformed in terms of ultimate load. However, the ultimate load may not be considered a direct indicator of clinical failure.

Abstract

Purpose

To compare postoperative clinical outcomes between posterior cruciate ligament (PCL) retaining and resecting total knee arthroplasty (TKA) using same cruciate-substituting (CS) inserts, and to elucidate the clinical relevance of the residual PCL in cruciate-retaining TKA, considering intraoperative influence factors, such as the posterior tibial slope, posterior condylar offset, joint gap, joint balance, and joint laxity.

During the COVID-19 pandemic, video/phone consultations (VPC) were increasingly utilised as an alternative to face-to-face (F2F) consultations, to minimise nosocomial viral exposure. We previously demonstrated that VPCs were highly rated by both patients and clinicians. This study compared satisfaction between both clinic modalities in contemporaneously delivered outpatient surveys. We also assessed the feasibility and effects of converting F2F orthopaedic consultations to VPC.

Surveys were posted to patients who attended VPCs and F2F consultations at a large tertiary centre from August to October 2020 inclusive, across 51 specialties. F2F and VPC patients ranked their overall satisfaction with their consultation on a 10-point numerical scale (10=highest satisfaction). Simultaneously, a pilot study was undertaken of outpatient fracture clinics to identify patients suitable for VPCs, with X-rays (if needed) taken and transferred from satellite sites to reduce tertiary centre footfall.

For F2F consultations, 1419 of 4465 surveys (31.8%) were returned with similar rates for VPCs (1332 of 4572, 29.1%). While mean satisfaction ratings were high for both clinic modalities, they were significantly higher for F2F: 9.13 (95% CI 9.05-9.22) for F2F clinics, compared to 8.23 (95% CI 8.11-8.35) for VPCs (p<0.001, t-test). F2F patients were almost four times more likely to state a preference for future F2F appointments compared to VPCs, whereas patients who attended VPCs showed an equal preference for either option (p< 0.001, chi2 test). 53% of 111 fracture clinic patients sampled were identified as suitable for VPCs. 1 patient (1.7%) requested their VPC to be converted to F2F due to poor symptom control.

Our study showed patients reported high satisfaction ratings for both F2F clinics and VPCs, with prior experience of VPCs affecting patients’ future preferences. Only 1.7% of F2F patients converted to VPCs declined their virtual appointment. Our results support future use of VPCs.

To compare the efficacy of intra-articular and intravenous modes of administration of tranexamic acid in primary total knee arthroplasty in terms of blood loss and fall in haemoglobin level.

Study Design: Randomized controlled trial.

Duration of Study: Six months, from May 2019 to Nov 2019.

Seventy-eight patients were included in the study. All patients undergoing unilateral primary total knee replacement were included in the study. Exclusion criteria were patients with hepatitis B and C, history of previous knee replacement, bilateral total knee replacement, allergy to TXA, Hb less than 11g/dl in males and less than 10g/dl in females, renal dysfunction, use of anticoagulants for 7 days prior to surgery and history of thromboembolic diseases. Patients were randomly divided into group A and B. Group A patients undergoing unilateral primary total knee replacement (TKR) were given intravenous tranexamic acid (TXA) while group B were infiltrated with intra-articular TXA. Volume of drain output, fall in haemoglobin (Hb) level and need for blood transfusion were measured immediately after surgery and at 12 and 24 hours post operatively in both groups.

The study included 35 (44.87%) male and 43 (55.13%) female patients. Mean age of patients was 61 ± 6.59 years. The mean drain output calculated immediately after surgery in group A was 45.38 ± 20.75 ml compared with 47.95 ± 23.86 ml in group B (p=0.73). At 24 hours post operatively, mean drain output was 263.21 ± 38.50 ml in intravenous group versus 243.59 ± 70.73 ml in intra-articular group (p=0.46). Regarding fall in Hb level, both groups showed no significant difference (p>0.05). About 12.82% (n=5) patients in group A compared to 10.26% (n=4) patients required blood transfusion post operatively (p=0.72).

Intra-articular and intravenous TXA are equally effective in patients undergoing primary total knee arthroplasty in reducing post-operative blood loss.

Autologous cancellous bone graft is the gold standard in large bone defect repair. However, studies using autologous bone grafting in rats are rare and donor sites as well as harvesting techniques vary. The aim of this study was to determine the feasibility of autologous cancellous bone graft harvest from 5 different anatomical sites in rats and compare their suitability as donor sites for autologous bone graft.

13 freshly euthanised rats were used to describe the surgical approaches for autologous bone graft harvest from the humerus, iliac crest, femur, tibia and tail vertebrae (n=4), determine the cancellous bone volume and microstructure of those five donor sites using µCT (n=5), and compare their cancellous bone collected qualitatively by looking at cell outgrowth and osteogenic differentiation using an ALP assay and Alizarin Red S staining (n=4).

It was feasible to harvest cancellous bone graft from all 5 anatomical sites with the humerus and tail being more surgically challenging. The microstructural analysis showed a significantly lower bone volume fraction, bone mineral density, and trabecular thickness of the humerus and iliac crest compared to the femur, tibia, and tail vertebrae. The harvested volume did not differ between the donor sites. All donor sites apart from the femur yielded primary osteogenic cells confirmed by the presence of ALP and Alizarin Red S stain. Bone samples from the iliac crest showed the most consistent outgrowth of osteoprogenitor cells.

The tibia and iliac crest may be the most favourable donor sites considering the surgical approach. However, due to the differences in microstructure of the cancellous bone and the consistency of outgrowth of osteoprogenitor cells, the donor sites may have different healing properties, that need further investigation in an in vivo study.

Total knee arthroplasty is a well-established treatment for degenerative joint disease, on the other hand metal ion release of cobalt or chromium and particle formation can trigger intolerance reactions. Biotribological examinations can help to assess the metal ion release in different settings. The purpose of this study was the evaluation of inter-laboratory differences in the metal ion concentration analysis. Samples were generated in a 3+1 station knee wear simulator (EndoLab GmbH, Thansau, Germany) with a medium size Columbus Knee System with or without AS multilayer coating. The wear simulation was performed under highly demanding activity (HDA) profile and samples were taken after 0.5, 5.0, 5.5. and 8.0 million cycles. The samples were blinded and sent to three different laboratories and the content of chromium, cobalt, molybdenum, nickel, and zirconium was assessed by inductively coupled plasma mass spectrometry (ICP-MS). The AS multilayer coating clearly reduced the release of chromium, cobalt and molybdenum. Mean levels were: Chromium 9329.78µg/l ± 985.44 vs 503.75µg/l ± 54.19, cobalt 10419.00µg/l ± 15.517.53 vs 2.60µg/l ± 1.35, molybdenum 2496.33µg/l ± 102.62 vs 2.46µg/l ± 2.31. Interestingly we found especially for nickel and zirconium big inter-laboratory differences in the metal assessment. There were up to 10-fold higher values in comparison of one laboratory to another. The data demonstrate that results of metal ion assessment should be evaluated by interlaboratory comparison and should be critically interpreted

Deriving autologous mesenchymal stem cells (MSCs) from adipose tissues without using enzymes requires sophisticated biomedical instruments. Applied pressure on tissues and cells are adjusted manually although centrifugation and filtration systems are frequently used. The number of derived MSCs therefore could differ between instruments. We compared the number of MSCs obtained from four commercially available devices and our newly designed and produced instrument (A2, B3, L3, M2 and T3). Three-hundred mL of adipose tissue was obtained from a female patient undergoing liposuction using the transillumination solution. Obtained tissue was equally distributed to each device and handled according to the producers' guides. After handling, 3 mL stromal vascular fraction (SVF) was obtained from each device. Freshly isolated SVF was characterized using multi-color flow cytometry (Navios Flow Cytometer, Beckman Coulter, USA). Cell surface antigens were chosen according to IFATS and ISCT. CD31-FITC, CD34-PC5,5, CD73-PE, CD90-PB and CD45-A750 (Backman Coulter, USA) fluorochrome-labeled monoclonal antibodies were assessed. Markers were combined with ViaKrome (Beckman Coulter, USA) to determine cell viability. At least 10⁵ cells were acquired from each sample. A software (Navios EX, Beckman Coulter, USA) was used to create dot plots and to calculate the cell composition percentages. The data was analyzed in the Kaluza 2.1 software package (Beckman Coulter, USA). Graphs were prepared in GraphPad Prism. CD105 PC7/CD31 FITC cell percentages were 23,9%, 13,5%, 24,6%, 11,4% and 28,8% for the A2, B3, L3, M2 and T3 devices, respectively. We conclude that the isolated MSC percentage ranged from 11,4% to 28,8% between devices. The number of MSCs in SVF are key determinants of success in orthobiological treatments. Developing a device should focus on increasing the number of MSCs in the SVF while preserving its metabolic activity.

Acknowledgments: Scientific and Technological Research Council of Türkiye (TÜBİTAK)- Technology and Innovation Funding Program Directorate (TEYDEB) funded this project (#321893). Servet Kürümoğlu and Bariscan Önder of Disposet Ltd., Ankara, Türkiye (www.disposet.com) contributed to the industrial design and research studies. Ali Tuncel and Feza Korkusuz are members of the Turkish Academy of Sciences (TÜBA). Nilsu Baysal was funded by the STAR Program of TÜBITAK Grant # 3210893.

Background. Innovative developments for total knee arthroplasty enhanced anatomical design and fixation in order to decrease particle-induced aseptic implant loosening. As hypersensitivity reactions to metallic implant materials have been recognized to possibly cause premature implant failure, ceramic materials might constitute a proper alternative solution. The aim of this prospective short-term study was the initial comparison of a completely metal-free ceramic with a geometrically identical metallic arthroplasty over a one-year follow-up period. Methods. Eighty patients requiring primary total knee arthroplasty were enrolled within this open-label prospective comparative study. Patients were randomly divided among two groups to either undergo implantation of a completely metal-free system using a composite matrix material containing aluminum oxide (Al2O3) and zirconium oxide (ZrO2) (n=40), or an anatomically identical metallic knee system made of a cobalt-chromium alloy (Co28Cr6Mo) (n=40) produced by the same manufacturer. Clinical assessment was performed preoperatively, and during follow-up at three and twelve months using the Knee Society Score, Oxford Knee Score and EQ-5D-VAS. For radiological evaluation, standard preoperative and postoperative standardized radiographs were taken at mentioned follow-up visits. Results. Demographical data were not significantly different among our two study groups, and no patient has been lost to follow-up. The postoperative clinical scores improved significantly at three and twelve month follow-ups, but did not differ statistically among groups. The radiologically evaluated mean postoperative mechanical and anatomical axes showed proper alignment within both groups at all times. Notably, no revision surgery had to be performed, and no complications were recorded whatsoever. Conclusion. To our knowledge, this is the first study comparing a total ceramic metal-free knee system with a geometrically identical metallic TKR. Within the short-term follow-up of minimally one year, no significant differences could be demonstrated clinically or radiologically, therefore making this ceramic knee system a suitable option for patients with a known hypersensitivity to metal. Mid-term and long-term studies will be required to demonstrate the overall efficiency of this TKR to potentially expand its medical indication

Objectives. In this study, we compared the pain behaviour and osteoarthritis (OA) progression between anterior cruciate ligament transection (ACLT) and osteochondral injury in surgically-induced OA rat models. Methods. OA was induced in the knee joints of male Wistar rats using transection of the ACL or induction of osteochondral injury. Changes in the percentage of high limb weight distribution (%HLWD) on the operated hind limb were used to determine the pain behaviour in these models. The development of OA was assessed and compared using a histological evaluation based on the Osteoarthritis Research Society International (OARSI) cartilage OA histopathology score. Results. Both models showed an increase in joint pain as indicated by a significant (p < 0.05) decrease in the values of %HLWD at one week post-surgery. In the osteochondral injury model, the %HLWD returned to normal within three weeks, while in the ACLT model, a significant decrease in the %HLWD was persistent over an eight-week period. In addition, OA progression was more advanced in the ACLT model than in the osteochondral injury model. Furthermore, the ACLT model exhibited a higher mean OA score than that of the osteochondral injury model at 12 weeks. Conclusion. The development of pain patterns in the ACLT and osteochondral injury models is different in that the OA progression was significant in the ACLT model. Although both can be used as models for a post-traumatic injury of the knee, the selection of appropriate models for OA in preclinical studies should be specified and relevant to the clinical scenario. Cite this article: T. Tawonsawatruk, O. Sriwatananukulkit, W. Himakhun, W. Hemstapat. Comparison of pain behaviour and osteoarthritis progression between anterior cruciate ligament transection and osteochondral injury in rat models. Bone Joint Res 2018;7:244–251. DOI: 10.1302/2046-3758.73.BJR-2017-0121.R2

There are few studies that have compared between continuous flexion activities and extension activities of normal knees. The purpose of this study is to compare in vivo kinematic comparison of normal knees between flexion activities and extension activities. Total of 8 normal male knees were investigated. We evaluated in vivo three-dimensional kinematics using 2D/3D registration technique. We compared femoral rotation angle relative to tibia, anterior/posterior (AP) translation of medial femoral sulcus (medial side) and lateral femoral epicondyle (lateral side) onto tibial plane perpendicular to tibial functional axis between flexion activities (F groups) and extension activities (E groups). Femoral external rotation was observed with the knee bending during both groups. The external rotation angle of F group was larger than that of E group significantly from 20 to 30 degrees with flexion (p < 0.05). Regarding medial side, anterior translation was observed up to 40 degrees in F group. From 40 to 140 degrees, posterior translation was observed. In E group, anterior translation was observed from 140 to 40 degrees with extension. From 40 degrees, posterior translation was observed. From 30 to 40 degrees, F group located anterior than E group (p < 0.05). Regarding lateral side, posterior translation was observed with flexion in F group. On the other hand, anterior translation was observed with extension in E group. Regarding AP location with flexion angle, there was no significant difference between two groups. In conclusion, there were different kinematics between flexion activities and extension activities

Introduction and Objective

Scapholunate instability is the most common cause of carpal instability. When this instability is left untreated, the mechanical relationship between the carpal bones is permanently disrupted, resulting in progressive degenerative changes in the radiocarpal and midcarpal joints. Different tenodesis methods are used in the treatment of acute or early chronic reducible scapholunate instability, where arthritis has not developed yet and the scapholunate ligament cannot be repaired. Although it has been reported that pain is reduced in the early follow up in clinical studies with these methods, radiological results differ between studies. The deterioration of these radiological parameters is associated with wrist osteoarthritis as previously stated. Therefore, more studies are needed to determine the tenodesis method that will improve the wrist biomechanics better and will last longer. In our study, two new tenodesis methods, spiral antipronation tenodesis, and anatomic front and back reconstruction (ANAFAB) were radiologically compared with triple ligament tenodesis (TLT), in the cadaver wrists.

Introduction and Objective

Interest for direct anterior approach (DAA) in hip hemiarthroplasty (HHA) has greatly increased in recent years, however which is the best surgical approach in hip replacement treating femoral neck fractures (FNFs) is already unclear. The aim of this study is to perform a radiographic and perioperative complications analysis by comparing the direct anterior approach (DAA) with the direct lateral approach (DLA) in patients treated with hemiarthroplasty for FNFs.