To describe clinical situations for use of modified VAC in POC based on: diagnosis, comorbidities, BMI, wound size in cm, days following trauma when VAC was first applied, total duration of uninterrupted use, frequency of change, settings, bacterial growth, outcomes. To report the outcomes of mVAC use in POC within 6 months to help improve and standardize its application in the institution. This study involves data gathering from inpatients handled by orthopedic surgeons in training and subspecialty rotations in POC. The data collected are highly dependent on the doctors-in-charge's complete charting, thorough reporting and accurate documentation. Modified Vacuum Assisted Closure (mVAC) is used frequently in this study and is defined as a form of revised, adapted and reformed use of VAC based on available materials in the involved institution. The materials that are included are, but not limited to the following: sterile Uratex™ blue foam, nasogastric or suction tubing, phlegm suction machine, Bactigras™ and Opsite™ or Ioban™. A total of 58 patients were included in the study. The average age of the population was 35 and are predominantly male. The most common mechanism of injury was motorcycle accident and 37 of the patients were diagnosed with an open fracture of the lower extremity with open tibia fractures (22) being the most common. Average wound area measured was 24.12 cm. 3. All patients yield a bacteria growth with e. coli being the most frequent. Average during of uninterrupted use was 39 days. Of the 58 included in the study, 8 patients underwent STSG, 2 had a flap coverage surgery, 4 patients eventually underwent amputation and 33 with complete resolution of soft tissue defect after conversion to biologic dressing post-mVAC. The rest of the population were still ongoing mVAC at the end of the study. mVAC is an alternative temporary medium for soft tissue coverage for cases with or without concomitant fractures. mVAC promotes removal of exudate from the wound, supports wound apposition and granulation bed proliferation. Usage mVAC helps prepare for skin coverage procedure and on some cases leads to full resolution of defect

There is no consensus on how to evaluate and grade pin site infection. A precise, objective and reliable pin site infectious score is warranted. The literature was reviewed for pin site infection classification systems, The Modified Gordon Score (MGS) grade 0-6 was used. The aim was to test the reliability of The Modified Gordon Infection Score. The observed agreement and inter-rater reliability were investigated between nurse and doctors. MGS was performed in the outpatient clinic at Aalborg University Hospital, Denmark on 1472 pin sites in 119 patients by one nurse and one of three orthopaedic surgeons blinded to each other's judgement. The data was stored in a Red Cap Database for further statistical analysis. The observed agreement between the nurse and the 3 orthopaedic surgeons was evaluated with a one-way random-effect model with interclass correlation with absolute agreement. Furthermore the observed agreement for each of the 3 surgeons with the nurse was calculated. The distribution of MGS infection grade in the 1472 pin sites was: Grade 0; n=1372, Grade 1; n=32, Grade 2; n=39, Grade 3; n=24, Grade 4; n=5, Grade 5; n=0, Grade 6; n=0. The observed agreement between the nurse and the surgeons was calculated as 98%. The ICC estimated between nurse and the surgeons was 0,8943 (ICC >0,85 = reliable). The grading was done by three different doctors with an agreement with the nurse as follows. Rater1 (n=416) =99,5 %, Rater2 (n=1440) =97,4%, Rater3 (n=1440) =96,6%. A limitation to this study is that the dataset represents mostly clean pin sites with MGS 0. Only 100 pin sites had signs of superficial infection MGS 1-4 none above 4. We found that the MGS infection score is highly reliable for low grade infections but we cannot conclude on reliability in severe infections

To validate the Modified Forgotten Joint Score (MFJS) as a new patient-reported outcome measure (PROM) in hip and knee arthroplasty against the UK's gold standard Oxford Hip and Knee Scores (OHS/OKS). The original Forgotten Joint Score was created by Behrend et al to assess post-op hip/knee arthroplasty patients. It is a new assessment tool devised to provide a greater discriminatory power, particularly in the well performing patients. It measures an appealing concept; the ability of a patient to forget about their artificial joint in everyday life. The original FJS was a 12-item questionnaire, which we have modified to 10-items to improve reliability and missing data. Postal questionnaires were sent out to 400 total hip/knee replacement (THR/TKR) patients who were 1–2 years post-op, along with the OHS/OKS and a visual pain analog score. The data collected from the 212 returned questionnaires (53% return rate) was analysed in relation to construct and content validity. A sub-cohort of 77 patients took part in a test-retest repeatability study to assess reliability of the MFJS. The MFJS proved to have an increased discriminatory power in high-performing patients in comparison to the OHS and OKS, highlighted by its more normal frequency of distribution and reduced ceiling effects in the MFJS. 30.8% of patients (n=131) scored 42–48 (equivalent to 87.5–100 in the MFJS) or more in the OKS compared to just 7.69% in the MFJS TKR patients. The MFJS proved to have an increased test-retest repeatability based upon its intra-class correlation coefficient of 0.968 compared to the Oxford's 0.845. The MFJS provides a more sensitive tool in the assessment of well performing hip and knee arthroplasties in comparison to the OHS/OKS. The MFJS tests the concept of awareness of a prosthetic joint, rather than pain and function and therefore should be used as adjunct to the OKS/OHS

Bone morphogenetic proteins (BMPs) have been widely investigated for treating non-healing fractures. They participate in bone reconstruction by inducing osteoblast differentiation, and osteoid matrix production.¹ The human recombinant protein of BMP-7 was among the first growth factors approved for clinical use. Despite achieving comparable results to autologous bone grafting, severe side effects have been associated with its use.² Furthermore, BMP-7 was removed from the market.³ These complications are related to the high doses used (1.5-40 miligrams per surgery)² compared to the physiological concentration of BMP in fracture healing (in the nanogram to picogram per milliliter range).⁴ In this study, we use transcript therapy to deliver chemically modified mRNA (cmRNA) encoding BMP-7. Compared to direct use of proteins, transcript therapy allows the sustained synthesis of proteins with native conformation and true post-translational modifications using doses comparable to the physiological ones.⁵ Moreover, cmRNA technology overcomes the safety and affordability limitations of standard gene therapy i.e. pDNA.⁶ BMP-7 cmRNA was delivered using Lipofectamine™ MessengerMAX™ to human mesenchymal stromal cells (hMSCs). We assessed protein expression and osteogenic capacity of hMSCs in monolayer culture and in a house-made, collagen hydroxyapatite scaffold. Using fluorescently-labelled cmRNA we observed an even distribution after loading complexes into the scaffold and a complete release after 3 days. For both monolayer and 3D culture, BMP-7 production peaked at 24 hours post-transfection, however cells transfected in scaffolds showed a sustained expression. BMP-7 transfected hMSCs yielded significantly higher ALP activity and Alizarin red staining at later timepoints compared to the untransfected group. Interestingly, BMP-7 cmRNA treatment triggered expression of osteogenic genes like OSX, RUNX-2 and OPN, which was also reflected in immunostainings. This work highlights the relevance of cmRNA technology that may overcome the shortcomings of protein delivery while circumventing issues of traditional pDNA-based gene therapy for bone regeneration.

Acknowledgement: This work has been performed as part of the cmRNAbone project and has received funding from the European Union's Horizon 2020 research and innovation programme under the Grant Agreement No 874790.

Introduction. Curved varus intertrochanteric osteotomy of the femur is an excellent and minimally invasive method for the treatment of osteonecrosis of the femoral head or osteoarthritis of the hip for joint preservation. However, the early postoperative complications of this procedure may be due to separation at the osteotomy site and an increase in varus angle due to early partial weight bearing. Methods. We modified the curved varus intertrochanteric osteotomy of the femur by performing an additional rotation. Regarding the surgical technique, curved varus osteotomy is performed at an angle of 30 degrees to the femoral shaft and an additional rotational osteotomy is also performed at an angle of 15 or 20 degrees to the osteotomy plane. Partial weight bearing with one-third body weight is permitted 3 weeks after surgery. Results. Curved varus intertrochanteric osteotomy of the femur was designed for developmental dysplastic hip by Nishio in 1969 and reported to have good outcomes in 1971. An important feature of this method is that the incidence of high riding of the greater trochanter or shortening of leg length is less than that in varus intertrochanteric osteotomy. Moreover, good contact at the osteotomy site and less lateral shift of the femoral shaft is observed. However, we have experienced a case of separation at the osteotomy site and increase of the varus angle in our hospital. Previous reports recommended that partial weight bearing with one-third body weight should be initiated after 5 weeks and full weight bearing after 6 months because the contact area is decreased at the osteotomy site by varus osteotomy. The post-operative recovery of the patients with total hip arthroplasty is rapid, therefore, we must consider important issues such as initiating the rehabilitation program early and reducing the duration of hospitalization. As per our experience, we think that partial weight bearing with one-third body weight should be initiated at 3 weeks. At the osteotomy site, we rotated the nearest bone segment to move it such that it intersects the proximal and distal bone cortex. Therefore, the osteotomy site will be stabilized and will have the ability to endure load. Another feature of this technique is that the partial removal of the necrotic area leads to an increase in the healthy load-bearing area. A limitation of this method is that an angle of an additional rotation is up to 30 degrees, because the joint capsule cannot be incised circumferentially and the short external rotator tendons should also be preserved. Conclusion. Modified curved varus intertrochanteric osteotomy is a useful method for the prevention of increased degree of a varus angle as well as for obtaining more intact area of femoral head in osteonecrosis

Abstract

Introduction. The purpose of this study was to evaluate the functional and radiographical results in patients who underwent a modified minimally invasive two-incision total hip arthroplasty using large-diameter metal-on-metal articulations for osteonecrosis of the femoral head. Methods. From December 2007 to July 2008, 45 hips (33 patients) underwent total hip arthroplasty for the treatment of osteonecrosis of the femoral head. There was 1 woman (2 hips) and 32 men (43 hips) who had a mean age of 39 years (range, 22 to 64 years). The minimum follow-up was 12 months (range, 12 to 19 months). The authors modified the original minimally invasive two-incision total hip arthroplasty technique and used large-diameter metal-on-metal articulations. In the lateral position, an anterolateral approach was used between the gluteus medius and tensor fascia lata muscles and for the posterior approach the muscle plane was between the piriformis and gluteus medius muscles. The acetabular components, Durom¯ (Zimmer) in 20 hips and Magnum¯ (Biomet) was used in 25 hips. M/L taper¯ (Zimmer) femoral stems were used in all cases. The size of the femoral heads were 38 mm (1 hip), 40 mm (3 hips), 42 mm (13 hips), 44 mm (18 hips), 46 mm (5 hips), 48 mm (4 hips) and 50 mm (1 hip). Postures such as excessive flexion or adduction which cause dislocation were not restricted, post-operatively. Functional results were measured by Harris hip scores (HHS), WOMAC scores, and range of motion. Radiographic evaluation was assessed for positions of components and post-operative complications were noted. Results. Mean operation time was 72 minutes (range, 54 to 94 minutes). The mean Harris hip score improved from 50 points (range, 38 to 73 points) pre-operatively to 96 points (range, 84 to 100 points) post-operatively, and the mean WOMAC score improved from 68 points (range, 50 to 93 points) to 28 points (range, 26 to 34 points). The mean flexion improved from 85° pre-operatively to 122° post-operatively. The mean internal rotation improved from 2.5° pre-operatively to 25.3° post-operatively. The mean external rotation improved from 31.8° pre-operatively to 60.1° post-operatively. The mean abduction improved from 24.0° pre-operatively to 41.6° post-operatively. The mean adduction improved from 19.4 ° pre-operatively to 26.6° post-operatively. All patients were able to sit cross legged and squat. On radiological evaluation, the mean lateral opening angle of the acetabular component was 39.4° (range, 32.2°-48.5°) and the mean stem position was valgus 0.3° (range, varus 2.8° to valgus 2.0°). At last follow-up, all femoral and acetabular components were well-fixed without loosening or subsidence. There were no complications such as dislocation, immediate post-operative deep infection or delayed infection. Conclusion. Modified minimally invasive two-incision total hip arthroplasty using large-diameter metal-on-metal articulations for osteonecrosis of the femoral head results in satisfactory early clinical and radiologic results

Musculoskeletal disorders is one of most important health problems human population is facing includes. Approximately 310 thousand of hip protheses have been used in 45 years and older patients in total according to the recent studies have been done. [1, 2]. Many factors, including poor osseointegration or relaxation of the implant due to stress, limit the life of the load-bearing implants [3]. To overcome these difficulties and to protect metal implants inside the body, the surfaces of the implants were coated with silver ion doped hydroxyapatite/bioglass. In this study, silver doped hydroxyapatite ceramic powder and 6P57 bioglass were synthesized. Two different coating suspensions, 100% bioglass and 70% Ag-HAp / 30% bioglass, were prepared in methyl alcohol with a solid content of 1% by weight.

Two layers were coated on the external fixator nails by using electrospray method with the bioglass and Ag-Hap/Bioglass suspensions respectively. The coated implants were cut with an equal surface area and kept in human blood plasma for different time. The scanning electron microscopy (SEM, Zeiss Supra 50VP and Zeiss Evo 50EP) and stereo microscope (Zeiss Axiocam Stemi 2000-C) were used to characterize microstructure and thickness of coated surface. Energy dispersive X-ray Spectroscopy was used characterized of chemical composition of coating. Changing of pH value of plasma was measured by pH meter (Hanna HI83414). In addition, the ICP method was used to determine the elements contained in the plasma fluid after dissolution. As a result of this study, physical and chemical changes occurring on the coating surface in different time periods are presented in detail

Abstract

Abstract

The large bone defects with high risk of delayed bone union and pseudoarthrosis remain significant clinical challenge. Aim of the present study was the investigation of the critical size fracture healing process in transgenic mice using a novel beta-TCP scaffold. The luciferase transgenic mice strains (BALB/C-Tg(NF-kappaB-RE-luc)-Xen) and FVB/N-Tg(Vegfr2-luc)-Xen were used. Critical size fracture on femur was performed and stabilized using external fixation (RISystem). The fracture was bridged with a synthetic scaffold with and without Strontium. In consequence, the expression levels of NF-kappaB and VEGFR2 could be monitored in a longitudinal fashion using the Xenogen imaging system for two months. Animals were euthanized, serial section of femur were prepared, and the fracture sites were histologically examined. Sr reduced inflammation in the early phase of healing (15th days), but it was increased in the late healing stage. The level of VEGFR2 activity increases in the Sr doped beta-TCP group at the 15th day, the luciferase activity starts to decrease in this group and show significantly less activity compared to other groups in the second half. In the group without scaffold a connective tissue formation were observed. In both, beta-TCP and beta-TCP+Sr, the connection of newly formed tissue within integrated canals in scaffold was visible. Tissue formation in beta-TCP+Sr group was significantly higher than in the beta-TCP group, whereas the percentage of osseous tissue in relation to the newly formed tissue was in beta-TCP scaffold much more than in beta-TCP+ Sr groups. This study presents the first data regarding VEGFR2 and NF-kappB and angiogenesis activity profiles during fracture healing. The collected longitudinal data reduces the number of experimental animals in the study. Addition of strontium in scaffolds influenced the inflammation in different stage of the healing. This effect might influence the healing process and may prove to be advantageous for osteoporosis fracture healing.

The modified Hedgehog technique was previously used to reattach pure chondral shear-off fragments in the pediatric knee. In the modified Hedgehog technique, the calcified side of chondral fragments is multiple times incised and trimmed obliquely for an interlocking fit in the defect site. Fibrin glue with or without sutures is subsequently applied to fix the fragment to the defect. This preliminary report further elucidates the potential of the technique by evaluation of its application in young adults using patient reported outcome measures (PROMs) and high-field Magnetic Resonance Imaging (MRI) as outcome measures. Three patients with a femoral cartilage defect (2 medial, 1 lateral), and a concomitant pure chondral corpus liberum were operatively treated by the modified Hedgehog technique. Age at surgery ranged from 20.6–21.2 years, defect size ranged from 3.8–6.0 cm2. Patients were evaluated at three months and one year after surgery by PROMs and 7.0T MRI. PROMs included the Internation Knee Documentation (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS) and Visual Analog Scale (VAS) questionnaires. 7.0T MRI (Magnetom, Siemens Healthcare, Erlangen, Germany) using a 28-channel proton knee coil (QED, Electrodynamics LLC, Cleveland, OH) included a proton density weighted turbo spin-echo sequence with fat suppression to assess morphological tissue structure andgagCEST imaging to measure the biochemical tissue composition in terms of glycosaminoglycans (GAG). Twelve months after surgery all patients reported no pain and showed full range of motion. While PROMs at three months showed large variability between patients, one year after surgery the scores were consistently improved. Over time, morphological MRI visualized improvements in integration of the cartilage fragment with the surrounding cartilage, which was supported by biochemical MRI showing increased GAG values at the defect edges. Statistics were not applied to the results because of the small sample size. The modified Hedgehog technique in young adults with an acute onset caused by a pure chondral corpus liberum can be considered promising. The improved PROM results over time were supported by 7.0T MRI that visualized improvements in tissue structure and biochemical composition. Inclusion of more patients in future studies would allow statistical analysis and more conclusive results. The etiology of loosening and time between onset of symptoms and surgery for successful graft integration may differ between pediatric and young adult patients and is subject for future studies.

Knee osteoarthritis (OA) is a serious health concern, requiring novel therapeutic options. Walking mechanics has long been identified as an important factor in the OA process. Specially, a larger peak knee adduction moment during the first half of stance (KAM) has been associated with the progression of medial knee OA. Consequently, various gait interventions have been designed to reduce the KAM, including walking with a decreased foot progression angle (FPA). Other gait variables have recently been associated with medial knee OA progression, particularly a larger peak knee flexion moment during stance (KFM) and a larger knee flexion angle at heel-strike (KFA). Currently, there is a paucity of data regarding the effect of reducing the FPA on the KFM and KFA.

This study aimed to test for correlations between the FPA and the KAM, KFM and KFA. It was hypothesized that reducing the FPA is beneficial with respect to these three OA-related gait variables.

Seven healthy subjects participated in this study after providing informed consent (4 male; 24 ± 5 years old; 21.9 ± 1.5 kg/m^2). Their walking mechanics was determined using a validated procedure based on a camera-based system (Vicon) and floor-mounted forceplates (Kistler). Participants were first asked to walk without instructions and these initial trials were used to determine their normal footstep characteristics. Then, footsteps with the same characteristics as during the normal trials, except for the FPA, were displayed on the floor and participants were requested to walk following these footsteps. Nine trials with visual instructions were collected for each participant, corresponding to FPA modifications in the range ± 20° compared to the normal FPA, with 5° increment. For each participant, the associations between FPA and knee biomechanics (KAM, KFM and KFA) were assessed using Pearson correlations based on the data from the 9 trials with FPA variations. Significant level was set a priori to 5%.

Significant correlations were noted between FPA and KAM for 5 out of the 7 participants, with R comprised between 0.75 and 0.96. Four participants also reported significant correlations between FPA and KFA (−0.88<R<−0.69). Significant correlations between FPA and KFM were observed in 2 participants, with inconsistent R (−0.68 and 0.78). There was no significant correlation between FPA and walking speed for none of the participants.

While the results confirmed that decreasing the FPA (toeing in) is often associated with a KAM reduction, they also showed relationships between decreased FPA and increased KFA. Therefore, this study suggests that reducing the FPA should be done in consideration of the possible negative changes in KFA. Similarly, although only one participant increased the KFM when decreasing the FPA, it seems important monitoring the effects FPA modifications could have on the KFM. The large variations observed among participants further suggest individualized gait modifications. This study should be extended to medial knee OA patients and longitudinal research is necessary to better understand the effects of decreasing the FPA.

Degree of early integration of titanium alloy implants into bone is an important predictor of long term implant success in arthroplasty. The correlation between observations on early cell adhesion and the ability of modified surfaces to affect osseointegration of implants in in vivo models is unclear. We hypothesised that observation of increased focal adhesion complexes in early cultures of osteoblasts would correlate with increased osseointegration of treated implants in an animal model. Longer term culture of rat osteoblasts for alkaline phosphatase activity indicated that cells cultured on the 9V treated surfaces were displaying greater alkaline phosphatase activity at 14 days. Bone nodule formation at 28 days demonstrated a trend towards smaller area of bone nodules on the surfaces treated at 9V then those treated at 3V and 5V. A rat model was employed for testing mechanical push-out strength of experimental implants and demonstrated a trend towards increased yield strength of the bone-implant interface for implants treated at 3V180s and 5V180s. Histomorphometry was performed and no statistically significant differences in percentage area of contact with mineralised bone matrix were seen, although there was a trend for greater mineralised matrix contact on the polished and 9V180s treated implants. Previous experiments demonstrated cells on the 9V treated surfaces were well spread and had significantly increased size and number of focal adhesions. This was regarded as indicating more successful cell adhesion. The above results demonstrate that this early trend disappeared in longer term culture did not persist in experiments in an animal model.

Though there are many techniques utilised in the correction of hallux valgus (HV), no single approach has been reported to be ideal for all patients to date. A great deal of controversy remains concerning the type of osteotomy, method of fixation, and inclusion of soft tissue procedures. Herein, we compared the outcomes of two different operative techniques, the minimally-invasive modified percutaneous technique and the distal chevron osteotomy, used to treat mild to moderate hallux valgus. This study was conducted in line with the CONSORT 2010 guidelines. 41 patients (58 feet) with mild to moderate hallux valgus were randomly assigned by computer to two different groups. The first group containing 24 patients (33 feet) was treated by the modified percutaneous technique, whereas the second group included 17 patients (25 feet) treated by distal chevron osteotomy. In the modified percutaneous group, after a mean follow up of 43 months, the mean correction of hallux valgus angle (HVA) was 26.69° (P=0.00001), the mean correction of intermetatarsal angle (IMA) was 9.45° (P=0.00001), and the mean improvement of AOFAS score was 47.94 points (P=0.00001). In the chevron osteotomy group, after a mean follow up of 44 months, the mean correction of hallux valgus angle was 26.72° (P=0.00001), the mean correction of intermetatarsal angle was 9° (P=0.00001), and the mean improvement of AOFAS score was 44.76 points (P=0.00001). In our study, the modified percutaneous technique proved to be equally effective as the distal chevron osteotomy, but with fewer complications and a higher rate of patient satisfaction.

Summary Statement

The present study demonstrates the beneficial effects of strontium (Sr) modified calcium phosphate cement to improve new bone formation in a metaphyseal osteoporotic fracture defects in rats compared to calcium phosphate cement and empty defects. Keywords: strontium, fracture, calcium phosphate, bone formation

Introduction

The purpose of this study was to evaluate the functional and radiographical results in patients who underwent a modified minimally invasive two-incision total hip arthroplasty using large-diameter ceramic-on-ceramic articulations for osteonecrosis of the femoral head.

Summary Statement

Collagen scaffolds modified with collagen-binding bFGF promotes the neural regeneration in the rat hemisected spinal cord injury model.

The aim is to investigate if there is a relation between patellar height and knee flexion angle. For this purpose we retrospectively evaluated the radiographs of 500 knees presented for a variety of reasons. We measure knee flexion angle using a computer-generated goniometer. Patellar height was determined using computer generated measurement for the selected ratios, namely, the Insall–Salvati (I/S), Caton–Deschamps (C/D) and Blackburne–Peel (B/P) indices and Modified I/S Ratio. A search of an NHS hospital database was made to identify the knee x rays for patients who were below the age of forty. A senior knee surgeon (DC) supervised three trainee trauma and orthopaedics doctors (HA, JM, ES) working on this research. Measurements were made on the Insall–Salvati (I/S), Caton–Deschamps (C/D) and Blackburne–Peel (B/P) indices and Modified I/S Ratio. The team leader then categorised the experimental measurement of patients’ knee flexion angle into three groups. This categorisation was according to the extent of knee flexion. The angles were specifically, 10.1 to 20, 20.1 to 30, and 30.1 to 40 degrees of knee flexion. Out of the five-hundred at the start of the investigation, four hundred and eighteen patients were excluded because they had had either an operation on the knee or traumatic fracture that was treated conservatively

Osteoarthritis (OA) is the leading cause of pain and disability worldwide and is characterized by the degenerative changes of articular cartilage. Joint loading is required for cartilage maintenance; however, hyper-physiologic loading is a risk factor for OA. Mechanosensitive ion channels Piezo1 and Piezo2 synergistically transduce hyper-physiologic compression of chondrocytes, leading to chondrocyte death and onset of OA. This injury response is inhibited by Piezo channel loss of function, however the mechanistic role of Piezo channels in vivo is unknown. We examined the hypothesis that deletion of Piezo in chondrocytes will protect mice from joint damage and pain-related behaviors following a surgical destabilization of the medial meniscus (DMM), investigating a key mechanistic and mechanobiological role of these channels in the pathogenesis of OA. Aggrecan-Cre Piezo1 and Piezo1/2 knockout mice ((Agc)1-CRE. ERT2. ;Piezo1. fl/fl. Piezo2. fl/fl. ) were generated and given a 5-day Tamoxifen regimen at 12-weeks of age (n=6–12/group/sex). Cre-negative mice served as controls. At 16-weeks, mice received DMM surgery on the left knee. 12-weeks following DMM prior to sacrifice, activity and hyperalgesia were measured using spontaneous running wheels and a small animal algometer. Structural changes in bone, cartilage, and synovium were characterized using microCT, histology, and Modified Mankin Score criteria. Knockout of Piezo1/2 channels was chondroprotective in both sexes following DMM surgery as demonstrated by reduced Modified Mankin Score compared to control animals. Piezo1 KO was chondroprotective in only female mice, indicating a sexually dimorphic response. Piezo1 and Piezo1/2 KO was protective against pain in male mice, while females displayed no differences compared to controls. No changes were observed in bone morphology. Chondrocyte-specific Piezo1/2 knockout protects the knee joint from structural damage, hyperalgesia and functional deficits in a surgical model of PTOA in male and female mice, illustrating the importance of Piezo channels in response to injury in vivo. Future work aims to interrogate potential sexually dimorphic responses to cartilage damage and investigating Piezo2 KO mice