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

Aims. Cartilage injuries rarely heal spontaneously and often require surgical intervention, leading to the formation of biomechanically inferior fibrous tissue. This study aimed to evaluate the possible effect of amelogenin on the healing process of a large osteochondral injury (OCI) in a rat model. Methods. A reproducible large OCI was created in the right leg femoral trochlea of 93 rats. The OCIs were treated with 0.1, 0.5, 1.0, 2.5, or 5.0 μg/μl recombinant human amelogenin protein (rHAM. +. ) dissolved in propylene glycol alginate (PGA) carrier, or with PGA carrier alone. The degree of healing was evaluated 12 weeks after treatment by morphometric analysis and histological evaluation. Cell recruitment to the site of injury as well as the origin of the migrating cells were assessed four days after treatment with 0.5 μg/μl rHAM. +. using immunohistochemistry and immunofluorescence. Results. A total of 12 weeks after treatment, 0.5 μg/μl rHAM. +. brought about significant repair of the subchondral bone and cartilage. Increased expression of proteoglycan and type II collagen and decreased expression of type I collagen were revealed at the surface of the defect, and an elevated level of type X collagen at the newly developed tide mark region. Conversely, the control group showed osteoarthritic alterations. Recruitment of cells expressing the mesenchymal stem cell (MSC) markers CD105 and STRO-1, from adjacent bone marrow toward the OCI, was noted four days after treatment. Conclusion. We found that 0.5 μg/μl rHAM. +. induced in vivo healing of injured articular cartilage and subchondral bone in a rat model, preventing the destructive post-traumatic osteoarthritic changes seen in control OCIs, through paracrine recruitment of cells a few days after treatment. Cite this article: Bone Joint Res 2023;12(10):615–623

Osteochondral injuries are a recognised factor in the development of osteoarthritis (OA). Mesenchymal stromal cells (MSCs) represent a promising biological therapeutic option as an OA-modifying treatment, and they also secrete factors that may have an anti-catabolic effect and/or encourage endogenous repair. We aim to study the effects of (i) intra-articular injection of human bone-marrow-derived MSCs and (ii) their secretome on recovery in a murine knee osteochondral injury model. The MSC secretome was generated by stimulating human bone-marrow-derived MSCs with tumour necrosis factor alpha (TNFα). Mice (n=48) were injected with i) MSC secretome, ii) MSCs or iii) cell culture medium (control). Pain was assessed by activity monitoring, and cartilage repair, subchondral bone volume and synovial inflammation were evaluated using histology and microCT. Both MSC- and MSC-secretome-injected mice showed significant pain reduction at day 7 when compared to control mice, but only the MSC-injected mice maintained a significant improvement over the controls at day 28. Cartilage repair was significantly improved in MSC-injected mice. No significant effects were observed with regards to synovial inflammation or subchondral bone volume. The MSC secretome demonstrates regenerative effects but this does not appear to be as sustained as a MSC cell therapy. Further studies are required to investigate if this can be overcome using different dosing regiments for injection of the MSC secretome. As we further understand the regenerative properties of the MSC secretome, we may be able to enhance the clinical translatability of these therapies. Direct intra-articular injection of MSCs for the treatment of OA also appears promising as a potential future strategy for OA management. Acknowledgements: MS is supported by a grant from the Wellcome Trust (PhD Programme for Clinicians)

Despite osteoarthritis (OA) representing a large burden for healthcare systems, there remains no effective intervention capable of regenerating the damaged cartilage in OA. Mesenchymal stromal cells (MSCs) are adult-derived, multipotent cells which are a candidate for musculoskeletal cell therapy. However, their precise mechanism of action remains poorly understood. The effects of an intra-articular injection of human bone-marrow derived MSCs into a knee osteochondral injury model were investigated in C57Bl/6 mice. The cell therapy was retrieved at different time points and single cell RNA sequencing was performed to elucidate the transcriptomic changes relevant to driving tissue repair. Mass cytometry was also used to study changes in the mouse immune cell populations during repair. Histological assessment reveals that MSC treatment is associated with improved tissue repair in C57Bl/6 mice. Single cell analysis of retrieved human MSCs showed spatial and temporal transcriptional heterogeneity between the repair tissue (in the epiphysis) and synovial tissue. A transcriptomic map has emerged of some of the distinct genes and pathways enriched in human MSCs isolated from different tissues following osteochondral injury. Several MSC subpopulations have been identified, including proliferative and reparative subpopulations at both 7 days and 28 days after injury. Supported by the mass cytometry results, the immunomodulatory role of MSCs was further emphasised, as MSC therapy was associated with the induction of increased numbers of regulatory T cells correlating with enhanced repair in the mouse knee. The transcriptomes of a retrieved MSC therapy were studied for the first time. An important barrier to the translation of MSC therapies is a lack of understanding of their heterogeneity, and the consequent lack of precision in its use. MSC subpopulations with different functional roles may be implicated in the different phases of tissue repair and this work offers further insights into repair process

Tibial pilon fractures are typically the result of high-energy axial loads, with complex intra- articular fractures that are often difficult to reconstruct anatomically. Only nine simultaneous pilon and talus fractures have been published previously, but we hypothesised the chondral surface of the dome is affected more frequently. Data was acquired prospectively from 154 acute distal tibial pilon fractures (AO/OTA 43B/C) in adults. Radiographs, photographs, and intra-operative drawings of each case were utilised to document the presence of any macroscopic injuries of the talus. Detailed 1x1mm maps were created of the injuries in each case and transposed onto a statistical shape model of a talus; this enables the cumulative data to be analysed in Excel. Data was analysed using a Chi-squared test. From 154 cases, 104 were considered at risk and their talar domes were inspected; of these, macroscopic injuries were identified in 55 (52.4%). The prevalence of talar dome injury was greater with B-type fractures (53.5%) than C-type fractures (31.5%) (ρ = .01). Injuries were more common in men than women and presented with different distribution of injuries (ρ = .032). A significant difference in the distribution of injuries was also identified when comparing falls and motor vehicle accidents (ρ = .007). Concomitant injuries to the articular surface of the dome of the talus are relatively common, and this perhaps explains the discordance between the post-operative appearance following internal fixation and the clinical outcomes observed. These injuries were focused on the lateral third of the dome in men and MVAs, whereas women and fall mechanism were more evenly distributed. Surgeons who operatively manage high-energy pilon fractures should consider routine inspection of the talar dome to assess the possibility of associated macroscopic osteochondral injuries

Aim. Septic arthritis (SA) is considered a medical emergency. The most common etiological agents are glucose consuming bacteria, so we evaluated the clinical utility of synovial fluid (SF) glucose levels and other biochemical parameters for supporting the diagnosis of the disease and their association with a positive bacteria culture and joint destruction. Methods. Adult patients with SA diagnose were enrolled prospectively between July 2018 and October 2019. As control group, adults with knee osteoarthritis, meniscus and/or knee ligaments lesions were enrolled. SF samples were obtained from the joints by arthrocentesis/arthrotomy. Microbiological analyses of SF were performed using Brucella broth blood culture flasks, samples were incubated at 37°C with 5% CO. 2. for 24 hours. Gram stain, chocolate and blood agar were used for the identification and growth of the bacteria. SF glucose levels, pH and leukocyte esterase were measured as biochemical parameters using a glucometer and colorimetric test strips. The Outerbridge classification was used for grading the osteochondral injury. Furthermore, blood samples were collected from patients and control subjects for determining glucose levels. Results. We included 8 subjects with knee ligaments lesions, 6 with meniscus lesions and 5 with osteoarthritis as control group, as well as 20 patients with SA diagnose. The mean age of the patients was 57.8 years with a 65% of male predominance. The most common affected joint was the knee (85%). SF culture was positive in 60% of the cases and the most common etiological agent was Staphylococcus aureus (58.3%). SF glucose levels from patients were lower than the controls (P=0.0018) and showed the lowest concentration in patients with a positive culture (P=0.0004). There was also a difference between blood and SF glucose concentration from the positive culture patients (P<0.0001). Leucocyte esterase presented the highest values in positive culture patients (P=<0.0001) and a more acidic pH was found compared to the control group (P<0.0001). Regarding the osteochondral injury, the lowest concentrations of SF glucose were found in patients with a higher grade in the classification (P = 0.0046). Conclusions. SF glucose and leukocyte esterase concentrations might be a quick and cheap useful parameter for the physician for distinguishing between bacterial infection and not infected joint. In addition, the lowest SF glucose levels might give information about the joint damage due to the disease

Introduction and Aims: Anterior cruciate ligament (ACL) injuries have historically been classified as non-contact or contact based on the mechanism of injury. The purpose of this study was to establish a detailed correlation between mechanism and the associated osteochondral, meniscal and other injuries to improve understanding of this common injury and its outcome. Method: A descriptive analysis of prospectively collected data on ACL injuries requiring reconstruction between 2000 and 2004 was completed. Mechanism of injury was clearly elicited and correlated with clinical, radiologic and operative findings. Magnetic resonance imaging (MRI) was performed on all patients to analyse patterns of ACL rupture and associated osteochondral, meniscal and ligament injuries. Osteochondral injuries were analysed by a musculoskeletal radiologist according to location, intensity and depth. Intra-operative documentation of intra-articular injury pattern was also performed and correlated with MRI findings. Classification into ‘active’ (non-contact) and ‘passive’ (contact) mechanisms was completed and correlated with injury pattern. Results: Seventy patients were identified with appropriate clinical, radiologic and operative data. A thorough review of the events surrounding the injury was documented. Forty-six patients described an active mechanism and 24 patients a passive mechanism of injury. Clinical examination demonstrated a similar proportion of medial collateral ligament injuries in each group. MRI within three months of injury demonstrated occult osteochondral lesions or ‘bone bruises’ in the majority of patients. Clear distinguishing patterns of femoral and tibial osteochondral injury were identified in the active and passive groups. Depth of osteochondral injury was most commonly classified as at least two-thirds the distance to the physeal scar in both groups. Intensity of the abnormal edema-like signal in the marrow of the distal femur and proximal tibia was most commonly classified as severe in both groups. Lateral meniscus injury was more common than medial, and was found in the majority of patients, more commonly in the passive group. Conclusion: Although surgical techniques continue to improve, the ACL injury mechanism and its relation to intra-articular pathology is less well defined. This study defines either ‘active’ or ‘passive’ mechanisms, with implications for likely associated osteochondral and meniscal injury. This gives valuable insight into the ACL injured knee, its management, and eventual prognosis

Objectives. Osteochondral injuries, if not treated adequately, often lead to severe osteoarthritis. Possible treatment options include refixation of the fragment or replacement therapies such as Pridie drilling, microfracture or osteochondral grafts, all of which have certain disadvantages. Only refixation of the fragment can produce a smooth and resilient joint surface. The aim of this study was the evaluation of an ultrasound-activated bioresorbable pin for the refixation of osteochondral fragments under physiological conditions. Methods. In 16 Merino sheep, specific osteochondral fragments of the medial femoral condyle were produced and refixed with one of conventional bioresorbable pins, titanium screws or ultrasound-activated pins. Macro- and microscopic scoring was undertaken after three months. . Results. The healing ratio with ultrasound-activated pins was higher than with conventional pins. No negative heat effect on cartilage has been shown. Conclusion. As the material is bioresorbable, no further surgery is required to remove the implant. MRI imaging is not compromised, as it is with implanted screws. The use of bioresorbable pins using ultrasound is a promising technology for the refixation of osteochondral fractures

Aims

Orthopaedic surgery requires grafts with sufficient mechanical strength. For this purpose, decellularized tissue is an available option that lacks the complications of autologous tissue. However, it is not widely used in orthopaedic surgeries. This study investigated clinical trials of the use of decellularized tissue grafts in orthopaedic surgery.

A retrospective review of 57 military patients undergoing ankle arthroscopy between 1999 and 2011 was performed. A case-note review of medical records was undertaken pertaining to military role, ankle injury sustained, mechanism, presenting symptoms and their duration. Arthroscopic findings were compared to findings on radiographs and MRI scans. At first presentation 23 patients had features of arthritis on radiographs. We found MRI was both highly sensitive (97.7%) and specific (93.4%) in detecting osteochondral defects (OCD). 16 of the patients had evidence of osteochondral injury. All OCDs picked up on MRI were confirmed at arthroscopy. Ankle injury may not be a benign injury in military personnel, with over half of these young patients having radiological features of osteoarthritis at presentation. We found MRI an effective tool for identifying occult injuries not seen on radiographs. Lateral ligament injury with associated gutter scarring can be successfully treated with arthroscopic debridement. This suggests pseudoinstability rather than a true mechanical instability as the main cause for patient's symptoms in this cohort

Aims

Arthroscopic microfracture is a conventional form of treatment for patients with osteochondritis of the talus, involving an area of < 1.5 cm². However, some patients have persistent pain and limitation of movement in the early postoperative period. No studies have investigated the combined treatment of microfracture and shortwave treatment in these patients. The aim of this prospective single-centre, randomized, double-blind, placebo-controlled trial was to compare the outcome in patients treated with arthroscopic microfracture combined with radial extracorporeal shockwave therapy (rESWT) and arthroscopic microfracture alone, in patients with ostechondritis of the talus.

Introduction. Osteochondral autologous autograft (also called mosaic arthroplasty) is the preferred treatment method for very large osteochondral defects in the ankle. For long-term success of this procedure, the transplanted plugs should reconstruct the curvature of the articular surface. The different curvatures between femoral-patella joint and the dome of the talus makes the reconstruction difficult and requires lots of experience. Material. Prior to the surgery a CT arthrogram of the ankle, as well as a CT of the knee were obtained and 3D bone models for the knee, the ankle as well as a model for the ankle cartilage were created. Using custom-made software a set of osteochondral grafts (“plugs”) positioned over the defect site were planned and an optimal harvest location for each plug was chosen. Intraoperatively, an optoelectronic navigation system was installed and sensors were attached to femur, talus, and conventional harvest and delivery chisels. A combined pair-point and surface matching was performed to register femur and talus. For each planned plug the surgeon positioned, oriented, and rotated the harvest and delivery chisels with respect to preoperative plan by using the visual and numerical feedback of the system. Results. We performed the above described procedure on a 37 year old female patient with osteochondral injury of the dome of the right talus with an approximate size of 20mm × 9mm. One 8mm and two 6mm plugs were planned and intraoperative navigated. At 6 months postoperative she had a significant improvement in her passive range of motion from 0–15° dorsi-flexion and 0–60° plantar-flexion, compared to her uninjured ankle of 0–15° dorsi-flexion and 0–80° plantar-flexion. The inversion and eversion of the ankle are normal and x-ray evaluation showed good and complete integration of the osteochrondal plugs. Discussion. A virtual preoperative planning tool helped to solve the complex geometrical problem of reconstructing the articular cartilage surface of the talus using multiple autologous osteochondral plugs from the knee. The intraoperative optoelectronic guidance allowed the surgeon to transfer this plan into the intraoperative situation

The purpose of this report was to describe a new arthroscopic finding in anterior cruciate ligament rupture: the presence of osteochondral injury beneath the posterior horn of the lateral meniscus. A single surgeon performed arthroscopic evaluation of 43 consecutive patients with ACL rupture within 12 months of injury. Nine patients (21 %) had a chondral lesion of the posterolateral tibia beneath the posterior horn of the lateral meniscus, not seen unless the meniscus was elevated with the arthroscopic probe. On four occasions a chondral loose body was identified and removed. Seven of the nine (78%) had an associated lateral meniscal tear and four (44 %) a chondral lesion of the lateral femoral condyle. MRI was not accurate in predicting the presence of a chondral lesion in those patients with a lesion that had an MRI preoperatively. We report a new arthroscopic finding in ACL rupture not previously mentioned in the literature. The clinical significance is that when chondral loose bodies are encountered of unknown origin, arthroscopic evaluation of the area beneath the posterior horn of the lateral meniscus should be involved in any systematic search for the lesion

Introduction: Autologous Chondrocyte Implantation (ACI) is a treatment option for full-thickness chondral, or osteochondral injuries that are painful and debilitating. Goals of surgery and rehabilitation include replacement of damaged cartilage with hyaline or hyaline-like cartilage, leading eventually to improved level of function. Intermediate and long-term results are promising in terms of functional and clinical improvement. Purpose: To explore the hypothesis that the quality of the repair tissue, formed following Autologous Chondrocyte Implantation (ACI), improves with time post-surgery. Methods and Results: Two hundred and forty eight patients who underwent autologous chondrocyte implantation in our institution were studied after having had post implantation biopsies of the repair tissue. Mean timing of biopsy was 14.8 months (range 3–55). 59 biopsies gave hyaline tissue (24%), 67 mixed hyaline and fibrocartilage (27%), 113 biopsies were fibrocartilage only (46%) and 9 patients had a fibrous tissue biopsy result (9%). Due to NHS restraints and waiting list targets biopsies were actually performed at various time points post implantation allowing us to statistically correlate histological findings with the maturity of the repair tissue. Our statistical analysis suggests that if time post implantation doubles then the likelihood of a favourable histological outcome increases significantly. Conclusion: Autologous chondrocyte implantation forms a durable repair tissue that remodels and continues to improve in quality with time. It is recommended that for future research/study purposes 24 months is used as an optimal time to look at histology, since our data show that outcome is still improving until this point

Introduction: Autologous Chondrocyte Implantation (ACI) is a treatment option for symptomatic, full-thickness chondral/osteochondral injuries. Goals of surgery and rehabilitation include replacement of damaged cartilage with hyaline/hyaline-like cartilage, leading eventually to improved level of function. Intermediate and long-term results are promising in terms of functional improvement. Purpose: To explore the hypothesis that non-hyaline cartilage repair tissue is associated with worse functional outcome and to assess whether the quality of the repair tissue formed following ACI improves with time post-surgery. Methods and Results: Two hundred and forty eight patients who underwent ACI at our institution were studied, having had post-implantation biopsies of the repair tissue. Mean timing of biopsy was 14.8 months (range 3–55). 59 biopsies showed hyaline tissue (24%), 67 mixed hyaline and fibrocartilage (27%), 113 biopsies were fibrocartilage only (46%) and 9 patients had a fibrous tissue biopsy result (9%). 126 patients (51%) had hyaline tissue in the regenerate and demonstrated a mean Modified Cincinnati Rating Score (MCRS) of 84 and a mean Lysholm Score of 88 at last follow-up (Group 1). 122 patients (49%) had no hyaline tissue in the regenerate and scored a mean MCRS of 71 and a mean Lysholm Score of 73 (Group 2). Both Groups 1 and 2 demonstrated a statistically significant improvement in functional outcome between pre and post-operative scores (p< 0.0001). There was significant difference in post-operative scores between Groups 1 and 2 suggesting that presence of hyaline tissue in the regenerate is associated with improved functional outcome (p< 0.05). Finally, our statistical analysis suggested that if time post-implantation doubles, then the likelihood of a favourable histological outcome increases significantly. Conclusion: ACI forms a durable repair tissue that remodels and continues to improve in quality with time. Poor functional outcome may reflect the presence of a non-hyaline cartilage repair tissue

Aim Post-traumatic osteoarthritis and osteochondral injuries can cause significant pain and morbidity. Appropriate MRI sequences combined with image analysis techniques can be used to reproducibly measure quantitative cartilage parameters, hence offering a tool for monitoring and detecting degenerative change earlier than previously possible. We demonstrate the performance of a directional gradient vector flow (dGVF) snake segmentation algorithm on an isotropic MR sequence, which allows segmentation of the full articular surfaces (including malleoli) of the ankle. Method Eight ankles were imaged using a 1.5T MRI scanner with an isotropic 3D T1 weighted FLASH sequence with water excitation, resolution 0.3 x 0.3 x 0.3 mm. A subset of five ankles were imaged four times with repositioning and re-shimming of the magnet between acquisitions. Images were interpolated to 0.15 mm3 and segmented using a dGVF snake. Following 3D reconstruction of the cartilage layers normal thickness from cartilage to bone was measured at each voxel on the cartilage surface. Results The mean cartilage thickness (±S.D) was 1.80 mm (±0.05 mm); 1.83 mm (±0.07 mm) and 1.81 mm (±0.07 mm) for the talus, tibia and cumulative ankle cartilage respectively. To measure the technical precision of the segmentation method we determined the coefficient of variation of the four repeated measurements in five ankles. The mean coefficients of variation (min-max) from the repeated measurements were 1.74% (0.69%–3.57%); 1.20% (0.26%–3.06%) and 1.52% (0.26%–3.57%) for the talus, tibia and cumulative ankle cartilage respectively. Conclusion We believe that the reported isotropic image sequence and segmentation algorithm is a valid tool for quantitative assessment of the entire ankle joint. A possible application is the early detection of cartilage injury and degenerative change due to injury or illness

Introduction and Aims: Knee dislocation is an uncommon but serious injury. This study assessed the initial mechanism of injury, pattern of ligament injury, osteochondral and peri-articular soft-tissue trauma, and associated neurovascular injuries in the multi-ligament knee injury. Outcomes following operative and non-operative management were reviewed. Method: Retrospective review of patients with multi-ligament knee injuries was performed. Inclusion criteria were either a confirmed knee dislocation, or complete rupture of two or more ligaments requiring reconstruction. Systematic review of hospital records and imaging was performed for all patients, and clinical assessment, including validated outcome scores, were performed in the majority of patients. All reconstructive surgery was performed by the two senior authors. Results: Forty-five patients with 47 knee injuries were identified over a 13-year period (1990–2003). The most common mechanisms of injury were motorcycle and motor vehicle accidents. Other mechanisms included pedestrians hit by cars, sporting injuries and falls. Approximately half had a documented knee dislocation, while the remainder were located at the time of presentation. Vascular injury occurred in around 25% of patients, all having positive clinical findings. Routine angiography was not performed in the absence of positive clinical findings. Neurological injury also occurred in approximately 20% of patients. Transient neuropraxia was more common than permanent nerve palsy, and there was an association between neurological and vascular injury. Associated injuries were varied, the most frequent being long-bone fracture. A significant number of patients had no associated injuries. Injury patterns were varied, though correlations were found between the reported mechanism and the pattern of ligament rupture and osteochondral injury. The majority of cases were managed with operative repair, and assessment of outcomes revealed that most returned to a good level of function, with some minor objective residual laxity and/or stiffness. Conclusion: Multi-ligament injuries of the knee are uncommon but serious injuries with potentially catastrophic consequences. This detailed analysis provides correlation between mechanism and resulting injury to the knee and periarticular structures. The analysis of this large series provides valuable information to better understand natural history, and improve future management

Purpose. Factors that contribute to early and late re-operation after cruciate reconstruction (CR) have not been evaluated on a population level in a public health system. After surgery patients are at risk for knee stiffness, infection or early graft failure prompting revision. Long-term, ipsilateral revision CR, contralateral CR and potentially even joint replacement may occur. Population research in total joint replacement surgery has demonstrated an inverse relationship between complication/failure rates and surgeon procedural volume. We hypothesized that in Ontario, younger patient age and lower surgeon volume would increase the risk of short and long-term re-operation after CR. Method. Billing, procedural and diagnostic coding from administrative databases (Ontario Health Insurance Plan, Canadian Institutes of Health Research) were accessed through the Institute for Clinical Evaluative Sciences to develop the cohort of all Ontario residents aged 14 to 60 who underwent anterior or posterior CR from July 1992 to April 2008. Logistic regression analysis was used to calculate the odds ratio for patient (age, gender, comorbidity, income, concurrent knee surgery) and provider (surgeon volume, teaching hospital status) factors for having a surgical washout of the knee, manipulation for stiffness or repeat of the index event within six months. A cox proportional hazards survivorship model was used to calculate the hazard ratio of the same covariates for repeat CR and partial/total knee arthroplasty from inception until end of 2009. Results. The cohort identified 34,735 CR patients with a median age 28 yrs (IQR 20–36) and 65% male. Re-operation for infection was 0.2% and stiffness 0.5%. The long-term rate of any repeat CR was 7.7% after a mean 4.23.4 years. Female gender (OR=2.8, p<0.0001), overnight hospital stay (OR=2.1, p=0.0005), meniscal repair with CR (OR=1.9, p=0.008) and surgeon volume of 0–12 CR/yr (OR=4.0, p=0.0006), significantly increased the odds of re-operation for stiffness. The odds of re-operation for infection were significantly increased for surgeons performing 0–12 CR/yr (OR=3.8, p=0.007), and for CR performed at a teaching hospital (OR=2.3, p=0.002). Repeat CR was not influenced by surgeon volume at any time-point. Survival analysis demonstrated a long-term repeat CR rate of 13% (HR=1.8, p<0.0001) for age 14–19 yrs compared to the mean cohort age. Late partial or total knee replacement occurred in 0.75% of patients, with increased risk found for patients >30 years (HR=2.5, p=0.002), or who had concurrent surgery for an osteochondral lesion at the index CR (HR=2.3, p=0.001). Conclusion. Although this data is limited by the ability to distinguish between anterior or posterior and revision or contralateral CR, we have demonstrated that lower volume surgeons have higher complication rates (stiffness, infection) after CR surgery. We have also identified at-risk groups, such as females for stiffness post-CR and osteochondral injury + CR for eventual knee replacement

Aims

Minimally manipulated cells, such as autologous bone marrow concentrates (BMC), have been investigated in orthopaedics as both a primary therapeutic and augmentation to existing restoration procedures. However, the efficacy of BMC in combination with tissue engineering is still unclear. In this study, we aimed to determine whether the addition of BMC to an osteochondral scaffold is safe and can improve the repair of large osteochondral defects when compared to the scaffold alone.

Aims

This study aimed to investigate whether human umbilical cord mesenchymal stem cells (UC-MSCs) can prevent articular cartilage degradation and explore the underlying mechanisms in a rat osteoarthritis (OA) model induced by monosodium iodoacetate (MIA).