INTRODUCTION. Osteochondral lesions of the knee are relatively common both in young and senior population. The very disabling clinical symptoms, in association to the scarce regenerative capacity of the articular cartilage and the increased risk of developing a secondary osteoarthritis make an effective treatment mandatory. MATERIALS AND METHODS. From December 2008 to January 2013, 34 patients (35 knees), 24 males and 10 females (mean age 36.2 years range 14–66) underwent implant of Maioregen® (Finceramica Faenza S.P.A, Italy) biomimetic osteochondral scaffold. In 17 cases the osteochondral lesion was cause by an osteochondritis dissecans (acute or sequela), in 13 cases by a spontaneous osteonecrosis and in 4 cases the etiology was traumatic. Patients were evaluated with subjective IKDC and Tegner Lysholm scores, VAS and Tegner Activity Scale before surgery and at regular follow up (mean follow up 38.4 months, range 13 months max 63 months). RESULTS. Both Lysholm and IKDC Subjective scores significantly increased from 57.5 and 48.2 before surgery to 89.7 and 76.3 at 1 year follow up. Mean VAS scale score decreased from 6.3 to 2 at 1 year follow up. At 3 years follow up 20 evaluated patients showed an increment on both scales (Lysholm 92.38, IKDC 84.7). Only 4 patients were evaluated at 5 years follow up with mean subjective IKDC 92.5, Lysholm 98.75 and VAS 1. DISCUSSION. Maioregen ® biomimetic osteochondral scaffold showed very good results as surgical treatment option in treating ICRS grade 3–4 osteochondral lesions whatever the etiology. In particular, the implant showed good results also in treatment of osteonecrosis and could provide an alternative to unicompartimental arthroplasty in young and active patients

Purpose. Osteochondral lesions of the knee are relatively common both in young and senior population. The very disabling clinical symptoms, in association to the scarce regenerative capacity of the articular cartilage and the increased risk of developing a secondary osteoarthritis make an effective treatment mandatory. Methods and Materials. From December 2008 to January 2013, 34 patients (35 knees), 24 males and 10 females (mean age 36.2 years range 14–66) underwent implant of Maioregen® (Finceramica Faenza S.P.A, Italy) biomimetic tri-layer osteochondral scaffold. In 17 cases the osteochondral lesion was cause by an osteochondritis dissecans (acute or sequela), in 13 cases by a spontaneous osteonecrosis and in 4 cases the etiology was traumatic. Patients were evaluated with subjective IKDC and Tegner Lysholm scores, VAS and Tegner Activity Scale before surgery and at regular follow up (mean follow up 38.4 months, range 13 months max 63 months). Results. Both Lysholm and IKDC Subjective scores significantly increased from 57.5 and 48.2 before surgery to 89.7 and 76.3 at 1 year follow up. Mean VAS scale score decreased from 6.3 to 2 at 1 year follow up. At 3 years follow up 20 evaluated patients showed an increment on both scales (Lysholm 92.38, IKDC 84.7). Only 4 patients were evaluated at 5 years follow up with mean subjective IKDC 92.5, Lysholm 98.75 and VAS 1. Conclusion. Maioregen® biomimetic osteochondral scaffold showed very good results as surgical treatment option in treating ICRS grade 3–4 osteochondral lesions whatever the etiology. In particular, the implant showed good results also in treatment of osteonecrosis and could provide an alternative to unicompartimental arthroplasty in young and active patients

Osteochondral lesions (OCL) of the talus occur in 38% of the patients with supination external rotation type IV ankle fractures and 6 % of ankle sprains. Osteoarthritis is reported subsequently in 8–48% of the ankles. Several marrow stimulation methods have been used to treat the symptomatic lesion, including arthroscopic debridement and micro fracture. Encouraging midterm results have been reported, but longterm outcome is unknown in relation to more invasive treatments such as transfer of autologous osteoarticular tissue from the knee or talus (OATS), autologous chondrocyte implantation (ACI), frozen and fresh allograft transplantation. Aim. The aim of our study was to review our long term results of arthroscopic treatment of osteochondral lesions of the talus. Materials and methods. 65 patients underwent arthroscopic treatment of the OCL between 1993 and 2000. There were 46(71%) men and 19(29%) women. The mean age at surgery was 34.2 years. The right side was affected in 43 patients and the left side in 22 patients. Results. 40/65(61.5%) patients who underwent arthroscopic treatment of the OCL were followed up. The mean follow-up was 13.1 years (9 to 18 years). The average age at final follow was 49.6 years (25–80 years). 15 (39.5%) patients reported poor, 14 (36.8%) fair, 9 (23.6%) good outcomes based on the Berndt and Harty criteria. 20/40 patients (50 %) needed further surgery. This appears a significant deterioration since this cohort were studied at 3.5 years, when the clinical results were 21.3% poor, 26.2% fair and 52.3% good, although losses to followup make exact comparison impossible. Conclusion. Arthroscopic treatment of osteochondral lesions of the talus gives medium term improvement in the majority of patients, but it appears that results deteriorate with time. Recurrence of symptoms sufficient to require further surgical intervention occurred in half the patients studied

Arthroscopic hip surgery is increasingly common in Australia. Hip arthroscopy is indicated for a range of diagnostic and therapeutic purposes, including labral tears, capsular laxity and femoral-acetabular impingement (FAI). Despite this, previous cohort studies aiming to characterise hip pathology seen on arthroscopic examination are mostly limited to patients with known diagnoses of FAI. Therefore, little is known of the native articular wear patterns encountered in other disease states. Therefore, we aimed to define common osteochondral wear patterns for a cohort of patients managed via hip arthroscopy. We retrospectively analysed intraoperative data for 1127 patients managed via hip arthroscopy between 2008 and 2013, for either therapeutic or diagnostic purposes. Intraoperative data was categorized by location (A-E as defined by Fontana et al. 2016) and chondral damage (0-4 scale as defined by Beck et al. 2005) with respect to both acetabulum and femoral head. Data for 1127 patients were included. Location of acetabular chondral pathology was variable with locations C. 1. and D. 1. representing the most common regions of damage. Labral tears predominated in locations C and D. Femoral chondral pathology was evenly distributed. The degree of femoral chondral injury was predominantly grade 1, whilst acetabular wear was evenly distributed. Large proportions of wear were observed at the peripheral superior and anterior regions of the lunate surface of the acetabulum in keeping with prior works. However, we observed higher rates of central wear and lower rates of grade 4 acetabular damage extending into superior/posterior zones, in our cohort. Our work characterises common articular wear patterns encountered at the time of hip arthroscopy. Further inquiry into the natural history of osteochondral lesions is needed to better understand and manage these conditions

Background:. Different surgical approaches have been proposed for the treatment of chondral lesions. However surgical management of osteochondral defects of the knee joint involving subchondral bone are still under debate. Purpose:. The aim of this prospective non-randomized uncontrolled clinical investigation is to confirm the effectiveness of a commercially available biomimetic osteochondral scaffold in regenerating cartilage and subchondral bone of severe osteochondral lesions of the knee joint with one step surgery. Methods:. The biomimetic scaffold has a multilayer structure consisting of a combination of type I collagen and type I collagen/hydroxyapatite, mimicking the osteochondral connective tissue of the knee joint. From 2009 to 2011, sixty-one patients affected by grade III or IV osteochondral lesions of the knee, according to Outerbridge Classification, were admitted to three centers and received the biomimetic scaffold. Four-nine patients were evaluated using the International Knee Documentation Committee (IKDC), Tegner and VAS scores, and MRI at 1-, 2- and 3-year follow-ups. Biopsies were carried out in 5 patients at an average time of 19.2 months to histologically evaluate the quality of the newly-formed tissue. Results:. All patients tolerated the surgery well; no major adverse events were observed in the early postoperative period. Clinical evaluation of the 49 patients showed a statistically significant improvement in all scores at 1- 2- and 3-year follow-ups as compared to preoperative baseline scores. Improvement in the scores and functional recovery seemed to reach a plateau after 2 years; no significant improvement was seen between the 2- and the 3-year follow-up. Conclusions:. A synthetic biomimetic scaffold used in one-step surgery for the treatment of severe osteochondral knee lesions significantly improved symptoms and joint function, as demonstrated by subjective and objective scoring system evaluation. Furthermore, the athletic subpopulation exhibited a significantly better outcome than the non-athletic subpopulation

The treatment of osteochondral lesions in the ankle joint remains a challenging problem. While debridement and drilling or microfracture of the lesion reduce symptoms initially, long-term stability of the fibrous repair tissue is questionable. Osteochondral transplantation or mosaicplasty provide hyaline cartilage and repair the bony defect at the same time. However, an open arthrotomy with medial, lateral or anterior osteotomy is necessary to repair lesions of the talus. Lesions of the distal tibia cannot be reached. Matrix Associated Chondrocyte Implantation (MACI) has been shown to produce hyaline like cartilage repair tissue, and the implantation can be performed arthroscopically. Long term follow up studies (up to 10 years) in the knee demonstrate promising results. The purpose of this study was to assess the efficacy of arthroscopic MACI for the treatment of osteochondral lesions in the ankle joint. We reviewed all patients (n=20) who had arthroscopic MACI treatment (n=22) between February 2006 and November 2008 clinically (Foot Function Index, AAOS Foot and Ankle Questionnaire, AOFAS-Hindfoot Score) and with MRI (3 Tesla Siemens MRI). The clinical results and MRI findings up to three years after MACI were compared to pre-operative data. Possible correlations with the individual history and the nature, size or location of the lesion will be discussed. The surgical technique will be described. The results of the procedure are promising

Introduction. Osteochondral lesions of the talus are common injuries following acute and chronic ankle sprains and fractures, the treatment strategies of which include both reparative and restorative techniques. Recently, restorative techniques (i.e., autologous osteochondral transplantation) have been become increasingly popular as a primary treatment strategy, in part due to the potential advantages of replacing “like with like” in terms of hyaline cartilage at the site of cartilage repair. The current study examines the functional results of autologous osteochondral transplantation of the talus in 72 patients. Methods. Between 2005 and 2009, 72 patients underwent autologous osteochondral transplantation under the care of the care of the senior author. The mean patient age at the time of surgery was 34.19 years (range, 16–85 years). The mean follow-up time was 28.02 months (range, 12–64 months). Patient-reported outcome measures were taken pre-operatively and at final-follow-up using the Foot and Ankle Outcome Score and Short-Form 12 general health questionnaire. Quantitative T2-mapping MRI was also performed on select patients at 1-year post-operatively. Results. The mean FAOS scores improved from 52.67 points pre-operatively to 86.19 points post-operatively (range, 71–100 points). The mean SF-12 scores also improved from 59.40 points pre-operatively to 88.63 points post-operatively (range, 52–98 points). Three patients reported donor site knee pain after surgery. Quantitative T2-mapping MRI demonstrated relaxation times that were not significantly different to those of native cartilage in both the superficial and deep halves of the repair tissue. Discussion and Conclusion. Autologous osteochondral transplantation is a reproducible and primary treatment strategy for large osteochondral lesions of the talus and provides repair tissue that is biochemically similar to that of native cartilage on quantitative T2-mapping MRI. This may ultimately allow the ankle joint to function adequately over time

INTRODUCTION. Osteochondral defects are still a challenge for the orthopaedic surgeon, since most of the current surgical techniques lead to fibrocartilage formation and poor subchondral regeneration, often associated to joint stiffness and/or pain. Thinking of the ideal osteochondral graft from both the surgical an commercial point of view, it should be an off-the-shelf product; this is the research direction and the explanation for the new biomaterials recently proposed to repair osteochondral defect inducing an “in situ” cartilage regeneration starting from the time of the implantation into the defect site. For the clinical pilot study we performed, a newly developed nanostructured biomimetic scaffold was used to treat chondral and osteochondral lesions of the knee; its safety and manageability, as much as the surgical procedure reproducibility and the clinical outcome, were evaluated in order to test its intrinsic potential without any cells colture aid. MATERIALS AND METHODS. A new osteochondral scaffold was obtained by enucleating equine collagen type 1 fibrils with hydroxyapatite nanoparticles in 3 different layers with 3 different gradient ratios at physiological conditions. 30 patients (9F, 21M, mean age 29,3yy) affected by either chondral or osteochondral lesions of the knee (8 medial femoral condyles, 5 lateral femoral condyles, 12 patellae, 8 femoral throcleas) underwent the scaffold implantation from January to July 2007. The sizes of the lesions were in between 2 and 6 squared cm. All patients and their clinical outcome were analyzed prospectively at 6, 12, 24 and 36 months using the Cartilage standard Evaluation Form as proposed by ICRS and an high resolution MRI. RESULTS. We observed a statistically significant scores improvement and function recovery comparing the pre-operative to the follow-up parameters evaluated. Moreover, we noticed a better improvement from 12 to 24mm follow up while the good results gained at 2yy were confirmed at 3yy follow up evaluation. The MOCART scoring scale was used to analyze the MRIs. In 80% of cases we obtained a complete filling of the cartilage defect and in some patients we even appreciated articular surface congruency. In this series we report 1 failure followed by a re-operation with different technique. CONCLUSIONS. This new minimally invasive one-step surgical approach to osteochondral defects seems to be an easy and effective procedure. The results obtained are very encouraging and this procedure show satisfactory outcomes even in big osteochondral defects

In foot and ankle surgery incorrect placement of implants, or inaccuracy in fracture reduction may remain undiscovered with the use of conventional C-arm fluoroscopy. These imperfections are often only recognized on postoperative computer tomography scans. The apparition of three dimensional (3D) mobile Imaging system has allowed to provide an intraoperative control of fracture reduction and implant placement. Three dimensional computer assisted surgery (CAS) has proven to improve accuracy in spine and pelvic surgery. We hypothesized that 3D-based CAS could improve accuracy in foot and ankle surgery. The purpose of our study was to evaluate the feasibility and utility of a multi-dimensional surgical imaging platform with intra-operative three dimensional imaging and/or CAS in a broad array of foot and ankle traumatic and orthopaedic surgery. Cohort study of patients where the 3D mobile imaging system was used for intraoperative 3D imaging or 3D-based CAS in foot and ankle surgery. The imaging system used was the O-arm Surgical Imaging System and the navigation system was the Medtronic's StealthStation. Surgical procedures were performed according to standard protocols. In case of fractures, image acquisition was performed after reduction of the fracture. In cases of 3D-based CAS, image acquisition was performed at the surgical step before implants placement. At the end of the operations, an intraoperative 3D scan was made. We used the O-arm Surgical Imaging system in 11 patients: intraoperative 3D scans were performed in 3 cases of percutaneus fixation of distal tibio-fibular syndesmotic disruptions; in 2 of the cases, revision of reduction and/or implant placement were needed after the intraoperative 3D scan. Three dimensional CAS was used in 10 cases: 2 open reduction and internal fixation (ORIF) of the calcaneum, 1 subtalar fusion, 2 ankle arthrodesis, 1 retrograde drilling of an osteochondral lesion of the talus, 1 Charcot diabetic reconstruction foot and 1 intramedullary screw fixation of a fifth metatarsal fracture. The guidance was used essentially for screw placement, except in the retrograde drilling of an osteochondral lesion where the guidance was used to navigate the drill tool. Intraoperative 3D imaging showed a good accuracy in implant placement with no need to revision of implants. We report a preliminary case series with use of the O-arm Surgical Imaging System in the field of foot and ankle surgery. This system has been used either as intraoperative 3D imaging control or for 3D-based CAS. In our series, the 3D computer assisted navigation has been very useful in the placement of implants and has shown that guidance of implants is feasible in foot and ankle surgery. Intraoperative 3D imaging could confirm the accuracy of the system as no revisions were needed. Using the O-arm as intraoperative 3D imaging was also beneficial because it allowed todemonstrate intraoperative malreduction or malposition of implants (which were repositioned immediately). Intraoperative 3D imaging system showed very promising preliminary results in foot and ankle surgery. There is no doubt that intraoperative use of 3D imaging will become a standard of care. The exact indications need however to be defined with further studies

Introduction. The incidence of osteochondral lesions following ankle fractures varies in the literature between 17-70%. They are commonly associated with chronic pain and swelling in patients diagnosed with such pathology. There is less evidence about the relationship between OCL and the development of post-traumatic osteoarthritis, the most common type of ankle arthritis. Methods. Through the use of MRI 8 weeks following ankle fractures, we investigated the incidence of OCL in patients treated both surgically and conservatively for ankle fractures of all AO subtypes. Results. 29 patients met our inclusion criteria, 16 females: 13 males with a mean age of 36 (range 16-64). Twelve patients required surgery with seventeen treated conservatively. The majority of patients (11) were classified as 44B1 fractures with the 44C1 and 44B2 the next most common. We did not detect any OCL in any patient but 65% of patients had both a tibiotalar effusion and associated bone bruising. Conclusion. Contrary to the current literature, we did not associate ankle fractures of any subtype with the development of OCL. Future evaluation of this same cohort will be necessary to evaluate the incidence of post traumatic ankle osteoarthritis

The TruFit® plug is a cylindrical scaffold designed to bridge defects in articular cartilages. It is a porous structure with interconnected pores, which gives it the capability of providing a framework for the ingrowth new tissue and remodelling to articular cartilage and bone. The aim of this study was to assess the radiological incorporation of TruFit® Plugs using MRI. Between December 2007 & August 2009, 22 patients underwent treatment of a chondral or osteochondral lesion using one or more TruFit Plugs. At a minimum of 2 years, 10 patients (12 lesions) were MRI scanned and assessed with a modified MOCART Scoring system by an independent Consultant Musculoskeletal Radiologist. 8 patients were no longer contactable and 4 patients declined MRI as their knee was asymptomatic. 8 of 12 lesions showed congruent articular cartilage cover with a surface of a similar thickness and signal to the surrounding cartilage and reconstitution of the subchondral bone plate. 2 lesions had a thicker congruent articular surface with a similar signal to the surrounding articular cartilage without restoration of the subchondral bone plate. 2 lesions showed no graft incorporation at all and were filled with granulation tissue. Full incorporation of the bony portion of the plug had occurred in only 3 lesions with partial incorporation in 7 lesions. The remaining portion of these 7 lesions looked cystic on MRI. The MRI appearances of the TruFit® Plug at 2 years are encouraging with the majority (83%) showing good restoration of the articular surface with tissue of similar thickness, congruity and signal as the surrounding articular cartilage. However complete incorporation of the TruFit® Plug is rare and cystic change is common. The significance of this cystic change is not clear

The autologous osteochondral grafting represents a treatment option for osteochondral lesions of the weight bearing articular surfaces of femoral condyles and talus. The aim of our study was to evaluate the MRI findings and to determine the correlation between the radiological and the functional outcome in the early follow up. We performed a retrospective study and followed up 33 patients 1 to 4 years after osteochondral auto-grafting. The grafts were harvested from the anterolateral region on the lateral femoral condyle of the ipsilateral knee using an insider rinsing diamond bone-cutting instrument (DBCS). The grafts were implanted using press fit technique and mosaic plasty. Sixteen (48%) women and 17 men were included in our follow up with an average age of 38.4 years (age range-16 to 58 yrs). The Lysholm and Foot and Ankle Osteoarthritis Scores were used for the assessment of the functional outcome. MRI scans were performed by all patients. While the MRI results illustrated graft incorporation, the cartilage contour interruption, irregularity of the subchondral lamina, inhomogeneity and subchondral oedema are typical findings between host and graft tissues. The clinical outcome demonstrated pain relief and improved function. There was no statistically significant correlation between radiological and functional outcome (p>0.05). The MRI is a well-recognised non-invasive diagnostic tool to assess the integration of osteochondral grafts and to evaluate the articular surface but it has a reduced clinical significance on the early post operative stages. The long-term prognostic value of the unsatisfying MRI results is unknown

Purpose. Osteochondral lesions (OCL) of the talus remain a challenging therapeutic task to orthopaedic surgeons. Several operative techniques are available for treatment, e.g. autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), matrix-induced autologous chondrocyte implantation (MACI). Good early results are reported; however, disadvantages are sacrifice of healthy cartilage of another joint or necessity of a two-stage procedure. This case describes a novel, one-step operative treatment of OCL of the talus utilizing the autologous matrix-induced chondrogenesis (AMIC) technique in combination with a collagen I/III membrane. Method. 20 patients (8 female, 12 male; mean age 36, range 17–55 years) were assessed in our outpatient clinic for unilateral OCL of the talus. Preoperative assessment included the AOFAS hindfoot scale, conventional radiography, magnetresonancetomography (MRI) and SPECT-CT. Surgical procedure consisted of debridement of the OCL, spongiosa plasty from the iliac crest and coverage with the I/III collagen membrane (Chondrogide, Geistlich Biomaterials, Wolhusen, Switzerland). Clinical and radiological followup was performed after one year. Results. The mean preoperative AOFAS hindfoot scale was poor with 63.1 points (SD 19.6). At one year followup the score improved significantly (p<0.01) to 86 points (SD 12). At one year followup conventional radiographs showed osseous integration of the graft in all cases. MRI at one year showed intact cartilage covering the lesions in all cases. Conclusion. The initial results of this ongoing study are encouraging. The clinical and radiological results at one year followup are comparable with the results of ACI, OATS and MACI. The AMIC procedure is a readily available, economically efficient, one step surgical procedure. No culturing after chondrocyte harvesting or destruction of viable cartilage is necessary

Purpose. One of the current research topics is the aim to produce tissue engineered osteochondral grafts for future treatment of osteochondral lesions (OCL) of the talus. For the exact anatomic reconstruction, the dimensions of the medial and lateral talar dome must be considered. Sparse data is available regarding the normal anatomic talar dimensions on standard radiographs of ankle joints [1, 2]. The purpose of this study was to describe normal anatomy of different sections of the talar dome on 3D reconstructions of computertomographic (CT) images. Method. CT data sets (Somatom 10, Siemens Erlangen, Germany) of 82 patients (86 ankles) (28 female, 54 male; average age 41.9y (range 15–76y)) without talar pathologies were included. Measurements were performed with a geometry analysis software (VGStudio MAX 2.0, Volume Graphics, Heidelberg, Germany). To assure measurement reproducibility, the reference planes were defined in a first step. To measure the frontal talar edge radius, circles were fitted into the medial and lateral talar edge on frontal planes. To allow measurement of different segments of the talus, the frontal plane was tilted through the center of the talus (defined as a circle fitted to the talus on sagittal view) at 15 and 30 anteriorly and posteriorly. To measure the sagittal radius of the medial and talar edge, ircles were fitted into the medial and lateral talar edge on sagittal planes. Results. The talar edge radius in the frontal plane at 0 wa s 4.9 mm medially (3.0 mm laterally), at 15 ant. 4.2 mm (3.1 mm), at 30 ant. 4.6 mm (3.1 mm), at 15 post. 4.5 mm (3.9 mm), and at 30 post 4.1 mm (6 mm). There was a significant difference (p<0.01) between the mean medial and lateral talar edge radius at all angles. The talar edge radius in the sagittal plane was 20.4 mm medially and 20.3 laterally. There was no significant difference between the mean medial and lateral sagittal talar edge radius. Conclusion. This study shows a significant difference between physiological medial and lateral edge configuration at different frontal planes of the talar dome. No difference was found comparing the sagittal radius of the medial and talar dome. The assessed data provides important aid for engineering of pre-formed, pre-sized osteochondral grafts. Such pre-shaped grafts could help restoring the physiological joint surface by matching exactly into the lesion and consequently achieving the recovery of the physiological joint biomechanics and prevention of secondary degenerative disease

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