Contrast-enhanced ultrasound (CEUS): one step forward in the identification of "high risk" solitary fibrotic tumors of the liver.

BACKGROUND: Solitary fibrous tumors of the liver (SFTL) are rare neoplasms, whose identification and definition of malignant potential are challenging. CASE PRESENTATION: A 62-year-old patient underwent conventional imaging and CEUS to characterize an indeterminate liver lesion after other imaging techniques were inconclusive. In fact, all diagnostic techniques concluded that it was a partially fibrotic lesion, while CEUS determined its extra-hepatocellular origin and malignant potential, initially hypothesized to be a cholangiocarcinoma. Due to the possible risk of seeding following a biopsy procedure, the patient was a candidate for surgery. Subsequently, histopathological examination revealed SFTL. CONCLUSION: CEUS confidently characterized the malignancy and hypothesized the origin of the liver lesion, thus aiding in treatment planning.

Learning curve of Persona Partial Knee (PPK) arthroplasty: a clinical trial.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) procedures are considered to be more technically demanding than conventional total knee arthroplasty (TKA), requiring a longer learning curve and more expert surgical skills. Despite some clear advantages of UKA over TKA (such as lesser blood loss, greater bone stock, greater knee performances, etc.), UKA evidenced a greater rate of revision. OBJECT: This study investigated the learning curve of Persona Partial Knee (PPK) arthroplasty for primary medial UKA performed by a single, non-designer surgeon. PPK is a fixed-bearing, compartment-specific implant. The primary outcome of interest for this study was to evaluate the learning curve of the surgical duration. The secondary outcome of interest was to evaluate the learning curve of radiological implant positioning. METHODS: Patients who underwent primary medial UKA using PPK (Zimmer-Biomet, Warsaw IN, USA) were prospectively enrolled for the study. All surgeries were performed by a single, non-designer surgeon experienced in knee and hip arthroplasty. The primary outcome of interest was to evaluate the surgical duration. The secondary outcome of interest was to evaluate the implant positioning. The learning curve was estimated using an appropriate nonlinear polynomial regression model with a lower Akaike Information Criterion (AIC). RESULTS: One hundred twenty five patients were enrolled in the study. 59% of them (74 of 125 patients) were women. The patients' mean age at the time of surgery was 70.1 ± 9.5 years and their mean body mass index (BMI) was 27.8 ± 4.2 kg/m2. Curve stabilisation of the surgical time was at the 94th patient, of the tibial angle at the 47th patient, of the tibial slope at the 54th patient, of the anterior protrusion at the 29th patient, and of the posterior protrusion at the 51st patient. CONCLUSIONS: The learning curve for component positioning was achieved in approximately 50 cases. The curve of the surgical time achieved a plateau at 94 Persona Partial Knee. Additionally, the factors directly correlated with earlier stabilization of the learning curve in terms of component positioning were: male gender, younger age, right side, and larger components.

Change in patellar height in medial and lateral unicompartmental knee arthroplasty: a clinical trial.

INTRODUCTION: Evidence on patellar height changes following unicompartmental knee arthroplasty (UKA) is lacking. Therefore, this study compared the patella height in patients who underwent medial versus lateral UKA. Moreover, a subgroup analysis was conducted to investigate whether sex, age, and BMI of the patients exert an influence on the postoperative patellar height. METHODS: Radiographs and hospital records of patients undergoing UKA were prospectively collected. Surgeries were performed by one author with long experience in UKA in a highly standardised fashion. The implants were fixed-bearing medial PPK (Zimmer Biomet, Warsaw, Indiana, USA) and fixed-bearing lateral ZUK (Lima Corporate, Udine, Italy). The patellar height was measured using the Insall-Salvati and Caton-Deschamps indices. RESULTS: A total of 203 patients were included: 119 patients were included in the medial and 84 in the lateral UKA. The mean age of the patients was 68.9 ± 6.7 years, and the mean BMI was 28.1 ± 4.1 kg/m2. 54% (110 of 203 patients) were women. On admission, between-group comparability was found in age, BMI, sex, and length of the follow-up. No between-group and within-group difference was detected pre- and post-operatively in the Insall-Salvati and Caton-Deschamps indices in patients who have undergone medial versus lateral UKA. Concerning the subgroup analyses, no between-group and within-group difference was detected pre- and post-operatively in all comparisons according to sex, age, and BMI. CONCLUSION: No difference was found in patella height in patients who have undergone medial compared to lateral UKA. Furthermore, there was no evidence of an association between patient characteristics (sex, age, BMI) and patella height between medial and lateral UKA.

Clinical outcomes, complications, and survivorship for unicompartmental knee arthroplasty versus total knee arthroplasty in patients aged 80 years and older with isolated medial knee osteoarthritis: a matched cohort analysis.

PURPOSE: The primary goal of this study is to compare clinical outcomes, complication rate, and survivorship in octogenarians who underwent total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) by performing a matched cohort analysis. METHODS: We analyzed 75 medial UKAs performed by a single experienced surgeon. The included cases were matched with 75 TKAs performed during the same study period. Potential TKA matches used identical exclusion criteria. UKAs were age-, gender-, and body mass index (BMI)-matched at the rate of 1 UKA to 1 TKA from our departmental database. Clinical evaluation included the visual analog scale for pain, range of motion (ROM-flexion and extension), Knee Society Score (KSS), and Oxford Knee Score (OKS). Each patient was clinically evaluated on the day before the surgery (T0) and at two follow-ups at least 12 months (T1) and 24 months (T2) after the surgery. For the survivorship, revision was defined as failure of the implant (periprosthetic joint infection, periprosthetic fracture, or aseptic loosening), and survival was based on implant revision or patient death. Undesirable clinical developments that were not present at baseline or that increased in severity after treatment were classified as adverse events. RESULTS: The mean age at the time of the surgery was 82.1 ± 1.9 years for UKA and 81.5 ± 1.8 years for TKA (p = 0.06). The two groups differed in regard to surgical time (UKA 44.9 ± 7.2 min; TKA 54.4 ± 11.3 min; p < 0.001); furthermore, the UKA group showed better function (ROM; flexion and extension) than the TKA group at each follow-up time point (p < 0.05). Both groups reported a significant improvement in all clinical scores (KSS and OKS) when compared with their preoperative status (p < 0.05), while no differences were found between the groups at each follow-up (p > 0.05). The UKA group reported 7 (9.3%) failures, while TKA reported 6 failures. There were no survival differences between the groups (T1: p = 0.2; T2: p = 0.5). Overall complication rate was 6% in the UKA group versus 9.75% in TKA (p = 0.2). CONCLUSION: The UKA and TKA patients had similar clinical outcomes, post-operative range of motion, and survivorship in octogenarians with medial knee osteoarthritis, with comparable complication rate. Both the surgical procedures may be considered in this patient population, but further long-term follow-up is needed. LEVEL OF EVIDENCE: Level III.

No difference in mobile and fixed bearing partial knee arthroplasty in octogenarians: a clinical trial.

BACKGROUND: A clinical trial comparing MB (mobile-bearing) versus FB (fixed-bearing) in medial partial knee arthroplasty (PKA) in octagenarians has been conducted. The focus of the present study was on PROMs, range of motion (ROM), implant positioning and implants survivorship. The hypothesis of the present study was that MB implants performed better than FB in PKA in octogenarians. METHODS: The first group received FB PKA-PPK®; the second received MB PKA-Oxford. Patients were not randomly allocated. The following PROMs were administered at T0 (pre-operatively), T1 (1 year after surgery), and T2 (3 years after surgery): visual analogue scale (VAS), Knee Society Score (KSS) and Oxford Knee Score (OKS). Data regarding the implant survivorship and ROM were also collected. Furthermore, the following radiographic parameters were measured: Femoral component varus/valgus; Tibial component varus/valgus; Anteroposterior slope. RESULTS: At T0, 28 patients were included in the FB and 33 in the MB group. The surgical time was shorter in the FB group (p < 0.001). No difference between FB and MB in ROM, VAS, KSS, and OKS at each follow-up (p > 0.05). No difference was found in implant positioning (p > 0.05). At last follow-up, FB group reported three failures caused by aseptic loosening. Four failures were observed in the MB cohort: two for bearing dislocation and two for aseptic loosening. The Kaplan-Meier Curve found no differences in implant survivorship. CONCLUSIONS: According to the main findings of the present clinical trial, MB implants performed similar to FB in PKA in octogenarians. The FB group demonstrated shorted surgical time. No difference was found in patient reported outcome measures, ROM, implant positioning, and survivorship. LEVEL OF EVIDENCE: Level II, prospective study.

Radiographic and Clinical Evolution of the Oxford Unicompartmental Knee Arthroplasty.

The aim of the study is to evaluate whether the use of the new instrumentation Microplasty (MP) improves component positioning and the reliability of the surgical technique, reducing the implant outliers from the recommended range and providing a more accurate resection, while avoiding insufficient or excessive tibial resection and clinical scores. We prospectively analyzed clinical and radiographic outcomes of three consecutive cohorts for a total of 227 implants at a minimum follow-up of 36 months. The first cohort consisted of 67 Oxford unicompartmental knee arthroplasty (OUKA), using the phase III (Ph-III). The second cohort consisted of 136 OUKA, with the MP instrumentation. The third cohort consisted of 24 hypoallergenic OUKA, using the MP instrumentation (TiNbN). Postoperative alignment of the knee in the coronal and sagittal plane was measured using radiographs. No clinical differences were found among the three groups (p > 0.05). A significant difference was found on the slope between Ph-III and MP (p = 0.0005). Moreover, a significant difference was found in tibial angle and in tibial slope in arthroplasty with femoral size small (S), compared with size medium (M) or large (Ly) (tibia varus/valugs angle: p = 0.0484; tibial slope: p = 0.04). Similar results were found between small (AA, A, B) tibial size and large (C, D, E, F) tibial size for tibial varus/valgus (p = 0.03) angle and tibial slope (p = 0.003). A significant difference was found between Ph-III and MP in tibial slope in patients with body mass index (BMI) ≥25 kg/m2 (p = 0.0003). A positive correlation was noted between the femoral and tibial sizes and the tibial angle and the slope, and a negative correlation between weight and the tibial slope; furthermore, a positive correlation was found between Oxford knee score and radiographic angles. The MP instrumentation seems to be effective in determining the tibial cut and, particularly, improving the tibial slope, compared with Ph-III. The tibial slope is directly affected by the weight and measurements of the components, regardless of the instruments or the number of pegs, while clinical outcomes are correlated with implant position. This prospective comparative study reflects level of evidence II.

Similar clinical and radiographic outcomes after two different hypoallergenic medial unicompartmental knee in patients with metal allergy.

BACKGROUND: The purpose in the present study was to compare clinical and radiological outcomes of patients who had undergone a mobile-bearing unicompartmental knee arthroplasty (UKA) with either titanium niobium nitride (TiNbN) alloy implants or with fixed-bearing oxidized zirconium alloy implants. METHODS: The records of two consecutive cohorts for a total of 86 hypoallergenic implants were prospectively analyzed. The first cohort consisted of 49 consecutive implantations of the hypoallergenic UKA Journey Uni Oxinium (Ox Group), while the second consisted of 37 consecutive series of UKA Oxford (TiNbN Group). All patients were evaluated by two independent surgeons who were not involved in the index surgery. The clinical evaluation consisted of evaluating each patient's Oxford Knee Score and Knee Society Score day before surgery (T0), and with two consecutive follow-ups at T1 (minimum follow-up 9 months) and T2 (minimum follow-up 24 months). RESULTS: The two groups were homogeneous in all preoperative values, except Body Mass Index (BMI) and duration of final follow-up [both statistically higher (p < 0.05) in the TiNbN group]. Both groups showed a clinically significant improvement for all scores at final follow-up (p < 0.05). The only differences between the two groups involved a higher pre-operative Oxford Score in TiNbN group (p = 0.031), and different tibial and femoral angles at the final follow-up. CONCLUSIONS: Both TiNbN and Oxinium UKA procedures enabled patients from good to excellent clinical and radiographic outcomes after the final follow-up, regardless of the age, gender, BMI bearing type, and implant size. LEVEL OF EVIDENCE: LEVEL II: Comparative study.

Similar survivorship at the 5-year follow-up comparing robotic-assisted and conventional lateral unicompartmental knee arthroplasty.

PURPOSE: This retrospective study aims to analyse the survivorship and functional outcomes of two samples with similar preoperative clinical and demographic data of lateral unicompartmental knee arthroplasty (UKA) performed with robotic and conventional surgery at a minimum 5-year follow-up. METHODS: In this retrospective study, the clinical records of two cohorts for 95 lateral UKA implants were analysed. The first cohort consisted of 43 patients with cemented lateral UKA performed with the conventional procedure (Conventional group). The second cohort consisted of 52 patients who received robot-assisted cemented lateral UKA (Robotic group). Clinical evaluation of the two samples entailed evaluating the Knee Injury and Osteoarthritis Outcome Score divided into subscales (symptoms and stiffness, pain, function in daily living, function in sport and recreation and quality of life) for each patient. Revision was defined as the failure of the implant (periprosthetic joint infection, periprosthetic fracture or aseptic loosening), and survival was based on implant revision. RESULTS: The mean follow-up time was 90.3 ± 9.1 months for the Conventional Group and 95.4 ± 11.0 months for the Robotic Group (n.s.). Each patient was clinically evaluated on the day before surgery (T0), at a minimum 1-year follow-up (T1) and at a minimum 5-year follow-up (T2). In both groups, all clinical scores improved between T0 and T1 and between T0 and T2 (p < 0.05); for both groups, no differences were noted in any clinical scores between T1 and T2 (n.s.). No significant differences in any clinical score were found between the two groups at each follow-up (n.s.). Survival analysis reported no differences between the two groups at the final 1-year follow-up, with three failures (2 aseptic loosening and 1 periprosthetic fracture) in the Conventional group and two failures (1 patellofemoral osteoarthritis and 1 inexplicable pain) in the Robotic group (n.s.). CONCLUSIONS: This study shows excellent clinical outcomes and revision rates in robotic arm-assisted and manual techniques for lateral UKA, with no clinical differences at medium- to long-term follow-up. LEVEL OF EVIDENCE: Level III-comparative study.

Similar rate of return to sports activity between posterior-stabilised and cruciate-retaining primary total knee arthroplasty in young and active patient.

PURPOSE: Cruciate-retaining and posterior-stabilised implant designs are available for primary total knee arthroplasty. However, whether the implant design is associated with a difference in the level of activity still remains unclear. This clinical trial compared posterior-stabilised and cruciate-retaining implants in sport-related patient-reported outcome measures, range of motion, rate of return to sport, and weekly time dedicated to sport in active adults. It was also hypothesised that in young and active patients both implants lead to a similar rate of return to sport in terms of hours per week, type of sport, and joint mobility. METHODS: All patients were evaluated preoperatively and for a minimum of 36 months follow-up. The University of California Los Angeles activity scores, High-Activity Arthroplasty Score, and Visual Analogue Scale were administered preoperatively and at the last follow-up. The range of motion was investigated at admission and the last follow-up. Data concerning the hours per week dedicated to sports and the type of sport practiced were also collected at admission and at the last follow-up. The Kaplan-Meier Curve was performed to compare implant survivorship. RESULTS: Data from 227 procedures (cruciate-retaining: 109, posterior-stabilised: 118) were prospectively collected. At the last follow-up, no difference was reported in The University of California Los Angeles activity scores (p = 0.6), High-Activity Arthroplasty Score (p = 0.1), Visual Analogue Scale (p = 0.9), flexion (p = 0.7) and extension (p = 0.4). No difference was found in the rate of return (p = 0.1) and weekly hours dedicated to sport (p = 0.3). The Kaplan-Meier curve evidenced no statistically significant difference in implant survivorship (p = 0.6). CONCLUSIONS: At approximately five years of follow-up, no difference was reported between cruciate-retaining and posterior-stabilised implants in active adults in sport-related patient-reported outcomes measures, range of motion, pain, weekly time dedicated to sport, rate of return to sport, and implant survivorship. LEVEL OF EVIDENCE: Level II, prospective study.

High tibial osteotomy with an external fixator or unicompartmental knee arthroplasty for varus knee in young patients?

Purpose: This study compares the functional results and survivorship of unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) with an external fixator for medial compartment osteoarthritis (OA) of the knee. Methods: Two cohorts of patients aged less than 60 years who had undergone either a cemented medial mobile-bearing UKA or an HTO with an external fixator were included in the study. The first cohort included patients undergoing a series of 197 consecutive medial UKA procedures (UKA group). The second cohort consisted of 60 consecutive patients undergoing HTO with an external fixator (HTO group). Each patient was assessed based on the Oxford Knee Score (OKS), the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Subjective International Knee Documentation Committee (IKDC) score/questionnaire. A clinical evaluation was conducted on the day of the surgery (T0) and at the follow-up visit (T1) (minimum follow-up time was 60 months). Complications and failures resulting from the surgery were recorded for each patient. Results: Only the age of the patients at the pre-operative time differed significantly between the two groups, with the HTO group being significantly younger (47.7 ± 8.0 versus 55.8 ± 2.2).After the final follow-up visit, all scores improved in both groups (p < 0.05).IKDC and Oxford scores were higher for the UKA group (p < 0.05). In the HTO group, three complications occurred (5%), including two superficial infections and one deep infection. On the other hand, the UKA group reported four complications (2%): three aseptic mobilisations and one infection requiring revision surgery. There was no difference in the complication rate between the two groups (p = 0.208). Conclusions: In young patients (<60 years) with an isolated medial knee OA, both HTO and UKA led to good to excellent clinical results with a low rate of complications at mid-term follow-up; both surgical procedures may be considered in this patient population. Level of evidence: Level III.

Octogenarians Are the New Sexagenarians: Cruciate-Retaining Total Knee Arthroplasty Is Not Inferior to Posterior-Stabilized Arthroplasty in Octogenarian Patients.

Purpose: The primary goal of this study was to compare survivorship and functional results in individuals aged 80 and over who underwent total knee arthroplasty (TKA) with cruciate-retaining (CR) or posterior-stabilized (PS) implants. Methods: We prospectively analyzed the clinical records of two consecutive cohorts for a total of 96 implants in patients aged 80 years or over. The first cohort consisted of 59 consecutive cemented PS cases, while the second cohort comprised 37 consecutive cemented CR cases. The decision to either perform a PS or CR arthroplasty was taken based on preoperative magnetic resonance imaging and intraoperative findings. The clinical evaluation entailed evaluating each patient's visual analogue scale for pain (VAS), range of motion (flexion and extension), Knee Society Score (KSS), and Oxford Knee Score (OKS). Each patient was clinically evaluated the day before surgery (T0) and at two consecutive follow-ups at least 1 (T1) and 2 (T2) years after surgery. Implant survival was calculated using the Kaplan−Meier method. Results: Both groups showed statistically significant improvements at each follow-up compared with the preoperative values (p < 0.05). The CR group showed a higher flexion degree at T1 than the PS group (116.14 ± 5.57° versus 113.16 ± 7.66°; p = 0.048). No differences were found between the two groups regarding survival rate (chi-squared test p-value = 0.789). Three failures were noted in the CR group, while there were four in the PS group. Conclusions: This prospective clinical study demonstrates that CR and PS TKA had similar clinical outcomes in octogenarians with regard to knee function, postoperative knee pain, and other complications. Prosthesis survivorship for CR and PS TKA were both satisfactory, and in selected octogenarian patients, CR TKA should always be considered because of the reduced surgical time.

Hypoallergenic unicompartmental knee arthroplasty and return to sport: comparison between Oxidized Zirconium and Titanium Niobium Nitride.

BACKGROUND: The present study aims to compare the rate of return to sports in patients who underwent surgery for mobile-bearing UKA with either hypoallergenic TiNbN or with oxidized zirconium alloy implants. METHODS: The records of two consecutive cohorts for a total of 90 hypoallergenic implants were prospectively analysed. The first cohort consisted of 41 consecutive series of medial mobile-bearing hypoallergenic TiNbN UKA, whereas the second cohort consisted of 49 consecutive medial fixed-bearing hypoallergenic Uni Oxinium.The clinical evaluation involved evaluating each patient's University of California, Los Angeles (UCLA) activity scoresand the High-Activity Arthroplasty Score(HAAS). Each patient was clinically evaluated on the day before surgery (T0), then after a minimum follow-up period of 12 months (T1), and finally after 24 months (T2).   Results:The only pre-operative difference between the two groups involved pre-operative BMI with significantly higher BMI in TiNbN Group (p<0.001). Both groups reported significant improvement at each follow-up compared with the previous and also at the final follow up with respect to UCLA and HAAS (p<0.05), except for UCLA in TiNbN between T1 and T2(p>0.05). Moreover, BMI improved significantly at the final follow up, but only in TiNbN group (p<0.05). CONCLUSIONS: Both TiNbN and Oxinium UKA procedures enabled patients to return to an acceptable level of sports activity with excellent radiographic outcomes after the final follow up regardless of the age, gender, BMI, and bearing type.

Satisfactory clinical and radiologic outcomes with a new shorter and modular stem for end-stage hip osteoarthritis: an international prospective multicentre pilot study.

INTRODUCTION: This multicenter prospective cohort study aimed to assess the safety and clinical and radiologic performance of the CLS® BreviusTM Stem with Kinectiv® Technology. MATERIAL AND METHODS: A total of 222 consecutive subjects, recruited in five different centers, qualifying for primary total hip arthroplasty (THA), were enrolled in the study. All the subjects received the CLS® BreviusTM Stem with Kinectiv® Technology. All the enrolled study subjects underwent pre-operative clinical and radiographic evaluation. Additionally, all subjects underwent post-operative clinical, functional and radiographic evaluations at 6 months and 1, 2, 3, and 5 years. These evaluations included implant survival, pain and functional performance (Harris Hip Score [HHS], University of California, Los Angeles [UCLA] Activity Score, Oxford Hip Score), subject quality-of-life (EQ-5D), radiographic parameters, complications, and concentration of metal ions (aluminum and titanium) in blood. RESULTS: No revisions were performed during the follow-up period. Of the 222 patients, only 76 completed the 5-year follow-up. Only 7 and 5 patients had aluminum and titanium 5-year evaluations, respectively. All the clinical parameters showed an overall improvement in the overtime measured with ANOVA for repeated measures; furthermore, the clinical scores showed a statistically significant improvement at 5 years with respect to pre-operative value (p < 0.001). Aluminum and titanium showed no variation for repeated measures at different time points (p > 0.05). A total of six complications were reported, of which only two were hip-related. CONCLUSIONS: The function of the CLS® BreviusTM Stem with Kinectiv® Technology indicated that subject well-being significantly increased following THA regardless of age, gender, BMI, previous surgery, primary diagnosis, and lifestyle.

Similar rates of return to sports and BMI reduction regardless of age, gender and preoperative BMI as seen in matched cohort of hypoallergenic and standard Cobalt Chromium medial unicompartmental knee arthroplasty.

PURPOSE: To compare the rate of return to sports and body mass index (BMI) reduction in patients who underwent surgery for unicompartmental knee arthroplasty (UKA) with either Cobalt-Chromium (CoCr) alloy UKA or with hypoallergenic UKA, stratified by age, gender and BMI. METHODS: Two consecutive cohorts of patients with a total of 172 UKA and a minimum 2-year follow-up period were prospectively included in this comparative study. The first cohort consisted of 136 consecutive series of standard Cobalt-Chromium (CoCr Group). The second cohort consisted of 36 consecutive mobile-bearing hypoallergenic Titanium Niobium Nitride UKA, (TiNbN Group). The clinical evaluation was based on the University of California, Los Angeles (UCLA) activity scores and the High-Activity Arthroplasty Score (HAAS) evaluated on the day before surgery (T0) and after a minimum follow-up of 12 months (T1) and 24 months (T2). Radiographic evaluation performed at T2 included the femoral component position in varus/valgus, the tibial component in varus/valgus and the anteroposterior slope. RESULTS: No statistical differences were found between the groups at each follow-up, as shown by the UCLA and HAAS score (n.s.). Both groups showed a statistically significant improvement (p < 0.05) at each follow-up.. Both groups showed a statistically significant BMI reduction between T0 and T2 (p < 0.05). Radiographic analysis revealed no statistical differences between the two groups in terms of the three measures after the final follow-up (n.s.). All the subgroups showed a significant (p < 0.05) rate of return to sport if compared with the preoperative value (T2 versus T0), except for male in TiNbN group. CONCLUSIONS: Both TiNbN and CoCr medial mobile-bearing UKA enabled patients to return to sports after the final follow-up, regardless of age, BMI, gender and metal sensitivity. These findings inform shared decision making and can help to manage patient expectations after surgery, in particular, in active patients with an overt metal allergy, a specific hypoallergenic implant should be considered the gold standard implant in partial knee replacement surgery. LEVEL OF EVIDENCE: Cohort Study, Level III. REGISTRATION: researchregistry6250- www.researchregistry.com .

No difference in return to amateur sports after medial and lateral unicompartmental knee arthroplasty in patients younger than 65 years.

PURPOSE: The aim of this study was to assess the return to amateur sports of patients under 65 years, following medial unicompartmental knee arthroplasty (mUKA) versus lateral unicompartmental knee arthroplasty (lUKA). It was hypothesized that patients younger than 65 years who underwent lateral or medial unicondylar knee replacement will result in similar rates to amateur sports, at a minimum follow-up of 2 years. METHOD: Patients who underwent medial or lateral UKA participated in a 2-year follow-up program, where they were clinically evaluated for their return to amateur sports, using the University of California, Los Angeles (UCLA) activity scale and the High-Activity Arthroplasty Score (HAAS). Furthermore, subgroup analyses by gender and age were performed. Power analysis was performed to ensure sample size considering that lUKA is implanted ten times less frequently than its medial counterpart. RESULTS: There were 85 patients who completed the entire minimum 2-year follow-up of which 73 belonged to the mUKA group and 12 to the lUKA group. No preoperative differences were found between the groups regarding the gender, the affected side, age, and mean follow-up. Both groups showed statistically significant improvement (p < 0.05) in their return to amateur sports in all parameters (UCLA and HAAS). No differences among the two groups were found at T0 and T1 (n.s.). All subgroups showed a statistically significant improvement (p < 0.05) with respect to the preoperative value, except for UCLA for lUKA with less than 60 years and HAAS for males in the lUKA group (n.s.). No differences were found among subgroups both at To and T1 (n.s.). CONCLUSION: Both mUKA and lUKA procedures enabled all young and active patients a certain return to amateur sports 2 years after surgery, regardless of age and gender. UKA, medial or lateral, should always be considered for the treatment of isolated osteoarthritis in young and active patients with high functional demands. LEVEL OF EVIDENCE: Cohort Study, Level of Evidence III. REGISTRATION: Researchregistry6221 - Research Registry www.researchregistry.com .

Patellar height after unicompartmental knee arthroplasty: comparison between fixed and mobile bearing.

PURPOSE: The purpose of this study was to determine the changes in patellar heights by comparing standardised pre- and post-operative radiographs in a consecutive series of patients undergoing unicompartmental knee arthroplasty (UKA) with two different approaches and implant designs [fixed bearing (FB) vs mobile bearing (MB)] and to correlate the patellar heights with clinical outcomes. METHODS: One hundred and seventy-two UKA patients were prospectively enrolled in the study. 75 patients underwent a minimally invasive FB medial UKA (referred to hereinafter as the 'FB group'); 97 patients were treated with a minimally invasive MB medial UKA. The pre-operative and mid-term (1-year) post-operative patellar heights and clinical scores of these groups of patients were compared using the Insall-Salvati (IS) and Caton-Deschamps (CD) indices and the Oxford Knee Score (OKS). RESULTS: No differences were found between the two groups either with regard to the pre-operative data (p > 0.05) or between pre- and post-operative radiographic scores at the time of each follow-up (p > 0.05). Both the groups reported a significant clinical improvement (p<0.05) as did all the sub-groups (p < 0.05). In the MB group, a higher CD index in females was found at the final follow-up stage (p = 0.043) and a higher pre-operative CD index was found in patients with BMI ≥ 28 (p = 0.040). A statistically negative correlation was found between the pre-operative OKS and pre-operative IS index (rho=- 0.165; p=0.031). CONCLUSIONS: Both FB and MB arthroplastys with different surgical approaches did not change the patellar height regardless of the age, gender and BMI at short-medium-term follow-up. The post-operative patellar height seems not to be correlated with the clinical outcomes. A higher pre-operative IS index was correlated with knee pain and function. LEVEL OF EVIDENCE: Level II-prospective comparative study. STUDY REGISTRATION: Researchregistry6433- www.researchregistry.com .

Return to physical activity and change in body mass index after hypoallergenic medial mobile-bearing unicompartmental knee arthroplasty.

BACKGROUND: The primary purpose of the present prospective study was to consecutively analyse the outcomes of the return to sports activity of patients with positive patch tests undergoing a medial mobile-bearing titanium niobium nitride (TiNbN) unicompartmental knee arthroplasty (UKA). The secondary purpose was to ascertain if a higher grade of physical activity leads to a reduction in the body mass index (BMI) of the patients. MATERIAL AND METHODS: Forty-one patients with positive skin patch tests were included in this prospective study. The clinical evaluation consisted of the University of California, Los Angeles (UCLA) activity scale and the High-Activity Arthroplasty Score (HAAS). Each patient was evaluated the day before surgery (T0), after 12.37 ± 0.70 months (T1), and on the day of the final follow-up, after 67.03 ± 18.2 months (T2). Furthermore, the BMI of each patient was analysed before surgery and during the final follow-up. RESULTS: The UCLA and HAAS mean preoperative values ranged from 3.68 ± 1.1.7 and 6.15 ± 0.76 to 6.1 ± 0.76 and 10.34 ± 1.3, respectively, at T1 (p < 0.0001) and to the final values of 6.34 ± 0.62 and 11.0 ± 8.9, respectively, at T2 (UCLA: T2 versus T1: p = 0.132; T2 versus T0: p < 0.0001; HAAS: T2 versus T1: p = 0.0027; T2 versus T0: p < 0.001). BMI ranged from a preoperative value of 27.97 ± 3.63 to a final value of 26.84 ± 3.11 (p < 0.0001). The only differences within the subgroups concerned patients with BMI ≥ 28, showing a superior HAAS at each follow-up (p < 0.05). A positive correlation was found between BMI and HAAS at T0 and T2 (p < 0.05). CONCLUSIONS: This is the first study to evaluate the rate of the return to sports activities and change in BMI following hypoallergenic UKA. The majority of patients reduced their weight following UKA and improved their physical activity, showing outcomes that were comparable to the standard cobalt-chrome (CoCr) prostheses, regardless of gender, age, BMI and implant size. LEVEL OF EVIDENCE: IV - Prospective Cohort Study. Trial registration researchregistry5978-Research Registry www.researchregistry.com.

Successful return to sport in patients with symptomatic borderline dysplasia following hip arthroscopy and T-shaped capsular plication.

PURPOSE: This study aims to evaluate the return to sport and correlations of patients with symptomatic borderline hip dysplasia (BHD) after hip arthroscopy and T-shaped capsular plication at a minimum follow-up of 24 months. METHODS: Twenty-five patients who underwent hip arthroscopy and T-shaped capsular plication for symptomatic BHD were included in the study. All the patients were evaluated clinically prior to surgery (T0) and at two consecutive follow-ups (T1:15 ± 1.2 months and T2: 53.9 ± 23.2 months) using the visual analogue scale (VAS) pain score, whereas sports activity was assessed by the Hip Outcome Score Sport Specific Subscale (HOS-SSS), the University of California, Los Angeles (UCLA) activity scale, the Tegner score and the physical component (PCS) of the Short Form-12 (SF-12). Furthermore, the presence of correlations and the possible differences between subgroups were evaluated and analysed. RESULTS: A significant difference was found for HOS-SSS, VAS, Tegner, UCLA and PCS with the Friedman test for repeated measures through time points (p < 0.0001). Moreover, all the scores reported significant improvement compared to the previous time point (p < 0.0001) except the HOS-SSS between T1 and T2 (n.s.). Body Mass Index (BMI) was negatively correlated with HOS-SSS at T0 (rho = - 0.526 p = 0.006) and T1 (rho = - 0.425; p = 0.034), with Tegner at each follow-up (T0: rho = - 0470 p = 0.017; T1: rho = - 0.450; p = 0.024; T2: rho = - 0.448; p = 0.024), with UCLA at T1 (rho = - 0.396 p = 0.049), with pre-operative PCS (rho = - 0.413 p = 0.0401), and positively correlated with pre-operative VAS (rho = 0.436 p = 0.0291). CONCLUSIONS: Hip arthroscopy and T-shaped capsular plication in young patients with symptomatic BHD demonstrates a significant increase in return to sport and physical activity and low risk of complications. T-shaped capsular plication procedure may be considered in young and active patients for whom non-operative treatment failed and who have a significant limitation in sports activity; in these patterns of patients, the ideal treatment should reliably allow fast recovery in combination with very low invasiveness which will prevent osteoarthritis. The results of this study provide more accurate information regarding return to sport in patients with BHD after hip arthroscopy and T-shaped capsular plication. LEVEL OF EVIDENCE: Level IV.

Titanium Niobium Nitride Mobile-Bearing Unicompartmental Knee Arthroplasty Results in Good to Excellent Clinical and Radiographic Outcomes in Metal Allergy Patients With Medial Knee Osteoarthritis.

BACKGROUND: The main purpose of the present study was to analyze the clinical and radiological outcomes of patients with positive skin patch tests who underwent medial mobile-bearing titanium niobium nitride unicompartmental knee arthroplasty (UKA) during a mid-term follow-up. METHODS: Thirty-seven patients with positive skin patch tests were included in this prospective study. The clinical evaluation consisted of Oxford Knee Score and Knee Society Score (KSS) reports. Each patient was clinically evaluated the day before surgery (T0) as well as at T1 (11.9 ± 1.3 months) and during the final follow-up T2 (67.2 ± 19.1 months). The positioning of the UKA was evaluated during the final follow-up using standardized radiographs (T2: 67.2 ± 19.1 months). RESULTS: Oxford and KSS ranged from a respective mean preoperative value of 23.0 ± 2.7 and 51.5 ± 5.0 to 42.1 ± 1.7 and 87.6 ± 2.2, respectively, at T1 (P < .001) and to the final values of 45.0 ± 1.9 and 91.9 ± 3.4, respectively, at T2 (P < .001 both vs T1 and T2). At T2, the mean femoral angle was 7.0° ± 4.5°, mean tibial angle was 3.0° ± 2.1°, and mean tibial slope was 5.1° ± 3.2°. A significant difference was found between KSS and Oxford with ANOVA for repeated measures over time (P < .001). The Oxford and KSS scores showed significant improvements during each follow-up. No complications were found, and not a single patient required a revision surgery during the follow-up period. CONCLUSION: The hypoallergenic titanium niobium nitride mobile-bearing UKA showed comparable results to standard CoCr UKA regardless of the gender, age, BMI, and implant size of metal allergy patients with medial knee osteoarthritis. Careful patient selection processes and accurate medical histories played key roles in the choice of hypersensitivity-friendly implants.

Role of dynamic perfusion magnetic resonance imaging in patients with local advanced rectal cancer.

BACKGROUND: The management of rectal cancer patients is mainly based on the use of the magnetic resonance imaging (MRI) technique as a diagnostic tool for both staging and restaging. After treatment, to date, the evaluation of complete response is based on the histopathology assessment by using different tumor regression grade (TRG) features (e.g., Dworak or Mandard classifications). While from the radiological point of view, the main attention for the prediction of a complete response after chemotherapy treatment focuses on MRI and the potential role of diffusion-weighted images and perfusion imaging represented by dynamic-contrast enhanced MRI. The main aim is to find a reliable tool to predict tumor response in comparison to histopathologic findings. AIM: To investigate the value of dynamic contrast-enhanced perfusion-MRI parameters in the evaluation of the healthy rectal wall and tumor response to chemo-radiation therapy in patients with local advanced rectal cancer with histopathologic correlation. METHODS: Twenty-eight patients with biopsy-proven rectal adenocarcinoma who underwent a dynamic contrast-enhanced MR study performed on a 1.5T MRI system (Achieva, Philips), before (MR1) and after chemoradiation therapy (MR2), were enrolled in this study. The protocol included T1 gadolinium enhanced THRIVE sequences acquired on axial planes. A dedicated workstation was used to generate color permeability maps. Region of interest was manually drawn on tumor tissue and normal rectal wall, hence the following parameters were calculated and statistically analyzed: Relative arterial enhancement (RAE), relative venous enhancement (RVE), relative late enhancement (RLE), maximum enhancement (ME), time to peak and area under the curve (AUC). Perfusion parameters were related to pathologic TRG (Mandard's criteria; TRG1 = complete regression, TRG5 = no regression). RESULTS: Ten tumors (36%) showed complete or subtotal regression (TRG1-2) at histology and classified as responders; 18 tumors (64%) were classified as non-responders (TRG3-5). Perfusion MRI parameters were significantly higher in the tumor tissue than in the healthy tissue in MR1 (P < 0.05). At baseline (MR1), no significant difference in perfusion parameters was found between responders and non-responders. After chemo-radiation therapy, at MR2, responders showed significantly (P < 0.05) lower perfusion values [RAE (%) 54 ± 20; RVE (%) 73 ± 24; RLE (%): 82 ± 29; ME (%): 904 ± 429] compared to non-responders [RAE (%): 129 ± 45; RVE (%): 154 ± 39; RLE (%): 164 ± 35; ME (%): 1714 ± 427]. Moreover, in responders group perfusion values decreased significantly at MR2 [RAE (%): 54 ± 20; RVE (%): 73 ± 24; RLE (%): 82 ± 29; ME (%): 904 ± 429] compared to the corresponding perfusion values at MR1 [RAE (%): 115 ± 21; RVE (%): 119 ± 21; RLE (%): 111 ± 74; ME (%): 1060 ± 325]; (P < 0.05). Concerning the time-intensity curves, the AUC at MR2 showed significant difference (P = 0.03) between responders and non-responders [AUC (mm2 × 10-3) 121 ± 50 vs 258 ± 86], with lower AUC values of the tumor tissue in responders compared to non-responders. In non-responders, there were no significant differences between perfusion values at MR1 and MR2. CONCLUSION: Dynamic contrast perfusion-MRI analysis represents a complementary diagnostic tool for identifying vascularity characteristics of tumor tissue in local advanced rectal cancer, useful in the assessment of treatment response.