Donor age has no relevant role in biomechanical properties of allografts used in anterior cruciate ligament (ACL) reconstruction: A systematic review.

PURPOSE: Surgeons generally consider the donor age as a factor that negatively influences the quality of allograft used in anterior cruciate ligament (ACL) reconstruction, however, the available evidence does not clearly support this statement. The purpose of the study was to investigate if donor age influences the biomechanical properties of allografts used in ACL reconstruction. METHODS: A comprehensive literature search was conducted for all relevant articles using MEDLINE (PubMed), Scopus, and Cochrane Collaboration Library, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Studies including the analysis of the correlation between biomechanical properties of the allografts and donor age were selected. The role of donor age was labelled as 'none' if absent, 'higher' or 'lower' if the properties were higher or lower in older specimens with respect to younger. The correlation was defined as 'weak' or 'strong' according to each study definition. RESULTS: No conflicting role of donor age was reported for modulus of elasticity, load to failure, strain, stiffness and displacement. The only parameters where the significant results were consistent were the tensile strength and the stress (low or moderate correlations). When considering the tested samples with a donor's age <65 years, a significant role of age was reported in only four out of 13 groups of graft tested (patellar tendon, fascia lata, anterior tibialis tendon and posterior tibialis tendon). CONCLUSION: The current literature did not allow to state that the donor age negatively influences the biomechanical properties of allografts, making it impossible to identify a clear age cut-off value to exclude them from ACL reconstruction procedures. LEVEL OF EVIDENCE: Level IV, systematic review.

An Innovative Topical Medical Device with Hyaluronic Acid and Polypeptides in Patients with Reduced Knee Function.

A topical medical device, AI500®, constituted of a single-chain polypeptide embedded in hyaluronic acid, was tested and evaluated in patients with reduced knee function due to osteoarthritis and other knee conditions. A total of 35 participants with reduced knee function assessed by the WOMAC Physical Function score were recruited. Four study visits were planned, from the first application at V0 to 1 week follow up at V3. Patient symptomatology was evaluated after 24 h (V1) and after 48 h (V2) through phone contact, and after 1 week from V0, on site (V3). The overall duration of the follow up was one week. An amelioration of 40% in WOMAC Physical Functional scores after 1 week of treatment was recorded, thus achieving the primary endpoint of 20%. Furthermore, a reduction of 29% in Physical Functional scores and of 28% in total WOMAC scores between V0-V2 was registered, together with a decrease of 39% between V0 and V3. The NRS scale showed a 29% and 37% reduction in pain between V0-V1 and V0-V2, respectively. Product safety was confirmed by the very low rate of adverse effects, non-device related, observed in only 2 patients out of 35, resolved spontaneously within 24-48 h. No safety concerns or risks associated with the use of the device were highlighted. There are few the studies on the topical use of HA-based gels for the treatment of knee problems. Compared to invasive intra-articular injections and oral pharmacological therapies used in cases of knee pain, the topical application of AI500® is non-invasive, safe, and appreciated by patients. Good results in terms of functional improvement and symptoms resolution were obtained in less than 1 week.

All-Polyethylene Versus Metal-Backed Tibial Components in Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: In the literature, there is no evidence suggesting the superiority in clinical performance between all-polyethylene (AP) and metal-backed (MB) tibial implants in total knee arthroplasty. The aim of this study was to systematically review the literature to collect only high-quality studies investigating the differences in terms of clinical and radiostereometric analysis (RSA) outcomes of AP compared to MB implants. METHODS: Only randomized controlled trials (RCTs) reporting either clinical or RSA outcomes have been included. Data sources were Embase, Medline, and the Cochrane Central Register of Controlled Trials. RESULTS: We included eleven RCTs evaluating the outcomes of 1,377 patients. Of the RCTs, 9 of them showed a low risk and 2 showed moderate risk of bias. There was no statistically significant difference in terms of clinical outcomes and survival rate between the AP and MB group; however, a statistically significant lower mean lift-off in the AP group (0.19 mm) compared to the MB group (0.3 mm) was observed on RSA. CONCLUSIONS: The performance of AP total knee arthroplasty in terms of clinical outcomes and 5-year survival was not statistically different when compared to the MB group. However, the RSA showed a statistically significant lower mean lift-off in the AP group.

Sub-optimal femoral fit in total knee arthroplasty, a systematic review of human femoral data vs off-the-shelf contemporary femoral components.

PURPOSE: The purpose of the current study is to investigate the inadequacy of fit between the human distal femur and the knee implants offerings and describe the available strategies to overcome this issue. METHODS: A systematic research of the literature was performed to identify studies reporting morphologic measures of the distal femur. Studies were excluded if they included unhealthy knees or the morphological analysis did not report the two key dimensions to identify the patient's unique anatomy: AP length and mediolateral (ML) width. Clinically relevant component overhang or underhang was considered when the metal-bone mismatch was > 3 mm as described in the literature. RESULTS: Six studies with anthropometric analysis of 1395 distal femurs met the inclusion criteria. The analysis revealed that by employing the available sizes of four current "state-of-the-art" primary off-the shelf (OTS) femoral implants up to 13-41% would show underhang and 9-27% overhang clinically relevant and the introduction of narrower sizes did not reduce this percentage of underhang but improved the overhang rate of 10-15%. CONCLUSIONS: Whenever an ML/AP mismatch in encountered in the operating room, adaptations are needed, and these bring about deleterious biomechanical and clinical complications. Therefore, this study highlights the need for implants design with multiple ML offerings per AP size, since they provide not only more sizes options but more femoral shapes to match the different ML sizes of the distal femur, compared to designs with single ML offerings for a given femoral AP dimension.

High return to sport rate and few re-ruptures at long term in professional footballers after anterior cruciate ligament reconstruction with hamstrings.

PURPOSE: Anterior cruciate ligament (ACL) ruptures are considered high burden injuries in sports with high pivotal activity, especially for professional footballers. A lack of evidence exists about long-term follow up of professional elite athletes who underwent ACL reconstruction. The purpose of the study is to analyze the return to play and the career of professional footballers who underwent ACL reconstruction with hamstrings, to evaluate re-rupture and reoperation at either indexed and contralateral knee, and to assess the long-term clinical subjective outcomes and satisfaction. METHODS: Twenty-eight professional footballers that underwent 33 ACL reconstructions were retrospectively included in the study. All surgical interventions were performed using hamstring tendons graft and an over the top technique. Inclusion criteria were: inability to compete due to joint instability caused by total or subtotal ACL lesion, patients contracted to a professional football team at time of surgery. Exclusion criteria were: multi-ligament reconstruction or concomitant meniscal allograft transplantation. Patients were contacted by phone and a brief questionnaire about surgery was administered. Subsequently, a Lysholm knee scoring scale was obtained. After that, an online research was performed on publicly available websites in order to retrieve information of the patients included after surgery. RESULTS: In all cases, ACL Reconstruction was performed with hamstring tendons using a non-anatomic Double-Bundle technique in 16 cases (49%), an Over-The-Top Single-Bundle technique in 9 cases (27%), and an Over-The-Top Single-Bundle plus Lateral Plasty technique in 8 cases (24%); moreover, a meniscal lesion was present in 20 cases (61%). Three (9%) of the 33 ACL reconstruction failed (2/16 Double-Bundle, 1/9 Single- Bundle, 0/8 Single-Bundle + Lateral Plasty; p = n.s.), with two of them within 12 months from surgery. Other procedures, mainly arthroscopic meniscectomies, were performed in 10 cases (30%). The first official match was played after an average of 8.0 ± 3.6 (4.6-18.2) months in 31 cases (94%). Patients were evaluated after 12.6 ± 3.3 years (6.7-17.5) from the indexed ACL reconstruction. The average Lysholm score was 94.2 ± 8.3. CONCLUSIONS: In our small case-series, professional soccer players were able to return to play at a competitive level with a hamstrings over the top technique. Patients with long careers had a high percentage of reoperation on the contralateral knee. LEVEL OF EVIDENCE: IV.

Do Clinical Outcomes and Failure Rates Differ in Patients With Combined ACL and Grade 2 MCL Tears Versus Isolated ACL Tears?: A Prospective Study With 14-Year Follow-up.

BACKGROUND: A combined injury to the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) is a common injury pattern encountered during clinical practice. Recent systematic reviews have found no consensus on the optimal method of managing this combined ligament injury pattern, and no long-term studies with modern techniques are available in the literature. PURPOSE: To compare 2 groups of patients who underwent isolated ACL reconstruction in terms of failures and clinical scores at long-term follow-up. In the first group were patients with isolated ACL tears (ACL group), while the second was composed of patients with combined ACL and MCL grade 2 tears (ACL + MCL group). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 57 patients (37 in the ACL group and 20 in the ACL + MCL group) underwent isolated ACL reconstruction with a double-bundle technique between January and December 2005. Patients were contacted for scores on the International Knee Documentation Committee subjective form, Western Ontario and McMaster Universities Osteoarthritis Index, and Tegner activity scale as well as data regarding ipsilateral or contralateral revision ACL surgery. A 2-way analysis of variance for repeated measures was used to statistically assess the differences between the groups. RESULTS: Overall, 49 patients (86%) completed the survey and were therefore included in the study. The minimum follow-up was 14.6 years (range, 14.1-15.2 years). There was a significant reduction in both groups of all the outcome scores between the intermediate and final-follow-up. The number of failures was 3 of 31 (9.7%) in the ACL group and 1 of 18 (5.5%) in the ACL + MCL group; this difference was not significant. Moreover, there were no clinical differences between the groups in terms of graft failures, contralateral lesions, and clinical scores. CONCLUSION: At 14-year follow-up, no clinical difference or increased failure rate was observed between the study groups, suggesting that isolated ACL reconstruction could represent an appropriate treatment for a combined ACL and MCL grade 2 lesion.

Long sports career and satisfactory clinical outcomes after Meniscal Allograft Transplantation (MAT) in young professional athletes involved in strenuous sports.

PURPOSE: To assess the return to sport rate of young professional athletes, to analyze their careers in terms of matches played and league participation over a minimum period of 6 years after Meniscal Allograft Transplantation (MAT), as well as to assess the long-term clinical subjective outcomes and satisfaction. METHODS: Thirteen professional athletes (ten soccer and one basketball players, one fencer and one wrestler) with a mean age at surgery of 23.4 ± 4.0 underwent MAT (six medial, seven lateral). The time required to return to sport, post-operative performance level and the number of reoperations were evaluated. At an average follow-up of 9.0 ± 2.8 years, Lysholm, KOOS and Cincinnati scores were administered and collected. RESULTS: Thirteen patients (100%) returned to sports practice after an average period of 11.8 ± 3.8 months. Nine athletes (69%) returned to sports at the same pre-injury level. Overall, 93%, 85%, 62% and 55% were active until the 3rd, the 5th, the 7th and the 9th season after MAT, respectively. Seven patients (54%) underwent a reoperation after MAT, where only two of them (15%) were related to graft problems (one meniscectomy and one graft suture). Of the ten athletes that completed subjective evaluation, the mean Lysholm score was 72 ± 15 (0% "Excellent", 10% "Good", 60% "Fair", 30% "Poor"). Of the athletes with lower scores, one suffered from patellar tendon rupture, one from post-operative infection and one from a previous femoral fracture. The mean Cincinnati knee score was 77 ± 18, while the average KOOS values were 60 ± 34 for sports. CONCLUSION: Meniscal Allograft Transplantation (MAT) in young professional athletes involved in strenuous activities allowed all patients to return to pre-injury sport and in nearly 70% of cases at their pre-injury level. After five seasons following MAT, 85% of patients were still active or playing more than 20-30 matches per season. On the other hand, nearly 50% underwent at least one reoperation and only 70% of patients were rated as "Good", or "Fair" using the Lysholm score. LEVEL OF EVIDENCE: IV.

Lateral meniscus allograft transplantation without bone plugs: technique and outcomes.

Once considered a non-fundamental structure, the menisci are now known to provide several functions within the knee, including protection of articular cartilage, load-bearing, shock absorption, joint stability, joint lubrification and joint congruity functions. Meniscal tears are one of the most common lesions in knee orthopedics, and partial or total meniscectomies are commonly performed procedures in orthopedic surgery. Despite meniscectomy is well recognized to lead improvement in clinical outcomes, it has been related to early onset knee osteoarthritis and joint degeneration which are associated with pain and functional limitations. Meniscal allograft transplantation has become a viable option for patients under 55 years old that have undergone total or near total meniscectomy and are in a painful state. This procedure can be performed using bone plugs or without bone plugs. In the bone plugs free technique allograft will be presented as a lateral meniscus with a portion of tibial plateau and is then introduced into the joint through an arthroscopic portal and fixed to the capsule with all-inside stitches. The most important aspect required to obtain good clinical results are graft size, anatomic placement and fixation, because extrusion is the most common complication related to meniscal transplantation. Although a lack of long-term follow-up (FU) studies, it has been demonstrated that lateral meniscus transplantation without bone plugs is a minimal invasive surgical procedure that improves the knee function, increases patient physical activity and reduces pain.

Increased Rotatory Laxity after Anterolateral Ligament Lesion in Anterior Cruciate Ligament- (ACL-) Deficient Knees: A Cadaveric Study with Noninvasive Inertial Sensors.

The anterolateral ligament (ALL) has been suggested as an important secondary knee restrain on the dynamic laxity in anterior cruciate ligament- (ACL-) deficient knees. Nevertheless, its kinematical contribution to the pivot-shift (PS) phenomenon has not been clearly and objectively defined, and noninvasive sensor technology could give a crucial contribution in this direction. The aim of the present study was to quantify in vitro the PS phenomenon in order to investigate the differences between an ACL-deficient knee and an ACL+ALL-deficient knee. Ten fresh-frozen paired human cadaveric knees (n = 20) were included in this controlled laboratory study. Intact, ACL-deficient, and ACL+ALL-deficient knees were subjected to a manual PS test quantified by a noninvasive triaxial accelerometer (KiRA, OrthoKey). Kinematic data (i.e., posterior acceleration of the tibial lateral compartment) were recorded and compared among the three statuses. Pairwise Student's t-test was used to compare the single groups (p < 0.05). Intact knees, ACL-deficient knees, and ACL+ALL-deficient knees showed an acceleration of 5.3 ± 2.1 m/s2, 6.3 ± 2.3 m/s2, and 7.8 ± 2.1 m/s2, respectively. Combined sectioning of ACL and ALL resulted in a statistically significant acceleration increase compared to both the intact state (p < 0.01) and the ACL-deficient state (p < 0.01). The acceleration increase determined by isolated ACL resection compared to the intact state was not statistically significant (p > 0.05). The ALL sectioning increased the rotatory laxity during the PS after ACL sectioning as measured through a user-friendly, noninvasive triaxial accelerometer.

The reliability of adductor tubercle as an anatomical landmark for joint line restoration in revision knee arthroplasty: a systematic review.

Joint line (JL) restoration is one of the major challenges in revision total knee arthroplasty (rTKA). There is debate regarding the most reliable methodology for the assessment of JL level during revision surgery. Among the strategies, the use of adductor tubercle (AT) as an anatomical landmark has been proposed. The purpose of this paper is to systematically review the available literature to understand the reliability of AT ratio to identify the JL, and the advantages and drawbacks of its application. A research was performed on the PubMed, Embase, Cochrane and Google Scholar databases based on the following inclusion criteria for articles' selection: (I) clinical reports of any level of evidence, (II) written in the English language, (III) published from 2010 to 2020, (IV) dealing with the use of the adductor tubercle as a landmark to restore JL in revision TKA. All relevant data were extracted by two independent investigators, and discrepancies were resolved by discussion and consensus. A total of 13 studies were included: nine were radiographic evaluations, 3 clinical reports and 1 was an ex-vivo study. Radiographic studies highlighted that AT is a landmark easy to identify, with high intra and inter-observer agreement, irrespective of gender, age and size of the patient. The comparison with other bony landmarks revealed superior reliability in favor of AT. Also during surgical procedures, AT can be safely located and some clinical studies confirmed that AT ratio helps surgeon in re-establishing a correct JL and achieve ligament balancing even in complex revision cases. AT is a reliable and easily detectable landmark, and AT ratio is a valid tool to determine the JL level and help surgeons to restore the JL and simultaneously achieve knee ligament balancing in r-TKA.

Knee Intraosseous Injections: A Systematic Review of Clinical Evidence of Different Treatment Alternatives.

OBJECTIVE: To systematically review the available clinical evidence regarding the safety and efficacy of knee intraosseous injections for the treatment of bone marrow lesions in patients affected by knee osteoarthritis. DESIGN: A literature search was carried out on PubMed, Embase, and Google Scholar databases in January 2020. The following inclusion criteria were adopted: (1) studies of any level of evidence, dealing with subchondral injection of bone substitute materials and/or biologic agents; (2) studies with minimum 5 patients treated; and (3) studies with at least 6 months' follow-up evaluation. All relevant data concerning clinical outcomes, adverse events, and rate of conversion to arthroplasty were extracted. RESULTS: A total of 12 studies were identified: 7 dealt with calcium phosphate administration, 3 with platelet-rich plasma, and 2 with bone marrow concentrate injection. Only 2 studies were randomized controlled trials, whereas 6 studies were prospective and the remaining 4 were retrospective. Studies included a total of 459 patients treated with intraosseous injections. Overall, only a few patients experienced adverse events and clinical improvement was documented in the majority of trial. The lack of any comparative evaluation versus subchondral drilling alone is the main limitation of the available evidence. CONCLUSIONS: Knee intraosseous injections are a minimally invasive and safe procedure to address subchondral bone damage in osteoarthritic patients. They are able to provide beneficial effects at short-term evaluation. More high-quality evidence is needed to confirm their potential and to identify the best product to adopt in clinical practice.

High survivorship rate and good clinical outcomes at mid-term follow-up for lateral UKA: a systematic literature review.

PURPOSE: The purpose of this paper is to systematically review the available literature to understand the effectiveness, the survivorship, the clinical outcomes and the complications of lateral UKA. METHODS: A review of the current literature available about lateral UKA was performed in March 2020, according to the PRISMA guidelines. Selection was based on the following inclusion criteria: (1) clinical reports of any level of evidence, (2) written in English language, (3) published from 1996 to 2020, (4) dealing with clinical data on lateral UKA. A total of 47 articles, published between 1996 and 2020, were included in the review. Quality of every article was assessed using the Modified Coleman Methodology Score. RESULTS: A total of 47 studies were included. Mean mCMS was 45.27 (range 30-62). Mean age at surgery was 64.5 years (range 34.1-88.0 years). In 1741 patients (65.5%) a metal back implant was used and in 421 patients (15.8%) an all poly design was used. Several scores were used to evaluate clinical results (OKS, AKSS, IKS, KOOS, WOMAC, VAS). Range of motion improved with an overall mean value of 120.3° (range: 105.9°-143.3°). The mean follow-up was 60.7 months (range, 7-204 months), mean survivorship (absence of a revision) with a minimum 60 months of follow-up was 88.6% (range 74.5-100) and mean satisfaction of patients was 78.5% (range 41.0-97.9). CONCLUSIONS: Lateral UKA seems to be an effective solution to manage lateral osteoarthritis (OA), based on preliminary results, with survivorship and satisfaction rate comparable to medial UKA and total knee arthroplasty (TKA). Nonetheless, this review highlights that the quality of studies available in current literature is low. LEVEL OF EVIDENCE: Systematic review of level IV studies.

In vitro validation of a novel inertial-based cutting guide for tibial resection in total knee arthroplasty.

BACKGROUND: Correct component alignment in total knee arthroplasty (TKA) is crucial for implant functionality and longevity. Several devices have been developed to help surgeons to achieve optimal component positioning. The purpose of our study was to evaluate the accuracy and reliability of a novel inertial-based cutting guide used to perform tibial resection in TKA taking into account users with different levels of experience. METHODS: Seven operators (raters) with different levels of experience participated in the study. To evaluate the accuracy, the varus/valgus (VV) and slope (SL) angles obtained with this novel device were compared with the reference angles obtained with the navigation system. To calculate intra-(rater) reliability repeated measurements of VV and SL angles by the same operator were used. To calculate inter-(rater) reliability repeated measurements of VV and SL by different operators were used. RESULTS: A total of 140 acquisitions were performed. In this study both for the VV and for the SL the maximum mean absolute error (MAE) that the inertial system registered was <1°. Intra-inter reliability was evaluated by calculating the Fleiss' Kappa coefficient, which recorded values close to 0.75 (75%) with regard to the VV and the SL for intra-reliability, while values were recorded around 0.9 (90%) for the inter subject reliability. CONCLUSIONS: The Perseus system is accurate, reliable and surgeon-friendly and could be very useful in improving results in low-volume centers.

Impact of the COVID-19 pandemic on orthopaedic and trauma surgery training in Europe.

PURPOSE: This study aimed to evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on orthopaedic and trauma surgery training in Europe by conducting an online survey among orthopaedic trainees. METHODS: The survey was conducted among members of the Federation of Orthopaedic and Trauma Trainees in Europe (FORTE). It consisted of 24 questions (single-answer, multiple-answer, Likert scales). Orthopaedic trainees' demographic data (six questions), clinical role changes (four questions), institutional changes due to the COVID-19 pandemic (nine questions), and personal considerations (five questions) were examined. RESULTS: Three hundred and twenty-seven trainees from 23 European countries completed the survey. Most trainees retained their customary clinical role (59.8%), but a significant number was redeployed to COVID-19 units (20.9%). A drastic workload decrease during the pandemic was reported at most institutions. Only essential activities were performed at 57.1% of institutions and drastic disruptions were reported at 36.0%. Of the respondents, 52.1% stated that faculty-led education was restricted and 46.3% pursued self-guided learning, while 58.6% stated that surgical training was significantly impaired. Concerns about the achievement of annual training goals were expressed by 58.2% of the participants, while 25.0% anticipated the need for an additional year of training. CONCLUSIONS: The SARS-CoV-2 pandemic significantly affected orthopaedic and trauma training in Europe. Most trainees felt the decrease in clinical, surgical, and educational activities would have a detrimental effect on their training. Many of them consulted remote learning options to compensate training impairment, stating that after the COVID-19 pandemic electronic educational approaches may become more relevant in future.

Are Metaphyseal Sleeves a Viable Option to Treat Bone Defect during Revision Total Knee Arthroplasty? A Systematic Review.

Purpose Bone loss is a challenging problem during revision total knee arthroplasty (TKA). Several studies have been published on the use of metaphyseal sleeves during revision TKA. Therefore, the aim of this systematic review was to summarize the clinical and radiographic outcomes of the use of metaphyseal sleeves in the setting of revision TKA. Methods A comprehensive search of PubMed, MEDLINE, CINAHL, Cochrane, EMBASE, and Google Scholar was performed, covering the period between January 1, 2000, and August 12, 2017. Various combinations of the following key words were used: "metaphyseal," "sleeves," "knee," and "revision." A total of 10 studies were included in the present systematic review. Results A total of 904 patients with 928 implants were recorded with a mean age of 69 years. They were evaluated at a mean follow-up of 45 months. Overall 1,413 sleeves, 888 in the tibia and 525 in the femur, were implanted. There were 36 septic re-revisions of the prosthetic components (4%). Five sleeves were found loose during septic re-revision; therefore, the rate of septic loosening of the sleeves was 0.35%. An aseptic re-revision of the prosthetic components was performed 27 times (3%). Ten sleeves were found loose during aseptic re-revision; therefore, the rate of aseptic loosening of the sleeves was 0.7%. Intraoperative fractures occurred 44 times (3.1%). Finally, clinical outcome was improved at final follow-up. Conclusion Metaphyseal sleeves demonstrate high radiographic signs of osteointegration, low septic loosening rate, low intraoperative fractures rate, and a good-to-excellent clinical outcome. Hence, they are a valid option to treat large metaphyseal bone defect during revision TKA. Level of Evidence This is a systematic review of level IV studies.

The role of alpha defensin in prosthetic joint infection (PJI) diagnosis: a literature review.

Prosthetic joint infection (PJI) management is not standardized worldwide and the outcome is frequently unsatisfactory.More and more arthroplasties are now being performed. An increasing number of highly virulent and antibiotic-resistant bacteria and an ageing population of patients presenting with many comorbidities make it necessary to focus on this important topic.Diagnosis of PJI remains challenging because the clinical signs and symptoms and elevation of systemic biomarkers (C-reactive protein, erythrocyte sedimentation rate) may be unclear.In the last few years, the clinical research has focused on synovial fluid biomarkers as a possible breakthrough in the complex scenario of PJI diagnosis.Synovial biomarkers have shown encouraging results and they should be used as diagnostic adjuncts to synovial white cell count and culture bacteriology. Synovial leukocyte esterase (LE) and synovial C-reactive protein (CRP) have been evaluated as good screening measures; however, the most promising synovial fluid biomarker in terms of sensitivity and specificity for PJI seems to be alpha defensin (AD).The laboratory-based alpha defensin enzyme-linked immunosorbent assay (ELISA) test demonstrated the highest ever reported accuracy for PJI diagnosis. However, an alpha defensin lateral flow test could have its place in ruling in a suspected PJI intraoperatively because of its high specificity and rapid results. Cite this article: EFORT Open Rev 2019;4:10-13. DOI: 10.1302/2058-5241.4.180029.

Evaluation of Blood Loss and Implant Alignment after Total Knee Arthroplasty with Inertial Based Extramedullary Femoral Cutting Guide.

Purpose The purpose of this study was to compare, in terms of blood loss and implant alignment, a new generation of smart extramedullary (EM) cutting guides with the conventional intramedullary (IM) guide for total knee arthroplasty (TKA). The hypothesis was that the EM system would result in less blood loss and fewer days of hospitalization, while ensuring equal or higher accuracy in the alignment of the femoral implant. Methods Thirty-six patients were enrolled for the present study: 18 patients underwent TKA using the EM guide and for the other 18 patients the IM guide was used. Preoperative and postoperative X-rays were acquired. The preoperative and postoperative hemoglobin values were compared. Lastly, length of hospital stay was recorded. Results The hemoglobin difference was significantly lower in the EM group. The alignment of the prosthetic femoral implant in the two groups was comparable but all patients in the EM cohort had a final alignment within 3 degrees of range on the frontal view, while 22% of the patients in the IM cohort had a final alignment exceeding 3 degrees of range. The mean hospitalization duration showed no significant difference between groups, though EM group showed 1.6 days less compared with IM group. Conclusions The inertial-based EM guide system could be useful for decreasing blood loss compared with conventional guide. This device tended to have better results even in terms of accuracy, but this difference was not significant. Level of Evidence This is a level II, prospective cohort study.

How Reliable Is the Cell Count Analysis in the Diagnosis of Prosthetic Joint Infection?

BACKGROUND: Synovial analysis of joint aspirates is a key diagnostic tool; all major diagnostic algorithms include cell count (CC) and polymorphonuclear percentage (PMN%) as important criteria to make the diagnosis. In this context, we conducted this study to analyze the overall accuracy of CC and PMN%. METHODS: A single-center retrospective analysis was performed with clinical data of included patients, with a total of 524 preoperative joint aspirations (255 hips, 269 knees). From the aspirated synovial fluid, we tested the leukocyte esterase activity, leukocyte CC, and PMN%, and sent specimens for aerobic and anaerobic bacterial culture. Depending on the clinical results in accordance with the Musculoskeletal Infection Society criteria for prosthetic joint infection (PJI), 203 patients were then admitted for aseptic revision and 134 patients for septic exchange. RESULTS: In 337 cases (64.3% of the study patients), it was possible to measure the CC. The best cutoff level for PJI of all study patients was 2582 leukocytes/µL (sensitivity [SE] 80.6%, specificity [SP] 85.2%) and a PMN% of 66.1% (SE 80.6%, SP 83.3%). The chosen cutoff levels for PJI of total knee and total hip arthroplasty were 1630 leukocytes/µL (SE 83.6%, SP 82.2%) and a PMN% of 60.5% (SE 80.3%, SP 77.1%) and 3063 leukocytes/µL (SE 78.1%, SP 80.0%) and a PMN% of 66.1% (SE 82.2%, SP 82.4%), respectively. CONCLUSIONS: CC and PMN% are sensitive methods for diagnosing PJI of total hip and total knee arthroplasty. However, there are differences in cutoff levels between knees and hips. International guidelines and diagnostic criteria need revisions in terms of these parameters.