"Recommendations for periprosthetic joint infections (PJI) prevention: the European Knee Associates (EKA)-International Committee American Association of Hip and Knee Surgeons (AAHKS)-Arthroplasty Society in Asia (ASIA) survey of members".

PURPOSE: Periprosthetic joint infections (PJIs) represent a devastating consequence of total joint arthroplasty. The European Knee Associates (EKA), the American Association of Hip and Knee Surgeons (AAHKS) International Committee, and the Arthroplasty Society in Asia (ASIA) board members were interested in quantifying differences in arthroplasty surgeons' use of various PJI prevention measures to provide clinical recommendations to reduce PJI incidence. METHODS: A prospective Microsoft Forms online survey was distributed among EKA, AAHKS International Committee, and ASIA members and their affiliated arthroplasty surgeons. The survey consisted of 20 single and multiple response questions focused on PJI prevention strategies at three perioperative periods: preoperatively, intraoperatively, and postoperatively. RESULTS: Three hundred and ninety-four arthroplasty surgeons from 6 different continents completed the survey. Preoperative: (A) PJI Risk Stratification: 40.6% routinely set thresholds (e.g., BMI, HgbA1C) to be met to qualify for surgery, 36.5% only review past medical history; 9.1% use machine learning to personalize PJI risk; (B) BMI limit: 36% no limit; 15.4% BMI < 35; 30.9% BMI < 40; 17.2% BMI < 45; (C) Nutritional status: 55.3% do not screen; among those who screen their patients (44.7%), albumin is the single most used marker (86.3%); (D) Hyperglycemia/Diabetes: 83.3% check this comorbidity; 88.1% use HgbA1C as single best screening test; (E) MRSA nasal colonization: 63.7% do not test; 28.9% test all patients; 7.4% test selectively. Intraoperative: (A) Antibiotic prophylaxis in high-risk patients: 43.4% use single antibiotic for 24 h; 21.3% use double antibiotic for 24 h; 14.2% use single/double antibiotic for 7 days postoperatively; (B) Skin-cleansing: 68.7% at home (45.6% chlorhexidine sponge; 11.9% clippers); (C) Intraoperative skin disinfection: 46.9% single chlorhexidine; 25% double chlorhexidine-povidone-iodine;15.4% single povidone-iodine; (D) Tranexamic acid (TXA) to reduce bleeding/SSI: 96% yes (51% double IV dose, 35.2% single IV dose, 23.6% intra-articular injection); (E) Surgical suction drain: 52% do not use drains; 19.7% use a drain < 24 h; (F) Intra-articular lavage: 64.9% use only saline; 28.1% use dilute povidone-iodine; (G) Antibiotic local delivery to prevent PJI: 82.4% use antibiotic-added cement. Postoperative: (A) Routine monitoring of PJI serologic markers: 42% only in symptomatic patients; 34.2% do not; 20.8% in all patients; (B) Serologic markers to rule in/out PJI: 95.9% CRP; 71% SEDRATE; 60.6% WBC; (C) Synovial fluid test to rule in/out PJI: 79.6% culture/sensitivity; 69.5% WBC count; 31.4% CRP. CONCLUSIONS: This survey demonstrated that notable differences still exist in the application of PJI preventive measures across different geographic areas: Optimizing the patient preoperatively and applying multimodal intraoperative strategies represent newer, clinically relevant steps in the effort to reduce the burden of PJI. More uniform guidelines still need to be produced from international scientific societies in order facilitate a more comprehensive approach to this devastating complication. LEVEL OF EVIDENCE: IV.

New insights on metal allergy in total joint arthroplasty.

Metal allergy is an uncommon and not completely understood cause of failure in total joint arthroplasty (TJA). However, either immunopathology neither histologic studies clarified the mechanisms through which the metal ions could lead to the complications related to them. The lack of evidence around this topic also reflects the difficulties to diagnose the MRP in TJA. In fact, the diagnosis is generally based on the exclusion of other causes. Currently, skin-patch testing and lymphocyte transformation test (LTT) are being commonly used to investigate about metal hypersensitivity and a delayed type-IV hypersensitivity is the immuno-histologic response to metals involved in TJA loosening. A review of the recent publications about this topic has been made focusing on immunology, histopathology, and clinics to better understand a still debated topic in orthopedic practice.

Two-stage reimplantation in periprosthetic knee infection.

OBJECTIVE: The increasing number of total knee arthroplasties performed yearly worldwide has resulted in a concomitant rise in bacterial infections. Two-stage reimplantation has been reported as the most successful method of treating periprosthetic knee infections. The purpose of this study was to describe all the phases of the two-stage reimplantation and to review the literature regarding the topic. MATERIALS AND METHODS: Most significant and recent papers about the management of periprosthetic knee infection through a two-stage reimplantation protocol were carefully analysed and reviewed. Our personal experience, previously published, with two-stage-reimplantation protocol was also briefly reported. RESULTS: Two-stage reimplantation has been reported as the most successful method of treating periprosthetic knee infections. The strategy of using an antibiotic-loaded cement spacer and intravenous antibiotics with delayed exchange arthroplasty is actually considered the state-of-the-art, with a reported success rate of 88-96%. The two-stage protocol has been reported as a viable option also for patients with a periprosthetic knee infection by multidrug-resistant organisms. On the other hand, open debridement with polyethylene exchange and single-stage reimplantation have been reported effective only in selective case series involving acute infections by low-virulence organisms. CONCLUSIONS: The strategy that involves the use of cement spacer, intravenous antibiotic therapy, and successive revision total knee implantation is nowadays considered the gold standard for the management of the periprosthetic knee infection. This treatment is actually considered the first choice not only for chronic but also for acute infections, especially in the presence of resistant bacteria.

Antibiotic-loaded bone cement reduces risk of infections in primary total knee arthroplasty? A systematic review.

PURPOSE: Antibiotic-loaded bone cement has been widely used for the treatment of infected knee replacement, but its routine use in primary TKA remains controversial. The aim of this systematic review was to analyze the literature about the antimicrobial efficacy and safety of antibiotic-loaded bone cement for its prophylactic use in primary TKA. METHODS: A detailed and systematic search of the Pubmed, Medline, Cochrane Reviews and Google Scholar databases had been performed using the keyword "total knee arthroplasty" "total knee replacement" "total knee prosthesis" and "antibiotic-loaded bone cement" with no limit regarding the year of publication. We used modified Coleman scoring methodology (mCMS) to identify scientifically sound articles in a reproducible format. The review was limited to the English-language articles. RESULTS: Six articles met inclusion criteria. In total, 6318 arthroplasties were included in our study. 3217 of these arthroplasties received antibiotic-loaded bone cement and 3101 arthroplasties served as the control. There was no statistical difference between the two groups in terms of the incidence of deep or superficial surgical site infection. The average mCMS score was 67.6, indicating good methodological quality in the included studies. CONCLUSIONS: Present review did not reveal any significant difference in terms of rate of deep or superficial surgical site infection in patients receiving antibiotic-loaded bone cement compared with the control (plain bone cement) during primary TKA. The clinical relevance of this study was that the use of antibiotic-loaded bone cement did not significantly reduce the risk of infection in primary TKA. LEVEL OF EVIDENCE: III.

Skeletal modifications in mucopolysaccharidoses: an overview.

The mucopolysaccharidoses (MPS) are a group of rare diseases characterized by deficiencies in different enzymes required for degradation of complex carbohydrates. The enzymatic deficiencies lead to lysosomal accumulation of dermatan sulphate, heparan sulphate, and keratan sulphate in different tissue resulting in multi-system complications. Six different principal types are described. Most MPS types, with the exception of MPS III, are associated with widespread skeletal abnormalities and joint disease. Authors analyzed clinical pathological and radiographical features of mucopolysaccharidoses focusing on pelvic and spine pathologies that generally limit activity and normal life so they have to be treated at the beginning of their manifestations in order to avoid major complication and improve quality of life.

Metallosis following knee arthroplasty: a histological and immunohistochemical study.

Metallosis represents a rare and severe complication of knee replacement surgery. It is caused by the infiltration and accumulation of metallic debris into the peri-prosthetic structures, deriving from friction between metallic prosthetic components. In knee arthroplasty, this event generally occurs as a result of polyethylene wear of the tibial or metal-back patellar component. The real incidence of metallosis is still unknown, although it seems to be more frequent in hip than in knee arthroplasty. The metallic debris induces a massive release of cytokines from inflammatory cells, making a revision necessary whenever osteolysis and loosening of the prosthesis occur. We report four patients who underwent revision of their knee arthroplasty because of severe metallosis. In one of these patients, polyethylene wear had determined friction between the metal-back patellar component and the anterior portion of the femoral component. In the remaining three cases, metallosis was caused by friction between the femoral and tibial prosthetic metal surfaces, resulting from full-thickness wear of the tibial polyethylene. T lymphocytes were activated by metal particles present in periprosthetic membranes. In all patients, one-stage revision was necessary, with rapid pain disappearance and a complete functional recovery of the knee joint.

The manangement of knee cartilage defects with modified amic technique: preliminary results.

Cartilage defects represent a common problem in orthopaedic practice. The knee is frequently involved and the medial femoral condyle is the most common localization. Predisposing factors are: traumas, inflammatory conditions and biomechanics alterations. Several surgical options are available once correct diagnosis is given and accurate patient evaluation has been performed. The aim of our study was to prospectively evaluate functional results of modified autologous matrix induced chondrogenesis (AMIC) technique in a population of patients affected by focal cartilage defects A population of 17 patients was enrolled in this study. 10 patients were male, mean age at the time of surgery was 39 years, right side was involved in 11 cases. All patients were evaluated with accurate physical exam and complete imaging study. At an average FU of 36 months, mean IKDC score and Lysholm score improved from 32 to 82 and from 38 to 74. 13 patients out of 17 (76.5%) were satisfied or extremely satisfied with their functional result. MRI control showed reduction of the defect area and subchondral oedema in 10 cases (58.8%). AMIC technique is a relatively new option in the treatment of full thickness cartilage lesions. It enhances the advantages of microfractures since the Chondrogide membrane protects and stabilizes the blood plug acting as a matrix for new cartilage formation. First reports on AMIC technique, show comparable results to autologous chondrocyte implantation (ACI) with the advantage of a single stage technique and no donor site morbidity. AMIC technique represents a new option in the treatment of full thickness cartilage defect. It is safe and reliable. Our data are in accordance with previously reported series in literature and confirm the good objective and subjective results of this procedure.

Graft-tunnel mismatch in endoscopic anterior cruciate ligament reconstruction. Intraoperative and cadaver measurement of the intra-articular graft length and the length of the patellar tendon.

The results of a study conducted on 50 knees endoscopically reconstructed for an anterior cruciate ligament (ACL) lesion with a free bone-patellar tendon-bone graft and 9 cadaver knees are reported. The mean lengths of the patellar tendon (45.48 +/- 4.71 mm) and intra-articular ACL graft (20.44 +/- 1.98 mm) were measured in the operated knees. The mean length of the tibial bone tunnel (51.62 +/- 2.60 mm) was also measured with a tibial guide at 55 degrees. No statistically significant correlation was found between these three measurements. The length of the patellar tendon was weakly correlated with body height. Measurement of the tibial tunnel on the cadaver knees with increasing degrees of inclination revealed a mean length increase of 0.68 mm per degree (confidence limits: 0.49-0.86). Comparison between the tunnel lengths obtained with the guide and those measured with a Kirschner wire showed a mean difference of 2.3 mm. It is thus desirable to make the tunnel about 53 mm long to ensure excellent fixation of a 28 mm bone block with a 25 mm interference screw. Correct measurement of the anatomical structures involved is in any event an essential requirement for proper execution of the surgical technique.

Meniscal allografts: cryopreservation vs deep-frozen technique. An experimental study in goats.

Meniscal transplantation was performed in two groups of 15 adult goats each, using cryopreserved (group I) and deep-frozen (group II) allografts. Animals were killed at 2 weeks, 1, 3, 6 and 12 months, and a gross, histological and biochemical (water and glycosaminoglycan) evaluation of the menisci was performed. The allografts of both groups showed a normal gross appearance and had in most cases healed at the horn attachments and at the peripheral capsular tissue with a dense scar tissue and no signs of rejection. Histological analysis showed that at 2 weeks in group I the cell number was decreased compared with the controls, and the cells were mainly distributed in the superficial layers. In group II at 2 weeks, only a few cells were present at the peripheral attachment of the menisci. At 1 month in both groups, the cell repopulation can be seen extending from the peripheral area to the superficial layers. Cell proliferation and vascularization are particularly evident in both groups in the 3-month samples. At 6 months and 1 year the grafts can be seen to be completely remodelled and morphologically similar to normal menisci in both groups. Biochemical analysis showed in both groups an increase in water content and a progressive decrease in the concentration of glycosaminoglycans. At 1 year in both groups, there were moderate degenerative changes in the articular cartilage of the tibial plateau, which were more evident in the area of exposed cartilage than in that covered by the meniscus. These results suggest that there are no significant differences between the cryopreserved and deep-frozen grafts, and that even if cryopreservation makes it possible to maintain a partial cell viability in the tissue, this does not seem to improve the morphological and biochemical characteristics of the graft.

Bone-ligament interaction in patellar tendon reconstruction of the ACL.

The bone-ligament junction is one of the most complex biological tissues. Its key function is distribution of mechanical loads applied to the ligament in such a way as to diminish the concentration of stresses or shearing at the interface. This paper reports an experimental assessment of the extent to which a nearly normal junction is formed following reconstruction of the anterior cruciate ligament (ACL) with patellar tendon in 20 New Zealand white rabbits sacrificed after 2-38 weeks. A histological comparison was also made with cadaver ACLs. After 5 weeks the new ligament was still separate from the tunnel wall, inflammation was no longer present, and there was no junction tissue. A thin fibrocartilage layer was observed between the bone and the ligament after 12 weeks and was thicker 6 weeks later. After 28 weeks, there was a substantial layer of fibrocartilage. The new junction was virtually "physiological" by the 38th week, with all four layers present. Many fibrocartilaginous cells were also visible between the collagen fibres. The bone-ligament insertion was almost normal. These findings indicate that tendon reconstruction results in the formation of a structure very similar to a physiological junction, and thus ensures better load distribution over a greater ligament insertion area.

The bone-ligament junction: a comparison between biological and artificial ACL reconstruction.

The physiological bone-ligament junction is composed of four zones: ligament, fibrocartilage, calcified fibrocartilage and bone. It plays a very important part in the distribution of mechanical loads applied to ligaments so as to diminish stress concentration or shearing at the interface. This paper examines types of bone and neoligament insertion after anterior cruciate ligament (ACL) reconstruction with a Dacron prothesis, the Leeds-Keio scaffold ligament (LK), patellar tendon with LAD augmentation (PT+LAD) and bone patellar tendon bone alone (PT). The anterior cruciate reconstructions were implanted in 16 sheep via double-isometric bone tunnels without postoperative knee immobilization. Histological examination of the new insertions (using haematoxylin-eosin, Giemsa, Masson, and Mallory stains) was performed following animal sacrifice after 2, 3, 6 and 9 months. A layer of fibrocartilage between the bone and the ligament was observed with PT, followed by a nearly normal insertion after 6 months. With PT, followed by PT+LAD, the augmentation was surrounded by fibrous tissue (also noted inside the LAD). The PT insertion was virtually physiological after 3-6 months. With the LK scaffold, fibrous tissue was noted in and around the scaffold, even after 6 and 9 months. With the Dacron prosthesis, fibrous tissue around the ligament was unaccompanied by ingrowth into the prosthesis. Nerve endings (pacinian corpuscles) were only present in the PT. These findings show that even after 9 months artificial ligaments are separated from bone by fibrous tissue and devoid of the histological and biomechanical features of a physiological junction.(ABSTRACT TRUNCATED AT 250 WORDS)

[Rare localization of a glomus tumor in the knee]. / Rara localizzazione di tumore glomico nel ginocchio.

The glomus tumor, characterized by the classic trio of tumefaction, acute pain on palpation, and sensitivity to cold, is localized most commonly in the hand and quite rarely in the knee. It occurs most frequently in subjects between the ages of 20 and 40, and its cause is unknown. Masson divided glomus tumors into 4 main types: angiomatous, stromal, nervous, and myxoid, according to the histo-pathological features present. The authors believe that the histological appearance may be affected by the functional phase of the tumor at the moment of surgery: with sphincters closed, meaning very little dilatation of the venous collection areas, or with sphincters open, meaning considerable dilatation of the venous collection areas due to increased hematic flow.

Free patellar graft for the reconstruction of juxtaarticular defects in the treatment of giant-cell tumors.

The patella may solve the problem of an osteocartilaginous autograft for the articular reconstruction of the knee after resection of certain bone neoplasms. Such a solution may be adopted mainly after the resection of tumors that have attacked part of the tibial plate or that have necessitated the removal of the tibial plate to ensure a radical procedure. The cartilaginous surface of either one or both of the patellar articular facets is well suited for restoring the continuity of the tibial articular surface lost through resection. Furthermore, all of the remaining part of the patella provides an excellent graft for replacing the underlying bone loss. This is sometimes sufficient in itself; at times, other bone grafts are required. In both cases, patellectomy is the preliminary procedure and is performed on the same side where tibial resection will be done immediately afterward. Using this procedure, eight cases of giant-cell tumor on the proximal extremity of the tibia and one case on the distal epiphysis have been treated. Consolidation, facilitated by a firm metal osteosynthesis, was rapid. The long-term results were excellent; there were no local recurrences of the tumor, and knee joint function was preserved with values only slightly below normal, even though roentgenograms showed signs of arthrosis.

[Antero-lateral laxity or a combination of anterior and postero-lateral laxity? Therapeutic considerations]. / Lassità antero-laterale o combinata anteriore e postero-laterale? Considerazioni terapeutiche.

The study involves a group of patients affected with inveterate lesion of the A.C.L. for at least 18 months. Homogeneous two-staged surgical treatment was carried out: 1) reconstruction of the A.C.L. according to Kenneth-Jones; 2) retention of the popliteus according to Bousquet. Results were: excellent: 18; good: 10; fair: 2. Follow-up was obtained after an average of 18 months.