Early functional improvements using continuous passive motion therapy after angular-stable plate osteosynthesis of proximal humerus fractures - results of a prospective, randomized trial.

BACKGROUND: The use of continuous passive motion therapy (CPM) has led to promising results in the early phase of rehabilitation after surgical treatment of rotator cuff tears and arthrolysis of the elbow. However, its use has not been proven in other pathologies of the upper extremity. Therefore, the aim of the underlying study was to evaluate the use of CPM therapy after plate osteosynthesis of proximal humeral fractures. METHODS: 95 patients with isolated proximal humerus fractures were enrolled in a prospective, randomized study. Patients were assigned to a treatment group with (n = 48, CPM) or without CPM therapy (n = 47, CG). Four patients (2 of each cohort) violated the study protocol and were excluded. CPM therapy was used for 6 weeks after surgery 2-3 times daily. Functional (range of motion) and patient reported outcomes (PROM, Constant Score [CSS], QuickDASH, subjective shoulder value [SSV], pain on visual analogue scale [VAS]) were evaluated at 6 weeks, 3 and 12months. 60 patients completed the 1-year follow-up. RESULTS: The average patient age was 65.3 years (min: 27, max: 88, SD: ± 14.7). Seventy-two patients were female (79%). There was no difference regarding injury severity (2/3/4 part-fracture: 6/32/7 vs. 9/26/11, p = 0.867) and sex (p = 0.08). However, patients in the CPM group were significantly younger (CPM: 67 [min: 34, max: 82], CG: 74 [min: 27, max: 88], p = 0.032). After 6 weeks we observed a better range of motion for forward flexion (CPM: 90° [min: 50°, max: 180°] vs. CG: 80° [min: 20°, max: 170°] p = 0.035) and abduction (CPM: 80° [min: 40°, max: 180°] vs. CG: 70° [min: 20°, max: 180°], p = 0.048) in the CPM group. There was no difference regarding the further planes of motion or the assessed PROMs at 6 weeks. At 3 and 12 months the results between the treatment groups equalized with no further significant differences. CONCLUSION: The treatment with CPM increases the range of motion after plate osteosynthesis of proximal humerus fractures in the first 6 weeks after surgery. This effect is not sustained after 3 and 12months. The evaluated PROMs are not being influenced by CPM therapy. Hence the results of this prospective randomized study suggest that CPM can be a beneficial asset in the early period of rehabilitation after proximal humerus plate osteosynthesis. TRIAL REGISTRATION: The study protocol was registered in the US National Institutes of Health's database ( http://www. CLINICALTRIALS: gov ) registry under NCT05952622.

Better Flexion but Unaffected Satisfaction After Treatment With Posterior Stabilized Versus Cruciate Retaining Total Knee Arthroplasty - 2-year Results of a Prospective, Randomized Trial.

BACKGROUND: Both the cruciate-retaining (CR) and posterior-stabilized (PS) implant systems are commonplace in modern total knee arthroplasty (TKA) practice. However, there is controversy regarding functional outcomes and survivorship. The aim of the underlying study was to evaluate differences between CR and PS TKA regarding knee function, patient-reported outcome measures (PROMs) as well as complication rates. METHODS: 140 patients with knee osteoarthritis scheduled for an unconstrained TKA were enrolled in a prospective, randomized study. Patients received either a CR or PS implant. Range of motion and PROMs (Oxford Knee Score, Knee Society Score, European Quality of Life 5 Dimensions 3 Level, University of California Los Angeles Activity scale and subjective satisfaction) were assessed prior to, 3 months, 1 and 2 years after surgery. RESULTS: We found minor differences between treatment groups regarding demographic factors. Within the PS group duration of surgery was longer (mean PS 81.4 min vs CR 76.0 min, P = .006). We observed better flexion (median PS 120.0° vs CR 115°, P = .017) and an overall better range of motion (median PS 120.0° vs CR 115.0°, P = .008) for the PS group. PROMs did not differ between groups. At 2-year follow-up there were no revisions in either cohort. Five patients needed reoperations. Three patients needed manipulation under anesthesia, 2 in the CR and one in the PS group. CONCLUSION: While PS TKA achieved a better flexion capability, PROMs were similar in CR and PS TKA. The CR implant design continues to be a reliable option for patients with an intact posterior cruciate ligament.

No difference in patient reported outcome and inflammatory response after coated and uncoated total knee arthroplasty - a randomized controlled study.

BACKGROUND: Allergies against implant materials are still not fully understood. Despite controversies about its relevance, some patients need treatment with hypoallergenic implants. This study compared coated and standard total knee arthroplasty (TKA) regarding inflammatory response and patient-reported outcome measures (PROMs). METHODS: 76 patients without self-reported allergies against implant materials were included in a RCT and received a coated or standard TKA of the same cemented posterior-stabilized knee system. 73 patients completed the 3-year follow-up. Two patients died and there was one revision surgery. Serum levels of cytokines with a possible role in implant allergy were measured in patient`s serum (IL-1beta, IL-5, IL-6, IL-8, IL-10, IFN γ, TNF α) prior to, one and three years after surgery. Furthermore, PROMs including knee function (Oxford Knee Score, Knee Society Score) and health-related quality of life (QoL, EuroQuol questionnaire) were assessed. Additionally, 8 patients with patch-test proven skin allergy against implant materials who received the coated implant were assessed similarly and compared to a matched-pair group receiving the same implant. RESULTS: There were no differences in function and QoL between the assessed groups at any follow-up. The majority of patients demonstrated no elevation of the measured blood cytokines. Cytokine patterns showed no differences between study groups at any follow-up. The allergy patients demonstrated slower functional improvement and minor differences in cytokine pattern. Yet these results were not significant. There were no differences in the matched-pair analysis. CONCLUSION: We observed no relevant increase in serum cytokine levels in any group. The inflammatory response measured seems limited, even in allergy patients. Furthermore, there were no differences between coated and standard TKA in non-allergy patients in the 3-year Follow-Up period. TRIAL REGISTRATION: The study protocol was registered in the US National Institutes of Health's database ( http://www. CLINICALTRIALS: gov ) registry under NCT03424174 on 03/17/2016.

Influence of bone density on stability in TBW.

Osteoporosis is a common disease that leads to a reduction in bone density and increases the risk of fractures. Stable surgical treatment is particularly important for these fractures. The aim of this study was to examine the influence of bone density in the area of ​​the proximal ulna on the failure of the fixation technique of K-wires in tension band wiring (TBW). We provided 10 ulna specimens with TBW and biomechanically examined the pull-out strength of bi- and tricortical K-wires. Bone density measurement was performed using qCT. In the paired t-test, the tricortical group showed a significantly higher pull-out strength in relation to bone density than the bicortical group (p = 0.001). Furthermore, the Pearson correlation showed a high influence of bone density on pull-out strength in the tricortical group (r = 0.544), but without significance (p = 0.100).Our work shows that bone density has a direct effect on the pull-out strength of K-wires in TBW. TBW should therefore be used as osteosynthesis technique, especially in young patients with non-osteoporotic bones. In the case of osteoporotic fractures, alternative procedures should be preferred.

Biomechanical and clinical evaluation of minimal invasive plate osteosynthesis for two-part clavicle shaft fractures.

BACKGROUND: Many surgical treatment methods exist for clavicle shaft fractures. A locking compression plate (LCP) fixation with three screws per fracture side is commonly used. For certain fractures a stabilization with 2 screws per side is potentially suitable, offering the advantage of reduced soft tissue approach, while avoiding the disadvantages of minimally-invasive nailing at the same time. This hypothesis was evaluated biomechanically and clinically. METHODS: Four treatment procedures were investigated biomechanically using composite human clavicle specimens. A load-to-failure test was performed using a three-point cantilever test. In group 1, a simple shaft fracture was simulated and stabilized with 2 screws per fracture side (5-hole LCP). In the second group 3 screws per side (7-hole LCP) were used. In group 3, a non-reduced fracture zone was simulated and treated with 3 screws per side (7-hole LCP). In group 4, an anatomically reduced fracture zone was simulated and treated with 3 screws per side (7-hole LCP). Furthermore 27 patients treated with a short plate and 2 screws per side (similar to group 1) were assessed after a minimum follow-up of 12 months (Constant and DASH Score). RESULTS: The maximum load-to-failure of group 1 was 367N. We observed the highest load-to-failure in group 2 with 497N and the lowest in group 3 with 90N. In group 4 a maximum load-to-failure of 298N could be evaluated. There was no significant difference in load-to-failure between the treatment of a simple clavicle fracture using 5- or 7-hole LCP (p = 0.121). However, we found a significant difference of load-to-failure between the simple and anatomically reduced fracture using a 7-hole plate (p = 0.014). The mean constant score of the surgically treated patients was 95 and the DASH score 3.0. Fracture consolidation was observed in 96.3%. CONCLUSIONS: For certain non-fragmented and well interlocking 2-part fractures, a plate osteosynthesis fixed with only 2 screws per fracture side might offer sufficient biomechanical stability, better soft tissue preservation and comparable fusion rates compared to the operative treatment with 3 screws per side. However, the maximum load-to-failure of the 7-hole LCP was higher than of the 5-hole LCP, but this difference was not statistically significant. TRIAL REGISTRATION: Approval from the ethics committee of the Technical University of Dresden was retrospectively obtained (EK 588122019).

[Therapy of Humeral Shaft Fractures]. / Therapie von Humerusschaftfrakturen.

Humeral shaft fractures are a rare but challenging entity of injuries of the upper extremity. Despite all advances in the past decades - including improved imaging, adjusted surgical techniques and new implant designs - the treatment of humeral shaft fractures and especially the treatment choice remains challenging. Treatment options need to be evaluated individually under consideration of fracture morphology, soft tissue and potential neurological damage as well as patient-specific factors (i.e., age, comorbidities). Moreover, the risk of common complications such as radial nerve palsy, infection, non-union and malrotation needs to be evaluated in order to facilitate the best possible therapy for each patient. The regular available treatment options include conservative (cast, brace, etc.) and surgical measures (ante- and retrograde nailing, angle-stable plate osteosynthesis). Furthermore, (temporary) external fixation remains an option in emergency and complicative cases. However, none of the aforementioned options have proven a superior gold standard. This review evaluates the currently available treatment options and their individual advantages as well as the probability of possible complications and is aiming to supply a guide for individual treatment choice.

Complex Functional Posttraumatic Shoulder Reconstruction Using Shoulder Arthroplasty and a Pedicled Innervated Latissimus Dorsi Flap-A Case Report and Literature Review.

BACKGROUND: The shoulder joint is one of the most freely movable joints in the human body and has therefore high importance for upper limb functionality. Several techniques have been developed to replace the glenohumeral joint including humeral hemiarthroplasty, anatomical total shoulder arthroplasty, and reverse total shoulder arthroplasty, depending on the underlying pathology. For the soft tissue reconstruction, the innervated latissimus dorsi musculocutaneous flap is a reliable solution flap in shoulder and arm reconstruction. CASE PRESENTATION: We present the case of a 16-year-old male patient with a complete destruction of the shoulder joint and soft tissues after ballistic trauma. We performed the reconstruction of the shoulder joint using a humeral hemiarthroplasty with a mesh fixation to the remaining glenoid. The soft tissue coverage and the restoration of the deltoid muscle function were insured with a pedicled innervated latissimus dorsi musculocutaneous flap. One year postoperatively, the patient showed a good function of the shoulder joint with an excellent aesthetical result and no pain. CONCLUSION: The pedicled latissimus dorsi musculocutaneous flap can safely restore the shoulder function, while the humeral hemiarthroplasty with mesh fixation can be a reliable solution for the reconstruction of a completely destructed shoulder joint.

A Novel Multilayer-Coating for Total Knee Arthroplasty Implants is Safe - 10-Year Results From a Randomized-Controlled Trial.

BACKGROUND: This randomized-controlled trial was initiated to compare a new multilayer hypoallergenic coating system with the standard implant in total knee arthroplasty (TKA) in terms of serum metal ion levels, patient-reported outcomes (PROs), and implant survival. METHODS: A total of 120 patients were randomized to receive a coated or standard TKA of the same knee system. Serum metal ion levels (ie, cobalt, chromium, molybdenum, and nickel) as well as knee function (Oxford Knee Score, OKS), quality of life (SF-36), and physical activity (UCLA activity scale) were assessed before surgery and until the 10 year follow-up. A total of 24 patients died and there was one revision in each group. This resulted in 85 patients who completed follow-up. RESULTS: Both groups demonstrated equally good improvement in PROs after surgery and constant score values thereafter. The majority of patients had metal ion serum levels below detection limit. Only cobalt levels demonstrated a slight increase in the standard group at 5- and 10-year follow-up. However, all patients displayed values below 3 µg/L. The cumulative 10-year survival was 98% in both groups. CONCLUSION: There were no problems with the new coating system. No relevant increase in metal ion serum levels were measured. A slight increase in cobalt serum levels in the standard TKA was noted, thus not reaching critical values. The new coating system demonstrated equally good PROs as the standard TKA. Excellent implant survival was observed in both groups. LEVEL OF EVIDENCE: I.

Monteggia fractures: analysis of patient-reported outcome measurements in correlation with ulnar fracture localization.

BACKGROUND: Monteggia fractures and Monteggia-like lesions result after severe trauma and have high complication rates. Preliminary biomechanical studies suggested a correlation between ulnar fracture localization and clinical result. OBJECTIVES: Key objective was to evaluate whether the site of the ulnar fracture can be correlated to clinical outcome after open reduction and internal stabilization. METHODS: In a retrospective, monocentric study 35 patients who underwent surgical treatment after suffering a Monteggia injury or Monteggia-like lesion were included. Fractures were classified according to Bado and Jupiter, the site of the fracture location at the proximal ulna and regarding the potential accompanying ligamentary injury. In a follow-up examination validated patient-reported outcome measures and functional parameters were evaluated. Furthermore, treatment strategy and complications were analysed. RESULTS: Mean patient age was 51.9 years (± 18.0). 69% were females (n = 24). Follow-up took place after 50.5 months (± 22.1). Fractures were classified according to Bado (I:2, II:27, III:4, IV:2). Bado II-fractures were further classified according to Jupiter (A:7, B:16, C:3, D:1). Cases were divided into subgroups depending upon the distance of the ulnar fracture site in respect to its distal endpoint (A: < 7 cm and B: > 7 cm). Average overall MEPS was 84.1 (± 19.0). Oxford elbow score and DASH were 37.2 (± 10.5) and 20.4 (± 20.5). Average extension capability reached - 7° (± 7.5). Mean flexion was 134.8° (± 19.7). Average pain according to visual analogue scale was 1.6 (± 1.9). We found no differences between the subgroups regarding the PROMs. Subgroup A displayed a worse extension capability (p = 0.027) and patients were significantly older (p < 0.01). Comparing patients with and without fracture of the radial head, we observed no differences. Patients with an accompanying injury of the coronoid process displayed higher pain levels (p = 0.011), a worse functionality (p = 0.027) and overall lower scoring in PROM. CONCLUSION: The presented results suggest that in Monteggia fractures and Monteggia-like lesions, the localization of the ulna fracture can give a hint for its postoperative outcome. However, we could not confirm the hypothesis of an increasing instability in ulnar fractures located further distally (high severity of the potential ligamentous injury). Intraarticular fractures or injuries with a close relation to the joint have a worse prognosis, especially if the coronoid process is injured. Trial registration Registration was done with ClinicalTrials.gov under NCT05325268.

Ultracongruent insert design is a safe alternative to posterior cruciate-substituting total knee arthroplasty: 5-year results of a randomized controlled trial.

PURPOSE: If substitution of the posterior cruciate ligament in total knee arthroplasty is necessary, there are two options available: posterior stabilized (PS) design with a post-cam mechanism or anterior-lipped ultracongruent (UC) inserts. UC inserts have the advantage that no femoral box is necessary and a standard femoral component can be used. The aim of this study was to compare the range of motion (ROM) and patient-reported outcome (PRO) after UC and PS fixed-bearing TKA. Better ROM in PS TKA and no difference in PRO between both designs was hypothesized. METHODS: A randomized controlled trial with 127 patients receiving a fixed-bearing UC or PS design of the same knee system was performed. Nine patients died and there were four revision surgeries. 107 patients completed the 5-year follow-up. Patient-reported outcome was assessed. Patellofemoral problems were evaluated using selected applicable questions of the Oxford Knee Score (getting up from a table, kneeling, climbing stairs). RESULTS: Surgical time was 10 min shorter in the UC group (p < 0.001). After 5 years, both groups demonstrated good knee function and health-related quality of life without significant differences between the groups. Both groups demonstrated a high satisfaction score and the majority of patients would undergo this surgery again. Patellofemoral problems were recognized more frequently in the PS group (p = 0.025). CONCLUSION: Both designs demonstrated similar good results after 5 years. Stabilization with an anterior-lipped UC insert can be considered a safe alternative to the well-established PS design if cruciate substitution is necessary.

[The use of knee prostheses with a hypoallergenic coating is safe in the medium term : A randomized controlled study]. / Die Anwendung antiallergisch beschichteter Knieendoprothesen ist mittelfristig sicher : Eine randomisierte kontrollierte Studie.

BACKGROUND: In Germany, patients with contact allergy to implant components usually receive coated joint arthroplasties. Whether the treatment using these hypoallergenic implants achieves comparable results to standard treatment with implants consisting of cobalt-chromium alloy (CoCr) implants is controversially discussed internationally and has rarely been investigated in the mid-term. OBJECTIVES: Are there differences in blood metal ion concentrations, knee function, and patient-reported outcomes (PROM) between coated and standard implants? MATERIAL AND METHODS: 118 patients were randomized to receive either a coated or a standard implant. Knee function as well as patient-reported outcome measures were assessed. Metal ion concentrations in blood samples were additionally determined for chromium, cobalt, molybdenum, and nickel, preoperatively, one and five years after surgery. RESULTS: After five years, it was possible to analyse the results of 97 patients. In metal ion concentrations, as well as PRO, consistently good results were seen, without any difference between the groups. While in 13 patients there was an increase in chromium concentration above 2 µg/l one year after surgery, there was no measured value above 1 µg/l after five years. CONCLUSION: In our study, similar mid-term results were detected for coated (TiNiN) and standard (CoCr)TKA. With respect to metal ion concentrations and PRO there are no disadvantages in using coated TKA.

Better short-term function after unicompartmental compared to total knee arthroplasty.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) is an established treatment option for patients with unicompartmental osteoarthritis (OA). However, strict patient selection is crucial for its success. The proposed advantages include nearly natural knee kinematics, faster rehabilitation and better functional outcomes. Despite the aforementioned facts and it's proven cost-effectiveness, there are still hesitations for the use of UKA as an alternative to total knee arthroplasty (TKA). Key objectives of this study were therefore to assess clinical and patient-reported outcome (PRO) as well as patient's satisfaction after medial UKA in comparison to TKA. METHODS: To assess the outcome after UKA we conducted a prospective multi-center study. 116 patients with unicompartmental OA and indication for UKA were included. Overall 54 females and 62 males with an average age of 62.7 years (±9.8) and an average body mass index (BMI) of 29.2 (± 3.7) were recruited. Clinical results and PRO were assessed using the Knee Society Score (KSS). Follow-ups took place 3 months, 1 and 2 years after surgery including clinical examination, radiographs, assessment of PRO and adverse events. Pain and satisfaction was evaluated using a visual analog scale (VAS, 0 (worst) to 10 (best)). For comparison with TKA a propensity score matched-pair analysis was performed to eliminate confounders. Matching criteria were gender, patient's age, BMI and comorbidities. A total of 116 matched-pairs were analysed. RESULTS: There was no revision in the UKA group until 2 years after surgery. Revision rates were higher in the TKA group (0.6%). Preoperative KSS-Scores were higher within the UKA cohort (p <  0.001). After surgical treatment, PROMs displayed a significant improvement (p <  0,001) in both cohorts. Regarding the Knee-Score (Pain, Alignment, ROM) we observed no differences between cohorts after 12 months. The Function-Score demonstrated significantly better results in the UKA cohort (UKA vs. TKA 95 vs 80, p <  0.001). Patient satisfaction was also higher in UKA patients (UKA vs TKA 9.0 vs 8.8, p = 0.019). CONCLUSION: Patients of both cohorts showed high satisfaction after knee arthroplasty. UKA resulted in higher function scores compared to TKA without increased revision rate during short-term follow-up. Therefore, UKA is a good treatment option for unicompartmental OA. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04598568 . Registered 22 October 2020 - Retrospectively registered.

Wound infection caused by Photobacterium damselae in a 32-year-old woman: case report and review of the literature.

The case of a 32-year-old woman is reported, who was affected by a persisting wound infection caused by Photobacterium damselae after an accident in the Mediterranean Sea. Besides the clinical case, microbiological characteristics based on the phenotypic and genotypic description of the isolate (including whole genome data) are presented and discussed.

Instability of the proximal radioulnar joint in Monteggia fractures-an experimental study.

BACKGROUND: A Monteggia fracture is defined as a fracture of the proximal ulna combined with a luxation of the radial head. The aim of the present work is to evaluate the extent of instability of the radius head in the proximal radioulnar joint (PRUJ) as a function of the severity of elbow fracture and ligamentous injury in an experimental biomechanical approach. METHODS: Eight fresh-frozen cadaver arms were used. All soft tissues were removed except for the ligamentous structures of the PRUJ and forearm. A tensile force of 40 N was exerted laterally, anteriorly or posteriorly onto the proximal radius. The dislocation in the PRUJ was photometrically recorded and measured by two independent examiners. After manual dissection of the ligamentous structures up to the interosseous membrane, the instability was documented and subsequently measured. The following dissection levels were differentiated: intact ligamentous structures, dissection of annular ligament, oblique cord and proximal third of interosseous membrane. RESULTS: An anterior instability remains relatively constant until the proximal third of the interosseous membrane is dissected. The radial head already dislocates relevantly in the posterior direction after dissection of the annular ligament with an additional considerable stability anteriorly and laterally. Subsequently, the posterior instability increases less pronouncedly in regard of distal resected structures. The lateral instability increases constantly during the progressing resection of the ligamentous structures. CONCLUSION: On the one hand, a complete healing of the ligament injury after functional treatment is hardly conceivable with ligamentary damage up to the level of the proximal interosseous membrane. A remaining instability of the proximal radius could therefore be a possible cause for the unsatisfactory clinical results after certain Monteggia fractures. On the other hand, the present study may give a possible explanation (i.e. early dorsal radius head dislocation after dissection of annular ligament) why the Bado II injury is the most frequent type of Monteggia fractures.

Intraarticular use of tranexamic acid reduces blood loss and transfusion rate after primary total knee arthroplasty.

BACKGROUND: Tranexamic acid (TXA) is effective in reduction of hemorrhage after major surgical procedures. In total joint replacement it is commonly administered intravenously. Despite various studies regarding the safety of its antifibrinolytic effect there are contraindications for systemic use. In total knee arthroplasty (TKA) TXA can also be administered intraarticular. However, there is a lack of studies focusing on dosage, effectiveness and complications of this local treatment. This study aimed to evaluate if blood loss and transfusion rate can be reduced in primary TKA by local application of TXA. METHODS: We included a total of 202 consecutive primary, unilateral TKA patients, 101 without and 101 with intraartricular application of 2 g TXA. Surgery was conducted after a standardized protocol. Blood loss, transfusion and complication rates were evaluated until three months after surgery. Blood loss was estimated using the hematocrit-value (Hk) prior and five days after surgery by Rosenecher's and Mercuriali's formula. RESULTS: By the use of TXA a significant reduction of blood loss (Rosencher average 1220 ml vs 1900 ml, Mercuriali average 430 ml vs 700 ml p < 0,001) and transfusion rate (0% vs 24.75% of patients, p < 0,001) was observed. There were no differences regarding complication rates. Due to the lower cost of TXA compared to applied erythrocyte concentrates a side effect of the treatment was a cost reduction of € 1.609 within this cohort. CONCLUSIONS: The intraarticular application of 2 g TXA resulted in a significant reduction of blood loss and transfusion rate after primary TKA without increased complication rates. This method therefore seems to be a safe and cost effective instrument to reduce perioperative blood loss. However, it has to be considered that this is an off-label use.

Similar outcome during short-term follow-up after coated and uncoated total knee arthroplasty: a randomized controlled study.

PURPOSE: Patients with known hypersensitivity to metals often require hypoallergenic TKA implants. Coating of a standard implant is a common solution, and although in vitro tests have demonstrated reduction of polyethylene wear for these coatings, it is still unknown whether these implants have any clinical benefit. This study was initiated to investigate metal ion concentrations, knee function and patient-reported outcome (PRO) after coated and uncoated TKA. METHODS: One hundred and twenty-two (122) patients were randomized to receive a coated or a standard TKA and, after exclusions, 59 patients were included in each group. Knee function and PRO were assessed with validated scores up to 3 years after surgery. Metal ion concentrations in blood samples were determined for chromium, cobalt, molybdenum and nickel, preoperatively and 1 year after surgery. RESULTS: Chromium concentrations in patient plasma increased from a median of 0.25 to 1.30 µg/l in the standard TKA group, and from 0.25 to 0.75 µg/l in the coated TKA group (p = 0.012). Thirteen patients (3 coated, 10 standard TKA) had chromium concentrations above 2 µg/l. The concentrations of cobalt, molybdenum and nickel did not change. Patient-reported outcome measures (PROM) demonstrated a substantial improvement after TKA, without any differences between the groups. CONCLUSION: The increase in chromium concentration in the standard group needs further investigation. If surgeons use coated implants, they can be confident that these implants perform as well as standard implants. LEVEL OF EVIDENCE: I.

Analysis of Total Knee Arthroplasty revision causes.

BACKGROUND: The number of revision Total Knee Arthroplasty (TKA) is rising in many countries. The aim of this study was the prospective assessment of the underlying causes leading to revision TKA in a tertiary care hospital and the comparison of those reasons with previously published data. METHODS: In this study patients who had revision TKA between 2010 and 2015 were prospectively included. Revision causes were categorized using all available information from patients' records including preoperative diagnostics, intraoperative findings as well as the results of the periprosthetic tissue analysis. According to previous studies patients were divided into early (up to 2 years) and late revision (more than 2 years). Additional also re-revisions after already performed revision TKA were included. RESULTS: We assessed 312 patients who underwent 402 revision TKA, 89.6% of them were referred to our center for revision surgery. In 289 patients (71.9%) this was the first revision surgery after primary TKA. Among the first revisions the majority was late revisions (73.7%). One hundred thirteen patients (28.1%) had already had one or more revision surgeries before. Overall, the most frequent reason for revision was infection (36.1%) followed by aseptic loosening (21.9%) and periprosthetic fracture (13.7%). CONCLUSIONS: In a specialized arthroplasty center periprosthetic joint infection (PJI) was the most common reason for revision and re-revision TKA. This is in contrast to population-based registry data and has consequences on costs as well as on success rates in such centers.

Lysine-specific demethylase-1 modifies the age effect on blood pressure sensitivity to dietary salt intake.

How interactions of an individual's genetic background and environmental factors, such as dietary salt intake, result in age-associated blood pressure elevation is largely unknown. Lysine-specific demethylase-1 (LSD1) is a histone demethylase that mediates epigenetic regulation and modification of gene transcription. We have shown previously that hypertensive African-American minor allele carriers of the LSD1 single nucleotide polymorphism (rs587168) display blood pressure salt sensitivity. Our goal was to further examine the effects of LSD1 genotype variants on interactions between dietary salt intake, age, and blood pressure. We found that LSD1 single nucleotide polymorphism (rs7548692) predisposes to increasing salt sensitivity during aging in normotensive Caucasian subjects. Using a LSD1 heterozygous knockout mouse model, we compared blood pressure values on low (0.02 % Na(+)) vs. high (1.6 % Na(+)) salt intake. Our results demonstrate significantly increased blood pressure salt sensitivity in LSD1-deficient compared to wild-type animals with age, confirming our findings of salt sensitivity in humans. Elevated blood pressure in LSD1(+/-) mice is associated with total plasma volume expansion and altered renal Na(+) excretion. In summary, our human and animal studies demonstrate that LSD1 is a genetic factor that interacts with dietary salt intake modifying age-associated blood pressure increases and salt sensitivity through alteration of renal Na(+) handling.