Clinical and functional outcome after partial or total claviculectomy without reconstruction for oncologic causes.

BACKGROUND: To achieve clear margins in rare malignant clavicular neoplasms, claviculectomy may become necessary. This study aimed to review clinical, functional, and oncologic outcomes following partial or total claviculectomy without reconstruction. METHODS: This study retrospectively included 15 patients from 2 tertiary sarcoma centers (mean age, 42.6 ± 20.3 years; 66.7% male patients). The median length of clinical and oncologic follow-up was 48.0 months (interquartile range [IQR], 24.0-83.5 months). Functional follow-up (Musculoskeletal Tumor Society score and QuickDASH score [short version of the Disabilities of the Arm, Shoulder and Hand questionnaire]) was available in 9 patients at a median of 36.0 months (IQR, 20.0-100.0 months). RESULTS: Of the 15 patients, 7 underwent total claviculectomy; 5, partial lateral claviculectomy; and 3, partial medial claviculectomy. No postoperative complications emerged. The median Musculoskeletal Tumor Society and QuickDASH scores at latest follow-up amounted to 26.0 points (IQR, 24.0-29.0 points) and 18.0 points (IQR, 11.0-22.0 points), respectively. Notably, scores tended to be lower in patients who underwent total claviculectomy (n = 2) in comparison to partial claviculectomy (n = 7). CONCLUSION: Satisfactory clinical and functional results can be achieved following partial or total claviculectomy without reconstruction, with a low complication rate and acceptable mid- to long-term function.

Sexual activity after short-stem total hip arthroplasty. Does stem size matter?

BACKGROUND: Sexual activity is an important component of quality of life. To date, no studies have examined the impact of stem design on return to sexual activity (RTS) and quality of sex life after total hip arthroplasty (THA). METHODS: A questionnaire was designed to assess preoperative and postoperative sexual habits, joint awareness and physical activity in working-age patients undergoing short-stem (n = 176) or straight-stem (n = 97) THA. RESULTS: No differences were noted in time until RTS based on the stem design (short stems vs. straight stems; 6 [IQR: 4-10] vs. 6 [4-10] weeks; p = 0.996). Multivariate analysis revealed that higher patient BMI (p = 0.04), female gender (p < 0.001) and lower FJS-12 (p = 0.006) were significantly associated with delayed RTS. Improved hip mobility and reduced pain mainly contribute to improved quality of sexual activity postoperatively. CONCLUSION: This study, hence, indicates that stem design has no impact on time until resumption of sexual activity in patients < 65 years. Female obese individuals who are aware of their artificial joint in daily life are at increased risk of delayed RTS after surgery. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Restoration of hip geometry after total hip arthroplasty: retrospective comparison of two short stems and one straight stem.

BACKGROUND: The preservation or restoration of hip geometry following total hip arthroplasty (THA) is of importance, considering that alterations in the centrum-collum-diaphysis (CCD)-angle, femoral offset (FO), acetabular offset (AO) and total offset (TO) change hip biomechanics. Therefore, the most suitable implant should be used. The aim of this study was to compare the ability of two short-stem-systems and one straight-stem-system to reconstruct hip geometry. METHODS: Two-hundred-fifty-one patients (mean age: 62.0 ± 10.0 years; 51.8% males) undergoing THA with three different stem types were retrospectively included, after excluding 11 patients with missing radiological follow-up. Pre- and postoperative radiographic images (group I, ANA.NOVA Alpha Schaft Proxy®, ImplanTec, 12 options: n = 99; group II, Optimys® Mathys, 24 options: n = 62; group III: Corail®-System, DePuy-Synthes, 76 options: n = 90) were analyzed. Differences in pre- and postoperative hip geometry (i.e. CCD, FO, AO, TO) were compared between groups with one-way-analysis-of-variance (ANOVA), and post-hoc t-tests. RESULTS: The CCD-angle increased by a mean of 8.4° ± 7.2° from pre-to postoperative, with no significant difference between groups (p = 0.097). Significantly larger increases in FO were observed for groups II (4.1 mm ± 7.8 mm) and III (4.9 ± 7.2 mm), in comparison to group I (1.6 ± 6.9 mm; p = 0.006). AO decreased by a mean of 2.2 ± 4.5 mm, with the largest decrease observed in group III (-3.3 ± 5.3 mm), and the smallest for group I (-1.4 ± 3.6 mm; p = 0.011). There was no significant difference in change of TO between groups (p = 0.177). CONCLUSIONS: Reconstruction of hip geometry using a single-version novel short-stem-system is achievable with comparable results to stem-systems offering multiple options.

Pre-operative templating in THA using a short stem system: precision and accuracy of 2D versus 3D planning method.

BACKGROUND: Total hip arthroplasty (THA) is the most successful orthopaedic surgery of the past century. The current study aimed to compare the accuracy of digital planning using 2D versus 3D templating. MATERIALS AND METHODS: Ninety-five THAs in 90 patients were included in the current study. Pre- and post-operative X-rays (in two planes) and low-dose rotation computed tomography scans from hip to foot were performed. Paired t-test and regression analyses were conducted to compare 2D and 3D templating accuracy of the definitive implant. RESULTS: Cup size planned both with 2D (p < 0.0001) and 3D (p = 0.012) templating was significantly different from the definitively used cup size. The difference between the 2D-planned and implanted stem size (p < 0.0001) was statistically significant. In contrast, there were no significant differences in the 3D-planned and implanted stem size (p = 0.181). Three-dimensional templating showed significantly higher accuracy than 2D templating in terms of cup size (1.1 ± 1.4 versus 1.7 ± 1.8; p = 0.007) and stem size (0.3 ± 0.6 versus 0.7 ± 0.7; p < 0.0001). With increasing body mass index (BMI), 2D templating of the stem became more inaccurate (p = 0.041). Remarkably, 3D templating remained accurate for all components (stem, p = 0.533; cup, p = 0.479) despite increasing BMI. CONCLUSION: Despite extended planning time and increased exposure to radiation, 3D-based planning showed higher accuracy than 2D templating, especially in obese patients. On the basis of our results, we believe that 3D-based pre-operative planning in THA is justifiable and beneficial in patients with increased BMI. LEVEL OF EVIDENCE: III.

The lymphocyte/monocyte ratio predicts poor clinical outcome and improves the predictive accuracy in patients with soft tissue sarcomas.

Increasing evidence indicates the involvement of inflammation and coagulation in cancer progression and metastases. Inflammatory biomarkers hold great promise for improving the predictive ability of existing prognostic tools in cancer patients. In the present study, we investigated several inflammatory indices with regard to their prognostic relevance for predicting clinical outcome in soft tissue sarcoma (STS) patients. Three hundred and forty STS patients were divided into a training set (n = 170) and a validation set (n = 170). Besides well-established clinico-pathological prognostic factors, we evaluated the prognostic value of the neutrophil/lymphocyte (N/L) ratio, the lymphocyte/monocyte (L/M) ratio and the platelet/lymphocyte (P/L) ratio using Kaplan-Meier curves and univariate as well as multivariate Cox regression models. Additionally, we developed a nomogram by supplementing the L/M ratio to the well-established Kattan nomogram and evaluated the predictive accuracy of this novel nomogram by applying calibration and Harrell's concordance index (c-index). In multivariate analysis, a low L/M ratio was significantly associated with decreased CSS and DFS (HR = 0.41, 95% CI = 0.18-0.97, p = 0.043; HR = 0.39, 95% CI = 0.16-0.91, p = 0.031, respectively) in the training set. Using the validation set for confirmation, we found also in multivariate analysis an independent value for CSS (HR = 0.33, 95% CI = 0.12-0.90, p = 0.03) and for DFS (HR = 0.36, 95% CI = 0.16-0.79, p = 0.01). The estimated c-index was 0.74 using the original Kattan nomogram and 0.78 when the L/M ratio was added. Our study reports for the first time that the pre-operative L/M ratio represents a novel independent prognostic factor for prediction the clinical outcome in STS patients. This easily determinable biomarker might be helpful in improved individual risk assessment.

Adverse reactions of artificial bone graft substitutes: lessons learned from using tricalcium phosphate geneX®.

BACKGROUND: Artificial bone graft substitutes are widely used to fill bony defects after curettage of benign tumors. We sought to evaluate the efficacy of one such bone graft substitute, geneX®, which contains tricalcium phosphate and calcium sulphate; however, during the course of this study we observed a high number of complications. QUESTIONS/PURPOSES: The primary aim of this prospective series was assessment of the effectiveness of geneX® concerning resorption profile and bone healing and remodeling after surgery. We present the types and frequencies of complications observed in patients treated for bone tumors by curettage and filling the defect using geneX®. METHODS: We planned to study 40 patients; however, after enrollment of the first 31 patients, the study was stopped as a result of serious complications. There were 20 female and 11 male patients with a mean age at surgery of 40 years (range, 6­71 years). Plain radiographs were obtained at different intervals during followup and CT scans were obtained 6 and 12 months postoperatively. Complications were assessed using a 5-point scale according to Goslings and Gouma. RESULTS: Five of the 31 patients (16%) had complications develop after surgery. In three cases, a sterile inflammation adjacent to the geneX® occurred, with delayed wound healing in two patients and local pain. In the third patient, geneX® produced moderate to severe skin damage in the area of the scar, needing revision surgery. In two other patients, inflammatory cystic formations developed in the soft tissues with sizes up to 15 cm, which gradually reduced in size with time. Overall, there were four Grade 1 complications and one Grade 2 according to Goslings and Gouma. CONCLUSIONS: We concluded from this series of patients that geneX® causes soft tissue inflammation and pain with its use. Based on this experience we believe that this type of bone substitute should not be used in the treatment of bony defects. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Surgical therapy of primary malignant bone tumours and soft tissue sarcomas of the chest wall: a two-institutional experience.

PURPOSE: Primary malignant bone tumours and soft tissue sarcomas of the chest wall are exceedingly rare entities. The aim of this study was a retrospective two-institutional analysis of surgical therapy with respect to the kind and amount of the resection performed, the type of reconstruction and the oncological outcome. METHODS: Between September 1999 and August 2010 31 patients (seven women and 24 men) were treated due to a primary malignant bone tumour or soft tissue sarcoma of the chest wall in two centres. Eight low-grade sarcomas were noted as well as 23 highly malignant sarcomas. The tumours originated from the sternum in six cases, from the ribs in 12 cases, from the soft tissues of the thoracic wall in 11 cases and from a vertebral body and the clavicle in one case each. RESULTS: In 26 cases wide resection margins were achieved, while four were intralesional and one was marginal. In all 31 cases the defect of the chest wall was reconstructed using mesh grafts. At a mean follow-up of 51 months 20 patients were without evidence of disease, three were alive with disease, seven patients had died and one patient was lost to follow-up. One recurrence was detected after wide resection of a malignant triton tumour. CONCLUSIONS: Primary malignant bone tumour or soft tissue sarcoma of the chest wall should be treated according to the same surgical oncological principles as established for the extremities. Reconstruction with mesh grafts and musculocutaneous flaps is associated with a low morbidity.

Novel biomarkers to detect infection in revision hip and knee arthroplasties.

BACKGROUND: A periprosthetic joint infection is one of the most challenging complications associated with THA and TKA. In the diagnostic process for detecting a periprosthetic joint infection, one of the most important steps is analysis of laboratory infection biomarkers. QUESTIONS/PURPOSES: We investigated the sensitivity and specificity of the biomarkers procalcitonin, interleukin 6 (IL-6), and interferon α (IFN-α) as compared with conventional biomarkers (C-reactive protein [CRP], leukocyte level) for a periprosthetic joint infection associated with revision arthroplasties. METHODS: We prospectively included and analyzed 84 patients (124 revision arthroplasties). The blood parameters of interest were procalcitonin, IL-6, IFN-α, leukocyte level, and CRP. Samples were taken preoperatively and on the first, third, and seventh postoperative days. The sensitivity and specificity of these biomarkers then were calculated. RESULTS: Considering the preoperative values of 84 patients (124 operations), procalcitonin, IL-6, CRP, and leukocyte level correlated with periprosthetic joint infection, whereas IFN-α did not. A procalcitonin cut-off level of 0.35 ng/mL revealed a sensitivity of 80% and specificity of 37%. An IL-6 cut-off level of 2.55 pg/mL had a sensitivity of 92% and specificity of 59%. CONCLUSIONS: In this study procalcitonin and IL-6 were helpful for detecting periprosthetic joint infections in revision arthroplasties, although CRP generally was superior. Procalcitonin and IL-6 may be considered adjuvant tests when the diagnosis of a periprosthetic joint infection is in doubt. This study showed, in addition to conventional biomarkers such as CRP and leukocyte level, procalcitonin and IL-6 were helpful for detecting infections associated with revision arthroplasties.

The influence of resveratrol on the synovial expression of matrix metalloproteinases and receptor activator of NF-kappaB ligand in rheumatoid arthritis fibroblast-like synoviocytes.

Medication of rheumatoid arthritis (RA) remains challenging and often controversial concerning side effects or long-term complications. We investigated the effect of resveratrol, a phytoalexin discussed for its chondro-protective and anti-inflammatory qualities, on the synovial expression of matrix-degrading enzymes like matrix metalloproteinases (MMPs) and bone-remodelling proteins in RA fibroblast-like synoviocytes (FLS). Interleukin-1beta-stimulated RA-FLS were treated with 100 microM resveratrol for 24 h. To evaluate the effect of resveratrol on the amount of bound/combined MMPs, a Luminex xMAP multiplexing technology was used. The alteration in expression of receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegrin (OPG) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Resveratrol reduced the expression of MMP-1 (p = 0.022), MMP-3 (p = 0.021), and MMP-9 (p = 0.047). qRT-PCR showed a significant reduction in the relative abundance of the transcripts of OPG (p = 0.012) and RANKL (p = 0.018). Our in vitro findings indicate that resveratrol could be a new target for further pharmacological studies in the field of RA. In the future it could play a role as a possible substitute or supplement to currently used drugs against RA to prevent cartilage matrix degradation and pathological bone resorption due to inhibition of MMPs and RANKL.

Simultaneous Bilateral Total Hip Arthroplasty with Straight-Stems and Short-Stems: Does the Short One Do a Better Job?

BACKGROUND: Total hip arthroplasty (THA) is known to be the most successful orthopaedic surgery of the last century, but it is still struggling with controversies concerning one-stage bilateral THA. The current study aimed to compare the clinical outcome of patients with unilateral or simultaneous bilateral THA by using short-stem and straight-stem designs and focusing on operation time, blood loss, and length of hospital stay (LOS). MATERIAL AND METHODS: Between 2006 and 2018, 92 patients were enrolled in this study. Forty-six patients underwent a bilateral THA in one session, and forty-six matched patients underwent a unilateral THA. In each of the two groups (unilateral vs. bilateral), 23 patients received either a straight (unilateral: 10 females, 13 males, mean age 63; bilateral: 12 females, 11 males, mean age 53 years) or short stem (unilateral: 11 females, 12 males, mean age 60 years; bilateral: 12 females, 11 males, 53 mean age 62 years). The blood count was checked preoperatively as well as one and three days after surgery. Furthermore, the operation time and LOS were investigated. RESULTS: Compared to THA with straight-stems, short-stem THA showed significantly less blood loss; there was no difference in the LOS of both groups. A significantly shorter operative time was only observed in the bilateral THA. CONCLUSION: The current study showed that simultaneous bilateral THA appears to be safe and reliable in patients without multiple comorbidities. In addition, short-stem THA appears to be beneficial in terms of clinical performance and outcome, and it appears to be superior to straight-stem THA, regardless of whether the patient underwent unilateral or simultaneous bilateral THA.

Femoral Anteversion in Total Hip Arthroplasty: Retrospective Comparison of Short- and Straight-Stem Models Using CT Scans.

Data on reconstruction of the femoral anteversion (FA) and the center of rotation after total hip arthroplasty (THA) are rare. We aimed to answer whether a short-stem fixation enables improved anatomical reconstruction of the FA compared to a straight-stem. METHODS: One hundred and thirty patients who underwent short- (n = 89, group A, prospective) or straight-stem THA (n = 41, group B, retrospective) were included. CT scans of the hip, knee, and ankle were performed pre- and postoperatively in group A and in group B during the last follow-up. Femoral torsion was determined using three-dimensional models. RESULTS: The mean preoperative FA was 22.4° ± 11.0°, and the mean postoperative FA was 23.4° ± 10.1°. The relative difference was -0.8° ± 8°, and the absolute difference was 6.4° ± 4.9°. Gender analysis revealed significant differences in preoperative FA between female (f) and male (m) patients (28.1° ± 11.2° (f) vs. 18.4° ± 8.3° (m); p > 0.001) as well as in postoperative FA (26.7° ± 23.5° (f) vs. 21.0° ± 9.7° (m); p < 0.007) in group A. Postoperative FA was higher in group A (mean 6.8°; 23.9° ± 10.1° (f) vs. 16.6° ± 8.6° (m); p < 0.001). CONCLUSIONS: The study's findings suggest that short-stem THA leads to improved anatomical FA reconstruction; however, a substantial postoperative gender-related FA difference was detectable, which may warrant consideration by surgeons when determining the final stem anteversion. It should be noted that the impact of the postoperative gender-related FA difference on clinical outcomes is not entirely clear, and further research is warranted to elucidate this relationship.

No adverse affect after harvesting of free fibula osteoseptocutaneous flaps on gait function.

The aim of this study was to analyze gait function and muscular strength on donor site after harvesting of a vascularized fibula osteoseptocutaneous flap. Nine patients with a mean follow-up of 33 months (range, 7-59) and a mean resection length of the middle portion of the fibula of 18.0 cm (range, 14.0-23.0) underwent an instrumented three-dimensional gait analysis to evaluate gait function. Furthermore, CYBEX II extremity system was used for muscular strength measurements. Subjective muscle strength measurements were performed according to Kendall et al. and were classified according to the British Medical Research Council. Intraindividual comparison between the operated and the nonoperated leg revealed no significant differences for gait function parameters (cadence, velocity, and stride length, P > 1.00) and for muscular strength measurements for flexion (knee: P = 0.93, ankle: P = 0.54) and extension (knee: P = 0.97, ankle: P= 0.21), respectively. In conclusion, intraindividual comparison of the operated and nonoperated sides after harvesting of the middle portion of the fibula for gaining a free fibula osteoseptocutaneous flap has no adverse affect on gait function or muscular flexion and extension strength on donor site at a mean follow-up of 33 months.

Serum metal ion levels after rotating-hinge knee arthroplasty: comparison between a standard device and a megaprosthesis.

PURPOSE: The effects of systemic metal ion exposure in patients with implants made of common prosthetic alloys continue to be a matter of concern. The aim of the study was to determine the measurement values of cobalt (Co), chromium (Cr) and molybdenum (Mo) in serum following rotating-hinge knee arthroplasty. METHODS: Blood was taken from 25 patients [mean follow-up 35 (range nine to 67) months] treated with megaprostheses (n=17) or standard rotating-hinge devices (n=8) and analysed using electrothermal graphite furnace atomic absorption spectrometry (ET-ASS). RESULTS: Determining the concentrations of metal ions following rotating-hinge knee arthroplasty revealed increments for Co and Cr but not Mo. Metal ion release was significantly higher in patients with megaprostheses compared to a standard rotating-hinge knee device (Co p=0,024; Cr p=0.025). CONCLUSION: The authors believe there might be an additional metal ion release from the surface of the prosthesis and not only from the articulating surfaces because, in cases of rotating-hinge knee prosthesis, there is a metal-on-polyethylene articulation and not a direct metal-on-metal junction. Nevertheless, long-term studies are required to determine adverse effects of Co, Cr and Mo following total hip replacement and total knee arthroplasty.

Failure rate of a rotating hinge knee design due to yoke fracture of the hinged tibial insert: a retrospective data analysis and review of the literature.

PURPOSE: Rotating hinge knee prostheses are known to provide inherent stability. Yoke fractures of the hinged tibial insert of modern generation rotating hinge devices are a matter of continued concern. The aim of this study was to describe incidence and management of yoke fracture of the LPS™ hinged tibial insert. METHODS: Retrospective data analysis of two institutions identified 40 patients with a LPS™ total knee arthroplasty. Implant survival and prosthetic complications was calculated according to Kaplan-Meier. RESULTS: Out of the group of 40 patients, four fractures of the metal yoke occurred in four cases (failure rate: 10%). Furthermore, a second fracture occurred in two patients. The overall revision-free prosthetic survival was 57% at 38 months, while prosthetic survival until yoke fracture was 86% at 38 months. CONCLUSION: Handling yoke fractures as mechanical complication includes replacing the hinged insert, stabilization of the joint and joint line height preservation in order to decrease the cantilever effect at the insert-base plate interface.

Three-year migration analysis of a new metaphyseal anchoring short femoral stem in THA using EBRA-FCA.

Cementless calcar-guided femoral short stems in total hip arthroplasty (THA) have become increasingly popular over the years. Early distal migration of femoral stems measured by Einzel-Bild-Roentgen Analyse, Femoral Component Analyse (EBRA-FCA) has been reported to be a risk factor for aseptic loosening. The aim of this study was to analyse axial migration behavior and subsidence of a new short stem (launched in 2015) over a follow-up period of 3 years. According to the study protocol, 100 hip osteoarthritis patients who consecutively received an unilateral cementless calcar-guided short stem (ANA.NOVA proxy) at a single department were prospectively included in this mid-term follow-up study. Thirteen patients were lost to follow-up, resulting in 87 patients with unilateral THA who fulfilled the criteria for migration analysis with EBRA-FCA. The cohort comprised 41 males (mean age: 60 ± 16.5; mean BMI (Body Mass Index): 30 ± 13) and 46 females (mean age: 61 ± 15.5; mean BMI: 27 ± 10). Seven standardized radiographs per patient were analyzed with EBRA-FCA. An average migration of 2.0 mm (0.95-3.35) was observed within the first 3 years. The median increase during the first year was higher than in the second and third year (1.2 mm [IQR: 0.5-2.15] vs. 0.3 mm [IQR: 0.1-0.6 mm] vs. 0.25 mm [IQR: 0.1-0.5 mm]. Detected migration did not lead to stem loosening, instability, dislocation, or revision surgery in any patient. A higher risk for subsidence was observed in male and heavyweight patients, whereas the female gender was associated with a lower risk. No correlation between migration and revision could be observed. Although moderate subsidence was detectable, the performance of the short stem ANA.NOVA proxy is encouraging. Yet, its use may be re-considered in overweight and male patients due to more pronounced subsidence.

Survival Prediction in Patients Treated Surgically for Metastases of the Appendicular Skeleton-An External Validation of 2013-SPRING Model.

INTRODUCTION: The aim of this study was to externally validate the 2013-SPRING model, a survival prediction tool for patients treated surgically for bone metastases in a retrospective patient cohort from a single institution. Moreover, subgroup analyses on patients treated with (A) endoprostheses or (B) osteosynthesis, as well as (C) upper limb and (D) lower limb metastases, were performed. METHODS: Altogether, 303 cancer patients (mean age: 67.6 ± 11.1 years; 140 males (46.2%)) with bone metastases to the extremities, treated surgically between March 2000 and June 2018 at a single tertiary sarcoma centre, were retrospectively included. Median follow-up amounted to 6.3 (interquartile range (IQR): 2.3-21.8) months, with all patients followed-up for at least one year or until death. The 2013-SPRING model was applied to assess the prognostication accuracy at 3, 6 and 12 months. Models were validated with area under the curve receiver operator characteristic (AUC ROC; the higher the better), as well as Brier score. RESULTS: Of the 303 patients, 141 had been treated with osteosynthesis (46.5%), and the remaining 162 patients with endoprosthesis (53.5%). Sixty-five (21.5%) metastases were located in the upper limbs, and two hundred and thirty-eight (78.5%) in the lower limbs. Using the 2013-SPRING model for the entire cohort, the accuracy of risk of death prediction at 3, 6 and 12 months, determined by the AUC ROC, was 0.782 (95% CI: 0.729-0.843), 0.810 (95% CI: 0.763-0.858) and 0.802 (95% CI: 0.751-0.854), respectively. Corresponding Brier scores were 0.170, 0.178 and 0.169 at 3, 6 and 12 months. In the subgroup analyses, predictive accuracy of the 2013-SPRING model was likewise encouraging, albeit being slightly higher in the osteosynthesis subgroup as compared with the endoprosthesis subgroup, and also higher in the upper limb in comparison to the lower limb metastasis subgroup. CONCLUSIONS: The current validation study of the 2013-SPRING model shows that this model is clinically relevant to use in an external cohort, also after stratification for surgical procedure and metastasis location.

Auto-aggressive metallic mercury injection around the knee joint: a case report.

BACKGROUND: Accidental or intentional subcutaneous and/or intramuscular injection of metallic mercury is an uncommon form of poisoning. Although it does not carry the same risk as mercury vapour inhalation, it may cause destructive early and late reactions. CASE PRESENTATION: Herein we present the case of a 29-year-old male patient who developed an obsessive-compulsive disorder causing auto-aggressive behaviour with injection of elemental mercury and several other foreign bodies into the soft tissues around the left knee about 15 years before initial presentation. For clinical examination X-rays and a CT-scan of the affected area were performed. Furthermore, blood was taken to determine the mercury concentration in the blood, which showed a concentration 17-fold higher than recommended. As a consequence, the mercury depots and several foreign bodies were resected marginally. CONCLUSION: Blood levels of mercury will decrease rapidly following surgery, especially in combination with chelating therapy. In case of subcutaneous and intramuscular injection of metallic mercury we recommend marginal or wide excision of all contaminated tissue to prevent migration of mercury and chronic inflammation. Nevertheless, prolonged clinical and biochemical monitoring should be performed for several years to screen for chronic intoxication.

Short-stem total hip arthroplasty is not associated with an earlier return to work compared to a straight-stem design.

Return to work (RTW) has been specifically identified as a high priority in patients undergoing total hip arthroplasty (THA). This investigation sought to assess the effect of the stem design on patients' RTW. Secondly, the study aimed to identify risk factors that lead to a delayed RTW. Questionnaires inquiring about RTW, employment history, educational level, type of work, physical demands and joint awareness were administered by post. Further data were collected from patients' hospital records. 176 patients who underwent THA using a short-stem and 97 patients using a straight-stem design were compared. The median return to work time was 10 weeks [IQR 7-14 weeks], with no significant difference between the two groups (short stems vs. straight stems; 10 [IQR 7-14] vs. 11 [7.5-13.5] weeks; p = 0.693). In the multivariate linear regression analysis, self-employment vs. employee (p = 0.001), dimension of preoperative workload (p = 0.001), preoperative sick leave (p < 0.001), and hospital length of stay (LOS) (p < 0.001) independently affected the period until work was resumed. The Forgotten-Joint-Score-12 showed no significant difference between the two groups. The data show that the majority of THA patients can expect to resume work and stem design has no impact on RTW. Employees with preoperative sick leave, prolonged hospital LOS and low workload are at higher risk for a delayed RTW.

Blood Management in Revision Total Hip Arthroplasty for Metal-on-Metal Devices: The Efficiency of an Intraoperative Cell Salvage System.

BACKGROUND: The aim of this series was to investigate the efficiency of an intraoperative cell salvage system (ICS) removing metal ions during revision of metal-on-metal (MoM) devices to proof the possibility of re-transfusion of the collected blood. MATERIALS AND METHODS: Between 2014 and 2018, five consecutive patients underwent revision surgery of their MoM total hip arthroplasty due to wear of the polyethylene-metal sandwich inlay or local massive metallosis with aseptic loosing of the cup. Aspiration of joint fluid of all hip prostheses was done and blood was taken to measure the metal ion concentrations, preoperatively. Perioperatively, blood was collected using an ICS before and after filtration and analyzed for Co and Cr concentrations. At that time, there was no re-transfusion of the collected and filtrated blood due to unknown metal ion concentrations. RESULTS: The mean preoperative serum Co and Cr concentrations in the blood were 31.28 µg/L (range 0.22-77.47) and 17.33 µg/L (range 0.59-51.31), whereas the mean local concentrations in the aspiration fluid were 728-fold and 822-fold higher. The Co and Cr concentrations measured in the collected blood before filtration were 70.61 µg/L (range 9.40-173.00) and 337.21 µg/L (range 8.76-1383.0) and decreased markedly to average concentrations of 15.49 µg/L and 41.88 µg/L, respectively. These differences were statistically not significant (Co: p = 0.117, Cr: p = 0.175), although the mean reduction rates were 78% and 88% for Co and Cr, respectively. CONCLUSION: The current series showed that in case of revision of MoM hip devices, metal ions are still contained in the collected blood following filtration using a modern high-level ICS. Therefore, we would only recommend blood re-transfusion in case of low preoperative Co and Cr concentrations and sufficient renal function to warrant patients' safety.

How is the outcome of the Limb Preservation System™ for reconstruction of hip and knee?

BACKGROUND: Despite tremendous advantages in the development and application of megaprostheses in tumour and revision surgery, complications are still not infrequently observed. Only two studies investigating the outcome of the LPS™ system in the proximal femur and distal femur/proximal tibia have been published thus far. Herein, mid-term implant survival rates one of the largest cohort of patients treated with the LPS™-system are presented aiming tp answer: 1) How is the outcome of the LPS™ system in the proximal femur and distal femur/proximal tibia? 2) Which factors are associated with altered implant survival? 3) What is the cumulative risk of complications according to Henderson? HYPOTHESIS: The LPS™-system is associated with high complication rates that depend on implant site, with infections being most common. PATIENTS AND METHODS: Fifty-seven patients who received the LPS™-system at the proximal femur (n=31), distal femur (n=21) and proximal tibia (n=5) between 2004 and 2010 for oncological (n=40) or non-oncological (n=17) causes, were retrospectively included. Median follow-up was 5.0 years (range, 0-12.4 years). Complications were classified according to Henderson into instability/soft tissue failure (type 1), aseptic loosening (type 2), structural failure (type 3), periprosthetic infection (type 4), tumour progression (type 5). Competing-risk-analyses were applied to estimate implant survival with death as the competing event. RESULTS: Twenty-six patients (45.6%) developed a complication, of whom 9 (29.0%) had a proximal femoral and 17 (65.4%) a distal femoral/proximal tibial implant. Type 4 complications were most common (n=11), followed by type 3 (n=6, including 2 yoke-fractures), type 1 and 2 (n=4 each), and type 5 (n=1). The only factor associated with the development of complications in the multivariate model was a distal femoral/proximal tibial implant (hazard-ratio: 7.418, 95% confidence-interval: 2.193-26.096, p=0.001), irrespective of reason for reconstruction and use of muscular flaps. The cumulative-incidence of failure including all complications was 34.3%, 40.7% and 67.1% at 3, 5 and 10 years, respectively. DISCUSSION: The LPS™-system may be used for proximal femoral reconstructions both in the oncological and non-oncological setting. Rates of complications are higher in our cohort than reported in literature for other, comparable, megaprosthesis systems. Especially in the distal femur/proximal tibia, complication rates were high, partially attributable to the former implant design leading to fractures of the yoke-mechanism. As the implant has been remodelled after these issues became evident, there is no objection to use this megaprosthesis system today. LEVEL OF EVIDENCE: IV, Observational Study.