Retrograde intramedullary nail fixation with oblique fixed angle screws versus locking plates in periprosthetic supracondylar fractures after total knee arthroplasty.

PURPOSE: Common surgical procedures in the treatment of periprosthetic distal femur fractures (PPFF) include osteosynthesis with fixed angle locking plates (LP) and retrograde intramedullary nails (RIN). This study aimed to compare LPs to RINs with oblique fixed angle screws in terms of complications, radiographic results and functional outcome. METHODS: 63 PPFF in 59 patients who underwent treatment in between 2009 and 2020 were included and retrospectively reviewed. The anatomic lateral and posterior distal femoral angle (aLDFA and aPDFA) were measured on post-surgery radiographs. The Fracture Mobility Score (FMS) pre- and post-surgery, information about perceived instability in the operated leg and the level of pain were obtained via a questionnaire and previous follow-up (FU) examinations in 30 patients (32 fractures). RESULTS: The collective (median age: 78 years) included 22 fractures treated with a RIN and 41 fractures fixed with a LP. There was no difference in the occurrence of complications (median FU: 21.5 months) however the rate of implant failures requiring an implant replacement was higher in fractures treated with a LP (p = 0.043). The aPDFA was greater in fractures treated with a RIN (p = 0.04). The functional outcome was comparable between both groups (median FU: 24.5 months) with a lower outcome in the post-surgery FMS (p = < 0.001). CONCLUSION: Fractures treated with RIN resulted in an increased recurvation of the femur however the rate of complications and the functional outcome were comparable between the groups. The need for implant replacements following complications was higher in the LP group.

Predictors of long-term mortality in older patients with hip fractures managed by hemiarthroplasty: a 10-year study based on a population registry in Saxony, Germany.

BACKGROUND: Mortality of patients with a femoral neck fracture is high, especially within the first year after surgery, but also remains elevated thereafter. The aim of this study was to identify factors potentially associated with long-term mortality in patients homogeneously treated with hemiarthroplasty for femoral neck fracture. METHODS: This retrospective cohort study was performed at a single level 1 national trauma center at the university hospital of Leipzig (Saxony, Germany). The study time-window was January 1, 2010 to December 31, 2020. Primary outcome measure was mortality depending on individual patient-related characteristics and perioperative risk factors. Inclusion criteria was a low-energy femoral neck fracture (Garden I-IV) in geriatric patients 60 years of age or older that were primarily treated with bipolar hemiarthroplasty. Date of death or actual residence of patients alive was obtained from the population register of the eastern German state of Saxony, Germany. The outcome was tested using the log-rank test and plotted using Kaplan-Meier curves. Unadjusted and adjusted for other risk factors such as sex and age, hazard ratios were calculated using Cox proportional hazards models and presented with 95% confidence intervals (CI). RESULTS: The 458 included patients had a median age of 83 (IQR 77-89) years, 346 (75%) were female and 113 (25%) male patients. Mortality rates after 30 days, 1, 5 and 10 years were 13%, 25%, 60% and 80%, respectively. Multivariate regression analysis revealed age (HR = 1.1; p < 0.001), male gender (HR = 1.6; p < 0.001), ASA-Score 3-4 vs. 1-2 (HR = 1.3; p < 0.001), dementia (HR = 1.9; p < 0.001) and a history of malignancy (HR = 1.6; p = 0.002) as independent predictors for a higher long-term mortality risk. Perioperative factors such as preoperative waiting time, early surgical complications, or experience of the surgeon were not associated with a higher overall mortality. CONCLUSIONS: In the present study based on data from the population registry from Saxony, Germany the 10-year mortality of older patients above 60 years of age managed with hemiarthroplasty for femoral neck fracture was 80%. Independent risk factors for increased long-term mortality were higher patient age, male gender, severe comorbidity, a history of cancer and in particular dementia. Perioperative factors did not affect long-term mortality.

Subtotal diaphyseal replacement of the femur with modular mega-endoprosthesis following interprosthetic fracture. A case report.

Mega-endoprostheses enable wide management options in the treatment of primary and periprosthetic fracture of the lower extremities. In this study, we report on the use of custom-made subtotal diaphyseal endoprosthetic replacement in treatment of interprosthetic femoral fracture. This procedure is off-label, but in this particular case, it was the safest and most stress-stable treatment option. The implant was delivered within three weeks. The surgical procedure for subtotal replacement of the femoral diaphysis was performed without any intra- or postoperative complication. The duration for the surgical intervention was one hour and 40 minutes. The patient was then mobilized with full weight bearing. At one-year follow-up, the patient did not complain of any pain. The Harris Hip Score HHS improved from 26 to 83 at one-year follow-up, the Western Ontario and McMaster Universities Osteoarthritis Index WOMAC improved from 88 to 16. Mega-endoprostheses enable a wide range of management options in the treatment of primary, peri- and interprosthetic fractures of the lower extremities. In many cases, an individual therapeutic plan is necessary ranging up to the use of custom-made implants.

Intramedullary arthrodesis of the knee joint with additional femoral neck screw to prevent periprosthetic fracture of the proximal femur. A case report.

Arthrodesis of the knee joint has proven effective in the treatment of chronic periprosthetic infections as well as in cases of previous multiple revision surgery after total knee replacement with insufficiency of the extensor apparatus. In this case report, we report on the use of a custom-made intramedullary arthrodesis nail of the knee joint following multiple revisions due to aseptic loosening after total knee replacement. Surgery was performed according to preoperative computerized planning. Microbiological and histological samples obtained intraoperatively showed no evidence of infection. Yet, the patient presented postoperatively with complete loss of active dorsiflexion of the ipsilateral foot. On one-year follow-up, the patient did not complain of any pain. The radiological findings one year after surgery showed no sign of loosening or any other pathological findings. The neurological lesion has completely recovered. The Harris Hip Score HHS improved from 24 (prior to implantation of the arthrodesis) to 75 on one-year follow-up, the Western Ontario and McMaster Universities Osteoarthritis Index WOMAC improved from 86 to 20. The particularity of this case lies in the fact that an additional femoral neck screw was brought in to prevent periprosthetic fracture of the proximal femur. Careful preoperative planning as well as surgical performance were necessary to adjust the rotation of the femoral nail to allow adequate positioning of the femoral neck screw. Intramedullary arthrodesis of the knee is a suitable management option following multiple revision surgery after total knee replacement with insufficiency of the extensor apparatus. In many cases, an individual therapeutic plan is necessary ranging up to the use of custom-made implants.

Preoperative dental screening can reduce periprosthetic infections of hip and knee endoprostheses in the first month after surgery: results of a cohort study.

PURPOSE: The oral cavity and, in particular, potential oral foci might pose a risk of periprosthetic joint infection (PJI). The aim of this cohort study was to determine whether practical preoperative dental screening would reduce the prevalence of early PJI in the first month after surgery. METHODS: Patients attending a specialized endoprosthesis implantation clinic between 2018 and 2022 were recruited. Two groups were examined. The test group consisted of patients attending the clinic between 2020 and 2022 and who were referred to their family dentist using a standardized form. The comparison group consisted of patients who were treated in the clinic between 2018 and 2020. They were not referred to their family dentist. The two groups were compared for the prevalence of PJI. Univariate analysis followed by multiple logistic regression was performed to confirm risk factors for PJI in this cohort. RESULTS: 2560 individuals (test group: 1227, comparison group: 1333) were included. The prevalence of PJI was significantly lower in the test group (0.8% vs. 1.8%, p = 0.04). Multiple logistic regression with PJI as the dependent variable showed that a dental referral was a strong predictor of a lower prevalence of PJI (OR: 0.43, CI95 0.205-0.917, p = 0.03). Male gender was also strongly associated with a higher frequency of PJI (OR: 2.68, CI95 1.32-5.42, p = 0.01). Age (OR: 1.06, CI95 1.01-1.10, p = 0.01) and BMI (OR: 1.11, CI95 1.05-1.17, p < 0.01) had little effect on the risk of PJI. CONCLUSION: Dental referral using a standardized form can reduce the prevalence of early PJI. Accordingly, orthopedists and dentists should collaborate in this practical way.

Cell-free DNA extraction from urine of lung cancer patients and healthy individuals: Evaluation of a simple method using sample volume up-scaling.

BACKGROUND: Urine holds promise as a source for cell-free DNA (cfDNA) analysis of cancer genetics due to its nature as a self-collectable biospecimen available in large quantities. However, pre-analytical variables such as preservation of cfDNA or efficiency of up-scaling specimen volume need to be better explored to increase analysis sensitivity. PATIENTS AND METHODS: Initially effects of pH levels on cfDNA stability of urine preserved with EDTA were investigated in three healthy probands. Furthermore, the efficiency of urine volume up-scaling was examined using a simple DNA extraction method and cfDNA in urine of 32 individuals. Quantification was performed by PCR detection of three relevant targets used for EGFR and KRAS gene mutational analysis. RESULTS: Only samples preserved with EDTA at alkaline pH levels showed cfDNA stability of up to 10 days at room temperature. Moreover, it was found that increasing the volume up to 100 mL was highly efficient. A similar amount of copies was detected in three different gene sites in all specimens indicating both a good availability and a non-random distribution pattern across genes. Since the median cfDNA copy number was 1642 copies/mL, abundance of cfDNA in this type of liquid biopsy is low. CONCLUSION: Predictable sensitivities with different urine volumes on the ground of detectable cfDNA in our study population revealed that up-scaling (>5 mL) is mandatory if the mutation allele frequency is less than 1%.

[Osteoporotic vertebral body fractures]. / Osteoporotische Wirbelkörperfrakturen.

The number of osteoporotic fractures of the spine is increasing. These fractures are associated with elevated morbidity and mortality. This article provides an overview of the special features of these fractures, the diagnostic procedure, their classification, and the conservative and surgical treatment options. For the mostly elderly patients, it is important to treat the underlying disease and to address associated problems such as frailty and sarcopenia. To meet this growing medical and socio-economic challenge, a holistic interdisciplinary and interprofessional treatment approach is required.

Dental Therapy of Patients Prior to Endoprostheses: A Retrospective, Telephone-Based Cohort Study.

The aim of this study was to assess, whether patients prior to endoprosthesis (EP) visit their dentist for need-oriented therapy and whether this would be associated with the occurrence of complications. Based on a cohort of patients, which was orally investigated prior to EP surgery between 04/2020 and 12/2021, a telephone interview was performed at least six months after EP implantation. Patients were classified into either low-risk (LR), moderate-risk (MR), or high-risk (HR) groups. Participants were interviewed based on a structured questionnaire regarding dental visits, dental therapy, and potential complications during the observational period. Out of the 311 patients from the baseline cohort, 96 patients after EP implantation could be included (participation rate of 31%). Nineteen patients were in LR (20%), 41 in MR (43%), and 36 in the HR group (37%). Overall, 79% (n = 76) of the patients followed the recommendation to visit their dentist; 94% of patients within the HR group visited the dentist (p = 0.02). Dental treatment procedures included tooth cleaning (57%), periodontal treatment (31%), restorative therapy/filling (28%), and tooth extraction (28%). In 64% of the HR patients (n = 23), the potential oral foci with a risk of EP infection were eliminated by their general dentist. Fourteen different complications occurred within the observation period, without any group effect (p > 0.05). In conclusion, most patients prior to EP visit their general dentist following referral, especially if they have a potential oral focus. The effect of dental clearance on infectious complications of EP remains unclear, whereby further clinical studies are needed.

Mechanical parameter assessment of fresh human cancellous bone of the femoral head in atraumatic femoral head necrosis and primary coxarthrosis.

BACKGROUND: Atraumatic femoral head necrosis is a rare pathological change of the femoral head. It is characterized by local necrosis of the cancellous bone as a result of reduced blood supply to the bone. Even today it remains unclear how to assess the hardness of the necrosis, whether it is soft tissue that is easily removed, or hard tissue that is difficult to resect. METHODS: Femoral heads with primary coxarthrosis were selected as a comparison group. For this purpose, 49 femoral heads obtained during total hip arthroplasty surgery with either condition (23 femoral head necrosis, 26 coxarthrosis) were transferred to the testing laboratory in fresh condition. Cylindrical specimens were obtained using a tenon cutter along the main trabecular load direction in the subchondral region of the femoral head. Additionally, thin bone slices were extracted proximal and distal to the specimens for density measurements. Brass plates were glued to the circular surfaces of the specimens. After curing of the adhesive, the specimens were mounted in the testing machine and destructive uniaxial compression tests were conducted. FINDINGS: The recorded mean compressive strengths and elastic moduli were almost identical for both groups, but the necrosis group showed significantly higher data scattering and range regarding the elastic modulus. The mean density of the coxarthrosis specimens was significantly higher than that of the necrotic specimens. INTERPRETATION: The mechanical properties of cancellous bone vary considerably in the presence of femoral head necrosis. The existence of hard necrosis implies a potential challenge regarding the clinical resection of these tissues.

Activation of distinct inflammatory pathways in subgroups of LR-MDS.

Aberrant innate immune signaling has been identified as a potential key driver of the complex pathophysiology of myelodysplastic neoplasms (MDS). This study of a large, clinically and genetically well-characterized cohort of treatment-naïve MDS patients confirms intrinsic activation of inflammatory pathways in general mediated by caspase-1, interleukin (IL)-1ß and IL-18 in low-risk (LR)-MDS bone marrow and reveals a previously unrecognized heterogeneity of inflammation between genetically defined LR-MDS subgroups. Principal component analysis resolved two LR-MDS phenotypes with low (cluster 1) and high (cluster 2) levels of IL1B gene expression, respectively. Cluster 1 contained 14/17 SF3B1-mutated cases, while cluster 2 contained 8/8 del(5q) cases. Targeted gene expression analysis of sorted cell populations showed that the majority of the inflammasome-related genes, including IL1B, were primarily expressed in the monocyte compartment, consistent with a dominant role in determining the inflammatory bone marrow environment. However, the highest levels of IL18 expression were found in hematopoietic stem and progenitor cells (HSPCs). The colony forming activity of healthy donor HSPCs exposed to monocytes from LR-MDS was increased by the IL-1ß-neutralizing antibody canakinumab. This work reveals distinct inflammatory profiles in LR-MDS that are of likely relevance to the personalization of emerging anti-inflammatory therapies.

Association between oral health and oral health-related quality of life in patients before hip and knee endoprosthesis surgery: a cross-sectional study.

OBJECTIVES: Aim of this cross-sectional study was the assessment of oral health-related quality of life (OHRQoL) health-related quality of life (HRQoL), oral health behaviour and oral health status in patients before hip and knee endoprosthesis (EP) surgery. Moreover, associations between OHRQoL, HRQoL and oral health should be examined. METHODS: Consecutive patients before hip and/or knee EP implantation were recruited and referred to the dental clinic for oral examination including: number of remaining teeth, dental findings (DMF-T-Index), periodontal condition (periodontal treatment need, Staging/Grading) and temporomandibular joint screening. OHRQoL was assessed by the German short form of oral health impact profile (OHIP G14), HRQoL by short-form 36 survey. RESULTS: Hundred and sixty two patients with a mean age of 66.80 ± 11.10 years were included, which had on average 18.22 ± 8.57 remaining teeth and a periodontal treatment need of 84.5%. The OHIP G14 sum score revealed a median of 1 (mean: 2.7 ± 4.4, 25-75th percentile: 0-4) and its dimension oral function of 0 (mean: 0.8 ± 1.8, 25-75th percentile: 0-1), what was also found for psychosocial impact (median: 0, mean: 1.4 ± 2.6, 25-75th percentile: 0-2). The OHIP G14 sum score and both dimensions were significantly associated with mental component summary (p < 0.01). A higher number of remaining teeth as well as remaining molars/premolars were associated with lower OHIP G14 sum score (p = 0.02). This was also found for the dimension oral function (p < 0.01). CONCLUSION: Patients prior to hip and knee EP had an unaffected OHRQoL, although they had an insufficient oral health. Individuals before EP implantation need increased attention in dental care, fostering information, sensibilization and motivation of the patients.

Point Shear Wave Elastography in Diagnosis and Follow-Up of Salivary Gland Affection after Head and Neck Cancer Treatment.

Therapies of head and neck squamous cell carcinoma (HNSCC), particularly irradiation and chemotherapy (C/RT), can affect salivary glands to some extent. Recent studies suggest that point shear wave elastography (pSWE) is well suited for the diagnosis and rating of homogenous damage to parenchymatous organs. The purpose of this study was to assess the value of this sonographic modality as a tool for the evaluation both of salivary gland affection after HNSCC therapy and the effect of a salivary replacement therapy based on liposomes. A total of 69 HNSCC patients were included in this study. All patients had finished cancer treatment and attended regular follow-up. pSWE values of ipsi- and contralateral parotid (PG) and submandibular glands (SMG) were obtained in a standardized manner and compared to those of a healthy control (HC) group. After a two months treatment with a liposomal saliva replacement therapy pSWE quantification was performed again. Ipsi- and contralateral salivary glands suffer under standard HNSCC tumor therapy. Here, the ipsilateral parotid gland (PG) is primarily affected. Therefore, a sequence of manifestation (surgery < surgery plus adjuvant C/RT < primary C/RT) is comprehensible, evaluated by pSWE measurements. The examination of all glands and statistical analysis of the values compared to controls resulted in an pSWE cutoff value for affected glandular tissue of >2 m/s. Using a liposomal saliva replacement therapy, pSWE values of the ipsilateral PG can be improved, although the level of HC could not be restored.

One Third of Patients before Endoprosthesis Implantation Show an Oral Focus as Potential Source of Infectious Complication-The Value of Pre-Operative Dental Risk Stratification in a German Cohort.

OBJECTIVE: The aim of this cross-sectional cohort study was to evaluate a comprehensive dental examination and referral concept for patients prior to endoprosthesis (EP) implantation in an interdisciplinary setting. METHODS: Patients, who were prepared for EP surgery in the clinic for orthopaedics, were referred to the dental clinic for a dental examination. Thereby, dental and periodontal treatment need, radiographic and temporomandibular joint findings were assessed. Based on oral and radiographic investigation, a risk classification for potential source of prosthetic infection was performed. If potential oral foci of EP infection were present (e.g., apically radiolucent teeth, severe periodontitis or additional inflammatory findings), patients were classified as at high risk for EP infection with oral origin. Those individuals were allocated to their family dentist or special clinic for dental treatment prior to EP surgery. RESULTS: A total of 311 patients were included (mean age: 67.84 ± 10.96 years, 51% male). A dental treatment need of 33% was found, while the periodontal treatment need was 83%. Thirty-one percent of patients showed at least one apical radiolucency (a sign of chronic infection/inflammation). Furthermore, additional findings such as radiographic signs of sinusitis maxillaris were found in 24% of patients. Temporomandibular disease was probable in 17% of individuals. One-third (34%) were assigned to the high risk group for an EP infection with oral origin. CONCLUSION: German patients before EP have a high periodontal treatment need and show frequently (34%) a potential oral focus of infection, underlining the necessity of including dental examination and risk stratification as part of the pre-operative assessment prior to EP implantation. Therefore, an approach as applied in this study appears reasonable for those individuals.

Effects of SARS-CoV­2 infections on inpatient mortality of geriatric patients after proximal femoral fracture surgery.

BACKGROUND: The medical challenges caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV­2) pose a tremendous burden on the healthcare system. This study aimed to analyze the effects of a SARS-CoV­2 infections or disease progression on inpatient mortality of geriatric patients after proximal femoral fracture surgery. METHODS: A retrospective analysis was conducted in all patients with a proximal femoral fracture surgically treated in an urban regional trauma center from 01/01/2020 to 01/31/2021. According to PCR test results detecting SARS-CoV­2, the patients were divided into two groups (SARS-CoV­2 positive vs. SARS-CoV­2 negative). Patient data, disease progression data, and treatment-related information were evaluated for all patients. Statistical data analysis was performed using unpaired Student's t test or non-parametric Mann-Whitney U test. RESULTS: A total of 311 patients (women: 70.4%, age: 82.0 ± 11.0 years) were included in this study. Of these 3.9% (12/311) had a positive test result for SARS-CoV­2. Significantly more deceased patients were found in the group tested positive for SARS-CoV­2 (SARS-CoV­2 positive: 41.7%, SARS-CoV­2 negative: 5.4%, p < 0.001). In addition, the number of proximal femoral fracture associated deaths correlated with the number of positive test results performed in the Clinic. The length of stay of SARS-CoV­2 COVID-19 survivors tended to be greater than in those who were tested negative (SARS-CoV­2 COVID-19 positive: 15.6 ± 13.1 days, SARS-CoV­2 COVID-19 negative: 11.5 ± 6.5 days, p = 0.683). Furthermore, a significant difference in age was found in SARS-CoV­2 survivors and SARS-CoV­2 decedents (deceased: 95.5 ± 7.5 years, alive: 83.5 ± 7.3 years, p = 0.020). CONCLUSION: The study was conducted before the introduction of SARS-CoV­2 vaccination. The results therefore refer to immune naive (unvaccinated) patients. In our study, more than 40% of all patients with proximal femoral fractures who tested positive for SARS-CoV­2 died during hospitalization. An additional, critical factor in this respect was the age of the infected patients. Nonetheless, a positive correlation was demonstrated between the mortality rate and the number of positive SARS-CoV­2 detections. Regarding the greater length of stay of patients tested positive for SARS-CoV­2, the limited transfer options (further rehabilitation, skilled nursing facility) of the infected ones can be considered as causal. Particularly the vulnerable older patients are increasingly endangered by a combination of proximal femoral fracture and SARS-CoV­2.

Simultaneous 18F-FDG-PET/MRI for the detection of periprosthetic joint infections after knee or hip arthroplasty: a prospective feasibility study.

PURPOSE: This study investigated the diagnostic value of simultaneous 18F-fluordeoxyglucose positron emission tomography/magnetic resonance imaging (PET/MRI) in suspected periprosthetic joint infection (PJI) of the hip and knee. METHODS: Sixteen prostheses from 13 patients with suspected PJI were prospectively examined using PET/MRI. Image datasets were evaluated in consensus by a radiologist and a nuclear physician for the overall diagnosis of 'PJI' (yes/no) and its anatomical involvement, such as the periprosthetic bone margin, bone marrow, and soft tissue. The imaging results were compared with the reference standard obtained from surgical or biopsy specimens and subjected to statistical analysis. RESULTS: Using the reference standard, ten out of the 13 prostheses (ten hips, threes knees) were diagnosed with PJI. Using PET/MRI, every patient with PJI was correctly diagnosed (sensitivity, 100%; specificity, 100%). Considering the anatomical regions, the sensitivity and specificity were 57% and 50% in the periprosthetic bone margin, 75% and 33% in the bone marrow, and 100% and 100% in the soft tissue. CONCLUSION: PET/MRI can be reliably used for the diagnosis of PJI. However, assessment of the periprosthetic bone remains difficult due to the presence of artefacts. Thus, currently, this modality is unlikely to be recommended in clinical practice.

Factors associated with dislocation after bipolar hemiarthroplasty through an (antero-)lateral approach in elderly patients with a femoral neck fracture: a retrospective cohort study with a nested case-control subanalysis of radiographic parameters.

INTRODUCTION: Dislocations of hip hemiarthroplasty (HHA) are serious complications. The aim of the study was to identify clinical aspects and radiographic parameters of the hip that put patients at risk for dislocation after HHA for femoral neck fractures. METHODS: This retrospective analysis included elderly patients with a femoral neck fracture treated with a HHA. A lateral (90.7%) and an anterolateral (9.3%) approach was applied. On pelvic radiographs, a nested-controlled analysis was performed. Two control patients were matched to one patient suffering a dislocation with respect to age, sex, and body-mass-index (BMI). RESULTS: In 527 HHA, 10 dislocations (1.9%) were identified. In the dislocation group (DG), all patients were female (100% vs. 73.5%, p = 0.071). No significant differences between the DG and the control group (CG) were found with respect to age, body-mass-index (BMI), ASA Score, routine laboratory parameters, and comorbidity. Radiographic analysis revealed a smaller center edge angle (CEA, 39.0, IQR 33.0-42.5 vs. 43.0, IQR 41.0-46.0, p = 0.013), a more varus neck-shaft angle (NSA, 130.0, IQR 125.8-133.5 vs. 135.0, IQR 134.0-137.0, p = 0.011) of the contralateral side and a higher femoral head extrusion index (FHEI) in the DG (FHEI, 11.5, IQR 9.8-16.3 vs. 2.0 IQR 0.0-9.0, p = 0.003). In addition, a greater trochanteric fracture was associated with an increased likelihood for HHA dislocations (30.0% vs 6.0%, p = 0.022). CONCLUSION: A smaller radiographic center edge angle, a more varus neck-shaft angle of the contralateral side, a higher femoral head extrusion index and intraoperative fractures of the greater trochanter are associated with an increased risk of HHA dislocation.

Intraoperative hyperspectral imaging (HSI) as a new diagnostic tool for the detection of cartilage degeneration.

To investigate, whether hyperspectral imaging (HSI) is able to reliably differentiate between healthy and damaged cartilage tissue. A prospective diagnostic study was performed including 21 patients undergoing open knee surgery. HSI data were acquired during surgery, and the joint surface's cartilage was assessed according to the ICRS cartilage injury score. The HSI system records light spectra from 500 to 1000 nm and generates several parameters including tissue water index (TWI) and the absorbance at 960 nm and 540 nm. Receiver operating characteristic curves were calculated to assess test parameters for threshold values of HSI. Areas with a cartilage defect ICRS grade ≥ 3 showed a significantly lower TWI (p = 0.026) and higher values for 540 nm (p < 0.001). No difference was seen for 960 nm (p = 0.244). For a threshold of 540 nm > 0.74, a cartilage defect ICRS grade ≥ 3 could be detected with a sensitivity of 0.81 and a specificity of 0.81. TWI was not suitable for cartilage defect detection. HSI can provide reliable parameters to differentiate healthy and damaged cartilage. Our data clearly suggest that the difference in absorbance at 540 nm would be the best parameter to achieve accurate identification of damaged cartilage.

Risk factors for intraoperative greater trochanteric fractures in hemiarthroplasty for intracapsular femoral neck fractures.

PURPOSE: Hemiarthroplasty is widely accepted as the treatment of choice in elderly patients with a displaced intracapsular femoral neck fracture. Intraoperative greater trochanteric fractures thwart this successful procedure, resulting in prolonged recovery, inferior outcome, and increased risk of revision surgery. Hence, this study analyzed factors potentially associated with an increased risk for intraoperative greater trochanteric fracture. METHODS: This retrospective study included 512 hemiarthroplasties in 496 patients with a geriatric intracapsular femoral neck fracture from July 2010 to March 2020. All patients received the same implant type of which 90.4% were cemented and 9.6% non-cemented. Intra- and postoperative radiographs and reports were reviewed and particularly screened for greater trochanteric fractures. RESULTS: Female patients accounted for 74% and mean age of the patients was 82.3 (± 8.7) years. 34 (6.6%) intraoperative greater trochanteric fractures were identified. In relation to patient-specific factors, only a shorter prothrombin time was found to be significantly associated with increased risk of intraoperative greater trochanteric fracture (median 96%, IQR 82-106% vs. median 86.5%, IQR 68.8-101.5%; p = 0.046). Other factors associated with greater trochanteric fracture were a shorter preoperative waiting time and changes in perioperative settings. Outcome of patients with greater trochanteric fracture was worse with significantly more surgical site infection requiring revision surgery (17.6% vs. 4.2%, p = 0.005). CONCLUSION: Prolonged prothrombin time, a shorter preoperative waiting time, and implementing new procedural standards and surgeons may be associated with an increased risk of a greater trochanteric fracture. Addressing these risk factors may reduce early periprosthetic infection which is strongly related to greater trochanteric fractures.

Management of Modular Mega-Implant Infection of the Lower Extremity.

INTRODUCTION: Revision arthroplasty involving mega-implants is associated with a high complication rate. In particular, infection is a serious complication of revision arthroplasty of hip and knee joints and has been reported to have an average rate of 18%, and for mega-implants, the range is from 3 to 36%. This study was designed to analyze the strategy of treatment of infection of mega-endoprostheses of the lower extremities in our patient cohort, particularly the management of chronic infection. MATERIAL AND METHODS: This was a retrospective study that focused on the results of the treatment of periprosthetic infections of mega-implants of the lower extremities. We identified 26 cases with periprosthetic infections out of 212 patients with 220 modular mega-endoprostheses of the lower extremities who were treated in our department between September 2013 and September 2019. As a reinfection or recurrence, we defined clinical and microbiological recurrences of local periprosthetic joint infections after an antibiotic-free period. RESULTS: In this study, 200 cases out of 220 were investigated. The average follow-up period was approximately 18 months (6 months to 6 years). Endoprosthesis infections after implantation of mega-implants occurred in 26 cases (13%). This group comprised 2 early infections (within the first 4 weeks) and 24 chronic infections (between 10 weeks and 6 years after implantation). Nineteen cases out of the identified 26 cases with infection (73.1%) belong to the group of patients who were operated on due to major bone loss following explantation of endoprosthetic components due to previous periprosthetic joint infection. The remaining seven cases with infection comprised four cases following management of periprosthetic fracture, two cases following treatment of aseptic loosening, and one case following tumor resection. All infections were treated surgically. In all cases, the duration of continuous antibiotic treatment did not exceed 6 weeks. Both cases with early infection were treated by exchanging polyethylene inlays and performing debridement with lavage (two cases). In two (7.7%) cases with chronic infection, one-stage surgery was performed. In all remaining cases with chronic infection (22 cases; 84.6%), explantation of all components and temporary implantation of cement spacers were carried out prior to reimplantation. CONCLUSION: There is still no gold standard therapeutic regimen for the management of periprosthetic infection of mega-implants, though radical surgical debridement and lavage accompanied by systemic antibiotic therapy are the most important therapeutic tools in all cases of periprosthetic infections, regardless of the time of onset. Further studies are needed to standardize management strategies of such infections. Nevertheless, it is not uncommon for compromises to be made based on the particular condition of the individual.