Surgical Site Infection in Patients Managed with an Endoprosthesis for the Treatment of Cancer: Evaluation of Patient, Disease, and Index Surgical Factors.

BACKGROUND: Surgical site infection (SSI) after segmental endoprosthetic reconstruction in patients treated for oncologic conditions remains both a devastating and a common complication. The goal of the present study was to identify variables associated with the success or failure of treatment of early SSI following the treatment of a primary bone tumor with use of a segmental endoprosthesis. METHODS: The present study used the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) data set to identify patients who had been diagnosed with an SSI after undergoing endoprosthetic reconstruction of a lower extremity primary bone tumor. The primary outcome of interest in the present study was a dichotomous variable: the success or failure of infection treatment. We defined failure as the inability to eradicate the infection, which we considered as an outcome of amputation or limb retention with chronic antibiotic suppression (>90 days or ongoing therapy at the conclusion of the study). Multivariable models were created with covariates of interest for each of the following: surgery characteristics, cancer treatment-related characteristics, and tumor characteristics. Multivariable testing included variables selected on the basis of known associations with infection or results of the univariable tests. RESULTS: Of the 96 patients who were diagnosed with an SSI, 27 (28%) had successful eradication of the infection and 69 had treatment failure. Baseline and index procedure variables showing significant association with SSI treatment outcome were moderate/large amounts of fascial excision ≥1 cm2) (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.001), use of local muscle/skin graft (OR,11.88 [95% CI, 1.83 to 245.83]; p = 0.031), and use of a deep Hemovac (OR, 0.24 [95% CI, 0.05 to 0.85]; p = 0.041). In the final multivariable model, excision of fascia during primary tumor resection was the only variable with a significant association with treatment outcome (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.018). CONCLUSIONS: The results of this secondary analysis of the PARITY trial data provide further insight into the patient-, disease-, and treatment-specific associations with SSI treatment outcomes, which may help to inform decision-making and management of SSI in patients who have undergone segmental bone reconstruction of the femur or tibia for oncologic indications. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

High fibrinogen levels are associated with poor survival in patients with liposarcoma.

The aim of this study was to evaluate whether (preoperative) plasma levels of fibrinogen, an essential clotting and acute phase protein, are associated with the prognosis of patients with a liposarcoma, a subtype of sarcoma derived from adipose tissue. We performed a retrospective cohort study of 158 patients with liposarcoma treated at the Department of Orthopaedics of the Medical University of Vienna in Austria from May 1994 to October 2021. Kaplan-Meier curves as well as uni- and multivariable Cox proportional hazard models were performed to evaluate the association between fibrinogen levels and overall survival. Elevated fibrinogen was associated with adverse overall survival in cause specific hazards analysis of mortality (hazard ratio [HR] per 10 mg/dL increase: 1.04; 95% CI 1.02-1.06; p < 0.001). This association prevailed in multivariable analysis after adjustment for AJCC tumor stage (HR 1.03; 95% CI 1.01-1.05; p = 0.013). Increasing levels of fibrinogen, a routinely available and inexpensive parameter, predicts the risk of mortality in patients with liposarcoma.

Quantitative and individualized assessment of the learning curve in preoperative planning of the acetabular cup size in primary total hip arthroplasty.

INTRODUCTION: The aim of the present study was to investigate the learning curves of 2 trainees with different experience levels to reach proficiency in preoperative planning of the cup size based on learning curve cumulative summation (LC-CUSUM) statistics and a cumulative summation (CUSUM) test. MATERIALS AND METHODS: One-hundred-twenty patients who had undergone primary total hip arthroplasty with a cementless cup were selected. Preoperative planning was performed by an experienced orthopedic surgeon. Trainee 1 (student) and trainee 2 (resident) planned the cup size. The trainees were blinded to the preoperative plan and the definitive cup size. Only after a cup size was chosen, the trainees were unblinded to the preoperative plan of the surgeon. LC-CUSUM was applied to both trainees to determine when proficiency in determining the appropriate cup size was reached. A CUSUM test was applied to ensure retention of proficiency. RESULTS: With reference to the preoperative plan of the surgeon, LC-CUSUM indicated proficiency after 94 planning attempts for trainee 1 and proficiency after 66 attempts for trainee 2, respectively. Trainee 1 and 2 maintained proficiency thereafter. With reference to the definitive cup size, LC-CUSUM did not signal competency within the first 120 planning attempts for trainee 1. Trainee 2 was declared competent after 103 attempts and retained competency thereafter. CONCLUSIONS: LC-CUSUM/CUSUM allow for an individualized, quantitative and continuous assessment of planning quality. Based on LC-CUSUM statistics, the two trainees of this study gain proficiency in planning of the acetabular cup size after 50-100 attempts when an immediate feedback is provided. Previous experience positively influences the performance. The study serves as basis for the medical education of students and residents in joint replacement procedures.

The Dysregulated Galectin Network Activates NF-κB to Induce Disease Markers and Matrix Degeneration in 3D Pellet Cultures of Osteoarthritic Chondrocytes.

This work aimed to study the dysregulated network of galectins in OA chondrocyte pellets, and to assess whether their recently discovered activity as molecular switches of functional biomarkers results in degradation of extracellular matrix in vitro. Scaffold-free 3D pellet cultures were established of human OA chondrocytes. Expression and secretion of galectin(Gal)-1, -3, and -8 were monitored relative to 2D cultures or clinical tissue sections by RT-qPCR, immunohistochemistry and ELISAs. Exposure of 2D and 3D cultures to an in vivo-like galectin mixture (Gal-1 and Gal-8: 5 µg/ml, Gal-3: 1 µg/ml) was followed by the assessment of pellet size, immunohistochemical matrix staining, and/or quantification of MMP-1, -3, and -13. Application of inhibitors of NF-κB activation probed into the potential of intervening with galectin-induced matrix degradation. Galectin profiling revealed maintained dysregulation of Gal-1, -3, and -8 in pellet cultures, resembling the OA situation in situ. The presence of the galectin mixture promoted marked reduction of pellet size and loss of collagen type II-rich extracellular matrix, accompanied by the upregulation of MMP-1, -3, and -13. Inhibition of p65-phosphorylation by caffeic acid phenethyl ester effectively alleviated the detrimental effects of galectins, resulting in downregulated MMP secretion, reduced matrix breakdown and augmented pellet size. This study suggests that the dysregulated galectin network in OA cartilage leads to extracellular matrix breakdown, and provides encouraging evidence of the feasible inhibition of galectin-triggered activities. OA chondrocyte pellets have the potential to serve as in vitro disease model for further studies on galectins in OA onset and progression.

Demyelinating Charcot-Marie-Tooth neuropathy associated with FBLN5 mutations.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease type 1 (CMT1) is a group of autosomal dominantly inherited demyelinating sensorimotor neuropathies. Symptoms usually start in the first to second decade and include distal muscle weakness and wasting, sensory disturbances and foot deformities. The most frequent cause is a duplication of PMP22 whilst point mutations in PMP22 and other genes are rare causes. Recently, FBLN5 mutations have been reported in CMT1 families. METHODS: Individuals with FBLN5-associated CMT1 were compiled from clinical and research genetic testing laboratories. Clinical data were extracted from medical records or obtained during patients' visits at our centres or primary care sites. RESULTS: Nineteen CMT1 families containing 38 carriers of three different FBLN5 missense variants were identified and a mutational hotspot at c.1117C>T (p.Arg373Cys) was confirmed. Compared to patients with the common PMP22 duplication, individuals with FBLN5 variants had a later age of diagnosis (third to fifth decade) and less severely reduced motor median nerve conduction velocities (around 31 m/s). The most frequent clinical presentations were prominent sensory disturbances and painful sensations, often as initial symptom and pronounced in the upper limbs, contrasting with rather mild to moderate motor deficits. CONCLUSIONS: Our study confirms the relevance of FBLN5 mutations in CMT1. It is proposed to include FBLN5 in the genetic work-up of individuals suspected with CMT1, particularly when diagnosis is established beyond the first and second decade and comparably moderate motor deficits contrast with early and marked sensory involvement. FBLN5-associated CMT1 has a recognizable clinical phenotype and should be referred to as CMT1H according to the current classification scheme.

Potential predictive value of axial T2 mapping at 3 Tesla MRI in patients with untreated patellar cartilage defects over a mean follow-up of four years.

OBJECTIVE: The objective was to demonstrate the potential of axial T2 mapping for quantification of untreated early-stage patellar cartilage lesions over time and to assess its capability as a potential predictive marker for future progression. STUDY DESIGN & METHODS: Thirty patients (mean age, 36.7 ± 11.1 years; 16 males), with early-stage patellar cartilage defects (≤ICRS grade 2) at baseline and no treatment during follow up (4.0 ± 1.6 years) were enrolled. Morphological cartilage changes over time were subdivided into a Progression, Non-Progression Group and Regression Group. Quantitative analysis of cartilage defects and healthy reference was performed by means of global and zonal T2 mapping (deep and superficial cartilage T2 values) at both time points. Statistical evaluation included analysis of variance (ANOVA), paired t Test's and ROC analysis. RESULTS: The Progression Group (N = 11) had significantly higher global T2 values at baseline (57.4 ± 7.8 ms) than patients without (N = 17) (40.6 ± 6.9 ms) (P < 0.01). Furthermore the Non-Progression Group showed only a minor increase in global T2 relaxation times to 43.1 ± 7.9 ms (P = 0.07) at follow up, whereas in the progression group global (68,7 ± 19 ms: P = 0.02) and superficial T2 values (65,8 ± 8.2-79.8 ± 24.4 ms; P = 0.03) increased significantly. T2 values for healthy reference cartilage remained stable. In 2 patients an improvement in ICRS grading was observed (Regression Group) with decreasing T2 values. The ROC analysis showed an area under the curve of 0.92 (95%CI 0.82-1.0). At a cut-off value of 47.15 ms, we found a sensitivity of 92% (false-positive rate of 18%) for future progression of cartilage defects. CONCLUSIONS: This study provides evidence regarding the possible potential of axial T2 mapping as a tool for quantification and prediction of patellar cartilage defect progression in untreated defects.

Correction to: Analysis and quantification of bone healing after open wedge high tibial osteotomy.

Correction to: Wien Klin Wochenschr 2019 https://doi.org/10.1007/s00508-019-01541-8The original version of this article unfortunately contained a mistake. The presentation of Tab. 4 was incorrect. The corrected table is given below.The original article has been ….

[Growing prostheses after sarcoma resection in children and adolescents]. / Wachstumsprothesen nach Sarkomresektionen im Kindes- und Jugendalter.

BACKGROUND: Growing prostheses are regarded as a valuable alternative to amputation and rotationplasty for the treatment of primary malignant bone and soft-tissue sarcomas in childhood. During the last three decades different devices have been introduced and technically improved from invasively to non-invasively extendable prostheses. THE CURRENT SITUATION OF STUDIES: Despite the long period, only 21 peer-reviewed publications could be detected containing relevant numbers and results. In these papers, 590 patients with mean follow-up times of 81.1 months were reported who had been fitted with growing prostheses at the age of 12.6 years. Besides satisfactory functional results (78.3 out of 100 MSTS points) there was a high complication rate of 27.3% infections and 22.4% mechanical failure. COMPLICATIONS: This increasing risk of infection over a long follow-up period, represents the biggest drawback of this method and, therefore, needs to be discussed extensively with the patients and parents when considering this procedure as an alternative to ablative surgery.

Performance of automated multiplex polymerase chain reaction (mPCR) using synovial fluid in the diagnosis of native joint septic arthritis in adults.

AIMS: This study aimed to assess the performance of an automated multiplex polymerase chain reaction (mPCR) technique for rapid diagnosis of native joint septic arthritis. PATIENTS AND METHODS: Consecutive patients with suspected septic arthritis undergoing aseptic diagnostic joint aspiration were included. The aspirate was used for analysis by mPCR and conventional microbiological analysis. A joint was classed as septic according to modified Newman criteria. Based on receiver operating characteristic (ROC) analysis, the area under the ROC curve (AUC) values of the mPCR and the synovial fluid culture were compared using the z-test. A total of 72 out of 76 consecutive patients (33 women, 39 men; mean age 64 years (22 to 92)) with suspected septic arthritis were included in this study. RESULTS: Of 72 patients, 42 (58%) were deemed to have septic joints. The sensitivity of mPCR and synovial fluid culture was 38% and 29%, respectively. No significant differences were found between the AUCs of both techniques (p = 0.138). A strong concordance of 89% (Cohen's kappa: 0.65) was shown. The mPCR failed to detect Staphylococcus aureus (n = 1) and Streptococcus pneumoniae (n = 1; no primer included in the mPCR), whereas the synovial fluid culture missed six microorganisms (positive mPCR: S. aureus (n = 2), Cutibacterium acnes (n = 3), coagulase-negative staphylococci (n = 2)). CONCLUSION: The automated mPCR showed at least a similar performance to the synovial fluid culture (the current benchmark) in diagnosing septic arthritis, having the great advantage of a shorter turnaround time (within five hours). Cite this article: Bone Joint J 2019;101-B:288-296.

Biomechanical evaluation of two methods of fixation of a flexor hallucis longus tendon graft.

Aims: The traditional transosseus flexor hallucis longus (FHL) tendon transfer for patients with Achilles tendinopathy requires two incisions to harvest a long tendon graft. The use of a bio-tenodesis screw enables a short graft to be used and is less invasive, but lacks supporting evidence about its biomechanical behaviour. We aimed, in this study, to compare the strength of the traditional transosseus tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis screw, in cyclical loading and ultimate load testing. Materials and Methods: Tendon grafts were undertaken in 24 paired lower-leg specimens and randomly assigned in two groups using fixation with a transosseus suture (suture group) or a tenodesis screw (screw group). The biomechanical behaviour was evaluated using cyclical and ultimate loading tests. The Student's t-test was performed to assess statistically significant differences in bone mineral density (BMD), displacement, the slope of the load-displacement curves, and load to failure. Results: The screw group showed less displacement (loosening) during cyclical loading, which was significant during 300, 500, 600, 700, 800, 900, and 1000 cycles (p < 0.05: other cycles: 0.079 < p < 0.402). Compared with the suture group, the screw group had higher mean ultimate load values (133.6 N, sd 73.5 vs 110.1 N, sd 46.2; p = 0.416). Conclusion: Fixation of the FHL tendon with a tenodesis screw enables a less invasive procedure to be undertaken and shows similar biomechanical behaviour and primary strength compared with fixation using a transosseus suture. Cite this article: Bone Joint J 2018;100-B:1175-81.

Peroneus brevis tendon in proximal 5th metatarsal fractures: Anatomical considerations for safe hook plate placement.

INTRODUCTION: The peroneus brevis tendon (PBT) inserts into the proximal aspect of the 5th metatarsal. Metatarsal bone fractures are encountered to be the most common fractures in the foot with predominantly fractures at the base of the fifth metatarsal bone. Mechanism of injury and treatment of the proximal 5th metatarsal fractures vary due to the complex anatomy and diverse biomechanical properties. The purpose of this study was to analyze the footprint of the PBT with regards to the proximal 5th metatarsal fractures and to define a "safe zone" for hook plate placement. MATERIALS AND METHODS: Forty-one (41) fixed human lower leg specimens were dissected to expose the PBT insertion. The following footprint characteristics were evaluated: area of insertion (AOI) (mm2), length (mm), width (mm), shape and insertional variations. The position of the main PBT footprint was localized according to the Lawrence and Botte classification for the proximal 5th metatarsal fractures (Zone I-III). A "safe zone" was defined for the fracture-specific hook plate placement. RESULTS: In 25 (61%) feet the PBT footprint was situated in Zone I and in 16 feet (39%) in Zone I&II. The mean AOI, length and width measured 54.5 mm2 (SD 16.5), 16.0 mm (SD 5.1) and 4.7 mm (SD 1.4), respectively. Analysis of the footprint shapes revealed four different shape types: kidney (29.3%), diamond (22.0%), crescent (31.7%) and oval (17.0%). A "safe zone" for hook plate placement without or minimal interference of the PBT at its insertion could be defined at the lateral aspect of the 5th metatarsal. CONCLUSION: The majority of the PBT footprints were found in Zone I. Hook plate placement demonstrated to be safe when placed strictly laterally at the proximal aspect of the 5th metatarsal. Precise knowledge of the peroneus brevis anatomy may help to better understand the biomechanical aspects of the proximal 5th metatarsal fractures.

A novel mechanotronic orthosis enables symmetrical gait kinematics in a patient with a femoral nerve palsy - a case study.

The usage of stance- and swing-phase control orthoses (SSCOs) is a good option in patients with neuromuscular insufficiency of the quadriceps muscle in a broad range of musculo-skeletal disorders. The subjective sensation of improved mobility in daily life and walking comfort could be objectively confirmed by the ability to walk without crutches and by harmonization of the gait patterns in hip and knee. They could also be a considered mobility device after limb salvage surgery, which may even have an impact on preoperative decision making. IMPLICATIONS FOR REHABILITATION Symmetric gate in spite of femoral nerve palsy. Early gate improvements even after hours. High patient?s motivation to use the device.

[Therapeutic utilization of stem cells in orthopedics]. / Therapeutische Anwendung von Stammzellen in der Orthopädie.

Stem cells are becoming increasingly more important in the field of regenerative medicine. Adult mesenchymal stem cells (MSCs) are harvested predominantly from bone marrow or adipose tissue, are already being used in the clinical setting and have a low potential for side effects. In orthopedics, experience has been gained in the treatment of bone defects, non-unions, cartilage defects, osteoarthritis and tendon pathologies. The current data are derived from case studies and randomized controlled trials are missing; therefore, there are many open questions concerning the optimal cell source, number of cells, administration technique (e.g. injections and matrices) or combinations with growth factors; however, it is evident from the data that MSCs have a positive effect on tissue regeneration and are safe to use.

[Allogeneic transplants for biological reconstruction of bone defects]. / Allogene Transplantate für biologische Rekonstruktionen von Knochendefekten.

A combination of allogeneic and autologous bone transplants is frequently used for the biological reconstruction of bone defects. Autologous bone transplants can be used either in the form of structural or cancellous bone transplants. The osteogenic potential of autologous cancellous bone is well-known and is still the gold standard with respect to osteoinduction and remodelling. Structural transplants, such as fibular and tricortical iliac crest grafts can be transplanted either free, i.e. non-vascularized or vascularized with anastomosed vessels. Allogeneic bone transplants can be used in a spongiose or structural form. In revision endoprosthetics the use of allogeneic bone transplants has essentially been reduced to impaction grafting, due to the introduction of trabecular metal as a permanently stable substitute. Allogeneic transplants have been restricted due to 3D-printing and the associated individually adapted reconstruction. In individual cases combined reconstruction consisting of allograft and endoprosthesis provide the advantage of safe load transmission and permanent reconstruction by the endoprosthesis and the possibility of soft tissue insertion of the allograft.

Pelvic reconstruction following resection of malignant bone tumours using a stemmed acetabular pedestal cup.

AIMS: Pelvic reconstruction after the resection of a tumour around the acetabulum is a challenging procedure due to the complex anatomy and biomechanics. Several pelvic endoprostheses have been introduced, but the rates of complication remain high. Our aim was to review the use of a stemmed acetabular pedestal cup in the management of these patients. PATIENTS AND METHODS: The study involved 48 patients who underwent periacetabular reconstruction using a stemmed pedestal cup (Schoellner cup; Zimmer Biomet Inc., Warsaw, Indiana) between 2000 and 2013. The indications for treatment included a primary bone tumour in 27 patients and metastatic disease in 21 patients. The mean age of the patients at the time of surgery was 52 years (16 to 83). RESULTS: At a median follow-up of 6.6 years (95% confidence interval 4.6 to 8.2), local control was achieved in all patients; 19 patients had died (16 of disease). Complications occurred in 19 patients (40%), of which deep infection was the most common, affecting eight patients (17%). Seven patients (15%) had a dislocation of the hip. Aseptic loosening was found in three patients (6%). Two (4%) underwent hindquarter amputation for non-oncological reasons. The risk of revision, with death being treated as a competing event, was 28% at one year, 39% at five years and 48% at ten years post-operatively. The mean Musculoskeletal Tumour Society Score at final follow-up was 71% (27% to 93%). CONCLUSION: This type of reconstruction is a satisfactory option for the treatment of patients with a periacetabular tumour. There remains, however, a high rate of complication, which may be reduced by future modifications of the device such as silver coating and tripolar articulation. Cite this article: Bone Joint J 2017;99-B:841-8.

[Acute haematogenous osteomyelitis in children : Diagnostic algorithm and treatment strategies]. / Akute hämatogene Osteomyelitis im Wachstumsalter : Diagnostischer Algorithmus und Behandlungsstrategien.

Acute haematogenous osteomyelitis (AHO) in children is a severe condition. A delay in diagnosis and insufficient treatment may result in deformities, chronicity and sepsis. Therefore a structured diagnostic workup has to be followed in order to diagnose or rule out osteomyelitis. To identify the causative agent for targeted antibiotic treatment, a bone biopsy or puncture should be performed. However, approximately 25% of cases are culture-negative even after biopsy. The knowledge of the typical age-dependent bacterial spectrum is essential for empirical antibiotic therapy. The principal causative organism is Staphylococcus aureus. Surgery is not routinely required in paediatric acute osteomyelitis but surgical intervention is indicated if an abscess is detected. Secondary septic arthritis is a serious complication which has to be treated immediately by surgical intervention. Nevertheless, complete regeneration can be expected in up to 80% of children with AHO.

[General diagnostic work-up for benign tumors of the musculoskeletal system]. / Allgemeine diagnostische Grundlagen bei benignen Tumoren des Bewegungsapparats.

INTRODUCTION: Benign bone tumors are heterogeneous and have different biological behaviors. Treatment requires knowledge of the principle diagnosis and clinical behavior to avoid, on the one hand, overtreatment and, on the other hand, incorrect diagnosis of a potentially malignant tumor. METHODS: Bone tumors of stage I (according to Enneking) should be observed clinically and radiologically. For stage II and stage III lesions, a biopsy should be performed, based on the corresponding oncological guidelines. RESULTS AND CONCLUSION: Soft tissue tumors have a different radiological behavior (especially in magnetic resonance images): while a lack of sharp cortical margins in bone tumors indicates an aggressive behavior, sharp margins in soft tissue tumors should not be misinterpreted as benign tumors. Subfascial soft tissue tumors, tumors larger than 2 cm, growing tumors, and persisting tumors after trauma require biopsy.

The outcome of the surgical treatment of pelvic chondrosarcomas: a competing risk analysis of 58 tumours from a single centre.

AIMS: Few studies dealing with chondrosarcoma of the pelvis are currently available. Different data about the overall survival and prognostic factors have been published but without a detailed analysis of surgery-related complications. We aimed to analyse the outcome of a series of pelvic chondrosarcomas treated at a single institution, with particular attention to the prognostic factors. Based on a competing risk model, our objective was to identify risk factors for the development of complications. PATIENTS AND METHODS: In a retrospective single-centre study, 58 chondrosarcomas (26 patients alive, 32 patients dead) of the pelvis were reviewed. The mean follow-up was 13 years (one week to 23.1 years). RESULTS: A total of 26 patients (45%) were alive and 32 patients (55%) had died. Overall survival was 76%, 55% and 45% at one, five and ten years post-operatively, respectively. In a competing risk model the cumulative risk of the development of a surgery-related complication was 64% at six months and 69% at one year, post-operatively, respectively. Endoprosthetic reconstruction was a significant risk factor for the development of complications (p = 0.006). Complications were not significantly related to age or the location or grade of the tumour (p = 0.823, p = 0.976, p = 0.858). The development of complications did not have a negative effect on survival (p = 0.147). CONCLUSION: This is the first study with competing risk analysis of surgery-related complications in patients with a pelvic chondrosarcoma. The surgery in these patients remains prone to complications. Endoprosthetic reconstruction significantly increases the risk of the development of complications (p = 0.006). A competing risk model showed that the development of complications does not have a negative influence on overall survival (p = 0.147). An aggressive, surgical resection with the goal of achieving wide margins whenever possible remains the mainstay of treatment. Cite this article: Bone Joint J 2017;99-B:686-96.