Aggressive granulomatous pseudotumor following total hip prosthesis: Diagnostic and therapeutic strategies from a single institution experience.

Introduction: Granuloma formation following total hip arthroplasty (THA) can occur regardless of the bearing surface. In very rare cases, extensive granulomas mimicking tumors may develop which are known as pseudotumors. The aim of this study is to report on these rare yet complex situations to stimulate reflection in diagnostic and therapeutic approaches. Methods: A retrospective case series study of 5 patients (2 females, 3 males) of aggressive granulomatous lesions on primary prostheses and 4 revision prostheses for aseptic loosening, implanted at a mean age of 74.8 years (range 64-83). A clinical, functional, radiographic, and anatomopathological analysis were conducted. Results: Four patients underwent revision surgery, while one died before intervention. Functional impairment was significant with a mean pre-reintervention Postel-Merle d'Aubigné (PMA) score of 8.2 (range 4-11). Femoral involvement was constant, associated with acetabular involvement in only one case. bony involvement was major, with a minimum of 5 Gruen zones affected, showing complete cortical lysis. Histopathological analysis consistently revealed multinucleated giant cells and macrophages, predominantly with metallic wear particles. In 2 cases, vascular involvement was suspected without a clearly delineated tumor. Two cases required femoral resection prostheses, one necessitated inter-ilio-abdominal amputation due to extensive soft tissue involvement, one underwent implant removal which failed to prevent progression, and one patient died before reoperation. Conclusion: The volume of lesions in these 5 cases appears markedly larger than reported cases.Extensive pseudo-tumoral granulomatous lesions following THA are rare but carry poor functional prognosis. Evaluation to rule out infection and neoplastic pathology is imperative. Surgical management often resembling tumor treatment should be considered. Early diagnosis is crucial to allow intervention before reaching the stage of massive prosthetic replacement. Level of evidence: IV retrospective study.

Buried de-epithelialized flap: An original solution to fill dead space after sarcoma resection in the thigh. Surgical technique and results of 12 cases.

INTRODUCTION: Soft tissue sarcomas (STS) are often treated with wide excision in combination with adjuvant or neoadjuvant radiotherapy. This is currently the gold standard procedure for the treatment of STS that arise in the extremities. Wound healing complications frequently occur and negatively affect the prognosis. One of the options is to use a buried de-epithelialized flap as it can increase the lymphatic flow, fill the dead space, and cover neurovascular structures and implants. This aim of this retrospective study were two-fold. 1) Describe the surgical technique for this buried de-epithelialized flap after STS removal in the thigh. 2)Evaluate the efficacy of the buried de-epithelialized flap for decreasing wound complications based on a small case series and compare it with previous publications. HYPOTHESIS: We hypothesized that the complication rate of this flap is not higher than the published complication rate for traditional flaps. MATERIALS AND METHODS: Twelve patients (7 women and 5 men) with a mean age of 62±12years (38-76), who underwent surgical removal of an STS in the thigh with coverage by a buried de-epithelialized flap were reviewed at a mean follow-up of 15.8months (range 8-24). RESULTS: Two patients presented with a postoperative wound infection (17%): one superficial and one deep at the surgical site. Neither required an additional plastic surgery procedure. Another patient had a dislocation of their total hip arthroplasty that was managed by closed reduction. One patient died from metastatic progression. There was no skin necrosis of the superficial skin edges, no hematoma or seroma in the other 10 patients. The flap was still visible on cross-sectional imaging at 1 month postoperative with no fluid between the tissue planes or signs of necrosis. The rate of wound healing complications that required surgical treatment was 17% in our case series, versus 16 to 56% in previous publications reporting the results of suture closure only. CONCLUSION: A buried de-epithelialized flap reduces the risk of skin complications by filling dead space, improving lymphatic flow and covering critical structures. It is a reliable and reproducible option after wide local excision of STS in the thigh, with no additional morbidity. LEVEL OF EVIDENCE: IV, retrospective study.

Comparison of bleeding during trochanteric fracture fixation with mini-invasive or conventional side plate fixation: A randomized controlled trial.

BACKGROUND: Trochanteric fractures are a public health issue due to the aging of the population. Treatment aims to reduce their related morbidity and mortality and to allow an early return to independence. Postoperative anemia is associated with poorer functional recovery and an increased mortality rate. The aim of this study was to assess whether minimally invasive side plate fixation (Minimal Invasive Screw System, MISS™) resulted in reduced perioperative bleeding compared with conventional fixation (Pertrochanteric Hip Screw, PHS™). HYPOTHESIS: We hypothesized that minimally invasive side plate fixation (MISS) would result in reduced perioperative bleeding compared with conventional fixation (PHS). PATIENTS AND METHODS: We conducted an open randomized controlled trial with blinded assessment of the primary outcome. Inclusion criteria were patients aged over 65 years with isolated reducible trochanteric fracture. The 2 surgical implants were of the same shape, the only difference between them being the locking mode of the femoral neck screw on the plate of the MISS device, allowing a percutaneous approach. Primary outcome was perioperative bleeding evaluated with Mercuriali's formula. Secondary outcomes included operating time, scar length, length of hospital stay, radiological criteria such as quality of fracture reduction, implant positioning, bone healing, complications and functional recovery compared between the 2 groups. RESULTS: One hundred and eight patients met the inclusion criteria and were randomized to receive either PHS (n=54) or MISS (n=54). Osteosynthesis with MISS significatively reduced perioperative bleeding (median 243mL, interquartile range [152-410] vs. 334mL [247-430] [p=0.0299]), operating time (65min [57-73] vs. 79min [66-89] [p=0.0002]) and scar length after 45 days (7cm [5-8] vs. 14cm [12-15] [p<0.0001]). There was no statistically significant difference between groups in postoperative complications, revision surgery or serious adverse events. CONCLUSION: Compared with PHS, MISS reduced operating time, perioperative bleeding and scar length with no observed functional difference. LEVEL OF EVIDENCE: I.

Signature of the vascular tumor microenvironment as a marker of the therapeutic response to doxorubicin in a preclinical model of osteosarcoma.

Predicting a response of osteosarcoma patients to chemotherapy, such as doxorubicin or high-dose methotrexate cocktail, remains a challenge in the clinic. Moreover, the prognostic value of currently used necrosis analysis is debatable. New markers of the therapeutic response or the prognostic response are urgently needed. The microenvironment plays a key role in the vascularization of highly heterogeneous tumors. Using the syngeneic MOS-J mouse model of osteosarcoma, we focused our study on the immunohistochemistry of tumor vascularization in order to identify new vessel markers, and to search for potential markers of the therapeutic response. Endomucin+, CD31+, and α-SMA+-positive elements were quantified in control (n=6) and doxorubicin-treated (n=6) mice in three different intra-tumor locations. We also used co-labeling to assess CD31+/Endomucin+ and CD31+/α-SMA+ co-expression. We identified a central tumor zone with a low vascularization profile for all of these markers. We identified two distinct types of vessels: CD31+/Endomucin+ vessels with a sprouting, neo-angiogenic, interlaced appearance, and CD31+/α-SMA+ vessel with a well-defined, mature structure. Doxorubicin appeared to reduce CD31+ expression in the tumor invasion front. In the doxorubicin-sensitive model, there were four times more CD31+/α-SMA+ elements than in the poorly responsive model. Therefore, we propose a methodology based on immunohistochemistry and multiplexed immunofluorescence to use endomucin as a promising new vascular marker in the osteosarcoma model. Moreover, our results suggest that CD31+/α-SMA+ vessels could be considered to be indicators of vasculature normalization and they may be used as specific markers of a good therapeutic response.

Knee arthrodesis using a compression clamp and a single-plane external fixator to treat infection.

BACKGROUND: In patients with knee infection, arthrodesis by external fixation is a limb-salvage procedure appropriate in highly selected patients. No hardware that might lead to infection is left in situ. However, the fusion rate is limited. Use of a device that applies compression in the coronal plane has been suggested in combination with sagittal external fixation to increase the fusion rate but has not been the focus of published studies. The objectives of this retrospective study were to determine: 1) the fusion rate and, 2) the rate of infection eradication. HYPOTHESIS: Knee arthrodesis using an external fixator and a compression clamp provides higher fusion rates compared to reports of external fixation without compression. MATERIAL AND METHODS: We retrospectively studied 30 patients who underwent knee arthrodesis using external fixation and a compression clamp. The reason for arthrodesis was recurrent infection after total knee arthroplasty in 18 patients and septic arthritis in 12 patients. There were 16 females and 14 males with a mean age of 66.0±11.6 years (range, 30-83 years). Mean follow-up was 42.5±23.6 months (range, 24-106 months). RESULTS: Fusion was achieved in 25 (83%) patients, after a mean of 7.5 months (range, 6-12 months). Of the 8 patients with severe bone loss (≤25% bone contact), 4 experienced non-union, compared to 1 of the 22 patients whose bone loss was moderate or mild (50% and >50% bone contact, respectively) (p=0.01). After at least 2 years of follow-up, the infection was eradicated in 28 (93%) patients. Complications occurred in 9 patients and consisted of pin-site infection managed by lavage (n=3), recurrent infection requiring revision surgery for debridement and lavage combined with material exchange and antibiotic therapy (n=2), and femoral shaft fracture (n=3) or traumatic fracture of the arthrodesis (n=1) treated by changing the clamp and fixator assembly. DISCUSSION: The fusion rate achieved using this combined technique is high and better than obtained with external fixation alone. Our results confirm that infection eradication is obtained more often than with nailing. This one-stage, simple, reproducible procedure does not leave any foreign material in situ. LEVEL OF EVIDENCE: IV, retrospective observational cohort study.

Fully hydroxyapatite-coated distal locking cementless femoral modular implant for revision total hip arthroplasty: A retrospective study of 94 Renaissance™ stems at a minimum 10 years' follow-up.

INTRODUCTION: Modular locking revision total hip arthroplasty femoral implants have been little assessed over the long term. We therefore conducted a retrospective assessment of the Renaissance™ fully hydroxyapatite-coated distal locking cementless femoral modular revision implant at a minimum 10 years' follow-up, analyzing: 1) survivorship, 2) complications, 3) radiologic and functional results, and 4) prevalence of thigh pain. HYPOTHESIS: This implant shows more than 90% 10-year survival. MATERIAL AND METHOD: Between December 2002 and December 2008, 213 implant exchanges were performed in 206 patients, including 97 Renaissance™ stems in 93 patients. Three patients were excluded for missing data. Survival was analyzed for 94 stems in 90 patients at a mean 11.2±3 years' follow-up; radiographic and clinical assessment was performed for 48 stems in 45 patients. The survival criterion was implant fracture and/or femoral stem removal. RESULTS: Survival was 93.5% at 10 years (95% CI: 86-97) and 91.3% at 15 years (95% CI: 82.9-96). Eight stems (8.5%) were exchanged or removed by last follow-up: 5 for infection (5.3%) and 3 for implant breakage (3.2%). The complications rate was 18.1% (N=17, including the 8 stem revisions): 3 stem exchanges for breakage (3.2%), 9 stem infections (9.6%), 3 dislocations (3.2%), and 2 traumatic greater trochanter fractures (2.1%). For the 45 patients with long-term clinical assessment, the mean Postel Merle d'Aubigné and Harris Hip scores were respectively 15±3 and 80 ±19 at last follow-up. Metaphysis reconstruction was satisfactory in 36/48 cases (75.0%). Seven of the 48 stems (14.6%) assessed at longest follow-up, in 45 patients, were causing thigh pain, unrelated to stress-shielding, distal locking screws or metaphyseal filling index. DISCUSSION: The Renaissance™ fully hydroxyapatite-coated modular locking stem with curved nail showed 90% 10-year survival, with satisfactory functional results and little thigh pain. LEVEL OF EVIDENCE: IV; case study without control group.

Management of adipose tumors in the limbs.

Adipose tumors of the limbs are the most common soft tissue lesions and are essentially benign (lipomas). However, in some cases, they can be considered as tumors with intermediate malignancy (atypical lipomatous tumor [ALT]) or sarcoma lineage (liposarcoma [LS]). The essential work-up for a potential adipose tumor consists of a clinical examination and initial ultrasound imaging to determine the size (more or less than 5 cm), the location (over or under the fascia) and any potential atypical vascularization. As needed, MRI will complete the assessment and validate the ultrasound results and confirm the fatty nature of the lesion. Percutaneous biopsy will be done when a deep fatty lesion is larger than 5 cm (long axis), with detection by amplification of the MDM2 gene that guides the diagnosis towards ALT or dedifferentiated LS. Superficial lesions without atypia are not challenging from a surgical point of view. However, large ALT can be more difficult to manage. Their local malignancy does not justify sacrificing any critical structures. As for true LS, their treatment is well defined, with tumor excision addressed at a center belonging to the Network of Sarcomas Reference Centers in France (NETSARC+) and for potential (neo)adjuvant treatment if needed. Inappropriate treatment of a malignant tumor can have serious consequences (loss of chance to survive or to be cured) for the patient. Furthermore, treatment at a specialized cancer center has been proven to be effective as it improves overall survival and reduces local recurrences.

Factors associated with complications after resection of soft tissue sarcomas of the groin.

INTRODUCTION: Soft tissue sarcomas (STS) are rare malignant tumors that require regimented treatment at designated cancer centers. The surgical care of groin tumors is difficult because of frequent local complications. Few studies have been done on prognostic factors and complications. This led us to conduct a retrospective study to: (1) identify factors associated with local postoperative complications during the surgical care of primary groin STS; (2) identify the factors associated with delayed adjuvant radiation therapy; (3) define the optimal surgical treatment strategy to allow adjuvant treatments to start as early as possible, if applicable. HYPOTHESIS: We hypothesized that certain patients presenting with an STS of the groin or inguinal area are at higher risk of complications. MATERIALS AND METHODS: This retrospective single-center study included all the patients admitted to our referral sarcoma center between 1995 and 2016 for the resection of a primary STS of the groin. Major complications were defined as surgical revision, an invasive procedure, or prolonged dressing use. RESULTS: Of the 55 included patients, 13 suffered major complications (24%) of which 10 were surgical revisions, two were repeated aspirations and one was prolonged dressing use. Among the 10 surgical revisions, there were two pedicled salvage flaps. The patients who suffered major complications were significantly more likely to be smokers than the patients who did not have major complications (31% vs 2% (p=0.002)). Obesity and surgical bone exposure were most often associated with complications but not significantly (23% vs 5%, p=0.053 and 38% vs 14% (p=0.057), respectively). Of the 39 patients (71%) who needed postoperative radiation therapy, 5 patients (13%) had it delayed, and 3 patients (8%) did not receive any at all due to major complications. CONCLUSION: In our study, smoking was associated with the occurrence of major complications after groin STS resection and there was a strong trend for obesity and surgical bone exposure. Major complications were associated with a delay in starting postoperative radiation therapy. Thus, we recommend flap coverage after tumor resection in patients who have factors known to contribute to complications. LEVEL OF EVIDENCE: IV, Retrospective study.

Pilot Study of an e-Cohort to Monitor Adverse Event for Patient with Hip Prostheses from Clinical Data Warehouse.

Hip arthroplasty represents a large proportion of orthopaedic activity, constantly increasing. Automating monitoring from clinical data warehouses is an opportunity to dynamically monitor devices and patient outcomes allowing improve clinical practices. Our objective was to assess quantitative and qualitative concordance between claim data and device supply data in order to create an e-cohort of patients undergoing a hip replacement. We performed a single-centre cohort pilot study, from one clinical data warehouse of a French University Hospital, from January 1, 2010 to December 31, 2019. We included all adult patients undergoing a hip arthroplasty, and with at least one hip medical device provided. Patients younger than 18 years or opposed to the reuse of their data were excluded from the analysis. Our primary outcome was the percentage of hospital stays with both hip arthroplasty and hip device provided. The patient and stay characteristics assessed in this study were: age, sex, length of stay, surgery procedure (replacement, repositioning, change, or reconstruction), medical motif for surgery (osteoarthritis, fracture, cancer, infection, or other) and device provided (head, stem, shell, or other). We found 3,380 stays and 2,934 patients, 96.4% of them had both a hip surgery procedure and a hip device provided. These data from different sources are close enough to be integrated in a common clinical data warehouse.

Evaluation of the Chemotherapy Drug Response Using Organotypic Cultures of Osteosarcoma Tumours from Mice Models and Canine Patients.

Improvements in the clinical outcome of osteosarcoma have plateaued in recent decades with poor translation between preclinical testing and clinical efficacy. Organotypic cultures retain key features of patient tumours, such as a myriad of cell types organized within an extracellular matrix, thereby presenting a more realistic and personalised screening of chemotherapeutic agents ex vivo. To test this concept for the first time in osteosarcoma, murine and canine osteosarcoma organotypic models were maintained for up to 21 days and in-depth analysis identified proportions of immune and stromal cells present at levels comparable to that reported in vivo in the literature. Cytotoxicity testing of a range of chemotherapeutic drugs (mafosfamide, cisplatin, methotrexate, etoposide, and doxorubicin) on murine organotypic culture ex vivo found limited response to treatment, with immune and stromal cells demonstrating enhanced survival over the global tumour cell population. Furthermore, significantly decreased sensitivity to a range of chemotherapeutics in 3D organotypic culture relative to 2D monolayer was observed, with subsequent investigation confirming reduced sensitivity in 3D than in 2D, even at equivalent levels of drug uptake. Finally, as proof of concept for the application of this model to personalised drug screening, chemotherapy testing with doxorubicin was performed on biopsies obtained from canine osteosarcoma patients. Together, this study highlights the importance of recapitulating the 3D tumour multicellular microenvironment to better predict drug response and provides evidence for the utility and possibilities of organotypic culture for enhanced preclinical selection and evaluation of chemotherapeutics targeting osteosarcoma.

Role of real-world digital data for orthopedic implant automated surveillance: a systematic review.

INTRODUCTION: Data collection automation through the reuse of real-world digital data from clinical data warehouses (CDW) could represent a great opportunity to improve medical device monitoring. For instance, this approach is starting to be used for the design of automated decision support systems for joint replacement monitoring. However, a number of obstacles remains, such as data quality and interoperability through the use of common and regularly updated terminologies, and the use of a Unique Device Identifier (UDI). AREAS COVERED: To present the existing models of automated surveillance of orthopedic devices, a systematic review of initiatives using real-world digital health data to monitor joint replacement surgery was performed following the PRISMA 2020 guidelines. The main objective was to identify the data sources, the target populations, the population size, the device location, and the main results of studies on such initiatives. EXPERT OPINION: Analysis of the identified studies showed that real-world digital data offer many opportunities for improving the automation of monitoring in orthopedics. The contribution of real-world data, especially through natural language processing, UDI use in CDW and the integration of device databases, is needed for automated and more robust health surveillance.

Antibiotic Therapy for 6 or 12 Weeks for Prosthetic Joint Infection.

BACKGROUND: The management of prosthetic joint infection usually consists of a combination of surgery and antimicrobial therapy. The appropriate duration of antimicrobial therapy for this indication remains unclear. METHODS: We performed an open-label, randomized, controlled, noninferiority trial to compare 6 weeks with 12 weeks of antibiotic therapy in patients with microbiologically confirmed prosthetic joint infection that had been managed with an appropriate surgical procedure. The primary outcome was persistent infection (defined as the persistence or recurrence of infection with the initial causative bacteria, with an antibiotic susceptibility pattern that was phenotypically indistinguishable from that at enrollment) within 2 years after the completion of antibiotic therapy. Noninferiority of 6 weeks of therapy to 12 weeks of therapy would be shown if the upper boundary of the 95% confidence interval for the absolute between-group difference (the value in the 6-week group minus the value in the 12-week group) in the percentage of patients with persistent infection within 2 years was not greater than 10 percentage points. RESULTS: A total of 410 patients from 28 French centers were randomly assigned to receive antibiotic therapy for 6 weeks (205 patients) or for 12 weeks (205 patients). Six patients who withdrew consent were not included in the analysis. In the main analysis, 20 patients who died during follow-up were excluded, and missing outcomes for 6 patients who were lost to follow-up were considered to be persistent infection. Persistent infection occurred in 35 of 193 patients (18.1%) in the 6-week group and in 18 of 191 patients (9.4%) in the 12-week group (risk difference, 8.7 percentage points; 95% confidence interval, 1.8 to 15.6); thus, noninferiority was not shown. Noninferiority was also not shown in the per-protocol and sensitivity analyses. We found no evidence of between-group differences in the percentage of patients with treatment failure due to a new infection, probable treatment failure, or serious adverse events. CONCLUSIONS: Among patients with microbiologically confirmed prosthetic joint infections that were managed with standard surgical procedures, antibiotic therapy for 6 weeks was not shown to be noninferior to antibiotic therapy for 12 weeks and resulted in a higher percentage of patients with unfavorable outcomes. (Funded by Programme Hospitalier de Recherche Clinique, French Ministry of Health; DATIPO ClinicalTrials.gov number, NCT01816009.).

Soft tissue reconstruction after pelvic amputation: The efficacy and reliability of free fillet flap reconstruction.

BACKGROUND: The majority of hindquarter amputation defects can be reconstructed with local anterior or posterior thigh flaps. Less than 5% of soft tissue defects require free flap reconstruction after tumour resection. Lower extremity fillet flap is described for reconstructing such defects, but the majority of publications are case reports or short single institutional series. There is a lack of data regarding the oncological outcomes of this highly selected patient group. METHODS: Three tertiary sarcoma units treated twelve patients with hindquarter amputation or hip disarticulation for oncological indications with a free flap reconstruction of the soft tissue defect. RESULTS: The median age of patients was 60 (range 12-76) years. Bone resection was carried out through the SI-joint in six patients and through the sacrum in five patients, with one patient undergoing hip disarticulation. Nine patients had R0 resection margin and three had R1 resection. The median surgical time and flap ischaemia time was 420 (249-650) and 89 (64-210) min, respectively. Median hospital and ICU stay was 18 (10-42) and 3 (1-8) days, respectively. Median blood loss was 2400 (950-10000) ml. There were three returns to theatre due to vascular compromise, with one total flap loss due to arterial thrombosis. Overall survival was 58% (95%CI 28-91%) both at 1-year and at 3-years. DISCUSSION: Carefully selected patients requiring hindquarter amputation with extensive soft tissue defect necessitating free flap reconstruction can be reconstructed with a lower extremity free fillet flap with low rate of local wound complications. Survival of these patients is similar to that in patients requiring less extensive resection.

In situ production of pre-vascularized synthetic bone grafts for regenerating critical-sized defects in rabbits.

Reconstructing large bone defects caused by severe trauma or resection of tumors remains a challenge for surgeons. A fibula free flap and its vascularized bed can be transplanted to the reconstruction site to achieve healing. However, this technique adds morbidity, and requires microsurgery and sculpting of the bone tissue to adapt the graft to both the vasculature and the anatomy of the defect. The aim of the current study was to evaluate an alternative approach consisting of the in situ production of a pre-vascularized synthetic bone graft and its subsequent transplantation to a critical-sized bone defect. 3D printed chambers containing biphasic calcium phosphate (BCP) granules, perfused by a local vascular pedicle, with or without the addition of stromal vascular fraction (SVF), were subcutaneously implanted into New Zealand White female rabbits. SVF was prepared extemporaneously from autologous adipose tissue, the vascular pedicle was isolated from the inguinal site, while BCP granules alone served as a control group. After 8 weeks, the constructs containing a vascular pedicle exhibited abundant neovascularization with blood vessels sprouting from the pedicle, leading to significantly increased vascularization compared to BCP controls. Pre-vascularized synthetic bone grafts were then transplanted into 15 mm critical-sized segmental ulnar defects for a further 8 weeks. Micro-CT and decalcified histology revealed that pre-vascularization of synthetic bone grafts led to enhanced bone regeneration. This pre-clinical study demonstrates the feasibility and efficacy of the in situ production of pre-vascularized synthetic bone grafts for regenerating large bone defects, thereby addressing an important clinical need. STATEMENT OF SIGNIFICANCE: The current gold standard in large bone defect regeneration is vascularized fibula grafting. An alternative approach consisting of in situ production of a pre-vascularized synthetic bone graft and its subsequent transplantation to a bone defect is presented here. 3D printed chambers were filled with biphasic calcium phosphate granules, supplemented with autologous stromal vascular fraction and an axial vascular pedicle and subcutaneously implanted in inguinal sites. These pre-vascularized synthetic grafts were then transplanted into critical-sized segmental ulnar defects. Micro-CT and decalcified histology revealed that the pre-vascularized synthetic bone grafts led to higher bone regeneration than non-vascularized constructs. An alternative to vascularized fibula grafting is provided and may address an important clinical need for large bone defect reconstruction.

Survival and complications in hinged knee reconstruction prostheses after distal femoral or proximal tibial tumor resection: A retrospective study of 161 cases.

INTRODUCTION: Hinged knee megaprostheses are mainly used for reconstruction after tumor resection. They may incur complications, but this has not been assessed in the French literature, except in small series at short follow-up. We therefore conducted a large-scale nationwide multicenter retrospective study with a minimum 5 years' follow-up. The objectives were (1) to compare survival between distal femoral and proximal tibial reconstruction prostheses, and (2) to analyze complications and failure. HYPOTHESIS: Distal femoral hinged reconstruction prostheses show longer survival with fewer complications than proximal tibial prostheses. MATERIAL AND METHODS: One hundred sixty-one patients were included: 118 in the distal femoral group, and 43 in the proximal tibial group. Tumors were mostly osteosarcomas (90 cases) or chondrosarcomas (31 cases). Mean age was 37 years (range, 12-86 years). Complications were assessed on the Henderson classification. Failure was defined by prosthesis anchor exchange or amputation. RESULTS: At a mean 9 years' follow-up (range, 5-23 years), implant survival was longer in the distal femoral group: 5- and 10-year survival, 84% [95% CI, 75-89] and 70% [95% CI, 59-79] versus 74% [95% CI, 69-85] and 43% [95% CI, 23-61] (p=0.02). Revision surgery for complications mainly concerned aseptic loosening (19%, 30 cases) or deep infection (16%, 25 cases) and more often involved the proximal tibia (65% vs. 43%, 28 vs. 51 cases; OR 2.4 [95% CI, 1.2-5.1]; p=0.02). DISCUSSION: Hinged knee reconstruction prosthesis is a solution in tumoral pathology, but with a high risk of complications (loosening and infection) and a higher failure rate in the proximal tibial reconstruction prosthesis. LEVEL OF EVIDENCE: IV, case series.

Fixed-hinge cemented modular implants: An effective reconstruction technique following primary distal femoral bone tumor resection. A 136-case multicenter series.

BACKGROUND: Reconstruction by endoprosthesis is widespread after bone tumor resection. The design and type of fixation and of hinge remain a matter of debate. The aim of the present study was to assess survival, complications and functional results in a homogeneous series of adult patients undergoing bone defect reconstruction following distal femoral tumor resection, using a single model of fixed-hinge cemented endoprosthesis, at a minimum 5 years' follow-up. HYPOTHESIS: The study hypotheses were that loosening and infection are the main causes of failure, and that this type of reconstruction is reliable following distal femoral resection. PATIENTS AND METHODS: All patients aged over 17 years undergoing reconstruction using the Stanmore Mets® fixed-hinge cemented modular endoprosthesis following distal femoral resection for primary bone tumor in 4 French reference centers between 2004 and 2013 were included. Epidemiological data, MSTS functional score, clinical and radiological examination results, complications and survival with types of failure according to the Henderson classification were assessed. RESULTS: One hundred and thirty-six patients (68 male, 68 female; mean age, 41.2 years [range, 17-77 years]) were included. Mean follow-up was 81 months [range, 61-134 months]. Thirty-two patients (38%) experienced a total 67 complications requiring surgical revision: mainly infection (n=28) or mechanical failure (n=26). Overall implant survival was 78% at 5 years. There were 30 implant failures on the Henderson classification. Mean MSTS score was 82%. DISCUSSION: The present results are comparable to those of the literature and for other types of reconstruction. Recent meta-analyses suggest that type of hinge and of stem fixation have little effect on implant survival. International comparative studies are needed to determine the exact role of each type of reconstruction according to the patient profile. LEVEL OF EVIDENCE: IV, multicenter retrospective series.

Early efficacy evaluation of mesenchymal stromal cells (MSC) combined to biomaterials to treat long bone non-unions.

BACKGROUND AND STUDY AIM: Advanced therapy medicinal products (ATMP) frequently lack of clinical data on efficacy to substantiate a future clinical use. This study aims to evaluate the efficacy to heal long bone delayed unions and non-unions, as secondary objective of the EudraCT 2011-005441-13 clinical trial, through clinical and radiological bone consolidation at 3, 6 and 12 months of follow-up, with subgroup analysis of affected bone, gender, tobacco use, and time since the original fracture. PATIENTS AND METHODS: Twenty-eight patients were recruited and surgically treated with autologous bone marrow derived mesenchymal stromal cells expanded under Good Manufacturing Practices, combined to bioceramics in the surgical room before implantation. Mean age was 39 ± 13 years, 57% were males, and mean Body Mass Index 27 ± 7. Thirteen (46%) were active smokers. There were 11 femoral, 4 humeral, and 13 tibial non-unions. Initial fracture occurred at a mean ± SD of 27.9 ± 31.2 months before recruitment. Efficacy results were expressed by clinical consolidation (no or mild pain if values under 30 in VAS scale), and by radiological consolidation with a REBORNE score over 11/16 points (value of or above 0.6875). Means were statistically compared and mixed models for repeated measurements estimated the mean and confidence intervals (95%) of the REBORNE Bone Healing scale. Clinical and radiological consolidation were analyzed in the subgroups with Spearman correlation tests (adjusted by Bonferroni). RESULTS: Clinical consolidation was earlier confirmed, while radiological consolidation at 3 months was 25.0% (7/28 cases), at 6 months 67.8% (19/28 cases), and at 12 months, 92.8% (26/28 cases including the drop-out extrapolation of two failures). Bone biopsies confirmed bone formation surrounding the bioceramic granules. All locations showed similar consolidation, although this was delayed in tibial non-unions. No significant gender difference was found in 12-month consolidation (95% confidence). Higher consolidation scale values were seen in non-smoking patients at 6 (p = 0.012, t-test) and 12 months (p = 0.011, t-test). Longer time elapsed after the initial fracture did not preclude the occurrence of consolidation. CONCLUSION: Bone consolidation was efficaciously obtained with the studied expanded hBM-MSCs combined to biomaterials, by clinical and radiological evaluation, and confirmed by bone biopsies, with lower consolidation scores in smokers.

Epidemiological, clinical and histological features of adipose tumors in the hand and wrist: Findings from a continuous series of 37 cases.

INTRODUCTION: Adipose tumors are the most common soft tissue tumor in adults; however, their epidemiology and histology in the hand and wrist are not well-defined. The aim of this study was to describe the histology and treatment strategy for this type of tumor at a specialized cancer center. HYPOTHESIS: The frequency of these tumors is underestimated, and their histology signature varies. MATERIALS AND METHODS: The clinical and paraclinical data of adults treated for an adipose tumor lesion in the hand or wrist were analyzed retrospectively: age, clinical history, time elapsed between discovery and treatment, type of treatment. The dimensions, location and histology of the tumor were collected. The patients were contacted to inquire about persistent symptoms and sequelae. RESULTS: Thirty-seven tumors (37 patients) were included between January 2003 and December 2018, thus making up 7.5% of all the soft tissue tumors in the hand or wrist. The mean patient age was 59years (28-84years). Except for one fortuitous discovery, the tumors were discovered because the patient had an unusual lump. The lump was associated with distal paresthesia in six cases. The mean time to treatment was 47.5months (1-240months). The lesion was a conventional lipoma (31 cases) or one of its benign variants (6 cases). The mean size was 3.76cm in the long axis (1-11.5cm) and the mean weight was 9.8g (3-60g). The mean follow-up was 73.5months (2-177months). Tumors in the fingers were smaller and lighter than those in the wrist (p=0.004 and p=0.034). DISCUSSION: The prevalence of adipose tumors is underestimated within hand and wrist tumors. The most common way these tumors are discovered is due to compressive neuropathy with paresthesia and/or dysesthesia. While these tumors are nearly always benign, this does not justify ignoring the opinion of the multidisciplinary tumor board or underestimating the small possibility of the lesion being a liposarcoma. LEVEL OF EVIDENCE: IV, retrospective, single-center study.

Clinical and dynamometric results of hip abductor system repair by trochanteric hydroxyapatite plate with modular implant after resection of proximal femoral tumors.

INTRODUCTION: The capacity of the hydroxyapatite-coated trochanteric screwed plates used with modular hip implants to restore abductor system efficacy after proximal femoral tumor resection has never been assessed. We therefore conducted a retrospective study aiming to: (1) quantitatively evaluate abduction conservation on dynamometry according to use of digastric reinsertion, conserving continuity between the gluteus medius and vastus lateralis muscles, or not, and of standard versus small-offset; (2) assess radiographic trochanteric plate fixation; (3) assess functional scores; and (4) assess complications. HYPOTHESIS: Trochanteric reinsertion better conserves abduction strength when reinsertion is digastric. PATIENTS AND METHODS: Thirty-one patients undergoing proximal femoral tumor resection between 2006 and 2016 with reconstruction by Stanmore METS™ modular implant with trochanteric plate were included. Twenty-one had digastric fixation between the gluteus medius and vastus lateralis and 10 had simple trochanteric fixation without digastric continuity. Abduction strength was compared between sides on dynamometer. Sixteen patients had full assessment of muscle strength, by a single observer; there were 8 deaths, 5 patients lost to follow-up, and 2 cases of material removal. RESULTS: Abduction strength conservation versus the contralateral side was 55.2±23.3% (range, 5.8-86.1%): 66.6±13.0% (46.4-86.1) with versus 36.0±24.7% (5.8-63.2%) without digastric continuity (p=0.01); severe limp rate was 4/21 when digastric continuity was preserved (19%) versus 6/10 (60%) (p=0.04), and radiologic trochanteric reinsertion stability rate was 19/21 (90%) versus 4/10 (40%) (p=0.005). Standard femoral offset conserved greater abduction strength: 64.9±20.0% versus small-offset 45.4±23.2% (p=0.05). Toronto Extremity Salvage Score (TESS) was 89±9.4%, and Musculoskeletal Tumor Society (MSTS) score 75.4±5.4%. There were 6 complications (19%): 4 infections, 1 dislocation, and 1 plate removal; the single dislocation (3%) was in the digastric conservation group. TESS (90.7±7.8% vs 88.3±4) and MSTS score (75.6±4.0% vs 75.1±3.7) and complications [4/21 (19%) vs 2/10 (20%)] did not differ according to digastric or non-digastric reinsertion (p=1). CONCLUSIONS: Abduction strength with a modular implant using a hydroxyapatite-coated trochanteric plate was better conserved by digastric trochanteric reinsertion, resulting in less limping, although the complications rate and functional scores were unaffected. Longer term assessment is needed to confirm this conservation of abduction strength. LEVEL OF EVIDENCE: IV, retrospective study without control group.

Early detection of multiple bone and extra-skeletal metastases by body magnetic resonance imaging (BMRI) after treatment of Myxoid/Round-Cell Liposarcoma (MRCLS).

INTRODUCTION: Myxoid Round cell containing myxoid liposarcomas (MRCLS) have a high propensity to metastasize to soft tissue and bone. Whole Body Magnetic Resonance Imaging (BMRI) has been reported as a critical modality to early detect disease spreading in asymptomatic patients. The purpose of this study is to describe metastatic patterns and outcomes in patients through annual BMRI surveillance after diagnosis of MRCLS of the extremities and trunk. MATERIEL AND PATIENTS: This retrospective study included patients with histology confirmed MRCLS. Initial BMRI were done within 6 months following the first line treatment then once a year. RESULTS: Forty-five out of 51 consecutive MRCLS patients were included. At the last follow-up 10 patients (22.2%) had an extra-pulmonary soft-tissue or/and bone metastasis detected in a median delay of 22.7±16 months [0-49] from the diagnosis of the MRCLS. Nine patients were asymptomatic. Finally, 5-years metastatic free survival was 72±8%. All metastatic patients had multiple lesion within the year following the first lesion diagnosis. CONCLUSION: Systematic BMRI in MRCLS patients following treatment frequently identify extra-pulmonary metastasis in asymptomatic patients within the first 5 years of follow-up. Despite a long survival can be expected after diagnosis, extra-skeletal metastasis was a signal of disseminated disease.