Mechanical complications of hip spacers: a systematic review of the literature.

INTRODUCTION: Temporary spacers used in the staged revision of a hip prosthetic joint infection (PJI) have been associated with several mechanical complications with very variable reported general complications rates up to 73%. The aim of this systematic review was to assess the mechanical complications associated with hip antibiotic-loaded spacers when treating periprosthetic hip PJI. METHODS: Through an electronic systematic search of PubMed, articles reporting mechanical complications of spacers used in the treatment of hip PJI were reviewed. Dislocations, spacer fracture, femoral fractures, and acetabular lysis rates were evaluated. RESULTS: Forty studies were included. Standardized molded spacers had a significantly higher weighted mean of total mechanical complication rates (37.2%) when compared to standardized preformed spacers (13.8%, p = 0.039), while no significant difference was found between molded spacers and manually shaped spacers. Spacer dislocation was the most frequent complication. No significant difference in mechanical complication rate was found between spacers with and without any metallic component. CONCLUSIONS: Spacer placement in chronic PJI of the hip with bone and soft-tissue defects is challenging and bears a high risk of mechanical failures and progressive bone loss during the interim period. A careful patient selection for spacer implantation is mandatory.

Does Surgical Approach Influence Complication Rate of Hip Hemiarthroplasty for Femoral Neck Fractures? A Literature Review and Meta-Analysis.

Background: Femoral neck fractures are an epidemiologically significant issue with major effects on patients and health care systems, as they account for a large percentage of bone injuries in the elderly. Hip hemiarthroplasty is a common surgical procedure in the treatment of displaced femoral neck fractures. Several surgical approaches may be used to access the hip joint in case of femoral neck fractures, each with its own benefits and potential drawbacks, but none of them has consistently been found to be superior to the others. This article aims to systematically review and compare the different approaches in terms of the complication rate at the last follow-up. Methods: an in-depth search on PubMed/Scopus/Web of Science databases and a cross-referencing search was carried out concerning the articles comparing different approaches in hemiarthroplasty and reporting detailed data. Results: A total of 97,576 hips were included: 1030 treated with a direct anterior approach, 4131 with an anterolateral approach, 59,110 with a direct lateral approach, and 33,007 with a posterolateral approach. Comparing the different approaches, significant differences were found in both the overall complication rate and the rate of revision surgery performed (p < 0.05). In particular, the posterolateral approach showed a significantly higher complication rate than the lateral approach (8.4% vs. 3.2%, p < 0.001). Furthermore, the dislocation rate in the posterolateral group was significantly higher than in the other three groups considered (p < 0.026). However, the posterolateral group showed less blood loss than the anterolateral group (p < 0.001), a lower intraoperative fractures rate than the direct anterior group (p < 0.035), and shorter mean operative time than the direct lateral group (p < 0.018). Conclusions: The posterolateral approach showed a higher complication rate than direct lateral approach and a higher prosthetic dislocation rate than the other three types of surgical approaches. On the other hand, patients treated with posterolateral approach showed better outcomes in other parameters considered, such as mean operative time, mean blood loss and intraoperative fractures rate. The knowledge of the limitations of each approach and the most common associated complications can lead to choosing a surgical technique based on the patient's individual risk.

Surgical treatment scenario for osteoblastoma of the pelvis: Long-term follow-up results.

BACKGROUND: The aim of this study was to evaluate the results of different treatments for pelvic Osteoblastoma (OB). METHODS: We retrospectively evaluated 34 patients affected by primary pelvic OB from 3 oncologic referral centers. Patients with a minimum follow-up of 24 months were included. Local recurrence (LR) rate and complications were recorded. RESULTS: The primary treatment was radio-frequency ablation (RFA) in 4 patients (11.8%), curettage (ILC) in 21 (61.7%) and resection (EBR) in 9 (26.5%). Mean follow-up was 8.9 years (SD ± 6.6). Local recurrence free survival (LRFS) rate after primary surgery was 79.4% at 3 and 5 years. In details, LRFS rate at 3 and 5 years was 50.0% in RFA, 81.0% in ILC and 88.9% in EBR. Post-operative complications occurred in 6/34 patients (17.7%), in particular after EBR. CONCLUSIONS: RFA is the least invasive technique to treat OB but with high LR rate. Thus, it should be reserved to very small lesions. ILC is a suitable treatment for stage II OB. For stage III OB, EBR is the treatment of choice, despite an increased risk of complications. For selected stage III OB (relatively small, periacetabular area) ILC might be considered.

Anatomical and reverse megaprosthesis in proximal humerus reconstructions after oncologic resections: a systematic review and meta-analysis.

AIM: Anatomic (AN) Endoprosthesis (EPR) reconstructions of the shoulder after intra-articular proximal humerus (Malawer type 1) resections are characterized by early recovery and low complications rate. However, shoulder instability and limited mobility can occur. Reverse shoulder (RS) EPR has been introduced to improve functional outcome. The aim of this systematic review is to evaluate shoulder reconstructions with AN or RS EPR after Malawer type 1 resection, comparing complications and functional results. METHODS: Through an electronic systematic search of PubMed, articles concerning EPR after shoulder Malawer type 1 resections were reviewed. Complications rate, range of motion (ROM) and functional outcome (Musculoskeletal Society Tumor Society-MSTS score) of AN and RS EPR were evaluated. RESULTS: Sixteen studies were included. A similar complication rate was observed between AN and RS EPR rate (26.4% and 22.4%, respectively, p = 0.37). Soft tissue failure was the most frequent complication and cause of revision in both groups. Mean post-operative flexion and abduction ROM and MSTS scores were significantly higher in RS EPR, particularly among patients with preserved deltoid function (p = 0.013, p = 0.025 and p = 0.005, respectively). CONCLUSIONS: Anatomic and reverse shoulder EPR represent safe and effective implants for shoulder reconstruction, with similar implant stability and complication rates. RS EPR significantly improves post-operative ROM and functional outcomes, especially when at least a partial function of the abductor apparatus is preserved.

The Biology of Synovial Sarcoma: State-of-the-Art and Future Perspectives.

OPINION STATEMENT: New molecular insights are being achieved in synovial sarcoma (SS) that can provide new potential diagnostic and prognostic markers as well as therapeutic targets. In particular, the advancement of research on epigenomics and gene regulation is promising. The concrete hypothesis that the pathogenesis of SS might mainly depend on the disruption of the balance of the complex interaction between epigenomic regulatory complexes and the consequences on gene expression opens interesting new perspectives. The standard of care for primary SS is wide surgical resection combined with radiation in selected cases. The role of chemotherapy is still under refinement and can be considered in patients at high risk of metastasis or in those with advanced disease. Cytotoxic chemotherapy (anthracyclines, ifosfamide, trabectedin, and pazopanib) is the treatment of choice, despite several possible side effects. Many possible drug-able targets have been identified. However, the impact of these strategies in improving SS outcome is still limited, thus making current and future research strongly needed to improve the survival of patients with SS.

Pathological fracture does not affect prognosis in dedifferentiated chondrosarcoma of the limbs.

BACKGROUND: The aim of this retrospective study is to analyze history and treatment outcomes of pathological fracture (PF) in dedifferentiated chondrosarcoma (DdChS) of the limbs.. METHODS: We retrospectively reviewed 175 adult patients with primary DdChS of the limbs.Disease-specific survival (OS) and local recurrence (LR) were analyzed. RESULTS: Median age was 66 years (range, 29-91). Most DdChS (121, 69.1%) were localized in the femur. Forty-nine (28.0%) had metastasis at diagnosis; thirty-nine DdChS (22.3%) had a PF.OS rate was lower in patients with metastasis at diagnosis (8.6% Vs 41.0% at 10 years, p < 0.001). A similar OS was observed among patients with localized disease, whether with/without PF (p = 0.638), with/without chemotherapy (p = 0.543) and independently from the type of surgery (resection/amputation) (p = 0.877). Amputation reduces the risk of LR (80.0% vs 63.1% at 5 years, p = 0.039), particularly in the PF group.. CONCLUSION: Patients with metastases have a particularly poor prognosis in DdChS, but pathological fracture does not influence prognosis in terms of survival and local control. Initial curative resection is essential in order to reduce the chance of recurrences. Amputation might be an option in patients with localized disease and a PF to reduce the risk of LR..

Silver-coated megaprosthesis in prevention and treatment of peri-prosthetic infections: a systematic review and meta-analysis about efficacy and toxicity in primary and revision surgery.

AIM: Prosthetic joint infection (PJI) is a common complication following orthopedic megaprosthetic implantations (EPR), estimated up to 50%. Silver coatings were introduced in order to reduce the incidence of PJI, by using the antibacterial activity of silver. Three different silver coatings are available: MUTARS® (Implantcast), Agluna® (Accentus Medical), PorAg® (Waldemar Link). The aim of this review is to provide an overview on efficacy and safety of silver-coated EPR both in primary and revision surgery, comparing infection rate according to the type of implant. METHODS: Through an electronic systematic search, we reviewed the articles concerning silver-coated EPRs. Infection rate, silver-related complications, local and blood concentrations of the silver were evaluated. Meta-analyses were performed to compare results from each study included. RESULTS: Nineteen studies were included. The overall infection rate in patients with silver-coated implants was 17.6% (133/755). Overall infection rate in primary silver-coated EPR was been 9.2% (44/445), compared to 11.2% (57/507) of non-silver-coated implants. The overall infection rate after revisions was 13.7% (25/183) in patients with silver-coated EPR and 29.2% (47/161) when uncoated EPR were used, revealing a strength statistically significative utility of silver coatings in preventing infections in this group (p: 0.019). Generally, the use of MUTARS® EPR had produced an almost constant decrease in the incidence of primary PJI but there are few data on the effectiveness in revisions. The results from the use of Agluna® in both primary and revisions implants are inconstant. Conversely, PorAg® had proven to be effective both in PJI prevention but, especially, when used in PJI revision settings. Local argyria was reported in 8 out of 357 patients (2.2%), while no systemic complications were described. Local and blood concentrations of silver were always reported very far to the threshold of toxicity, with the lowest concentration found using PorAg®. CONCLUSIONS: Silver-coated EPRs are safe and effective in reduction in PJI and re-infection rate, in particular when used in higher risk patients and after two-stage revisions to fight PJI.

Correction to: Silver-coated (PorAg®) endoprosthesis can be protective against reinfection in the treatment of tumor prostheses infection.

The original version of this article unfortunately contained a mistake. The correct information is given below.

Silver-coated (PorAg®) endoprosthesis can be protective against reinfection in the treatment of tumor prostheses infection.

INTRODUCTION: We aim to evaluate the use of silver (PorAg®) coated compared to uncoated prosthesis in two-stage revision for prosthetic joint infection (PJI) of distal femur and proximal tibia megaprosthesis in oncological patients. MATERIALS AND METHODS: In total, 68 patients were retrospectively evaluated. Median age was 30 years (range 14-83). In total, 29 patients were re-implanted with PorAg® prosthesis and 39 with uncoated prosthesis (Megasystem C®, Waldemar Link GmbH & Co. KG, Hamburg, Germany). All patients had PJI confirmed according to Musculoskeletal Infection Society (MSIS) criteria. In 10 cases, no microorganism was identified at the time of first-stage revision, but all had a sinus communicating with the prosthesis. Successful eradication of the infection was defined by the absence of clinical/serologic evidence of infection at 6 months after the second stage or at latest follow-up. Infection was again defined according to the MSIS criteria. RESULTS: At 3-year follow-up, estimated reinfection rate in the silver group was slightly lower than in uncoated EPR (10.3% vs. 17.5%, p = 0.104). Among reinfected patients, only one out of three patients (33%) in the silver group required an amputation compared to 80% in the nonsilver group (p = 0.047). CONCLUSIONS: Our results show the efficacy of PorAg® coating in the two-stage revision of knee EPR. PorAg®-coated EPR may have possible advantages over this traditional strategy, in particular when applied to patients with a higher risk of reinfection.

Intercalary bone graft of the tibia: case series and review of the literature.

AIMS: We report a series of patients treated with intercalary bone graft (IBG) of the tibia diaphysis (TD) after resection of primary bone tumors. The purpose of this study was to evaluate the mid- and long-term survival of TD IBG reconstruction in children and adults, characterizing patterns of success and failure. METHODS: A total of 35 patients were included in this retrospective study. Median age was 22 years (range, 8-57). This series included 19 patients (54.3%) treated with homologous bone graft alone and 16 patients (45.7%) treated combining intercalary allograft with fibular autograft. Complications were recorded according to Henderson classification. RESULTS: Median follow-up was 36 months (range, 1-165). Local recurrence occurred in 2 patients (5.7%) after 12 and 60 months, respectively. Major complications included graft fracture (9 cases), non-union (5 cases) and infection (4 cases). Other complications were axial deformity (2 cases), superficial infection (2 cases), compartmental syndrome (1 case). CONCLUSION: Intercalary bone grafts of TD have been recommended as a reliable solution with long-term success rates and good functional outcome in more than 80% of patients. However, approximately half of the patients may require further surgeries to treat major complications (deep infection, delayed or non-union and graft fracture). Additional vascularized fibula graft may ameliorate final result.

Correction to: Intercalary bone graft of the tibia: case series and review of the literature.

The original version of this article unfortunately contained a mistake. The spelling of the name 'Valerio Bochicchio' was incorrect.

Is there a role for chemotherapy after local relapse in high-grade osteosarcoma?

BACKGROUND: High-grade bone osteosarcoma has a high relapse rate. The best treatment of local recurrence (LR) is under discussion. The aim of this study is to analyze LR patterns and factors prognostic for survival. METHODS: LR diagnostic modality (clinical or imaging), pattern of recurrence, and post-LR survival (PLRS) were assessed. RESULTS: Sixty-two patients were identified, with median age 21 years (range, 9-75 years), including 11 (18%) ≤15 years, 30 (48%) from 16 to 29 years; 21 (34%) were older. Patterns of relapse were LR only 58%, LR + distant metastases (DM) 42%. Seventy-nine percent of patients relapsed within 24 months, and diagnosis was clinical in 88%. LR treatment was surgery 85%, chemotherapy 55%, chemotherapy + surgery 45%. Surgical complete remission after LR (CR2) was achieved in 60% (LR 86%; LR + DM 23%). With a median follow-up of 43 months (range, 5-235 months), the five-year PLRS was 37%, significantly better for patients with longer LR-free interval (LRFI; ≤24 months 31% vs > 24 months 61.5%, P = 0.03), absence of DM (no DM 56% vs DM 11.5%, P = 0.0001), and achievement of CR2 (no CR2 0% vs CR2 58.5%, P = 0.0001). No difference was found according to age and chemotherapy (LR only: five-year PLRS: 53% without chemotherapy vs 58% with chemotherapy, P = 0.9; LR + DM: five-year PLRS: 25% without chemotherapy vs 9% with chemotherapy, P = 0.7). CONCLUSIONS: Early relapse is detected by symptoms in 90% of cases and associated with worse outcome. The achievement of CR2, not age, is crucial for survival. For patients with LR only, better survival was demonstrated, as compared with DM, and no improvement with chemotherapy after surgery was found.

The role of FDG PET/CT in patients treated with neoadjuvant chemotherapy for localized bone sarcomas.

PURPOSE: The histological response to neoadjuvant chemotherapy is an important prognostic factor in patients with osteosarcoma (OS) and Ewing sarcoma (EWS). The aim of this study was to assess baseline primary tumour FDG uptake on PET/CT, and serum values of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), to establish whether these factors are correlated with tumour necrosis and prognosis. METHODS: Patients treated between 2009 and 2014 for localized EWS and OS, who underwent FDG PET/CT as part of their staging work-up, were included. The relationships between primary tumour SUVmax at baseline (SUV1), SUVmax after induction chemotherapy (SUV2), metabolic response calculated as [(SUV1 - SUV2)/SUV1)] × 100, LDH and ALP and tumour response/survival were analysed. A good response (GR) was defined as tumour necrosis >90 % in patients with OS, and grade II-III Picci necrosis (persitence of microscopic foci only or no viable tumor) in patients with Ewing sarcoma. RESULTS: The study included 77 patients, 45 with EWS and 32 with OS. A good histological response was achieved in 53 % of EWS patients, and 41 % of OS patients. The 3-year event-free survival (EFS) was 57 % in EWS patients and 48 % OS patients. The median SUV1 was 5.6 (range 0 - 17) in EWS patients and 7.9 (range 0 - 24) in OS patients (p = 0.006). In EWS patients the GR rate was 30 % in those with a high SUV1 (≥6) and 72 % in those with a lower SUV1 (p = 0.0004), and in OS patients the GR rate was 29 % in those with SUV1 ≥6 and 64 % in those with a lower SUV1 (p = 0.05). In the univariate analysis the 3-year EFS was significantly better in patients with a low ALP level (59 %) than in those with a high ALP level (22 %, p = 0.02) and in patients with a low LDH level (62 %) than in those with a high LDH level (37 %, p = 0.004). In EWS patients the 3-year EFS was 37 % in those with a high SUV1 and 75 % in those with a low SUV1 (p = 0.004), and in OS patients the 3-year EFS was 32 % in those with a high SUV1 and 66 % in those with a low SUV1 (p = 0.1). Histology, age and gender were not associated with survival. In the multivariate analysis, SUV1 was the only independent pretreatment prognostic factor to retain statistical significance (p = 0.017). SUV2 was assessed in 25 EWS patients: the median SUV2 was 1.9 (range 1 - 8). The GR rate was 20 % in patients with a high SUV2, and 67 % in those with a low SUV2 (p = 0.02). A good metabolic response (SUV reduction of ≥55 %) was associated with a 3-year EFS of 80 % and a poor metabolic response with a 3-year EFS of 20 % (p = 0.05). In the OS patients the median SUV2 was 2.7 (range 0 - 4.5). Neither SUV2 nor the metabolic response was associated with outcome in OS patients. CONCLUSION: FDG PET/CT is a useful and noninvasive tool for identifying patients who are more likely to be resistant to chemotherapy. If this finding is confirmed in a larger series, SUV1, SUV2 and metabolic response could be proposed as factors for stratifying EWS patients to identify those with high-grade localized bone EWS who would benefit from risk-adapted induction chemotherapy.

Soft Tissue Vascular Anomalies of the Extremities: A Proposed Diagnostic Approach.

This narrative review aims to summarise the classification of vascular anomalies, their clinical presentation, and their radiological features to propose a diagnostic algorithm to approach patients with suspected soft tissue vascular anomalies of the extremities. The management of vascular anomalies necessitates a multidisciplinary approach. Clinical presentation and physical examination are sufficient in most cases to achieve a correct diagnosis. This is especially true for small congenital lesions of the skin and subcutaneous tissue. Imaging is used for accurate characterization of these lesions, especially in cases of atypical or vague clinical presentation, and to assess extension in cases of lesions that are larger and localized in deeper tissues.

Personalizing Prophylactic Radiotherapy for Hip Heterotopic Ossification: An AMSTAR-2 Compliant Review of Meta-analyses.

BACKGROUND/AIM: Heterotopic ossification (HO) is a common complication following total hip arthroplasty. Various prophylactic treatments have been proposed, including radiotherapy (RT). This review summarizes the evidence from meta-analyses on the efficacy of RT in preventing hip HO. MATERIALS AND METHODS: A literature search was conducted on PubMed. The quality of the meta-analyses was assessed using the AMSTAR-2 tool. RESULTS: Seven meta-analyses were included. One meta-analysis reported a significant reduction in HO occurrence after RT compared to the control group. Comparing RT and non-steroidal anti-inflammatory drugs, one and two meta-analyses showed significantly greater efficacy of RT in preventing severe HO and better outcomes in patients receiving drugs, respectively. Regarding RT settings, the postoperative and preoperative RT were each supported by one meta-analysis. Furthermore, two meta-analyses showed an advantage of multi-fractionated RT over single fraction RT. The overall confidence rate of the meta-analyses was moderate, low, and critically low in one, three, and three meta-analyses, respectively. CONCLUSION: RT is a confirmed prophylactic intervention for HO. However, the precise optimization of timing, dosage, and fractionation requires elucidation. Future research should focus on the development of predictive models through large-scale data collection and advanced analytics to refine individualized treatment strategies and assess RT comparative effectiveness with drugs.

The use of iliac stem prosthesis for acetabular defects following resections for periacetabular tumors.

INTRODUCTION: The management of pelvic tumors is a challenge for orthopaedic oncologists due to the complex anatomy of the pelvis and the need to have extensive exposure. Various reconstructive techniques have been proposed with poor functional results and a high percentage of complications. Our purpose is to determine the functional results and the rate of complications of iliac stem prosthesis for acetabular defects following resections for periacetabular tumors. MATERIALS AND METHODS: Between 1999 and 2012, 45 patients underwent pelvic resections for periacetabular bone tumors followed by reconstruction with stem cup prosthesis. The most common diagnosis was CS (chondrosarcoma, 29 cases), followed by OS (osteosarcoma, 9 cases) and metastasis (3 cases). In 33 cases, this implant was associated with massive bone allografts. Minimum follow-up required to evaluate functional outcome was 2 years. We classified pelvic resections according to Enneking and Dunham's classification and we used MSTS (musculoskeletal tumor system) score to evaluate functional outcomes. RESULTS AND DISCUSSION: Sixteen patients died of their disease, three were lost to follow-up, four are alive with disease, and twenty-two are alive with no evidence of disease. Fifteen patients had local recurrence. Sixteen patients had bone or lung metastasis. We have had 6 infections, 2 aseptic loosening, and 2 cases of hip dislocation. Iliac sovracetabular osteotomy was fused in all cases at 10 months from surgery. Functional results were good or excellent in 25 of 31 patients with long-term follow-up (77%), with a percentage similar to that reported in the literature. CONCLUSION: The use of iliac stem prosthesis is a simple reconstructive technique that reduces operative times and risk of infection. It allows having good results and low rate of complications, but it should be performed in selected cases and centres of reference.

Two-stage, combined, three-level en bloc spondylectomy for a recurrent post-radiation sarcoma of the lumbar spine.

En bloc or extralesional resection means resection of the tumor in one piece together with a layer of healthy tissue: the margin is either marginal or wide. The prerequisite for an en bloc or extralesional spondylectomy is a tumor involvement of no more than one side of the posterior structures, so that a corridor can be created through which the spinal cord is released. This article presents a two-stage, combined anterior and posterolateral, three-level en bloc spondylectomy, and local flap wound coverage for a patient with a recurrent post-radiation sarcoma of the lumbar spine and infected wound after intralesional treatment. The patient had radiation therapy for an L4 Hodgkin's lymphoma 5 years before the development of the post-radiation sarcoma. Two-stage, three-level en bloc spondylectomy was done through a combined anterior and posterolateral approach. The resection margins were microscopically negative. Dural tear occurred intraoperatively because of tightly adherent dense scar tissue. Two years after spondylectomy, there was no evidence of tumor or infection recurrence; however, the patient died from her lymphoma. In surgically difficult spinal resections, we recommend the two-stage, combined anterior and posterolateral approach for en bloc spondylectomy. The staged procedure may provide for reduced perioperative complications and mortality, and meticulous dissection in the irradiated area, especially if infected. The combined approach provides for easier and safer dissection of the tumor and the spine from the anterior elements under direct visual control, and wide tumor resection.

Porous tantalum acetabular cups for reconstructions after peri-acetabular resections of primary bone tumours.

INTRODUCTION: Periacetabular reconstruction after resection of primary bone tumour is a very demanding procedure. They are frequently associated with scarce functional results and a high rate of complications. We report a series of patients with periacetabular resections for primary bone tumours and reconstruction with a porous tantalum (PT) acetabular cup (AC). MATERIALS AND METHODS: 27 patients (median age 30 years) were included, being affected by primary bone tumours of the pelvis and treated with peri-acetabular resection and reconstruction with a PT AC. The diagnoses were 13 osteosarcomas, 7 chondrosarcomas and 7 Ewing sarcomas. Function was assessed with the Harris Hip Score and complications were classified according to Zeifang. RESULTS: The median follow-up was 70 months. 1 patient required removal of the PT AC because of implant associated infection 55 months after surgery. There was 1 hip dislocation and no case of aseptic loosening. At final follow-up, the median HHS was 81 points (range 48-92). CONCLUSIONS: The used PT AC had good medium-term survival rates and good functional results. This technique is a viable reconstructive option after resections of periacetabular primary bone sarcomas.

Functional Outcome after Reimplantation in Patients Treated with and without an Antibiotic-Loaded Cement Spacers for Hip Prosthetic Joint Infections.

Purpose: A staged revision with placement of a temporary antibiotic-loaded cement spacer after removal of the implant is the "gold standard" for treatment of chronic prosthetic joint infection (PJI). It enables local delivery of antibiotics, maintenance of limb-length and mobility, easier reimplantation. However, bacterial colonization of spacers and mechanical complications can also occur. The aim of this study is to evaluate functional results and infection control in two-stage treatment of total hip arthroplasty (THA) PJI with and without a spacer. Materials and Methods: A retrospective review of 64 consecutive patients was conducted: 34 underwent two-stage revision using a cement spacer (group A), 30 underwent two-stage revision without a spacer (group B). At the final follow-up, functional evaluation of patients with a THA in site, without PJI recurrence, was performed using the Harris hip score (HHS). Measurement of limb-length and off-set discrepancies was performed using anteroposterior pelvic X-rays. Results: Most patients in group B were older with more comorbidities preoperatively. Thirty-three patients (97.1%) in group A underwent THA reimplantation versus 22 patients (73.3%) in group B (P<0.001). No significant differences in limb-length and off-set were observed. The results of functional evaluation performed during the final follow-up (mean, 41 months) showed better function in patients in group A (mean HHS, 76.3 vs. 55.9; P<0.001). Conclusion: The use of antibiotic-loaded cement spacer seems superior in terms of functional outcomes and reimplantation rate. Resection arthroplasty might be reserved as a first-stage procedure in patients who are unfit, who might benefit from a definitive procedure.

Differences in hip musculoskeletal loads between limbs during daily activities in patients with 3D-printed hemipelvic reconstructions following tumor surgery.

BACKGROUND: Anatomical custom-made prostheses, thanks to computer-aided design and 3D-printing technology, help improve osseointegration and reduce mechanical complications in bone reconstructions following bone tumors. A recent quantitative analysis of long-term recovery in patients with 3D-printed reconstructions following pelvic tumor surgery showed asymmetries in ground reaction forces between limbs during different motor activities, while standing very good motor performance and quality of life. RESEARCH QUESTION: We analyzed hip contact forces and muscle forces in that cohort of six patients with an innovative custom-made reconstruction of the hemipelvis, and we tested the hypothesis that asymmetries in ground reaction forces would result in more marked differences in musculoskeletal forces. METHODS: State-of-the-art musculoskeletal modeling in an optimization-based inverse-dynamics workflow was used to calculate hip contact forces and muscle forces during five motor activities, and the differences between limbs were statistically evaluated across the motor activity cycles and on the force peaks. RESULTS: The musculoskeletal loads were found to be not symmetric, as hip loads were generally higher in the contralateral limb. We found significant differences in considerable portions of the motor activities cycles except squat, load symmetry indices indicating a load increase (median up to 25%) on the contralateral limb, especially during stair descent and chair rise/sit, and significantly higher values in the contralateral limb at force peaks. SIGNIFICANCE: We confirmed the hypothesis that residual asymmetries found in ground reaction forces were amplified when hip musculoskeletal loads were investigated, reflecting a shift of the loads toward the intact limb. Despite the general trend of higher loads found in the contralateral hip, this cannot be considered a risk of overloading, as both hips supported loads in a physiological range or lower, indicating a likely optimal recovery.