Lorenzo Di Prinzio

Background: Determining infection eradication before reimplantation remains challenging during two-stage revision for chronic periprosthetic joint infections (PJI). This exploratory study investigated the association between serial postoperative C-reactive protein (CRP) trajectories and treatment outcome following prosthesis explantation during two-stage revision for chronic periprosthetic joint infection (PJI). Methods: We retrospectively reviewed patients undergoing two-stage revision for chronic hip or knee PJI between January 2020 and August 2024. Patients with weekly CRP measurements and at least 12 months of follow-up were included. Treatment failure was defined according to modified Delphi criteria. Weekly CRP concentrations and percentage changes from postoperative Week 1 (ΔCRP) were compared between groups. ROC analysis assessed CRP discrimination weekly. Results: Ninety-one patients were included; 50 (54.9%) achieved infection eradication and 41 (45.1%) experienced treatment failure. CRP increased during the first post-operative week in both groups. Week 1 CRP concentrations were not significantly different between groups (5.24 vs. 6.79 mg/dL, p = 0.108). From Week 2 onwards, postoperative CRP trajectories and relative reductions from Week 1 differed between patients with treatment success and those experiencing treatment failure. From Week 2 onward, CRP remained significantly higher in patients with treatment failure (Week 2: 3.91 vs. 2.27 mg/dL, p = 0.0017; Week 4: 3.28 vs. 0.94 mg/dL, p < 0.0001; Week 6: 2.16 vs. 0.70 mg/dL, p = 0.0007). Relative CRP reduction was significantly higher in the success group from Week 2 onward. Discriminatory performance improved over time, with AUCs of 0.699–0.782 at Weeks 2–6. Conclusions: In this exploratory cohort, postoperative CRP trajectories differed according to treatment outcome. A slower decline in CRP was associated with treatment failure, but these findings do not establish an independent prognostic effect. CRP should not determine reimplantation timing in isolation, but an unfavourable trajectory should prompt reassessment and consideration of repeat debridement and spacer exchange. Larger prospective multicentre studies are needed to confirm these associations and determine their clinical utility.

Hip arthroplasty failures (either septic or aseptic) often require multiple revisions, thus leading to severe bone defects. The most common reconstruction methods do not allow the management of severe defects. For this reason, in recent years, techniques borrowed from surgical oncology have been applied in the field of revision surgery to deal with both acetabular and femoral bone losses. In this article, two cases of severe bone deficiency following multiple hip arthroplasty revisions that were treated with a custom-made hip prosthesis combined with a proximal femur megaprosthesis are presented. Both implants were silver coated. A review of the literature was conducted to analyze similar cases treated with either a custom-made prosthesis or a proximal femur megaprosthesis. At the 2-year follow-up, all prostheses were in site without clinical or radiographic signs of implant loosening. No postoperative complications occurred. At the last follow-up, both patients resumed their daily life activities with an MSTS score of 23 and 21, respectively. The combined approach of a proximal femur megaprosthesis with a custom-made partial pelvic replacement is a solution that allows severe bone deficiency cases to be tackled with good functional results. Additionally, silver coating may help prevent recurrence of infection.

Phosphaturic mesenchymal tumors (PMT) are rare neoplasms, which can give rise to a multifaceted syndrome, otherwise called tumor-induced osteomalacia (TIO). Localizing these tumors is crucial to obtain a cure for the phosphate metabolism derangement, which is often the main cause leading the patient to seek medical help, because of invalidating physical and neuromuscular symptoms. A proportion of these tumors is completely silent and may grow unnoticed, unless they become large enough to produce pain or discomfort. FGF-23 can be produced by several benign or malignant PMTs. The phosphate metabolism, radiology and histology of these rare tumors must be collectively assessed by a multidisciplinary team aimed at curing the disease locally and improving patients’ quality of life. This narrative review, authored by multiple specialists of a tertiary care hospital center, will describe endocrine, radiological and histological features of these tumors, as well as present surgical and interventional strategies to manage PMTs.

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.

Modular megaprostheses (MPs) are commonly used after bone-tumor resection, but they can offer a limb salvage solution in massive bone defects. The aim of this systematic review of the Literature is to provide a comprehensive data collection concerning the use of MPs in non-oncologic cases, and to provide an overview of this topic, especially from an epidemiologic point of view. Three different databases (PubMed, Scopus, and Web of Science) were searched for relevant articles, and further references were obtained by cross-referencing. Sixty-nine studies met the inclusion criteria, reporting on cases of MP in non-oncologic cases. A total of 2598 MPs were retrieved. Among these, 1353 (52.1%) were distal femur MPs, 941 (36.2%) were proximal femur MPs, 29 (1.4%) were proximal tibia MPs and 259 (10.0%) were total femur MPs. Megaprostheses were most commonly used to treat periprosthetic fractures (1158 cases, 44.6%), in particular in the distal femur (859, 74.2%). Overall, complications were observed in 513 cases (19.7%). Type I (soft tissue failures) and type IV (infection) according to the Henderson classification were the most frequent (158 and 213, respectively). In conclusion, patients with severe post-traumatic deformities and/or significant bone loss who have had previous septic complications should be considered as oncologic patients, not because of the disease, but because of the limited therapeutic options available. The benefits of this treatment include relatively short operative times and immediate weight-bearing, thus making MP particularly attractive in the lower limb.