How Does Customized Cutting Guide Design Affect Accuracy and Ergonomics in Pelvic Tumor Resection? A Study in Cadavers.

BACKGROUND: Customized cutting guides are technical aids that make primary pelvic bone tumor resection safer and more reliable. Although the effectiveness of such devices appears to be widely accepted, their conception and design remain varied. Two main designs have been reported: the heavier block-type customized cutting guides and the lighter patch-type customized cutting guides. As recent tools, there must be more evidence regarding the impact of design on their accuracy and ergonomics. Thus, an evaluation of their respective performances appears warranted. QUESTIONS/PURPOSES: In a cadaver model, we assessed whether (1) a thinner, patch-type customized cutting guide design results in resections that are closer to the planned resections than the heavier block-type customized cutting guides, and (2) the patch-type customized cutting guide design is more ergonomic than the block-type customized cutting guide with improved usability in surgery (in terms of bulkiness, ease of placement, primary and secondary stability, and stability during cutting). METHODS: We conducted an experimental study involving five fresh whole-body anatomic specimens (three women and two men with a median age of 79 years and median weight of 66 kg) by simulating six virtual tumors in three areas according to the Enneking classification (Zones I: iliac wing, II: periacetabular area, and I and IV: sacroiliac joint area). We compared the impact of the customized cutting guide's design on performance in terms of the resection margin accuracy using CT scan analysis (deviation from the planned margin at the closest point and the maximum deviation from the planned margin) and the intraoperative ergonomic score under conditions simulating those of an oncologic resection of a bone tumor (with a range of 0 to 100, with 100 being best). RESULTS: The patch customized cutting guides performed slightly better than the block customized cutting guides regarding deviation from the planned margin at the closest point, with median values of 1 mm versus 2 mm (difference of medians 1 mm; p = 0.02) and maximum deviation from the planned margin of 3 versus 4 mm (difference of medians 1 mm; p = 0.002). In addition, the patch design was perceived to be slightly more ergonomic than the block design, with a 92% median score versus 84% for the block design (difference of medians 8%; p = 0.03). CONCLUSION: We observed an equivalence in performance regarding accuracy and ergonomics, with slight advantages for patch customized cutting guides, especially in complex zones (Zone I and IV). Owing to a small cohort in a cadaver study, these results need independent replication. CLINICAL RELEVANCE: The patch-type customized cutting guide with thinner contact spots to the bone in specific areas and less soft tissue dissection might offer an advantage over a larger block design for achieving negative oncologic bony margins, but it does not address issues of soft tissue margins.

French translation and validation of the cross-cultural adaptation of the MSTS functional assessment questionnaire completed after tumor surgery.

INTRODUCTION: Malignant tumors of the extremities are uncommon. Their surgical treatment, whether conservative or not, may cause sequelae. Functional assessment of patients is essential for research purposes, but also follow-ups and adaptation of treatments. The Musculoskeletal Tumor Society Rating Scale (MSTS) is a disease-specific functional scoring system often used in English literature. Currently, no studies have been published on a valid French translation of the MSTS, whether for the lower or upper extremities. We, therefore, conducted a prospective study to answer the following questions: (1) Are the proposed adapted French versions of the MSTS valid? (2) Do the psychometric properties of the two versions obtained make their use relevant? MATERIALS AND METHODS: The translation and cross-cultural adaptation were carried out following the recommendations of Beaton and Guillemin to obtain two versions: one for patients who had undergone upper extremity surgery (MSTS-UE) and one for those who had undergone lower extremity surgery (MSTS-LE). A prospective multicenter cohort study was then carried out to analyze the psychometric properties of these two versions. RESULTS: A total of 250 patients from 3 referral centers were enrolled in this study. A confirmatory factor analysis (CFA) demonstrated that the two French versions of the MSTS (MSTS-LE and MSTS-UE) were a good fit with a root mean square error of approximation (RMSEA)<0.08 and a comparative fit index (CFI)>0.90. The psychometric properties of the two versions were validated with internal consistency (Cronbach alpha>0.7), convergent validity of each item with its score (> 0.4), and sufficient criterion validity (Pearson correlation coefficient>0.4). The discriminant validity analysis showed that there was a significant correlation between each version and the performance status (PS) (p<0.05). CONCLUSION: This study produced a French version of the MSTS scoring system and validated the psychometric properties of the two versions obtained (MSTS-UE and MSTS-LE). Therefore, the French MSTS scoring system is a valid measurement that can be used in international studies. LEVEL OF EVIDENCE: I.

A Short-Course Antibiotic Prophylaxis Is Associated with Limited Antibiotic Resistance Emergence in Post-Operative Infection of Pelvic Primary Bone Tumor Resection.

Resections of primary pelvic bone tumors are frequently complicated by surgical site infections (SSIs), thereby impairing the functional prognosis of patients, especially in case of implant removal. Although prophylactic antibiotics play an essential role in preventing SSIs, there are presently no recommendations that support their appropriate use. This study aimed to assess the impact of a 24 h prophylactic protocol on the bacterial ecology, the resistance pattern, and the SSI healing rate. We hypothesized that this protocol not only limits the emergence of resistance but also results in a good cure rate with implant retention in case of SSI. A retrospective study was performed that included all patients with an SSI following a pelvic bone tumoral resection between 2005 and 2017 who received a 24 h antibiotic prophylaxis protocol. Twenty-nine patients with an SSI were included. We observed a 75.9% rate of polymicrobial infection, with a high prevalence of digestive flora microorganisms and a majority of wild-type phenotypes. We confirmed that there was no significant emergence of resistant flora. After first-line debridement, antibiotics (DA) if any implant was used, or debridement, antibiotics, and implant retention (DAIR) whenever possible, we obtained a 79.3% cure rate, with implant removal in 20% of cases. The absence of an implant was significantly associated with SSI healing. Early infection management and low resistance profiles may also have a positive effect, but this needs to be confirmed in a larger cohort. In light of this, the use of a 24 h prophylactic protocol in primary pelvic bone tumor resections is associated with a favorable infection cure rate and implant retention in case of SSI, and minimal selection of resistant microorganisms.