Talonavicular (TN) arthrodesis is an established procedure for symptomatic TN joint pathology and medial column dysfunction. Open techniques provide direct visualization but may be associated with approach-related soft-tissue morbidity. Minimally invasive surgery (MIS) has been proposed to reduce tissue disruption; however, comparative clinical evidence focusing on functional outcomes remains limited. This study compared functional outcomes between MIS and open TN arthrodesis. This retrospective cohort study included 56 feet (55 patients) treated with TN arthrodesis between January 2021 and January 2025. Thirty-two feet underwent MIS TN arthrodesis and 24 feet an open approach. The primary endpoint was the American Orthopaedic Foot Ankle Society (AOFAS) ankle–hindfoot score assessed preoperatively and at final follow-up. Secondary endpoints were operative time and complications. Radiographic follow-up was performed as part of routine care to assess osseous fusion and to guide postoperative rehabilitation. Mean follow-up was 361 ± 69 days. Functional outcomes improved substantially in both groups. Mean AOFAS increased from 53.2 ± 17.6 to 89.4 ± 9.5 in the MIS group (mean gain 36.2 ± 13.3) and from 56.9 ± 14.5 to 87.7 ± 12.7 in the open group (mean gain 30.9 ± 9.1). Between-group differences were not significant for postoperative AOFAS (p = 0.853; Cohen’s d = 0.15) or operative time (59.2 ± 35.6 vs. 69.6 ± 35.1 min; p = 0.415). No complications were documented in the MIS cohort; one patient in the open cohort developed symptomatic nonunion requiring revision (between-group comparison p = 0.389). In this retrospective comparative cohort, MIS and open TN arthrodesis were associated with substantial and comparable functional improvement at short-to-midterm follow-up. Complications were uncommon overall; the low event rate precludes firm conclusions regarding comparative safety or nonunion risk. MIS may be considered when soft-tissue preservation is prioritized, and future prospective studies with standardized protocols and PROM-based outcomes are needed. III.

OBJECTIVE:The primary objective of the minimally invasive Cotton osteotomy is to correct sagittal malalignment of the medial column by targeted plantarflexion, thereby restoring alignment and contributing to the reconstruction of complex pes planovalgus deformities within a joint-preserving surgical approach. INDICATIONS:The procedure is indicated in cases of flexible forefoot supination as part of a progressive collapsing foot deformity (PCFD), particularly when isolated hindfoot correction is insufficient to re-establish medial arch stability. Additional indications include tibialis posterior tendon insufficiency and overload syndromes of the medial column. CONTRAINDICATIONS:Contraindications include general surgical inoperability and acute infection at the operative site. Relative contraindications comprise advanced peripheral arterial disease, severe osteoporosis, neuropathic foot deformities with loss of protective sensation, and symptomatic arthritis of the medial column joints. SURGICAL TECHNIQUE:The Cotton osteotomy is performed via a minimally invasive, closed-wedge technique through a small plantar-medial incision. A wedge-shaped bone fragment is resected from the medial cuneiform using a Shannon burr. The osteotomy gap is then closed by controlled compression to achieve plantarflexion of the medial ray. Fixation is accomplished with a percutaneously inserted, cannulated compression screw under fluoroscopic guidance. POSTOPERATIVE MANAGEMENT:Postoperatively, patients are immobilized in a below-knee walker boot with touch-down weight-bearing for six weeks. After radiographic confirmation of consolidation, progressive loading is initiated with transition to full weight-bearing and regular footwear around week 12. Physical therapy supports restoration of mobility and strength throughout the recovery period. RESULTS:This retrospective study included 13 feet in 12 patients who underwent minimally invasive Cotton osteotomy as part of a combined hindfoot reconstruction. Significant functional improvement was observed, with the AOFAS score increasing from 71.5 ± 14.0 preoperatively to 91.0 ± 5.6 postoperatively (p < 0.05), corresponding to a very large effect size (Cohen's d = 2.20). One case of prolonged wound secretion occurred at the calcaneal osteotomy site and was managed conservatively without revision surgery.

Background: Standardized operating procedures (SOPs) for intravenous vancomycin therapy have been shown to improve population-level trough target attainment and to reduce nephrotoxicity in orthopedic inpatients. However, mean target attainment on a population level does not capture how stably an individual patient remains within the therapeutic window. Intra-individual variability of vancomycin trough concentrations has remained underreported as a patient-level quality indicator in the orthopedic stewardship literature, despite its direct clinical relevance, as alternating sub- and supratherapeutic phases compromise both efficacy and safety independently of the mean exposure. Methods: We conducted a secondary analysis of the prospectively and retrospectively collected data of the Halle Vancomycin SOP cohort. Pre-SOP (n = 58) and post-SOP (n = 23) patient cohorts were compared with respect to patient-level variability metrics, including the coefficient of variation (CV%), swing index, mean absolute successive difference (MSSD), range of trough values, zone-transition frequencies, and the proportion of "stable" patients defined as CV% below 20%. First-order Markov transition matrices were computed to characterize the directionality of trough movements between subtherapeutic, target, and supratherapeutic zones. The primary analysis was restricted to patients with at least three documented trough measurements. Results: The median CV% decreased from 43.5% (IQR 33.5-51.5) pre-SOP to 32.5% (IQR 21.9-38.6) post-SOP (Mann-Whitney U, p = 0.011). The swing index decreased from 1.09 to 0.75 (p = 0.002), and the median range of individual trough concentrations shrank from 19.1 mg/L to 13.2 mg/L (p = 0.029). The absolute number of zone transitions per patient did not differ significantly between cohorts, but their directionality differed substantially: target-zone persistence increased from 37.8% to 57.6%. Across all 403 measurements, subtherapeutic values declined from 38.5% to 26.6%, while target-zone measurements rose from 28.5% to 44.7%. In the post-SOP cohort, longer therapy duration was associated with lower CV% (Spearman ρ = -0.52, p = 0.032). Conclusions: In addition to improvements in population-level target attainment, implementation of the SOP was associated with stabilization of the individual exposure profile of orthopedic inpatients receiving intravenous vancomycin. Intra-individual variability was lower in the post-SOP cohort, and transitions between zones were more often oriented toward the target range. These findings, derived from a single-centre secondary analysis with a small post-SOP cohort, support patient-level variability metrics as a complementary quality indicator in protocolized vancomycin management and warrant prospective multicentre validation.

Topical intrawound vancomycin powder has been widely adopted in orthopaedic surgery as an adjunct for the prevention of surgical site infection (SSI) and periprosthetic joint infection (PJI). Retrospective cohorts and derived meta-analyses have long suggested a consistent benefit, and the technique became established practice at many institutions. Over the past 5 years, prospective randomised evidence has added an important corrective to this picture. The VPIP trial (Saba et al., 2025) randomised 1901 high-risk patients undergoing primary hip or knee arthroplasty across 17 US centres and found no benefit of vancomycin, dilute povidone-iodine, or their combination over saline for any 3-month infection endpoint; a biostatistical projection to 80 000 patients left the number needed to treat near 500, and enrolment was closed for statistical futility. The VANCO trial in high-risk tibial fractures (O'Toole et al., 2021) narrowly missed its primary endpoint ( P = 0.06 ) but demonstrated a significant post hoc reduction in gram-positive deep infections without gram-negative shift. Mechanistic data indicate that sub-inhibitory vancomycin concentrations increase Staphylococcus aureus biofilm formation and raise infection rates in vivo - an effect not reproduced by cefazolin. Current international guidance does not issue a general recommendation for topical vancomycin, a position consistent with this more differentiated evidence base. The present review integrates these strands into an indication-specific framework that separates prophylactic application in clean surgical fields, where benefit is now in serious doubt, from adjunctive-therapeutic application in established infection, and identifies the settings in which topical vancomycin may still be considered individually and those in which it should be avoided.

Minimalinvasive Verfahren haben die operative Therapie von Kleinzehenfehlstellungen wesentlich verändert und stellen heute bei vielen Deformitäten ein etabliertes Vorgehen dar. Ziel ist eine gewebeschonende, funktionell und kosmetisch günstige Korrektur bei geringer Invasivität. Die Indikationsstellung basiert auf einer präzisen klinischen Analyse der Fehlstellung im MTP-, PIP- und DIP-Gelenk, der betroffenen Fehlstellungsebene sowie der Flexibilität oder Rigidität der Deformität. Das operative Konzept folgt einem sequenziellen Vorgehen mit weichteiligen und knöchernen Techniken, die regelhaft kombiniert werden. Neben perkutanen Tenotomien und Kapsulotomien ermöglichen insbesondere minimalinvasive Osteotomien der Phalangen, PIP- und DIP-Arthrodesen, Exostosen- und Kondylenabtragungen sowie distale minimalinvasive metatarsale Osteotomien Korrekturen in verschiedenen Ebenen. Eine interne Osteosynthese ist meist nicht erforderlich, da die Korrektur durch redressierende Tape-Verbände gesichert wird. Minimalinvasive Kleinzehenkorrekturen ermöglichen eine effektive Korrektur mit niedriger Komplikationsrate und frühfunktioneller Nachbehandlung. Bei schweren, kontrakten oder luxierten Fehlstellungen können weiterhin offene Verfahren oder die Kombination aus minimalinvasiven und offenen Verfahren erforderlich sein.

In Germany, 9.3 million people are affected by type 2 diabetes mellitus [27, 29]. Diabetic foot syndrome encompasses the structural and functional damage to the foot that occurs as a result of this underlying condition and can progress to Charcot foot in advanced stages. This complex clinical condition requires specialized, experienced treatment, with the preservation of the limb and its function as the primary therapeutic goal. Conventional open surgical procedures have so far been only moderately successful due to high complication rates. In contrast, minimally invasive surgery (MIS) offers significant advantages, particularly for patients with increased peri- and postoperative risk. Through precise correction of deformities using minimally invasive surgery (MIS) and the appropriate selection of internal and/or external osteosynthesis techniques based on the specific indication, favorable postoperative outcomes can be achieved and the amputation rate reduced.

In Deutschland sind 9,3 Mio. Menschen von einem Diabetes mellitus Typ 2 betroffen [27, 29]. Das diabetische Fußsyndrom umfasst die im Rahmen dieser Grunderkrankung auftretenden strukturellen und funktionellen Schädigungen des Fußes und kann in fortgeschrittenen Stadien in einen Charcot-Fuß übergehen. Diese komplexe Krankheitsentität erfordert eine spezialisierte, erfahrene Behandlung, wobei der Erhalt der Extremität und ihrer Funktion als primäres Therapieziel anzustreben ist. Konventionelle offene chirurgische Verfahren sind aufgrund hoher Komplikationsraten bislang nur eingeschränkt erfolgreich. Demgegenüber weist die minimalinvasive Chirurgie (MIS) insbesondere bei Patient:innen mit erhöhtem peri- und postoperativen Risiko relevante Vorteile auf. Durch eine präzise Deformitätenkorrektur mittels MIS sowie die indikationsgerechte Auswahl interner und/oder externer Osteosyntheseverfahren können günstige postoperative Ergebnisse erzielt und die Amputationsrate reduziert werden.

BACKGROUND:Talonavicular (TN) arthrodesis can be performed open or minimally invasively (MIS); whether MIS reproduces the radiographic medial-column re-alignment of open surgery remains unclear. METHODS:Retrospective cohort of 56 feet (32 MIS, 24 open) treated 2021-2025. Co-primary endpoints: absolute talo-first metatarsal (Meary) angle in dorsoplantar (DP) and lateral (LAT) projections, and radiographic union. RESULTS:Absolute Meary angle decreased significantly in both groups (all p < 0.001). Open feet had greater preoperative malalignment (DP 14.8° vs 10.8°, p = 0.019). Postoperative angles did not differ significantly (DP 0.92° vs 1.96°, p = 0.091; LAT 1.38° vs 2.53°, p = 0.073); 32/32 (100%) MIS and 21/24 (87.5%) open feet reached ±5° physiological range (DP, p = 0.073). Union: 32/32 (100%) MIS, 23/24 (95.8%) open. CONCLUSIONS:MIS and open TN arthrodesis achieved comparable medial-column re-alignment and union rates, despite greater baseline deformity in the open cohort, complementing previously reported comparable functional outcomes. LEVEL OF EVIDENCE:III, retrospective comparative cohort study.

BACKGROUND:Minimally invasive techniques have substantially changed the surgical management of lesser toe deformities. The therapeutic objective is a tissue-sparing correction that restores function, improves alignment, and achieves a favorable cosmetic result with minimal surgical morbidity. Indication for surgery requires a detailed clinical assessment of the deformity at the metatarsophalangeal, proximal interphalangeal, and distal interphalangeal joints, including the affected plane, severity, and degree of flexibility or rigidity. OPERATIVE STRATEGY:The operative strategy is based on a sequential concept combining soft-tissue and osseous procedures as required. Percutaneous tenotomies and capsulotomies may be supplemented by minimally invasive phalangeal osteotomies, proximal and distal interphalangeal joint arthrodeses, exostosis and condylar resections, and distal minimally invasive metatarsal osteotomies, allowing multiplanar correction. Internal fixation is usually not required, as postoperative alignment is maintained by corrective taping. RESULTS:Minimally invasive correction of lesser toe deformities provides effective realignment with low complication rates and allows early functional postoperative management. In severe, rigid, or dislocated deformities, combined open procedures may remain necessary.

Die minimal-invasive Cotton-Osteotomie zielt auf die Korrektur einer sagittalen Fehlstellung der medialen Säule ab. Dadurch wird die anatomische Ausrichtung wiederhergestellt und im Rahmen eines gelenkerhaltenden operativen Vorgehens zur Rekonstruktion komplexer Pes-planovalgus-Deformitäten beigetragen. Flexible Supinationskomponente des Vorfußes bzw. dorsiflektierter medialer Strahl im Kontext einer „progressive collapsing foot deformity“ (PCFD), insbesondere wenn eine isolierte Rückfußkorrektur die Stabilität des medialen Längsgewölbes nicht suffizient wiederherstellt. Weitere Indikationen sind die Insuffizienz der Tibialis-posterior-Sehne sowie Überlastungssyndrome der medialen Säule. Allgemeine Operationsunfähigkeit und akute Infektionen im Operationsgebiet. Relative Kontraindikationen sind eine fortgeschrittene periphere arterielle Verschlusskrankheit, ausgeprägte Osteoporose, neuropathische Fußdeformitäten mit Verlust des Schutzgefühls sowie symptomatische Arthrosen der Gelenke der medialen Fußsäule. Die Cotton-Osteotomie erfolgt minimal-invasiv als „Closed-wedge-Technik“ über eine kleine plantar-mediale Inzision. Mit einer Shannon-Fräse wird ein keilförmiges Knochenfragment aus dem Os cuneiforme mediale reseziert. Der Osteotomiespalt wird durch kontrollierte Kompression geschlossen, um die Plantarflexion des medialen Strahls zu erzielen. Die Fixation erfolgt mittels perkutan eingebrachter kanülierter Kompressionsschraube unter Bildwandlerkontrolle. Sechs Wochen Immobilisation im Unterschenkel-Walker mit Bodenkontaktlauf. Nach radiologischer Konsolidationskontrolle stufenweiser Belastungsaufbau mit Übergang zur Vollbelastung und regulärem Schuhwerk etwa ab Woche 12. Die Physiotherapie unterstützt die Wiederherstellung von Mobilität und Kraft. In diese retrospektive Untersuchung wurden 13 Füße von 12 Patientinnen und Patienten eingeschlossen, bei denen die minimal-invasive Cotton-Osteotomie als Bestandteil einer kombinierten Rückfußrekonstruktion durchgeführt wurde. Es zeigte sich eine signifikante funktionelle Verbesserung: Der AOFAS-Score stieg von präoperativ 71,5 ± 14,0 auf postoperativ 91,0 ± 5,6 Punkte (p < 0,05; sehr große Effektstärke, Cohen’s d = 2,20). Eine prolongierte Wundsekretion an der Kalkaneusosteotomie trat in einem Fall auf und konnte konservativ ohne operativen Revisionseingriff behandelt werden.

Minimalinvasive Verfahren beim Pes planovalgus bieten eine sichere Alternative zu offenen Eingriffen und reduzieren die postoperative Morbidität deutlich. Das signifikant geringere Risiko für Wundheilungsstörungen sowie der deutlich reduzierte Bedarf an Schmerzmitteln zählen zu den wesentlichen Faktoren, die minimalinvasive Verfahren begünstigen. Aufgrund des deutlich geringeren Komplikationsrisikos bei gleichzeitig hohem Korrekturpotenzial kann die perkutane Kalkaneus-Verschiebeosteotomie heute als Goldstandard betrachtet werden. Die Behandlung des erwachsenen Knick-Senk-Fußes erfordert, abhängig vom jeweiligen Deformitätsmuster, meist eine Kombination unterschiedlicher operativer Prozeduren, die häufig minimalinvasiv durchgeführt werden können. Dieser Beitrag gibt neben der perkutanen Kalkaneusosteotomie eine Übersicht über den endoskopischen FDL-Transfer sowie die perkutane „Reverse-cotton“-Osteotomie, Verfahren, die im Rahmen der Behandlung des flexiblen Pes planovalgus häufig kombiniert eingesetzt werden.

Background/Objectives: In methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, randomized evidence indicates comparable efficacy of cefazolin and antistaphylococcal penicillins with less nephrotoxicity; whether this extends to bone and joint infection (BJI) is unknown. We compared both agents in MSSA BJI. Methods: We retrospectively analyzed all adults at a single center with culture-confirmed, monomicrobial MSSA BJI treated with inpatient intravenous cefazolin or flucloxacillin monotherapy (January 2022-January 2025)-a selected population excluding rifampicin-based combination therapy, outpatient parenteral therapy, polymicrobial infection, and concurrent bacteremia/endocarditis. Endpoints, a priori exploratory, comprised effectiveness (mortality; clinical success) and renal safety (peri-treatment acute kidney injury [AKI]); the AKI comparison was additionally adjusted for confounders. Results: Among 110 patients (64 cefazolin, 46 flucloxacillin), baseline characteristics were comparable except for more frequent nephrotoxic co-medication with cefazolin (56.2% vs. 26.1%; p = 0.002). No statistically significant differences in effectiveness were detected: 30-day clinical success was 89.1% versus 80.4% (ARD 8.6 percentage points, 95% CI -4.7 to +23.3) and one-year clinical success 79.7% versus 65.2% (ARD 14.5, 95% CI -2.2 to +31.0); these imprecise estimates are compatible with effects ranging from no difference to a clinically relevant benefit of cefazolin. Peri-treatment AKI occurred in 19.0% versus 30.4% (ARD 11.4, 95% CI -4.7 to +27.7; adjusted odds ratio 2.27, 95% CI 0.87-5.91); the difference was confined to stage 1. Conclusions: In this selected inpatient monotherapy cohort, cefazolin was associated with numerically fewer AKI events, without statistically significant differences in any comparison. These exploratory findings support cefazolin as a rational targeted option for MSSA BJI, pending prospective confirmation.

Background: Calcaneal osteotomy plays a central role in the correction of hindfoot axis deformities, with minimally invasive techniques becoming increasingly established in recent years. For minimally invasive calcaneal osteotomy (MICO), V-shaped osteotomy and the 4-quadrant sliding osteotomy (4Q) are widely used techniques. Toepfer et al recently introduced the so-called rising sun (RS) technique for MICO. In this surgical technique, perforating drillings are performed instead of a sliding osteotomy. The present cadaveric study aimed to compare the risk of cutaneous nerve injury between the RS technique and the established 4Q technique. Methods: A total of 24 human anatomical specimens were used. Eight specimens underwent osteotomy using the 4Q technique. In 16 specimens, the RS technique was performed. Allocation was randomized. Subsequently, the cutaneous nerves of the foot were dissected and stained. The osteotomy plane was then exposed, distances to the dissected nerves were measured using standardized methods. All nerve injuries were recorded. Results: In the osteotomies performed using the 4Q technique, nerve injury occurred in 6 of 45 evaluable nerves (13.3 %). In the osteotomies performed using the RS technique, a total of 3 nerve injuries were identified in the anatomical dissections of 90 evaluable nerves (3.3%). A statistically significant difference was not found ( P = .06). The lateral dorsal cutaneous nerve was the most frequently injured nerve with a total of 4 lesions (44.4%). Conclusion: The new RS technique appears to be a safe method for MICO; however, based on the available numbers, no statistically significant difference in nerve injury rates between the 2 techniques was detected. Complete avoidance of nerve injury does not seem achievable with percutaneous techniques. Further studies, especially in clinically evaluable patients, are desirable to better assess this technique and its potential for broader clinical application.

Hallux valgus (HV) is a common forefoot deformity that often leads to foot pain and functional limitations, requiring surgical intervention when conservative treatments fail. Tarsometatarsal arthrodesis is a widely used procedure for severe HV deformities, with plantar plate fixation demonstrating superior biomechanical outcomes. However, the biomechanical equivalence of different plantar plate designs remains unclear. Specifically, there is a lack of biomechanical studies comparing how design variations affect load distribution, durability, and the risk of material failure postoperatively. This study aims to address this gap by evaluating the biomechanical performance of 2 commonly used plantar plate designs. This study involved a biomechanical analysis of 2 widely used plantar Lapidus plating designs: U-shaped plates and straight-shaped plates. A total of 20 fresh frozen cadaveric feet from 10 donors were included. The plates were assigned randomly to each specimen, and tarsometatarsal arthrodesis was performed according to the manufacturers' guidelines. Mechanical testing was conducted using a universal testing machine, focusing on cyclic loading and maximum load capacity to assess the mechanical stability of each system. Cyclic loads were systematically applied in 4 increments, culminating in a ramp test to ascertain the maximum load to material failure. Both the U-shaped and the straight-shaped plantar Lapidus plates demonstrated commendable mechanical stability under cyclic loading, with nearly no significant differences in stiffness across the 4 cyclic loading force cycles. In the maximum load capacity test, the straight-shaped plate showed a higher mean load capacity (540.6 N, SD = 36.09) compared with the U-shaped plate (446.6 N, SD = 91.32), with a statistically significant difference (P = .03) and a large effect size (Cohen d = 1.56). This biomechanical study demonstrated that both U-shaped and straight-shaped plantar Lapidus plating systems provided comparable mechanical performance under stepwise cyclic loading conditions. The straight-shaped plates showed a higher failure rate during cyclic loading but achieved a significantly greater maximum load capacity in the final load-to-failure test. In contrast, the U-shaped plates were more consistent under repeated loading, suggesting potential advantages in fatigue resistance. These findings may reflect a trade-off between repetitive load endurance and maximum load-bearing capacity. Although these results offer biomechanical insight into the design-specific behavior of 2 commonly used plantar plating systems, their clinical relevance should be interpreted with caution, given the limitations of cadaveric testing, the absence of biological bone healing, and small sample sizes. Further clinical and long-term outcome studies are needed to confirm whether the observed mechanical differences translate into meaningful differences in patient function or fusion success. Level V, preclinical biomechinal study.

Background: Intravenous vancomycin is a mainstay for prosthetic joint infections, osteomyelitis, and implant-associated infections, yet real-world dosing frequently misses PK/PD targets. We assessed whether a ward-embedded standard operating procedure (SOP) improves target attainment and dosing efficiency. Methods: Single-centre, non-randomized pre-post study in an orthopedic service. SOP mandated weight-adapted loading dose, renal function-adjusted maintenance dosing, a 15–20 mg/L trough target, and scheduled TDM. Adults receiving ≥72 h IV vancomycin were included; major renal failure and incomplete TDM were excluded. Pre-SOP data were retrospective; post-SOP data were prospective (03/2024–06/2025). Primary outcome: proportion of troughs within 15–20 mg/L (first and repeated). Repeated measures were modeled with GEE. Time to first in-range trough used Kaplan–Meier (indexed by measurement number). Results: We included 154 patients (pre-SOP n = 58; post-SOP n = 96); baseline characteristics were broadly similar. Use of a weight-based loading dose rose from 31.0% pre-SOP to 100% post-SOP (p < 0.001). At the first trough, 17.2% vs. 26.0% were within 15–20 mg/L (p = 0.238). Across 847 troughs (pre = 319; post = 528), the in-range proportion increased from 28.2% to 41.7%, with subtherapeutic values declining from 38.2% to 26.3% and supratherapeutic values remaining nearly similar (33.5% → 32.0%). Time to first in-range trough shortened from a median of 4 to 2 measurements (log-rank p < 0.001). Post-SOP measurements had higher odds of being in range (aOR 1.68, 95% CI 1.29–2.20; p < 0.001), with marginal predicted probabilities of 33.4% (pre) vs. 47.8% (post). Dose adjustments per patient decreased from a mean 4.0 to 2.48 (p < 0.001). Conclusions: A pragmatic, orthopedic ward–embedded SOP for intravenous vancomycin improved pharmacologic precision: more measurements within target, fewer subtherapeutic exposures, faster target attainment, and fewer dose changes. These data support protocol-first implementation as an immediately actionable step toward more consistent vancomycin exposure in orthopedic care. Future work should integrate AUC-guided, model-informed precision dosing and evaluate clinical endpoints and generalizability across centres.

Introduction: Topical vancomycin powder is increasingly used in orthopedic surgery to prevent surgical site infections (SSIs). While its efficacy is well established, data on systemic safety – particularly renal effects – are limited. Given vancomycin's known nephrotoxicity when administered systemically, we evaluated whether local intraoperative application affects short-term renal function. Methods: This retrospective single-center cohort included 50 adults who underwent orthopedic surgery with the application of intraoperative topical vancomycin powder (January–July 2024). Serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) were measured preoperatively and at two routine postoperative time points. The primary endpoint was acute kidney injury (AKI) per KDIGO serum creatinine criteria; secondary endpoints were within-patient changes in SCr and eGFR. Prespecified subgroups were nephrotoxic concomitant medication (yes/no), application site (epifascial/subfascial), vancomycin dose (< 1000 vs. ≥ 1000 mg), and indication (aseptic/septic). Analyses used Wilcoxon signed-rank and Fisher's exact tests. Results: The most common applied dose was 1000 mg (48 %; median 1000 mg; range 500–4000). Postoperative labs were obtained at median day 1 and day 3. AKI occurred in 2/50 patients (4 %), both stage 1; no stage 2–3 events were observed. Both AKI cases had concomitant exposure to potentially nephrotoxic medication; however, AKI incidence did not statistically differ across prespecified subgroups (nephrotoxic co-medication, application plane, dose category, indication; all p>0.05). Paired analyses showed minimal within-patient change in renal indices: eGFR exhibited no central shift from baseline at either time point, and serum creatinine showed no systematic postoperative increase. Conclusions: Local intraoperative vancomycin powder application was not associated with short-term renal impairment. These findings support its renal safety in orthopedic surgery. Prospective trials with pharmacokinetic monitoring are warranted to confirm long-term safety. Level of evidence: IV (retrospective case series).