Arnd Fredrik Viehöfer

Zusammenfassung: Die arthroskopische Arthrodese des oberen Sprunggelenks (OSG) führt bei OSG-Arthrose in geübten Händen zuverlässig zu einer Schmerzreduktion und Fusion des oberen Sprunggelenks. Sie ist der offenen Arthrodese in vielen Fällen durch eine schnellere Rehabilitation mit tendenziell besserem klinischem Outcome bei vergleichbaren radiologischen Ergebnissen überlegen. Allerdings bleibt das offene Verfahren der Goldstandard, wenn ein Knochenersatz, stärkere Achsenkorrektur oder eine rigidere Plattenfixierung notwendig ist. Die durch die Arthrodese entstehende funktionelle Einschränkung wird von angrenzenden Gelenken teilweise kompensiert. Diese Mehrbelastung wird als Ursache für die langfristig beobachtete vermehrte Arthrose des unteren Sprunggelenks (USG) und des Mittelfußes angesehen und kann zu persistierenden Beschwerden führen.

Background/Objectives: In orthopedic (diabetic) foot surgery, the serum C-reactive protein (CRP) level is frequently measured not only as a diagnostic tool, but also as a control inflammatory marker in the follow-up of postoperative surgical-site infections (SSIs) Methods: We investigated the predictive value of the post-debridement routine (control) serum CRP level in adult (diabetic) patients with an SSI in the foot. We excluded community-acquired (diabetic foot) infections and focused on the predictive accuracy of routine (control) CRP measurements in terms of ultimate therapeutic failures. Results: The median pre- and postoperative CRP levels were 25 mg/L and 8.8 mg/L, respectively. In group comparisons and multivariate assessment, neither the immediate (relative and absolute) drop in the serum CRP level, nor its values between 5 and 8 weeks and between 11 and 14 weeks predicted the failure risk of 19%. In contrast, in cases of surprisingly elevated CRP levels, this finding leads to unnecessary radiological (median costs approximatively USD 200), clinical, microbiological urinary sample (median costs USD 50), and laboratory (one CRP sample USD 10) exams. These additional exams also likely prolong the duration of hospitalization by one to two days (e.g., whilst awaiting the microbiological results) and often generate unnecessary consultations among internist and/or infectious diseases experts (USD 50). Conclusions: Routine, postoperative CRP monitoring during the treatment of established orthopedic (diabetic) foot SSIs is unnecessarily costly, and should be avoided in favor of clinical surveillance of the postoperative evolution.

Background/Objectives: In orthopedic (diabetic) foot surgery, the serum C-reactive protein (CRP) is frequently measured not only as a diagnostic tool, but also as a control inflammatory marker in the follow-up of operated surgical site infections (SSI) Methods: We investigate the predictive value of the post-debridement routine (control) serum CRP level in adult (diabetic) patients with SSI in the foot. We exclude community-acquired (diabetic foot) infections and focus on the predictive accuracy of routine (control) CRP measurements in terms of ultimate therapeutics failures. Results: The median pre- and postoperative CRP were 25 mg/L and 8.8 mg/L, respectively. In group comparisons and multivariate assessment, neither the immediate (relative and absolute) drop of the serum CRP level, nor its values between 5 and 8 weeks and between 11 and 14 weeks predicted the failure risk of 19%. In contrast, in cases of a surprisingly elevated CRP levels, this finding leads to unnecessary radiological, clinical and laboratory exams during clinical treatment of infections. Conclusions: Routine, postoperative CRP monitoring during the treatment of established (diabetic) foot SSIs is futile, unnecessarily costly, and should be avoided in favor of a clinical surveillance of the postoperative evolution.

Despite growing numbers of scientific publications on the optimal antibiotic treatment for diabetic foot infections, the data on the adult population with non-diabetic (postsurgical) foot infections is limited. Therefore, one of the largest single-center databases at the Balgrist University Hospital in Zurich, Switzerland, was established between January 2014 and August 2022. Using a case–control study design, we retrospectively investigated failures of combined surgical and antibiotic therapy for surgical site foot infections (SSIs). Overall, 17.4% of the episodes experienced therapeutic failures, particularly in patients with infected ankle prostheses. However, age, biological sex, pathogens, the duration of post-debridement antibiotic treatment, the number of surgical debridements, or the use of negative-pressure wound care altered the failure risk. In the multivariate logistic regression analyses, the duration of postsurgical antibiotic use was completely indifferent (as a continuous variable with an odds ratio of 1.0 and a 95% confidence interval ranging from 0.96 to 1.03) when stratified into inter-tertiary groups. Our findings suggest that shorter courses of systemic antibiotics may be appropriate in non-diabetic adults, supporting better antibiotic stewardship. Ongoing randomized controlled trials are under way to investigate which patients might safely receive shorter antibiotic treatments for surgical site infections following elective foot and ankle procedures.

Whereas there is an increasing number of scientific publications investigating the optimal anti-biotic treatment for diabetic foot infections, we are lacking corresponding data in the adult non-diabetic (postsurgical) foot infection population. We therefore established one of the largest single-center databases on this topic and retrospectively investigate failures of a combined sur-gical and antibiotic therapy for surgical site foot infections. Overall, 17.4% of the episodes expe-rienced any therapeutic failures; especially among the infected ankle prostheses. In contrast, neither the age, the biological sex, pathogens, the duration of post-debridement antibiotic treatment, the number of surgical debridement, or the use of negative-pressure wound care could alter the failure risk. In multivariate logistic regression analyses, the duration of postsur-gical antibiotic use was completely indifferent (as a continuous variable with odds ratio 1.0, 95% confidence interval 0.96-1.03), or when stratified into inter-tertiary groups. Our results poten-tially enable shorter applications of systemic antibiotics in favor of a better stewardship in the non-diabetic adult population. Consecutive prospective-randomized trials are under way to identify eligible patient populations for a potentially shorter durations in surgical site infections after elective foot and ankle surgery.

Background: If tibiofibular syndesmotic injury is undetected, chronic instability may lead to persistent pain and osteoarthritis. So far, no reliable diagnostic method has been available. The primary objectives of this study were to determine whether defined lesions of the syndesmosis can be correlated with specific tibiofibular joint displacements caused by external rotational torque and to compare the performance of bilateral external torque computed tomography (BET-CT) and arthroscopy. Secondary objectives included an evaluation of the reliability of CT measurements and the suitability of the healthy contralateral ankle as a reference. Methods: Seven pairs of healthy, cadaveric lower legs were tested and assigned to 2 groups: (1) supination-external rotation (SER) and (2) pronation-external rotation (PER). In the intact state and after each surgical step, an ankle arthroscopy and 3 CT scans were performed. During the scans, the specimens were placed in an external torque device with 2.5, 5.0, and 7.5 Nm of torque applied. Results: The arthroscopic and CT parameters showed significant correlations in all pairwise comparisons. The receiver operating characteristic (ROC) curve analyses yielded the best prediction of syndesmotic instability with the anterior tibiofibular distance on CT, with a sensitivity of 84.1% and a specificity of 95.2% (area under the curve [AUC], 94.8%; 95% confidence interval [CI], 0.916 to 0.979; p < 0.0001) and with the middle tibiofibular distance on arthroscopy, with a sensitivity of 76.2% and specificity of 92.3% (AUC, 91.2%; 95% CI, 0.837 to 0.987; p < 0.0001). Higher torque amounts increased the rate of true-positive results. Conclusions: BET-CT reliably detects experimental syndesmotic rotational instability, compared with the healthy side, with greater sensitivity and similar specificity compared with the arthroscopic lateral hook test. Translation of these experimental findings to clinical practice remains to be established. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Zusammenfassung: Grundlagen: Die 3‑D-Analyse und Umsetzung mit patientenindividuellen Schnitt- und Repositionsblöcken ermöglicht die Korrektur komplexer Tibiafehlstellungen. Die Korrektur kann anhand der Gegenseite oder eines statistischen Modells geplant werden. Patientenspezifische 3‑D-gedruckte Schnittführungsblöcke ermöglichen eine präzise Osteotomie, und Repositionsblöcke helfen, eine anatomische Reposition zu erreichen. Je nach Art und Ausmaß der Korrektur muss eine Fibulaosteotomie erwogen werden, um eine Korrektur in der gewünschten Reposition zu erreichen. Kontraindikationen: a) Schlechte Weichteilsituation, Vorsicht insbesondere bei adhärenter Haut und Lappenplastiken im Zugangsbereich; b) Infektionen; c) periphere arterielle Verschlusskrankheit (Stadium III und IV, kritischer transkutaner Sauerstoffpartialdruck tcpO₂ im Operationsgebiet); d) allgemeine Kontraindikation einer Operation. Operationstechnik: Vor der Operation wird ein 3‑D-Modell beider Unterschenkel anhand von CT-Daten erstellt. Analyse der Deformität anhand der Gegenseite im 3‑D-Computermodell (CASPA) und Planung der Osteotomie. Falls die Gegenseite eine Fehlstellung zeigt, kann ein statistisches Modell benutzt werden. Drucken der patientenspezifischen Schnittblöcke aus Nylon (PA2200) für die Osteotomie und Reposition. Die Operation erfolgt in Rückenlagerung, Antibiotikaprophylaxe präoperativ, Oberschenkelblutsperre, welche bei Bedarf aktiviert wird. Ventrolateraler Zugang zur Tibia. Anbringen des patientenspezifischen Schnittblocks, Durchführung der Osteotomie. Reposition über den Repositionsblock und Fixieren mittels medialer Platte. Falls die Fibula die Reposition behindert, erfolgt eine Fibulaosteotomie in der Regel über einen separaten lateralen Zugang. Je nach Präferenz des Operateurs kann diese ebenfalls mit patientenspezifischen Schnittblöcken erfolgen. Verschluss der Wunde. Postoperatives Management: Kompartmentüberwachung. Passive Mobilisation des oberen Sprunggelenks aus dem Gips, sobald die Wundheilung fortgeschritten ist. Teilbelastung im abnehmbaren Unterschenkelgips für mindestens 6 bis 12 Wochen, abhängig von der routinemäßig durchgeführten Röntgenkontrolle 6 Wochen postoperativ. Bis zur Gipsabnahme Thromboseprophylaxe mittels niedermolekularen Heparins. Ergebnisse: Die patientenspezifische Korrektur der Fehlheilung ermöglicht im Allgemeinen eine gute Korrektur. Für die distalen Korrekturen der Tibia wurden gute Ergebnisse erzielt. Für die Korrektur von Tibiaschaftdeformitäten sind die endgültigen Ergebnisse noch ausstehend. Vorläufige Ergebnisse zeigen eine gute Machbarkeit mit einer Pseudarthrosenrate von 10 % ohne postoperative Infekte.

Surgical site infection (SSI) after elective orthopedic foot and ankle surgery is uncommon and may be higher in selected patient groups. Our main aim was to investigate the risk factors for SSI in elective orthopedic foot surgery and the microbiological results of SSI in diabetic and non-diabetic patients, in a tertiary foot center between 2014 and 2022. Overall, 6138 elective surgeries were performed with an SSI risk of 1.88%. The main independent associations with SSI in a multivariate logistic regression analysis were an ASA score of 3–4 points, odds ratio (OR) 1.87 (95% confidence interval (CI) 1.20–2.90), internal, OR 2.33 (95% CI 1.56–3.49), and external material, OR 3.08 (95% CI 1.56–6.07), and more than two previous surgeries, OR 2.86 (95% CI 1.93–4.22). Diabetes mellitus showed an increased risk in the univariate analysis, OR 3.94 (95% CI 2.59–5.99), and in the group comparisons (three-fold risk). In the subgroup of diabetic foot patients, a pre-existing diabetic foot ulcer increased the risk for SSI, OR 2.99 (95% CI 1.21–7.41), compared to non-ulcered diabetic patients. In general, gram-positive cocci were the predominant pathogens in SSI. In contrast, polymicrobial infections with gram-negative bacilli were more common in contaminated foot surgeries. In the latter group, the perioperative antibiotic prophylaxis by second-generation cephalosporins did not cover 31% of future SSI pathogens. Additionally, selected groups of patients revealed differences in the microbiology of the SSI. Prospective studies are required to determine the importance of these findings for optimal perioperative antibiotic prophylactic measures.