[Postoperative outcome of 30 patients with navicular bone fractures-In connection with AOFAS-Score, SF-12 and fracture classifications]

BACKGROUND

Fractures of the navicular bone are rare and the number of those treated surgically is even smaller. Moreover, scientific analyses on this topic are only sporadically present in the literature, therefore this retrospective and monocentric study was initiated.

METHODS

A total of 30 patients with 30 fractures were included. With the exception of one primary fusion, all patients underwent open reduction with internal osteosynthesis. Clinical and radiological follow-up was performed at least 2 years postoperatively using AOFAS-Score, SF-12 and a radiological examination. The primary objectives were the clinical and radiologic outcomes as mid-term to long-term outcomes. The secondary objective was to compare these results with two existing computed tomography (CT) fracture classifications in terms of their association with the outcome.

RESULTS

The median follow-up was 7.8 years (range 2-16.2 years) postoperatively. One patient suffered an infection, four patients required secondary arthrodesis and eight patients had to change their occupation. The mean AOFAS-Score was 80.8/100 and the mean physical and mental SF-12 component summary scores were 47.1 and 55.7 points, respectively. Male sex and arthrodesis were associated with worse outcomes in both scores but not patient age or ipsilateral concomitant injuries. Both CT fracture classifications showed low predictive value.

CONCLUSION

The severity of the injury in the preoperative CT showed no connection with the clinical outcome in the AOFAS-Score and SF-12 scores. Posttraumatic osteoarthritis and secondary arthrodesis are associated with a poor outcome. In the course of the observational period the reduction results improved, which was accompanied by a better clinical outcome.

Are Process Changes Measurable? An Analysis of 4136 Proximal Femur Fractures over 16 Year

Prozessänderungen im perioperativen Setting werden selten analysiert, weil ihre Ergebnisse nicht unmittelbar fassbar sind und es einer hohen Fallzahl bedarf. Primäres Ziel war es, Prozessänderungen retrospektiv anhand proximaler Femurfrakturen (PF) zu evaluieren und deren Effekt mit verschiedenen Zielkriterien zu überprüfen. Sekundäres Ziel war die Definition möglicher Qualitätskriterien für die Versorgung von PF.Retrospektive Analyse der Datenbank eines Level-1-Traumazentrums zu PF. Eingeschlossen wurden alle osteosynthetisch und endoprothetisch versorgten PF im Behandlungszeitraum vom 01.01.2006 bis 31.12.2021. Der Zeitraum von 16 Jahren wurde für die Statistik trichotom aufgeteilt und die ersten 6 Jahre als Ausgangsbasis verwendet. Insgesamt 10 Prozessänderungen wurden in den folgenden 10 Jahren vorgenommen. Die Auswirkungen dieser Änderungen wurden anhand 1. der operativen Revisionsrate, 2. der Infektionsrate, 3. der perioperativen Transfusionsrate sowie 4. der 1-Jahres-Letalität überprüft.Insgesamt 4163 PF wurden analysiert. Hinsichtlich der Zielkriterien zeigten die Änderungen der ersten 5 Jahre (2012-2016; intramedulläres Verfahren für Osteosynthesen sowie Einwegabdeckung und Einwegkittel) den stärksten Effekt mit einer erstmaligen Senkung der operativen Revisionsrate unter 10% auf Dauer. Weitere Prozessoptimierungen der letzten 5 Jahre (2017-2021) erbrachten ebenfalls messbare Verbesserungen (Senkung der Infektions- und Transfusionsrate). Die 1-Jahres-Letalität blieb unverändert, auch während der COVID-19-Pandemie.Prozessänderungen bei PF führen nicht unmittelbar zu objektiv messbaren Verbesserungen. Rückblickend erscheint der Paradigmenwechsel von extra- auf intramedulläre Osteosynthese den höchsten Effekt erzielt zu haben, wenngleich über die letzten 10 Jahre eine schrittweise Besserung aller Zielkriterien eintrat - mit Ausnahme der Letalität. Als objektive Qualitätskontrolle sollte eine 1-Jahres-Revisionsrate unter 10% angestrebt sein.

Therapy aspects of peri-implant femoral fractures-a retrospective analysis of 64 patients

PURPOSE

The incidence of peri-implant femoral fractures (PIFF) is increasing. Information regarding outcomes, timing of surgery, risk factors, and a clinically applicable treatment algorithm are lacking. The aim of this study was to identify outcome-related risk factors and to derive a treatment algorithm.

METHODS

Sixty-four PIFFs treated between 01.01.2006 and 31.12.2020 in a level I trauma centre were evaluated retrospectively for fracture pattern, surgical technique, risk factors, complications, and 1-year mortality. The study was approved by the ethics committee (No. 21-2714-104).

RESULTS

One-year mortality was 24.1%. Surgical complications occurred in 4.7%, and general complications in 15.6% of the patients. General complications, low haemoglobin level at admission, elevated CHA2DS2-VASc, and Charlson score resulted in increased 1-year mortality. Time to surgery > 24 h did not increase complication or mortality rates. The three predominant fracture patterns were fractures close or distal to cephalomedullary nails, close or proximal to distal lateral plates, and close or distal to sliding hip screws. Recommendations for surgical treatment were derived: Osteosynthesis should enable as much weight-bearing as possible; the initial implant should only be removed, if this is essential for the new osteosynthesis; lateral locking plates should span the whole femur; antegrade nails should have a cephalomedullary component to avoid consecutive femoral neck fractures; implants should overlap to reduce the risk of consecutive inter-implant fractures.

CONCLUSION

Risk factors for 1-year mortality in patients with PIFFs were identified. A treatment algorithm and general principles for surgery of PIFFs were developed.

Surgery Within 24 Hours Reduces Mortality and General Complication Rates in Patients Who Have Periprosthetic Femoral Fractures at the Hip

BACKGROUND

In patients who have hip fractures, treatment within 24 hours reduces mortality and complication rates. A similar relationship can be assumed for patients who have hip periprosthetic femoral fractures (PPFs) owing to the similar baseline characteristics of the patient populations. This monocentric retrospective study aimed to compare the complication and mortality rates in patients who had hip PPF treated within and after 24 hours.

METHODS

In total, 350 consecutive patients who had hip PPF in a maximum-care arthroplasty and trauma center between 2006 and 2020 were retrospectively evaluated. The cases were divided into 2 groups using a time to surgery (TTS) of 24 hours as the cutoff value. The primary outcome variables were operative and general complications as well as mortalities within 1 year.

RESULTS

Overall, the mean TTS was 1.4 days, and the 1-year mortality was 14.6%. The TTS ≤ 24 hours (n = 166) and TTS > 24 hours (n = 184) groups were comparable in terms of baseline characteristics and comorbidities. Surgical complications were equally frequent in the 2 groups (16.3 versus 15.2%, P = .883). General complications occurred significantly more often in the late patient care group (11.4 versus 28.3%, P < .001). In addition, the 30-day mortality (0.6 versus 5.5%, P = .012), and 1-year mortality (8.3 versus 20.5%, P = .003) rates significantly increased in patients who had TTS > 24 hours. Cox regression analysis yielded a hazard ratio of 4.385 (P < .001) for the TTS > 24 hours group.

CONCLUSIONS

Prompt treatment is required for patients who have hip PPF to reduce mortality and overall complications.

Locking plate for periprosthetic femoral fractures according to Vancouver C: Outcome and radiological subanalysis of 40 patients

PURPOSE

Periprosthetic femoral fractures (PFF) according to type Vancouver C are less common and outcome is limited reported. Therefore, we conducted this retrospective single center study.

METHODS

We performed analysis of patients who underwent open reduction and internal fixation (ORIF) with locking plates for PPF occurring distally of a primary standard hip stem. Data on demographics, revisions, fracture patterns, and mortality were evaluated. At least two years after operation, we examined outcome using the Parker and Palmer mobility score. Primary aim of this study was revision, outcome and mortality. Secondary aim was evaluation of fracture subtypes within type Vancouver C fractures.

RESULTS

Between 2008 and 2020, 383 patients with periprosthetic femoral fracture after hip replacement were surgically treated according to our database. Among them, 40 patients (10.4%) with type Vancouver C fractures were enrolled for this study. The mean patient age was 81.5 years (59-94) at the time of fracture. Thirty-three patients were women, and 22 fractures were on the left side. Without exception, locking plates were used. The 1-year mortality rate for the sample was 27.5% (n = 11). Three revisions (7.5%) were performed for plate breakage. Rate of infection and non-union was zero. Three different fracture patterns were assessed: (1) transverse or oblique fractures below the tip of the stem (n = 9); (2) spiral-shaped fractures within the diaphysis (n = 19); and (3) burst fractures at the supracondylar region (n = 12). Demographic or outcome effects between fracture patterns were not found. On average of 4.2 years (2.0-10.4) after treatment, the mean reported Parker score was 5.5 (1-9).

CONCLUSION

ORIF with a single lateral locking plate is safe for type Vancouver C fractures with a well-fixed hip stem. Therefore, we do not recommend routinely revision arthroplasty or orthogonal double plating. Three subtypes of fractures within Vancouver C demonstrated no significant differences in baseline data and outcome.

[Treatment aspects of interprosthetic femur fractures-retrospective analysis of 70 patients]

BACKGROUND

Interprosthetic femur fractures (IFF) are rare injuries, whose surgical treatment is basically with osteosynthesis or revision arthroplasty. Various therapy algorithms have been proposed based on very small study collectives. Factors influencing the outcome are not known.

OBJECTIVES

The aim of the retrospective monocentric study is to derive a treatment algorithm based on a large number of cases and to identify factors influencing the outcome.

MATERIALS AND METHODS

Between 2006 and 2020, 70 IFF were identified. The surgical treatment comprised 38 osteosyntheses, 30 revision arthroplasties and 2 amputations. With classification and time to surgery, 69 perioperative variables were recorded. General and operative complications, as well as mortality, were determined in the follow-up period of 1 year.

RESULTS

ASA and Charlson score correlated with 1‑year-mortality. In addition, preoperatively increased CRP levels, reduced hemoglobin and the CHA2DS2-VASc score were identified as factors influencing mortality. Surgery within 24 h showed a trend towards fewer general complications. Transferred patients indicated an increased mortality. Based on classification according to Pires et al. or Füchtmeier et al. no clear treatment decision could be made. Relevant criteria for the surgical treatment were fracture localization, implant stability, bone vitality, anchoring possibility of the revision stem, as well as general condition of the patient.

CONCLUSIONS

The identified factors influencing the outcome correspond to those of patients with hip fractures. IFF should be treated timely. A treatment path was developed on the basis of the largest patient group to date.

How Relevant Is the Parallax Effect on Low Centered Pelvic Radiographs in Total Hip Arthroplasty

The correct cup position in total hip arthroplasty (THA) is usually assessed on anteroposterior low centered pelvic radiographs, harboring the risk of misinterpretation due to projection of a three-dimensional geometry on a two-dimensional plane. In the current study, we evaluate the effect of this parallax effect on the cup inclination and anteversion in THA. In the course of a prospective clinical trial, 116 standardized low centered pelvic radiographs, as routinely obtained after THA, were evaluated regarding the impact of central beam deviation on the cup inclination and anteversion angles. Measurements of the horizontal and vertical beam offset with two different methods of parallax correction were compared with each other. Furthermore, the effect of parallax correction on the accuracy ofmeasuring the cup position was investigated. The mean difference between the two parallax correction methods was 0.2° ± 0.1° (from 0° to 0.4°) for the cup inclination and 0.1° ± 0.1° (from -0.1° to 0.2°) for the anteversion. For a typically intended cup position of a 45° inclination and 15° anteversion, the parallax effect led to a mean error of -1.5° ± 0.3° for the inclination and 0.6° ± 1.0° for the anteversion. Central beam deviation resulted in a projected higher cup inclination up to 3.7°, and this effect was more prominent in cups with higher anteversion. In contrast, the projected inclination decreased due to the parallax effect up to 3.2°, especially in cups with high inclination. The parallax effect on routinely obtained low centered pelvic radiographs is low and not clinically relevant due to the compensating effect of simultaneous medial and caudal central beam deviation.

[Operative treatment of distal radial fractures under vitamin K antagonist or DOAC : Is preoperative interruption of these drugs necessary?]

BACKGROUND

Scientific data on emergency operations during ongoing treatment with vitamin K antagonists or with direct oral anticoagulants (DOAC) are lacking, because interruption or bridging of this treatment is routinely performed for up to several days. To reduce time delays and to simplify this procedure, we perform operations of distal radial fractures immediately and without interruption of antithrombotic medication.

MATERIAL AND METHODS

For this retrospective and monocentric study, we included only patients with distal radial fractures treated within 12 h after diagnosis with open reduction and volar plating and who received anticoagulation with a vitamin K antagonist or DOAC. Primary aim of the study was evaluation of specific complications, such as revision due to bleeding or hematoma formation and secondary aims were thromboembolic events or infections. The endpoint was 6 weeks after the operation.

RESULTS

Between 2011 and 2020, 907 consecutive patients with distal radial fractures were operatively treated. Of these, 55 patients met the inclusion criteria. The mean age was 81.5 Jahre (63-94 years) and women (n = 49) were primarily affected. All operations were performed without tourniquets. With a study endpoint 6 weeks after operation, no revisions were performed for bleeding, hematoma, or infection and primary wound healing was assessed for all patients. One revision was performed for fracture dislocation. Thromboembolic events were also not documented.

CONCLUSION

In this study the treatment of distal radial fractures within 12 h and without interruption of antithrombotic treatment was not associated with any imminent systemic complications. This applies to both vitamin K antagonists and DOAC; however, higher case numbers must confirm our results.

Alpha-particle emitting 213Bi-anti-EGFR immunoconjugates eradicate tumor cells independent of oxygenation

Hypoxia is a central problem in tumor treatment because hypoxic cells are less sensitive to chemo- and radiotherapy than normoxic cells. Radioresistance of hypoxic tumor cells is due to reduced sensitivity towards low Linear Energy Transfer (LET) radiation. High LET α-emitters are thought to eradicate tumor cells independent of cellular oxygenation. Therefore, the aim of this study was to demonstrate that cell-bound α-particle emitting ²¹³Bi immunoconjugates kill hypoxic and normoxic CAL33 tumor cells with identical efficiency. For that purpose CAL33 cells were incubated with ²¹³Bi-anti-EGFR-MAb or irradiated with photons with a nominal energy of 6 MeV both under hypoxic and normoxic conditions. Oxygenation of cells was checked via the hypoxia-associated marker HIF-1α. Survival of cells was analysed using the clonogenic assay. Cell viability was monitored with the WST colorimetric assay. Results were evaluated statistically using a t-test and a Generalized Linear Mixed Model (GLMM). Survival and viability of CAL33 cells decreased both after incubation with increasing ²¹³Bi-anti-EGFR-MAb activity concentrations (9.25 kBq/ml–1.48 MBq/ml) and irradiation with increasing doses of photons (0.5–12 Gy). Following photon irradiation survival and viability of normoxic cells were significantly lower than those of hypoxic cells at all doses analysed. In contrast, cell death induced by ²¹³Bi-anti-EGFR-MAb turned out to be independent of cellular oxygenation. These results demonstrate that α-particle emitting ²¹³Bi-immunoconjugates eradicate hypoxic tumor cells as effective as normoxic cells. Therefore, ²¹³Bi-radioimmunotherapy seems to be an appropriate strategy for treatment of hypoxic tumors.