Direct comparison of postoperative monitoring of free flaps with microdialysis, implantable cook-swartz Doppler probe, and clinical monitoring in 20 consecutive patients.

BACKGROUND: There is an increasing demand for successful free tissue transfer, with postoperative monitoring of flaps a key to early salvage. Monitoring methods have ranged from clinical techniques to invasive options, of which two are particularly applicable to buried flaps (Cook-Swartz Doppler probe and microdialysis). The evidence for these options has been represented largely in separate cohort studies, with no single study comparing these three techniques. We aim to perform this comparison in a single cohort of patients. METHODS: A prospective, consecutive cohort study comparing clinical monitoring, microdialysis and the implantable Doppler probe was undertaken. In 20 patients receiving 22 flaps, 21 flaps were monitored with microdialysis, 18 flaps with clinical observation, and 21 flaps with the Cook-Swartz Implantable Doppler probe. Exclusion was based on applicability and availability intra-operatively. Efficacy was assessed through sensitivity, specificity, positive, and negative predictive values. RESULTS: Nineteen of 22 flaps had no suspected anastomotic problems; 3 of 22 flaps were explored for anastomotic problems, with two salvaged and one lost. The implantable Doppler and microdialysis were found to detect flap statistically earlier than clinical assessment, with microdialysis better at detecting flap compromise: 100% specificity (confidence interval 31-100%) when compared to the implantable probe and clinical assessment (67%: 13-98% and 33%: 2-87%, respectively). CONCLUSIONS: Each of the Cook-Swartz Doppler probe, microdialysis and clinical assessment was found suitable for monitoring in free tissue transfer. The implantable Doppler and microdialysis offer the potential for earlier detection of flap compromise.

Electrical impedance detects early stages of bone healing: An in vivo explanatory study of tibial fractures in rabbits.

Purpose: Healing after bone fracture is assessed by clinical examination and frequent radiographs, which expose patients to radiation and lack standardisation. This study aimed to explore electrical impedance patterns during bone healing using electrical impedance spectroscopy in 18 rabbits subjected to tibial fracture stabilised with an external fixator. Methods: Impedance was measured daily across the fracture site at a frequency range of 5 Hz to 1 MHz. Biweekly radiographs were analysed using modified anterior-posterior (AP) radiographic union score of the tibia (RUST). The animals were divided into three groups with different follow-up times: 1, 3 and 6 weeks for micro-computer tomography and mechanical testing. Results: A decreasing trend in impedance was observed over time for all rabbits at lower frequencies. Impedance closest to 5 Hz showed a statistically significant decrease over time, with greatest decrease occurring during the first 7 postoperative days. At 5 Hz, a statistically significant correlation was found between impedance and the modified AP RUST score and between impedance and bone volume fraction. Conclusions: This study showed that the electrical impedance can be measured in vivo at a distance from the fracture site with a consistent change in impedance over time and revealed significant correlation between increasing radiographic union score and decreasing impedance. Level of Evidence: Not applicable.

Do Surgeons Agree on Severity and Origin of Complications in Bone-lengthening Nails? An Inter- and Intra-rater Reliability Study.

Background: Bone-lengthening nails result in various complications with different severity and origin. However, no universal reporting system for complications has been agreed upon, making it difficult to compare different nail designs and patient populations. This study aimed to assess the inter- and intra-rater agreement of a classification system of complications according to severity and origin. Materials and methods: Four orthopaedic surgeons assessed 48 complications retrieved from patient charts in a single-centre cohort and 49 literature complications cases. Complications were classified according to severity grading (I, II, IIIA and IIIB) from Black et al. and origin with eight main types and 33 subtypes. A blinded independent assessment was performed twice at least six weeks apart. Cohen/Congers kappa estimated for the inter- and intra-rater agreement was interpreted after Svanholm et al. Results: The surgeons had a good inter-rater agreement for complication severity with a kappa value of 0.68 [95% confidence interval (CI): 0.56-0.79] and complication origin with a kappa value of 0.63 (CI: 0.53-0.73), respectively, on the cohort cases. In literature cases, a good agreement on complication severity and origin grading was shown by kappa values of 0.64 (CI: 0.53-0.75) and 0.74 (CI: 0.65-0.83). The intra-rater assessment of complication severity and origin grading had good to excellent agreement with kappa values ranging from 0.51 to 0.97. Conclusion and clinical significance: The study presents the first structured complication classification on severity and origin in intramedullary bone-lengthening nails. A good reproducibility agreement in both severity and origin was found between four orthopaedic surgeons for both cohort and literature complication cases. For clinical and research purposes, a shared language for communicating complications is essential. We encourage future studies to use a structured and validated complication classification. How to cite this article: Frost MW, Rahbek O, Fridberg M, et al. Do Surgeons Agree on Severity and Origin of Complications in Bone-lengthening Nails? An Inter- and Intra-rater Reliability Study. Strategies Trauma Limb Reconstr 2022;17(3):153-158.

Radiographs of 366 removed limb-lengthening nails reveal differences in bone abnormalities between different nail types.

AIMS: Limb-lengthening nails have largely replaced external fixation in limb-lengthening and reconstructive surgery. However, the adverse events and high prevalence of radiological changes recently noted with the STRYDE lengthening nail have raised concerns about the use of internal lengthening nails. The aim of this study was to compare the prevalence of radiological bone abnormalities between STRYDE, PRECICE, and FITBONE nails prior to nail removal. METHODS: This was a retrospective case series from three centres. Patients were included if they had either of the three limb-lengthening nails (STYDE, PRECICE, or FITBONE) removed. Standard orthogonal radiographs immediately prior to nail removal were examined for bone abnormalities at the junction of the telescoping nail parts. RESULTS: In total, 306 patients (168 male, 138 female) had 366 limb-lengthening nails removed. The mean time from nail insertion to radiological evaluation was 434 days (36 to 3,015). Overall, 77% of STRYDE nails (20/26) had bone abnormalities at the interface compared with only 2% of FITBONE (4/242) and 1% of PRECICE nails (1/98; p < 0.001). Focal osteolysis in conjunction with periosteal reaction at the telescoping interface was only observed in STRYDE nails. CONCLUSION: Bone abnormalities at the interface of telescoping nail parts were seen in the majority of STRYDE nails, but only very rarely with FITBONE or PRECICE nails. We conclude that the low prevalence of radiological changes at the junctional interface of 242 FITBONE and 98 PRECICE nails at the time of nail removal does not warrant clinical concerns. Cite this article: Bone Joint J 2021;103-B(11):1731-1735.

Primary cutaneous myoepithelial carcinoma: a case report and review of the literature.

This study describes a case of primary myoepithelial carcinoma of the skin and reviews the available literature on this topic. Myoepitheliomas and carcinomas arise most frequently from myoepithelial cells within the salivary glands but are found in many anatomical locations. We documented a case of an 80-year-old man with a 2 × 2 × 1 cm tumour located on the scalp. This tumour emerged over a period of 2 months. The tumour was radically excised, and histological examination revealed a cutaneous myoepithelial carcinoma. At an 18-month follow-up, no recurrence of the tumour was found. A systematic literature search identified 23 papers that reported 58 cases of cutaneous myoepitheliomas and myoepithelial carcinomas. All cases are reviewed in the presented paper. This case report and literature review serves to increase awareness regarding myoepithelial carcinomas. These tumours exhibit high metastatic potential, and it is thus very important to perform radical surgery.

Turbulence downstream of subcoronary stentless and stented aortic valves.

Regions of turbulence downstream of bioprosthetic heart valves may cause damage to blood components, vessel wall as well as to aortic valve leaflets. Stentless aortic heart valves are known to posses several hemodynamic benefits such as larger effective orifice areas, lower aortic transvalvular pressure difference and faster left ventricular mass regression compared with their stented counterpart. Whether this is reflected by diminished turbulence formation, remains to be shown. We implanted either stented pericardial valve prostheses (Mitroflow), stentless valve prostheses (Solo or Toronto SPV) in pigs or they preserved their native valves. Following surgery, blood velocity was measured in the cross sectional area downstream of the valves using 10MHz ultrasonic probes connected to a dedicated pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at two different blood pressures (baseline and 50% increase). We found no difference in maximum RNS measurements between any of the investigated valve groups. The native valve had significantly lower mean RNS values than the Mitroflow (p=0.004), Toronto SPV (p=0.008) and Solo valve (p=0.02). There were no statistically significant differences between the artificial valve groups (p=0.3). The mean RNS was significantly larger when increasing blood pressure (p=0.0006). We, thus, found no advantages for the stentless aortic valves compared with stented prosthesis in terms of lower maximum or mean RNS values. Native valves have a significantly lower mean RNS value than all investigated bioprostheses.

Aortic root distensibility and cross-sectional areas in stented and subcoronary stentless bioprostheses in pigs.

A flexible aortic root is essential for natural leaflet stress distribution. It is suggested that stentless bioprosthetic valves retain the flexibility of native valves. We investigated aortic root distensibility and cross-sectional area (CSA) in stentless (Solo, n=4; Toronto SPV, n=7), stented (Mitroflow, n=8) and in native valves (n=8) in pigs. Magnetic resonance imaging was performed to assess aortic root areas. At the annular level the Solo valve had a larger CSA (2.83+/-0.26 cm(2)) than both the Mitroflow (2.24+/-0.23 cm(2)) and Toronto SPV (1.87+/-0.59 cm(2)) (P=0.003; P=0.01). At the sino-tubular junction the Mitroflow valve had a significantly larger CSA (2.96+/-0.80 cm(2)) than the Toronto SPV (2.05+/-0.47 cm(2); P=0.02). At the annular level the percentage change in area between end-diastole and end-systole was lower for the Mitroflow than for all the other valves (P=0.006). No difference was found between native and stentless valves. In conclusion, the Solo valve had a larger CSA at the annulus than both the Mitroflow and the Toronto SPV. However, the stentless valves had a smaller CSA at the sino-tubular junction than the Mitroflow. We, furthermore, found that implantation of stentless heart valves preserves aortic root distensibility at the annular level in pigs.