A quantitative analysis of microcirculation during healing of split-thickness skin grafts in standardized full-thickness wounds.

BACKGROUND: Full-thickness skin defects often are managed with split-thickness skin grafting. The wound healing process, including formation of new vessels during the healing of skin grafts, is complex. OBJECTIVE: To evaluate the microcirculatory changes in the treated tissue after skin grafting to analyze perfusion dynamics during the wound healing process. MATERIALS AND METHODS: Fourteen full-thickness skin defects were created on the back of 14 adult male Lewis rats. All wounds were treated with autologous split-thickness skin grafts. The perfusion dynamics were assessed for 84 days with an O2C device that combines a laser light to determine blood flow and white light to determine postcapillary SO2 and the rHb. RESULTS: Blood flow increased for 50 days after grafting. SO2 decreased in superficial skin layers (depth of 2 mm) and increased in deep skin layers (depth of 8 mm) during the entire observation period. The rHb increased until day 10 in superficial layers and until day 20 in deep tissue layers. CONCLUSION: The microcirculatory changes reflect the different phases of wound healing. Long after the skin transplants were macroscopically healed, alterations in microcirculation were still detected. These alterations were caused by the long-lasting changes in tissue metabolism due to the formation, conversion, and degradation of the dermal matrix and vessels during wound healing and scar formation.

[Rhizarthrosis: Resection Arthroplasty versus Resection Suspension Arthroplasty - Still the Gold Standard?] / Rhizarthrose: Resektionsarthroplastik versus Resektionssuspensionsarthroplastik ­ immer noch der Goldstandard?

Rhizarthrosis is one of the most common arthritic changes in the hand, which has led to the development of a large number of surgical methods in recent years. In addition to the traditional resection arthroplasty with tendon suspension or interposition, if needed, thumb saddle joint prostheses are being used more and more frequently. However, these are not an option for all patients such as those with severe osteoporosis, severe nickel allergy, insufficient height of the trapezium or STT osteoarthritis. This study examined whether the traditional surgical methods continue to have their "right to exist" or whether they will be replaced by prostheses. In a retrospective study with prospective data collection, 48 hands of 45 patients diagnosed with rhizarthrosis in stages II and III according to Eaton and Littler were clinically examined 2.5 years after resection arthroplasty/resection-suspension-interposition arthroplasty using flexor carpi radialis (FCR) or abductor pollicis longus (APL) tendon strips in the years 2015-2018. The postoperative outcome was assessed using mobility, grip strength, two-point discrimination, postoperative satisfaction with regard to pain and resilience, as well as the DASH and MHQ questionnaires. There were no significant differences in surgery duration, inability to work, time to full weight-bearing, pain, satisfaction, grip strength and mobility. Regardless of the surgical method used, patients achieved an almost free range of motion in the thumb and wrist as well as age-appropriate hand strength. Pain at rest was rare; 48% were pain-free during exercise. The DASH questionnaire scored 20.2, 13.9 and 22.1 points and the MHQ scored 76.3, 79.3 and 79.4 points. Hence, the traditional surgical techniques showed good postoperative results with high patient satisfaction. "Newer procedures" such as endoprosthesis offer promising results in terms of faster regeneration times. However, this is offset by a longer surgery time and higher material costs, which means that resection arthroplasty represents a long-established procedure with a low potential for complications and a lower revision rate and should continue to be used, especially if there are relative contraindications to an endoprosthesis.