Incision Lines on the Female Breast

Surgical procedure and retrospective comparative series of Microport's AnteriorPath® vs. AMIS® in total hip arthroplasty. Preliminary findings from a single institution

Objective

In recent years, the paradigm of surgical approaches for total hip arthroplasty (THA) has evolved, with portal-assisted techniques emerging as a promising avenue for increasing precision and minimizing invasiveness. The purpose of this study was to compare early experience with the Microport anterior percutaneously assisted total hip arthroplasty (MAP) system, with the established AMIS direct anterior approach (DAA).

Material and Methods

A retrospective chart analysis was performed on 200 consecutive patients who underwent DAA or MAP at our institution in 2022. The research was conducted in accordance with the Declaration of Helsinki (as revised in 2013), and was approved by the institutional review board of the University Duisburg-Essen (23-11274-BO).

Results

Two hundred patients were enrolled (100 DAA and 100 MAP; time to follow-up 1.7 years ±88 days). The mean operative time was 81 minutes (MAP) and 67 minutes (DAA, p>0.05). The mean cup tilt angle was 39° (MAP) and 40° (DAA; p>0.05). The mean cup anteversion angle was 13° (MAP) and 16° (DAA; p>0.05). The mean postoperative hemoglobin (Hb) decrease was 2.6 mg/dL ±0.9 mg/dL (MAP) and 2.5 mg/dL ±0.9 mg/dL (DAA; p>0.05). No major complications were documented in any of the 200 cases during the observation period. Additional screw fixation was performed in 7 cases and hybrid stem cementation was performed in 3 cases due to lack of rotational stability. All 10 cases were in patients with DAA. In only one of the 200 cases, two units of RBC were transfused postoperatively in a DAA case after a postoperative decrease of 5.7 mg/dL Hb.

Conclusion

Anterior Path® has been demonstrated to provide reliable results, despite the presence of a steep learning curve. The employment of a working cannula has been shown to enhance the surgeon's perspective during the preparation of the acetabulum. In relation to skin incision, the bikini line incision, which is regarded as advantageous due to its alignment with the cleavage lines, has been identified as a notable benefit that is acknowledged by the patient.

Dynamic characteristics of skin reaction force in different body postures

Mechanical stress influences scarring of a surgical wound. Several lines have been proposed for the best excision direction. It is unknown if these lines still apply when the body posture changes. The objective is to measure the skin reaction force in four directions and determine the direction of least force. Secondary objective is to determine if the reaction force varies in a different body posture. Skin reaction force was measured with the compressiometer in 30 participants on four different locations (forearm/upper arm/shoulder blade/lower back) in four directions (0°-45°-90°-135°) and two body postures. The direction of least skin reaction force changed with a different body posture and was significant for the forearm (p < 0.01) and shoulder blade (p = 0.05) The skin reaction force in all four direction changed significantly in a different body posture, except the 45° line in the upper arm and shoulder blade. Our results demonstrate that the skin reaction force in four directions in four locations varies with change in body posture. Focus should therefore not only lay on choosing the right direction, but also on managing skin tension postoperatively.

The Compressiometer: Toward a New Skin Tensiometer for Research and Surgical Planning

After surgery, around 35% of patients experience problems of excessive scarring, causing disfiguring and impaired function. An incision placed in the wrong direction causes unnecessary skin tension on the wound, resulting in increased collagen disposition and potentially hypertrophic scars. Currently, skin tension lines are used for incision planning. However, these lines are not universal and are a static representation of the skin tension that is in fact under influence of muscle action. By designing a new skin force measurement device the authors intend to make research on dynamic skin characteristics possible and to objectify incision planning and excision closure planning. The device applies a known compressive force to the skin in standardized directions and measures the displacement of the skin. This allows users to measure the skin reaction force in response to compression and to determine the optimal incision line or best wound closure direction. The device has an accuracy of 96% and a sensitivity of < 0.01 mm. It is compact, works non-invasively and standardizes measurement directions and is therefore an improvement over previously designed skin tensiometers.