Hypesthesia after anterolateral versus midline skin incision in TKA: a randomized study

Area of Science:

• Orthopedic Surgery
• Knee Arthroplasty
• Surgical Incisions

Background:

• The standard midline incision for total knee arthroplasty (TKA) offers good exposure but can lead to nerve damage, causing lateral skin numbness and neuromas.
• Sectioning the infrapatellar branch of the saphenous nerve is a common complication of the midline TKA incision.

Purpose of the Study:

• To evaluate if an anterolateral skin incision in TKA reduces the area of skin hypesthesia and postoperative discomfort compared to a midline incision.
• Assessing the impact of different TKA incision types on sensory disturbances and patient outcomes.

Main Methods:

• A randomized study involving 69 knees undergoing TKA, comparing midline and anterolateral skin incisions.
• Skin sensitivity was measured using Semmes-Weinstein monofilaments at 13 points, with hypesthesia area quantified by software.
• Patient-reported outcomes included the Knee Injury and Osteoarthritis Outcome Score (KOOS) and WOMAC score, alongside knee range of motion (ROM).

Main Results:

• The anterolateral incision group showed significantly smaller areas of hypesthesia at 6 weeks, 6 months, and 1 year post-surgery compared to the midline group.
• At 1 year, the anterolateral incision resulted in 7 cm² of hypesthesia versus 19 cm² for the midline incision.
• No significant differences in knee ROM, KOOS, or WOMAC scores were observed between the groups, though reduced hypesthesia correlated with better scores.

Conclusions:

• The anterolateral incision in TKA is associated with reduced sensory disturbances, specifically lateral cutaneous hypesthesia.
• This approach appears to be a safe and effective alternative to the traditional midline incision for TKA.
• Minimizing nerve disruption through incision choice can improve patient comfort without compromising functional outcomes.