TKA Incisions should avoid Choke zone to minimize risk of postoperative skin ischemia: study

Xinhua Yang et al conducted a study to investigate the anatomical characteristics of the lateral skin region in valgus knee arthroplasty incisions, specifically the size and distribution of the lateral perforator Choke zone, in order to guide incision placement during knee arthroplasty and reduce the risk of compromised skin perfusion. The article has been published in ‘Indian journal of orthopaedics’.

The authors followed 70 patients undergoing valgus knee arthroplasty with iliotibial band (ITB) release, to record the incidence of lateral skin perfusion impairment, including a detailed report of a typical case of lateral skin necrosis. Additionally, 10 knees from 5 adult cadavers were perfused via the femoral artery using red latex-lead oxide. The lateral superior genicular artery (LSGA) perforators, Choke zone, and surrounding skin and soft tissue perfusion were anatomically dissected, observed, and measured.

The key findings of the study were:

• Postoperatively, 10 patients (14.3%) showed lateral knee skin swelling with perfusion impairment.

• The distance from the center of the perfusion-compromised area to the joint line was 1.9 ± 0.6 cm, and the area of perfusion deficit was 15.0 ± 6.6 cm2; all cases healed with conservative treatment.

• One patient developed lateral skin necrosis, which was successfully treated with debridement and flap reconstruction.

• Cadaveric dissection revealed an average of 2.20 ± 0.75 LSGA perforators per knee.

• The origin of the perforators was 4.61 ± 1.16 cm from the joint line, with a diameter of 2.06 ± 0.35 mm, and the exit point located 4.24 ± 1.36 cm from the joint line. The perforator length averaged 7.36 ± 2.42 cm. Distal skin perfusion extended 2.45 ± 1.78 cm beyond the joint line, while proximal perfusion reached 13.56 ± 4.72 cm.

• The center of the Choke zone was 2.00 ± 1.12 cm from the joint line, with an area of 10.00 ± 3.51 cm2.

The authors concluded – “This study demonstrates that in patients with valgus knee deformity undergoing TKA combined with ITB release, the occurrence of lateral knee skin perfusion impairment and necrosis is closely associated with the distribution of perforating branches of the SLGA and ILGA. Clinical observations revealed that perfusion deficits were predominantly concentrated near the lateral femoral condyle, with the central location closely coinciding with the anatomical Choke zone identified in our cadaveric study. Anatomical analysis further confirmed that the number of SLGA perforators is limited and may exhibit developmental insufficiency in valgus knees, while the Choke zone demonstrates relatively weak perfusion, representing a high-risk area for skin necrosis.

Recommentations by the authors: “Based on these findings, during TKA with ITB release and lateral incision planning, surgeons should avoid making incisions along the joint line and should carefully preserve the Choke zone and the main perforator pathways to minimize the risk of postoperative skin ischemia and necrosis. For severe valgus deformities exceeding 30°, overcorrection should be avoided; osteotomy may be performed first, followed by staged TKA. Moreover, high-risk patient populations, such as elderly individuals or those with rheumatoid arthritis, require thorough preoperative assessment and rigorous postoperative monitoring to optimize wound healing, joint function recovery, and overall patient quality of life.”

For further details on the article refer to:

Microscopic Anatomical Study of the Choke Zone in Valgus Knee Arthroplasty Incisions and its Clinical Implications Xinhua Yang et al Indian Journal of Orthopaedics (2026) 60:1347–1354 https://doi.org/10.1007/s43465-025-01652-7