Ectropion and entropion are medical terms, commonly known as entropion is O-shaped leg, rotundity, and ectropion is X-shaped leg, which is a relatively common lower limb deformity. To understand the deformity, we must first know what it is like when it is normal. The normal human lower limb is not completely straight, but the thigh and calf into an angle, about 5-7 degrees outward angle – that is, ectropion, when because of congenital developmental deformity or arthritis and other diseases, the angle deviates from the normal value, it produces ectropion and inversion deformity. If the angle is greater than this, the deformity is ectropion. There is a simple way to test yourself, which is that when the knees come together on the inside, the two feet cannot come together; the opposite is the case of inversion, when the feet come together on the inside, the knees cannot come together on the inside. Ectropion or valgus deformity can be due to internal or external causes of the knee joint, and there are different treatments for different causes.
Valgus Knee, commonly known as X-leg, has a variety of causes, most of which are due to congenital dysplasia. In contrast to valgus knee, if the patient’s medical history is followed carefully, most patients with valgus knee did not have valgus when they were younger, but had valgus deformity in old age when they developed osteoarthrosis, mostly due to wear and tear. In contrast, most patients with valgus knee have valgus in their youth or even adolescence, which is a developmental cause, and wear and tear can gradually worsen with age, and is more common in women. Some of the causes are poor healing of the femoral epicondyle fracture due to trauma, increased lateral wear due to lateral meniscectomy after years of lateral meniscus injury, and overcorrection due to previous osteotomy for valgus deformity.
The percentage of knee replacements for valgus deformity is approximately 10% of patients undergoing knee arthroplasty, and this 10% is one of the more difficult knee deformities to manage in an initial replacement. In particular, moderate and severe valgus deformities with a valgus angle of more than 15° are more difficult to operate on than internal knee deformities, and the postoperative results are often inferior to those of patients with internal knee deformities. The main reasons for this are: 1. The medial collateral ligament is often elongated or lax due to valgus, and the conventional medial approach tends to aggravate the laxity of the medial structures, and it is more difficult to loosen the lateral structures with the medial approach; 2. In the medial approach, poor joint capsule suture and soft tissue coverage after prosthesis installation can easily lead to lateral tension and blood supply distress; 4.
Therefore, there is still no uniform approach and procedure for the surgical approach, osteotomy, soft tissue release and prosthesis selection, and the surgical technique is very demanding.