No abstract

The comparison of bilateral dynamic X-rays in passive anterior and posterior drawer with a load of 9 kg, and the arthrometer KT 1000 measurements obtained from 100 patients before anterior cruciate ligament reconstruction, confirms the good diagnostic efficiency of the following methods: (1) radiological measurement of the anterior translation of the medial compartment, as an absolute value and especially as a differential value in relation to the opposite, uninjured knee, the normal value limits being respectively 5 and 2 mm; and (2) arthrometric measurement of the maximal manual translation, also as absolute and differential values, the normal value limits being 10 and 2 mm respectively. These two measurements have a predictive value of 90%. No numerical equivalency exists between the radiological and arthrometric values, but their variations in relation to each other are statistically correlated. The arthrometer, simple to use and totally innocuous, is an excellent test device for consultation, while dynamic X-rays allow separate studies of each compartment to look for lesions of the posteromedial or posterolateral corners.

Sixty patients were operated on for primary gonarthrosis by means of a cemented, posterior cruciate preserving total knee and were randomly allocated to postoperative drainage or nondrainage. The primary criterion was duration of hospital stay. Secondary criteria included serial evaluation of knee pain, knee flexion, knee circumference, calculated blood loss after 7 days, complications, reoperations, and the need for blood transfusions. There was no difference between the two groups in any of the criteria during the entire follow-up. There was a nonsignificant trend to a decreased calculated blood loss in the nondrained group and significantly less transfused blood units in the nondrained group. Lack of drainage does not increase complication risk after total knee prosthesis implantation. We therefore recommend using no routine drainage after this procedure.

Level IV. Prospective study.

III.

One hundred patients were operated on by the Maquet procedure for chondromalacia patellae. All of them were first re-examined after a mean follow-up of 4 years, and 65 of them re-examined after a mean follow-up of 11 years (range, 8-15 years). The pain score improved significantly after the operation and remained unchanged with longer follow-up. The success rate was only 62% at both follow-ups. Outerbridge grade IV chondral lesions at the time of surgery were associated with a significant improvement of the pain score at the 4-year follow-up and a success rate of 69%. The Maquet procedure should only be proposed for chronic retropatellar pain with grade IV chondral lesions, after conservative treatment has proven unsuccessful, as the expected failure rate is about 30%.

III.

The author developed a non-image-guided navigation system for unicompartmental knee replacement that can be used with conventional surgery or minimally invasive surgery. The author performed a radiological analysis of the accuracy of implantation for unicompartmental knee replacement with conventional surgery, navigated minimally invasive surgery, and conventional navigated surgery. A significant increase in the rate of prostheses implanted in the desired angular range for all criteria in conventional navigated minimally invasive surgery and conventional navigated surgery was found. The conventional navigated technique was significantly more accurate than minimally invasive surgery.