Purpose The knee stiffness acquired following an Anterior Cruciate Ligament (ACL) injury might affect clinical knee tests, i.e., the pivot-shift maneuver. In contrast, the motor effects of spinal anesthesia could favor the identification of rotatory knee deficiencies prior to ACL reconstruction. Hence, we hypothesized that the intra-operative pivot-shift maneuver under spinal anesthesia generates more acceleration in the lateral tibial plateau of patients with an injured ACL than without. Methods Seventy patients with unilateral and acute ACL rupture (62 men and 8 women, IKDC of 55.1 ± 13.8 pts) were assessed using the pivot-shift maneuver before and after receiving spinal anesthesia. A triaxial accelerometer was attached to the skin between Gerdys’ tubercle and the anterior tuberosity to measure the subluxation and reduction phases. Mixed ANOVA and multiple comparisons were performed considering the anesthesia and leg as factors (alpha = 5%). Results We found a higher acceleration in the injured leg measured under anesthesia compared to without anesthesia (5.12 ± 1.56 m.s− 2 vs. 2.73 ± 1.19 m.s− 2, p < 0.001), and compared to the non-injured leg (5.12 ± 1.56 m.s− 2 vs. 3.45 ± 1.35 m.s− 2, p < 0.001). There was a presence of significant interaction between leg and anesthesia conditions (p < 0.001). Conclusions The pivot-shift maneuver performed under anesthesia identifies better rotatory instability than without anesthesia because testing the pivot-shift without anesthesia underestimates the rotatory subluxation of the knee by an increased knee stiffness. Thus, testing under anesthesia provides a unique opportunity to determine the rotational instability prior to ACL reconstruction.

The main goal in anterior cruciate ligament reconstruction (ACLR) should be to restore normal knee biomechanics so the chances of failure decrease. The persistence of knee instability after ACLR goes from 0.7% to 20%. Several factors have been identified and studied, but there are some selected cases in which it seems that without adding lateral extra-articular tenodesis (LET) it is not possible to control rotational instability. Data exist supporting that LET could reduce pivot shift (PS), without losing flexion/extension range of motion nor adding risk of osteoarthritis. Recently, LET has been used in addition to ACLR to add restriction to internal tibial rotation forces, and different authors have shown their techniques to achieve this task. Also, biomechanical studies have compared different techniques for LET procedures. This article aims to describe our technique performing a modified Macintosh LET as an addition to ACLR in selected patients who require extra internal tibial rotation control. This is a reproducible, easy to learn, and inexpensive procedure in terms that only a high resistance suture is needed and not any other implant, such as a stapler, anchors, or screws, reducing the risk of tunnel coalition.

Introduction. Traditional techniques can enlarge the medial tibiofemoral joint space width (JSW) for meniscal repairs, but a remnant ligament laxity may be developed. Alternatively, the debridement of the inner retinaculum layer may result in a balanced JSW without causing extra-ligament damage (retinaculum layers II and collateral ligament). Purpose. The purpose of this study was to determine whether a concentric arthroscopic debridement of the inner retinaculum layer increases the tibiofemoral JSW in patients with meniscal injuries. Secondarily, we determine whether the increase in JSW is symmetrical between compartments and describe the rate of complications and patient satisfaction. Method. Twenty middle-aged (15 male and five female) patients diagnosed with acute meniscal injury aged 36 ± 12 years were enrolled. The patients were submitted to an arthroscopic debridement of the inner layer of the knee retinaculum for both the medial and lateral compartments. The tibiofemoral JSW was measured intra-articularly using a custom instrument. A two-way ANOVA for repeated measures was used to compare the JSW. A Bland–Altman analysis and test-retest analysis were performed. Results. The JSW increased following the debridement of the inner retinaculum layer, for both the medial and lateral compartments p < 0.001 . No complications were identified, and the patients were satisfied with the intervention. The minimal detectable change and bias of the custom instrument were 0.06 mm and 0.02 mm, respectively. Conclusion. The debridement allows a clinically important (>1 mm) symmetric tibiofemoral JSW enlargement. The technique suggests favoring the diagnosis of meniscus injuries and manipulating arthroscopic instruments without secondary complications after one year.