Purpose of the study: The tibial slope is an important parameter for knee surgery. Tibial slope designates the inclination of the tibial plateaus in the sagittal plane. The presence of a tibial slope and its value is intimately related to the condylotrochleal profile. The importance of tibial slope in knee disease and knee surgery is now universally recognised.

Material and method: We reviewed 140 cases of anterior cruciate ligament (ACL) ligamentoplasty performed at the institute; 25 failures were identified. After analysis of the position of the tunnels, particularly the femoral tunnels, the most documented cause of failure, as well as other factors of failure, we measured the mean tibial slope in all operated patients.

Results: Subjective Lachmann and the IKDC and ARPEGE scores associated with the dynamic study (TELOS) helped understand why knees can become unstable despite good surgical technique.

Discussion: William and Lissner established a mathematical relations between tibial slope and stress forces applied to the ACL. Dejour and Bonnin demonstrated the effect of the tibial slope on anterior subluxation and single leg stance. The tibial slope should thus be considered for all knee procedures. Bonnin demonstrated that an excessive slope can be a factor of plasty failure.

Purpose of the study: This work examined the clinical, radiological, and videoarthroscopic features of partial tears of the anterior cruciate ligament (ACL) and analysed results of ligament plasties.

Material and method: Mean age was 32 years. Patients complained of instability accidents in 70% of cases. The Lachman test was noted soft endpoint to + or ++ in 90%. A palpable click was found in 60% but was considered severe in two cases only. Telos laxity was moderate (about 5 mm) in 80%. Mean time to surgery was relatively short (9 months). Arthroscopic exploration revealed rupture of the anteromedial head of the ACL with preservation of the posterolateral component. There was a meniscal injury in nine knees. Early in our experience we performed a total plasty for nine patients (six using hamstring tendons and three with the patellar tendon). At the present time, we spare the posterolateral head and make a partial plasty of the anteromedial head (11 knees: 3 harvesting a single tendon [gracilis] and eight using the gracilis and the semitendious) associated with lateral reinforcement in five.

Results: Mean follow-up was 30 months; 30% of patients had knee pain. Three knees exhibited a soft endpoint (+) all after a total plasty. There were no cases of quadriceps motion deficit or amyotrophy.

Discussion: The existence of partial tears of the ACL were confirmed in this series. This type of tear corresponds to an objective condition seen arthroscopically and also to precise clinical presentations and biological findings: minor signs of instability with moderate objective anterior instability to the order of 5 mm.

Conclusion: Considering this work and a review of the literature, the diagnosis of partial tears of the ACL could be established from the physical examination and measurements of anterior knee laxity. Reconstruction of a single head provides better results than complete reconstruction which would sacrifice an intact portion of the ACL.