There are a few papers in the literature to indicate the likely functional outcome of conservatively managed sportsmen in whom primary outcome cruciate ligament [ACL] healing occurs. We reviewed 298 sportsmen presenting with isolated ACL rupture that were conservatively managed with a rehabilitation programme, based on regaining proprioceptive and hamstring control, and aimed at achieving primary ACL healing. All were protected in a hinged brace. In 50 patients, the ACL was determined as having healed clinically; these patients underwent instrumented laximetry testing with KT 1000 arthrometry and were determined: IKDC A [Normal] or IKDC B [nearly normal]. An MRI was also performed which confirmed healing in 39 patients with ACL fibres parallel to Blumenstat's line. In 11 patients the ACL stump had healed to the PCL. The 50 patients were followed up for an average 16 months [range, 14 to 17 months]. 56% of patients suffered recurrent instability when they returned to their preinjury level of contact or pivoting sport. For competitive athletes, 76.5% suffered further instability on return to sport despite the four-month rehabilitation and independent arthrometry score or MRI findings. However, for occasional, recreational athletes only 7% suffered recurrent instability. This study suggests that a rehabilitation programme aimed at primary ACL healing affords satisfactory results for the occasional, recreational athlete but does not achieve the quality of restraint sufficient for contact or pivoting sports in competitive athletes. These patients suffer high levels of recurrent instability and are exposed to the risk of secondary chondral and meniscal injury.
On the tibia, the centre of the AM attachment was located 18 mm anterior to the Retro-eminence ridge (RER). The centre of the PL bundle lay 8.4 mm posterior to the centre of the AM bundle. These positions were at 35% and 52% along Amis and Jacob’s line
Cadaveric experiments using knee testing machines have suggested that anatomical ACL reconstruction, replacing both antero-medial (AM) and postero-lateral (PL) bundles, restores knee rotation kinematics more effectively than does a single-bundle. The aim of this study was to measure intra-operatively the control of the translation and coupled rotations that occur with standard clinical laxity tests (anterior drawer, Lachman and pivot shift). The knee kinematics of 10 patients were measured using a surgical navigation system and described in terms of tibial axial rotation and antero-posterior translation. In the ACL deficient knee, the average maximum tibial rotation during the pivot shift test was 29.0° and the mean maximum translation 17.0 mm. Reconstruction of the AM bundle (which behaves in a biomechanically similar way to a single-bundle reconstruction) reduced the rotational component to 16.4° (p<
0.0001) and translation to 6 mm (p = 0.0002). Addition of the PL bundle further reduced rotation to 12.6° (p = 0.0007) but had no significant effect on translation. Addition of the PL bundle also significantly reduced coupled tibial internal rotation during the Lachman and Anterior draw tests. The pivot shift test simulates the instability suffered by patients with ACL deficiency and this study suggests that its rotational component is better restrained by anatomical, 2 bundle ACL reconstruction.