The presence of proprioceptive mechanoreceptors in the remnants of the ruptured ACL as a possible source of re-innervation of the ACL autograft.

Abstract

This study investigated the presence of neural mechanoreceptors in the remnants of the ruptured ACL as a possible source of reinnervation of the ACL autologous graft. The remainder of the torn ACL was selected for further histological investigation from 17 patients during ACL reconstruction 3 months to 3.5 years after injury. Perioperatively two types of ACL remnant were identified. Fifteen patients had portions of ACL adapted at the PCL. In all of these patients we found mechanoreceptors (I and II). In five patients we found mushroomlike remnants which included either none or small numbers of mechanoreceptors. Free neural ends were found in both patient groups. There was a significant difference between the groups in regard to the mean number of mechanoreceptors I and II per slice. In conclusion, in patients with an ACL remnant adapted to the PCL, mechanoreceptors exist even 3 years after injury. If we accept that restoration of proprioception is the result of reinnervation of the ACL, leaving the ACL remnants as a source, if this is surgically possible without risk of Cyclop's lesion, may be of potential benefit to the patient.

A Pilot Study of Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With Ligament Remnant Tissue Preservation

“…25 However, we believe that the difference of approximately 10 minutes may not be a problem for patients, and we will be able to shorten the operation time of the remnant-preserving procedure by developing some useful devices in the near future. A Cyclops lesion may be a possible problem in remnant preserving surgery, 8 Table 1. The postoperative clinical results of our remnant-preserved double-bundle ACL reconstruction and radiological evaluations on location of 4 tunnels actually created in the femur and the tibia using our remnant-preserving technique.…”

“…The mean interval between injury and the time of operation was 4 (range [1][2][3][4][5][6][7][8] months. The height and body weight of the patients were 168 +/-9 (the mean +/-S.D.)…”

“…It is known that the ACL-injured knee frequently has a ligament remnant tissue, 6 in which mechanoreceptors and free neural ends are found. [7][8][9][10] Therefore, theoretically, there is a strong possibility that preservation of the ACL remnant tissue may be able to restore proprioceptive functions of the graft after ACL reconstruction. Additionally, preservation of the ACL remnant tissue may enhance the revascularization and cellular proliferation of the graft after ACL reconstruction, because the ACL remnant tissue has good subsynovial and intrafascicular vascularity.…”

Insufficient recovery of neuromuscular activity around the knee after experimental anterior cruciate ligament reconstruction

“…Some studies (Goertzen et al 1992, Wada et al 1997, Georgoulis et al 2001, Adachi et al 2002 have claimed that surgery helps recovery of the proprioceptive apparatus in the ACL-reconstructed knee, from morphological findings. In line with this possibility, we did not resect the injured ACL remnants and we included reconstructions with pediculated grafts.…”

Fluorescence immunohistochemistry and confocal scanning laser microscopyA protocol for studies of joint innervation

“…Studies of human joint tissue using the gold chloride technique have included the elbow collateral ligaments (Petrie et al 1998), knee anterior cruciate ligament (Georgoulis et al 2001), palmar wrist ligaments (Petrie et al 1997), lumbar and thoracic facet joint capsules (McLain and Pickar 1998), metacarpophalangeal collateral ligaments (Sathian and Davanandan 1983), myotendinous junctions (Jozsa et al 1993), and posterior sacroiliac ligaments (Vilensky et al 2002). However, the appearance of stained structures may vary both within a section and between samples, and, since nonneural structures are also stained, nerves and nerve endings must be distinguished from other structures on the basis of their anatomical features.…”