Remnant preservation may improve proprioception after anterior cruciate ligament reconstruction

Abstract

Aim Our aim was to evaluate the literature investigating proprioception improvement after anterior cruciate ligament reconstruction (ACLR) and test the hypothesis that ACL tibial remnant-preserving reconstruction (ACLR-R) is more beneficial than standard technique (ACLR-S) in terms of postoperative proprioceptive function with various reported tests, including joint position sense (JPS) and threshold to detect passive motion (TTDPM). Methods An online search was performed in Embase, MEDLINE/PubMed, Cochrane, SPORTDiscus, and Web of Science databases before 5 October 2020, on the basis of the guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Key terms [(‘ACLR’ or ‘ACL-R’ or ‘anterior cruciate ligament reconstruction’) AND (‘remnant’ or ‘stump’) AND (‘proprioception’ or ‘proprioceptive’)] were used. The Oxford Centre for Evidence-Based Medicine and The McMaster Critical Review Form for Quantitative Studies were used for quality assessment. In total, four articles comparing proprioceptive functions between ACLR-R and ACLR-S were included, two of which were randomized clinical trials rated as level of evidence II, and two were retrospective cohort studies rated as level of evidence III. The outcomes were then compared. Evaluation of proprioception involved joint position sense (JPS) [reproduction of active positioning (RAP) and reproduction of passive positioning (RPP)] and threshold to detect passive motion (TTDPM) tests. Results Only four studies were included, with a total of 234 patients (119 ACLR-R patients and 115 ACLR-S patients). High heterogeneity in characteristics and outcome measurements was observed among the studies. Three studies performed sparing technique, and one performed tensioning technique. One study tested RAP and reported better results at an average of 7 months follow-up in ACLR-R (P < 0.05). Three studies tested RPP, one of which measured RPP within 12 months after surgery and reported better results in ACLR-R than in ACLR-S (P < 0.05). The other two studies reported similar results; however, the findings of one study were statistically insignificant. TTDPM was tested in one study, with no statistically significant difference found. Conclusion The current literature, although limited, reported proprioception improvement after ACLR-R (compared with ACLR-S) in terms of JPS. However, owing to the heterogeneity of the relevant studies, further research is required to determine remnant preservation effect on knee proprioceptive restoration. Level of evidence Level III, systematic review of Level II and III studies.

Reliability of the Tibial Spine Versus ACL Stump in Assisting Tibial Tunnel Positioning During ACL Reconstruction: Analysis Based on 3-Dimensional Computed Tomography Modeling

“…With the ASP technique, the medial tibial spine is covered by ACL fibers, which means that surgeons mainly reference ACL remnants and other landmarks such as the posterior border of the ARLM and PCL for tibial tunnel placement. 8,19,22 Additionally, the ASP technique has shown benefits in retaining proprioceptors on the synovium of residual ligamentous tissue, accelerating the recovery of neuromuscular control and knee function, 1,7 maintaining the stability of the knee joint and decreasing the mechanical load on the graft, 9,14,25 and hastening biological healing of the graft by enhancing cell proliferation and revascularization . [24][25][26]29 Moreover, owing to the presence of functional cells in the remnants, tunnel widening, which is thought to result from synovial fluid egress, can be prevented.…”

The apex of the deep cartilage is a stable landmark to position the femoral tunnel during remnant‐preserving anterior cruciate ligament reconstruction

“…c, d One year after the ACL reconstruction procedure, which used ADC as the landmark positioning femoral tunnel, the ACL was reconstructed without sacrificing the remnant, and there were no abnormal symptoms such as joint swelling and surrounding structural abnormalities [6,12,43]. The remnants that are truly worth preserving might be those that are "functional", and the criteria for "functional" remain to be explored [5,30]. Additionally, most of the studies on remnant-preserving ACLR have focussed on tibial remnants instead of femoral remnants since femoral remnants are usually small [38] and relatively rare [30].…”

ACL stump and ACL femoral landmarks are equally reliable in ACL reconstruction for assisting ACL femoral tunnel positioning

“…Thus, remnants of the ruptured ligament need to be removed properly to achieve accurate tunnel positioning in the NRP technique. However, RP may show certain benefits in terms of proprioceptive function [6], stability [14], and graft healing [31]. Takahashi et al reported that preserving ACL residues might enhance the synovial coverage of the grafted tendon and the outcome of graft healing without increasing cyclops lesions, and sufficient remnant tissue coverage might contribute to better knee stability [31].…”

“…Several landmarks have been used for anatomical femoral tunnel positioning, including the lateral intercondylar ridge, the lateral bifurcate ridge, and the cartilage margin [8, 17, 34], but it is often difficult to locate anatomical landmarks without sacrificing the remnant tissue both at the tibial and femoral sites. Remnant preservation (RP) has shown multiple advantages including preservation of the proprioceptive function [1, 6, 32], preservation of laxity [7], reduction of tunnel enlargement [7, 33], and promotion of graft healing [19]. During the implementation of the RP technique, surgeons generally refer to the location of remnants to centre the graft within the remnant tissue, though a foreshortened view must be used to judge the position inside a covered footprint.…”

“…Fig 6. The grid method showing the anatomical centre point locations and actual locations of the mean tunnel in the remnant preservation (RP) and nonremnant preservation (NRP) groups…”