The detached stump of the torn anterior cruciate ligament adheres to the femoral notch wall and then to the posterior cruciate ligament within 6 months from injury

Clinical application of modified Crain classification in the Design of Anterior Cruciate Ligament Reconstruction with remnant preservation

BACKGROUND

To investigate the clinical application of modified Crain classification in anterior cruciate ligament (ACL) reconstruction (ACLR) with remnant preservation.

METHODS

The subjects were 70 patients with ACL injury who underwent ACLR from May 2016 to June 2018, and their general data were recorded. They were randomly divided into modified remnant-preserved ACLR group (group M, n = 35) and non remnant-preserved ACLR group (group N, n = 35). ACLR program with remnant preservation was designed based on modified Crain classification in group M, while ACL remnants were completely cleaned during ACLR in group N. Subsequently, the two groups were compared in terms of operation time, complications, as well as Lysholm score, international knee documentation committee (IKDC) score and positive rate of Lachman test of knee joint before operation and at 3, 6 and 12 months after operation.

RESULTS

Both the groups showed good postoperative efficacy, and none had complications like limited knee extension or cyclops lesion. The comparison results found that group M (72.49 ± 7.64 min) required longer operation time than group N (66.06 ± 6.37 min) (P < 0.05). Lysholm score and IKDC score at 3, 6 and 12 months after operation in the two groups were significantly higher than those before operation (P < 0.05); group M had higher Lysholm score and IKDC score at 3 months and 6 months after operation compared with group N (P < 0.05). Additionally, the positive rate of Lachman test at 3, 6 and 12 months after operation in both groups was significantly lower than that before operation (P < 0.05), but there was no significant difference between group M and group N.

CONCLUSION

With the modified Crain classification, many remnant-preserved reconstruction techniques can be rationally used to completely preserve the remnant ligament tissue during operation and improve knee joint function and joint stability with few complications.

Primary Repair for Treating Acute Proximal Anterior Cruciate Ligament Tears: A Histological Analysis and Prospective Clinical Trial

Reconstruction surgery for acute proximal anterior cruciate ligament (ACL) tears remains controversial. Recently, ACL primary repair has received increasing attention in ACL treatment. This study aimed to explore the histological characteristics of ACL healing in primary repair and compare its therapeutic and prognostic results with the reconstruction of acute proximal ACL tears. Histological experiments using rabbits and a prospective clinical trial were conducted. We established a rabbit model of ACL primary repair, and histological changes were observed using haematoxylin and eosin (HE) and toluidine blue staining. We performed immunohistochemical analysis of CD34 and S-100 and measured the expression of collagen I and II using qRT-PCR, Western blotting, and immunohistochemistry. The prospective clinical trial involved performing ACL primary repair and reconstruction in patients with acute proximal ACL tears to detect proprioception and evaluate the function of joints. We discovered that primary repair promoted cell proliferation in the tendon-bone transition and ligament portions, reduced osteoarthritis-like pathological changes, and maintained blood vessels and proprioceptors within the ACL. In the clinical trial, primary repair achieved similar therapeutic outcomes, including recovery of knee function and proprioception, in the follow-up period as ACL reconstruction. However, the primary repair had a significantly shorter operative time and lower cost than reconstruction. Therefore, doctors should consider the benefit of primary repair in treating acute proximal ACL tears.

Remnant preserving ACL reconstruction with a functional remnant is related to improved laxity but not to improved clinical outcomes in comparison to a nonfunctional remnant

PURPOSE

The Anterior cruciate ligament (ACL) remnant has been pointed out as a ligamentization enhancer. Nonetheless, the remaining tissue can be functional if it still provides some stability or nonfunctional. This study intends to compare the clinical results and knee stability of functional vs. nonfunctional remnant preservation ACL reconstruction (ACLR).

METHODS

One hundred and seventy-five patients with ACL injuries were included and underwent remnant preservation ACLR. They were divided into two groups accordingly to remnant tissue functionality: functional (Group F) and nonfunctional (Group NF). Primary outcome was defined as patient reported outcomes measured with Lysholm, IKDC and Tegner continuous scales and improvements. Secondary outcomes comprised of Lachman test, anterior drawer test, pivot shift test, extension and flexion deficit, graft coverage by remnant preserved tissue and failure rate (persistent instability or new ACL lesion). Menisci lesions, cartilage lesions and time to surgery were also recorded for each group.

RESULTS

One hundred and forty-four patients were available at a mean of 30.2 ± 10.1 months: 69 Functional and 75 Nonfunctional. Lysholm, IKDC and Tegner functional outcomes demonstrated no difference between the groups, Functional compared to Nonfunctional: 88.4 ± 10.5 vs. 92.2 ± 4.9, n.s. and 83.2 ± 11.3 vs. 87 ± 5.3, n.s. and 6 (5-10) vs. 6 (5-9), n.s., respectively. Lysholm and IKDC functional outcomes improvements demonstrated differences between the groups: Functional compared to Nonfunctional (39.3 ± 9.4 vs. 42.3 ± 7.4, p = 0.014 and 37.7 ± 10 vs. 41.0 ± 6.6, p = 0.032); however, they were not clinically significant. Functional group showed more stability on physical examination pre- and post-operatively (p < 0.001, p < 0.001). There was no difference regarding extension deficit (n.s.); however, functional group had more flexion deficit (p = 0.02). Nonfunctional group had better graft coverage (p = 0.001). There was no difference regarding failure rate: 4% vs. 9%, (n.s.).

CONCLUSION

Both remnant preservation ACLR techniques were able to achieve satisfactory functional outcomes. A functional remnant was not related to improved functional outcomes in comparison to a nonfunctional remnant; however, it was related to less laxity pre and postoperatively and inferior graft coverage.

LEVEL OF EVIDENCE

II.

The Reliability of Classifying the Morphology of Anterior Cruciate Ligament Remnants during Surgery

Arthroscopic classification of the torn anterior cruciate ligament (ACL) morphology is fundamental for clinical studies on emerging techniques such as repair and preservation. At present, the most acknowledged classification is Crain description of four morphological patterns. The purpose of the study was to analyze the intra- and interobserver reliability of Crain classification in patients undergoing ACL reconstruction surgeries. The study included 101 patients who had ACL reconstruction surgery between the years 2014 and 2017. The morphological pattern of ACL remnant scar formation during surgery was observed and classified according to Crain by three orthopaedic surgeons. Inter- and intraobserver reliabilities were measured using kappa statistics. Intraobserver reliability for the Crain classification ranged from 0.63 to 0.83 (substantial to almost perfect agreement). Interobserver reliability was 0.51 (moderate agreement). In almost a third of the cases, observers reported on additional morphological pattern of scar formation that was not well defined by Crain. A modified classification of four patterns was suggested: (A) without scar tissue, (B) with adhesion to the femoral notch (wall or roof), (C) with adhesion to the notch and posterior cruciate ligament (PCL), and (D) with adhesion to the PCL. Reanalysis of these four morphological configurations resulted in interobserver reliability of 0.82 (almost perfect agreement). In conclusion, the Crain classification of torn ACL remnant morphology has moderate interobserver reliability; however, a suggested classification with modified and additional configurations has almost perfect reliability and may be useful for studies on ACL repair and preservation.

[Effectiveness of partial anterior cruciate ligament suture repair with wide awake local anesthesia no tourniquet technique]

OBJECTIVE

To investigate the effectiveness of partial anterior cruciate ligament (ACL) suture repair with wide awake local anesthesia no tourniquet (WALANT) technique.

METHODS

Between July 2017 and July 2019, 18 patients with partial ACL injury were admitted. There were 10 males and 8 females, with an average age of 40.5 years (range, 22-57 years). There were 5 cases on the left knee and 13 cases on the right knee. Forteen cases had a clear history of trauma or sports injury, and 4 cases had no obvious cause. The time from injury to operation was 1-6 months (median, 3 months). Partial ligament was sutured using WALANT technique under arthroscopy. The operation time, total hospital stay, and postoperative hospital stay were recorded. Lachman test and anterior drawer test were performed to evaluate the knee joint stability after treatment, and Lysholm and International Knee Documentation Committee (IKDC) scores were used to evaluate the knee function. Five-point Likert scaling were used to evaluate postoperative patient satisfaction.

RESULTS

The operation time was 30-100 minutes (mean, 64.2 minutes). The total hospital stay was 2-12 days (mean, 4.5 days). Postoperative hospital stay was 1-4 days (mean, 1.8 days). All incisions healed by first intention after operation, and no surgery-related complications occurred. All patients were followed up 12-36 months (mean, 19.1 months). Lachman test and anterior drawer test were negative after operation. Lysholm score and IKDC score at 6 and 12 months after operation were significantly higher than those before operation, and at 12 months after operation were higher than those at 6 months after operation, the differences were significant ( P<0.05). At last follow-up, according to five-point Likert scaling of patient satisfaction, 7 cases were very satisfied, 10 cases were relatively satisfied, and 1 case was general. The total patient satisfaction rate was 94.4% (17/18). MRI scan showed the good ligament tension.

CONCLUSION

Using WALANT technique to repair partial ACL injuries under arthroscopy can retain the patient's own ligament tissue to the maximum extent and achieve satisfactory short-term effectiveness.