Clinical and radiological comparison between partial and complete resection of the anterior cruciate ligament in patients with mucoid degeneration of the anterior cruciate ligament: a controlled clinical trial

Abstract

Introduction The pathology of a mucoid degeneration of the anterior cruciate ligament (MDACL) has been mentioned in several publications but due to its rare incidence it is not a well-known pathology. Partial or complete resection of the ACL is the option of choice after failed non-surgical treatment. However, the success rate of both surgical techniques and the subsequent risk of an ACL instability is not known. The purpose of this study was to compare the clinical and radiological outcome between partial resection and complete resection of the ACL in patients with MDACL. Materials and methods Patients with MDACL verified by MRI and persistent knee pain were treated by partial (Group I) or complete resection (Group II) of the ACL and were included in a controlled clinical trial after unsuccessful conservative treatment for at least 6 months. Demographic, clinical and radiological data including the thickness of ACL, ACL/intercondylar ratio, patient’s age at the time of surgery, the presenting symptoms, range of motion and ligament stability assessed by the ACL ligament score (Lachman test) were collected. In addition, Tegner activity score and Lysholm score were evaluated preoperatively and at final follow-up after a minimum of 12 months. Results At final follow-up with a mean of 16.8 ± 8.8 months (range 12–41; Group I: 18.3 ± 9.7 vs. Group II: 15.3 ± 8.0; ns), all patients were pain free. Postoperatively, positive Lachman tests were noted in all patients (100%) in Group II (n = 5 patients with grade II and n = 5 patients with grade III). In Group I, 8 patients (80%) showed a negative Lachman test (grade I) and 2 patients (20%) a slightly elongated Lachman test with a firm stop (grade II). The mean knee flexion at follow-up examination was 132° ± 7° (range 120°–140°; Group I: 129° ± 9° vs. Group II: 135° ± 4°; ns). In pairwise comparison, flexion angle increased significantly in both groups (Group I: p = 0.0124 and Group II: p < 0.001). Pairwise comparison of thickness of the ACL and ACL/intercondylar ratio prior to and post-surgery in Group I showed non-significant differences. Conclusion Both arthroscopic debridement and complete resection of the ACL lead to improvement of clinical and radiological findings in isolated MDACL. However, complete resection of the ACL will result in higher instability. Therefore, partial resection might be the better treatment option, especially in young patients with MDACL.

Partial debridement is the most commonly reported treatment option for mucoid degeneration of the anterior cruciate ligament: a systematic review

“…Three studies defined partial debridement as shaving < 50% thickness of the ACL, but seven studies did not have a specific definition for partial debridement [5, 20, 22]. Five studies used only a motorized shaver to perform partial debridement [5, 13, 20, 26, 27]. One of these studies compared a motorized shaver less than 25%, and from 25 to 50% [20].…”

“…The mean postoperative Knee Outcome and Osteoarthritis Score (KOOS) was 78.0 and was reported in only one study [22]. Mean flexion range of motion ranged from 96.4° to 119.0° preoperatively in two studies [26, 28]. Three studies reported mean postoperative ranges of motion ranging from 117.9° to 137.7° [20, 26, 28].…”

“…Complete debridement was used in two studies comprising 23 patients (23 knees) with a mean age of 49.1 years [10, 26]. The mean follow‐up time was 12.8 months and the mean loss to follow‐up was 15.7%.…”

“…Operative management can include partial or complete debridement of the ACL. Excision can be performed with a shaver or with radiofrequency ablation, with the goal of removal of all or some of the mucoid tissue in the ACL [26]. It is important for orthopaedic surgeons to understand the benefits and risks of management strategies for MD‐ACL that have been reported in the literature, so that they are able to guide their decision making for patients with the same condition.…”

Posterior tibial slope, notch width index and tibial tubercle to trochlear groove distance contribute to development of mucoid degeneration of the anterior cruciate ligament: a systematic review

“…Magnetic resonance imaging (MRI) is the gold standard for diagnosing mucoid degeneration of the ACL, and is characterised by a celery stalk sign, with subsequent diagnosis confirmed via tissue biopsy and histology [23]. Management options include non‐surgical measures such as oral analgesics and physiotherapy, whilst operative measures include partial resection of the area affected by degeneration, ACL reconstruction or total resection of the ACL [24, 26].…”