MR variability of collagen meniscal implant remodelling in patients with good clinical outcome

Abstract

Purpose Collagen meniscal implants (CMI) have variable imaging indings on MRI and it remains ambiguous, if alterations may be present in asymptomatic patients. The aim was, to evaluate MR morphological characteristics and volume of CMI in the early, mid-and long-term follow-up. Methods Fifty-seven patients (mean age, 43.6±11 years; 41 male/16 female) with good clinical outcome (subjective visual analogue scale for satisfaction < 2 and a Lysholm-score ≥ 84) after CMI were assessed retrospectively using MRI 1, 2 and 3-8 years postoperatively. CMI morphology, signal intensity (SI), homogeneity and size were assessed and a meniscal score was calculated. Chondral defects and bone marrow edema pattern were reported and summarized in a chondral score. Meniscal extrusion and volume were evaluated. Intra-and inter-reader reliabilities were calculated. Spearman and partial correlations were used (p < 0.05). Results One year postoperatively, the CMI varied in size [10% (4/40) normal, 30% (12/40) small, 60% (24/40) hypertrophic] and was hyperintense and inhomogeneous in all patients. At long-term follow-up, the size of CMI decreased [6% (1/17) resorbed, 18% (3/17) normal, 41% (7/17) small, 35% (6/17) hypertrophic]. The SI of the CMI changed to normal in only 13% (2/16). The majority was still hyperintense [87% (14/16)]. Less meniscal extrusion was present in the follow-up [71% (11/16) versus initially 93% (37/40)]. The meniscal score improved signiicantly (ρ = 0.28). Over time, full-thickness femoral chondral defects were increasingly present [65% (10/17) versus initially 33% (13/40)] and the chondral score worsened signiicantly (p = 0.017). Conclusion Abnormal and inhomogeneous SI and irregular margins of the early postoperative CMI on MRI are indings seen in patients with good clinical results and should not necessarily be overcalled when reporting MRI. These features tend to decrease over time. Level of evidence IV.

Biosynthetic scaffolds for partial meniscal loss: A systematic review from animal models to clinical practice

“…The analysis of the available literature yielded 10 trials, all prospective, that included 593 patients in total [ [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] ] ( Fig. 3 ).…”

“… At second-look arthroscopy ↑ total tissue surface area Zaffagnini S et al Knee Surg Sports Traumatol Arthrosc 2007 [ 75 ] 57 Prospective study: 8 pz (Mean 25 yrs) Irreparable meniscal tear or a previous meniscectomy involving the medial meniscus CMI 3, 6, 12, 24, and from 72 to 96 mo: X-ray, MRI, CKRS, IKDC, VAS, subjective evaluation, second look artroscopy ↓ VAS, CKRS, IKDC. At second look arthroscopy presence of new tissue in some cases Kovacs BK et al Knee Surg Sports Traumatol Arthrosc 2019 [ 76 ] 54 Prospective study: 57 pz (43.6 ± 11 yrs) Meniscectomy involving medial or lateral meniscus CMI 12, 24, and 36–96 mo: VAS, Lysholm score, MRI, CMI morphology ↓ VAS; ↑ Lysholm score. Abnormal and inhomogeneous signal intensity and irregular margins of the CMI which tend to decrease over time Bouyarmane H et al Orthop Traumatol Surg Res 2014 [ 77 ] 48 Prospective, single-arm, multicentric study: 54 pz (16–50 yrs) Postmeniscectomy syndrome: painful LM tear or partial lateral meniscectomy (32–60 mm) Actifit® 6, 12, 24 mo: VAS, IKDC, KOOS ↓ VAS; ↑ IKDC, KOOS than presurgery.…”

“…Looking at the clinical results, all the trials revealed positive findings in terms of pain reduction and increase in subjective functional scores. Few studies documented stability of results up to a long-term evaluation (in the range of 8–10 years' follow-up) [ 67 , 75 , 76 ]. Anyway, these encouraging findings should be carefully weighed against the high number of concomitant procedures performed in most of the trials ( Table 3 ), which represents a confounding bias in the assessment of the CMI scaffold contribution to the final outcome.…”

“…With regard to MRI evaluations, the most adopted method was the Genovese score: overall, the MRI appearance of the CMI scaffold evolved positively over time, with just a very few cases of complete resorption of the scaffold. Anyway, complete healing and restoration of normal “meniscus-like” tissue occurred in a limited percentage of patients, whereas the majority of them still showed different intensity of signal at the site of CMI implantation, smaller overall size of the treated meniscus and a certain amount of extrusion [ 67 , 70 , 74 , 76 ].…”

“…Furthermore, it should induce cell migration, attachment, proliferation, and differentiation, and be biocompatible and non-toxic [ 13 ]. Several different natural, synthetic, and hybrid scaffolds have been tested in the 46 in vivo preclinical studies [ [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] , [58] , [59] , [60] , [61] , [62] , [63] ], but only one natural (CMI) and one synthetic (Actifit®) scaffold have been translated into clinical practice [ [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] ,…”