Article

Femoral tunnel enlargement after anatomic ACL reconstruction: a biological problem?

Military Hospital D. Pedro V, Avenida da Boavista, Porto, Portugal.
Knee Surgery Sports Traumatology Arthroscopy (Impact Factor: 2.84). 09/2010; 18(9):1189-94. DOI: 10.1007/s00167-010-1046-z
Source: PubMed

ABSTRACT Tunnel enlargement after anterior cruciate ligament (ACL) reconstruction may compromise revision surgery. The cause of this tunnel enlargement is not yet fully understood, but it is thought to be multifactorial, with biomechanical and biological factors playing a role. Tunnel enlargement has been described particularly in patients who underwent ACL reconstruction with hamstring tendons with extracortical fixation devices. The purpose of our study was to evaluate prospectively with magnetic resonance imaging (MRI) the changes in femoral tunnel diameter following arthroscopic anatomic ACL reconstruction with hamstring tendons. At 3-month post-op, all tunnels had enlarged compared to the diameter of the drill and most tunnels enlarged more in the midsection than at the aperture. In the posterolateral tunnels, the entrance increased 16% in diameter and the middle of the tunnel increased 30% in diameter. In the anteromedial femoral tunnels, the tunnels enlarged 14% at the aperture and 35% in the midsection. All femoral tunnels enlarged and most of them enlarged in a fusiform manner. The biological factors explain better our findings than the mechanical theory, although mechanical factors may play a role and the cortical bone at the entrance of the tunnel may modify the way tunnels respond to mechanical stress.

Full-text

Available from: Alcindo Silva, Feb 23, 2014
3 Followers
 · 
261 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, the use of biologics for the primary treatment and augmentation of treatment in patients with knee pathology has increased substantially. Techniques and applications for biologic preparations such as platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs) have been developed and refined to increase the healing response in bone, ligaments, cartilage, meniscal tissue, and other areas of the knee. Beginning with basic science and animal models, and finally proceeding to clinical human trials, the effect of biologics on clinical outcomes has been widely studied; however, many results have been inconclusive on their true effectiveness. The purpose of this article is to review current strategies for evaluating outcomes after biologic treatment and to propose new recommendations for assessing outcomes following the use of biologics in the knee. In addition, the importance of study design, current challenges, and future directions will be reviewed to describe the current standards for future studies to follow.
    The journal of knee surgery 09/2014; 28(01). DOI:10.1055/s-0034-1390028
  • [Show abstract] [Hide abstract]
    ABSTRACT: To systematically review the current literature for evidence that would substantiate the use of platelet-rich plasma (PRP) in the treatment of anterior cruciate ligament (ACL) ruptures. We performed a systematic search in PubMed and Embase of studies written in the English and Spanish languages that compared the use of PRP with a control group in patients with ACL injuries assessing graft-to-bone healing, graft maturation, and/or clinical outcomes and were randomized controlled trials or prospective cohort studies. Eleven studies fulfilled the inclusion criteria, comprising 516 patients (266 ACL reconstructions using PRP and 250 ACL reconstructions without PRP). Six studies reported a statistically significant difference (4 studies) or tendency toward faster graft maturation in the platelet group (2 studies). One study found no differences. Regarding tunnel healing/widening, 1 study showed faster healing in the PRP group and 5 studies showed no differences between the 2 groups. Considering clinical outcomes, 1 study showed better clinical outcomes with PRP use and 5 studies showed no benefits with the use of PRP. Concerning ACL graft maturation, there is promising evidence that the addition of PRP could be a synergic factor in acquiring maturity more quickly than grafts with no PRP, with the clinical implication of this remaining unclear. Regarding tunnel healing, it appears that there is not an improvement with the addition of PRP. There is no proof that clinical outcomes of ACL surgery are enhanced by the use of PRP. Level III, systematic review of Level I through III studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 01/2015; 31(5). DOI:10.1016/j.arthro.2014.11.022 · 3.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the effect of differing postoperative immobilization periods on femoral bone tunnel enlargement and clinical outcome after double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring grafts. Fifty-one patients undergoing primary double-bundle ACL reconstruction with hamstring grafts were divided into 3 postoperative immobilization protocol groups: 2-day immobilization with the knee in 20° of flexion postoperatively (group A, n = 18); 1-week immobilization (group B, n = 17); and 2-week immobilization (group C, n = 16). Bone tunnel enlargement was determined by computed digital radiographs taken on the first postoperative day and at 24 months in the anteroposterior (AP) and lateral views. Each tunnel diameter was shown as a percentage of the maximum joint width of the proximal tibia on the AP view or a percentage of the maximum diameter of the patella on the lateral view. To determine the incidence of tunnel enlargement, a percentage diameter change of more than 10% was defined as an enlarged tunnel. The standard clinical evaluation was also performed. This study used nonrandomized procedures. In each group there were no significant differences in the incidence and magnitude of anteromedial and posterolateral bone tunnel enlargement on both the AP and lateral views (1-factor analysis of variance). Group C showed significantly less muscle strength in knee extension compared with the contralateral knee (85.3% ± 18.4%) than group A (93.7% ± 13.1%, P = .049) and group B (96.8% ± 12.9%, P = .044). This prospective radiographic study showed that femoral bone tunnel enlargement, in both the anteromedial and posterolateral tunnels, may occur after double-bundle ACL reconstruction with hamstring grafts despite different postoperative immobilization periods, with no significant difference in the incidence and magnitude among groups with differing postoperative immobilization periods. In addition, a 2-week immobilization period after surgery showed harmful effects, such as significantly less quadriceps muscle strength. Level II, prospective comparative study. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 12/2014; DOI:10.1016/j.arthro.2014.10.015 · 3.19 Impact Factor