Objective To summarize the research progress on knee laxity of biomechanics and prevention and treatment after posterior cruciate ligament (PCL) reconstruction. MethodsThe domestic and international literature on the prevention and treatment of knee laxity after PCL reconstruction in recent years was extensively reviewed and analyzed. Results Different degrees of knee laxity often occur after PCL reconstruction, which can lead to poor prognosis in patients. The causes are associated with a variety of factors, including abnormal graft remodeling (such as differences in healing time and biomechanics among different types of grafts), tunnel position deviation (such as graft wear caused by the “killer turn” effect), and mechanical factors in postoperative rehabilitation (such as improper early weight-bearing and range of motion). These factors may promote graft elongation, increase early posterior tibial translation, and thereby induce knee laxity. ConclusionWhile PCL reconstruction improves knee stability, it is crucial to focus on and prevent postoperative knee laxity. However, current surgical methods are limited by factors such as graft characteristics, surgical technique flaws, and rehabilitation protocols, and thus can not fully correct the issue of abnormal postoperative laxity. Surgical techniques and treatment strategies still need further improvement and optimization to enhance patients’ postoperative outcomes and quality of life.
Objective To review the application progress of internal brace ligament augmentation (IBLA) technology in the repair and reconstruction of anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) injuries, and to clarify the development trends of IBLA technology. Methods A comprehensive review of recent domestic and international in vitro and in vivo biomechanical studies, animal experiments, and clinical research on IBLA technology was conducted. The effects of this technology on postoperative biomechanics, histological changes, and clinical outcomes following ACL and PCL repair and reconstruction were analyzed and summarized. Results IBLA technology provides enhanced knee stability in the early postoperative period after ACL and PCL repair and reconstruction. It promotes healing at the ligament injury site and increases the biomechanical strength of tendon grafts, thereby reducing postoperative failure rates. IBLA demonstrates good histocompatibility in vivo. Clinical follow-up shows that IBLA improves early postoperative knee stability, range of motion, and functional scores. Patients undergoing rapid rehabilitation achieve more satisfactory outcomes, with no reported serious complications. Conclusion The combination of IBLA with ACL and PCL repair and reconstruction promotes rapid early postoperative recovery and shows promising application prospects. However, further optimization of IBLA material properties and related surgical techniques is needed. Additionally, the long-term effectiveness, structural remodeling of the grafts and repaired ligaments, and the underlying biomechanical functional mechanisms require further clarification.
Objective To explore the biosafety of a novel elastic internal tension-relieving augmentation tape (hereinafter referred to as “novel tension-relieving tape”) for posterior cruciate ligament (PCL) reconstruction and its regulatory effects on graft healing and tendon-bone integration via a Diannan miniature pig PCL reconstruction model. Methods Eighteen female Diannan miniature pigs aged 6-8 months were randomly assigned to tension-relieving group and non-tension-relieving group, with 9 pigs per group. One hind limb of each pig was randomly selected as the experimental limb for PCL reconstruction (n=9): autologous tendon combined with the novel tension-relieving tape was applied in tension-relieving group, while only autologous tendon was used in non-tension-relieving group; the contralateral hind limb was served as self-normal control. Postoperative general conditions of animals were observed, and complete blood count (CBC) tests were performed. Knee joint specimens were harvested at 3, 6, and 12 months postoperatively for gross observation and Marburger Arthroscopy Score (MAS) evaluation. Toluidine blue staining, safranin O-fast green staining, hematoxylin-eosin (HE) staining, collagen type Ⅰ/Ⅲ immunohistochemistry staining, and Sirius red staining were conducted to assess tendon-bone interface healing. HE staining of liver, lung, spleen, and the tissues around tendon-bone implantation area were performed to evaluate the biosafety of the material. Results All animals survived to the experimental endpoint. The indicators of CBC tests of both groups before operation and at different time points after operation, including white blood cell counting, hemoglobin, platelet counting, and neutrophil percentage, remained within normal physiological ranges, with no significant intergroup differences (P>0.05). No difference was found in histological scores of liver, lung, and spleen between groups (P>0.05). No giant cell aggregation, chronic inflammatory granuloma, or tissue erosion and degradation was observed in soft tissues around the implantation area, which indicated that the novel tension-relieving tape exhibited favorable biocompatibility without systemic or local toxic reactions. At 3 and 6 months postoperatively, the tension-relieving group obtained superior MAS score, tendon-bone healing score, nuclear morphological score, collagen type Ⅰ immunohistochemical score, and collagen volume fraction (P<0.05) as well as more regularly arranged elastic fibers compared with non-tension-relieving group, whereas no intergroup difference was detected in collagen type Ⅲ immunohistochemical score (P>0.05). At 12 months postoperatively, the degree of graft ligamentization and tendon-bone interface integration were comparable between the two groups, and no significant intergroup difference was observed in all above indicators (P>0.05). Conclusion The novel tension-relieving tape possesses reliable biosafety. It can effectively accelerate early graft collagen remodeling and tendon-bone interface healing after PCL reconstruction, and improve early knee joint stability.
Objective To summarize research progress on enhanced recovery after posterior cruciate ligament (PCL) reconstruction, clarify the core contradictions, effective intervention methods, and evaluation shortcomings in current clinical practice, and provide theoretical support for optimizing clinical rehabilitation strategies. Methods Relevant domestic and international literature in recent years was systematically searched. The key technologies and challenges for enhanced recovery after PCL reconstruction were analyzed from three aspects: the core issues of enhanced recovery after PCL reconstruction, treatment strategies, and the post-reconstruction effectiveness evaluation system. Results Enhanced recovery after PCL reconstruction mainly faces two core problems. First, there is a balance dilemma between graft tendon protection and knee joint function recovery: the tensile capacity of the graft tendon is weak in the early postoperative period, so excessive weight-bearing easily leads to relaxation, while overly conservative immobilization causes muscle atrophy and joint adhesion. Second, the return-to-sport rate is significantly affected by injury type and treatment method: patients with combined multiple ligament or meniscus injuries have a much lower return-to-sport rate than those with isolated PCL injury, and the risk of return-to-sport failure is higher. Current research mainly promotes rehabilitation from two aspects: physical therapy and surgical technology. Physical therapy runs through the perioperative period: preoperatively, muscle strength training, swelling control, and maintenance of joint range of motion are used to optimize surgical conditions; postoperatively, phased intervention is implemented. Surgical technology focuses on minimally invasive and anatomical approaches: arthroscopic surgery reduces injury, double-bundle reconstruction and internal tension-relief technology improve stability, and modified tunnel positioning and special surgical methods avoid the risk of “Killer Turn”. Postoperative functional evaluation adopts multi-dimensional indicators: subjective evaluation relies on scales such as Lysholm and International Knee Documentation Committee (IKDC); objective evaluation assesses stability through Telos stress test and posterior drawer test; imaging evaluation takes MRI as the core; psychological evaluation is assisted by the Tampa scale of kinesiophobia-11 (TSK-11). However, there are obvious shortcomings, such as the lack of PCL-specific evaluation tools. Conclusion Enhanced recovery after PCL reconstruction requires the integration of precise surgery, individualized rehabilitation, and comprehensive subjective and objective evaluation. In the future, biomaterials and digital technologies should be integrated to optimize the full-cycle management of PCL reconstruction, thereby improving functional recovery and the effect of return to sports.
