Ligament Replacement: Anterior Cruciate Ligament - Assignment Example

Ligament Replacement Name: Course: Instructor: Institution: Date of Submission: Anterior Cruciate Ligament (ACL) Introduction ACL is the surgery for replacing the ligament at the center of the knee. The ACL ensures the shinbone is always in its place. A minor injury to the ACL can lead to knee complications during physical activities. That is; knee injuries are very common, mainly the ACL caused at the sports field mainly. The ligament replacement is conducted where during the surgery the knee joint is replaced with synthetic medical joint identified as Prosthesis (nlm, 2016). The prosthesis is a medical device used to replace damaged cartilage where during surgery the bone is removed from the knee joint and are replaced with the prosthetic device. The Prosthesis device is used to replace the femur, where the replacement is made of metal. It also replaces the tibia where the prosthesis is made from metal and also has a resilient plastic liner. The device also substitutes the patella, and the device contains a solid plastic. (nlm, 2016) The biomedical expedient is used in patients who have challenges with their knees such as a stiff or painful knee, which hinders one from walking well, pain due to arthritis that keeps one from sleeping or performing other standard activities. The device is also used when other treatments have proved unreliable in treating the pain. Mainly those that require the device are older people. Young people who use the device due to much activity lead to wearing out the device (Aichroth & Cannon, 1992). ACL injuries are related to sports treated with ligament replacement though not widely used. Ligaments are soft tissues that link bones to form joints. The ACL are ligaments inside the knee that spread from a subsequent location on the medial wall of the adjacent femoral condyle to an attachment at the frontal part of the central tibia plateau. The function of the ACL is to act as a control to the frontal conversion of the tibia comparative to the femur while also restraining the internal tibia turning. It is important in certifying the steadiness of the knee joints throughout the motions it participates. MATERIALS AND METHODS Materials Used Past devices have been made from materials such as carbon fibers, polytetrafluoroethylene, polyethylene terephthalate, polyester, polyurethane urea and polypropylene. Have the devices made from these materials have not provided patients with long-term satisfactory results due to biocompatibility insufficiencies and other mechanical issues. Carbon fiber, polypropylene, and Dacron materials are related to chronic inflammation as well as the generation and relocation of wear elements in the joint space and lymph lumps. Dissatisfaction of devices made from these materials derived from excessive creep, fatigue, wears damage and other reported rates of rupture that led to the advancement of persistent joint laxity after several year of the device implantation. Such complaints were linked to products made of carbon fiber among others named above. Consequently, patients opted for allografts and auto grafts, which are more durable and resist mechanical failure, compared to other biomaterials that aid in the manufacturing of the prosthetics. Currently, the materials used are still in the research phase identified as tissue engineering through culturing progenitor ligament cells (Freeman, et al., 2007). The process is conducted through involving the planting with the platform with ACL fibroblast antecedent cells. Through applying mechanical filling and other chemical nods that spark the cells and tissues to advance in the correct alignment while duplicating the usual ACL configuration and geometry. Regarding tissue-engineered ligaments, neo-ligamentous ingrowth occurs though they depict insufficient strength and stiffness (Freeman, et al., 2007). Thus, they do not provide the anticipated satisfaction of the patients. The methods used to define the devices derive from the Lysholm knee score and the pivot shift of the devices. It also included analyzing the timeline of the devices after the surgery and the issues surrounding the devices such as the satisfaction and complaints from patients. DISCUSSION Design and Application of the Prosthesis Geometric Design of the Prosthesis The ACL is one of knee ligaments that assist in maintaining the proper tibia-femoral alignment, knee movement, and knee steadiness. The prosthesis is used mainly if the installation method is familiar to the surgeon. The design of the device is comparable to a biological graft that encompasses an intra-articular segment that substitutes the ligament amid the fragments fortified inside the femoral and tibia shafts with some initial fixation. The device is advanced over a collection of dimensions and widths to accommodate the different knee sizes among patients (Aichroth & Cannon, 1992, 340). Method of Application The surgery of ACL includes the use of synthetic graft using the prosthetics such as LARS as discussed below. The employment of the implant begins with the average tibia-opening tunnel where the graft is directed at the top of the adjacent femoral condyle through an incision made in the thigh. The fixation of the scion occurs through safeguarding the femoral and tibia positions with the screw chosen for the surgery to ensure a successful ligament replacement. The application of the prosthesis occurs through the usage of operation that transpires for about one hour or more. The application/surgery of the prosthetic device occurs through ligament replacing of using an auto graft or allograft that is installed between the tibia and femur. It is also hooked within the bone tunnels with the aim of providing stability and restoring knee function. The application/operation occurs through two femoral shafts; one, it is drilled transtibial or second, through the usage of an auxiliary anteromedial portal model. The engagement of the transtibial drilled femoral tunnel method is forced by the collinear with the tibia shaft. At this point, the knee is at the position that it is drilled at, which is corporate at 90° of the knee flexion. After the femoral tunnel is pierced transtibial, the subsequent location of the graft is erect where the femoral tunnel enters to the roof of the indentation. The grafts postponed from the transtibial-drilled shafts are operative by repelling the extreme forward tibia translation. However, they also may probably result in progressive axis shift and greater rotating laxity. The transtibial application occurs as: The substitute of this application is the anteromedial portal practice where the drilling of the tibia and femoral tunnels occurs individually. The end from an ancillary anteromedial portal located at the medial sideways of the patella where in this procedure the flexion of the knee is between 110° to 130°. The method consequences to a sideways location for the femoral tunnel entry to the midpoint of the built-in footprint while advancing the rotating stability. The anteromedial portal application occurs as: During the time of the application, an allograft or auto graft is committed to the bone shafts while expending a fixation device liable to the graft type used. That is; it is dependent on the tunnel placement, surgeon inclinations, and the patient-explicit knee features. The fixator used must offer adequate strength to support the graft through the surgery and after the completion of the operation. To ensure it is in place after the patient has undergone the surgery and ligament replacement has occurred, a rehabilitation etiquette is provided. The etiquette is intended to defend the joint early by regulating the doings of the knee (Aichroth & Cannon, 1992). It also considers the actions that produce loads not beyond the graft fixation power until at least stronger mixing with the bone customs over time. A synthetic prosthetic device is used to replace the ACL, which is advantageous as it precludes the donor site and other problems associated with infections of the biological grafts. The operation for the ligament replacement with a synthetic prosthetic uses less invasive operation as the harvest procedure is unnecessary. Manufacture The development and engineering of the prosthetics follow a different range, as the explicit needs of patients must be considered. A graphical representation of the mechanical manufacture of the prosthetics can be presented as: The manufacturing process considers the particular wants of the user such as knee size and diameters or the side that needs the device. After the needs of the user are placed in position the design process begins and must be verified, and validated as a medical device. For this to happen, the device must first undergo a risk analysis process. The ACL prosthetic device should fit into the drilled bone tunnel positions with a compatible and functionality structure that equals with the knee joint composition. The engineering of the device should have the intra-articular ligament-replacing unit with the femoral tunnel section on one side of the tibia tunnel section. The dimensions of the allograft and the auto graft differs among patients stretching from 6 to 11 mm in widths. The ligament replacing should be obtainable in a variety of lengths bridging from 22 to 41 mm in adults. The fragment tunnel tracks for about 12mm and at least for 15 mm of length of each bone tunnel. The constituents used in the engineering of the device should be free of difficulties such as immunogenicity, biocompatible, unresolved inflammation, and cytotoxicity (Rowden, et al., 1997). Mode of Operation for the Prosthesis An ACL does not heal after an injury due to lack of significant vascularization and the limited supply of blood. The inadequate blood supply is due to the damage that occurs in the adjoining synovial lining that steers to blood indulgence within the joint when averting creation of a local hematoma. Thus, the surgical ligament replacement is introduced where it is secured between pierced tunnels into the tibia and the femur. Fixators such as cross-pins, buttons, or screws are used to fasten the ligament trimmings of the replacement with the shafts of the bone throughout the surgery. The tenacity of the ligament replacement is to reinstate the steadiness and kinematics of the damaged knee while averting the future deteriorating changes. History of Device Development The earliest ligament replacement of the ACL reported used a non-biological graft in 1903 by F. Lange using silk braids, which failed quickly. After the trial, other materials such as silk, nylon, and metal wires among other materials. The materials encountered key recurring mechanical failures and lack of biocompatibility leading to its failure (Lange, 1903). Innovative prosthetic devices were advanced from the 1970s through to the 1990s, which contained more innovative materials such as carbon fiber, polytetrafluoroethylene, polyethylene, terephthalate and polypropylene (Mascarenhas & MacDonald, 2008). In the late 1980, the Stryker-Meadox Dacron and Gore-Tex were approved as ligament replacement devices. However, due to dissatisfaction for the patients, these devices are no longer used (Pruitt & Chakravartula, 2011). Carbon fiber was rejected and is no longer used due to the fragments perceived on the device as well as the regional lymph nodes. The ABC prosthetic ligament consisted of polyester and carbon fiber were rejected due to poor performance. The acceptable performance was only recorded in 41 patients, which stipulated failure as the larger group was unsatisfied (Mody, et al., 1993). Dacron graft and that of polyester failed to maintain knee stability after four years due to pivot shift among other challenges. The failure of the devices was linked to the elongation of ruptures and creep that were in the femoral insertion, the central part of the graft and the tibia insertion. The Gore-Tex graft was also a biomaterial that contained expanded polytetrafluoroethylene, which originally had good results. However, it failed in future because of complaints relating it to chronic and effusion-synovitis from particulate debris or other disturbed exposed fibers (López-Vázquez, et al., 1991). The graft estrangement that occurred after the recurring loading also steered to the disappointment of the drug. The device also experienced tension linked to the osteolysis and the expansion of the bone tunnel (Aichroth & Cannon, 1992, 298). The implant complaints also linked it to infection. These disappointments influenced the failure of the device and necessity for innovative expedients. The polyester Leeds-Keio was also an artificial ligament expedient that was industrialized to perform as a scaffolding for neo-ligamentous ingrowth (Fujikawa, et al., 1989, 567). The device had a decisive weight of 2100 N, which was adjacent to the bulkiness of the inherent ACL. The expedient had high presentation though it did not have sufficient fatigue opposition after the first year. The disaster was due to the unsuitable alignment to reinstate the ligament purpose because of the gristly tissue ingrowth (Christel, 1994). The Kennedy LAD device contained polypropylene, which was designed to fund the autogenesis graft. The material used led to the reactive synovitis and irritation that was escorted by the explosion of foreign body colossal cells and macrophages (McPherson, et al., 1985). Currently, a newer version of the ACL artificial prosthetics exists as the “Ligament Advanced Reinforcement System” (LARS). The device encompasses the polyethylene terephthalate (PET) that also holds the free fibers that are set in the intra-articular unit of the device that is positioned in a matching longitudinally perverse to the left or right liable upon the knee side imitating the innate ACL fiber alignment (Dericks, 1995, 193). The LARS is intended to struggle the torsional exhaustion by dropping shear pressures that are relative to the circular distance from the affiliation of replacement. The radial space is lesser within the free self-governing fibers than in a concept of fibers required to screw together as a single bigger unit. Free fibers support in decreasing the inter-fiber wear through eliminating the positions where the fibers cross over and scrub beside each other. The LARS device has been assessed in several lessons that report high patient gratification for about five years after the grafting. The mechanical fiascos of the PET tendon were slight to around 4%-8% of the LARS. Other problems related to the device contain insincere wound pollution, pain from the fixes and once it has been reported concerning the synovitis (Machotka, et al., 2010). However, regardless of that history, the prosthetic devices are not used extensively around the world due to the occurrence related to its mechanical and absence of biocompatibility (Mascarenhas & MacDonald, 2008). Current Designs Available Recently, the designs contain tissue-engineered replacements. The tissue manufacturing of the ligament necessitates a frame that can be broadcasted with fibroblast and other mesenchymal stalk cells that fund the neo-ligamentous progress before the application of the device/surgery. The scaffolds/frames ought to derive from genetic polymers such as silk fibroin and collagen, as well as recyclable engineered polymers such as poly-L-Lactic acid (Guidoin M, et al., 2000). Others contain poly-caprolactone and polycarbonate. The scaffoldings are capable of supporting the cellular bond, matrix installation, and growth if they are provided with an apt mixture of the mechanical stimulation and development factors (Petrigliano, et al., 2006). However, the accurate regimen of cell explicit growth aspects, nutrients, metabolites, and the accurate bodily and self-motivated mechanical setting essential to growing appropriately controlled ligament tissue have not yet been discovered. Current research is promising enough that none of the tissue-engineered concepts has been revealed to retain satisfactory strength or construction for practical ligament replacement in vivo (Venjak-Novakovic, et al., 2004). Current designs also include the biological grafts such as auto grafts and allografts. The synthetic implants such as the ACL prosthetics include permanent prosthetics, augmentation devices, and scaffolds. Permanent prosthetics have the function to replace the knee ACL (Aichroth & Cannon, 1992, 547). Others include the augmentation devices provided initial protection auto grafts. The scaffolds are intended to regrow the native tissue without being accompanied by an auto graft. Conclusion Prosthetics devices have been developed and innovated over a series of years. As many fails, the newer version of the artificial forms is industrialized to handle the problems encountered by the earlier versions. However, during the manufacturing process of the products. The control process of the design and risk analysis of the device provide ways to improve the performance of the manufactured device. The measures have led to the improved performances linked to the newer versions of the ACL prosthetic devices. The research presents that former devices have failed due to fatigue and elongation after several years of usage. Other challenges included the fiber abrasion damages against the flexural exhaustion of the bone surface as observed. The newer versions of the artificial device are designed in ways to mitigate the past-perceived undesirable effects. Synthetic ACL graft is successful and lead to long-term results with minimal complications. The issues linked to artificial prosthetics include the failure of the graft through rupture, increases in laity and recurrent effusions among other complications reported. However, they also offer advantages such as lack of donor site morbidity, lack of disease transmission and others such as revascularization among others. The ACL prosthetic assists in eliminating some of the problems linked to the biocompatibility among other recurrent failures. Bibliography Aichroth, M. P. & Cannon, D. W., 1992. Knee Surgery: Current Practice. Illustrated ed. New York: CRC Press. Christel, P., 1994. Prosthetic replacement of the anterior cruciate ligament: A challenge.. Clinical Materials, 15(1), pp. 3-13. Dericks, G., 1995. Ligament advanced reinforcement system anterior cruciate ligament reconstruction. Operative Techniques in Sports Medicine, 3(3), pp. 187-205. Freeman, J. W., Woods, M. D. & Laurencin, T. C., 2007. Tissue Engineering of the Anterior Cruciate Ligament Using a Braid-Twist Scaffold Design.. Journal of Biomechanics, 40(9), p. 2029–2036. Fujikawa, K., Iseki, F. & Seedhom, B. B., 1989. Seedhom, Arthroscopy after Anterior Cruciate Reconstruction with the Leeds-Keio Ligament.. Journal of Bone and Joint Surgery, British Volume, 71(4), pp. 566-570. Guidoin M, F. et al., 2000. Analysis of retrieved polymer fiber based replacements for the ACL. Biomaterials, 21(23), pp. 2461-2474. Lange, F., 1903. Uber Die Sehnenplastik. Veh Dtsch Orthop Ges, pp. 10-12. López-Vázquez, E., Juan, J. A., Vila, E. & Debon, J., 1991. Reconstruction of the anterior cruciate ligament with a Dacron prosthesis.. Journal of Bone and Joint Surgery, American Volume, 73(9), pp. 1294-1300. Machotka, Z. et al., 2010. Anterior cruciate ligament repair with LARS (ligament advanced reinforcement system): a systematic review. Sports Medicine, Arthroscopy, Rehabilitation, Therapy $ Technology, pp. 2-29. Mascarenhas, R. & MacDonald, P. B., 2008. Anterior Cruciate Ligament Reconstruction: A Look at Prosthetics - past, Present and Possible Future. McGill Journal of Medicine , 11(1), pp. 29-37. McPherson, G. K. et al., 1985. Experimental mechanical and histologic evaluation of the Kennedy ligament augmentation device.. Clinical Orthopaedics and Related Research, Volume 196, pp. 186-195. Mody, B. S., Howard, L., Harding, M. L. & Learmonth, D. J., 1993. The ABC carbon and polyester prosthetic ligament for ACLdeficient knees. Early results in 31 cases. The Journal of Bone $ Joint Surgery, British Volume, 75(5), pp. 818-821. nlm, 2016. NIH U.S National Library of Medicine. Medline Plus: Knee Joint Replacement. [Online] Available at: https://www.nlm.nih.gov/medlineplus/ency/article/002974.htm [Accessed 17 3 2016]. Petrigliano, F. A., McAllister, D. R. & Wu, B. M., 2006. Tissue engineering for anterior cruciate ligament reconstruction: a review of current strategies. Arthroscopy.. The Journal of Arthroscopic and Related Surgery, 22(4), pp. 441-451. Pruitt, L. A. & Chakravartula, A. M., 2011. Mechanics of Biomaterials: Fundamental Principles for Implant Design. Cambridge, UK: Cambridge University Press. Rowden, N. J., Sher, D., Rogers, G. J. & Schindhelm, K., 1997. Anterior Cruciate Ligament Graft Fixation: Initial Comparison of Patellar Tendon and Semitendinosus Autografts in Young Fresh Cadevers. The American Journal of Sports Medicine, 25(4), pp. 472-478. Venjak-Novakovic, G., Altman, G., Horan, R. & Kaplan, D. L., 2004. Tissue engineering of ligaments.. Annual Review of Biomedical Engineering, Volume 6, pp. 131-156. Read More