Anatomical And Clinical Studies For Selective Denervation To Therapy The Chronic Knee Pain After Total Knee Arthroplasty (TKA)

BACKGROUND: As the science and technology developed, various technologies inthe field of medicine have improved. However, the life expectancy and the aging havebecome increasingly serious and the improvement of people’s life quality has derivedmore and more attention. The rate of osteoarthritis caused by variety reasons is alsogrowing. With the development of medicine and the new materials research as well asthe emergence of new technology, total knee arthroplasty (TKA) has gradually becomean important method to treat knee joint osteoarthropathy and recover its function.According to the American orthopedic physicians (AAOS), there are about600000cases of knee joint replacement surgery each year in United States. It is estimated that more than3million patients would receive TKA each year till2030. Although therehas no statistics on this are in China, the amount of patients received total kneereplacement should be increase rapidly with the rising of domestic economy. However,knee joint pain after TKA is a serious challenge to the surgeon. Despite the clinicalsuccess of primary TKA, about20%of patients after TKA are not satisfied with theiroutcomes for several reasons. And15%of patients have chronic pain after TKA.However, the therapy about those patients always was not satisfied.Early denervation in1950was applied to the patient with wrist pain. Since then,there are more research reports related to neuropathic pain. In1994a U.S. surgeonnamed AL Dellon investigated the cutaneous nerve of knee and made a detailedanatomical study. Totally,45specimens were dissected in his study, the branch nervearound the knee, those nerves and the relative positional relationship between the softtissue and bony landmarks were observed. His results then were be used in clinicalstudy to treat nerve-related pain in patients after TKA，and satisfactory results wereachieved.15patients received denervation treatment after they were underwentprimary total knee arthroplasty and showed postoperative pain lasted more than sixmonths. Through the9to15months follow-up postoperative, these15patients getsatisfactory pain relief and the ROM of their knees had been improved significantlycompared with the preoperative.When the joint pain still persist，a neurogenic pain should be considered. As amatter of no related report about the innervation nearby the knee joint, conventionalview of the diagnosis excluded neurogenic pain. However this nerve really exists andthe pain impulses from arthritis or trauma, such as tumble or postoperative. Althoughnerve is the ultimate pathways of common pain, no reference of nerve distribution ofjoint. Many denervation surgery used in the other parts to release pain, however,denervation used in knee joint was reported earlier in foreign, poorly reported and used in domestic. Those patients accepted revision surgery or long-term use of drugs. Theanatomy of the articular and cutaneous nerves about the knee was investigated throughhuman anatomic specimens. The purpose of the current study was to confirm thefindings of the previous authors while expanding the number of specimens used in thestudy to determine variability in the patterns of innervation of the knee joint. Inaddition, we use MRI to scan the specimens to provide a three-dimensional model fordiagnostic nerve blocks, as well as surgical approaches to these structures.Relationship between cutaneous nerve around knee joint and postoperativepain of total knee arthroplasty (TKA)Objective：To explorer the innervation of knee joint and the possibility of selectivedenervation for the treatment of chronic pain after total knee arthroplasty (TKA).Methods: The anatomy of articular and cutaneous nerves of knee joint wasinvestigated by using eight cadavers, which included two adult corrosion and two freshbodies. The variability and location of the nerves were described and relationship ofthem to the soft tissue and bony landmarks were observed. And then, we used magneticresonance to scan the nerves and depicted their location by three-dimensionalreconstruction imaging. Results: There are three constant nerves existing at the medialaspect of the knee, two of which have cutaneous territories that extend across themidline. The innervation to the lateral knee skin is variable from either the lateralfemoral cutaneous nerve or branches of the femoral nerve. With very slim diameter,these nerves are superficial location and difficult to distinguish. Throughthree-dimensional magnetic resonance imaging, we can further clarify the nerve and itslocation as well as relationship to the bone marks around them. Conclusion: Thisanatomy provides a basis for nerve blocks and selective denervation in the treatment ofknee pain caused by neuroma or others unfamiliar neurogenic pain. Selective denervation to therapy persistent pain after Total Knee Arthroplastyand related researchObjectiv: To explore the effective of selective denervation to therapy persistentpain after TKA. Methods: A systematic diagnosis were used to exclude componentloosening, malalignment, knee instability, and infection, two patients with knee painafter TKA received selective denervation to reduce their pain. HSS and VAS were usedto evaluate the patients for one week before operation and one week, one month, sixmonth and one year after operation. Lower limbs myodynamia and superficialsensibility were evaluated before and after operation. Results: Compared with thepreoperative, HSS scored90and94points in one month,95and94in three month，outcome in six month and one year same as the third month. VAS scored3and2pointsin one month，1and2points in six month, score in six month and one year same as thethird month. HSS scored65and60in pre-operation, and VAS scored4and3points.Conclusion: Selective knee denervation is effective in the management of intractableknee pain of neuroma origin after total knee arthroplasty.