In recent years, artificial joint surgery has developed rapidly, with great advances in mold design, prosthetic materials, biomechanics, component interchangeability, surgical instrumentation, and surgical techniques, resulting in encouraging surgical outcomes and prosthetic survival rates, with the major advancement in surgical techniques being the development of minimally invasive arthroplasty. Although minimally invasive techniques continue to advance and have strong theoretical and practical appeal, controversies and misconceptions still exist regarding the understanding, application, and performance of this technology. This article reviews the history and problems of minimally invasive techniques in joint surgery, and also looks forward to the development trend of minimally invasive joint surgery. Development history At present, minimally invasive replacement of artificial joints mainly involves the hip and knee joints. The concept of minimally invasive surgery of total knee arthroplasty (MIS-TKA) originated in the early 1990s, when Repicci and Eberle, and Romanowski introduced the use of minimally invasive techniques. The unicondylar replacement described by Repicci et al. differs from conventional TKA in that the incision is only 7-10 cm long, from the superior pole of the patella to the tibial joint line; it can be performed with a medial or lateral approach Price et al. compared small-incision UKA with standard-incision UKA and standard TKA, suggesting that small-incision UKA is twice as fast as conventional-incision UKA and three times faster than standard TKA in terms of recovery. In the late 1990s, inspired by the minimally invasive UKA technique, small-incision TKA techniques emerged: (1) Tenholder et al. used a limited quadriceps separation medial parapatellar approach, with the incision of the joint capsule starting 2-4 cm above the patella and the quadriceps tendon separated along the medial 1/3, along the medial edge of the patella to the medial patellar ligament stop; (2) Laskin et al. and Haas et al. ‘s transmedial femoral approach, the parapatellar support band and joint capsule were incised from the medial superior pole of the patella down to the top of the tibial tuberosity, and the medial femoral muscle belly was separated obliquely in a full layer 2-3 cm medially; (3) Masri et al.’s inferior femoral approach, the medial joint capsule was incised along the medial edge of the patellar tendon to the end of the tibial tuberosity, and the quadriceps and quadriceps tendons and suprapatellar capsule were left in place. The lower leg was internally rotated, the belly of the internal oblique femoral muscle was stretched, and a 2-3 cm medial incision was made along the midpoint of the medial edge of the patella, followed by blunt separation of the medial femoral space. Subsequently, Tria and Coon proposed a limited medial capsulotomy for MIS-TKA (quadficeps sparing TKA, Qs-TKA) without damage to the quadriceps muscle. the distal end of the Qs approach capsulotomy follows the medial edge of the patellar tendon, through the medial edge of the patella, to the attachment of the quadriceps tendon at the superior edge of the patella, and the surgical approach does not interfere with the The surgical approach does not interfere with the quadriceps muscle and tendon. The basic conditions of minimally invasive surgery are gradually formed without destroying the activity mechanism of the quadriceps muscle, without destroying the suprapatellar capsule, and without turning the patella. Minimally invasive artificial hip replacement The minimally invasive replacement of artificial hip joint has undergone a process from the miniaturization of traditional incision to the minimally invasive replacement that does not damage the muscles. Early total hiparthroplasty (THA) included: (1) Nakamura et al.’s postero-lateral approach, which was a miniaturized and precise version of the conventional postero-lateral approach, and although part of the short extensor muscle was cut, the repair of the severed joint capsule and tendon was emphasized intraoperatively; (2) Jones et al.’s antero-lateral approach, in which the anterior 1/3 and posterior 2/3 of the gluteus medius muscle were cut. (2) Jones et al.’s anterolateral approach, i.e., the anterior 1 /3 and posterior 2/3 of the gluteus medius, with an “L” shaped incision of the gluteus minimus and its inferior capsule, also emphasizing repair of the severed capsule and re-suturing of the severed gluteus minimus and gluteus medius at the stop. Without compromising the efficacy of conventional THA and minimizing the impact of surgery on the local anatomical and biological environment, two types of minimally invasive surgery of THA (MIS-THA) have emerged: (1) the anterolateral approach: the interval between the broad fascial tensor and suture muscles and the interval between the rectus femoris muscles, in which The anterolateral capsule is exposed after cutting and ligating the external vascular plexus, including the double-incision approach of Berger et al. for MIS-THA, the anterolateral single-incision approach of Siguier et al. for MIS-THA, and the triple-incision approach of Kennon et al. for MIS-THA.( 2) Anterolateral approach: the gluteus medius and broad fascial tensor muscle gap approach is chosen, that is, Rfttinger’s Munich bone surgery (Orthopadische Cherurgie Mfinchen, OCM) approach, the operation is chosen in the gluteus medius and broad fascial tensor muscle gap, there is no dissociation or cleavage of the gluteus medius muscle, no lameness caused by damage to the gluteus medius muscle; the acetabulum can be viewed directly and The femur can be operated without fluoroscopic positioning during surgery. In addition to the minimally invasive operation, the advantages of minimally invasive techniques are further reflected by the continuous improvement of postoperative pain control and rehabilitation training. Minimally invasive arthroplasty is truly minimally invasive when it minimizes interference with the local anatomical and biological environment of the joint without compromising the efficacy of traditional arthroplasty. Traditional arthroplasty requires adequate visualization as a guarantee of surgical safety and thoroughness, as well as precise placement of endosseous implants. Minimally invasive replacement is becoming more and more accepted by orthopedic surgeons and patients, but there are still controversies and misconceptions in the development of minimally invasive replacement: the concept of minimally invasive, small incision does not mean minimally invasive, not the smaller the incision the less traumatic, minimally invasive replacement emphasizes the protection of soft tissues, the quality of surgery should not be sacrificed for the pursuit of small incision in difficult cases, and the incision should be extended in time if necessary. The unilateral pursuit of small incisions will only bring about greater intrinsic surgical trauma and even unnecessary complications. Minimally invasive joint replacement surgery is still in its infancy in China. Due to the high technical requirements of minimally invasive joint replacement with small incisions, the surgeon must be skilled in the surgical operation process. Therefore, only skilled joint replacement specialists with formal training and an understanding of the essentials of minimally invasive joint replacement are suitable to perform this technique. The use of minimally invasive surgical instruments, a dedicated surgical team, strict surgical indications, meticulous surgical planning, meticulous surgical operations, aggressive rehabilitation and good analgesia can reduce complications and make minimally invasive joint replacement surgery truly beneficial to patients. 159 postoperative complications of orthopaedic surgeons performing the double-cut El procedure after training in this procedure, with the first 1O cases performing the procedure having the most complications, and good training and surgical technique significantly reducing the incidence of complications. Similarly, the successful performance of minimally invasive surgery requires special minimally invasive tools. In MIS-THA, a special traction surgical bed, modified overbend Hohmann pulling hook, filing and placement tools with offset, and standard component prosthesis are necessary to ensure a successful procedure. Also in MIS-TKA, reduced and modified surgical instruments are required to complete the surgical operation with a staged osteotomy and a moving window technique. The indications for MIS-TKA include: patients with a body mass index (BMI) of ≤30, but not those with a BMI >30, especially those with developed leg muscles; those who can detach the femoral head intraoperatively; those who do not require revision and reconstruction of the acetabulum; and those who are not in need of the MIS-TKA. The indications for MIS-TKA are: inversion of the knee should be limited to 15, valgus to 2O, flexion contracture to less than 1O, and mobility to at least 90; moderate width of the femoral condyle and long patellar ligament length. Minimally invasive surgery can significantly improve the immediate postoperative results, reduce postoperative pain due to less trauma, reduce intraoperative and postoperative bleeding, and shorten postoperative rehabilitation and hospitalization time. However, there is no data to show that it can significantly improve the long-term results of joint replacement, and some literature shows that the results are comparable to those of conventional joint replacement surgery at 3-6 months postoperatively. At the same time, there are more and more clinical reports about the occurrence of complications of minimally invasive surgery, so it is necessary to objectively assess its clinical effects. Fourth, exaggerating and ignoring surgical complications In MIS-TKA, the surgical results can be directly affected by the reduction of the revealed surgical incision, split osteotomy, incomplete removal of bone flab, incomplete restoration of force lines, poor placement of the prosthesis, and incomplete removal of spilled bone cement, which may increase the incidence of potential complications. The same issues also affect MIS-THA. Bal and Hahom summarized that 87 patients undergoing initial MIS-THA with a double incision had to undergo revision surgery for complications in 10% of patients at 6-month follow-up, a higher rate of complications than with conventional THA. archibeck and while suggested that in patients undergoing double-incision MIS-THA Complications of MIS-TKA due to smaller incisions and less exposure include malposition of the prosthesis, contusion of the wound edges, muscle injury, and hematoma. injury, poor rotation of the femoral prosthesis, proximal femoral fracture, fracture hematoma formation, wound edge contusion, muscle injury, etc. However, while attention should be paid to these complications, overstatement of the relationship between the occurrence of complications and the minimally invasive procedure itself should be avoided. Complications are not the inevitable result of the application of new technologies, but are mostly due to various factors such as the surgeon’s early inexperience, incomplete mastery of surgical indications, failure to use the correct operating techniques and unavailability of hardware conditions, which can be avoided by strict training of the operator, correct patient selection and improvement of hardware conditions. V. Other factors affecting outcome evaluation Minimally invasive surgery is an enrichment and development of traditional techniques, and is not intended to replace the existing ones; its emergence has changed the concept of successful arthroplasty. The aim of minimally invasive surgery is to reduce postoperative pain and shorten the length of hospital stay and the use of mobility aids. For the patient, the clinical outcome and long-term functional results are what matters most. The longest clinical follow-up is now less than 10 years, so the long-term results of minimally invasive surgery need to be further evaluated. Some of the early short-term follow-up results suggest that minimally invasive arthroplasty may be beneficial, but these studies were performed on screened cases with modified postoperative analgesia and rehabilitation programs, and the results of a large, randomized, double-blind controlled study of MIS-THA, first reported by Ogonda et al, raise questions about the possible benefits of minimally invasive techniques. . After close follow-up observations, the authors found no significant short-term superiority of the minimally invasive technique over standard surgery, either in terms of postoperative pain levels, analgesic medication, or perioperative blood loss, length of hospital stay, and early functional recovery. Therefore, statistical analysis should be performed in I clinical comparison studies to objectively and scientifically evaluate the immediate as well as long-term clinical outcomes of minimally invasive joint replacement surgery. In addition, clinical evaluation results are influenced by multiple factors, such as improvement in recent outcomes, patient satisfaction is influenced by multiple factors such as patient expectations, aesthetics, pain management, postoperative rehabilitation, and quality of service of medical and nursing staff, and minimally invasive techniques are not the only factor for patient satisfaction. Similarly, clinical outcomes are influenced by postoperative pain levels, patient activity, quality and position of prosthesis fixation, and complication rates. Therefore, an objective clinical outcome evaluation must be confirmed by more cases and longer follow-ups. The development of minimally invasive arthroplasty is now aimed at reducing incisions, reducing soft tissue trauma, improving anesthesia and analgesia, and accelerating the recovery process, but still using existing prostheses. Minimally invasive surgery through small incisions is achieved through precise positioning of the surgical incision, flexible retraction, improved surgical tools, and increased use of regional block anesthesia. Precise positioning of the incision means that the skin incision is just long enough to fit the prosthesis in place and that the osteotomy tool takes up as little space as possible within the incision. The small incision also pursues the most advantageous approach: in MIS-TKA, the Qs approach is the least disruptive to the knee joint and best protects the knee extensor device, but due to the different types of quadriceps ventral access points, the low access point of the medial femoral muscle is not suitable for the Qs approach. A transmedial femoral approach can meet the needs of most procedures, and forcing a Qs approach can result in surgical failure. Theoretically, the muscle gap approach is the true superior approach for MIS-THA surgery, but the long and challenging learning curve of the double incision and the need for repeated intraoperative fluoroscopic positioning limit the promotion of this procedure. conditions and the choice of indications. The minimally invasive postero-lateral approach to THA has the advantage of easy exposure of the femur and operation, short learning curve, and most orthopaedic surgeons are used to the lateral postero-lateral approach, so the minimally invasive postero-lateral approach can be the recommended approach for beginners. A more important line of development for minimally invasive arthroplasty is the new technology line, which includes computer-assisted surgery, combined prosthesis and prosthesis miniaturization. In particular, computer-hased Mignment systems have been developed and used in TKA to address the inherent shortcomings of the mechanical surgical operating system. Both image-free navigation systems and passive navigation systems that require images (most commonly preoperative CT images) are basically based on optoelectronic positioning systems. The advantages of the navigation system are: accurate placement of the prosthesis; more accurate soft tissue release, so that the postoperative joint tightness is closer to the actual; no invasion of the femoral and tibial medullary cavities, so mechanical intramedullary and extramedullary guidance is not required, avoiding errors and reducing the possibility of postoperative bleeding and fat embolism; high accuracy; real-time TKA alignment and lower extremity force lines, which can be corrected at any time during the operation. Passive navigation systems without imaging data are also used in THA and have the advantage of overcoming the shortcomings of traditional preoperative design plans with two-dimensional simulation; intraoperative positioning is not influenced by the patient’s position and pelvic position and gives the orthopaedic surgeon immediate intraoperative feedback about the position and orientation of the bone, implanted prosthesis and surgical instruments. The combination of computer navigation system and minimally invasive replacement technology can effectively compensate for the defects of difficult anatomical positioning in minimally invasive surgery, obtain accurate prosthesis placement and correct force lines, and reduce the risks associated with minimally invasive surgery, making minimally invasive arthroplasty more promising. Future directions for minimally invasive arthroplasty are: further improvements in tools, ease of handling and miniaturization for accurate operations in limited environments; refinement of existing techniques and proper use of minimally invasive techniques; proper assessment of clinical outcomes of minimally invasive arthroplasty; selection of the optimal surgical approach; more physiologically correct prosthesis design, individualization, miniaturization, and advances in materials; and introduction of navigation systems. In conclusion, the concept of minimally invasive joint replacement surgery is to exchange minimal additional local and systemic damage for optimal treatment results. Through improvements in surgical technique and prosthesis design, as well as the development of computer-assisted technology, it is expected that uniform standards will be established and extended to most minimally invasive arthroplasties. Any mapping and research in this process should be done in a way that does not sacrifice the interests of the patient and ensures that minimally invasive surgery has at least comparable clinical results to standard surgery.