Objective To conclude the failure factors of unicompartmental knee arthroplasty (UKA), and summarize the research progress of revision surgery. MethodsThe literature on UKA at home and abroad in recent years was reviewed to summarize its risk factors, treatment methods, including the evaluation of bone loss, prosthesis selection, and surgical techniques. ResultsThe factors inducing UKA failure mainly include improper indications, technical errors, and others. The application of digital orthopedic technology can reduce failures caused by surgical technical errors and shorten the learning curve. There are a variety of options for revision surgery after UKA failure, including polyethylene liner replacement, revision with UKA or total knee arthroplasty, with adequate preoperative evaluation prior to implementation. The biggest challenge in revision surgery is the management and reconstruction of bone defects. ConclusionThere is a risk of failure in UKA, which needs to be treated with caution and should be determined according to the type of failure.
ObjectiveTo summarize research progress of change in bone mineral density (BMD) after knee arthroplasty and its diagnostic methods, influencing factors, and drug prevention and treatment.MethodsThe relevant literature at home and abroad was reviewed and summarized from research status of the advantages and disadvantages of BMD assessment methods, the trend of changes in BMD after knee arthroplasty and its influencing factors, and the differences in effectiveness of drugs.ResultsThe central BMD and mean BMD around the prosthesis decrease after knee arthroplasty, which is closely associated with body position, age, weight, daily activities, and the fixation methods, design, and material of prosthesis. Denosumab, bisphosphonates, and teriparatide et al. can decrease BMD loss after knee arthroplasty.ConclusionBMD after knee arthroplasty decreases, which is related to various factors, but the mechanism is unclear. At present, some inhibitors of bone resorption can decrease BMD loss after knee arthroplasty. However, its long-term efficacy remains to be further explored.
Objective To conclude the research progress of unicompartmental knee arthroplasty (UKA) in the treatment of elderly patients with knee osteoarthritis (KOA). Methods The literature on UKA at home and abroad in recent years was reviewed to summarize the clinical characteristics of elderly patients with KOA, perioperative management (including evaluating indications preoperatively, intraoperative prosthesis selection, postoperative complication management, etc). Results Through reasonable preoperative evaluation, prosthesis selection, and advanced perioperative management, for elderly patients with KOA who meet the indications, UKA can be considered. Compared with total knee arthroplasty, the incidence of postoperative complications in elderly patients undergoing UKA is lower, joint awareness is reduced, functional improvement and satisfaction are higher. Meanwhile, choosing appropriate prostheses and fixation methods can lead to a good survival rate. ConclusionUKA can provide a safe and effective treatment option for elderly patients with KOA within a certain range of indications.
ObjectiveTo compare the patient-reported outcomes regarding function, joint amnesia, and the quality of life after unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). Methods The clinical data of patients who received UKA or TKA between September 2017 and June 2018 were retrospectively analyzed. After propensity score matching, 40 patients (40 knees) each in TKA group and UKA group were finally included in the study. There was no significant difference between the two groups in gender, age, body mass index, surgical side, preoperative knee range of motion, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, clinical and function scores of knee society score (KSS) (P>0.05). At 2 years after operation, WOMAC score, KSS clinical and function scores were performed on the two groups of patients, and compared with preoperative ones; knee injury and osteoarthritis outcome score-physical function short form (KOOS-PS), short-form 36 health survey scale (SF-36 scale), and forgotten joint score (FJS) were also performed. Results At 2 years after operation, the total score of WOMAC, the clinical and function scores of KSS in the two groups significantly improved when compared with preoperative ones (P<0.05), but there was no significant difference in the total score of WOMAC, the individual score of WOMAC, the clinical and function scores of KSS between the two groups (P>0.05). The total KOOS-PS score in the UKA group was significantly lower than that in the TKA group (t=4.243, P=0.000), and the scores of writhing/knee rotation, kneeling, and squatting in the UKA group were significantly lower than those in the TKA group (P<0.05). The total FJS score in the UKA group was significantly higher than that in the TKA group (t=−6.334, P=0.000). In the UKA group, the scores of 7 items were significantly lower than those of the TKA group (P<0.05) including when walking over 15 minutes, when climbing stairs, when walking on uneven ground, when standing for long periods, when doing housework or gardening, when taking a walk or hiking, and when doing your favorite sport. The SF-36 scales of physiological function, energy, social function, emotional function, and mental health in the UKA group were significantly higher than those in the TKA group (P<0.05). Conclusion Compared with TKA, patients treated with UKA may have better knee function recovery, joint amnesia, and higher quality of life.
Objective To investigate the short- and mid-term effectiveness of unicompartmental knee arthroplasty (UKA) for post-traumatic arthritis (PTA) of knee. Methods The clinical data of 30 patients with PTA of unilateral knee between March 2014 and September 2021 was retrospectively analyzed. There were 14 males and 16 females with an average of 64.5 years (range, 33-81 years). The average body mass index was 26.7 kg/m2 (range, 19.8-35.6 kg/m2). The types of injuries that caused PTA included intra-articular fracture in 16 cases, extra-articular fracture in 8 cases, and soft tissue injury in 6 cases. The initial injuries were treated by conservative therapy in 12 cases and by surgical therapy in 18 cases. Ten cases were medial compartment osteoarthritis and 20 cases were lateral compartment osteoarthritis. According to Kellgren-Lawrence staging, there were 19 cases of grade Ⅲ and 11 cases of grade Ⅳ. The operative time, the length of hospital stay, complications, and subjective satisfaction were recorded. The Oxford Knee Function Score (OKS), Hospital for Special Surgery (HSS) score, and knee range of motion (ROM) were used to evaluate knee function. Weight-bearing X-ray films were taken to measure the femoro-tibial angle (FTA) and to assess alignment correction of the lower limb. Results The operative time ranged from 50 to 95 minutes (mean, 63.7 minutes), the length of hospital stay ranged from 3 to 8 days (mean, 6.9 days). Superficial infection occurred in 2 patients, while the remaining incisions healed by first intention. There was no deep vein thrombosis or neurovascular injury. All patients were followed up 17-109 months (median, 70 months). At last follow-up, OKS score, HSS score, and ROM in 30 cases significantly improved when compared with those before operation (P<0.05). Lower limb alignment was significantly corrected and there was significant difference in FTA of the varus and valgus knees between pre- and post-operation (P<0.05). The patient satisfaction rate was 86.7% (26/30). Two cases developed contralateral osteoarthritis progression during follow-up. No bearing dislocation, prosthesis loosening or sinking occurred and none required further revision. Conclusion For patients with PTA of knee, UKA can obtain definite short- and mid-term effectiveness with high patient satisfaction.
ObjectiveTo compare the short-term effectiveness of unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) in the treatment of medial compartment osteoarthritis (OA) of the knee so as to provide a reference for clinical selection of appropriate treatment. MethodsBetween January 2010 and June 2011, 28 cases of medial compartment OA of the knee underwent UKA in 16 cases (UKA group) and HTO in 12 cases (HTO group). Biomet Oxford phase Ⅲ unicompartmental knee prosthesis was used in UKA group, and closing wedge osteotomy in HTO group. There was no significant difference in gender, age, course of disease, side, body mass index, articular cartilage degeneration classification, preoperative knee range of motion (ROM), Lysholm knee score, Tegner activity score, and femorotibial angle (FTA) between the 2 groups (P>0.05). The patients of UKA group began weight-bearing walking with walking aids within 48 hours after operation, and the patients of HTO group began weight-bearing walking with walking aids at 6 weeks after operation, and gradually began full weight-bearing walking at 8-12 weeks. ResultsThere was no significant difference in operation time and intraoperative blood loss between 2 groups (t=0.406, P=0.688; t=-1.552, P=0.133). All incision healed primarily in both groups. No complications occurred in 2 groups. All patients were followed up 3.5 years on average (range, 3.0-4.5 years) in UKA group and 3.6 years on average (range, 3-4 years) in HTO group. There were significant differences in Lysholm knee score, Tegner activity score, and FTA in the 2 groups between before and after operation (P<0.05), but there was no significant difference in knee ROM (P>0.05). At last follow-up, there was no significant difference in all above indexes between 2 groups (P>0.05). The postoperative X-ray showed that all force lines of the lower limbs were corrected, and the prosthesis and internal fixation were fixed reliably. During follow-up, Kellgren-Lawrence Ⅱ degeneration of the lateral compartment was observed in 1 case of 2 groups respectively; Kellgren-Lawrence Ⅱ degeneration of the patellofemoral joint was observed in 1 case of the HTO group, there was no significant difference between the 2 groups (χ2=0.778, P=0.378). ConclusionBoth UKA and HTO have good short-term effectiveness for treating unicompartmental OA; however, the long-term effectiveness need further study and follow-up.
ObjectiveTo conclude the revision reason of unicompartmental knee arthroplasty (UKA) using computer-assisted technology so as to provide reference for reducing the revision incidence and improving the level of surgical technique and rehabilitation. MethodThe relevant literature on analyzing revision reason of UKA using computer-assisted technology in recent years was extensively reviewed. ResultsThe revision reasons by computer-assisted technology are fracture of the medial tibial plateau, progressive osteoarthritis of reserved compartment, dislocation of mobile bearing, prosthesis loosening, polyethylene wear, and unexplained persistent pain. ConclusionsComputer-assisted technology can be used to analyze the revision reason of UKA and guide the best operating method and rehabilitation scheme by simulating the operative process and knee joint activities.
ObjectiveTo review the research progress on finite element analysis (FEA) of unicompartmental knee arthroplasty (UKA) in medial knee compartmental osteoarthritis.MethodsThe FEA research literature on the medial knee UKA at home and abroad was reviewed, and the progress on the aspects of the influences of the prosthesis arrangement and the postoperative joint line on the mechanical distribution of the knee joint, the improvement of the UKA prosthesis, and the related research of different types of prostheses were summarized.ResultsAt present, scholars have conducted a large number of FEA studies on UKA in the medial knee compartmental osteoarthritis. The results of the study show that the recommended coronal alignment and the tibial slope angle of tibial component in medial fixed-bearing UKA are 0° and 5°-7°, respectively; and the coronal alignment and the tibial slope angle of tibial component in mobile-bearing UKA are 4° varus to 4° valgus and 5°-7°, respectively. The femoral component is arranged in the neutral position of the distal femur. The joint line is recommended to be the primary alignment. The anatomical UKA prosthesis can restore the biomechanical properties of the normal knee joint.ConclusionFEA research can clarify the best arrangement and joint line of the medial knee UKA prosthesis based on the mechanical distribution results, and guide the design of UKA prostheses that are more suitable for patients.
ObjectiveA prospective randomized controlled study was conducted to investigate the early postoperative analgesic effectiveness of using liposomal bupivacaine (LB) for local infiltration anesthesia (LIA) in unicompartmental knee arthroplasty (UKA). Methods Between January 2024 and July 2024, a total of 80 patients with knee osteoarthritis (KOA) who met the selection criteria were enrolled in the study. Patients were randomly assigned to either the LB group or the “cocktail” group in a 1∶1 ratio using a random number table, with 40 patients in each group. Baseline characteristics, including gender, age, body mass index, operated side, Kellgren-Lawrence grade, and preoperative American Society of Anesthesiologists (ASA) classification, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and knee joint range of motion, showed no significant difference between the two groups (P>0.05). Both groups received LIA and comprehensive pain management. The surgical duration, incision length, pain-related indicators [resting and activity visual analogue scale (VAS) scores, total dosage of oral morphine, WOMAC scores], knee joint range of motion, first ambulation time after operation, length of hospital stay, and postoperative adverse events. ResultsThere was no significant difference between the two groups in surgical duration, incision length, first ambulation time after operation, length of hospital stay, total dosage of oral morphine, and pre-discharge satisfaction with surgery and WOMAC scores (P>0.05). At 4, 12, and 24 hours after operation, the resting and activity VAS scores in the “cocktail” group were lower than those in the LB group; at 60 and 72 hours postoperatively, the resting VAS scores in the LB group were lower than those in the “cocktail” group, with the activity VAS scores also being lower at 60 hours; all showing significant differences (P<0.05). There was no significant difference in the above indicators between the two groups at other time points (P>0.05). On the second postoperative day, the sleep scores of the LB group were significantly higher than those of the “cocktail” group (P<0.05), while there was no significant difference in sleep scores on the day of surgery and the first postoperative day (P>0.05). Additionally, the incidence of complications showed no significant difference between the two groups (P>0.05). ConclusionThe use of LB for LIA in UKA can provide prolonged postoperative pain relief; however, it does not demonstrate a significant advantage over the “cocktail” method in terms of short-term analgesic effects or reducing opioid consumption and early functional recovery after UKA. Nevertheless, LB may help reduce postoperative sleep disturbances, making it a recommended option for UKA patients with cardiovascular diseases and insomnia or other mental health issues.