ObjectiveTo evaluate the short-term effectiveness of unicompartmental knee arthroplasty (UKA) for medial compartmental osteoarthritis of the knee. MethodsBetween January 2008 and October 2013, 18 patients with medial compartmental osteoarthritis of the knee were treated by UKA, including 11 males and 7 females with an average age of 67.2 years (range, 60-72 years). The disease duration ranged from 3 to 5 years (mean, 3.7 years). All patients had loading pain and walk-associated pain of the medial compartmental knee. The preoperative visual analogue scale (VAS) score was 6.8±1.4. The full-length radiograph of lower limb and anteroposterior and lateral radiographs of the knee showed medial compartmental osteoarthritis of the knee. According to Ahlback staging, 8 knees were at stageⅡand 10 knees at stageⅢ. The knee range of motion (ROM) was (112.3±11.3)°, and the angle of genu varus was (13.2±1.3)°. The American Hospital for Special Surgery (HSS) score was 59.0±6.4. ResultsPrimary healing of incision was obtained in all patients, and no infection or lower limb deep venous thrombosis occurred. All of the patients were followed up 6-50 months (mean, 28 months). No prosthetic loosening and dislocation or lesions of contralateral compartment and patellofemoral joint developed. At 6 months after operation, the VAS score was significantly reduced to 2.8±1.2 (t=9.20, P=0.00); most of patients achieved significant relief of pain. The HSS score was significantly increased to 92.0±3.1 (t=19.69, P=0.00); and the results were excellent in 12 cases, good in 5 cases, and poor in 1 case, with an excellent and good rate of 94.4%. The knee ROM was (115.2±10.2)°, showing no significant difference when compared with preoperative one (t=-0.81, P=0.23). The alignment of limbs showed that the angle of genu varus was significantly reduced to (6.8±2.1)° (t=10.99, P=0.00). ConclusionUKA has satisfactory short-term effectiveness in the treatment of medial compartmental knee osteoarthritis, however, long-term effectiveness need further studies.
Unicompartmental knee arthroplasty (UKA) has a long history and has many advantages in some aspects over total knee arthroplasty (TKA) for patients with suitable indications, but it has not been established as a treatment at the same level with TKA. Therefore, 80 members of the British Association for Surgery of the Knee (BASK) and the European Knee Society (EKS) were invited to attend a joint meeting with the aim of creating an evidence-based consensus statement on UKA, in London, UK (December 2019). A formal consensus process was undertaken at the meeting incorporating a multiple round Delphi exercise, with group discussion of areas of agreement and disagreement between rounds. Five consensus statements were issued: ① UKA should be offered as a successful alternative to TKA in patients undergoing arthroplasty who meet agreed indications. ② When consenting a patient for UKA, information including the benefits and risks that are specific to UKA, should be tailored to and discussed with the individual patient. ③ Evidence suggests that surgeons should avoid low-volume use of UKA to optimise outcomes for their patients. ④ Surgeons should use the contemporary evidence-based indications and contraindications for medial UKA. ⑤ Knee arthroplasty surgeons should have exposure to and training in UKA. On the basis of full study of the consensus, combined with the Expert Consensus on Perioperative Management of Unicompartmental Knee Arthroplasty in China in 2020, this paper elaborates the meaning of the final evidence-based consensus for clinicians’ reference.
ObjectiveTo summarize the priority and indications of the unicompartmental knee arthroplasty (UKA) and the evolution of minimally invasive surgery-UKA (MIS-UKA), and to discuss the effectiveness. MethodsThe related literature on UKA was extensively reviewed, summarized, and analyzed. ResultsRecently, satisfactory results has been achieved in UKA for the treatment of single room knee osteoarthritis. Both the design of the single condyle prosthesis and the surgical technique are becoming more advanced, which make the MIS-UKA possible. Especially the application of navigation computer and robot assisted system on UKA improves the accuracy of unicompartmental prosthesis implantation greatly. ConclusionThe superiority and indications of MIS-UKA are gradually expanding with the progress of surgical technique and the design of the single condyle prosthesis. However, whether the application of navigation computer and robot assisted system can improve the effectiveness needs to be further confirmed.
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 summarize the research progress of Oxford unicompartmental knee arthroplasty (UKA) in treating partial thickness cartilage loss (PTCL) in the medial compartment of the knee joint, aiming to further clarify the indications and optimize the effectiveness of Oxford UKA. MethodsA comprehensive review of recent domestic and international literature on Oxford UKA for PTCL in the medial compartment of the knee joint was conducted to summarize its application and research advancements. ResultsBased on current researches, the main indication for Oxford UKA is full thinckness cartilage loss in the medial compartment of the knee joint. Although it has shown certain effectiveness in treating PTCL in the medial compartment of the knee joint, there are also reports of opposite conclusions. Therefore, there is still controversy over whether Oxford UKA can be chosen for PTCL, and the large-sample and multi-center studies are needed to further clarify the controversy. Studies indicate that accurate preoperative assessment of cartilage damage severity is crucial for selecting appropriate candidates for Oxford UKA to optimize postoperative effectiveness. ConclusionOxford UKA may represent an effective treatment for patients with PTCL in the medial compartment of the knee joint. However, strict patient selection and precise preoperative evaluation are essential to ensure surgical success and long-term effectiveness.
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.
Objective To investigate the effect of Navio robot-assisted unicompartmental knee arthroplasty (UKA) on the biomechanics of knee joint during sitting-up movement, and to determine whether UKA can maintain the biomechanical characteristics of knee joint. Methods The clinical data of 8 patients with medial compartment osteoarthritis treated with medial fixed platform of Navio robot-assisted UKA between January 2018 and January 2019 and had the complete follow-up data were retrospectively analyzed. There were 4 males and 4 females; the age ranged from 58 to 67 years, with an average of 62.3 years. The disease duration was 6-18 months, with an average of 13 months. The varus deformity ranged from 4° to 6°, with an average of 5°; the knee flexion range of motion was 0°-130°, with an average of 110°. All patients had no extension limitation. The imaging data of bilateral knees during sitting-up movement were collected by biplane C-arm X-ray machine at 3 weeks before operation and 7 months after operation. The three-dimensional models of femur and tibia were established by dual-energy CT scanning, and the three-dimensional models of femur and tibia were matched and synchronized with the femur and tibia in X-ray film by automatic matching tracer software. The biomechanical parameters of femur and tibia were measured, including internal rotation/external rotation, varus/valgus, forward/backward displacement of medial and lateral tibia contact center, and lateral compartment joint space. Results Eight patients were followed up 5-7 months, with an average of 6.4 months. In the comparison of the affected side before and after operation, except for the difference of varus/valgus which was significant (t=4.959, P=0.002), the differences in other indicators was not significant (P>0.05). There were significant differences in varus/valgus and internal rotation/external rotation between healthy and affected sides at 3 weeks before operation (P<0.05), and the differences in other indicators was not significant (P>0.05). At 7 months after operation, the difference in the forward and backward displacement of medial tibia contact center was significant (t=3.798, P=0.007), and the differences in other indicators was not significant (P>0.05). Conclusion UKA can effectively correct the varus and valgus of the knee joint, and restore the rotational biomechanical characteristics of the affected knee joint. It does not affect the establishment of the lateral compartment joint space, but the medial and lateral tibia contact center still changes.
ObjectiveTo explore the feasibility and short-term effectiveness of lateral unicompartmental knee arthroplasty (LUKA) through a lateral parapatellar approach for lateral compartmental osteoarthritis (LCOA). MethodsBetween November 2010 and August 2012, 15 consecutive patients (15 knees) with LCOA were treated with LUKA. There were 7 men and 8 women with a mean age of 67.3 years (range, 51-82 years). The mean duration of disease was 5.4 years (range, 3-15 years). The left knee was involved in 6 cases and the right knee in 9 cases. According to Ahlback rating, there were 2 cases (2 knees) of grade I, 8 cases (8 knees) of grade Ⅱ, and 5 cases (5 knees) of grade Ⅲ. The incision length, operation time, blood loss, drainage, and complication were recorded. The pre- and post-operative knee function was evaluated by Hospital for Special Surgery (HSS) score system. The pre- and post-operative range of motion (ROM) and alignment of the lower limbs (hip-knee-ankle angle) were measured and compared. ResultsACL rupture or medial compartmental osteoarthritis occurred in 2 patients (2 knees) who changed to total knee arthroplasty (TKA); 1 case (1 knee) failed to follow up. The other 12 cases (12 knees) were followed up 32.5 months on average (range, 26- 45 months). The mean length of incision was 6.9 cm (range, 6-8 cm); the mean operation time was 115.8 minutes (range,90-155 minutes); the mean blood loss volume during operation was 152.2 mL (range, 105-250 mL); and mean drainage was 145.6 mL (range, 50-300 mL). At last follow-up, the average HSS score was significantly improved from 73.4±4.6 preoperatively to 94.6±2.1 postoperatively (t=14.240, P=0.000). The results were excellent in 9 cases, good in 2 cases, and fair in 1 case, with an excellent and good rate of 91.7%. The hip-knee-ankle angle was significantly decreased from valgus angle of (10.08±1.38)° preoperatively to valgus angle of (5.17±0.94)° postoperatively (t=14.626, P=0.000). Postoperative ROM was significantly improved to (123.75±4.09)° from (108.67±5.10)° preoperatively (t=8.998, P=0.000). Two patients developed superficial skin infection, which was managed with anti-inflammatory therapy and dressing. No patient had complication of deep vein thrombosis, prosthesis dislocation and loosing, or development of medial osteoarthritis. ConclusionLUKA through a lateral approach has the advantages of rapid recovery of joint function, less complication, and small trauma in the treatment of LCOA. Correct patient selection and further mid- and long-term studies, however, are essential.
ObjectiveTo investigate the effect of anterior cruciate ligament (ACL) integrity on the short- and mid-term effectiveness of mobile-bearing medial unicompartmental knee arthroplasty (UKA). MethodsThe clinical data of 128 patients with anteromedial osteoarthritis who underwent mobile-bearing medial UKA between June 2019 and June 2021 was retrospectively analyzed. According to the integrity of ACL structure under direct vision during operation, the patients were divided into normal group (30 cases), synovial defect group (53 cases), and longitudinal split group (45 cases). There was no significant difference in gender, age, body mass index, preoperative knee range of motion (ROM), hip-knee-ankle angle (HKA), Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and other baseline data among the 3 groups (P>0.05). The knee ROM, KSS score (including clinical and functional scores), WOMAC score (including pain, stiffness, and function scores) before operation and at last follow-up, the Lysholm score, International Knee Documentation Committee (IKDC) score, and Forgetting Joint Score (FJS-12) at last follow-up were recorded and compared among the 3 groups. Imaging examination was performed to evaluate the wear of cartilage in the lateral tibiofemoral compartment and patellofemoral compartment of the knee joint. HKA and posterior tibial slope (PTS) were measured at last follow-up. ResultsAll the patients of 3 groups were followed up 22-56 months (mean, 40.4 months). There was no significant difference in follow-up time among the 3 groups (P>0.05). At last follow-up, imaging examination showed no obvious cartilage wear progression of the lateral tibiofemoral compartment and patellofemoral compartment, and no adverse events such as aseptic loosening of the prosthesis, dislocation of the removable pad, or infection occurred during the follow-up. At last follow-up, knee ROM, HKA, KSS scores, and WOMAC scores of the 3 groups significantly improved when compared with preoperative ones (P<0.05). There was no significant difference in the changes of the above indicators before and after operation, and also the Lysholm score, IKDC score, FJS-12 score, and PTS among the 3 groups (P>0.05). ConclusionThe integrity of ACL has no significant effect on the short- and mid-term effectiveness of mobile-bearing medial UKA.
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.