Effectiveness of unicompartment allografts replacement for bone tumor around the knee / 中国修复重建外科杂志

Objective: To analyze the effectiveness of unicompartment allografts replacement for reconstructing bone defect after bone tumor resection around knee.

Analysis and Treatment of Complications after Unicompartmental Knee Arthroplasty

PURPOSE: To analyze the causes and types of complications after unicompartmental knee arthroplasty (UKA) and determine proper prevention and treatment methods. MATERIALS AND METHODS: A total of 1,576 UKAs were performed for osteoarthritis of the knee from January 2002 to December 2014 at one institution. We analyzed complications after UKA retrospectively and investigated proper methods of treatment. RESULTS: A total of 89 complications (5.6%) occurred after UKA. Regarding the type of complications after UKA, there were 42 cases of dislocation of the mobile bearing, 23 cases of loosening of the prosthesis, 6 cases of periprosthetic fracture, 3 cases of polyethylene wear, 3 cases of progression of arthritis in the contralateral compartment, 2 cases of medial collateral ligament injury, 2 cases of impingement, 5 cases of infection, 1 case of arthrofibrosis, and 2 cases of failure due to unexplained pain. The most common complication after UKA was mobile bearing dislocation in the mobile-bearing knees and loosening of the prosthesis in the fixed-bearing knees, but polyethylene wear and progression of arthritis were relatively rare. The complications were treated with conversion to total knee arthroplasty in 58 cases and simple bearing change in 21 cases. CONCLUSIONS: The most common complication after UKA was dislocation of the mobile bearing. When a complication occurs after UKA, appropriate treatment should be performed after accurate analysis of the cause of complication.

Are "Patellofemoral Symptoms" Truly Related to the Patellofemoral Joint?

PURPOSE: The pattern of symptoms of knee osteoarthritis has been thought to be indicative of specific compartment involvement. This study investigated whether there was a true correlation between patellofemoral joint (PFJ) symptoms and unicompartmental patellofemoral arthritis. MATERIALS AND METHODS: A prospective analysis of 34 patients rendered to be suffering from PFJ osteoarthritis and subsequently undergoing unicompartmental patellofemoral arthroplasty (PFA) was performed. A control cohort of 32 patients suffering from medial tibiofemoral joint (MTFJ) osteoarthritis was included in the analysis. Four questions derived from the Oxford knee score questionnaire, traditionally deemed to be indicative of PFJ osteoarthritis, were combined to create a PFJ subscore and statistically analyzed for their potential relationship with PFJ osteoarthritis and outcomes following PFA. RESULTS: The PFJ subscore indicated slightly worse pathology in patients undergoing PFA compared to MTFJ replacement, but the difference was not significant (9.7 and 9.6, respectively; p=0.851). The improvement in PFJ symptoms was higher in those undergoing PFA compared to MTFJ surgery; however, the difference was not statistically significant (3.7 and 2.2 respectively, p=0.074). CONCLUSIONS: We were unable to prove that these symptoms were predictive of PFJ pathology in the preoperative setting, nor were they useful in interpreting which symptoms would likely improve following PFA.

Clinical Results of Lateral Unicompartmental Knee Arthroplasty: Minimum 2-Year Follow-up

BACKGROUND: We investigated the clinical results and early complications after lateral unicompartmental knee arthroplasty (UKA) using the Zimmer unicompartmental high-flex knee (ZUK) prosthesis with a minimum follow-up of 2 years. METHODS: Twenty-seven patients (30 cases) who underwent lateral UKA with the ZUK prosthesis between January 2011 and February 2014 were selected for this study. The mean age of the patients was 63.3 years at the time of surgery, and the mean follow-up was 3 years and 2 months (range, 24 to 48 months). A retrospective investigation method was used to evaluate the clinical and radiographic results with use of the Knee Society (KS) clinical rating system and plain radiography. RESULTS: The mean KS pain score was improved from 17.9 points (range, 10 to 30 points) preoperatively to 40.5 points (range, 30 to 45 points) at the final follow-up (p < 0.001). The mean KS knee score and function score significantly increased from 63.2 points (range, 48 to 70 points) and 68.6 points (range, 35 to 80 points), respectively, preoperatively to 86.0 points (range, 74 to 95 points) and 92.4 points (range, 60 to 100 points), respectively, at the final follow-up (p < 0.001). The mean range of motion of the knee was recovered from 127.1° (range, 110° to 135°) preoperatively to 131.6° (range, 120° to 135°) at the final follow-up. The mean tibiofemoral angle changed from 6.2° of valgus (range, 0.1° to 11.4° of valgus) preoperatively to 3.4°of valgus (range, 0.2° to 9.5° of valgus) at the final follow-up. The overall results classified based on the KS knee score were "excellent" in 21 cases and "good" in 8 cases. Revision total knee arthroplasty was required in one case because of consistent pain on the medial side of the knee after surgery. CONCLUSIONS: The early clinical results of lateral UKA using the ZUK prosthesis were satisfactory for improvement of pain, knee score, function score, and recovery of knee motion. Therefore, the lateral UKA could be a useful method in the treatment of osteoarthritis in the lateral compartment of the knee. Long-term survivorship remains to be confirmed through ongoing follow-up.

Outcome of Unicompartmental Knee Arthroplasty: A Systematic Review of Comparative Studies between Fixed and Mobile Bearings Focusing on Complications

The purpose of this systematic review is to collate results of studies comparing fixed and mobile bearing unicompartmental knee arthroplasty (UKA), focusing on complications and timing for reoperations. Out of 723 results derived from PubMed, EMBASE and Cochrane database search engines on bearings in arthroplasty, 10 studies comparing clinical results of fixed bearings to mobile bearings in UKA were found eligible for analysis. The reoperation rate was calculated using a novel method such as reoperations per hundred component years, and the causes of specific reoperations were investigated. The overall reoperation rate per hundred component years was similar between the mobile bearings (1.392) and fixed bearings (1.377); however, mobile bearings were more susceptible to reoperations in cases with aseptic loosening (0.393>0.255), progression of arthritis (0.428>0.357) and implant dislocation (0.286>0). The overall incidence of complications is similar for fixed and mobile bearing designs in UKA. The discussion on complications presented above may assist surgeons in their choice of bearing design.

The Influence of Postoperative Tibiofemoral Alignment on the Clinical Results of Unicompartmental Knee Arthroplasty

PURPOSE: To evaluate the influence of postoperative tibiofemoral alignment on the clinical results and failure in patients who underwent unicompartmental knee athroplasty (UKA). MATERIALS AND METHODS: We reviewed 246 cases of medial UKA which were followed up for at least 5 years after the operation. The clinical results were compared between 5 groups classified according to the tibiofemoral angle that was measured at 3 months after surgery. We analyzed the relationship between the tibiofemoral alignment and the failure after UKA. RESULTS: The preoperative tibiofemoral angle was changed from 0.4degrees of varus to 5.4degrees of valgus after surgery and the average correction angle was 5.8degrees. During the follow-up, which averaged 7 years and 5 months, the knee score and function score were improved significantly in all groups regardless of the tibiofemoral angle (p0.05). However, there were significant differences in the cumulative survival rate of implants between the groups and the highest rate was found in the group with a tibiofemoral angle of 4degrees to 6degrees of valgus (p<0.01). CONCLUSIONS: The tibiofemoral angle after UKA had no significant influence on the midterm clinical scores, but there was a significant relationship between the postoperative tibiofemoral angle and failure rate of implant.

The Influence of Symtomless Degenerative Changes of the Patellofemoral Joint on Clinical Results of Medial Unicompartmental Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: To evaluate the influence of degenerative changes in the patellofemoral joint on the clinical results of medial unicompartmental knee arthroplasty (UKA). MATERIALS AND METHODS: Between January and December 2002, we operated on 180 cases of minimally invasive UKA using the Oxford(R) phase 3. Of the 180 cases, 156 were followed up for a minimum period of 5 years. Based on intraoperative degenerative findings of the patellofemoral joint, we classified cases into 4 groups (Group I-78 cases, Group II-40 cases, Group III-27 cases, Group IV-11 cases), and the clinical data were analyzed prospectively. RESULTS: During follow-up, which averaged 6 years and 2 months, the knee score, the knee function score, the range of knee motion and the tibiofemoral angle were improved significantly (p0.05). To date, no complication or failure involving the patellofemoral joint has been observed. CONCLUSION: Clinical results of UKA are satisfactory for all groups, and the severity of patellofemoral degeneration has no influence on clinical outcome. Symptomless degenerative arthritis of the patellofemoral joint is not a contraindication for medial UKA.

Causes and Treatments of the Early Failure after Unicompartmental Knee Arthroplasty

PURPOSE: We wanted to evaluate the causes, treatments and preventive measures for early failure of unicompartmental knee arthroplasty (UKA) by performing an analysis of the cases. MATERIALS AND METHODS: We retrospectively analyzed 687 cases of UKA that had been performed from January 2002 to December 2006. There are 622 cases of the meniscal bearing type, 31 cases of the tracked bearing type and 34 cases of the fixed bearing type. All of the cases were performed by minimally invasive surgery. RESULTS: Early failures after UKA were seen in 36 cases, and these failures occurred from 4 months postoperatively to 5 years 7 months postoperatively. There were 20 mobile bearing dislocations, 18 femoral or tibial component loosenings, 4 infections, 1 medial tibial condylar fracture and 1 case of pain of unknown origin. The most common cause of the failed cases of the meniscal bearing type was bearing dislocation. All of the failed cases of the tracked and fixed types were from loosening of the component. Simple dislocations of bearing were treated by bearing change. All of the other cases were treated with revision TKA or UKA. CONCLUSION: Selection of an appropriate prosthesis and accurate surgical technique are needed to improve the clinical results and reduce failures. Open bearing change can be done for the cases of simple bearing dislocation, and revision TKA is needed if this is accompanied by other complications.

Comparative Study for the Results of Unicompartmental Knee Arthroplasty in Patients Younger and Older than 60 Years of Age / 대한정형외과학회잡지

PURPOSE: We wanted to assess the relations between age and the outcome of unicompartmental knee arthroplasty (UKA) based on a comparative study of UKA patients younger than 60 years and UKA patients older than 60 years of age. MATERIALS AND METHODS: Among the patients who underwent a UKA between January 2002 and June 2003, 230 cases (the group of patients with ages under sixty consisted of 89 knees - group I, and the group of patients with ages over sixty consisted of 141 knees - group II) were followed up for at least 5 years after the operation. Clinical assessments were made using the Knee Society Score (KSS) rating system. RESULTS: The average KSS knee and function scores improved from 54.2 and 57.1 preoperatively to 87.3 and 85.2 at the last follow-up in group I, and from 54.7 and 54.3 to 89.5 and 81.7 in group II, respectively. The mean range of knee motion also improved from 129.4degrees to 132.9degrees in group I and from 126.8degrees to 133.2degrees in group II, respectively. There were 5 cases of failed UKAs in each group, and the survival rate of the implant at 5 years was 94.7% in group I and 96.6% in group II. CONCLUSION: The clinical results of UKA were satisfactory in both age groups. Group I had better results on the knee function score at the last follow-up, but there was no significant difference between both age groups. UKA can be a one of the reliable methods for the treatment of osteoarthritis in patients younger than 60 years of age.

Treatment of Spontaneous Osteonecrosis of the Knee Using the Oxford Unicompartmental Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the clinical and radiographic outcomes of unicompartmental knee arthroplasty (UKA) in patients with spontaneous osteonecrosis. MATERIALS AND METHODS: Between September 2002 and March 2005, 15 patients with 16 knees were treated with UKA for the treatment of spontaneous osteonecrosis. There were thirteen women and two men with a mean age of 64 years old. The clinical assessment was performed using the American Knee Society Score system. The preoperative radiography was analyzed according to the size and stage of the osteonecrotic lesion and the osteoarthritic changes. Postoperatively, the presence of new osteonecrotic lesion, loosening of the implant, subsidence and arthritic changes was recorded. RESULTS: The mean preoperative knee score and the knee function score was improved from 52.5 to 89.2 and 56.0 to 85.2, respectively. There was no new necrotic lesion in the lateral compartment, loosening of the implant, subsidence or arthritic change. CONCLUSION: UKA in patients with spontaneous osteonecrosis provided satisfactory clinical and radiological results in the short to medium term.

Investigation of the application value of arthroscope in unicompartmental knee arthroplasty / 中国矫形外科杂志

[Objective]To explore the value of the application of the arthroscope in unicompartmental knee arthroplasty(UKA)for the patients with medial osteoarthritis of the knee.[Method]A clinical retrospective study has been done on 30 knees in 21 patients.The patients were evaluated in preoperative X-rays,physical examination,the knee society score(KSS)evalution,the presentation of arthroscopical examination as well as the ultimate operation method.[Result]Arthroscopic examination showed that the osteoarthritis were mainly located in medial compartment of the knee.Tibia terrace cartilage and condyle of femur showed outbrige Ⅲ～Ⅳ degrees degeneration.26/30(87%)of the patients showed medial menisci injury in different degree,and 4/30(13.3%)of the patients showed lateral menisci degenerated,and pathological changes of osteoarthritis were located at front medial compartment.And 19/30(63%)of the patients combined Ⅰ～Ⅳ degrees of localized or broad patellar cartilage degeneration,the lateral compartment normal or localized patellar cartilage degeneration less than Ⅱ degrees for all patients.The result of the arthroscopic examination was consistent with the preoperative clinical examination and the imaging examination.All the patients received Oxford Ⅲ prosthesis UKA by microinvasive approach and there was no case that had to change operation method due to arthroscope detection.[Conclusion]1.The main purpose for the application of the arthroscopic in UKA is to deal with other disease inside the knee rather than to confirm the indication of the operation.2.Arthroscopy is an effective way for the patients combined lateral menisci injury and other compartmental mild osteoarthritis.