Cadherin-11 involves in synovitis and increases the migratory and invasive capacity of fibroblast-like synoviocytes of osteoarthritis.

OBJECTIVE: To detect the expression of cadherin-11 and its correlation with synovitis in osteoarthritis (OA), to explore the mechanism of over expression of cadherin-11 and its role in migratory or invasive capacity of fibroblast-like synoviocytes (FLS). METHODS: Synovitis severity was recorded according to Krenn's scoring system in 25 osteoarthritis patients undergoing total knee arthroplasty. Cadherin-11 expression in OA synoviums and its correlation with synovitis score and systemic inflammation markers were explored. After induction with Interleukin-1 beta (IL-1ß) or tumor necrosis factor-alpha (TNF-α),cadherin-11 expression on OA FLS was assessed by qPCR and western blot,the capacity of migration and invasion of OA FLS was tested by transwell assay, and matrix metalloproteinase-2 production was assessed with ELISA as cadherin-11 expression was up regulated after infection with cadherin-11 cDNA-containing lentivirus, also when cadherin-11 expression was knocked down after infection with cadherin 11 shRNA containing lentivirus. RESULTS: Cadherin-11 expression in OA synovium showed significant differences among different grades of synovitis. Cadherin-11 in the lining layer was positively correlated with hyperplasia of the lining layer, density of the resident cells, inflammatory infiltrate, total synovitis score and D-dimer. Cadherin-11 in the sublining layer was positively correlated with the density of the resident cells, inflammatory infiltrate, total synovitis score and erythrocyte sedimentation rate. IL-1ß or TNF-α could up-regulate cadherin-11 expression on OA FLS at transcriptional and protein level. Over expression of cadherin-11 increased migratory or invasive capacity of OA FLS, while cadherin-11 knock down reduced migratory or invasive capacity and MMP-2 production in OA FLS. CONCLUSION: The over expression of cadherin-11 in osteoarthritis is positively correlated with synovitis severity, and can be driven by proinflammatory cytokines on OA FLS; cadherin-11 increases migratory or invasive capacity and MMP-2 production of fibroblast-like synoviocytes of osteoarthritis.

The mid-term follow-up of revision total knee athroplasty / 中华外科杂志

<p><b>OBJECTIVE</b>To summarize the mid-term follow-up results of revision of total knee arthroplasty and compare the different strategies for infective revisions.</p><p><b>METHODS</b>All of 45 patients (47 operated knees) lived in Beijing were treated from April 1989 to October 2010 in Arthritis Clinic and Research Center, Peking University People's Hospital. There were 6 male and 39 female patients, who aged from 31 to 77 years (mean (62 ± 11) years). The function of knee, satisfaction and imaging then were compared retrospectively. American Knee Society Scores (KSS), Western Ontario & McMaster University Osteoarthritis Index (WOMAC), the medical outcomes study item short form health survey (SF-36) scales and satisfaction/pain visual analogue scales (VAS) of patients were evaluated. The patients were divided into infection group (33 patients, 34 knees) and non-infection group (12 patients, 12 knees) according to the indication of revision of total knee arthroplasty and compared by t-tests.</p><p><b>RESULTS</b>The time from operation to follow-up was 1 year and 2 months to 17 years. The mid-term follow-up time was 8 years 3 months. There were significant improvements of KSS clinical and function scores (from 66.9 ± 28.0 and 44.4 ± 37.6 to 25.4 ± 24.2 and 10.0 ± 24.8, t = 7.043 and 3.797, both P = 0.001). Patients of infection group had lower KSS clinical and function scores than non-infection group before operation, and lower Society Function (t = 2.225, 3.520 and 2.885, P = 0.035, 0.002 and 0.007). About the septic group, the II-stage group had significant better post-operation KSS function scores, Society Function, physical component summary, WOMAC functional score and WOMAC score than I-stage group (t = 2.160-3.268, P = 0.004-0.042). The 1-year, 2-year, 6-year, 17-year survival rate were 83.6%, 78.7%, 62.1%, 44.5%.</p><p><b>CONCLUSIONS</b>Revision total knee arthroplasty is an effective method for solving the failure of primary total knee arthroplasty. It can improve the pain and activity difficulty following the failure of primary total knee arthroplasty, and partially improve function along with quality of life. The results of non-infection group are better than infection group. There may be better results for II-stage revision total knee arthroplasty than I-stage revision. Both I-stage and II-stage revision total knee arthroplasty are effective.</p>

[Medium and long-term clinical results of using Zweymüller cup to treat protrusio acetabuli].

OBJECTIVE: To discuss long-term clinical results of using Zweymüller cup to treat protrusio acetabuli. METHODS: From May 1998 to September 2006, 31 patients with 39 hips diagnosed protrusio acetabuli were treated with Zweymüller cup in total hip arthroplasties or revisions. There were 12 men and 19 women with average age of 57.6 years (from 30 to 82 years). The reasons causing protrusio acetabuli were as followed: rheumatoid arthritis 3 cases 6 hips, osteoarthritis followed femoral head necrosis 7 cases 12 hips, acetabular wear after hemi-arthroplasty 11 cases 11 hips and acetabular component loosening 10 cases 10 hips. During all operations, Zweymüller cup was used to fix the acetabular part. RESULTS: All cases were followed up 6 months and one year after operations. Two patients with 3 hips were died for lung cancer and acute myocardial infarction respectively. Twenty-four cases with 31 hips got recent follow-up with average 7.4 years (from 5.0 to 11.5 years). The average Harris score improved from 31.0 (from 14 to 61) preoperatively to 84.7 (from 70 to 95) postoperatively. There was one infection in right hip after bilateral hip arthroplasty treating by removal prosthesis and cement spacer insert. But until now this patient still did not get revision for her internal medicine. One rheumatoid arthritis patient with two-stage bilateral hip arthroplasty was found slight internal migration and loosening line of left acetabular component, but the patient had no pain with good hip function. All other cases had good hip functions and were very satisfied with clinical results. CONCLUSION: Using Zweymüller cup to treat protrusion acetabuli can get strong fixations and perfect medium and long-term clinical results for over 7.4 years.

[Comparison of the status of STAT4 tyrosine phosphorylation in peripheral T-lymphocytes induced by IL-12 in rheumatoid arthritis and osteoarthritis].

OBJECTIVE: To compare the levels of STAT4 tyrosine phosphorylation in peripheral T-lymphocytes induced by IL-12 in rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: From May 2007 to August 2009, peripheral blood mononuclear cells (PBMCs) were isolated from RA patients [RA group, all the cases were female, the age was from 28 to 55 years with an average of (45.0 +/- 13.0) years] and OA patients [OA group, all the cases also were female; the age was from 55 to 75 years with an average of (67.0 +/- 9.6) years]. The purity of T-lymphocytes from PBMCs was accredited by flow cytometry. The IL-12 of 50 ng/ml added in T-lymphocytes, the levels of STAT4 tyrosine phosphorylation were detected by western blot after different time intervals (0, 10, 30, 60 min). RESULTS: The purity of T-lymphocytes were above 91% through diremption and depuration for peripheral blood monouclear cells. The levels of STAT4 tyrosine phosphorylation in T-lymphocytes from RA induced by IL-12 were higher than that from OA in the different times (10, 30, 60 min); after 30 min, its levels from RA and OA achieved to crest value. CONCLUSION: STAT4 in peripheral T-lymphocytes of rheumatoid arthritis was more easily to be activated than osteoarthritis.

[Primary study of relationship between lumbar degenerative disease and morbidity of primary knee osteoarthritis].

OBJECTIVE: To study the relationship between lumbar degenerative disease and morbidity of primary unilateral knee osteoarthritis. METHODS: The clinical data of 115 unilateral knee osteoarthritis patients and 119 bilateral knee osteoarthritis patients undergoing TKR (total knee replacement) at our hospital in 2008 were retrospectively analyzed. According to clinical signs of lumbar degenerative disease and radiological changes, these patients were divided into upper/lower/whole/none lumbar degenerative disease group respectively. chi(2) test was performed to compare the difference of lumbar degenerative conditions between unilateral knee osteoarthritis and bilateral knee osteoarthritis patients. RESULTS: The morbidity side of lumbar intervertebral disc protrusion or nerve root canal stenosis in primary unilateral osteoarthritis patients was the same as the morbidity side of primary unilateral osteoarthritis. Lumbar degenerative disease morbidity [(34 + 20 + 15)/115 = 60%] of primary unilateral knee osteoarthritis was higher than that [(3 + 5 + 4 + 6 + 19)/119 = 31.1%] of primary bilateral knee osteoarthritis (chi(2) = 19.723, P = 0.000);Upper lumbar degenerative disease morbidity (34/115 = 29.6%)of primary unilateral knee osteoarthritis was higher than that [(3 + 5)/119 = 6.7%] of primary bilateral knee osteoarthritis, (chi(2) = 20.720, P = 0.000); lower lumbar degenerative disease morbidity (20/115 = 17.4%)of primary unilateral knee osteoarthritis was higher than that [(4 + 6)/119 = 8.4%] of primary bilateral knee osteoarthritis (chi(2) = 4.227, P = 0.040); there was no difference for whole lumbar degenerative disease morbidity between primary unilateral and bilateral knee osteoarthritis patients (chi(2) = 0.402, P = 0.526). CONCLUSION: The primary unilateral knee osteoarthritis morbidity is correlated with lumbar degenerative disease for the same elder patient. Upper lumbar degenerative disease can induce the incidence and aggravation of primary unilateral knee osteoarthritis; the flexion deformity of primary knee osteoarthritis may cause the aggravation of lower lumbar degenerative disease, even upper lumbar degenerative disease.

Regulation of TNFalpha and IL1beta in rheumatoid arthritis synovial fibroblasts by leukotriene B4.

Arachidonic acid metabolites, such as leukotriene B4 (LTB4), are known to play an important role in pathogenesis of rheumatoid arthritis (RA). Apart from leukocytes, RA synovial fibroblasts (RASF) produce a broad array of inflammatory mediators to recruit, retain and activate immune cells and resident mesenchymal cells in the joints to promote ongoing inflammation and tissue destruction. To determine how LTB4 may contribute to this process, RASF was cultured from synovial tissues collected from RA patients undergoing total knee replacement. The level of LTB4 in culture medium was determined using ELISA, and expression of LTB4 receptors (BLT1 and BLT2) by RT-PCR. In the presence of exogenous LTB4, mRNA and protein levels of tumor necrosis factor-alpha (TNFalpha) and interleukin 1beta (IL1beta) were determined by real-time PCR and ELISA. Furthermore, we examined the effects of leukotrienes synthesis inhibitors, MK886 and bestatin, on mRNA and protein levels of TNFalpha and IL1beta in RASF. We found that LTB4 was present at a low concentration in the culture medium of RASF, and the major LTB4 receptor expressed in RASF was BLT2. LTB4 synthesis was activated by treatment with LIT (LPS, ionomycin and thapsogargin), and suppressed by MK886 and bestatin. Exogenous LTB4 remarkably increased the expression of TNFalpha and IL1beta at both the mRNA level and the protein level. In contrast, MK886 and bestatin significantly inhibited their expression. These data suggested that LTB4 contributed to RA by regulating the expression of TNFalpha and IL1beta in RASF. BLT2 was probably the major receptor mediating such effects.

[Effects of primary deep venous valvular incompetence of lower limb in deep vein thrombus after total knee replacement].

OBJECTIVE: To evaluate the effects of primary deep venous valvular incompetence of lower limb (PDVI) to the occurrence of deep vein thrombosis (DVT) after human total knee replacement (TKR). METHODS: One hundred and twenty-six patients who planed to receive TKR were examined by color doppler flow imaging (CDFI). The patients were divided into 2 groups depending on whether they were found backstreaming in femoral vein or not. When the refluxing time > 1 s, the patients were included in PDVI group; When the refluxing time < or = 1 s, the patients were included in without PDVI group. In 7 d after operation all the patients were re-examined by CDFI to find if there was DVT. The results were tested by chi2 statistical analysis. RESULTS: Among the 126 patients, 54 had PDVI, and 72 without PDVI. Fifty patients had DVT, total incidence rate 39.7% (50/126). In PDVI group 33 patients had DVT (61.1%, 33/54); In without PDVI group 17 patients had DVT (23.6%, 17/72), which was lower than PDVI group (chi2 = 21.227, P < 0.05). CONCLUSIONS: PDVI may be a risk for occurrence of DVT after TKR.

[Total knee arthroplasty in Charcot arthritis patients].

OBJECTIVE: To discuss the results of total knee arthroplasty undertaken for Charcot arthritis patients. METHODS: Between September 2000 and January 2007, 4 consecutive patients (2 men and 2 women; 5 TKAs) with Charcot arthritic knees were treated. At the time of surgery, the mean age of the patients was 67.3 years (64 to 72 years). One had bilateral and 2 had unilateral TKA and one had ipsilateral total hip and total knee arthroplasty. The mean knee society score before operation was 33.75 points. RESULTS: The mean follow-up was 65 months (19 to 96 months). The mean knee society score post-operation had improved to 95.25 points in 5 TKAs with no occurrence of infection and loosening. All 4 patients were very satisfactory with the clinical results at the last follow-up. CONCLUSIONS: The midterm follow-up data indicated that total knee arthroplasty to treat Charcot arthritis could get good clinical results. The postoperative results in Charcot arthritis were closed related with the proper prosthesis and surgical technique.

[Correlation between single nucleotide polymorphism of prothrombin gene G20210 and deep vein thrombosis after total joint replacement].

OBJECTIVE: To evaluate the correlation between prothrombin gene G20210A mutation and deep vein thrombosis after total joint replacement through detecting distribution frequency of single nucleotide polymorphism of the gene in patients undergoing total joint replacement. METHOD: PCR and direct sequencing of DNA are used to analyze the frequency of prothrombin gene G20210A mutation in 55 patients undergoing total joint replacement, and the relationship between the mutation and deep vein thrombosis after total joint replacement is evaluated. RESULT: Morbidity of prothrombin gene G20210A mutation in 55 patients is 0, both in either DVT group (27 patients) or non-DVT group (28 patients). There is no significant difference between the two groups (P>0.05). CONCLUSION: Mutation of prothrombin gene G20210A in Chinese patients is rare, and there is no correlation between the genetic mutation and deep vein thrombosis after total joint replacement.

Discoidin domain receptor 2 is associated with the increased expression of matrix metalloproteinase-13 in synovial fibroblasts of rheumatoid arthritis.

Regulation of matrix metalloproteinase-13 (MMP-13) by collagen matrix in the synovial fibroblasts of rheumatoid arthritis (RA) is critical event in the progressive joint destruction. Our previous study indicated that a collagen receptor, discoidin receptor 2 (DDR2), was highly expressed in the synovial fibroblasts of RA. However, the functional role of DDR2 in the regulation of MMP-13 production in synovial fibroblasts has not been elucidated. In this study, we initially demonstrated that the DDR2 and MMP-13 proteins are both highly expressed in the synovial lining layer of RA. MMP-13 mRNA and protein in synovial fibroblasts of RA were preferentially induced by collagen type II compared with MMP-1. Furthermore, stable overexpression of wild type DDR2 in murine synoviocytes dramatically augments the production of MMP-13. The activation of DDR2 also mediates the up-regulation of MMP-13 promoter activity in 293T cells. Inhibitor specific for extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) cascade was shown to decrease MMP-13 level induced by collagen II in RA synovial fibroblasts and DDR2-induced MMP-13 promoter activity. Runx2 and activator protein-1 (AP-1) binding sites in MMP-13 promoter region are required for DDR2-induced transcription. The data in this study suggest that DDR2-mediated MMP-13 induction by collagen matrix in synovial fibroblasts of RA contributed to articular cartilage destruction.

Bony landmarks and rotational alignment in total knee arthroplasty for Chinese osteoarthritic knees with varus or valgus deformities.

The purpose of this study was to investigate the rotational mismatch of total knee arthroplasty when taking the medial one third of the tibial tuberosity as a rotational landmark in Chinese osteoarthritic knees. Computed tomographic images of 49 osteoarthritic knees (42 with varus and 7 with valgus deformities) and 10 healthy knees were analyzed. The angle (alpha) between the 2 baselines for the anteroposterior axis of the femoral and tibial components was measured. The mean value of alpha in healthy knees was +6.45 degrees, which increased significantly to +11.53 degrees in varus knees (P = .002) and +12.17 degrees in valgus knees (P = .04). It showed that there is a tendency for the tibial component to be externally rotated when the medial one third of the tibial tuberosity is defined as a rotational landmark. This finding is particularly prominent in Chinese osteoarthritic knees with varus or valgus deformities.

[Muscle strength analysis of patella resurfacing in total knee arthroplasty].

OBJECTIVE: To investigate the influence of patella tracking and thickness for muscle strength after patellar resurfacing in total knee arthroplasty (TKA). METHODS: Quadriceps muscle strength of 100 cases 134 knees with osteoarthritis were analysed with isokinetic testing and extension lag after patellar resurfacing in TKA. Result was analyzed statistically through T test. RESULTS: Significant decreasing of quadriceps muscle strength and endurance were detected on mal-patellofemoral tracking (61 +/- 24, P <0.01) and improper position of patella prosthesis (56 +/- 33, P < 0.01). Anterior knee pain with patella resurfacing was mainly associated with mal-patellofemoral tracking. CONCLUSION: Asymptomatic weakness of quadriceps muscle was mainly associated with improper patella thickness.

[Total knee arthroplasty by lateral parapatellar approach for valgus knee].

OBJECTIVE: To investigate the effect of lateral parapatellar approach in total knee arthroplasty (TKA) of valgus knee. METHODS: Lateral parapatellar approach of total knee arthroplasty was applied in 8 patients (10 knees) with severe valgus osteoarthritis knee (bilateral in 2 cases and unilateral in 6 cases), with the valgus angle > 15 degrees , 1 male (1 knee) and 7 females (9 knee), aged 68.2 (58 - 79), 7 cases (9 knees) being of the Krackow type I and 1 case (1 knee) of the Krackow type I, I. After incision of the skin through lateral knee, ilio-tibial band was prolonged by apple pie arthroplasty. The joint capsule was cut open laterally 2 - 4 cm from the para-patellar edge. Soft tissue balance was performed by releasing I - T band in Gerdy tubercle, lateral collateral ligament and poster-lateral capsule from the femur and tibial side. Valgus angle of distal femur cutting were five degree. Whiteside line and trans-epicondylar line were used as AP rotational cutting reference. All patellar of the group were resurfaced. Capsule closure is completed with the knee flexed. The expanded deep lateral soft tissue sleeve (coronal Z-plasty) is sutured with the medial retinaculum sleeve (superficial layer). Follow-up was conducted for 19.6 months (1 - 51 months). RESULTS: Seven cases (9 knees) were replaced by posterior stabilized cemented prostheses (TC-Dynamic, PLUS), one case (1 knee) was replaced by RT prosthesis (RT-PLUS(TM) Solution, PLUS). After operation, the valgus deformity of all patients was corrected and all patients could walk 100 m with or without the help of walking holders. The average range of motion (ROM) was improved from the pre-operative. 95.6 degrees (85 degrees - 110 degrees ) to the post-operative 117.1 degrees (100 degrees - 125 degrees ). The average femorotibial angle (FTA) was corrected from the pre-operative. 27.6 degrees (20 degrees - 40 degrees ) to the post-operative 6.8 degrees (5 degrees - 9 degrees ). The Knee Score System (KSS) score and functional score were improved from the pre-operative 22.7 points (9 - 48 points) and 26.5 points (12 - 55 points) to the post-operative 86.4 points (85 - 95 points) and 89.1 points (80 - 95 points) respectively. Follow-up showed that the FTA remained unchanged and the knee stability of all patients was good. CONCLUSION: Through lateral approach, "Z" plasty of the capsule can release the lateral structure and decrease the pressure of common peroneal nerve. For TKR with moderate to severe fixed valgus knee, lateral approach is an effective way to correct the deformity.

[Total knee arthroplasty and perioperative management of hemophilic arthritis].

OBJECTIVE: To evaluate the clinical results and perioperative management of primary total knee arthroplasty (TKA) in hemophilic patients. METHODS: From February 1997 to February 2006, the data of 6 total knee arthroplasty performed in 4 hemophilic patients was reviewed retrospectively. The values of coagulation factor were maintained at suitable level by monitoring the activity of the factors and their inhibitors during perioperative period. The mean follow-up time was 4.4 years, knee society score and the last postoperative radiographs were recorded. RESULTS: After TKA, the hemophilic patients felt pain of knee relieved, the knee function was improved, but the range of motion increased limitedly. At the early post-operative stage, 3 knees in 2 patients with hemarthrosis or muscle bleeding, 1 of the 2 patients complicated with formation of inhibitor of factor VIII and healing problem in 1 knee after TKA, 1 patient with transient paralysis of the common peroneal nerve, 1 patient with venous circulation insufficiency crisis, but no compartment syndrome. In the late stage after TKA, 1 patient with hemarthrosis of both elbows, but no late infection, loosening, displacement and fracture of the prosthesis in the 6 knees. CONCLUSIONS: Total knee arthroplasty could alleviate knee pain and improve joint function in advanced severe hemophilic arthritic patients. It is important to monitor the activity and inhibitors of coagulation factor VIII or IX, which could decrease the early and late postoperative complications.

[Total knee arthroplasty for extension ankylosing deformity].

OBJECTIVE: To discuss the outcomes and complications of total knee arthroplasty (TKA) for extension ankylosing deformity of the knee. METHODS: From January 1996 to June 2006, total knee arthroplasty was performed on 8 patients (9 knees) with extension ankylosing deformity. The preoperative ROM of all patients was 0 degrees . Preoperative knee and function score of KSS were 44 points (from 10 to 68) and 17 points (from -10 to 55) respectively. RESULTS: The complications of all TKAs included patellar tendon avulsion in 1 knee, partial fracture of inferior patella in 1 knee, hematoma in 1, superficial infection in 1. All patients were followed up for an average of 40.4 months (from 7.0 to 120.0). The average postoperative ROM was 89 degrees (from 50 degrees to 120 degrees ). Postoperative knee and function score of KSS were 81 points (from 55 to 93) and 79 points (from 50 to 90) respectively. Extension lag occurred in 2 knees, one was 10 degrees and the other was 25 degrees . One knee had undergone re-revision of changing the thicker tibial spacer for the reason of instability of joint 1 year after revision. CONCLUSIONS: TKA performed in extension ankylosing deformity can get less satisfactory clinical results comparing with fixed flexion deformity. Exposure of the knee joint and separation of the fused bones, providing a mobile joint space plays crucial procedure for the next step of surgery. Preservation of sufficient bone stock of patella, protection of patellar tendon and blood supply of the knee and proper soft tissue balance are the key to TKA for extension ankylosing deformity.

Involvement of PDCD5 in the regulation of apoptosis in fibroblast-like synoviocytes of rheumatoid arthritis.

Apoptosis is reduced in the synovial tissue of patients with rheumatoid arthritis (RA), possibly due to decreased expression of pro-apoptotic genes. Programmed Cell Death 5 (PDCD5) has been recently identified as a protein that mediates apoptosis. Although PDCD5 is down-regulated in many human tumors, the role of PDCD5 in RA has not been investigated. Here we report that reduced levels of PDCD5 mRNA and protein are detected in RA synovial tissue (ST) and fibroblast-like synoviocytes (FLS) than in tissue and cells from patients with osteoarthritis (OA). We also report differences in the PDCD5 expression pattern in tissues from patients with these two types of arthritis. PDCD5 showed a scattered pattern in rheumatoid synovium compared with OA, in which the protein labeling was stronger in the synovial lining layer than in the sublining. We also observed increased expression and nuclear translocation of PDCD5 in RA patient-derived FLS undergoing apoptosis. Finally, overexpression of PDCD5 led to enhanced apoptosis and activation of caspase-3 in triptolide-treated FLS. We propose that PDCD5 may be involved in the pathogenesis of RA. These data also suggest that PDCD5 may serve as a therapeutic target to enhance sensitivity to antirheumatic drug-induced apoptosis in RA.

[The second stage revision for infected total hip arthroplasty using antibiotic-loaded cement prosthesis].

OBJECTIVE: To investigate the effect of two-stage revision for infected total hip arthroplasty (THA) using antibiotic-loaded cement prosthesis. METHODS: From June 1999 to October 2004, 14 patients who admitted for infected primary total hip arthroplasty surgeries were performed revision surgery with antibiotic-loaded cement prosthesis in two-stage. The mean Harris score of pre-operation was 23. In the first stage operation, the following steps were performed, complete debridement, removal of infected prosthesis, implantation of cement spacer with antibiotics, treatment involved concomitant administration of 3 weeks of intravenous (IV) and 1 month of oral. After 6 months, antibiotic-loaded prosthesis was implanted in the second stage. RESULTS: The mean follow-up was 18 months (7 - 26 months), no recurrent infection occurred in all 14 patients. The mean post-operation Harris score was 70. CONCLUSIONS: The success of the protocol to control the delayed infection after THA are complete debridement, enough interval and using antibiotic-loaded cement prosthesis in two stage revision.

[Influence of preoperative range of motion on the early clinical outcome of total knee arthroplasty].

OBJECTIVE: To retrospectively analyze the influence of preoperative range of motion (ROM) and maximal flexion degree on the early clinical outcome of total knee arthroplasty (TKA). METHODS: From January 2000 to December 2003, 97 knees of 65 patients that were underwent total knee arthroplasty with Scorpio posterior-stabilized knee prosthesis were reviewed. There were 55 osteoarthritis patients (81 knees), and 10 rheumatoid arthritis (16 knees). Thirty-three patients were underwent unilateral TKA, 32 patients were underwent bilateral TKA. According to the preoperative ROM of knee, these patients were divided into two groups, one 90 degrees (range, 95 degrees - 140 degrees ). Finally the clinical outcomes of two groups (include ROM, maximal flexion degree, KSS score and function score) were evaluated. Three days later after operation, continuous passive motion (CPM) and active functional exercise of the knee were begun, and the wound healed well in all patients. All these operations were primary total knee arthroplasty. RESULTS: The patients were followed up for average 2 years 5 months (range, 10 months to 3 years 8 months). The average ROM of knee was improved to 101.6 degrees (range, 40 degrees - 140 degrees ) after operation from 84.2 degrees (range, 5 degrees - 140 degrees ) before operation (P = 0.000); the average maximal flexion degree was decreased from 103.5 degrees (range, 25 degrees - 140 degrees ) before operation to 101.6 degrees (range, 40 degrees - 140 degrees ) after operation (P = 0.439); KSS of knee joint was improved to 78.8 points after operation (range, 50 - 95 points) from 19.5 points (-24 - 62 points) before operation (P = 0.000). There was statistically difference between the clinical outcomes (ROM, maximal flexion degree, KSS score and function score) in the two groups before and after operation. Those knees with good preoperative ROM tend to lose flexion, while those with poor preoperative ROM gain flexion after TKA. No revision and deep infection happened. CONCLUSIONS: TKA is a complex operation, the clinical outcome of TKA is mainly determined by the good operation skill, abundant clinical experience and the familiarity with the prosthesis of the surgeon. At the same conditions such as same surgeon, same prosthesis and same physical therapy, preoperative range of motion of knee influence on the early clinical outcome of total knee arthroplasty, knees that have good preoperative ROM have better clinical outcomes postoperatively than those with poor preoperative ROM.

[Total knee replacement in valgus knee].

OBJECTIVE: To investigate the methods and clinical results of total knee replacement (TKA) in patients with valgus knee deformity. METHODS: Between January 1996 and August 2004, 87 TKAs were performed by means of medial parapatellar approach, standard osteotomy and only lateral soft tissue release with posterior stabilized implants on 74 patients (11 men and 63 women) with valgus deformity. The average age at the time of operation was 62.93 years (range, 26-80 years). Clinical and radiographic evaluations including range of motion (ROM), Knee Society Score System (KSS) and the tibial and femur angle (T-F angle) were performed at follow-up. RESULTS: After a mean follow-up of 33.8 months (range, 5 months-9 years), the average ROM improved from 91 degrees (range, 70 degrees-120 degrees) preoperatively to 112.4 degrees (range, 80 degrees-130 degrees) postoperatively, the average KSS improved from 22.7 points (0-48 points) preoperatively to 81.7 points (range, 71-93 points) postoperatively. The average function score improved from 26.5 points preoperatively to 86.3 points postoperatively, the average T-F angle was corrected from 21.59 degrees (range, 12 degrees-40 degrees) of valgus preoperatively to 8.7 degrees (0 degrees-11 degrees) of valgus postoperatively. One knee had lightly instability at follow-up, one knee with patellar dislocation preoperatively had subdislocation postoperatively, no other complication occurred. CONCLUSIONS: The techniques of medial parapatellar approach, standard osteotomy and only lateral soft tissue release with posterior stabilized implants can correct a fixed valgus deformity very successfully in patients undergoing primary total knee replacement, and provides excellent results.