Objective. We performed total knee arthroplasty (TKA) without patella resurfacing in patients with osteoarthritis (OA) of the knee. The purpose of the present study was to evaluate the clinical results and the appropriateness TKA without patella resurfacing. Methods. A total of 61 patients (61 affected knees) who had undergone a Low Contact Stress mobile − bearing knee arthroplasty (LCS− TKA) (Depuy, Warsaw, IN. USA) 10 years or more before the present study were enrolled. The LCS− TKAs did not include patella resurfacing. The patients' mean age was 77.7 ± 6.1 years (range: 59−94 years). The mean follow-up period was 121 ± 2.4 months (range: 120−129 months). The clinical evaluation used the scoring system for OA of the knees issued by the Japanese Orthopaedic Association (JOA score). We defined patellofemoral (PF) pain, crepitation, patellar clunk syndrome, spin-out, and reoperation as complications. We also used X-Ray imaging to measure the component angle, patella height, lateral shift ratio, tilting angle, femorotibial angle, posterior condylar offset and joint line, and evaluated the localization of sclerotic changes in the patella. All of the LCS− TKAs were performed by one surgeon using the midvastus approach. During the operation, the osteophyte around the patella was resected, and the osteophyte on the articular surface was shaped using a bone saw. For statistical analysis we performed Mann-Whitney's U test and adopted a significance level of P<5%. Results. The average JOA score improved significantly from 46.2 ± 10.4 before the LCS− TKA to 82.6 ± 6.1 after the LCS− TKAs (P = 0.0002). No cases of patellar clunk syndrome or spin-out. occurred. Revision surgery was performed for two cases, one involved an infection, and the other involved a patella fracture. Postoperative PF pain was found in 6 patients (6 affected knees) at the final evaluation. However, in these patients, the pain was less severe than it had been preoperatively, and revision surgery for PF pain was needed or performed. The postoperative radiological evaluation was favorable on the whole. The localization of sclerotic changes in the patella on X-ray were in 32 cases around tip of the patella, on the other no remarkable change were in 29 cases. Conclusion. The clinical and radiological evaluations of the patella non−resurfacing mobile bearing total knee arthroplasty was favorable overall. Treatment of the patella in total knee arthroplasty remains controversial. We suggest that the patella in LCS−TKAs does not always need to be resurfaced

From October 2005 to March 2014, we performed 46 arthroscopic surgeries for painful knee after knee arthroplasty. We excluded 16 cases for this study such as, unicompartmental knee arthroplasty, infection, patellar clunk syndrome, patellofemoral synovial hyperplasia, aseptic loosening, and follow-up period after arthroscopic surgery less than 6 months. Thirty cases matched the criteria. They had knee pain longer than 6 months after initial total knee arthroplasty (TKA), they had marked tenderness at medial and/or lateral tibiofemoral joint space, and also they complained walking pain with or without resting pain. Twenty one cases had initial TKA at our institute. In consideration of total number of TKA (n=489) in the period at our institute, incident rate of painful knee after initial TKA was 4.3%. Of 30 cases, 3 cases were male, and 27 cases were female. Types of implant were 4 in cruciate retaining type, 1 in cruciate substituting type, and 25 in posterior stabilized type. Age at the arthroscopy was 72 years old (51–87 years old), and period form initial TKA to pain perception was 18 months(1 – 144 months), and period from initial TKA to arthroscopic surgery was 29 months (6 – 125 months), and follow-up period after arthroscopy was 36 months (6 – 93 months). All arthroscopic debridement were performed through 3 portals, anteromedial, anterolateral, and proximal superomedial portal. Scar tissue impingements more than 5 mm wide were found in 87% of the cases both medial and lateral femorotibial joint spaces. Infrapatellar fat pad were covered with whitish scar tissue in all cases, and the scar tissue were connecting with the scar tissue which found at medial or lateral femorotibial joint spaces. We removed all scar tissue with motorized shaver or punches. At final follow-up, complete pain free in 63%, marked improvement in 3%, half improvement in 20%, slight improvement in 3%, and no change in 10% of the cases. Previously in the literatures, two reasons of the pain after total knee arthroplasty had been reported, patellar clunk syndrome, and patellar synovial hyperplasia. All cases reported this study had marked tenderness at tibiofemoral joint space. It was difficult to explain the tenderness by previously reported pathological mechanisms. We had to find another pathological mechanism to explain the pain of our cases. Painful knee due to scar tissue formation known as “infrapatellar contracture syndrome” after anterior cruciate ligament reconstruction surgery was previously reported. We hypothesized similar scar tissue formation should occur after TKA that caused painful knee. Continuity of the solid scar tissue between infrapatellar fat pad with the scar tissue at tibiofemoral joint space should be the cause of impingement at femorotibial joint even small size of scar tissue. From this study, we have to recognize that painful knee after TKA is not infrequent complication. And, if we could deny infection, and aseptic loosening in painful knee after TKA, arthroscopic debridement was good option to solve the pain. We could expect improvement of the pain more than half in 87% of cases

Introduction. Following total knee arthroplasty (TKA), some patients show patella baja. It is possible that patella baja after posterior stabilized (PS)-type TKA causes the patellar clunk syndrome and limitation of flexion. The purpose of this study was to examine patellar height before and after PS-type TKA and identify the factors related to the change in patellar height. Methods. Lateral X-ray films were taken at 90 degrees flexion before and after TKA using fluoroscopy in 87 patients (95 knees) (Fig. 1a, b). The components and surgical technique for TKA were Scorpio NRG (Stryker) and the modified gap control technique, respectively. The Insall-Salvati ratio (ISR) and the Labelle-Laurin method (LL) were measured as parameters of patellar height (Fig. 1c, d). Posterior condylar offset (PCO) (Fig. 1e), the distance from the anterior femoral line to the tibial tuberosity (TA), and the distance from the tibial tuberosity to the posterior condyle of the femur [TP; {TA-F (the length of the femoral condyle)}] (Fig. 1f) were examined as parameters that could be associated with the change in patellar height. All parameters were divided by patellar length to compensate for the expansion rate in each photograph. The mean LL/P, PCO/P, TA/P, and TP/P before TKA were set at 100%. Results. The mean ISR was not significantly different before and after TKA, but the mean LL before TKA was significantly decreased after TKA (−231%). The mean PCO/P of the femur were not significantly different after TKA. The mean length of TA/P and TP/P increased significantly after TKA (TA/P: 103%, TP/P: 110%). Sex, patellar replacement, lateral release of the patella and MCL release were not significantly related with the difference in LL after TKA. The difference in LL after TKA was significantly correlated with the distance from the tibial tuberosity to the posterior condyle of the femur (R. 2. = 0.44, Fig. 2). The difference in LL after TKA was not correlated with flexion motion after TKA. The patellar clunk syndrome after TKA was not seen in any of the cases. Discussion. The patellar height defined by the length from the anterior femoral line to the top of the patella was lower after PS-type TKA than before TKA, although the ISR did not change after TKA. The changing patellar height correlated with the difference in the distance from the tibial tubercle to the posterior condyle of the femur before and after TKA. Since the PCO was not significantly changed after TKA, it appears that the length of proximal tibia was prolonged. The prolonged proximal tibia and the distal positioning of the patella after TKA might be due to the reduced pre-operative instability of the knee and the inferior traction of the patellar tendon and quadriceps muscle. In conclusion, the patellar height after PS-type TKA decreased after surgery. The change in patellar height was due to the length of proximal tibia

Background. We have performed total knee arthroplasties for valgus and varus in the knees of one person and investigate the clinical characteristics of these patients and the relationship between the kind of deformity and postoperative result. Methods. From March 2002 to February 2010, 25 patients who had simultaneous varus and valgus knee deformities underwent total knee arthroplasties and followed more than 12 months were included. The average age was 66.9 years and the average follow-up period was 61.1 months. Follow-up imaging assessments were taken and clinical outcome were evaluated using HSS score at last follow-up. Results. 11 cases had more pain in varus knee and 8 cases had more pain in valgus knee preoperatively. In 11 cases, degenerative scoliosis were associated with the knee deformity and among the cases, 10 cases had valgus deformities in concave side of scoliosis. In three cases, hip deformities were noted in ipsilateral side of the valgus deformity. One case showed both hip deformities with ankylosing spondylitis. Preoperative mean valgus angle was 11.4 degree and varus angle was 7.5 degree. Postoperative valgus and varus angle improved to 6.3 and −5.7 degree. HSS score improved from 64.3 to 84.7 point in valgus deformities and from 62.1 to 85.1 point in varus deformities. Postoperative patellar clunk syndrome was identified in one valgus knee, but resolved by arthroscopic debridement. And postoperatively, one case showed out-toeing gait caused by equinovarus deformity in varus knee, but resolved by correction of foot deformity. Conclusions. Simultaneous or staged total knee arthroplasties in patients with simultaneous varus with contralateral valgus knee deformities brought satisfactory outcomes with regard to objective orthopedic criteria such as radiographic and clinical results. Concave aspect of scoliosis and hip deformity correlate with valgus knee in statistically. But rheumatoid factor and VDRL do not correlate with valgus deformity. And we found no significant difference between the kind of deformity and postoperative result