Long-term Follow-up of Patellar Nonresurfacing in Total Knee Arthroplasty

BACKGROUND: We aimed to confirm the long-term effect of patellar nonresurfacing (patellar decompression) in preventing anterior knee pain after total knee arthroplasty (TKA) and to investigate the possible complications.METHODS: Among patients who underwent primary TKA after being diagnosed as having advanced osteoarthritis (Kellgren-Lawrence grade 4) at our institution from January 2004 to December 2010, 121 patients who were followed up for more than 7 years were included in this study. Patients who underwent TKA with and without patellar decompression were classified as the study group and control group, respectively. A clinical knee rating score was used to compare the postoperative clinical outcomes between groups. To identify complications after patellar decompression, simple radiographs (weight-bearing anteroposterior and lateral views, patella in 30° and 45° axial views, and whole scanogram) were taken during follow-up.RESULTS: There were no complications such as patellar fracture, osteonecrosis, and subluxation. At 2 years after surgery, the prevalence of anterior knee pain was 12.7% and 18.0% in the study group and control group, respectively (p = 0.42), and the number of patients with patellofemoral osteoarthritis grade II or over was lower in the study group (p = 0.03). At 7 years after surgery, the prevalence of anterior knee pain was 18.3% and 24.0% in the study group and control group, respectively (p = 0.45), and there was no statistically significant intergroup difference in the number of patients with patellofemoral osteoarthritis grade II or over (p = 0.11).CONCLUSIONS: Patellar nonresurfacing TKA reduces anterior knee pain in the early postoperative period. The procedure can be considered a relatively safe option with fewer complications; however, its effectiveness appears to decrease over time.

Management of Tibial Bony Defect with Metal Block in Primary Total Knee Replacement Arthroplasty

PURPOSE: To analyze minimum 2-year clinical and radiological follow-up results of primary total knee replacement arthroplasty (TKRA) with metal block augmentation for tibial bony defect. MATERIALS AND METHODS: We analyzed 67 cases (52 patients) of primary TKRA with metal block augmentation for tibial bony defects from March 1999 and March 2008. Clinical results were evaluated using the Knee Society clinical rating system and the Western Ontario and McMaster University (WOMAC) score. Radiologic results were evaluated using the Knee Society roentgenographic evaluation system. RESULTS: The mean knee score and function score improved from 42.0 and 45.6 preoperatively to 94.5 and 85.4 postoperatively. At last follow-up, the mean WOMAC score was 16.8. The incidence of radiolucent lines was 10% (7 cases) during the follow-up period, but there was no case of progression. There were no statistically significant differences between the groups divided according to the block size (below 5 mm and over 8 mm) and between the stem and no-stem groups for all parameters. CONCLUSIONS: Primary TKRA with a metal block produced satisfactory results for the minimum 2-year follow-up and can be considered as a simple and effective method for the treatment of tibial bony defect in primary TKRA.

The Effectiveness of C-Reactive Protein Surveillance as a Method to Monitor the Post-Operative Antibiotics Administration after Total Knee Replacement Arthroplasty / 대한정형외과학회잡지

PURPOSE: To evaluate the effectiveness of using C-reactive protein (CRP) surveillance as a method to monitor the effect of postoperative antibiotics for the prevention of early infection after total knee replacement arthroplasty (TKRA). MATERIALS AND METHODS: A prospective study was performed in 115 primary TKRAs. We examined the values of CRP of all cases on the 3rd, 5th, 7th, 10th and 14th days post-operatively. Some patients were administrated additional antibiotics under certain specific situations based on the pattern of CRP. The patients were divided into two groups: group I with planned period of administration and group II with administration longer than the planned period. RESULTS: No acute infection after TKRA due to CRP surveillance was observed. The mean duration of antibiotics administration was 5.9 days in all cases, 5 days in group I and 13.3 days in group II. Twelve cases (10.4%) were included in group II. The CRP was increased on the 5th and 10th days after operation in group II. CONCLUSION: The surveillance of CRP was thought to be helpful in monitoring the effects of post-operative antibiotics and prevention of early infection after TKRA.

Synovial Impingement after Total Knee Replacement Arthroplasty: A Case Report

A thickened soft tissue impingement after total knee replacement arthroplastyis a complication that causes pain and is usually developed between patella and femoral component such as patellar clunk syndrome. But we experienced a case that medial and lateral synovial tissues were impinged between femoral component and polyethylene liner after total knee replacement arthroplasty with medial pivot prosthesis for degenerative arthritis and were treated with arthroscopic excision. We report this case with literature review.

Efficacy of Physiotherapist after Total Knee Arthroplasty

PURPOSE: The range of motion (ROM) of the knee and the satisfaction rate after total knee arthroplasty are the most important factors when evaluating the result of an operation. The purpose of this study was to determine whether the ROM and the functional outcome of these patients increase after joint exercise that is performed by special physiotherapists. MATERIALS AND METHODS: 200 cases of 120 patients, who underwent total knee replacement arthroplasty for osteoarthritis between August 2006 and May 2008, were enrolled in this study. These cases were randomly divided into 3 groups. Only CPM (continuous passive movement) and MSE (muscle strengthening exercise) were performed after KTA in the first group. In the second group, pROME was performed by physical therapists in our rehabilitation institution during the hospital stay, as well as CPM and MSE. CPM, MSE and pROME were performed by special physiotherapists during the hospital stay and also in the outpatient department after being discharged from the hospital in the third group. We compared the results of these groups. RESULTS: The range of motion was not increased among the groups. On the other hand, the third group showed a significantly higher functional outcome, as compared to that of the first and second groups. Conclusion: Although the range of motion of the knee joint was not increased enough to achieve statistical significance, the functional outcome showed significant increases with the pROME performed by physiotherapists. This result demonstrates that the knee exercises performed by special physiotherapists are useful and they can yield good outcomes in patients who underwent TKA.

Choroidal Ischemia and Serous Macular Detachment Associated with Severe Postoperative Pain

To report the association of a unilateral serous macular detachment with severe postoperative pain. A 71-year-old woman presented with a sudden decrease in vision in the right eye, seven days after a total knee replacement arthroplasty. The patient's history was unremarkable except for a severe pain greater than the visual analog scale of 8 points for about 2 days after surgery. Retinal examination showed a well differentiated serous detachment that was about 3.5 disc diameter in size and located in the macular area. Fluorecein angiography and indocyanine green angiography showed delayed perfusion of the choriocapillaris without leakage points in the early phase and persistent hypofluorescence with pooling of dye in the subretinal space in the late phase. There was a spontaneous resolution of the serous detachment and the choroidal changes with residual pigment epithelial changes. Severe postoperative pain may influence the sympathetic activity and introduce an ischemic injury with a focal, choroidal vascular compromise and secondary dysfunction of overlying RPE cells in select patients.

Hemodynamic Changes using Partial CO2 Rebreathing Method and Esophageal Doppler Monitor during Bilateral Total Knee Replacement Arthroplasty / 대한마취과학회지

BACKGROUND: We studied hemodynamic changes using a noninvasive partial CO2 rebreathing cardiac output method (NICO) and esophageal Doppler monitor (EDM), and metabolic changes in elderly patients undergoing bilateral total knee replacement arthroplasty (BTKA). METHODS: Twenty patients undergoing BTKA were studied. Hemodynamic and metabolic parameters were measured before tourniquet inflation (TI), 0, 3, 6, 9, 15, 30, 45 min after TI, and 0, 3, 6, 9, 15, 30 min after tourniquet deflation (TD) and skin suture. Stroke volume (SV), cardiac output (CO) and systemic vascular resistance (SVR) were measured using NICO and EDM. RESULTS: Mean blood pressure (MBP), central venous pressure (CVP), and SVR had significant increases in TI, and decreases in TD compared with value measured before TI (baseline value). Especially, MBP had higher decrease in the second tourniquet compared with first tourniquet, SV and CO were decreased in TI, and increased in TD compared with baseline value, HR had significant increases in the TD of second tourniquet. pH and lactate were shown significantly lower values at the second tourniquet compared with the first tourniquet (P < 0.05). The bias and precision derived from CO between EDM and NICO was 0.27 +/- 0.41 L/min, and CO by NICO was smaller than that by EDM. The correlation coefficient between NICO and EDM was calculated to be 0.43. CONCLUSIONS: MBP, SV, CO, pH and lactate were shown to be higher in the second tourniquet in BTKA. NICO showed lower CO compared with EDM after TD in patients undergoing BTKA, but statistically insignificant at most measurement.

The Value of (99m)Tc-HMPAO-WBC Scan in the Diagnosis of Infection after Total Knee Arthroplasty

PURPOSE: The early diagnosis and detection of prosthetic infection after TKA is very important and difficult for deter- mination of the plan in management and reduction of complications. In these reasons, this study was performed to evaluate the usefulness and limitation of (99m)Tc-HMPAO(Technetium (99m)-hexamethyl- propylene amine oxime)-labeled WBC scan in the patients with clinically suspicious prosthetic infection. MATERIALS AND METHODS: The study subjects were 25 patients(3 men and 19 women, mean age: 66.5 years) performed (99m)Tc-HMPAO WBC scan in the patients with clinically suspicious prosthesis infection after TKA from January, 2005 to May, 2007. And in 6 patients who had undergone bilateral arthroplasty, we regarded one patient as two cases. Thus, total 31 prostheses were included in this study. Final diagnosis of infection was based on bacteriological result by intrao- perative cultures, surgical findings, and histological evidence intraoperatively obtained in the suspicious site and clinical follow-up. RESULTS: In the final diagnosis, we confirmed that total 16 prosthetic joints were infected. Of these infected prostheses, increased (99m)Tc-HMPAO WBC scan uptake waspositive in 15, negative in 1. Finally, 15 cases were confirmed as nonin- fected prosthesis, 6 showed positive by (99m)Tc-HMPAO WBC scan uptake, 9 showed negative. Over all sensitivity, speci- ficity, and positive predictive value for diagnosisof infected TKA were 93.75, 60%, and 71.43%. CONCLUSION: (99m)Tc-HMPAO WBC scan was a highly sensitive method for the diagnosis of prosthetic infection after TKA. But low specificity and high false positive of (99m)Tc-HMPAO WBC scan demand more clinical follow-up for confirmed diagnosis. To increase specificity, additionally scan will be needed.

Results of Cruciate-Retaining Total Knee Arthroplasty with Maxim(R) System : More than 5-Year Follow Up

PURPOSE: To evaluate the mid-term (over 5 years) clinical and radiologic results of Maxim(R) (Biomet, Warsaw, USA) Cruciate Retaining total knee replacement arthroplasty (TKRA). MATERIALS AND METHODS: Between Feb. 1997 and Nov. 2000, 103 knees in 65 patients who had been followed up for 5 years after TKRA with Maxim(R) Cruciate Retaining were evaluated retrospectively for clinical and radiologic results. RESULTS: The average range of motion increased from 114degrees (80~130degrees) preoperatively to 128degrees (105~130degrees) at the last follow-up. The average range of flexion contracture decreased from 6.5degrees preoperatively to 0.8degrees (0~15degrees) at the last follow- up. In patients with osteoarthritis, the mean preoperative knee score (59.2) and functional score (40.7) improved to 88.6 and 90.1, respectively. In rheumatoid arthritis patients, the mean knee score and functional score also improved from 47.4 and 39.2 to 80.6 and 88.3. Roentgenographic evaluation revealed a radiolucency rate of 19.5%. Complications were deep infection in 2 cases and periprosthetic fractures in 3 cases. The former had received reimplantations. CONCLUSION: The mid-term results of Maxim(R) Cruciate Retaining total knee replacement arthroplasty were reliable and satisfactory in terms of improvements of range of motion, restoration of function, and rare complications. However, long-term follow-up evaluation is necessary.

Medium-term clinical report of rotating hinge knee prostheses / 中国矫形外科杂志

[Objective]To refine operative indications of rotating hinge prostheses and report the medium term results of these implants,and to analyze the reasons for postoperative complications.[Method]From 1999 to 2007,42 Endo-Model(Link) rotating hinge prostheses were used in 34 patients.The cases were all gonarthrosis with severe genu varus,genu valgus or flexion contracture.Bone defect or instability was found in these cases before operation.The mean follow-up was 6.4 years(2.3-10.4 years).[Result]One case of deep infection,and one periprosthetic fracture were noted.And 3 cases of patella subluxation or tilt were detected by postoperative X-ray.All patients had excellent pain relief and restoration of walking capability.The average HSS score improved from 40.5 points to 89 points after surgery.[Conclusion]Besides being used in revision surgery,rotating hinge prostheses are indicated in primary arthroplasties for patients with severe ligament laxity,substantial deformity or bone losses.With appropriate indication selection and accurate operative skill,satisfactory medium term result can be obtained.

Total Knee Arthroplasty with NexGen(R) System: Minimum Two Years Follow up Results / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical and radiological results of patients that underwent total knee replacement arthroplasty (TKRA) using a NexGen(R). implant, and who were followed up for at least 2 years. MATERIALS AND METHODS: Between July 1996 and June 2002, 100 knees in 67 patients, and followed up for at least 2 years following TKRA using a NexGen(R). implant were retrospectively assessed for clinical and radiological results using the assessment standards of the Knee and Functional Score of the American Knee Society. RESULTS: The average preoperative range of motion in patients with osteoarthritis and rheumatoid arthritis were 107.4degrees (50-140degrees) and 105.8degrees (70-120degrees), respectively, which had improved to 127.2degrees (85-140degrees) and 125.6degrees (90-140degrees), respectively, at the final follow up. In addition, the preoperative flexion contracture improved from 11.3degrees (0-30degrees) and 10.6degrees (0-30degrees) to 1.3degrees (0-15degrees) and 3degrees (0-15degrees) postoperatively. The results using the assessment standards of the Knee and Functional Score of the American Knee Society were improved from 62 (35-82) and 40 (0-70) to 95.8 (87-100) and 97 (70-100) in patients with osteoarthritis, whereas the patients with rheumatoid arthritis were improved from 53.8 (32-73) and 36 (0-50) to 95.1 (89-98) and 79 (55-95). As a complication, infection occurred in 2 cases; they were given a reimplantation. CONCLUSION: TKRA using a NexGen(R). implant showed satisfactory improvement in pain relief and function, such as range of motion, as well as a lower occurrence rate of complications.

Reconstruction of Necrosis Following Total Knee Replacement Arthroplasty

In spite of proper maneuver of total knee replacement arthroplasty, some patients suffer from skin necrosis just above the implant. From Mar. 2000 to Jan. 2004, the authors performed reconstruction of knee skin defects after total knee replacement athroplasty. Total 6 cases of flap surgery were performed and patients ranged between 43-years-old to 82-years-old. Rectus femoris perforator based reversed adipofascial flaps were used in 2 cases, medial gastrocnemius muscular island flaps were used in 2 cases and sural artery based on adipofascial rotation flap was used in 1 case. One patient with extended necrosis underwent reconstruction with dual flaps of sural artery based adipofascial rotation flap and medial gastrocnemius muscular island flap. There were no distinctive complication needing additional procedure in all cases during the long term follow up. Reconstruction of necrosis following total knee replacement arthroplasty had several characteristics different from simple knee defect. The patients might have the history of long term steroid usages, excessive skin tension due to implants, underlying disease such as diabetes, rheumatoid disease, and etc. In addition, the early ambulation is mandatory in these patients of total knee replacement arthroplasty. With regards to these special considerations, a single stage and reliable operation must be needed. The authors introduce various reconstruction methods and algorithm that may aid easy decision making.

Effect of Norepinephrine Irrigation in Primary Total Knee Replacement Arthroplasty / 대한정형외과학회잡지

PURPOSE: We studied the effect of norepinephrine irrigation during total knee replacement arthroplasty (TKRA) on blood loss reduction. MATERIALS AND METHODS: A prospective study of 30 patients who received TKRA from the same surgeon between March 2003 and November 2003, was done. Patients were alternately allocated into two groups. The study group included 15 cases in which 1: 200, 000 diluted norepinephrine was used for irrigation intra-operatively, whereas the control group included 15 cases received normal saline irrigation. Postoperative drain and transfusion amounts were compared between the two groups using the independent t-test. RESULTS: Early bleeding amounts for 6 hours after surgery were a significant difference between the two groups (study group 410.3 cc, control group 517.3 cc, p-value=0.03). However, delayed bleeding amounts during postoperative 6-48 hours (study group 163.8 cc, control group 244.7 cc, p-value=0.05) and transfusion amounts (study group 0.80 unit, control group 1.47 unit, p-value=0.07) were smaller in the study group, but showed no significant differences. CONCLUSION: Using norepinephrine diluted in normal saline as an irrigation solution during TKRA can be considered for reducing early post operative bleeding.

Hemodynamic and Metabolic Changes Induced by Tourniquet Release during Both Total Knee Replacement Arthroplasty / 대한마취과학회지

BACKGROUND: A tourniquet is usually used for total knee replacement arthroplasty (TKR) to provide a bloodless surgical field. However, hemodynamic and metabolic changes result from the ischemia after application of a tourniquet. Moreover, the hemodynamic and metabolic effects of tourniquet application during both TKR under general anesthesia have been rarely reported. METHODS: Fifteen patients undergoing both TKR were studied during general anesthesia. Hemodynamic and metabolic parameters were measured before inflating the tourniquet, just before release of the tourniquet and 3, 6, 15 min after tourniquet release. Stroke volume (SV), cardiac index (CI), systemic vascular resistance (SVR) and end-tidal CO2 (ETCO2) were measured using a non-invasive cardiac output monitor. RESULTS: Mean arterial pressure (MAP) decreased after tourniquet release, but was not different from MAP before tourniquet inflation. After tourniquet release, central venous pressure, SVR, arterial pH, bicarbonate and calcium decreased significantly (P <0.05), and heart rate, CI, ETCO2, PaCO2 and potassium increased significantly (P <0.05). But, the hemodynamic and metabolic changes after tourniquet release in the subsequent TKR were not affected by those after tourniquet release in the antecedent TKR. CONCLUSIONS: During both TKR, although there was no difference in the hemodynamic and metabolic changes after tourniquet release between the antecedent and the subsequent TKR, there were significant hemodynamic and metabolic changes after tourniquet release. These findings indicate the need for more active hemodynamic and metabolic monitoring in patients with a compromised cardiopulmonary function.

The Thickness of Patella in Korean, Measured During Total Knee Replacement Arthroplasty / 대한정형외과학회잡지

PURPOSE: To report patella thickness measurements in Korean. MATERIALS AND METHODS: Between July 1990 and December 2000, the thicknesses of the patella in 1,245 patients who underwent total knee replacement arthroplasty (TKRA) were measured in 0.5 mm increment using caliper during operation. The diagnoses of the 833 knees were degenerative osteoarthritis and 386 knees rheumatoid arthritis. The difference of the thicknesses of the patellas in the same individuals were evaluated in cases of bilateral TKRAs. The relationships between the patellar thickness and sex, body weight and height were evaluated. RESULTS: The average thickness of the patella was 21.46+/-1.59 (18-32) mm. The thickness of the patella was increased significantly in the male (p0.05). CONCLUSION: Because the thickness of the patella in Korean adult was less than that in the Caucasian, the thickness of the patella after resurfacing the patella during TKRA may be reduced unnecessarily, which may cause increased strain on the surface of the patella. This increased strain may result in the fracture of the patella consequently. In the present study, the thickness of the patella after resurfacing during TKRA was 13.9+/-0.7 mm. Considering the fact that the prevalence of patella fracture was low (0.24%) in our study, the author's method of patella resurfacing is believed to be appropriate in Koreans.

Prevalence of Lateral Discoid Meniscus / 대한정형외과학회잡지

PURPOSE: Lateral discoid meniscus is a well known disease entity with an uneventfully high incidence in Koreans and Japanese. However, the reported incidence had been obtained mainly by using arthroscopy. The purpose of this study was to determine the prevalence of discoid lateral meniscus obtained by arthroplasty, unrelated to arthroscopic surgery. MATERIALS AND METHODS: We studied the prevalence of lateral discoid meniscus in 465 cases of total knee replacement arthroplasty, after disregarding patients with any possibility of an affecting lateral meniscus. To conduct the comparison, we measured the incidence of lateral discoid meniscus in 423 arthroscopy cases, performed during study period, and in 1,364 of our arthroscopy cases. RESULTS: We found 18 discoid lateral menisci during 465 total knee replacement arthroplasties, Therefore, its prevalence of lateral discoid meniscus was 3.9%. but 38 cases (9.0%) out of 423 arthroscopy cases, and 145 cases (10.6%) out of 1,364 arthroscopy cases were diagnosed as a lateral discoid meniscus. We also founded that 50% of lateral discoid meniscus cases were bilateral. CONCLUSION: We suspect that the prevalence of lateral discoid meniscus is similar in the Korean and Western populations. However, due to different lifestyles and ethnicity, Koreans might experience in one discomfort and confront a treatment, and thus the reported prevalence of discoid lateral meniscus is higher in Koreans.

Total Knee Rephacement Arthroplasty in Rheumatoid Arthritis: Mid-term follow-up

PURPOSE: Rheumatoid arthritis patients have difficulty in rehabilitative movement postoperatively, and prosthesis fixation due to osteoporosis. We evaluate the mid-term clinical, radiographic results and patients satisfaction degree of total knee replacement arthroplasty for rheumatoid arthritis retrospectively. MATERIALS AND METHODS: Between October, 1989 and May, 1994, 125 total knee replacement arthro- plasties were performed in 83 rheumatoid arthritis patients. Of these, we can follow up 99 knees in 70 patients, who were evaluated retrospectively for at least 5 years. The average age of the patients at the operation was 48.7(23-71) years old. The average follow up period was 87(60 112) months RESULTS: The average range of motion was increased 90.7 degrees preoperatively to 113.9 degrees at the final followup examination. The radiolucency score was average 1.14(1-9) points on roentgenographic evaluation and there was one loosening of tibial component, which was performed revision arthroplasty. CONCLUSION: In patients with rheumatoid arthritis, the total knee replacement arthroplasty relieve pain and increase range of motion, restore the function, cause rare complication and good patients own satisfaction, with relatively satisfactory results.

Polyethylene Failure Following TKRA

PURPOSE: We purpose to analyze the factors related to the polyethylene failure through the 7 exchanged polyethylene. MATERIALS AND METHODS: We experienced 7 cases of polyethylene failure from Apr. 1988 to Jan. 2000. The average duration of reoperation is 5 year 2 months(1 year 8 months-8 year 11 months), age at primary operation is 62 years old(55-64 years old), weight is 65kg(56-78kg) and height is 155cm(150-162cm). The used prostheses were AGC(Biomet, Warsaw, U.S.A) in 2 patients, AMK(Depuy, Warsaw, U.S.A) in 1 patient, ,MG II(Zimmer, Warsaw, U.S.A) in 1 patient, PFC(Johnson and Johnson, Warsaw U.S.A) in 2 patients and Series 7000(Osteonics, New Jersey, U.S.A.) in 1 patient. RESULTS: The thickness of polyethylene is Smm in 6 patients and 9mm in 1 patient. All of prostheses are cruciate retaining type with relatively flat surface geometry and low-height intercondylar eminence, and the minimal thickness of each system. CONCLUSION: We consider that the thicker polyethylene should be used when feasible in order to avoid reoperation which is caused by accelerated wear of polyethylene, and early detection of polyethylene wear is important. This can be got through knee standing AP, fluroscopic evaluation with varus and valgus stress.

Component Size Matched Extension Gap Osteotomy for TKRA: A New Concept in Knee Osteotomy for TKRA / 대한정형외과학회잡지

PURPOSE: We designed a new osteotomy technique in order to get a consistent extension gap along with a tibial polyethelene insert in TKRA. The results were compared to the independent osteotomy technique. MATERIAL AND METHODS: Forty two patients were divided into an independent osteotomy group and a linked osteotomy group according to the technique adopted. In the linked osteotomy group, the extension gap was made by using a linker which was designed to provide a consistent gap between the distal femur and the proximal tibia during knee extension. The widths of the extension gap and the polyethylene thickness was compared between the two groups. RESULTS: The extension gap of the independent osteotomy group was 18.1 +/- 4.2 mm (2SD) and that of the linked femorotibial osteotomy group was 20.3 +/- 1.3 mm (2SD). The polyethylene thickness was 8.1 +/- 2.6 mm (2SD) in the independent group and 9.4 +/- 0.9 mm (2SD) in the linked group. CONCLUSION: This linked femorotibial osteotomy technique provided an improved method for obtaining a tibial insert matched extension gap in TKRA. This technique might also increase the longevity of the polyethylene insert.

Analysis of 1,000 Cases of Total Knee Arthroplasty: Preliminary Report / 대한정형외과학회잡지

PURPOSE: To analyze the results and complications arising from 1,000 cases of primary total knee arthroplasty (TKRA), as performed by one surgeon. MATERIALS AND METHODS: From February, 1992 to June, 2000, 1,000 cases of primary TKRA were performed by a single surgeon. Among the 1,000 cases, 573 cases followed up for more than one year (average 2.9 years) were evaluated try allocating special surgery (HSS) scores and by determining the range of motion (ROM), and presence of complications retrospectively. RESULTS: There were 872 cases of primary osteoarthritis, 70 cases of rheumatoid arthritis, 32 cases of osteonecrosis, and 26 cases of miscellaneous diseases. The HSS score increased from 57.8 preoperatively to 90.4 postoperatively, ROM increased from 111degrees to 113degrees and flexion contracture decreased from 9degrees to 2degrees, but no statistical differences in results were observed between diseases. Common causes of complications were superficial infection (3.6%), deep infection (2.4%) and deep vein thrombosis (1.8%). Two patients died, one due to myocardial infarct and the other due to an unknown etiology. Revision arthroplasties were performed in 19 cases. CONCLUSION: After primary TKRA, ROM and functional score improved satisfactorily. No statistical differences were apparent between diseases. Infection was the most common complication.