Young-Hoo Kim

Uncemented porous-coated anatomic total hip replacement. Results at six years in a consecutive series

We studied 108 patients (116 hips) who were followed for a minimum of six years (73 to 89 months) after primary total hip arthroplasty using an uncemented porous-coated anatomic hip. The average age of the patients at operation was 48.4 years, and the diagnosis was avascular necrosis of the femoral head in 46 hips, neglected femoral neck fracture in 27, osteoarthritis secondary to childhood pyogenic arthritis in 24 and to childhood tuberculous arthritis in five, and miscellaneous in 14. The average preoperative Harris hip score was 55, which improved to 91 at latest follow-up. All patients with loose femoral components or disabling thigh pain had received prostheses which were undersized in the coronal or the sagittal plane, or in both. No patient with a satisfactory fit in both coronal and sagittal planes had loosening of the femoral component or disabling thigh pain. Three acetabular components showed aseptic loosening and 20 showed excessive wear (5 to 11 mm) of the polyethylene liner. Excessive wear was related to young age, but not to body-weight, gender, primary diagnosis, hip score, or range of hip movement. There was a high incidence of osteolysis (38 of 116 hips, 33%). We recommend careful preoperative planning, with the use of a contemporary cemented technique when a satisfactory fit cannot be obtained. The high incidence of excessive wear and of osteolysis needs further investigation.

Contemporary Total Hip Arthroplasty with and without Cement in Patients with Osteonecrosis of the Femoral Head

We previously evaluated ninety-eight consecutive patients (148 hips) at mean of 9.3 years after total hip arthroplasty; the mean age at the time of the index surgical procedure was 47.3 years. Fifty patients (100 hips) had simultaneous bilateral arthroplasty with a cemented stem in one hip and a cementless stem in the contralateral hip. Forty-eight patients (forty-eight hips) had unilateral hip arthroplasty with a cementless stem. All patients had a cementless acetabular component. In our first report, we found no difference in clinical results, as measured with the Harris hip score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), between the cementless and cemented stems. One hip (2%) in the hybrid group (a cementless cup and a cemented stem) had revision because of infection and two hips (2%) in the fully cementless group had revision of the femoral component because of a periprosthetic fracture. Between the time of follow-up in that study (at a mean of 9.3 years) and the time of follow-up in the present study (at a mean of 17.3 years), twenty-two revisions of acetabular components were performed, with eight in the hybrid group and fourteen in the fully cementless group. There was no difference in clinical results, as measured with the Harris hip score and the WOMAC, between the hybrid and fully cementless groups. At the time of the present review, forty (83%) of forty-eight acetabular components in the hybrid group and eighty (85%) of ninety-four acetabular components in the fully cementless group were intact. Most of the femoral components (98%) in both groups were intact. Wear and periacetabular osteolysis were the causes of failure in the hips requiring revision.

Primary Total Hip Arthroplasty With a Cementless Porous-Coated Anatomic Total Hip Prosthesis 10- to 12-Year Results of Prospective and Consecutive Series

We performed a prospective study in 108 consecutive patients (116 hips) who were followed for a minimum of 10 years (10-12 years) after primary total hip arthroplasty using an uncemented porous-coated anatomic (PCA) hip prosthesis. The average age of the patients at operation was 48.4 years (range, 19-85 years), and the diagnosis was avascular necrosis of the femoral head in 46 hips, neglected femoral neck fracture in 27, osteoarthrosis secondary to childhood pyogenic arthritis in 24, childhood tuberculous arthritis in 5, and miscellaneous in 14. The average preoperative Harris Hip Score was 55 points, which improved to 87 points at 11 years. Seventy-five hips (65%) were excellent, 11 (9%) were good, and 30 (39%) were poor. The overall rate of revision was 15% (17 of 116 hips). The rate of revision of the femoral component was 11% (13 of 116 hips), and the rate of revision of the acetabular component was 15% (17 of 116 hips). The prevalence of thigh pain was 28% at 11 years. The increase in the incidence of aseptic loosening of the femoral component was found to explain the high incidence of severe thigh pain at 11 years follow-up. At 11 years, there was femoral osteolysis in 69 hips (59%) and acetabular osteolysis in 65 hips (56%). At 6 years, 20 hips (17%) showed definite wear of the polyethylene liner. At 11 years, 81 hips (70%) showed definite wear of the polyethylene liner. Because the complication rate of the PCA hip prosthesis with respect to loosening, osteolysis, and excessive wear in the polyethylene liner is high, we abandoned the use of this implant.

Comparison of Porous-Coated Titanium Femoral Stems with and without Hydroxyapatite Coating

BACKGROUNDnThe purpose of this prospective, randomized study was to evaluate the clinical and radiographic results associated with proximally porous-coated titanium stems that were identical in geometry but differed with regard to proximal surface treatment (with or without hydroxyapatite coating).nnnMETHODSnA prospective, randomized study was performed to evaluate fifty patients (100 hips) who had undergone sequential bilateral primary total hip replacement. A proximally porous-coated titanium stem with hydroxyapatite coating was implanted on one side and a proximally porous-coated titanium stem without hydroxyapatite coating was implanted on the other side during the same operative setting in all fifty patients. A cementless acetabular component made of titanium was used in all hips. There were thirty-six men and fourteen women; the mean age at the time of the operation was 45.3 years. The mean duration of follow-up was 6.6 years. Clinical and radiographic evaluations were performed preoperatively; at six weeks; at three, six, and twelve months; and yearly thereafter.nnnRESULTSnThe Harris hip scores in the hydroxyapatite-coated group (mean, 94 points) and non-hydroxyapatite-coated group (mean, 92 points) were similar at the final follow-up examination. The prevalence of transient pain in the thigh was 4% in each group. No acetabular or femoral component demonstrated aseptic loosening. Bone-remodeling patterns, including calcar atrophy, were similar in the two groups. No acetabular or femoral osteolysis was seen.nnnCONCLUSIONSnAt a mean of 6.6 years postoperatively, the clinical and radiographic results associated with proximally porous-coated femoral prostheses with identical geometries that differed only with regard to the presence or absence of hydroxyapatite coating were similar.

Comparison of fixed-bearing and mobile-bearing total knee arthroplasties.

The purpose of the current study was to directly compare the results of fixed-bearing and mobile-bearing total knee arthroplasties in the same patient who had bilateral simultaneous total knee replacements. A fixed-bearing total knee prosthesis (AMK) was implanted in one knee and a mobile-bearing total knee prosthesis (LCS) was implanted in the other knee in 116 patients. The average age of the patients was 65 years (range, 33–70 years). The average followup was 7.4 years (range, 6–8 years). Clinical and radiographic followup was done using Knee Society and Hospital for Special Surgery knee rating systems at 6 weeks, 3 months, 6 months, 1 year after surgery, and yearly thereafter. Total knee score, pain score, mean functional score, and range of motion were comparable in both groups. Two knee replacements (2%) in one patient with AMK prostheses were revised because of complete wear of tibial bearing polyethylene. One knee replacement (1%) in one patient with an LCS prosthesis was revised because of dislocation of the medial tibial bearing polyethylene and one knee replacement (1%) in one patient with an LCS prosthesis was revised because of complete wear of the medial tibial bearing polyethylene. No knee had aseptic loosening or osteolysis in either group. After a minimum followup of 6 years, the results of fixed-and mobile-bearing total knee prostheses in the current series are favorable. However, there is no evidence to prove the superiority of the mobile-bearing total knee design.

Incidence and natural history of deep-vein thrombosis after total knee arthroplasty: A PROSPECTIVE, RANDOMISED STUDY

We have evaluated prospectively the incidence and location of deep-vein thrombosis (DVT), the risk factors for pulmonary embolism, and the natural history of thrombosis after total knee replacement (TKR) in patients who did not receive prophylactic or therapeutic treatment for DVT. We studied 227 patients who underwent primary TKR; 116 had one-stage bilateral and 111 unilateral procedures. Coagulation assays, the full blood count and blood typing tests for the serum chemical profile were undertaken in all patients on three separate occasions. Bilateral simultaneous or unilateral venograms were carried out at six or seven days after operation. Perfusion lung scanning was undertaken before and at seven or eight days after operation. Bilateral simultaneous or unilateral venograms were repeated six months after operation in all patients who had thrombi. In the 116 patients with a bilateral replacement, 97 of 232 venograms (41.8%) were positive for fresh thrombi while there were 46 positive venograms (41.4%) in the 111 patients with a unilateral replacement (p = 1.000). Of the 116 venograms in knees with a cemented replacement, 45 (38.8%) were positive for thrombi while 52 of the 116 venograms (44.8%) were positive in those with a cementless replacement (p = 0.675). Further venograms at six months after operation in all 143 limbs which had thrombi showed that all had completely resolved regardless of the size or location. No pulmonary embolism occurred as shown by negative perfusion lung scans and the absence of symptoms. Although the current prevailing opinion is that patients with thrombosis in the proximal veins should receive anticoagulant treatment, our study has shown that all thrombi regardless of their size or location resolved without causing pulmonary embolism.

Total knee arthroplasty in neuropathic arthropathy

We describe the results of total knee arthroplasty (TKA) undertaken for severe, neurosyphilitic Charcot arthropathy in ten patients (19 knees). A cemented condylar, constrained prosthesis was implanted in all but two knees. The mean follow-up was 5.2 years (5 to 6). The mean knee score before operation was 36.5 points (30 to 42) which improved to 76 points (58 to 90) after operation as judged by the Hospital for Special Surgery score. At final follow-up three knees (16%) had aseptic loosening which required salvage by an arthrodesis, six (31%) were functioning poorly and ten (53%) were satisfactory. We conclude that although Charcot arthropathy is not an absolute contraindication to total knee replacement, there is a high incidence of serious complications.

Low incidence of deep-vein thrombosis after cementless total hip replacement.

The incidence of deep-vein thrombosis was studied in 146 consecutive Korean patients who had a cementless total hip replacement with a porous-coated anatomic prosthesis. All of the patients had discontinued taking aspirin, aspirin-containing compounds, or other antiplatelet medications fourteen days before admission to the hospital for the operation. Deep-vein thrombosis was diagnosed by roentgenographic venography, and pulmonary embolism, by perfusion lung-scanning. There was an unusually low incidence (10 per cent) of deep-vein thrombosis in this series. In contrast to other reports, we did not identify a relationship between deep-vein thrombosis and so-called risk factors such as advanced age, number of venous valves (more than five) in the lower extremity, abnormal coagulation-assay data, certain diseases, or preoperative limitation of mobility. In addition, hypertension, blood group, surgical approach, and choice of cemented or cementless total hip replacement did not seem to affect the incidence of deep-vein thrombosis. There was a low incidence of deep-vein thrombosis in patients in whom obesity, prolonged immobilization postoperatively, varicose veins, and hyperlipemia were not factors.

Results of the Harris-Galante cementless hip prosthesis

We reviewed 82 primary arthroplasties (in 71 patients) in which cementless porous-coated hip prostheses were used. The mean age of the patients at operation was 52 years (24 to 86); they were followed up for an average of 62.1 months (60 to 66). The diagnosis was avascular necrosis of the femoral head in 35%, fracture of the femoral neck in 24%, primary osteoarthritis in 16% and miscellaneous in 25%. The average preoperative Harris hip score was 56.7 points and the average postoperative score was 83.3 points. Eight hips (10%) had component loosening; four had been revised and four were awaiting revision. In 27 hips (33%) there was a radiolucent line wider than 2 mm in zones 1 and 7. In 55 hips (67%) there was calcar resorption of more than 10 mm. Twenty patients (28%) complained of thigh pain although they had no radiographic evidence of loosening of a component. Factors that may have contributed to the poor clinical and radiographic results were: 1) inadequate surface area for bone ingrowth, particularly on the lateral aspect of the upper part of the prosthesis, 2) poor initial fit of the stem in the metaphysis, which resulted in cantilever motion of the proximal part of the stem about the well-fixed distal stem, and 3) the collar of the prosthesis, which prevented it from subsiding to a naturally stable position and caused damage to the calcar.

Drainage versus nondrainage in simultaneous bilateral total hip arthroplasties

A prospective study of 48 patients (96 hips) who had undergone primary simultaneous bilateral total hip arthroplasty was conducted to assess the effect of postoperative suction drainage on wound healing and infection. A suction drain was placed by randomization of the drained versus undrained side. The same surgical technique was used in all total hip arthroplasty wounds. Statistical analysis of the results showed significant differences with respect to drainage from the wound, soaked dressings requiring reinforcements, ecchymosis, and erythema about the wound in the group without drainage. There was no specific correlation between the incidence of wound complications and infection after total hip arthroplasty and the use or nonuse of closed-suction drainage. The hip score and range of motion of the hip were unaffected by the use or nonuse of the drains. The cost of 1 set of hemovac drains is