Elizabeth S. Soileau

The Rates of Osteolysis and Loosening Associated with a Modular Posterior Stabilized Knee Replacement: Results at Five to Fourteen Years

BACKGROUND Osteolysis and increased polyethylene wear have been reported in association with several designs of modular total knee prostheses. The purpose of the present study was to evaluate a modular posterior stabilized prosthesis to determine its clinical performance as well as the rates of component loosening and osteolysis. METHODS We performed a prospective, consecutive study of 193 knees in 131 patients who were managed with the modular Insall-Burstein II posterior stabilized total knee prosthesis by one surgeon. The mean age of the patients at the time of surgery was sixty-eight years, and the mean duration of follow-up was seven years (range, five to fourteen years). Clinical evaluation was performed with use of standard knee-scoring systems. Radiographs were evaluated for the presence of radiolucent lines, osteolysis, and loosening. RESULTS The overall result (as determined with the Hospital for Special Surgery scoring system) was rated as excellent for 112 knees, good for sixty, fair for fifteen, and poor for six. The mean postoperative flexion was 112 degrees. No clinical or radiographic loosening of the tibial component was noted. Eight knees had osteolytic lesions of the tibia. Thin, incomplete, nonprogressive radiolucent lines were noted around thirty tibial components (16%). There were three reoperations. CONCLUSIONS Despite previous reports of osteolysis, polyethylene wear, and loosening in association with some modular total knee implant designs, there was no loosening in this series of posterior stabilized total knee replacements and only eight knees had tibial osteolysis after a mean duration of follow-up of seven years. We believe that total knee arthroplasties that are performed with use of cemented modular posterior stabilized components can have a high rate of intermediate-term success. LEVEL OF EVIDENCE Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Fifteen-year survival and osteolysis associated with a modular posterior stabilized knee replacement. A concise follow-up of a previous report.

We report the results of a consecutive series of total knee arthroplasties with use of a modular posterior stabilized prosthesis after a mean follow-up of twelve years (range, ten to eighteen years). In the five years since the original publication of our study, two additional knees were revised; one was revised for aseptic loosening and one, for polyethylene wear with tibial osteolysis. With mechanical failure as an end point, the fifteen-year survival was 96.8%. With failure defined as any reoperation, the fifteen-year survival was 90.6%. Osteolysis occurred in eight of the 117 knees with a minimum ten-year follow-up. With the relatively small number of subjects, no significant association was identified between polyethylene thickness or sterilization method and osteolysis. A significant association was identified between younger patient age and osteolysis. We continue to routinely implant a similar modular posterior stabilized total knee prosthesis.

Dislocation of primary total hip arthroplasty with 36 and 40-mm femoral heads

Some authors suggest the use of larger (36 and 40 mm) femoral heads against highly cross-linked polyethylene acetabular liners will reduce the prevalence of early dislocation after primary total hip arthroplasty (THA). We prospectively followed 61 consecutive patients at high risk for dislocation to determine the prevalence of early dislocation after primary THA with 36 and 40 mm femoral heads. We established specific indications for the use of these larger heads in primary arthroplasty. There were 65 hips in 61 patients with a minimum followup of 1 year (mean 2 years, range 1-4 years). There were 55 36 mm heads and 10 40 mm heads. All arthroplasties were performed by the posterior approach with capsular repair. The prevalence of early dislocation was 4.6% (3 of 65). There was one patient with an anterior dislocation and two with posterior dislocation. No patient underwent reoperation for dislocation. There was no dislocation in the 10 hips that had a 40 mm head. We identified no complications related to the larger femoral heads. The use of larger femoral heads did not notably reduce the prevalence of early dislocation after primary THA in high risk patients compared to historical controls.Therapeutic study: Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Multimodal prophylaxis for THA with mechanical compression.

We used mechanical thromboembolism prophylaxis using intraoperative thigh-calf pneumatic compression and other measures in 1032 consecutive primary and revision total hip arthroplasties. No chemical prophylactic measures were used until after duplex ultrasonography was performed by experienced technologists before discharge. Asymptomatic proximal thrombi were treated with low molecular weight heparin and warfarin, whereas those patients with a negative scan or distal thrombi only were advised to take aspirin 325 mg twice a day for 6 weeks. Regional anesthesia was used in 95% of the arthroplasties. Using this protocol, the 30-day mortality was 0.3%. There was one autopsy-proven fatal pulmonary embolism (0.09%). One other patient died suddenly with cardiac arrest after abdominal pain and vomiting, but no autopsy was performed. Symptomatic pulmonary embolism occurred in seven patients (0.7%), four occurring early and three late. Only one of these seven patients had a positive duplex scan. Deep vein thrombosis occurred in 41 patients (3.9%) and 35 remained asymptomatic. We observed no association between type of surgery (primary or revision), age, gender or preoperative diagnosis and pulmonary embolism or deep vein thrombosis. The data confirm the efficacy of a multimodal protocol with thigh-calf mechanical prophylaxis for almost all patients undergoing primary or revision total hip arthroplasty.Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Stability of total hip arthroplasty in patients 75 years or older.

Increasing patient age (> 75 years) is a known risk factor for dislocation of total hip arthroplasty. This is a study of total hip arthroplasties by one surgeon in patients 75 years or older to determine the prevalence of dislocation and a review of the surgical options for prevention and treatment of instability in this population. Of 140 primary total hip arthroplasties done in patients 75 years or older who were followed up for at least 1 year, the preoperative diagnosis was osteoarthritis in 82% and the mean followup time was 4 years. The acetabular component was cementless: modular in 121 arthroplasties and cemented in 19 arthroplasties. There were five dislocations (3.5%), but only two were recurrent and the patients were treated successfully by modular component exchange. Bipolar arthroplasty has a lower rate of dislocation, but there are problems with residual pain and high rates of reoperation, wear, and osteolysis. Constrained components may be indicated in older patients with dementia, abductor insufficiency, or failure of modular exchange. Large femoral heads, to increase the range of motion before dislocation occurs, may be used with highly cross-linked acetabular liners. Modular cementless acetabular components are preferable in patients who are 75 years or older. A 28-mm or 32-mm femoral head is recommended, but larger femoral heads should be considered in patients with fractures and for the treatment of recurrent dislocation.

Fixation, Survival, and Dislocation of Jumbo Acetabular Components in Revision Hip Arthroplasty

BACKGROUND Acetabular revision of a total hip arthroplasty using jumbo components (Mayo definition, ≥62 mm in women and ≥66 mm in men) offers distinct advantages in patients with notable acetabular bone loss. However, there are little data on the long-term survival and complications associated with use of these components. METHODS This retrospective study of prospectively collected data included 120 patients who underwent 129 revision total hip arthroplasties with jumbo cups. Data on infection, aseptic loosening, reoperation, and dislocation were analyzed. One hundred and one patients (108 hips) with a mean follow-up of 8.1 years (range, two to twenty years) were evaluated with use of the Harris hip score and radiographic evidence of loosening, radiolucent lines, and osteolysis. Kaplan-Meier survivorship was calculated at ten and fifteen years with use of three different end points. Demographic and operative factors associated with implant survival and dislocation were analyzed with use of chi-square and Wilcoxon tests. RESULTS Four (3.1%) of the jumbo components were removed for infection and four hips (3.1%) had aseptic implant loosening. Reoperation for any reason was performed in twenty hips. With failure defined as cup revision for aseptic loosening or radiographic evidence of loosening, implant survival was 97.3% (95% confidence interval [CI], 89.6% to 99.3%) at ten years and 82.8% (95% CI, 59% to 97.6%) at fifteen years. With failure defined as cup removal for any reason, implant survival was 93.8% (95% CI, 83.4% to 97.2%) at ten years and 79.8% (95% CI, 61.1% to 95.4%) at fifteen years. There was no significant association between Paprosky type, component coating, or patient characteristics and failure. Dislocation occurred in twelve (9.3%) of the hips (10% of the patients) and three underwent reoperation. A femoral head size of ≥32 mm was associated with a significantly lower risk of dislocation compared with smaller sizes. CONCLUSIONS Jumbo acetabular components with screw fixation were associated with low rates of infection and loosening after revision total hip arthroplasty and had high survival at fifteen years. Reoperation for wear and loosening increased in the second decade. Dislocation was the most common complication and was significantly associated with smaller femoral head sizes.

Mechanical calf compression and aspirin prophylaxis for total knee arthroplasty.

We used aspirin and mechanical calf pneumatic compression for thromboembolism prophylaxis in 856 consecutive primary and revision total knee arthroplasties. Regional anesthesia was used in 97% of the procedures. Duplex ultrasonography was performed before discharge. We advised patients with calf thrombi to continue aspirin and have repeat duplex scans in 7 to 10 days. Patients with popliteal or femoral thrombi were given low-molecular-weight heparin and warfarin for 6 weeks. Using this protocol, the 90-day mortality rate was 0.14%. There was one fatal myocardial infarction. Three patients developed symptomatic nonfatal pulmonary embolisms, two occurring early and one late. Deep vein thrombosis occurred in 56 patients (9.3%). Only nine patients (1.5%) had symptomatic thrombosis, with four ipsilateral calf and five ipsilateral proximal thrombi. The data confirm the efficacy of a multimodal protocol with calf mechanical prophylaxis for almost all patients undergoing primary or revision total knee arthroplasty.Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Patella maltracking in posterior-stabilized total knee arthroplasty.

Maltracking of the patella component in total knee arthroplasty usually leads to complications such as subluxation, dislocation, fracture, excessive wear, or implant failure. After using a new posterior-stabilized total knee arthroplasty and a specific protocol for the patellofemoral articulation we determined the incidence of lateral retinacular release and patella complications. We retrospectively reviewed 255 consecutive primary posterior-stabilized total knee arthroplas- ties with an anatomic femoral component and a three-peg offset-dome patella. Component alignment was achieved using Whitesides lines for the femoral component, the medial border of the tubercle for the tibial component, and previously reported techniques for the patella. Lateral release was performed in 15 knees (6.2%), most of which had excessive preoperative valgus (mean, 15°). There were no reoperations for the patellofemoral joint at a mean followup of 3.7 years (range, 2-7 years). Two patients had asymptomatic osteonecrosis of the patella with complete radiolucent lines, and one patella fracture was treated with immobilization. We believe patella maltracking a largely avoidable problem in total knee arthroplasty. We found a low incidence of lateral retinacular release and patella complications using these components and this protocol for the patellofemoral articulation. Level of Evidence: Level IV, therapeutic study (case series). See Guidelines for Authors for a complete description of levels of evidence.

A 30-mm Cemented Stem Extension Provides Adequate Fixation of the Tibial Component in Revision Knee Arthroplasty

BackgroundThe optimal stem length and method of fixation for the tibial component in revision knee arthroplasty remains controversial. The use of a cemented 30-mm stem extension provides certain advantages compared with other methods of fixation, but there are few published results.Questions/purposesWe therefore asked (1) what is the survivorship (with respect to loosening and repeat revision) of tibial component revisions when a 30-mm stem extension is used; and (2) what factors are associated with the appearance tibial radiolucent lines?MethodsWe retrospectively reviewed 54 patients (58 knees) with fixation of the revision tibial component with a 30-mm cemented stem extension; another seven patients died and 11 patients had these components but were lost to followup. These implants represented 74% of our tibial revisions during the period in question (76 of 103); general indications for using them were need for a varus-valgus constrained liner or proximal bone loss requiring a metaphyseal cone or metal augment with an intact diaphysis. The Anderson Orthopaedic Research Institute tibial defect was Grade 1 in 37, 2A in 10, 2B in four, and Grade 3 in seven knees; constrained liners were used in 34% (20 of 58 knees). Patients were evaluated and followed for a mean of 5 years (range, 2–12 years).ResultsThere were no revisions for tibial component loosening. One patient had débridement and liner exchange for late infection. Radiolucent lines were seen in 25 tibial components but only eight knees had radiolucencies in four or more zones. There were significantly fewer radiolucencies in revisions that used metaphyseal cones (20 in eight knees with cones compared with 53 in 17 without, p = 0.013).ConclusionsThe cemented 30-mm tibial stem extension provided excellent fixation in knee revision arthroplasty, even with metaphyseal defects and constrained polyethylene liners, although this series included relatively few patients with severe tibial defects. Longer followup is required for patients with radiolucent lines to confirm that the fixation will remain durable.Level of EvidenceLevel IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Survival of Polished Compared with Precoated Roughened Cemented Femoral Components: A Prospective, Randomized Study

BACKGROUND The optimal surface finish for cemented femoral components remains controversial. The purpose of this randomized clinical trial was to compare the survival of two femoral components with similar geometry but substantially different surface finishes. METHODS During a five-year period, 201 patients (219 hips) were prospectively randomized to be treated with a total hip arthroplasty with either a polished (Ra, 0.18 to 0.3 microm) or a precoated roughened (Ra, 1.8 to 2.3 microm) cemented femoral component with similar geometry. There were no significant differences between the patient groups in terms of age, sex, weight, preoperative diagnosis, component size, or cement grade. So-called third-generation cementing techniques were used. One hundred and thirteen polished components and 106 precoated roughened components were followed for a mean of 5.3 years. Complete clinical and radiographic data were available for 134 hips at a minimum of five years (mean, 6.1 years; range, five to ten years) postoperatively. RESULTS In the entire cohort of 219 hips, there was no significant difference (log rank p = 0.66) in survival, with the end point defined as component removal for any reason or definite radiographic loosening, between the precoated components (96.2%; 95% confidence interval, 90.9% to 100%) and the polished components (97.1%; 95% confidence interval, 93.8% to 100%). There was a periprosthetic fracture in three hips with a polished component. Two precoated roughened components were revised because of loosening, and two polished components were revised: one because of loosening and one because of a nonunion of a periprosthetic fracture. There was no significant difference between the groups with regard to the Harris hip scores or the clinical results. There was also no significant difference with regard to the presence or number of bone-cement radiolucent lines. CONCLUSIONS Kaplan-Meier survival analysis showed no significant differences between two types of cemented femoral components with similar geometry but substantially different surface finishes at seven years. In the patient population selected for treatment with a cemented femoral component, the surface finish may not be a crucial factor affecting component survival at a minimum of five years, provided that good cement technique is used.