Background: Total knee arthroplasty (TKA) has been shown to be very successful with long-term follow-ups. But there are no reports showing prosthesis survival at 25-30 years. Here, we report the outcomes for 25-30 years using the Anatomic Graduated Component (Biomet, Warsaw, IN) TKA and elucidate the etiology and cause of failure of the components.Methods: We reviewed the outcomes of 5649 primary total knee arthroplasties for 25-30 years using the Anatomic Graduated Component. Statistical analysis was performed by the Kaplan-Meier survival analysis. Clinical outcomes included the Knee Society Score and standardized radiographs to check for loosening of the implants. The reason for revision surgery was reviewed retrospectively. We compared our results with those at another institution with similar long-term follow-up.Results: There were 112 failures, 48 with aseptic loosening and 25 with instability for an overall prosthesis survival rate of 94.2% at 25 years and 92.4% at 30 years follow-up. In the third decade after TKA, patients are substantially more likely to experience death than experience a failing prosthesis, with a 3811% greater risk of dying relative to failing (Risk ratio = 38.1, Odds ratio = 56.7, P < .0001).Conclusion: There was a greater risk of dying than failing over time. The primary reason for revision knee surgery was due to aseptic loosening of the prosthesis followed by instability. (C) 2016 Elsevier Inc. All rights reserved.
Cementless acetabular components are associated with a significant incidence of polyethylene wear and secondary osteolysis. 3-dimentional (3-D) porous coating and enhanced shell to a liner fixation are expected to reduce the polyethylene wear and to increase the longevity of an acetabular cup. The authors report the early clinical outcome with a cementless acetabular cup, Regenerex Ringloc+ (Zimmer Biomet, Warsaw, IN) for total hip arthroplasty. Between 2007 and 2013, the registry with 476 hip joints was reviewed retrospectively. There were 210 (48.4%) female and 224 (51.6%) male patients. The average age of the patients at the surgery was 63.9 (± 12.0) years and the average follow-up period was 2.6 years [0.5, 6.5]. At the final follow-up, there was no loosening or cup failure. There were 2 infections, 1 dislocation and 1 liner fracture, resulting in revision hip surgery. Average Harris hip score improved from 53.9 preoperatively to 91.4 postoperatively. The survivorship of Regenerex Ring Loc+ cup and the low complication rate is comparable with previous studies using other 3-D porous metal prostheses. Although this short-term outcome from the institute is very encouraging, a longer follow-up study is required.
Background Uncemented stems have been used in THA for well over two decades, but there are relatively few studies reporting on the results after 20 years. Questions/purposes The purpose of this study was to evaluate at a minimum followup of 20 years (1) hip scores; (2) radiographic findings, including stem fixation and osteolysis; (3) reoperations; and (4) survivorship free from aseptic loosening in a group of patients who underwent primary THA using a proximally porous-coated, plasma-sprayed, straight-stemmed, titanium-alloy femoral component. Methods Between 1987 and 1993, we performed 1517 primary THAs, of which 447 were cementless, and 157 used the implant under study here (representing 10% of the THAs during the period in question). General indications for the use of the study stem included (1) younger age with relatively stronger bone (average age 55 years in this study); (2) patients not involved in another study protocol (as were the 278 other cementless hips implanted during this time); and (3) patients who, at the surgeon’s discretion, would be compliant with protected weightbearing. Of those, 111 were available for followup at a minimum of 20 years (mean, 20 years), whereas 36 had died and nine (6%) were lost to followup or declined participation. The primary diagnosis was osteoarthritis in 77 hips (69%). The mean age at operation was 55 years. The clinical result was evaluated on the basis of the Harris hip score. Radiographic analysis was performed at each followup visit for distal cortical hypertrophy, spot welds, radiolucencies, stem subsidence, varus or valgus shift, osteolysis, and femoral component loosening. Kaplan-Meier analysis was performed to evaluate the survival of the femoral component. Results The mean Harris hip score improved from 46 points to 87 points (of a possible 100 points) at the most recent followup. All hips had evidence of proximal femoral remodeling consistent with osseous ingrowth. Femoral osteolyis was seen in 22 hips (20%). One stem was revised as a result of a periprosthetic fracture. No femoral component had evidence of loosening, and none was revised. Thirty-three acetabular components (30%) were revised. Conclusions This femoral component provided durable long-term fixation for over two decades after THA. The porous stem geometry is still in use today and will continue to be studied into the third decade of use. Level of Evidence Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
BACKGROUND:The orthopedic literature has not shown a universal and replicated difference, outside of flexion, in clinical results between posterior cruciate ligament retention and posterior cruciate ligament substitution in total knee arthroplasty.QUESTIONS/PURPOSES:This study was performed to compare the restoration of flexion and knee function in a large series of cruciate-retaining and cruciate-substituting total knee arthroplasties (TKRs). In addition, we aimed to study how other variables, such as those unique to each surgeon, may have affected the results.PATIENTS AND METHODS:The current study evaluated 8,607 total knee arthroplasties in 5,594 patients performed by six surgeons, each using one of four prosthesis designs (two posterior cruciate ligament retaining, two posterior cruciate ligament substituting). Knees were compared at the level of cruciate-retaining and cruciate-substituting knees, at the level of the four prostheses, and at the level of surgeon-implant combinations. Least squared means scores were obtained through multiple linear regression, analysis of variance, and the maximum likelihood method.RESULTS:At the level of posterior cruciate ligament treatment, posterior cruciate ligament substitution as a whole showed 3.2° greater flexion than posterior cruciate ligament retention. At the prosthesis level, cruciate-substituting models provided greater flexion and cruciate-retaining models provided higher function scores. In the surgeon-implant combinations, surgeons provided mixed results that often did not reflect findings from other levels; one surgeon's use of a posterior cruciate ligament retaining prosthesis achieved 14.7° greater flexion than the surgeon's use of a corresponding posterior cruciate ligament substituting design.CONCLUSIONS:Posterior cruciate ligament treatment is confounded by other variables, including the operating surgeon. The arthroplasty surgeon should choose a prosthesis based, not only on outside results, but also on personal experience and comfort.
The purpose of this study was to investigate the use for screws and cement, and primary and revision specific prosthesis for revision TKA. Between July 1989 and February 2010, 839 consecutive revision TKAs were performed, with 609 knees meeting inclusion criteria. At 17years followup, Kaplan–Meier survivorship was 0.9859 for revision specific prosthesis with screws and cement, 0.9848 for revision prosthesis with no screws, 0.9118 for primary prosthesis with screws, and 0.9424 for primary prosthesis with no screws. Revision TKAs using screws had greater defects (P<.0001). Use of revision prosthesis along with screws and cement to correct largely defective revision TKAs is highly recommended.
The purpose of this study was to investigate screws and cement for large tibial bone defects during primary TKA. Of 14,686 consecutive primary TKAs performed between December 1988 and February 2010, 256 received screws and cement for tibial defects. Cox regression was used for the analysis. 20-year survival probability was 0.9897 (screws) and 0.9339 (no screws) (P = .4225 log-rank). Tibial bone condition was significantly worse in knees receiving screws (P < .0001) with 73.0% having defects in the screws group and 3.4% (P < .0001) for non-screws. Radiolucency appeared in 13.7% (screws) and 6.4% (no screws) postoperatively. Screws were $137 each, wedges $910 to $2240. Knees with tibial defects and screws performed similarly if not better than knees without defects at substantially lower cost than alternatives.
Large-diameter metal-on-metal articulations reportedly improve stability and wear in THAs. However, some reports suggest some patients have unexplained hip and early failures with these implants. Thus, the potential benefits may be offset by these concerns. However, the incidence of these problems is not clearly established.
BACKGROUND:TKA provides demonstrable pain relief and improved health-related quality of life. Yet, a decline in physical function may occur over the long term despite the absence of implant-related problems.QUESTIONS/PURPOSES:(1) Does pain relief diminish over 20 years after TKA? (2) Does function decline over 20 years in terms of Knee Society function, knee, and walking scores? And (3) what is the patient-reported activity level at most recent followup?PATIENTS AND METHODS:We retrospectively identified 1471 patients with 1757 primary cruciate-retaining TKAs implanted between 1975 and 1989 and identified 128 living patients (8.7%) with 171 TKAs. Ninety-three patients were women. We determined Knee Society scores prospectively and UCLA scores retrospectively. Minimum followup was 20 years (average, 21.1 years; range, 20-27 years). Average age at last followup was 82.3 years (range, 45-103 years). Of the 128 patients, 66 (73 TKAs) died after 20-year followup.RESULTS:Pain scores did not diminish over time (average, 49; range, 20-50). Average knee score was 78 (range, 39-97). Function, stair, and walking scores diminished over time. Average function score was 70 (range, 5-100), primarily due to an average stair score of 35 (range, 0-50); average walking score was 37 (range, 10-50). All but two patients (two TKAs) could negotiate stairs; 95 patients (124 TKAs) could walk at least five blocks; three patients (three TKAs) were housebound. Of the 62 patients still living (98 TKAs), the average UCLA activity score was 8.3 (range, 5-10).CONCLUSIONS:Although aging may cause a gradual decline in physical activity, an improved functional capacity and activity level continue 20 years or more after TKA.
BACKGROUND:Polyethylene wear may be affected by the type of polyethylene resin, manufacturing technique, degree of thermal stabilization, and sterilization technique.QUESTIONS/PURPOSES:We therefore compared femoral head penetration into the PE and cup survival using the same cup system with different PE resins, manufacturing, and sterilization techniques.METHODS:Our study group consisted of 1912 THAs performed using the same uncemented cup and identical 28-mm cobalt-chrome heads. The polyethylene varied as follows: Group 1 (94 cups), GUR 4150 resin, ram-extruded, sterilized in air, no barrier packaging; Group 2 (74 cups), same as Group 1 but sterilized in argon; Group 3 (75 cups), Himont 1900 resin, compression-molded bar stock, sterilized in argon, no barrier packaging; Group 4 (620 cups), same as Group 3 except with barrier packing; Group 5 (711 cups), GUR 1050 resin, compression-molded bar stock, sterilized in argon gas with barrier packaging; and Group 6 (338 cups), GUR 1050 resin, compression-molded bar stock, sterilized in argon with barrier packaging, irradiated with 50 kGy, heated below melting temperature, machined, and finally placed in nonbarrier packaging with gas plasma sterilization. Minimum followup was 2 years (average, 7 years; range, 2-17 years).RESULTS:Femoral head penetration averaged 0.05 mm per year for Groups 5 and 6 and was substantially lower than for Groups 1 to 4. Cup survival was higher at seven years in Groups 3, 4, and 5, and at 10 years in group 4 when compared to groups 1, 2, and 3.CONCLUSIONS:We observed lower FHP rates and higher cup survival with polyethylene machined from direct compression-molded bar stock, sterilized in argon gas, with barrier packaging.LEVEL OF EVIDENCE:Level III Therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Dislocation after total hip arthroplasty (THA) is multifactorial and is dependent on surgical, implant, and patient factors. We hypothesized that high preoperative hip range of motion is an important variable contributing to instability after THA. We retrospectively reviewed 3379 THAs performed during a 21-year period. Average follow-up was 6.6 years. We examined the effect of surgical approach, femoral head size, and preoperative range of motion on dislocation rates. Patients with a posterior approach and 115 degrees or greater of combined preoperative flexion, adduction, and internal rotation dislocated at a significantly higher frequency than those with less than 115 degrees of combined motion (odds ratio, 1.9; P = .007). High preoperative motion in conjunction with a posterior approach and femoral head size less than 32 mm had the highest dislocation rate in our sample (5.9%). Preoperative range of motion is an important variable that should be taken into consideration during operative planning to help reduce the risk of dislocation.
"Thin" modular polyethylene bearings have previously been associated with failure from wear. This study examined the influence of polyethylene thickness on survivorship in primary total knee arthroplasty (TKA). Do "thinner" or "thicker" bearings fail more? Six thousand seventy primary TKAs with a single implant design were reviewed. The failure rate in knees with bearings 14 mm or less was 0.7%, whereas the failure rate of knees with bearings 16 mm or greater was 2.3% (P < .0001; hazard ratio, 3.2). No knee was revised for polyethylene wear. Thicker bearings did not directly cause failure, but factors that lead to the insertion of a thicker bearing such as a deeper tibial resection and ligament imbalance may contribute to the observed increased failure. The significant influence of this often-unrecognized surgical variable has not been previously reported and must be carefully considered during TKA.
Pain relief from osteoarthritis is the primary goal of a TKA. The purpose of this study was to determine the preoperative and intraoperative factors that may predict greater pain after TKA.
Total joint replacement infection is a serious complication that is occurring with more virulent organisms more frequently.
The treatment of unicompartmental osteoarthritis of the knee by high tibial osteotomy has been carried out by closing-wedge osteotomy. The advantages for opening-wedge osteotomy are ease of procedure and improved correction with comparable short-term to midterm results. It is not known how the opening-wedge high tibial osteotomy procedure alters the load distribution between the medial and lateral compartments of the knee. The current biomechanical study investigated opening-wedge vs closing-wedge osteotomies in 5 pairs of cadaver knees. The results showed that at 5 degrees osteotomy, the closing-wedge provided superior results of load transfer from medial to lateral compartment than that seen with opening-wedge, but at 10 degrees osteotomy, there was no significant difference in load transfer in the knee compartments between the 2 surgery modes.
A retrospective study of 201 anatomic graduated component total knee arthroplasties implanted with hybrid fixation at the authors’ center was performed in response to conflicting data in the literature concerning the benefits of a hybrid method. Selection for hybrid fixation was nonrandomized and based on femoral component fit. Survivorship analysis was performed, and rates of radiolucent lines surrounding the femoral component and occurrence of osteolysis were noted. At 7 and 13 years, survivorship with tibial or femoral revision as the end point was 0.9926 and 0.9732, respectively. Radiolucencies were found adjacent to 15 femoral components at final followup (seven in Zone 1, three in Zone 2, five in Zone 3, one in Zone 4, two in Zone 5, zero in Zone 6). Osteolysis was observed in one knee after secondary evaluation. Hybrid fixation in a selected patient population can result in excellent results in middle to long-term followup. Level of Evidence: Level IV, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.
The purpose of this study is to report the outcome for a consecutive series of isolated nonmodular tibial component revisions. A consecutive series of 6548 total knee arthroplasties (6024 metal backed; 524 all-polyethylene) were performed with nonmodular tibial components of which 54 knees (0.82%) (22 metal backed; 32 all-polyethylene) underwent isolated tibial component revision with femoral component retention. Clinical outcome and component survivorship were examined. Pain scores improved from 19 to 42 points and Knee Society score improved from 62 to 87 points after revision. At a mean of 6.6-year follow-up, the survivorship of the revised tibial components and retained femoral components, with aseptic loosening as the end point, was 100%.
This randomized trial assessed the effect of recombinant human erythropoietin (EPO) vs preoperative autologous donation (PAD) on postoperative vigor and handgrip strength in patients undergoing primary total joint arthroplasty. Adults with baseline hemoglobin level of 11 to 14 g/dL received EPO (600 IU/kg once weekly for 4 doses, n = 130) or PAD (n = 121) before primary, unilateral hip or knee arthroplasty. Mean changes in vigor score and handgrip strength from baseline were not significantly different between treatment groups. Multivariate analyses found a significant treatment effect favoring EPO over PAD for vigor, but not for handgrip strength. Patients in the EPO group had higher hemoglobin levels and required fewer transfusions. Both treatments were well tolerated. Additional study is needed to elucidate the influence of blood management strategies on postoperative vigor.
BACKGROUNDFollowing total knee arthroplasty, some patients who fail to achieve >90 degrees of flexion in the early perioperative period may be considered candidates for manipulation of the knee under anesthesia. The purpose of this study was to assess the outcomes of manipulation following total knee arthroplasty.METHODSOne hundred and thirteen knees in ninety patients underwent manipulation for postoperative flexion of < or =90 degrees at a mean of ten weeks after surgery. Flexion was measured with a goniometer prior to total knee arthroplasty, at the conclusion of the operative procedure, before manipulation, immediately after manipulation, at six months, and at one, three, and five years postoperatively.RESULTSEighty-one (90%) of the ninety patients achieved improvement of ultimate knee flexion following manipulation. The average flexion was 102 degrees prior to total knee arthroplasty, 111 degrees following skin closure, and 70 degrees before manipulation. The average improvement in flexion from the measurement made before manipulation to that recorded at the five-year follow-up was 35 degrees (p < 0.0001, paired t test). There was no significant difference in the mean improvement in flexion when patients who had manipulation within twelve weeks postoperatively were compared with those who had manipulation more than twelve weeks postoperatively. Patients who eventually underwent manipulation had significantly lower preoperative Knee Society pain scores (more pain) than those who had not had manipulation (p = 0.0027).CONCLUSIONSManipulation generally increases ultimate flexion following total knee arthroplasty. Patients with severe preoperative pain are more likely to require manipulation.