Showing papers in "Journal of Arthroplasty in 2003"
TL;DR: Patients in the mini-incision group had significant improvement in limp and ability to climb stairs compared with the traditional group, and there was no significant difference between groups for pain, function, or range of motion at the 1-year follow-up examination.
Abstract: This prospective study compares a mini-incision technique and traditional posterior approach for total hip arthroplasty (THA). Thirty-three patients who had undergone a mini-incision THA were matched by diagnosis, gender, average age, and preoperative Harris Hip Score (HHS) to 33 patients who had undergone THA using the traditional posterior approach. The average length of the incision for group 1 was 11.7 cm (range, 7.3–13.0) and for group 2 was 20.2 cm (range, 14.8–26.0). At the 3-month follow-up, patients in the mini-incision group had significant improvement in limp ( P P P P P
308 citations
TL;DR: In linear regression models, WOMAC pain and function scores at 12 months were both correlates of patient satisfaction and perceived improvement in QOL, but knee flexion was not.
Abstract: We investigated the relationship of knee range of motion (ROM) and function in a prospective, observational study of primary total knee arthroplasty (TKA). Preoperative and 12-month data were collected on 684 patients, including knee ROM, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function questionnaire scores, patient satisfaction, and perceived improvement in quality of life (QOL). Only modest correlations were found between knee ROM and WOMAC function (r or =95 degrees (mean, 61.9 vs 75.0; P 3.5; P<.0001), but knee flexion was not. For assessment of these outcomes, WOMAC function appears to be more important than knee flexion.
237 citations
TL;DR: In this paper, the authors compared outcomes of total hip or knee arthroplasty for patients who were treated using clinical pathways as opposed to patients treated without these pathways, and concluded that clinical pathways appear successful in reducing costs and length of stay in the acute care hospital, with no compromise in patient outcomes.
Abstract: Although many hospitals have implemented clinical pathways to standardize the process of care, the effectiveness of clinical pathways for total hip and knee arthroplasties has not been reviewed critically. We searched for articles comparing outcomes of total hip or knee arthroplasty for patients who were treated using clinical pathways as opposed to patients treated without these pathways. Eleven studies met criteria for inclusion. Ten used historical controls, and 1 was a randomized trial. The studies had important methodological limitations. In general, the articles showed that patients treated using pathways experienced shorter hospital stays and lower costs, with comparable clinical outcomes as compared with patients treated without clinical pathways. We concluded that clinical pathways appear successful in reducing costs and length of stay in the acute care hospital, with no compromise in patient outcomes. However, interpretation of these studies is complicated by substantial methodological limitations, particularly the use of historical controls and failure to account for length of stay in rehabilitation facilities.
222 citations
TL;DR: The results suggest that more thorough rehabilitation after TKA would improve functional outcomes and suggest that relatively greater quadriceps strength was associated with a better functional score.
Abstract: Fifty-two knees in normal healthy subjects and 32 knees more than 2 years after total knee arthroplasty (TKA) were evaluated. Average isometric extension peak torque values in TKA patients were reduced by up to 30.7% (P=.01). Isometric flexion peak torque values in patients with TKA were, on average, 32.2% lower than those from control subjects throughout the motion arc (P=.004). Knee Society Functional Scores were positively correlated to the average isometric extension peak torque (r=0.57; P=.004) and negatively correlated to the average isometric hamstring to quadriceps (H/Q) ratio (r=-0.78, P /=70 years) generated lower isometric extension peak torque values in terminal extension than younger TKA patients (>24.2%; P=.05). Higher body mass index (BMI) was associated with relative quadriceps weakness (r=0.44; P=.007). These results suggest that more thorough rehabilitation after TKA would improve functional outcomes.
213 citations
TL;DR: The 2-year results for a prospective randomized trial comparing highly cross-linked with standard polyethylene in total hip replacements show a significant reduction in 2- and 3-dimensional linear wear rates.
Abstract: We report the 2-year results for a prospective randomized trial comparing highly cross-linked with standard polyethylene in total hip replacements. In our study, 46 hips were available for radiographic analysis at 2- and 3-year follow-up. Femoral bearings were 28-mm cobalt chrome with the polyethylene insert randomly selected at the time of implantation to be highly cross-linked polyethylene (Crossfire; Stryker Howmedica Osteonics, Allendale, NJ) or standard polyethylene (N(2)/Vac, Stryker Howmedica Osteonics). Polyethylene wear rates were measured based on anterior-posterior (AP) and lateral pelvis radiographs at 6 weeks and at yearly intervals using a validated computer-assisted edge-detection method. Wear rates between the 2 groups were compared using the nonparametric Mann-Whitney test at the 95% level. A significant reduction in 2- and 3-dimensional linear wear rates (42% and 50%) was found in the highly cross-linked group (P =.001 and P =.005).
211 citations
TL;DR: In this article, the authors developed and validated an easily administered method of predicting a patient's risk of needing extended inpatient rehabilitation after hip or knee arthroplasty based on seven factors generated by experts and from the literature.
Abstract: This study developed and validated an easily administered method of predicting a patient's risk of needing extended inpatient rehabilitation after hip or knee arthroplasty Seven factors generated by experts and from the literature were shown to be statistically significantly related to discharge destination (P
191 citations
TL;DR: The high failure rate of debridement and component retention suggests that immediate component removal should be considered in the presence of acute S. aureus infection in total knee arthroplasty.
Abstract: The purpose of this study was to review our experience in treating acute gram-positive infections after total knee arthroplasty with debridement, component retention, and intravenous antibiotics. Thirty-one total knee arthroplasties with acute gram-positive infections, seen at our institution over a 10-year period, were treated with open debridement and component retention. Eleven (35%) of 31 patients successfully retained their components at most recent follow-up, without ongoing infection (mean, 4 years; range, 2-10 years). Only one (8%) of the 13 patients infected with Staphylococcus aureus was successfully treated, compared with 10 (56%) of 18 patients with either Staphylococcus epidermidis or a streptococcal species. The difference between these groups is statistically significant (P=.007). The high failure rate of debridement and component retention suggests that immediate component removal should be considered in the presence of acute S. aureus infection in total knee arthroplasty.
164 citations
TL;DR: Early results demonstrate the superiority of LISS treatment with low infection rates, no requirement for acute bone grafting, and secure fixation allowing for immediate postoperative mobilization, and LISS fixation may offer a superior surgical treatment option for periprosthetic distal femur fractures.
Abstract: Periprosthetic fractures of the distal femur above a total knee arthroplasty present a challenging surgical problem for orthopedic surgeons. Numerous operative and nonoperative treatment options exist including casting, Rush rods, supracondylar nails, and plate fixation. Potentially significant complications are associated with all current treatment alternatives. Plate or nail constructs frequently achieve limited distal fixation, leading to loss of fixation and varus angulation. This complication was not observed with the Less Invasive Stabilization System (LISS). In addition, our early results demonstrate the superiority of LISS treatment with low infection rates, no requirement for acute bone grafting, and secure fixation allowing for immediate postoperative mobilization. LISS fixation may offer a superior surgical treatment option for periprosthetic distal femur fractures.
146 citations
TL;DR: Patients with worse preoperative function had higher expectations of THA and were more likely to rate their expectations as very important compared with patients with better function, according to the Hospital for Special Surgery Total Hip Replacement Expectations Survey.
Abstract: Recent reports indicate that patients' expectations should be assessed as part of routine practice before total hip arthroplasty (THA). A total of 1,103 THA patients preoperatively completed the Hospital for Special Surgery Total Hip Replacement Expectations Survey, an 18-item scale tested for validity and reliability. Patients also completed measures of hip-specific function (American Academy of Orthopaedic Surgeons Hip/Knee Module), and overall physical function (SF-36). Patients with worse preoperative function had higher expectations of THA and were more likely to rate their expectations as very important compared with patients with better function. In multivariate analysis, older patients, men, and those with worse functional status (both hip-specific and overall physical function) had more expectations of THA. Identifying and addressing expectations, particularly possibly unrealistic expectations, are important elements in discussions with patients before THA.
145 citations
TL;DR: The clinical outcome of 35 patients with 40 cemented long-stemmed kinematic stabilizer revision total knee arthroplasties at followup evaluation is detailed, with the incidence of tibial radiolucencies similar to that with a nonstemmed revision cemented total kneeArthroplasty previously reported from the authors' institution.
Abstract: From 1981 to 1989, 38 cemented, posterior, stabilized, revision, total knee arthroplasties (TKAs) were performed at the authors' institution using the stemmed kinematic stabilizer prosthesis of a single design. The mean clinical follow-up after the index procedure was 10.1 years. The Knee Society pain score averaged 17 points before revision and improved to 51 points at last follow-up, and the function score averaged 48 points before revision and improved to 57 at last follow-up. Ten-year component survival free of revision or removal for any reason was 96.7%; 11-year component survival free of revision for aseptic loosening was 95.7%. Cemented stem fixation in revision TKA provides good clinical results with durable fixation at an average of 10 years' follow-up.
142 citations
TL;DR: Subtrochanteric shortening osteotomy is a safe and predictable method of restoring the anatomic hip center in high developmental hip dislocation, however, the complication rate in patients with Crowe grade 3 or 4 hip dysplasia is higher than primary hip arthroplasty for osteoarthritis.
Abstract: Twenty-one primary hip arthroplasties were performed in Crowe grade 3 or 4 hip dysplasia using a subtrochanteric shortening osteotomy. Average patient age was 48.2 years. Average follow-up was 5.8 years (minimum, 2 years). Femoral fixation was cemented in 10 hips and uncemented in 11 hips. All acetabular components were uncemented, with 33% requiring structural autograft. Ninety-one percent of femoral osteotomies healed without complication. Two osteotomy nonunions required revision. Two acetabular revisions were performed for malposition and polyethylene failure. Three patients experienced postoperative dislocation. One cemented femoral component was revised for loosening. However, no neurologic deficiencies were identified. Harris hip score improved from 32.5 to 73.6. Limp improved in 60% of patients and dependence on assistive walking device improved in 40% of patients. Subtrochanteric shortening osteotomy is a safe and predictable method of restoring the anatomic hip center in high developmental hip dislocation. However, the complication rate in these patients is higher than primary hip arthroplasty for osteoarthritis.
TL;DR: It is found that the Link MP hip stem allows successful revision THA reconstruction of the proximally compromised femur and good to excellent functional restoration and pain relief is achievable.
Abstract: Proximal femoral bone deficiency in the failed total hip arthroplasty (THA) is addressed with difficulty using proximally fixed implants. The Link MP reconstruction hip stem is proximally modular but utilizes distal fixation. This series consists of 143 patients from 3 clinical sites. Of the patients, 81 were women. The average follow-up time was 40 months, and the average patient age was 67 years. The preoperative diagnoses included 108 cases of aseptic loosening and 14 periprosthetic fractures. Clinical follow-up of all patients included radiographic assessment of the hip. This study found a 97.2% survival rate. The average subsidence was 2.1 mm. The average postoperative Harris hip score was 92. Complications included 7 wound infections and 4 deep venous thromboses. We found that the Link MP hip stem allows successful revision THA reconstruction of the proximally compromised femur. Good to excellent functional restoration and pain relief is achievable.
TL;DR: The synovial fluid WBC count differential analysis is a statistically relevant indicator of the presence or absence of infection in revision knee arthroplasty.
Abstract: A white blood cell count (WBC) of >50000 cell/mm(3) from a knee aspirate with >or=80% polymorphonuclear cells (PMNCs) is suggestive of infection. This study sought to determine if these same criteria were applicable when interpreting aspirates from a total knee. Of 440 revision total knee arthroplasties, 86 patients had preoperative aspirations of the knee before revision. Fifty-five aspirates were from aseptic failures; 31 aspirates were from patients determined to have septic failure. The mean white blood cell (WBC) count in aspirates from the aseptic group was 645 cells/mm(3) (SD = 878). The mean WBC count in the septic group was 25951 cells/mm(3) (SD = 34994; P=<.001). The mean percentage of PMNCs was statistically higher in the septic group compared with the aseptic group (72.8% vs 27.3%; P=<.001). The synovial fluid WBC count differential analysis is a statistically relevant indicator of the presence or absence of infection in revision knee arthroplasty. Aspirates with a WBC count of 2500 per milliliter and 60% PMNCs are highly suggestive of infection.
TL;DR: Gender was a significant independent predictor of morbidity and length of stay for total knee arthroplasty and rates of adverse outcomes in this population of veterans were very low.
Abstract: The relationship between patient characteristics and outcomes of total joint arthroplasty (TJA) was examined in a population of veterans treated in VA hospitals Outcomes included 30-day mortality and morbidity, postoperative length of stay, and readmission caused by surgical complications A larger proportion of women then men were functionally impaired before surgery in both the hip (22% vs 14%) and knee samples (14% vs 7%; all P<01) Rates of adverse outcomes in this population were very low Preoperative comorbid conditions, abnormal laboratory values, and being nonwhite were related to poor outcomes of TJA Gender was a significant independent predictor of morbidity and length of stay for total knee arthroplasty
TL;DR: Of the 3 groups evaluated, the total knee group had the least variation and greatest accuracy of implant placement and limb alignment and the UKA groups had small but significant differences in postoperative alignment and AP tibial position.
Abstract: This is a retrospective radiographic analysis of implant position in minimally invasive unicompartmental knee arthroplasty (UKA), open UKA, and total knee arthroplasty (TKA). Implant position and limb alignment were recorded in the AP and lateral planes. Of the 3 groups evaluated, the total knee group had the least variation and greatest accuracy of implant placement and limb alignment. UKA groups had small but significant differences in postoperative alignment and AP tibial position. Using contemporary instrumentation, UKA is less accurate than TKA in implant placement and limb alignment. Minimally invasive UKA was not as accurate as open UKA in AP tibial placement or postoperative limb alignment.
TL;DR: The goals of any rehabilitation protocol should be to control pain, improve ambulation, maximize range of motion, develop muscle strength, and provide emotional support.
Abstract: The goals of any rehabilitation protocol should be to control pain, improve ambulation, maximize range of motion,develop muscle strength, and provide emotional support. Over 85% of total knee arthroplasty (TKA) patients will recover knee function regardless of which rehabilitation protocol is adopted. However, the remaining 15% of patients will have difficulty obtaining proper knee function secondary to significant pain, limited preoperative motion, or the development of arthrofibrosis. This subset will require a special, individualized rehabilitation program that may involve prolonged oral analgesia, continued physical therapy, additional diagnostic studies, and occasionally manipulation. Controlling pain is the mainstay of any treatment plan. The program described herein has been used at the Ranawat Orthopaedic Center over the past 10 years in more than 2,000 TKAs.
TL;DR: The poor results of surgical treatment of chronic instability after total hip arthroplasty (THA) led to the development of a constrained acetabular component, which represents a significant improvement over other methods reported.
Abstract: The poor results of surgical treatment of chronic instability after total hip arthroplasty (THA) led to the development of a constrained acetabular component. In this study, 87 constrained THAs implanted for recurrent instability were reviewed retrospectively. Eighty-five hips were available for follow-up evaluation, with an average follow-up period of 58 months. These 85 hips were evaluated at a minimum of 3 years. Two recurrent dislocations were seen, caused by dissociation of the liner from the shell. Four acetabular components and 1 femoral component were revised. Overall, a 2.4% dislocation rate and an 8.2% revision rate were seen. The recurrent dislocation rate of 2.4% represents a significant improvement over other methods reported. Repeat dislocation was only seen in dissociation of cemented liners into well-fixed shells. We do not recommend this mode of fixation.
TL;DR: With the correct orientation of components and an enhanced soft-tissue repair, the posterior surgical approach can result in an extremely low dislocation rate.
Abstract: Although a posterior approach is frequently used for total hip arthroplasties (THAs), some reports have associated this approach with higher dislocation rates than anterior or lateral approaches. To deter dislocations following primary THAs using the posterior approach, the senior author repairs the posterior capsule and the short external rotators to the greater trochanter with nonabsorbable suture. We retrospectively reviewed the occurrence of dislocations among 945 primary THAs performed with this technique at a mean 6.4-year follow-up (range, 2.0-9.3 years). The average patient age was 62.3 years (range, 36-86 years). Eight patients (0.85%) dislocated. Of these, 3 dislocated within the first postoperative year and were treated without surgery; 3 required revision surgery and placement of a constrained liner; and 2 dislocated after trauma and were treated without surgery. With the correct orientation of components and an enhanced soft-tissue repair, the posterior surgical approach can result in an extremely low dislocation rate.
TL;DR: The reduced mediolateral shift of the patella suggests that alignment of the femoral component with the FE axis will aid patellar tracking about a circular arc with small deviations in the medial-lateral direction.
Abstract: A laboratory-based study was performed to describe the tibial axis and patellar position relative to the femoral epicondylar (FE) axis during squatting. During the squat, the angle between the tibial and FE axes averaged 90.5°, and 66% of internal rotation of the tibia occurred before 15° flexion. In the mid-sagittal plane of the femur, the patella followed a circular arc, and mediolateral patellar shift averaged 4.3 mm. These findings can be used as the basis for development of new total knee arthroplasty components that recreate normal patellofemoral kinematics, and may provide important guidelines for alignment of the tibial and femoral components. The perpendicular relationship between the tibial and the FE axes may be useful in locating the FE axis intraoperatively. The reduced mediolateral shift of the patella suggests that alignment of the femoral component with the FE axis will aid patellar tracking about a circular arc with small deviations in the medial-lateral direction.
TL;DR: In this article, a case of an acetabular liner fracture of the ceramic sandwich cup was presented, and the fracture occurred 1.4 years after the operation without trauma, and at revision surgery, the fractured ceramic liner was replaced with a polyethylene liner without inner ceramic liner.
Abstract: In total hip arthroplasty, a modular acetabular component with a sandwich insertion (alumina ceramics/polyethylene/titanium) was proposed. The polyethylene layer might reduce the rigidity of the ceramics and prevent an impingement between the ceramic liner rim and the femoral neck. A case of an acetabular liner fracture of the ceramic sandwich cup was presented. The fracture occurred 1.4 years after the operation without trauma. Because the ceramic liner rim was hit by the head following the impingement between the neck and the polyethylene, the cause of the fracture might be the stress concentration at the rim of the ceramic liner, of which the thickness was only 4 mm. At revision surgery, the fractured ceramic liner was replaced with a polyethylene liner without inner ceramic liner.
TL;DR: Joint gap during surgery was measured using a simple device with a torque meter in 45 osteoarthritis knee joints (43 patients) with varus deformity to measure soft tissue balancing in a step-by-step procedure during total knee arthroplasty.
Abstract: Using a step-by-step procedure, we measured joint gap during surgery using a simple device with a torque meter in 45 osteoarthritis knee joints (43 patients) with varus deformity. The effects of specific cuts or releases of the anatomic portion on joint gaps were investigated. Each cut or release resulted in various increases in the medial gap from 1.2 to 3.8 mm on average. The final gap measurements averaged 24.1 mm medially and 27.6 mm laterally in extension, and 24.6 mm medially and 27.2 mm laterally in flexion. The results of the measurements showed that each step-by-step procedure had a tendency of gap increase. The results led us to measure soft tissue balancing in a step-by-step procedure during total knee arthroplasty. © 2003 Elsevier Inc. All rights reserved.
TL;DR: Sixty-three failed total knee arthroplasties in 60 patients treated consecutively with revision using cemented component fixation and an uncemented stem improved, and Knee Society Pain Scores improved from 56 to 81, and function scores improved from 49 to 62 points.
Abstract: Sixty-three failed total knee arthroplasties in 60 patients (27 females, 33 males; average age, 66 years) were treated consecutively with revision using cemented component fixation and an uncemented stem. Patients were followed for a mean of 5.75 years (range, 2-10 years); none were lost to follow-up. There were 12 (19%) re-revisions: 6 (10%) were revised for aseptic loosening, 4 (6%) for recurrent infection, and 2 (3%) for instability. Knee Society Pain Scores improved from 56 to 81, and function scores improved from 49 to 62 points. Latest radiographs in retained knees showed none with definite femoral loosening but 4 with tibial component loosening. Combining those revised for aseptic loosening and radiographic aseptic loosening, mechanical failure occurred in 10 patients (16%).
TL;DR: Eighty percent of patients with a resurfaced patella were extremely satisfied with their total knee arthroplasty versus 48% without patellar resurfacing, and when satisfied and extremely satisfied patients were grouped together, there was no difference between the 2 groups.
Abstract: Patellar resurfacing in total knee arthroplasty is a topic debated in the literature. Concerns include fracture, dislocation, loosening, and extensor mechanism injury. Residual anterior knee pain has been reported when the patella is not resurfaced. One hundred patients with osteoarthritic knees were prospectively randomized to either have their patella resurfaced or left not resurfaced. All patients were treated with a single prosthesis that featured an anatomically designed patellofemoral articulation (Anatomic Medullary Knee, DePuy, Warsaw, IN) Two patients in the unresurfaced group and one in the resurfaced group required repeat surgery for patellofemoral complications. At 8- to 10-year follow-up evaluations, Knee Society Clinical Ratings scores were not different between the 2 groups. Rates of anterior knee pain with walking and stair climbing were significantly less in the resurfaced group. Eighty percent of patients with a resurfaced patella were extremely satisfied with their total knee arthroplasty versus 48% without patellar resurfacing. When satisfied and extremely satisfied patients were grouped together, there was no difference between the 2 groups.
TL;DR: In this article, the wear performance of a radiation cross-linked melted ultrahigh-molecular-weight polyethylene (UHMWPE) articulating against 28mm cobalt chrome femoral heads in the presence of third-body particulate debris was investigated in a hip simulator and compared with the wear of conventional UMWPE.
Abstract: The wear performance of a radiation cross-linked melted ultrahigh-molecular-weight polyethylene (UHMWPE) articulating against 28-mm cobalt chrome femoral heads in the presence of third-body particulate debris was investigated in a hip simulator and compared with the wear of conventional UHMWPE. Particles of aluminum oxide or bone cement containing barium sulfate were added to the serum. In the presence of aluminum oxide particles, the incremental wear rates of conventional UHMWPE averaged as high as 149 ± 116 mg/million cycles compared with 37 ± 38 mg/million cycles for the highly cross-linked components. The difference in the average weight loss was statistically significant at P
TL;DR: The results of this study strongly support the hypothesis that the degradation of mechanical properties for the liners occurred during implantation, and analysis of the Fourier transform infrared spectroscopy data revealed a significant association between the oxidation index and mechanical degradation of the UHMWPE.
Abstract: We tested the hypothesis that the mechanical and chemical behavior of gamma radiation-sterilized ultrahigh-molecular-weight polyethylene (UHMWPE) changes after implantation. Relationships between the mechanical behavior and oxidation index were explored in a cohort of 16 consecutive traceable Hexloc acetabular components (Biomet, Warsaw, IN) that were machined from extruded, stearate-containing UHMWPE and gamma sterilized in air. Shelf aging time (average, 0.4 years) and implantation time (average, 11.5 years) were determined for all 16 inserts. The retrieved liners exhibited significant mechanical degradation, which was most severe in the unloaded surface regions. Analysis of the Fourier transform infrared spectroscopy data revealed a significant association between the oxidation index and mechanical degradation of the UHMWPE. The results of this study strongly support the hypothesis that the degradation of mechanical properties for the liners occurred during implantation.
TL;DR: Considering the complexity of the cases, the tripolar constrained acetabular component has provided durable fixation and hip stability at this intermediate-term follow-up.
Abstract: The short-term efficacy of using constrained acetabular components for hip instability in the total hip arthroplasty construct has been documented. However, long-term concerns including late dislocation, loosening of components, and osteolysis have not been addressed. The authors evaluated, at an average 10.3-year follow-up, 101 tripolar constrained components (Stryker Howmedica Osteonics) used in the total hip arthroplasty construct. At final follow-up, 6 hips had dislocated or had failure of the constrained component, 5 of which were revised. In addition, 4 hips were revised for aseptic loosening of the acetabular component, 4 hips were revised for aseptic femoral loosening, and 1 hip was revised for acetabular osteolysis. Considering the complexity of the cases, this component has provided durable fixation and hip stability at this intermediate-term follow-up.
TL;DR: This study directly compared the clinical and radiographic results and patient satisfaction of a group of simultaneous, bilateral total knee arthroplasties with a year of surgery matched unilateral total knees to reveal a 98% 7-year survivorship for unilateral procedures and 97% for bilateral procedures.
Abstract: This study directly compared the clinical and radiographic results and patient satisfaction of a group of simultaneous, bilateral total knee arthroplasties (92) with a year of surgery matched unilateral total knee arthroplasties (92). Death within 1 month of surgery occurred in 1 bilateral patient and no unilateral patients. Significant cardiorespiratory complications were recorded in 6 bilateral patients and 2 unilateral patients. Patients with pre-existing cardiorespiratory conditions were particularly at risk. Analysis revealed a 98% 7-year survivorship for unilateral procedures and 97% for bilateral. In this study, 95% of bilateral patients stated they would choose the same option again.
TL;DR: Total knee arthroplasty is an effective method of treatment for the majority of patients with a prior distal femoral or tibial plateau fracture and end-stage arthritis, but patients with suboptimal component positioning or residual deformity have a poorer outcome.
Abstract: Total knee arthroplasty is an effective method of treatment for the majority of patients with a prior distal femoral or tibial plateau fracture and end-stage arthritis. There is a higher complication rate and overall poorer outcome when compared with routine primary total knee arthroplasty. In patients for whom the goals of optimal limb and implant alignment are achieved, the results are comparable with routine primary knee arthroplasty. Patients with suboptimal component positioning or residual deformity have a poorer outcome. The technical challenges encountered can require skills, implant systems, and methods usually reserved for complex revision arthroplasty.
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TL;DR: 9 causes of failure are proposed: i) aseptic loosening with or without osteolysis or progression of arthritis in a unicondylar arthroplasty; ii) tibial femoral instability because of collateral ligament instability; iii) patellar complications and malrotation; iv) no diagnosis, the so-called mystery knee.
Abstract: Successful revision knee arthroplasty requires an accurate understanding of the cause of failure. Because a differential diagnosis is necessary, 9 causes of failure are proposed: i) aseptic loosening with or without osteolysis or progression of arthritis in a unicondylar arthroplasty; ii) tibial femoral instability because of collateral ligament instability; iii) patellar complications and malrotation; iv) no diagnosis, the so-called mystery knee; v) structural failure of the implant; vi) sepsis; vii) extensor mechanism rupture; viii) stiffness; and ix) fracture. A revision surgery should correct shortcomings in the original arthroplasty and not simply restore a mechanical situation that has failed.
TL;DR: In this article, surface active phospholipid (SAPL) produced in type B synoviocytes will also lubricate prostheses after implantation, which could explain why implanted hips display far less wear than hip articular surfaces.
Abstract: Much evidence supports the hypothesis that surface-active phospholipid (SAPL), which imparts the thin hydrophobic outermost lining to the normal articular surface, is the boundary lubricant reducing friction to remarkably low levels. We review this evidence and further hypothesize that SAPL produced in type B synoviocytes will also lubricate prostheses after implantation. This could explain why implanted hips display far less wear than hips in simulated wear trials do, even using protein as the lubricant whereas rougher surfaces can be tolerated in vivo. We introduce the concept that a deficiency of SAPL might explain the selective failure of prostheses just as osteoarthritic articular surfaces are deficient. This, in turn, leads to the replenishment of SAPL, as tested in OA, and the concept of prelubricating prostheses before implantation.