Does design change in total knee arthroplasty implants affect patient-reported outcomes?

PURPOSE: The purpose of this study is to compare the early results of patient-reported outcomes between two generations of a total knee system. METHODS: Between June 2018 and April 2020, 121 first-generation, cemented TKAs (89 patients) and 123 s-generation, cemented TKAs (98 patients) were performed by a single surgeon. Demographic and surgical data were collected from all patients. Starting at the 6-month follow-up, patient-reported outcome measures Knee Injury and Osteoarthritis Outcome Score, Joint Reconstruction (KOOS-JR) and Knee Society (KS) clinical and radiographic scores were prospectively recorded. This study represents a retrospective review of these prospectively collected data. RESULTS: There were no statistically significant differences between the two groups in terms of demographic variables such as age, body mass index, gender and race. KOOS-JR and Knee Society (KS) scores improved significantly (p < 0.001) from their preoperative values in both device generations. There were no differences, pre-operatively, between the two groups in terms of KOOS-JR, KS functional, KS objective, patient satisfaction, and expectation scores; however, there were statistically significant (p < 0.001) lower values of KOOS-JR and KS functional scores for first versus second generation at 6 months (81 vs. 89 and 69 vs. 74, respectively). CONCLUSION: While significant improvement in KS objective, subjective, and patient satisfaction scores were noted with both knee systems, KOOS-JR and KS function scores were significantly higher at the early (6-month) follow-up in the second-generation group. Patients responded acutely to the design change as evidenced by significantly improved patient-reported outcome scores for the second generation.

Cementless and Cemented Dual-Pivot Total Knee Arthroplasty: A Matched Comparison With a Minimum Two-Year Follow-Up.

BACKGROUND: With the use of newer biomaterials, many authors have reported similar results between cementless and cemented total knee arthroplasty (TKA). The purpose of this study was to compare the early clinical and radiographic outcomes of cementless and cemented TKA using the same dual-pivot articulation. METHODS: A consecutive series of 806 TKAs were implanted by a single surgeon using the same dual-pivot articulation. There were 634 TKAs (79%) cemented and 172 (21%) uncemented. One patient in the cementless group was lost before two years. The remaining 171 cementless TKAs were matched 1:1 with cemented TKAs with respect to age, sex, and body mass index. All patients were followed for a minimum of two years (range, 24-66 months) using the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement , and Knee Society clinical and radiographic evaluation. The average follow-up was 3.8 years (range, 24-66 months) in the cemented group and 3.4 years (range, 24-56 months) in the cementless group. RESULTS: At final follow-up, the average Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was higher in the cementless group (86 points (range, 64-100) versus 80 points (range, 57-100). Postoperative Knee Society scores (including pain and function) were similar. There was one deep infection (cemented TKA). The manipulation rate was 1.2% in the cementless group and 2.4% in the cemented TKA group. Excluding infection, two knees (1.2%) were revised in each group. No cases of femoral or tibial component loosening were identified. CONCLUSION: Patients implanted with either a cemented or cementless TKA using the same conforming dual-pivot articulation design had similar early outcomes and functional improvements. The type of fixation did not appear to influence the early clinical results.

Custom Triflange Acetabular Implants: Average 10-Year Follow-Up.

BACKGROUND: Acetabular reconstruction options in the setting of substantial bone deficiency (Paprosky 3A and 3B) remain limited. Custom triflange acetabular implants are one choice for this challenging problem. However, few studies have reported on survivorship beyond 3 to 5 years. The purpose of this study was to report our 6 to 13-year clinical results using these custom-made acetabular components. METHODS: Between 2008 and March 2015, 42 revision total hip arthroplasties (41 patients) were performed at our institution with a custom triflange acetabular component. All revisions involved either Paprosky 3A or 3B acetabular defects. Two patients died before the five-year follow-up. Harris Hip Scores were obtained at 6 months, 1 year, and every 2 to 3 years thereafter. The average follow-up in the remaining 40 revision total hip arthroplasties was 10 years (range, 6 to 13 years). RESULTS: At the final follow-up, the mean Harris score was 74 points. There were two deep infections (5%). One custom implant was removed for deep infection (2.5%). Three hips (7.5%) experienced a total of four dislocations necessitating revision in one hip (femoral component only). One custom implant was judged to be loose. There were no cases of femoral nerve palsy. At final follow-up, 38 (95%) of the custom acetabular implants were considered radiographically stable. CONCLUSION: Instability and infection remain a major concern and cause of failure in these complex reconstructions. At an average follow-up of 10 years, however, custom triflange acetabular implants appear to work at least as well as jumbo cups and cup/cage constructs in the setting of extensive erosion of acetabular bone.

Press-Fit Dual-Pivot Total Knee Arthroplasty: Early Results With a Minimum 2-Year Follow-Up.

BACKGROUND: Ultracongruent (UC) tibial bearings are being used with increasing frequency in the United States. Evidence suggests that the use of certain UC bearings may lead to improved patient satisfaction when compared with using conventional inserts. However, little is known as to what effect the use of UC tibial inserts has on bone ingrowth in uncemented total knee arthroplasty (TKA). The purpose of this study was to determine the early clinical and radiographic results of TKA using a press-fit dual-pivot design. METHODS: Between 2017 and 2019, a consecutive series of 232 TKAs were implanted using a press-fit tibial and femoral component and a UC dual-pivot tibial insert. Sixty-two percent of patients were male. The average age was 56 years. Patients were followed for a minimum of 2 years (range, 24-42 months) using KOOS-JR and Knee Society clinical and radiographic evaluation. RESULTS: No patient had more than mild knee stiffness at the final follow-up. Two patients reported moderate knee pain with stair climbing. All other patients reported either mild or no pain with activity. Knee Society pain scores averaged 42 points. Flexion averaged 118 degrees. Three knees (1.3%) were revised (one each for flexion instability, tibial plateau fracture, and suspected femoral component loosening). No other cases of femoral or tibial loosening were identified. CONCLUSION: Although the success of uncemented TKA is determined by a variety of factors, the use of this dual-pivot knee design did not appear to influence tibial or femoral component fixation at early follow-up, yielding acceptable clinical and radiographic outcomes.

Progressive Tibial Bearing Sagittal Plane Conformity in Cruciate-Retaining Total Knee Arthroplasty.

BACKGROUND: We hypothesized that when the posterior cruciate ligament (PCL) is found deficient at total knee arthroplasty (TKA), using an anterior-stabilized (AS) tibial insert would provide similar function and survivorship when compared to using a more traditional cruciate-retaining (CR) bearing when the (PCL) is balanced. METHODS: A total of 1731 TKAs were performed using the same TKA design. Of them, 868 TKAs had a standard CR insert implanted (CR-S), 480 TKAs used a lipped CR insert (CR-L), and 383 TKAs used an AS insert. If the PCL was considered nonfunctional or absent, an AS bearing was placed. When the PCL was balanced, a CR-S or CR-L bearing was used. Follow-up was performed using the Knee Society scoring system. Kaplan-Meier survivorship was used with failure defined as aseptic loosening. RESULTS: At final follow-up, there were no significant differences in knee flexion, pain, function, or stair scores. Walking scores were significantly lower in the AS group. Posterior instability was higher in the CR-S group, whereas the manipulation rate was highest in the CR-L group (1.7%, 1.3%, and 0% for CR-L, CR-S, and AS groups, respectively). Kaplan-Meier survivorship at 5 years demonstrated no significant difference between the 3 groups (99% 100%, and 99% for CR-S, CR-L, and AS groups, respectively). CONCLUSION: Using an AS insert provided similar function and 5-year survivorship as compared to using a CR-S and CR-L tibial insert when the PCL was balanced. Using an ultracongruent AS dished tibial component appears to be a reasonable option when the PCL is completely released or found deficient at operation.

Pain relief and functional improvement remain 20 years after knee arthroplasty.

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.

Low incidence of groin pain and early failure with large metal articulation total hip arthroplasty.

BACKGROUND: 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. QUESTIONS/PURPOSES: We therefore assessed hip pain, function, osteolysis, and complications in patients with large-diameter metal-on-metal THA. PATIENTS AND METHODS: We retrospectively reviewed 611 patients who had 681 large-diameter metal-on-metal THAs with the same cup and head design. The average age at operation was 62 years, 53% of the THAs were in men, and the average body mass index was 32 kg/m(2). The diagnosis was osteoarthritis in 92% of the THAs. The minimum followup was 24 months (mean, 37 months; range, 24-60 months). RESULTS: Nine of the 611 patients (1.5%) experienced moderate or severe pain in the hip region that we considered to be coming from an extraarticular source in each case. Harris hip scores for pain averaged 42 points. Total Harris hip scores averaged 93 points. Cup abduction averaged 42°, and cup anteversion averaged 26°. There were no infections. Three cups (0.4%) were considered radiographically loose. All were secondary to inadequate seating of the shell. CONCLUSION: Our observations suggest with this implant the concerns of higher incidences of groin pain, early failures, and adverse tissue reactions were not confirmed. Early successes or failures with large-diameter metal-on-metal articulations may be implant specific. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.