ABSTRACT
Cementless implant use continues to increase primarily due to increased numbers of younger and obese patients opting for primary total knee arthroplasty (TKA). Given the increased use of cementless implants, the purpose of this study was to evaluate the midterm clinical performance of cementless TKA using a highly porous tibial baseplate compared with its cemented counterpart of the same system. We conducted a retrospective case-control study of 400 patients undergoing primary TKA that included 200 patients with cementless components matched for age and body mass index (BMI) to 200 patients with cemented implants of the same implant design with a 5-year follow-up. We evaluated clinical results, complications, revisions, and overall survivorship between the cohorts. Statistical analysis was performed using student t-test and chi-square analysis. There was no statistical difference in age (64.3 vs. 64.3 p = 0.81), BMI (34 vs. 33.1 p = 0.19), preoperative Knee Society Score (KSS) function (41 vs. 32.3 p = 0.22), and preoperative KSS knee score (39.2 vs. 38.3 p = 0.54) between the cementless and cemented cohorts, respectively. The cementless group had seven revisions, while the cemented group had nine revisions (p = 0.609). The cementless group had one revision due to aseptic loosening versus five in the cemented group (p = 0.09). Postoperative 5-year KSS knee scores were 92.84 versus 91.75 (p = 0.386) and function scores were 81.81 versus 69.65 (p = 0.00004) in the cementless and cemented groups, respectively. The cementless group had survivorship of 96.5% for all-cause revision compared with 95.5% in the cemented group at 5-year follow-up (p = 0.60). Cementless TKA using a highly porous tibial baseplate showed excellent midterm results with one case of aseptic loosening at 5-year follow-up and with similar Knee Society outcome scores and survivorship compared with the cemented group. Cementless TKA demonstrated noninferiority to cemented TKA and could be used as an alternative mode of fixation in patients opting for primary TKA. Additional long-term follow-up is needed to determine if cementless TKA can demonstrate improved survivorship over cemented TKA.
ABSTRACT
BACKGROUND: Controversy exists in reverse total shoulder arthroplasty in regard to variability in the center of rotation (COR), which modifies the superior-inferior position of the humerus to affect the acromiohumeral interval (AHI), and its effect on the deltoid lever arm (DLA), acromial index (AI), and critical shoulder angle (CSA). The purpose of this study was to investigate the variation in biomechanics and the association with patient-reported outcomes (PROs) and range of motion (ROM) measurements. METHODS: Radiographs, ROM, and 2-year PRO scores were retrospectively reviewed for 108 patients. RESULTS: There was large variability in preoperative and postoperative biomechanics. The COR was medialized 12.01 ± 4.8 mm. The CSA increased 2.64° ± 12.45°. The AHI increased 20.6 ± 9.80 mm. The DLA lengthened 21.21 ± 10.15 mm. The AI increased 0.009 ± 0.3. Postoperative AI positively correlated with American Shoulder and Elbow Surgeons score and Penn Shoulder Score (P = .03). Specifically, a postoperative AI of 0.62 corresponded to American Shoulder and Elbow Surgeons score (72.5 ± 18.3 vs. 62.3 ± 24.7; P = .02) and Penn Shoulder Score (71.2 ± 21.4 vs. 61.8 ± 25.6; P = .05), an average 10 points higher than AI of <0.6. Also, a smaller postoperative CSA (<25°) correlated with improved forward elevation (P = .02). CONCLUSIONS: This is the first study that evaluates the variability of biomechanical factors and their impact on postoperative ROM and PROs. An increased AI and decreased CSA are associated with improved PROs in this study, and a smaller CSA is associated with better forward elevation. Change in the COR, AHI, or DLA, however, did not affect patient outcomes or ROM. Further study is warranted to determine the optimal position.
ABSTRACT
BACKGROUND: The treatment of 3- and 4-part proximal humeral fractures in the older adult is controversial. No study has directly compared reverse shoulder arthroplasty (RSA) with nonoperative treatment for these fractures. The purpose of this study was to compare clinical and patient-reported outcomes between RSA and nonoperative treatment groups. METHODS: A retrospective review was performed on all 3- and 4-part proximal humeral fractures treated with either RSA or nonoperative treatment with minimum 1-year follow-up. All patients in the nonoperative cohort were offered RSA but declined. Objective patient data were obtained from medical records. Patient-reported outcomes including visual analog scale score, Single Assessment Numeric Evaluation score, Penn Shoulder Score, American Shoulder and Elbow Surgeons score, resiliency score, and Veterans Rand-12 scores were obtained at follow-up. Statistical analysis was performed by use of the Student t test for continuous variables and χ2 analysis for nonparametric data. RESULTS: We analyzed 19 nonoperative and 20 RSA patients with a mean follow-up period greater than 2 years (29 months in nonoperative group and 53 months in RSA group). There were no differences in range of motion between groups (forward elevation, 120° vs 119° [P = .87]; external rotation, 23° vs 31° [P = .06]). No differences between the nonoperative and RSA groups were noted for any patient-reported outcomes. Among patients receiving RSA, there was no difference in outcomes in those undergoing surgery less than 30 days after injury versus those receiving delayed RSA. CONCLUSIONS: This study suggests that there are minimal benefits of RSA over nonoperative treatment for 3- and 4-part proximal humeral fractures in older adults.
