In a study of more than 11,000 patients, when comparing outcomes after total knee replacement among several age groups, older patients (≥ 75) reported statistically significant better pain relief and quality of life compared to patients 55 and younger. Prior to surgery younger patients had worse mental health scores and a higher incidence of obesity (BMI>35) and medical comorbidities. Despite these differences, all age groups achieved significant improvement in pain, function, and quality of life at one-year after TKR compared to scores obtained prior to the surgery.

Ayers DC, Yousef M, Yang W, Zheng H. Age-Related Differences in Pain, Function, and Quality of Life Following Primary Total Knee Arthroplasty: Results from a FORCE-TJR Cohort. Proceedings of the American Association of Hip and Knee Surgeons 2022. J. Arthroplasty. 2023 Apr 28:S0883-5403(23)00350-9. doi: 10.1016/j.arth.2023.04.005. PMID: 37121490

A small percentage of TKR patients report dissatisfaction after the surgery. Research efforts to understand the factors contributing to dissatisfaction have pointed to back pain, but there is a dearth of data regarding pain intensity and dissatisfaction after TKR. In this study of more than 1,600 TKR patients, severe back pain was associated with increased risk of dissatisfaction one-year after surgery. However, patients with mild or moderate back pain were not more likely to be dissatisfied compared to patients with no back pain.

Ayers DC, Zheng H, Yang W, Yousef M. How Back Pain Affects Patient Satisfaction After Primary Total Knee Arthroplasty. Proceedings of the Knee Society 2022. J. Arthroplasty. 2023 Mar 30:S0883-5403(23)00323-6. doi: 10.1016/j.arth.2023.03.072.  PMID: 37001625

In our analyses of 2,964 primary unilateral TKR and 2,040 primary unilateral THR patients, stratified by obesity level, we found significant improvement in pain and function 6 month after surgery across all patient groups. This was the first data of TJR outcomes in relation to obesity to emerge from a large nationally representative US cohort. The findings support that BMI should not be a deterrent to surgery to relieve hip and knee osteoarthritis symptoms. We also conclude that it remains important for surgeons to discuss potential complications associated with higher levels of obesity. Future research will consider benefits vs. risk of TJR among patients with higher BMI levels.

Li W, Ayers DC, Lewis CG, Bowen TR, Allison JJ, Franklin PD. Functional Gain and Pain Relief After Total Joint Replacement According to Obesity Status. J Bone Joint Surg Am. 2017 Jul 19;99(14):1183-1189. PMID: 28719557

Analyses of pre-operative patient characteristics were performed in the following TJR cohorts: 6,680 primary TKA(US) and 823 primary TKA(Swiss); 4,647 primary THA(US) and 1,023 primary THA(Swiss). The level of functional impairment at the time of TKA and THA reflected significant, and similar, disability in both countries. Of importance, there were clinically important differences in age, education level, obesity prevalence, medical comorbidities, preoperative pain levels and emotional health between the two cohorts. We recommend that risk-adjustment for these variables will be necessary before cross-cultural comparisons of TJR outcomes can be performed.

Franklin PD, Miozzari H, Christofilopoulos P, et al. Important Patient Characteristics Differ Prior to TKA and THA Between Switzerland and the United States. BMC Musculosklet Disord Jan 11;18(1):14. doi: 10.1186/s12891-016-1372-5. PMC5225636

Younger patients report the same or greater joint-specific and global pain and decreased function pre-operatively when compared to older adults.  In addition, patients under 65 years of age are more obese and more likely to smoke as compared to older patients. Overall, younger patients pose similar risks as older patients, and have similar successful outcomes.

Ayers DC, Harrold L, Snyder B, Person S, Franklin PD. Clinical profile and disability levels of younger vs. older TKR and THR patients: results from a national research consortium. 2013 Orthopaedic Research Society Annual Meeting, San Antonio, TX.

Despite the rapid growth in TJR utilization in the US, our analysis suggests surgeons use comparable indications for surgery. Across 150 surgeons, the mean pre-operative pain and function were similar. Overall, more than 92% of patients report significant pain and functional limitations, with the remaining patients reporting quality of life limitations. Monitoring pre-operative PROs can help patients and surgeons determine the optimal time for TJR.

Ayers DC, Li W, Harrold LR, et al. Pre-Operative Pain And Function Profiles Reflect Consistent TKR Patient Selection Among US Surgeons. Clin Orthop Relat Res; 2015 (Jan);473(1):76-81. DOI: 10.1007/s11999-014-3716-5. PMID: 24957788

After a survey of 1,609 TJR patients, we found that 33% had not received any information prior to surgery in regards to post-surgery pain management and 11% had not found the information received useful. Of importance, this lack of pain management information was associated with poorer functional outcomes at 6 months post-surgery. By contrast, patients who had received pain management information reported lower levels of pain at 2 weeks post-TJR, more use of non-medication method and less interference with daily activities as compared to patients who had not received any pain management information. The data illustrates the need to improve patient information.

Lemay CA, Lewis CG, Singh J, Franklin PD. Receipt of pain management information pre-operatively is associated with improved functional gain after elective total joint replacement. J Arthroplasty. 2017 Jun;32(6):1763-1768. doi: 10.1016/j.arth.2017.01.028. Epub 2017 Jan 26

The burden of musculoskeletal comorbidities- specifically moderate or severe pain in the lumbar spine and non-operative hips and knees- is associated with poorer function at 6 months after surgery. Future public comparisons of PROs after TJR must be cautious to adjust for co-existing musculoskeletal conditions that can limit functional gain after successful surgery in one knee or hip.

Ayers DC, Harrold L, Li W, Snyder B, Allison JJ, Lewis C. Greater musculoskeletal pain in TKR and THR patients correlates with poorer function in a national consortium. 2013 Orthopaedic Research Society Annual Meeting, San Antonio, TX.