This study confirmed the demographic, clinical and socioeconomic characteristics of patients who underwent TKA, and after the establishment of the center, the need for an inpatient-intensive rehabilitation program after TKA increased from 3–59.2% in OO regional rheumatoid and degenerative arthritis centers. These trends of increasing male sex and older patients (age ≥ 70) were similar to those of a study using the HIRA Korean database, which reported procedure rates of 155.5 (2013), 155.8 (2014) and 173.3 (2015) per 100,000 people. It also reported that the proportion of patients more than 70 years old increased markedly from 48.1% (2010) to 61% (2018). In this study, the mean age of all participants (72.0 ± 5.8) was in the early 70s, which was recommended as an optimal age for TKA that could achieve the maximal passive range of motion (PROM) without increasing the revision or mortality rates. A total of 60.2% lived in urban areas, 65.9% lived in Jeju city of current administrative districts, and 47.6% lived in Jeju city of formal administrative districts. Manual workers accounted for 28.2% of all participants, approximately 20% of Jeju and 33% of Seogwipo.
Interestingly, the mean duration of LOS was 16.7 ± 2.2 days, and it might be prolonged compared with Western countries such as the United States (3.6 ± 1.7 days) and Denmark (3 ± 3 days in elective cases, 5 ± 6 days in nonelective cases). However, notably, our data were shorter than the average LOS of the HIRA (21.2 days in 2018)
However, the national medical insurance systems worldwide that guarantee universal coverage to treatment usually allowed longer LOS if there were reasonable reasons such as bilateral arthroplasty, intractable pain, gait instability, and other perioperative complications and especially, the national medical insurance systems of Japan supported coverage during much longer LOS (35.1 ± 1.7 days) and provided comprehensive rehabilitation therapy in long-term care wards for community-based integrated care systems.
A recent large-scale study based on HIRA registries reported a gradual increase in TKA growth in Korea from 2010 to 2018, contrary to the dramatic increase in the growth rate before 2010, which might be caused by improved accessibility to the medical system as well as an increase in the geriatric population. They concluded that the demographic characteristics of Korea are quite different and that the revision rates were very low, although primary TKA use was popular and similar to the most developed Western countries. They also insisted that further studies on various demographic variables would be necessary and that Korean policymakers and healthcare providers should prepare for revision burdens and comorbidity care for the elderly and very elderly based on a comprehensive analysis of various patients’ demographical and clinical information.
Our data also indicated that the total number of TKAs had been steady or had increased gradually after EC by 114% between 2014 and 2015, and they showed higher proportions of females and geriatrics and a substantial prevalence of comorbidities such as HTN and DM. Interestingly, the number of males, geriatrics and manual workers increased, which might be affected by the westernization of lifestyle and manual work that prevented rapid osteoarthritis progression. The regional rheumatoid and degenerative arthritis center is an emerging experimental model for managing arthritis, comorbidities and perioperative side effects that integrates medical and surgical treatment with rehabilitation in Korea.
This result was the first study with a detailed review of various characteristics of patients undergoing TKA in the regional rheumatoid and degenerative arthritis center, and it was comparable to represent the general population of Korean TKA use. Notably, the need for post-TKA rehabilitation was very high, but the main factor differentiating participation in rehabilitation was the location of residence despite slightly different distributions of education level between the two groups (Table 5). Thus, establishing regional rheumatoid and degenerative arthritis centers in their residence is appropriate for the integrated care of arthritis in geriatrics.
On the other hand, the mean duration of LOS in this study was relatively constant regardless of EC and rehabilitation. This might be explained by the fact that the hospital preferred readmission after discharge rather than transfer to the inpatient rehabilitation ward because the Korean HIRA cut or reduced the Medicare payment if the LOS was more than 15 days. Considering the average LOS (21 days) and lack of long-term care wards for TKA in Korea, policy support would be necessary to ensure sufficient days of hospitalization after TKA and to build incentive programs for early rehabilitation and a qualified integrated care system.
This study had some limitations. First, it was a retrospective cohort study, and the available demographical and clinical data were very limited, especially in the TKA-only group. Second, it was a cross-sectional analysis without follow-up. Thus, we could not analyze the effect of preoperative status or monitor functional changes between admission and discharge. Third, we excluded revision procedures and could compare primary TKA with revision. Third, the practice patterns might differ according to the facilities and region, which might affect LOS, and participation in rehabilitation might differ according to the facilities. Finally, this study has a limitation in exploring the causative and longitudinal relationship of rehabilitation therapy with functional outcome.
In conclusion, this study revealed that the demographical and clinical characteristics of patients who underwent primary TKA in an OO regional rheumatoid and degenerative arthritis center showed a predominance of females and geriatrics and a high prevalence of comorbidities and obesity. Additionally, the only factor differentiating participation in intensive rehabilitation was the location of residence. Thus, the regional rheumatoid and degenerative arthritis center was appropriate to meet the high need for participating in intensive rehabilitation after TKA and for the qualified integrated post-TKA care system. Furthermore, policy support should ensure adequate hospital stay after TKA, build incentive programs for early rehabilitation and qualified integrated care systems and prepare for the increased burden of revision, and future longitudinal studies should be conducted to assess the long-term effect of the integrated post-TKA rehabilitation program on functional outcomes and patient survivorship free from revision.