Fewer Adverse Events Following Outpatient Compared with Inpatient Unicompartmental Knee Arthroplasty

The outpatient experience in unicompartmental knee arthroplasty: How to perform safely in the ambulatory surgery center

The number of outpatient unicompartmental knee arthroplasty (UKA) procedures has increased substantially over the last decade. The ambulatory surgery center (ASC) and hospital outpatient department provide a safe, cost-effective alternative with significant cost savings to the healthcare system. Advancements in technology and perioperative management strategies have expanded the number of eligible patients to optimize outcomes with a focus on safety. Therefore, this review will describe the safety, efficacy, economics, and perioperative protocols for performing UKA in an outpatient setting. Patient selection, risk factors, patient education and expectations, anesthesia, pain management strategies, and outcomes will be discussed.

Advanced Concepts in Outpatient Joint Arthroplasty

As the adoption and utilization of outpatient total joint arthroplasty continues to grow, key developments have enabled surgeons to safely and effectively perform these surgeries while increasing patient satisfaction and operating room efficiency. Here, the authors will discuss the evidence-based principles that have guided this paradigm shift in joint arthroplasty surgery, as well as practical methods for selecting appropriate candidates and optimizing perioperative care. There will be 5 core efficiency principles reviewed that can be used to improve organizational management, streamline workflow, and overcome barriers in the ambulatory surgery center. Finally, future directions in outpatient surgery at the ASC, including the merits of implementing robot assistance and computer navigation, as well as expanding indications for revision surgeries, will be debated.

Safety evaluation of outpatient vs inpatient unicompartmental knee arthroplasty: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the safety of outpatient and inpatient Unicompartmental Knee Arthroplasty (UKA) based on the incidence of adverse events.

METHOD

A systematic search of the literature was performed in October 2022 on PubMed, Web of Science, Cochrane library, and Embase. The Meta package for R was used to perform the meta-analysis.

RESULT

Five studies with a total of 26,301 patients were included. 5813 patients (22.1%) were treated with outpatient UKA, and 20,488 patients (77.9%) were treated with inpatient UKA. There were no statistically significant differences in the incidence of total complications (RR = 1.36, 95% CI = 0.64-2.89, Z = 0.79, P = 0.43), readmission (RR = 1.02, 95% CI = 0.40-2.60, Z = 0.05, P = 0.96), and venous thrombosis (RR = 1.43, 95% CI = 0.96-2.11, Z = 1.78, P = 0.08). Incidence rates were lower in outpatient UKA regarding urinary tract infection (RR = 1.48, 95% CI = 1.07-2.04, Z = 2.40, P = 0.02), pulmonary embolus (RR = 7.48, 95% CI = 1.80-31.17, Z = 2.76, P < 0.01), and transfusion (RR = 2.77, 95% CI = 1.63-4.71, Z = 3.78, P < 0.01).

CONCLUSION

In summary, outpatient UKA shows lower incidences of hospital-acquired complications such urinary tract infection, pulmonary embolus, and transfusion. It's worth noting that the incidences of total complications, readmission, and venous thrombosis in outpatient UKA were not higher than the incidences of inpatient UKA, suggestting that outpatient UKA can be considered a safe alternative to inpatient UKA.

Using orthopaedic health care resources efficiently: A cost analysis of day surgery for unicompartmental knee replacement

BACKGROUND

Day surgery for unicompartmental knee replacement (UKR) could potentially reduce hospital costs. We aimed to measure the impact of introducing a day surgery UKR pathway on mean length of stay (LOS) and costs for the UK NHS, compared to an accelerated inpatient pathway. Secondly, the study aimed to compare the magnitude of costs using three costing approaches: top-down costing; simple micro-costing; and real-world costing.

METHODS

We conducted an observational, before-and-after study of 2,111 UKR patients at one NHS hospital: 1,094 patients followed the day surgery pathway between September 2017 and February 2020; and 1,017 patients followed the accelerated inpatient pathway between September 2013 and February 2016. Top-down costs were estimated using Average NHS Costs. Simple micro-costing used the cost per bed-day. Real-world costs for this centre were estimated by costing actual changes in staffing levels.

RESULTS

532 (48.5%) patients in the day surgery pathway were discharged on the day of surgery compared with 36 (3.5%) patients in the accelerated inpatient pathway. The day surgery pathway reduced the mean LOS by 2.2 (95% CI: 1.81, 2.53) nights and was associated with an 18% decrease in Average NHS Costs (p < 0.001). Mean savings were £1,429 per patient with the Average NHS Costs approach, £905 per patient with the micro-costing approach, and £577 per patient with the "real-world" costing approach. Overall, moving NHS UKR surgeries to a day surgery pathway could save the NHS £8,659,740 per year.

CONCLUSION

Day surgery for UKR could produce substantial cost savings for hospitals and the NHS.

Rheumatoid Arthritis Is Not a Contraindication to Unicompartmental Knee Arthroplasty

BACKGROUND

Rheumatoid arthritis (RA) has historically been considered a contraindication for unicompartmental knee arthroplasty (UKA). However, the widespread use of disease-modifying antirheumatic drugs has substantially improved the management of RA and prevented disease progression. The objective of this study was to ascertain whether RA impacts UKA revision-free survivorship.

METHODS

Patients undergoing UKA from 2010 to 2021 were identified in an administrative claims database (n = 105,937) using Current Procedural Terminology code 27446. All patients who underwent UKA who had a diagnosis of RA with a minimum of 2-year follow-up (n = 1,422) were propensity score matched based on age, sex, and Elixhauser Comorbidity Index to those who did not have RA (n = 1,422). Laterality was identified using the 10th Revision of International Classification of Diseases codes. The primary outcome was ipsilateral revision to total knee arthroplasty (TKA) within 2 years, and the secondary outcome was ipsilateral revision at any time.

RESULTS

Among the 1,422 patients who had a UKA and a diagnosis of RA, 37 patients (2.6%) underwent conversion to TKA within 2 years, and 48 patients (3.4%) underwent conversion to TKA at any point. In comparison, 28 patients (2.0%) in the propensity-matched control group underwent conversion to TKA within 2 years, and 40 patients (2.8%) underwent conversion to TKA at any point. Statistical analysis revealed no significant difference in conversion to TKA between patients who had and did not have RA, either within 2 years (P = .31) or anytime (P = .45).

CONCLUSIONS

Patients who had RA and underwent UKA did not have an increased risk of revision to TKA compared to those who did not have RA. This may indicate that modern management of RA could allow for expanded UKA indications for RA patients.

Trends in unicompartmental knee arthroplasty among 138 international experienced arthroplasty knee surgeons

Purpose

Unicompartmental knee arthroplasty (UKA) is an established option for treating isolated unicompartmental knee osteoarthritis (OA), but controversies still exist about patient selection, indications, perioperative management and alignment goals. This survey was designed to understand the current trends of experienced arthroplasty knee surgeons performing UKA.

Methods

An online questionnaire was created with SurveyMonkey® to assess global tendencies in the utilization of UKA. A link to the survey was shared with all ESSKA (European Society for Sports Traumatology, Knee Surgery and Arthroscopy) members. The questionnaire consisted of free and multiple-choice questions and was divided into four sections: demographic information, the surgical activity of the respondents, indications for surgery and postoperative alignment goals.

Results

A total of 138 ESSKA members from 34 different countries completed the survey. A total of 81 % of the responders performed fewer than 50 UKAs per year; 53 % of UKAs represented less than 20 % of their knee replacements; 71 % used mainly or only fixed-bearing implants; 81 % performed UKA in a shorter time compared to TKA; and 61 % and 72 % were interested in custom-made UKA and robotics, respectively. Thirty-six percent considered a minimum postoperative alignment of 0° for medial UKA, and 32 % considered 10° as the maximum valgus deformity for lateral UKA. Fifty-five percent had no minimum age cut-off, 47 % had no BMI cut-off, and 57 % believed TKA was better than UKA in knees with concomitant high-grade patellofemoral OA. Approximately 50 % of the surgeons desired a coronal alignment that was the same as the predegeneration alignment.

Conclusion

A high level of agreement was reached regarding the following: preference for fixed-bearing UKAs, lower surgical time for UKA compared to TKA, interest in custom-made and robotic UKAs, no age and weight cut-off, TKA preferred in the presence of patellofemoral OA, and a final alignment goal of the predegenerative state both for medial and lateral. There was no agreement regarding length of stay, rehabilitation protocol, preoperative varus and valgus cut-off values, and treatment in cases of absence of anterior cruciate ligament or previous osteotomy.

Over Half of All Medicare Total Knee Arthroplasty Patients Are Now Classified as an Outpatient-Three-Year Impact of the Removal From the Inpatient-Only List

BACKGROUND

In 2018, Centers for Medicare & Medicaid Services removed total knee arthroplasty (TKA) from its inpatient-only list, triggering many unintended consequences. The purpose of this study was to determine how the impact of TKA removal affected the number of outpatient TKA patients, which patients were being labeled outpatient, and how outpatient classification affected discharge location and readmission rates.

METHODS

Using a large administrative claims database, we reviewed a consecutive series of 216,365 primary TKA Medicare patients from 2015 to 2020. Patients who had an inpatient status (n = 63,356) were compared to patients who had an outpatient status (n = 38,510) from 2018 to 2020 based on demographics, comorbidities, discharge dispositions, and readmissions.

RESULTS

In 2015, only 1.8% of TKA patients were designated as outpatients, but by 2020, 57.2% of Medicare TKA patients were classified as outpatients. A majority of patients (72%) who had an outpatient designation remained in the hospital for >24 hours (average length of stay was 2.7 days). Patients who had an outpatient status were discharged to skilled nursing facilities more frequently than patients who had an inpatient status (3.1 versus 2.0%, P < .001) with increased emergency visits (5.1 versus 3.9%, P < .001) and 90-day readmissions (2.2 versus 0.9%, P < .001).

CONCLUSION

Over half of all Medicare TKA patients are being classified as outpatients 3 years following the policy to remove TKA from the inpatient-only list. Patients designated as outpatients had higher readmissions than those designated as inpatients. This policy should be re-evaluated in the context of failure to demonstrate safer discharge of Medicare patients who undergo TKA.

Emergency Department Visits After Outpatient Spine Surgery

STUDY DESIGN

A retrospective study.

OBJECTIVE

This study sought to characterize the incidence and timing of postoperative emergency department (ED) visits after common outpatient spinal surgeries performed at ambulatory surgery centers (ASCs) and at hospital outpatient departments (HOPDs).

SUMMARY OF BACKGROUND DATA

Outpatient spine surgery has markedly grown in popularity over the past decade. The incidence of ED visits after outpatient spine surgery is not well established.

METHODS

This study was a retrospective analysis of a large commercial claims insurance database of patients 65 years old and below. Patients who underwent single-level anterior cervical discectomy and fusion, laminectomy, and microdiscectomy were identified. Incidence, timing, and diagnoses associated with ED visits within the postoperative global period (90 d) after surgery were assessed.

RESULTS

In total, 202,202 patients received outpatient spine surgery (19.1% in ASC vs. 80.9% in HOPD). Collectively, there were 22,198 ED visits during the 90-day postoperative period. Approximately 9.0% of patients had at least 1 ED visit, and the incidence varied by procedure: anterior cervical discectomy and fusion 9.9%, laminectomy 9.5%, and microdiscectomy 8.5% ( P <0.0001). After adjusting for age, sex, and comorbidity index, the odds of at least 1 ED visit were higher among patients who received surgery at HOPD versus ASC for all 3 procedures. The majority (56.1%) ED visits occurred during the first month postoperatively; 30.8% (n=6841) occurred within the first week postoperatively, and 10.7% (n=2370) occurred on the same day as the surgery. Postoperative pain was the most common reason for ED visits.

CONCLUSIONS

Among commercially insured patients who received outpatient spine surgery, the incidence of ED visits during the 90-day postoperative period was ~9%. Our results indicate opportunities for improved postoperative care planning after outpatient spinal surgery.