Patient Outcomes After Total Knee Arthroplasty in Patients Older Than 80 Years

The Impact of Preoperative Medical Evaluation in an Orthopaedic Perioperative Medical Clinic on Total Joint Arthroplasty Outcomes: An Observational Study

BACKGROUND

A preoperative medical evaluation (PME) in total joint arthroplasty (TJA) is routine despite considerable variation and uncertainty regarding its benefits. The orthopaedic department in our academic health system established a perioperative medical clinic (PMC) to standardize perioperative management and to study the effect of this intervention on total hip arthroplasty (THA) and total knee arthroplasty (TKA) outcomes. This observational study compared the impact of a PME within 30 days prior to surgery at the PMC (Periop30) versus elsewhere ("Usual Care") on postoperative length of stay (LOS), extended LOS (i.e., a stay of >3 days), and Patient-Reported Outcomes Measurement Information System-10 (PROMIS-10) Global Physical Health (GPH) score improvement in TJA.

METHODS

We stratified adult patients (≥18 years of age) who underwent primary TJA between January 2015 and December 2020 into Periop30 or Usual Care. We utilized univariate tests (a chi-square test for categorical variables and a t test for continuous variables) to assess for differences in patient characteristics. For both TKA and THA, LOS was assessed with use of multivariable negative binomial regression models; extended LOS, with use of binary logistic regression; and PROMIS-10 GPH score, with use of mixed-effects models with random intercept and slope. Interaction terms between the focal predictor (Periop30, yes or no) and year of surgery were included in all models.

RESULTS

Periop30 comprised 82.3% of TKAs (1,911 of 2,322 ) and 73.8% of THAs (1,876 of 2,541). For THA, the Periop30 group tended to be male (p = 0.005) and had a higher body mass index (p = 0.001) than the Usual Care group. The Periop30 group had a higher rate of staged bilateral THA (10.6% versus 7.5%; p = 0.028) and a lower rate of simultaneous bilateral TKA (5.1% versus 12.2%; p < 0.001) than the Usual Care group. Periop30 was associated with a lower mean LOS for both TKA (43.46 versus 54.15 hours; p < 0.001) and THA (41.07 versus 57.94 hours; p < 0.001). The rate of extended LOS was lower in the Periop30 group than in the Usual Care group for both TKA (15% versus 26.5%; p < 0.001) and THA (13.3% versus 27.4%; p < 0.001). There was no significant difference in GPH score improvement between Periop30 and Usual Care for either TKA or THA.

CONCLUSIONS

Periop30 decreased mean LOS and the rate of extended LOS for TJA without an adverse effect on PROMIS-10 GPH scores.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Total knee replacement in octogenarians, Is age a determining factor in predicting complications? a retrospective cohort study

INTRODUCTION

Given the increase in life expectancy in the general population of our country, there is an exponential increase since the last decades of functional older adults who undergo total knee replacement (TKR). There is a direct relationship between the increase in age and the prevalence of both functional and cognitive disabling chronic diseases, however, little we know about whether age is an independent factor in predicting worse functional outcomes and readmissions after TKR. The objective of this study was to evaluate the clinical-functional results and unplanned readmissions within the first 90 postoperative days in patients older than 80 years compared with a control group of patients younger than 80 years.

METHODS

From our institutional patient database, 450 patients who underwent TKR between 2016 and 2019 were retrospectively analyzed. All patients had the medical assurance of Hospital Italiano (Plan de Salud), for which none of these was lost on the follow-up nor were treated in another hospital. Patients were divided in two groups: Group A with 186 patients over 80 years and a control group B with 264 patients between 70 and 80 years. The fragility of these was defined according to the Charlson Comorbidity Index and the Simple Frail Score. Comorbidities were divided in eight groups to define which were the most influential in the final results.

RESULTS

No significant differences were observed in terms of unplanned readmissions, pain or in functional scores within 90 days between both groups. There was a significant difference in the length of postoperative hospital stay in favor of group A (A: 2.56 SD + - 0.76, B: 4.08 SD =  - 2.23; p = 0.00001). The Charlson score was higher in the group of patients older than 80 years (p = 0.02) as well as the Simple Frail Score (p = 0.004). The ASA score did not show significant differences between both groups.

CONCLUSION

Age as an independent factor proved not to be a predictor by itself of unplanned readmissions or worse clinical-functional results in a period of 90 postoperative days between both groups. We believe that the preoperative evaluation of octogenarian patients should be multidisciplinary, with special attention to the identification of comorbidities that can influence the fragility of a patient and the optimization of the pathology.

Simultaneous bilateral total knee arthroplasty is safe and effective for patients in different ages

BACKGROUND

Simultaneous bilateral total knee arthroplasty is considered beneficial for patients with bilateral end-stage knee osteoarthritis, even though there could be potential postoperative complications. Presently, there is a paucity of evidence of the efficacy and safety of SB-TKA for elderly patients. This study aimed to compare the clinical outcomes of simultaneous bilateral total knee arthroplasty by different age groups.

METHODS

A total of 216 knees of 108 patients, who underwent simultaneous bilateral total knee arthroplasty for osteoarthritis at our hospital between April 2015 and September 2018, were divided into three groups based on age: 60s (44 knees), 70s (106 knees), and 80s (66 knees). Perioperative data and postoperative clinical outcomes 1 year after surgery were compared between the age groups.

RESULTS

The patients in the Group 60s were characterized by a higher body mass index (BMI) (P < 0.01), a lower pre-operative knee function score (P < 0.01), longer operation time (P < 0.01), greater intra-operative (P < 0.01), and postoperative bleeding (P = 0.026). No significant difference was found in terms of occurrence of various postoperative complications, although deep vein thrombosis and delirium occurred slightly more frequently in the Group 70s and the Group 80s than in the Group 60s group. The Knee Society Knee Score, a function score, and patient satisfaction scores were significantly improved in all groups 1 year after surgery. Moreover, these indexes of clinical outcomes were similar among the three groups.

CONCLUSION

Performing simultaneous bilateral total knee arthroplasty in 80s patients was found to be as safe and effective as in the 60s and 70s patients.

LEVEL OF EVIDENCE

3 (A retrospective cohort study).

Similar survival rate but lower functional outcomes following TKA in the elderly people compared to younger patients: analysis of a posterior stabilised implant with minimum 5-year follow-up

BACKGROUND

Literature regarding outcomes in patients over 80 years old after total knee arthroplasty (TKA) is inconsistent. We aimed to compare implant survivorship and functional outcomes between elderly patients (≥ 80 years) and younger patients (< 80 years) following TKA, using a single modern posterior-stabilized (PS) prosthetic design.

METHODS

This is a retrospective cohort study of 80 patients over 80 years old who underwent TKA between January 2015 and December 2016, who were compared with younger patients (60-75 years old) operated during the same period. Patients were matched with a ratio of 1:3 based on logistic regression analysis of gender and body mass index. All patients received the same cemented PS prosthesis with a fixed bearing polyethylene insert, with or without patellar resurfacing. Implant survival and patient-reported outcome measurements were compared between the two groups. At last follow-up, data were available for 41 knees in the elderly group (including 17 patients who died before 5-year follow-up) and 123 knees in the younger group.

RESULTS

Functional results were better at final follow-up in the group < 80 years with a significantly higher Knee Society Function Subscore (88.6 ± 16.9 vs 79.4 ± 22.1, p < 0.01), but no significant differences in Knee Subscore and global Knee Society Score (p > 0.05), nor regarding maximum flexion (121° ± 12 and 117° ± 13, p = 0.08). The implant survivorship was 100.0% after a mean 64.4-month follow-up (range 60-78), without revision requiring removal of the implant in any group. The survival rate without any reoperation was 97.6% (95% CI 93.0-100.0) in the elderly group and 95.9% (95% CI 92.5-99.5) in the younger group (p = 0.64).

CONCLUSION

At a minimum of 5-year follow-up, there was no revision surgery and a very low rate of complications requiring reoperations both in the group over 80 years of age and in the younger population, with the use of a PS prosthesis. The functional results were slightly lower for elderly patients and correlate with the lower functional demands of this population. The indication for TKA, especially with a PS implant, may be encouraged in appropriately selected elderly patients.

LEVEL OF EVIDENCE

III (retrospective cohort study).

The long-term results of total knee arthroplasty in octogenarian

Aims: With increasing life expectancy and ageing population, more octogenarians would benefit from total knee arthroplasty (TKA). The aim of this study is to evaluate the survivorship of TKA in octogenarian and their long-term outcomes. Methods: This was a retrospective review of 67 patients aged above 80 years who had primary TKA performed between 2005 and 2013 at a single centre. A sex-matched younger cohort of 67 primary TKAs during the same time-period was recruited for control. Five and 10-year survival was calculated. Pre- and peri-operative factors were collected and compared. Post-operative range of motion, Knee Society Score (KSS) and Function Score (KFS) were collected and compared. Rate of revision, infection, aseptic loosening and mortality was collected. Results: The mean follow-up period was 10.39 ± 2.29 years. The 5- and 10-year survival of octogenarian group was 85.1% and 54.6%, respectively. Pre- and peri-operative factors between the octogenarian and control groups were comparable (p > 0.05). Both groups showed improvement in range of motion, KSS and KFS post-operatively. Rate of revision, aseptic loosening and deep infection was 0% in octogenarian and 1.5% in control group. Conclusion: TKA can be performed in patients with age above 80 years old with comparable post-op knee range, complication rate and long-term functional score. Advanced age should not be a limiting factor for TKA.

Higher rates of surgical and medical complications and mortality following TKA in patients aged ≥ 80 years: a systematic review of comparative studies

The purpose of this systematic review was to synthesize studies published since the last systematic review in 2015 that compare outcomes of primary total knee arthroplasty (TKA) in older patients (≥ 80 years) and in younger patients (< 80 years), in terms of complication rates and mortality.

An electronic literature search was conducted using PubMed, Embase®, and Cochrane Register. Studies were included if they compared outcomes of primary TKA for osteoarthritis in patients aged 80 years and over to patients aged under 80 years, in terms of complication rates, mortality, or patient-reported outcomes (PROs).

Thirteen studies were eligible. Surgical complications in older patients ranged from 0.6–21.1%, while in younger patients they ranged from 0.3–14.6%. Wound complications in older patients ranged from 0.5–20%, while in younger patients they ranged from 0.8–22.0%. Medical complications (cardiac, respiratory, thromboembolic) in older patients ranged from 0.4–17.3%, while in younger patients they ranged from 0.2–11.5%.

Mortality within 90 days in older patients ranged between 0–2%, while in younger patients it ranged between 0.0–0.03%.

Compared to younger patients, older patients have higher rates of surgical and medical complications, as well as higher mortality following TKA. The literature also reports greater length of stay for older patients, but inconsistent findings regarding PROs. The present findings provide surgeons and older patients with clearer updated evidence, to make informed decisions regarding TKA, considering the risks and benefits within this age group. Patients aged over 80 years should therefore not be excluded from consideration for primary TKA based on age alone.

Cite this article: EFORT Open Rev 2021;6:1052-1062. DOI: 10.1302/2058-5241.6.200150

Safety of Total Knee Arthroplasty without Using a Tourniquet in Elderly Patients

This study retrospectively compared the perioperative bleeding, hemodynamics, and clinical outcomes of total knee arthroplasty (TKA) performed with and without a tourniquet between two age groups. We grouped 103 patients with knee osteoarthritis who underwent primary TKA based on age at surgery: <76 years and ≥76 years. Tourniquet was used for TKA until March 2010 and stopped thereafter; hence, the patients were further classified according to TKA performed with or without a tourniquet. The differences in the operation time; perioperative bleeding; estimated bleeding; and hemoglobin (Hb) and hematocrit (Ht) levels immediately, 1 day, and 7 days postoperatively were evaluated. The clinical outcomes for range of motion, and Knee Society Knee Scores preoperatively and at 4 weeks postoperatively were assessed. Operation time was longer in the ≥76-year-old non-tourniquet group. No difference was observed in estimated bleeding among the groups. Changes in the Hb and Ht levels at postoperative days 1 and 7 were negatively correlated with age but were not different for TKA performed with or without a tourniquet in the ≥76-year-old-patient group. There were no differences in clinical outcomes among the groups. TKA can be performed with or without a tourniquet in patients aged ≥ 76 years with careful assessment of postoperative anemia.

New-Onset Depression After Total Knee Arthroplasty: Consideration of the At-Risk Patient

BACKGROUND

Postoperative new-onset depression (NOD) has gained recent attention as a previously unrecognized complication which may put patients at risk for poor outcomes after elective total hip arthroplasty. We aimed to investigate risk factors for the development of NOD after total knee arthroplasty (TKA) and assess its association with postoperative complications.

METHODS

This is a retrospective, population-level investigation of elective TKA patients. Patients with a preoperative diagnosis of depression were excluded from this study. Two groups were compared: patients who were diagnosed with depression within one year after TKA (NOD) and those who did not (control). The association of both preoperative patient factors and postoperative surgical and medical complications with NOD was then determined using multivariate and univariate analyses.

RESULTS

Of 196,728 unique TKA patients in our cohort, 5351 (2.72%) were diagnosed with NOD within one year of TKA. Age <54 year old, female gender, preoperative anxiety disorder, drug, alcohol, and/or tobacco use, multiple comorbidities, and opioid use before TKA were all associated with a diagnosis of NOD postoperatively (all P < .001). Postoperative NOD was associated with periprosthetic fracture (OR 2.11; 95% CI 1.29-3.52; P = .033), aseptic failure (OR 1.61; 95% CI 1.24-2.07; P = .020), prosthetic joint infection (OR 1.55, 95% CI 1.30-1.85; P < .001), stroke (OR 1.24; 95% CI 1.09-1.42; P = .006), and venous thromboembolism (OR 1.24; 95% CI 1.12-1.37; P < .001).

CONCLUSION

Post-TKA NOD is common and is associated with poor outcomes. This may aid surgeons in developing both anticipatory measures and institute preventative measures for patients at risk for developing NOD.

Factors Influencing Functional Outcome at Discharge: A Retrospective Study on a Large Sample of Patients Admitted to an Intensive Rehabilitation Unit

OBJECTIVE

Functional outcome represents the most central objective of rehabilitation programs. Understanding which factors could affect functional status at discharge is crucial for the planning of appropriate treatments in both neurologic and orthopedic patients. The aim of this study was to investigate which clinical and demographic variables, collected at the patient's admission, could influence the functional outcome, assessed by the modified Barthel Index (mBI), at discharge.

DESIGN

A retrospective study was conducted on a large cohort (n = 3548) of orthopedic and neurologic patients. Functional, demographic, and clinical records at patient admission and mBI score at discharge were collected. General linear model analysis was performed to assess the influence of these variables on functional outcome at discharge.

RESULTS

The results reported a significant effect of mBI score at admission (P < 0.0001), age (P < 0.0001), and time from the acute event (P < 0.0001) on mBI score at discharge. Moreover, the disease type (neurologic or orthopedic) adjusted by sex (male or female) and presence of different impairments (cognitive and behavioral impairments) and complications (hypertension and cardiovascular diseases) significantly influenced mBI score at discharge (P < 0.05) (R2 = 0.497). No significant interactions between other factors were found (P > 0.05).

CONCLUSION

Several prognostic factors should be considered when planning an appropriate tailored rehabilitation program.

Reduction in anxiety and depression symptoms one year after knee replacement: a register-based cohort study of 403 patients

Background

Anxiety and depression are associated with patient dissatisfaction after total knee arthroplasty (TKA). Understanding whether preoperative knee-related symptoms could be a cause of anxiety and depression might help prevent unnecessary delay of surgery for this group of patients. We investigated changes in prevalence of anxiety and depression symptoms one year after TKA, and compared demographic data between patients with and without anxiety and depression symptoms preoperatively.

Methods

This was a prospective cohort study of 403 patients scheduled for TKA. Data on patient-related outcome measures and the prevalence of anxiety and depression symptoms were collected preoperatively and one year postoperatively. Before–after differences in anxiety/depression prevalence were compared with a chi-square test, and differences in demographic data between the groups with and without anxiety and/or depression symptoms were compared with an independent t test.

Results

Among the 15% of patients with anxiety symptoms before surgery, 59% had improved in these symptoms one year after surgery; while among the 10% with depression symptoms before surgery, 60% had improved one year after surgery. Patients with preoperative anxiety and/or depression were younger, and had higher body mass index, lower general quality of life (EQ-5D-3L), higher pain scores (visual analog scale), and lower knee-related (KOOS) scores on all subscales except sport.

Conclusion

Presurgical symptoms of anxiety and depression seem to be partly caused by knee symptoms. Understanding of this issue would offer better strategies to prevent unnecessary delay of surgery in this group of patients.

Reporting and utilization of Patient-Reported Outcomes Measurement Information System® (PROMIS®) measures in orthopedic research and practice: a systematic review

Background

The Patient-Reported Outcomes Measurement Information System^Ⓡ (PROMIS^Ⓡ) is a dynamic system of psychometrically sound patient-reported outcome (PRO) measures. There has been a recent increase in the use of PROMIS measures, yet little has been written about the reporting of these measures in the field of orthopedics. The purpose of this study was to conduct a systematic review to determine the uptake of PROMIS measures across orthopedics and to identify the type of PROMIS measures and domains that are most commonly used in orthopedic research and practice.

Methods

We searched PubMed, Embase, and Scopus using keywords and database-specific subject headings to capture orthopedic studies reporting PROMIS measures through November 2018. Our inclusion criteria were use of PROMIS measures as an outcome or used to describe a population of patients in an orthopedic setting in patients ≥ 18 years of age. We excluded non-quantitative studies, reviews, and case reports.

Results

Our final search yielded 88 studies published from 2013 through 2018, with 57% (50 studies) published in 2018 alone. By body region, 28% (25 studies) reported PROMIS measures in the upper extremity (shoulder, elbow, hand), 36% (32 studies) reported PROMIS measures in the lower extremity (hip, knee, ankle, foot), 19% (17 studies) reported PROMIS measures in the spine, 10% (9 studies) reported PROMIS measures in trauma patients, and 6% (5 studies) reported PROMIS measures in general orthopedic patients. The majority of studies reported between one and three PROMIS domains (82%, 73 studies). The PROMIS Computerized Adaptive Test (CAT) approach was most commonly used (81%, 72 studies). The most frequently reported PROMIS domains were physical function (81%, 71 studies) and pain interference (61%, 54 studies).

Conclusion

Our review found an increase in the reporting of PROMIS measures over the recent years. Utilization of PROMIS measures in orthopedic populations is clinically appropriate and can facilitate communication of outcomes across different provider types and with reduced respondent burden.

Registration

The protocol for this systematic review was designed in accordance with the PRISMA guidelines and is registered with the PROSPERO database (CRD42018088260).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-020-02068-9.

Does Age Influence Patient-Reported Outcomes in Unilateral Primary Total Hip and Knee Arthroplasty?

BACKGROUND

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are used to treat patients with end-stage arthritis. Previous studies have not demonstrated a consistent relationship between age and patient-reported outcomes. The purpose of this study is to assess the impact of age on patient-reported outcomes after unilateral primary THA or TKA.

METHODS

A retrospective review of available data in Alberta Bone and Joint Health Institute (ABJHI) Data Repository was performed. We identified 53,498 unilateral primary THA and TKA between April 2011 and 2017. Patients were divided by age into 3 categories: <55, 55-70, and >70. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and EuroQoL 5-dimension (EQ-5D) Canada scores were obtained at presurgery, 3 and 12 months postoperatively.

RESULTS

For TKA, younger patients had larger improvements in WOMAC scores at 3 and 12 months (P = <.001-.033), and in EQ-5D scores at 3 months (P < .001). When adjusted, patients <55 had lower WOMAC and EQ-5D scores at 3 months postoperatively compared to those 55-70 or >70 (all P < .01). Outcomes at 12 months did not differ between age-groups. For THA, younger patients had larger improvements in WOMAC at 3 months (P = .03). When adjusted, patients <55 had higher WOMAC scores at 12 months postoperatively compared to those 55-70 or >70, and higher EQ-5D scores compared to those 55-70 (all P < .05).

CONCLUSION

While a multitude of factors go in to quantifying successful THA or TKA, this study suggests that patient age should not be a deterrent when considering the impact of age on patient-reported outcomes.

Can Octogenarians Undergoing Total Knee Arthroplasty Experience Similar Functional Outcomes, Quality of Life, and Satisfaction Rates as Their Younger Counterparts? A Propensity Score Matched Analysis of 1188 Patients

BACKGROUND

Current literature lacks consensus regarding the impact of advanced age on the clinical outcomes of total knee arthroplasty (TKA). Moreover, there is paucity of literature on the subjective benefit reported by elderly patients. We compared the functional outcomes, quality of life, and satisfaction rates between octogenarians and age-appropriate controls undergoing primary TKA with a minimum follow-up of 2 years.

METHODS

Prospectively collected registry data of 594 patients aged ≥80 years (n = 594) and a propensity score matched cohort of 594 patients aged 65-74 years who underwent primary TKA at a single institution were reviewed. The range of motion, clinical outcome scores, and satisfaction rates were assessed at 6 months and 2 years. Revision rates were also recorded.

RESULTS

Octogenarians had a significantly lower Knee Society Function Score, Oxford Knee Score, and SF-36 Physical Component Summary at 6 months and 2 years (P < .05 for each). Furthermore, a lower proportion of octogenarians achieved the minimal clinically important difference for each score (P < .05 for each). Although the rates were similar at 6 months (P = .853), octogenarians were less satisfied at 2 years compared to age-appropriate controls (89.3% vs 93.3%, P = .042), and there was a trend toward poorer expectation fulfillment (88.4% vs 92.1%, P = .062).

CONCLUSION

Octogenarians undergoing TKA had a relatively lower rate of satisfaction and clinically meaningful improvement compared to younger controls. Nevertheless, elderly patients still experienced a successful outcome after surgery. The clinical trajectory outlined may help clinicians provide valuable prognostic information to elderly patients and guide preoperative counseling.

HIGHER RISK OF COMPLICATIONS AFTER TOTAL KNEE ARTHROPLASTY IN OCTOGENARIANS

Objective:

To evaluate the complication rate of total knee arthroplasty (TKA) in octogenarian patients and identify predictive factors.

Methods:

The study comprised 70 octogenarians and 70 non-octogenarian patients as control group, all submitted to TKA. We analyzed the medical records of these patients, seeking for complications during the first postoperative year. Regarding the risk factors, we evaluated: age, sex, race, American Society of Anesthesiologists score, body mass index, smoking, hypertension and diabetes mellitus.

Results:

In the control group, the incidence of complications was 7.1%. Whereas in the octogenarian group it was significantly higher, reaching 34.3% (OR 6.8; 95% CI 2.4-19.1). We found no association to sex, skin color, and comorbidities. Age is an independent risk factor for postoperative complications. Our data may help patients to acknowledge the risks of undergoing primary TKA and physicians to assess and adjust perioperative risk.

Conclusion:

The incidence of postoperative complications is significantly higher in octogenarians. Level of Evidence III, Case-control study.

Preoperative psychological distress no reason to delay total knee arthroplasty: a register-based prospective cohort study of 458 patients

INTRODUCTION

Total knee arthroplasty (TKA) is effective in alleviating pain and improving function in patients with knee arthritis. Psychological factors are known to affect patient satisfaction after TKA. It is important to determine the effectiveness of TKA in patients with presurgical anxiety and/or depression to avoid excluding them from surgery.

MATERIALS AND METHODS

A prospective cohort study was conducted on all patients who underwent TKA during 2016-2018. Patients were divided into four groups: with anxiety, without anxiety, with depression, and without depression. Outcome measures comprised both generic and knee-specific instruments. Each patient group was compared regarding changes in outcome measures one year after surgery. Between-group comparison was also performed.

RESULTS

Of the 458 patients with complete data, 15.3% and 9.6% had experienced presurgical anxiety and depression, respectively. All patient groups displayed statistical (P < 0.001) and clinical improvement in all outcome measures. Patients with presurgical anxiety and/or depression generally displayed less improvement, though the only significant mean differences concerned the Knee Injury and Osteoarthritis Outcome Score (KOOS)-sport score in the non-anxiety and non-depression groups (P = 0.006 and 0.03, respectively), a higher proportion of clinically improved KOOS pain in the non-anxiety group (P = 0.03), and the general health state in the anxiety and depression groups (P = 0.004 and 0.04, respectively).

CONCLUSIONS

All patients improved in outcome measures 1 year after TKA, regardless of presurgical psychological state. Patients with presurgical anxiety and/or depression benefit greatly from surgery and should not be discriminated against based on presurgical psychological distress, though this fact should not eliminate the preoperative psychological assessment of patients.

LEVEL OF EVIDENCE

II.

Preoperative Weight Loss for Morbidly Obese Patients Undergoing Total Knee Arthroplasty: Determining the Necessary Amount

BACKGROUND

Many surgeons require or request weight loss among morbidly obese patients (those with a body mass index [BMI] of ≥40 kg/m) before undergoing total knee arthroplasty. We sought to determine how much weight reduction was necessary to improve operative time, length of stay, discharge to a facility, and physical function improvement.

METHODS

Using a retrospective review of cohort data that were prospectively collected from 2011 to 2016 at 1 tertiary institution, we identified 203 patients who were morbidly obese at least 90 days before the surgical procedure and had their BMI measured again at the immediate preoperative visit. All heights and weights were clinically measured. We used logistic and linear regression models that adjusted for preoperative age, sex, year of the surgical procedure, bilateral status, physical function (Patient-Reported Outcomes Measurement Information System [PROMIS]-10 physical component score [PCS]), mental function (PROMIS-10 mental component score [MCS]), and the Charlson Comorbidity Index.

RESULTS

Of the 203 patients in the study, 41% lost at least 5 pounds (2.27 kg) before the surgical procedure, 29% lost at least 10 pounds (4.54 kg), and 14% lost at least 20 pounds (9.07 kg). Among morbidly obese patients, losing 20 pounds before a total knee arthroplasty was associated with lower adjusted odds of discharge to a facility (odds ratio [OR], 0.28 [95% confidence interval (CI), 0.09 to 0.94]; p = 0.039), lower odds of extended length of stay of at least 4 days (OR, 0.24 [95% CI, 0.07 to 0.88]; p = 0.031), and an absolute shorter length of stay (mean difference, -0.87 day [95% CI, -1.39 to -0.36 days]; p = 0.001). There were no differences in operative time or PCS improvement. Losing 5 or 10 pounds was not associated with differences in any outcome.

CONCLUSIONS

Losing at least 20 pounds before total knee arthroplasty was associated with shorter length of stay and lower odds of facility discharge for morbidly obese patients, even while most patients remained morbidly or severely obese. Although there were no differences in operative time or physical function improvement, this has considerable implications for patient burden and cost reduction. Patients and providers may want to focus on larger preoperative weight loss targets.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.