Are complication rates for elective primary total hip arthroplasty in Ontario related to surgeon and hospital volumes? A preliminary investigation

Objective

To test the hypothesis that complication rates for elective total hip replacement operations are related to surgeon and hospital volumes.

Design

Retrospective population cohort study.

Study cohort

Patients who had undergone elective total hip replacement in Ontario during 1992 as captured in the Canadian Institute for Health Information database.

Main outcome measures

In-hospital complications, 1- and 3-year revision rates, 1- and 3-year infection rates, length of hospital stay, and 3-month and 1-year death rates.

Results

Surgeons with patient volumes above the 80th percentile (more than 27 hip replacements annually) discharged patients approximately 2.4 days earlier (p < 0.05) than surgeons with volumes below the 40th percentile (less than 9 hip replacements annually) even after adjusting for discharge disposition, hospital volume, patient age, sex, comorbidity and diagnosis. Complication rates requiring hospital readmission and death rates did not differ by surgeon or hospital volume (p > 0.05).

Conclusions

There is no evidence to support regionalization of elective hip replacement surgery in Ontario based on adverse clinical outcomes. Surgeons who perform a large number of total hip replacements are discharging patients earlier than less experienced surgeons, without any demonstrable increase in complications leading to hospital readmission. The explanation for this observation remains unknown and will require further study.     

Patient-reported history of leg ulceration 12-16 years after total primary knee or hip replacement

Background and purpose

Deep vein thrombosis is common after total joint replacement. It is frequently asymptomatic, and it is unclear whether this leads to longer-term problems such as post-thrombotic syndrome and leg ulceration. We investigated whether the postoperative prevalence of ulceration in patients who had undergone primary total hip replacement (THR) or total knee replacement (TKR) was higher than that found in a control group who had not undergone total joint replacement.

Methods

The study group consisted of patients who had undergone THR or TKR at one orthopedic center 12–16 years previously without routine chemothromboprophylaxis, and who had not undergone revision surgery. The control group was recruited via primary care. All participants were recruited by post and asked to complete a questionnaire. Age- and sex-adjusted prevalence of self-reported leg ulceration was calculated, and logistic regression was used to determine whether there were any associations between THR or TKR and leg ulceration.

Results

Completed questionnaires were received from 441 THR patients (54% response rate), 196 TKR patients (48%) and 967 control participants (36%). No statistically significant differences in age- and sex-adjusted prevalence of ulceration were found between the groups, for either lifetime prevalence or prevalence over the previous 15 years.

Interpretation

Patients who undergo THR and TKR without chemothromboprophylaxis are unlikely to be at a higher risk of long-term venous ulceration than the normal population.Deep vein thrombosis (DVT) is common after total hip replacement (THR) and total knee replacement (TKR) (Geerts et al. 2001). This is frequently asymptomatic, and it is unclear whether there are any longer-term implications of DVT identified only by venography, in terms of patient morbidity such as post-thrombotic syndrome (PTS) (Cordell-Smith et al. 2004). Chemothromboprophylaxis reduces rates of DVT, but there is no evidence that it reduces deaths from pulmonary embolism (PE) or deaths for any reason (Atkins 2010). In fact, it has been suggested to increase mortality after THR and TKR (Sharrock et al. 2008). This would be difficult to test in a randomized controlled trial, as postoperative mortality is very low after joint replacement ( Parry et al. 2008, Cusick and Beverland 2009).PTS is a collection of symptoms including swelling, pain, and—in severe cases—venous ulceration. The symptoms of PTS are not uniformly defined, and it is therefore difficult to compare results from different studies (Kahn 2009). It is unclear whether patients who have had TKR or THR are more at risk of PTS than the general population, and whether there are long-term consequences of asymptomatic DVT in this group. Debate about whether to use routine chemothromboprophylaxis is centered mainly on postoperative DVT and pulmonary embolism (Atkins 2010), but the long-term consequences of thrombus are also being increasingly considered (Campbell et al. 2010). This is important, both in the choice of thromboprophylaxis and in ensuring that patients are informed about all potential adverse effects of joint replacement.Ulceration has been used previously as a “hard” endpoint of PTS to investigate medium-term outcomes of TKR in a study that found no association between postoperative DVT identified by venography and ulceration 5 years after surgery (Muller et al. 2001). Although in that study the prevalence of leg ulceration was considered to be similar to the estimated prevalence of ulceration in the general population, both PTS and leg ulceration are found frequently in the general population (Kahn 2006), and it is difficult to determine whether TKR and THR patients are at an increased risk without a control group.In this study, we built on the work performed by Muller et al. 2001) by looking at the 12–16-year postoperative prevalence of leg ulceration in both TKR and THR patients. The inclusion of a control group allowed comparison of the prevalence of leg ulceration to that of the general population, in order to identify whether THR or TKR is indeed a risk factor for leg ulceration.     

Antibiotic prophylaxis for total joint replacement surgery: results of a survey of Canadian orthopedic surgeons

Background

The role of perioperative antibiotic prophylaxis in total joint replacement (TJR) surgery is well established. Whereas guidelines have been published in some countries, in Canada controversy persists concerning the best clinical practice for perioperative antibiotic prophylaxis in TJR.

Methods

We conducted a survey of 590 practising orthopedic surgeons performing TJR in Canada to assess current antibiotic prophylaxis practice. The survey included questions pertaining to antibiotic prophylaxis indications, antibiotic choice, dosing, route and timing of administration in the primary and revision arthroplasty setting, as well as postoperative wound drainage evaluation and management.

Results

The response rate after 2 mail-outs was 410 of 590 (69.5%). Current antibiotic prophylaxis regimens varied widely among surgeons, underscoring the controversy that exists regarding what constitutes best clinical practice.

Conclusion

Opinions regarding use of perioperative antibiotic prophylaxis in TJR vary widely among orthopedic surgeons in Canada, illustrating the controversy as to what constitutes best clinical practice. This survey also points to a lack of consensus about the current management of postoperative wound drainage.     

Temporal trends in primary total hip and knee arthroplasty surgery: results from a UK regional joint register, 1991�C2004

INTRODUCTION

The aim of this study was to evaluate temporal trends in the prevalence of primary total hip and knee replacements (THRs and TKRs) throughout the Trent region from 1991 to 2004.

PATIENTS AND METHODS

The Trent Regional Arthroplasty Study records details of primary THR and TKR prospectively and data from the register were examined. Age and gender population data were provided by the Office for National Statistics.

RESULTS

A total of 26,281 THRs and 23,606 TKRs were recorded during this period. Analysis showed that females had an increased incidence rate ratio (IRR) for both primary THR (IRR = 1.29; 95% CI 1.26–1.33; P < 0.001) and TKR (IRR = 1.17; 95% CI 1.14–1.20; P < 0.001). Patients aged 74–85 years had the largest IRR for both primary THR (IRR = 6.7; 95% CI 6.4–7.0; P < 0.001) and TKR (IRR = 15.3; 95% CI 14.4–16.3; P < 0.001).

CONCLUSIONS

The prevalence of primary TKR increased significantly over time whereas THR remained steady in the Trent region between 1991 and 2004.     

The effect of hospital volume on length of stay, re-admissions, and complications of total hip arthroplasty

Background and purpose

Hospital volume has been suggested to be one of the best indicators of adverse orthopedic events in patients undergoing THR surgery. We therefore evaluated the effect of hospital volume on the length of stay, re-admissions, and complications of THR at the population level in Finland.

Methods

30,266 THRs performed for primary osteoarthritis were identified from the Hospital Discharge Register. Hospitals were classified into 4 groups according to the number of THRs performed on an annual basis over the whole study period: 1–50 (group 1), 51–150 (group 2), 151–300 (group 3), and > 300 (group 4).

Results

In 2005, the length of the period of surgical treatment was 5.5 days in group 4 and 6.8 days in group 1 (the reference group). During the whole study period (1998–2005), the length of surgical treatment period was shorter in group 4 than in group 1 (p < 0.001). The odds ratio for dislocations (0.7, 95% CI: 0.6–0.9) was lower in group 3 than in group 1.

Interpretation

Hip replacements performed in high-volume hospitals reduce costs by shortening the length of stay, and they may reduce the dislocation rate.The association between hospital volume and results of total hip replacement (THR) has been investigated in several studies (Lavernia and Guzman 1995, Battaglia et al. 2006, Doro et al. 2006, Shervin et al. 2007). The surgeon volume and the hospital volume have been suggested to be the best indicators of adverse orthopedic events in patients undergoing THR surgery (Solomon et al. 2002). A systematic review of the literature found an association between high hospital volumes and low numbers of hip dislocations (Shervin et al. 2007). Lower provider volumes have been related to longer hospital stay after THR surgery (Lavernia and Guzman 1995, Doro et al. 2006, Judge et al. 2006).We evaluated the effects of hospital volume on the length of stay, the number of re-admissions, and the number of complications of THRs in the whole population of Finland.     

The impact of surgeon handedness in total hip replacement

Introduction

Total hip replacement (THR) is successful and performed commonly. Component placement is a determinant of outcome. Influence of surgeon handedness on component placement has not been considered previously. This study was a radiographic assessment of component positioning with respect to handedness. Early data from 160 patients are reported.

Methods

Overall, 160 primary THRs for osteoarthritis were included. Equal numbers of left and right THRs were performed by four surgeons, two right-handed and two left-handed. Postoperative radiography was assessed for THR component position by measurement of leg length inequality, acetabular inclination and centre of rotation. Surgeons’ handedness was assessed using the Edinburgh inventory.

Results

For leg length inequality, no significant interaction was seen between hip side and surgeon handedness. Acetabular inclination angles showed a statistically significant difference, however, depending on hand dominance, with higher inclination angles recorded when operating on the dominant side. There was a trend towards greater medialisation of the centre of rotation on the non-dominant side although this did not reach statistical significance.

Conclusions

Surgeon handedness appears to influence acetabular component position during THR but it is one factor of many that interact to achieve a successful outcome.     

Review of 10-year results of PCA hip arthroplasty

Objective

To assess the long-term results of the PCA uncemented total hip replacement.

Design

A prospective nonrandomized clinical trial. Follow-up ranged from 8 to 11 years (mean 10.3 years).

Setting

A university hospital.

Patients

One hundred consecutive PCA arthroplasties were performed on 89 patients. All operations were supervised by a single surgeon. The patients’ status was reviewed between September and November 1996 by an independent observer. Seventy-three total hip replacements were available for review.

Intervention

PCA uncemented acetabular and femoral replacement through a lateral surgical approach.

Main outcome measures

The need for revision, which was classified as failure, and definite 3-zone acetabular radiolucency, which was considered radiologic evidence of loosening.

Results

The time to failure of the acetabulum averaged 8 years. Femoral failure occurred in 3 patients an average of 4 years postoperatively. The overall failure rate for the acetabulum was 13% and for the femur 7%.

Conclusions

The acetabular failure rate is unacceptably high. Patients who have had hip replacement with the PCA prosthesis should be followed over the long term.     

Enhanced recovery programmes can reduce length of stay after total knee replacement without sacrificing functional outcome at one year

Introduction

Enhanced recovery programmes (ERPs) are being widely adopted in total knee replacement (TKR) procedures but studies confirming that they have no adverse effects on functional outcomes are lacking. The aim of this study was to compare length of stay, postoperative functional outcome and range of motion at one year postoperatively between patients undergoing TKR with an ERP and those with traditional rehabilitation.

Methods

A total of 165 consecutive patients undergoing primary unilateral TKR were included in the study. Overall, 84 patients undergoing TKR with an ERP were compared with a series of 81 patients undergoing primary unilateral TKR with traditional rehabilitation, immediately before the introduction of the ERP.

Results

The median postoperative length of stay was 3 days in the ERP cohort and 4 in the traditionally rehabilitated cohort (p<0.001). There were no significant differences in the preintervention characteristics of the groups and there was no significant difference in operative time, transfusion or rates of manipulation under anaesthesia. There was no difference in magnitude of improvement in American Knee Society score (p=0.12) or range of motion (p=0.81) between the groups.

Conclusions

ERP can reduce length of stay after TKR while offering improvements in knee function equivalent to those experienced by patients undergoing TKR with traditional rehabilitation. Furthermore, ERP can be implemented successfully in the setting of a district general hospital.     

Not all total joint replacement patients are created equal: preoperative factors and length of stay in hospital

Background

We conducted a cross-sectional study of primary total joint replacement (TJR) patients to determine predictors for prolonged length of stay (LOS) in hospital to identify patient characteristics that may inform resource allocation, accounting for patient complexity.

Methods

Preoperative demographics, medical comorbidities and acute hospital LOS from a consecutive series of primary TJR patients from an academic arthroplasty centre were abstracted. We categorized patients as LOS of 3 or fewer days, 4 days, or 5 or more days to align results with varying LOS benchmarks. To identify predictors for LOS, we used a generalized logistic regression model fitted on an LOS ternary outcome, using LOS of 3 or fewer days as a reference category.

Results

The sample included 1459 patients: 61.7% total knee and 38.3% total hip. Male sex was predictive of an LOS of 3 or fewer days (4 d: odds ratio [OR] 0.48, 95% confidence interval [CI] 0.364–0.631; ≥ 5 d: OR 0.57, 95% CI 0.435–0.758), as was current smoking status (4 d: OR 0.425, 95% CI 0.274–0.659; ≥ 5 d: OR 0.489, 95% CI 0.314–0.762). Strong predictors of prolonged LOS included total hip versus total knee arthroplasty, age 75 years or older, American Society of Anesthesiologists classification of 3 and 4 and number of cardiovascular comorbidities.

Conclusion

Not all patients undergoing TJR are equal. The goal should be individual patient-focused care rather than a predetermined LOS that is not achievable for all patients. Hospital resource planning must account for patient complexity when planning future bed management.     

Oxidative properties and surface damage mechanisms of remelted highly crosslinked polyethylenes in total knee arthroplasty

Purpose

Remelted highly crosslinked polyethylenes (HXLPEs) were introduced in total knee replacement (TKR) starting in 2001 to reduce wear and particle-induced lysis. The purpose of this study was to investigate the damage mechanisms and oxidative stability of remelted HXLPEs used in TKR.

Methods

A total of 186 posteriorly stabilised tibial components were retrieved at consecutive revision operations. Sixty nine components were identified as remelted HXLPE. The conventional inserts were implanted for 3.4 ± 2.7 years, while the remelted components were implanted 1.4 ± 1.2 years. Oxidation was assessed using Fourier transform infrared spectroscopy.

Results

Remelted HXLPE inserts exhibited lower oxidation indices compared to conventional inserts. We were able to detect slight regional differences within the HXLPE cohort, specifically at the bearing surface.

Conclusion

Remelted HXLPE was effective at reducing oxidation in comparison to gamma inert sterilised controls. Additional long-term HXLPE retrievals are necessary to ascertain the long term in vivo stability of these materials in TKR.     

PCL-retaining versus PCL-substituting TKR – Outcome assessment based on the “forgotten joint score”

Background

Posterior cruciate ligament (PCL) retention or sacrifice figures prominently among the current controversies in total knee arthroplasty (TKA). Even though biomechanical advantages and disadvantages have been claimed for each type of TKA, clinical studies have not shown significant differences in the outcomes.

Methods

In this retrospective study, the recently introduced “forgotten joint score” (FJS) was used to assess whether any differences exist between the two types of total knee replacement (TKR). FJ scores of 169 patients with PCL-retaining TKA and 178 patients with PCL sacrificing were obtained. The mean follow-up period was 3.5 years and the minimum follow-up period was 2.5 years.

Results

Both groups showed high FJ scores indicating that majority of the patients were oblivious to the presence of the artificial joint during daily activities. There was no statistically significant difference between the mean FJ scores of the two groups. Scores of subsets based on gender, age and unilateral and bilateral TKR also did not show significant differences.

Conclusions

Since there are no clinically important differences between the two types of TKR, the choice of the TKA should be based on surgeon preferences and training and local conditions of the knee. Patient-reported outcomes appear to be similar regardless of the choice of TKA. Further prospective studies and validation of FJS outcomes with those of other questionnaires are essential to confirm the absence of differences between PCL retention and sacrifice.     

Younger age increases the risk of early prosthesis failure following primary total knee replacement for osteoarthritis: A follow-up study of 32,019 total knee replacements in the Finnish Arthroplasty Register

Background and purpose

Total knee replacements (TKRs) are being increasingly performed in patients aged ≤ 65 years who often have high physical demands. We investigated the relation between age of the patient and prosthesis survival following primary TKR using nationwide data collected from the Finnish Arthroplasty Register.

Materials

From Jan 1, 1997 through Dec 31, 2003, 32,019 TKRs for primary or secondary osteoarthritis were reported to the Finnish Arthroplasty Register. The TKRs were followed until the end of 2004. During the follow-up, 909 TKRs were revised, 205 (23%) due to infection and 704 for other reasons.

Results

Crude overall implant survival improved with increasing age between the ages of 40 and 80. The 5-year survival rates were 92% and 95% in patients aged ≤ 55 and 56–65 years, respectively, compared to 97% in patients who were > 65 years of age (p < 0.001). The difference was mainly attributable to reasons other than infections. Sex, diagnosis, type of TKR (condylar, constrained, or hinge), use of patellar component, and fixation method were also associated with higher revision rates. However, the differences in prosthesis survival between the age groups ≤ 55, 56–65, and > 65 years remained after adjustment for these factors (p < 0.001).

Interpretation

Young age impairs the prognosis of TKR and is associated with increased revision rates for non-infectious reasons. Diagnosis, sex, type of TKR, use of patellar component, and fixation method partly explain the differences, but the effects of physical activity, patient demands, and obesity on implant survival in younger patients warrant further research.     

Interpretation by radiologists of orthopedic total joint radiographs: Is it necessary or cost-effective?

Objective

To examine the necessity and cost-effectiveness of interpretation by radiologists of orthopedic radiographs obtained for patients who undergo total hip or knee replacement.

Design

A prospective study. Serial preoperative and postoperative x-ray films of the joint in patients scheduled to undergo total hip or knee joint replacement during one calendar year were interpreted by both radiology and orthopedic department staff and compared. Intraoperative findings were used to confirm the radiologic interpretation. The follow-up was 1 year.

Setting

A university teaching hospital.

Interventions

Primary or revision total hip or knee replacement.

Main Outcome Measures

Differences in interpretation of radiographs by radiologists and orthopedic surgeons for any of the four procedures. A change in orthopedic management.

Results

For preoperative radiographs, there were no discrepancies between the radiologists and orthopedic surgeons with respect to primary joint replacement. For 100 revision procedures there were 15 discrepancies, but in all cases the orthopedic surgeon’s interpretation proved to be correct. For the postoperative radiographs, there were no discrepancies in the group of revision hip replacements. For the other three groups there were a total of six discrepancies and in all cases the orthopedic surgeon’s interpretation was correct. In two cases conditions were present that were not recognized by staff from either the radiology department or orthopedic department.

Conclusion

Interpretation by radiologists of total joint radiographs in patients who undergo primary or revision total hip or knee replacement arthroplasty is not necessary or cost-effective.     

A population-based study of prevalence and hospital charges in total hip and knee replacement

The purpose of this study was to explore the increasing prevalence of factors affecting hospital charges for primary total hip replacement/total knee replacement (THR/TKR). This study analysed 37,918 THR and 76,727 TKR procedures performed in Taiwan from 1996 to 2004. Odds ratio (OR) and effect size (ES) were calculated to assess the relative change rate. Multiple regression models were employed to predict hospital charges. The following factors were associated with increased hospital charges: age younger than 65 years old; increased disease severity (Charlson comorbidity index [CCI] = 1 or > or = 2); absence of primary diagnoses of osteoarthritis (OA), rheumatoid arthritis (RA), avascular necrosis (AVN); treatment at a hospital or by a surgeon performing a high volume of operations; and longer average length of stay (ALOS). The Bureau of National Health Insurance (BNHI) should ensure that surgeons take precautionary measures to minimise complications and maximise quality of life after surgery. Use of joint prostheses from different manufacturers can reduce costs without compromising patient satisfaction.     

Comparison between open and arthroscopic acromioplasties: evaluation of absenteeism

Objective

To evaluate the rate of absenteeism from work in patients who had undergone open or arthroscopic acromioplasty.

Design

A retrospective case series.

Setting

A university hospital.

Patients

Eighteen patients with excellent results after open acromioplasty performed by one orthopedic surgeon and 20 patients with excellent results after arthroscopic acromioplasty performed by another orthopedic surgeon.

Main Outcome Measure

The time between operation and return to work.

Results

There were no statistical differences between the two techniques with respect to the return to work, age, sex and type of work. The overall time off work averaged 203 days (range from 42 to 840 days) for the arthroscopic group compared with 144 days (range from 60 to 540 days) for the open group.

Conclusions

Open acromioplasty, a safe and reliable procedure for the general orthopedic surgeon, is associated with a shorter, though not significant, delay in return to work than the arthroscopic technique.     

Predictors for moderate to severe acute postoperative pain after total hip and knee replacement

Purpose

The ability to identify and focus care to patients at higher risk of moderate to severe postoperative pain should improve analgesia and patient satisfaction, and may affect reimbursement. We undertook this multi-centre cross-sectional study to identify preoperative risk factors for moderate to severe pain after total hip (THR) and knee (TKR) replacement.

Methods

A total of 897 patients were identified from electronic medical records. Preoperative information and anaesthetic technique was gained by retrospective chart review. The primary outcomes were moderate to severe pain (pain score ≥ 4/10) at rest and with activity on postoperative day one. Logistic regression was performed to identify predictors for moderate to severe pain.

Results

Moderate to severe pain was reported by 20 % at rest and 33 % with activity. Predictors for pain at rest were female gender (OR 1.10 with 95 % CI 1.01–1.20), younger age (0.96, 0.94–0.99), increased BMI (1.02, 1.01–1.03), TKR vs. THR (3.21, 2.73–3.78), increased severity of preoperative pain at the surgical site (1.15, 1.03–1.30), preoperative use of opioids (1.63, 1.32–2.01), and general anaesthesia (8.51, 2.13–33.98). Predictors for pain with activity were TKR vs. THR (1.42, 1.28–1.57), increased severity of preoperative pain at the surgical site (1.11, 1.04–1.19), general anaesthesia (9.02, 3.68–22.07), preoperative use of anti-convulsants (1.78, 1.32–2.40) and anti-depressants (1.50, 1.08–2.80), and prior surgery at the surgical site (1.28, 1.05–1.57).

Conclusions

Our findings provide clinical guidance for preoperative stratification of patients for more intensive management potentially including education, nursing staffing, and referral to specialised pain management.     

Closed suction drains,reinfusion drains or no drains in primary total knee replacement?

INTRODUCTION

Controversy still surrounds the use of drains after total knee replacement (TKR). We compared closed suction drains, reinfusion drains and no drains by studying haemoglobin (Hb) levels, blood transfusion requirements and functional knee outcome scores in a single surgeon series.

METHODS

A total of 102 consecutive primary TKRs were performed by the senior author between September 2006 and July 2008. All were cemented fixed bearing devices with patellar resurfacing. Of the 102 patients, 30 had closed suction drainage, 33 had an unwashed reinfusion drainage system and 39 had no drains. Data regarding pre and post-operative Hb and units transfused were gathered retrospectively. Pre and post-operative American Knee Society scores (AKSS) and Oxford knee scores (OKS) were recorded prospectively.

RESULTS

The pre-operative Hb levels were comparable among the groups. There was no statistically significant difference in Hb level reduction or autologous transfusion rates among the groups. Pre-operative AKSS and OKS were statistically comparable in each group. There was no statistical difference between the improvement in AKSS knee and function scores in all three groups. There was a slightly smaller improvement in the OKS of the ‘no drain’ group. There were no complications of drain usage and no deep infections. No patient required manipulation under anaesthesia and range of movement outcomes were the same for each group.

CONCLUSIONS

Our study does not support the use of either closed suction drains or reinfusion drains in primary elective TKR.     

The Influence of Obesity on the Outcome of TKR: Can the Impact of Obesity be justified from the Viewpoint of the Overall Health Care System?

Background

There is controversy in the literature regarding the justification of performing total knee replacement (TKR) in obese patients in view of their increased risk of poor outcomes and how those poorer outcomes impact the health care system overall.

Questions/Purposes

Is TKR justifiable in the obese patient? Can the negative impact of continuing to perform TKR in the obese be quantified?

Methods

A Cochrane Library, PubMed (MEDLINE), and Google Scholar search related to the justification of TKR in the obese patient and its impact on the health care system was analyzed. The main criteria for selection were that the articles were focused in the aforementioned questions.

Results

Two thousand one hundred seventy-three articles were found, but only 50 were selected and reviewed because they were focused on the questions of this paper. Although some articles (with low grade of evidence) did not find that obesity adversely affected the outcome of TKR, most of them found that obesity adversely affected the results of TKR. Regarding complications rates and survival rates, obesity has shown to have a negative influence on outcome after TKR. The improvements in patient-reported outcome measures, however, were similar irrespective of body mass index. Regarding the impact of TKR in obese patients, an extra cost of US$3,050 has been reported per patient. Considering that 50% of the US population is obese and that 600,000 TKRs are implanted per year, the impact for the US health system could be as much as 915 million dollars (300,000 × 3,050).

Conclusion

TKR in obese patients may be justifiable because the functional improvements appear equivalent to those of patients with a lower BMI. However, in obese patients, the risk of complications is higher and the prosthetic survival is lower. Moreover, TKR in obese patients has a huge impact on the health system which should be considered.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9385-9) contains supplementary material, which is available to authorized users.     

Intra-articular Analgesia and Discharge to Home Enhance Recovery Following Total Knee Replacement

Background

The increasing demand for total knee arthroplasty (TKR) and the initiatives to reduce health care spending have put the responsibility for efficient care on hospitals and providers. Multidisciplinary care pathways have been shown to shorten length of stay and result in improved short-term outcomes. However, common problems such as post-op nausea, orthostasis, and quad weakness remain, while reliance on discharge to rehabilitation facilities may also prolong hospital stay.

Questions/Purposes

Our aim was to document that combined modifications of our traditional clinical pathway for unilateral TKR could lead to improved short-term outcomes. We pose the following research questions. Can pathway modifications which include intra-articular infusion and saphenous nerve block (SNB) provide adequate pain relief and eliminate common side effects promoting earlier mobilization? Can planning for discharge to home avoid in-patient rehab stays? Can these combined modifications decrease length of stay even in patients with complex comorbidities indicated by higher ASA class? Will discharge to home incur an increase in complications or a failure to achieve knee range of motion?

Patients and Methods

A retrospective review was performed and identified two cohorts. Group A included 116 patients that underwent unilateral TKR for osteoarthritis between August 2009 and August 2010. Group B included 171 patients that underwent unilateral TKR for osteoarthritis between February 2012 to February 2013. Group A patients were treated with spinal anesthesia with patient-controlled epidural analgesia (PCEA)/femoral nerve block (FNB) for the first 48 h after surgery. Discharge planning was initiated after admission. Group B had spinal anesthesia with SNB and received a continuous intra-articular infusion of 0.2% ropivicaine for 48 h post-op. Discharge planning was initiated with a case manager prior to hospitalization and discharge to home was declared the preferred approach. An intensive home PT program was made available through a program with our local home care agency. Outcomes assessed and compared between groups included length of stay, incidence of post-op nausea, dizziness, in-hospital falls, occurrence of complications including wound infection and the recovery of range of motion at 6 weeks, 3 months, and 1 year post-op.

Results

Pain control was similar between the groups but Group B had fewer side effects. With the new pathway, length of stay (LOS) was reduced from 4.32 to 3.64 days with a similar LOS reduction across all ASA classes. There was no increase in Group B wound or other complications. Return of ROM was similar between groups.

Conclusions

Our findings suggest that replacing PCEA and FNB with intra-articular analgesia with a SNB allows for improved early recovery following TKR. That, combined with pre-op discharge planning and initiation of an intensive home PT program, reduced average length of stay.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9414-8) contains supplementary material, which is available to authorized users.     

Outpatient Surgery as a Means of Cost Reduction in Total Hip Arthroplasty: A Case-Control Study

Background

The current healthcare market coupled with expedited recovery and improvements in analgesia have led to the development of total hip arthroplasty being performed as an outpatient procedure in selected patients.

Questions/Purposes

The purpose of this study is to compare outcomes and cost-effectiveness of traditional inpatient THA with outpatient hip replacement at the same facility.

Patients and Methods

This observational, case-control study was conducted from 2008 to 2011. One hundred nineteen patients underwent outpatient THA through a direct anterior approach. These cases were all performed by a single surgeon. Outpatient cases were then compared to inpatient hospital controls performed by the same surgeon at the inpatient hospital facility.

Results

Complications, length of stay, demographic data, and overall costs were compared between groups. There was no difference in complications or estimated blood loss between groups. Most notably, the average overall cost in the outpatient setting was significantly lower than inpatient, $24,529 versus $31,327 (p = 0.0001).

Conclusions

This study demonstrates that appropriately selected patients can undergo THA in an outpatient setting with no increase in complications and at a substantial savings to the healthcare system.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9401-0) contains supplementary material, which is available to authorized users.