High patient satisfaction in 445 patients who underwent fast-track hip or knee replacement

Background and purpose — Patient satisfaction is important in fast-track total hip and knee replacement (THR, TKR). We assessed: (1) how satisfied patients were with the treatment; (2) factors related to overall satisfaction; and (3) whether there was a difference between THR and TKR regarding length of stay (LOS) and patient satisfaction.

Patients and methods — In this follow-up study, a consecutive series of 445 patients undergoing THR and TKR completed a questionnaire 2 weeks after discharge. LOS and short-term patient satisfaction with the fast-track management were measured. Patient satisfaction was measured using a numerical rating scale (NRS; 0–10).

Results — For THR, the median satisfaction score was 9–10 and for TKR it was 8.5–10 in all parameters. Older THR patients had higher overall satisfaction. No association was found between overall satisfaction following THR or TKR and sex comorbidity, or LOS. THR patients had shorter mean LOS than TKR patients, even though the median LOS was 2 days for both groups. THR patients were more satisfied than TKR patients in the first weeks after discharge.

Interpretation — Patient satisfaction is high following fast-track THR and TKR, with scores ranging from 8.5 to 10 on the NRS. A qualitative investigation of the first weeks after discharge is required to learn more about how to improve the experience of recovery.     

Sick leave in Sweden before and after total joint replacement in hip and knee osteoarthritis patients

Background and purpose — Little is know about patterns of sick leave in connection with total hip and knee joint replacement (THR and TKR) in patients with osteoarthritis (OA).

Patients and methods — Using registers from southern Sweden, we identified hip and knee OA patients aged 40–59 years who had a THR or TKR in the period 2004–2012. Patients who died or started on disability pension were excluded. We included 1,307 patients with THR (46% women) and 996 patients with TKR (56% women). For the period 1 year before until 2 years after the surgery, we linked individual-level data on sick leave from the Swedish Social Insurance Agency. We created a matched reference cohort from the general population by age, birth year, and area of residence (THR: n = 4,604; TKR: n = 3,425). The mean number of days on sick leave and the proportion (%) on sick leave 12 and 24 months before and after surgery were calculated.

Results — The month after surgery, about 90% of patients in both cohorts were on sick leave. At the two-year follow-up, sick leave was lower for both cohorts than 1 year before surgery, except for men with THR, but about 9% of the THR patients and 12–17% of the TKR patients were still sick-listed. In the matched reference cohorts, sick leave was constant at around 4–7% during the entire study period.

Interpretation — A long period of sick leave is common after total joint replacement, especially after TKR. There is a need for better knowledge on how workplace adjustments and rehabilitation can facilitate the return to work and can postpone surgery.     

Does Regional Anesthesia Reduce Complications Following Total Hip and Knee Replacement Compared With General Anesthesia? An Analysis From the National Joint Registry for England,Wales, Northern Ireland and the Isle of Man

BackgroundRegional anesthesia is increasingly used in enhanced recovery programs following total hip replacement (THR) and total knee replacement (TKR). However, debate remains about its potential benefit over general anesthesia given that complications following surgery are rare. We assessed the risk of complications in THR and TKR patients receiving regional anesthesia compared with general anesthesia using the world’s largest joint replacement registry.MethodsWe studied the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man linked to English hospital inpatient episodes for 779,491 patients undergoing THR and TKR. Patients received either regional anesthesia (n = 544,620, 70%) or general anesthesia (n = 234,871, 30%). Outcomes assessed at 90 days included length of stay, readmissions, and complications. Regression models were adjusted for patient and surgical factors to determine the effect of anesthesia on outcomes.ResultsLength of stay was reduced with regional anesthesia compared with general anesthesia (THR = −0.49 days, 95% confidence interval [CI] = −0.51 to −0.47 days, P < .001; TKR = −0.47 days, CI = −0.49 to −0.45 days, P < .001). Regional anesthesia also had a reduced risk of readmission (THR odds ratio [OR] = 0.93, CI = 0.90-0.96; TKA OR = 0.91, CI = 0.89-0.93), any complication (THR OR = 0.88, CI = 0.85-0.91; TKA OR = 0.90, CI = 0.87-0.93), urinary tract infection (THR OR = 0.85, CI = 0.77-0.94; TKR OR = 0.87, CI = 0.79-0.96), and surgical site infection (THR OR = 0.87, CI = 0.80-0.95; TKR OR = 0.84, CI = 0.78-0.89). Anesthesia type did not affect the risk of revision surgery or mortality.ConclusionRegional anesthesia was associated with reduced length of stay, readmissions, and complications following THR and TKR when compared with general anesthesia. We recommend regional anesthesia should be considered the reference standard for patients undergoing THR and TKR.     

Peptic ulcer disease and heart disease are associated with periprosthetic fractures after total hip replacement

Background and purpose There have been no published studies assessing the possible association of medical comorbidities with periprosthetic fracture risk. We therefore assessed whether medical comorbidity is associated with risk of periprosthetic fractures after total hip replacement (THR).

Material and methods We used prospectively collected data from 1989–2008 in the Mayo Clinic Total Joint Registry for 2 cohorts: primary THR and revision THR. The main variables of interest were Deyo-Charlson comorbidities at the time of surgery. Outcome of interest was p ostoperative periprosthetic fracture at postoperative day 1 onwards. Multivariable

Cox regression models were additionally adjusted for age, sex, body mass index, American Society of Anesthesiology (ASA) class, and operative diagnosis.

Results We identified 14,065 primary THRs and 6,281 revision THRs with mean follow-up times of 6.3 and 5.6 years, respectively. There were 305 postoperative periprosthetic fractures in the primary THR cohort and 330 in the revision THR cohort. In patients who underwent primary THR, 2 comorbidities were associated with higher risk of periprosthetic fracture: peptic ulcer disease with adjusted hazard ratio of 1.5 (95% CI: 1.1–2.2) and heart disease with adjusted hazard ratio of 1.7 (CI: 1.2–2.4). In patients with revision THR, peptic ulcer disease was associated with a higher adjusted risk of periprosthetic fracture, 1.6 (CI: 1.1–2.3).

Interpretation Peptic ulcer disease and heart disease in primary THR patients and peptic ulcer disease in revision THR patients were associated with higher postoperative periprosthetic fracture risk. Further studies are needed to understand whether disease severity or specific medications used for treatment, or both, are responsible for this association. This may allow identification of modifiable factors.     

Poor glycemic control in bariatric patients: a reason to delay or a reason to proceed?

BackgroundMore than 90% of patients with type 2 diabetes (T2D) have obesity, and over 85% of diabetic patients who undergo metabolic and bariatric surgery (MBS) will see improvement or resolution of diabetes. However, diabetes is a known risk factor for surgical complications.ObjectivesTo determine whether poor preoperative glycemic control confers an increased perioperative risk after MBS.SettingAcademic Hospital.MethodsRetrospective review of data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). From the 2017–2018 MBSAQIP databases, we identified patients with diabetes who underwent Roux-en-Y gastric bypass or gastric sleeve surgery. Unmatched and propensity-matched univariate analyses, as well as multivariate logistic regressions, were performed to compare 30-day postoperative outcomes and complication rates between patients with poor (glycated hemoglobin [HbA1C] > 7.0) and good (HbA1C ≤ 7.0) glycemic control.ResultsOf 40,132 T2D patients, 19,094 (52.42%) had an HbA1C level ≤ 7.0. Patients with poor glycemic control had slightly higher rates of overall morbidity (6.53% versus 5.49%, respectively; relative risk = 1.188; P < .001). However, in a 1:1 matched analysis of 23,930 patients controlling for body mass index, surgery type, approach, and co-morbidities, the findings of poorer outcomes were largely mitigated. In a multivariate analysis, poor glycemic control was not associated with morbidity.ConclusionsIn T2D patients, poor glycemic control does not independently increase the risk of 30-day morbidity following MBS. Adverse outcomes in the setting of poor glycemic control appear to be largely mediated by associated co-morbidities. Performing MBS in the setting of suboptimal glycemic control may be justified, with the understanding that delaying or refusing surgery can contribute to worsening of diabetes-related co-morbidities that, in turn, may ultimately have a more deleterious effect on outcomes.     

Patella osteotomy for lateral retinaculum decompression in total knee arthroplasty

Background and purpose — Fast-track care programs in elective total hip and knee replacement (THR/TKR) have been introduced in several countries during the last decade resulting in a significant reduction of hospital stay without any rise in readmissions or early adverse events (AE). We evaluated the risk of readmissions and AE within 30 and 90 days after surgery when a fast-track program was introduced in routine care of joint replacement at 8 Swedish hospitals.

Patients and methods — Fast-track care programs were introduced at 8 public hospitals in Västra Götaland region from 2012 to 2014. We obtained data from the Swedish Hip and Knee Arthroplasty Registers for patients operated with THR and TKR in 2011–2015. All readmissions and new contacts with the health care system within 3 months with a possible connection to the surgical intervention were requested from the regional patient register. We compared patients operated before and after the introduction of the fast-track program.

Results — Implementation of the fast-track program resulted in a decrease in median hospital length of stay (LOS) from 5 to 3 days in both THR and TKR. The total readmission rate <90 days for THR was 7.2% with fast-track compared with 6.7% in the previous program, and for TKR 8.4% in both groups. Almost half of the readmissions occurred without any AE identified. There was no statistically significant difference concerning readmissions or AE when comparing the programs.

Interpretation — Implementation of a fast-track care program in routine care of elective hip and knee replacement is effective in reducing hospital stay without increasing the risk of readmissions or adverse events within 90 days after surgery.     

Pain threshold correlates with functional scores in osteoarthritis patients

Background and purpose — Pain sensitization may be one of the reasons for persistent pain after technically successful joint replacement. We analyzed how pain sensitization, as measured by quantitative sensory testing, relates preoperatively to joint function in patients with osteoarthritis (OA) scheduled for joint replacement.

Patients and methods — We included 50 patients with knee OA and 49 with hip OA who were scheduled for joint replacement, and 15 control participants. Hip/knee scores, thermal and pressure detection, and pain thresholds were examined.

Results — Median pressure pain thresholds were lower in patients than in control subjects: 4.0 (range: 0–10) vs. 7.8 (4–10) (p = 0.003) for the affected knee; 4.5 (2–10) vs. 6.8 (4–10) (p = 0.03) for the affected hip. Lower pressure pain threshold values were found at the affected joint in 26 of the 50 patients with knee OA and in 17 of the 49 patients with hip OA. The American Knee Society score 1 and 2, the Oxford knee score, and functional questionnaire of Hannover for osteoarthritis score correlated with the pressure pain thresholds in patients with knee OA. Also, Harris hip score and the functional questionnaire of Hannover for osteoarthritis score correlated with the cold detection threshold in patients with hip OA.

Interpretation — Quantitative sensory testing appeared to identify patients with sensory changes indicative of mechanisms of central sensitization. These patients may require additional pain treatment in order to profit fully from surgery. There were correlations between the clinical scores and the level of sensitization.     

Quadriceps muscle characteristics and subcutaneous fat assessed by ultrasound and relationship with function in patients with knee osteoarthritis awaiting knee arthroplasty

BackgroundPatients with severe knee osteoarthritis are evaluated for total knee replacement (TKR), whose main indications are persistent pain and severe functional limitations substantially affecting mobility. However, evaluation of pain intensity and functional disability is difficult to standardize.ObjectiveTo evaluate the relationship between quadriceps muscle thickness (QMT) and quality; the QMT and subcutaneous fat thickness (SFT) and QMT and function in patients with knee OA on a waiting list for TKR.MethodsCross-sectional study in consecutively-enrolled patients. Variables: SFT, QMT and rectus femoris muscle quality, assessed by echointensity (EI). Function by the Timed Up & Go Test (TUG); sociodemographic and clinical variables and physical activity were determined. Karl Pearson correlations and multiple linear regression were used.Results61 patients (45 female, mean age 69.7 years [SD 7.2], mean BMI 33.0 [SD 5.7], mean comorbidities 3.3 [SD 2.0], 52.5% regular physical activity) were studied. Mean TUG was 15.1 (SD 6.1). Variables retained in the regression model explained 36% of variability in the TUG. Greater muscle content (percentage) (r = −0,291) was associated with better TUG scores (p = 0.001). Greater muscle EI was negatively (r = −0,364) associated with function (p = 0.006). Older age was associated with worse TUG scores while regular physical activity was associated with better TUG scores (p = 0.001 and p = 0.008, respectively).ConclusionsA higher percentage of quadriceps muscle and better muscle quality (lower EI) was associated with better function. Age and exercise levels influenced function. Ultrasound may provide     

Electric toothbrush application is a reliable and valid test for differentiating temporomandibular disorders pain patients from controls

Background

Inpatient satisfaction with care is a standard indicator of the quality of care delivered during hospitalization. Total hip and knee replacement (THR/TKR) for osteoarthritis (OA) are among the most successful orthopaedic interventions having a positive impact on health-related quality of life (HRQoL). The aim was to evaluate the effect of satisfaction shortly after hospital discharge on 1-month, 6-month and 1-year Medical Outcomes Study 36-item Short Form (SF-36) scores for OA patients after THR and TKR, controlling for patient characteristics, clinical presentation and preoperative SF-36 scores.

Methods

A multicenter prospective cohort study recruited 231 patients with OA scheduled to receive THR or TKR. Satisfaction was assessed by the Patients Judgment of Hospital Quality (PJHQ) questionnaire and HRQoL by the SF-36 questionnaire. Linear models for repeated measures assessed the relation between satisfaction (scores were dichotomized) and postoperative SF-36 scores.

Results

Of 231 participants, 189 were followed up 12 months after discharge (mean age 69 SD = 8; 42.6% male). The mean length of hospital stay was 13.5 (SD = 4) days. After adjustment for preoperative SF-36 scores, sociodemographic and clinical patient characteristics, satisfied patients (PJHQ score > 70) had higher SF-36 scores 1 year after surgery than did less-satisfied patients. Admission, medical care, and nursing and daily care scores mainly predicted bodily pain, mental health, social functioning, vitality and general health scores of the SF-36.

Conclusion

Besides being a quality-of-care indicator, immediate postoperative patient satisfaction with care may bring a new insight into clinical practice, as a predictor of self-perceived health status after surgery.     

A clinician's guide to the treatment of foot burns occurring in diabetic patients

IntroductionDiabetes mellitus affects 25.8 million Americans and is predicted to almost double by 2050. The presence of diabetes complicates hospital courses because of the microvascular complications associated with disease progression. Patients with diabetes represent 18.3% of annual burn admissions to our unit and 27% have burns to the feet. The purpose of this project was to develop an evidence-based guideline for care of the patient with diabetes and foot burnsMethodsA multidisciplinary group was charged with developing an evidence-based guideline for the treatment of foot burns in patients with diabetes. Evidence was evaluated in the areas of diabetes, burn care, hyperbaric medicine, care of diabetic foot wounds and physical therapy. After guideline development and approval, key aspects were incorporated into order sets.ResultsKey aspects of this guideline are the ability to identify patients with undiagnosed diabetes, assess diabetic control, optimize glycemic and metabolic control, optimize burn wound management, treat microvascular disease, and provide education and a discharge plan. Evaluated outcomes are glycemic control, length of stay, complication rates, amputation rates, infection rates and the use of hyperbaric oxygen.ConclusionsBest outcomes for this high risk population will be attainable with an evidence based guideline.     

Functional Outcomes and Health-Related Quality of Life Before and After Primary Total Knee Replacement for Patients From Diverse Geographic Regions

BackgroundThe purpose of this study was to investigate whether patient-reported knee function and health status before and after primary total knee replacement (TKR) at an academic medical center differs among patients from diverse geographic regions.MethodsWe assessed patient-reported outcomes (PROs) as measured by the Oxford Knee Score (OKS) and EuroQoL-5D (EQ-5D) in 2855 TKR patients at preprimary and one year postprimary TKR procedure between January 1, 2012 and June 30, 2014. We compared the demographic characteristics, response rates, and changes in OKS, EQ-5D, and EQ visual analog scale among local, regional, and national patient groups. Patient- or hospital-related predictors of the postoperative scores were identified after controlling for preoperative scores on the PRO measures.ResultsLocal patients had more comorbid conditions. Groups were similar in clinical outcomes such as length of stay at hospital, complication, and reoperation rates. Local, regional, and national patients had similar response rates and reported a similar level of knee function and health-related quality of life before and after TKR. Eighty nine percent had clinically important improvement on OKS, 69% on EQ-5D index, and 28% EQ visual analog scale, and there were no differences among groups in the proportions of clinically meaningful change. Better postoperative PRO scores were associated with older age, shorter hospital stay, fewer comorbidities, nonsmoking status, fewer complications, and private health insurance.ConclusionSome patient characteristics such as comorbidities were greater in the local patient cohort versus the national cohort. Nevertheless, clinical outcomes and PROs were comparable across all geographic tiers.     

Preoperative psychosocial risk factors for poor outcomes at 1 and 5 years after total knee replacement

Background and purpose — Psychosocial factors are important risk factors for poor outcomes in the first year after total knee replacement (TKR), however their impact on long-term outcomes is unclear. We aimed to identify preoperative psychosocial risk factors for poor outcomes at 1 year and 5 years after TKR.

Patients and methods — 266 patients were recruited prior to TKR surgery. Knee pain and function were assessed preoperatively and at 1 and 5 years postoperative using the WOMAC Pain score, WOMAC Function score and American Knee Society Score (AKSS) Knee score. Preoperative depression, anxiety, catastrophizing, pain self-efficacy and social support were assessed. Statistical analyses involved multiple linear regression and mixed effect linear regression.

Results — Higher anxiety was a risk factor for worse pain at 1 year postoperative. No psychosocial factors were associated with any outcomes at 5 years postoperative. Analysis of change over time found that patients with higher pain self-efficacy had lower preoperative pain and experienced less improvement in pain up to 1 year postoperative. Higher pain self-efficacy was associated with less improvement in the AKSS up to 1 year postoperative but more improvement between 1 and 5 years postoperative.

Interpretation — Preoperative anxiety was found to influence pain at 1 year after TKR. However, none of the psychosocial variables were risk factors for a poor outcome at 5 years post­operative, suggesting that the negative effects of anxiety on outcome do not persist in the longer-term.     

Worse health-related quality of life and hip function in female patients with elevated chromium levels

Background and purpose — Blood metal ion levels can be an indicator for detecting implant failure in metal-on-metal (MoM) hip arthroplasties. Little is known about the effect of bilateral MoM implants on metal ion levels and patient-reported outcomes. We compared unilateral patients and bilateral patients with either an ASR hip resurfacing (HR) or an ASR XL total hip replacement (THR) and investigated whether cobalt or chromium was associated with a broad spectrum of patient outcomes.

Patients and methods — From a registry of 1,328 patients enrolled in a multicenter prospective follow-up of the ASR Hip System, which was recalled in 2010, we analyzed data from 659 patients (311?HR, 348 THR) who met our inclusion criteria. Cobalt and chromium blood metal ion levels were measured and a 21-item patient-reported outcome measures (PROMs) questionnaire was used mean 6 years after index surgery.

Results — Using a minimal threshold of ≥7?ppb, elevated chromium ion levels were found to be associated with worse health-related quality of life (HRQoL) (p < 0.05) and hip function (p < 0.05) in women. These associations were not observed in men. Patients with a unilateral ASR HR had lower levels of cobalt ions than bilateral ASR HR patients (p < 0.001) but similar levels of chromium ions (p = 0.09). Unilateral ASR XL THR patients had lower chromium and cobalt ion levels (p < 0.005) than bilateral ASR XL THR patients.

Interpretation — Chromium ion levels of ≥7?ppb were associated with reduced functional outcomes in female MoM patients.     

Local infiltration analgesia: a technique for the control of acute postoperative pain following knee and hip surgery: A case study of 325 patients

Background?We have developed a multimodal technique for the control of pain following knee and hip surgery, called "local infiltration analgesia" (LIA). It is based on systematic infiltration of a mixture of ropiva-caine, ketorolac, and adrenaline into the tissues around the surgical field to achieve satisfactory pain control with little physiological disturbance. The technique allows virtually immediate mobilization and earlier discharge from hospital.

Patients and methods?In this open, nonrandomized case series, we used LIA to manage postoperative pain in all 325 patients presenting to our service from Jan 1, 2005 to Dec 31,2006 for elective hip resurfacing (HRA), primary total hip replacement (THR), or primary total knee replacement arthroplasty (TKR). We recorded pain scores, mobilization times, and morphine usage for the entire group.

Results?Pain control was generally satisfactory (numerical rating scale pain score range 0–3). No morphine was required for postoperative pain control in two-thirds of the patients. Most patients were able to walk with assistance between 5 and 6 h after surgery and independent mobility was achieved 13–22 h after surgery. Orthostatic hypotension, nausea, and vomiting were occasionally associated with standing for the first time, but other side effects were unremarkable. 230 (71%) of the 325 patients were discharged directly home after a single overnight stay in hospital.

Interpretation?Local infiltration analgesia is simple, practical, safe, and effective for pain management after knee and hip surgery.     

Increased risk of revision for infection in rheumatoid arthritis patients with total hip replacements

Background and purpose — Medical treatment of rheumatoid arthritis (RA) has changed dramatically over the last 15 years, including immune modulation. We investigated the risk of revision for infection after primary total hip replacement (THR) in patients with rheumatoid arthritis over a 16-year period, and compared it with that in THR patients with osteoarthritis (OA).

Patients and methods — We identified 13,384 THRs in RA patients and 377,287 THRs in OA patients from 1995 through 2010 in a dataset from the Nordic Arthroplasty Register Association (NARA). Kaplan-Meier survival curves, with revision for infection as the endpoint, were constructed. Cox regression analyses were performed to calculate the relative risk (RR) of revision for infection adjusted for age, sex, fixation technique, and year of primary surgery.

Results — RA patients had a 1.3 times (95% CI 1.0–1.6) higher risk of revision for infection. After 2001, this risk increased more for RA patients than for OA patients. During the first 3 months and from 8 years postoperatively, the risk of revision for infection was higher in RA patients with THRs fixated with antibiotic-loaded cement than in corresponding OA patients.

Interpretation — We found a slightly higher overall risk of revision for infection in RA patients than in OA patients, but this difference was only present after 2001. In THRs with antibiotic-loaded cement, the risk of very early and late infections leading to revision was higher in RA patients than in OA patients.     

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.     

Predictors of periprosthetic fracture after total knee replacement: An analysis of 21,723 cases

Background and purpose Periprosthetic fracture is a devastating complication of total knee replacement (TKR). Most published studies have not comprehensively assessed clinical and demographic predictors. We wanted to determine the incidence and predictors of postoperative periprosthetic fracture after primary and revision TKR.

Patients and methods We used prospectively collected data in the Mayo Clinic Total Joint Registry on all patients who underwent primary or revision TKR at the Mayo Clinic, Rochester, from 1989 through 2008. We assessed incidence of postoperative periprosthetic fractures and modifiable (comorbidity, body mass index) and unmodifiable factors (age, sex, operative diagnosis, ASA class, previous cardiac disease, and previous thromboembolic disease) as predictors of postoperative periprosthetic fractures. We used multivariable-adjusted Cox regression analyses separately for primary and revision TKR.

Results 12,914 patients underwent 17,633 primary TKRs and 3,286 patients underwent 4,090 revision TKRs during the period 1989–2008. 1.1% of patients (188/17,633) after primary TKR and 2.5% of patients (104/4,090) after revision TKR sustained a postoperative periprosthetic fracture on or after postoperative day 1. Older age was associated with lower risk of periprosthetic fractures after primary TKR (p < 0.001). Compared to ≤ 60 years, risk was lower for ages 61–70 years (hazard ratio (HR) = 0.5, 95% confidence interval (CI): 0.3–0.7)) and 71–80 years (HR = 0.6, CI: 0.4–0.8), but not for age > 80 years (HR = 0.9, CI: 0.5–1.6). In revision TKR cohort, a diagnosis of non-union (HR = 4.9, CI: 1.2–20), infection (HR = 2.9, CI: 1.3–6.4) or previous surgery with components removed (HR = 2.1, CI: 1.3–3.4) increased the risk of postoperative periprosthetic fracture, compared to a diagnosis of loosening/wear/osteolysis.

Interpretation We identified significant risk factors for periprosthetic fracture after primary and revision TKR. Patients with these risk factors can be informed by their surgeons of increased risk of this uncommon, but serious complication of TKR.     

Body mass index and risk of perioperative cardiovascular adverse events and mortality in 34,744 Danish patients undergoing hip or knee replacement

Background and purpose — Obesity is a risk factor for osteoarthritis in the lower limb, yet the cardiovascular risks associated with obesity in hip or knee replacement surgery are unknown. We examined associations between body mass index (BMI) and the risk of a major adverse cardiovascular event (MACE: ischemic stroke, acute myocardial infarction, or cardiovascular death) or the risk of all-cause mortality in a nationwide Danish cohort of patients who underwent primary hip or knee replacement surgery.

Methods — Using Danish nationwide registries, we identified 34,744 patients aged ≥ 20 years who underwent elective primary hip or knee replacement surgery between 2005 and 2011. We used multivariable Cox regression models to calculate the 30-day risks of MACE and mortality associated with 5 BMI groups (underweight (BMI < 18.5 kg/m²), normal weight (18.5–24 kg/m²), overweight (25–29 kg/m²), obese 1 (30–34 kg/m²), and obese 2 (≥ 35 kg/m²)).

Results — In total, 232 patients (0.7%) had a MACE and 111 (0.3%) died. Compared with overweight, adjusted hazard ratios (HRs) were 1.2 (95% CI: 0.4–3.3), 1.3 (0.95–1.8), 1.6 (1.1–2.2), and 1.0 (0.6–1.9) for underweight, normal weight, obese 1, and obese 2 regarding MACE. Regarding mortality, the corresponding HRs were 7.0 (2.8–15), 2.0 (1.2–3.2), 1.5 (0.9–2.7), and 1.9 (0.9–4.2). Cubic splines suggested a significant U-shaped relationship between BMI and risks with nadir around 27–28.

Interpretation — In an unselected cohort of patients undergoing elective primary hip or knee replacement surgery, U-shaped risks of perioperative MACE and mortality were found in relation to BMI. Patients within the extreme ranges of BMI may warrant further attention.     

Risk factors for perioperative hyperglycemia in primary hip and knee replacements

Background and purpose — Perioperative hyperglycemia has been associated with adverse outcomes in several fields of surgery. In this observational study, we identified factors associated with an increased risk of hyperglycemia following hip and knee replacement.

Patients and methods — We prospectively monitored changes in glucose following primary hip and knee replacements in 191 patients with osteoarthritis. Possible associations of patient characteristics and operation-related factors with hyperglycemia (defined as glucose > 7.8 mmol/L in 2 consecutive measurements) and severe hyperglycemia (glucose > 10 mmol/L) were analyzed using binary logistic regression with adjustment for age, sex, operated joint, and anesthesiological risk score.

Results — 76 patients (40%) developed hyperglycemia, and 48 of them (25% of the whole cohort) had severe hyperglycemia. Glycemic responses were similar following hip replacement and knee replacement. Previously diagnosed diabetes was associated with an increased risk of hyperglycemia and severe hyperglycemia, compared to patients with normal glucose metabolism, whereas newly diagnosed diabetes and milder glucose metabolism disorders had no effect. In patients without previously diagnosed diabetes, increased values of preoperative glycosylated hemoglobin (HbA1c) and fasting glucose on the day of operation were associated with hyperglycemia. Higher anesthesiological risk score—but none of the operation-related factors analyzed—was associated with an increased risk of hyperglycemia.

Interpretation — Perioperative hyperglycemia is common in primary hip and knee replacements. Previously diagnosed diabetes is the strongest risk factor for hyperglycemia. In patients with no history of diabetes, preoperative HbA1c and fasting glucose on the day of operation can be used to stratify the risk of hyperglycemia.     

Changes in load-bearing area after Ganz periacetabular osteotomy

Background and purpose?Implant dislocation is one of the commonest complications following primary total hip replacement (THR). We investigated the effect of body mass index (BMI) and tobacco use on the risk of this complication.

Subjects and methods?Through linkage between the Swedish Construction Workers’ cohort and the Swedish Inpatient Register, 2,106 male patients who had undergone primary THR between 1997 and 2004 were identified. We used Cox multivariable regression analysis to study the association between BMI and tobacco use and the risk of implant dislocation.

Results?53 patients (2.5%) developed implant dislocation during a mean of 2 (0–3) years of follow-up. We found overweight and obesity to be associated with increased risk of implant dislocation (HR = 2.5,95% CI: 1.1–5.5 and HR = 3.7, 95% CI: 1.5–9.3, respectively as compared to those of normal weight). There was no statistically significant association between tobacco use and the risk of dislocation.

Interpretation?Greater attention should be given to high BMI as a risk factor for implant dislocation following THR.