Relationship of body mass index to early complications in hip replacement surgery : study performed at Hinchingbrooke Hospital, Orthopaedic Directorate, Huntingdon, Cambridgeshire

Relationship between Body Mass Index and Complications during the First 45 Days after Primary Total Hip and Knee Replacement: A Single-Center Study from South America

Background

The goal of this study was to evaluate the relationship between body mass index (BMI) and early complications of total hip replacement (THR) and total knee replacement (TKR).

Methods

This is a retrospective study of patients who underwent primary THR and TKR between January 2011 and December 2015. We included patients between 18 and 90 years of age with BMI less than 40 kg/m² with a minimal postoperative follow-up time of 45 days. The primary outcomes were the presence of infection, mechanical complications (dislocation, fractures, arthrofibrosis, or neuropraxia), and thromboembolic events. Overweight and obesity were defined as a BMI of 25-29.9 kg/m² and ≥ 30 kg/m², respectively.

Results

In total 750 patients were included (THR, 268; TKR, 482) with a mean age of 65.0 ± 12.4 years. The percentage of patients with normal weight, overweight, and obesity was 24.9% (n = 187), 41.7% (n = 313), and 33.4% (n = 250), respectively. The early complication rate was 8.9% (95% confidence interval [CI], 7.1% to 11.2%). Infection and mechanical complications were most prevalent. There was no statistically significant relationship between the incidence of complications and BMI (obesity vs. normal weight: hazard ratio [HR], 1.49; 95% CI, 0.72 to 3.06; p = 0.282); however, there was a tendency toward a greater risk of infectious complications in the patients with obesity (HR, 6.08; 95% CI, 0.75 to 49.16; p = 0.090). Patients with diabetes mellitus (DM) had more risk of infectious complications than those without DM (HR, 2.60; 95% CI, 1.00 to 6.79).

Conclusions

There was no statistical relationship between BMI and early complications of THR and TKR. Nonetheless, there was a tendency toward a higher risk of infection in patients with some degree of obesity.

The impact of body mass index on metatarsalgia surgical outcomes

INTRODUCTION

Several studies have suggested that an increased body mass index (BMI) is a negative factor for forefoot plantar pain but its influence in the surgical correction of metatarsalgia is unknown. The purpose of the present study is to evaluate the influence of the BMI on the surgical outcomes of metatarsalgia. It has been hypothesized that the higher the BMI, the worse the functional outcomes after metatarsalgia surgical treatment at one year follow-up.

MATERIAL AND METHODS

A prospective cohort study that included all patients operated on for third rocker metatarsalgia was conducted. Weil's osteotomy was performed on all the patients operated on. The patients' pre-operative height, weight, and BMI were recorded. The patients were subsequently divided into three groups based on their BMI. There was group 1 or the normal group (18.5 > BMI ≤ 25 kg/m2), group 2 or the overweight group (25 > BMI ≤ 30 kg/m2), and group 3 or the obese group (BMI > 30 kg/m2). Pre-operative, post-operative, and differential AOFAS were used to evaluate and compare the groups. The post-operative VAS was also measured to assess pain. The correlation between the BMI and those variables was also analyzed.

RESULTS

After the exclusion criteria were applied, 107 patients were finally assessed. There were 22 patients (20.6%) in group 1, 52 patients (48.6%) in group 2, and 33 patients (30.8%) in group 3. No correlation was observed between the BMI and AOFAS (p > 0.05). Neither were any differences found when the three groups were compared (p > 0.05). Moreover, no correlation between the BMI and the VAS score was observed (p = 0.690).

CONCLUSION

Obesity does not negatively influence functional outcomes after surgery for metatarsalgia in short to medium term. Regardless of their BMI, patients with propulsive metatarsalgia improve in functionality after surgical treatment.

Correlation Between Hip Arthroscopy Outcomes and Preoperative Anesthetic Hip Joint Injections, MR Arthrogram Imaging Findings, and Patient Demographic Characteristics

OBJECTIVE

The purpose of this study is to determine whether the preoperative response to intraarticular hip anesthetic injection correlates with the outcome of hip arthroscopy. A secondary aim is to determine whether the outcome of arthroscopy correlates with intraarticular pathologic findings or patient demographic characteristics.

MATERIALS AND METHODS

Ninety-three patients who underwent MR arthrography (MRA), preoperative injections of anesthetic into the hip joint (with pain scores documented), and subsequent hip arthroscopy (with a modified Harris Hip Score [mHHS] determined at 1 year after arthroscopy) were included in the study. MRA images and surgery reports were retrospectively reviewed to identify information about labral tear type and size and cartilage damage grade. The correlation between the response to hip anesthetic injection (defined as poor [0-30% improvement], moderate [31-60% improvement], or good [61-100% improvement]) and the surgical outcome (poor, fair, or good, as determined on the basis of the mHHS or the need for repeat surgery) was evaluated using the Fisher exact test. Univariate analysis (performed using the Fisher exact test) and multivariate analysis (performed using ANOVA) of correlations with age, sex, body mass index (BMI [weight in kilograms divided by the square of height in meters]), the interval between injection and surgery, labral tear type and size, and cartilage damage grade were also performed.

RESULTS

Comparison of the response to preoperative hip anesthetic injection with the outcome of arthroscopy at 1 year indicated no statistically significant association (p = 0.59). The BMI of the patient, however, was statistically significantly associated with surgical outcome (p = 0.03), with a BMI of less than 25 denoting a higher likelihood of a good surgical outcome. No statistically significant correlations were noted in analyses of surgical outcomes and patient age (p = 0.31) and sex (p = 0.83); the interval between injection and surgery (p = 0.28); labral tear type, as determined by MRA (p = 0.34) and arthroscopy (p = 0.47); labral tear size, as determined by MRA (p = 0.34); and cartilage grade, as determined by MRA (p = 0.58) and arthroscopy (p = 0.26).

CONCLUSION

No positive or negative correlation was noted between the response to preoperative hip anesthetic injection and the outcome at 1 year after hip arthroscopy. Only BMI was shown to correlate with the surgical outcome.

The influence of obesity on primary total hip arthroplasty outcomes: A meta-analysis of prospective cohort studies

BACKGROUND

Whether or not, obesity negatively influencing the outcomes of primary total hip arthroplasty (THA) remains a controversial issue. Though observational studies focused on this topic, the reported conclusions remain inconsistent. Therefore, we performed a meta-analysis of prospective cohort studies to evaluate if obesity negatively affects: (1) the overall complication rate (incidence of dislocation, deep infection and osteolysis); (2) functional outcome; (3) operative time and stay duration in hospital for the primary THA.

METHODS

We searched the PubMed, Embase, Web of Science, and the Cochrane Library until July 2014 to identify the eligible prospective studies. The Newcastle Ottawa Scale (NOS) was used for quality assessment of the included studies. We extracted and pooled the data. As for continuous data, mean difference (MD) was calculated; for dichotomous variables, we calculated a weighted relative risk (RR) with its 95% confidence interval. Heterogeneity was evaluated using I(2) statistics. P ≤ 0.05 was thought to be significant.

RESULTS

Fifteen studies were eligible for data extraction, which involved 11,271 total hip arthroplasties. The pooled data of complication rate demonstrated that obese patients suffered higher rates of complication (RR: 1.68, 95% CI 1.23 to 2.30, P = 0.0004), dislocation (RR: 2.08, 95% CI 1.54 to 2.81, P < 0.0001) and deep infection (RR: 2.92, 95% CI 0.74 to 11.49, P = 0.13). For the functional result, obese patients acquired relatively lower Harris Hip Score than non-obese patients (MD: -2.75, 95% CI -4.77 to -0.6), no difference was found regarding Oxford Hip Score (MD: -0.46, 95% CI -2.18 to 1.26, P = 0.60). Obese patients compared to non-obese patients showed an increase duration of operation (MD: 10.67, 95% CI 3.00 to 18.35, P = 0.006). However, no significant difference was found in the length of stay in hospital between obese and non-obese patients (MD: -0.16, 95% CI -0.34 to 0.02, P = 0.08).

CONCLUSIONS

This meta-analysis of prospective cohort studies demonstrates that obesity negatively influences the overall complication rate, dislocation rate, functional outcome and operative time of primary total hip arthroplasty.

Incidence of acute kidney injury following total joint arthroplasty: a retrospective review by RIFLE criteria

Background

Total joint arthroplasty (TJA) is a common procedure with demand for arthroplasties expected to increase exponentially. Incidence of acute kidney injury (AKI) following TJA is reportedly low, with most studies finding an incidence of <2%, increasing to 9% when emergency orthopaedic patients are included.

Methods

Retrospective medical record review of consecutive primary, elective TJA procedures was undertaken at a large tertiary hospital (Alfred). Demographic, peri-operative and post-operative data were recorded. Factors associated with AKI (based on RIFLE criteria) were determined using multiple logistic regression.

Results

Between January 2011 and June 2013, 425 patients underwent TJA; 252 total knee replacements (TKR) and 173 total hip replacements (THR). Sixty-seven patients (14.8%) developed AKI, including 51 TKR. Factors associated with AKI (adjusting for known confounders) include increasing body mass index [adjusted odds ratio (AOR) 1.14; 95% CI: 1.07, 1.21], older age (AOR 1.07; 95% CI 1.02, 1.13) and lower pre-operative glomerular filtration rate (AOR 0.97; 95% CI 0.96, 0.99) and taking angiotensin-converting enzyme inhibitors (AOR 2.70; 95% CI 1.12, 6.48) and angiotensin-II receptor blockers (AOR 2.64; 95% CI 1.18, 5.93). In most patients, AKI resolved by discharge, however, only 62% of patients had renal function tests after discharge.

Conclusions

This study showed a rate of AKI of nearly 15% in our TJA population, substantially higher than previously reported. Given that AKI and long-term complications are associated, prospective research is needed to further understand the associated factors and predict those at risk of AKI. There may be opportunities to maximize the pre-operative medical management and mitigate risk.

Does preoperative American Society of Anesthesiologists score relate to complications after total shoulder arthroplasty?

BACKGROUND

For hip and knee arthroplasties, an American Society of Anesthesiologists (ASA) score greater than 2 is associated with an increased risk of medical and surgical complications. No study, to our knowledge, has evaluated this relationship for total shoulder arthroplasty (TSA) or reverse total shoulder arthroplasty (reverse TSA).

QUESTIONS/PURPOSES

We aimed to assess the relationship between the ASA score and (1) surgical complications, (2) medical complications, and (3) hospitalization length after TSA, reverse TSA, and revision arthroplasty.

METHODS

We retrospectively analyzed all patients who had undergone TSAs, reverse TSAs, or revision arthroplasties by the senior author (EGM) from November 1999 through July 2011 who had at least 6 months' followup. Of the 485 procedures, 452 (93.2%) met the inclusion criteria. Data were collected on patient demographics, comorbidities, hospitalization length, and short-term (≤ 6 months) medical and surgical complications. Logistic regression analysis modeled the risk of having postoperative complications develop as a function of the ASA score.

RESULTS

Patients with an ASA score greater than 2 had a greater risk of having a surgical complication develop (p < 0.001; OR, 2.27; 95% CI, 1.36-3.70) and three times the risk of prosthesis failure (ie, component dislocation, component loosening, and hardware failure) (p < 0.001; OR, 3.23; 95% CI, 1.54-6.67). Higher ASA scores were associated with prolonged length of hospitalization (effect size 0.46, p < 0.001), but not medical complications.

CONCLUSIONS

ASA score is associated with surgical, but not medical, complications after TSA and reverse TSA. The ASA score could be used for risk assessment and preoperative counseling.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Functional outcome of primary hamstring anterior cruciate ligament reconstruction in patients with different body mass index classes

PURPOSE

We compared functional outcomes after primary hamstring-graft anterior cruciate ligament (ACL) reconstruction in patients with different body mass index (BMI) classes.

METHODS

Functional outcomes after ACL reconstruction were measured using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Lysholm score. The procedures were carried out by a single surgeon between 2001 and 2009 in 2 groups of patients with different BMI classes: a normal-BMI group (BMI 18.5 to 24.9) and a high-BMI group (BMI ≥ 25), with a minimum of 2 years' follow-up. Rolimeter readings for ligament laxity as well as complications between the 2 groups were also analyzed.

RESULTS

A total of 92 patients were reviewed, with the normal-BMI group consisting of 49 patients, whereas there were 43 patients in the high-BMI group. There were no significant differences between the groups in any of the preoperative and postoperative scores or ligament laxity. Both groups showed comparable clinically significant improvement in their postoperative scores compared with their preoperative scores. Patients in the high-BMI group had a slightly increased postoperative complication rate when compared with the normal-BMI group.

CONCLUSIONS

Primary hamstring ACL reconstruction is an effective treatment option in patients irrespective of preoperative BMI. High BMI does not adversely affect functional outcomes as measured by the KOOS and Lysholm scores up to and at 2 years postoperatively, and these patients benefit in a manner comparable to that of patients with normal BMI.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

American Society of Anesthesiologist Physical Status score may be used as a comorbidity index in hip fracture surgery

Comorbidities affect outcome, but there is no consensus which comorbidity instrument is best in orthopedic surgery. We assessed whether the American Society of Anesthesiologists Physical Status score (ASA) predicts long-term mortality after hip fracture. We followed 1635 patients for 5 to 10 years after operative treatment of hip fracture. Unadjusted Kaplan-Meyer statistics indicated that the overall survival of the patients was 4.7 (95% confidence interval [CI], 4.5-4.9) years, but survival varied significantly between the ASA groups. Survival for ASA 1 was 8.5 years (95% CI, 7.8-9.2); for ASA 2, it was 5.6 years (95% CI, 5.3-5.9); for ASA 3, it was 3.5 years (95% CI, 3.2-3.7); and for ASA 4, survival was 1.6 years (95% CI, 1.0-2.1). The ASA predicts long-term mortality after hip fracture treatment.

Accuracy of computer navigation for acetabular component placement in THA

The accuracy and precision of any computer-aided surgical device is critical to its utility. We asked the following question: how accurate and precise are the values measured by an imageless computer navigation system as compared with those measured using postoperative CT scans? Twenty-five patients (26 hips) underwent primary THA using an imageless computer navigation system for placement of the acetabular component. Inclination and anteversion were measured in the operative coordinate system as defined by Murray. Accuracy, precision, and bias were computed, and Bland-Altman analysis was used to assess levels of agreement. The accuracy (mean +/- standard deviation of the absolute difference between computer-assisted navigation and CT) was 1.8 degrees +/- 1.2 degrees for inclination and 2.0 degrees +/- 2.0 degrees for anteversion. Precision was 3.4 degrees for inclination and 5.5 degrees for anteversion. Bias was 0.52 degrees for inclination and 0.35 degrees for anteversion. Limits of agreement were 4.26 degrees for inclination and 5.58 degrees for anteversion. An imageless computer navigation system can precisely determine acetabular cup position.