Ten-year risk of complication and mortality after total hip arthroplasty in morbidly obese patients: a population study

Background: The relationship between morbid obesity and long-term patient outcomes after primary total hip arthroplasty (THA) has been understudied. The purpose of this study was to determine the association between morbid obesity and 10-year complications (revision surgery, reoperation, dislocation) and mortality in patients undergoing primary THA. Methods: We conducted a population-based cohort study of patients aged 45­74 years who underwent primary THA for osteoarthritis between 2002 and 2007 using Ontario administrative health care databases. Patients were followed for 10 years. We estimated risk ratios (RRs) of mortality, reoperation, revision and dislocation in patients with body mass index (BMI) greater than 45 kg/m2 (morbidly obese patients) compared with patients with a BMI of 45 kg/m2 or less (nonmorbidly obese patients). Results: There were 22 251 patients in the study cohort, of whom 726 (3.3%) were morbidly obese. Morbid obesity was associated with higher 10-year risk of death (RR 1.38, 95% confidence interval [CI] 1.18­1.62). Risks of revision (RR 1.43, 95% CI 0.96­2.13) and dislocation (RR 2.38, 95% CI 1.38­4.10) were higher in morbidly obese men than in nonmorbidly obese men; there were no associations between obesity and revision or dislocation in women. Risk of reoperation was higher in morbidly obese women than in nonmorbidly obese women (RR 1.59, 95% CI 1.05­2.40); there was no association between obesity and reoperation in men. Conclusion: Morbidly obese patients undergoing primary THA are at higher risk of long-term mortality and complications. There were differences in complication risk by sex. The results of this study should inform perioperative counselling of patients considering THA.

Contexte: Le lien entre l'obésité morbide et les issues à long terme des patients ayant subi une arthroplastie totale primaire de la hanche (ATH) est sous-étudié. Cette étude visait à caractériser l'association entre l'obésité morbide et les complications (chirurgie de révision, réintervention, dislocation) et la mortalité sur 10 ans chez les patients ayant subi une ATH. Méthodes: Nous avons mené une étude de cohorte basée sur la population auprès de patients de 45 à 74 ans atteints d'arthrose ayant subi une ATH primaire entre 2002 et 2007 en utilisant les bases de données administratives en santé de l'Ontario. Les patients ont été suivis pour une période de 10 ans. Nous avons estimé des rapports de risque (RR) pour la mortalité, la réintervention, la chirurgie de révision et la dislocation chez les patients ayant un indice de masse corporelle (IMC) de plus de 45 kg/m2 (obésité morbide) en comparaison avec les patients ayant un IMC de 45 kg/m2 ou moins. Résultats: L'étude de cohorte comptait 22 251 patients, dont 726 (3,3 %) étaient atteints d'obésité morbide. L'obésité morbide a été associée à un risque de mortalité sur 10 ans accru (RR 1,38; intervalle de confiance [IC] de 95 % 1,18­1,62). Le risque de chirurgie de révision (RR 1,43; IC de 95 % 0,96­2,13) et de dislocation (RR 2,38; IC de 95 % 1,38­4,10) était plus élevé chez les hommes atteints d'obésité morbide que chez les autres hommes; aucune association n'a été observée entre l'obésité et la chirurgie de révision ou la dislocation chez les femmes. Par contre, le risque de réintervention était accru chez les femmes atteintes d'obésité morbide (RR 1,59; IC de 95 % 1,05­2,40), mais aucune association n'a été établie entre l'obésité et la réintervention chez les hommes. Conclusion: Les patients atteints d'obésité morbide qui subissent une ATH primaire courent un risque plus élevé de complications et de mortalité à long terme. Des différences ont été observées dans les risques de complications selon le sexe. Les résultats de cette étude devraient guider l'offre de conseils aux patients qui envisagent l'ATH.

Implementation of a novel night float call system: resident satisfaction and quality of life.

BACKGROUND: Compliance with Professional Association of Internes and Residents of Ontario duty hour guidelines has been problematic at our institution. To facilitate orthopedic residents' ability to go home postcall without significant disruption of ongoing clinical activities, a novel call system was adopted at our tertiary care centre. We sought to evaluate the satisfaction and quality of life of orthopaedic residents with that system. METHODS: We administered questionnaires to on-service residents. These included the Short Form-36 questionnaire and others addressing topics including education, stress, work-related problems and miscellaneous concerns. RESULTS: Seventeen residents were surveyed: 6 who had just completed a night float rotation, and 11 who were on a regular orthopedic service rotation while the night float system was in place. Quality of life was similar between residents on the night float block and those on the standard rotation; it was also similar to age-matched Canadian normative data. Eighty-nine percent of residents agreed that the presence of the night float rotation improved their quality of life on standard rotations, and 100% felt that their education was improved on standard rotations by having the night float system in place. CONCLUSION: This call system results in improved resident quality of life and widespread overall satisfaction, and may be considered as a viable alternative to traditional call formats. Follow-up data as more residents experience the night float block will be valuable.

CONTEXTE: La conformité aux lignes directrices de l'Association professionnelle des résidents et internes de l'Ontario en matière d'horaires de travail pose un problème dans notre établissement. Pour permettre aux résidents en orthopédie de retourner plus facilement à la maison après un appel, sans nuire significativement aux activités cliniques en cours, notre établissement de soins tertiaires s'est doté d'un nouveau système d'appel. Nous avons voulu mesurer la satisfaction des résidents en orthopédie à l'endroit de ce système et évaluer leur qualité de vie. MÉTHODES: Nous avons administré des questionnaires aux résidents de garde, incluant le questionnaire SF-36 (Short Form-36) et d'autres questionnaires sur la formation, le stress, les problèmes liés au travail et diverses autres questions. RÉSULTATS: Dix-sept résidents ont répondu aux questionnaires : 6 venaient de terminer leur garde dans une équipe de nuit et 11 travaillaient selon l'horaire régulier de l'orthopédie pendant que le système de garde de nuit était en place. La qualité de vie a été similaire entre les résidents de l'équipe de garde de nuit et ceux qui suivaient l'horaire régulier; elle s'est également révélée similaire en comparaison avec des données canadiennes assorties selon l'âge. Quatre-vingt-neuf pour cent des résidents se sont dits d'avis que la présence de l'équipe de nuit améliorait leur qualité de vie lors de leurs gardes régulières et 100 % ont estimé que leur formation se trouvait améliorée lors des gardes régulières du fait que le système de garde de nuit était en place. CONCLUSION: Ce système d'appel entraîne une amélioration de la qualité de vie des résidents qui s'en disent globalement satisfaits et pourrait être considéré comme une solution de rechange viable aux types de gardes habituels. À mesure que d'autres résidents participeront à l'équipe de nuit, des données de suivi se révéleront utiles.

Determining patient concerns before joint arthroplasty.

Despite the prevalence of studies relating to hip and knee arthroplasties, no Canadian studies exist in the literature regarding patients' perceptions and concerns prior to undergoing these procedures. A 32-question, 5-point Likert scale questionnaire was developed and administered to a Canadian cohort. One hundred fifty-six knee and 85 hip arthroplasty patients returned the survey. Results consistently showed complications arising from surgery, ways to reduce pain after surgery, and ability to walk properly again as the 3 top concerns for patients whether stratified by age, sex, residential status or joint replacement type. Other results discussed include resources used by patients to become better informed about joint arthroplasty, differences in Western Ontario and McMaster Universities Index of Osteoarthritis scores between groups, and significant differences in patient concerns as determined by ridit analyses.

Role of the advanced practice physiotherapist in decreasing surgical wait times.

The role of the advanced practice physiotherapist (APP) in outpatient orthopedic clinics has been present in Ontario for over five years. These professionals have additional duties beyond those of a regular physiotherapist in order to screen patients pre- and post-operatively, triage patients for surgery, prescribe conservative management and monitor patients on an ongoing basis. The purpose of this role is to improve patient access to timely surgical care by reducing wait times for hip and knee replacement surgeries. Several positive outcomes have been reported in the literature. It has been established that an APP can effectively manage over 30% of the patients referred to a surgeon for hip or knee replacement surgery because these patients do not require surgery; rather, they require conservative management.

Easing the burden for joint replacement wait times: the role of the expanded practice physiotherapist.

There is a critical shortage of orthopedic surgeons in Canada today due to a decreasing number of surgeons practising here and the increased demand for their services from a population with record-high rates of osteoarthritis and obesity. A method of managing the increased demand for total joint replacement was implemented and evaluated. A physiotherapist and orthopedic surgeons performed assessments on patients referred for surgery and found that 34% did not require surgery and that all patients required appropriate conservative management. This has led to the development and implementation of a model of care that not only meets orthopedic demands but improves treatment options for orthopedic patients.

Reducing hip and knee replacement wait times: an expanded role for physiotherapists in orthopedic surgical clinics.

This paper describes a research project that examined an expanded role for physiotherapists to provide pre- and post-operative consultation to patients with hip and knee complaints with the overall goal to save the surgeon's time and improve patient throughput, thereby reducing wait times.

Influence of obesity on outcome after knee arthroscopy.

PURPOSE: To compare the clinical outcomes in overweight women with those of a group of normal-weight women 4 to 11 years after arthroscopic debridement of the knee. METHODS: A questionnaire containing the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the short form health survey SF-36, and a survey regarding satisfaction with surgery was mailed to 121 patients. Questionnaire data were supplemented by chart review. RESULTS: Ninety patients (74%) returned completed questionnaires. All scored significantly lower than age-matched normative data on all domains of the SF-36. The normal-weight group had better scores than the obese group, particularly in the physical functioning ( P =.01), role physical ( P =.05), mental health ( P =.11), and role emotional ( P =.11) domains. They were also more satisfied with their surgery ( P <.05), more likely to indicate that they would have the surgery again, and had fewer recurrences of knee pain ( P <.05). CONCLUSIONS: Overweight women have poorer outcomes related to quality of life and satisfaction with surgery than normal-weight women. LEVEL OF EVIDENCE: Level III, Case control study.

Estimating the density of femoral head trabecular bone from hip fracture patients using computed tomography scan data.

The purpose of this study was to compare computed tomography density (ρCT ) obtained using typical clinical computed tomography scan parameters to ash density (ρash ), for the prediction of densities of femoral head trabecular bone from hip fracture patients. An experimental study was conducted to investigate the relationships between ρash and ρCT and between each of these densities and ρbulk and ρdry . Seven human femoral heads from hip fracture patients were computed tomography-scanned ex vivo, and 76 cylindrical trabecular bone specimens were collected. Computed tomography density was computed from computed tomography images by using a calibration Hounsfield units-based equation, whereas ρbulk, ρdry and ρash were determined experimentally. A large variation was found in the mean Hounsfield units of the bone cores (HUcore) with a constant bias from ρCT to ρash of 42.5 mg/cm3. Computed tomography and ash densities were linearly correlated (R 2 = 0.55, p < 0.001). It was demonstrated that ρash provided a good estimate of ρbulk (R 2 = 0.78, p < 0.001) and is a strong predictor of ρdry (R 2 = 0.99, p < 0.001). In addition, the ρCT was linearly related to ρbulk (R 2 = 0.43, p < 0.001) and ρdry (R 2 = 0.56, p < 0.001). In conclusion, mineral density was an appropriate predictor of ρbulk and ρdry , and ρCT was not a surrogate for ρash . There were linear relationships between ρCT and physical densities; however, following the experimental protocols of this study to determine ρCT , considerable scatter was present in the ρCT relationships.

A comparison of plate versus staple-and-cast fixation in maintaining femoral tibial alignment after valgus tibial osteotomy.

PURPOSE: To compare 2 methods of fixation for maintenance of alignment during healing of valgus tibial osteotomies. METHODS: We performed a retrospective chart and radiographic review of valgus tibial osteotomy cases of staple fixation supplemented by a postoperative cast and of blade plate fixation for maintenance of femoral-tibial alignment during healing of the osteotomy. RESULTS: Both groups (staple-and-cast, n = 16; plate, n = 28) were similar in terms of age, preoperative alignment, extent of osteoarthritis and degree of intra-operative correction. Between-group differences in the maintenance of femoral-tibial alignment during healing were not significant. In both groups there was a strong correlation between degree of bone contact at the osteotomy site and maintenance of alignment (p < 0.005). In cases done with the plate, 90% of osteotomies with good or excellent bone contact maintained alignment during healing; with poor or fair bone contact, 75% had loss of alignment > 5 degrees during healing. There was a trend toward a greater incidence of delayed or non-union with plate fixation compared with staple fixation that did not reach statistical significance. All of these cases of delayed/non-union had loss of femoral-tibial alignment > 5 degrees during healing. CONCLUSION: As a result of this study, we have modified our surgical technique. We now use intra-operative fluoroscopy for optimization of bone contact, and we have reverted to the less invasive staple method for fixation of tibial osteotomies.

Repeatability of a novel technique for in vivo measurement of three-dimensional patellar tracking using magnetic resonance imaging.

PURPOSE: To determine the repeatability of a novel noninvasive MRI-based technique for measuring patellofemoral kinematics in vivo. MATERIALS AND METHODS: The patellar kinematics measurement method relies on registering bone models (with associated coordinate systems) developed from a high resolution MRI scan to loaded bone positions derived from fast, low resolution MRI scans. The intrasubject variability, high resolution to low resolution registration error, and interexperimenter repeatability were quantified in experiments on three healthy subjects. RESULTS: The intrasubject variability and registration error were within range of the accuracy of our procedure; specifically, less than or equal to 1.40 degrees for orientation and 0.81 mm for translation. The interexperimenter repeatability was less than or equal to 1.28 degrees for orientation, with the exception of patellar spin, and 0.68 mm for translation. CONCLUSION: Our novel measurement technique can measure three-dimensional patellar tracking noninvasively during loaded flexion in a repeatable manner. Our results compare well to another noninvasive tracking protocol, fast phase-contrast MRI, which has a reported subject interexam variability of 2.4 degrees or less for patellar orientation. A particular strength of our method is that axes and high-resolution bone models need only be determined once for intrasubject comparisons. The method is sufficiently accurate and repeatable to detect clinically significant changes in patellofemoral kinematics.

Incidence of undiagnosed sleep apnea in patients scheduled for elective total joint arthroplasty.

We investigated the frequency of undiagnosed sleep apnea in patients scheduled for elective total joint arthroplasty. Two hundred fifty-four patients were assessed between September 1999 and May 2001. At intake, patients were given a standard systems review with the addition of targeted questions about sleep apnea. Ten patients reported symptoms consistent with undiagnosed obstructive sleep apnea (OSA). The identification of undiagnosed OSA is an issue for orthopedic practice because many patients referred to an arthroplasty service for hip and/or knee surgeries are obese. A few screening questions, readily incorporated into the preoperative assessment, may prevent perioperative complications such as postextubation airway obstruction, negative pressure pulmonary edema, or opioid-induced airway obstruction.