Knee biomechanics variability before and after total knee arthroplasty: an equality of variance prospective study

This study evaluated gait variability in patients before and after total knee arthroplasty (TKA) using the equality of variance method to determine where variability differences occur in the movement cycle. Twenty-eight patients underwent TKA with cruciate-sacrificed implants. Patients underwent motion analysis which measured knee biomechanics as they walked overground at their preferred pace before and 12 months after TKA. Equality of variance results were compared with 14 healthy controls of similar age. Before surgery, patients had reduced knee extension moment variability throughout the early stance phase (4-21% gait cycle, p < 0.05) compared to controls. Knee power variability was lower preoperatively compared to controls for most of the stance phase (0-13% and 17-60% gait cycle, p < 0.05). Sagittal knee moment and power variability further decreased following TKA. Knee extension moment variability was lower postoperatively throughout stance phase compared to preoperatively (4-22% and 36-60% gait cycle, p < 0.05) and compared to controls (4-30% and 45-60% gait cycle, p < 0.05). Knee power variability remained lower following TKA throughout stance phase compared to preoperatively (10-24% and 36-58% gait cycle, p < 0.05) and controls (3-60% gait cycle, p < 0.05). TKA patients may be less stable, and this may be in part due to an unresolved adaptation developed while awaiting TKA surgery and the cruciate sacrificing design of the implants utilized in this study.

Surgeon-Performed Intraoperative Peripheral Nerve Blocks and Periarticular Infiltration During Total Hip and Knee Arthroplasty: A Critical Analysis Review

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Surgeon-performed intraoperative peripheral nerve blocks may improve operating room efficiency and reduce hospital resource utilization and, ultimately, costs. Additionally, these blocks can be safely performed intraoperatively by most orthopaedic surgeons, while only specifically trained physicians are able to perform ultrasound-guided peripheral nerve blocks.

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IPACK (infiltration between the popliteal artery and capsule of the knee) blocks are at least noninferior to periarticular infiltration when combined with an adductor canal block for analgesia following total knee arthroplasty.

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Surgeon-performed intraoperative adductor canal blocks are technically feasible and offer reliable anesthesia comparable with ultrasound-guided blocks performed by anesthesiologists. While clinical studies have shown promising results, additional Level-I studies are required.

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A surgeon-performed intraoperative psoas compartment block has been described as a readily available and safe technique, although there is some concern for femoral nerve analgesia, and temporary sensory changes have been reported.

Patellar maltracking: an update on the diagnosis and treatment strategies

Patellar maltracking occurs as a result of an imbalance in the dynamic relationship between the patella and trochlea. This is often secondary to an underlying structural abnormality. The clinical evaluation can provide useful clues for the presence of such entity; however, the diagnosis can often be challenging especially in the absence of a documented history of patellar dislocation. Imaging, particularly MRI, can detect subtle features that could lead to the diagnosis, probably even more importantly when there is no clear history of patellar dislocation or before its development. This can provide a road map for formulating a treatment strategy that would be primarily aimed at stabilizing the patellofemoral joint to halt or slow the progression of articular cartilage loss. The purpose of this article is to discuss the clinical and radiologic evaluation of patellar maltracking providing an update on the cross-sectional imaging assessment and also a synopsis of the management options.

Predicting hospital length of stay and short-term function after hip or knee arthroplasty: are both performance and comorbidity measures useful?

PURPOSE

Variations in hospital length of stay (LOS) and function are present after hip or knee arthroplasty. Comorbidity and performance measures have been associated with post-operative outcomes. It is however not known if both independently contribute to outcome prediction. The objective of this study was to evaluate the combined predictive ability of comorbidity scores (American Society of Anesthesiologists classification system (ASA), Charlson comorbidity index (CCI), 2008 version of the CCI (CCI08)) and a performance measure (Timed-Up-and-Go (TUG)) on LOS and short-term function in patients undergoing knee or hip arthroplasty.

METHODS

One hundred eight patients undergoing hip or knee arthroplasty were assessed preoperatively with the ASA, CCI, CCI08, and TUG. LOS was determined through administrative data. The Older Americans Resources and Services ADL questionnaire (OARS) was used to assess function two and six weeks after surgery. Logistic regression was used to assess the relationship between pre-operative assessments and LOS and OARS scores.

RESULTS

Both the ASA and TUG significantly contributed to LOS prediction. Odds ratio (OR) was 3.57 (95% confidence interval (CI) 1.26-10.07) for the ASA, and 2.18 (95% CI 1.67-4.15) for a one-standard deviation (SD) increase of 4.45 s of the TUG. Only the TUG was predictive of two weeks function and trending towards significance for six weeks function. One SD TUG increase yielded an OR of 2.14 (95% CI 1.53-3.79) for two week function.

CONCLUSIONS

The TUG and ASA can be used pre-operatively in combination to predict LOS, and TUG can also be used to predict short-term post-operative function.

Effect of patient decision aid was influenced by presurgical evaluation among patients with osteoarthritis of the knee

BACKGROUND

Decision aids help patients make total joint arthroplasty decisions, but presurgical evaluation might influence the effects of a decision aid. We compared the effects of a decision aid among patients considering total knee arthroplasty at 2 surgical screening clinics with different evaluation processes.

METHODS

We performed a subgroup analysis of a randomized controlled trial. Patients were recruited from 2 surgical screening clinics: an academic clinic providing 20-minute physician consultations and a community clinic providing 45-minute physiotherapist/nurse consultations with education. We compared the effects of decision quality, decisional conflict and surgery rate using Cochran-Mantel-Haenszel χ² tests and the Breslow-Day test.

RESULTS

We evaluated 242 patients: 123 from the academic clinic (61 who used the decision aid and 62 controls) and 119 from the community clinic (59 who used the decision aid and 60 controls). Results suggested a between-site difference in the effect of the decision aid on the patients' decision quality (p = 0.09): at the academic site, patients who used the decision were more likely to make better-quality decisions than controls (54% v. 35%, p = 0.044), but not at the community site (47% v. 51%, p = 0.71). Fewer patients who used decision aids at the academic site than at the community site experienced decisional conflict (p = 0.007) (33% v. 52%, p = 0.05 at the academic site and 40% v. 24%, p = 0.08 at the community site). The effect of the decision aid on surgery rates did not differ between sites (p = 0.65).

CONCLUSION

The decision aid had a greater effect at the academic site than at the community site, which provided longer consultations with more verbal education. Hence, decision aids might be of greater value when more extensive total knee arthroplasty presurgical assessment and counselling are either impractical or unavailable.

Decision aids for patients considering total joint replacement: a cost-effectiveness analysis alongside a randomised controlled trial

BACKGROUND

Shared decision-making (SDM) is a key priority to improve patient-centred care, and can play an important role in helping patients decide whether to undergo total joint arthroplasty (TJA). Patient decision aids can support SDM; however, they may incur an upfront cost. We aimed to estimate the health and economic effects of patient decision aids for TJA.

METHODS

A cost-effectiveness analysis of a randomised controlled trial (RCT) with 2-year follow-up. 343 patients were recruited from two orthopedic screening clinics in Ottawa, Canada. Patients were randomized to either a patient decision aid plus surgeon preference report (decision aid) or usual care. Primary outcomes were costs (in 2014 CAD$), quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio (ICER). Costs were calculated by multiplying self-reported resource use by unit costs. QALYs were calculated by mapping the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to EuroQol 5-Dimension (EQ-5D) health utilities. Costs and QALYs were discounted at 5%. Multiple imputation was used to handle missing data, and bootstrapping was used to estimate uncertainty.

RESULTS

The sample comprised 167 intervention and 167 control group patients. The decision aid arm had fewer surgeries over the 2-year period thereby incurring a negative incremental cost of -$560 (95% CI: -$1358 to $426) per patient while providing 0.05 (95% CI: -0.04 to 0.13) additional QALYs per patient. Consequently, the decision aid arm was dominant.

CONCLUSION

The use of a patient decision aid was associated with fewer health care costs, while producing similar health outcomes.

CLINICAL TRIAL REGISTRATION NUMBER

CT00911638 (clinicaltrials.gov).

Cost savings of outpatient versus standard inpatient total knee arthroplasty

BACKGROUND

With diminishing reimbursement rates and strained public payer budgets, a high-volume inpatient procedure, such as total knee arthroplasty (TKA), is a common target for improving cost efficiencies.

METHODS

This prospective case-control study compared the cost-minimization of same day discharge (SDD) versus inpatient TKA. We examined if and where cost savings can be realized and the magnitude of savings that can be achieved without compromising quality of care. Outcome variables, including detailed case costs, return to hospital rates and complications, were documented and compared between the first 20 SDD cases and 20 matched inpatient controls.

RESULTS

In every case-control match, the SDD TKA was less costly than the inpatient procedure and yielded a median cost savings of approximately 30%. The savings came primarily from costs associated with the inpatient encounter, such as surgical ward, pharmacy and patient meal costs. At 1 year, there were no major complications and no return to hospital or readmission encounters for either group.

CONCLUSION

Our results are consistent with previously published data on the cost savings associated with short stay or outpatient TKA. We have gone further by documenting where those savings were in a matched cohort design. Furthermore, we determined where cost savings could be realized during the patient encounter and to what degree. In carefully selected patients, outpatient TKA is a feasible alternative to traditional inpatient TKA and is significantly less costly. Furthermore, it was deemed to be safe in the perioperative period.

Can Surgeons Adequately Capture Adverse Events Using the Spinal Adverse Events Severity System (SAVES) and OrthoSAVES?

BACKGROUND

Physicians have consistently shown poor adverse-event reporting practices in the literature and yet they have the clinical acumen to properly stratify and appraise these events. The Spine Adverse Events Severity System (SAVES) and Orthopaedic Surgical Adverse Events Severity System (OrthoSAVES) are standardized assessment tools designed to record adverse events in orthopaedic patients. These tools provide a list of prespecified adverse events for users to choose from-an aid that may improve adverse-event reporting by physicians.

QUESTIONS/PURPOSES

The primary objective was to compare surgeons' adverse-event reporting with reporting by independent clinical reviewers using SAVES Version 2 (SAVES V2) and OrthoSAVES in elective orthopaedic procedures.

METHOD

This was a 10-week prospective study where SAVES V2 and OrthoSAVES were used by six orthopaedic surgeons and two independent, non-MD clinical reviewers to record adverse events after all elective procedures to the point of patient discharge. Neither surgeons nor reviewers received specific training on adverse-event reporting. Surgeons were aware of the ongoing study, and reported adverse events based on their clinical interactions with the patients. Reviewers recorded adverse events by reviewing clinical notes by surgeons and other healthcare professionals (such as nurses and physiotherapists). Adverse events were graded using the severity-grading system included in SAVES V2 and OrthoSAVES. At discharge, adverse events recorded by surgeons and reviewers were recorded in our database.

RESULTS

Adverse-event data for 164 patients were collected (48 patients who had spine surgery, 51 who had hip surgery, 34 who had knee surgery, and 31 who had shoulder surgery). Overall, 99 adverse events were captured by the reviewers, compared with 14 captured by the surgeons (p < 0.001). Surgeons adequately captured major adverse events, but failed to record minor events that were captured by the reviewers. A total of 93 of 99 (94%) adverse events reported by reviewers required only simple or minor treatment and had no long-term adverse effect. Three patients experienced adverse events that resulted in use of invasive or complex treatment that had a temporary adverse effect on outcome.

CONCLUSION

Using SAVES V2 and OrthoSAVES, independent reviewers reported more minor adverse events compared with surgeons. The value of third-party reviewers requires further investigation in a detailed cost-benefit analysis.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Impact of patient decision aids on appropriate and timely access to hip or knee arthroplasty for osteoarthritis: a randomized controlled trial

OBJECTIVE

To evaluate the effectiveness of patient decision aids (PtDA) compared to usual education on appropriate and timely access to total joint arthroplasty in patients with osteoarthritis.

METHOD

A randomized controlled trial (RCT) with patients undergoing orthopedic screening. Control and intervention arms received usual education; intervention arm also received a PtDA and a surgeon preference report. Wait times (primary outcome) were described using stratified Kaplan-Meier survival curves with patients censored at the time of death or loss to follow-up, and multivariable Cox proportional hazards regression. Secondary outcomes were compared using stratified Cochran-Mantel-Haenszel chi-squared tests.

RESULTS

343 patients were randomized to intervention (n = 174) or control (n = 169). The typical patient was 66 years old, retired, living with someone, and 51% had high school education or less. The intervention was associated with a trend towards reduction in wait time (hazard ratio (HR) 1.25, 95% confidence interval (CI) 0.99-1.60, P = 0.0653). Median wait times were 3 weeks shorter in intervention than in control at the community site with no difference at the academic site. Good decision quality was reached by 56.1% intervention and 44.5% control (Relative risk (RR) 1.25; 95% CI 1.00-1.56, P = 0.050). Surgery rates were 73.2% intervention and 80.5% controls (RR 0.91: 95% CI 0.81-1.03) with 12 intervention (7.3%) and eight control participants (4.9%) returning to have surgery within 2 years (P = 0.791).

CONCLUSION

Compared to controls, decision aid recipients had shorter wait times at one site, fewer surgeries, and were more likely to reach good decision quality, but overall effect was not statistically significant.

TRIALS REGISTRATION

The full trial protocol is available at ClinicalTrials.Gov (NCT00911638).

Decision aid for patients considering total knee arthroplasty with preference report for surgeons: a pilot randomized controlled trial

Background

To evaluate feasibility and potential effectiveness of a patient decision aid (PtDA) for patients and a preference report for surgeons to reduce wait times and improve decision quality in patients with osteoarthritis considering total knee replacement.

Methods

A prospective two-arm pilot randomized controlled trial. Patients with osteoarthritis were eligible if they understood English and were referred for surgical consultation about an initial total knee arthroplasty at a Canadian orthopaedic joint assessment clinic. Patients were randomized to the PtDA intervention or usual education. The intervention was an osteoarthritis PtDA for patients and a one-page preference report summarizing patients’ clinical and decisional data for their surgeon. The main feasibility outcomes were rates of recruitment and questionnaire completion; the preliminary effectiveness outcomes were wait times and decision quality.

Results

Of 180 patients eligible for surgical consultation, 142 (79%) were recruited and randomized to the PtDA intervention (n = 71) or usual education (n = 71). Data collection yielded a 93% questionnaire completion rate with less than 1% missing items. After one year, 13% of patients remained on the surgical wait list. The median time from referral to being off the wait list (censored using survival analysis techniques) was 33.4 weeks for the PtDA group (n = 69, 95% CI: 26.0, 41.4) and 33.0 weeks for usual education (n = 71, 95% CI: 26.1, 39.9). Patients exposed to the PtDA had higher decision quality based on knowledge (71% versus 47%; p < 0.0001) and quality decision being an informed choice that is consistent with their values for option outcomes (56.4% versus 25.0%; p < 0.001).

Conclusions

Recruitment of patients with osteoarthritis considering surgery and data collection were feasible. As some patients remained on the surgical waiting list after one year, follow-up should be extended to two years. Patients exposed to the PtDA achieved higher decision quality compared to those receiving usual education but there was no difference in wait for surgery.

Trials registration

ClinicalTrials.Gov NCT00743951

Decision quality instrument for treatment of hip and knee osteoarthritis: a psychometric evaluation

BACKGROUND

A high quality decision requires that patients who meet clinical criteria for surgery are informed about the options (including non-surgical alternatives) and receive treatments that match their goals. The aim of this study was to evaluate the psychometric properties and clinical sensibility of a patient self report instrument, to measure the quality of decisions about total joint replacement for knee or hip osteoarthritis.

METHODS

The performance of the Hip/Knee Osteoarthritis Decision Quality Instrument (HK-DQI) was evaluated in two samples: (1) a cross-sectional mail survey with 489 patients and 77 providers (study 1); and (2) a randomized controlled trial of a patient decision aid with 138 osteoarthritis patients considering total joint replacement (study 2). The HK-DQI results in two scores. Knowledge items are summed to create a total knowledge score, and a set of goals and concerns are used in a logistic regression model to develop a concordance score. The concordance score measures the proportion of patients whose treatment matched their goals. Hypotheses related to acceptability, feasibility, reliability and validity of the knowledge and concordance scores were examined.

RESULTS

In study 1, the HK-DQI was completed by 382 patients (79%) and 45 providers (58%), and in study 2 by 127 patients (92%), with low rates of missing data. The DQI-knowledge score was reproducible (ICC = 0.81) and demonstrated discriminant validity (68% decision aid vs. 54% control, and 78% providers vs. 61% patients) and content validity. The concordance score demonstrated predictive validity, as patients whose treatments were concordant with their goals had more confidence and less regret with their decision compared to those who did not.

CONCLUSIONS

The HK-DQI is feasible and acceptable to patients. It can be used to assess whether patients with osteoarthritis are making informed decisions about surgery that are concordant with their goals.

Comparison of the stability of various internal fixators used in the treatment of osteochondritis dissecans--a mechanical model

The purpose of this study was to determine what characteristics of fixation devices used in the treatment of osteochondritis dissecans (OCD) contribute to improved stability to resist shear loading. An OCD model was designed using rigid polyurethane foam. Each specimen consisted of two components, an osteochondral fragment and a corresponding defect. A total of 40 specimens were prepared and assigned to one of four groups: control (no extrinsic stabilizer); two 2-mm-diameter Kirschner wires (K-wires), 40 mm in length; one threaded washer and a 28-mm screw; and one threaded washer and a 38 mm screw. Each specimen was mounted onto an Iosipescu shear test fixture and subjected to shear loads at a pseudo-static displacement rate of 0.075 mm/s. All groups demonstrated some stability; controls were significantly less stable than all other groups. The group with the threaded washer and 38-mm screw demonstrated the greatest stability (p < 0.001), and no difference was noted between the K-wire and 28-mm screw groups. These results suggest that, in this OCD model, friction conferred some intrinsic stability to resist loads in shear. However, stability was improved with the use of long implants that compressed the fragments together.

Heparin prophylaxis for deep venous thrombosis in a patient with multiple injuries: an evidence-based approach to a clinical problem

OBJECTIVE

To demonstrate a clinical decision-making process by which to determine if heparin prophylaxis for deep venous thrombosis (DVT) is appropriate in a specific patient with multiple injuries.

DATA SOURCES

A Medline search of the literature. Search terms included trauma, heparin, deep venous thrombosis, thrombophlebitis, phlebitis, and trauma.

STUDY SELECTION

Eleven studies were selected from 789 publications using published criteria. Incidence, risk and potential for prophylaxis were established through a structured review process.

DATA EXTRACTION

After the structured review, a small number of studies were available for the consideration of incidence (2), natural history (4) and prophylactic therapy (2).

DATA SYNTHESIS

The incidence of DVT in a patient with such multiple injuries is significant (58%-63%). The resulting risk of pulmonary embolism was 4.3% with an associated 20% death rate. Prophylaxis with low molecular weight heparin is associated with a statistically and clinically significant risk reduction for DVT when compared with unfractionated heparin and untreated controls.

CONCLUSIONS

Few of the multiple available studies concerning trauma, DVT and pulmonary embolism meet reasonable standards to establish clinical validity. Available guidelines for literature evaluation allow surgeons to select relevant articles for consideration. Patients with multiple trauma appear to be at significant risk for DVT. The death rate associated with subsequent pulmonary embolism is significant. There is reasonably good evidence to suggest that low molecular weight heparin will reduce this likelihood without a significant risk of treatment complications.

Role of prostaglandin E1 in reducing pulmonary vascular resistance in an experimental model of acute lung injury

To determine the role and efficacy of prostaglandin E1 (PGE1) on the cardiopulmonary derangements induced by glass bead embolism, two studies were performed. In the first study, a dose response of PGE1 was tested in six animals that were first embolized with sufficient glass beads to double the pulmonary artery pressure (PAP). This study demonstrated that PGE1 reduced PAP and cardiac output by a preload-mediated mechanism, as evidenced by a reduction in the right ventricular (RV) end-diastolic segment length, at doses of 15 and 30 ng/kg.min. The second study was performed in two groups of animals, the control group (n = 6), and the treated group (n = 6), which were given PGE1 at 15 ng/kg.min after the PAP had been doubled by glass bead embolism. RV preload was kept constant. This study demonstrated that there was no difference in pulmonary vascular resistance between either the treated group or the control group. There were no other significant differences between the two groups. The results of both of these studies suggest that there is little afterload reducing effect of PGE1 in this model and at these dose ranges. Part of the mechanism of PGE1 that improves pulmonary edema and gas exchange may be the reduction of filtration surface area and hydrostatic pressures in the lungs.

Intravenous ibuprofen blocks the hypoxemia of pulmonary glass bead embolism in the dog

To determine the influence of arachidonic acid metabolites on acute lung injury induced by glass bead embolism, two groups of animals were studied before and after the pulmonary artery pressure was doubled by glass bead embolism. One group represented an untreated time control (n = 6) while the second group (n = 6) was pretreated with 25 mg/kg of iv ibuprofen. Repeat measurements were taken at 30, 60 and 90 min after glass bead embolism. Compared to the untreated group, the pretreated group had only a slightly decreased PaO2 (pretreated, 82% of baseline vs. untreated, 35% of baseline, p less than .05). The initial elevation in pulmonary vascular resistance (PVR) was similar in both groups but in the pretreated group it had returned nearly to baseline values by the end of the study in contrast to the persistent elevation of the PVR observed in the untreated group. We conclude that pretreatment with ibuprofen resulted in improved arterial oxygenation and a reduction in PVR over the time period studied. This implicates a role for arachidonic acid metabolites in the pathophysiology of this injury.