James I. Huddleston

Clinical recovery from surgery correlates with single-cell immune signatures

Single-cell mass cytometry revealed immune correlates of patient-associated variability in surgical recovery. Signaling Surgical Recovery The speed and ease of recovery after surgery differ for every patient, and determining the mechanisms that drive recovery could lead to patient-specific recovery protocols. Gaudilliere et al. used mass cytometry to characterize postsurgical immunological insult at a single-cell level and found a surgical immune signature that correlated with clinical recovery across patients. Specifically, cell signaling responses, but not cell frequency, were linked to recovery. Moreover, the correlated signaling responses occurred most notably in CD14+ monocytes, suggesting that these cells may play a predominant role in surgical recovery. The consistency of this signature across patients suggests a tightly regulated immune response to surgical trauma, which, if validated, may form the basis of a diagnostic guideline for personalized postsurgical care. Delayed recovery from surgery causes personal suffering and substantial societal and economic costs. Whether immune mechanisms determine recovery after surgical trauma remains ill-defined. Single-cell mass cytometry was applied to serial whole-blood samples from 32 patients undergoing hip replacement to comprehensively characterize the phenotypic and functional immune response to surgical trauma. The simultaneous analysis of 14,000 phosphorylation events in precisely phenotyped immune cell subsets revealed uniform signaling responses among patients, demarcating a surgical immune signature. When regressed against clinical parameters of surgical recovery, including functional impairment and pain, strong correlations were found with STAT3 (signal transducer and activator of transcription), CREB (adenosine 3′,5′-monophosphate response element–binding protein), and NF-κB (nuclear factor κB) signaling responses in subsets of CD14+ monocytes (R = 0.7 to 0.8, false discovery rate <0.01). These sentinel results demonstrate the capacity of mass cytometry to survey the human immune system in a relevant clinical context. The mechanistically derived immune correlates point to diagnostic signatures, and potential therapeutic targets, that could postoperatively improve patient recovery.

Primary Total Hip Arthroplasty Using an Anterior Approach and a Fracture Table Short-term Results From a Community Hospital

There are no data regarding the efficacy and safety of minimally invasive hip arthroplasty technique performed by community practice orthopedists. The early clinical and radiographic results of primary total hip arthroplasty using a minimally invasive anterior approach to the hip performed on a fracture table were studied. Two hundred thirty-one consecutive patients (247 hips) of 5 community practice surgeons were studied. The average surgical time (164 minutes) and estimated blood loss (858 mL) were more than double, and the major complication rate (9%) was 6 times that reported by an innovator of the procedure. However, no postoperative dislocations occurred. Adequate training is critical to reduce the risk of complications during the learning experience of minimally invasive hip arthroplasty procedures by community practice surgeons.

Readmission and Length of Stay After Total Hip Arthroplasty in a National Medicare Sample

Evaluation of hospital readmissions after total hip arthroplasty may help improve patient safety and cost reduction. This study investigates the rates and reasons for readmission as well as length of hospital stay (LOS) for 1802 total hip arthroplasty patients from 2002 to 2007. Data were abstracted from the Medicare Patient Safety Monitoring System. The overall 30-day rate of readmission was 6.8%. There was no difference in readmission rate from 2002 to 2004 (7.1%) to 2005 to 2007 (6.3%) (odds ratio, 0.90; 95% confidence interval, 0.63-1.30; P = .58). The overall mean LOS was 4.2 ± 2.2 days. There was a significant reduction in LOS from 2002 to 2004 (4.4 ± 2.5 days) to 2005 to 2007 (3.8 ± 1.7 days) (odds ratio, 1.28; 95% confidence interval, 1.25-1.31; P < .0001). The most common causes for readmission were cardiac related. A reduction in LOS was not associated with an increase in the rate of readmission in this sample. Efforts to optimize cardiac status before discharge may lead to lower rates of readmission in the future.

Shared decision making in patients with osteoarthritis of the hip and knee: results of a randomized controlled trial.

BACKGROUND Despite evidence that shared decision-making tools for treatment decisions improve decision quality and patient engagement, they are not commonly employed in orthopaedic practice. The purpose of this study was to evaluate the impact of decision and communication aids on patient knowledge, efficiency of decision making, treatment choice, and patient and surgeon experience in patients with osteoarthritis of the hip or knee. METHODS One hundred and twenty-three patients who were considered medically appropriate for hip or knee replacement were randomized to either a shared decision-making intervention or usual care. Patients in the intervention group received a digital video disc and booklet describing the natural history and treatment alternatives for hip and knee osteoarthritis and developed a structured list of questions for their surgeon in consultation with a health coach. Patients in the control group received information about the surgeons practice. Both groups reported their knowledge and stage in decision making and their treatment choice, satisfaction, and communication with their surgeon. Surgeons reported the appropriateness of patient questions and their satisfaction with the visit. The primary outcome measure tracked whether patients reached an informed decision during their first visit. Statistical analyses were performed to evaluate differences between groups. RESULTS Significantly more patients in the intervention group (58%) reached an informed decision during the first visit compared with the control group (33%) (p = 0.005). The intervention group reported higher confidence in knowing what questions to ask their doctor (p = 0.0034). After the appointment, there was no significant difference between groups in the percentage of patients choosing surgery (p = 0.48). Surgeons rated the number and appropriateness of patient questions higher in the intervention group (p < 0.0001), reported higher satisfaction with the efficiency of the intervention group visits (p < 0.0001), and were more satisfied overall with the intervention group visits (p < 0.0001). CONCLUSIONS Decision and communication aids used in orthopaedic practice had benefits for both patients and surgeons. These findings could be important in facilitating adoption of shared decision-making tools into routine orthopaedic practice.

Adverse Events After Total Knee Arthroplasty

Adverse events from 2033 total knee arthroplasty patients were documented by nonphysician abstractors. The annual rate of adverse events from 2002 to 2004 was 9.2%, 6.4%, and 5.8%, respectively. Congestive heart failure (odds ratio, 2.1; 95% confidence interval, 1.2-3.5; P < .01) and chronic obstructive pulmonary disease (odds ratio, 1.8; 95% confidence interval, 1.2-2.7; P < .01) were associated with a significantly increased risk of experiencing any adverse event during the index hospitalization. The 30-day postprocedure rate of readmission for all causes was 5.5%. Experiencing an adverse event during the index hospitalization increased the length of stay (P < .001). The rate of symptomatic venous thromboembolism 30 days postprocedure was 1.7%. The 30-day postprocedure mortality rate was 0.3%. Experiencing any adverse event was associated with an increased 30-day postprocedure mortality (P < .001). Compared with previous studies of Medicare claims, these data reveal a substantial decrease in the mortality rate, an increased readmission rate, and no substantial change in the rate of venous thromboembolism.

Synovial tissue–infiltrating natural killer cells in osteoarthritis and periprosthetic inflammation

OBJECTIVE Infiltrating immune cells play a central role in degenerative joint disease associated with osteoarthritis (OA) and particle-mediated periprosthetic osteolysis. The goal of this study was to characterize a newly identified population of synovial tissue-infiltrating natural killer (NK) cells obtained from patients with OA or patients with periprosthetic joint inflammation. METHODS Synovial and interfacial tissue samples were collected from patients with OA who were undergoing primary or revision total joint replacement (TJR) surgery. The histologic features of OA synovium obtained from patients undergoing primary surgery and interfacial tissue obtained from patients undergoing revision surgery were determined by immunohistochemistry and immunofluorescence. Synovial tissue-infiltrating NK cells were evaluated for the expression of surface receptors, using flow cytometry. Chemoattractant and cytokine protein and RNA levels in synovial and interfacial tissue and fluid were assessed by Luminex assay and real-time quantitative polymerase chain reaction. Cytokine production and degranulation by stimulated synovial tissue versus normal blood NK cells were evaluated by intracellular cytokine staining. RESULTS NK cells comprised nearly 30% of the CD45+ mononuclear cell infiltrate in synovial tissue obtained from patients undergoing primary TJR and from patients undergoing revision TJR. NK cells from both groups expressed CXCR3, CCR5, L-selectin, α4 integrins, and cutaneous lymphocyte antigen. Synovial fluid from patients undergoing revision surgery contained elevated concentrations of the NK cell attractants CCL4, CCL5, CXCL9, and CXCL10; all levels in synovial fluid obtained from patients undergoing revision surgery were higher than those in synovial fluid from patients undergoing primary surgery. Cytokine-stimulated interferon-γ production was significantly impaired in NK cells derived from primary and revision TJRs compared with blood NK cells. CONCLUSION NK cells are a principal tissue-infiltrating lymphocyte subset in patients with OA and patients with periprosthetic inflammation and display a quiescent phenotype that is consistent with postactivation exhaustion.

Determination of neutral tibial rotational alignment in rotating platform TKA.

Use of a fixed anatomic landmark to set rotation of the tibial component may lead to rotational malalignment. Post wear in stabilized components, backside wear in any conforming modular system, and patellar maltracking may result from tibiofemoral rotational incongruence. We aimed to quantify tibial rotational alignment in 109 primary rotating platform TKAs. After trial components were inserted with the knee properly balanced, we recorded the neutral point of the rotating tibial insert, in extension, relative to the most medial aspect of the tibial tubercle. We hypothesized that all neutral points would lie within 10° of the mean. Divergence of the neutral point was recorded as being internal or external to the medial border of the tibial tubercle to the nearest 5° increment. Our results showed a mean divergence of 5° ± 5° external to the medial border of the tubercle. Five percent of knees, however, had neutral points ≥ 10° from the mean. Surgeons who use fixed-bearing modular components with any rotational constraint must be cautious in choosing a fixed anatomic tibial landmark to determine the rotational alignment of the tibial component. Doing so may create tibiofemoral rotational malalignment in full extension that may lead to suboptimal outcomes. Level of Evidence: Diagnostic study, Level II-3. See the Guidelines for Authors for a complete description of levels of evidence.

How have alternative bearings (such as metal-on-metal, highly cross-linked polyethylene, and ceramic-on-ceramic) affected the prevention and treatment of osteolysis?

&NA; Osteolysis is a multifactorial process dependent on surgical technique, implant design, patient factors, and material composition. Alternative bearing surfaces, such as highly crosslinked polyethylene, ceramic‐on‐ceramic, and metal‐on‐metal articular surfaces, have been introduced in an attempt to reduce wear and osteolysis following total hip arthroplasty. Intermediateterm follow‐up data available suggest that the prevalence and severity of osteolysis may be reduced with these materials compared with conventional metal‐on‐polyethylene bearing surface couples. However, long‐term data are presently unavailable; the future performance of these bearings awaits clinical validation.

Advanced Age and Comorbidity Increase the Risk for Adverse Events After Revision Total Hip Arthroplasty

With the institution of quality-assurance parameters in health care, physicians must accurately measure and report the true baseline rates of adverse events (AEs) after complex surgical interventions. To better quantify the risk of AEs for revision total hip arthroplasty (THA), we divided a cohort of 306 patients (322 procedures) into age groups: group I (<65 years, n = 138), group II (65-79 years, n = 119), and group III (≥80 years, n = 65). Ninety-day rates of major AE were 9%, 19%, and 34% in the groups, respectively. Group III had an increased chance of experiencing major AE compared with groups I and II. Age and Charlson Comorbidity Index independently predicted major complications, whereas body mass index, sex, and type of revision did not.

Aseptic versus septic revision total knee arthroplasty: patient satisfaction, outcome and quality of life improvement.

We prospectively compared the clinical outcomes and patient satisfaction rates of aseptic (n=30) versus septic revision TKA (n=15) at a mean follow-up of 40 months. We hypothesized that the clinical results of septic revision TKA would be inferior to aseptic revision TKA. The indication for revision in aseptic group was stiffness in 11 patients, aseptic loosening in 13, patellar loosening or maltracking in 6 patients. Patients operated for infection had better post-operative Knee Society Scores (KSS), Function Scores and SF-36 Mental Scores than aseptic group but there were no significant differences in the satisfaction rates. Patients operated for infection had more improvement in their KSS (p=0.004) and Function Scores (p=0.02) than patients revised for stiffness. Moreover, patients operated on for patellar problems had higher satisfaction rates than patients revised for stiffness (p=0.01) or aseptic loosening (p=0.01). Thus, patients undergoing septic revision TKA had better outcomes compared to those with aseptic revision TKA. However, in the aseptic group, revision TKA for stiffness was associated with the poorest outcomes. The indication for aseptic revision is an important variable when discussing treatment and outcome with patients.