Brian T. Nickel

Lingering Risk: Bariatric Surgery Before Total Knee Arthroplasty

BACKGROUND Obesity continues to increase in the United States with an estimated 35% obesity and 8% bariatric (body mass index >40) rate in adults. Bariatric patients seek advice from arthroplasty surgeons regarding the temporality of bariatric surgery (BS), yet no consensus currently exists in the literature. METHODS A total of 39,014 patients were identified in a claim-based review of the entire Medicare database with International Classification of Diseases, Ninth Revision codes to identify patients in 3 groups. Patients who underwent BS before total knee arthroplasty (group I: 5914 experimental group) and 2 control groups that did not undergo BS but had either a body mass index >40 (group II: 6480 bariatric control) or <25 (group III: 26,616 normal weight control). International Classification of Diseases, Ninth Revision, Clinical Modification codes identified preoperative demographics or comorbidities and evaluated short-term medical (30 day) and long-term surgical (90 days and 2 years) complications. RESULTS Group I had the greatest female predominance, youngest age, and highest incidence of: deficiency anemia, cardiovascular disease, pulmonary disease, liver disease, ulcer disease, polysubstance abuse, psychiatric disorders, and smoking. Medical and surgical complication incidences were greatest in group I including: 4.98% deep vein thrombosis; 5.31% pneumonia; 10.09% heart failure; and 2-year infection, revision, and manipulation rates of 5.8%, 7.38%, and 3.13%, respectively. These values were significant elevation compared to III and slightly greater than II. CONCLUSIONS This study demonstrates that BS before total knee arthroplasty is associated with greater risk compared to both nonobese and obese patients. This is possibly due to a higher incidence of medical or psychiatric comorbidities determined in the Medicare BS patients, wound healing difficulties secondary to gastrointestinal malabsorption, malnourishment from prolonged catabolic state, rapid weight loss before surgery, and/or age.

Psychiatric disorders increase complication rate after primary total knee arthroplasty

BACKGROUND Psychiatric disease is difficult to screen preoperatively and the incidence of mental health disorders in patients undergoing total knee arthroplasty (TKA) may be underappreciated. The purpose of this study is to evaluate the perioperative complication profile in patients with psychiatric disorders. METHODS A search of the entire Medicare database from 2005 to 2011 was performed to identify patients who underwent primary TKA with bipolar disorder (20,972), depression (187,448), and schizophrenia (7607). A cohort of 1,271,464 patients as controls with minimum 2.5-year follow-up. Medial and surgical complications at 30-days, 90-days, and overall were compared between the two cohorts. RESULTS Patients with any psychiatric disease were more likely to be younger (age<65 OR 5.5, p<0.001), female (OR 2.61, p<0.001), and more medically complex (significant increase in 28/28 Elixhauser medical comorbidities, p<0.05). There was a significant increase (p<0.001) in 11/14 (78.5%) of recorded postoperative medical complication rates at 90-days. There was a statistically significant increase in periprosthetic infection (OR 2.17 p<0.001), periprosthetic fracture (OR 2.40, p<0.001), revision TKA (OR 2.06, p<0.001), and extensor mechanism rupture (OR 2.41, p<0.001) at 90day and overall time points. CONCLUSIONS Patients with psychiatric disorders who undergo elective primary TKA have significantly increased medical and surgical complication rates in the global period and short term follow-up. An ideal screening tool is yet to be determined and these patients need to be counseled appropriately regarding the increased complication rates before proceeding with TKA.

The Impact of Lumbar Spine Disease and Deformity on Total Hip Arthroplasty Outcomes

Concurrent spine and hip disease is common. Spinal deformities can restrict lumbar range of motion and lumbar lordosis, leading to pelvic obliquity and increased pelvic tilt. A comprehensive preoperative workup and component templating ensure appropriate compensation for altered pelvic parameters for implantation of components according to functional positioning. Pelvic obliquity from scoliosis must be measured to calculate appropriate leg length. Cup positioning should be templated on standing radiograph to limit impingement from cup malposition. In spinal deformity, the optimal position of the cup that accommodates pelvic parameters and limits impingement may lie outside the classic parameters of the safe zone.

Ultrasonography-guided de Quervain Injection: Accuracy and Anatomic Considerations in a Cadaver Model.

Introduction: Confirmation of pertinent anatomy and accurate needle placement for de Quervain injection may improve outcomes and limit complications. We evaluated the accuracy of the first extensor compartment in regard to the following: (1) anatomic assessment, (2) needle placement without imaging guidance, and (3) ultrasonography-guided injection with priority for the extensor pollicis brevis subcompartment.Methods: Anatomic assessment and ultrasonography-guided first extensor compartment injection was completed in 50 cadaver specimens. Initial needle placement was done without the guidance of ultrasonography; its final position was evaluated with ultrasonography. Then, using ultrasonography, 1 mL of India ink was injected into the extensor pollicis brevis compartment. Open evaluation confirmed pertinent anatomy and injection accuracy.Results: A subcompartment of the first extensor compartment was identified in 27 of 50 wrists; 18 of 27 compartments were complete and 9 of 27 were incomplete, with ultrasonographic evaluation having an accuracy rate of 94%. Accurate needle placement occurred in 26 of 50 wrists (52%) when ultrasonography was not used, but only 2 of 27 needles (7%) were located within the extensor pollicis brevis subcompartment. Ultrasonography-guided injection was 100% accurate (50 out of 50) and extensor pollicis brevis injection was 96% accurate (26 of 27) when two compartments were present. Minimal extravasation was identified in 6 of 50 wrists (12%).Discussion: Ultrasonography-guided de Quervain injection improves injection accuracy through the visualization of compartmental anatomy and needle placement and may improve clinical outcomes by minimizing complications associated with extra-compartmental injection.

Percent Body Fat Is More Predictive of Function After Total Joint Arthroplasty Than Body Mass Index.

BACKGROUND Obesity has an important impact on the future of total joint arthroplasty; however, the definition and influence of obesity on surgical risks and outcomes remain controversial. Our hypothesis was that percent body fat was better than body mass index (BMI) at identifying clinical risks and patient-reported functional outcomes following arthroplasty. METHODS Clinical and functional outcomes were collected prospectively in 215 patients undergoing primary total knee arthroplasty (115 patients) or total hip arthroplasty (100 patients) at a mean time of twenty-four months (range, twelve to forty months). Clinical data included patient demographic characteristics, preoperative evaluation including measurements of BMI and percent body fat, intraoperative records, hospital course or events, and postoperative outpatient follow-up. Patient-reported outcomes were obtained through a series of questionnaires: a surgical satisfaction survey; the University of California, Los Angeles (UCLA) activity scale; the Knee Injury and Osteoarthritis Outcome Score (KOOS) for total knee arthroplasty; and the Hip Disability and Osteoarthritis Outcome Score (HOOS) for total hip arthroplasty. Multivariable regression models were used to identify significant body mass predictors of outcomes (p < 0.05). RESULTS Higher percent body fat predicted occurrence of any medical or surgical complication (odds ratio per one standard deviation increase, 1.58 [95% confidence interval, 1.04 to 2.40]; p = 0.033). Percent body fat was also a predictor of the UCLA activity score (risk ratio, 0.92 [95% confidence interval, 0.85 to 0.98]; p = 0.013) and pain scores (risk ratio, 1.18 [95% confidence interval, 1.03 to 1.36]; p = 0.017), and it trended toward significance for the surgical satisfaction score (odds ratio, 1.96 [95% confidence interval, 0.93 to 4.15]; p = 0.078), whereas BMI was not predictive of these functional outcomes. Additionally, with regard to surgical procedure-specific outcome scores, percent body fat was predictive of outcomes after total knee arthroplasty (KOOS pain, p = 0.015, and KOOS activities of daily living, p = 0.002), but not for those after total hip arthroplasty. CONCLUSIONS Percent body fat should be considered when predicting clinical and functional outcomes at two years following total joint arthroplasty. Percent body fat may help surgeons to improve risk stratifications, to project patient-reported functional outcomes, and to better educate obese patients with regard to postoperative expectations prior to undergoing elective total joint arthroplasty. LEVEL OF EVIDENCE Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

What Should Define Preoperative Anemia in Primary THA

BackgroundThe use of tranexamic acid (TXA) in THA decreases the risk of transfusion after surgery. However, nearly 10% of patients still undergo a transfusion, which has been independently associated with an increased risk of complications. Preoperative anemia has been proven to be a strong predictor of transfusion after THA, but the ideal “cutoff” values in today’s population that maximize sensitivity and specificity to predict transfusion have yet to be established.Questions/purposes(1) Which preoperative factors are associated with postoperative transfusion in the setting of TXA use? (2) If preoperative hemoglobin (Hgb) remains associated with transfusion, what are the best-supported preoperative Hgb cutoff values associated with increased transfusion after THA?MethodsA retrospective chart analysis was performed from January 1, 2013, to January 1, 2015, on 558 primary THAs that met prespecified inclusion criteria. A multivariable logistic regression analysis model was used to identify independent factors associated with transfusion. Area under the receiver-operator curve (AUC) was used to determine the best-supported preoperative Hgb cut point across all participants, as well as adjusted by sex and TXA use. Overall, 60 patients with a blood transfusion were included and compared with 498 control subjects (11% risk of transfusion).ResultsAfter controlling for potential confounding variables such as age, sex, American Society of Anesthesiologist score, intravenous TXA (IV TXA) use, and preoperative Hgb, we found that patients with lower preoperative Hgb (g/dL per 1-unit decrease, odds ratio [OR], 2.6; 95% CI, 2.0–3.5; p < 0.001), female sex (vs male, OR, 4.2; 95% CI, 1.7–10.3; p = 0.002), and those unable to receive IV TXA (topical TXA/no TXA, OR, 13.5; 95% CI, 6.3–28.6; p < 0.001) were more likely to receive a transfusion. Of these, preoperative Hgb was found to be the variable most highly associated with transfusion (AUC, 0.876). A preoperative Hgb cutoff value of 12.6 g/dL maximized the AUC (0.876) for predicting transfusion across all patients unadjusted for baseline characteristics (sensitivity = 83, specificity = 84) with values of 12.5 g/dL (sensitivity = 85, specificity = 77) and 13.5 g/dL (sensitivity = 92, specificity = 77) for women and men, respectively.ConclusionsThe 1968 WHO definitions of anemia (preoperative Hgb < 13 g/dL for men and < 12 g/dL for women) used currently may underestimate patients at risk of transfusion after THA today. Further studies are needed to see if blood conservation referral decreases the risk of transfusion with preoperative treatment of anemia.Level of EvidenceLevel III, therapeutic study.

Dislocation rate increases with bariatric surgery before total hip arthroplasty

Introduction: Annually in the USA, 113,000 patients with refractory obesity undergo bariatric surgery (BS), and a subset does so in order to lower body mass index to become a more desirable total hip arthroplasty (THA) candidate. This study aims to evaluate THA risk with and without bariatric surgery. Methods: 12,160 patients were identified in a claim-based review of the entire Medicare database with ICD-9 codes to identify patients in three groups. Patients who underwent BS prior to THA (Group I: 1,545 experimental group) and two control groups that did not undergo BS but had either a body mass index >40 (Group II: 6,918 bariatric control) or <25 (Group III: 3,697 normal weight control). Preoperative demographics/comorbidities and short-term medical (30 day) and long-term surgical (90-day and 2-year) complications were evaluated. Results: Group I had female predominance, youngest age, and highest incidence of: deficiency anaemia, cardiovascular disease, liver disease, diabetes, polysubstance abuse, psychiatric disorders and smoking. At 2 years, Group I had approximately twice the dislocation and revision risk compared to both Groups II and III; Groups I and II had over four times the risk of infection and wound complications compared to Group III. Conclusion: In the Medicare population, these patients continue to have complication rates similar to and sometimes greater than obese patients with no prior bariatric surgery. Greater dislocation risk is possibly due to ligamentous laxity related to decreased collagen/elastin and/or component malposition due to intraoperative visualisation challenges.

Ultrasound-guided Cubital Tunnel Injection: Description of Technique and Accuracy in a Cadaver Model

Introduction: Ulnar nerve (UN) and cubital tunnel morphology is influenced by elbow positioning, potentially compromising injection accuracy and placing the nerve at risk during cubital tunnel injection. Materials and methods: Based on previous anatomical studies of the cubital tunnel, a proof of concept injection model was developed. Eighteen above-elbow cadaver specimens were positioned in 45° elbow flexion and in neutral forearm rotation. The ultrasound transducer was oriented in the transverse plane, in-line with the medial epicondyle and olecranon tip, facilitating visualization of the UN and cubital tunnel. A 25-gauge needle oriented parallel to the ulna was inserted percutaneously at the midpoint between olecranon and epicondyle. The needle was advanced under ultrasound guidance to replicate injection and was secured. Open dissection confirmed its location. Results: 18/18 needle tips were within the cubital tunnel and no needles penetrated the UN. Discussion: Ultrasound-guided cubital tunnel injection, with the elbow in 45° flexion and with neutral forearm rotation was a safe and reliable technique in this cadaveric model. Future clinical studies may evaluate the efficacy of both diagnostic and therapeutic cubital tunnel injection.

Reproducible transient asystolic arrest during intramedullary reaming of the femoral canal: A case report

The utilization of intramedullary devices in the surgical fixation of hip fractures is increasing. Although intramedullary devices offer many advantages in the treatment of these injuries, they are also associated with a unique set of potential complications, particularly during preparation of the femoral canal. Cardiac dysrhythmia resulting from reaming the femoral canal is rare and has not been previously described in detail in the literature. We present the case of a 69-year-old male with an infected right cephalomedullary femoral nail who underwent removal of hardware and experienced reproducible, transient asystolic cardiac arrest during reaming of the femoral canal and offer potential explanations for this event.

Glenohumeral arthritis as a risk factor for proximal humerus nonunion

BACKGROUND Proximal humerus fractures are common injuries and nonsurgical treatment has proven to yield good to excellent clinical results. A small percentage of these fractures go on to delayed or nonunion and the incidence and risk factors for this complication are poorly understood. We hypothesize that adjacent joint stiffness of the glenohumeral joint might lead to an increased rate of nonunion for proximal humerus fractures. METHODS A search of the entire Medicare database from 2005 to 2011 was performed to identify 38,754 patients who sustained a proximal humerus fracture including 13,802 with co-existing ipsilateral shoulder osteoarthritis (OA) and 24,952 with co-existing diagnosis of rheumatoid arthritis (RA). A cohort of 301,987 patients served as a control. Medical co-morbidities and fracture complications were compared between the cohorts. RESULTS The incidence of delayed union at 3 and 6 months for OA and RA groups were significantly increased compared to control at 0.79% and 1.74%, and 0.67% and 1.86%, respectively (p < 0.001). Nonunion rates were also significantly increased (p < 0.001) in the OA and RA cohorts at 9 months and 1 year with incidences of 2.39%, 2.89% and 2.59% and 3.08%, Respectively. The incidence of nonunion in the control cohort at the same time points was 1.13% and 1.35%. CONCLUSIONS The coexistence of shoulder OA or a diagnosis of RA nearly doubled in the incidence of proximal humerus nonunion. This is the first study investigating this association in the shoulder and should be considered along with traditional nonunion risk factors in the treatment algorithm.