Ronald Huang

Treatment of Femoroacetabular Impingement in Athletes Using a Mini–Direct Anterior Approach

Background: Femoroacetabular impingement (FAI) is an increasingly common diagnosis in active patients with hip pain. Surgical options for FAI include arthroscopy, open surgical dislocation, or mini–direct anterior approaches. Arthroscopic and open treatments of FAI have been commonly performed and have had promising results in athletes. Hypothesis/Purpose: We hypothesized that the mini–direct anterior approach would provide the advantages of a minimally invasive procedure and still allow adequate exposure of the hip joint to successfully treat FAI in an athletic population. The purpose of this study was to determine if a mini-open approach for the treatment of FAI in athletic patients would allow a return to preoperative activity. Study Design: Case series; Level of evidence, 4. Methods: A total of 234 patients (257 hips) with FAI were treated by a mini-open approach; 59 were athletic patients (66 hips) with a preoperative University of California, Los Angeles (UCLA) activity score of 7 or higher or Super Simple Hip (SUSHI) activity score of 70 or greater. Forty-four of the 59 athletic patients (47 hips) have reached 1-year minimum follow-up. No patients were lost to follow-up. The mini-open approach was performed through a 4-cm incision and modified Smith-Peterson approach with no muscle detachment. All patients were prospectively evaluated using the following outcome measures: preoperative and postoperative UCLA activity, Short-Form 36 Health Survey (SF-36), Western Ontario and McMaster Osteoarthritis Index (WOMAC), modified Harris Hip Score (HHS), and SUSHI scores. Results: The average age at the time of surgery was 32 years (range, 17-60 years), with an average follow-up of 22 months. Labral changes—whether tear, detachment, or ossification—were present in all patients, and 84% had chondral lesions. The mean HHS improved from 55 preoperatively to 79 postoperatively (P < .001). The WOMAC scores also improved from 47.9 to 8.3 (P < .001). Mean SF-36 scores improved from 65 to 85 postoperatively (P < .001). The mean preoperative SUSHI general score was 31.1, pain score was 26.6, and limitation score was 28.9. The mean postoperative SUSHI general score was 53.6, pain score was 47.5, and limitation score was 51.6 (P < .001). There was minimal change from preinjury to postoperative UCLA (8.0 to 8.7, respectively; P = .07) or SUSHI activity scores (76.3 to 67.7, respectively; P = .048), indicating a reliable return to preinjury activity levels. Twenty-four of 44 patients (55%) reported a return to their specific preoperative sports. Nine patients (20%) developed meralgia paresthetica postoperatively, which resolved within 1 year. Conclusion: The mini-open approach for the treatment of FAI is a safe and effective procedure that allows surgical treatment of FAI in athletic patients and a successful return to high activity levels. The outcome of the mini-open approach for athletes may be comparable with open and arthroscopic treatment of FAI.

Diagnosis of periprosthetic joint infection

Liaison: Benjamin Zmistowski BS Leaders: Craig Della Valle MD (US), Thomas W Bauer MD (US), Konstantinos N. Malizos MD, PhD (International) Delegates: Abbas Alavi MD, Hani Bedair MD, Robert E Booth MD, Peter Choong MD, Carl Deirmengian MD, Garth D Ehrlich PhD, Anil Gambir MD, Ronald Huang MD, Yair Kissin MD, Hideo Kobayashi MD, Naomi Kobayashi MD, Veit Krenn MD, Drago Lorenzo MD, SB Marston MD, Geert Meermans MD, Javier Perez MD, JJ Ploegmakers MD, Aaron Rosenberg MD, C Simpfendorfer MD, Peter Thomas MD, Stephan Tohtz MD, Jorge A Villafuerte MD, Peter Wahl MD, Frank-Christiaan Wagenaar MD, Eivind Witzo MD

Aspirin: An Alternative for Pulmonary Embolism Prophylaxis After Arthroplasty?

BackgroundThe most effective agent for prophylaxis against venous thromboembolic disease after total joint arthroplasty (TJA) remains unknown. The paucity of literature comparing different methods of pulmonary embolism (PE) prophylaxis and fear of litigation make it difficult for surgeons to abandon the use of aggressive chemical prophylaxis.Questions/purposesWe compared the (1) overall frequency of symptomatic PE, (2) risk of symptomatic PE after propensity matching that adjusted for potentially confounding variables, and (3) other complications and length of stay before and after propensity matching in patients undergoing TJA at our institution who received either aspirin or warfarin prophylaxis.MethodsA total of 28,923 patients underwent TJA between January 2000 and June 2012 at our institution, had either aspirin (325 mg twice daily; 2800 patients) or warfarin prophylaxis (26,123 patients), and were registered in our institutional electronic database. The incidence of symptomatic PE, symptomatic deep vein thrombosis (DVT), hematoma formation, infection, wound complications, and mortality up to 90 days postoperatively was collected from the database. We performed multivariate analysis and 3:1 and 5:1 propensity score matching for comorbid and demographic variables.ResultsThe overall symptomatic PE rate was lower (p < 0.001) in patients receiving aspirin (0.14%) than in the patients receiving warfarin (1.07%). This difference did not change after matching. The aspirin group also had significantly fewer symptomatic DVTs and wound-related problems and shorter hospital stays, which did not change after matching.ConclusionsAfter publication of the American Academy of Orthopaedic Surgeons’ guidelines, some surgeons have utilized aspirin as thromboprophylaxis after TJA. Based on our findings from a large institutional database, aspirin offers suitable prophylaxis against symptomatic PE in selected patients.Level of EvidenceLevel III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

The Effect of Malnutrition on Patients Undergoing Elective Joint Arthroplasty

Malnutrition has been linked to serious complications in patients undergoing elective total joint arthroplasty (TJA). This study prospectively evaluated 2,161 patients undergoing elective TJA for malnutrition as defined by either an abnormal serum albumin or transferrin. The overall incidence of malnutrition was 8.5% (184 of 2,161) and the rate of overall complications in the malnourished group was 12% as compared to 2.9% in patients with normal parameters (P<0.0001). Malnutrition predicted serious complications involving hematoma formation, infection, renal and cardiac complications. Obesity, defined by a body mass index (BMI) of 30kg/m(2) was present in 42.9% of malnourished patients with a significantly higher complication rate in this cohort. Malnutrition remains prevalent in patients >55years-old undergoing TJA and is associated with a significant increase in post-operative complications.

Periprosthetic joint infection diagnosis: a complete understanding of white blood cell count and differential.

Recent research has raised doubts regarding the utility of serum white blood cell count (WBC) for diagnosis of periprosthetic joint infection (PJI). As synovial WBC and neutrophil (PMN) percentage have been adopted as accurate markers of PJI, this study investigated the correlation of WBC in serum versus joint fluid and diagnostic value of all WBC levels for failed arthroplasty patients. 153 patients (73 PJI) undergoing revision knee arthroplasty were identified. Weak correlations between joint fluid and serum for WBC (R = 0.19), PMN count (R = 0.31), and lymphocyte count (R = -0.22) were observed. Diagnostic accuracy of PMN (93%) and WBC (93%) synovial count relative to serum was similar to synovial WBC (93%) and PMN% (95%) alone. Serum WBC analysis does little to improve the accurate diagnosis of PJI.

Culture-negative Periprosthetic Joint Infection Does Not Preclude Infection Control

BackgroundPeriprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty. Lack of confirmation of an infecting organism poses a challenge with regard to the selection of an appropriate antibiotic agent and surgical treatment. It is unclear whether patients with negative cultures presumed to have infections achieve similar rates of infection-free survival as those with positive cultures.Questions/purposesThe purposes of this study were (1) to report the infection control rates using irrigation and débridement and two-stage exchange for treatment of culture-negative PJIs; and (2) to compare infection control rates in culture-negative cases with those in culture-positive cases.MethodsWe retrospectively reviewed 55 patients with culture-negative PJI treated between 2000 and 2007. We compared the infection-free survival rate in the culture-negative patients with that of 295 culture-positive cases of PJI.ResultsOverall infection control rate in culture-negative cases was 73% at minimum 1-year followup (mean, 47 months; range, 12–119 months). We found similar infection control rates in culture-negative and culture-positive PJI. Infection-free survival rates in both groups were highest after two-stage exchange arthroplasty and postoperative vancomycin therapy.ConclusionOur observations suggest aggressive two-stage exchange arthroplasty and postoperative parenteral vancomycin therapy in patients with culture-negative PJI achieves similar rates of infection-free survival as with patients having culture-positive PJI.Level of EvidenceLevel III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Risk Factors for Early Mortality Following Modern Total Hip Arthroplasty.

The aim of this study was to evaluate the incidence of early mortality and identify risk factors for early death following modern uncemented THA. Between 2000 and 2006, we identified patients who died within 90days of THA. Demographics, comorbidities, laboratory studies, and complications were analyzed as risk factors for mortality. 38 of 8261 patients undergoing THA (0.46%) died within 90days postoperatively. Of these, 26% were due to myocardial infarction. Multivariate analysis revealed Charlson index >3, peripheral vascular disease, elevated postoperative glucose, and abnormal postoperative cardiac studies as independent predictors of early mortality following THA. Caution should be taken in patients with increased comorbidities, PVD, perioperative hyperglycemia, and impaired renal function in order to reduce mortality following THA.

Serum White Blood Cell Count and Differential Do Not Have a Role in the Diagnosis of Periprosthetic Joint Infection

Serum white blood cell (WBC) count and neutrophil differential are frequently ordered during preoperative workup of suspected cases of periprosthetic joint infection (PJI). However, their roles in diagnosis of PJI have remained unclear despite previous studies. In this study, preoperative serum WBC and neutrophil percentages were retrieved from hospital charts. The diagnostic cutoff point determined by receiver operating characteristic curve analysis was 7800 cells/μL with 55% sensitivity and 66% specificity for WBC count, whereas the cutoff value for neutrophil percentage was 68% with 52% sensitivity and 75% specificity. Our study confirms the long-held belief that serum WBC count and differential has minimal role in routine workup of patients with suspected PJI.

Revision total knee arthroplasty using metaphyseal sleeves at short-term follow-up.

The treatment of bone loss in revision total knee arthroplasty (TKA) has involved using revision implants in association with cement, augments, particulate, and structural allograft. Newer metaphyseal augments were introduced to allow for metaphyseal fixation of the prosthesis while managing significant bone loss. The purpose of the current study was to evaluate the outcome of revision TKA using metaphyseal sleeves. The authors prospectively followed 96 knees that underwent revision TKA with metaphyseal sleeves. Eighty-three knees met the minimum 2-year criteria for follow-up. Thirty-six sleeves were used in femoral revisions and 83 sleeves were used in tibial revisions. The defects were classified according to the Anderson Orthopaedic Research Institute classification. Femoral defects were classified as type I in 4 knees, type IIb in 25 knees, and type III in 7 knees. Tibial defects were classified as type I in 9 knees, type IIa in 1 knee, type IIb in 68 knees, and type III in 5 knees. The patients were followed for an average of 2.4 years (range, 2.0-3.7 years). Mean Knee Society function score improved from 47.9 to 61.1 points. Mean Short Form 36 physical score improved from 43.3 to 56.3 points. Mean Western Ontario and McMaster Universities Arthritis Index improved from 55.3 to 25.9 points. None of the implants demonstrated progressive radiolucent lines around the metaphyseal sleeves. At final follow-up, only 2 (2.7%) tibial components required revision for aseptic loosening. At short-term follow-up, revision TKA with metaphyseal sleeves provided reliable fixation. This is especially encouraging given the severe nature of bone loss in the majority of patients in whom a metaphyseal sleeve was used. Long-term follow-up is needed to demonstrate the true effectiveness of these devices.

Administration of Aspirin as a Prophylaxis Agent Against Venous Thromboembolism Results in Lower Incidence of Periprosthetic Joint Infection

The efficacy and safety of aspirin (ASA) for prevention of venous thromboembolism (VTE) following total joint arthroplasty (TJA) have been demonstrated. Our hypothesis was that postoperative ASA compared to warfarin lowers the incidence of periprosthetic joint infection (PJI). Between January 2006 and December 2012, 1456 patients received ASA and 1700 patients received warfarin following primary TJA as standard VTE prophylaxis. Logistic regression was utilized to identify independent risk factors of PJI. Incidence of PJI was significantly lower at 0.4% in patients receiving ASA vs. 1.5% in patients receiving warfarin (P<0.001). Warfarin and elevated BMI were independent risk factors for PJI following TJA (P<0.05). Our research suggests that the use of ASA compared to warfarin for VTE prophylaxis reduces the risk of PJI following TJA.