Acetabular Labral Tears Are Common in Asymptomatic Contralateral Hips With Femoroacetabular Impingement.

BACKGROUND: The number of patients undergoing hip arthroscopy for labral tears has increased, but labral tears are sometimes seen in asymptomatic patients with femoroacetabular impingement (FAI). The frequency of this finding, however, has not been well characterized nor is the proportion of patients with previously asymptomatic labral tears who may later become symptomatic. QUESTIONS/PURPOSES: The purpose of this study was to determine (1) the prevalence of labral tears and other intraarticular pathology in the asymptomatic contralateral hip of patients undergoing surgery for symptomatic FAI; (2) the likelihood that the asymptomatic hip had become symptomatic at latest followup; and (3) any association between MRI findings and age, sex, and body mass index (BMI) in both symptomatic and asymptomatic sides. METHODS: This study included patients who were diagnosed with unilateral symptomatic FAI between 2013 and 2015 and who had an available MRI of both hips. The study included 100 patients (47 females, 53 males) with a mean age of 33 years (range, 17-57 years). Patients with a symptomatic contralateral hip (n = 56) or an unsuitable MRI for review based on both reviewers' consensus (n = 344) were excluded. The MRI of both hips was independently evaluated by two orthopaedic surgeons and interobserver reliability tested. The interobserver reliability for the two surgeons' MRI ratings was almost perfect (κ ≥ 0.85). The presence of a labral tear, an acetabular chondral lesion, subchondral acetabular cysts, and fibrocystic changes in the femoral head-neck junction was documented for both hips. At latest followup, asymptomatic hips were investigated for any symptomatic labral tears or surgical procedures resulting from FAI. RESULTS: A labral tear was recorded in 97 (97%) and 96 (96%) of symptomatic hips, respectively, for each surgeon's evaluation. A labral tear was also detected in 41 (41%) and 43 (43%) of asymptomatic hips. In addition, an acetabular chondral lesion was detected in 32 (32%) and 35 (35%) of the symptomatic hips and 15 (15%) and 17 (17%) of the asymptomatic hips. At latest followup, nine of the patients were diagnosed with symptomatic labral tears in the contralateral asymptomatic hip and were treated. None of the radiologic parameters examined demonstrated an association with patient age, sex, or BMI in either symptomatic or asymptomatic hips. CONCLUSIONS: Labral tears and acetabular chondral lesions are common in the asymptomatic contralateral hip of patients undergoing surgery for FAI. The incidence of a symptomatic labral tear in these asymptomatic hips was 9% during 2 years of followup. We suggest that the decision to perform chondral or labral surgery in patients with FAI should be made with caution considering the relatively high prevalence of labral tears in asymptomatic hips and the low chance of development of symptoms. LEVEL OF EVIDENCE: Level IV, case-series study.

Acetabular Retroversion Is a Risk Factor for Less Optimal Outcome After Femoroacetabular Impingement Surgery.

BACKGROUND: Patients with acetabular retroversion are at risk of labral tear and hip pain. It is unknown whether femoroacetabular osteoplasty (FAO) without reverse periacetabular osteotomy can be used in these patients. This study evaluated the outcome of mini-open FAO in patients with acetabular retroversion and compared that to patients without acetabular retroversion. METHODS: Fifty-one patients (29 male, 22 female) with acetabular retroversion who had undergone FAO between 2007 and 2015 were identified. The minimum 2-year clinical and radiological outcome was compared with 550 patients without dysplasia or retroversion who underwent FAO by the same surgeon. The preoperative and postoperative alpha angle, center-edge angle, Tonnis grade, joint space, and presence of labral tear and chondral lesion were determined. RESULTS: The mean age in the retroversion cohort was 27.4 ± 9.5 years compared to 34.5 ± 11.2 years in the control. The mean follow-up was 4.8 ± 1.5 years for retroversion and 4.1 ± 1.2 years for the control. The mean preoperative Short-Form 36 Health Survey and modified Harris hip score were not different between the cohorts. At the latest follow-up, the mean modified Harris hip score and Short-Form 36 Health Survey were significantly lower in the retroversion group (75.4 and 76.5) compared to the control (83.4 and 85.6). There was a higher percentage of failure among retroversion patients (13.7%) compared to the control (2.5%). CONCLUSION: Acetabular retroversion resulting in femoroacetabular impingent may be treated by FAO, but the outcome appears to be less optimal compared to patients with femoroacetabular impingent and no evidence of dysplasia and acetabular retroversion. Hip preservation surgeons should be aware of this anatomic variation and possible inferior treatment results after FAO in these patients.

Hip Dysplasia Compromises the Outcome of Femoroacetabular Impingement Surgery.

BACKGROUND: The optimal treatment for patients with symptomatic hip dysplasia presenting with labral tear is unknown. Although femoroacetabular osteoplasty (FAO) has excellent outcome for most femoroacetabular impingement patients, the presence of concomitant hip dysplasia has been implicated as an adverse prognostic factor. This study evaluated the outcome of FAO in a group of dysplastic hips and compared the outcome to a cohort of patients without dysplasia. METHODS: Seventy-three patients (38 males, 35 females) with hip dysplasia who underwent FAO between 2007 and 2015 were identified. The minimum 2-year clinical, functional (modified Harris Hip Score and Short-Form 36 Health Survey), and radiological outcome was compared with 550 patients without dysplasia who underwent FAO by the same surgeon. The preoperative and postoperative alpha angle, Tonnis grade, joint space, and presence of chondral lesion were determined and compared. Conversion to total hip arthroplasty or revision FAO was considered as treatment failure. RESULTS: The mean age in the dysplasia cohort was 30.7 ± 11.8 years compared to 34.5 ± 11.2 in the nondysplastic group. The mean follow-up was 4.3 years for dysplasia cohort and 4.1 for the nondysplastic group. The mean modified Harris Hip Score and Short-Form 36 Health Survey6 was significantly lower in the dysplastic group at 75.1 and 74.3 compared to 83.4 and 85.6 for the comparison group. There was a higher percentage of failure at 28.8% among dysplasia patients compared to 2.5% in the nondysplastic group. CONCLUSION: Although labral repair and FAO may be an option for patients with hip dysplasia, the outcome in this population appears to be less optimal compared to femoroacetabular impingement patients with no evidence of dysplasia. Labral repair and osteoplasty should be limited to those with mild and borderline dysplasia.

Longer Operative Time Results in a Higher Rate of Subsequent Periprosthetic Joint Infection in Patients Undergoing Primary Joint Arthroplasty.

BACKGROUND: Whether prolonged operative time is an independent risk factor for subsequent surgical site infection (SSI) and periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant and underexplored issue. The aim of this study is to investigate the association between operative time and the risk of subsequent SSI and PJI in patients undergoing primary TJA. METHODS: We retrospectively reviewed 17,342 primary unilateral total knee arthroplasty and total hip arthroplasty performed at a single institution between 2005 and 2016, with a minimum follow-up of 1 year. A multivariate logistic regression model was conducted to identify the association between operative time and the development of SSI within 90 days and PJI within 1 year. RESULTS: Overall, the incidence of 90-day SSI and 1-year PJI was 1.2% and 0.8%, respectively. Patients with an operative time of >90 minutes had a significantly higher incidence of SSI and PJI (2.1% and 1.4%, respectively) compared to cases lasting between 60 and 90 minutes (1.1% and 0.7%), and those lasting ≤60 minutes (0.9% and 0.7%, P < .01). In the multivariate model, the risk for infection increased by an odds ratio of 1.346 (95% confidential interval 1.114-1.627) for 90-day SSI and 1.253 (95% confidential interval 1.060-1.481) for 1-year PJI for each 20-minute increase in operative time. CONCLUSION: In patients undergoing primary TJA, each 20-minute increase in operative time was associated with nearly a 25% increased risk of subsequent PJI. We advocate that surgeons pay close attention to this underappreciated risk factor while maintaining safe operative practices, which minimize unnecessary steps and wasted time in the operating room.

Extended Antibiotic Prophylaxis Confers No Benefit Following Aseptic Revision Total Hip Arthroplasty: A Matched Case-Controlled Study.

BACKGROUND: Administration of perioperative antibiotic prophylaxis is one of the most important practices for prevention of periprosthetic joint infection (PJI) in patients undergoing total hip arthroplasty (THA). It is common to continue perioperative antibiotic prophylaxis for 48 hours or longer in patients undergoing revision arthroplasty, until results of intraoperative culture samples become available. However, the utility of this practice remains unclear. We examined whether extended antibiotic prophylaxis following aseptic revision THA reduces the risk of subsequent PJI. METHODS: We retrospectively reviewed records of patients undergoing aseptic revision THA between January 2000 and December 2015. At our institution, some surgeons administer prophylactic antibiotics to revision patients for only 24 hours while others prefer to extend until intraoperative culture results become available. We matched 209 patients undergoing revision THA who received extended antibiotic prophylaxis (>24 hours) in a 1:1 ratio with 209 patients receiving standard antibiotic prophylaxis (≤24 hours). The matching criteria were age, sex, body mass index, Charlson comorbidity index, and operative time. RESULTS: The incidence of subsequent PJI was 4.8% in patients receiving extended antibiotic prophylaxis vs 2.4% in patients receiving standard. After adjusting for all cofounders and using multivariate logistic regression, the administration of extended prophylactic antibiotics did not reduce the incidence of subsequent infection. When stratified by postoperative antibiotic regimens, the 2 groups had similar infection-free implant survival rate (95.2% in extended and 97.6% in standard). CONCLUSION: It appears that extending perioperative prophylactic antibiotics until intraoperative culture results become available in patients undergoing revision THA for aseptic failures does not provide any additional benefit in terms of reducing the risk of subsequent PJI.

Malnutrition and the Development of Periprosthetic Joint Infection in Patients Undergoing Primary Elective Total Joint Arthroplasty.

BACKGROUND: Although an abundance of literature exists linking malnutrition with infectious complications in surgical patients, there is little specifically examining the link between malnutrition and periprosthetic joint infection (PJI). This study evaluated the relationship between abnormal nutritional parameters and development of PJI in patients undergoing primary total joint arthroplasty (TJA). METHODS: We retrospectively reviewed TJA patients from 2000 to 2016 with preoperative nutritional screening at a single institution. Any development of PJI at 2 years was assessed as the primary outcome. The Musculoskeletal Infection society criteria were used to define PJI. The association between the aforementioned nutritional markers and PJI was evaluated in a bivariate analysis followed by multivariate logistic regression. Performance for markers was assessed using receiver operator characteristic curves. Sensitivity and specificity were also compared. RESULTS: Multivariate analysis demonstrated that low albumin (adjusted odds ratio [OR], 4.69; 95% confidence interval [CI], 2.428-9.085; P < .001) and low hemoglobin (adjusted OR, 2.718; 95% CI, 1.100-2.718; P = .018) were significantly associated with PJI. Albumin had the highest specificity and (95% CI, 97.8%-98.4%) and positive predictive value compared to all other markers. Platelet-to-white blood cell ratio had the highest sensitivity (95% CI, 29.5%-40.3%). The area under the curve was greatest for albumin (0.61; 95% CI, 0.55-0.67) followed by hemoglobin (0.57; 95% CI, 0.51-0.63), platelets (0.56; 95% CI, 0.50-0.62), and platelet-to-white blood cell ratio (0.54; 95% CI, 0.49-0.60). CONCLUSION: The most valuable predictor of PJI following primary TJA, among nutritional parameters examined, was preoperative albumin with a very high specificity and positive predictive value.

Available Findings Fail to Provide Strong Evidence of the Role of Bone Morphogenic Protein-2 in Femoral Head Osteonecrosis.

Despite widespread research on non-traumatic femoral head osteonecrosis (FHON), there is no consensus about preventative treatment options. Insufficient blood supply and increased intra-osseous pressure are the initiating events in the majority of cases. BMPs are growth factors that belong to the transforming growth factor ß (TGFß) superfamily. Two specific formulations of BMPs have already been approved by the FDA: 1. BMP-2 (Infused, Medtronic) for the treatment of tibial open fractures and spinal fusion; 2. BMP-7 (OP-1, Stryker) in the setting of long bone non-unions. To our knowledge there is no published work reviewing the utility of BMP-2 in the setting of FHON. Online databases (EMBASE, Cochrane, MEDLINE and PubMed) for literature relating to the use of BMP-2 in the treatment of FHON on 2nd June 2017. Animal studies: A total of 169 animal subjects with induced FHON were treated with BMP-2 in all the included in vivo studies. Improved histological parameters, areas of revascularization, areas of new bone formation and osteoid deposition were seen in all studies. The number of osteoclasts decreased post operatively, in the ibandronate and BMP-2 group. Human studies: In combination, 96 human hips were treated in two studies utilizing BMP-2 and mean follow-up was at least five years. Success rate of BMP-2 was above 80 % (based on Harris score and WOMAC score) in both studies. Both are level III studies. The present review of animal and clinical studies could not find well-designed prospective comparable studies with large sample size and preliminary evidence is not sufficient to supports the utilization of BMP-2, and its impact on the midterm outcomes of FHON.