Jeffrey J. Nepple

Risk factors for surgical site infection following orthopaedic spinal operations.

BACKGROUND Surgical site infections are not uncommon following spinal operations, and they can be associated with serious morbidity, mortality, and increased resource utilization. The accurate identification of risk factors is essential to develop strategies to prevent these potentially devastating infections. We conducted a case-control study to determine independent risk factors for surgical site infection following orthopaedic spinal operations. METHODS We performed a retrospective case-control study of patients who had had an orthopaedic spinal operation performed at a university-affiliated tertiary-care hospital from 1998 to 2002. Forty-six patients with a superficial, deep, or organ-space surgical site infection were identified and compared with 227 uninfected control patients. Risk factors for surgical site infection were determined with univariate analyses and multivariate logistic regression. RESULTS The overall rate of spinal surgical site infection during the five years of the study was 2.0% (forty-six of 2316). Univariate analyses showed serum glucose levels, preoperatively and within five days after the operation, to be significantly higher in patients in whom surgical site infection developed than in uninfected control patients. Independent risk factors for surgical site infection that were identified by multivariate analysis were diabetes (odds ratio = 3.5, 95% confidence interval = 1.2, 10.0), suboptimal timing of prophylactic antibiotic therapy (odds ratio = 3.4, 95% confidence interval = 1.5, 7.9), a preoperative serum glucose level of >125 mg/dL (>6.9 mmol/L) or a postoperative serum glucose level of >200 mg/dL (>11.1 mmol/L) (odds ratio = 3.3, 95% confidence interval = 1.4, 7.5), obesity (odds ratio = 2.2, 95% confidence interval = 1.1, 4.7), and two or more surgical residents participating in the operative procedure (odds ratio = 2.2, 95% confidence interval = 1.0, 4.7). A decreased risk of surgical site infection was associated with operations involving the cervical spine (odds ratio = 0.3, 95% confidence interval = 0.1, 0.6). CONCLUSIONS Diabetes was associated with the highest independent risk of spinal surgical site infection, and an elevated preoperative or postoperative serum glucose level was also independently associated with an increased risk of surgical site infection. The role of hyperglycemia as a risk factor for surgical site infection in patients not previously diagnosed with diabetes should be investigated further. Administration of prophylactic antibiotics within one hour before the operation and increasing the antibiotic dosage to adjust for obesity are also important strategies to decrease the risk of surgical site infection after spinal operations.

Meniscal repair outcomes at greater than five years: a systematic literature review and meta-analysis.

BACKGROUND Meniscal repair offers the potential to avoid the long-term articular cartilage deterioration that has been shown to result after meniscectomy. Failure of the meniscal repair can occur several years postoperatively. Limited evidence on the long-term outcomes of meniscal repair exists. METHODS We performed a systematic review of studies reporting the outcomes of meniscal repair at a minimum of five years postoperatively. Pooling of data and meta-analysis with a random-effects model were performed to evaluate the results. RESULTS Thirteen studies met the inclusion criteria. The pooled rate of meniscal repair failure (reoperation or clinical failure) was 23.1% (131 of 566). The pooled rate of failure varied from 20.2% to 24.3% depending on the status of the anterior cruciate ligament (ACL), the meniscus repaired, and the technique utilized. The rate of failure was similar for the medial and the lateral meniscus as well as for patients with an intact and a reconstructed ACL. CONCLUSIONS A systematic review of the outcomes of meniscal repair at greater than five years postoperatively demonstrated very similar rates of meniscal failure (22.3% to 24.3%) for all techniques investigated. The outcomes of meniscal repair at greater than five years postoperatively have not yet been reported for modern all-inside repair devices.

Arthroscopic Disease Classification and Interventions as an Adjunct in the Treatment of Acetabular Dysplasia

Background Treatment of hip dysplasia has focused on corrective osteotomy surgery, while hip arthroscopy remains controversial. Improved understanding of intra-articular disease patterns associated with hip dysplasia will help delineate the role of arthroscopy as an adjunct to osteotomy surgery for dysplastic hips. Purpose The authors set out to describe the intra-articular disease patterns of patients undergoing combined hip arthroscopy and periacetabular osteotomy for the treatment of symptomatic acetabular dysplasia with associated mechanical symptoms. Secondly, they wanted to identify the potential role for arthroscopy in treating intra-articular problems as an adjunct to acetabular reorientation surgery. Study Design Case series; Level of evidence, 4. Methods Seventy-three hips in 71 patients undergoing arthroscopy for mechanical symptoms before a redirectional osteotomy of the acetabulum were reviewed. Radiographic findings of acetabular dysplasia were compared with intraoperative labral and chondral disease patterns. Arthroscopic interventions were recorded. Results Labral tears and acetabular cartilage lesions were present in 65.8% and 68.5% of hips, respectively. Combined acetabular articular cartilage lesions and labral disease were observed in 58.9% of hips. When disease was present, acetabular labrum and chondral lesions were primarily located at the anterior (81.0%, 76.0%) and superolateral (66.7%, 84.0%) labrochondral junctions. A lateral center-edge angle <15° was associated with an increased likelihood of acetabular chondromalacia, as well as moderate to severe acetabular cartilage disease. An acetabular inclination of >20° was associated with an increased risk of larger labral tears (>2 cm). Sixty-three percent had at least 1 arthroscopic treatment of central compartment disease, most commonly acetabular chondroplasty (30.1%), partial labral resection (26.0%), and labral repair (16.4%). Conclusion Acetabular rim disease is common in symptomatic acetabular dysplasia, and 63% of cases have a central compartment abnormality amenable to arthroscopic treatment. Lateral center-edge angle <15° and acetabular inclination >20° are associated with more severe labrochondral disease.

Combined hip arthroscopy and limited open osteochondroplasty for anterior femoroacetabular impingement

BACKGROUND A variety of surgical techniques have been introduced for the treatment of femoroacetabular impingement, but clinical outcome studies of less-invasive treatment with a minimum duration of follow-up of two years are limited. The purpose of this study was to evaluate the early clinical and radiographic outcomes of combined hip arthroscopy and limited open osteochondroplasty of the femoral head-neck junction for the treatment of cam femoroacetabular impingement. METHODS We performed a retrospective review of our first thirty-five patients (thirty-five hips) in whom cam femoroacetabular impingement had been treated with combined hip arthroscopy and limited open osteochondroplasty. Thirty-five patients (twenty-eight men and seven women) with an average age of thirty-four years and a minimum duration of follow-up of two years were analyzed. The modified Harris hip score was utilized to assess hip function. The Tönnis osteoarthritis grade and the alpha angle were determined to assess osteoarthritis progression and deformity correction, respectively. RESULTS The average modified Harris hip score improved from 63.8 points preoperatively to 87.4 points at the time of the last follow-up. Twenty-nine (83%) of the thirty-five patients had at least a 10-point improvement in the Harris hip score, and 71% had a score of >80 points. The average alpha angle was reduced from 58.6 degrees preoperatively to 37.1 degrees at the time of follow-up when measured on cross-table lateral radiographs, from 63.9 degrees to 37.8 degrees when measured on frog-leg lateral radiographs, and from 63.1 degrees to 44.8 degrees when measured on anteroposterior radiographs. Two patients had osteoarthritis progression from Tönnis grade 0 to grade 1. Minor complications included one superficial wound infection, one deep vein thrombosis, and four cases of asymptomatic Brooker grade-I heterotopic ossification. There were no femoral neck fractures or cases of femoral head osteonecrosis, and no hip was converted to an arthroplasty. CONCLUSIONS Early results indicate that combined hip arthroscopy and limited open osteochondroplasty of the femoral head-neck junction is a safe and effective treatment for femoroacetabular impingement. In our small series, most patients had symptomatic relief, improved hip function, and enhanced activity after two years of follow-up.

Clinical and Radiographic Predictors of Intra-articular Hip Disease in Arthroscopy

Background: The arthroscopic treatment of intra-articular hip disease and associated structural abnormalities continues to evolve. Nevertheless, contemporary diagnostic tools have significant limitations in predicting severity of disease preoperatively. Hypothesis: Clinical characteristics and radiographic parameters correlate with and predict intra-articular disease patterns in patients undergoing hip arthroscopy. Study Design: Cohort study; Level of evidence, 3. Methods: In sum, 355 hips in 338 patients undergoing hip arthroscopy by a single surgeon were retrospectively reviewed. Clinical characteristics and radiographic findings (on anteroposterior pelvis and frog lateral radiographs) of mild dysplasia, cam, and pincer-type femoroacetabular impingement were compared with intraoperative labral and chondral disease patterns. Results: Labral tears were present in 90.1% of hips, and acetabular cartilage lesions were present in 67.3%, including 41.7% with grade 3 or 4 chondromalacia. Multivariate logistic regression analysis found male sex, older age (<30, 30-50, >50 years old), Tönnis osteoarthritis grade, and alpha angle >50° on frog lateral radiograph to be independently associated with increased risk of grade 3 or 4 acetabular chondromalacia (all P < .001). Insidious onset of pain (in contrast to acute onset) was independently associated with the presence of acetabular chondromalacia (P = .002). Cam-type femoroacetabular impingement (alpha angle >50°) was strongly associated with more severe labral disease (P < .001). Findings of acetabular dysplasia and pincer femoroacetabular impingement did not remain significantly associated with acetabular chondral disease in the multivariate analysis. Conclusion: Several clinical and radiographic characteristics—most notably, male sex, older age, Tönnis grade, and elevated alpha angle—are associated with more severe intra-articular hip disease. The recognition of these associations between clinical and radiographic characteristics and hip disease patterns is important for patient selection, surgical planning, and patient counseling.

Radiographic Findings of Femoroacetabular Impingement in National Football League Combine Athletes Undergoing Radiographs for Previous Hip or Groin Pain

PURPOSE The purpose of this study was to investigate the prevalence of radiographic findings of femoroacetabular impingement (FAI) in elite football players with a history of hip pain or groin injury who underwent radiographs. METHODS We performed a retrospective review of athletes undergoing hip radiography at the National Football League Combine from 2007 to 2009. Radiographs were obtained in athletes with a history of hip pain or injury. Anteroposterior pelvis and frog-lateral radiographs were obtained in 123 hips (107 players) that met our inclusion criteria. Radiographic indicators of cam-type FAI (alpha angle, head-neck offset ratio) and pincer-type FAI (acetabular retroversion, center-edge angle, acetabular inclination) were recorded. Findings were correlated with clinical factors (previous groin/hip pain, position, race, and body mass index). RESULTS The most common previous injuries included groin strain (n = 57) and sports hernia/abdominal strain (n = 21). Markers of cam- and/or pincer-type FAI were present in 94.3% of hips (116 of 123). Radiographic evidence of combined cam- and pincer-type FAI was the most common (61.8%, 76 hips), whereas isolated cam-type FAI (9.8%, 12 hips) and pincer-type FAI (22.8%, 28 hips) were less common. The most common deformities included acetabular retroversion (71.5%) and an abnormal alpha angle (61.8%). A body mass index greater than 35 was associated with the presence of global overcoverage (46.2% v 17.3%, P = .025). CONCLUSIONS Radiographic indicators of FAI are very common among athletes evaluated at the National Football League Scouting Combine subjected to radiographic examination for the clinical suspicion of hip disease. Elite football athletes with significant or recurrent pain about the hip should be evaluated clinically and radiographically for FAI, because pain from FAI may be falsely attributed to or may be present in addition to other disorders. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Do plain radiographs correlate with CT for imaging of cam-type femoroacetabular impingement?

BackgroundThree-dimensional imaging (CT and MRI) is the gold standard for detecting femoral head-neck junction malformations in femoroacetabular impingement, yet plain radiographs are used for initial diagnostic evaluation. It is unclear, however, whether the plain radiographs accurately reflect the findings on three-dimensional imaging.Questions/PurposesWe therefore: (1) investigated the correlation of alpha angle measurements on plain radiographs and radial reformats of CT scans; (2) determined which radiographic views are most sensitive and specific in detecting head-neck deformities present on CT scans; and (3) determined if specific radiographic views correlated with specific locations on the radial oblique CT scan.MethodsWe retrospectively reviewed 41 surgical patients with preoperative CT scans (radial oblique reformats) and plain radiographs (AP pelvis, 45° Dunn, frog lateral, and crosstable lateral). Alpha angles were measured on plain radiographs and CT reformats.ResultsThe complete radiographic series was 86% to 90% sensitive in detecting abnormal alpha angles on CT. The maximum alpha angle on plain radiographs was greater than that of CT reformats in 61% of cases. Exclusion of the crosstable lateral did not affect the sensitivity (86%–88%). The Dunn view was most sensitive (71%–80%). The frog lateral showed the best specificity (91%–100%). Substantial correlations (intraclass correlation coefficients, 0.64–0.75) between radiograph and radial oblique CT position were observed, including AP/12:00 (superior), Dunn/1:00 (anterolateral), frog/3:00 (anterior), and crosstable/3:00 (anterior).ConclusionsFor diagnostic and treatment purposes, a three-view radiographic hip series (AP pelvis, 45° Dunn, and frog lateral) effectively characterizes femoral head-neck junction malformations.Level of EvidenceLevel II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Coxa profunda is not a useful radiographic parameter for diagnosing pincer-type femoroacetabular impingement

BACKGROUND Coxa profunda is commonly viewed as a radiographic parameter that is indicative of pincer-type femoroacetabular impingement, and this finding can impact diagnostic and surgical decision-making. Validation of coxa profunda as a measure of pincer-type femoroacetabular impingement has not been rigorously analyzed. Our hypothesis was that coxa profunda is a very common radiographic finding in females and is not a finding that is specifically associated with pincer-type femoroacetabular impingement. METHODS A retrospective review was performed to determine the prevalence of coxa profunda in four groups of hips: those with acetabular dysplasia (fifty-eight hips), femoroacetabular impingement (fifty hips), symptomatic residual Legg-Calvé-Perthes deformities (sixteen hips), and asymptomatic hips (thirty-three). Coxa profunda was present when the floor of the acetabular fossa touched or was medial to the ilioischial line. The association between coxa profunda and hip disorder diagnosis, lateral center-edge angle, acetabular inclination, patient age, and sex was analyzed. RESULTS Coxa profunda was seen in 55% of the 157 hips and was slightly less common in the hips with acetabular dysplasia or residual Legg-Calvé-Perthes deformities (41% and 31%, respectively). Coxa profunda was evident in 76% of the thirty-three asymptomatic hips compared with 64% of the fifty hips with femoroacetabular impingement. Coxa profunda was more common in females than males (70% compared with 24%; p < 0.001). Acetabular overcoverage (a lateral center-edge angle of >40° or acetabular inclination of <0°) was seen in only 22% of hips with coxa profunda. CONCLUSIONS Coxa profunda should be considered a normal radiographic finding, at least in females. Coxa profunda is a nonspecific radiographic finding, seen in a variety of hip disorders and asymptomatic hips. The presence of coxa profunda is neither necessary nor sufficient to support a diagnosis of pincer-type femoroacetabular impingement.

Effect of Changes in Pelvic Tilt on Range of Motion to Impingement and Radiographic Parameters of Acetabular Morphologic Characteristics

Background: The current understanding of the effect of dynamic changes in pelvic tilt on the functional acetabular orientation and occurrence of femoroacetabular impingement (FAI) is limited. Purpose: To determine the effect of changes in pelvic tilt on (1) terminal hip range of motion and (2) measurements of acetabular version as assessed on 2- and 3-dimensional imaging. Study Design: Controlled laboratory study. Methods: Preoperative pelvic computed tomographic scans of 48 patients (50 hips) who underwent arthroscopic surgery for the treatment of FAI were analyzed. The mean age of the study population was 25.7 years (range, 14-56 years), and 56% were male. Three-dimensional models of the hips were created, allowing manipulation of the pelvic tilt and simulation of hip range of motion to osseous contact. Acetabular version was measured and the presence of the crossover sign, prominent ischial spine sign, and posterior wall sign was recorded on simulated plain radiographs. Measurements of range of motion to bony impingement during (1) hip flexion, (2) internal rotation in 90° of flexion, and (3) internal rotation in 90° of flexion and 15° adduction were performed, and the location of bony contact between the proximal femur and acetabular rim was defined. These measurements were calculated for −10° (posterior), 0° (native), and +10° (anterior) pelvic orientations. Results: In native tilt, mean cranial acetabular version was 3.3°, while central version averaged 16.2°. Anterior pelvic tilt (10° change) resulted in significant retroversion, with mean decreases in cranial and central version of 5.9° and 5.8°, respectively (P < .0001 for both). Additionally, this resulted in a significantly increased proportion of positive crossover, posterior wall, and prominent ischial spine signs (P < .001 for all). Anterior pelvic tilt (10° change) resulted in a decrease in internal rotation in 90° of flexion of 5.9° (P < .0001) and internal rotation in 90° of flexion and 15° adduction of 8.5° (P < .0001), with a shift in the location of osseous impingement more anteriorly. Posterior pelvic tilt (10° change) resulted in an increase in internal rotation in 90° of flexion of 5.1° (P < .0001) and internal rotation in 90° of flexion and 15° adduction of 7.4° (P < .0001), with a superolateral shift in the location of osseous impingement. Conclusion/Clinical Relevance: Dynamic changes in pelvic tilt significantly influence the functional orientation of the acetabulum and must be considered. Dynamic anterior pelvic tilt is predicted to result in earlier occurrence of FAI in the arc of motion, whereas dynamic posterior pelvic tilt results in later occurrence of FAI, which may have implications regarding nonsurgical treatments for FAI.

What Is the Association Between Sports Participation and the Development of Proximal Femoral Cam Deformity?: A Systematic Review and Meta-analysis

Background: Femoroacetabular impingement (FAI) is recognized as a common cause of hip pain and intra-articular disorders in athletes. Studies have suggested a link between participation in athletics during adolescence and the development of cam-type deformities of the proximal femoral head-neck junction. Purpose: To investigate the association of sporting activity participation during adolescence and the development of cam deformity. Study Design: Systematic review. Methods: The PubMed, EMBASE, and Cochrane databases were searched to identify potential studies. Abstracts and manuscripts (when applicable) were independently reviewed by 2 reviewers. Nine studies met the inclusion criteria, including 8 studies that compared the prevalence of cam deformity in athletes with that in controls and 3 studies that compared the prevalence of cam deformity before and after physeal closure (2 with both). A meta-analysis was performed with pooling of data and random-effects modeling to compare rates of cam deformity between athletes and controls. Results: High-level male athletes are 1.9 to 8.0 times more likely to develop a cam deformity than are male controls. The pooled prevalence rate (by hip) of cam deformity in male athletes was 41%, compared with 17% for male controls. The pooled mean alpha angle among male athletes was 61°, compared with 51° for male controls. Conclusion: Males participating in specific high-level impact sports (hockey, basketball, and possibly soccer) are at an increased risk of physeal abnormalities of the anterosuperior head-neck junction that result in a cam deformity at skeletal maturity.