Faculty Bibliography

BACKGROUND: Hemiarthroplasty (HA) has been a mainstay treatment for displaced femoral neck fractures for many years. The purpose of this study was to report the conversion rate of HA to total hip arthroplasty (THA) for displaced femoral neck fractures and compare outcomes between implant constructs (bipolar vs unipolar), fixation options (cemented vs cementless stems), and age groups (<75 years vs >/=75 years). METHODS: We retrospectively reviewed the results of a consecutive cohort of 686 patients who underwent HA for the treatment of femoral neck fractures at our institution between 1999 and 2013 with a minimum of 2-year follow-up. RESULTS: The overall component revision rate, including conversion to THA, revision HA, revision with open reduction internal fixation, and Girdlestone procedure, was 5.6% (39/686). Seventeen patients (2.5%) were converted from HA to THA at an average of 1.9 years after index procedure. A significantly lower conversion rate of 1.4% (7/499 patients) was found in the older patient cohort (>/=75 years old) compared to 5.3% (11/187) in the younger cohort. The most common causes for conversion surgery to THA were acetabular wear (5 patients), aseptic loosening (4 patients), and periprosthetic fracture (3 patients). There was a significantly lower rate of periprosthetic fracture (0.4% vs 2.5%, P value .025) in the cemented implant group compared to the cementless group. We observed a higher rate of dislocations in the bipolar vs unipolar group (3.8% vs 1%, P value .02) and no other significant differences between these groups. CONCLUSION: We observed a low reoperation rate for this cohort of patients, relatively higher conversion rates for the younger population, fewer periprosthetic fractures with the use of cemented stems, and no advantage of bipolar over unipolar prostheses.

BACKGROUND: The goal of this study was to evaluate the effectiveness of the American Orthopaedic Association's Own the Bone secondary fracture prevention program in the United States. METHODS: The objective of this quality improvement cohort study was dissemination of Own the Bone and implementation of secondary prevention (osteoporosis pharmacologic and bone mineral density [BMD] test recommendations). The main outcome measures were the number of sites implementing Own the Bone and implementation of secondary prevention, i.e., orders for BMD testing and/or pharmacologic treatment. The 177 sites participating in the program were academic and community hospitals, orthopaedic surgery groups, and a health system; data were obtained from the first 125 sites utilizing its registry, between January 1, 2010, and March 31, 2015. It included all patients, aged 50 years or older, presenting with fragility fractures (n = 23,132) who were enrolled in the Own the Bone web-based registry. The interventions were education, development of program elements, dissemination, implementation, and evaluation of the Own the Bone program at participating sites. RESULTS: A growing number of institutions implemented Own the Bone (14 sites in 2005-2006 to 177 sites in 2015). After consultation, 53% of patients had a BMD test ordered and/or pharmacologic therapy for osteoporosis. CONCLUSIONS: The Own the Bone intervention has succeeded in improving the behaviors of medical professionals in the areas of osteoporosis treatment and counseling, BMD testing, initiation of pharmacotherapy, and coordination of care for patients who have experienced a fragility fracture.

BACKGROUND: The purpose of this study is to compare acetabular component version measurements from cross-table lateral (XTL) radiographs, anteroposterior pelvis (AP-P) and anteroposterior hip (AP-H) radiographs, and axial pelvic computed tomography (CT) scans. METHODS: One hundred fifty hips met our inclusion criteria of having a CT, XTL, and AP-P done postoperatively. Version was measured by 2 authors. Pearson regression analysis assessed correlation between versions of the modalities. Analysis of variance testing compared the averages of the values as a whole and based on demographics. When available, comparisons were also done with AP-H radiographs. RESULTS: Mean version for XTL and CT scan was 21.7 degrees and 23.8 degrees , respectively, whereas that from AP-P and AP-H radiographs was 12.5 degrees and 17.2 degrees , respectively. XTL and AP-H version measures were closely correlated with CT (P = .81), whereas AP-P measurements were only moderately correlated with CT (P = .75). AP-P and AP-H were significantly (P < .05) different from CT, whereas XTL was not (P = .36). CONCLUSION: The XTL radiograph remains a useful, cheaper, and safer substitute for CT scan when assessing supine version in the postoperative setting.

BACKGROUND: Significant variability exists across orthopedic surgeons in the management of the displaced femoral neck fracture in the elderly patient (>75 years old). These patients tend to be less healthy, have inferior bone quality, and gait instability leading to increased risk of periprosthetic fracture, compromised implant fixation, dislocation, and need for revision. The surgeon's goals should be to restore mobility while eliminating pain and need for reoperation. METHODS: In this review article, we examine the best available evidence in the literature to determine which strategy achieves optimal outcomes. We examine outcome studies comparing use of hemiarthroplasty and total hip arthroplasty, unipolar and bipolar hemiarthroplasty, and cemented vs cementless fixation of femoral stems. RESULTS AND CONCLUSIONS: For the active, healthy, and lucid patient, or one who has preexisting groin pain, who sustains a displaced femoral neck fracture, the literature supports a total hip arthroplasty. Patients sustaining a displaced femoral neck fracture and who are less active, have decreased bone mass, and are at increased risk of falls would benefit most from a device that optimally balances the need for revision surgery, restores ambulation, and eliminates pain. Thus, the current evidence favors cemented, unipolar hemiarthroplasty for the dependent osteopenic elderly patient with a displaced femoral neck fracture.

BACKGROUND: This study evaluated patient-reported outcomes in patients undergoing primary total hip arthroplasty with a polyethylene liner to determine the influence of cup orientation and other variables on patient-reported outcomes. METHODS: A total of 477 cases were prospectively monitored through average 4.7 years follow-up. Cup position was measured on pelvis radiographs. Patients completed the Western Ontario and McMaster Universities Osteoarthritis Index and Short Form 12 Health Survey questionnaires. RESULTS: Average cup abduction was 43.1 degrees +/- 7.5 degrees and anteversion was 13.3 degrees +/- 7.5 degrees . Three hundred cups were within the target zone. All outcomes' improvement from baseline and cup position was not an independent risk factor for the Western Ontario and McMaster Universities Osteoarthritis Index or Short Form 12 Health Survey improvement. CONCLUSION: Accurate cup orientation may not be critical to maximizing patient-perceived outcomes if the combined anteversion is within a normal range, the hip joint is properly balanced, and a polyethylene liner is coupled with a metal or ceramic femoral head.

BACKGROUND: Acetabular component orientation influences joint stability in total hip arthroplasty (THA). The purpose of this study was to evaluate the effect of cup orientation and other variables on hip dislocation risk and to define a posterior approach specific safe zone. METHODS: A cohort of 1289 posterior approach primary THA cases was prospectively followed and component position measured radiographically. RESULTS: Cup malposition, with respect to the Lewinnek safe zone, was an independent risk factor for dislocation (OR1.88). Modifying the anteversion safe zone limits to 10-25 degrees strongly predicted increased dislocation risk (OR2.69). No dislocations occurred within a zone defined by a circle centered at 41.4 degrees abduction and 17.1 degrees anteversion, radius 4.3 degrees . CONCLUSION: Utilizing a posterior approach specific safe zone of 10-25 degrees anteversion and 30-50 degrees abduction may minimize THA dislocations. LEVEL OF EVIDENCE: Level III.

BACKGROUND: Osteoporotic hip fractures are common injuries typically occurring in patients who are older and medically frail. Studies have suggested that creation of a multidisciplinary team including orthopaedic surgeons, internal medicine physicians, social workers, and specialized physical therapists, to comanage these patients can decrease complication rates, improve time to surgery, and reduce hospital length of stay; however, they have yet to achieve widespread implementation, partly owing to concerns regarding resource requirements necessary for a comanagement program. QUESTIONS/PURPOSES: We performed an economic analysis to determine whether implementation of a comanagement model of care for geriatric patients with osteoporotic hip fractures would be a cost-effective intervention at hospitals with moderate volume. We also calculated what annual volume of cases would be needed for a comanagement program to "break even", and finally we evaluated whether universal or risk-stratified comanagement was more cost effective. METHODS: Decision analysis techniques were used to model the effect of implementing a systems-based strategy to improve inpatient perioperative care. Costs were obtained from best-available literature and included salary to support personnel and resources to expedite time to the operating room. The major economic benefit was decreased initial hospital length of stay, which was determined via literature review and meta-analysis, and a health benefit was improvement in perioperative mortality owing to expedited preoperative evaluation based on previously conducted meta-analyses. A break-even analysis was conducted to determine the annual case volume necessary for comanagement to be either (1) cost effective (improve health-related quality of life enough to be worth additional expenses) or (2) result in cost savings (actually result in decreased total expenses). This calculation assumed the scenario in which a hospital could hire only one hospitalist (and therapist and social worker) on a full-time basis. Additionally, we evaluated the scenario where the necessary staff was already employed at the hospital and could be dedicated to a comanagement service on a part-time basis, and explored the effect of triaging only patients considered high risk to a comanagement service versus comanaging all geriatric patients. Finally, probabilistic sensitivity analysis was conducted on all critical variables, with broad ranges used for values around which there was higher uncertainty. RESULTS: For the base case, universal comanagement was more cost effective than traditional care and risk-stratified comanagement (incremental cost effectiveness ratios of USD 41,100 per quality-adjusted life-year and USD 81,900 per quality-adjusted life-year, respectively). Comanagement was more cost effective than traditional management as long as the case volume was more than 54 patients annually (range, 41-68 patients based on sensitivity analysis) and resulted in cost savings when there were more than 318 patients annually (range, 238-397 patients). In a scenario where staff could be partially dedicated to a comanagement service, universal comanagement was more cost effective than risk-stratified comanagement (incremental cost effectiveness of USD 2300 per quality-adjusted life-year), and both comanagement programs had lower costs and better outcomes compared with traditional management. Sensitivity analysis was conducted and showed that the level of uncertainty in key variables was not high enough to change the core conclusions of the model. CONCLUSIONS: Implementation of a systems-based comanagement strategy using a dedicated team to improve perioperative medical care and expedite preoperative evaluation is cost effective in hospitals with moderate volume and can result in cost savings at higher-volume centers. The optimum patient population for a comanagement strategy is still being defined. LEVEL OF EVIDENCE: Level 1, Economic and Decision Analysis.

Imaging used for the evaluation of knee pain has historically included weight-bearing anteroposterior (AP), lateral, and sunrise radiographs. We wished to evaluate the utility of adding the weight-bearing (WB) posteroanterior (PA) view of the knee in flexion. We hypothesize that (1) the WB tunnel view can detect radiographic osteoarthritis (OA) not visualized on the WB AP, (2) the combination of the AP and tunnel view increases the radiographic detection of OA, and (3) this may provide additional information to the clinician evaluating knee pain. We retrospectively reviewed the WB AP and tunnel view radiographs of 100 knees (74 patients) presenting with knee pain and analyzed for evidence of arthritis. The combination of the WB tunnel view and WB AP significantly increased the detection of joint space narrowing in the lateral (p < 0.001) and medial (p = 0.006) compartments over the AP view alone. The combined views significantly improved the identification of medial subchondral cysts (p = 0.022), sclerosis of the lateral tibial plateau (p = 0.041), and moderate-to-large osteophytes in the medial compartment (p = 0.012), intercondylar notch (p < 0.001), and tibial spine (p < 0.001). The WB tunnel view is an effective tool to provide additional information on affected compartments in the painful knee, not provided by the AP image alone.

Glomus tumors are rare neoplasms that are usually subungual in location, but can infrequently be found elsewhere in the body. When they occur in extradigital locations, they present a diagnostic challenge that may result in delay of definitive management. We report a case of a 51-year-old male who experienced decade long chronic pain because of a glomus tumor in the suprapatellar fat pad of the knee. This case is unique not only because of the glomus tumor's location, but also because it ultimately required ultrasound-guided needle localization for excision.