William Macaulay

Tip-apex distance of intramedullary devices as a predictor of cut-out failure in the treatment of peritrochanteric elderly hip fractures.

A tip-apex distance (TAD) of greater than 25xa0mm has been shown to be an accurate predictor of lag screw cut-out when sliding hip screws (SHS) are used to treat peritrochanteric (PT) hip fractures. The purpose of this study was to determine which factors, including TAD, correlated with successful clinical outcomes of PT hip fractures surgically treated with intramedullary (IM) devices. A total of 192 patients were included in this retrospective study. The TAD values of this cohort were radiographically analysed at a mean follow-up of 13xa0months. This was correlated with limited functional status and the rate of revision for implant failure or inability to achieve fracture union. Only 82 patients had adequate follow-up to fracture union or definitive failure. There were 46 intertrochanteric (IT) hip fractures and 36 subtrochanteric (ST) fractures. Overall, seven patients (8.5%) went on to experience lag screw cut-out. The average TAD of the patients who did not cut-out was 18xa0mm, compared to 38xa0mm for those who did (pu2009=u20090.012). All patients who cut-out had IT fractures (pu2009=u20090.017). The percentage of cut-outs correlated directly to both the severity of IT fractures and the TAD. Using a cutoff of 25xa0mm there was a statistically significant difference in the incidence of lag screw cut-out (pu2009<u20090.001). As in sliding hip screws, surgeons should strive for a TAD less than 25xa0mm when using IM devices in the treatment of PT hip fractures to help avoid lag screw cut-out.

Patient Education Before Hip or Knee Arthroplasty Lowers Length of Stay

From April 2006 to May 2007, 261 patients undergoing primary unilateral total hip arthroplasty or total knee arthroplasty were offered voluntary participation in a one-on-one preoperative educational program. Length of stay (LOS) and inpatient data were monitored and recorded, prospectively. Education participants enjoyed a significantly shorter LOS than nonparticipants for both total hip arthroplasty (3.1 +/- 0.8 days vs 3.9 +/- 1.4 days; P = .0001) and total knee arthroplasty (3.1 +/- 0.9 days vs 4.1 +/- 1.9 days; P = .001).

New developments in ochronosis: review of the literature

Ochronosis commonly affects all connective tissue. Recognition of changes secondary to the deposition of ochronotic pigments has increased with advances in diagnostic technology, allowing both improved imaging and early biochemical and genetics-based diagnosis of alkaptonuria, the cause of ochronosis. Successful symptomatic treatment of ochronotic arthropathy with joint replacement has been documented, and a new pharmacotherapeutic agent, nitisinone, is currently under investigation for both prevention and treatment of ochronosis. This review of the literature highlights recently recognized complications, new diagnostic techniques, and treatment options.

Imageless Computer Navigation in Total Knee Arthroplasty Provides Superior Short Term Functional Outcomes: A Meta-Analysis

Computer navigation in total knee arthroplasty (TKA) is intended to produce more reliable results, but its impact on functional outcomes has not been firmly demonstrated. Literature searches were performed for Level I randomized trials that compared TKA using imageless computer navigation to those performed with conventional instruments. Radiographic and functional outcomes were extracted and statistically analyzed. TKA performed with computer navigation was more likely to be within 3° of ideal mechanical alignment (87.1% vs. 73.7%, P < .01). Navigated TKAs had a higher increase in Knee Society Score at 3-month follow-up (68.5 vs. 58.1, P = .03) and at 12-32 month follow-up (53.1 vs. 45.8, P < .01). Computer navigation in TKA provides more accurate alignment and superior functional outcomes at short-term follow-up.

Cost-effectiveness analysis of fixation options for intertrochanteric hip fractures.

BACKGROUNDnIntertrochanteric hip fractures are a major source of morbidity and financial burden, accounting for 7% of osteoporotic fractures and costing nearly

Dedicated Perioperative Hip Fracture Comanagement Programs are Cost-effective in High-volume Centers: An Economic Analysis

6 billion annually in the United States. Traditionally, stable fracture patterns have been treated with an extramedullary sliding hip screw whereas unstable patterns have been treated with the more expensive intramedullary nail. The purpose of this study was to identify parameters to guide cost-effective implant choices with use of decision-analysis techniques to model these common clinical scenarios.nnnMETHODSnAn expected-value decision-analysis model was constructed to estimate the total costs and health utility based on the choice of a sliding hip screw or an intramedullary nail for fixation of an intertrochanteric hip fracture. Values for critical parameters, such as fixation failure rate, were derived from the literature. Three scenarios were evaluated: (1) a clearly stable fracture (AO type 31-A1), (2) a clearly unstable fracture (A3), or (3) a fracture with questionable stability (A2). Sensitivity analysis was performed to test the validity of the model.nnnRESULTSnThe fixation failure rate and implant cost were the most important factors in determining implant choice. When the incremental cost for the intramedullary nail was set at the median value (

Redefining the Acetabular Component Safe Zone for Posterior Approach Total Hip Arthroplasty

1200), intramedullary nailing had an incremental cost-effectiveness ratio of

Comparison of Total Hip and Knee Arthroplasty Cohorts and Short-Term Outcomes From a Single-Center Joint Registry

50,000/quality-adjusted life year when the incremental failure rate of sliding hip screws was 1.9%. When the incremental failure rate of sliding hip screws was >5.0%, intramedullary nails dominated with lower cost and better health outcomes. The sliding hip screw was always more cost-effective for A1 fractures, and the intramedullary nail always dominated for A3 fractures. As for A2 fractures, the sliding hip screw was cost-effective in 70% of the cases, although this was highly sensitive to the failure rate.nnnCONCLUSIONSnSliding hip screw fixation is likely more cost-effective for stable intertrochanteric fractures (A1) or those with questionable stability (A2), whereas intramedullary nail fixation is more cost-effective for reverse obliquity fractures (A3). These conclusions are highly sensitive to the fixation failure rate, which was the major influence on the model results.

Predicting short-term outcome of primary total hip arthroplasty:a prospective multivariate regression analysis of 12 independent factors.

BackgroundOsteoporotic 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/PurposesWe 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.MethodsDecision 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.ResultsFor 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.ConclusionsImplementation 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 EvidenceLevel 1, Economic and Decision Analysis.

Metal-on-metal hip resurfacing compared with total hip arthroplasty: two to five year outcomes in men younger than sixty five years

BACKGROUNDnAcetabular 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.nnnMETHODSnA cohort of 1289 posterior approach primary THA cases was prospectively followed and component position measured radiographically.nnnRESULTSnCup 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° strongly predicted increased dislocation risk (OR2.69). No dislocations occurred within a zone defined by a circle centered at 41.4° abduction and 17.1° anteversion, radius 4.3°.nnnCONCLUSIONnUtilizing a posterior approach specific safe zone of 10-25° anteversion and 30-50° abduction may minimize THA dislocations.nnnLEVEL OF EVIDENCEnLevel III.