James A. Keeney

Magnetic resonance arthrography versus arthroscopy in the evaluation of articular hip pathology

In this study, we compared magnetic resonance arthrography results with hip arthroscopy findings to assess the diagnostic value of this imaging technique in evaluating acetabular labral tears and concurrent articular hip pathology. One hundred one consecutive patients (102 hips) with a clinical diagnosis of acetabular labral tear were assessed using magnetic resonance arthrography and had hip arthroscopy after failing to improve with nonoperative treatment. Magnetic resonance arthrography detected 71 of 93 (76%) acetabular labral tears (92 patients) with five false positive studies in five patients (4.9%). Articular cartilage findings diagnosed by magnetic resonance arthrography were confirmed by arthroscopy in 64 hips in 64 patients (62.7%). With respect to labral pathology, magnetic resonance arthrography showed a sensitivity of 71%, specificity of 44% positive predictive value of 93%, negative predictive value of 13%, and accuracy of 69%. With respect to articular cartilage pathology, magnetic resonance arthrography had a sensitivity of 47%, specificity of 89%, positive predictive value of 84%, negative predictive value of 59%, and accuracy of 67%. Although magnetic resonance arthrography is an excellent positive predictor in diagnosing acetabular labral tears and articular cartilage abnormalities, it has limited sensitivity. A negative imaging study does not exclude important intra-articular pathology that can be identified and treated arthroscopically.

What is the Evidence for Total Knee Arthroplasty in Young Patients?: A Systematic Review of the Literature

BackgroundTKA is commonly performed to treat advanced inflammatory and degenerative knee arthritis. With increasing use in younger patients, it is important to define the best practices to enhance clinical performance and implant longevity.Questions/purposesWe systematically reviewed the literature to assess: (1) how TKAs perform in young patients; (2) whether the TKA is a durable procedure for young patients, and (3) what guidance the literature outlines for TKA in young patients.MethodsWe searched the literature between 1950 and 2009 for all studies reporting on TKAs for patients younger than 55 years that documented clinical and radiographic assessments with a minimum 2-year followup. Thirteen studies, reporting on 908 TKAs performed for 671 patients, met these criteria.ResultsMean Knee Society clinical and functional scores increased by 47 and 37 points, respectively. Implant survivorship was reported between 90.6% and 99% during the first decade and between 85% and 96.5% during the second decade of followup. The literature does not direct specific techniques for TKA for young patients.ConclusionsTKA provides surgeon-measured clinical and functional improvements with a moderate increase in second-decade implant failures. Improvements in study design and reporting will be beneficial to guide decisions regarding implant selection and surgical technique.Level of EvidenceLevel IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Revision total knee arthroplasty for restricted motion.

Persistent stiffness is an infrequent but notable complication occurring after total knee arthroplasty. A limited approach (soft tissue releases and component retention with tibial insert downsizing) has previously been associated with poor results, although comprehensive revision of both components seems more successful. We retrospectively reviewed 23 patients (25 knees) who had revision total knee arthroplasty for painful limitation of motion. At a mean of 36.7 months after surgery we assessed pain, motion arc, and Knee Society clinical and functional scores. The effectiveness of a limited approach for selected patients (n = 12) was compared with more comprehensive revision of both components (n = 11). Patients with the limited approach had improvements in mean knee motion arc (25.7°), mean clinical score (37.8 points), and mean functional score (20.8 points). Patients with component revision had a mean improvement in knee motion arc (17.9°) but little change in the clinical score (3.6 points) or functional score (−1.0 points). The severity of preoperative flexion contractures and limited motion in patients having component revision likely contributed to the limited improvement. The data suggest a limited soft tissue approach may be appropriate for a select group of patients. The success of component revision for patients with severely restricted motion and more extensive flexion contracture was less predictable than authors of previous reports suggest. Level of Evidence: Therapeutic study, Level III-1 (retrospective comparative study). See the Guiudelines for Authors for a complete description of levels of evidence.

Assessing Readmission Databases: How Reliable Is the Information?

Databases are being used to shape health care policy. However, the reliability of coding information entered into the databases may be difficult to validate. In this study, we assess readmission data from an institutional database that identified 1515 readmissions (708 patients) after total hip or total knee arthroplasty during a 5-year interval. After exclusions, 223 readmissions (190 patients) underwent medical record review. Bleeding, wound-related, and arthroplasty-related complications constituted most (62.8%) of readmissions. Bleeding and wound complications were nearly 6 times more frequently associated with readmission than venous thromboembolism events. On secondary review, there was discordance between the diagnosis obtained by a surgeon reviewer and coding for diagnoses consistent with periprosthetic infection (996.66, 77, 78, and 998.59) in 70% of cases. The findings of our study raise questions regarding the validity of accepting information obtained from larger databases without closer scrutiny.

The reliability and variation of acetabular component anteversion measurements from cross-table lateral radiographs.

Although cross-table lateral (CL) radiographs are frequently used to assess acetabular component anteversion, the reliability of this method has not been established. We compared serial CL radiographs with computed tomography (CT) scans for 98 total hip arthroplasty patients (119 hips) undergoing surveillance of primary or revision total hip arthroplasty. Acetabular anteversion averaged 26.1° (range, -2° to 48.3°) on CL imaging and 28.8° (range, -7° to 54°) on CT scan. There was a strong correlation between anteversion determined from CT scans and serial CL images. However, variation on serial CL studies exceeded 10° for 20% of patients. Although CL imaging provides acceptable assessment of general component position, it has limited use for precise analysis in research, outcome reporting, or determination of cause of implant failure.

The Impact of Risk Reduction Initiatives on Readmission: THA and TKA Readmission Rates

We assessed whether sequential incorporation of initiatives to decrease postoperative surgical complications were similarly effective in reducing 30-day readmission rates following total knee arthroplasty (TKA) and total hip arthroplasty (THA). Readmission rates following TKA decreased substantially (5.6% vs. 3.0%, P<0.001), but readmissions following THA (4.0% vs. 3.4%, P=0.41) were not significantly reduced. The greatest impact of the multimodal treatment approach was a reduction of surgically related TKA complications. Advanced medical disease, facility discharge status, and Medicare or Medicaid coverage contributed to the highest risk for 30-day readmission after THA. Risk models defining expected readmission rates should account for these factors to avoid penalizing hospitals that provide higher proportional care to Centers for Medicaid and Medicare Services (CMS) beneficiaries.

Increased risk of failure following revision total knee replacement in patients aged 55 years and younger

The aims of this retrospective study were to compare the mid-term outcomes following revision total knee replacement (TKR) in 76 patients (81 knees) < 55 years of age with those of a matched group of primary TKRs based on age, BMI, gender and comorbid conditions. We report the activity levels, functional scores, rates of revision and complications. Compared with patients undergoing primary TKR, those undergoing revision TKR had less improvement in the mean Knee Society function scores (8.14 (-55 to +60) vs 23.3 points (-40 to +80), p < 0.001), a similar improvement in UCLA activity level (p = 0.52), and similar minor complication rates (16% vs 13%, p = 0.83) at a mean follow-up of 4.6 years (2 to 13.4). Further revision surgery was more common among revised TKRs (17% vs 5%, p = 0.02), with deep infection and instability being the most common reasons for failure. As many as one-third of patients aged < 55 years in the revision group had a complication or failure requiring further surgery. Young patients undergoing revision TKR should be counselled that they can expect somewhat less improvement and a higher risk of complications than occur after primary TKR.

Highly cross-linked polyethylene improves wear and mid-term failure rates for young total hip arthroplasty patients

We compared clinical outcomes and polyethylene wear for 2 young primary THA patient cohorts (<50 years of age) at mid-term follow-up. In total, 72 patients (84 hips) received a coventional polyethylene liner (CPE) and 84 patients (89 hips) received a highly cross-linked polyethylene liner (HXLPE). Mean Harris Hip Score improved to 81 points for both groups. UCLA activity scores were higher for HXLPE patients (6.0 vs 5.3, p = 0.03), with lower mean linear wear (0.02 vs 0.13 mm/year, p<0.001) and lower mean volumetric wear (75.1 vs 229.8 mm3, p<0.001) at an average of 70 months follow-up. No HXLPE patient required revision for wear related concerns, compared to 5 CPE patients with revision for aseptic loosening or impending radiographic failure (0% vs 5.9%, p = 0.02). HXLPE is associated with reduced wear among young, active THA patients without increased risk of early mechanical failure.

Socioeconomically Disadvantaged CMS Beneficiaries Do Not Benefit From the Readmission Reduction Initiatives

We assessed the impact of minority and socioeconomic status on 30-day readmission rates after 3825 primary total hip arthroplasty (THA) and 3118 primary total knee arthroplasty (TKA) procedures. Minority patients had higher THA (7.4% vs 3.2%, P=0.001) and TKA (5.4% vs 3.7%, P<0.001) readmission rates. Low socioeconomic status was associated with higher THA (6.0% vs 3.1%, P<0.001) and TKA (6.3% vs 3.8%, P=0.02) readmission rates. Risk reduction initiatives were effective after TKA, but minority status and low socioeconomic status were still associated with higher 30-day readmission rates (4.6% vs 1.8%, P<0.01). Focused postoperative engagement for Centers for Medicare and Medicaid Services (CMS) beneficiaries less than 65 years of age may help reduce complications and 30-day readmissions.

The Use of Warfarin for DVT Prophylaxis Following Hip and Knee Arthroplasty: How Often Are Patients Within Their Target INR Range?

The purpose of this study was to determine the percentage of time that patients are therapeutic when prescribed warfarin for chemical thromboprophylaxis following a hip or knee arthroplasty procedure. One hundred eighty-four patients receiving warfarin for 4weeks postoperatively, dosed using a Web-application accounting for patient demographics, INR levels, and concomitant medication use, were included. Patients with a target INR range between 1.7 and 2.7 were therapeutic for only 54.4% of the time (32.5% subtherapeutic, 13.0% supratherapeutic) while patients with a target INR range between 2.0 and 3.0 were therapeutic for only 45.9% of the time (39.2% subtherapeutic, 14.8% supratherapeutic). Patients receiving warfarin for chemical thromboprophylaxis are within their targeted INR range for only a limited period of time during their postoperative course.