Wear of Third-Generation Cross-Linked Polyethylene in Primary Total Hip Arthroplasty: A 10-Year Analysis.

BACKGROUND: Sequential modifications to the manufacturing process of highly cross-linked polyethylene (HXLPE) have improved the wear resistance and implant survival of these liners in total hip arthroplasty (THA). However, no study has examined the long-term (mean 10 year) wear rates and clinical outcomes of third-generation HXLPE in THA. The aim of our study was to report the longest-to-date analysis of wear rates and clinical outcomes of a third-generation HXLPE liner. METHODS: A series of 133 THAs using a specific HXLPE acetabular liner were retrospectively evaluated. Linear and volumetric wear rates were determined using a validated radiographic technique and clinical outcomes were analyzed. Multivariate analyses were performed to determine risk factors for accelerated wear. RESULTS: At a mean follow-up of 10.4 years (range, 8 to 13.4), the mean linear wear rate was 0.0172 mm/year and the mean volumetric wear rate was 16.99 mm3/year. There were no instances of osteolysis or mechanical failures at any time point and there was a 100% acetabular component survival rate. Younger age and use of offset liners were independent risk factors for increased wear (P < .01 for both). CONCLUSIONS: Our series of a third-generation HXLPE demonstrated very low wear rates and excellent implant survival at a mean of 10.4 years following primary THA. Future comparative studies at the 15- and 20-year follow-up timepoints are necessary to determine if such findings translate to true improvements in the tribological properties and longevity of these liners when compared to previous generations of HXLPE liners.

Conversion Total Hip Arthroplasty in the Era of Bundled Care Payments: Impacts on Costs of Care.

BACKGROUND: Conversion hip arthroplasty is defined as a patient who has had prior open or arthroscopic hip surgery with or without retained hardware that is removed and replaced with arthroplasty components. Currently, it is classified under the same diagnosis-related group as primary total hip arthroplasty (THA); however, it frequently requires a higher cost of care. METHODS: A retrospective study of 228 conversion THA procedures in an orthopaedic specialty hospital was performed. Propensity score matching was used to compare the study group to a cohort of 510 primary THA patients by age, body mass index, sex, and American Society of Anesthesiologists score. These matched groups were compared based on total costs, implants used, operative times, length of stay (LOS), readmissions, and complications. RESULTS: Conversion THA incurred 25% more mean total costs compared to primary THA (P < .05), longer lengths of surgery (154 versus 122 minutes), and hospital LOS (2.1 versus 1.56 days). A subgroup analysis showed a 57% increased cost for cephalomedullary nail conversion, 34% increased cost for sliding hip screw, 33% for acetabular open reduction and internal fixation conversion, and 10% increased costs in closed reduction and percutaneous pinning conversions (all P < .05). There were 5 intraoperative complications in the conversion group versus none in the primary THA group (P < .01), with no statistically significant difference in readmissions. CONCLUSION: Conversion THA is significantly more costly than primary THA and has longer surgical times and greater LOS. Specifically, conversion THA with retained implants had the greatest impact on cost.

A Short-Term Multicenter Analysis of Radiolucent Lines in a Single Uncemented Rotating Platform Implant for Total Knee Arthroplasty.

Background: Uncemented total knee arthroplasty is increasing as a potential solution for aseptic loosening via biologic fixation and to increase operative efficiency. However, postoperative radiolucent lines (RLLs) remain a concern for some clinicians. We report on a multicenter analysis of these RLLs over a 2-year period to identify their incidence, progression, and clinical significance. Material and methods: Institutional review board approval was obtained for this retrospective, multicenter case series. A total of 312 patients treated with a single cruciate-retaining, fully porous coated femoral and tibial component design were included in the study. All patients were evaluated clinically and radiographically in the early postoperative period and at final follow-up (average 2.0 years). Average age of the study group was 58.2 years, and average body mass index was 30.7. Of the total, 66% were male, and 34% were female. Two independent surgeons evaluated the radiographs at the initial postoperative visit and at the most recent follow-up for RLLs. Knee Society Scores and range of motion (ROM) were collected at each visit. Results: We identified RLLs in 25% of patients. All RLLs were less than 1 mm in size and located at the periphery of the tibial implant. None of the RLLs were progressive. At the final follow-up, compared with early postoperative imaging, no new RLLs were identified. Average ROM in flexion was 124 degrees, and the average Knee Society Scores at the most recent clinical follow-up was 96. Conclusion: RLLs are commonly seen following cementless TKA, most commonly underneath the tibial tray. Based on this data set, there does not appear to be progression of these RLLs with time, and they do not appear to have an effect on ROM or clinical outcome at 2 years.

Use of Tetrahydrocannabinol and Cannabidiol Products in the Perioperative Period Around Primary Unilateral Total Hip and Knee Arthroplasty.

BACKGROUND: Given the opioid crisis in America, patients are trying alternative medications including tetrahydrocannabinol (THC) and other cannabidiol (CBD) containing products in the perioperative period, especially in states where these products are legal. This study sought to analyze usage rates of CBD/THC products in the perioperative period for primary unilateral total hip and knee arthroplasty (THA/TKA) patients and identify a possible association with post-operative opioid use. METHODS: A prospective cohort of primary unilateral THA/TKA patients were enrolled at a single institution. Patients who completed detailed pain journals were retrospectively surveyed for CBD/THC product usage. Pain medications were converted to morphine milligram equivalents (MME). RESULTS: Data from 195 of the 210 patients (92.9% response rate) following primary arthroplasty were analyzed. Overall, 16.4% of arthroplasty-22.6% (n = 19) of TKA and 11.7% (n = 13) of THA-patients used CBD/THC products in the perioperative period. There was a wide variety of usage patterns among those using CBD/THC products. In comparing CBD/THC users and non-users, there was no significant difference in the length of narcotic use, total morphine milligram equivalents taken, narcotic pills taken, average post-op pain scores, the percentage of patients requiring a refill of narcotics, or length of stay. CONCLUSION: Understanding that CBD/THC usage was not consistent for patients who used these products, 22.6% of TKA and 11.7% of THA patients tried CBD/THC products in the perioperative period. In this small sample, CBD/THC use was not associated with a major effect on narcotic requirements. Further studies on the effects of CBD/THC are needed as these therapies become more widely available.

Opioid Use After Discharge Following Primary Unilateral Total Hip Arthroplasty: How Much Are We Overprescribing?

BACKGROUND: The opioid crisis pressures orthopedic surgeons to reduce the amount of narcotics prescribed for postoperative pain management. This study sought to quantify postoperative opioid use after hospital discharge for primary unilateral total hip arthroplasty (THA) patients. METHODS: A prospective cohort of primary unilateral THA patients were enrolled at a single institution. Detailed pain journals tracked all prescription and over-the-counter pain medication, quantity, frequency, and visual analog scale pain scores. Pain medications were converted to morphine milligram equivalents (MME). RESULTS: Data from 121 subjects were analyzed; the average visual analog scale pain score was 3.44 while taking narcotics. The average number of days taking narcotics was 8.46 days. The distribution of days taking narcotics was right shifted with 50.5% of patients off narcotics after 1 week, and 82.6% off by 2 weeks postoperatively. The average number of narcotic pills prescribed was significantly greater than narcotic pills taken (72.5 vs 28.8, P < .0001). The average MME prescribed was significantly greater than MME taken (452.1 vs 133.8, P < .0001). The average excess narcotic pills prescribed per patient was 51.7 pills. And 71.9% took fewer than 30 narcotic pills; 90.9% patients took fewer than 50 narcotic pills. Also, 10.7% did not require any narcotics; 9.9% required a refill of narcotics; and 33.1% went home the day of surgery. CONCLUSION: Significantly more narcotics were prescribed than were taken in the postoperative period following THA with an average 51.7 excess narcotic pills per patient. Adjusting prescribing patterns to match patient narcotic usage could reduce the excess narcotic pills following THA.

Opioid Use After Discharge Following Primary Unilateral Total Knee Arthroplasty: How Much Are We Over-Prescribing?

BACKGROUND: The opioid crisis pressures orthopedic surgeons to reduce the amount of narcotics prescribed for post-operative pain management. This study sought to quantify post-operative opioid use after hospital discharge for primary unilateral total knee arthroplasty (TKA) patients. METHODS: A prospective cohort of primary unilateral TKA patients performed by one of 5 senior fellowship-trained arthroplasty surgeons were enrolled at a single institution. Detailed pain journals tracked all prescriptions and over-the-counter pain medications, quantities, frequencies, and visual analog scale pain scores. Narcotic and narcotic-like pain medications were converted to morphine milligram equivalents (MME). Statistical analysis was performed using Student's t-test with α < 0.05. RESULTS: Data from 89 subjects were analyzed; the average visual analog scale pain score was 6.92 while taking narcotics. The average number of days taking narcotics was 16.8 days. The distribution of days taking narcotics was right shifted with 52.8% of patients off narcotics after 2 week, and 74.2% off by 3 weeks post-op. The average MME prescribed was significantly greater than MME taken (866.6 vs 428.2, P < .0001). The average number of narcotic pills prescribed was significantly greater than narcotic pills taken (105.1 vs 52.0, P < .0001). The average excess narcotic pills prescribed per patient was 53.1 pills. About 48.3% took fewer than 40 narcotic pills; 75.3% took fewer than 75 narcotic pills. About 3.4% did not require any narcotics; 40.5% required a refill of narcotics. Also, 9.0% went home the day of surgery. CONCLUSION: Significantly more narcotics were prescribed than were taken in the post-operative period following TKA with an average 53.1 excess narcotic pills per patient. Adjusting prescribing patterns to match patient narcotic usage could reduce the excess narcotic pills following TKA.

Impact of Femoral Stem Design on Failure After Anterior Approach Total Hip Arthroplasty.

BACKGROUND: An increased rate of complications related to femoral component failure has been described with less invasive total hip arthroplasty (THA). This study evaluated the incidence of femoral complications associated with the direct anterior approach for THA. METHODS: Retrospective review was performed of the initial 1120 consecutive patients who underwent direct anterior THA by 2 surgeons. RESULTS: A total of 899 patients (80.3%) had a 2-year follow-up (range, 2-8 years). Complications within 90 days occurred in 20 patients (1.8%): 10 calcar fractures, 1 greater trochanter fracture, 1 canal perforation, 3 hematomas, 2 dislocations, 2 superficial, and 1 deep infection. Nine patients (1%) underwent revision: 5 for aseptic femoral loosening (0.55%), 1 for periprosthetic joint infection, 1 for dislocation, 1 for hip flexor irritation, and 1 for a damaged polyethylene liner. Of the 5 patients with aseptic femoral loosening, 3 had a short, mediolateral tapered stem, 1 cemented stem, and 1 S-ROM stem placed to bypass a canal perforation. There were no revisions for aseptic loosening in the collared, fully hydroxyapatite (HA)-coated compaction broached or triple tapered proximal fit and fill stem designs (70.6% of all stems). Revision rate for femoral loosening was significantly higher for tapered wedge over HA-coated, compaction broached stems (P < .005). CONCLUSION: Pain and function improved predictably with a 0.55% rate of femoral loosening at 2-year follow-up. Among collared, fully HA-coated and triple taper fit and fill femoral stems, there were no instances of revision for aseptic loosening vs 3 in the short stem, collarless mediolateral tapered group.

Is the Anterior Approach Safe? Early Complication Rate Associated With 5090 Consecutive Primary Total Hip Arthroplasty Procedures Performed Using the Anterior Approach.

BACKGROUND: Few publications have raised concern with the safety of the anterior approach (AA) to total hip arthroplasty (THA). The purpose of this study is to report the early complications with AA THA in a combined, multicenter patient population from three different institutions. METHODS: The study cohort consisted of 5090 consecutive primary procedures in 4473 patients who had undergone THA utilizing the anterior approach between August 2006 and July 2013. Surgeries were performed by five surgeons at three sites that maintain prospective databases. Preoperative, intraoperative, and postoperative data were recorded on all patients. Demographic data including age, gender, and BMI were queried, as well as all intraoperative and postoperative complications in the first 90 days. RESULTS: The 5090 patients had a mean body mass index of 27.5, and mean age of 63.6 years. The overall 90-day complication rate was 1.9%. There were 41 intraoperative femur fractures including 29 calcar fractures, 9 greater trochanter fractures and 3 femoral shaft fractures. There were 7 postoperative femur fractures including 3 greater trochanter fractures, 2 calcar fractures, and 2 femur fractures. Other complications included 15 superficial infections, 5 deep infections, 12 dislocations, 8 hematomas, 3 cases of cellulitis, 2 sciatic nerve palsies, 1 peroneal nerve palsy, and intrapelvic bleed. The nonsurgical complication rate was 1.4%. Deep vein thrombosis occurred in 0.3% of cases. CONCLUSION: This large multicenter study of consecutive AA THAs demonstrates an acceptable risk profile within the first 90 days after surgery.

Ten Year Follow-Up of Gap Balanced, Rotating Platform Total Knee Arthroplasty in Patients Under 60 Years of Age.

68 patients (91 primary total knee arthroplasties) were evaluated at a mean 10-year, minimum 5 year follow up in patients younger than sixty years of age utilizing the gap balanced, rotating platform design. Follow up assessment included implant survivorship, adverse events, x-rays, Knee Society rating system and clinical evaluation. Three revisions were performed with only one for aseptic loosening at 45 months. Two manipulations were performed in the early postoperative period. Survivorship of the rotating platform, gap balanced knee was 96.7% using surgical revision for any reason and 98.9% using aseptic loosening as endpoints. The rotating platform design using the gap balancing technique in young patients had excellent survivorship at 10-year mean follow up.

Simultaneous Bilateral Anterior Approach Total Hip Arthroplasty.

Simultaneous bilateral total hip arthroplasty (THA) has been performed successfully, with good outcomes and low complication rates reported. Most published studies on the topic used anterolateral or posterior surgical approaches. The anterior approach is performed under live fluoroscopy with the patient supine, obviating the need for patient repositioning during bilateral surgery. The authors report their experience with simultaneous bilateral anterior approach total hip arthroplasty. The authors retrospectively reviewed data for 75 patients (150 hips). Mean follow-up was 26 months (range, 5-60 months). Mean patient age was 59 years and the majority were American Society of Anesthesiology class 2 (range, 1-3). Mean total surgical time was 144 minutes (72 minutes per hip). Mean blood loss was 565 mL. Mean hospital length of stay was 2.75 days (range, 1-4 days). Ninety-six percent of patients were able to ambulate on postoperative day 1. Sixty-eight percent of patients were discharged to home. Mean Harris Hip Score improved from 50 to 97. All patients noted a return to preoperative level of activity or higher. Complications included 1 atraumatic minimally displaced trochanteric fracture occurring 2 weeks postoperatively, 1 pulmonary embolism on postoperative day 3 treated without sequelae, 1 episode of postoperative atrial fibrillation, and 4 minor local wound complications. No readmission, infection, nerve palsy, dislocation, reoperation, or death occurred. Anterior approach THA has the advantage of a single supine position for bilateral simultaneous surgery and the current study supports its use in appropriate patients.

Use of stepped porous titanium metaphyseal sleeves for tibial defects in revision total knee arthroplasty: short term results.

Stepped porous titanium metaphyseal sleeves may provide an option for enhanced fixation in managing challenging tibial defects in revision total knee arthroplasty (TKA). We retrospectively reviewed data on 51 patients who underwent revision TKA utilizing a metaphyseal sleeve for Anderson Orthopaedic Research Institute (AORI) Type II and III tibial defects between June 2007 and July 2011. Of these 51 patients, 36 patients had complete clinical and radiographic data. At final follow-up (mean: 38 months) significant improvements in knee range of motion and Knee Society scores were observed postoperatively (P < 0.001). Four revision procedures were necessary, but none for aseptic implant fixation failure. Radiographic review at final follow-up revealed stable, osteointegrated components without component migration or clinically significant osteolysis. Metaphyseal sleeve use in the management of moderate to severe tibial defects in revision TKA resulted in satisfactory clinical outcomes and is a versatile option for achieving stable fixation.

Why are total knee arthroplasties being revised?

Despite technical improvements, revision rates for total knee arthroplasties (TKAs) remain high. Our goal was to report the reason(s) for revision TKA in a large, current, multicenter series and compare those reasons with previously published reasons. We retrospectively identified 820 consecutive revision TKAs (693 patients, 2000-2012) from our 3 centers and recorded the primary reason for the revision. The top seven reasons for the revision were aseptic loosening (23.1%), infection (18.4%), polyethylene wear (18.1%), instability (17.7%), pain/stiffness (9.3%), osteolysis (4.5%), and malposition/malalignment (2.9%). Comparison with previously published reasons showed fewer TKA revisions for polyethylene wear, osteolysis, instability, and malalignment. These changes may represent improvements in surgical technique and implants.