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.

Retained Functional Antibiotic Hip Spacers Have High Rates of Stem Loosening, Subsidence, and Reoperation.

BACKGROUND: Functional antibiotic hip spacers for treatment of periprosthetic joint infection may be retained in patients deemed too sick for reimplantation, or who elect to forego additional surgery. Our aim was to characterize reoperations, modes of failure, and function outcomes in patients who have retained hip spacers. METHODS: We performed a retrospective review of 43 hips that underwent placement of an articulating hip spacer between January 1, 2014 and November 30, 2021. There were 28 hips that completed 2-stage exchange (TS group) and were reimplanted at mean 4 months (range, 2 to 10). The other 15 hips underwent planned spacer retention (RS group). Mean follow-up was 2.9 years (range, 1 to 6.1 years). The RS group was older (74 versus 66 years, P = .005) and had a higher age-adjusted Charlson Comorbidity Index (4.4 versus 3.3, P = .04) compared with the TS group. RESULTS: Overall survivorship free of reinfection was 91% at 1 year and 86% at 5 years. There were 6 RS hips that underwent reimplantation for spacer failure at a mean of 23 months (range, 6 to 71 months) and 8 had radiographic stem loosening/subsidence. Patients who had a retained spacer at final follow-up were more likely to require a walker (P = .005) or wheelchair (P = .049) compared with patients who underwent reimplantation. CONCLUSIONS: Retained hip spacers can decrease overall surgical burden, but are associated with high rates of stem loosening, subsidence, and unplanned reoperation. Planned spacer retention should be undertaken with caution in patients healthy enough to undergo reimplantation.

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 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.

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.