Brian R. Hamlin

Topical tranexamic acid reduces blood loss and transfusion rates in total hip and total knee arthroplasty

The objective of this study was to determine if tranexamic acid (TXA) applied topically reduced postoperative bleeding and transfusion rates after primary total hip arthroplasty (THA) and primary total knee arthroplasty (TKA). Two hundred and ninety consecutive patients from a single surgeon were enrolled. In TKA, TXA solution was injected into the knee after closure of the arthrotomy. In THA, the joint was bathed in TXA solution at three points during the procedure. In both THA and TKA the TXA solution was at a concentration of 3 g TXA per 100 mL saline. The mean blood loss was significantly higher in the non-TXA patients in both TKA and THA groups. Postoperative transfusions decreased dramatically with TXA, dropping from 10% to 0%, and from 15% to 1%, in the TKA and THA groups, respectively. Topical application of TXA significantly reduces postoperative blood loss and transfusion risk in TKA and THA.

Topical versus intravenous tranexamic acid in total knee arthroplasty

The objective of this study is to compare the effectiveness of intravenous versus topical application of tranexamic acid in patients undergoing knee arthroplasty. All patients who underwent primary knee arthroplasty at our total joint center over a 12-month period were included in the study. One surgeon utilized 1 g of IV TXA at time of incision in all patients (n=373) except those with a documented history of venous thromboembolism (VTE). Two surgeons utilized a topical application of TXA for all patients without exception (n=198) in which the joint was injected after capsular closure with 3 g TXA/100 mL saline. The transfusion rate was 0% in the topical group vs. 2.4% in the IV group and this was statistically significant (P<0.05).

Effect of Femoral Component Design on Patellofemoral Crepitance and Patella Clunk Syndrome After Posterior-Stabilized Total Knee Arthroplasty

The purpose of this study was to determine if recent changes to the femoral component of a particular posterior-stabilized total knee prosthesis would affect the incidence of postoperative patellofemoral crepitance and patella clunk syndrome. One hundred eight total knee arthroplasties were performed with the conventional design; 136 were performed after the femoral component was changed. Complications were compared between the groups with an average follow-up of 17.7 months and 12.4 months, respectively. Thirteen knees with the conventional design (12%) were found to have patellofemoral complications; no complications were noted with the new design (P < .0001). Femoral components with a deep trochlear groove and smooth transition of the intercondylar box appear to better accommodate any peripatellar fibrous nodule that may form after total knee arthroplasty.

Does Taper Size Have an Effect on Taper Damage in Retrieved Metal-on-Polyethylene Total Hip Devices?

BACKGROUNDnTaper design has been identified as a possible contributor to fretting corrosion damage at modular connections in total hip arthroplasty systems, but variations in as-manufactured taper interfaces may confound this analysis. This study characterized taper damage in retrievals with 2 different taper sizes but comparable taper surface finishes and investigated if fretting and corrosion damage is related to taper size in the context of a multivariable analysis for metal-on-polyethylene bearings.nnnMETHODSnA total of 252 cobalt chromium femoral heads were identified in a collection of retrievals: 77 with taper A and 175 with taper B. Implantation time averaged 5.4 ± 6.0 years (range, 0-26 years). Explants were cleaned and analyzed using a 4-point semiquantitative method. Clinical and device factors related to head taper fretting corrosion damage were assessed using ordinal logistic regression with forward stepwise control. Components were then selected to create 2 balanced cohorts, matched on significant variables from the multivariable analysis.nnnRESULTSnIncreased head offset (P < .001), longer implantation time (Pxa0= .002), heavier patients (P < .001), and more flexible tapers (P < .001) were associated with increased taper fretting and corrosion damage. When damage scores were compared between the balanced groups, no significant differences were found.nnnCONCLUSIONnThese results suggest that fretting and corrosion damage is insensitive to differences in taper size. The final model derived explains almost half of the fretting corrosion damage observed and identifies contributing factors that are consistent with other inxa0vitro and retrieval studies.

Trunnion Failure of the Recalled Low Friction Ion Treatment Cobalt Chromium Alloy Femoral Head

BACKGROUNDnGross trunnion failure (GTF) is a rare complication in total hip arthroplasty (THA) reported across a range of manufacturers. Specific lots of the Stryker low friction ion treatment (LFIT) anatomic cobalt chromium alloy (CoCr) V40 femoral head were recalled in August 2016. In part, the recall was based out of concerns for disassociation of the femoral head from the stem and GTF.nnnMETHODSnWe report on 28 patients (30 implants) with either GTF (nxa0= 18) or head-neck taper corrosion (nxa0= 12) of the LFIT CoCr femoral head and the Accolade titanium-molybdenum-zirconium-iron alloy femoral stems. All these cases were associated with adverse local tissue reactions requiring revision of the THA.nnnRESULTSnIn our series, a conservative estimate of the incidence of failure was 4.7% (nxa0= 636 total implanted) at 8.0 ± 1.4 years from the index procedure. Failures were associated with a high-offset 127° femoral stem neck angle and increased neck lengths; 43.3% (13 of 30) of the observed failures included implant sizes outside the voluntary recall (27.8% [5 of 18] of the GTF and 75.0% [8 of 12] of the taper corrosion cases). Serum cobalt and chromium levels were elevated (cobalt: 8.4 ± 7.0 μg/mL; chromium: 3.4 ± 3.3 μ/L; cobalt/chromium ratio: 3.7). The metal artifact reduction sequence magnetic resonance imaging demonstrated large cystic fluid collections typical with adverse local tissue reactions. During revision, a pseudotumor was observed in all cases. Pathology suggested a chronic inflammatory response. Impending GTF could be diagnosed based on aspiration of black synovial fluid and an oblique femoral head as compared with the neck taper on radiographs.nnnCONCLUSIONnIn our series of the recalled LFIT CoCr femoral head, the risk of impending GTF or head-neck taper corrosion should be considered as a potential diagnosis in a painful LFIT femoral head and Accolade titanium-molybdenum-zirconium-iron alloy THA with unknown etiology. Almost half of the failures we observed included sizes outside of the voluntary recall.

Do Stem Taper Microgrooves Influence Taper Corrosion in Total Hip Arthroplasty? A Matched Cohort Retrieval Study

BACKGROUNDnPrevious studies identified imprinting of the stem morphology onto the interior head bore, leading researchers to hypothesize an influence of taper topography on mechanically assisted crevice corrosion. The purpose of this study was to analyze whether microgrooved stem tapers result in greater fretting corrosion damage than smooth stem tapers.nnnMETHODSnA matched cohort of 120 retrieved head-stem pairs from metal-on-polyethylene bearings was created controlling for implantation time, flexural rigidity, apparent length of engagement, and head size. There were 2 groups of 60 heads each, mated with either smooth or microgrooved stem tapers. A high-precision roundness machine was used to measure and categorize the surface morphology. Fretting corrosion damage at the head-neck junction was characterized using the Higgs-Goldberg scoring method. Fourteen of the most damaged heads were analyzed for the maximum depth of material loss and focused ion beam cross-sectioned to view oxide and base metal.nnnRESULTSnFretting corrosion damage was not different between the 2 cohorts at the femoral head (Pxa0= .14, Mann-Whitney) or stem tapers (Pxa0= .35). There was no difference in the maximum depths of material loss between the cohorts (Pxa0= .71). Cross-sectioning revealed contact damage, signs of micro-motion, and chromium-rich oxide layers in both cohorts. Microgroove imprinting did not appear to have a different effect on the fretting corrosion behavior.nnnCONCLUSIONnThe results of this matched cohort retrieval study do not support the hypothesis that taper surfaces with microgrooved stems exhibit increased inxa0vivo fretting corrosion damage or material release.

A Multicenter Study of Irrigation and Debridement in Total Knee Arthroplasty Periprosthetic Joint Infection: Treatment Failure Is High

BACKGROUNDnIn total knee arthroplasty (TKA) periprosthetic joint infection (PJI), irrigation and debridement (I&D) with component retention is a treatment option with a wide variation in reported failure rates. The purpose of this study was to determine failure rates, outcomes, and factors that predict failure in I&D for TKA PJI.nnnMETHODSnA multicenter observational study of patients with a TKA PJI and subsequently undergoing an I&D with retention of components was conducted. The primary outcome was failure rate of I&D, where failure was defined as any subsequent surgical procedures.nnnRESULTSnTwo hundred sixteen cases of I&D with retention of components performed on 206 patients met inclusion criteria. The estimated long-term failure rate at 4 years was 57.4%. Time-to-event analyses revealed that the median survival time was 14.32 months. Five-year mortality was 19.9%. Multivariable modeling revealed that time symptomatic and organism were independent predictors of I&D failure. Culture-negative status had a higher hazard for failure than culture-positive patients. When primary organism and time symptomatic were selected to produce an optimized scenario for an I&D, the estimated failure rate was 39.6%.nnnCONCLUSIONnI&D with retention of components has a high failure rate, and there is a high incidence of more complex procedures after this option is chosen. The patient comorbidities we investigated did not predict I&D success. Our results suggest that I&D has a limited ability to control infection in TKA and should be used selectively under optimum conditions.

Viable bacteria persist on antibiotic spacers following two-stage revision for periprosthetic joint infection†

Treatment in periprosthetic joint infection (PJI) remains challenging. The failure rate of two‐stage revision and irrigation and debridement with component retention in PJI suggests that biofilm cells have a high tolerance to antibiotic chemotherapy. Previous work has demonstrated that biofilm cells have high antibiotic tolerance in vitro, but there is little clinical evidence to support these observations. The aim of this study was to determine if retrieved antibiotic spacers from two‐stage revision total knee arthroplasty for PJI have evidence of remaining viable bacteria. Antibiotic poly (methyl methacrylate) (PMMA) spacers from two‐stage revision total knee arthroplasty for PJI were prospectively collected and analyzed for bacterial 16s rRNA using polymerase chain reaction (PCR), reverse transcription (RT)‐PCR, quantitative RT‐PCR (qRT‐PCR), and single genome analysis (SGA). PCR and RT‐PCR identified bacterial species on 53.8% (7/13) of these samples. When initial culture negative cases are excluded, 68% (6/9) samples were identified with bacterial species. A more rigorous qRT‐PCR analysis showed a strong positive signal for bacterial contamination in 30.7% (4/13) of cases. These patients did not show any clinical evidence of PJI recurrence after 15 months of follow‐up. Because the half‐life of bacterial rRNA is approximately a few days, the identification of bacteria rRNA on antibiotic PMMA spacers suggests that viable bacteria were present after conclusion of antibiotic therapy. This study provides evidence for the high tolerance of biofilm cells to antibiotics in vivo and the important role of bacterial persisters in PJI.

Liposomal Bupivacaine vs Plain Bupivacaine in Periarticular Injection for Control of Pain and Early Motion in Total Knee Arthroplasty: A Randomized, Prospective Study

BACKGROUNDnThe use of multimodal pain regimens has been shown to be an effective technique for the treatment of postoperative pain after total knee arthroplasty. Periarticular injections, of both short-acting and long-acting anesthetics, have emerged as an additional method of providing significant improvement in postoperative pain relief. The purpose of this study is to compare the efficacy of periarticular injection using long-acting vs short-acting preparations.nnnMETHODSnA randomized, prospective study of 80 consecutive patients was performed comparing liposomal bupivacaine vs plain bupivacaine periarticular injection. The primary outcomes included pain relief, total narcotic usage, and completion of physical therapy goals, specifically range of motion.nnnRESULTSnNo significant improvements were noted between liposomal bupivacaine and plain bupivacaine injection groups in overall pain reduction, range of motion, or total narcotic usage. At 24xa0hours, small statistically significant differences in physical therapy pain scores were noted with liposomal bupivacaine vs plain bupivacaine and control patients, but these differences did not persist at later time points. Both preparations demonstrated statistically significant improvements in range of motion when compared to historical controls, but no differences were noted between preparations.nnnCONCLUSIONnOverall, minimal significant differences were noted between liposomal bupivacaine and plain bupivacaine at early and late time points. Both preparations of periarticular injection demonstrated superiority over control pain regimens but were relatively equivalent to one another in direct comparison.

Implant orientation accuracy of a hand-held robotic partial knee replacement system over conventional technique in a cadaveric test.

Abstract Unicondylar Knee Arthroplasty (UKA) is a minimally-invasive surgical procedure for treating isolated compartmental knee osteoarthritis. Accurate implant placement is crucial for a successful UKA procedure. Previous work has shown the improvement in UKA by using robotic systems. Here, we present the implant alignment accuracy of a hand-held robotic UKA system compared with a conventional manual UKA system for 12 cadaver specimens. Two surgeons carried out equal number of medial UKAs with robotic UKA on one knee and the manual UKA on the other knee. Preoperative and postoperative computed tomography (CT) scans were obtained for each cadaveric model. The final implant positions were identified in the postoperative CT scan. The implant orientations were compared with the planned implant positions to obtain femoral and tibial implant alignment errors. Our results show that the femoral flexion, varus, and rotation root mean square errors for the robotic and conventional approach were 1.23°, 2.81°, 1.62° and 7.52°, 6.25°, 5.0°, respectively. The tibial slope and varus errors for the robotic and conventional approaches were 2.41°, 2.96° and 4.06°, 1.8°, respectively. We did not find any statistical significant difference (pu2009=u2009.05) in the performance of the two surgeons. We conclude that the hand-held robotic UKA system offers significant improvement in the final implant placement