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Background: Venous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index (BMI) > 40 undergoing primary and revision total joint arthroplasty, and second, to investigate aspirin (ASA) efficacy and safety., Methods: We identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision total joint arthroplasty from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any VTE event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively., Results: The total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = .669). The VTEs consisted of 6 deep venous thromboses (DVTs), 14 pulmonary embolisms, and one concomitant deep venous thrombosis and pulmonary embolism. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant (AC) 0.5% (n = 6), and AC alone 0.4% (n = 5) (P = .954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + AC, or AC alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = .351)., Conclusions: The use of aspirin 325 and 81 mg was found to have similar VTE rates as aspirin + ACs and ACs alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Cefazolin is the standard of care for perioperative antibiotic prophylaxis in total joint arthroplasty (TJA) in the United States. The potential allergic cross-reactivity between cefazolin and penicillin causes uncertainty regarding optimal antibiotic choice in patients who have a reported penicillin allergy (rPCNA). The purpose of this study was to determine the safety of perioperative cefazolin in PCNA patients undergoing primary TJA., Methods: We identified all patients (n = 49,842) undergoing primary total hip arthroplasty (n = 25,659) or total knee arthroplasty (n = 24,183) from 2016 to 2022 who received perioperative intravenous antibiotic prophylaxis. Patients who had an rPCNA (n = 5,508) who received cefazolin (n = 4,938, 89.7%) were compared to rPCNA patients who did not (n = 570, 10.3%), and to patients who did not have an rPCNA (n = 43,359). The primary outcome was the rate of allergic reactions within 72 hours postoperatively. Secondary outcomes included the rates of superficial infections, deep infections, and Clostridioides difficile infections within 90 days., Results: The rate of allergic reactions was 0.1% (n = 5) in rPCNA patients who received cefazolin, compared to 0.2% (n = 1) in rPCNA patients who did not (P = .48) and 0.02% (n = 11) in patients who have no rPCNA (P = .02). Allergic reactions were mild in all 5 rPCNA patients who received cefazolin and were characterized by cutaneous symptoms (n = 4) or dyspnea in the absence of respiratory distress (n = 1) that resolved promptly with antibiotic discontinuation and administration of antihistamines and/or corticosteroids. We observed no differences in the rates of superficial infections (0.1 versus 0.2%, P = .58), deep infections (0.3 versus 0.4%, P = .68), or C difficile infections (0.04% versus 0%, P = .99) within 90 days in rPCNA patients who received cefazolin versus alternative perioperative antibiotics., Conclusions: In this series of more than 5,500 patients who had an rPCNA undergoing primary TJA, perioperative prophylaxis with cefazolin resulted in a 0.1% incidence of allergic reactions that were clinically indolent. Cefazolin can be safely administered to most patients, independent of rPCNA severity., Level of Evidence: III., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Dislocation after total hip arthroplasty (THA) is a primary reason for THA revision. During THA through the direct anterior approach (DAA), the iliofemoral ligament, which provides the main resistance to external rotation (ER) of the hip, is commonly partially transected. We asked: (1) what is the contribution of the medial iliofemoral ligament to resisting ER after DAA THA? and (2) how much resistance to ER can be restored by repairing the ligament?, Methods: A fellowship-trained surgeon performed DAA THA on 9 cadaveric specimens. The specimens were computed tomography scanned before and after implantation. Prior to testing, the ER range of motion of each specimen to impingement in neutral and 10° of extension was computationally predicted. Each specimen was tested on a 6-degrees-of-freedom robotic manipulator. The pelvis was placed in neutral and 10° of extension. The femur was externally rotated until it reached the specimen's impingement target. Total ER torque was recorded with the medial iliofemoral ligament intact, after transecting the ligament, and after repair. Torque at extremes of motion was calculated for each condition. To isolate the contribution of the native ligament, the torque for the transected state was subtracted from both the native and repaired conditions., Results: The medial iliofemoral ligament contributed an average of 68% (range, 34 to 87) of the total torque at the extreme of motion in neutral and 80% (58 to 97) in 10⁰ of extension. The repaired ligament contributed 17% (1 to 54) of the total torque at the extreme of motion in neutral and 14% (5 to 38) in 10⁰ of extension, restoring on average 18 to 25% of the native resistance against ER., Conclusions: The medial iliofemoral ligament was an important contributor to the hip torque at the extreme of motion during ER. Repairing the ligament restored a fraction of its ability to generate torque to resist ER., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Bilateral hip osteoarthritis is evident in approximately 20% of patients who present to the clinic for evaluation of hip pain, and for those undergoing total hip arthroplasty (THA), 22% will end up needing a contralateral THA. The risk and benefits of simultaneous bilateral total hip arthroplasty (SBTHA) versus staged bilateral THA procedures have been well studied, demonstrating equivalent safety profiles comparable to unilateral and SBTHA. However, the influence of the surgical approach on SBTHA on postoperative outcomes remains unclear. We sought to compare perioperative outcomes and complication rates between the direct anterior approach (DAA) and posterior approach (PA) in patients undergoing SBTHA., Methods: We performed a 1:1 propensity score match based on age, sex, and body mass index. A total of 252 patients were available after matching, 126 patients in the DAA group and 126 in the PA group. Perioperative outcomes as well as surgical complications at the latest follow-up were retrospectively collected for each group. The mean follow-up was 36.7 months (range, 12.5 to 74.4)., Results: A SBTHA with DAA had significantly shorter surgical time (P < 0.001), anesthesia time (P < 0.001), and length of stay (P < 0.001), compared to the PA. A greater percentage of patients in the DAA group (91%) were discharged home compared to the PA group (57%) (P < 0.001). There were no differences in in-hospital complications (P = 0.617), 90-day complications (P = 0.605), or reoperation rates (P = 0.309) between surgical approaches., Conclusions: A SBTHA, either through the DAA or PA, can be safely performed with low complication rates. The DAA in the setting of SBTHA provides shorter surgical times, a shorter length of stay, and a greater percentage of patients discharged home., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Instability following total knee arthroplasty (TKA) is a common cause for revision. Isolated polyethylene exchange (IPE) can be performed to increase knee joint stability, but results have been mixed. The purpose of this study was to compare the survivorship and patient-reported outcomes of patients undergoing revision TKA for instability with IPE versus full component revision., Methods: We reviewed 280 primary TKAs undergoing revision TKA for instability. There were 181 knees that underwent revision with IPE, compared to 99 knees treated with full component revision. The mean follow-up was 32.8 months (range, 24.8 to 82.5). Patient demographics, radiographic parameters, prosthesis constraints, reoperations for instability, and patient-reported outcomes were compared., Results: The survivorship for instability was significantly higher at 2 years (99 versus 92%, P = .024) and 5 years (94 versus 84%, P = .024) for patients undergoing full component revision. Although there was no difference in Knee Injury and Osteoarthritis Outcome Score for Joint Replacements and Veterans RAND 12 physical component scores between the 2 groups at 6 weeks, 1 year, and 2 years after surgery, full revision patients reported greater pain relief (P = .006) and greater improvements in Veterans RAND 12 physical component scores (P = .027) at 1 year and Knee Injury and Osteoarthritis Outcome Score for Joint Replacements scores at 2 years (P = .017) compared to IPE patients. Men were associated with an increased risk for recurrent instability following IPE (hazard ratio 3.3, 95% confidence interval: [1.0 to 10.6])., Conclusions: Isolated polyethylene exchange was not as reliable or durable compared to full component revision for the management of postoperative instability. These procedures should only be reserved in cases with competent collaterals and when component position, offset, and rotation are optimized., (Copyright © 2024. Published by Elsevier Inc.)

Background: Sleep disturbance is a common problem following total knee arthroplasty (TKA). The objective of this study was to determine if exogenous melatonin improves sleep quality following primary TKA., Methods: A randomized, double-blind, placebo-controlled trial was conducted. A total of 172 patients undergoing unilateral TKA for primary knee osteoarthritis were randomized to receive either 5 mg melatonin (n = 86) or 125 mg vitamin C placebo (n = 86) nightly for 6 weeks. The primary outcome was the Pittsburgh Sleep Quality Index (PSQI) at 6 weeks and 90 days postoperatively. Secondary outcomes included 6-week and 90-day patient-reported outcome measures (PROMs), morphine milligram equivalents prescribed, medication compliance, adverse events, and 90-day readmissions., Results: Mean PSQI scores worsened at 6 weeks before returning to the preoperative baseline at 90 days in both groups. There were no differences in PSQI scores between melatonin and placebo groups at 6 weeks (10.2 ± 4.2 versus 10.5 ± 4.4, P = .66) or 90 days (8.1 ± 4.1 versus 7.5 ± 4.0, P = .43). Melatonin did not improve the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Lower Extremity Activity Scale, Visual Analog Scale for pain, or Veterans Rand 12 Physical Component Score or Mental Component Score at 6 weeks or 90 days. Poor sleep quality was associated with worse PROMs at 6 weeks and 90 days on univariate and multivariable analyses, but melatonin did not modify these associations. There were no differences in morphine milligram equivalents prescribed, medication compliances, adverse events, or 90-day readmissions between both groups., Conclusions: Exogenous melatonin did not improve subjective sleep quality or PROMs at 6 weeks or 90 days following TKA. Poor sleep quality was associated with worse patient-reported function and pain. Our results do not support the routine use of melatonin after TKA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Periprosthetic fractures (PPFs) account for approximately 25% of early revisions following total hip arthroplasty (THA). Cemented femoral fixation is associated with a lower-risk of PPF, and collared-cementless stems may reduce the risk as well. The objective of this study was to compare early-PPF rates between cemented, collared-cementless, and non-collared cementless stems in elderly patients., Methods: A consecutieve-series of 11,522 primary THAs performed between 2016 and 2021 at our institution in patients >65 years of age was identified. Stem types used were categorized as cemented, collared-cementless, or non-collared cementless. Patients undergoing THA who had cemented-stems were older, more commonly women, and more likely to have a posterior-approach. To reduce confounding of patient characteristics, we matched patients in the 3 stem-categories according to age, sex, and body mass index. This generated 3-groups (cemented, collared-cementless, and non-collared cementless) consisting of 936 patients per group. The mean age of these 2,808 patients was 73 years, the mean body mass index was 27, and 67% were women. Logistic regressions were used to evaluate risk-factors for early-PPF. In the entire cohort of primary THA in elderly patients, there were 85 early PPFs (0.7%) over the study period., Results: Non-collared cementless stems were associated with an increased risk of early PPF (OR: 3.11; P = .03) compared to collared-cementless stems. There were no early PPFs in the matched cemented cohort, 6 early PPFs in the matched collared-cementless cohort, and 16 early-PPFs in the matched non-collared cementless cohort (0% versus 0.64% versus 1.71%, P < .001)., Conclusions: In this large-series of patients >65 years of age undergoing primary THA, cemented stem fixation had the lowest incidence of early PPF, but collared-cementless stems had a nearly 3-fold decrease in risk for early PPF compared to non-collared cementless stems., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Patients who have spinal stiffness and deformity are at the highest risk for dislocation after total hip arthroplasty (THA). Previous reports of this cohort are limited to antero-lateral and postero-lateral (PL) approaches. We investigated the dislocation rate after direct anterior (DA) and PL approach THA with a contemporary high-risk protocol to optimize stability., Methods: We investigated patients undergoing THA who had preoperative biplanar imaging from January-December 2019. Patients were identified using radiographic criteria of spinal-stiffness (<10-degree change in sacral slope from standing to seated) and deformity (flatback deformity with >10-degree difference in pelvic incidence and lumbar lordosis). There were 367 patients identified (181 DA, 186 PL). The primary outcome was dislocation rate at 2-years postoperatively. Risk-factors for dislocation were evaluated using logistic regressions (significance level of 0.05)., Results: There were 6 (1.6%) dislocations in the entire cohort, with low dislocation rates for both DA (0.6%) and PL-THA (2.7%). We observed increased utilization of dual mobility with larger outer head bearings (>38 mm) with PL-THA (34.4 versus 5.0%, P < .01) and conversely increased utilization of 32-mm femoral-heads with DA-THA (39.4 versus 7.0%, P < .001). Surgical approach (PL) was not a significant risk-factor for dislocation (odds ratio: 5.03, P = .15). Patients who had a history of lumbar-fusion had 8-times higher odds for dislocation (OR: 8.20, P = .020)., Conclusions: To the best of our knowledge, this is the largest series to date evaluating DA and PL-THA in the hip-spine 2B-group. Our results demonstrate lower dislocation rate than expected with either surgical approach using a high-risk protocol., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: As ambulatory total knee arthroplasty (TKA) becomes increasingly common, unplanned admission after surgery presents a challenge for the health care system. Studies evaluating the reasons and risk factors for this occurrence are limited. We sought to evaluate the reasons for unplanned admission after surgery and identify risk factors associated with this occurrence., Methods: Patients registered in an institutional ambulatory joint arthroplasty program who underwent a TKA from 2017-2020 were retrospectively reviewed. The criteria for enrollment include candidates for unilateral TKA between the ages of 18 and 70 years, with a body mass index (BMI) of less than 35, and appropriate social and material support at home. Patients who had certain comorbidities including coronary artery disease, valvular heart disease, and opioid dependence were not eligible. A total of 274 patients who underwent TKA with planned same-day discharge (SDD) were identified in the medical record and reviewed. In this cohort, 140 patients (51.1%) were discharged on the day of surgery and 134 patients (48.9%) required a minimum 1-night admission. Demographics, comorbidities, and perioperative data were collected. Factors associated with failed SDD were identified using multivariate logistic regression., Results: The most common reasons for failed SDD were failure to meet ambulation goals (25%) and logistical issues related to a late-day case (19%). Risk factors for failed SDD include general anesthesia (odds ratio (OR) 12.60, P = .047), procedure start time after 11:00 am (OR 5.16, P < .001), highest postoperative pain score >8 (visual analogue scale, OR 5.78, P = .001). Willingness to accept a higher pain threshold before discharge (visual analogue scale 4 to 10) was associated with successful SDD (OR 3.0, P < .001). Age and American Society of Anesthesiologists (ASA) classification were not associated with failed SDD., Conclusions: The most common reasons for failed SDD were related to logistical issues and postoperative mobilization. Risk factors for failed SDD involve case timing and pain control. Modifiable perioperative factors may play an important role in successful SDD after TKA., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Early periprosthetic fractures (PPFx) following primary total hip arthroplasty (THA) create significant morbidity. Established risk factors for early PPFx include age, gender, body mass index, surgical approach, and implant fixation. We investigated the role of femoral fixation on early PPFx (<90 days postoperatively) in a high-risk cohort undergoing direct anterior approach (DAA) THA., Methods: The final cohort comprised 344 consecutive patients (390 hips) with risk factors for PPFx (age >68 years and body mass index <25 kg/m 2 ) who underwent primary DAA THA between May 4, 2009 and December 31, 2019 and had 90-day follow-up. Noncemented fixation was used in 229-hips, while cemented fixation was used in 161 hips. The primary outcome was early PPFx. Fisher's exact test was used for categorical variables, while t-tests were used to compare continuous variables., Results: We observed 8 early PPFx (2.1%), all fractures occurring in the noncemented group. Baseline demographics were similar but not equal, with the cemented group being older (78.0 versus 76.3 years; P = .004) with a greater proportion of females (91.9% versus 69.4%; P < .001). The rate of early PPFx was significantly higher with noncemented fixation compared to cemented fixation (3.5% versus 0.0%; P = .023). A post hoc power analysis confirmed sufficient power (1-β = 0.81)., Conclusion: Although baseline risk factors for early PPFx are not easily modifiable, surgical factors can be modified. Cemented fixation has the potential to markedly reduce the risk of early PPFx in high-risk patients undergoing DAA THA., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Insurance companies are increasingly making unilateral determinations of admission status for primary total knee arthroplasty (TKA). These determinations may differ from those based on surgeon-derived criteria for outpatient knee replacement. The goal of this study is to determine if insurance company determinations of outpatient status are as reliable as surgeon-derived criteria in predicting outpatient discharge after TKA., Methods: We retrospectively reviewed 709 patients who were preoperatively authorized for outpatient TKA. Patients were stratified into 2 groups: "outpatient per surgeon" (appropriate for outpatient surgery per institutional protocols) or "outpatient per insurance" (appropriate for inpatient surgery per institutional protocols but denied inpatient status by insurance). The primary endpoint of this study was the conversion rate of outpatient to inpatient stay. Univariate logistic regression was performed to compare the odds of conversion to inpatient stay between outpatient per surgeon and outpatient per insurance procedures and other covariates., Results: The cohort included 434 outpatient per insurance (61.2%) and 275 outpatient per surgeon (38.8%) patients. Surgeons accurately predicted outpatients' discharge 92.0% of the time, while insurance companies did so 81.3% of time (P < .001). Outpatient per insurance procedures (odds ratio [OR] 2.20, P = .003) and body mass index >35 kg/m 2 (OR 1.82, P = .026) had higher odds of being converted to inpatient. Males had higher odds (OR 1.52, P < .001) of being discharged as outpatient., Conclusion: Determining inpatient versus outpatient status is a complex decision involving both clinical and social factors. Surgeons accurately predicted outpatient discharge 92% of the time. Moreover, outpatient per insurance procedures were twice as likely to be converted to inpatient status. Therefore, insurance companies should leave deciding admission status up to both the patient and surgeon., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: The direct anterior (DA) approach to total hip arthroplasty (THA) is associated with higher rates of surgical site complications (SSCs) compared to other approaches, particularly among high-risk patients. Closed incision negative pressure therapy (ciNPT) is effective in reducing SSCs and surgical site infections (SSIs) in other populations. We asked whether ciNPT could decrease SSCs in high-risk patients undergoing DA THA., Methods: This prospective randomized controlled trial (RCT) enrolled high-risk DA THA patients at 3 centers. Patients were offered enrollment if they had previously identified risk factors for SSC: Body mass index (BMI) >30 kg/m 2 , diabetes, active smoking, or before hip surgery. Patients were randomized after closure to either an occlusive (control) dressing or ciNPT dressing for 7 days. All 90-day SSCs were recorded. A priori power analysis demonstrated 116 patients were required to identify a 4.5x relative reduction in SSCs. Chi-square tests were used to evaluate probability of complications., Results: One hundred and twenty two patients enrolled; 120 completed data collection. SSCs occurred in 18.3% (11/60) of control patients compared to 8.3% (5/60) of ciNPT patients (χ 2  = 2.60, P = .107). SSCs included dehiscence to the subcutaneous level (13) and prolonged drainage (3). Nine control (15.0%) and 2 ciNPT (3.3%) patients met CDC criteria for superficial SSI (χ 2  = 4.90, P = .027). Fifteen of 16 SSCs resolved with local wound care. One in the ciNPT group required reoperation for acute PJI., Conclusion: Among patients at risk of surgical site complications undergoing DA THA, we identified a significant reduction in superficial SSIs and a trend toward lower overall SSCs with ciNPT., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: An extended trochanteric osteotomy (ETO) safely addresses femoral component removal during challenging revision total hip arthroplasty. However, no prior study has evaluated whether a difference in axial stability exists between ETO closure performed before (reconstitution) or after (scaffolding) canal preparation and stem impaction. We hypothesized that given the absence of clinical reports of outcome differences despite the wide use of both practices, no significant difference in the initial axial stability would exist between the 2 fixation techniques., Methods: ETOs were performed and repaired using the reconstitution technique for the 6 right-sided femora and the scaffolding technique for the six left-sided femora. The 195-mm long, 3.5°-tapered splined titanium monobloc stems were impacted into 6 matched pairs of human fresh cadaveric femora. Three beaded cables were placed in a standardized fashion on each specimen, 1 for prophylaxis against osteotomy propagation during reaming/impaction and 2 to close the ETO. Stepwise axial loading was performed to 2600 N or until failure, which was defined as subsidence >5 mm or femoral/cable fracture., Results: All specimens successfully resisted axial testing, with no stem in either ETO repair group subsiding >2 mm. The mean subsidence for the reconstitution group was 0.9 ± 0.4 mm, compared to 1.2 ± 0.5 mm for the scaffolding group (P = .2)., Conclusion: In this cadaveric model with satisfactory proximal bone stock, no difference existed between the reconstitution and scaffolding ETO repair techniques, and both provide sufficient immediate axial stability in a simulated revision total hip arthroplasty setting under physiologic loads., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: There is a paucity of data on blood loss and the risk of allogeneic blood transfusion after simultaneous bilateral total hip arthroplasty (SBTHA) with contemporary blood management including neuraxial anesthesia, routine tranexamic acid use, and a restrictive transfusion protocol. As such, we sought to determine the in-hospital outcomes of SBTHA, specifically analyzing blood loss and the rate and risk factors for transfusion., Methods: We identified 191 patients who underwent SBTHA at a single institution from 2016 to 2019. No drains were utilized and no patients donated blood preoperatively. Mean age was 59 years with 96 females (50.3%). The surgical approach was posterior in 138 (72.3%) and direct anterior in 53 (27.7%) patients. We analyzed blood loss, the rate of allogeneic blood transfusions, and in-hospital thromboembolic complications. We analyzed risk factors for transfusion with a logistic regression analysis., Results: Twenty-two patients (11.5%) underwent allogeneic blood transfusion. All transfused patients were female. Univariate analysis revealed female gender as a transfusion risk factor since it had statistically significant higher proportion in the transfusion group than the nontransfusion group (100% vs 43.5%, respectively, P < .001). We did not identify any other singular significant risk factors for transfusion in a multivariable regression analysis. However, females with a preoperative Hb <12 had an elevated risk of transfusion at 37.5% (15/40 patients)., Conclusion: With contemporary perioperative blood management protocols, there is a relatively low (11.5%) risk of a blood transfusion after SBTHA. Females with a lower preoperative Hb (<12 g/dL) had the highest risk of transfusion at 37.5%., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Titanium tapered stems (TTS) achieve fixation in the femoral diaphysis and are commonly used in revision total hip arthroplasty. The initial stability of a TTS is critical, but the minimum contact length needed and impact of implant-specific taper angles on axial stability are unknown. This biomechanical study was performed to better guide operative decision-making by addressing these clinical questions., Methods: Two TTS with varying conical taper angles (2° spline taper vs 3.5° spline taper) were implanted in 9 right and left matched fresh human femora. The proximal femur was removed, and the remaining femoral diaphysis was prepared to allow for either a 2 cm (n = 6), 3 cm (n = 6), or 4 cm (n = 6) cortical contact length with each implanted stem. Stepwise axial load was then applied to a maximum of 2600N or until the femur fractured. Failure was defined as either subsidence >5 mm or femur fracture., Results: All 6 femora with 2 cm of stem-cortical contact length failed axial testing, a significantly higher failure rate (P < .02) than the 4 out of 6 femora and all 6 femora that passed testing at 3 cm and 4 cm, respectively, which were not statistically different from each other (P = .12). Taper angle did not influence success rates, as each matched pair either succeeded or failed at the tested contact length., Conclusion: 4 cm of cortical contact length with a TTS demonstrates reliable initial axial stability, while 2 cm is insufficient regardless of taper angle. For 3 cm of cortical contact, successful initial fixation can be achieved in most cases with both taper angle designs., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The objective of this study is to evaluate the incidence, natural history, response to treatment, and risk factors for anterior iliopsoas impingement (AIPI) after direct anterior approach (DAA) total hip arthroplasty (THA)., Methods: Between January 1, 2009 and January 4, 2014, 600 patients (655 hips) who underwent primary DAA THA were retrospectively reviewed. AIPI incidence was calculated. Natural history and response to a stepwise treatment approach was assessed. Radiographic anterior acetabular component overhang was measured. Asymptomatic controls were used to identify risk factors for the development of AIPI., Results: In total, 518 patients (559 hips) met the inclusion criteria. The incidence of AIPI was 32/559 (5.7%). Symptom resolution occurred in 22/32 (68.8%) patients at final follow-up. Nonoperative management was successful in 15/32 (46.9%) patients. Operative intervention resulted in symptom resolution in 5/8 (62.5%) patients. On univariate analysis, female gender (odds ratio [OR] 2.79), acetabular component to native femoral head diameter ratio above 1.1 (OR 3.85), and any measurable overhang (OR 7.07) significantly raised the risk of AIPI, while increasing native femoral head diameter was protective for AIPI (OR 0.83)., Conclusion: AIPI is a cause of groin pain after DAA THA, which often improves with conservative measures. Significant predisposing factors for AIPI include female gender, small native femoral head diameter, increased acetabular component to femoral head diameter ratio, and most notably, any measurable acetabular component overhang., Level of Evidence: Level III, retrospective cohort study., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Mechanically assisted crevice corrosion (MACC) at modular junctions can cause a spectrum of adverse local tissue reactions (ALTRs) in patients who have undergone total hip arthroplasty (THA). The purpose of this study is to describe the presentation, treatments, and related complications of a cohort of patients presenting with late instability following metal-on-polyethylene THA due to underlying MACC and ALTR., Methods: This multicenter retrospective case series presents 17 patients (12 women, mean age 62.6, range 42-73) presenting with late instability secondary to ALTR and MACC. All patients had a metal (Cobalt Chrome)-on-polyethylene bearing surface. Patients experienced a mean 2.7 dislocations (range 1-6) at mean 4.3 years (range 0.4-17.0) following their index surgery. Serum metal levels (n = 12) demonstrated a greater elevation of cobalt (mean 6.9, range 0.13-20.88 ng/mL) than chromium (mean 1.9, range 0.13-3.23 ng/mL)., Results: Patients were revised for instability at a mean of 6.8 years (range 2.1-19.4) following their index surgery. ALTR was encountered in every case and the modular head-neck junction demonstrated visible corrosion. An exchange of the CoCr head to a ceramic head with a titanium sleeve and placement of a constrained liner was performed for a majority of patients (n = 15, 88.2%). Five patients (29.4%) had complications postoperatively including peroneal palsy (n = 2), periprosthetic joint infection (n = 2), and ALTR recurrence (n = 1)., Conclusion: Recurrent instability in the setting of otherwise well-positioned THA components and without another obvious cause should raise concern for ALTR as a potential underlying etiology., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Aseptic loosening remains one of the leading causes for failure of total knee arthroplasty (TKA). We sought to identify early radiographic measures that may associate with aseptic tibial component loosening, emphasizing systematic evaluation of the cement mantle., Methods: All TKA revisions from 2007 to 2015 with the primary indication of tibial aseptic loosening were identified using in an institutional implant retrieval database. After exclusion criteria, 61 TKAs comprised the study group. A matched control group of 59 TKAs that had not failed at a minimum of 3 years was identified for comparison. Radiographic analysis on all 6-week postoperative radiographs included angulation of components, cement penetration depth, and presence of radiolucency at the implant-cement and bone-cement interfaces. Groups were compared with Student's t-test, chi-squared test, and Mann-Whitney U-test. A final multivariable logistic regression model was formed for the outcome of aseptic loosening., Results: On multivariable analysis, failure was associated with a greater number of zones with cement penetration <2 mm (5.6 vs 3.4 zones, odds ratio [OR] 1.89, P < .001), increasing percent involvement of radiolucency at the implant-cement interface (8.7% vs 3.1%, OR = 1.15, P = .001), and increased varus alignment of the tibial component (1.5° vs 0°, OR = 1.35, P = .014). A greater number of zones with a radiolucent line at the bone-cement interface did not significantly associate (1.1 vs 0.3, P = .091)., Conclusion: Our results suggest that radiographic indicators of poor cement mantle quality associate with later aseptic loosening. This emphasizes the need for surgeons to perform careful cement technique in order to reduce the risk of TKA failure., Level of Evidence: III (Case-control)., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The aim of this study was to evaluate the results of revision surgery for the treatment of stiffness after total knee arthroplasty (TKA)., Methods: An IRB-approved retrospective review was performed to identify patients who were revised due to stiffness after a primary TKA. Patients were included when at least one major component had to be revised due to stiffness after primary TKA with a minimum follow-up of 2 years. Patients with history of previous infection and those treated with isolated polyethylene exchange were excluded., Results: The study group involved 42 knees. Mean follow-up was 47 months (24-109 months). Mean flexion contracture improved from 9.7° (0°-35°) preoperatively to 2.3° (0°-20°) postoperatively (P < .00). Mean flexion improved from 81.5° (10°-125°) preoperatively to 94.3° (15°-140°) postoperatively (P .02). Mean range of motion improved from 72.0° preoperatively (10°-100°) to 92° (15°-140°) postoperatively (P < .00). Mean Knee Society knee scores improved from 43.9 points (15-67) preoperatively to 72.0 points (50-93) at latest follow-up and mean Knee Society Function scores improved from 48.7 (35-80) preoperatively to 70.1 points (30-90) postoperatively. Pain improved in 73% of the patients., Conclusion: Revision surgery appears to be a reasonable option for patients presenting with pain and stiffness after TKA. However, the benefits may be modest as the outcomes still do not approach those achieved with primary TKA., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Acetabulum positioning affects dislocation rates, component impingement, bearing surface wear rates, and need for revision surgery. Novel techniques purport to improve the accuracy and precision of acetabular component position, but may have a significant learning curve. Our aim was to assess whether adopting robotic or fluoroscopic techniques improve acetabulum positioning compared to manual total hip arthroplasty (THA) during the learning curve., Methods: Three types of THAs were compared in this retrospective cohort: (1) the first 100 fluoroscopically guided direct anterior THAs (fluoroscopic anterior [FA]) done by a surgeon learning the anterior approach, (2) the first 100 robotic-assisted posterior THAs done by a surgeon learning robotic-assisted surgery (robotic posterior [RP]), and (3) the last 100 manual posterior (MP) THAs done by each surgeon (200 THAs) before adoption of novel techniques. Component position was measured on plain radiographs. Radiographic measurements were taken by 2 blinded observers. The percentage of hips within the surgeons' "target zone" (inclination, 30°-50°; anteversion, 10°-30°) was calculated, along with the percentage within the "safe zone" of Lewinnek (inclination, 30°-50°; anteversion, 5°-25°) and Callanan (inclination, 30°-45°; anteversion, 5°-25°). Relative risk (RR) and absolute risk reduction (ARR) were calculated. Variances (square of the standard deviations) were used to describe the variability of cup position., Results: Seventy-six percentage of MP THAs were within the surgeons' target zone compared with 84% of FA THAs and 97% of RP THAs. This difference was statistically significant, associated with a RR reduction of 87% (RR, 0.13 [0.04-0.40]; P < .01; ARR, 21%; number needed to treat, 5) for RP compared to MP THAs. Compared to FA THAs, RP THAs were associated with a RR reduction of 81% (RR, 0.19 [0.06-0.62]; P < .01; ARR, 13%; number needed to treat, 8). Variances were lower for acetabulum inclination and anteversion in RP THAs (14.0 and 19.5) as compared to the MP (37.5 and 56.3) and FA (24.5 and 54.6) groups. These differences were statistically significant (P < .01)., Conclusion: Adoption of robotic techniques delivers significant and immediate improvement in the precision of acetabular component positioning during the learning curve. While fluoroscopy has been shown to be beneficial with experience, a learning curve exists before precision improves significantly., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Previous studies have suggested that wound complications may be higher after direct anterior approach (DAA) hip arthroplasty, but, specific risk factors have not been closely examined., Methods: We conducted a retrospective case-control study of 651 consecutive DAA hip arthroplasty surgeries performed by 2 surgeons over a 3-year period. Outcome measures included any postoperative wound problem (including prolonged drainage, wound dehiscence, wound necrosis, suture granuloma, and superficial infection) requiring additional intervention or reoperation. Univariate odds ratios (ORs) were calculated, and multivariate logistic regression analysis was performed to determine risk correlation. Receiver operator characteristic (ROC) curves were created to determine disease predictability., Results: A total of 75 patients (11.5%) experienced wound complications requiring additional intervention, of which, 13 (1.9%) required reoperation. Multivariate regression analysis found that development of wound complications was significantly and independently associated with body mass index (BMI) 30-35 kg/m 2 (OR 2.05; 95% confidence interval [CI] 1.08-3.88), BMI 35-40 kg/m 2 (OR 3.40; 95% CI 1.42-8.26), BMI > 40 kg/m 2 (OR 7.28; 95% CI 2.55-20.78), and diabetes mellitus (OR 2.97; 95% CI 1.46-6.07). Reoperation for wound complication was significantly associated with BMI > 40 kg/m 2 (OR 5.68; 95% CI 1.17-27.48) and diabetes mellitus (OR 13.08; 95% CI 3.97-43.11). Optimal cutoff values for BMI were found through receiver operator characteristic curve analysis to be 28.0 kg/m 2 for development of wound complications and 28.2 kg/m 2 for reoperation for wound complications., Conclusion: Obesity and diabetes mellitus are significantly associated with postoperative wound-healing complications and the need for reoperation for these wound complications after DAA hip arthroplasty., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Total knee arthroplasty and its relation to gait abduction or adduction moment has not been fully described., Methods: Gait analysis was performed on 25 patients (27 knees) preoperatively, 6 months and 1 year after total knee arthroplasty. Reflective markers were placed on the lower extremity, and motion data were collected at 60 Hz using 6 infrared cameras. Ground reaction forces were recorded at 960 Hz with a force plate. Stance phase was divided into braking and propulsive phases. Coronal knee angles and moments were calculated. Repeated-measures analysis of variance was used to compare frontal plane knee impulse over time and between the braking and propulsive phases of stance., Results: In varus knees, static alignment was corrected from 2.2° varus to 3.3° valgus and in valgus knees from 15.2° valgus to 2.7° valgus (P < .010). Braking phase adduction impulse decreased from 0.145 to 0.111 at 6 months but increased to 0.126 Nm/kg s (P > .05) at 1 year. Propulsive phase impulse changed from 0.129 to 0.085 and persisted at 1 year. Impulse changed from 0.01 (abduction) to 0.11 Nm/kg s (adduction) at 6 months and persisted (P = .01)., Conclusion: Restoration of anatomic alignment and soft tissue balancing changes the lateral loading conditions of valgus knees. Both cases, between 6 months and 1 year, increased peak moment., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Design parameters affecting initial mechanical stability of tapered, splined modular titanium stems (TSMTSs) are not well understood. Furthermore, there is considerable variability in contemporary designs. We asked if spline geometry and stem taper angle could be optimized in TSMTS to improve mechanical stability to resist axial subsidence and increase torsional stability. Initial stability was quantified with stems of varied taper angle and spline geometry implanted in a foam model replicating 2cm diaphyseal engagement. Increased taper angle and a broad spline geometry exhibited significantly greater axial stability (+21%-269%) than other design combinations. Neither taper angle nor spline geometry significantly altered initial torsional stability., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The use of tapered, fluted, modular, distally fixing stems has increased in femoral revision surgery. The goal of this retrospective study was to assess mid-term to long-term outcomes of this implant. Seventy-one hips in 70 patients with a mean age of 69 years were followed for an average of 10 years. Preoperative HHS averaged 50 and improved to 87 postoperatively. Seventy-nine percent hips had Paprosky type 3A or more bone-loss. All stems osseointegrated distally (100%). Two hips subsided >5mm but achieved secondary stability. Sixty-eight percent hips had evidence of bony reconstitution and 21% demonstrated diaphyseal stress-shielding. One stem fractured near its modular junction and was revised with a mechanical failure rate of 1.4%. Distal fixation and clinical improvement were reproducibly achieved with this stem design., (Published by Elsevier Inc.)

Bone mineral density (BMD), as measured by DEXA, can vary depending on bone rotation and fat content of soft tissues. We performed DEXA measurements, under controlled positioning, on 24 autopsy-retrieved femora from patients who had fully functional and asymptomatic successful TKA to determine periprosthetic BMD changes and compared results to 24 normal cadaveric femora. In TKA specimens, BMD was affected by gender, preoperative diagnosis, and zone under analysis. The lowest mean BMD was in the anterior femoral condylar zone. Males had higher mean BMD at all zones while patients with preoperative diagnosis of osteoarthritis had higher BMD in the posterior condylar zone. The mean BMD in the anterior femoral condylar zone in TKA specimens was significantly lower than in normal specimens without arthroplasties, most likely due to stress shielding., (Copyright © 2014 Elsevier Inc. All rights reserved.)

We compared gait parameters prior to, at 6 months and 1 year following total hip arthroplasty (THA) performed via direct anterior approach (DAA) and posterior approach (PA) by a single surgeon in 22 patients. A gait analysis system involving reflective markers, infrared cameras and a multicomponent force plate was utilized. Postoperatively, the study cohort demonstrated improvement in flexion/extension range of motion (ROM) (P = 0.001), peak flexion (P = 0.005) and extension (P = 0.002) moments with no differences between groups. Internal/external ROM improved significantly in the DAA group (P = 0.04) with no change in the PA group. THA performed via DAA and PA offers similar improvement in gait parameters with the exception of internal/external ROM which might be related to the release and repair of external rotators during PA THA., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Recovery expectations (RE) after total hip and knee arthroplasty (THA-TKA) influence outcomes. We surveyed AAHKS members to determine variation in surgeon RE. Four vignettes depicting patients with high and low expectations after THA and TKA were distributed with a validated RE survey. Responses were analyzed for clinically significant differences between surgeons and within surgeons. Of 1049 surgeons surveyed, 358 (34%) responded. There was a clinically significant difference in 85% (high-THA), 46% (low-THA), 74% (high-TKA), and 57% (low-TKA) of pairs. Disagreement was significantly greater in high expectation vignettes. Individual surgeons distinguished between high and low expectation patients in 76% (THA) and 72% (TKA) of cases. There was no association between surgeon RE and practice demographics. Wide variations in RE were observed, especially among high expectation patients., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The purpose of this study was to analyze wear rates of highly cross-linked polyethylene comparing the Martell and the Roman methods in 112 total hip arthroplasties in patients 65 years and younger, with a mean follow-up of 5.7 years. The mean wear rates in the Martell and Roman methods were 0.014 ± 0.05 mm/y and 0.011 ± 0.04 mm/y when including all values and 0.043 ± 0.028 mm/y and 0.038 ± 0.02 mm/y when negative values were assumed to be zero, respectively. Both Roman and Martell methods showed similar low wear rates with negative values. The Roman method had higher precision and was more user friendly because it required less steps to measure wear, especially when comparing with the manual feature of Martell method., (Copyright © 2012 Elsevier Inc. All rights reserved.)

This is a long-term follow-up report of all-polyethylene tibial components in 60 years and younger, active patients. At the mean follow-up of 12.4 ± 2.7 (range, 10-18 years), no more patients were deceased or lost to follow-up, leaving 32 patients (44 knees) for final analysis. Good to excellent results were achieved in 96% of patients. The mean Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score were 31 and 97, respectively. Sixty-two percent of patients were participating in sport activities such as running, gym exercises, and playing tennis or golf, with a mean UCLA score of 7.2. There were no cases of malalignment, aseptic loosening, excessive wear, or osteolysis. Seven patients (9 knees) had incomplete, nonprogressive demarcation at the zone 1 tibial interface. Kaplan-Meier survivorship at 10 years for revision due to mechanical reasons and for all failures was 97.7% and 95.5%, respectively., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Radiographic signs of osseointegration with the use of fluted, tapered, modular, titanium stems in revision hip arthroplasty with bone loss have not been previously categorized. Serial radiographs of 64 consecutive hips with mean follow-up of 6.2 years were retrospectively reviewed. Bone loss was classified as per Paprosky classification, osseointegration was assessed according to a modified system of Engh et al, and Harris Hip Score was used to document pain and function. Seventy-four percent of the hips had type 3 or 4 bone loss. All stems were radiographically osseointegrated. Early minor subsidence was seen in 6.2% of the hips; definite bony regeneration, 73% of the hips; and stress shielding, 26% of the hips. These osseointegration patterns were different from those described for extensively porous-coated cobalt-chromium stems and had a bearing on the evaluation of fixation of these stems., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Despite excellent long-term results of proximally coated tapered wedge femoral stems in noncemented total hip arthroplasty, we have consistently observed a minority fail to achieve osteointegration. We retrospectively reviewed 320 consecutive total hip arthroplasties performed by a single surgeon using a single stem over a 4-year period. Clinical and radiographic parameters were analyzed for risk factors predisposing to a failure of osteointegration, defined as a progressive circumferential radiolucency around the proximal porous coating on both anteroposterior and lateral radiographs. Fifteen stems (4.7%) failed to osteointegrate; 3 underwent femoral revision for persistent thigh pain, whereas the remainder expressed varying degrees of symptomatology. Risk factors associated with failure of osteointegration were male sex, a smaller canal-flare index, larger stem size, and greater canal fill at the mid- and distal-thirds of the stem. Awareness of variability in proximal femoral morphology and problems caused by distal fixation with a proximally coated implant may help avoid this uncommon but potentially serious complication., (Copyright © 2011. Published by Elsevier Inc.)

Failure of internal fixation of intertrochanteric fractures is associated with delayed union or malunion resulting in persistent pain and diminished function. We evaluated 15 elderly patients treated with a tapered, fluted, modular, distally fixing cementless stem. At an average follow-up of 2.86 years, mean Harris hip score improved from 35.90 preoperatively to 83.01 (P < .01). Fourteen stems had stable bony on growth, and one stem was loose. Distal fixation with a tapered, fluted, modular cementless stem allows stable fixation with good functional outcome in a reproducible fashion in this challenging cohort of patients., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Tibial insert locking mechanisms are intended to limit interface motion and "backside" wear in modular total knee arthroplasty (TKA). Nevertheless, anterior polyethylene subluxation is occasionally apparent on lateral radiographs after TKA, suggesting locking mechanism failure. We retrospectively identified 10 modular posterior-stabilized implants of a single design that were found to have failure of the locking mechanism at the time of revision surgery for osteolysis. Operative reports were reviewed for the presence of backside wear, and preoperative radiographs were inspected for polyethylene subluxation. All 10 implants demonstrated significant backside wear. Nine had anterior polyethylene subluxation evident on preoperative radiographs. Anterior polyethylene subluxation on the lateral radiograph is a subtle sign of failure of the locking mechanism in this modular posterior-stabilized TKA., (Copyright © 2011 Elsevier Inc. All rights reserved.)

It is not uncommon to encounter patients with atypical hip or lower extremity pain, ill-defined clinicoradiological features, and concomitant hip and lumbar spine arthritis. The purpose of this study is to present our experience using the response resulting from a combined anesthetic-steroid hip injection for treatment selection in these patients. A retrospective analysis of 204 consecutive diagnostic hip injections was undertaken. Patient charts were scrutinized for outcomes of injection and treatment. Our findings suggest that the relief of symptoms following injection of local anesthetic and steroid into the hip joint has a sensitivity of 91.5%, specificity and positive predictive value of 100%, and negative predictive value of 84.6% for response to total hip arthroplasty. We thereby believe that this is a reliable test with low morbidity and can predict the potential benefit of total hip arthroplasty in this diagnostically challenging group of patients., (Copyright 2010 Elsevier Inc. All rights reserved.)

Femoral deficiency has been shown to adversely affect the results of revision total hip arthroplasty. Tapered titanium modular stems allow distal fixation of the fluted, conical portion of the implant in the setting of proximal bone loss. One hundred two consecutive hips with proximal bone loss underwent revision femoral reconstruction between 1998 and 2002 at 3 centers using the Link MP modular stem. Forty-three hips had Mallory type 3C femoral deficiency. Ninety-seven hips were observed for an average of 45 months (range, 24-72; median, 36 months). Clinically, mean Harris hip score improved from 36 to 84 (range, 54-99). Radiographically, 93 hips were considered stable, with no circumferential lucencies at the distal fixation surface. Three hips migrated and required revision, along with one periprosthetic fracture. Five other hips had nonprogressive migration of 1 to 2 mm.

Highly cross-linked polyethylene has been used with success in total hip arthroplasty. The reduction of femoral head penetration has been a uniform finding among researchers at 5 to 7 years of follow-up. However, there have also been newly highlighted modes of failure, as increased brittleness of the material can adversely affect the integrity of the acetabular locking mechanism; and some materials can oxidize in vivo, with additional alterations in mechanical properties and early delamination. The mechanics of articulation in a knee arthroplasty are markedly different and will impose more severe stresses on the polyethylene material than hip arthroplasties. Each change that is made to improve polyethylene wear comes with mechanical trade-offs. It is not clear that the gains in wear that have been shown in hips will translate to knees without adverse ramifications from the altered mechanical properties.

The optimal surface finish on cementless total hip arthroplasty is still a matter of debate. 145 hips in 130 patients with hybrid total hip arthroplasty using a hemispherical, titanium plasma-sprayed cup were followed for an average of 8.5 years. The average age was 63 years, and the average weight was 165 lb. Three hips were revised for polyethylene wear and synovitis/osteolysis. In all 3 cases, the acetabular component remained well fixed. Radiographically, 5 hips had femoral osteolysis, and 5 sockets had osteolysis in zone 2, with 4 in zone 1. There were no cases of progressive lucent lines, and no acetabular components were revised. Plasma-sprayed acetabular components remain durable up to 12 years. Moreover, in cases with wear particle overload and osteolysis, fixation was maintained at revision surgery.

This study evaluates steady-state serum metal levels in patients with 4 different combinations of fixation modalities, materials, and bearing couples. Forty patients with a minimum of 5 years of follow-up and with well-functioning primary total hip arthroplasty were recruited to have serum metal levels measured. Serum chromium and cobalt levels in the metal-on-metal cohort were significantly higher (P < .05) than the other 3 cohorts. The noncemented ceramic-polyethylene cohort had significantly lower (P < .05) serum chromium levels compared to cemented and noncemented metal-polyethylene cohorts and significantly higher serum titanium levels compared to the cemented metal-polyethylene cohort which had no titanium-containing implants. Debris generated at the metal head/neck modular junction likely accounts for the significantly lower serum chromium concentration in ceramic-polyethylene bearing couples.

The basis of cement fixation is the interdigitation of cement into the cancellous bone while being supported by the cortical bone. If this is achieved, socket fixation is durable for 10 to 15 years. Cementless socket fixation using a titanium hemispherical socket with a porous surface has had excellent clinical results. Titanium fibermesh cups with supplemental screw fixation have the longest published results for uncemented sockets, with a survivorship of 99% using fixation failure as the end point. Similar findings at 8- to 10-year follow-up have been shown for sintered bead surfaces, as well as plasma spray surfaces, with and without hydroxyapatite coating. Regardless of the fixation technique chosen, a physical, 3-dimensional interlocking between the socket and the supporting bone is necessary for long-term fixation.

There are few modern reports that document the results of all-polyethylene (all-poly) tibial components in younger, active patients. The potential benefits of this design are the elimination of backside wear and lower implant cost than modular, metal-backed components. Nonetheless, since the mid 1980s, modular, metal-backed tibial trays have dominated the total knee arthroplasty market based on finite-element analysis studies that demonstrated superior force distribution compared with conventional all-poly components. As a result, backside wear has become an emerging problem and refocused design efforts on unitized components. Our clinical experience indicates that an all-poly tibial component fixed with cement can provide excellent performance and survivorship even in younger, active patients at intermediate follow-up.

This prospective randomized double-blind study aims to evaluate the effect of surface finish of the cemented femoral stem in primary total hip arthroplasty. Between January 1996 and May 1997, a single surgeon prospectively implanted 244 primary THAs (237 patients) using cemented femoral stems with modified third-generation cement technique in selected patients. Patients were randomized to receive the Ranawat-Burstein prosthesis (Biomet, Warsaw, IN) with 1 of 2 finishes (smooth-Ra 17 or rough-Ra 170). At a minimum 5-year follow-up, no statistical differences were found between the 2 groups. One patient with a smooth stem underwent revision of the femoral component at 2 years secondary to aseptic loosening. There was no other evidence of radiographic loosening or osteolysis. As an isolated variable, surface finish does not appear to significantly influence results at mean follow-up of 6.5 years.

This study compares the fixed-bearing PFC Sigma Total Knee Arthroplasty to the recently introduced rotating-platform version of the same design in 26 patients. At an average follow-up time of 46 months for the fixed-bearing side and 16 months for the rotating-platform side, no significant differences were found in terms of knee preference, knee pain, range of motion, overall satisfaction, or Knee Society scores (KSSs). No revisions, subluxations, dislocations, or infections were seen. Also no radiographic evidence of component loosening, osteolysis, or malalignment was found in any knee. The results of cementing the PFC Sigma rotating-platform, posterior-stabilized total knee show excellent patient satisfaction at 1 year and comparable clinical and radiographic results to the fixed-bearing version.

This prospective review aimed to evaluate 15-year survivorship of the collarless, third-generation cemented, normalized, Omnifit (Osteonics, Allendale, NJ) femoral stem in hybrid total hip arthroplasty (THA). Between January 1986 and June 1990, a single surgeon prospectively implanted 250 consecutive hybrid THAs (215 patients) using a modified third-generation cement technique in selected patients. A Harris-Galante (I or II) (Zimmer, Warsaw, IN) cementless shell with modular polyethylene (4150 resin) liners gamma-sterilized in air were implanted. Kaplan-Meier survivorship of the femoral or acetabular component with mechanical failure (revision for aseptic loosening) as the end-point was 100% +/- 0% at 15 years. Wear couple exchange and bone grafting was performed in 1 case (0.4%) for progressive acetabular osteolysis. This report supports femoral component centralization and good cement mantle to ensure durability of the collarless, cemented, normalized femoral stem with a surface roughness of 30-40 microinches.

Although several methods of intraoperative limb-length measurements have been described, their success in predicting the limb-length correction is not well documented. A new technique of measuring intraoperative limb lengthening using a vertical Steinmann pin at the infracotyloid groove of the acetabulum was studied in 100 consecutive primary total hip arthroplasties. Correlation of the predicted intraoperative correction was done with the postoperative radiographic measurements. Preoperative limb-length inequality ranged from -24 mm (short) to +2 mm (long) (mean, -4.2 mm). Intraoperative measurement of lengthening ranged from 0 to 15 mm (mean, 5.9 mm). Radiographic measurements of postoperative radiographs showed lengthening ranging from 0 to 17 mm (mean, 7.4 mm). There was significant correlation between the 2 values (r =.84). Postoperative limb-length inequality ranged from -7 mm to +8 mm (mean, 1.9 mm). None of the patients had to use shoe lifts for equalization of limb lengths.

Since the introduction of the Total Condylar Prosthesis (TCP) in 1974, concomitant improvements in surgical technique and prosthetic design have occurred. The individual effects of each of these variables have not been investigated, however. This study evaluates 2 different knee designs using the same operative technique by a single surgeon. All primary total knee arthroplasties performed between 1986 and 1989 were entered into a database of 2 cohorts, TCP and Press Fit Condylar (PFC) knees, matched for age, gender, body weight, and diagnosis. Follow-up data within 12 months of each other were used, evaluating patients clinically and using a self-administered questionnaire. In each cohort, 74 knees were matched by these criteria. Follow-up time was 4.04 and 4.45 years for the TCP and PFC cohorts. Range of motion averaged 107 degrees and 112 degrees for the TCP and PFC cohorts. This difference was statistically significant. Total knee score and functional score improved significantly. Anterior knee pain was present in 9 TCP and 3 PFC knees. Lateral release was performed in 30 TCP and 18 PFC knees. The PFC showed an advantage in ROM, stair function, anterior knee pain, and use of lateral release. Both designs showed comparable pain relief and walking ability.

A retrospective evaluation of the clinical and radiographic results of the Harris-Galante acetabular cups was performed in 112 patients with 127 total hip arthroplasties. Patients with 14 hips had died, and patients with 20 hips were lost to follow-up. A total of 82 patients with 93 hips was available for follow-up. There were 67 men and 45 women. The mean follow-up was 87 months (range, 48-113 months). There were a total of 9 revisions: 2 for recurrent dislocations, 1 for a loose cup, and 6 for wear and osteolysis. Radiographic evaluation demonstrated that 22 (24%) hips had periacetabular osteolysis, and 16 of these 22 (73%) were associated with the screws. Twenty-two hips (23%) demonstrated osteolytic lesions around the femoral stem. Mean femoral head displacement was of 1.00 mm (range, 0.40-4.5 mm) with a rate of 0.16 mm/yr (range, 0.05-0.44 mm/yr). The Harris-Galante socket has maintained a low implant failure rate at intermediate term, even in these young patients. As follow-up increases, wear of the polyethylene and periprosthetic osteolysis may become growing concerns.

Numerous legislative proposals to cut reimbursement to surgeons and hospitals are presently included in U.S. congressional and senate agendas. Perioperative x-ray films in arthroplasty surgery are standard operating procedure. Our objective was to assess the effects of the radiologist reading on the clinical and economic outcome of arthroplasty procedures. One hundred consecutive cases were prospectively studied. The radiologist reading, clinical management, and outcome of each case were carefully reviewed. The amount billed for the radiologist interpretation was noted for each examination. A total of 398 studies in 100 patients were done. Ninety-six preoperative, 110 intraoperative, and 192 postoperative radiographic studies were reviewed. These reports took an average of 1.71 days to be recorded on the chart (SD +/- 2.45). The total radiologic professional fees billed to Medicare in these cases was $11,054. (The radiologist's interpretation was not useful in the clinical management and did not affect the outcome in any case.) Assuming that each surgeon takes 1 x-ray film on every arthroplasty case, the total actual savings to Medicare of not having a radiologist reading these studies could reach $536,000 per year; if 2 intrahospital x-ray studies are performed per procedure (preoperative, intraoperative, or postoperative), the savings are $1.1 million per year. These cost reductions are achieved at no sacrifice to quality of care or outcome. Numerous areas of excessive spending with no improvement in outcome exist in the treatment of Medicare patients. There areas should be identified and eliminated before surgical fees are lowered even further.

A retrospective clinical and radiographic analysis was performed in 27 hips (23 patients), in which a threaded, porous-coated acetabular component with cylindrical liner was implanted (Sintered T-Tab-ST cup, Biomet, Warsaw, IN). Sixteen hips had cemented stems; 11 had cementless, circumferentially porous-coated stems. The mean clinical and radiographic follow-up period was 68 months. The mean patient age was 49 years; the mean patient weight was 68 kg. The mean rates of linear and volumetric wear were 0.25 mm/y and 149 mm3/y, respectively. Osteolysis occurred in 51.8% (14 hips). Wear rate and young age correlated with osteolysis (P = .0002 and P = .01, respectively). There were no cases of distal femoral osteolysis.

A consecutive series of 100 patients undergoing primary total hip arthroplasty were assessed for functional leg-length inequality (FLLI). In addition, the medical records of all patients treated for FLLI by the senior author (C.S.R.) in the past 15 years was reviewed. A questionnaire was distributed to the members of the Hip Society specifically to query the prevalence, etiology, and management of FLLI. Fourteen percent of patients were noted to have pelvic obliquity and FLLI.1 month after surgery. All had resolution of the symptoms by 6 months after surgery. Nine patients have been identified over the past 15 years with persistent FLLI. Among the causes suggested by respondents to the questionnaire are tightness of periarticular soft tissues with resultant pelvic obliquity and degenerative conditions of the spine with contracture. Methods of treatment and prevention are discussed.