Does interaction occur between risk factors for revision total knee arthroplasty?

INTRODUCTION: Several risk factors for revision TKA have previously been identified, but interactions between risk factors may occur and affect risk of revision. To our knowledge, such interactions have not been previously studied. As patients often exhibit multiple risk factors for revision, knowledge of these interactions can help improve risk stratification and patient education prior to TKA. MATERIALS AND METHODS: The State Inpatient Databases (SID), part of the Healthcare Cost and Utilization Project (HCUP), were queried to identify patients who underwent TKA between January 1, 2006 and December 31, 2015. Risk factors for revision TKA were identified, and interactions between indication for TKA and other risk factors were analyzed. RESULTS: Of 958,944 patients who underwent TKA, 33,550 (3.5%) underwent revision. Age, sex, race, length of stay, Elixhauser readmission score, urban/rural designation, and indication for TKA were significantly associated with revision (p < 0.05). Age was the strongest predictor (p < 0.0001), with younger patients exhibiting higher revision risk. Risks associated with age were modified by an interaction with indication for TKA (p < 0.0001). There was no significant interaction between sex and indication for TKA (p = 0.535) or race and indication for TKA (p = 0.187). CONCLUSIONS: Age, sex, race, length of stay, Elixhauser readmission score, urban/rural designation, and indication for TKA are significantly associated with revision TKA. Interaction occurs between age and indication.

Posterior Tibial Slope Increases Anterior Cruciate Ligament Stress in Bi-Cruciate Retaining Total Knee Arthroplasty: In Vivo Kinematic Analysis.

The study design involved here is experimental in nature. The resection of the anterior cruciate ligament (ACL) during conventional total knee arthroplasty (TKA) has been considered a potential factor leading to abnormal in vivo knee kinematics. Bi-cruciate retaining (BCR) TKA designs allow the preservation of the ACL with the potential to restore native knee kinematics. This study aimed to investigate the effect of posterior tibial slope (PTS) on stress experienced by the ACL during weight bearing sit-to-stand (STS) and single-leg deep lunge. The ACL elongation patterns were measured in 30 unilateral BCR TKA patients during weight-bearing STS and single-leg deep lunge using a validated dual fluoroscopic tracking technique. The minimum normalized stress within the anteromedial (AM) and posterolateral (PL) bundle of the ACL during weight-bearing STS and single-leg deep lunge was found at a PTS of 3.7 degrees. The maximum AM and PL bundle stresses were observed at a PTS of 8.5 and 9.3 degrees, respectively during STS and at 8.4, and 9.1 degrees, respectively during single-leg deep lunge. There was a significant positive correlation between PTS and stress observed within the AM and PL bundle of the ACL during weight-bearing STS (R 2 = 0.37; p < 0.01; R2 = 0.36; p = 0.01) and single-leg deep lunge (R 2 = 0.42; p < 0.01; R 2 = 0.40; p < 0.01). The study demonstrates that PTS of operated BCR TKA knees has a significant impact on the stress experienced by the preserved ACL during weight-bearing STS and single-leg deep lunge. This suggests that avoiding excessive PTS may be one of the surgical implant alignment factors to consider during surgery to minimize increased loading of the preserved ACL.

Outcome of revision surgery for adverse local tissue reactions in patients with recalled total hip arthroplasty.

INTRODUCTION: Recalls of total hip arthroplasty (THA) implants, including metal-on-metal (MoM) THA and dual taper stems, due to increased risk of adverse local tissue reaction (ALTR), represent a challenge for both surgeons and patients. This study aims to analyze the revision surgery outcomes for ALTR in patients with recalled THA implants. METHODS: A total of 118 consecutive patients who underwent revision surgery due to ALTR with recalled THA were analyzed. Sub-group analysis was performed for recalled MoM THAs, head-neck modular stems, and dual taper neck-stems. RESULTS: At a mean follow-up of 6.6 years, the complication and reoperation rates of the recalled THAs were 32.2% and 25.4% respectively. The most common post-revision complication was dislocation (16%). Revision of modular taper corrosion THA and high-grade intraoperative tissue damage were risk factors associated with post-revision complications. CONCLUSION: This study reports high complication and reoperation rates of recalled THAs at mid-term follow-up. The high revision surgery complication rates in both groups suggest the importance of a systematic evaluation of all THA patients with at-risk implants. LEVEL OF EVIDENCE: Level III, case control retrospective analysis.

Outcome and risk factors of failures associated with revision total hip arthroplasty for recurrent dislocation.

INTRODUCTION: Recurrent dislocation represents the third most common cause of revision surgery after total hip arthroplasty (THA). However, there is a paucity of information on the outcome of revision total hip arthroplasty for recurrent dislocation. In this study, we investigated (1) clinical outcomes of patients that underwent revision THA for recurrent dislocation, and (2) potential risk factors associated with treatment failure in patients who underwent revision total hip arthroplasty for recurrent dislocation. METHODS: We retrospectively reviewed 211 consecutive cases of revision total hip arthroplasty for recurrent dislocation, 81 implanted with a constrained liner and 130 with a non-constrained liner with a large-diameter femoral head (> 32 mm). Patient- and implant-related risk factors were analyzed in multivariate regression analysis. RESULTS: At 4.6-year follow-up, 32 of 211 patients (15.1%) underwent re-revision surgery. The most common causes for re-revision included infection (14 patients) and dislocation (10 patients). Kaplan-Meier analysis demonstrates a 5-year survival probability of 77% for patients that underwent revision THA for recurrent dislocation. Osteoporosis, obesity (BMI ≥ 40), spine disease and abductor deficiency are independent risk factors for failure of revision surgery for recurrent dislocation. Liner type (constrained vs. non-constrained) was found not to be associated with failure of revision THA for recurrent dislocation (p = 0.44). CONCLUSION: This study suggests that THA revision for recurrent dislocation is associated with a high re-revision rate of 15% at mid-term follow-up. Osteoporosis, obesity (BMI ≥ 40) spine disease and abductor deficiency were demonstrated to be independent risk factors for failure of revision THA for recurrent dislocation. LEVEL OF EVIDENCE: Level III, case-control retrospective analysis.

Three-dimensional kinematic analysis of dislocation mechanism in dual mobility total hip arthroplasty constructs.

Dual mobility (DM) total hip arthroplasty (THA) is associated with reduced dislocation rates; however, the kinematic mechanism of dislocation in DM THA constructs is still not well understood. This study hypothesizes that the difference in kinematics between DM THA and conventional THA designs contributes to reduced dislocation rates of DM THA. In addition, this study aims to quantify and compare those kinematic parameters between DM THA and conventional THA using a validated dual fluoroscopy imaging system (DFIS) and finite element (FE) modelling. Fresh frozen cadavers were measured to compare the impingement-free range of motion and provocative subluxation kinematics among three THA constructs: (1) DM, (2) constrained liner (CS), and (3) 36 mm head diameter neutral liner (NL). The DFIS was used to measure the in vitro kinematics of the hip. Subject-specific FE models were developed to assess the horizontal dislocation distance and resistive torque at dislocation. The DM construct head exhibited increased provocative anterior and posterior subluxation range of motion before dislocation when compared to CS constructs (p = .05; p = .03), as well as NL constructs (p = .05). The DM THA showed a significantly larger posterior horizontal dislocation distance, as well as smaller resistive torque at dislocation, when compared to NL (p = .05; p = .03) and CS constructs (p = .04; p = .01). Our findings demonstrate there was increased provocative subluxation range of motion as well as normalized jump distance for the DM constructs compared to the NL and CS constructs, suggesting the DM THA may provide increased stability hip during at-risk functional hip positions.

Outcomes and Risk Factors Associated With 2-Stage Reimplantation Requiring an Interim Spacer Exchange for Periprosthetic Joint Infection.

BACKGROUND: Patients undergoing a 2-stage revision for periprosthetic joint infection (PJI) often require a repeat spacer in the interim due to persistent infection. This study aims to report outcomes for patients with repeat spacer exchange and to identify risk factors associated with interim spacer exchange in 2-stage revision arthroplasty. METHODS: A total of 256 consecutive 2-stage revisions for chronic infection of total hip arthroplasty and total knee arthroplasty with reimplantation and minimum 2-year follow-up were investigated. An interim spacer exchange was performed in 49 patients (exchange cohort), and these patients were propensity score matched to 196 patients (nonexchange cohort). Multivariate analysis was performed to analyze risk factors for failure of interim spacer exchange. RESULTS: Patients in the propensity score-matched exchange cohort demonstrated a significantly increased reinfection risk compared to patients without interim spacer exchange (24% vs 15%, P = .03). Patients in the propensity score-matched exchange cohort showed significantly lower postoperative scores for 3 patient-reported outcome measures (PROMs): hip disability and osteoarthritis outcome score physical function (46.0 vs 54.9, P = .01); knee disability and osteoarthritis outcome score physical function (43.1 vs 51.7, P < .01); and patient-reported outcomes measurement information system physical function short form (41.6 vs 47.0, P = .03). Multivariate analysis demonstrated Charles Comorbidity Index (odds ratio, 1.56; P = .01) and the presence of Enterococcus species (odds ratio, 1.43; P = .03) as independent risk factors associated with 2-stage reimplantation requiring an interim spacer exchange for periprosthetic joint infection. CONCLUSION: This study demonstrates that patients with spacer exchange had a significantly higher risk of reinfection at 2 years of follow-up. Additionally, patients with spacer exchange demonstrated lower postoperative PROM scores and diminished improvement in multiple PROM scores after reimplantation, indicating that an interim spacer exchange in 2-stage revision is associated with worse patient outcomes.

Impact of Smoking and Drinking on Complications After Revision Total Joint Arthroplasty: A Matched Cohort Analysis.

INTRODUCTION: Smoking and drinking have been shown to impair postoperative outcomes in primary hip and knee total joint arthroplasty (TJA). This study aimed to evaluate the potential impact of smoking and drinking on complications after revision TJA. METHODS: We retrospectively evaluated a total of 4,302 consecutive patients who underwent revision TJA. Patient demographics and complications were compared between four cohorts based on smoking and drinking status: (1) nonusers (nonsmokers and nondrinkers), (2) smokers, (3) drinkers, and (4) concurrent users. RESULTS: A total of 1,924 patients were matched using propensity score analysis: 808 nonusers (42.0%), 421 smokers (21.9%), 483 drinkers (25.0%), and 212 concurrent users (11.1%). When compared with nonusers, smokers, drinkers, and concurrent users (simultaneous smokers and drinkers) exhibited higher odds for both inhospital complications (odds ratios, smokers: 2.40, drinkers: 1.55, and concurrent users: 5.13, P < 0.01). Among the user cohorts, although smokers and drinkers showed similar rates of 90-day postdischarge complications (smokers: 14.95% and drinkers: 14.80%, P = 0.95), concurrent users demonstrated the highest significant odds for these complications (odds ratio, 1.64, P = 0.02). DISCUSSION: Our propensity-score-matched cohort study results demonstrate that although the smokers and drinkers groups shared similarly poor outcomes after discharge, concurrent users were found to have the worst outcomes compared with either single user group.

Outcome of Spinal Versus General Anesthesia in Revision Total Hip Arthroplasty: A Propensity Score-Matched Cohort Analysis.

INTRODUCTION: Spinal anesthesia has been previously shown to offer improved patient outcomes compared with general anesthesia in revision total knee arthroplasty. This study aimed to evaluate the potential differences in perioperartive and postoperative outcomes in revision total hip arthroplasty (THA) between spinal or general anesthesia. METHODS: A total of 2,656 consecutive patients who underwent revision THA were evaluated. Propensity-score-adjusted multivariate logistic regression analyses were applied to control for intergroup variability and evaluate the differences in outcomes and complications with anesthesia type. RESULTS: Propensity score matching resulted in 1:1 matching with 265 patients in each anesthesia cohort. Multivariate analyses demonstrated that patients administered general anesthesia had a significantly longer procedure time (174.8 versus 161.3, P < 0.01), higher intraoperative (402.6 versus 305.5 mL, P < 0.01), and total perioperative blood loss (1802.2 versus 1,684.2 mL,P < 0.01). In addition, patients administered general anesthesia were found to have higher odds for two or more inhospital complications (odds ratio, 4.51, P < 0.01) and extended length of stay (odds ratio, 2.45, P = 0.02). DISCUSSION: Our study shows that propensity-matched patients who received spinal anesthesia for revision THA exhibited notable reduction in surgical time, perioperative blood loss, and complications compared with patients who received general anesthesia, suggesting that spinal anesthesia is a viable alternative to general anesthesia in revision THA.

Effect of postural changes on in vivo pelvic tilt and functional component anteversion in total hip arthroplasty patients with lumbar disc degenerations.

AIMS: The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients. METHODS: A total of 50 patients with unilateral THA underwent CT imaging for radiological evaluation of presence and severity of lumbar DDD. In all, 18 patients with lumbar DDD were compared to 32 patients without lumbar DDD. In vivo PT and FCA, and the magnitudes of changes (ΔPT; ΔFCA) during supine, standing, swing-phase, and stance-phase positions were measured using a validated dual fluoroscopic imaging system. RESULTS: PT, FCA, ΔPT, and ΔFCA were significantly correlated with the severity of lumbar DDD. Patients with severe lumbar DDD showed marked differences in PT with changes in posture; there was an anterior tilt (-16.6° vs -12.3°, p = 0.047) in the supine position, but a posterior tilt in an upright posture (1.0° vs -3.6°, p = 0.005). A significant decrease in ΔFCA during stand-to-swing (8.6° vs 12.8°, p = 0.038) and stand-to-stance (7.3° vs 10.6°,p = 0.042) was observed in the severe lumbar DDD group. CONCLUSION: There were marked differences in the relationship between PT and posture in patients with severe lumbar DDD compared with healthy controls. Clinical decision-making should consider the relationship between PT and FCA in order to reduce the risk of impingement at large ranges of motion in THA patients with lumbar DDD. Cite this article: Bone Joint J 2020;102-B(11):1505-1510.

Effect of postural changes on in vivo pelvic tilt and functional component anteversion in total hip arthroplasty patients with lumbar disc degenerations.

AIMS: The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients. METHODS: A total of 50 patients with unilateral THA underwent CT imaging for radiological evaluation of presence and severity of lumbar DDD. In all, 18 patients with lumbar DDD were compared to 32 patients without lumbar DDD. In vivo PT and FCA, and the magnitudes of changes (ΔPT; ΔFCA) during supine, standing, swing-phase, and stance-phase positions were measured using a validated dual fluoroscopic imaging system. RESULTS: PT, FCA, ΔPT, and ΔFCA were significantly correlated with the severity of lumbar DDD. Patients with severe lumbar DDD showed marked differences in PT with changes in posture; there was an anterior tilt (-16.6° vs -12.3°, p = 0.047) in the supine position, but a posterior tilt in an upright posture (1.0° vs -3.6°, p = 0.005). A significant decrease in ΔFCA during stand-to-swing (8.6° vs 12.8°, p = 0.038) and stand-to-stance (7.3° vs 10.6°,p = 0.042) was observed in the severe lumbar DDD group. CONCLUSION: There were marked differences in the relationship between PT and posture in patients with severe lumbar DDD compared with healthy controls. Clinical decision-making should consider the relationship between PT and FCA in order to reduce the risk of impingement at large ranges of motion in THA patients with lumbar DDD.

Total Hip Arthroplasty to Treat Chronic Native Hip Obturator Dislocation: A Case Report.

CASE: A 37-year-old woman presented with a rare chronic dislocation of her native right hip where the head of the femur was incarcerated in the obturator foramen of her pelvis. After optimization of sociomedical factors, she underwent successful total hip arthroplasty. CONCLUSION: Total hip arthroplasty is a viable treatment option for the chronic incarcerated obturator hip dislocation.

Simultaneous Bilateral Knee Dislocation During Weight Training: A Case Report and Review of the Literature.

CASE: We describe the clinical course and treatment of a patient who sustained simultaneous bilateral knee dislocation under low-velocity atraumatic conditions, and provide a review of the literature. Dislocations of the native knee joint are uncommon orthopaedic injuries but they are true emergencies because of the concern for concomitant neurovascular injury; therefore, they may be limb-threatening injuries. CONCLUSION: To our knowledge, there are few reports of simultaneous bilateral knee dislocation and no reports of this occurring during weight training. The risk of knee dislocation can be reduced by avoiding locking and hyperextension of the knees during any type of leg press or squatting exercise.