Background Two-stage exchange arthroplasty remains the preferred method to treat periprosthetic joint infection. The aim of this study was to investigate the clinical course of periprosthetic joint ...infection following resection arthroplasty and insertion of a spacer. Methods Our institutional database was used to identify 504 cases of periprosthetic joint infection (326 knees and 178 hips) treated with resection arthroplasty and spacer insertion as part of a two-stage exchange arthroplasty. A review of the patient charts was performed to extract information relevant to the objectives of this study that included the details of the clinical course following resection arthroplasty. Results The mean follow-up duration after initial spacer implantation was 56.2 months. Reimplantation occurred in the joints of 417 (82.7%) of 504 cases. Of these 417 cases, 329 (78.9%) had a minimum one-year follow-up, and 81.4% of these had successful treatment. The mean duration from resection arthroplasty to reimplantation was 4.2 months (range, 0.7 to 131.7 months). Sixty (11.9%) of the 504 joints required interim spacer exchange(s). Of the eighty-seven cases that did not undergo reimplantation, six (6.9%) required amputation, five (5.7%) underwent a Girdlestone procedure, four (4.6%) underwent arthrodesis, and seventy-two (82.8%) underwent spacer retention. Thirty-six patients died in the interstage period. Conclusions The commonly held belief that two-stage exchange arthroplasty carries a high success rate for the eradication of periprosthetic joint infection may need to be reexamined. A considerable number of patients undergoing the first stage of a two-stage procedure do not undergo a subsequent reimplantation for a variety of reasons or require an additional spacer exchange in the interim. Reports on the success of two-stage exchange should account for the mortality of these patients and for patients who never undergo reimplantation. Level of Evidence Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.
Backgroud Previous knee injury requiring surgical intervention increases the rate of future arthroplasty. Coding modifiers for removal of previous hardware or increased complexity offer inconsistent ...results. A CPT code for knee conversion does not currently exist as it does for conversion hip arthroplasty. We investigate the extra time associated with conversion knee arthroplasty. Methods Sixty-three total knee arthroplasty cases in the setting of previous knee hardware were identified from our institution between 2008 and 2015. Knee conversions were matched to primary TKA by age, gender, BMI, Charlson Comorbidity Index, and surgeon, in a three to one ratio. Patients who underwent knee conversions were compared to matched TKA with regard to operative time, length of stay, discharge destination, readmission, and repeat procedures within 90 days from index procedure. Results The mean operating room time for primary TKA was 71.7 minutes (range 36-138). The mean operating room time for knee conversion was significantly greater by an additional 31 minutes; mean 102.1 minutes (range 56-256 minutes, p<0.0001). Rates of readmission, 0.5% vs 3.2%, and repeat procedures, 5.3% vs. 12.7%, within 90 days was greater for knee conversions. There was no difference in length of stay or discharge destination. Conclusion Total knee conversion results in a 43% increase in operative time and more than twice the rate of readmission and repeat procedures within 90 days compared to TKA. This suggests the need for an additional CPT code for knee conversion arthroplasty to compensate surgeons for the extra time required for conversions.
Abstract In comparison to primary total knee arthroplasty, surgical time was 1.8 times greater for all knee revisions and 2.4 times greater for complex knee revisions. Knee revisions had an 8.5% ...higher rate of 90-day repeat procedures. In comparison to primary total hip arthroplasty, surgical time was 1.8 greater for all hip revisions and 2.6 fold greater for complex hip revisions. Hip revisions had a 3.4% higher rate of 90-day repeat procedures. Practices based on revisions or complex revisions alone would see a 32% and 50% decrease in reimbursement respectively compared to the ones based on primary arthroplasty. The projected future increase in primary arthroplasties and the relative incentive to perform primary arthroplasty may soon put patient access to physicians willing to perform revision arthroplasty at risk.
BACKGROUND:Modular femoral heads provide procedural enhancement by allowing accurate restoration of hip offset and limb-length equalization. However, corrosion may lead to adverse local tissue ...reactions. Severe trunnion corrosion can also lead to femoral head dissociation and catastrophic implant failure following primary total hip arthroplasty.
METHODS:We describe 5 cases, from our institution, in which the femoral head became dissociated from the femoral stem trunnion secondary to severe corrosion. Possible causes are evaluated.
RESULTS:Demographic commonalities among the 5 patients included a body mass index (BMI) of ≥30 kg/m and male sex. All femoral heads were made of cobalt-chromium alloy and were larger-diameter implants (≥36 mm). Four of the 5 patients had a femoral head that increased the neck length above the default on a so-called standard head and 3 of the 5 had a stem with a 127° neck-shaft angle.
CONCLUSIONS:Although dissociation of the femoral head from the femoral trunnion following total hip arthroplasty is exceedingly rare, the prevalence may increase with longer follow-up. The dissociation is likely related to multiple factors, including a BMI of ≥30 kg/m, male sex, and corrosion resulting from the use of a larger metal head with a neck length of greater than the default and a stem with high offset. It is critical that surgeons be able to recognize this mode of implant failure and appropriately prepare to remove the femoral component during revision surgery.
LEVEL OF EVIDENCE:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Although hinged prostheses have been used successfully in complex revision total knee arthroplasty (TKA), concerns exist regarding early failure due to aseptic loosening and other mechanical ...complications. The use of metaphyseal cones and hybrid cement fixation have been studied in unlinked constrained primary or revision TKA, but their impact on the survivorship of hinged prostheses has yet to be investigated.
We identified a consecutive series of 164 hinged prostheses and collected data on demographics, indications, complications, and re-revisions in patients who had fully cemented versus hybrid stems, with and without metaphyseal cones. A multivariate analysis was performed to identify independent variables associated with re-revision as the primary end point.
In total, 84 patients (51.2%) had fully cemented stems, and 80 patients (48.8%) had hybrid stems. Cones were used in 73 patients (44.5%). At a mean follow-up of 3.4 ± 2.2 years, 42 patients underwent re-revision (25.8%), most commonly for infection (12.2%), followed by loosening (6.7%) and periprosthetic fracture (3.7%). Patients who had fully cemented stems had lower re-revision rates than hybrid fixation constructs (19 versus 26%, P = .043). Using multivariable regression, a construct with hybrid fixation with cones (odds ratio = 2.39; P = .037) was an independent risk factor for failure. Utilization of cones alone did not have an effect on re-revision rates at 3.4-year follow-up.
While we found no difference with the use of cones, patients undergoing revision TKA with a hinge prosthesis and fully cemented stems had better overall survivorship than hybrid stems.
Abstract Background The optimal prophylaxis for prevention of venous thromboembolic events (VTEs) after revision total joint arthroplasty (TJA) remains unknown. The objective of this study was to ...evaluate whether aspirin, known to be effective for prevention of VTEs after primary arthroplasty, is also effective after revision TJA. Methods We studied 2997 consecutive patients who underwent revision TJA between 2005 and 2013 and were treated with intermittent pneumatic compression devices and either aspirin (534 patients) or warfarin (2463 patients) for VTE prophylaxis. Pertinent data including the incidence of symptomatic VTEs, bleeding events, infection, and mortality were retrieved from our prospectively collected database. Results The incidence of symptomatic VTEs was significantly higher in the warfarin group at 1.75% (43 of 2463) compared with 0.56% (3 of 534) in the aspirin group (odds ratio: 3.2; 95% CI: 1.03-16.3; P = .03). There was a higher rate of bleeding events with administration of warfarin (1.5%) compared with aspirin (0.4%; P = .02; odds ratio: 4.1; 95% CI: 1.2-34.0). The rate of surgical site infection was similar between the aspirin group and the warfarin group (1.61% and 1.70%, respectively). Conclusion Administration of aspirin as prophylaxis against VTEs after revision arthroplasty may be a viable option as it appears to be more effective than warfarin in prevention of symptomatic VTEs and is associated with a lower rate of complications.
BACKGROUND:There is no consensus whether the interim antibiotic spacer utilized in the 2-stage exchange arthroplasty should immobilize the joint or allow for motion. The purpose of this multicenter, ...randomized clinical trial was to compare static and articulating spacers as part of the 2-stage exchange arthroplasty for the treatment of chronic periprosthetic joint infection complicating total knee arthroplasty as defined with use of Musculoskeletal Infection Society criteria.
METHODS:Sixty-eight patients undergoing 2-stage exchange arthroplasty were randomized to either a static (32 patients) or an articulating (36 patients) spacer. An a priori power analysis determined that 28 patients per group would be necessary to detect a 13° difference in range of motion between groups. Six patients were excluded after randomization, 6 died, and 7 were lost to follow-up before 2 years.
RESULTS:Patients in the static group had a hospital length of stay that was 1 day greater than the articulating group after stage 1 (6.1 compared with 5.1 days; 95% confidence interval CI, 5.3 to 6.9 days and 4.6 to 5.6 days, respectively; p = 0.032); no other differences were noted perioperatively. At a mean of 3.5 years (range, 2.0 to 6.4 years), 49 patients were available for evaluation. The mean motion arc was 113.0° (95% CI, 108.4° to 117.6°) in the articulating spacer group, compared with 100.2° (95% CI, 94.2° to 106.1°) in the static spacer group (p = 0.001). The mean Knee Society Score was higher in the articulating spacer cohort (79.4 compared with 69.8 points; 95% CI, 72.4 to 86.3 and 63.6 to 76.1, respectively; p = 0.043). Although not significantly different with the sample size studied, static spacers were associated with a greater need for an extensile exposure at the time of reimplantation (16.7% compared with 4.0%; 95% CI, 0.6% to 38.9% and 0.5% to 26.3%, respectively; p = 0.189) and a higher rate of reoperation (25.0% compared with 8.0%; 95% CI, 9.8% to 46.7% and 1.0% to 26.0%, respectively; p = 0.138).
CONCLUSIONS:Articulating spacers provided significantly greater range of motion and higher Knee Society scores at a mean of 3.5 years. Static spacers were associated with a longer hospital stay following removal of the infected implant. When the soft-tissue envelope allows and if there is adequate osseous support, an articulating spacer is associated with improved outcomes.
LEVEL OF EVIDENCE:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
There is no consensus whether the interim antibiotic spacer utilized in the 2-stage exchange arthroplasty should immobilize the joint or allow for motion. The purpose of this multicenter, randomized ...clinical trial was to compare static and articulating spacers as part of the 2-stage exchange arthroplasty for the treatment of chronic periprosthetic joint infection complicating total knee arthroplasty as defined with use of Musculoskeletal Infection Society criteria.
Sixty-eight patients undergoing 2-stage exchange arthroplasty were randomized to either a static (32 patients) or an articulating (36 patients) spacer. An a priori power analysis determined that 28 patients per group would be necessary to detect a 13° difference in range of motion between groups. Six patients were excluded after randomization, 6 died, and 7 were lost to follow-up before 2 years.
Patients in the static group had a hospital length of stay that was 1 day greater than the articulating group after stage 1 (6.1 compared with 5.1 days; 95% confidence interval CI, 5.3 to 6.9 days and 4.6 to 5.6 days, respectively; p = 0.032); no other differences were noted perioperatively. At a mean of 3.5 years (range, 2.0 to 6.4 years), 49 patients were available for evaluation. The mean motion arc was 113.0° (95% CI, 108.4° to 117.6°) in the articulating spacer group, compared with 100.2° (95% CI, 94.2° to 106.1°) in the static spacer group (p = 0.001). The mean Knee Society Score was higher in the articulating spacer cohort (79.4 compared with 69.8 points; 95% CI, 72.4 to 86.3 and 63.6 to 76.1, respectively; p = 0.043). Although not significantly different with the sample size studied, static spacers were associated with a greater need for an extensile exposure at the time of reimplantation (16.7% compared with 4.0%; 95% CI, 0.6% to 38.9% and 0.5% to 26.3%, respectively; p = 0.189) and a higher rate of reoperation (25.0% compared with 8.0%; 95% CI, 9.8% to 46.7% and 1.0% to 26.0%, respectively; p = 0.138).
Articulating spacers provided significantly greater range of motion and higher Knee Society scores at a mean of 3.5 years. Static spacers were associated with a longer hospital stay following removal of the infected implant. When the soft-tissue envelope allows and if there is adequate osseous support, an articulating spacer is associated with improved outcomes.
Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
Conversion from a prior knee procedure has been demonstrated to require greater operative times and resources, but still lacks a separate procedural or facility code from primary total knee ...arthroplasty (TKA). The purpose of this study is to determine differences in facility costs between patients who underwent primary TKA and those who underwent conversion TKA.
We retrospectively reviewed a consecutive series of patients undergoing primary TKA at 2 hospitals from 2015 to 2017, comparing itemized facility costs between primary and conversion TKA patients. A multivariate regression analysis was performed to identify independent risk factors for increased facility costs, the need for additional implants, length of stay, and discharge disposition.
Of 2447 TKA procedures, 678 (27.7%) underwent conversion TKA, which was associated with greater implant costs ($3931.47 vs $2864.67, P = .0120) and total facility costs in a multivariate regression ($94.30 increase, P = .0316). When controlling for confounding variables, patients with a prior ligament reconstruction ($402 increase, P = .0002) and prior open reduction and internal fixation ($847 increase, P = .0020) had higher costs and were more likely to require stemmed implants (P < .05). There was an increase in TKA implant cost by $538 in patients with implants from a prior procedure (P < .0001).
Conversion TKA is associated with greater implant and inpatient facility costs than primary TKA, particularly those who had a history of an open knee procedure. A separate diagnosis-related group should be created for conversion TKA given the increased cost and complexity of these procedures compared to primary TKA.
Introduction Two-stage revision is frequently used for the treatment of periprosthetic joint infection (PJI). Because antibiotic-loaded cement spacers are constructed and implanted as temporary ...devices, mechanical complications are possible. The purpose of our study was to define the incidence of such mechanical complications, determine associated risk factors, and establish if such complications influence the subsequent success of PJI treatment. Methods We identified patients who received an antibiotic spacer for the treatment of PJI at a single center over a six-year timeframe. Medical records and all radiographs were collected and reviewed. Radiographic changes over time were recorded, and mechanical complications were noted. We used multivariate logistic regression analysis to assess risk factors for mechanical spacer complications and assess whether such complications influence the likelihood of subsequent reimplantation and ultimate component retention. Results A total of 236 patients were included in the study. There were 82 hip spacers (28% dynamic and 72% static) with a mechanical complication rate of 8.5% and 154 knee spacers (44% dynamic and 56% static) with a mechanical complication rate of 18.2%. Knee spacers were significantly more likely to have mechanical complications than hip spacers. Other risk factors for mechanical complications included bone loss and elevated body mass index (BMI). Bone loss and advanced age were found to be independent risk factors for failure to undergo second-stage reimplantation. Mechanical spacer failure was not an independent risk factor for the likelihood of subsequent reimplantation or ultimate component retention. Conclusions Mechanical complications of antibiotic spacers are common but do not appear to negatively impact the likelihood of subsequent reimplantation or component retention. In knee spacers and in patients with bone loss or elevated BMI, appropriate patient counseling and strategies to prevent such complications are recommended.
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