Reverse total shoulder arthroplasty provides stability and better function than hemiarthroplasty following resection of proximal humerus tumors.

BACKGROUND: Tumors may necessitate resection of a substantial portion of the proximal humerus and surrounding soft tissues, making reconstruction challenging. We evaluated outcomes in patients undergoing treatment of tumors of the proximal humerus with reverse total shoulder arthroplasty (rTSA) or shoulder hemiarthroplasty. METHODS: Patients who underwent rTSA (n = 10) or shoulder hemiarthroplasty (n = 37) for tumors of the proximal humerus in 2009 to 2017 were reviewed. Of these patients, 27 had died, leaving 20 for review. The mean follow-up period of the survivors was 27.1 months. They were evaluated clinically and contacted to determine the American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, and visual analog scale score. RESULTS: Postoperative complications occurred in 13 hemiarthroplasty patients (34%). Tumor recurrence occurred in 3 hemiarthroplasty patients (7.9%), whereas in the rTSA group, 1 patient (10%) had a postoperative complication, with no recurrences. One hemiarthroplasty patient required revision surgery with rTSA to improve shoulder function. Six dislocations and two subluxations occurred in the hemiarthroplasty group, whereas no subluxations occurred in the rTSA group (P = .14). Mean range of motion was 85° of forward flexion for rTSA patients (n = 10) compared with 28° for hemiarthroplasty patients (P < .001). The mean American Shoulder and Elbow Surgeons score was 63 for hemiarthroplasty patients (n = 5) and 59 for rTSA patients (n = 4). The mean Simple Shoulder Test scores were 3.8 and 2.4, respectively. The mean visual analog scale pain scores were 2.4 and 2.5, respectively. CONCLUSION: Reverse total shoulder arthroplasty can reproducibly reconstruct the shoulder in patients requiring oncologic proximal humerus resection. Patients have good outcomes, better range of motion, and no increase in instability rates compared with hemiarthroplasty.

Oncologic reconstruction of the proximal humerus with a reverse total shoulder arthroplasty megaprosthesis.

BACKGROUND AND PURPOSE: Both malignant and benign tumors of the proximal humerus may necessitate resection of a substantial portion of the proximal humerus, making reconstruction options challenging. While hemiarthroplasty has been a classic treatment, reverse total shoulder replacement may provide better pain relief and function for these patients. METHODS: We utilize a two-surgeon approach for these challenging cases. The orthopedic oncologist resects the tumor. A shoulder-trained surgeon implants the reverse shoulder replacement. Modern implants, with large glenospheres and modular components, can allow reliable, straightforward reconstructions for these patients. We prefer 6 weeks of postoperative immobilization to decrease the risk of instability. RESULTS: We have completed 13 reverse total shoulder replacements for oncologic shoulder resections, with acceptable clinical outcomes and no complications to date. CONCLUSION: Reverse total shoulder replacement with long-stem, modular components can reliably and reproducibly reconstruct the shoulder in patients with oncologic resections of the proximal humerus.

Aseptic Lymphocytic-Dominated Vasculitis-Associated Lesions Scores Do Not Correlate With Metal Ion Levels or Unreadable Synovial Fluid White Blood Cell Counts.

BACKGROUND: Failed metal-on-metal (MoM) bearings are being increasingly encountered with little information to guide evaluation for aseptic lymphocytic-dominated vasculitis-associated lesions (ALVAL). It is often assumed that elevated metal ion levels correlate with the occurrence of ALVAL. Our purpose was to determine the utility of the erythrocyte sedimentation rate, C-reactive protein, synovial white blood cell count, differential (%PMN), and serum metal ion levels in diagnosing ALVAL. METHODS: We identified 80-failed MoM total hip arthroplasties. Tissue was examined under light microscopy and graded on a scale of ALVAL severity. Mean laboratory values were compared between groups and receiver operating curves generated with an area under the curve to determine test performance and optimal cutoffs. RESULTS: ALVAL scores were graded as low in 30 (37.5%), moderate in 39 (49%), and severe in 8 (10%), with 3 being unreadable. No clear cutoff values for erythrocyte sedimentation rate, C-reactive protein, or synovial white blood cell count could be determined to reliably diagnose moderate or severe ALVAL. Furthermore, serum metal levels had no correlation with ALVAL score. The best test to diagnose ALVAL was the synovial fluid monocyte percentage with an optimal cutoff value of 39% and area under the curve of 69% (moderate testing performance). CONCLUSION: The diagnosis of ALVAL remains challenging, with most of the screening tests being unreliable. Although serum metal ion levels are typically elevated in failed MoM bearings, higher levels do not appear to correlate with ALVAL grade. Elevated synovial fluid monocytes may provide diagnostic utility for ALVAL, suggesting a possible delayed-type hypersensitivity reaction.

Is There a Benefit to Head Size Greater Than 36 mm in Total Hip Arthroplasty?

This study compares the rate of dislocation and revision for instability between 36-mm and anatomic femoral heads (large diameter metal-on-metal THA, dual-mobility bearings, and hip resurfacing arthroplasty) in patients at high risk for dislocation. A total of 501 high-risk patients, over a 10-year period, were identified (282 36-mm THA, 24 dual-mobility bearings, 83 metal-on-metal arthroplasty, and 112 hip resurfacing arthroplasty). There were 13 dislocations in the 36-mm group compared to 1 in the anatomic group (4.6% vs 0.5%; P = .005). Four patients dislocated more than once in the 36-mm group (1.4% vs 0%; P = .04), and 2 patients in the 36-mm group required a revision for instability (0.7% vs 0%; P = .11). These results suggest that anatomic head sizes significantly lower the risk of dislocation in high-risk patients.

The James A. Rand Young Investigator's Award: A Randomized Controlled Trial of Oral and Intravenous Tranexamic Acid in Total Knee Arthroplasty: The Same Efficacy at Lower Cost?

BACKGROUND: Tranexamic acid (TXA) is a synthetic antifibrinolytic agent successfully used intravenously (IV) to reduce blood loss after total knee arthroplasty (TKA). An oral formulation of the medication is available, at a fraction of the cost of the IV preparation. The purpose of this randomized controlled trial is to determine if oral TXA is equivalent to IV TXA in reducing blood loss in TKA. METHODS: In this double-blinded, placebo-controlled trial, patients undergoing primary TKA were randomized to receive 1.95g of TXA orally 2 hours preoperatively or 1g IV bolus before wound closure. The primary outcome was reduction of hemoglobin. Power analysis determined that 30 patients were required in each group. Equivalence analysis was performed with pooled and Satterthwaite t tests with a P-value of <.05 suggesting equivalence between treatments. RESULTS: Thirty-four patients received oral TXA and 37 patients received IV TXA. There was no difference in the mean reduction of hemoglobin between oral and IV groups (3.45g/dL vs 3.31g/dL, respectively; P = .001, equivalence), and total blood loss was equivalent at 1281 mL vs 1231 mL, respectively (P = .02, equivalence). One patient in each group was transfused. CONCLUSION: Oral TXA provides equivalent reductions in blood loss, at a cost of $14 compared with $47-$108 depending on the IV formulation selected. As approximately 700,000 primary TKA are performed in the United States annually, a switch to oral TXA could yield total cost savings of between $23 million and $67 million dollars per year for our health care system.

Leukocyte Esterase: Metal-on-Metal Failure and Periprosthetic Joint Infection.

BACKGROUND: Adverse local tissue reactions (ALTRs) and periprosthetic joint infection can occur after metal-on-metal total hip arthroplasty (THA), both potentially generating purulent synovial fluid (SF) and elevated white cell count. This makes it difficult to distinguish between diagnoses; therefore, we evaluated leukocyte esterase (LE) strip test's reliability in ruling out periprosthetic joint infection in ALTR revision THA. METHODS: Sixty-one patients with ALTRs and an LE strip test were evaluated, excluding 15 cases with SF metallic debris. LE strip tests were classified -/trace, + (mildly positive), and ++ (strongly positive). RESULTS: LE strip tests were ++, +, -/trace in 8 patients (13.1%), 14 (23.0%), and 39 (63.9%), respectively. Means and ranges of SF white cell count and polymorphonuclear percentage were 1291.4 (0-10,886 cells/µL), and 46.1% (0%-94%), respectively. CONCLUSION: ++ LE strip test, in conjunction with preoperative work-ups, reliably rules out infection in 92.9% of patients undergoing THA revision secondary to ALTR.

Diagnosing Infection in the Setting of Periprosthetic Fractures.

BACKGROUND: The diagnosis of periprosthetic joint infection is particularly challenging in patients with periprosthetic fractures. The purpose of this study was to investigate the utility of commonly used diagnostic tests for periprosthetic joint infection in patients with a periprosthetic fracture. METHODS: Of 121 patients treated with a periprosthetic fracture (97 hips, 24 knees, mean age: 72.9), 14 (11.6%) met Musculoskeletal Infection Society criteria for infection. Diagnostic variables were evaluated using logistic regression models for the prediction of infection and receiver operating characteristics curves. RESULTS: The synovial white blood cell (WBC) count and differential were the best diagnostic tests, with good test performance (area under the curve, 84%) and optimal cutoffs of 2707 WBC/uL and 77% polymorphonuclear cells. The erythrocyte sedimentation rate and C-reactive protein were found to have overall lower test performance but remained relatively sensitive at standard cutoff values of 30 mm/h and 10 mg/L, respectively. CONCLUSION: The synovial fluid WBC count and differential are the best tests with optimal cutoff values that are similar to those used for patients without a periprosthetic fracture.

Dual-Mobility Articulations for Patients at High Risk for Dislocation.

BACKGROUND: The purpose of this study was to evaluate the performance of dual-mobility articulations in patients at high risk for dislocation after revision total hip arthroplasty. METHODS: We reviewed the results of 36 consecutive revision total hip arthroplasties performed on patients considered high risk for instability. Indications for inclusion included abductor insufficiency, recurrent instability, failure of constrained liner, or inadequate intraoperative stability when trialing. RESULTS: At a minimum of 2 years, there were 4 (11.1%) repeat revisions including both dual-mobility liners that were cemented into an acetabular shell and 2 for deep infection treated with a 2-stage exchange. There was one dislocation that was successfully closed reduced but no revisions for recurrent instability. The mean Harris hip score improved from 45 to 90 points (P < .001). CONCLUSION: Dual-mobility articulations are associated with a low rate of failure with no revisions for instability in this challenging group of patients.

Salvage of Monoblock Metal-on-Metal Acetabular Components Using a Dual-Mobility Bearing.

BACKGROUND: Large-diameter, monoblock acetabular components have been used for both hip resurfacing arthroplasty and metal-on-metal (MoM) total hip arthroplasty (THA). If revision is required, one solution is to retain the shell and use a dual-mobility bearing. METHODS: We reviewed the results of 25 revision THAs including 11 hip resurfacing arthroplasty and 14 MoM THAs where a monoblock acetabular component was mated to a dual-mobility bearing. RESULTS: At a mean of 29 months, there was one failure, an intraprosthetic dislocation of the dual-mobility bearing. There was a significant decrease in serum metal ion levels postoperatively. CONCLUSION: Retention of a well-fixed, monoblock MoM acetabular shell and mating it to a dual-mobility bearing in the setting of revision surgery seems to be a reasonable, low-morbidity option at short-term follow-up in appropriately positioned cups.

Diagnosis and Management of Adverse Local Tissue Reactions Secondary to Corrosion at the Head-Neck Junction in Patients With Metal on Polyethylene Bearings.

We reviewed 27 patients who underwent revision for an adverse local tissue reaction (ALTR) secondary to corrosion at the head-neck junction with MoP bearings. Serum cobalt and chromium levels were elevated in all cases, with a mean cobalt of 11.2 ppb and chromium of 2.2 ppb. Patients underwent modular bearing exchange, including a ceramic head with a titanium sleeve in 23 of 27 cases with only one recurrence of ALTR in one of the four patients not treated with a ceramic head. The diagnosis of ALTR secondary to corrosion is associated with cobalt levels of >1 ppb with cobalt levels elevated above chromium. Retention of a well-fixed stem and modular exchange to a ceramic head leads to resolution of symptoms and decreases in metal levels.

Does Hip Arthroscopy Affect the Outcomes of a Subsequent Total Hip Arthroplasty?

BACKGROUND: Hip arthroscopy utilization is on the rise in the United States. Thus, determining the impact of prior hip arthroscopy on subsequent total hip arthroplasty (THA) is important to understand. METHODS: A retrospective review of a high-volume orthopedic surgery practice's billing database yielded 42 hip arthroscopies that underwent subsequent THA. An age-, sex-, and body mass index (2:1)-matched cohort of primary THAs was used for comparison. RESULTS: No difference was observed in the postoperative Harris Hip Score between groups (92.1 ± 10.9 vs 90.1 ± 6.6, P = .20); however, there was greater overall improvement in Harris Hip Score in the control group (40.4 ± 18.4 vs 45.1 ± 8.7, P = .05). There were no differences observed in the complication (P = .5) or revision rates (P = .4). CONCLUSION: With the numbers available, prior hip arthroscopy does not appear to have an impact on the functional outcomes of a subsequent THA.

Does Prior Cartilage Restoration Impact Outcomes Following Knee Arthroplasty?

This study compared patients who failed a cartilage restoration procedure and underwent ipsilateral knee arthroplasty with matched control subjects undergoing knee arthroplasty without prior cartilage restoration. Although patients with a failed cartilage procedure derived benefit from knee arthroplasty, their magnitude of improvement and final outcomes scores were lower than the matched control subjects. In this cohort, the cartilage patients also experienced little to no benefit from cartilage restoration, suggesting that unmeasured shared patient characteristics may play a role. This information can be used to counsel this difficult patient population on expected outcomes following arthroplasty procedures. Further research identifying characteristics of responders to treatment remains critical to refine clinical decision-making for this difficult patient group.

Oral and Intravenous Tranexamic Acid Are Equivalent at Reducing Blood Loss Following Total Hip Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Tranexamic acid is an antifibrinolytic that has been shown to reduce blood loss and the need for transfusions when administered intravenously in total hip arthroplasty. Oral formulations of the drug are available at a fraction of the cost of the intravenous preparation. The purpose of this randomized controlled trial was to determine if oral and intravenous formulations of tranexamic acid have equivalent blood-sparing properties. METHODS: In this double-blinded trial, 89 patients undergoing primary total hip arthroplasty were randomized to receive 1.95 g of tranexamic acid orally 2 hours preoperatively or a 1-g tranexamic acid intravenous bolus in the operating room prior to incision; 6 patients were eventually excluded for protocol deviations, leaving 83 patients available for study. The primary outcome was the reduction of hemoglobin concentration. Power analysis determined that 28 patients were required in each group with a ±1.0 g/dL hemoglobin equivalence margin between groups with an alpha of 5% and a power of 80%. Equivalence analysis was performed with a two one-sided test (TOST) in which a p value of <0.05 indicated equivalence between treatments. RESULTS: Forty-three patients received intravenous tranexamic acid, and 40 patients received oral tranexamic acid. Patient demographic characteristics were similar between groups, suggesting successful randomization. The mean reduction of hemoglobin was similar between oral and intravenous groups (3.67 g/dL compared with 3.53 g/dL; p = 0.0008, equivalence). Similarly, the mean total blood loss was equivalent between oral and intravenous administration (1,339 mL compared with 1,301 mL; p = 0.034, equivalence). Three patients (7.5%) in the oral group and one patient (2.3%) in the intravenous group were transfused, but the difference was not significant (p = 0.35). None of the patients in either group experienced a thromboembolic event. CONCLUSIONS: Oral tranexamic acid provides equivalent reductions in blood loss in the setting of primary total hip arthroplasty, at a greatly reduced cost, compared with the intravenous formulation. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Dual mobility in total hip arthroplasty.

Dual-mobility articulations have shown promising results. Postoperative instability remains the most common reason for revision of a total hip arthroplasty (THA). Dual-mobility cups have been shown to decrease the rate of dislocation in primary THA and have been used to treat and prevent instability in revision THA. Greater range of motion and a greater head-to-neck ratio and a greater jump distance are achieved, resulting in a lower risk of instability. Concerns with dual-mobility cups include wear and intraprosthetic dislocation. Specific design modifications have aimed to improve cup fixation and decrease polyethylene wear and the risks of intraprosthetic dislocation.