Increased Risk of Periprosthetic Fractures and Revision Arthroplasty in Patients Undergoing Shoulder Arthroplasty With a History of Prior Fragility Fractures: A Matched Cohort Analysis.

INTRODUCTION: As rates of anatomic and reverse total shoulder arthroplasty (SA) continue to grow, an increase in the number of osteoporotic patients undergoing SA, including those who have sustained prior fragility fractures, is expected. The purpose of this study was to examine short-term, implant-related complication rates and secondary fragility fractures after SA in patients with and without a history of fragility fractures. METHODS: A propensity score-matched retrospective cohort study was done using the PearlDiver database to characterize the effect of antecedent fragility fractures in short-term complications after SA. Rates of revision SA, periprosthetic fractures, infection, and postoperative fragility fractures were evaluated using multivariate logistic regression analysis. Risks of these complications were also studied in patients with and without preoperative osteoporosis treatment. Statistical significance was set at P < 0.05. RESULTS: A total of 91,212 SA patients were identified, with 13,050 (14.3%) experiencing a fragility fracture within the 3 years before SA. Two years after SA, there were increased odds of periprosthetic fracture (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.68 to 2.99), fragility fracture (OR 9.11, 95% CI 8.43 to 9.85), deep infection (OR 1.68, 95% CI 1.34 to 2.12), and all-cause revision SA (OR 1.68, 95% CI 1.44 to 1.96) within those patients who had experienced a fragility fracture within 3 years before their SA. Patients who were treated for osteoporosis with bisphosphonates and/or vitamin D supplementation before their SA had similar rates of postoperative periprosthetic fractures, fragility fractures, and all-cause revision SA to those who did not receive pharmacologic treatment. CONCLUSION: Sustaining a fragility fracture before SA portends substantial postoperative risk of periprosthetic fractures, infection, subsequent fragility fractures, and all-cause revision SA at the 2-year postoperative period. Pharmacotherapy did not markedly decrease the rate of these complications. These results are important for surgeons counseling patients who have experienced prior fragility fractures on the risks of SA.

Single Wedge Femoral Stem Designs are Associated With a Higher Risk for Revision After Cementless Primary Total Hip Arthroplasty.

BACKGROUND: Cementless total hip arthroplasty (THA) femoral stems are the most commonly selected prostheses in the United States. Optimal stem geometry remains controversial with excellent survivorship reported for many designs. We compared cause-specific stem revision of single-wedge versus double-wedge designs from a multicenter US cohort. METHODS: Data from an integrated healthcare network's total joint replacement registry were used to conduct a cohort study. Primary elective cementless THAs were identified (2001 to 2018). Implant exposure groups were classified by design geometry using the system proposed by Khanuja et al. Type 1 single-wedge (n = 11,082) and type 2 double-wedge (n = 32,380) designs were compared, and other design types were excluded; the final study cohort comprised 43,462 THAs. Cause-specific multivariable Cox regressions were used to evaluate risk for revision due to infection or aseptic reasons, including loosening, instability, periprosthetic fracture, or other reasons. RESULTS: After adjustment for covariates, a higher aseptic revision risk was observed for type 1 when compared to type 2 designs (hazard ratio = 1.91, 95% confidence interval = 1.33-2.75). When looking at specific revision reasons, revision for aseptic loosening (hazard ratio = 3.46, 95% confidence interval = 2.24-5.34) was higher for type 1 versus type 2 designs. No differences were found for septic revision, instability, periprosthetic fracture, or revisions for other reasons. CONCLUSIONS: Type 1 single-wedge designs were found to have a higher risk of revision due to aseptic loosening relative to type 2 double-wedge designs. Femoral stem geometry should be considered when selecting a cementless femoral implant. LEVEL OF EVIDENCE: Level III.

Do alumina matrix composite bearings decrease hip noises and bearing fractures at a minimum of 5 years after THA?

BACKGROUND: Ceramic-on-ceramic bearing couples are theoretically attractive in total hip arthroplasty (THA) because of low wear, but concerns regarding ceramic fracture and squeaking have arisen. Improved material properties of newer alumina matrix composite (AMC) materials, known as Delta ceramics, may reduce these risks. In addition, the use of thinner liners and larger femoral heads may be helpful clinically to lower the rate of dislocation. However, limited short-term clinical results are available and intermediate-term effects are unclear. QUESTIONS/PURPOSES: (1) What is the frequency of bearing-related complications (dissociation, fracture, and noise) with ceramic-on-ceramic AMC bearings in cementless THA? (2) What other complications arose in patients treated with these bearings? (3) What are the Harris hip scores (HHS) and survivorship free from reoperation and revision at a minimum of 5 years after cementless THA performed with AMC bearings? METHODS: Over a 9-month period in 2009, one surgeon performed 125 THAs, of which 100 (80% of the total) were performed with cementless, AMC bearings. During the period in question, the exclusion criteria for this implant were primary THAs with severe acetabular or femoral bone defect and revision THAs. Of these, 94 hips (95%) in 91 patients were available for analysis at a minimum of 5 years (range, 5-6 years), because five patients (six hips) had died. Mean age at the time of arthroplasty was 55 ± 14 years. Prostheses with an identical design and Biolox(®) Delta ceramics were used in all patients. Noise was classified into squeaking, clicking, grinding, and popping. Ceramic fracture, dislocation, and any other complications associated with the use of AMC ceramics were also investigated. Clinical evaluation included the modified HHS preoperatively and at each followup. Survivorship free from reoperation and revision was calculated using the Kaplan-Meier method. RESULTS: Of 91 patients, four developed bearing-related complications, including one with liner dissociation despite initial square seating and three with clicking. No patients had ceramic fractures. A single event of perioperative dislocation occurred in one patient and postoperative periprosthetic fracture occurred in two hips. Mean HHS improved from 56 to 93 points at the final followup (p < 0.001). Survivorship at 5 years free from reoperation and revision was 96.8% and 97.9%, respectively. CONCLUSIONS: Improved material properties combined with the possible use of larger diameter heads make AMC ceramics a promising alternative bearing option with seemingly comparable clinical outcomes reported by others with conventional ceramic bearings. Despite these encouraging results, however, meticulous technical precautions such as square seating and proper impaction in particular should be taken during liner insertion, because we did observe one liner dissociation and several patients with hip noises. LEVEL OF EVIDENCE: Level IV, therapeutic study.

A biomechanical comparison of periprosthetic femoral fracture fixation in normal and osteoporotic cadaveric bone.

Several techniques are described for fixation of Vancouver B1 femoral shaft fractures after total hip arthroplasty. Twenty-four femurs were scanned by dual x-ray absorptiometry scanned and matched for bone mineral density. Femurs were implanted with a cemented simulated total hip prosthesis with a simulated periprosthetic femur fracture distal to the stem. Fractures were fixed with Synthes (Paoli, Pa) 12-hole curved plates and 4 different constructs proximally. Each construct was loaded to failure in axial compression. Constructs with locking and nonlocking screws demonstrated equivalent loads at failure and were superior in load at failure compared with cables. Cable constructs failed proximally. No proximal failures occurred in specimens fixed with screws and cables. A combination of locked or nonlocked screws and supplemental cable fixation is recommended for the treatment of Vancouver B1 periprosthetic femur fractures.