Early- to mid-term outcome of a short, cementless, titanium, flat, tapered stem for primary total hip arthroplasty: an independent series.

INTRODUCTION: This study aims to: (1) describe perioperative complications amongst patients who underwent primary total hip arthroplasty (THA) using a short cementless, titanium, flat, tapered stem; (2) estimate this stem's early- to mid-term survival; (3) identify factors associated with revision arthroplasty; and (4) describe femoral remodelling at minimum 6 years postoperatively. METHODS: A retrospective review of consecutive patients who underwent THA using a Taperloc Microplasty stem (Zimmer-Biomet, Warsaw, Indiana, USA) with minimum 2-year follow-up was performed. Surgeries were performed by 1 of 6, non-designer, arthroplasty surgeons between 2014 and 2018. Outcomes included perioperative complications including revision arthroplasty, and survival. Cox analysis was used to analyse the effect of different factors on risk of revision arthroplasty. Radiographs with 6-year follow-up served to describe femoral remodelling. RESULTS: In 1205 patients, followed for 5.1 ± 1.4 years, the incidence of perioperative complication was 5.2% for which 29 patients (2.4%) required revision arthroplasty. The 5- and 7-year survival rates were 97.8% (95% CI, 96.9-98.5) and 97.0% (95% CI, 95.6-98.0), respectively. The only factor associated with revision arthroplasty was proximal femur morphology, as per Dorr classification (HR 1.24 [95%CI, 1.09-1.41]; p = 0.005). During radiographic assessment, 12% of patients showed ⩾25% of relative change in cortical thickness in Gruen zones 3 or 5. We observed calcar remodelling in 50% of radiographs while 10% showed presence of a pedestal sign. CONCLUSIONS: The 7-year survivorship of the Taperloc Microplasty stem is within National Institute for Health and Care Excellence (NICE) guidelines. Patients ⩽65 years with osteoarthritis and Dorr A/B femoral morphology may be ideal candidates for THA with this stem. Femoral remodelling is common and not associated with adverse outcome.

Can We Predict Fracture When Using a Short Cementless Femoral Stem in the Anterior Approach?

BACKGROUND: Short cementless femoral stems may allow for easier insertion with less dissection. The use of short stems with the anterior approach (AA) may be associated with a considerable perioperative fracture risk. Our aim was to evaluate whether patient-specific femoral and pelvic morphology and surgical technique, influence the perioperative fracture risk. Furthermore, we sought to describe important anatomical thresholds alerting surgeons. METHODS: A single-center, multi-surgeon retrospective, case-control matched study was performed. Thirty nine periprosthetic fractures (3.4%) in 1,145 primary AA THAs using short cementless stems were identified. These were matched with 78 THA nonfracture controls for factors known to increase the fracture risk. A radiographic analysis using validated software measured femoral (canal flare index [CFI], morphological cortical index [MCI], and calcar-calcar ratio [CCR]) and pelvic (Ilium-ischial ratio [IIR], ilium overhang, and anterior superior iliac spine [ASIS] to greater trochanter distance) morphologies and surgical techniques (% canal fill). A multivariate and Receiver-Operator Curve (ROC) analysis was used to identify fracture predictors. RESULTS: CFI (3.7 ± 0.6 vs 2.9 ± 0.4, P < .001) and CCR (0.5 ± 0.1 vs 0.4 ± 0.1, P = .006) differed. The mean IIR was higher in fracture cases (3.3 ± 0.6 vs 3.0 ± 0.5, P < .001). Percent canal fill was reduced in fracture cases (82.8 ± 7.6 vs 86.7 ± 6.8, P = .007). Multivariate and ROC analyses revealed a threshold CFI of 3.17 which was predictive of fracture (sensitivity: 84.6%/specificity: 75.6%). The fracture risk was 29 times higher when patients had CFI >3.17 and II ratio >3 (OR: 29.2 95% CI: 9.5-89.9, P < .001). CONCLUSION: Patient-specific anatomical parameters are important predictors of a fracture-risk. A careful radiographic analysis would help identify those at a risk of early fracture using short stems, and alternative stem options should be considered.

Is There a Role for Preclosure Dilute Betadine Irrigation in the Prevention of Postoperative Infection Following Total Joint Arthroplasty?

BACKGROUND: Conflicting evidence exists surrounding the use of preclosure irrigation solutions in primary total joint arthroplasty (TJA). We aimed to determine the role of dilute betadine lavage in preventing early infection after primary TJA. METHODS: We retrospectively reviewed primary TJAs between 2010 and 2018. Dilute betadine lavage was introduced to our practice in November 2014. We included 3513 total hip arthroplasties, 3932 total knee arthroplasties, and 1033 hip resurfacings (HRs). In group 1 (n = 5588), surgical wounds were irrigated with saline; group 2 used dilute betadine solution (n = 2890). Subanalyses using propensity matching based on known risk factors of infection-age, body mass index, American Society of Anesthesiologists grade, diabetes, and procedure-were completed. RESULTS: There were 48 acute infections in group 1 (0.9%) and 23 in group 2 (0.8%) (P = .762). HR without betadine had the highest acute infection prevalence (P = .028). When groups in the whole cohort were propensity score-matched, group 1 had more acute infections than group 2 (P = .033). The effect of betadine was isolated to HR patients. After excluding HR cases, betadine continued to reduce the acute infection rate when compared with the no betadine group, but this was not statistically significant (0.4% vs 0.8%; P = .101). Likewise, we did not find a significant difference in total hip arthroplasty and total knee arthroplasty patients (P = .796). CONCLUSION: There was a decreased infection rate in the betadine group overall when groups were propensity-matched. Because the reduction in the acute infection rate was clinically significant, we feel this practice is an effective means to prevent infections.