Is an "Outpatient Arthroplasty Risk Assessment Score" Needed for Predicting Safe Selection of Outpatient Arthroplasty Candidates?

BACKGROUND: Total joint arthroplasty is rapidly shifting to the outpatient space. One of the challenges of same-day discharge adoption has been determining which patients are suitable candidates. Risk assessment tools have been developed, including the Outpatient Arthroplasty Risk Assessment (OARA) score. The purpose of this study was to assess its predictive utility. METHODS: A retrospective review was performed on all total joint arthroplasties performed at a single ambulatory surgery center in 2018, yielding a cohort of 1,105 patients (1,332 arthroplasties). The institution's outpatient criteria required optimization of all medical conditions; if the patient had no failing organ, they were candidates for same-day discharge. OARA scores were calculated based on preoperative histories and physical examinations. Analyses were performed on the statistical utility of the OARA score in predicting successful same-day discharge. The mean age was 59 years (range, 27-82), the mean body mass index was 33.3 kg/m2 (range, 16-66), and 51.5% were women. A total of 45% of patients had one or more major comorbidity. RESULTS: There were 81.6% of patients who had an acceptable OARA score (<60). In addition, 97% of patients who had an "unacceptable" OARA score were successfully discharged the same day. There were 23 patients who required inpatient observation; of these, 7 (30.4%) had an OARA score ≥60. CONCLUSION: The OARA score was accurate in predicting patients who successfully had same-day discharge but poor at predicting who would not. This system is time consuming and may be too restrictive on which patients are candidates for outpatient arthroplasty. Surgeons may consider a more simplified criteria for outpatient arthroplasty.

Survivorship of a Metal-on-Metal Total Hip Implant With Modular Titanium Adapter.

BACKGROUND: Use of metal-on-metal (MoM) articulations in total hip arthroplasty (THA) has sharply declined due to high failure rates from metal-related complications. Although certain MoM designs have demonstrated only 46% survival, not all MoM designs have performed the same. The purpose of this study is to evaluate mid-term to long-term survival of a specific MoM implant with a modular titanium taper adapter. METHODS: A retrospective review was performed on all patients who underwent primary THA at our center with the M2a-Magnum system (Zimmer Biomet, Warsaw, IN). Of 829 patients (956 hips) identified, 754 patients (869 hips) met inclusion criteria of signed research consent, minimum 2-year follow-up, and/or any revision surgery. RESULTS: Mean follow-up was 11.0 years (range 2-16; ±3.5). Mean cup angle of inclination was 42.8° (range 24°-70°, ±6.3°), with 88.0% reconstructed within the 40° ± 10° safe zone. There were 64 revisions (7.36%): 7 (0.81%) septic and 57 (6.56%) aseptic. Of those, 32 (3.68%) were adverse reactions to metal debris. Kaplan-Meier survival free of revision for all causes was 88.6% at 16 years (95% confidence interval 86.8-90.4). Univariate analysis of risk factors for all-cause, aseptic, and adverse reaction to metal debris revision found no relationship with female gender, age ≥65 years, body mass index >30 kg/m2, higher activity level, or inclination angle outlier. CONCLUSION: The results of this study demonstrate a more favorable mid-term to long-term survivorship with this specific MoM implant compared to other designs. Although our institution no longer performs MoM THA, further investigation into differences in MoM implant designs is warranted.

Long-term Follow-up of Lisfranc Injuries Treated With Open Reduction Internal Fixation Patient-Reported Outcomes.

BACKGROUND: There remains a paucity of data regarding long-term patient-reported outcomes following Lisfranc injuries. We sought to collect long-term clinical outcome data following Lisfranc injuries using PROMIS Physical Function (PROMIS-PF) and visual analog scale-foot and ankle (VAS-FA). METHODS: A chart review was performed to identify all patients who had surgical treatment of an acute Lisfranc injury at our institution from 2005 to 2014. Of the 45 patients identified, we were able to recruit 19 for a follow-up clinic visit consisting of physical examination, administration of questionnaires addressing pain and medication usage, radiographs, and completion of outcome surveys including PROMIS-Physical Function and visual analog scale-foot and ankle. RESULTS: There were 14 female and 5 male patients enrolled in the study with a mean time of 6.25 years from the time of injury. Within this cohort, the mean PROMIS-PF score was 52.4±8.2 and the mean VAS-foot and ankle score was 76.6±22.3. CONCLUSION: We report satisfactory long-term patient-reported outcomes using PROMIS-PF and VAS-FA. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Oncogenic PIK3CA-driven mammary tumors frequently recur via PI3K pathway-dependent and PI3K pathway-independent mechanisms.

PIK3CA gain-of-function mutations are a common oncogenic event in human malignancy, making phosphatidylinositol 3-kinase (PI3K) a target for cancer therapy. Despite the promise of targeted therapy, resistance often develops, leading to treatment failure. To elucidate mechanisms of resistance to PI3K-targeted therapy, we constructed a mouse model of breast cancer conditionally expressing human PIK3CA(H1047R). Notably, most PIK3CA(H1047R)-driven mammary tumors recurred after PIK3CA(H1047R) inactivation. Genomic analyses of recurrent tumors revealed multiple lesions, including focal amplification of Met or Myc (also known as c-Met and c-Myc, respectively). Whereas Met amplification led to tumor survival dependent on activation of endogenous PI3K, tumors with Myc amplification became independent of the PI3K pathway. Functional analyses showed that Myc contributed to oncogene independence and resistance to PI3K inhibition. Notably, PIK3CA mutations and c-MYC elevation co-occur in a substantial fraction of human breast tumors. Together, these data suggest that c-MYC elevation represents a potential mechanism by which tumors develop resistance to current PI3K-targeted therapies.