Readmissions after elective orthopedic surgery in a comprehensive co-management care system-a retrospective analysis.

BACKGROUND: No surgical intervention is without risk. Readmissions and reoperations after elective orthopedic surgery are common and are also stressful for the patient. It has been shown that a comprehensive ortho-medical co-management model decreases readmission rates in older patients suffering from hip fracture; but it is still unclear if this also applies to elective orthopedic surgery. The aim of the current study was to determine the proportion of unplanned readmissions or returns to operating room (for any reason) across a broad elective orthopedic population within 90 days after elective surgery. All cases took place in a tertiary care center using co-management care and were also assessed for risk factors leading to readmission or unplanned return to operating room (UROR). METHODS: In this observational study, 1295 patients undergoing elective orthopedic surgery between 2015 and 2017 at a tertiary care center in Switzerland were investigated. The proportion of reoperations and readmissions within 90 days was measured, and possible risk factors for reoperation or readmission were identified using logistic regression. RESULTS: In our cohort, 3.2% (42 of 1295 patients) had an UROR or readmission. Sixteen patients were readmitted without requiring further surgery-nine of which due to medical and seven to surgical reasons. Patient-related factors associated with UROR and readmission were older age (67 vs. 60 years; p = 0.014), and American Society of Anesthesiologists physical status (ASA PS) score ≥ 3 (43% vs. 18%; p < 0.001). Surgery-related factors were: implantation of foreign material (62% vs. 33%; p < 0.001), duration of operation (76 min. vs. 60 min; p < 0.001), and spine surgery (57% vs. 17%; p < 0.001). Notably, only spine surgery was also found to be independent risk factor. CONCLUSION: Rates of UROR during initial hospitalization and readmission were lower in the current study than described in the literature. However, several comorbidities and surgery-related risk factors were found to be associated with these events. Although no surgery is without risk, known threats should be reduced and every effort undertaken to minimize complications in high-risk populations. Further prospective controlled research is needed to investigate the potential benefits of a co-management model in elective orthopedic surgery.

Prolonged antibiotic prophylaxis use in elective orthopaedic surgery - a cross-sectional analysis.

PURPOSE: Surgical antibiotic prophylaxis (SAP) prevents surgical site infections (SSI). In orthopaedic surgery, the use of prolonged SAP (PSAP) has been reported in daily routine, despite guidelines advising against it. Therefore, we asked: What is the proportion of PSAP use, defined as administration of SAP ≥24 h after elective orthopaedic surgery? Are there patient- and surgery-related predictors of PSAP use? METHODS: This cross-sectional analysis investigated 1292 patients who underwent elective orthopaedic surgery including total joint arthroplasties at one Swiss centre between 2015 and 2017. Patient comorbidities, surgical characteristics and occurrence of SSI at 90 days in PSAP group were compared to the SAP group (< 24 h post-operative). RESULTS: PSAP use was 12% (155 of 1292). Patient-related factors associated with PSAP compared to the SAP group included older age (63 vs. 58y; p < 0.001), higher BMI (29 vs. 27 kg/m2; p < 0.001), ASA classification ≥3 (31% vs. 17%; p < 0.001) and lung disease (17% vs. 9%; p = 0.002). Surgery-related factors associated with PSAP were use of prosthetics (62% vs. 45%; p < 0.001), surgery of the knee (65% vs. 25%; p < 0.001), longer surgery duration (87 vs. 68 min; p < 0.001) and presence of drains (90% vs. 65%; p < 0.001). All four SSI occurred in the SAP group (0 vs. 4; p = 1.0). Surgeons administered PSAP with varying frequencies; proportions ranged from 0 to 33%. CONCLUSION: PSAP use and SSI proportions were lower than reported in the literature. Several patient- and surgery-related factors associated with PSAP use were identified and some were potentially modifiable. Also, experienced surgeons seemed to implement differing approaches regarding the duration of SAP administration.

Preoperative decolonization and periprosthetic joint infections-A randomized controlled trial with 2-year follow-up.

Preoperative decolonization, especially of Staphylococcus aureus carriers, has been proposed to reduce periprosthetic joint infections (PJI), but the evidence-based consensus is still lacking and data on long-term outcomes is scarce. In a previous randomized, single-blinded trial, decolonization produced no significant reduction of surgical site infections in overall elective orthopedic surgery at 3-month follow-up. A 2-year follow-up was then performed to specifically detect the impact of decolonization on delayed-onset PJI (3-24 months after surgery). Between November 2015 and September 2017, 613 of 1318 recruited patients underwent prosthetic surgery. Individuals were allocated into either the S. aureus carrier group (34%, 207 of 613 patients) or the noncarrier group (406 of 613 patients), according to nasal swab screening results. Both groups were then randomized into intervention and control arms. In the S. aureus group, the intervention consisted of daily chlorhexidine showers and application of mupirocin nasal ointment twice a day for 5 days before surgery. In noncarriers, only chlorhexidine showers were prescribed. Sample size calculation was based on the initial trial for overall and not for the prosthetic surgery group. No PJI was found at 2 years in either the carrier or in the noncarrier group. Therefore, no definite conclusion about the efficacy of preoperative decolonization to reduce PJI can be drawn. PJI proportions in this study were lower than described in the literature (mostly around 0.3%). Despite the insufficient sample size, this trial is the largest randomized trial on decolonization with a long-term follow-up, and results may be helpful for future meta-analyses.

The Hip Sports Activity Scale (HSAS) for patients with femoroacetabular impingement.

PURPOSE: To develop and validate a sports activity scale for patients with a diagnosis of femoroacetabular impingement (FAI).
 METHODS: A nine level Hip Sports Activity Scale (HSAS) was constructed both in German and English languages. Fifty-nine consecutive patients undergoing surgical treatment for FAI at two centers in Switzerland and in the US completed a questionnaire set consisting of the HSAS, the University of California at Los Angeles (UCLA) activity scale and different hip joint-specific and generic outcome tools. For reliability assessment, the HSAS was completed twice about nine days apart. Evidence of reliability, validity and responsiveness was investigated by classical psychometric analyses.
 RESULTS: Reliability was excellent for both the German and the English versions with intraclass correlation coefficients of 0.94 and 0.96, respectively. Evidence of convergent validity was supported by moderate to high correlations with the UCLA activity scale and with the joint-specific measures used. Evidence of divergent validity was supported by low correlations with the SF-12 Mental Component Scale and the WOMAC stiffness subscale. The standardised response mean was 0.69.
 CONCLUSIONS: The HSAS is a reliable and valid tool to determine sports levels in patients suffering from FAI. Its use in future studies investigating outcomes in young patients with hip disease can be recommended.
 LEVEL OF EVIDENCE: Level III, Diagnostic Studies - An independent, masked comparison with an appropriate population of patients, but reference standard not applied to all study patients.

MR arthrography of the hip: diagnostic performance of a dedicated water-excitation 3D double-echo steady-state sequence to detect cartilage lesions.

OBJECTIVE: The objective of our study was to compare the diagnostic performance of a dedicated cartilage MR sequence (water-excitation 3D double-echo steady-state) with a standard MR sequence (T1-weighted spin-echo) in detecting articular cartilage lesions of the hip after intraarticular injection of gadopentetate dimeglumine. MATERIALS AND METHODS: In 50 MR arthrograms of the hip joint obtained in 47 consecutive patients, a sagittal 3D double-echo steady-state sequence (TR/TE, 24/6.5; flip angle, 25 degrees ) was compared with a sagittal T1-weighted spin-echo sequence (350/14). Two musculoskeletal radiologists independently evaluated articular cartilage. Sensitivity and specificity for detecting cartilage defects were calculated for those hips that underwent open surgery (n = 21). Lesion conspicuity was retrospectively reviewed and graded between 1 (not visible) and 5 (well defined). RESULTS: At surgery, a total of 26 lesions of the acetabular (n = 20) and femoral (n = 6) cartilage were found. For the 3D double-echo steady-state and T1-weighted spin-echo sequences, sensitivities and specificities for cartilage lesion detection were 58% and 88% and 81% and 81% for reviewer 1 and 62% and 94% and 62% and 100% for reviewer 2, respectively. Lesion conspicuity was significantly superior (p = 0.036) for the 3D double-echo steady-state sequence (mean grade, 3.4) compared with the T1-weighted spin-echo sequence (mean grade, 3.0). The kappa value was fair for the 3D double-echo steady-state sequence (kappa = 0.40) and moderate for the T1-weighted spin-echo sequence (kappa = 0.55). CONCLUSION: The 3D double-echo steady-state sequence optimized for cartilage imaging improves lesion conspicuity but does not improve diagnostic performance.

An animal model for interface tissue formation in cemented hip replacements.

OBJECTIVE: To create a model in sheep for investigation of early changes related to the formation of an interface membrane in hip prosthesis. STUDY DESIGN: Experimental study. ANIMALS: Twenty-four female adult Swiss Alpine sheep. METHODS: Sheep were divided into 2 groups of 12 for unilateral cemented total hip arthroplasty. In Group I, the prosthesis was fixed with retrograde cement gun injection to achieve a complete cement mantle, whereas in Group II a primary cement mantle defect was produced. Groups I and II were further divided into 2 sub-groups with study end points of 2 and 8.5 months after surgery. Radiographs were evaluated postoperatively and at euthanasia for migration of the femoral component and bone resorption. Histologic sections were evaluated semiquantitatively for changes in cell types and numbers, and bone reactions; and quantitatively for size of interface membrane and new bone formation. RESULTS: Radiographically, there tended to be an increase in bone resorption and periosteal bone formation throughout the femoral shaft in Group II compared with Group I, but this was only statistically significant at the region of the femoral neck (R5) at both time periods (P<.05). Semiquantitative histologic evaluation revealed significant increases (P<.05) in cellularity, numbers of fibroblasts, giant cells, macrophages, and mononuclear cells, in Group II primarily at 2 months after surgery. This was also true for interface membrane formation and bone remodeling. Quantitative data showed an increased in the size of the interface membrane and area of bone formation at 8.5 months in Group II. CONCLUSIONS: The cement defect model offered controlled and repeatable production of an interface membrane. The results suggest that a primary cement mantle defect could be a possible trigger for implant instability, eliciting a cascade of biomechanical and molecular events in bone tissue leading to aseptic loosening. CLINICAL RELEVANCE: The results show the effect of defects in the cement mantle in promoting interface membrane formation. Long-term and biochemical studies are required to evaluate the relevance of this interface membrane formation.